By D. Dan. State University of New York College Maritime College at Fort Schuyler. 2019.
Vancomycin is the drug of choice for serious infections due to methicillin-re- sistant S safe actoplus met 500 mg. Vancomycin is typi- cally used intravenously quality actoplus met 500 mg, although orally available order discount actoplus met online, and does not provide adequate coverage for bowel sterilization buy actoplus met with mastercard. Although orally available, erythromycin, nitrofurantoin, and ciprofloxacin also do not have adequate coverage. Doxycycline, a tetracycline (30S ribosome inhibitor), is the antibiotic of choice to treat Rocky Mountain spotted fever, a rickettsial disease. Ciprofloxacin can be used to treat an- thrax, and erythromycin is the most effective drug for the treatment of Legionnaires disease. Steven-Johnson syndrome is a form of erythema multiforme, rarely associated with sulfonamide use. Patients with glucose-6-phosphate dehydrogenase deficiency are at risk of developing hemolytic anemia. The antibiotic classes that inhibit the 30S ribosome include amino- glycosides and tetracycline. Inhibitors of the 50S ribosome include chloramphenicol, erythromycin, and clindamycin. Bacterial cell wall inhibitors include penicillins, cephalosporins, and vancomycin. Often rifampin, ethambutol, streptomycin, isonia- zid, and pyrazinamide are used for months together, as many strains are multidrug resistant. Patients with increased risk of Neisseria meningitides infection can be given rifampin for prophylaxis. Amphotericin is used in the treatment of severe disseminated candidiasis, sometimes in conjunction with flucytosine. It is often toxic and causes fevers and chills on infu- sion, the ‘‘shake and bake. Cycloserine is an alternative drug used for mycobacterial infections and is both nephrotoxic and causes seizures. Mefloquine is the primary agent used for prophylaxis in chloroquine-resistant areas. Doxycycline is used with quinine for acute malarial attacks due to multiresistant strains. Metronidazole is used to treat protozoal infections due to Giardia, Entamoeba, and Trichomonas spp. Mebendazole is used to treat round worm infections, and thiabendazole is used to treat Strongyloides infection. Ivermectin is used to treat filariasis, whereas praziquantel is used to treat schistosomiasis. Niclosamide can be used to treat tapeworm infections, and pyrantel pamoate is used to treat many helminth infections. Valacyclovir is related to acyclovir, both of which are used for the treatment of oral and genital herpes in immunocompetent individuals. Vidarabine is used in more severe infections in neonates as well as in the treatment of zoster. Because cancer may potentially arise from a single malignant cell, the therapeutic goal of can- cer chemotherapy may require total tumor cell kill, which is the elimination of all neoplastic cells. Early treatment is critical because the greater the tumor burden, the more difficult it is to treat the disease. A therapeutic effect is usually achieved by killing actively growing cells, which are most sensitive to this class of agents. Because normal cells and cancer cells have similar sensitivity to chemotherapeutic agents, adverse effects are mostly seen in normally dividing nonneo- plastic cells, such as bone marrow stem cells, gastric and intestinal mucosa, and hair follicles. Achievement of the therapeutic effect may involve the use of drugs, sometimes sequentially, that act only at specific stages in the cell cycle (e. Primary resistance is seen in tumor cells that do not respond to initial therapy using cur- rently available drugs. The probability that any tu- mor population has primary resistance to two non–cross-resistant drugs is even less likely (approximately the product of the two individual probabilities). In this case, cells overproduce cell surface glycoproteins (P-glycoproteins) that actively transport bulky, natural product agents out of cells (Table 12-1). As a result, the cell fails to accumulate toxic concentrations of several different types of drugs. Resistance may occur due to the inability of chemotherapeutic agents to reach sufficient ‘‘kill’’ levels in certain tissues (e. Clinically useful alkylating agents have a nitrosourea, bis-(chloroethyl)amine, or ethylenimine moiety. The electrophilic center of these agents becomes covalently linked to the nucleophilic centers of target molecules. These agents also target other critical biologic moieties—including carboxyl, imidazole, amino, sulfhydryl, and phosphate groups—which become alkylated. These agents can act at all stages of the cell cycle, but cells are most susceptible to alkylation in late G1 to S phases. With the exception of cyclophosphamide, parenterally administered alkylating agents are direct vesicants and can damage tissue at the injection site. Some degree of leucopenia occurs at adequate therapeutic doses with all