[Patient with recurrent gastrointestinal hemorrhage and generalized hemorrhagic telangiectasia (Osler disease)].
Explore the source record for details and available documents.
Gastric Mucosa↗
Biomedical subjects
R Weber
Publications and source records attributed to R Weber.
[Frontal sinus impression fracture as a collision sequelae in football].
4 soccer accidents, causing the rare case of impression fracture of the frontal sinus, are introduced as soccer-specific lesions, which are caused by head-to-head collisions, being due to heading-maneuvers. Mostly the right frontal sinus was hurt. The indication for an operation is the obvious dislocation of the osseous fragments. Primary intentions for an intervention are the precise reconstruction of the anterior wall of the frontal sinus because of esthetic reasons and a permanent drainage in order to avoid late complications as for instance mucopyoceles, if the infundibulum has been damaged. The therapy of choice is the osteoplastic frontal sinus operation, using a bicoronary incision.
Adult↗
Temporary unilateral amaurosis with pneumosinus dilatans of the sphenoid sinus.
Pneumosinus dilatans (PSD), first described by Meyes in 1898, is an abnormal dilatation of one or more of the paranasal sinuses without bony erosion. The term sinus pneumocele indicates the presence of bony erosion. Review of the literature from 1968 to 1992 revealed 24 cases of idiopathic PSD and 17 cases of pneumocele of various paranasal sinuses. PSD occurred most commonly in the frontal sinus. Males were more often affected than females. The average age for males ranged from 16.5 for the maxillary sinus to 35.5 years for the sphenoid sinus. Pneumoceles occurred most commonly in the maxillary sinus. The average age for males ranged from 29 years for the frontal sinus and 47 years for the ethmoid sinus. Two patients (1 pneumocele and 1 PSD) had a temporary loss of vision. We report the case of a 37-year-old mountain climber who experienced temporary loss of vision in his left eye above 3000 m. Vision returned below 2000 m. High resolution computed tomography scan revealed pneumosinus dilatans of the sphenoid sinus with dehiscence of the optic canal on the left side. Endonasal microendoscopic resection of the anterior wall of the left sphenoid sinus was performed. The patient has remained symptom-free after 2 years of follow-up. Pneumosinus dilatans should always be considered in the differential diagnosis of sudden visual loss associated with atmospheric pressure changes.
Case Reports↗
Detection of Septata intestinalis in stool specimens and coprodiagnostic monitoring of successful treatment with albendazole.
We describe two patients with AIDS and chronic diarrhea in whom the microsporidian Septata intestinalis was detected with use of light and electron microscopic coprodiagnostic techniques. The ultrastructure of the microsporidian spores found in their stool specimens was distinctly different from that of Enterocytozoon bieneusi, another intestinal microsporidian found in patients infected with human immunodeficiency virus. Electron microscopic examination of duodenal biopsy specimens available from one of the patients enabled identification of S. intestinalis and confirmed the similarity of spores found in feces and in duodenal tissue. Both patients' diarrhea stopped when they were treated with albendazole. Coprodiagnostic monitoring indicated disappearance of the parasites and allowed the diagnosis of a relapse in one patient, who responded well to a second course of treatment.
AIDS-Related Opportunistic Infections↗
Microsporidial infections in immunodeficient and immunocompetent patients.
Microsporidia are obligate, intracellular, spore-forming protozoal parasites. Their host range is extensive and includes most invertebrates and all classes of vertebrates. Five microsporidial genera (Enterocytozoon, Encephalitozoon, Septata, Pleistophora, and Nosema) and unclassified microsporidia have been associated with human disease, which appears to manifest primarily in immunocompromised persons. The clinical manifestations of microsporidiosis are diverse and include intestinal, pulmonary, ocular, muscular, and renal disease. The majority of microsporidial infections in persons infected with human immunodeficiency virus (HIV) are attributed to Enterocytozoon bieneusi, an important cause of chronic diarrhea and wasting. Four cases of microsporidial infection among persons not infected with HIV who had documented or presumed cellular immunodeficiency and four cases of corneal stroma infection due to microsporidia in immunocompetent patients have been described. Furthermore, the first case of traveler's diarrhea due to E. bieneusi in an immunocompetent and otherwise healthy patient is reported in this issue. The sources of human microsporidial infections and modes of transmission are unknown.
