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Biomedical subjects

L Hanson

Publications and source records attributed to L Hanson.

At least 19 recordsLinked to original sources
PubMed1995

Oral contraceptives and breast cancer risk among younger women.

BACKGROUND: Several studies have suggested a link between oral contraceptive use and breast cancer in younger women, but it is possible that chance or bias, including selective screening of contraceptive users, contributed to the putative association. PURPOSE: Given that oral contraceptives were first marketed in the United States in the early 1960s, we conducted a population-based case-control study to examine the relationship between use of oral contraceptives and breast cancer among women in a recently assembled cohort, focusing on women younger than 45 years of age who had the opportunity for exposure throughout their entire reproductive years. METHODS: Breast cancer patients and healthy control subjects were identified, the latter group by random-digit dialing, in Atlanta, Ga., Seattle/Puget Sound, Wash., and central New Jersey. In Seattle and New Jersey, the study was confined to women 20 through 44 years of age; in Atlanta the age range was extended through 54 years. Patients included women with in situ or invasive breast cancer newly diagnosed during the period of May 1, 1990, through December 31, 1992. In-person interviews were completed by 2203 (86.4%) of 2551 eligible patients and 2009 (78.1%) of 2571 eligible control subjects. Analyses focused on women younger than 45 years of age (1648 patients and 1505 control subjects) to maximize opportunities for extended exposure. Logistic regression analyses were used to obtain maximum likelihood estimates of relative risks (RRs) and their 95% confidence intervals (CIs). RESULTS: Among women younger than 45 years, oral contraceptive use for 6 months or longer was associated with an RR for breast cancer of 1.3 (95% CI = 1.1-1.5). Risks were enhanced for breast cancers occurring prior to age 35 years (RR = 1.7; 95% CI = 1.2-2.6), with the RR rising to 2.2 (95% CI = 1.2-4.1) for users of 10 or more years. The RR for breast cancer for those whose oral contraceptive use began early (before age 18 years) and continued long-term (> 10 years) was even higher (RR = 3.1; 95% CI = 1.4-6.7). The RRs observed for those who used oral contraceptives within 5 years of cancer diagnosis were higher than for those who had not, with the effect most marked for women younger than age 35 years (RR = 2.0; 95% CI = 1.3-3.1). Oral contraceptive associations were also strongest for cancers diagnosed at advanced stages. Evaluation of screening histories and methods of diagnosis failed to support the speculation that associations could be due to selective screening. Among women 45 years of age and older, no associations of risk with use of oral contraceptives were noted. CONCLUSIONS: The relationship between oral contraceptives and breast cancer in young women appears to have a biologic basis rather than to be an artifact or the result of bias.

Adult↗
PubMed1992

Is trichomoniasis often associated with bacterial vaginosis in pregnant adolescents?

The same criteria for identifying bacterial vaginosis are often present in women with trichomoniasis. These criteria include elevated vaginal pH, vaginal odor, homogeneous discharge, increased anaerobic bacteriologic vaginal flora, and elevated levels of bacterial enzymes. Clinically mixed vaginal infections occur, and because the treatment for these two conditions can be different, it is important to distinguish between them. Trichomoniasis can interfere with a Gram stain diagnosis or the proline aminopeptidase test for bacterial vaginosis. Clue cells are not generally found in women with Trichomonas vaginalis, but when present, they strongly indicate the concomitant presence of bacterial vaginosis.

Adolescent↗
PubMed1992

Invasive cervical cancer following cryotherapy for cervical intraepithelial neoplasia or human papillomavirus infection.

