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Biomedical subjects

J H Smith

Publications and source records attributed to J H Smith.

At least 91 records · Page 5Linked to original sources
PubMed1992

Nd:YAG laser endometrial ablation: histological aspects of uterine healing.

Laser ablation of the endometrium performed under hysteroscopic control is a novel procedure for the conservative management of menorrhagia in cases of dysfunctional uterine bleeding. The effect this has on the uterine cavity and the mechanism of reepithelialisation and endometrial regeneration have been examined by means of histological examination of endometrial biopsies and four hysterectomy specimens obtained for various indications at varying time intervals after laser endometrial ablation. During the first 3 months, fragments of necrotic and granulation tissue are found surrounded by a limited polymorph response. By 3 months, the uterine cavity appears to be completely reepithelialised. After 6 months, areas of normal-appearing endometrium may persist, but in other areas there is an attenuated cuboidal surface epithelium closely applied, to the underlying myometrium. Stromal fibrosis reminiscent of Asherman syndrome is also apparent.

Adult↗
PubMed1991

The decedent affairs office. A unique centralized service.

The success of a centralized decedent affairs office depends on support by clinicians, the department chairman, and hospital administration. The benefits to the institution include improved public relations with a decedent's family, compliance with state and federal laws, increased organ donations, and better risk management programs. The only drawback of establishing such an office is the additional personnel necessary for 24-hour coverage. However, modifications in the functions and staffing levels of a decedent affairs office may be made, depending on the needs of individual institutions. We hypothesized that consent for autopsy would be easier to obtain and cause less emotional upheaval for family members if procedures were well established and specially trained individuals were involved in the process. With these ideas in mind, we established a decedent affairs office at The University of Texas Medical Branch in 1984.

Autopsy↗
PubMed1991

Cytogenetic studies of amniotic fluid taken before the 15th week of pregnancy for earlier prenatal diagnosis: a report of 114 consecutive cases.

One hundred and fourteen samples of amniotic fluid taken before 15 weeks of gestation were cultured for cytogenetic studies. The results of culturing these early amniotic fluid (EAF) samples were compared with the results of culturing 114 standard amniotic fluid (SAF) samples taken after 15 weeks of gestation matched for maternal age and received in the laboratory within the same week. Cell culture was successful in all 114 of the EAF samples and in 111 SAF samples. There was no significant difference in the days to harvesting and days to reporting in the two groups. Three samples of SAF failed to grow and two EAF samples produced tetraploid karyotypes, so that in these five cases amniocentesis had to be repeated. These problems were attributed to toxicity of a fungicide used in the culture medium. Pseudo-mosaicism was noted in two EAF samples and one SAF sample; and maternal cell contamination was noted in one EAF and one SAF sample. Thus, culturing and karyotyping cells harvested from EAF and SAF are similar, indicating that EAF samples from 12-14-week pregnancies could be used for prenatal diagnosis.

Adult↗
PubMed1991

Early amniocentesis at 11-14 weeks' gestation for the diagnosis of fetal chromosomal abnormality--a clinical evaluation.

Early amniocentesis between 11 and 14 weeks' gestation was offered to 110 women at risk of a chromosomally abnormal fetus due to maternal age. Four were found to be unsuitable for the procedure, and 106 early amniocenteses were performed. In 102 cases, clear amniotic fluid was obtained with a single tap. There were two dry taps and two bloodstained taps; sampling was repeated in three of these cases before 15 weeks. In the fourth case, placental biopsy was performed at 16 weeks. Thus, we were able to obtain a satisfactory sample in all but three cases (2.8 per cent). Karyotyping of cells harvested from the early amniotic fluid samples was successful in all the 105 cases. Cell culture from the initial samples revealed a normal karyotype in 99 cases, two balanced translocations, two tetraploid karyotypes, and two cases of pseudomosaicism. Of the 105 pregnancies successfully sampled, there have been two losses to date (1.8 per cent). Two further patients presented with premature rupture of membranes, both pregnancies having successful outcomes. Sixty-two babies have delivered to date, with four congenital anomalies. There were no respiratory problems. Twenty-nine pregnancies are continuing without known complications, and details are not yet available on the remaining 12. The results indicate that early amniocentesis may replace the traditional test at 15-17 weeks.