oral alkylating agents. Leukopenia and thrombocytopenia are dose-limiting toxicities; repeat courses of treat- ment are given only after marrow function has recovered. It is metabolically activated to 4-hydroxycyclophosphamide, which in turn is nonenzymatically cleaved to aldophosphamide. In tumor cells aldophospamide is cleaved to phosphoramide mustard, which is toxic to tumor cells, and acrolein, the agent suspected to cause hemorrhagic cystitis. Cyclophosphamide is used to treat lymphomas, leukemias, mycosis fungoides, multiple myeloma, retinoblastoma, breast and ovarian carcinoma, and small cell lung cancer. It is a component of many combination treatments for a variety of cancers (Table 12-2). Cyclophosphamide has less incidence of thrombocytopenia than mechlorethamine, but immunosuppression is still the most important toxic effect. This agent is also usedin someautoimmune conditions,such aslupus nephritis, and arteritis. Ifosfamide (Ifex) is a cyclophosphamide analog with less potential to cause hemorrhagic cystitis. Melphalan and chlorambucil are derivatives of nitrogen mustard that contain phenylalanine and an aromatic ring, respectively. Chlorambucil is the slowest-acting nitrogen mustard and is the agent of choice in the treat- ment of chronic lymphocytic leukemia, some lymphomas, and Hodgkin disease. Busulfan is administered orally to treat chronic myelogenous leukemia and other myeloproli- ferative disorders. In high doses, it produces a rare but sometimes fatal pulmonary fibrosis, ‘‘busulfan lung. Carmustine, lomustine, and semustine are highly lipophilic; they cross the blood–brain barrier. Carmustine, lomustine, and semustine are useful in Hodgkin disease and other lympho- mas, as well as in tumors of the brain. These agents are markedly myelosuppressive, but with delayed effect, possibly up to 6 weeks. The use of these agents for various brain cancers has been declining since the introduction of temozolomide (see below). Streptozocin is a natural antibiotic that is composed of methylnitrosourea linked to the 2-carbon of glucose. It is administered orally and is primarily used to treat refractory anaplastic astrocytoma, such as glioblastoma multiforme; malignant mela- noma; and uterine leiomyosarcoma. This agent also inhibits enzymes involved in folate metabolism, including dihydrofolate reductase.
Are there related samples (because of matching or repeated measures) or are there independent samples? Department of Molecular and Functional Imaging The Cleveland Clinic Foundation Physics and Radiobiology of Nuclear Medicine Third Edition With 111 Figures Gopal B 500 mg actoplus met otc. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media order 500mg actoplus met with amex, Inc discount actoplus met 500 mg otc. Use in connection with any form of information storage and retrieval 500mg actoplus met amex, electronic adaptation, computer software, or by similar or dissimilar methodology now known or here- after developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identiﬁed as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Although the basics of physics, instrumentation, and radiobiology have not changed, their techno- logical applications have been changing and improving continually. Nuclear medicine professionals worldwide appreciate the book so much that the previous edition has been published in Japanese. Changes in content and appreciation of the book are the two guiding factors in writing this third edition. Like the previous editions, the book is aimed at residents taking the American Board of Nuclear Medicine, the American Board of Radiology (Physics part), and the American Board of Radiology with Special Com- petency in Nuclear Medicine examinations, and for the technologists taking the Nuclear Medicine Technology Certifying Board. The book contains 16 chapters, and at the end of each chapter, references and suggested readings have been updated and new questions have been added where appropriate. The ﬁrst 10 chapters have only minor changes because of the basic nature of the contents. A section on the chi-square test and evaluation of diagnostic tests has been added in Chapter 4. In Chapter 8, the section on scintillation detectors has been rearranged and the section on dead time has been expanded. In Chapter 10, the sections on uniformity, gamma camera tuning, and quality control tests have been revised. Chapter 15 has been expanded to include more information on cellular damage by radiation, and also a section on dirty bomb and radiation phobia. Rita Konyves for typing meticulously and conscientiously the major part of the manuscript and to Mrs. My sincere thanks and gratitude are due to Robert Albano, Senior Clin- ical Medical Editor of Springer, for his constant support and encourage- ment, and to others at Springer for their help in the successful completion of the book. These two entities are interchangeable