OBJECTIVE: To determine the following: 1) the causes for the failure of cervical cryotherapy to prevent cervical cancer, and 2) whether cervical cryotherapy is associated with the development of cervical adenocarcinoma rather than squamous carcinoma. METHODS: We reviewed the medical charts of 327 women with cervical cancer. One hundred forty-seven for whom pertinent history was missing were contacted by telephone or at clinic visits. History obtained verbally was confirmed by outside medical records. Cervical biopsies (N = 16) and endocervical curettages (ECCs) (N = 15) performed before cryotherapy and biopsies at the diagnosis of cancer (N = 21) were reviewed. RESULTS: Twenty-one women with cervical cancer had a history of cryotherapy for cervical intraepithelial neoplasia (CIN) or human papillomavirus infection (HPV). The interval between cryotherapy and cancer was more than 2 years in 19 and more than 5 years in ten. Several categories of pre-treatment errors were identified. Evaluation before cryotherapy was appropriate in only nine cases. Interpretive errors were noted in three of 16 cervical biopsies and ten of 15 ECCs. After cryotherapy, 12% of women had appropriate follow-up. Of the invasive cancers that developed, 24% in the cryotherapy group and 21% in the non-cryotherapy group were adenocarcinomas. CONCLUSIONS: Careful evaluation before cryotherapy, accurate pathology reports, and consistent long-term follow-up are necessary if cryotherapy is to be used to treat CIN or HPV. We found no evidence that cryotherapy is associated with the development of cervical adenocarcinoma.

Adenocarcinoma↗
PubMed1991

Efficacy and safety of alprazolam, imipramine and placebo in treating panic disorder. A Scandinavian multicenter study.

As part of the cross-national collaborative panic study, a double-blind comparison of alprazolam, imipramine and placebo was performed in Scandinavian outpatients with panic disorder according to DSM-III; 41 patients were randomly allocated to each drug. Doses were increased for 3 weeks to an average of about 6 mg alprazolam, 150 mg imipramine and a corresponding number of placebo capsules, which were then given for 5 weeks. No more than supportive psychotherapy was given. Key symptoms were rated weekly. The drugs were tapered for 4 or 8 weeks and the patients were followed up for 6 months. Compliance at 3 weeks was 95% for alprazolam, 83% for imipramine and 88% for placebo; at 8 weeks 95% for alprazolam, 73% for imipramine and 46% for placebo. At 3 weeks plasma determination showed that the proportion taking diazepam outside the protocol was 0% for alprazolam, 19% for imipramine and 31% for placebo; at 8 weeks the corresponding proportions were 3%, 11% and 16%. Intention-to-treat analysis showed that freedom from panic attacks was obtained for 68% with alprazolam, 61% with imipramine and 34% with placebo. Alprazolam was more effective than imipramine and placebo on anticipatory anxiety and phobic symptoms. Globally rated by physicians and patients, about 60% had complete remission with alprazolam and imipramine and 30% on placebo. At least partial remission was obtained in about 85% with alprazolam, 70% with imipramine and 40% with placebo. Alprazolam had a more rapid onset of action than imipramine on all symptoms. Side effects were generally mild, with a preponderance of drowsiness for alprazolam and anticholinergic effects for imipramine. Tapering was uneventful without significant discontinuation phenomena. During taper and follow-up, several patients in remission relapsed, leaving approximately 30% patients in complete remission in all groups. To obtain more stable improvement, either long-term drug treatment or combinations of drug treatment and psychotherapy should be evaluated.

Adolescent↗
PubMed1989

Melanocytic nevi in schoolchildren in Queensland.

In a group of 211 schoolchildren in Queensland less than 12 years of age, the mean total melanocytic nevus (mole) count was 28 (median 19), and the mean count for raised nevi was 11 (median 8). The upper aspect of the back and chest were the most commonly affected sites, with the neck being the third. Boys had significantly (p less than 0.01) more melanocytic nevi than girls, and prevalence was highest in children with pale skin and light-colored hair. Nonwhite heritage had a protective effect independent of pigmentary characteristics. Total numbers of nevi on children also were related to maternal tendency to large numbers of moles and to family history of melanoma. The only significant association observed for the presence of large (greater than 5 mm) nevi on children was a family history of melanoma. The children studied come from a general population that has the highest known risk of melanoma. In Australia they have been shown to have the highest prevalence of nevi ever reported in the prepubertal age group. These descriptive data, together with the specific pigmentary and family associations described, extend the known links between benign nevi and malignant melanoma.

