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H Jenkins

Publications and source records attributed to H Jenkins.

18 recordsLinked to original sources
PubMed1992

Breast augmentation: a risk factor for breast cancer?

BACKGROUND: A relation between breast augmentation and the subsequent risk of breast cancer has been postulated. Since an estimated 2 million women in the United States alone have received breast implants, even a small increase in the risk of breast cancer could have considerable public health consequences. METHODS: We performed a population-based nonconcurrent cohort-linkage study. All women in Alberta, Canada, who underwent cosmetic breast augmentation from 1973 through 1986 were included in the implant cohort (n = 11,676). This cohort was compared with the cohort of all women in Alberta in whom a first primary breast cancer was diagnosed (n = 13,557). The expected number of breast-cancer cases in the implant cohort was estimated by applying age-specific and calendar year--specific incidence rates of breast cancer (obtained from the Alberta Cancer Registry) to the implant cohort. Standardized incidence ratios were calculated by dividing the observed by the expected number of breast-cancer cases in the implant cohort. RESULTS: Forty-one patients with implants were subsequently found to have breast cancer. The expected number was 86.2. The standardized incidence ratio was thus 47.6 percent, significantly lower than expected (P less than 0.01). The average length of follow-up in the implant cohort was 10.2 years, and the average length of time from breast augmentation to the diagnosis of breast cancer was 7.5 years. CONCLUSIONS: Women who undergo breast augmentation with silicone implants have a lower risk of breast cancer than the general population. This finding suggests that these women are drawn from a population already at low risk and that the implants do not substantially increase the risk.

Adult↗
PubMed1992

Identification and characterization of a gene at D10S94 in the MEN2A region.

We have identified a candidate for the gene responsible for multiple endocrine neoplasia type 2A (MEN 2A) at D10S94 in proximal 10q11.2. An evolutionarily conserved sequence from D10S94 was used as a probe to isolate cDNAs corresponding to a gene that we have termed mcs94-1. The gene spans 11 kb and has an unmethylated CpG island at its 5' end. The mcs94-1 transcript is approximately 2.4 kb in length and is widely expressed. It encodes a putative 415-amino-acid polypeptide that is similar in sequence to nucleolin, an abundant nucleolar protein. Mcs94-1 was examined as a candidate for MEN2A through nucleotide sequence analysis of mcs94-1 exons from an MEN 2A chromosome and its wildtype homologue from an MEN 2A patient. The major portion of the expressed mcs94-1 sequence was examined. No differences in sequence were found between the two alleles.

Amino Acid Sequence↗
PubMed1991

Correlation between c-erbB-2 amplification and risk of recurrent disease in node-negative breast cancer.

Drawing upon the comprehensive population-based Northern Alberta Breast Cancer Registry containing 704 patients with histologically negative axillary lymph nodes who have been followed for 5-16 years, we have undertaken a retrospective case-control study to evaluate the utility of genomic amplification of specific protooncogenes [c-erbB-2 (nee HER-2/neu), c-erbA, c-myc, int-2, and hst-1] as predictive indicators of clinical outcome in node-negative disease. To this end, 115 women with node-negative breast cancer who had recurred at any time up to 16 years posttreatment (cases) were matched pairwise for appropriate clinicopathological variables (size of primary tumor, menopausal state, estrogen receptor status, anniversary year of treatment, and patient age) with a second group of 115 women (controls) selected from a cohort of 502 node-negative patients who had not relapsed during long-term follow-up. Tumor DNA extracted from archival formalin-fixed, paraffin-embedded tissue blocks were analyzed for protooncogene copy number by slot-blot hybridization. Taking a gene copy number of 3 as the cutoff, 27 of the 230 tumor samples examined contained from 3- to 22-fold elevation in c-erbB-2 genomic equivalents. Twenty-one of the 27 tumors amplified for c-erbB-2 were derived from cases and 6 from controls, signifying that 18% of the node-negative patients who had relapsed harbored excessive copies of the protooncogene in their malignant tissue compared to only 5% for the patients who had remained in remission. Accordingly, the occurrence of amplification of c-erbB-2 proved to be a statistically significant predictor of poor prognosis, especially disease-free interval (P = 0.006). Moreover, this genetic alteration appeared to be independent of and to have greater predictive power than most commonly used prognostic factors. Our findings also indicated that as a clinical test, measurement of c-erbB-2 amplification suffers from low sensitivity; however, when greater than 6 gene copies are present, the test has a positive predictive value for recurrence of 70%. Concurrent analysis of tumor DNA blots with probes for the other four protooncogenes examined revealed that their amplification, which others have reported to arise often, especially in node-positive disease, was seldom found even in our high-risk case group (2-3%). In short, our data strongly suggest that amplification of c-erbB-2 may contribute to the pathogenesis of some forms of node-negative breast cancer and thus may serve as a useful genetic marker to identify a subset of high-risk patients.

