By W. Angar. University of Georgia.
However cheap zudena 100 mg fast delivery impotence in xala, these abnormalities would be correlative to those determined by the assessment of physiological and behavioral changes of human disease cheap zudena 100 mg on-line erectile dysfunction jokes. Additional studies should proceed only after phenotypic analysis has been appropriately performed buy zudena 100 mg line impotence yahoo answers. The ideal mouse model of a human genetic disease should recapitulate exactly the genotypic and phenotypic characteristics of the human disease. It is important to recognize the strengths and weaknesses of any model, as well as to use the model to address testable hypotheses and answer questions. Animal models of monogenic disorders created by these techniques, such as cystic ﬁbrosis, Duchenne’s muscular dystrophy, and hemophilia, can be used in gene therapy experiments. Less straightforward is the modeling and evaluation of gene therapy for poly- genic diseases (see Chapter 1) such as cancer, diabetes mellitus, and cardiovascular disease. However, hypotheses regarding pathogenesis and treatment can be addressed using mice that have been genetically manipulated such that they exhibit altered susceptibility to that disease. For many monogenic disorders, the inherited mutant allele has decreased or absent function (hypo- or nullimorph) compared to the normal allele. Here, a normal copy of the gene could be introduced into affected cells to correct the genetic basis of disease. For monogenetic diseases, either targeted mutagenesis or high-efﬁciency germline mutagenesis are generally the most efﬁcient methods for creating appro- priate models. Other genetic diseases result from increased or novel function of a mutant allele (hyper- or neomorph). For these diseases, a transgenic approach may produce a phenotypic model of the disease. Transgenic animal models also are useful for introducing highly expressed can- didate target genes into a mouse for testing of gene therapy strategies. These mice may not model a particular disease but produce a particular protein that can serve as a gene therapy target. In many instances, mutation of a locus in the mouse does not produce the same phenotype observed in patients with mutation of the corresponding human locus. That is, different sites in the gene may have been mutated in the mouse and human. There may be different patterns of expression of the target gene or modiﬁer genes between species. Finally, there may exist biochemical or physiological differences between species that affect the resulting phenotype. Although in principle, one desires models that closely mimic the disease in humans, models that fall short of this ideal are still useful. For example, humans carrying germline mutations in the tumor suppressor gene retinoblastoma (rb) develop the ocular tumor retinoblastoma. However, mice deﬁcient for the same gene develop tumors of the intermediate lobe of the pituitary. In spite of this difference, rb-null mice can provide general infor- mation about mechanisms of rb-mediated tumor genesis. Such studies allow an eval- uation of gene therapy protocols designed to restore rb function to deﬁcient cells regardless of speciﬁc tumor. Nonetheless, devel- opment of a model to evaluate gene-based treatment may be difﬁcult. The following sections discuss the genetic bases of these diseases and evaluate the strengths and shortcomings of current models being used to study both disease pathogenesis and treatment. Because it is present on the X chromosome, all carrier males (with only one X chromosome) are affected. They are (1) an a-actinin-like actin binding domain at the amino terminus, (2) the rod domain, composed of a series of 24 spec- trinlike a-helical repeats, (3) a cysteine-rich region, and (4) a variable C-terminal domain that is subject to alternative transcript splicing. The exact function of the protein is poorly understood, but it is pre- sumed to serve a structural function in force transmission or stabilization of the sarcolemma. As the disease progresses, muscle ﬁbers are replaced by fat and connective tissue. Histologically, these mice display muscle necrosis, ﬁbro- sis and phagocytic inﬁltration within muscle tissue, variation in myoﬁber size, an increased proportion of myoﬁbers with centrally located nuclei (an indicator of regeneration), and elevated serum levels of muscle creatinine kinase. Clinically, these animals do not exhibit visible signs of muscle weakness or impaired movement. It is a monogenic disorder, and the distinctive properties of skeletal muscle favor deliv- ery of gene targeting vectors. If these cells could be genetically manipulated, they could serve as a future and potentially unlimited source of targeting vector expres- sion in regenerating muscle. For this disease, gene therapy has been attempted using virtually every gene transfer technique developed. These include retroviral and ade- noviral vector infection, direct gene transfer, receptor-mediated gene transfer, and surgical transfer of genetically manipulated muscle cells. Expression of as little as 5% of the normal level of dystrophin was able to par- tially reverse the histopathological lesions. Expression of approximately 20 to 30% of the normal level prevented essentially all dystrophic histopathology and restored diaphragmatic muscle function. Therefore, a truncated gene with an in-frame deletion (exons 17 to 48) in the rod domain (which produces a very mild phenotype in humans with the corresponding mutation) was expressed as a transgene in mdx mice. When an adenovirus capable of expressing a recombinant truncated dystrophin was injected into muscles of newborn mdx mice, reduction in the histological evidence of muscle degeneration was noted. Also, protection from stretch-induced mechani- cal damage in these mice as adults were seen. More recently, it was found that trun- cated utrophin, a structurally similar protein present in skeletal muscle, could substitute for dystrophin as a therapeutic molecule when expressed in transgenic mdx mice. Thus, it may be possible to reverse or prevent muscle damage by up- regulating utrophin expression. Cystic Fibrosis Cystic ﬁbrosis is a common recessive disorder in the Caucasian population that affects about 1 in 2500 live births in populations of northern European ancestry. Clinical manifestations of this devastating disease include chronic pulmonary obstruction, bacterial colonization of the airways, pancreatic enzyme insufﬁciency, meconium ileus, elevated sweat electrolytes, and reduced fertility in males. This ﬂushing process is thought to be important in maintaining proper mucociliary clearance in the airways. Hundreds of additional mutant alleles have been identiﬁed, each occur- ring at a much lower frequency. However, despite producing an apparent phenocopy of the biochemical and elec- trophysiological defect, the histopathological features of the human disease were only partially reproduced in these models. The most striking phenotypic abnormal- ity in mouse homozygotes in three of the four mutant lineages was a high incidence of death between birth and weaning.
