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Biomedical subjects

G Adams

Publications and source records attributed to G Adams.

At least 91 records · Page 5Linked to original sources
PubMed1993

Pulmonary sequestration with primary blastomycosis. Failure of ketoconazole therapy after resection.

Infection with Blastomyces dermatitidis developed in a girl with occult pulmonary sequestration. Six months after resection, while receiving ketoconazole, she developed an abscess due to B dermatitidis over the scar from thoracotomy, with a sinus tract to the eighth rib. This was successfully managed with débridement, rib resection, and amphotericin B. Contiguous bone involvement should be suspected in sequestra infected with this organism; débridement and therapy with amphotericin B might be indicated.

Blastomycosis↗
PubMed1993

[Use of fluorine-19 nuclear resonance spectroscopy for the measurement of changes induced in blood perfusion volume in experimental tumors in vivo].

The biological response of some anti-cancer therapeutic agents is probably mediated via the tumour vasculature. A novel approach using 19F NMR spectroscopy in vivo has been developed to directly measure changes in vascular perfusion volume in experimental tumours. A 100% w/v perfluorooctylebromide (PFOB) emulsion was used as a tracer. For a fixed position of a 7 mm surface coil placed over the tumour, the signal from the PFOB rapidly reached an equilibrium value remaining unchanged for at least 2 hours. Since the strength of the fluorine signal is directly proportional to the perfusion volume of the tumour vasculature, reduction of signal intensity should correspond directly to any reduction in volume which may be a manifestation of a change in the tumour blood flow. This hypothesis was investigated using hydralazine as a physiological modifier of tumour blood flow. Administration of 5 mg/kg of hydralazine following dosing with the PFOB emulsion reduced the 19F signal intensity from the murine tumors RIF-1 and KHT and from the human tumour HT29 with no or little reduction in the SCCVII/Ha murine and HX118 human tumours. Changes in blood volume in KHT tumour accompanied local changes in tumour blood flow rate as measured by the Xe-133 clearance rate technique. Thus, these data demonstrate the potential of the PFOB emulsion as a 19F NMR tracer of the vasculature to measure changes induced by therapeutic agents on blood volume in accessible tumours. This method may also be useful to detect early changes in blood volume produced during angiogenesis of solid tumours or angiostatic activity of anti-cancer drugs.

Animals↗
PubMed1993

Phase II evaluation of Taxol in advanced head and neck cancer: an Eastern Cooperative Oncology group trial.

The Eastern Cooperative Oncology Group (ECOG) is conducting a phase II trial of Taxol in patients with histologically confirmed, advanced squamous cell carcinoma of the head and neck. Patients entered in the study to date either had recurrent disease or were newly diagnosed with incurable local-regional disease or distant metastases. Prior chemotherapy was limited to induction or adjuvant chemotherapy at least 12 months prior to entry in the study. All patients had an ECOG performance status of 0 or 1 and measurable disease. The treatment schedule was Taxol 250 mg/m2 by 24-hour continuous intravenous infusion followed by r-met Hu granulocyte-colony stimulating factor 5 micrograms/kg/day subcutaneous injection day 3 to 15 or until the absolute neutrophil count was greater than 1500. Cycles were repeated every 3 weeks. As of September 1, 1992, 27 patients were registered in the study. Of these, three patients were determined to be ineligible, and three were too early to evaluate. There were two early deaths, one definitely and one possibly drug related. Two complete and five partial responses have been observed. Twenty-three patients receiving 83 courses were evaluable for toxicity. Myelosuppression was the primary toxicity observed with 17 (74%) patients experiencing grade 3 or 4 leukopenia and with 20 (87%) patients experiencing grade 3 or 4 neutropenia lasting an average of 2 days (range, 1-4). Peripheral neuropathy occurred in nine patients (grade 1, five patients; grade 2, three patients; grade 3, one patient). Other infrequent toxicities were stomatitis, nausea and vomiting, and myalgias. This trial will continue until 30 eligible patients are accrued.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Squamous Cell↗
PubMed1993

Disseminated herpes simplex virus infection during pregnancy. A case report.

Hepatitis due to herpes simplex virus (HSV) developed in a pregnant women at 38 weeks' gestation. She delivered a live-born infant who had serologically documented HSV 2 infection but did well with acyclovir therapy. The mother, however, died five days postpartum from fulminant hepatic failure despite antiviral treatment, and HSV was demonstrated in the liver. Twenty-three reported cases clearly establish pregnancy as a condition that can predispose to disseminated HSV infection. The majority of cases have been due to HSV 2, and primary infection in the latter part of pregnancy appears to constitute the greatest risk. The major disease manifestations appear to be hepatitis and encephalitis. Historically, maternal and fetal mortality rates have been high, but there is a trend toward improved survival in the acyclovir era.

