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Biomedical subjects

C Joyce

Publications and source records attributed to C Joyce.

At least 37 records · Page 2Linked to original sources
PubMed1995

Detection of the heat-stable toxin coding gene (ST-gene) in enterotoxigenic Escherichia coli: development of a colour amplified PCR detection system.

Screening biological samples using the polymerase chain reaction (PCR) has obvious advantages compared with current molecular analytical methods based on gel electrophoresis and/or hybridisation, both of which are expensive and time-consuming, therefore the development of a PCR assay format that is applicable to large sample numbers and that can readily use equipment commonly found in diagnostic laboratories would be advantageous. This report describes the development of a colour amplified PCR detection system which is simple in design and could be universally applied to the detection of any DNA template. As an example, the system has been applied in the detection of the heat-stable toxin coding gene (ST-gene) from enterotoxigenic Escherichia coli (ETEC). The assay is sensitive, detecting 10 fg of a purified DNA template and 270 cfu of an ST-gene-positive ETEC strain.

Bacterial Toxins↗
PubMed1993

Effect on lung volumes of oxygen concentration when breathing is restricted.

We have examined the effect of the fractional concentration of nitrogen (FIN2) on the decrease in lung volumes which occurs during restricted breathing with oxygen-nitrogen mixtures. Conscious human subjects breathed one of five gas mixtures of oxygen and nitrogen for 15 min on each of five occasions. For the final 5 min of each 15-min period, functional residual capacity (FRC) was reduced by one tidal volume, by external pressurization. After return to normal breathing, the subjects showed a statistically significant decrease in FRC and residual volume (RV), which became larger as FIO2 increased from 30% to 100%. This reduction in lung volumes was resistant to early reexpansion. The maximum decrease in both FRC and RV was found with 100% oxygen, and was 10% of the control lung volumes. The use of a mixture of 75% nitrogen and 25% oxygen prevented this decrease in lung volumes. Nitrogen 50% reduced the decrease in FRC, but did not affect the decrease in RV. The difference in effect on lung volumes between FIO2 25% and 30% was statistically significant, indicating a watershed area for FIN2 between 70% and 75%.

Adult↗
PubMed1992

Estimates of the frequency of chromosome abnormalities detectable in unselected newborns using moderate levels of banding.

Data on structural chromosome abnormalities identified during prenatal diagnosis were used to estimate the number of such abnormalities that would be detectable in an unselected series of newborns using moderate levels of banding (400 to 500 bands). These estimates were compared with the rates detected in nonbanded surveys of newborns. Between 1976 and 1990 prenatal diagnosis using banding techniques was carried out in our laboratory on 14,677 women aged 35 and over. Among these, we detected 112 structural rearrangements, 32 unbalanced and 80 balanced. These figures were adjusted by two methods to give an estimate of the frequency of structural abnormalities in the newborn. Our data suggest that the use of moderate levels of banding increases the frequency of unbalanced structural abnormalities from 0.052 to 0.061% and of balanced structural abnormalities from 0.212 to 0.522%. Thus, the total number of chromosome abnormalities detectable in the newborn is increased from 0.60% in unbanded preparations to 0.92% in banded preparations.

Adult↗
PubMed1992

Telephone modem access improves diabetes control in those with insulin-requiring diabetes.

OBJECTIVE: To assess whether modem access improves diabetes control in IDDM patients. RESEARCH DESIGN AND METHODS: Forty-two patients participated in the study and were followed for 12 wk. The patients were randomly divided into two groups at baseline, a modem group and a control group. There were no significant differences between HbA1c, random blood glucose, and weight between the groups at the beginning of the study. Patients were asked to perform five blood glucose determinations/day (before breakfast, before lunch, afternoon [1500], before dinner, and at bedtime) twice/week. The modem group transferred their data over the phone once/week. The control group would bring in their results on their regular visits every 6 wk. Patients in the modem group were counseled every week over the telephone after transferring results to adjust insulin and food intake if necessary. RESULTS: In the modem group, HbA1c improved from 0.106 to 0.092 (13.20%). The control group improved from 0.112 to 0.102 (8.9%). There was no significant change in weight, random blood glucose, or insulin. CONCLUSIONS: The use of telephone modem-based patient-monitoring systems in diabetes clinical research seems to stimulate the patient to keep closer control of blood glucose levels. It might be especially useful in rural settings, for which this study was designed.

