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Biomedical subjects

D Armstrong

Publications and source records attributed to D Armstrong.

At least 433 records · Page 24Linked to original sources
PubMed1988

Light and electron microscopic appearance of the inner ear in juvenile ceroid lipofuscinosis (CL).

Inner ear cells were studied by histology, histochemistry and electron microscopy in one case of juvenile form of ceroid lipofuscinosis (Batten's disease). It was found that despite the clinically normal range of auditory acuity (nonaudiometric evaluation) there was a storage process of moderate degree with intralysosomal deposition of a lipopigment of variable ultrastructure with two patterns predominating, curvilinear and fingerprint. Storage was demonstrable in slightly variable degree in every cell type including the receptor cells of the organ of Corti and sensory cells of crista ampullaris. The cochlear neurons displayed a so far unique storage with enormous monovacuolar distension of perikarya comparable only to the lymphocytic vacuolization also present in the juvenile form of the disease. The distension of vacuoles was only partly caused by accumulation of the lipopigment mass and actually led to neuronal deterioration. The results shown here offer a new modell for functional-structural relationship and point to the urgent need of further studies of the inner ear in CL and lysosomal storage generally.

Child↗
PubMed1988

Graft-versus-host disease in the central nervous system. A real entity?

Graft-versus-host disease (GVHD) classically involves the skin, intestines, liver, esophagus, and tongue. clinically apparent disease involving the heart, lungs, kidneys, and central nervous system (CNS) is frequently secondary to other complicating factors. This report describes a case of an infant with severe combined immune deficiency (SCID) who developed unusual manifestations of GVHD following a bone marrow transplant (BMT). These were complete heart block and respiratory insufficiency in the absence of significant pulmonary disease. He lived 133 days post-transplantation. At autopsy, the brain showed focal lymphohistiocytic aggregates which may represent a hitherto unreported lesion of GVHD.

Acute Disease↗
PubMed1988

Distribution of pentamidine in patients with AIDS.

We used a bioassay to measure pentamidine concentrations in autopsy specimens from 22 patients with AIDS. Patients received pentamidine isethionate (approximately 4 mg/kg per day) parenterally for Pneumocystis carinii pneumonia; one received monthly prophylaxis. We found that lung levels of 30 micrograms/g were achieved only after the fifth dose; tissue accumulation was usually greater in the liver, kidney, adrenal, and spleen than in the lung; detectable levels were present in some tissues as late as one year after the last dose; and low but detectable levels were present in the brain of six of 17 patients. Two patients had no detectable lung levels after two days of therapy; one had a level of 17.5 micrograms/g after four doses, and two had levels of 30 micrograms/g after five doses. A more rapid and effective method of delivery, such as aerosol, should achieve higher concentrations earlier. Because pentamidine persists in lung tissue over days to weeks, daily administration may not be necessary.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Aerosol amphotericin B is effective for prophylaxis and therapy in a rat model of pulmonary aspergillosis.

Invasive pulmonary aspergillosis is a major life-threatening complication among transplant recipients and patients receiving cancer chemotherapy. In a rat model of progressive pulmonary aspergillosis that is characterized by hyphal bronchopneumonia, aerosol amphotericin B (aero-AmB; 1.6 mg/kg given 2 days before infection) significantly delayed mortality in rats compared with animals in a control group. The first death in the aero-AmB-treated group occurred on day 11, by which time seven of the eight control animals had died. The same dose of aero-AmB given as treatment (1.6 mg/kg given 24 h after infection and then daily for 6 days) was also effective. In this trial, eight of the ten animals treated with aero-AmB survived for 7 days, whereas only one of ten control animals survived. Colony counts in lung homogenates obtained 24 h after infection showed an 80-fold reduction in the number of viable spores in animals that had received 6.4-mg/kg doses of aero-AmB 2 days prior to infection. At 48 h after administering a single 1.6- or 3.2-mg/kg dose of aero-AmB, mean lung concentrations were 2.79 and 5.22 micrograms/g of tissue, respectively. We conclude, therefore, that aero-AmB kills inhaled spores and delays the progression of pulmonary aspergillosis by inhibiting mycelial proliferation.