Two forms of disease produced by Actinomyces are cervicofacial actinomyces and pelvic actinomyces cheap zudena 100mg amex doctor for erectile dysfunction. The former consists of an indurated (lumpy) jaw with multiple draining fistulas or abscesses cheap 100 mg zudena with amex age related erectile dysfunction causes. Small yellow colonies called sulfur granules may be seen in the draining material order zudena 100 mg with mastercard erectile dysfunction pills at gas stations. Histologic section reveals tangled masses of gram-positive fila- mentous bacteria. Cultures of Actinomyces grow as white masses with a domed surface, which is called a “molar tooth” appearance. A characteristic that helps to differentiate these two is the fact that Nocardia is partially acid-fast. Nocardiae are aerobic and acid-fast, in contrast to Actinomyces species, which are strict anaerobes and not acid-fast. Progressive pneumonia with purulent sputum and abscesses is suggestive of nocardiosis, especially if dissemination to the brain or subcutaneous tissue occurs. Nocardia is also one cause of myce- toma, a form of chronic inflammation of the skin that causes indurated abscesses with multiple draining sinuses. These rods tend to arrange themselves at right angles, producing characteristic V or Y configurations described as “Chinese characters. This toxin can produce a pseudomembrane covering the larynx, which is difficult to peel away without causing bleeding, and heart General Pathology Answers 147 damage with fatty change. Characteristics that are unique to Listeria include a tumbling motility on hanging drop and an umbrella-shaped motility pattern when a specimen is stabbed into a test tube agar slant. Since the organisms grow slowly on enrichment media, they may be overgrown by other coliforms at 37°C. Infection results in a chronic disease that is characterized by superficial ulcers of the genital region. Regional lymph node involvement produces large nodular masses that develop extensive scarring. Instead, histologic examination is used to demonstrate Donovan bodies, which are organisms within the cytoplasm of macro- phages. Chancroid is an acute venereal disease that is characterized by painful genital ulcers with lymphadenopathy. Gram stains of the suppurative lesions or cultures on spe- cialized media may be used to make the diagnosis. Neisseria gonorrheae, a gram-negative diplococcus, causes gonor- rhea, an acute suppurative infection of the genital tract. In women, it may be asymptomatic (50%), or it may produce infection of the cervix with accom- panying vaginal discharge, dysuria, and abdominal pain. In newborns, infection acquired during birth can produce a purulent conjunctivitis (ophthalmia neonatorum). A Gram stain of the urethral or cervical exudate may reveal the intracytoplasmic gram- negative diplococci, or the exudate can be cultured on special media. Dark-field or immunofluorescence examination may be used to detect organisms in the genital ulcers of primary syphilis. Antibodies to cardi- olipin, a substance in beef heart that is similar to a lipoid released by T. Chlamydia species are obligate intracellular parasites that form elementary bodies and reticulate bodies. The former are small, extra- cellular, and infectious, while the latter are intracellular and noninfectious. Specialized culture media and direct examination procedures are available to aid in the diagnosis of these diseases. The regional lymph nodes in patients with lymphogranuloma venereum have a characteristic histologic appearance typified by necrotizing granulomas forming stellate areas of necrosis. It is a chronic infection of the conjunctiva that eventu- ally scars the conjunctiva and cornea. Lymphogranuloma venereum is a sexually transmitted disease that is characterized by the formation of a gen- ital ulcer with local necrotizing lymphadenitis. It produces a severe pul- monary disease and should be suspected in patients with a history of bird contact, such as pet shop workers or parrot owners. This disorder was first described in the mid-1970s in Connecticut General Pathology Answers 149 when small clusters of cases of children who developed an illness resem- bling juvenile rheumatoid arthritis were first noted. The disease has now been shown to be caused by a spirochete, Borrelia burgdorferi, through the bite of a tick belonging to the genus Ixodes. The spirochete-infested ticks reside in wooded areas where there are deer and small rodents. In the spring the tick larval stage emerges and evolves into a nymph, which is infective for humans if they are bitten. The bite is followed by a rash called erythema chronicum migrans, which may resolve spontaneously. However, many patients have a transient phase of spirochetemia, which may allow the spread of the spiro- chete to the meninges, heart, and synovial tissue. Originally thought to be confined to New England, Lyme disease has now been shown to be present in Europe and Australia as well. These disorders include Reiter’s syn- drome, ankylosing spondylitis, psoriatic arthritis, and enteropathic arthri- tis. Reiter’s syndrome refers to the triad of arthritis, nongonococcal urethritis, and conjunctivitis. It may be an autoimmune reaction to previous gas- trointestinal or genitourinary