Child↗
PubMed1988

Severed intestine in channel catfish.

Six cases of severed intestines in farm-raised channel catfish were examined at fish disease diagnostic laboratories in Mississippi and Alabama. This condition has not been reported previously in fish. Affected fish had a 4-7-cm-long intestinal section (hyperemic where it was severed) attached to the stomach. The remainder of the intestine was completely missing in all six cases except for a 1-1.5-cm section of intestine prolapsed from the anus in fish from three of the cases. Ischemia, autodigestion following intussusception, or intestinal epithelium degradation are suggested as possible etiologies for this condition.

Animals↗
PubMed1986

Identification of an activated c-Ki-ras oncogene in rat liver tumors induced by aflatoxin B1.

Weanling male Fischer rats were administered 40 intraperitoneal injections of aflatoxin B1 (25 micrograms per animal per day) over a 2-month period. This chronic dosing regimen resulted in the sequential formation of hyperplastic foci, preneoplastic nodules, and hepatocellular carcinomas in all of the animals treated. The presence of transforming DNA sequences was detected by formation of anchorage-independent foci after transfection of tumor-derived DNA in NIH 3T3 mouse fibroblasts. Transfection of genomic DNA isolated from individual tumors from eight animals resulted in specific transforming activities ranging from 0.05 to 0.2 foci per micrograms of DNA. Primary transfectant DNAs were analyzed by Southern blot hybridization with DNA probes homologous to c-Ha-ras, c-Ki-ras, and N-ras oncogenes. A highly amplified c-Ki-ras oncogene of rat origin was detected in transformants derived from tumors in two of the eight animals tested. There was no evidence to suggest the presence of c-Ha-ras or N-ras sequences in any of the transformants. Analysis of primary liver tumor DNA showed no Ki-ras DNA amplification when compared to control liver DNA samples. Increased levels of c-Ki-ras p21 proteins were detected in 3T3 transformants containing activated rat c-Ki-ras genes. The presence of c-Ki-ras sequences of rat origin capable of inducing transformed foci can be taken as evidence that the c-Ki-ras gene has been activated in the primary liver tumors.

Aflatoxin B1↗
PubMed1984

A non-supervised training program for Carkhuff's discrimination and communication skills and its effects upon the reactions of others during brief interactions.

Used Carkhuff's Indices of Communication and Discrimination along with other measures to assess the level of communication and discrimination skills at various stages of communication training. Ss were 14 male and 9 female students in a psychology of adjustment class. Results indicated that: (a) treatment and control groups did not differ in communication skills before they went through training; (b) the treatment group offered higher levels of communication skill after it had completed training than did the control group before it began training; (c) the control group offered levels of communication skill equal to those of the treatment group once the control group also had completed training. A similar pattern was found for discrimination skill. The effects of training cannot be dismissed as paper-and-pencil artifacts because others who were ignorant of the growth conditions concept reacted differently in brief unstructured interactions to those who had completed training.

Adult↗
PubMed1982

Antibody-dependent cell-mediated cytotoxicity against Escherichia coli O antigens.

Antibodies against Escherichia coli O antigen from rabbits immunized with formalin-killed bacteria were tested for cytotoxic capacity in an antibody-dependent cell-mediated cytotoxicity (ADCC) assay with human lymphocytes as effector cells and autologous papainized erythrocytes coated with O antigen as target cells. The cytotoxic titres were compared with the titres obtained with three methods of antibody quantitation. It was found that ADCC recorded antibodies with similar sensitivity as the enzyme-linked immunosorbent assay (ELISA) for IgG, but was much more sensitive than the ammonium sulphate precipitation (ASP) and indirect haemagglutination (IHA) using beta-mercaptoethanol reduced sera. The ADCC titres were found to correlate very well with the titres obtained with ASP, ELISA and IHA for IgG but not for IgM, which is in accordance with a previous notion that ADCC is primarily mediated via IgG antibodies. ADCC should be considered as a possible immunopathologic mechanism in renal parenchymal damage in connection with urinary tract infections.

Animals↗