Animals↗
Human microsporidial infections.
Microsporidia are obligate intracellular spore-forming protozoal parasites belonging to the phylum Microspora. Their host range is extensive, including most invertebrates and all classes of vertebrates. More than 100 microsporidial genera and almost 1,000 species have now been identified. Five genera (Enterocytozoon spp., Encephalitozoon spp., Septata spp., Pleistophora sp., and Nosema spp.) and unclassified microsporidia (referred to by the collective term Microsporidium) have been associated with human disease, which appears to manifest primarily in immunocompromised persons. The clinical manifestations of microsporidiosis are diverse and include intestinal, pulmonary, ocular, muscular, and renal disease. Among persons not infected with human immunodeficiency virus, ten cases of microsporidiosis have been documented. In human immunodeficiency virus-infected patients, on the other hand, over 400 cases of microsporidiosis have been identified, the majority attributed to Enterocytozoon bieneusi, an important cause of chronic diarrhea and wasting. Diagnosis of microsporidiosis currently depends on morphological demonstration of the organisms themselves. Initial detection of microsporidia by light microscopic examination of tissue sections and of more readily obtainable specimens such as stool, duodenal aspirates, urine, sputum, nasal discharge, bronchoalveolar lavage fluid, and conjunctival smears is now becoming routine practice. Definitive species identification is made by using the specific fluorescein-tagged antibody (immunofluorescence) technique or electron microscopy. Treatment options are limited, but symptomatic improvement of Enterocytozoon bieneusi infection may be achieved with the anthelmintic-antiprotozoal drug albendazole. Preliminary observations suggest that Septata intestinalis and Encephalitozoon infections may be cured with albendazole. Progress is being made with respect to in vitro propagation of microsporidia, which is crucial for developing antimicrosporidial drugs. Furthermore, molecular techniques are being developed for diagnostic purposes, taxonomic classification, and analysis of phylogenetic relationships of microsporidia.
Animals↗
Direct detection of Mycobacterium tuberculosis complex in respiratory specimens by a target-amplified test system.
A total of 938 respiratory specimens (633 sputa, 249 bronchial and tracheal aspirates, and 56 bronchoalveolar lavages) from 589 patients were tested for direct detection of Mycobacterium tuberculosis complex by the Gen-Probe amplified Mycobacterium tuberculosis direct test (MTD), and the results were compared with those of the conventional methods of fluorescence microscopy and cultivation (solid and radiometric media). One series of specimens (n = 515) was decontaminated with N-acetyl-L-cysteine (NALC)-NaOH: the other one (n = 423) was decontaminated with sodium dodecyl (lauryl) sulfate (SDS)-NaOH. Of the specimens decontaminated with NALC, 39 were MTD and culture positive, 455 were MTD and culture negative, 18 were MTD positive and culture negative, and 3 were MTD negative and culture positive, indicating a sensitivity of 92.9% and a specificity of 96.2% for the MTD. Of the specimens decontaminated with SDS, 35 were MTD and culture positive, 372 were MTD and culture negative, 15 were MTD positive and culture negative, and 1 was MTD negative and culture positive, indicating a sensitivity of 97.2% and a specificity of 96.1% for the MTD. After resolution of discrepant results by review of the patients' clinical data, the sensitivity of the MTD was 93.9%, the specificity was 97.6%, the positive predictive value was 80.7%, and the negative predictive value was 99.3% for the NALC series; the corresponding values were 97.4, 96.9, 76.0, and 99.7%, respectively, for the SDS series. In conclusion, the MTD is a highly sensitive and specific technique for detecting M. tuberculosis complex within hours in both smear-positive and smear-negative respiratory specimens.
Adult↗
The kinetics of simian virus 40-induced progression of quiescent cells into S phase depend on four independent functions of large T antigen.