Adolescent↗
PubMed1991

A chemical score to evaluate the protein quality of commercial parenteral and enteral formulas: emphasis on formulas for patients with liver failure.

Essential amino acids, found in abundance in high-quality dietary protein, are required daily by hospitalized patients and healthy persons to maintain the dynamic process of protein metabolism. One method for assessing dietary protein quality is by determining a diet's chemical score, ie, the ratio of a gram of the limiting amino acid in a test diet to the same amount of the corresponding amino acid in a reference diet (eg, whole-egg protein) multiplied by 100. This investigation used the chemical score to evaluate the protein quality of 9 parenteral and 17 enteral diets commonly used to feed hospitalized patients. Standard parenteral and enteral products (ie, formulas that had not been designed for patients with a specific disease state) had chemical scores that ranged from 46% to 70%. Limiting amino acids were either methionine (plus cysteine) or phenylalanine (plus tyrosine). Products designed for patients with renal failure had the highest scores, which ranged from 85% to 145%. Products that were enriched with branched-chain amino acids for trauma patients had scores that ranged from 38% to 73%. The only product available for patients with pulmonary compromise had a score of 50%. The lowest scores, which ranged from 5% to 13%, were found in products for patients with hepatic failure. All products, except those with chemical scores below 13%, may be fed in relatively small amounts of protein (7 to 33 g) to satisfy the minimum daily requirements of essential amino acids, although such levels would not meet minimal daily nitrogen requirements. We recommend that dietitians use the chemical score to assess the protein quality of parenteral and enteral diets.

Amino Acids, Essential↗
PubMed1990

Gene transfer, expression and inheritance of pRSV-rainbow trout-GH cDNA in the common carp, Cyprinus carpio (Linnaeus).

A recombinant plasmid containing the Rous sarcoma virus-long terminal repeat (RSV-LTR) promoter linked to rainbow trout (Salmo gairdneri) growth hormone (GH) cDNA was microinjected into fertilized carp eggs. Genomic DNA extracted from pectoral fin of individual presumptive transgenic fish was analyzed by dot blot and Southern blot hybridization, using the RSV-LTR and/or the GH cDNA sequences as probes. Out of 365 presumptive transgenic fish analyzed, 20 individuals were found to contain pRSV-rtGH-cDNA sequence in the genomic DNA. Expression of the trout GH polypeptide was detected by immunobinding assay in the red blood cells of nine transgenic fish tested. The level of expression, however, varied among the transgenics and could not be correlated with exogenous DNA copy number. Although there was considerable variation in the sizes of the transgenic fish, those microinjected during the one-cell stage were (P less than 0.05) 22% larger, on the average, than their sibling controls. A randomly selected fraction of the progeny derived from crosses between transgenic males and non-transgenic females inherited the foreign DNA. These transgenic progeny grew faster (P less than 0.05) than their non-transgenic siblings.

Animals↗
PubMed1988

The prevalence of mental handicap in New Zealand.

The administrative prevalence of mental handicap at the age of 10 years was ascertained for a group of children born 1973 and 1974. There was a birth cohort prevalence of 4.35 per 1000 live births.

Child↗
PubMed1988

Hypertension in diabetic clinic patients and their siblings.

The prevalence of hypertension was investigated in a systematically chosen sample of patients attending a diabetic clinic. One hundred ninety-one patients were classified as Type 1 (insulin-dependent), 183 were classified as Type 2 (non-insulin-dependent) and 12 were deemed unclassifiable. Two hundred fifty-five control subjects attending non-medical out-patient clinics were also examined under similar conditions. Hypertension was significantly (p less than 0.001) more common among Type 2 patients (38%) than among Type 1 patients (15%) or control subjects (16%). The difference between Type 2 patients and control subjects, but not between Type 2 and Type 1 patients, persisted when the influences of age and body mass index were controlled. We also investigated the prevalence of hypertension among the siblings of the hypertensive patients identified, together with a matched normotensive group. One hundred eighty-eight siblings were examined and historical details were obtained for a further 451 siblings. When age and body mass index were controlled for in examined siblings, the risk of hypertension was greater in those with a hypertensive proband than in those with a normotensive proband, in the control (p less than 0.06) and Type 1 (p less than 0.02) groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Acrosomal enzymes of human spermatozoa before and after in vitro capacitation.

