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METABOLISM, ENDOCRINOLOGY AND IMMUNOLOGY
The aim of the was to evaluate the contraction frequency /force relationship, determine if pathological conditions change the contractile force of the muscle and observe whether contraction force is different in a longitudinal versus transverse axis. Since species-dependent variations have been described, only human tissues are included to permit deductions for clinical practice. The authors stimulated electrically according to different schemes 405 normal and pathological ureteral and renal pelvic strips. Reflux strips produced stronger contractions than normal ones, while transversally excised strips contracted more strongly than longitudinal ones. The amplitude of a test pulse after a series of stimuli increased with increasing delay until a constant value was reached (at 30 seconds). The first contraction after a rest period had a lower latency and higher amplitude (rest contraction). The time to peak force of contractions was constant. Elongation of the strips increased the amplitude but not the latency of the contractions. The similarities between the contractile behavior of the pyeloureteral muscle and the heart are discussed. G. P. M. 3 figures, 5 tables, 14 references
Canado Med. Ass.
133: 122
1985
Two patients had hypotensive reactions to excretory urography in an office setting. Both patients were taking jJ-adrenergic blocking agents and both recovered with administration of steroids or epinephrine. The incidence of such reactions was only 2 of 635 patients undergoing the study. Iodinated contrast agents are known to stimulate the release of histamine by a mechanism unrelated to lgE (antigen-antibody response). This may be a direct stimulation of histamine release by mast cells. /]-Blockade may interfere with the adrenergic response of the body to the hypotensive tendency of the contrast material, thereby potentiating the hypotension. The author recommends that patients be withdrawn from ,6-blockers 2 to 3 days before examination and that an antihistamine should be administered orally 2 hours before the injection. J. H. N. 4 references
METABOLISM, ENDOCRINOLOGY AND IMMUNOLOGY
Contractile Behaviour of the Human Pyeloureteral Musculature, II. Repetitive Electrical Stimulation Effects
Implications of the Acquired Immunodeficiency Syndrome for Health Policy
R. L. VEREECKEN AND J. DAS, Department of Urology, University Clinic St. Pieter, K. U. Leuven, Leuven, Belgium
E. N. BRANDT, JR., University of Maryland at Baltimore, Baltimore, Maryland
Urol. Res., 14: 31-35 (Feb.) 1986
Ann. Intern. Med., 103: 771-773 (Nov.) 1985
The authors showed previously that ureteral and cardiac muscles have many contractile similarities, such as an after rest activation, a long refractory period and a frequency /force relationship. Since the heart muscle is known to adapt its contractile force to the frequency of repeated stimulations, it seems logical to study the reaction of the pyeloureteral system to repeated electrical stimuli. By changing the parameters of the stimuli the authors hoped to compare the influence of transmural nerve and direct muscle stimulation. Only human normal and pathological strips were used to exclude species variation. In normal proximal and distal pyeloureteral human strips, and in pathological reflux or obstructive segments the influence of repetitive electrical stimulation at frequencies between 0001 and 200 Hz. on their contractile behavior was studied. Between 0.01 and 1 Hz. baseline tone and maximum amplitude of contraction were dependent on stimulation frequencies but some showed an irregular response pattern. At frequencies of 1 to 200 Hz. half of the strips showed a typical on and off contraction (at the beginning and end of the stimulus period, a plateau. The authors considered respectively) separated the off reaction to be a response to an ionic displacement at the end of the stimulus. Spontaneous activity was observed mostly in Tyrode's solution, and in the calix and renal pelvis. Transmural nerve stimulation did not change the contraction patterns. G. P. M. 8 figures, 1 table, 9 references
The incidence of acquired immunodeficiency syndrome (AIDS) has increased rapidly since it was first detected in 1981. The health policy implications of this syndrome have been difficult to assess because of limited knowledge of the disease process, and because it affects primarily homosexual men and intravenous drug abusers. These features have sociopolitical implications absent in other previous epidemics and make evaluation difficult. The scientific community is urged to approach the problem with objectivity and intellectual curiosity. A continuous nationwide surveillance system is recommended, and the auth01· suggests that effective mechanisms should be developed for the dissemination of information to the public, that a rational approach to funding should be made and that public health service agencies fulfill their role in helping to control the disease process. R. C. N.