and exist in different forms to make up all things visible or invisible in the universe. Whereas matter has a deﬁnite size, shape, and form, energy has different forms but no size and shape. Matter is characterized by its quantity, called the mass, and is composed of the smallest unit, the atom. In atomic physics, the unit of mass is the atomic mass unit (amu), which is equal to 1. Energy is the capacity to do work and can exist in several forms: kinetic energy (which is due to the motion of matter); potential energy (which is due to the position and conﬁguration of matter); thermal energy (which is due to the motion of atoms or molecules in matter); electrical energy (which is due to the ﬂow of electrons across an electric potential); chemical energy (which is due to chemical reaction); and radiation (energy in motion). Of all these forms, radiation is of great importance in nuclear medicine and, therefore, will be discussed in detail. Mass and energy are interchangeable, and one is created at the expense of the other. This relationship states that every- thing around us can be classiﬁed as matter or energy. Particulate radiations: Examples of these radiations are energetic elec- trons, protons, neutrons, a-particles, and so forth. The particulate radiations originate from radioactive decay, cosmic rays, nuclear reactions, and so forth. Electromagnetic radiations: These radiations are a form of energy in motion that does not have mass and charge and can propagate as either waves or discrete packets of energy, called the photons or quanta. Various examples of electromagnetic radiations include radio waves, visible light, heat waves, g-radiations, and so forth, and they differ from each other in wavelength and hence in energy. The energy of an electromagnetic radiation is given in electron volts (eV), which is deﬁned as the energy acquired by an electron when acceler- ated through a potential difference of 1 volt. The Atom For the purpose of this book, the atom can be considered as the smallest unit in the composition of matter. The atom is composed of a nucleus at the center and one or more electrons orbiting around the nucleus. The protons and neutrons are about 1836 times heavier than the electrons but the neutron is heavier than the proton by one electron mass (i. The number of electrons is equal to the number of protons, thus resulting in a neutral atom of an element. The size of the atom is about 10−8cm (called −13 the angstrom, Å), whereas the nucleus has the size of 10 cm (termed the 14 3 fermi, F). The elec- tronic arrangement determines the chemical properties of an element, whereas the nuclear structure dictates the stability and radioactive trans- formation of the atom. Electronic Structure of the Atom Several theories have been put forward to describe the electronic structure of the atom, among which the theory of Niels Bohr, proposed in 1913, is the most plausible one and still holds today. The Bohr’s atomic theory states that electrons rotate around the nucleus in discrete energy shells that are stationary and arranged in increasing order of energy. These shells are des- ignated as the K shell, L shell, M shell, N shell, and so forth. When an elec- tron jumps from the upper shell to the lower shell, the difference in energy between the two shells appears as electromagnetic radiations or photons. When an electron is raised from the lower shell to the upper shell, the energy difference is absorbed and must be supplied for the process to occur. The detailed description of the Bohr’s atomic structure is provided by the quantum theory in physics. According to this theory, each shell is des- ignated by a quantum number n, called the principal quantum number, and 4 1. Structure of Matter denoted by integers, for example, 1 for the K shell, 2 for the L shell, 3 for the M shell, 4 for the N shell, and 5 for the O shell. Each energy shell is subdivided into subshells or orbitals, which are designated as s, p, d, f, and so on. These orbitals are assigned the azimuthal quantum numbers, l, which represent the electron’s angular momentum and can assume numerical values of l = 0,1,2... Thus for the s orbital, l = 0; the p orbital, l = 1; the d orbital, l = 2; the f orbital, l = 3; and so forth. According to this descrip- tion, the K shell has one orbital, designated as 1s, the L shell has two orbitals, designated as 2s and 2p, and so forth. The orientation of the elec- tron’s magnetic moment in a magnetic ﬁeld is described by the magnetic quantum number, m. Each electron rotates about its own axis clockwise or anticlock- wise, and the spin quantum number, s (s =−1/2 or +1/2) is assigned to each electron to specify this rotation. The electron conﬁguration of the atoms of different elements is governed by the following rules: 1. No two electrons can have the same values for all four quantum numbers in a given atom. The orbital of the lowest