摘要:

Both clinical and epidemiological data suggest that inapparent infection byChlamydia trachomatisoccurs in humans. To confirm and study such infections, we developed a hybridization screening system directed toward chlamydial ribosomal RNA (rRNA). Six restriction endonuclease fragments derived from the clonedrrnAoperon of chlamydial serovar L2(434) were tested as hybridization screening probes, but only one fragment encoding the 5′ portion of the 16s rRNA gene plus some upstream flanking sequence was both sensitive and highly specific in such experiments. In Northern slot blot assays, hybridization analyses with this fragment as probe routinely detected one picogram or less of chlamydial RNA when that RNA was bound to membranes alone or as part of a mixture with a vast excess of mammalian RNA. The probe did not hybridize to RNA from mammalian and relevant bacterial sources but did hybridize to rRNA from B (ocular) and E (genital) serovars ofC. trachomatis.Experiments using RNA from conjunctival biopsies and standard conjunctival swab samples from cynomolgus monkeys showed that the probe reliably distinguishes between known chlamydia-infected and uninfected samples. This suggests that it may be useful for clinical screening. Characterization assays for the RNA-directed probe screening system in this monkey model of trachoma provide initial molecular evidence that ocular chlamydial infection may persist longer than previously thought, based solely on direct fluorescence antibody assay (DFA) and culture analyses.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Chronic fatigue is a common and disabling problem in primary care practice. The differential diagnosis of chronic fatigue is extensive and includes medical disorders, altered physiologic states (eg, pregnancy, exertion), psychiatric disorders, lifestyle derangements, drugs, and controversial entities (eg, chronic candidiasis, food allergies, environmental illness, and chronic fatigue syndrome). The most common diagnoses are psychiatric disorders, including mood, anxiety, and somatoform disorders. A comprehensive approach to diagnosis and management is necessary, including structured psychiatric interviewing, functional assessment, and elicitation of the patient's diagnostic beliefs. Patients often believe they are suffering from an organic medical disorder (eg, viral or immunologic) and resist psychiatric labelling of their symptoms and referral to mental health practitioners. Establishing and maintaining rapport, having a flexible approach, and demonstrating a personal concern for the patient is essential. Drug therapy for specific psychiatric and medical illnesses and cognitive-behavioral approaches for enhancing coping mechanisms are effective.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The relationship between the intensities of IgA, C3c, and C9 deposition in renal glomeruli and the severity of histopathologic injuries in patients with IgA nephropathy was examined using Microscope-Photometer O1K and a computer. Percentages of glomerular adhesion to Bowman's capsules, crescent formation, and glomerular sclerosis were calculated in the renal specimens. There was a significant correlation between the intensity of each C3c and C9 deposition in glomeruli and the degree of glomerular adhesion to Bowman's capsules and crescent formation in patients with IgA nephropathy. There was no significant correlation between the intensity of C3c or C9 deposition in glomeruli and the degree of glomerular sclerosis. No relationship was found between the intensity of IgA deposition in glomeruli and the degree of histopathologic injuries. The patients with negative or trace amounts of glomerular C3c deposits showed less severe glomerular injuries. Thus, the intensity of C3c and C9 deposition in glomeruli appears to be one of the critical factors responsible for the active progression of glomerular inflammatory process in patients with IgA nephropathy.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Oxygen consumption of the rabbit femoral artery after hemorrhagic shock was studied. Hemorrhagic shock was initiated and maintained at 60 mm Hg of systolic blood pressure for 2 hours. A significant reduction in femoral artery oxygen consumption was observed after hemorrhagic shock (1.64 ± 0.14 μl/g/hr) when compared to oxygen consumption in the normal condition (2.52 ± 0.22 μl/g/hr). Application of the β-agonist isoproterenol significantly increased oxygen consumption in the isolated femoral artery after hemorrhagic shock (2.66 ± 0.20 μl/g/hr), but did not exceed the normal values recorded without stimulation. Also, isoproterenol significantly increased oxygen consumption in the femoral artery of nonhemorrhagic condition (4.84 ± 0.42 μl/g/hr). The increase in oxygen consumption conditioned by isoproterenol was significantly lower after hemorrhagic shock compared with values in the nonhemorrhagic state. The data suggest that oxygen consumption is regulated by β-adrenergic receptors, and the phenomenon of diminished oxygen consumption after hemorrhagic shock probably occurs because of changes in β-adrenergic receptors, causing the appearance of change in the mechanism of oxygen consumption.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Oxygen-derived free radicals are cytotoxic and promote tissue damage. Dimethyl sulfoxide (DMSO) and allopurinol scavenge hydroxyl radicals, and the latter agent also inhibits the enzyme xanthine oxidase, which is responsible for the formation of superoxide anions. These agents were given daily by gavage (1 ml/d). After 2 days of administration as 1, 2, or 5% solutions, the H+output of the rat with or without pyloric ligation was not significantly affected.After six hours reserpine (5 mg/kg i.p.) or serotonin (50 mg/kg i.p.) produced ischemic mucosal injury in all stomachs (39 ± 5.2 mm2and 25.9 ± 2.8 mm2, mean ± standard error of the mean [SEM], n = 10). Pretreatment for 2 days with 1 ml/d of 1% allopurinol or DMSO significantly (p < 0.001) protected the rat against the reserpine (23 ± 2.1 mm2and 24 ± 1.9 mm2, respectively, vs 39 ± 5.2 mm2, n = 10) and serotonin injury (10 ± 1.5 mm2and 11 ± 1.8 mm2, respectively, vs 25.9 ± 2.8 mm2, n = 10). However, 2 days pretreatment with 1 ml/d of 2% allopurinol or DMSO was more effective (p < 0.001) in this respect, and injury only developed in 40% of the rats given reserpine (8 ± 1.2 mm2and 9 ± 1.6 mm2) and in 20% of those given serotonin (2.4 ± 0.4 mm2and 1.9 ± 0.5 mm2). Similar pretreatment with 5% solutions completely protected the rat stomach against the reserpine and serotonin injuries without significantly influencing the H+output.The similarity in efficacy between allopurinol and DMSO and the fact that scavenging oxyradicals is the only action they share suggests that oxygen-derived free radicals are directly implicated in the mechanism of development of ischemia-induced acute gastric mucosal injury and that scavenging these radicals protects against the injury without influencing acid secretion (ie, cytoprotection).