Adult↗
PubMed1991

Optical isomers of rocastine and close analogues: synthesis and H1 antihistaminic activity of its enantiomers and their structural relationship to the classical antihistamines.

The enantiomers of 2-[2-(dimethylamino)ethyl]-3,4-dihydro-4-methylpyrido[3,2-f]-1,4- oxazapine-5(2H)-thione (rocastine) and two of its more potent analogues were prepared with an enantiomeric purity of greater than 99.9%. The antihistaminic activity of these compounds was assessed by their ability to block histamine-induced lethality in guinea pigs and to inhibit [3H]mepyramine binding to guinea pig cortex. In this series, compounds having the R configuration at the 2-position are at least 300 times more potent than the S isomers. Conformational analysis and molecular modeling suggest that rocastine can adopt a conformation in which the pyridine ring, ether oxygen, and protonated amine functions are positioned similarly to the corresponding elements of the probable binding conformers of some of the more classical antihistamines. This conformation, boatlike in the oxazepine ring with the side chain quasi-equatorial and folded back toward the ring, is the likely binding conformer at the histamine H1 receptor, and the available structure-activity relationship data is consistent with this interpretation.

Animals↗
PubMed1989

Family history of ovarian cancer patients: a case-control study.

In order to obtain a more correct estimate of cancer incidence in relatives of cases with ovarian cancer and relatives of age-matched controls, information was obtained on family size, date of birth and death, and cancer history. The average total number of first degree (parents and siblings) and some second degree (uncles and aunts) relatives for cases (15.03) and controls (15.22) is very similar. Of all the relatives 33% were Alberta residents or decreased in Alberta after 1966 so they could be checked in the population based Alberta Cancer Registry. There was a 14% level of error in the information provided, 9% for first degree relatives and 25% for uncles and aunts. The errors included missed malignancies, benign lesions quoted as malignancies, incorrect cancer site and inaccurate dates of birth, diagnosis or death. Results were compared between the relatives of cases and controls using either all relatives or only Alberta residents. For the Alberta residents, expected numbers of malignancies were calculated by age/sex-specific person/years and age/sex-specific incidence rates. The number of relatives with ovarian cancer is significantly higher in cases than in controls in both data sets, but shows a limited relative risk of 2.61 (95% confidence limits 1.12-1.59). Clustering of cases is exceptional, only one patient out of 197 had two relatives with ovarian cancer and this was a case with a larger than average total number of relatives. In conclusion, although there is a significantly higher incidence of ovarian cancer in the family history of cases than of controls, it is not very common and only nine out of 197 cases (4.6%) presented with such background.

Adolescent↗
PubMed1989

Speech tracking in the evaluation of a multichannel cochlear prosthesis.

