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Biomedical subjects

J Hutson

Publications and source records attributed to J Hutson.

At least 19 recordsLinked to original sources
PubMed2004

Synthesis, conformation, receptor binding and biological activities of monobiotinylated human insulin-like peptide 3.

Biotin-avidin immobilization has been routinely used as a tool to study peptide-receptor and peptide-antibody interactions. Biotinylated peptides can also be employed to localize cells that express the peptides' receptor, and to analyse ligand-receptor binding. Insulin-like peptide 3 (INSL3) is a peptide hormone which contains A- and B-chains connected by two disulphide bonds and plays a role in testicular descent during sexual development. In order to study the interaction of INSL3 with its receptor LGR8, a G protein-coupled receptor, we chemically synthesized Nalpha-mono-biotinylated human INSL3 (B-hINSL3) and compared it structurally and biologically with hINSL3. Both peptides exhibited similar, but high, receptor binding affinities on human foetal kidney fibroblast 293T cells transfected human LGR8 based on a competition radioreceptor assay with 33P-labelled relaxin H2 (B33). The modified B-hINSL3 showed full biological activity as determined by the stimulation of gubernacular cell proliferation. The labelled B-hINSL3 contains a higher alpha-helix content, and this increased helical structure is accompanied by an increase in ability to stimulate cAMP accumulation in 293T cells expressing LGR8. Our results suggest that the N-terminal region of the A-chain is not involved in the interaction of INSL3 with its receptor. However, the introduction of biotin onto the N-terminus of the A-chain promoted conformational stability which, in turn, permitted better receptor activation.

Amino Acid Sequence↗
PubMed2003

Uptime as a measure of recovery in children postappendectomy.

PURPOSE: The aim of this study was to objectively measure recovery time after open and laparoscopic appendectomy using an activity monitor (PAL 1). METHODS: The PAL 1 records the amount of time that the subject is upright (uptime). Children wore the PAL 1 for 10 days continuously, beginning within the first 48 hours postoperatively. RESULTS: Uptime data were collected for 5 or more days for 42 children (open, n = 16; laparoscopic, n = 26). All children had low levels of uptime in the initial postoperative period. There was weak evidence of a quicker recovery rate for children in the laparoscopic group (P =.09). The difference in mean uptime between groups was of statistical significance by day 7 postoperatively with children in the laparoscopic group having a higher mean uptime than those in the open group (difference of 0.7 hours; 95% confidence intervals 0.0 to 1.4 hours in a 24-hour period). CONCLUSIONS: The results of this study show that recovery postappendectomy can be quantified by the measurement of uptime and that children undergoing a laparoscopic procedure may recover marginally more quickly than those undergoing an open procedure.

Adolescent↗
PubMed2001

The adsorption of cyanobacterial hepatotoxins from water onto soil during batch experiments.

Public health concerns associated with cyanobacteria, both chronic and acute, arise from their ability to produce toxins. Rural communities within Australia and those in developing countries require an inexpensive and low-cost method for removing toxins from drinking water. A candidate technology is bank filtration. Adsorption of cyanobacterial hepatotoxins was measured in batch studies to determine the applicability of bank filtration as an efficient removal strategy. Five soils with different physicochemical properties were collected from regions around South Australia. The soils were mixed with either nodularin or microcystin-LR in distilled water and buffered solutions (pH 4.8, 6.9 and 9.1). Additionally, nodularin was mixed in unbuffered solutions (pH 4.8 and 8.9). The three soils with the high clay and/or organic carbon contents (Paringa A, McLaren Flat and Lakes Plains) had the higher nodularin adsorption coefficients, ranging from 0.2 to 16.59 L kg-1. Soil suspensions in acetate buffer (pH 4.8) generally produced significantly higher nodularin adsorption coefficients, when compared to the other buffer systems. The background interference from the ionic strength of the buffers, however, made interpretation of the effect of pH on toxin sorption difficult. Increases in solution ionic strength, from freshwater to seawater, resulted in corresponding increases in the nodularin adsorption coefficients for all sites, except the sandy Hallett Cove site. The implications for bank filtration are that higher water pH values and lower salinities will enhance the in situ mobility of the toxins, resulting in an increased distance of filtration through the river bank before toxin free water could be abstracted for human consumption.

Adsorption↗
PubMed1995

Renal transplantation in very young children.

Results of renal transplantation in very young children with end-stage chronic renal failure have been poor compared with those in older children and adults. Consequently small children either may not be treated or may be placed on chronic dialysis programmes. Between 1988 and 1992, six children under the age of 5 years received seven renal transplants at the Royal Children's Hospital, Parkville, Victoria, Australia; five from live donors and two from cadaver donors. All children were treated with peritoneal dialysis before transplantation, and immunosuppressed with a standardized regimen of cyclosporine, azathioprine and prednisolone. An extraperitoneal incision was used, and the donor renal vessels were anastomosed to the lower abdominal aorta and inferior vena cava or the common iliac vein. All children received intensive monitoring and fluid replacement during the peri-operative period. Patient survival was 100%. One cadaver graft failed 1 week after transplantation because of irreversible acute rejection. This child subsequently received a successful second transplant. Two children developed postoperative urinary fistulae which were treated successfully by further operation. Current renal function in all children is excellent. The success of this programme has led us to review our attitude towards renal transplantation in this age group and to advocate live donor renal transplantation as the treatment of choice in very young children with end-stage chronic renal failure whenever possible.

