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Biomedical subjects

J Wiseman

Publications and source records attributed to J Wiseman.

At least 19 recordsLinked to original sources
PubMed2001

Training background as a factor in the conversion rate of laparoscopic cholecystectomy.

The present study reports findings concerning the impact of the learning environment on the conversion rate of laparoscopic cholecystectomy (LC) to open cholecystectomy (OC). At Metro-West Medical Center (Framingham, MA) seven surgeons performed 866 LCs between 1990 and 1995. Group I consisted of three surgeons who learned the procedure as part of their General Surgery Residency training, whereas the remaining four surgeons representing Group II learned the procedure through private courses. We emphasize the importance of the surgeons' training background on the conversion rates, operative times, and length of hospitalization for patients undergoing LC. The conversion rates, operative times, and complication rates were analyzed with and without a 2-year period of adjustment to compensate for the learning curve of early procedures. Operative times and conversion rates from LC to OC were lower for cases done by surgeons from Group I, even when the learning curve was corrected. The complication rates were higher for surgeons in Group II, but this did not reach statistical significance. As surgeons from Group II gained more experience their operation times and conversion rates decreased. However, there still was a statistically significant difference in favor of surgeons who learned the procedure as part of a structured curriculum. These data suggest a long-lasting influence of the learning environment on the conversion rates and operative times.

Adolescent↗
PubMed2001

Diverting loop colostomy for the treatment of refractory gastrointestinal bleeding secondary to radiation proctitis.

Chronic radiation proctitis is an uncommon and serious complication of radiotherapy for pelvic malignancies. It has been suggested that fecal stream diversion decreases bowel irritation, resulting in decreased rectal bleeding. We report on the outcome of patients after a diverting loop colostomy for the treatment of severe radiation proctitis. All consecutive patients with chronic proctitis treated with diverting loop colostomy for bleeding at one institution between October 1991 and June 1999 were studied. Four patients presented with rectal bleeding and diarrhea, and two patients had only bleeding. The mean dose of radiation received was 6,115.11 +/- 955.11 rad. Symptoms of chronic proctitis appeared at varying intervals of time after radiation, ranging from 14 months to 17 years. There were no operative complications. During follow-up (36 +/- 29 months), only one of nine patient continued to bleed. Four patients died during the study (cancer relapse, two patients; heart failure, one patient; one death was caused by severe radiation proctitis). Diverting sigmoid loop colostomy, when performed in properly selected patients with severe bleeding secondary to radiation proctitis refractory to medical management, is well tolerated and effective.

Aged↗
PubMed2000

Evaluation of polyethylene terephthalate for ABO and Rh typing and alloantibody screening.

BACKGROUND: For many years, hospitals and laboratories have used evacuated glass tubes for blood collection. To improve the safety of blood collection, plastic polyethylene terephthalate (PET) tubes (Vacutainer PLUS, Becton Dickinson) have been developed. The objectives of this study were to compare the accuracy of ABO grouping, Rh typing, and antibody screening of blood samples collected in plastic tubes with that in glass tubes and to determine if refrigerated blood samples collected in plastic tubes remained stable over a 28-day period. STUDY DESIGN AND METHODS: Samples were collected from 121 volunteers, at least 30 from each of the A, B, O, and AB blood groups, in four types of Vacutainer tubes: silica-coated plastic, K(2) EDTA plastic, uncoated glass, and K(2) EDTA glass. Samples from each tube were tested for ABO group and Rh type by use of the microtyping gel identification card system and the tube method. A three-cell antibody screen was performed by the microtyping gel card technique with a monospecific IgG reagent. Initial samples were tested within 3 hours of collection. Refrigerated samples were retested for ABO and Rh type and antibody screening 1, 2, 21, and 28 days later. Agreement between test results was determined by using Cohen's Kappa statistic. RESULTS: Complete agreement was observed between the ABO and Rh typing results in samples drawn into glass and plastic tubes of both the EDTA and nonanticoagulated type (kappa = 1.0). In retesting, there were no examples of a change in ABO or Rh type over the 28-day study period. Only two alloantibodies (1.7%) were identified in the 121 samples, and no difference was observed in alloantibody expression in either plastic or glass Vacutainer tubes over the 28-day study period. CONCLUSION: Samples collected into the PET serum or EDTA tubes provided accurate ABO and Rh typing results that remained consistent over a 28-day period. Samples collected in these tubes also appeared to enable accurate alloantibody identification. However, the number of alloantibodies identified in this study was small, and this result should be confirmed in a larger series.

ABO Blood-Group System↗
PubMed1999

Effects of age and diet on the viscosity of intestinal contents in broiler chicks.