Microinjection of purified simian virus 40 large-T-antigen protein or DNA encoding T antigen into serum-starved cells stimulates them to re-enter the cell cycle and progress through G1 into the S phase. Genetic analysis of T antigen indicated that neither its Rb/p107-binding activity nor its p53-binding activity is essential to induce DNA synthesis in CV1P cells. However, T antigens bearing missense mutations that inactivate either activity induced slower progression of the cells into the S phase than did wild-type T antigen. Inactivation of both activities resulted in a T antigen essentially unable to induce DNA synthesis. Missense mutations in either the DNA-binding region of the N terminus also impaired the ability of full-length T antigen to stimulate DNA synthesis in CV1P cells. The wild-type kinetics of cell cycle progression were restored by genetic complementation after coinjection of plasmid DNAs encoding different mutant T antigens or coinjection of purified mutant T-antigen proteins, suggesting that the four mitogenic functions of T antigen are independent. The maximal rate of induction of DNA synthesis in secondary primate cells and established rodent cell lines required the same four functions of T antigen. A model to explain how four independent activities could cooperate to stimulate cell cycle progression is presented.
Animals↗
RAPID AND SIMULTANEOUS MEASUREMENT OF ANODIC AND CATHODIC HAEMOGLOBINS AND ATP AND GTP CONCENTRATIONS IN MINUTE QUANTITIES OF FISH BLOOD
Oxygen transport to vertebrate tissues is dependent upon (a) the intrinsic O2-binding properties of haemoglobin (Hb) and (b) modulation by allosteric effectors, such as nucleoside triphosphates (NTP), that depress Hb O2-affinity in fish red cells. While some species, such as flatfish, primarily use adenosine triphosphate (ATP) to modulate O2-binding to Hb, others, such as eel and carp, also use guanosine triphosphate (GTP) (Kono and Hashimoto, 1977; Leray, 1982; Weber and Jensen, 1988). Unlike mammals, fish exhibit high degrees of molecular and functional Hb heterogeneity, which is manifested interspecifically but is also evident from polymorphism in different individuals of the same species (Weber, 1990). While some species such as carp have multiple Hbs that migrate anodally in normal electrophoresis and exhibit similar intrinsic oxygenation properties and sensitivities to NTP (Gillen and Riggs, 1972), others such as trout and eel have both anodic and cathodic components that exhibit different intrinsic O2-binding properties and different sensitivities to cofactors. Having higher O2 affinities and lower Bohr effects, the cathodic Hbs may be better adapted for O2 transport under hypoxic, hypercapnic or acidotic conditions than the anodic ones from the same species (Hashimoto et al. 1960; Binotti et al. 1971; Weber et al. 1975; Weber, 1990). Ambient hypoxia induces decreases in erythrocytic NTP (Wood and Johansen, 1972), which safeguards blood O2-loading in the gills. The concentrations of the major NTPs and anodic or cathodic Hbs are thus important indices of respiratory and adaptational status in fish. Erythrocytic ATP and GTP levels are generally assayed by thin layer or column chromatography or enzymatically, total Hb is measured by spectrophotometry, and the anodic and cathodic composition of the Hbs present by electrophoresis or isoelectric focusing. We here report a method for rapid and simultaneous assay of ATP and GTP, and of anodic and cathodic Hbs, in minute (approximately 3 µl) quantities of fish blood. We used trout [Oncorhynchus mykiss, 101±8 g (s.e.m.); N=9], eel (Anguilla anguilla, 114±17 g; N=9) and carp (Cyprinus carpio, 1407±104 g; N=9) supplied by local pisciculturists. The fish were kept for at least 1 week in 1 m3 glass fibre tanks with aerated running fresh water at 15 °C before experimentation. Blood samples were drawn from the caudal blood vessels into heparinised syringes.
Journal Article↗
CHLORIDE-DEPENDENT ORGANIC PHOSPHATE SENSITIVITY OF THE OXYGENATION REACTION IN CROCODILIAN HEMOGLOBINS
We show that crocodilian hemoglobins (Hbs), which previously have been considered to be model pigments lacking allosteric interaction with organic phosphate esters, do exhibit oxylabile ATP and 2,3-diphosphoglycerate (DPG) binding that decreases O2 affinity and increases pH sensitivity (Bohr effect), in the absence of Cl- and at the low Cl- concentrations that may occur in crocodilian plasma during 'post-ingestive alkaline tides'. Hbs from different species vary in their phosphate sensitivities. In Alligator mississippiensis Hb, O2 affinity shows greater ATP than DPG sensitivity at low [cofactor]/[Hb] ratios. In Paleosuchus palpebrosus Hb, where even a high Cl- concentration (0.1 mol l-1) does not completely suppress the phosphate effects, the opposite is true, whereas both ATP and DPG exert similar effects in Caiman crocodilus Hb. Lactate, at concentrations that may occur after intensive exercise, similarly depresses Hb O2-affinity, indicating an O2 demand/O2 supply feedback regulation. Curiously, inositol hexaphosphate (IHP), a potent allosteric effector in other vertebrate Hbs, has no effect on A. mississippiensis and P. palpebrosus Hb and only small effects on C. crocodilus Hb, presumably because of steric hindrance at the binding site. The molecular mechanisms underlying the observations (particularly the implication of ss82-Lys, i.e. the lysine residue at position 82 of the ss-chains that binds phosphate and Cl-) are considered. Their physiological significance requires further study.
