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Biomedical subjects

S Alpert

Publications and source records attributed to S Alpert.

At least 37 records · Page 2Linked to original sources
PubMed1992

Breast cancer. Importance of adequate surgical excision prior to radiotherapy in the local control of breast cancer in patients treated conservatively.

The extent of excision performed for mammary carcinoma prior to radiotherapy as a risk factor for local recurrence was studied in 503 patients. Three hundred twenty-three tumors (62%) were excised with a minimal rim of tissue (tumorectomy). One hundred forty-two patients (27%) had wide excision and 56 (11%) had quadrantectomy. Tumor stage, size, and radiation treatment were similar for all groups. Forty-one percent of tumorectomies had involved margins, and only 14% and 7% were involved in the wide excision and quadrantectomy groups, respectively. Local failure was 15% for tumorectomy, 7% for wide excision, and 5% for quadrantectomy. In T1 ductal carcinoma, only 4% of those with excisions greater than 5 cm had recurrences. Lesser excision had 20% recurrence. Extent of excision before radiotherapy is an important risk factor for recurrence. Failure was inversely proportional to the amount of breast tissue resected. Narrow excision should be discouraged since a larger tumor burden remains that may not be sterilized by radiation.

Adult↗
PubMed1990

Determinants of the B-cell response against a transgenic autoantigen.

The failure to induce self-tolerance of simian virus 40 large tumor antigen (T antigen) expressed in the pancreatic beta cells of transgenic mice results in an autoimmune response against this protein and the cells that synthesize it. In every transgenic mouse with delayed onset of T-antigen expression and consequent nontolerance, B cells, T cells, and macrophages are attracted to and infiltrate the pancreatic islets. In contrast, the incidence, onset, and intensity of the B-cell response to produce anti-T-antigen autoantibodies vary considerably with genetic background. Thus the initial attraction of lymphocytes to the cells synthesizing a non-self antigen can be separated from the activation of a B-cell response against it. Haplotypes of the major histocompatibility complex (MHC) differentially influence the character of the autoimmune response, with H-2d and H-2k conferring a high incidence of humoral autoimmunity. Additional non-MHC linked genes are also implicated in control of the B-cell response.

Animals↗
PubMed1988

Hybrid insulin genes reveal a developmental lineage for pancreatic endocrine cells and imply a relationship with neurons.

Insulin appears in the developing mouse pancreas at embryonic day 12 (e12). Transgenic mice harboring three distinct hybrid genes utilizing insulin gene regulatory information first express the transgene product two days earlier, at e10, in a few cells of the pancreatic bud. Throughout development and postnatal life, all of the insulin-producing (beta) cells coexpress the hybrid insulin gene. In addition, islet cells containing glucagon, somatostatin, pancreatic polypeptide, and the neuronal enzyme tyrosine hydroxylase coexpress the transgene when they first arise. Similarly, coexpression of these normally distinct islet cell markers occurs during differentiation of the four endocrine cell types. The transgene product also appears transiently during embryogenesis in cells of the neural tube and in neural crest. The results suggest a common precursor for the endocrine cells of the pancreas. Moreover, they imply a relationship between neural and pancreatic endocrine tissue.

Animals↗
PubMed1988

Proliferation, senescence, and neoplastic progression of beta cells in hyperplasic pancreatic islets.

Three different cases of pancreatic beta cell hyperplasia in mice are accompanied by an increase in a subclass of cells expressing tyrosine hydroxylase (TH), a neuronal enzyme. In the nontumorigenic cases of islet growth during normal pregnancy and in the obese mutant mouse, the TH-insulin cells do not divide, in contrast to the "insulin-only" cells. In later stages the number of proliferating insulin-only cells decreases concomitant with an increase in the number of nondividing TH-insulin cells, suggesting that the TH-insulin cells are on a pathway to senescence. In the presence of an oncoprotein the TH-insulin cells are able to proliferate. The proliferation of this cell type may represent an escape from the senescence pathway and progression to immortal tumor cells.

Animals↗
PubMed1987

Expression of cell type-specific markers during pancreatic development in the mouse: implications for pancreatic cell lineages.

The islet cells of the mammalian pancreas are comprised of four different endocrine cell types, each containing a specific hormone. Islet cells also contain two enzymes of the catecholamine biosynthetic pathway : tyrosine hydroxylase (TH) and aromatic L-amino acid decarboxylase (AADC). The cell lineage relationships of these different cell types have not been examined and it is not known whether, during development, they originate from the same or from different precursor populations. In this study we used immunocytochemical procedures to determine whether developing pancreatic cells express markers common to endocrine and exocrine cell types. We found that acinar cell precursors express AADC prior to the appearance of an exocrine marker and that the expression of AADC in acinar cells persists throughout embryogenesis to the first month of postnatal life. At this time, acinar cells do not contain AADC. We also found that exocrine cells containing AADC never express other islet-cell markers. These findings suggest that while acinar and islet cells both arise from precursor cells containing AADC, these progenitor cells do not express a combined endocrine-exocrine phenotype.