1. A standard methodology was developed for the determination of the viscosity of digesta in broiler chickens. 2. The best variables considered for use (those which gave the most consistent results) were: digesta obtained from the foregut area (defined as the region from the pancreas to Meckel's diverticulum) using a minimum of 6 replicates and offering experimental diets for 5 d before slaughter at 25 d of age. 3. There was evidence that the viscosity of digesta obtained from the hindgut (defined as the region between Meckel's diverticulum and the ileo-caecal junction) was reduced the longer the birds were fed on one diet, suggesting possible dietary acclimatisation. Hindgut digesta viscosity from birds fed on a barley-based diet over a longer period was 10% to 30% less than that of birds fed for 5 d. 4. There was an apparent reduction in viscosity with age of bird up to 45 d of age, with hindgut digesta viscosity from birds fed on barley-based diets falling from 20.6 cps at 25 d to 9.8 cps at 45 d. 5. In an assessment of the procedure developed, the following digesta viscosities were obtained at 25 d: 3.1 cps (wheat-based diet, foregut), 19.8 cps (barley-based diet, foregut), 5.7 cps (wheat-based diet, hindgut), 22.8 cps (barley-based diet, hindgut).

Aging↗
PubMed1996

Development and validation of a pig model for colon-specific drug delivery.

The purpose of this investigation was to develop a pig model for colonic drug delivery and to validate the model by determining whether the physiology of the pig colon had been significantly altered after the surgical implantation of a gut cannula into the terminal ileum of the pig. A fistula was created in the terminal ileum of the pig, and a cannula fitted for the purpose of directly administering drug formulations to a point just anterior to the ileocaeco-colonic valve of the gastrointestinal tract. The cephalic vein of the pig was also cannulated to enable continued blood sampling. Sulphasalazine was used as the model drug for the validation study. In the intact colon, sulphasalazine is metabolized by the gut microflora to sulphapyridine which is then absorbed. Sulphasalazine was administered orally to non-fistulated and fistulated pigs and then ileally, via the gut cannula, to fistulated pigs. Absorption of sulphapyridine was monitored by HPLC analysis of plasma samples. There was no significant difference in the absorption obtained for the three groups. Thus it is demonstrated that the colon physiology had not been altered. The colonic pig model is ideal for studying factors affecting the colonic absorption of drugs and as a means for developing drug delivery systems with improved absorption properties.

Animals↗
PubMed1996

A localisation signal in the 3' untranslated region of c-myc mRNA targets c-myc mRNA and beta-globin reporter sequences to the perinuclear cytoplasm and cytoskeletal-bound polysomes.

There is increasing evidence that in mammalian cells some mRNAs are localised to specific parts of the cytoplasm and a proportion of mRNAs and polyribosomes are associated with the cytoskeleton. It has been shown previously that c-myc mRNA is present in the perinuclear cytoplasm and associated with the cytoskeleton, and that this localisation is dependent upon the 3' untranslated region of the mRNA. The present studies show that in transfected fibroblasts the c-myc 3' untranslated region is able to localise beta-globin reporter sequences to the perinuclear cytoplasm. Studies with constructs containing deletions within the 3' untranslated region identify the region between bases 194 and 280 as critical for localisation. Transfection of cells with constructs in which this region is linked to beta-globin sequences showed that it was sufficient to localise the chimaeric transcripts to the perinuclear cytoplasm and to cytoskeletal-bound polyribosomes. Transfection with constructs containing a mutated AUUUA sequence within the 194-280 base region showed that this conserved AUUUA is required for targeting of both c-myc mRNA and a chimaeric transcript of beta-globin transcripts linked to the c-myc 3' untranslated region. The region between bases 194 and 280 did not induce instability of beta-globin transcripts and the AUUUA mutation had little effect upon mRNA stability. We propose that this 86 nt region of the 3' untranslated region contains a localisation signal to target c-myc mRNA so that it is retained on cytoskeletal-bound polysomes in the perinuclear cytoplasm; a conserved AUUUA sequence appears to be a critical part of this signal.

Animals↗
PubMed1995

Inhibition of constitutive and inducible cyclooxygenase activity in human platelets and mononuclear cells by NSAIDs and Cox 2 inhibitors.

