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Biomedical subjects

H Masur

Publications and source records attributed to H Masur.

At least 163 records · Page 9Linked to original sources
PubMed1989

Admission of AIDS patients to a medical intensive care unit: causes and outcome.

As the number of cases of AIDS increases, it is important to determine whether ICUs can be productively and safely used for this patient population. From July 1981 to March 1987, 216 patients were admitted to the medical ICU: 166 (77%) were admitted for procedures and 50 (23%) were admitted for life-sustaining support. Most of the patients were admitted for respiratory failure (36 of 50), primarily as a result of Pneumocystis carinii pneumonia. Other patients were admitted for cardiovascular instability (six of 50 patients), CNS dysfunction (four patients), or other reasons (four patients). Of 50 patients admitted to the ICU, 13 (26%) were alive 3 months after hospital discharge. Despite 25 needle-stick injuries and 56 mucosal splashes involving human immunodeficiency virus (HIV)-infected patients and staff, no staff member converted HIV serology. These results suggest that AIDS patients may benefit from ICU admission. These patients appear to pose a low risk to the hospital staff in terms of occupationally acquired HIV infection, but strong emphasis needs to be placed on minimizing accidental exposures to potentially infected body fluids and to adhering to universal precautions.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Cerebellar atrophy following acute intoxication with phenytoin.

A patient developed marked cerebellar atrophy after a single suicidal intoxication with 7 grams phenytoin. The clinical signs of cerebellar dysfunction subsided very slowly and incompletely within 18 months. We documented the cerebellar atrophy by CTs 4 weeks and 1 year after the intoxication, and we suggest that a single severe acute intoxication with phenytoin may directly cause cerebellar degeneration.

Adult↗
PubMed1989

[Electromagnetic stimulation of the nervous system. I. Normal values in the central nervous system and a comparison with electric stimulation].

After non-invasive stimulation of the motor cortex by brief electromagnetic pulses evoked potentials were biolaterally recorded in 29 healthy individuals. Normal values for the following target muscles were calculated: abductor pollicis brevis (APB), biceps brachii (BIC), tibialis anterior (TIB) and extensor digitorum brevis (EDB). In a subgroup (N = 12) results for APB and EDB were compared with those obtained by electrical stimulation techniques.

Adult↗
PubMed1989

[Electromagnetic stimulation of the nervous system. II. Normal values in the peripheral nervous system and comparison with electrical stimulation methods].

In 15 healthy subjects we stimulated the peripheral nervous system by a brief intense magnetic field and recorded evoked muscle potentials from peripheral muscles. Latencies were compared with those obtained by conventional electrical stimulation techniques. Amplitudes of muscle responses after magnetic stimulation were often smaller than those obtained after electrical stimulation; however, latencies were comparable at all stimulation sites.

Adult↗
PubMed1988

Nonspecific interstitial pneumonitis without evidence of Pneumocystis carinii in asymptomatic patients infected with human immunodeficiency virus (HIV).

STUDY OBJECTIVE: To assess how often Pneumocystis carinii organisms, P. carinii pneumonia, or other pulmonary pathologic processes were present in persons infected with human immunodeficiency virus (HIV) without pulmonary symptoms or previous history of P. carinii, and with a normal chest roentgenogram. DESIGN: Serial, prospective assessment of eligible HIV-seropositive patients over 21 months. PATIENTS: Twenty-four HIV-seropositive patients with either a nonpulmonary manifestation of the acquired immunodeficiency syndrome (AIDS) (n = 12) or an absolute CD4 lymphocyte count of 0.200 X 10(9) cells/L or less (n = 12), no pulmonary symptoms, a normal chest roentgenogram, no history of P. carinii pneumonia, and no history of treatment with antipneumocystis prophylaxis. INTERVENTIONS: Pulmonary assessment with arterial blood gases, pulmonary function tests, gallium-67 citrate scans, and bronchoscopy with bronchoalveolar lavage and transbronchial biopsies. MEASUREMENTS AND MAIN RESULTS: Mean alveolar-arterial gradient was 11.1 mm Hg +/- 8.5 and mean diffusion capacity was 73.0% +/- 20.0% of predicted. None of the 24 patients showed P. carinii or other pathogens on stains of bronchoalveolar lavage fluid. No patient had histologic evidence of P. carinii pneumonia. Transbronchial biopsy specimens showed chronic, nonspecific interstitial pneumonitis (11 of 23) and no pathologic abnormality (12 of 23). Six patients have developed P. carinii pneumonia during 2 to 18 months of follow-up. CONCLUSIONS: HIV-infected patients without pulmonary symptoms did not have detectable Pneumocystis organisms in bronchoalveolar lavage fluid or transbronchial biopsy specimens; but 11 of 23 had evidence of chronic, nonspecific interstitial pneumonitis. Pneumocystis organisms in a pulmonary specimen from a symptomatic patient probably indicate the cause of the pulmonary dysfunction even if only a few are detected.

