[Rodent fleas (Siphonaptera, Insecta) in the Terek-Kuma interfluve].

The fauna of rodent fleas comprises 19 species in the Terek-Kuma interfluve. Most detected parasites settle together with their hosts within and outside this area. Only gerbils and their parasites are limited to the spread in a semi-desert zone. The attribution of the fleas to various hosts, such as little sousliks, gerbils, jerboas, mice, and common voles, is not absolute and the parasites are, in addition to the principal hosts, encountered on the rodents of other species. Exchange of the parasites between different host species makes possible the passaging of pathogens of infectious diseases among them.

A larger spectrum of severe HIV-1--related disease in intravenous drug users in New York City.

Increasing mortality in intravenous (IV) drug users not reported to surveillance as acquired immunodeficiency syndrome (AIDS) has occurred in New York City coincident with the AIDS epidemic. From 1981 to 1986, narcotics-related deaths increased on average 32% per year from 492 in 1981 to 1996 in 1986. This increase included deaths from AIDS increasing from 0 to 905 and deaths from other causes, many of which were infectious diseases, increasing from 492 to 1091. Investigations of these deaths suggest a causal association with human immunodeficiency virus (HIV) infection. These deaths may represent a spectrum of HIV-related disease that has not been identified through AIDS surveillance and has resulted in a large underestimation of the impact of AIDS on IV drug users and blacks and Hispanics.

Virus-induced pancreatic disease by Venezuelan encephalitis virus. Alterations in glucose tolerance and insulin release.

Viral infections have been implicated in the induction of diabetes mellitus in man and laboratory animals. Since virus-specific immunofluorescence (FA) is detectable in hamster pancreas during the acute phase of Venezuelan encephalitis (VE), experiments were designed to correlate pathologic and virologic events with metabolic studies in VE-infected hamsters. Golden Syrian hamsters were inoculated s.c. in groups of four to 12 with 100,000 plaque-forming units (PFU) of the vaccine strain (TC-83) of VE or 1,000 PFU of the virulent Trinidad strain of VE. Ultrastructurally, during Trinidad infection, mature virions were associated with the cell surfaces and within pancreatic beta cells in contrast to absence of virus-related changes in TC-83-infected hamsters. Virus-specific-FA was noted in islet cells and acinar cells of Trinidad-infected hamsters. VE growth curves demonstrated viral replication in pancreas with both strains. Although ultrastructural and FA changes were much more prominent in Trinidad-infected hamsters in contrast to TC-83-infected hamsters during the first few days of illness, the rapid lethality of the Trinidad-infected group necessitated performing all metabolic studies in TC-83-strain-infected hamsters. Accordingly, for the metabolic studies, glucose tolerance tests (GTT) using 2 mg. or 5 gm./kg. glucose i.p. were performed in groups of hamsters acutely infected two days earlier with the TC-83 vaccine strain and in 24-day and 90-day convalescent hamsters after TC-83 vaccine strain. Samples were obtained for glucose and immunoreactive insulin (IRI) determinations. Glucose intolerance occurred in hamsters in each of the infected groups given 5 gm./kg. glucose except for the 90-day convalescent TC-83 group. Severely decreased IRI responses occurred in the 24-day and 90-day convalescent TC-83 hamsters following both 2- and 5-gm./kg. glucose. Pancreatic IRI content in 24-day convalescent TC-83 hamsters was within normal limits, suggesting a defect in IRI release from the beta cells at this stage of convalescence.

Lyme carditis. Electrophysiologic and histopathologic study.

To further define the nature of Lyme carditis, electrophysiologic study and endomyocardial biopsy were performed in a patient with Lyme disease, whose principal cardiac manifestation was high-degree atrioventricular block. Intracardiac recording demonstrated supra-Hisian block and complete absence of an escape mechanism. Gallium 67 scanning demonstrated myocardial uptake, and right ventricular endomyocardial biopsy revealed active lymphocytic myocarditis. A structure compatible with a spirochetal organism was demonstrated in one biopsy specimen. It is concluded that Lyme disease can produce active myocarditis, as suggested by gallium 67 imaging and confirmed by endomyocardial biopsy. Furthermore, the presence of high-grade atrioventricular block in this disease requires aggressive management with temporary pacemaker and corticosteroid therapy.

Extraintestinal amebiasis in infancy: report of three patients and epidemiologic investigations of their families.