Individual speech tracking data were analyzed in relation to other variables in 11 adult users of the Nucleus multichannel cochlear implant. Patients were categorized according to postoperative speech tracking results. The resultant groups could also be differentiated on the basis of postoperative MAC scores, surgeon's rating of overall success, and duration of deafness before implantation. The speech tracking paradigm appears to be a useful technique for the evaluation of performance with a cochlear prosthesis.

Adult↗
PubMed1988

Risk factors of ovarian cancer of epithelial origin: a case control study.

Possible risk factors for ovarian cancer of epithelial origin were tested in a case control study consisting of personal interviews with 200 patients and 211 age-matched controls. Some lifestyle factors such as urban versus rural residence show differences between patients and controls, but this may be due to a low response rate in the randomly selected control group. Confirmation of the potentially protective effect of oral contraceptives will require several more years of use, as most of the women who are now reaching the age of highest incidence of ovarian cancer of epithelial origin had several children prior to the availability of oral contraceptives. The only consistent risk factor when a discriminant analysis is carried out is a low number of pregnancies.

Adult↗
PubMed1987

Suprathreshold abnormalities of the stapedius reflex in acoustic tumor: a series of case reports.

Suprathreshold morphologic characteristics of the acoustic stapedius reflex are reported for five subjects with acoustic tumor. Results support the hypothesis that changes in suprathreshold morphology may be more sensitive to acoustic tumor than conventional reflex threshold and decay measures. Both the afferent relative amplitude index (AI) and measures of sequential variability of individual waveforms appear to be especially promising.

Adult↗
PubMed1985

Efficacy of a simplified lower gastrointestinal flexible endoscope cleaning method.

Published guidelines from the Center for Disease Control (CDC) "strongly recommended" gas sterilization or 30 minutes of high-level disinfection with either 2 percent glutaraldehyde or 6 percent hydrogen peroxide following each flexible endoscope cleansing for proper care. The guidelines were proposed on the basis of previous CDC studies performed on glutaraldehyde disinfection of respiratory equipment. A prospective study was performed culturing flexible endoscopes following cannulation of the lower gastrointestinal tract and cleansing. A uniform endoscope cleansing method without gas sterilization or high-level disinfection was used between patients. Thirty aerobic and 30 anaerobic RODAC bacterial culturings revealed no obligate anaerobic organism growth and only sparse, aerobic, environmental and cutaneous organism growth. There were no instances of documented or suspected postendoscopy infectious complications. Our results indicate that high-level disinfection and gas sterilization of flexible endoscopes are not necessary to prevent bacterial disease transmission from patient to patient.

Bacteria, Aerobic↗
PubMed1979

Diarrhea and medullary carcinoma of the thyroid.

The authors present the case of a 34-year-old woman with disseminated medullary carcinoma of the thyroid to emphasize the value of calcitonin assay in the diagnosis of this condition despite the absence of a thyroid mass and negative scans. An increased concentration of serum carcino-embryonic antigen was confirmed. The diarrhea associated with the disease did not respond to indomethacin in this patient suggesting that in some cases of medullary carcinoma diarrhea is not due to excessive production of prostaglandins.

Adult↗
PubMedDate not supplied

A test protocol for large groups.

An effective and time-saving test protocol is presented for nurse educators who must cope with evaluating the progress of large numbers of students. Processes for the administration of tests to large groups are explained, and advantages and disadvantages are explored. The protocol may be used successfully with the expectation of greater ease and flexibility for nurse educators and reduced anxiety and frustration for students.

Education, Nursing↗
PubMedDate not supplied

Stapedius reflex to electrical stimulation in a patient with a cochlear implant.

In a patient with a multichannel cochlear implant, it was possible to demonstrate stapedius reflex contraction to intracochlear electrical stimulation. Using a standard immittance measurement technique, characteristics of the electrically evoked reflex were compared to analogous characteristics of the acoustically evoked reflex. Latency-intensity functions were similar for the two modes of excitation, but reflex waveform morphology and amplitude growth functions were different.

Acoustic Stimulation↗