energy will be ﬁlled in ﬁrst, followed by the next higher energy orbital. The relative energies of the orbitals are 1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s < 4f < 5d < 6p < 7s. This order of energy is valid for lighter elements and is somewhat different in heavier elements. For given values of n and l, each of the available orbitals is ﬁrst singly occupied such that no electron pairing occurs. The helium atom has two electrons, which are accommodated in the 1s orbital, and thus has the structure of 1s2. There are three p orbitals, designated as px, py, pz, which will be occupied by three electrons individually. The eighth electron will occupy the px orbital pairing with the electron already in it. The electronic structure of the atom characterizes the chemical proper- ties of elements. The outermost shell in the most stable and chemically inert elements such as neon, argon, krypton, and xenon has the electronic struc- ture of ns2np6. The electrons in these shells are called the valence electrons and are primarily responsible for the chemical bond formation.
The mesial and distal preparation might seem rather radical in comparison to that required when a cast crown is constructed for a permanent tooth order actoplus met australia, but the principles of retention and resistance of the two types of crown are different order 500mg actoplus met amex. A cast crown is retained by friction between the walls of the prepared tooth and the internal surface of the crown cheap actoplus met on line. A stainless-steel metal crown is retained by contact between the margins of the crown and the undercut portion of the tooth below the gingiva buy actoplus met with a visa. The shape of the preparation above the gingiva is relatively unimportant and difficulty in fitting these crowns is most often because of under-preparation. However, it is most important that a shoulder is not formed at the gingival margin as this would make the seating of a well-adapted crown impossible. If it is over-extended, cut down in that area with a stone or scissors and smooth off before retrying. Check contacts with adjacent teeth and finally polish the margins with a stone or rubber wheel. Although not proven statistically beneficial, some operators favour making small holes in the approximal surfaces of the stainless-steel crown, to confer the benefits of fluoride release from the glass ionomer cement to the adjacent teeth (Fig. Success rates of stainless-steel crown restoration Over the last 20-30 years authors have consistently recorded and reported higher success rates for stainless-steel crowns as compared with other restorations in primary molars. In a recently published meta-analysis, it was clear that stainless-steel crowns were by far the most durable restorations for primary molars, and the most remarkable fact was that once placed they seldom needed replacing. The lower incisors are rarely affected as they are protected during suckling by the tongue and directly bathed in secretions from the submandibular and sublingual glands. This utilizes celluloid crown forms and a light-cured composite resin to restore crown morphology. Either calcium hydroxide or glass ionomer cement can be used as a lining and the high polishability of modern hybrid composites make them aesthetically, as well as physically, suitable for this task. In older children over 3 or 4 years of age new lesions of primary incisors, although not usually associated with the use of pacifiers, do indicate high caries activity (Fig. Such lesions do not progress so rapidly and usually appear on the mesial and distal surfaces, here a glass ionomer cement or composite resin can be used for restoration. Glass ionomer lacks the translucency of composite resin but has the useful advantages of being adhesive and releasing fluoride. Fractures of the incisal edges in primary teeth, as in permanent teeth, should be restored with composite resin. Unfortunately, owing to their low sales in the United Kingdom and the rest of Europe, the company has discontinued the sale of these crowns and now they are only available on special request. In the authors opinion, these crowns are excellent for building primary incisors where extensive tooth tissue has been lost due to either caries or trauma. The technique for their use is similar to that of such crowns used in permanent teeth; the crowns are easily trimmed with sharp scissors, filled with composite, and seated on a prepared and conditioned tooth. Dental caries and traumatic dental injuries are still prevalent and treatment of the damage they cause is still a major component of paediatric dental practice. The principal goals of paediatric operative dentistry are to prevent the extension of dental disease and to restore damaged teeth to healthy function. To this end, a range of conservative endodontic procedures can provide alternatives to extraction for many