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Biomedical subjects

J S White

Publications and source records attributed to J S White.

At least 19 recordsLinked to original sources
PubMed2006

Use of tissue expanders and pre-operative external beam radiotherapy in the treatment of retroperitoneal sarcoma.

INTRODUCTION: We report our experience of treating retroperitoneal sarcoma (RPS) using pre-operative external beam radiotherapy (EBRT) in combination with radical resectional surgery from 1990 to 2005. METHODS: Twenty-eight primary and 10 recurrent tumors were identified from a prospective database. RESULTS: The resection rate was 71% overall; 82% in primary (23/28) and 40% (4/10) in recurrent cases. EBRT was administered preoperatively in 25 patients, postoperatively in 1, and palliatively in 11. In 33 patients a saline-filled tissue expander was inserted into the abdomen before radiotherapy to displace small bowel from the radiation field. 4,500-5,000 cGy was administered in fractions of 180-200 cGy over a 5-week period; surgery followed 6-8 weeks later. Expander insertion was associated with minimal morbidity; 31/37 patients received a dose of 4,000 cGy or more (median 4,650 cGy). Median resected tumor diameter was 13 cm, and a median of three adjacent organs was resected per patient. Complete macroscopic resection was achieved in 25/27 patients (93%); R0 in 9 (33%) and R1 in 13 (48%) (microscopic margins unclear in 5). There was no postoperative mortality. Tumors were high-grade in 20 patients, low-grade in 14 and ungraded in 4. Actuarial 5- and 10-year survival for all patients was 74 and 60%. For operable primary tumors, the 5-year survival and disease-free rates were 90 and 80%. In four patients with operable recurrent tumors, median disease-free interval was 91 months (27-160). In the 11 inoperable cases, median survival after radiotherapy was 48 months (9-77). CONCLUSIONS: We conclude that a combination of pre-operative tissue expander placement, high-dose EBRT and radical resectional surgery can achieve acceptable morbidity, extended survival and low long-term recurrence in patients with RPS. STATISTICS: Median (interquartile range).

Female↗
PubMed2006

11q13 amplification status and human papillomavirus in relation to p16 expression defines two distinct etiologies of head and neck tumours.

Two distinct etiologies of head and neck squamous cell carcinoma (HNSCC) have been proposed, DNA damage owing to tobacco and alcohol exposure and human papillomavirus (HPV) oncogene-mediated transformation. Common genetic alterations in HNSCC include TP53 mutations, 11q13 amplification (amp) and CDKN2A/p16 mutations or promoter methlyation. However, in HPV+ HNSCC it is frequent to observe wild-type TP53 and expression of p16. The relationship of this unusual pattern with 11q13 amp has not been tested. In a retrospective study on 125 HNSCC patients, only 17% (five out of 30) of HPV+ vs 44% (39 out of 89) of HPV - tumours expressed 11q13 amp (adjusted odds ratio (OR)=0.2, 95% confidence interval (CI)=0.1-0.6). A subpopulation of tumours (n=69) were classified according to the three molecular markers, TP53, p16 and 11q13 amp. In addition to wild-type TP53, and p16 expression, HPV+ tumours were more likely not to be amplified at 11q13 (OR=6.5, 95% CI=1.8-23.9). As HPV+ HNSCC lack the genetic alterations which are common in other tumours, we hypothesise that HPV infection may represent an early event in the HNSCC carcinogenic process, thus suggesting a distinct molecular pathway.

Adult↗
PubMed2006

The probiotic bacterium Lactobacillus plantarum species 299 reduces intestinal permeability in experimental biliary obstruction.