infections. Causes of these gastrointestinal infections include Shigella, Salmonella, Yersinia, and Campylobacter. Serologic tests for rickettsia include complement fixation tests and the Weil-Felix agglutination reaction. The basis for the latter test is the fact that the sera of infected patients can agglutinate strains of Proteus vulgaris. The vector in the Rocky Mountains is the wood tick (Dermacentor andersoni), while in the southeast it is the dog tick (Der- macentor variabilis) and in the south central United States it is the Lone Star tick. Intracellular bacilli form parallel rows in an end-to-end arrangement (“flotilla at anchor facing the wind”). Histologically, this disease is characterized by the formation of stellate microabscesses with necrotizing granulomas. Numerous bacilli in packets within histiocytes (lepra cells) are also found in the lesions of lepromatous leprosy.
Cassar (7) cheap 100mg zudena fast delivery erectile dysfunction statistics age, for example buy cheap zudena 100 mg online erectile dysfunction doctors in richmond va, describes the earliest recorded Mal- tese medicolegal report (1542): medical evidence established that the male partner was incapable of sexual intercourse cheap zudena 100 mg erectile dysfunction medications cost, and this resulted in a marriage annulment. Beck (8) identifies Fortunatus Fidelis as the earliest writer on medi- cal jurisprudence, with his De Relationibus Medicorum being published in Palermo, Italy, in 1602. Subsequently, Paulus Zacchias wrote Quaestiones Medico-Legales, described by Beck as “his great work” between 1621 and 1635. Beck also refers to the Pandects of Valentini published in Germany in 1702, which he describes as “an extensive retrospect of the opinions and deci- sions of preceding writers on legal medicine. Late 18th Century Onward Beginning in the latter part of the 18th century, several books and trea- tises were published in English concerning forensic medicine and medical History and Development 5 jurisprudence. What is remarkable is that the issues addressed by many of the authors would not be out of place in a contemporary setting. It seems odd that many of these principles are restated today as though they are new. In 1783, William Hunter (9) published an essay entitled, On the Uncer- tainty of the Signs of Murder in the Case of Bastard Children; this may be the first true forensic medicine publication from England. John Gordon Smith writes in 1821 in the preface to his own book (10): “The earliest production in this country, professing to treat of Medical Jurisprudence generaliter, was an abstract from a foreign work, comprised in a very small space. Davis (11) refers to these and to Remarks on Medical Jurispru- dence by William Dease of Dublin, as well as the Treatise on Forensic Medi- cine or Medical Jurisprudence by O. Davis considers the latter two works of poor quality, stating that the: “First original and satis- factory work” was George Male’s Epitome of Juridical or Forensic Medicine, published in 1816 (second edition, 1821). Male was a physician at Birming- ham General Hospital and is often considered the father of English medical jurisprudence. John Gordon Smith (9) stated in The Principles of Forensic Medicine Systematically Arranged and Applied to British Practice (1821) that: “Forensic Medicine—Legal, Judiciary or Juridical Medicine—and Medical Jurisprudence are synonymous terms. Beck published the first American textbook 2 years later in 1823 and a third edition (London) had been published by 1829 (8). John Gordon Smith (9) wrote that “Every medical practitioner being liable to a subpoena, should make it his business to know the relations of physi- ological and pathological principles to the facts on which he is likely to be interrogated, and likewise the principal judiciary bearings of the case. The former of these are to be found in works on Forensic Medicine; the latter in those on Jurisprudence. Personal identity Real & apparent death Identity Sudden dath Age Survivorship Sex 8. Foeticide or criminal abortion Spontaneous combustion Infanticide Death by lightning Legitimacy Death from cold 5. The first Chair of Forensic Medicine had been established in the United Kingdom in Edinburgh in 1803—the appointee being Andrew Duncan, Jr. Subse- quent nonprofessorial academic forensic medicine posts were established at Guy’s Hospital and Charing Cross Hospital, London. In 1839 and 1875, respec- tively, academic chairs of medical jurisprudence were created in Glasgow and Aberdeen (15). The relevant areas of interest to forensic medicine and medical jurispru- dence were gradually becoming better defined. Table 2 summarizes the chap- ter contents of Principles of Forensic Medicine by William Guy (16), Professor of Forensic Medicine at King’s College, London, in 1844. Much of this mate- rial is relevant to forensic physicians and forensic pathologists working today. Thus, by the end of the 19th century, a framework of forensic medicine that persists today had been established in Europe, the United Kingdom, America, and related jurisdictions. Even though medicine and law interact more frequently in cases of living individuals, forensic pathology has long been established as the academic basis for forensic