Adult↗
PubMed1988

Ribosomal RNA sequence shows Pneumocystis carinii to be a member of the fungi.

Pneumocystis carinii pneumonia is the most common opportunistic infection in AIDS, and accounts for significant morbidity and mortality in these and other immunocompromised patients. P. carinii is a eukaryotic microorganism of uncertain taxonomy that can infect numerous mammalian hosts. Developing from a small, unicellular 'trophozoite' into a 'cyst' containing eight 'sporozoites', its life cycle superficially resembles those seen both in the Protozoa and Fungi. Morphological and ultrastructural observations have lead some investigators to conclude that the organism is a protozoan, while others have felt that it more closely resembles a fungus. Phylogenetic relationships can be inferred from comparisons of macromolecular sequences. Small subunit ribosomal RNAs (16S-like rRNAs) are well-suited for this purpose because they have the same function in all organisms and contain sufficient information to estimate both close and distant evolutionary relationships. Phylogenetic frameworks based upon such comparisons reveal that the plant, animal and fungal lineages are distinct from the diverse spectrum of protozoan lineages. In this letter, phylogenetic analysis of Pneumocystis 16S-like rRNA demonstrates it to be a member of the Fungi.

Animals↗
PubMed1988

Identification of antigens and antibodies specific for Pneumocystis carinii.

To increase understanding of Pneumocystis carinii and its interaction with its hosts, Ag specific for rodent and human P. carinii were identified by the immunoblot method after PAGE of P. carinii organism extracts. The m.w. of the major Ag of rat P. carinii were 45,000, 110,000, and a broad band of 49,000 to 64,000, and of human P. carinii were 22,000, 24,000, and a broad band of 35,000 to 45,000 daltons. Human and rat pneumocystis were not antigenically identical. Specific antibodies against rat P. carinii Ag were found in 18 of 79 rats by the immunoblot method. Specific antibodies against human P. carinii Ag were found in 32 of 33 adult human sera, but in only 1 of 8 sera from infants and children. Specific antibodies were found in sera of 13 of the 14 adults with no history of P. carinii pneumonia, and all 19 patients with recently diagnosed P. carinii pneumonia, including 9 patients with P. carinii pneumonia associated with AIDS. The results of this study support previous suggestions that a large proportion of adults have been exposed to P. carinii and provide a basis for the further investigations of host-P. carinii interactions.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Diagnosis of Pneumocystis carinii pneumonia: improved detection in sputum with use of monoclonal antibodies.

With the dramatic increase in the frequency of Pneumocystis carinii pneumonia associated with human immunodeficiency virus infection, there has been a need for more rapid and less invasive diagnostic techniques. Recent studies have shown that examination of induced sputum can establish the diagnosis of P. carinii pneumonia in about 55 percent of cases. To assess whether a recently developed indirect immunofluorescent stain using monoclonal antibodies was more sensitive than Giemsa or toluidine blue O stains in detecting P. carinii in sputum, we undertook two prospective studies. Of 63 patients at one institution from whom sputum specimens were obtained, 49 were ultimately given a diagnosis of P. carinii pneumonia, 46 of them by staining of sputum. The sensitivity of the three stains in detecting P. carinii was 45 of 49 (92 percent) for immunofluorescence; 37 of 49 (76 percent) for Diff-Quik (a Giemsa-type stain); and 39 of 49 (80 percent) for toluidine blue O. There were no false positive immunofluorescent stains. In a similar study of a series of 25 patients at another institution, a diagnosis of P. carinii pneumonia was made in 23 of 25 patients by staining of induced sputum. We conclude that examination of induced sputum is a rapid, sensitive, and inexpensive method for diagnosing P. carinii pneumonia and that indirect immunofluorescence is a practical and highly sensitive staining technique for establishing this diagnosis.