AIMS: Extrahepatic biliary obstruction is associated with the failure of intestinal barrier function, allowing bacteria and other substances from the intestine to enter the circulation and initiate a systemic inflammatory response, causing impairment of organ function. Probiotic bacteria have been shown to have beneficial effects on intestinal barrier function in other conditions, but their effects have never been studied in biliary obstruction. METHODS AND RESULTS: This study examined the effects of enteral administration of Lactobacillus plantarum species 299 (LP299) in oatmeal fibre compared with sterile oatmeal fibre in water or water alone in an animal model of biliary obstruction. Administration of LP299 was associated with reduced intestinal permeability compared with sterile oatmeal alone (0.262 +/- 0.105%vs 0.537 +/- 0.037%, P=0.019, percentage excretion of (14)Carbon), but there was no evidence of reduced endotoxin exposure or blunting of the systemic inflammatory response. Animals receiving sterile oatmeal fibre alone also failed to develop the hyperpermeability after biliary obstruction seen in animals receiving water only (0.512+/- 0.05%vs 0.788 +/- 0.18%), suggesting that oatmeal itself may have some beneficial effects on intestinal barrier function. CONCLUSION: Enteral administration of the probiotic bacterium LP299 reduces intestinal hyperpermeability associated with experimental biliary obstruction. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides insight to direct further work into the modulation of intestinal barrier function by probiotic bacteria.

Animals↗
PubMed2006

Intravasation of barium sulphate at barium enema examination.

We report a case of venous intravasation of barium sulphate occurring during a routine barium enema examination for investigation of rectal bleeding. The patient suffered a cardiopulmonary arrest, but made a full recovery after organ support in intensive care. Review of radiographs from the examination showed intravasated barium in pelvic vessels. We review the literature on this rare, but serious, complication of barium enema examination and suggest measures by which intravasation can be prevented.

Aged↗
PubMed2005

Patterns of bacterial translocation in experimental biliary obstruction.

INTRODUCTION: Biliary obstruction is associated with impaired intestinal barrier function and translocation of enteric bacteria to the systemic circulation. Traditional live culture techniques may overlook translocation of dead bacterial fragments that stimulate the inflammatory response. The aim of this study was to estimate the extent and pattern of bacterial translocation in experimental biliary obstruction. MATERIALS AND METHODS: Thirty 9-week-old male Wistar rats were randomized to undergo bile duct ligation (BDL, n = 20) or sham operation (n = 10). Seven days after operation, each animal received 1 ml of (111)indium-oxyquinolone-labeled Escherichia coli p.o. Samples of liver, spleen, mesenteric lymph nodes, and lung were harvested 4 h later and analyzed for live bacteria and (111)indium activity. RESULTS: There was significantly more live bacterial translocation detected in BDL animals than in sham-operated animals (P = 0.00008, chi(2)). Labeled bacterial fragments were detected in all locations sampled in all animals. Sham-operated animals had significantly more labeled bacterial fragments detected in the liver (P = 0.0001) and the spleen (P = 0.03) than the BDL animals. The mean total bacterial survival in the BDL group was 30 +/- 13% and 0% in the sham operated group. CONCLUSION: These results demonstrate that non-viable bacterial fragments are present in sterile extra-intestinal sites in normal animals and that translocation of live bacteria is markedly increased in experimental biliary obstruction. These results also suggest that failure of bacterial killing is an important factor facilitating bacterial translocation in the presence of established biliary obstruction.

Animals↗
PubMed2004

Systemic absorption of lithium following ingestion of a lithium button battery.

Accidental ingestion of electrical batteries occurs commonly in children. This rarely is associated with severe morbidity and mortality. Significant symptoms can arise due to leakage of alkali or heavy metals from the battery after degradation in the gastrointestinal tract. The main heavy metal of concern in electrical batteries is mercury; this is the first report of ingestion of a lithium battery in a child associated with systemic absorption of lithium.

Child, Preschool↗
PubMed2003

Inorganic tin and organotin interactions with Candida maltosa.

