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Biomedical subjects

S Alpert

Publications and source records attributed to S Alpert.

82 records · Page 5Linked to original sources

Elective postoperative radiotherapy after incomplete resection of colorectal cancer.

It is known that patients with incompletely resected epithelial cancers are at high risk of local recurrence. A prospective study to determine whether elective postoperative radiotherapy can decrease the incidence of local recurrence and thus improve survival of those patients with an incompletely resected tumor was made of 125 irradiated patients with locally advanced colorectal cancer (B2, C1, C2) 78 patients had rectosigmoid tumors and 47 had colonic cancers. Complete resection (R0) was performed in 94 patients (75 per cent). Thirteen (10 per cent) had microscopic (R1) and 18 (14 per cent) had gross residual disease (R2). Local control and survival (average follow-up, 38 months) of patients with microscopic residual cancer (RI) were 84 per cent (11/13) and 77 per cent (10/13) respectively. These results were identical to those obtained in patients without residual disease (R0). Patients with gross residual disease (R2) had a local control of 50 per cent (9/18) and a survival of 39 per cent (7/18). Radiation complication occurred in seven of 125 patients (6 per cent). One patient died, of radiation enteritis. One patient required a nephrostomy. The remaining five patients were treated conservatively. Elective postoperative radiotherapy given to patients who had incomplete resection of a colorectal cancer prevented local recurrence in the majority and may have increased survival.

Adenocarcinoma↗

State specificity of DST abnormalities in geriatric depression.

Pre-treatment and posttreatment dexamethasone suppression test (DST) results in physically healthy elderly major depressives without dementia demonstrated an association between treatment and DST normalization. Sixty percent of subjects were nonsuppressors at baseline compared to 17% after intensive treatment. DST results normalized in 75% of initial nonsuppressors; none of the initial suppressors converted to nonsuppression. A strong correlation between clinical improvement and decreases in afternoon cortisol levels was identified. Initial suppression status did not influence this association. There was a nonsignificant trend for very high (> 15 micrograms/dl) afternoon cortisol levels to be associated with delusional depression. The advantage of using continuous rather than categorical measures to assess the relationship between reversal of depression and DST results is discussed.

Aged↗

Bovine papillomavirus genome elicits skin tumours in transgenic mice.

Transmission of the bovine papillomavirus-1 (BPV-1) genome through the mouse germ line results in the heritable formation of fibropapillomas of the skin, a tissue-specific phenotype analogous to that observed in natural BPV-1 infection of cattle. Oncogenesis is slow, with tumours first arising at 8-9 months of age, usually in areas prone to wounding. Extrachromosomal BPV-1 DNA is detected in all tumours, whereas normal tissues show only integrated DNA.

Age Factors↗

Non-tolerance and autoantibodies to a transgenic self antigen expressed in pancreatic beta cells.

Transgenic mice expressing simian virus 40 T antigen under control of the insulin gene regulatory region vary in their response to this protein. Each lineage is characteristically either tolerant to T antigen, or not, in which case autoantibodies arise with high frequency, and lymphocytes infiltrate and disrupt the pancreatic islets. Both non-tolerance and the autoimmune response appear to result from delayed onset of T antigen expression during beta cell development.

Animals↗

Orogenital contact and the isolation of Neisseria gonorrhoeae, Mycoplasma hominis, and Ureaplasma urealyticum from the pharynx.

Men and women who came to clinics in Boston underwent pharyngeal examinations, and pharyngeal specimens were obtained for cultures for Neisseria gonorrhoeae, Mycoplasma hominis, and Ureaplasma urealyticum. Fifty-one (4.9%) of 1,037 participants had gonococcal pharyngeal infection. M. hominis and U. urealyticum were recovered from the pharynges of 149 (14.3%) and 154 (14.8%) of 1,044 participants, respectively. The history of ever having performed fellatio was associated with pharyngeal infection with N. gonorrhoeae (P less than 0.02), M. hominis (P less than 0.05), and U. urealyticum (P less than 0.006). A history of fellatio was also associated with a history of a recent sore throat. There was, however, no association between pharyngeal infection with N. gonorrhoeae, M. hominis, or U. urealyticum and a recent sore throat. Cunnilingus was not associated with symptoms or signs or pharyngitis or with the isolation of gonococci or genital mycoplasmas from the pharynx. The pharyngitis associated with fellatio remains a microbiologic enigma.

Female↗

Vaginal colonization with mycoplasma hominis and ureaplasma urealyticum.

Vaginal cultures obtained from unselected young women who consulted the gynecologist in a student health service were examined for Ureaplasma urealyticum and Mycoplasma hominis. Each participant completed a confidential questionnaire. Multiple logistic regression analysis was used to determine which variables, of a large number ascertained, were associated with mycoplasmal colonization. U. urealyticum was isolated from 273 (56.8%) of 481 participants. The following variables were significantly predictive of colonization with U. urealyticum: black race, absence of antibiotic use, cigarette smoking, and number of sexual partners during the last year. Lifetime number of sexual partners was significantly predictive only in women who used nonbarrier methods of contraception. M. hominis was isolated from 85 (17.7%) of the 481 participants. Independent variables that were significantly predictive of colonization with M. hominis included black race, young age, and, for users of nonbarrier methods of contraception, lifetime number of sexual partners.

Black or African American↗

Ultrastructure and electron immunocytochemistry of insulin-producing B-cell tumors from transgenic mice: comparison with counterpart human tumors.

This paper reports on an ultrastructural and electron-microscopic immunocytochemical study of pancreatic B cells from normal mice, pancreatic B cells and derivative tumors from transgenic mice, and tissue from human pancreatic B-cell tumors. In normal and neoplastic B cells from both species, typical immature and mature beta-granules (with spherical cores of variable density) were observed, whereas typical beta-granules with a crystalloid core were only present in human B cells (normal and tumor). A small number of atypical granules were found in distinct neoplastic cells which contained no typical beta-granules. The atypical granules were smaller (100-200 nm diameter) than typical beta-granules (250-450 nm diameter) seen in other cells. Immunoreactivity for proinsulin was localized only to immature granules, whereas insulin and C-peptide immunoreactivities were demonstrated in atypical, immature, and mature granules. In transgenic mouse and human B-cell tumors, insulin immunoreactivity was consistently weaker than the immunostaining for C-peptide. An intragranular, topographic segregation of immunoreactive C-peptide was observed in a population of transgenic tumor cells. Our results showed similarities in antigenic distribution and only slight differences in morphology between human and mouse B cells. Therefore, the transgenic mouse system may prove to be an effective model for studying mammalian B-cell tumorigenesis.

Adenoma, Islet Cell↗