Adult↗
PubMed1991

Is the grading of breast carcinomas affected by a delay in fixation?

The effect of delay in fixation on the modified Bloom and Richardson grade of eight breast carcinomas was investigated. Topologically shuffled samples of each tumour were immersed in fixative at times of 0.5, 2, 4, 6, 18 and 24 h after surgical removal. The grade of each tumour was assessed at delays of 0.5 and 6 h. The tubule formation and nuclear pleomorphism components of the grade showed no change with a delay in fixation of 6 h. The number of mitotic figures declined by a mean of 53% over the same period and this resulted in a decrease in the histological grade of one of the tumours. The implications of these findings for the handling of breast specimens in a diagnostic histopathological laboratory are discussed.

Breast Neoplasms↗
PubMed1991

Liposarcoma of the esophagus.

Liposarcoma is one of the most common soft tissue sarcomas found in adults, yet it rarely develops in the alimentary tract. This report describes the pathological features and management of a liposarcoma of the esophagus.

Aged↗
PubMed1991

The incidence of WESa in 3,072 donors in the United States.

The rare red cell antigen, WES(a), which is controlled by an autosomal dominant gene, was reported by Sistonen et al.(1) to have an incidence in the Finnish population of 0.56 percent. A study was undertaken to determine the incidence of the WES(a) antigen within the United States. A total of 3,072 donor samples were obtained for testing from eight different geographical locations. It was determined that the incidence of the WES(a) antigen in the white donor population tested was 2 per 1,610 or 0.12 percent and in the black donor population tested, 7 per 1,460 or 0.48 percent. In the random population the incidence would he 0.29 percent.

Journal Article↗
PubMed1991

Altered patterns of gap junction distribution in ischemic heart disease. An immunohistochemical study of human myocardium using laser scanning confocal microscopy.

Arrhythmias are a common and potentially life-threatening complication of myocardial ischemia and infarction in humans. The structural pathways for the rapid intercellular conduction of the electrical impulse that stimulates coordinated contraction in the myocardium are formed by the gap junctions situated at intercalated disks. By raising antibodies to cardiac gap-junctional protein, and using these antibodies in an immunohistochemical procedure in combination with the technique of laser scanning confocal microscopy, we have succeeded in localizing gap junctions, with a clarity not previously possible, through thick volumes of human myocardial tissue. To explore the structural basis for ischemia and infarction-related arrhythmogenesis, antibody labeling and laser scanning confocal microscopy were applied to study the organization, distribution, and other characteristics of gap junctions in the explanted hearts of patients undergoing cardiac transplantation for advanced ischemic heart disease. In areas of myocardium free from histologically detectable structural damage, there was no significant difference in the size of distribution of labeled gap junctions, or in their number per intercalated disk, between left ventricular tissue (in which functional impairment was severe) and right ventricular tissue (in which functional impairment was minimal). However, in myocytes at the border of healed infarcts--zones to which the slow conduction responsible for reentry arrhythmias has been localized--the organization of gap junctions was markedly disordered; instead of being aggregated into discrete intercalated disks, gap-junctional immunostaining was spread extensively over myocyte surfaces. Some infarct zones were bridged by continuous strands of myocytes, coupled to one another by gap junctions, thereby linking healthy myocardium on either side. At their thinnest, these bridges were in some instances no wider than a single attenuated myocyte. The conclusions are 1) a widespread, generalized derangement of gap junction organization does not appear to underlie functional impairment in the ischemic heart, 2) a disorderly arrangement typifies gap junctions in myocytes of the infarct border zone, and this may contribute to alterations in conduction that are capable of precipitating reentry arrhythmias, and 3) delicate chains of myocytes traverse some healed infarcts, apparently forming electrically coupled bridges across what would otherwise constitute blocked zones. The weakest link in this chain can be a single, degenerating myocyte; avoidance of arrhythmia may therefore depend on the continued survival of this single cell.