As a consequence of the widespread industrial and agricultural applications of organotins, contamination of various ecosystems has occurred in recent decades. Understanding how these compounds interact with microorganisms is important in assessing the risks of organotin pollution. The organotins, tributyltin (TBT), trimethyltin (TMT) and inorganic tin, Sn(IV), were investigated for their physical interactions with non-metabolising cells and protoplasts of the yeast Candida maltosa, an organism that is often associated with contaminated environments. Uptake, toxicity and membrane-acting effects of these compounds, at concentrations approximating those found in polluted environments, were assessed. Sn(IV) and TBT uptake occurred by different mechanisms. Uptake of Sn(IV) was 2-fold greater in intact cells than protoplasts, underlining the importance of cell wall binding, whereas TBT uptake levels by both cell types were similar. TBT uptake resulted in cell death and extensive K+ leakage, while Sn(IV) uptake had no effect. TMT did not interact with cells. Of the three compounds, TBT alone altered membrane fluidity, as measured by the fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene incorporated into cells. Anisotropy of 1-(4-trimethylaminophenyl-6-phenyl-1,3,5-hexatriene) was not affected, implying that TBT is not confined to the surface of the cytoplasmic membrane, but acts within membrane lipids. These results indicate that the cell wall is the dominant site of Sn(IV) interactions with yeast, while lipophilic interactions play an important role in uptake and toxicity of TBT.

Candida↗
PubMed2003

Treatment of infantile hypertrophic pyloric stenosis in a district general hospital: a review of 160 cases.

BACKGROUND: Ramstedt's pyloromyotomy has long been the standard operation for the treatment of infantile hypertrophic pyloric stenosis. Controversy exists over whether this procedure can be performed safely in the district general hospital setting or whether it should be restricted to specialist pediatric units only. METHODS: Retrospective analysis was performed on the medical records of a series of 160 infants treated by Ramstedt's pyloromyotomy by 2 surgeons in a district general hospital over 16 years. RESULTS: There was no perioperative mortality. Oral feeding was achieved by 24 hours in 76% of infants, and there was persistent vomiting in only 3.8%. Wound discharge was encountered in 4.4% and confirmed wound infection in 1.3%. Wound dehiscence occurred in 1.9% of infants. Inadvertent mucosal perforation occurred in 19% of cases, although all cases were recognized and repaired at once with no apparent ill effects. These results are comparable with those reported from specialist pediatric units and from pediatric surgeons working within general surgical units. CONCLUSIONS: Infantile hypertrophic pyloric stenosis can be treated safely in a district general hospital when care is provided by appropriately trained surgical, anesthetic, and pediatric staff.

Digestive System Surgical Procedures↗
PubMed1999

Injuries and risk factors in a 100-mile (161-km) infantry road march.

BACKGROUND: Light infantry soldiers (N = 218) completed a 161-km cross-country march over 5 days carrying an average +/- SD load mass (i.e., the weight of all equipment and clothing) of 47 +/- 5 kg. METHODS: Prior to the march, height, weight, body fat, and physical fitness (3.2-km run, sit-ups, push-ups) were measured. Soldiers completed a demographic questionnaire which included questions on age and tobacco use history. RESULTS: Thirty-six percent (78/218) of the soldiers suffered one or more injuries. Of the total injuries, 48% presented were blisters and 18% were foot pain (not otherwise specified). Eight percent (17/218) of the soldiers were unable to complete the march because of injuries. Thirty-five percent (27/78) of the injured soldiers had 1 or more limited duty days for a total of 69 days. Risk of injury was higher among smokers (risk ratio = 1.8, P = 0.03 compared to nonsmokers) and lower among older soldiers (risk ratio = 3.2, P = 0.02, < 20 years compared to > 24 years). CONCLUSIONS: Carrying heavy loads over long distances can result in a high injury incidence to the lower body, since 36% of soldiers were injured during the 161-km march. Smoking and younger age (< 20 years) were independent risk factors for injuries.

Adult↗
PubMed1999

Correlation of cytogenetics, BCR-ABL PCR studies and fluorescence in situ hybridisation (FISH) in adult acute lymphoblastic leukaemia.