RADIOLOGY, NUCLEAR MEDICINE AND SONOGRAPHY Severe Adverse Reactions to U:rography in Patients Taking ,6-Adrenergic Blocking Agents G.
HAMILTON, Department of Radiology, University of Western Ontario, London, Ontario, Canada
The Acquired Immunodeficiem.cy Synd:rome in Gay Men
W. w. Center for Infectious Diseases, Centers for Disease Control, Public Health Service, U. S. Department of Health and Human Services, Atlanta, Georgia
H. W.
JAFFE, A. M. HARDY, W. M. MORGAN AND DARROW, AIDS Branch, Division of Viral Diseases,
Ann. Intern. Med., 103: 662-664 (Nov.) 1985 Since 1981 the number of homosexual men with the acquired immunodeficiency syndrome (AIDS) reported in the United States has increased dramatically. About 75 per cent of all reported cases occurred in homosexual men. Most of these men with AIDS or related conditions had human T-lymphotrophic virus type III/lymphadenopathy-associated virus antibody detected by an enzyme-linked immunosorbent assay, including more than 50 per cent of asymptomatic men. Up to 20 per cent of homosexual men with generalized lymphadenopathic conditions had progression to AIDS. In most studies men with large
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METABOLISM, ENDOCRINOLOGY AND IMMUNOLOGY
numbers of sexual partners, and who engaged in receptive anal intercourse and "fisting" emerged as an important risk factor. Recently, many homosexual men have changed their sexual life-styles. Since vaccines, antiviral agents or other treatments still are not available the major factor in controlling AIDS in homosexual men will remain the behavioral change. F. T. A. 2 figures, 3 tables, 24 references
The Acquired Immunodeficiency Syndrome in Haiti J. W. PAPE, B. LIAUTAUD, F. THOMAS, J.-R. MATHURIN, M.M. A. ST. AMAND, M. BONCY, V. PEAN, M. PAMPHILE, A. C. LAROCHE, J. DEHOVITZ AND w. D. JOHNSON, the Haitian
Study Group on Kaposi's Sarcoma and Opportunistic Infections, Port-au-Prince, Haiti and Department of Medicine, Division of Internal Medicine, Cornell University Medical College, New York, New York Ann. Intern. Med., 103: 674-678 (Nov.) 1985 Between June 1979 and December 1984, 229 patients with the acquired immunodeficiency syndrome (AIDS) were evaluated in Haiti. The clinical and laboratory findings were similar in most respects to those reported in patients in the United States. However, there were some differences in the epidemiology of AIDS in Haiti compared to other countries. Major risk factors, such as bisexuality, blood transfusions and intravenous drug abuse, were found in only 43 per cent of the Haitian patients. The most common pathogens seen in Haiti are Candida, Cryptosporidia and Mycobacteria, while in the United States the most common is Pneumocystis carinii. Hepatitis B surface antigen was detected by enzyme-linked immunosorbent assay in 15 per cent of 39 men and in 13 per cent of women with AIDS. This test also was positive in 14 per cent of 56 male siblings and friends, and in 4 per cent of 25 female siblings and friends. Of the Haitian patients with AIDS 23 per cent are women compared to 7 per cent in the United States. The only mechanisms of transmission of the syndrome to date are homosexual and heterosexual activity, blood transfusions, and use of contaminated needles and syringes. Other potential modes of transmission of infection require further evaluation. F. T. A. 4 tables, 18 references
Mechanisms of T-Cell Functional Deficiency in the Acquired Immunodeficiency Syndrome QUINNAN, JR., J. P. SIEGEL, J. S. EPSTEIN, J. MANISCHEWITZ, BARNES AND M. A. WELLS, Division
G. V.
F. of Virology, Office of Biologics Research and Review, Center for Drugs and Biologies, Food and Drug Administration, Bethesda, Maryland
s.