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

It is well known that most patients with hypoparathyroidism have radiologically detectable basal ganglia calcification. Not as well known is that the brain calcinosis may be more extensive. We describe a 55-year-old woman with a 44-year history of symptomatic idiopathic hypoparathyroidism who has extensive calcification of her cerebrum and cerebellum as well as her basal ganglia, evident on computed tomography of the head. When first evaluated here 32 years ago, plain radiography of the skull demonstrated calcification of both caudate and lentiform nuclei (basal ganglia). Despite fair control of her serum calcium level, she has developed focal seizures, possibly related to the calcinosis of her brain.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

We report the case of a healthy young Hispanic man withSalmonella typhimuriumbacteremia and leukocytoclastic vasculitis. Leukocytoclastic vasculitis has not been previously reported as a complication of salmonella gastroenteritis and bacteremia. Salmonella gastroenteritis is rarely associated with bacteremia in healthy young adults.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Gene therapy offers the promise of a definitive cure of the hemoglobinopathies and thalassemias. The background of gene therapy for these disorders is discussed along with the obstacles that must be overcome before this promise becomes reality.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Cells of higher organisms respond to external stimuli with a cascade of intracellular biochemical events initiated by binding of a hormone, growth factor, or neurotransmitter to a specific cell surface receptor. Previously well-characterized signal transduction pathways involve cyclic nucleotides as intracellular second messengers. Over the past decade, increasing attention has been focused on other signaling pathways in which membrane lipids serve as second messengers or their precursors. This review describes current understanding of these pathways and points to recent discoveries likely to open new frontiers in the coming decade.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Academic midicine is entering a period of introspection created by changing patterns of health and disease and changing pattersn in reimbursement and health policy. To respond to existing health challenges, innovative strategies for health care delivery and education must be devised. The migration of medical education and health care delivery into centralized and frequently difficult-to-access campuses is being reviewed by payors, police analysts, and purchasers of care. One proposed solution to this problem responds to the indentified shortcomings in medical education and some of the failures of our health care delivery system. Community Oriented Primary Care (COPC) and the related discipline of Community Responsive medicinedefine health-oriented strategies that blend traditional primary care and public health. The classroom in community Responsive Medicine is the community. The curriculum is defined by the health status of the target community.The model allows the student and resident to appreciate and experience the entire spectrum of health and disease and to understand the sequence of events that may lead to illness. Tertiary care is a critical curriculum component, but in Community Responsive Medicine the curriculum is balanced between the ambulatory and tertiary care settings. Community Responsive Medicine defines a role for new leadership that can create responsive educational and health care delivery systems accountable to the communities they serve.

ISSN:0002-9629    

出版商:OVID    

年代:1991

数据来源: OVID