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Biomedical subjects

C James

Publications and source records attributed to C James.

At least 109 records · Page 6Linked to original sources
PubMed1994

Removal of the ovarian surface epithelium from the rabbit ovary--a cause of adhesions following a standard injury.

To assess the effect of the removal of ovarian surface epithelium on repair, a standard injury was induced in the ovaries of 10 rabbits. In one ovary the surface cells were denuded, and in the other they were left intact. The effect on adhesion formation was assessed at 12 days. Adhesions were assessed by visual inspection at laparotomy and histological examination of adhesion formation, including a stereological assessment of scar volume. On visual assessment the overall adhesion scores for the denuded ovaries were greater than for the intact ovaries. Histology showed the adhesions were attached only to the site of injury. The Fallopian tube was adherent to 35 and 4% of the denuded and intact ovarian segments respectively (P = 0.003). The scar volumes for each side were similar. After 12 days there was only partial re-epithelialization on the denuded ovaries. Electron microscopy confirmed the slow healing, with much of the surface still covered by a fibrinous-like exudate. The findings of this small study lend further weight to the importance of the surface epithelium in the control of adhesion formation. Standard surgical procedures may generate adhesions by the inadvertent denuding of surface epithelium from adjacent healthy tissues, possibly by the loss of plasminogen activator activity that is found in the mesothelium of the peritoneum. This study highlights the importance of controlling for inadvertent cell loss whilst investigating methods for adhesion prevention.

Animals↗
PubMed1994

Widespread dissemination of metal debris from implants.

In a post-mortem study, we compared subjects with metal implants with and without visible wear with an age-matched control group to determine the extent and effects of dissemination of wear debris. In subjects with stainless-steel and cobalt-chrome prostheses metal was found in local and distant lymph nodes, bone marrow, liver and spleen. The levels were highest in subjects with loose, worn joint prostheses and the main source of the debris was the matt coating. Metal levels were also raised in subjects with implants without visible wear and, to a less extent, in those with dynamic hip screws. Necrosis of lymph nodes was seen in those cases with the most wear, and potential damage to more distant organs such as the bone marrow, liver and spleen in the long term cannot be discounted. The consequences for the immune system and the role of metal dissemination in the possible induction of neoplasia are discussed.

Aged↗
PubMed1993

Effects of chronic NSAIDs on gastric mucosal injury related to mucosal prostanoids, and plasma drug concentrations in human volunteers.

The relationship between endoscopically observed gastric mucosal damage, elicited following repeated oral intake for 7 d of four NSAIDs, to their effects on antral and fundic production of PGE2, 6-keto-PGF1 alpha and TxB2 (assayed by GC-MS), mucosal histology and plasma concentration profiles was studied in 40 normal males. Subjects received azapropazone (APZ) 600 mg b.i.d., indomethacin (IND) 50 mg t.i.d., naproxen (NAP) 500 mg b.i.d., piroxicam (PIR) 20 mg qq.d., or one placebo capsule t.i.d. (N = 8/group). Plasma NSAIDs (HPLC) levelled at 7 d. Mucosal damage occurred in the antrum region with IND and NAP. APZ and PIR exhibited no differences compared to placebo. NAP and IND reduced all three prostanoids in the antrum while APZ and PIR were ineffective. Fundic PGE2 was reduced by IND, NAP and PIR; APZ had no effects. Thus, mucosal damage relates to effects on prostanoid production in the antrum but not in the fundus.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

Identification of the microsporidian parasite, Enterocytozoon bieneusi in faecal samples and intestinal biopsies from an AIDS patient.

The microsporidian parasite, Enterocytozoon bieneusi, is currently recognized as a potentially important cause of chronic diarrhoea in patients infected with the human immunodeficiency virus (HIV). Faecal concentrates from a 38-year-old, HIV-seropositive patient examined by light and electron microscopy revealed the presence of numerous microsporidian spores. The structural characteristics of the spores were consistent with those previously described for Enterocytozoon bieneusi. Each spore contained a single nucleus, a posterior vacuole and a polar filament with 6-7 overlapping coils which appeared in cross-section as a series of 3 doublets. Mature spores were surrounded by an inner unit membrane, an electron-lucent endospore and a thin, electron-dense exospore. The identity of the parasite was confirmed by the detection of unique endogenous developmental stages in duodenal biopsies. Both proliferative and sporogonial plasmodia (meronts and sporonts) were observed and all stages were monokaryotic (single nucleus) and apansporoblastic (sporophorous vesicle absent). Proliferative and sporogonial plasmodia divided by plasmotomy and spore organelles (polar filament, attachment disc and polaroplast) were well developed prior to fission of the sporogonial plasmodium.

AIDS-Related Opportunistic Infections↗
PubMed1993

Multivariate FTIR analysis of substrates for protein, polysaccharide, lipid and microbe content: potential for solid-state fermentations.

Components of fermentation processes such as protein, polysaccharide and lipid, as well as microbes, such as fungi grown on solid substrates, are difficult to measure in situ. The potential of Fourier Transform Infrared (FTIR) analysis of solid-state fermentations from mid-infrared absorption spectra has been investigated. The problem under consideration was to build a calibration model containing no irrelevant information to enable a multivariate mathematical approach for prediction of component concentrations. Methods for solid sample preparation and preprocessing of FTIR data were developed to assure Beer-Lambert law compliance and produce a well-conditioned multivariate system. The model was tested using composite samples of zein protein, corn starch and azolectin lipid, and corn samples containing known levels of fungal contamination. Preliminary concentration estimates were remarkably close to the correct values, with less than 5% standard error of prediction for all components measured.