Journal Article↗
[The transparent village. The community and child rearing in Trinidad and Tobago].
Explore the source record for details and available documents.
Americas↗
Microsporidiosis in HIV positive patients: current methods for diagnosis using biopsy, cytologic, ultrastructural, immunological, and tissue culture techniques.
Microsporidiosis is an increasingly important opportunistic infection in HIV-positive patients. Five species of microsporidia (Enterocytozoon bieneusi, Encephalitozoon hellem and E. cuniculi, Septata intestinalis, and Pleistophora sp.) have been reported to occur in AIDS, with each agent producing a different clinicopathologic spectrum of disease. This communication reviews routine and specialized methods for diagnosis of these important pathogenic protozoa, including biopsy, cytology, ultrastructural and immunologic examination, and tissue culture, and describes the current knowledge of organ distribution for microsporidia in persons with AIDS.
AIDS-Related Opportunistic Infections↗
Patient-focused care ... playing to win.
An inside look at the components of patient-focused care, an outline of attainable benefits, and the managerial practices affected by this model are discussed. This method of delivery assumes a complete redesign of traditional hospital organization and strives to increase interdisciplinary collaboration, to improve patient care, and to decentralize services.
Humans↗
Shortcomings of chest radiography in detecting Pneumocystis carinii pneumonia.
The radiographic presentation of Pneumocystis carinii pneumonia (PCP) was studied in 93 consecutive patients to determine the frequency of normal findings on chest roentgenograms and possible correlations with clinical or laboratory findings. The roentgenograms were reviewed by two radiologists in an independent, blinded way and judged with a score distinguishing between none, interstitial, and acinar infiltrates. Discordance mainly between absent versus interstitial and interstitial versus acinar infiltrates occurred in 23% of roentgenograms and was settled by consensus. The majority of patients presented with moderate-to-mild symptoms; the combination of dyspnea, cough, and fever was present in 53%. Lactate dehydrogenase (LDH) was elevated in 63%, hypoxemia (PaO2 < 75 mm Hg) was present in 57%. Findings on chest roentgenograms were normal in 39%, whereas 36% showed interstitial and 25% acinar infiltrates. These three radiographic groups represented an increasingly severe PCP, indicated by higher LDH levels and hypoxemia (both p < 0.05). In a multivariate logistic regression, normal roentgenograms were predicted by low LDH and low peripheral blood granulocytes (p < 0.005). Mortality within 3 weeks was only 4% and correlated with the severity of infiltrates (p < 0.05). Normal roentgenograms thus corresponded to an oligosymptomatic, less severe PCP. In immunodeficient HIV-infected patients, a normal chest roentgenogram does not exclude PCP and should not distract from attaining a definite diagnosis by examination of induced sputum or bronchoalveolar lavage.
Adult↗
Enteric viruses and diarrhea in HIV-infected patients. Enteric Opportunistic Infections Working Group.