Aerosols↗
PubMed1988

MIC and fungicidal activity of terbinafine against clinical isolates of Aspergillus spp.

Terbinafine and amphotericin B MICs for 90% of strains tested were 1.6 and 0.4 micrograms/ml against Aspergillus fumigatus (16 strains), 0.8 and 3.2 micrograms/ml against Aspergillus flavus (10 strains), and 0.4 and 1.6 micrograms/ml against Aspergillus niger (10 strains), respectively. For all species tested, the minimal inhibitory and fungicidal concentrations for 90% of strains of both drugs were identical and the inoculum size did not have a major effect on the results.

Amphotericin B↗
PubMed1988

Postradiation meningioma in a child.

Tumors caused by radiation treatment are not unknown. They may be benign or malignant. Among these, postradiation meningiomas (PRM) are considered to be a distinct entity. A case of a child who developed a PRM is presented. She received radiation therapy for a presumed thalamic glioma 11 years earlier. An unusual and interesting aspect of this tumor was its attachment to the membrane of the old subdural hematoma, following a shunting procedure. There was no dural attachment. The pathology of PRMs and meningiomas in children are discussed in light of our recent experience.

Brain Neoplasms↗
PubMed1988

Fungal infections in AIDS. Histoplasmosis and coccidioidomycosis.

Histoplasma capsulatum and Coccidioides immitis are two fungi that are regional in occurrence and cause opportunistic fungal infections in patients with AIDS. Many cases of histoplasmosis have been reported in patients months or years after they have been in an endemic area. These are obviously cases of reactivation of latent infections. With coccidioidomycosis, the cases have been reported from endemic areas, but some also appear to be reactivation infections, and we should anticipate such cases in nonendemic areas just as with histoplasmosis. The clinical presentations may be atypical, even mimicking acute bacterial sepsis. The diagnosis should be sought in any HIV-infected patient with an unexplained infection and residence or travel in an endemic area even in the remote past. Studies should include bone marrow examinations for histoplasmosis as well as skin biopsies with special strains and cultures for fungi for both infections. Sputum or bronchoscopy specimens have often been the source of a diagnosis in coccidioidomycosis. Serologic tests for antibody in both diseases yield inconsistently positive results in AIDS patients. Treatment of the acute infection should be with amphotericin B followed by maintenance suppressive therapy with ketoconazole or Amphotericin B.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Fungal infections in AIDS. Cryptococcosis.

Cryptococcus neoformans, Histoplasma capsulatum, and Coccidioides immitis are the three fungi that regularly cause disseminated, life-threatening disease in patients with AIDS. Cryptococcosis is the fourth most common opportunistic infection in patients with AIDS and results in meningitis or pneumonia or both, in most cases. In addition, there have been unusual focal infections described and even unexplained fever alone. In any patient at risk for HIV infection, routine screening tests should include serum cryptococcal antigens, and this test should be repeated whenever new symptoms or signs appear. Once the diagnosis is established, treatment with amphotericin B is mandatory and a response should be expected. The necessity for combination therapy with flucytosine has not been documented. When the disease is under control and a course of 1 to 2 gm of amphotericin B has been administered, a maintenance suppressive regimen using amphotericin B at least weekly must be given. Oral azole regimens, such as ketoconazole or fluconazole, are under study and offer promise of a more easily managed maintenance program.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Measuring general practitioner referrals: patient, workload and list size effects.

Individual general practitioners are known to vary widely in the number of patients they refer to hospital outpatient departments; indeed there is increasing concern that the 'high' referrers use a disproportionate quantity of National Health Service resources. Data from a one-week survey of referrals by 122 general practitioners in one health district showed that a different age-sex mix of patients consulting individual general practitioners might account for about one quarter of his or her referrals. The results also showed that different referral rates, calculated by using either workload or list size denominators, identified markedly different groups of high referrers. These different methods of measurement are discussed, and on practical grounds a referral rate based on actual referrals divided by mean practice list size is suggested for future comparisons.

Data Collection↗