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Biomedical subjects

J Casey

Publications and source records attributed to J Casey.

At least 37 records · Page 2Linked to original sources
PubMed1991

Cognitive changes at high altitude in healthy climbers and in climbers developing acute mountain sickness.

We report the cognitive functions of 17 non-acclimatized mountaineers who ascended from low lands to an altitude of 4,559 m in 24 h and were studied there within 6 h. We found that this rapid ascent to high altitude had small, but differential effects upon cognitive performance depending upon the later development of acute mountain sickness (AMS). Subjects who developed AMS within a 24-48-h stay at high altitude were mildly impaired in short term memory, but improved in conceptual tasks, while subjects who remained healthy had a better short term memory performance but no improvement in cognitive flexibility. Possible explanations for these unexpected effects of high altitude are discussed.

Adult↗
PubMed1990

Discrimination between HIV-1 and HIV-2-seropositive individuals using mouse monoclonal antibodies directed to HIV transmembrane proteins.

Mouse monoclonal antibodies directed against the transmembrane proteins of HIV-1 or HIV-2 provided site-directed, unambiguous discrimination between HIV-1 and HIV-2 antibody-positive sera, when employed in immunoassays as competitive probes against serum antibodies. These monoclonal antibodies mapped to epitopes outside of the well-characterized immunodominant regions (IDR) of the transmembrane proteins. The monoclonal competitive immunoassay was a superior method for discrimination compared with immunoprecipitation of metabolically radiolabeled HIV envelope glycoproteins, Western blot against viral envelope glycoproteins, or noncompetitive enzyme immunoassays employing HIV recombinant transmembrane proteins or synthetic IDR peptides as serological targets. The monoclonal competitive assay was not affected by antigenic cross reactivity or nonspecific reactivity exhibited by selected serum samples toward envelope proteins or peptides, respectively. Results of the monoclonal competitive immunoassay were supported by results of a peptide inhibition assay employing free IDR peptides in competition with IDR peptides on a solid support for binding of serum antibody. IDR peptide inhibition clearly demonstrated non-cross-reactive antigenic specificity of sera toward either the HIV-1 IDR or the HIV-2 IDR. The monoclonal competitive assay also identified samples containing antibody to both HIV-1 and HIV-2 transmembrane proteins. Analysis of these samples by IDR peptide inhibition indicated they contained two distinct, non-cross-reactive populations of antibodies, one directed to the HIV-1 IDR and the other directed to the HIV-2 IDR.

AIDS Serodiagnosis↗
PubMed1990

An effective technique for enrichment and isolation of Candida cloacae mutants defective in alkane catabolism.

Techniques are described which allow mutated populations of Candida cloacae to be enriched efficiently (up to 167-fold in one round of enrichment) for mutants deficient in the alkane degradation pathway (Alk-). Such mutants, as well as being of scientific importance in studies of the degradation pathway, are also of commercial interest because several of the degradative intermediates are of value to the chemical industry. The Alk- mutants were readily isolated by their inability to grow on agar plates supplied with hexadecane as sole carbon source. A total of 288 Alk- mutants were isolated from, effectively, 4 x 10(6) mutagen-treated cells. They were further characterized by replica-plating using palmitic acid (PA) or acetate (Ac) as sole carbon source. Preliminary screening studies showed that of the 84 Alk- PA- Ac+ mutants, most could accumulate dicarboxylic acids from hexadecane and palmitic acid and at least one mutant also produced 3-hydroxyhexadecanedioic acid. Of the 80 mutants characterized as Alk- PA+, 16 produced small amounts of hexadecanol.

Alkanes↗
PubMed1989

Clinical significance of immunophenotype in diffuse aggressive non-Hodgkin's lymphoma.