Antibodies↗
PubMed1991

In vitro studies of uterine electrosurgery.

This study investigated electrosurgical techniques in vitro with emphasis on the tissue effects and heat transfer through full-thickness blocks of excised uterine tissue. Uterine morphometry was also examined. The 7-mm cutting resection loop was associated with a surrounding zone of thermal necrosis between 1.07-1.40 mm. There was no variation in this zone when power was altered, but a statistically significant increase was demonstrated with duration of exposure. A depth of destruction of 3.24-3.49 mm was possible with the desiccating coagulation technique, but fulguration achieved a depth of only 1.70-1.78 mm. A greater tissue effect was demonstrated as time intervals were increased. There was a fall-off in the measured rise in temperature with distance; at 4 mm from the active electrode, a mean rise of 4.5C was noted, whereas at 12 mm the mean temperature rise was 3.9C. There was a statistically significant increase in the mean temperature as power output in the cutting mode was increased. At 180 W, the mean rise was 2.0C but by 260 W, it was 3.9C. When the time interval was increased and the power held constant (220 W), a mean rise of 2.5C was recorded at 1 second, compared with 4.6C at 5 seconds, achieving statistical significance. Power increments in the coagulating mode did not alter the temperature profile, but increasing duration of exposure was associated with a significant rise in mean temperature (from 0.8 to 4.6C). A stepwise increase in the baseline temperature was noted with repetitive insults. The mean myometrial thickness of the anterior and posterior walls measured 1.8 and 1.9 cm, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Subchronic toxicity evaluation of tridecyl acetate in rats.

Tridecyl acetate was administered to male and female Sprague-Dawley rats by oral gavage, 5 days per week for 13 weeks (90 days). Treated rats received daily doses of 0.1, 0.5, or 1.0 g/kg/day and control rats received distilled water at a dose of 1.0 g/kg/day. After 45 days an interim termination was made to evaluate potential hematologic or hepatic effects of tridecyl acetate. Blood samples were collected for routine hematology and serum chemistry determinations and liver tissue was obtained for histological examination. After 90 days all animals were necropsied. Blood samples were obtained and selected organs were weighed and prepared for histological examination. Treatment-related effects observed in the mid and high dose groups consisted of (1) increased liver weights and/or liver/body weight ratios in both sexes at the interim and 13 week termination, (2) increased kidney weights and/or kidney/body weight ratios in both sexes at the terminal necropsy, (3) histopathologic evidence of hydrocarbon nephropathy in males, and (4) a slight decrease in serum glucose levels in male rats at both the interim and terminal necropsies. The increases in liver weight are believed to be a normal physiological response to a chemical challenge. The nephropathy produced by tridecyl acetate is characteristic of that produced by a diverse group of hydrocarbons and, to date, appears to be limited to male rats. The low dose in this study was a no observed effect level. These results are indicative of an overall low degree of systemic toxicity following subchronic oral administration of tridecyl acetate at doses up to 1 g/kg body weight.

Acetates↗
PubMed1990

Plasma LH, FSH, testosterone, prolactin and androstenedione in male white-tailed deer after ACTH and dexamethasone administration.

1. In order to investigate the role of the adrenocortical system in the regulation of plasma levels of reproductive hormones, adult male white-tailed deer (five intact and one castrated) from a captive herd were sedated with xylazine and ketamine and then challenged with various doses of ACTH with and without dexamethasone (DX) pretreatment. 2. Plasma levels of LH, testosterone (T), FSH, prolactin (PRL) and androstenedione (A) were determined by RIA in serial samples taken from the jugular vein. 3. An increase of A levels detected after ACTH in both intact and castrated deer indicated stimulation of secretion of adrenal androgens by ACTH. 4. No effect on FSH and PRL levels was observed in either group. 5. A significant decline of LH and T observed in various treatments could not be attributed to ACTH or DX administration. It is speculated that the decrease may be caused by anaesthetics which alleviate the stress induced in deer by the pre-immobilization activities.

Adrenal Cortex↗