The effect of in vitro capacitation (events that occur before the acrosome reaction) on the acrosomal enzymes of human spermatozoa was determined. Capacitation of human spermatozoa was assessed by their ability to penetrate denuded hamster oocytes. The activities of a number of enzymes commonly associated with the sperm acrosome, including nonzymogen acrosin, proacrosin, inhibitor-bound acrosin, hyaluronidase, acid phosphatase, beta-glucuronidase, beta-glucosidase, beta-N-acetylglucosaminidase, beta-galactosidase and beta-N-acetylgalactosaminidase were assessed. With the exception of acid phosphatase, no alteration in enzyme activity occurred after 4 h of incubating the spermatozoa under capacitation conditions although gamete fusion took place. The acid phosphatase levels decreased twofold, presumably due to the loss of seminal (prostatic acid phosphatase that loosely adheres to spermatozoa. After 8 h of capacitation, a large decrease in sperm enzyme levels took place only in the case of hyaluronidase, although small decreases were also noted in total acrosin, proacrosin and inhibited acrosin. No new electrophoretically migrating forms of acrosin were observed. Decreases in total acrosin and proacrosin, but not in inhibited acrosin, also occurred when spermatozoa were incubated under noncapacitating conditions for 8 h, indicating that capacitation may specifically cause the release of some acrosin inhibitor from human spermatozoa. It is concluded that, with the possible exception of hyaluronidase, the in vitro capacitation of human spermatozoa does not cause a major change in its acrosomal enzyme content so that these hydrolases are fully present before the acrosome reaction takes place during gamete fusion. Serum albumin appears to protect against the loss of some of these enzymes since the activity of several glycosidases was significantly reduced when the spermatozoa were incubated for 8 h in human serum albumin-free medium.

Acetylglucosaminidase↗
PubMed1982

Inhibition of mouse sperm capacitation by ethanol.

Ethanol reduced the in vitro fertilizing capacity of mouse spermatozoa in a dose-dependent manner, at concentrations commonly observed after ethanol ingestion by man and experimental animals (100-400 mg%). At these ethanol levels, sperm motility and the integrity and fertilizing capacity of the oocyte were not affected, nor was parthenogenic cleavage induced. Data indicated that ethanol prevents the capacitation of the spermatozoa. Its inhibitory effect could be reversed by incubation of the alcohol-treated spermatozoa in alcohol-free capacitation medium. At similar concentrations, t-butanol had no effect on fertilization, suggesting that inhibition by ethanol is mediated by a mechanism other than a "solvent" effect. Although the alcohol dehydrogenase inhibitor, pyrazole, prevented the inhibition of fertilization by ethanol, acetaldehyde (the product of ethanol oxidation) was without effect. These data indicate that the inhibition of capacitation by ethanol is mediated via its metabolism by spermatozoa but not by the immediate product of ethanol oxidation.

Acetaldehyde↗
PubMed1979

Contraceptive effects of intravaginal application of acrosin and hyaluronidase inhibitors in rabbit.

Eight single-drug and combinations of two-drug treatments were used to study the contraceptive efficacy of the intravaginal application of acrosin inhibitors (TLCK; NPGB) and hyaluronidase inhibitors (Compound 53D/k; Phosphorylated hesperidin) in the rabbit. Drug concentrations were selected so that they did not inhibit rabbit sperm motility upon incubation at 37 degrees C for 30 minutes. In the first series, the drugs were added to semen before artificial insemination; in the second series, the drugs were administered intravaginally before artificial insemination with untreated rabbit semen. The data show that these drugs are highly effective intravaginal contraceptives in the rabbit. The data suggest that this is a specific inhibitory effect on fertilization since the drug concentrations used did not affect sperm motility.

Amino Acid Chloromethyl Ketones↗