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Biomedical subjects

D L Morris

Publications and source records attributed to D L Morris.

At least 271 records · Page 15Linked to original sources

Suckling inhibits release of luteinizing hormone-releasing hormone from the bovine median eminence following ovariectomy.

The effect of suckling on depletion of hypothalamic LHRH from the median eminence (ME) following ovariectomy (OVX) was determined in cattle. Multiparous, postpartum Holstein cows were assigned randomly to three groups: intact, nonsuckled (INT, n = 4); ovariectomized (3 to 5 d after parturition), nonsuckled (OVX, n = 4); and ovariectomized (3 to 5 d after parturition) and suckled by three calves (OVX-S, n = 5). Blood samples were collected at three periods (1 to 7 d before parturition and 3 to 5 d and 31 to 37 d after parturition) to determine plasma LH concentration. At 31 to 37 d after parturition, all cows were slaughtered and each ME was collected and mid-sagitally sectioned. The left half of each ME was used to determine content and concentration of LHRH. Concentrations of LH and LHRH were determined by RIA. Plasma LH concentration was similar among the three groups at 1 to 7 d before parturition and 3 to 5 d after parturition; however, at 31 to 37 d after parturition, OVX cows had a greater (P less than .05) concentration of LH (2.25 +/- .64 ng/ml) than either INT (.47 +/- .10 ng/ml) or OVX-S (.92 +/- .14 ng/ml) cows. Content of LHRH in the ME of INT (80.12 +/- 15.0 ng) and OVX-S 109.8 +/- 16.4 ng) cows was similar but was greater (P less than .05) than that in OVX cows (48.95 +/- 5.9 ng).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

A study on the effects of estradiol and estramustine on gastrointestinal cell lines.

We have studied the effect of estradiol and the combined estradiol/nitrogen mustard compound estramustine on cell lines derived from human gastric and colorectal cancers. Significant stimulation of the two gastric and two fo the colorectal cell lines occurred at physiological concentrations of estradiol. Estramustine showed an inhibitory effect in all of the cell lines at 10 micrograms/l, and a direct dose-dependent inhibition was seen in two of the cell lines. Each of the cell lines was immunohistologically stained using the estrogen-receptor-related protein ERD5, and all of the cell lines except one were positive for this protein. The inhibitory effect of estramustine was lost with increasing concentrations of estradiol, suggesting that the effects of estramustine may be linked to estrogen receptors. We conclude that reduction of circulating levels of estradiol, or treatment with estramustine may have a beneficial effect in the palliation of gastrointestinal malignancy.

Cell Division↗

Initial table treatment of decompression sickness and arterial gas embolism.

This descriptive, nonrandomized, multicenter-based study compares the treatment outcomes of two major categories of recompression treatment tables for recreational sport SCUBA divers suffering from decompression sickness and/or arterial gas embolism. Stratified and logistic regression analyses were used to compare the enhanced tables, which use pressures of 165 fsw (feet of salt water) or 60 fsw with extended recompression time, to the regular tables, which use pressures of 60 fsw or less without extended recompression time. A total of 113 cases were treated with enhanced tables, 54 being successes. A total of 214 cases were treated with regular tables, 135 being successes. The final logistic statistical model after adjusting for confounding factors found a significant improvement in successful treatment outcomes for divers treated with tables that use pressures of 60 fsw or less without extended recompression time (OR = 0.47, 95% CI = 0.28-0.78).

Adult↗

A pilot randomized control trial of proglumide (a gastrin receptor antagonist) in advanced colorectal cancer.

Forty-one patients with advanced colorectal cancer were entered into a randomized controlled trial of treatment with proglumide--a gastrin receptor antagonist. There was no difference in survival between the treated and the untreated groups of patients, although there was a trend towards increased survival in those treated patients with hepatic metastases alone. Proglumide does not cause regression in advanced colorectal cancer but larger studies would be required to detect an effect on tumour growth.

Adenocarcinoma↗

Evaluation of blood flow in human rectal tumours using a laser Doppler flowmeter.

A TSI laser Doppler flowmeter was used via a rigid sigmoidoscope in 20 consecutive patients with rectal carcinoma. Blood flow and velocity was evaluated at the tumour centre, tumour edge and adjacent normal mucosa; blood flow in the centre of the tumour was significantly higher than in normal mucosa (P = 0.05) and the tumour edge (P = 0.037). Two patients with ulcerated lesions had much lower blood flow in the centre of the ulcerative lesion.

Blood Flow Velocity↗

The effect of tamoxifen and estrogen receptor status on survival in gastric carcinoma.