We performed a prospective study of the clinical significance of immunophenotype in 110 patients with aggressive non-Hodgkin's lymphoma (NHL) treated by oncologists in the Nebraska Lymphoma Study Group between October 1982 and May 1986. All patients were immunophenotyped from biopsies performed before therapy was administered. The patients were treated with a uniform protocol of radiotherapy for minimal nonbulky, stage I or II disease (seven patients) or a single, six-drug chemotherapy regimen cyclophosphamide, doxorubicin, procarbazine, bleomycin, vincristine, and prednisone (CAP-BOP) in patients with more extensive disease (103 patients). Ninety-one patients (83%) had B-cell lymphoma and 19 patients (17%) had T-cell lymphoma. The histologic diagnosis of diffuse mixed-cell lymphoma was significantly associated with T-cell immunophenotype (45% v 5%; P less than .001), and the diagnosis of diffuse large-cell lymphoma was significantly associated with B-cell immunophenotype (40% v 5%; P = .006). However, no significant difference in frequency of prognostic variables such as age, stage, systemic symptoms, tumor bulk, serum lactic dehydrogenase, or performance status was found between the B-cell and T-cell groups. Patients with B-cell NHL had a slightly higher complete remission rate (74% v 53%; P = NS), similar durability of complete remission (75% v 70% at 3 years; P = NS), and a slightly but not significantly better overall survival (50% v 41% at 3 years; P = NS). The slight advantage in response rate and survival for B-cell patients was related to a very poor outcome for patients with stage IV T-cell NHL. For patients with stage I to III disease, neither the complete remission rate (B-cell, 82% v T-cell, 91%; P = NS) nor overall survival (3-year survival for B cell, 58% v T cell, 73%; P = NS) were significantly different. However, with stage IV disease B-cell patients fared far better than those with T-cell NHL for both complete remission rate (67% v 0%; P = .002) and overall survival (3-year survival, 44% v 0%; P = .002). Immunophenotyping intermediate- and high-grade NHL allowed identification of a subgroup of patients who had a very poor prognosis with this treatment approach and for whom alternate therapy might be considered.

Antigens, CD↗
PubMed1988

A focus of Rocky Mountain spotted fever within New York City.

In the spring and summer of 1987, four persons acquired Rocky Mountain spotted fever within New York City, an area in which the disease had not previously been known to be endemic. Three of the four patients were residents of the Soundview area of the Bronx. All diagnoses were confirmed by indirect fluorescent-antibody tests. Environmental investigation revealed that the tick vector for Rickettsia rickettsii, Dermacentor variabilis, was present in a local park. Of the 66 specimens of D. variabilis collected, 5 (8 percent) were positive for rickettsiae from the spotted fever group. Of an additional 96 specimens of D. variabilis, 5 (5 percent) were found positive for rickettsiae by a more specific monoclonal antibody assay. Eight additional New York City parks in all five boroughs were searched for ticks. D. variabilis was found in only one other park; of the 147 ticks collected there, none were positive for rickettsiae. These findings emphasize the focal nature of Rocky Mountain spotted fever and the need to consider that disease in the differential diagnosis of any obscure acute febrile illness, even in the absence of a history of travel to known endemic areas.

Adult↗
PubMed1986

HTLV-III serology in hemophilia: relationship with immunologic abnormalities.

We investigated the relationship of the presence of antibodies to HTLV-III and immunologic abnormalities in patients with hemophilia. Serum antibodies to HTLV-III were analyzed by ELISA assay, immunoprecipitation of labeled cell extracts, and immunoprecipitation of purified HTLV-III p24. Thirty-four (61%) of the total group (n = 56) had antibody to HTLV-III; 34 (76%) of 45 patients given commercial factor VIII preparations were seropositive, compared with none of 11 patients treated exclusively with cryoprecipitate obtained from volunteer blood donors. Of patients who were seropositive for HTLV-III antibody, 94% had abnormal T4/T8 ratios, and 33% of those whose serum was antibody negative had abnormal T4/T8 ratios; five patients, each antibody positive, have lymphadenopathy syndrome. Sequential studies in a subset of patients indicate that there is a changing pattern of antibody production to HTLV-III antigens after seroconversion.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Gastrocolic fistula.