pulpally compromised primary teeth. They are within the grasp of all practitioners and are central to the practice of paediatric dentistry. While many of the general principles and operative procedures in paediatric endodontics are shared with adult endodontics, a number of important differences exist which justify the special coverage given in this chapter. Key Points Disadvantages of unplanned extractions in the primary and mixed dentitions: • loss of space, promoting malocclusion; • reduced masticatory function (especially posterior teeth); • impaired speech development (especially anterior teeth); • psychological disturbance (especially anterior teeth); • anaesthetic and surgical traumas. Histologically, it is composed of loose connective tissue, surrounded on its periphery by a continuous layer of specialized secretory cells, the odontoblasts. Odontoblasts are unique to the dental pulp and are responsible for dentine deposition. Blood vessels and nerves enter the pulp through the apical foramen and occasionally through lateral or accessory root canals. The pulps of primary and young permanent teeth, especially those with incomplete apices, have a very rich blood supply. The most important function of the pulp is to lay down dentine which forms the basic structure of teeth, defines their general morphology, and provides them with mechanical strength and toughness. Dentine deposition commences many months (primary teeth) or years (permanent teeth) before tooth eruption and while the crown of a newly erupted tooth has a mature external form, the pulp within still has considerable work to do in completing tooth development. Newly erupted teeth have short roots, their apices are wide and often diverging, and the dentine walls of the entire tooth are thin and relatively weak. Provided the pulp remains healthy, dentine deposition will continue during the posteruptive year for primary teeth. One of the key goals of paediatric dentistry is therefore to protect and preserve the pulps of teeth in a healthy state at least until this critical phase of tooth development is complete. Research carried out recently in the Department of Paediatric Dentistry of the Leeds Dental Institute (Duggal et al. In this study, it was shown that most teeth had pulp inflammation involving the pulp horn adjacent to the proximal carious lesion, even when caries had involved less than half the marginal ridge, studied by measuring the inter-cuspal distance (bucco-lingual) involved in the carious process. This suggests that inflammation of the pulp in primary molars develops at an early stage of proximal carious attack and by the time most proximal caries is manifest clinically, the pulp inflammation is quite advanced. These findings have important clinical implications, the most important being that restoration carried out without pulp therapy in most primary molars, where proximal caries has manifest clinically with the involvement of the marginal ridge, will fail. Once the breakdown of marginal ridge is evident pulp therapy is invariably required. Because of this early onset of inflammation in primary molars direct pulp capping is also contraindicated. A clinical dilemma is presented by a deep lesion in a vital, symptom-free tooth where complete removal of softened dentine on the pulpal floor is likely to result in frank exposure. Provided the bulk of infected overlying dentine is removed, a small amount of softened dentine may often be left in the deepest part of the preparation without endangering the pulp. All caries is first cleared from the cavity margins with a steel round bur running at slow speed. Gentle excavation then follows on the pulpal floor, removing as much of the softened dentine as possible without exposing the pulp. Precisely how much dentine should be removed becomes a matter of experience and clinical judgement, although some have advocated the use of indicator dyes (e. A thin layer of setting calcium hydroxide cement is then placed on the cavity floor to destroy any remaining micro- organisms and to promote the deposition of reparative secondary dentine. More commonly, the calcium hydroxide pulp cap is simply covered with a layer of hard setting cement and the tooth permanently restored at the same visit. Periodic clinical and radiographic review is then undertaken to monitor the pulp response. If, as has been discussed in the previous sections, the pulp is deemed to be inflamed, pulp therapy should be considered even in the absence of a clinical exposure. Direct pulp capping should not be carried out if an exposure is found on removal of caries, as placing a medicament, such as calcium hydroxide on an inflamed pulp will lead to failure. A pulpotomy involves the coronal removal of the pulp tissue that is diagnosed to be inflamed or infected as a result of deep caries. This usually leaves an intact radicular pulp tissue upon which a medicament is