One hundred patients were entered in a randomized, controlled study of adjuvant tamoxifen therapy in gastric carcinoma. Estrogen receptor status was established by an immunohistologic method (ERD5) and 55.8% of the tumors were positive. Tamoxifen had no overall effect on survival, but there was a significant decrease in the survival time of the patients with ERD5-positive tumors. Estrogen receptor status (by the ERD5 method) is an independent prognostic factor in gastric cancer. Tamoxifen therapy does not prolong survival, and new therapeutic strategies require investigation.

Clinical Trials as Topic↗

The effect of sex hormones and tamoxifen on the growth of human gastric and colorectal cancer cell lines.

The authors studied the effect of serial concentrations of estradiol, 4-hydroxytamoxifen with estradiol, and 5-dihydrotestosterone on cell lines derived from human gastric and colorectal cancers. Significant stimulation of the gastric and 2 colorectal cell lines occurred at physiologic concentrations of estradiol. Addition of the active metabolite of the estrogen-receptor blocker/partial-agonist 4-hydroxytamoxifen had a stimulating effect on the growth rate of the gastric cell lines. The androgen, 5-dihydrotestosterone, had a modest inhibitory effect on the two gastric cell lines and two of the colorectal cell lines, and a stimulating effect on two further cell lines.

Cell Line↗

The in vitro growth response of primary human colorectal and gastric cancer cells to gastrin.

A series of 31 colorectal and 13 gastric primary human tumours were screened for their growth response to human gastrin-17 in vitro, as assessed by 75Se-seleno-methionine incorporation. Fifty-five percent of colorectal and 69% of gastric tumours showed a significant trophic response to the hormone. The responses were achieved at physiological gastrin concentrations (post-prandial circulating gastrin levels) in 35% of colorectal and 55% of gastric tumours. Lymphocytes from tumour-associated lymph nodes showed no response to the hormone and "normal" mucosal cells (obtained from the resection margin of the surgical specimen) showed lower mean levels of 75Se-seleno-methionine uptake (colorectal: 110%; gastric: 119%, expressed as a percentage of the control) when compared to tumours (colorectal: 151%; gastric: 147%). The small number of well differentiated and/or Dukes' stage A colorectal tumours examined were gastrin-responsive, but all the responsive gastric tumours were poorly differentiated. With respect to ploidy, 89% of diploid and 67% of aneuploid colorectal tumours responded trophically to gastrin. Patients with colorectal or gastric tumours may benefit from treatment with gastrin antagonists.

Animals↗

Oesophageal transit of marshmallow after the Angelchik procedure.

The oesophageal transit time of half a marshmallow was measured radiologically in 17 controls, 28 patients with gastro-oesophageal reflux pre-operatively, 36 patients soon after implantation of the Angelchik prosthesis (2-9 weeks) and in 23 patients later postoperatively (9-48 months). Sixteen postoperative patients also underwent oesophageal manometry. All control and pre-operative patients had a marshmallow transit time of less than 1 min; 67 per cent of the early postoperative patients had prolonged transit and 70 per cent of the late tests were similarly abnormal. Prolonged oesophageal transit as measured by marshmallow swallow correlated well with symptoms of solid food dysphagia. Most, but not all, patients with an abnormal marshmallow swallow had abnormal manometric findings. The oesophageal transit of solid food is significantly slowed after the Angelchik procedure and this is not a transient postoperative phenomenon.

Adult↗

Cryotherapy for liver metastases: a new approach.

A new system designed for cryosurgery of liver metastases is described. The cryoprobe, which utilizes circulating liquid nitrogen and produces a spherical iceball around each metastasis, is controlled by operative ultrasound. There was nor mortality and all patients left hospital within 10 days. Cryotherapy produced an area of destruction within the liver substance which decreased in size by 6 weeks as shown on serial computed tomographic scanning.

Cryosurgery↗

Genotoxic effects of fly ash in bacteria, mammalian cells and animals.