Peptic ulcer disease is a less common cause of gastrocolic fistula than either carcinoma of the stomach or colon. However, use of steroids or aspirin appear to make this a more common complication of benign disease. The typical symptoms are pain, diarrhea, weight loss, foul eructation, and feculent vomiting. The most accurate method of diagnosis is with barium enema. The treatment is surgical.

Adult↗
PubMed1984

Isolation of proteins from crude mixtures with silica and silica-based adsorbents.

Silica and silica-based adsorbents have been used to isolate specific proteins from crude mixtures. Acid-activated Nugel silica and Nugel SP-Silica were used to extract human immune interferon from the conditioned medium of mixed lymphocyte cultures. Human interleukin-2 was extracted from the conditioned medium of Jurkat cells with LiChroprep RP-8. In each case, batch absorption was accomplished by gentle stirring in a microcarrier vessel. The adsorbate was collected by sedimentation, and either batch-eluted or packed into a column for gradient elution. A high degree of concentration and purification was achieved with a high recovery of biological activity.

Adsorption↗
PubMed1983

Correlation of immune and nutritional status with wound complications in patients undergoing vascular operations.

The acquired failure of host immunocompetence that may result from significant protein and caloric malnutrition has been associated with an increased incidence of septic complications in patients undergoing operation. Wound infection in patients undergoing vascular surgical procedures may lead to exposure or contamination of a vascular graft, with the subsequent risk of hemorrhage, limb loss, or death. The present study was undertaken to correlate the immune and nutritional status of patients undergoing vascular surgical procedures with the development of significant wound complications. Seventy-nine patients undergoing a variety of vascular operations were subjected to comprehensive nutritional assessment, including anthropometric measurements (height, weight, midarm circumference, triceps skin fold), serologic testing (albumin, transferrin, lymphocyte count, serum zinc), cutaneous assessment of delayed hypersensitivity (anergy battery), and neutrophil functional analysis. After operation the patients were observed for the development of delayed wound healing or wound infection. Statistical analysis of measured variables was performed to identify immune and nutritional markers with prognostic value. Patients with serum albumin levels above 3 gm/dl were much more likely to have uncomplicated wound healing (P less than 0.001). Similarly, patients with serum transferrin levels above 150 mg/dl had significantly fewer wound problems (P less than 0.01). Only 29% of patients with cutaneous anergy had normal wound healing, while 56% of those with intact cutaneous reactivity healed primarily; this difference, however, was not statistically significant. Diabetics in this series were more likely to develop wound problems (P less than 0.05). Anthropometric measurements provided no predictive information regarding the likelihood of uncomplicated healing. Similarly, measurement of total lymphocyte count and serum zinc yielded no significant prognostic information. The urgent nature of many vascular surgical procedures may preclude preoperative immune and nutritional assessment; however, the outcome of these procedures may ultimately depend upon intact host defense. The contribution of protein and caloric malnutrition to immunocompromise can be easily assessed in these patients. The detection and subsequent reversal of immunoincompetence through the use of enteral or parenteral alimentation should provide a significant reduction in operative morbidity and mortality.

Aged↗
PubMed1982

Incidence of lobular carcinoma in bilateral breast cancer.

The histology and clinical records of 52 patients with bilateral breast cancer recorded in a community tumor registry were reviewed. Previous studies have demonstrated the propensity of lobular carcinoma to occur bilaterally. This view is supported by the large number of lobular cancers found in our patients. Thirty-six percent of the patients with bilateral disease had lobular cancer in at least one breast. Those with lobular cancer tended to be younger and more likely to have simultaneous cancers than did patients with nonlobular carcinoma. In those patients in whom the occurrence of tumors was not simultaneous, they were smaller in the second breast but had similar rates of axillary metastases. This study raises the question of how best to manage the contralateral breast in patients with breast cancer. Lobular carcinoma is one marker of the likelihood for development of disease in the second breast; but if advantage is to be gained by this finding, investigation of the opposite breast is best done early. Finally, thorough examination of patients with nonlobular carcinoma must not be ignored because they still comprise the majority of bilateral breast cancers.

Adult↗