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Biomedical subjects

D H Jacobs

Publications and source records attributed to D H Jacobs.

27 records · Page 2Linked to original sources
PubMed1992

Meningiomas are not significantly associated with breast cancer.

We studied 283 meningiomas seen at the University of Kansas, Kansas City, from 1948 through 1984, identifying all additional nonmeningeal malignancies and primary brain tumors in these patients and calculating the expected number of additional tumors by the use of a person-year method from age and sex-matched cancer incidence data. We determined expected numbers of total neoplasms in our meningioma population as well as the expected numbers in each major organ system for the sexes independently and together. We then calculated standard morbidity ratios and 95% confidence intervals for each tumor type. The number of breast cancers did not reach statistical significance. We found a significantly increased number of second primary brain tumors in women (standard morbidity ratio, 8.0; 95% confidence interval, 2.2 to 20.4) and an increased number of thyroid cancers in both sexes (standard morbidity ratio, 7.5; 95% confidence interval, 1.5 to 21.9).

Adult↗
PubMed1990

Matrix vesicle biogenesis in vitro by rachitic and normal rat chondrocytes.

Calcifying matrix vesicles (MVs) are released from chondrocytes and osteoblasts in monolayer culture. In the present studies, we tested the ability of rachitic versus normal rat growth plate chondrocytes in micromass or monolayer primary cultures to produce MVs. Unlike earlier reports of in vitro MV biogenesis by chicken chondrocytes in which most MVs were released into the medium, we found that most of the released rat matrix vesicles were entrapped in a newly formed cartilaginous matrix enveloping the cells. These matrix-associated MVs could be isolated by mild collagenase treatment and concentrated by differential centrifugation. Vesicle production slowed in the older 2- to 4-week-old cultures and, unlike vesicle release from cultured chicken chondrocytes, active vesicle production did not show a second burst of activity at 3 to 4 weeks. Alkaline phosphatase (ALP) activity diminished with time in culture in cells and matrix vesicles, suggesting a decrease in differentiative expression. Protein profiles on SDS polyacrylamide gels of native matrix vesicles and culture-derived MVs from rachitic and normal cells were quite similar and showed a typical simplified protein pattern as compared to chondrocyte plasma membrane proteins. There were distinctive proteins migrating at 130, 80 to 95, 66, 43, 20, and 14 kd. Culture-derived MVs showed vigorous in vitro calcifying activity that was ALP related. We conclude that 1) rachitic chondrocytes are essentially normal in their matrix vesicle production; 2) matrix entrapment of MVs is a characteristic of rat chondrocyte cultures; and 3) culture-produced MVs are similar to native MVs in protein profile and calcifiability, and thus can be studied as a model for normal MV composition and calcification.

Animals↗
PubMed1987

Female patients with meningioma of the sphenoid ridge and additional primary neoplasms of the breast and genital tract.

Of 283 meningioma patients seen at the University of Kansas from 1948 to 1984, eight women acquired two primary extraneural cancers in addition to their meningiomas. Of these eight patients, six (75%) had sphenoid ridge meningiomas compared with 15% of meningioma patients overall (P less than 0.001). Seven (87.5%) had at least one breast or genital cancer (P less than 0.001). Of the six with sphenoid ridge meningiomas, five (83.3%) had both of their additional tumors in these two organ systems, and the sixth had one such tumor. It is proposed that this grouping of sphenoid ridge meningioma, breast cancer, and genital cancer represents a unique constellation of neoplasms in women.

Adult↗
PubMed1986

T cell-induced expression of membrane IgG by 70Z/3 B cells.

To study T cell regulation of B cell isotype differentiation, we determined the capacity of clonal T cell populations (hybridomas derived by fusing BW5147 with Con A-activated Peyer's patch (PP) and spleen T cells) to induce "downstream" isotype expression by the pre-B cell lymphoma 70Z/3. In initial studies, we found that 70Z/3 B cells cultured in the presence of LPS (1 microgram/ml) expressed membrane IgM (mIgM) but not membrane IgG (mIgG). In contrast, 70Z/3 B cells cultured with HAJ-3 T cells, a PP-derived T cell hybridoma (as well as other similarly derived PP and spleen hybridomas), or with HAJ-3 T cells plus LPS do express mIgG. Such expression occurred in spite of mitomycin C-induced blockage of cell proliferation, and is observed in 70Z/3 B cell subclones cultured with HAJ-3 T cells. For these reasons, it is not due to selective expansion of a small pre-switched mIgG-bearing 70Z/3 B cell subpopulation. In other studies it was shown that 70Z/3 B cells expressing mIgG after induction by HAJ-3 T cells continue to express mIgM and do not secrete IgG. Finally, exposure of 70Z/3 B cells to the macrophage factor IL 1 and the T cell factors IL 2, BSF-pl, and BCGF-II present in EL-4 cell supernatants did not result in mIgG expression. On the basis of these studies, we conclude that a clonal B cell population expressing mIgM can be induced by T cells to co-express mIgG. Because the B cells do not express mIgG unless exposed to T cells, this represents a T cell-induced isotype switch.

Animals↗
PubMed1984

Esophageal cryptococcosis in a patient with the hyperimmunoglobulin E-recurrent infection (Job's) syndrome.

Patients with the hyperimmunoglobulin E-recurrent infection (Job's) syndrome, which is characterized by an elevated immunoglobulin E level, recurrent staphylococcal infections, and an abnormality of neutrophil chemotaxis, have been reported to have visceral Candida infections in addition to their more frequent pyogenic infections. We report a patient with Job's syndrome who presented with massive hematemesis secondary to esophageal cryptococcosis. A thorough evaluation for an occult neoplasm or extraesophageal cryptococcosis was negative. The patient received a 6-wk course of amphotericin B (970 mg) and 5-fluorocytosine with complete radiographic and endoscopic resolution of the lesion. He is doing well 18 mo after therapy. The patient was not anergic, and his response to T-cell mitogens, helper-to-suppressor T-cell ratio, total number of T cells, and immunoglobulin-producing capability were all normal. This case is unusual in that it is the first documentation of a cryptococcoma of the esophagus and underscores the importance of culturing abnormal specimens for unsuspected pathogens in unusual clinical circumstances.

Adult↗
PubMed1982

The neglected alliance: the inpatient unit as a consultant to referring therapists.

During two years of work on an inpatient psychiatry unit in a general hospital, the authors became impressed with how often patient-therapist difficulties preceded the need to hospitalize a patient. Difficulties in the therapeutic relationship sometimes precipitated the hospitalization; other times they were complicating factors. Unresolved difficulties in this relationship had to be addressed during hospitalization if inpatient treatment was to be successful. The authors present several typical cases that demonstrate different kinds of difficulties in the patient-therapist relationship and the use of consultation by an inpatient staff in resolving them. They conclude that an inpatient unit with sufficient staff should serve as a consultant to the referring therapist in almost every case.

Adult↗