Ann. Intern. Med., 103: 710-714 (Nov.) 1985
It has been established that human T-lymphotrophic virus type III (HTL V-III) has a role in the development of the acquired immunodeficiency syndrome (AIDS). However, most patients harboring HTLV-III do not suffer AIDS. When the syndrome does develop it appears to be owing to a slowly progressive or delayed effect of HTLV-III on cell mediated immunity. Since cytomegalovirus infections are common in AIDS patients, cell mediated immune responses to cytomegalovirus infections were studied to define deficient effector T-cell responses in this patient group. Potential explanations for deficient cytotoxic T-cell responses in these patients include lysis
of precursors to the cells by HTLV-III, a critical deficiency in T-helper cell dysfunction and a defect in the process of maturation of precursors into cytotoxic cells. In vitro experiments indicate that cytotoxic T-cell precursors exposed to interleukin-2 develop HLA-restricted cytotoxicity. Clinical trials with interleukin-2 have provided additional evidence for an interleukin-2-related maturation arrest in effector T-cells. Other studies indicate that sera from AIDS patients contain an inhibitor of interleukin-2 production. In essence, the pathogenesis of AIDS has not been elucidated fully. While HTL V-III does cause lysis of T-helper cells the direct effects of the virus may not account fully for the immunodeficiency state. The authors suggest that an arrest in maturation of T-effector cells occurs in the syndrome. Because of its role in determining susceptibility of AIDS patients to cytomegalovirus infections, the serum inhibitor of interleukin-2 production appears to be important in the process. In addition, this inhibitor probably is involved in the process of determining susceptibility to opportunistic infections in general. The source of this inhibitor in vivo and the mechanism by which its production is induced by HTLV-III remain to be determined. R. C. N. 3 figures, 29 references
Infection by the Retrovirus Associated With the Acquired Immunodeficiency Syndrome: Clinical, Biological, and Molecular Features J. A. LEVY, L. S. KAMINSKY, W. J. W. MORROW, K. STEIMER, P. LUCIW, D. DINA, J. HOXIE AND L. OSHIRO, Cancer Re-
search Institute, Department of Medicine, University of California, School of Medicine, San Francisco; Chiron Corporation, Emeryville, and the California Department of Health Services, Berkeley, California, and the Cancer Institute, University of Pennsylvania, Philadelphia, Pennsylvania Ann. Intern. Med., 103: 694-699 (Nov.) 1985 The authors isolated acquired immunodeficiency syndrome (AIDS)-associated retrovirus from more than 160 persons from the known risk groups for the syndrome (homosexual and bisexual men, intravenous drug users, recipients of transfusions and blood products, such as factor VIII and factor XI, newborn children of mothers from 1 of the risk groups, and Haitians and central Africans). Antibodies to AIDS-associated retrovirus were detected in persons with AIDS from San Francisco and in the risk groups but not in the control population. Further observations indicate that a negative state for antibody can be owing to either early infection with the virus or the presence of high titers of virus (antigen excess) that mask the antibody response. These studies have shown that 34 of 62 plasma and serum samples selected from persons with virus release from their cultured peripheral mononuclear cells contained infectious virus particles at levels that can reach 25,000 per ml. serum. Recovery of AIDS-associated retrovirus from semen and saliva has been low. These studies also have shown that AIDSassociated retrovirus cannot infect fibroblast and epithelial cells from many different avian and mammalian species. Biological studies have demonstrated cytopathic changes in lymphocytes, such as formation of multinucleated cells and degenerative ballooning cells reduced by AIDS-associated retrovirus. The possible mechanisms of these effects is accumulation of unintegrated proviral linear and circular forms of AIDS-associated retrovirus in the infected cells. Molecular characteristics indicate a polymorphism of nucleotide sequences, particularly