Three infants (aged 6 weeks, 7 weeks, and 10 months) had severe Entamoeba histolytica infections characterized by colitis, hepatic abscesses, and peritonitis. The two younger children died after fulminant illnesses while the third recovered. Diagnosis was delayed in all three children by a low index of suspicion and negative stool examinations for parasites. Epidemiologic investigations of the infants' families revealed a high prevalence of amebic infections and elevated antibody titers to E histolytica; however, most family members were asymptomatic. The original source of the infections could not be identified but person-to-person spread within the families was implicated.

Pseudomicrobes: some potential diagnostic pitfalls in the histopathologic assessment of inflammatory lesions.

In the histopathologic evaluation of inflammatory lesions, numerous structures suggestive but not representative of microbial agents are encountered and may lead to erroneous diagnoses. Examples of pseudomicrobes are illustrated and discussed to prevent potential incorrect histopathologic assessments.

Staining qualities of cytomegalovirus inclusions in the lungs of patients with the acquired immunodeficiency syndrome: a potential source of diagnostic misinterpretation.

Gomori's methenamine silver and the periodic acid--Schiff reaction stain cytoplasmic but not intranuclear cytomegalovirus inclusions. The biochemical basis of these staining qualities is discussed, and the staining characteristics are correlated with supporting ultrastructural observations. Failure to recognize this phenomenon may lead to erroneous diagnostic conclusions at the light microscopic level.

Respiratory obstruction caused by a multicentric granular cell tumor of the laryngotracheobronchial tree.

An unusual case of acute respiratory obstruction caused by multicentric granular cell tumors of the laryngotracheobronchial tree is presented. The patient also had granular cell tumors in the tongue, vulva, and chest wall. Multiplicity of the lesions in the left lung and recurrent episodes of intercurrent pulmonary infections necessitated left pneumonectomy. The extreme rarity of such a clinical circumstance is illustrated by a review of the literature. Salient clinical and pathological features of the tumor are briefly discussed.

An outbreak of acute gastroenteritis caused by a small round structured virus in a geriatric convalescent facility.

An outbreak of acute gastroenteritis (AGE) occurred in a 201-bed geriatric convalescent facility in Los Angeles County during December 1988 through January 1989. The attack rate was 55% among residents and 25% among employees. Illnesses were characterized by vomiting and diarrhea to a lesser extent, and the absence of fever. Bacterial and parasitic tests in a sample of patients were negative. A 27 nm small round structured virus (SRSV) was identified in one of 30 stools studied by immune electron microscopy (IEM). While rotavirus and influenza A and B were found in three, one and three cases, respectively, no alternative etiologic agent could be demonstrated for most cases. The outbreak met Centers for Disease Control (CDC) clinical and epidemiologic criteria for Norwalk-like gastroenteritis. The death rate of residents was not elevated beyond baseline during the outbreak; however, one healthy employee had diarrhea and dehydration and died after developing an arrhythmia. An autopsy showed moderate, diffuse lymphocytic and neutrophilic myocarditis, and viral studies found influenza A in left ventricular tissue. Fourteen (25%) of 57 employee cases worked in occupations without routine stool or patient contact. At least nine of these employees lacked evidence of direct fecal contact, and transmission of infection in these cases may have been airborne.

The presence of Enterocytozoon bieneusi spores in the lamina propria of small bowel biopsies with no evidence of disseminated microsporidiosis. Enteric Opportunistic Infections Working Group.

Enterocytozoon bieneusi is the most frequently reported microsporidial infection of humans. In patients with the acquired immunodeficiency syndrome, Enterocytozoon infects the lining epithelial cells of the small intestine, hepatobiliary tract, and gallbladder. Because Enterocytozoon has been thought to be limited to infecting lining epithelial cells, the mechanism of spread of E bieneusi within the intestine, to the biliary tract, and, in two case reports, to distant organs remains unknown. This report describes a patient with acquired immunodeficiency syndrome and intestinal microsporidiosis due to E bieneusi. Histopathologic examination of well-oriented biopsies from the duodenum and jejunum revealed both intra- and extracellular spores of Enterocytozoon extending deeply into the lamina propria, where they were located adjacent to capillaries. The patient has not developed disseminated disease 20 months after the initial diagnosis. In this patient, the demonstration of E bieneusi spores in extraepithelial tissues does not appear to be associated with development of subsequent systemic infection.

Fibroleiomyomatous hamartoma: a rare benign pulmonary "coin lesion".

A discussion of pulmonary hamartomas is presented along with a case presentation of a rare form, the fibroleiomyomatous variety. The need to differentiate these tumors from primary or even secondary malignant neoplasms always requires tissue diagnosis, necessitating surgical excision.

Venezuelan equine encephalomyelitis in an adult animal host. An electron microscopic study.