A range of NSAIDs and reported Cox 2 selective compounds were tested in human freshly isolated platelets and LPS-stimulated mononuclear cells to determine their potency and selectivity as inhibitors of constitutive (presumably Cox 1) and inducible (presumably Cox 2) cyclooxygenase respectively. All compounds tested were either equipotent at inhibiting constitutive and inducible cyclooxygenase or were selective for the inducible form. The most selective compound was Dup697 and the least selective, ketoprofen. Several compounds only produced a partial inhibition of constitutive cyclooxygenase as the maximum inhibitor concentration achievable in the assay was limited to 1 mM. With the exception of paracetamol, all compounds were able to produce full inhibition curves against the inducible form. Potency estimates against constitutive Cox compare closely with published data but most compounds were consistently more potent against the inducible isoform than in published data for human cloned, microsomal Cox 2. These data suggest that human mononuclear cells are either exquisitely sensitive to some NSAIDs or they may contain another Cox isoform as yet indistinguishable from Cox 2.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1995

Effect of povidone iodine dermatologic ointment on wound healing.

OBJECTIVE: To evaluate the effect of topical povidone iodine ointment on wound healing. MATERIALS AND METHODS: 60 female mice randomly divided into four groups, A-D. Each mouse had a 2 cm linear incision made on the dorsal skin. Group A had povidone iodine ointment, and group B had ointment base applied for 7 days to the healing incision. Group C were given steroids for 7 days, and group D were allowed to heal without treatment. On Day 8, the strength of the incision was tested with an in vivo tensometer, and the hydroxyproline content of the incision was determined. RESULTS: Using ANOVA and Fischer's LSD test (P < 0.05), povidone iodine as well as steroid groups had significantly reduced wound strengths as compared to the controls and the group with ointment base. No significant difference in the hydroxyproline content was seen. CONCLUSIONS: Povidone iodine significantly reduces wound strength without reducing the total hydroxyproline content of the wound.

Administration, Cutaneous↗
PubMed1994

Non-specific effects of the tachykinin NK1 receptor antagonist, CP-99,994, in antinociceptive tests in rat, mouse and gerbil.

We have examined the antinociceptive activity of the potent and selective tachykinin NK1 receptor antagonist, CP-99,994, and its less active enantiomer, CP-100,263, in a variety of models in rat, mouse and gerbil. Administered systemically to gerbil or mouse CP-99,994 but not CP-100,263 stereo selectively inhibited a caudally directed biting and scratching elicited by intrathecal administration of the tachykinin NK1 receptor agonist, GR73632. In contrast, both CP-99,994 (ED50 = 3 (1-6) mumol.kg-1 s.c.) and CP-100,263 (4 (2-10)), were equipotent at inhibiting acetylcholine-induced abdominal constrictions in mice. Similarly, both enantiomers were also equipotent in reducing formalin-induced licking in gerbil (CP-99,994 (10.1 (5.7-18.6)), CP-100,263 (13.8 (7.8-27.1)) and rat (100 mumol.kg-1 s.c.). Finally, in the spinalised, anaesthetised rat, CP-99,994 dose-dependently and significantly inhibited the flexion reflex evoked by noxious pinch (5.0 (3.3-7.5) mumol.kg-1 i.v.), whereas the less active enantiomer, CP-100,263, was without significant effect when tested up to 30 mumol.kg-1. Our results demonstrate that in the spinal cord, CP-99,994 exhibits a tachykinin NK1 receptor mediated antinociceptive action.

Analgesics↗
PubMed1994

Pre treatment with MK-801, a non-competitive NMDA antagonist, prevents development of mechanical hyperalgesia in a rat model of chronic neuropathy, but not in a model of chronic inflammation.

In the rat, loose ligation of the sciatic nerve results in behavioural signs of hyperalgesia reminiscent of neuropathy in man. A further rat model, of chronic inflammatory hyperalgesia, is produced by intraplantar administration of Freund's complete adjuvant (FCA). We report here that preemptive administration of a non-competitive antagonist of the glutamate N-methyl-D-aspartate (NMDA) receptor, MK-801 (0.3 mg kg-1, s.c.) 30 min prior to and twice daily for a further 8 days following loose ligation of the sciatic nerve, blocks the development of mechanical hyperalgesia measured 27 days later. In contrast, MK-801 administration using the same dosing regimen did not significantly inhibit the hyperalgesia apparent 15 days following i.pl. administration of FCA. Our results suggest that the mechanisms responsible for the development of mechanical hyperalgesia associated with chronic nerve injury and chronic inflammation differ.

Animals↗
PubMed1994

Effect of insulin and isoproterenol on lipid metabolism in porcine adipose tissue from different depots.

Significant differences were found in the rates of lipogenesis, glucose oxidation and lipolysis in porcine adipose tissue from four depots; outer subcutaneous (OSC), middle subcutaneous (MSC), perirenal (PR) and omental (OM). Lipogenesis was stimulated by insulin in all depots in the order PR > OM > MSC > OSC. Lipolysis was stimulated by isoproterenol in all depots in the order PR > OM > MSC > OSC. Differences in lipid metabolism by the different depots may have an important impact on lipid accretion in vivo.

Adipocytes↗