Aging↗
PubMed1987

Transgenic mouse model: a new approach for the investigation of endocrine pancreatic B-cell growth.

The transformation and adaptation of pancreatic insulin-producing (B) cells has been studied in a transgenic mouse model using a panel of antisera recognising peptides and general neuroendocrine markers at both light and electron microscopical levels. Stages of tumour genesis in the transgenic mouse model from hyperplasia to neoplasia, have been compared with human B-cell tumours. A normal complement of peptide containing cells was seen in the transgenic mouse pancreas, but cells containing pro-insulin-derived peptides became more numerous as hyperplasia commenced. The transgenic mouse tumours were composed of B cells, although 30-35% of the tumours were also found to contain PP cells--a finding which is directly comparable with that in human insulin-producing tumours. NSE, 7B2 and chromogranin immunoreactivities were found in most cells from all the tumours examined. Antisera to PGP 9.5, a novel marker for elements of the neuroendocrine system, were found to stain hyperplastic and neoplastic B-cells intensely. In contrast, normal mouse B-cells did not show PGP 9.5 immunoreactivity thus it appears that PGP 9.5 is differentially expressed in transformed and/or growing mouse B-cells and hence may be used as an indicator in studies of early tumour growth.

Adenoma, Islet Cell↗
PubMed1986

Small-bowel varices due to mesenteric metastasis.

Small-bowel varices are rare, occurring almost exclusively in patients with portal hypertension. A patient with ileal varices due to mesenteric venous occlusion by metastatic tumor is reported. This association has not been described previously.

Adenocarcinoma↗
PubMed1981

Sexually transmitted conditions among women college students.

We studied 500 unselected young women who consulted a gynecologist in a student health service. Most participants were symptom-free and had normal physical examinations. Few sexually transmitted infections were encountered. Neisseria gonorrhoeae was recovered from two and Trichomonas vaginalis was obtained from 14 of 500 women. Chlamydia trachomatis was recovered from 20 (4.6%) of 439 participants. Genital warts, genital herpes, and molluscum contagiosum, respectively, were noted in seven, four, and one of the 500 participants. There was no cases of syphilis, scabies, or pediculosis pubis. Mycoplasma hominis and Ureaplasma urealyticum, respectively, were recovered from 17.6 and 56.8% of the subjects. Prevalent vaginal bacteria included lactobacilli, streptococci, Staphylococcus epidermidis, and diphtheroids. Gardnerella vaginalis was isolated from the vaginal specimens of about one third of the participants.

Adolescent↗
PubMed1979

Effect of anti-HLA antisera on macrophage-T-cell interactions.

Human T lymphocytes were shown to proliferate in response to tetanus toxoid antigen only in the presence of macrophages. This response was inhibited by anti-DRw but not by anti-HLA (A and B loci) antisera added to the cultures and by pretreatment of macrophages but not of T cells with anti-DRw antisera and complement. Macrophages pulsed for 18 hr with antigen and then washed were capable of triggering T-cell proliferation. Addition of anti-DRw but not anti-HLA (A and B loci) antisera during the pulse period inhibited the macrophages' ability to trigger T-cell proliferation. The data obtained indicate that human T cells recognize and proliferate in response to antigen presented by the macrophages in association with Ia-like antigens.

Antibody Formation↗
PubMed1979

Chlamydia trachomatis in women: antibody in cervical secretions as a possible indicator of genital infection.

One hundred eighty-five women college students were examined for genital infection with Chlamydia trachomatis. This organism was isolated from nine (5%) of the 185 women. Antibody was demonstrated in the genital secretions of 26 (14%) and in the serum of 70 (38%) of the women. None of the sexually inexperienced women was infected. Among those sexually experienced, the prevalence of isolation of C. trachomatis and of detection of local antibodies in cervical secretions and serum antibodies to C. trachomatis increased in relation to the number of life-time sexual partners. Local antibody appeared to be a more reliable indicator of infection with C. trachomatis than serum antibody in this college population.

Adolescent↗
PubMed1979

The treatment of locally advanced carcinoma of the colon and rectum by a surgical procedure and radiotherapy postoperatively.

Following resection of locally advanced carcinomas of the rectum and colon, 95 patients received moderate dose elective radiotherapy either to an inverted T field or the entire abdomen. In 27 instances, carcinomas invaded adjacent structures and were incompletely resected. Fifty-seven patients had tumors of the rectosigmoid and had either an abdominoperineal or an anterior resection. Thirty-five patients had a mean follow-up period of 26 months. Three of 35 carcinomas recurred locally, 26 of 35 patients are alive without disease. Thirty-eight patients had carcinomas of the colon and had either a partial or hemicolectomy. Thirty-one had a mean follow-up period of 24 months. Five of 31 carcinomas recurred locally. Seventeen of 31 patients are alive, without disease. Sixty-six of 95 patients have survived two years free of disease. One death occurred from radiation enteritis. Radiotherapy postoperatively for patients at a high risk of failure resulted in a low incidence of local recurrence.