Adult↗
PubMed1992

Isolation and partial purification of a melanocyte-stimulating hormone receptor from B16 murine melanoma cells. A novel approach using a cleavable biotinylated photoactivated ligand and streptavidin-coated magnetic beads.

The alpha-melanocyte-stimulating hormone (alpha-MSH) receptor of B16 mouse melanoma cells was characterized by photoaffinity labelling using radiolabelled photoactive derivatives of alpha-MSH. A doublet band of 43-46 kDa representing a ligand-receptor complex was identified. A novel adaptation of the streptovadin/biotin-based affinity system was used to isolate the alpha-MSH receptor. A probe was synthesized which contained biotin connected to a photolabelled alpha-MSH analogue via a cleavable disulphide linker and which displayed high affinity for the alpha-MSH receptor. Streptavidin-coated magnetic beads were used as a solid support instead of an affinity column. Covalently linked probe-receptor complexes solubilized in Triton X-100 were equilibrated with the beads, and after magnetic separation and washing, specifically bound complexes were treated with dithiothreitol to cleave the disulphide bridge in the biotin-peptide spacer arm and so release the receptor-ligand complex. The identity of the isolated protein was established by SDS/PAGE analysis. Methods to achieve purification to homogeneity and to allow quantitative isolation of the receptor are discussed.

Affinity Labels↗
PubMed1992

Long-term effects of bone marrow transplantation on lysosomal enzyme replacement in beta-glucuronidase-deficient mice.

This study uses bone marrow transplantation (BMT) between congenic strains of mice as an experimental model to examine enzyme replacement therapy of lysosomal storage diseases. Bone marrow cells from donor mice which have normal levels of the lysosomal enzyme beta-glucuronidase (Gus), which is heat-stable, rapidly repopulated the haematopoietic compartment of irradiated recipient mice which have only low levels of a thermolabile form of this enzyme. Gus activity was found to increase progressively in the tissues of the recipients, including the liver, heart and skeletal muscle. Elevated levels were also observed in the kidney and brain. The increase in enzyme activity in the host tissues was not due to the presence of contaminating blood cells, but rather to the acquisition of new, heat-stable enzyme from the donor bone marrow cells. High levels of Gus activity persisted for at least 72 weeks, showing the potential therapeutic value of BMT for enzyme deficiency diseases.

Animals↗
PubMed1992

Emergence and control of methicillin-resistant Staphylococcus aureus in a children's hospital and pediatric long-term care facility.

BACKGROUND: After a 6-year quiescence, methicillin-resistant Staphylococcus aureus (MRSA) was isolated from 30 patients in a children's hospital and a pediatric long-term care facility from November 1987 through April 1989. After six nosocomial cases had occurred at the children's hospital, increased infection control measures directed at MRSA were initiated in August 1988. Because MRSA had been identified in three patients in the pediatric long-term care facility within 24 hours of their admission to the children's hospital, other patients transferred from the pediatric long-term care facility to the children's hospital were isolated and screened for MRSA. METHODS: We reviewed the medical records of these patients and evaluated their response to therapy with rifampin alone or in combination with trimethoprim-sulfamethoxazole. RESULTS: In the 8-month period after initiation of infection control measures, MRSA was identified in 10 residents of the pediatric long-term care facility; there was also one nosocomial children's hospital case. Phage typing showed that one MRSA strain predominated in patients at the pediatric long-term care facility but did not implicate this strain as the source for MRSA introduction into the children's hospital. Of 16 patients with MRSA who completed therapy and were available for follow-up, 13 (81%) had elimination of colonization. CONCLUSION: Prompt institution of MRSA surveillance, barrier isolation, and therapy to eliminate colonization should be considered in hospitals with a new introduction of MRSA.

Adolescent↗
PubMed1991

Microwave blood plasma defroster.

A microwave blood plasma defroster capable of thawing up to four bags of frozen blood plasma at a time is described. The unit stops automatically when the plasma reaches a preset temperature, and all operating parameters are monitored for safety. Comparative testing showed that blood plasma thawed in this device was indistinguishable from plasma thawed in a water bath.

Equipment and Supplies↗