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T Mills

Publications and source records attributed to T Mills.

At least 37 records · Page 2Linked to original sources
PubMed1990

Prebiotic synthesis of histidyl-histidine.

Histidyl-histidine (His-His) has been synthesized in a yield of up to 14.4% under plausible prebiotic conditions using histidine (His), cyanamide, and 4-amino-5-imidazole carboxamide. A trace amount of His trimer was also detected. Because the imidazole group of His is involved in a number of important enzymatic reactions, and His-His has been shown to catalyze the prebiotic synthesis of glycyl-glycine, we expect this work will stimulate further studies on the catalytic activities of simple His-containing peptides in prebiotic reactions.

Aminoimidazole Carboxamide↗
PubMed1989

Chemical evolution of primitive solar system bodies.

In this paper we summarize some of the most salient observations made recently on the organic molecules and other compounds of the biogenic elements present in the interstellar medium and in the primitive bodies of the solar system. They include the discovery of the first phosphorus molecular species in dense interstellar clouds, the presence of complex organic ions in the dust and gas phase of Halley's coma, the finding of unusual, probably presolar, deuterium-hydrogen ratios in the amino acids of carbonaceous chondrites, and new developments on the chemical evolution of Titan, the primitive Earth, and early Mars. Some of the outstanding problems concerning the synthesis of organic molecules on different cosmic bodies are also discussed from an exobiological perspective.

Amino Acids↗
PubMed1986

Effect of gavage vehicle on hepatotoxicity of carbon tetrachloride in CD-1 mice: corn oil versus Tween-60 aqueous emulsion.

This investigation was conducted to evaluate the effect of gavage vehicles on altering the severity of the subchronic hepatotoxicity of carbon tetrachloride (CCl4). Male and female CD-1 mice were gavaged with 0, 1.2, 12, and 120 mg/kg CCl4 in either a corn oil or 1% Tween-60 vehicle once daily for 5 consecutive days per week for 90 days. The study revealed that the hepatotoxicity was greater in the mid- and high-dose groups of mice that had received CCl4 administered in corn oil. Increases in serum enzyme activities were detected in the mid-dose groups of mice that were gavaged with CCl4 in corn oil. The serum enzyme activities were significantly higher in the high-dose groups of animals in which CCl4 was administered in corn oil. Histopathological findings indicated that hepatocellular changes following the administration of CCl4 at the mid- and high-dose levels were more frequent and more severe when CCl4 was given in corn oil than when it was administered in Tween-60. The experimental findings indicate that the no-observed-adverse-effect level from CCl4 exposure was lowered by an order of magnitude (from 12 to 1.2 mg/kg) and that the hepatotoxicity of CCl4 was enhanced in the high-dose treatment groups when corn oil was employed as the gavage vehicle.

Animals↗
PubMed1986

The effects of porcine follicular fluid inhibin on gonadotropin secretion in the rabbit.

Porcine follicular fluid (pff), treated with charcoal to remove steroids, was used to determine whether inhibin is active in the laboratory rabbit. When pff (5 ml/4 kg body weight) was injected (ip) into does that had been castrated 2 weeks earlier, there was a significant decline in blood follicle-stimulating hormone (FSH) levels; the decline lasted for 8-12 h. Blood levels of luteinizing hormone (LH) were suppressed, but only briefly at 3 h after injection. In other experiments, intact does which had been injected with pff 9 h and 10 min before receiving a single, i.v. injection of luteinizing hormone-releasing hormone (LHRH) (10 micrograms/kg body weight) showed a sharp reduction in the concentration of LH in the blood samples collected 15, 30 and 60 min after LHRH administration. Secretion of FSH responded poorly to LHRH stimulation, and pff had little suppressive action on blood levels. Having established that the pff preparation had inhibin activity, its action on the postovulatory surge of FSH secretion was next examined. This release of FSH, which occurs 6 to 36 h after ovulation, has been hypothesized to be required for the establishment of pregnancy by stimulating the growth of the ovarian follicles supplying the luteotropic estradiol. To test this hypothesis, pff was injected into rabbits every 8 h for the first 5 days of pregnancy and found to block the postovulatory FSH surge. The patterns of secretion of LH and progesterone in the same pff-injected animals were, however, not altered from normal pregnancy patterns by pff.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Efficiency of canine renal blood flow autoregulation in kidneys with or without glomerular filtration.