Cadaver↗
PubMed1992

Association of Hirschsprung's disease and Müllerian inhibiting substance deficiency.

An infant who presented with Hirschsprung's disease was found to also have the clinical features of persistent Müllerian duct syndrome and on testing to have Müllerian inhibiting substance deficiency. This association has not been previously reported. While this may be a coincidence, recent reports indicate intersex conditions can be associated with Hirschsprung's disease.

Anti-Mullerian Hormone↗
PubMed1988

A PvuII polymorphism in the 5' flanking region of the apolipoprotein AIV gene: its use to study genetic variation determining serum lipid and apolipoprotein concentration.

We have used a 1.05-kb unique genomic fragment from the 5' end of the apolipoprotein (apo) CIII gene to identify a restriction fragment length polymorphism (RFLP) detected with the restriction enzyme PvuII, in the apoCIII-apoAIV intergenic region. In a sample of 220 normolipidaemic individuals from the UK population, the frequency of the rare allele, VB2 is 0.054. The PvuII polymorphism is in apparent linkage equilibrium with three other RFLPs of this gene cluster, detected with the restriction enzymes XmnI, PstI and SstI, but in linkage disequilibrium with an RFLP in the apo-CIII gene also detected with PvuII. Taken together, these five RFLPs have a PIC (polymorphism information content) value of 0.8, and therefore are informative for genetic studies. Individuals with the genotype VB1VB2 had lower mean concentrations of apoAI, and HDL-cholesterol than individuals with the genotype VB1VB1. However these differences were not statistically significant.

Apolipoprotein C-III↗
PubMed1981

The ontogeny of Mullerian inhibiting substance in the gonads of the chicken.

Mullerian inhibiting substance (MIS) was studied in the testis, ovary, and ovotestis of the domestic fowl, from early embryonic development to adulthood by a graded organ-culture method using the urogenital ridge of a 14.5 day fetal rat. The chick testis had high levels of MIS from 8 days of embryonic development (4-5+) until sexual maturity, when activity declined (2+) but persisted throughout adulthood. The right gonad (ovotestis) of the hen showed moderate levels of MIS activity from 8 to 12 days of embryonic life (1-3+) before its normal involution by the time of hatching (21 days). The left gonad (ovary) of the hen also produced MIS at levels similar to that seen in the testis. Activity was high during embryonic development (4+) and after hatching, and persisted in the adult hen at diminished levels (2+). MIS production by the female gonads explains regression of the right Mullerian duct, but the mechanisms that allow preservation of the left duct remain unexplained. Evidence suggests that ovarian estrogens may interact with MIS at the receptor level to protect the left Mullerian duct. MIS persists in the sexually mature gonads of both the hen and cockeral, long after the Mullerian duct has regressed, suggesting a wider role for this substance in reproductive physiology.

Age Factors↗
PubMed1981

Distribution and kinetic properties of alcohol and aldehyde-dehydrogenase in the rat testis.

The distribution of both alcohol (ADH) and aldehyde-dehydrogenase (ALDH) was studied in the rat testis. Testicular ADH was mainly localized into the interstitial tissue. Testicular ALDH activity was distributed between the interstitial tissue and the seminiferous tubules with greater activity measured in the former component. The apparent Km for ADH in the whole testis was greater than that measured in the interstitial tissue. A low Km value was determined for ALDH in the seminiferous tubules, compared to a higher mean Km value for this enzyme in the interstitial tissue of the testis. The study shows that interstitial tissue possesses both ADH and ALDH, which are essential for the respective metabolism of ethanol and acetaldehyde, and that the seminiferous tubules possesses greater affinity for the metabolism of acetaldehyde than that of the interstitial tissue.

Acetaldehyde↗
PubMed1978

Urethral reaction to catheter materials in dogs.

The reaction of the urethra to two new polyurethrane polymers was compared with those produced by materials currently used in the manufacture of urethral catheters. The comparison included silicone, latex rubber, tetrafluoroethylene polymer (Teflon) coated latex, and polyvinyl chloride. There were no significant differences in the reaction of the urethra to the various materials. The present study was carried out in the absence of bacterial contamination.

Animals↗
PubMed1975

Epithelialization after cystotomy.

Cystotomies were performed on mature guinea pigs using aseptic technique, and one layer closure with polypropylene sutures. It was found that epithelialization over the suture material was completed by 3 days and that epithelialization of the bladder mucosa itself after a mucosa-mucosa approximation was completed within 4 days. The main significance of this investigation is that the normal bladder mucosa was completely healed within 4 days.

Animals↗