Adult white mice were inoculated intravenously with a virulent strain of Venzuelan equine encephalomyelitis virus. They were sacrificed sequentially, and cerebral tissue was collected for light and electron microscopic examination and virus titer determination. Viruses were first seen on the fifth day postinoculation infecting and arising from endothelial cells in the cerebrum. Subsequently, oligodendrocytes became infected, giving rise to mature virions. At this time in the infection, a particular electron-dense cell, probably representing a glial cell type, phagocytized mature virions. This resulted in autoinfection, as seen by viral growth in and destruction of these dense cells at a later stage of the infection.

Immunofluorescence staining of adenovirus in fixed tissues pretreated with trypsin.

We describe an immunofluorescence staining procedure for adenovirus in Formalin-fixed, paraffin-embedded tissue sections pretreated with a 0.25% trypsin solution. In trypsinized tissue sections stained with fluorescein-labeled antibody to adenovirus, viral antigen was brightly fluorescent and easily detected each time specimens were processed, and the nonspecific background fluorescence was always minimal. Viral antigen was nonfluorescent or only weakly fluorescent in tissue sections not pretreated with trypsin. Because pathology laboratories usually receive Formalin-fixed tissues for examination, this rapid and practical procedure can be routinely used to extend the diagnostic capability of conventional histopathology.

Virus-initiated septic shock. Acute death of Venezuelan encephalitis virus-infected hamsters.

Hamster hematopoietic and lymphatic organs were studied sequentially by light and electron microscopy following Venezuelan encephalitis virus inoculation. In addition to extensive marrow and splenic necrosis nearly transmural necrosis of the ileum in Peyer's patch areas, with concomitant bacterial overgrowth, was noted. Viruses were observed ultrastructurally in reticular cells of Peyer's patches. In addition, bacterial blood cultures, consistent with an enteric origin, were generally positive in late stages of the infection. Reticuloendothelial function, measured by clearance of colloidal carbon, was significantly depressed in Venezuelan encephalitis virus-infected hamsters. It is proposed that the acute death of hamsters infected with Venezuelan encephalitis virus may be determined by the development of an endotoxic shock syndrome mediated by the extensive ileal lesions, coupled with impaired reticuloendothelial detoxifying function.

Selective clearance of a benign clone of Venezuelan equine encephalitis virus from hamster plasma by hepatic reticuloendothelial cells.

A benign small-plaque clone of Venezuelan equine encephalitis virus was efficiently removed from the blood of inoculated hamsters by adsorption to cells of the hepatic reticuloendothelial system. More than 99% of infectious small-plaque virus, intrinsically labeled with 32P, was cleared from the blood within 30 min of inoculation; 47.6% of the 32P-labeled small-plaque virus inoculum was concentrated in the liver. In contrast, only 0.8% of a virulent large-plaque clone of the virus was cleared from the blood. The affinity of small-plaque virus for liver tissue was confirmed by electron microscopy, since inoculated small-plaque virions were readily visualized in phagocytic vacuoles of hepatic endothelial and Kupffer cells, where they appeared to be undergoing degradation. In contrast, large-plaque virus was not visualized in the liver. A critical determinant of virulence for viruses that do not replicate in hepatic reticuloendothelial cells may be the efficiency with which they are removed from the blood by adsorption to such cells.

Spindle cell lipoma: a benign lipoma variant with potential hazards of diagnostic misinterpretation.

Spindle cell lipoma is a relatively common, recently described benign lipoma variant. It demonstrates highly characteristic clinical and pathologic features. Knowledge of its existence and features should prevent any misinterpretation of its true benign biologic behavior, a pitfall which has unfortunately occurred in the past, resulting in poor prognosis and exaggerated modes of therapy.

Pancreatic involvement by Venezuelan equine encephalomyelitis virus in the hamster.

Pancreatic tissue from hamsters inoculated with a virulent strain of Venezuelan equine encephalomyelitis virus (VEE) was studied sequentially with fluorescent antibody, light and electron microscopic technics. Progressive viral growth and cellular necrosis in the pancreas were demonstrated. Pancreatic infection resulted from both viremia and direct extension from the spleen across contaminated serosal planes. Mature viruses traversed the endothelium within endothelial vesicles and were associated with acinar as well as islet cells.

[Problem of tuberculosis in Kirgizstan]. / Poblema tuberkuleza v Kirgizskoi Respublike.

The socioeconomic factors have exerted a decisive impact on tuberculosis morbidity and mortality in the Kirghiz Republic. The National Tuberculosis Programme which defines the priorities of antituberculous measures adjusted to local conditions has been adopted up to 2000 to stabilize the endemia, by taking into account some recommendations.