Animals↗
PubMed1988

Disseminated Mycobacterium haemophilum infection in two patients with the acquired immunodeficiency syndrome.

In two patients with the acquired immunodeficiency syndrome (AIDS), multiple erythematous cutaneous lesions developed, revealing acid-fast organisms on Fite's stain. Initial culture results on the first patient were negative; however, repeat cultures on hemin-enriched media were positive for Mycobacterium haemophilum. Despite antimycobacterial therapy, lesions persisted until the patients' death. M. haemophilum should be a diagnostic consideration when smears of peripheral (especially skin) lesions from AIDS patients show acid-fast organisms. Cultures in such patients should be done with iron hemin- or ferric ammonium citrate-enriched media.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Bioavailability of oral trimetrexate in patients with acquired immunodeficiency syndrome.

The combination of the lipophilic antifolate trimetrexate and the rescue agent leucovorin has shown promise in the treatment of Pneumocystis carinii pneumonia in patients with acquired immunodeficiency syndrome. The pharmacokinetic behavior of trimetrexate administered either by intravenous bolus or orally was studied in six patients with acquired immunodeficiency syndrome with a reversed-phase high-pressure liquid chromatography assay. The mean clearance following bolus injection was 38 ml/min per m2, with a range of 15 to 55 ml/min per m2. The postdistributive half-life ranged from 6 to 16 h. With oral administration, the mean bioavailability was 44% (range, 19 to 67%). An oral dose of 60 mg/m2 (162 mumol/m2) resulted in concentrations in plasma that approximated those achieved with a 30-mg/m2 (81-mumol/m2) intravenous dose. The toxicity of this combination regimen was minimal. It appears that the oral route is a practical route of administration for trimetrexate in patients with acquired immunodeficiency syndrome requiring long-term outpatient treatment or prophylaxis for P. carinii pneumonia.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Potent antipneumocystis and antitoxoplasma activities of piritrexim, a lipid-soluble antifolate.

Piritrexim, a lipid-soluble antifolate, was evaluated for its activity against Pneumocystis carinii and Toxoplasma gondii. The concentration of piritrexim needed to inhibit 50% of the catalytic activity of P. carinii dihydrofolate reductase (DHFR) was 19.3 nM, and that for T. gondii DHFR was 17.0 nM, concentrations that were 40- to over 1,000-fold less than those needed for the inhibition of activity by trimethoprim and pyrimethamine, the antifolates conventionally used in treating these organisms. Piritrexim was able to inhibit replication of T. gondii in a mouse peritoneal macrophage model at concentrations of 0.1 to 1.0 microM. Leucovorin, a reduced folate that can bypass the inhibition of DHFR by antifols in mammalian cells but not in protozoa, did not affect the ability of piritrexim to inhibit T. gondii replication. The addition of sulfadiazine, which alone was ineffective, to piritrexim allowed inhibition of T. gondii replication at lower concentrations of piritrexim than when piritrexim was used alone. These results suggest that piritrexim, alone or combined with a sulfonamide, may be a highly potent antitoxoplasma and antipneumocystis agent that could provide major pharmacologic and clinical advantages over available agents.

Animals↗
PubMed1988

Efficacy of trimetrexate, a potent lipid-soluble antifolate, in the treatment of rodent Pneumocystis carinii pneumonia.

Trimetrexate is a lipid-soluble antifolate that has been shown in vitro to be a much more potent inhibitor of Pneumocystis carinii dihydrofolate reductase than the conventionally used inhibitor trimethoprim. To evaluate the in vivo efficacy of trimetrexate, steroid-treated rats which spontaneously develop P. carinii pneumonia were used. Rats treated with trimetrexate (25 mg/kg/d) plus sulfamethoxazole (250 mg/kg/d) orally responded at least as well as rats treated with trimethoprim (50 mg/kg/d) plus sulfamethoxazole. Trimetrexate alone administered orally was ineffective in treating P. carinii infection, but subcutaneous (sc) trimetrexate (7 mg/kg/d) significantly decreased the intensity of infection compared to controls. Trimetrexate is a potent antifolate that may provide an effective alternative to pentamidine and trimethoprim-sulfamethoxazole for treatment of P. carinii pneumonia in humans.