BACKGROUND: Diarrhea occurs frequently among persons with the acquired immunodeficiency syndrome, but the cause often remains unknown. We used a group of diagnostic assays to determine which viruses were etiologic agents of diarrhea in a group of persons infected with the human immunodeficiency virus (HIV). METHODS: Stool and serum specimens were obtained from HIV-infected patients enrolled in a longitudinal study in Atlanta. Fecal specimens from patients with diarrhea and from control patients without diarrhea were screened by electron microscopy, polyacrylamide-gel electrophoresis, and enzyme immunoassays for rotaviruses, enteric adenoviruses, caliciviruses, picobirnaviruses, and astroviruses. Paired serum samples were tested for antibody responses to Norwalk virus and picobirnavirus. RESULTS: Viruses were detected in 35 percent of 109 fecal specimens from patients with diarrhea but in only 12 percent of 113 specimens from those without diarrhea (P < 0.001). Specimens from patients with diarrhea were more likely than those from patients without diarrhea to have astrovirus (12 percent vs. 2 percent, P = 0.003); picobirnavirus (9 percent vs. 2 percent, P = 0.017); caliciviruses, including small round structured viruses (6 percent vs. 1 percent, P = 0.062); and adenoviruses (9 percent vs. 3 percent, P = 0.047). They were also more likely to have a mixed viral infection (6 percent vs. 0 percent, P = 0.006). With the use of polyacrylamide-gel electrophoresis to analyze concentrated RNA extracts from stool, picobirnavirus was detected in fecal specimens from 6 of the 65 patients with diarrhea and was associated with prolonged viral shedding and chronic diarrhea. No rotaviruses, enteric adenoviruses, or instances of seroconversion to positivity for Norwalk virus were observed. CONCLUSIONS: Novel enteric viruses such as astrovirus and picobirnavirus may be more important etiologic agents of diarrhea in HIV-infected patients than previously recognized and may be more common than either bacterial or parasitic enteropathogens.
Adenoviruses, Human↗
Pathologic features and immunofluorescent antibody demonstration of ocular microsporidiosis (Encephalitozoon hellem) in seven patients with acquired immunodeficiency syndrome.
We studied the clinicopathologic features of seven patients with acquired immunodeficiency syndrome (AIDS) and ocular microsporidiosis. All patients had decreased levels of CD4-positive cells (mean, 26/ml3) and ocular symptoms; five had bilateral punctate epithelial keratopathy, one had intermittent red eyes with conjunctivitis, and one had red eyes only. Light and electron microscopy of corneal and conjunctival biopsy and cytologic specimens and intact globes disclosed microsporidia belonging to the genus Encephalitozoon. Because E. cuniculi and E. hellem, the two species of the Encephalitozoon genus, are morphologically identical, an immunofluorescent antibody technique was used for species identification. In all seven patients, the agent was identified as E. hellem. Pathologic examination of globes obtained after autopsy disclosed E. hellem infection to be restricted to the corneal and conjunctival epithelium. We studied methods for the routine diagnosis of ocular microsporidiosis in patients with AIDS, including the role of immunofluorescent antibody staining.
AIDS-Related Opportunistic Infections↗
Protective sensitivity changes of the motor cortex due to epileptiform experience of the visual cortex.
In awake rats, experiments were performed to study early epileptiform events (interictal spike, myoclonic jerk) in relation to a) the strength of the convulsive stimulus, b) the site of the focus, and c) epileptiform experience. For this reason, Na-penicillin G (PCN) was injected either into the motor or visual cortex and, in a second test 2 weeks thereafter, into the motor cortex in all these rats. The median latencies of both the first interictal potential and jerk were independent of the applied PCN concentration in the range between 16-1,000 IU/0.5 microliter (90.5-113 s, and from 106-196 s, respectively), as well as from the injection site in the visual or motor cortex (potential: 80 vs. 69 s; jerk: 124 vs. 129 s, respectively). After epileptiform experience in the visual cortex, the latencies of the first potential and jerk were significantly (p < 0.05) increased compared to animals with an experience in the motor cortex (first potential: 100 vs. 66 s; first jerk: 159 vs. 116 s, respectively). The results show that a PCN focus in the visual cortex decreases the susceptibility of the motor cortex for the convulsant action of PCN. This means that an autoprotective mechanism is activated whose efficiency depends upon a close linkage between the visual and motor cortex.
Animals↗
Salivary neoplasms of the palate: a flow cytometric and clinicopathological analysis.
In order to test the clinical and prognostic significance of flow cytometrically assessed DNA content in minor salivary gland tumours we evaluated 75 neoplasms of the palate, 55 of which were carcinomas. Benign neoplasms were exclusively DNA diploid with low S-phase fractions while 22 per cent of malignant tumours manifested a DNA aneuploidy and 23.5 per cent high S-phase fractions (> 5 per cent). Significant statistical correlations between DNA content and tumour size, histological grade, lymph node metastasis and lethality were observed. Our findings suggest a potentially important role for flow-cytometry in the evaluation of these neoplasms.
Adenocarcinoma↗