BACKGROUND: Philadelphia positive (Ph+) acute lymphoblastic leukaemia (ALL) accounts for 11-29% of adult ALL. Reverse transcriptase polymerase chain reaction (RT-PCR) for the BCR-ABL fusion mRNA has identified patients with the fusion mRNA without cytogenetic evidence of the 9;22 translocation. The reason for discrepancies between cytogenetic and molecular diagnoses is unclear. AIM: Our aim was to study cases of ALL with discordant cytogenetic and RT-PCR results and identify any reasons for such discrepancies. METHODS: Laboratory records were scanned for cases of ALL tested by both RT-PCR and cytogenetics and positive by either for the 9;22 translocation. Fluorescence in situ hybridisation (FISH) was used to study discordant results where a specimen was available. RESULTS: We identified 15 patients with ALL who had both cytogenetic and RT-PCR studies for BCR-ABL. Seven had discordant results; five patients had positive RT-PCR studies with normal (four/five) or abnormal but Ph negative cytogenetics (one/five), and two were Ph+ but RT-PCR negative. FISH, using Vysis LSI bcr/abl translocation probes, showed fused signals in 12% interphase cells but not in metaphase cells in one specimen with normal cytogenetics, and 6% interphase cells in the Ph negative patient with abnormal cytogenetics. This second patient subsequently relapsed with a minor Ph+ cell line derived from the Ph negative line. CONCLUSIONS: These results confirmed the need for both cytogenetics and RT-PCR to identify Ph+ ALL. FISH did not show sub-microscopic rearrangements of BCR-ABL in normal metaphases. Failure to identify the Philadelphia chromosome cytogenetically appeared due rather to Ph+ cells failing to divide.

Adolescent↗
PubMed1999

Organotin compounds and their interactions with microorganisms.

Organotin compounds are ubiquitous in the environment. The general order of toxicity to microorganisms increases with the number and chain length of organic groups bonded to the tin atom. Tetraorganotins and inorganic tin have little toxicity. Because of their lipophilicity, organotins are regarded as membrane active. There is evidence that the site of action of organotins may be both at the cytoplasmic membrane and intracellular level. Consequently, it is not known whether cell surface adsorption or accumulation within the cell, or both is a prerequisite for toxicity. Biosorption studies on a fungus, cyanobacteria, and microalgae indicates that cell surface binding alone occurred in these organisms, while studies on the effects of TBT (tributyltin) on certain microbial enzymes indicated that in some bacteria TBT can interact with cytosolic enzymes. Microorganism-organotin interactions are influenced by environmental conditions. In aquatic systems, both pH and salinity can determine organotin speciation and therefore reactivity. These environmental factors may also alter selectivity for resistant microorganisms in polluted systems. Tin-resistant microorganisms have been identified, and resistance can be either plasmid or chromosomally mediated. In one TBT-resistant organism, an Altermonas sp., an efflux system was suggested as the resistance mechanism. Biotransformation of organotin compounds by debutylation or methylation has been observed. These reactions may influence the toxicity, mobility, and environmental fate of organotin compounds.

Bacteria↗
PubMed1999

The 1653 English edition of De motu cordis, shown to be Harvey's vernacular original and revealing crucial aspects of his pre-circulation theory and its connection to the discovery of the circulation of the blood.

From a comparative study of the first Latin edition of William Harvey's De motu cordis published in 1628, and the first English edition published in 1653, it is argued that the latter is the printed copy of Harvey's original manuscript written in the vernacular. It will also be shown that Harvey's pre-circulation theory described the heart as an impulsor of blood for several years before his discovery of the circulation of the blood. The crucial aspect of his description was a new explanation of the cause of the arterial pulse as felt at the extremities.

Blood Circulation↗
PubMed1998

How provider fraud flattens corporate profits.

New laws are giving the private sector some real enforcement clout--and a better shot at recovering or preserving huge sums of money at a time when other dampers on costs are screwed down about as tight as they can get.

Cost Savings↗
PubMed1995

In vitro recall of proliferative and cytolytic responses to minor histocompatibility antigens by dendritic cell enriched canine peripheral blood mononuclear cells.