Journal Article↗
PubMed1993

A distant 10-bp sequence specifies the boundaries of a programmed DNA deletion in Tetrahymena.

Programmed DNA deletion occurs at thousands of specific sites in most ciliates studied. To understand the mechanism of this prominent DNA rearranging process, we analyzed one of the deletion elements (the M-element) in Tetrahymena by making specific mutations in cloned DNAs and testing their effects on rearrangement in vivo. We found that a 10-bp polypurine sequence (5'-AAAAAGGGGG) plays a crucial role. This sequence is located at a short distance (approximately 45 bp) outside of the element on either side. Removal of it abolishes the deletion process. Moving it short distances away causes the deletion boundary to move with it. Insertion of this sequence into a site within the element induces new boundaries to form near the insertion site. Sequence analysis reveals that all new boundaries created are 41-54 bp away from the sequence. Thus, this sequence is necessary and sufficient to determine the boundaries of DNA deletion, and it does so from a short distance outside of the element. These results offer a possible explanation for the control of DNA deletion in ciliates and suggest that a new type of mechanism for site-specific DNA rearrangements is involved.

Adenine↗
PubMed1992

Effects of misoprostol on the pharmacokinetics of indomethacin in human volunteers.

The effects of misoprostol (200 micrograms as a single dose or q.i.d. as a multiple dose) on the pharmacokinetics of indomethacin (100 mg single-dose administration or 50 mg t.i.d. multiple-dose administration) were studied in 16 healthy human volunteers under single-dose and steady-state conditions in a randomized, double-blind, placebo-controlled, balanced three-period study design. The overall absorption as shown by the values for area under the concentration curve of indomethacin was unaffected by concurrent administration of misoprostol. However, misoprostol did significantly enhance the steady-state maximum concentration of indomethacin by 32%. Thus misoprostol does not interfere with the absorption of indomethacin despite the known inhibitory effects of this protaglandin analog on acid secretion.

Administration, Oral↗
PubMed1992

General practitioners' confidence in diagnosing and managing eye conditions: a survey in south Devon.

In order to open dialogue aimed at increasing eye care in general practice and reduce waiting times for ophthalmic outpatient appointments general practitioners in the Torbay health district were asked about their levels of confidence in ophthalmology as a subject, and in the diagnosis and management of specific eye conditions. They were also asked about ophthalmic equipment available to them, their management policies for 34 specific eye conditions, and their perceived need for further training in this subject. A total of 75% of the general practitioners responded to the questionnaire. Despite more than half of the general practitioners indicating that they did not feel confident with ophthalmology generally, most expressed confidence in diagnosing and managing common eye conditions. Basic equipment for examining the eye was available to most doctors. Referral policies varied considerably, and these have resource implications. Seventy eight per cent of respondents were prepared to take on more eye care in general practice, and over 80% of general practitioners requested informal teaching sessions in ophthalmology. Support must be forthcoming if general practitioners are to provide eye care in general practice.

Clinical Competence↗
PubMed1991

Intraoperative management of ureteral injury during operative laparoscopy.

Injury to the ureter from operative laparoscopy is rare. The diagnosis is usually made radiologically, in the postoperative period, when the patient presents with symptoms and signs suggestive of ureteral injury. We report herein a case of ureteral injury resulting from operative laparoscopy for endometriosis. The injury was diagnosed and treated via laparoscopy during the same procedure. The increased utilization of operative laparoscopy to perform more complex procedures increases the potential for operative injury to the ureter. Prior visualization or retroperitoneal dissection of the ureter, in appropriate cases, will help reduce this complication and/or permit a prompt diagnosis in the event of such injury.

Adult↗
PubMed1991

Sternomastoid muscle twitch maximum relaxation rate: prolonged slowing with fatigue and post-tetanic acceleration.

1. The maximum rate of relaxation of stimulated twitches (twitch maximum relaxation rate) of the sternomastoid muscle was compared with its frequency-force curve (expressed as the ratio of force produced at a stimulation frequency of 20 Hz to that produced at 50 Hz, the 20:50 ratio) before and after fatiguing exercise of the sternomastoid muscle in 10 normal subjects. The mean (+/- SEM) fresh state twitch maximum relaxation rate was 9.51 (+/- 0.64)% force loss/10 ms and the mean (+/- SEM) 20:50 ratio was 73.4 (+/- 2.6)%. 2. The mean twitch maximum relaxation rate fell to 71.5 (+/- 2.2)% of the pre-fatigue value at 2 min after exercise, recovering to 73.1 (+/- 1.6)% by 5 min, 78.4 (+/- 2.34)% by 10 min and 80.6 (+/- 2.70)% by 60-min. The 20:50 ratio fell to 72.3 (+/- 3.56)% of pre-fatigue levels at 10 min after exercise and recovered to 78.8 (+/- 3.16)% by 60 min. There was no significant difference in the percentage falls between the two techniques. 3. Further studies were performed to determine the response of the twitch maximum relaxation rate to a prior brief tetanic stimulus or a brief maximal voluntary contraction of the muscle. Both tetanic stimulation and maximal voluntary contraction accelerated the twitch maximum relaxation rate to over 140% of the fresh state value. Both manoeuvres temporarily returned the slowed twitch maximum relaxation rate after fatiguing exercise back to the fresh state value. 4. The effect of fatiguing exercise on the time course of recovery of quadriceps twitch maximum relaxation rate was also studied in two subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