The increasing use of fossil fuels has raised concerns about possible deleterious health effects of the final combustion product, fly ash. Seven ash samples from coal sources obtained from Battelle Columbus Laboratories were evaluated in the Salmonella/mammalian microsome mutagenicity assay to determine their mutagenic potential. While dimethyl sulfoxide extracts of five samples showed no mutagenicity, sample 102 caused an increase in the number of revertants per plate over controls in TA100 and TA98 with activation by liver homogenate (2-fold and 2.4-fold, respectively), and without (2-fold and 6-fold). This ash was thus evaluated in whole animal studies. Animals treated by inhalation or oral gavage were assayed for the presence of mutagens in the urine, micronuclei in polychromatic erythrocytes, and chromosomal aberrations in metaphase bone marrow cells. Those animals treated by inhalation were also examined for local damage in the lung. The assay for mutagens in the urine was negative as shown by the Ames assay with TA100 and TA98 and there was no increase in micronuclei or in metaphase aberrations. Histological sections from the animals treated by inhalation did not show the presence of particles, macrophage infiltrations and generalized lung damage. We tested the same fly ash with an in vitro cell transformation assay with the cell line Balb/c 3T3 subclone A31-1-13. Although there was not an increase in Type III foci, there was a dose-dependent increase of Type II foci in the treated cells over the controls. In one assay, there was approximately a 14-fold increase in Type II foci in the highest dose (2 mg/ml) compared to the solvent control. One other ash sample induced cell transformation without being markedly cytotoxic, while a third sample was highly toxic but did not induce transformation.

Animals↗

Palliation of malignant upper-third oesophageal stricture by bipolar diathermy probe.

Bipolar thermocoagulation probes have been used to palliate dysphagia in six patients with an inoperable squamous cell carcinoma of the upper third of the oesophagus. Median dysphagia grade was improved following treatment, and the only serious complication was the development of a tracheo-oesophageal fistula in one patient. Bipolar thermocoagulation probes are an alternative treatment for malignant strictures of the upper third of the oesophagus, a group that may be difficult otherwise to palliate.

Aged↗

LHRH and LH in peripubertal female rats following prenatal and/or postnatal ethanol exposure.

The effects of pre- and postnatal exposure to ethanol (ETOH) on LHRH and LH were investigated. Pregnant and/or lactating dams were fed ETOH during: 1) gestation, 2) lactation, or 3) gestation-lactation. Female offspring were decapitated at 30 or 40 days-of-age; trunk blood was collected for plasma LH RIA; and hypothalamic tissues were collected for LHRH RIA. Hypothalamic LHRH content of all ETOH-exposed groups was less than that of non-ETOH-fed controls at 30 and 40 days-of-age (p less than 0.05). Plasma LH concentrations of all ETOH-exposed groups were less than those of non-ETOH-fed controls at 30 and 40 days-of-age (p less than 0.05). Also, at 30 and 40 days-of-age, the plasma LH concentrations of the animals exposed to ETOH during lactation and gestation-lactation were less than those of the animals exposed to ETOH during gestation (p less than 0.05). These data suggest that ETOH exposure during gestation and/or lactation negatively affects hypothalamic LHRH content of female rat offspring. Decreased hypothalamic LHRH content with corresponding lowered plasma LH concentration suggests that ETOH influences development or maturation of hypothalamic LHRH neurons by possibly decreasing their number or synthesizing capability.

Alcoholism↗

Correlation of scrotal circumference and age in American Brahman bulls.

Scrotal circumference (SC) measurements were taken of 921 American Brahman bulls located on two ranches in southcentral Texas. Measurements were taken at various seasons of the year over an 11-yr time span. Body condition scores, as reflected by fat cover, and a subjective estimate of overall nutritional status were 4 or better, based upon a 1 to 9 scoring system, with 5 representing an animal with an average amount of body fat. Associated body weights were not measured and semen evaluations were not performed. Ages were calculated from exact birthdates and rounded to the nearest whole month. Ages from 8 mo to more than 36 mo were reported. SC measurements ranged from 16.0 cm to 42.5 cm. The relationship of SC and age was positively correlated (r=0.74) (P<0.0001) and could be predicted using the equation y=0.525x + 18.702 where y=SC in centimeters and x=age in months. These data provide evidence that the relationship of scrotal circumference and age of American Brahman bulls is similar to that of other cattle breeds.

Journal Article↗

Randomised study of prophylactic parenteral sulbactam/ampicillin and cephazolin in biliary surgery: significant benefit in jaundiced patients.

Two hundred consecutive patients undergoing biliary-tract surgery were entered into a randomized trial of prophylactic single dose cephazolin or sulbactam/ampicillin. There was no overall difference in the infection rates between the two antibiotic groups, but in the group of patients with jaundice there was an excess of wound infections in the cephazolin group compared to the sulbactam/ampicillin group (35% vs. 14%). We conclude that sulbactam/ampicillin is a satisfactory prophylactic agent for use in biliary-tract surgical sepsis, and that it may be superior to cephazolin in jaundiced patients.

Ampicillin↗