applied before placing a coronal restoration. Indications for a pulpotomy The indications for a pulpotomy that are of direct relevance to general dental practitioners are given in Table 8. There are certain conditions such as congenital heart defects, history of heart surgery where pulpotomy is not usually performed due to the risk of precipitating bacterial endocarditis. Pulpotomy medicament Formocresol has traditionally been used and widely recognized within the profession, as a medication that has delivered the best long-term results. A one-fifth dilution of original Buckleys formulation has been shown to be as effective as the full strength concentrate. Formocresol is not easily available in the United Kingdom and there have been some concerns about its toxicity, both locally and systemically. These concerns have grown recently with formaldehyde, one of the important components of formocresol linked to certain forms of cancer. Attempts have been ongoing for the last few years to find a suitable replacement and one material that has generated a lot of interest recently as a suitable alternative to formocresol is ferric sulfate.
In severe cases discount 500 mg actoplus met amex, it can affect choice of many causes purchase actoplus met amex, including infection with a virus order 500 mg actoplus met visa, fun- birth control method and cause pain in the pelvic gus buy cheapest actoplus met and actoplus met, or bacteria or the result of a side effect of a area, especially during intercourse. This situation can be easily missed by Vv the patient and even by the physician on exam. If the patient becomes sexually active prior to diagnosis, one of the vaginas stretches and becomes dominant. Its munication between the esophagus and cause is unknown, but it may occur in women who trachea) with esophageal atresia (part of fear that penetration will be painful or may develop the esophagus is not hollow); in response to a previous traumatic or painful experience. R = Renal (kidney) abnormalities; and L = Limb abnormalities, most often vaginitis Inflammation of the vagina. Vaginitis is radial dysplasia (abnormal formation a common condition and is often caused by a fun- of the thumb or the radius bone in the gus. It is more common in women who have diabetes have vaginitis more often the children of diabetic mothers than in the general than other women. For some years that was all that was fungal intravaginal creams and oral medications. It is usually 6 to 7 inches in length, and its walls are lined with mucous vaginosis, bacterial See bacterial vaginosis. It includes two vaultlike structures: the anterior (front) vaginal fornix and the posterior vagus nerve A nerve that supplies nerve fibers to (rear) vaginal fornix. The cervix protrudes slightly the pharynx (throat), larynx (voice box), trachea http://www. Treatment includes elevating the The vagus nerve also brings sensory information affected limb, wearing support hose to increase back to the brain from the ear, tongue, pharynx, and pressure on the vein, and in some cases surgery. It originates in the medulla oblongata, a part of the varicosity 1 An enlarged and tortuous vein, brain stem, and extends all the way down from the artery, or lymphatic vessel. The voice is hoarse and nasal, and the vocal varix An enlarged and convoluted vein, artery, or cord on the affected side is immobile. Treatment of varices depends on difficulty swallowing (dysphagia) and speaking where they are and whether they are causing prob- (dysphonia). A varix in the esophagus can be caused by branches, including the recurrent laryngeal nerve. This form of varix can require treatment to prevent dan- Valley fever Lung infection with the fungus gerous bleeding. The fungus is common in the sands of the deserts of the southwest, including the vas deferens The tube that connects the testes San Joaquin valley in California, after which it was with the urethra. Valsalva maneuver A maneuver in which one tries with force to exhale with the windpipe closed, vasa previa A condition in which blood vessels impeding the return of venous blood to the heart. Vasa previa carries a high risk that the fetus will die from blood loss due to a vessel tearing vanishing twin A twin detected in early preg- at the time the fetal membranes rupture or during nancy that is miscarried, frequently by resorption, labor and delivery. And, a vascular surgeon is an varicella vaccination See chickenpox immu- expert at evaluating and treating problems of the nization. For example, the pulmonary vascular bed that leave the testis to form the testicular vein. Risk factors include high blood pressure Varicose veins are most common in older adults, and advanced age. Symptoms include confusion, particularly women, and occur especially on the problems with recent memory, wandering or getting legs. Varicose veins can cause cramping pain and lost in familiar places, loss