Administration, Oral↗
PubMed1988

Intestinal infections in patients with the acquired immunodeficiency syndrome (AIDS). Etiology and response to therapy.

STUDY OBJECTIVE: To determine the frequency of pathogenic gastrointestinal microorganisms in patients with the acquired immunodeficiency syndrome (AIDS) and diarrhea, and to determine if treatment for identifiable microorganisms improves symptoms. DESIGN: Prospective, consecutive sample study. SETTING: Referral-based clinic and wards, National Institutes of Health. PATIENTS: Twenty of twenty-two consecutive homosexual males with AIDS and diarrhea, and 10 homosexual males with AIDS without diarrhea. INTERVENTIONS: All patients had a complete physical examination; serial stool examinations for viral, bacterial, fungal, and protozoan pathogens; and esophagogastroduodenoscopy and colonoscopy to obtain duodenal fluid and mucosal tissue to analyze for enteric pathogens or histopathology. Patients with diarrhea had a malabsorption evaluation. Patients with treatable pathogenic microorganisms received standard antimicrobial therapy. MEASUREMENTS AND MAIN RESULTS: The 20 patients with AIDS and diarrhea had greater weight loss, lower mean numbers of helper-inducer (OKT4) lymphocytes, and a higher incidence of extraintestinal opportunistic infections than the 10 patients without diarrhea. One or more enteric pathogen was identified in 17 of 20 patients (85%; 95% confidence interval [CI], 65% to 96%) with diarrhea. Only 1 patient without diarrhea was infected with an enteric pathogen. Nineteen of twenty patients with diarrhea and all 10 patients without diarrhea had chronic inflammatory changes in their intestinal biopsy specimens. Sixteen patients with identifiable enteric pathogens and diarrhea were treated; 11 (69%; 95% CI, 43% to 87%) showed microbiologic, histologic, or clinical improvement. CONCLUSIONS: Thorough diagnostic evaluation can lead to the identification of enteric pathogens in a high percentage of patients with AIDS and diarrhea. Specific therapy can lead to symptomatic improvement.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Anemia and erythropoiesis in patients with the acquired immunodeficiency syndrome (AIDS) and Kaposi sarcoma treated with zidovudine.

We evaluated the development of anemia as part of a trial of zidovudine therapy in patients with the acquired immunodeficiency syndrome (AIDS) with Kaposi sarcoma. Patients were randomized to one of three treatment groups or a placebo group. Transfusion-requiring anemia (hemoglobin less than 100 g/L) developed in 6 of 15 patients on zidovudine therapy at a mean of 6 weeks after starting treatment. A fall in the reticulocyte count was the earliest peripheral blood indicator of toxicity. Mean corpuscular volume increased markedly in patients on zidovudine therapy not developing anemia yet remained stable or only slightly increased in those who became anemic. Bone marrow examination showed pure red cell aplasia in 2 patients, erythroid maturation arrest in 1, and erythroid hypoplasia in 3. Megaloblastic erythropoiesis was present in 2 of the 6 anemic patients. Erythropoietin levels measured at the time of first transfusion were increased. Thus, the anemia associated with zidovudine therapy is due to red cell hypoplasia or aplasia.

Acquired Immunodeficiency Syndrome↗
PubMed1988

[Function of the long spinal cord pathways in cervical spinal stenosis--an electrophysiologic study].

Cervical spinal stenosis is radiologically defined by a reduced inner diameter (X less than 13 mm) of the cord canal and in most cases etiologically connected with spondylosis. The following study describes the results of non-invasive assessment of the long ascending and descending spinal tracts in 12 patients. The long ascending spinal tracts were examined by spinal and cortical SEP after stimulation of the tibial nerve; for the assessment of the descending spinal tracts motor responses of the tibial anterior muscle were recorded after non-invasive stimulation of the motor cortex. Clinically symptomatic patients (N = 2) exhibited clear-cut functional motor and sensory deficits of the central pathways. In asymptomatic patients (N = 10) corticomotoneuronal latencies to the lower limbs were increased in 8 cases. In comparison, increased central sensory latencies were found in 9/10. In conclusion, the studies showed that the technique of non-invasive stimulation of the motor cortex may play a role in the detection of subclinical lesions of the long descending motor tracts due to a chronic mechanical irritation.

Cerebral Cortex↗