medicine. It is only in the last two decades that research and academic interest in clinical forensic medi- cine have become an area of more focused research. The recent growth in awareness of abuses of human rights and civil lib- erties has directed attention to the conditions of detention of prisoners and to the application of justice to both victim and suspect. Examples of injustice and failure to observe basic human rights or rights enshrined in statute in which the input of medical professionals may be considered at least of poor quality and at worst criminally negligent have occurred and continue to occur worldwide. The death of Steve Biko in South Africa, the conviction of Carole Richardson in England, and the deaths of native Australians in prison are widely publicized instances of such problems. Reports from the European Committee for the Prevention of Torture and Inhuman and Degrading Treat- ment in the early 1990s drew attention to the problem of lack of indepen- dence of some police doctors. The conflicting needs and duties of those involved in the judicial system are clear, and it is sometimes believed that recognition of such conflicts is comparatively recent, which would be naïve and wrong. In England and Wales, the Human Rights Act 1998, whose pur- pose is to make it unlawful for any public authority to act in a manner incom- patible with a right defined by the European Convention of Human Rights, reinforces the need for doctors to be aware of those human rights issues that touch on prisoners and that doctors can influence. It is worth noting that this law was enacted almost 50 years after publication of the European Conven- tion of Human Rights and Fundamental Freedoms. The future role of the forensic physician within bodies, such as the recently established Interna- tional Criminal Court, is likely to expand. The forensic physician has several roles that may interplay when assess- ing a prisoner or someone detained by the state or other statutory body. Three medical care facets that may conflict have been identified: first, the role of medicolegal expert for a law enforcement agency; second, the role of a treat- ing doctor; and third, the examination and treatment of detainees who allege that they have been mistreated by the police during their arrest, interroga- tion, or the various stages of police custody (18). Grant (19), a police surgeon 8 Payne-James appointed to the Metropolitan Police in the East End of London just more than a century ago, records the following incident: “One night I was called to Shadwell [police] station to see a man charged with being drunk and disorderly, who had a number of wounds on the top of his head…I dressed them…and when I fin- ished he whispered ‘Doctor, you might come with me to the cell door’…I went with him. We were just passing the door of an empty cell, when a police con- stable with a mop slipped out and struck the man a blow over the head…Boiling over with indignation I hurried to the Inspector’s Office [and] told him what had occurred. Grant rightly recognized that he had moral, ethical, and medical duties to his patient, the prisoner. Grant was one of the earliest “police surgeons” in En- gland, the first Superintending Surgeon having been appointed to the Metro- politan Police Force on April 30, 1830. In 1951, the association was reconstituted as a national body under the leadership of Ralph Summers, so that improvements in the education and training for clinical forensic medicine could be made. The Association of Forensic Physicians, formerly the Associa- tion of Police Surgeons, remains the leading professional body of forensic phy- sicians worldwide, with more 1000 members. It shows how clinical forensic medicine operates in a variety of coun- tries and jurisdictions and also addresses key questions regarding how important aspects of such work, including forensic assessment of victims and investigations of police complaints and deaths in custody, are under- taken. The questionnaire responses were all from individuals who were familiar with the forensic medical issues within their own country or state, and the responses reflect practices of that time. The sample is small, but nu- merous key points emerge, which are compared to the responses from an earlier similar study in 1997 (20). In the previous edition of this book, the following comments were made about clinical forensic medicine, the itali- cized comments represent apparent changes since that last survey. There appears to be wider recognition of the interrelationship of the roles of forensic physician and forensic pathology, and, indeed, in many jurisdic- tions, both clinical and pathological aspects of forensic medicine are under- taken by the same individual. The use of general practitioners (primary care physicians) with a special interest in clinical forensic medicine is common; England, Wales, Northern Ireland, Scotland, Australasia, and the Netherlands all remain heavily dependent on such professionals. Academic appointments are being created, but these are often honorary, and until governments and states recognize the importance of the work by fully funding full-time academic posts and support these with funds for research, then the growth of the discipline will be slow.