In order to evaluate vascular (myogenic) and tubular (tubuloglomerular feedback) mechanisms involved in renal blood flow (RBF) autoregulation, canine kidneys with filtration (normal) and without filtration (nonfiltering, NFK; ureteral-obstructed, UO) were studied. RBF was monitored in response to stepwise reductions in renal perfusion pressure of -20, -40, and -60 mm Hg from control pressure. None of the three groups demonstrated significant changes in RBF from their respective control values (normal, 380 ml/min/100 g; NFK, 179 ml/min/100 g; UO, 153 ml/min/100 g) until the lowest pressure (-60 mm Hg from control pressure). All three groups responded to the pressure reductions with significant decreases in renal vascular resistance. However, the calculated efficiency of the autoregulatory response for the NFK and UO groups was significantly less than for the normal group. Elimination of tubuloglomerular feedback (NFK and UO) did not necessarily eliminate renal vascular autoregulation, but did reduce the efficiency of autoregulation. It is suggested that both vascular (myogenic) and tubular (tubuloglomerular) mechanisms may coexist to efficiently autoregulate blood flow in normal filtering kidneys. However, a reduction in metabolic activity as a contributor to the reduced ability to autoregulate in these kidneys could be an additional possibility.

Animals↗
PubMed1984

Victims of violence and psychiatric illness.

The authors investigated the relationship between physical and sexual abuse and psychiatric illness. The life experiences of 188 male and female psychiatric patients were reconstructed through an in-depth examination of psychiatric inpatient records. Almost half of the patients had histories of physical and/or sexual abuse; 90% of the abused patients had been victimized by family members. The abused patients' responses to chronic victimization included difficulty in coping with anger and aggression, impaired self-esteem, and inability to trust. The authors compare male and female victims and discuss the clinical implications of abuse.

Adolescent↗
PubMed1984

Immunization with zona pellucida proteins results in abnormal ovarian follicular differentiation and inhibition of gonadotropin-induced steroid secretion.

Changes in rabbit ovarian hormonal responses and cellular differentiation of ovarian follicles after immunization with porcine zona pellucida (ZP) have been examined. Steroid and peptide hormone levels were monitored after immunization to evaluate ovulation and pseudopregnancy cycles in immunized and control animals. All immunized rabbits developed serum antibodies to specific ZP antigens and failed to form functional corpora lutea in response to hCG administration, as evidenced by the absence of elevated serum progesterone concentrations. This is in contrast to control rabbits, which had elevated progesterone levels 8-9 days after hCG administration. Furthermore, all immunized animals showed greatly increased serum levels of FSH and LH compared to those of control animals. These effects on ovarian function were apparent within 20 weeks of the primary immunization. Follicular development was analyzed by light and electron microscopies. The numbers of primary, secondary, and tertiary follicles in ovaries of immunized animals were markedly reduced within 7 weeks compared with control values. By 23 weeks, few if any growing follicles were present. Although numerous distinct clusters of cells with ultrastructural properties that resemble those of normal follicular cells were present in immunized animals, they contained no oocytes. These studies suggest that antibodies to ZP glycoprotein alter ovarian function by interfering with cells during the stage of follicle differentiation at which the ZP proteins are being synthesized and secreted. This system should provide an excellent model with which to study the early events associated with ovarian follicular cell differentiation and subsequent hormonal responsiveness.

Animals↗
PubMed1982

Humoral and cellular immune responses of rabbits to sub-viral fractions of human cytomegalovirus.

We have raised specific sera against human CMV (strain AD 169) and have tested the immunogenicity of viral envelopes, removed using the non-ionic surfactant Triton X-100. Glycine-buffered extracts of infected MRC-5 cells elicited virus-neutralizing antibody to a titre of 1/1600. Incubation of this material also elicited a considerable reaction against host cell antigens. Inoculation of viral envelope material in Freund's complete adjuvant also elicited virus-neutralizing antibodies. Specific in vitro transformation of peripheral blood lymphocytes taken from inoculated rabbits was not always demonstrable, but could be achieved with blood taken from one rabbit up to one year after the initial inoculation of envelope material.