It is difficult in vitro to demonstrate existent in vivo sensitization of dogs and humans to minor histocompatibility antigens. Using conventional one-way mixed leukocyte culture, when sensitized blood cells are stimulated with MHC antigen-matched sibling PBMC bearing the minor histocompatibility antigens, there is usually no proliferative or cytotoxic response detected. We reported previously that 0 of 17 dogs sensitized by transfusion of dog leukocyte antigen-identical littermate blood had proliferative responses in mixed leukocyte culture when unfractionated sibling PBMC were used as stimulator cells. We reasoned that this result might be due to the inability of unfractionated PBMC to efficiently present minor histocompatibility antigens to the in vivo-primed T cells, a function thought best performed by dendritic cells. When we used a low buoyant density Percoll fraction of canine PBMC, shown previously to be enriched in dendritic cells, as stimulator cells, we were able to generate cytotoxic and/or proliferative responses in mixed leukocyte culture in all 5 dogs that had been sensitized to minor histocompatibility antigens by transfusions of dog leukocyte antigen-identical sibling littermate blood. By contrast, using unfractionated PBMC as stimulator cells, we found evidence of sensitization in only 1 of the 5 dogs. These data support the concept that the presentation of minor histocompatibility antigens, in contrast to major histocompatibility antigens, to the immune system may be restricted to a subpopulation of professional APC.

Animals↗
PubMed1993

Manufacturing, composition, and applications of fructose.

High-fructose syrups (HFS) comprise fructose, dextrose, and minor amounts of oligosaccharides. The predominant syrups of commerce contain 42% and 55% fructose. HFS production was made possible by concurrent developments in refining, isomerization, and separation technologies in the 1960s. Fructose contributes many useful physical and functional attributes to food and beverage applications, including sweetness, flavor enhancement, humectancy, color and flavor development, freezing-point depression, and osmotic stability. HFS is used extensively in carbonated beverages, baked goods, canned fruits, jams and jellies, and dairy products. The use of crystalline fructose and crystalline fructose syrup have recently expanded from pharmaceutical and specialty food products to mainstream food and beverage applications.

Carbohydrate Sequence↗
PubMed1989

Persistent infection of rabbits with bovine leukemia virus associated with development of immune dysfunction.

Bovine leukemia virus (BLV) infection of rabbits provides a safe and relatively inexpensive in vivo mammalian system for the study of the mechanisms controlling expression of a unique group of lymphotropic retroviruses. This group of viruses, which includes C-type human T-lymphotropic virus types I and II and lentiviruslike human immunodeficiency virus type 1, possesses genes coding for "trans-activating" products. Rabbits experimentally inoculated with BLV became persistently infected, as demonstrated by a number of tests. All BLV-inoculated rabbits developed persistent serum antibody to BLV. Furthermore, all BLV-inoculated rabbits had peripheral blood mononuclear cells which, when stimulated, expressed the virus, as demonstrated by viral induction of syncytium formation in a BLV-susceptible fibroblast line. The presence of BLV in circulating cells was confirmed by using peripheral blood mononuclear cells from randomly selected BLV-inoculated rabbits, which showed the presence of viral reverse transcriptase activity, BLV transcriptional activity, or BLV proviral DNA. Additional tests showed that infected lymphocytes maintained in culture with recombinant human interleukin-2 formed multinucleated giant cells and produced virus when incubated in cytokine-containing medium. BLV-infected rabbits also showed alterations in several parameters associated with immunity, beginning 6 months after inoculation. Thirty-eight percent of infected rabbits developed abnormally low T-cell responses, as measured by phytolectin stimulation, and T-cell responses cycled between normal and abnormally low over a period of 20 to 24 months. Forty-four percent of rabbits infected for longer than 12 months suffered from recurrent conjunctivitis and rhinitis. By 24 months postinoculation, 28% of infected rabbits were dead or were killed because of poor clinical condition.

Animals↗