Adult↗
PubMed1978

Anaerobic microflora of the vagina in children.

Vaginal cultures from 25 healthy girls from two months to 15 years of age were examined for aerobic, facultatively anaerobic, and obligately anaerobic bacteria. An average of 8.7 species (3.7 aerobic and facultatively anaerobic species; 5.3 obligately anaerobic species) were isolated from these cultures. Staphylococcus epidermidis (21), diphtheroids (20), bacteroides (19), peptococci (19), peptostreptococci (14), and Bacteroides melaninogenicus (14) were most prevalent organisms.

Adolescent↗
PubMed1978

Primary management of operable breast cancer by minimal surgery and radiotherapy.

109 cases of breast cancer were treated by tumorectomy and radiotherapy or radiotherapy alone. Almost 30% with small tumors (T1, T2) were considered inoperable for medical reasons and 70% refused mastectomy. Over the past five years the number of patients refusing mastectomy has definitely increased. 59 cases of surgically resectable cancers (T1, T2, T3, N0, N1) had a minimum followup of two years (average 4 years +/- 3 months). Absolute and determinate survivals NED were 65% and 86%. There were four local recurrences (8%). Secondary mastectomy could be performed on three. Microscopic involvement of the surgical margin by cancer did not alter the local control rate. The cosmetic results were good in 98%. Gross removal of the tumor followed by radiotherapy may be offered as an alternative to mastectomy in patients with operable breast cancer.

Adult↗
PubMed1978

Clinical and microbiological investigation of men with urethritis.

Of 377 men attending clinics for the treatment of sexually transmitted disease, 104 had gonococcal urethritis, 72 had definite nongonococcal urethritis, 53 had possible nongonococcal urethritis, and 123 had no urethritis. A purulent urethral discharge was noted in 78% and 14% of patients with gonococcal urethritis and definite nongonococcal urethritis, respectively (P less than 0.001). In contrast, 4% and 64% of men with gonococcal urethritis and definite nongonococcal urethritis, respectively, had a clear urethral discharge (P less than 0.001). Black men with urethritis were more likely to have gonococcal infection, whereas white men were more likely to have nongonococcal urethritis. Homosexual and bisexual white men with urethritis were more likely to have gonorrhea, whereas heterosexual white men with urethritis were more likely to have nongonococcal urethritis. Heterosexual men were more likely than homosexual men to be colonized with Ureaplasma urealyticum. There were no differences in the rates of colonization with Mycoplasma hominis among heterosexual and homosexual men.

Adolescent↗
PubMed1978

Isolation of Mycoplasma hominis from blood cultures in patients with postpartum fever.

Eight women with postpartum fever are presented in whom Mycoplasma hominis was isolated from cultures of their blood. Clinical disease consisted of a mild although often prolonged febrile illness, and all but one recovered without appropriate antimicrobial therapy. Five patients demonstrated elevated convalescent titers of mycoplasmacidal antibodies. The isolates of M. hominis were recovered from routine blood cultures in the diagnostic bacteriology laboratory using blind subcultures to blood agar plates. These cases lend support to the concept that endometritis with M. hominis is a cause of postpartum fever and suggest that these organisms may be recovered with increased frequency if minor changes in standard bacteriologic technique are introduced.

Bacteriological Techniques↗
PubMed1978

Microbiology of the vagina in children: normal and potentially pathogenic organisms.

Vaginal cultures from 100 healthy girls, 2 months to 15 years of age, were examined for the presence of normal and potentially pathogenic microorganisms. Corynebacterium vaginale, yeast species, and genital mycoplasmas were isolated from vaginal cultures from 13.5 %, 28%, and 28% of the girls examined, respectively. Colonization with these organisms was not associated with signs or symptoms of vaginitis. Neisseria gonorrhoeae was isolated from a 4-year-old with purulent vaginitis. Trichomonas vaginalis was recovered from two 13-year-olds, both of whom had an abnormal vaginal discharge. Vaginal antibody to Chlamydia trachomatis was found in two girls 4 and 13 years of age. In neither girl was the organism recovered from the vaginal culture. Chlamydia trachomatis was recovered from the vaginal culture of another 4-year-old who had no abnormal findings on examination. Cultures from 59 of the girls were examined for aerobic and facultatively anaerobic bacteria. Diphtheroids and Staphylococcus epidermidis were the most frequently isolated organisms. Lactobacilli were isolated most frequently from the older girls, whereas enteric organisms were isolated most frequently from the younger girls.

Adolescent↗