Animals↗
PubMed1979

Dynamic hormonal tests in a case of premature ovarian failure.

The case of a patient with premature ovarian failure and a history of polycystic ovarian disease was described. Dynamic gonadal and pituitary tests were done. Ovarian, adrenal, and peripheral veins were catheterized to determine the steroid secretion under HCG stimulation. In vitro studies of the capacity of ovarian steroidogenesis confirmed the refractory nature of the gonad. Lack of gonadal response, both in vivo and in vitro, to stimulation suggests a possible alteration in ovarian sensitivity to gonadotropins as a possible cause of premature menopause.

Adult↗
PubMedDate not supplied

Intravenous saline has no effect on blood ethanol clearance.

For patients presenting to emergency departments with ethanol intoxication, intravenous (i.v.) fluids are initiated for varied reasons. This investigation determined the effect of i.v. fluid therapy on the rate of blood ethanol clearance in such patients. Volunteers received a predetermined dose of ethanol on two separate occasions. On the second occasion, volunteers rapidly received a liter of i.v. saline directly following ethanol ingestion. At intervals on both occasions, blood ethanol levels were estimated using a breath analyzer. Using linear regression analysis, no difference was found in rates of alcohol clearance with or without i.v. fluid intervention. The common rate of clearance between both groups was 15 mg/dL/h (95% CI 12 to 18). We conclude that i.v. fluid therapy does not accelerate ethanol clearance in intoxicated patients. While such therapy may be justified for other reasons, practitioners are cautioned against initiating fluids in such patients solely to expedite ethanol elimination.

Adult↗
PubMedDate not supplied

Development and consumer validation of the Functional Evaluation in a Wheelchair (FEW) instrument.

PURPOSE: The purpose of the study is to develop an outcome measurement tool to investigate functional performance of consumers using seating and wheelchair systems as their primary seating and mobility device. The instrument is undergoing systematic development in three phases. The results of Phase 1 will be reported. METHOD: Manual and power wheelchair users were interviewed using a modified version of a client-centred outcome measure. An item bank was derived based on the interview data. Subjects were then asked to validate item categories of the new instrument, and finally to self-administer the first version of the instrument. RESULTS: Subjects reported 154 self-care, productivity, and leisure occupational performance issues related to their current seating-mobility system. Based on their input, 10 categories (i.e. transfers, reach, accessing task surfaces, transportation-portability, human-machine interface, architectural barriers, transportation-accessibility, transportation-securement, natural barriers and accessories) were validated for inclusion in the new outcome measure, Functional Evaluation in a Wheelchair (FEW). CONCLUSION: The items on the FEW focus on the interaction between the consumer, the technology, and the milieu. Consumers viewed the overall importance of FEW categories for seating-mobility system users differently than when they self-administered the FEW.

Adult↗
PubMedDate not supplied

A simple method to avoid thrombus formation at the de-airing port of the acute ventricular assist device.

De-airing of the acute ventricular assist device using the designed port has resulted in thrombus formation at the site of device puncture in three of four ventricular assist devices in place during long-term (more than 72 hours) support. Disruption of the inner biomer coating by blunt needle insertion for de-airing of the prosthetic ventricle is the apparent underlying cause. Because of the obvious hazard of subsequent embolization, we describe a simple and effective method of de-airing the acute ventricular assist device with use of a jejunostomy kit.

Enteral Nutrition↗
PubMedDate not supplied

Successful treatment of acute allograft failure using pneumatic biventricular assistance.

A 61-year-old man underwent orthotopic heart transplantation complicated by acute allograft failure. Management entailed placement of two ventricular assist devices, and there was subsequent hemodynamic stabilization. Ventricular assistance continued for 8 days, at which time graft recovery resulted in successful explanation of the devices. Subsequent recovery was uneventful, and the patient was discharged on the 28th postoperative day. Methods of optimizing interoperative device cardiac output and synchronous-mode weaning are discussed.

Cardiomyopathy, Dilated↗