of bladder or bowel http://www. The damage is typically so slight that the change is vasoconstriction Narrowing of the blood vessels noticeable only as a series of small steps. However, that results from contraction of the muscular walls over time, as more small blood vessels in the brain of the vessels. The opposite of vasoconstriction is are blocked, there is noticeable gradual mental vasodilation. Vascular dementia commonly begins between the ages of 60 and 75 and affects men more vasodepressor syncope See syncope, situa- often than women. The actual causes of these vas- vasomotor Relating to the nerves and muscles culitis diseases are usually not known, but immune that cause blood vessels to constrict or dilate. Examples of vasculitis include Kawasaki disease, Behcet’s dis- vasomotor rhinitis Inflammation of the nose ease, polyarteritis nodosa, Wegener’s granulomato- (rhinitis) due to abnormal nerve control of the sis, Takayasu’s arteritis, Churg-Strauss syndrome, blood vessels in the nose. Vasomotor rhinitis is not giant cell arteritis (temporal arteritis), and Henoch- allergic rhinitis. Vasculitis can also accompany to temporarily reduce swelling of sinus and nasal infections, such as hepatitis B; exposure to chemi- tissues leading to an improvement of breathing and cals, such as amphetamines and cocaine; cancers, a decrease in obstruction. The ultimate diagnosis and, at the same time, affects the nerves to the blood for vasculitis is typically established after a biopsy of vessels in the legs, permitting those vessels to dilate involved tissue demonstrates the pattern of blood (widen). Treatment depends on the type the blood pressure drops, and the blood that is cir- and severity of the illness and the organs involved. The brain is deprived of oxygen, and a faint- the inflammation and suppressing the immune sys- ing episode (syncope) occurs. Typically, cortisone-related medications, such as prednisone, are used, as are other immune- vasovagal syncope The temporary loss of con- suppression drugs, such as cyclophosphamide sciousness in a particular kind of situation (situa- (brand name: Cytoxan). Also known as angiitis and tional syncope, or fainting) due to a vasovagal vasculitides (the plural form of vasculitis). Venlafaxine is believed to affect the the vector that carries and transfers the infectious neurotransmitters serotonin, norepinephrine, and agent. Examples are bee venom, snake venom, hemoglobin) in venous blood makes it appear dark. Snake venom is Veins are part of the afferent wing of the circulatory also called venin. In con- trast, an artery is a vessel that carries blood that is venous aneurysm A localized widening and high in oxygen away from the heart to the body. Velvet ant stings can trigger aller- is the most frequently used method for administra- gic reactions that vary greatly in severity. In selected venous catheterization is infection at the site of the cases, allergy injection therapy is highly effective. The superior vena cava sons) airs out their feelings by putting their prob- is located in the middle of the chest and is sur- lems into words. Structures bordering the superior vena cava include ventilator A machine that mechanically assists a the trachea, aorta, thymus, right bronchus of the patient in the exchange of oxygen and carbon diox- lung, and pulmonary artery. Compression of the ide, a process sometimes referred to as artificial superior vena cava by disease of any of the struc- respiration. See also superior ventral Pertaining to the front or anterior of a vena cava syndrome. Something that is ventral is oriented toward the belly, toward the front of the body. For vena cava syndrome, superior See superior example, the bellybutton (umbilicus) is in the ven- vena cava syndrome. For example, elevated pressure in the arteries to the lungs (pul- the four connected cavities in the central portion of monary hypertension). Vernix is still all over the under low pressure into the lungs via the pulmonary skin of a baby at birth. Both are life- threatening arrhythmias that are commonly vertebra One of 33 bony segments that form the associated with heart attacks and scarring of the human spinal column. For example, the second cer- vical vertebra is known as the axis, or C2, vertebra. The vertebral col- right ventricle, which has to do extra work to han- umn also protects the spinal cord, which runs from dle the additional blood. The right ventricle may the brain through the hollow space in the middle of have trouble keeping up with the load, enlarge, and the vertebral column. The lungs also receive too much blood under 12 thoracic (T1–T12), 5 lumbar (L1–L5), 5 sacral too great pressure. The small arteries (arterioles) (S1–S5), and 3 to 5 coccygeal vertebrae in the ver- in the lungs thicken up in response, and permanent tebral column, each separated by intervertebral vascular damage can be done to the lungs.