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Biomedical subjects

A J Ross

Publications and source records attributed to A J Ross.

At least 37 records · Page 2Linked to original sources
PubMed1996

Prison rights: mandatory drugs tests and performance indicators for prisons.

Mandatory drugs testing of prisoners applies throughout England and Wales. Data from the 1995 pilot study in eight prisons show that the proportion testing positive for opiates or benzodiazepines rose from 4.1% to 7.4% between the first and second phase of random testing and that there was a 20% increase over 1993-4 in the provisional total of assaults for 1995. Interpretation of these data is difficult, but this is no excuse for prevarication over the danger that this policy may induce inmates to switch from cannabis (which has a negligible public health risk) to injectable class A drugs (a serious public health risk) in prison. The performance indicators for misuse of drugs that are based on the random mandatory drugs testing programme lack relevant covariate information about the individuals tested and are not reliable or timely for individual prisons.

Adult↗
PubMed1996

Murine gammaherpesvirus-induced splenomegaly: a critical role for CD4 T cells.

Murine gammaherpesvirus (MHV-68) causes an acute respiratory infection followed by a latent infection in B lymphocytes. In the first 2-3 weeks after infection mice develop a marked splenomegaly, where the spleen cell number increases by 2-3 fold. Cytofluorimetric analysis during splenomegaly revealed an increase in numbers of B lymphocytes and of both CD4+ and CD8+ T lymphocytes. The largest increase relative to uninfected spleens was in the CD8+ population. The number of latently infected cells in the spleen peaked at day 10 post-intraperitoneal infection, then declined to 1/10(6)-1/10(7) cells per spleen. Depletion of CD4+ T lymphocytes prevented the splenomegaly and greatly reduced the peak infective centre level, while having no effect on the long-term of latently infected cells. Given the similarity between MHV-68-induced splenomegaly and Epstein-Barr virus-induced infectious mononucleosis, these data highlight the usefulness of MHV-68 as a mouse model for the study of gammaherpesvirus immunology and pathobiology.

Animals↗
PubMed1995

Drug injection and HIV prevalence in inmates of Glenochil prison.

OBJECTIVE: To determine prevalence of HIV infection and drug injecting behaviour among inmates of Glenochil Prison on a specified date a year after an outbreak of hepatitis B and HIV infection. DESIGN: Cross sectional: voluntary, anonymous HIV salivary antibody surveillance and linked self completion questionnaire on risk factors. SETTING: Glenochil prison, Scotland, a year after an outbreak of hepatitis B and HIV transmission related to drug injection. SUBJECTS: 352 prisoners, of whom 295 (84%) took part; 284 questionnaires (96%) passed logical checks. MAIN OUTCOME MEASURES: HIV prevalence; proportion of all inmates who had ever injected drugs, had ever injected inside prison, had started injecting drugs while inside prison. RESULTS: More than half (150/284) the current inmates were also in Glenochil Prison during the critical period of January to June 1993, when hepatitis B and HIV were transmitted. Similar proportions of current inmates and men who were also in Glenochil during the critical period were drug users (27% (75/278) v 30% (44/149)). A quarter of injecting drug users (18/72) had first injected inside prison, irrespective of whether they were in Glenochil in January to June 1993 and regardless of the calendar period when they first injected. Significantly more inmates from Glasgow (41%; 56/138) than from Edinburgh (21%; 7/34) or elsewhere (11%; 12/106) were injecting drug users. On testing for HIV, seven saliva samples out of 293 gave positive results--four were presumed to be from inmates known to be infected with HIV, and the others from injecting drug users from Glasgow, all of whom had been in Glenochil during January to June 1993, when two of the three had injected drugs and had been tested for HIV, with negative results. The ratio of overall (2.4%) to disclosed (1.4%) HIV prevalence was 1.7. For men who had injected drugs in Glenochil during January to June 1993, HIV prevalence was estimated at 29%. CONCLUSION: Between a quarter and a third of prisoners who injected drugs in Glenochil in January to June 1993 were infected with HIV. There is widespread ongoing risk of bloodborne virus infection within prisons, which is probably long standing but demands urgent attention.

Adult↗
PubMed1995

The role of surgery in the management of stage IV neuroblastoma: a single institution study.

The role of surgery in the management of Stage IV neuroblastoma is still far from clear. Seventy-nine patients with this diagnosis presented to the Children's Hospital of Philadelphia during the 10-year period, 1977 to 1986. Four-year survival was 23%. A major resection of the primary tumor was undertaken in 54 patients. The timing of the procedure (at presentation or delayed) had no effect on survival. The patients were divided into three groups based on the extent of surgical resection: Group 1, no surgery or biopsy only (25); Group 2, complete gross resection (34); Group 3, incomplete resection with residual gross disease (20). Four-year survival was 16, 15, and 45%, respectively. The patients were then classified as favorable or unfavorable, on the basis of biological prognostic factors at presentation. When this analysis was combined with the extent of surgery it was discovered that Group 3 contained a higher proportion of favorable patients, accounting for the better survival. Within each group survival correlated with the expected prognosis. The outcome for a patient with Stage IV neuroblastoma depends on the biological characteristics of the tumor, and there is currently no evidence that these can be favorably altered by the timing or extent of surgical resection. Defining the appropriate role of surgery in the management of these patients will require a prospective randomized study which takes into account the inherent biological variability of the disease.

Adolescent↗
PubMed1995

Octreotide does not prevent bacterial translocation in an infant piglet model of intestinal ischemia-reperfusion.

The process of bacterial translocation (BT) after ischemia/reperfusion (I/R) injury is reported to be mediated by local mucosal factors, the effects of pancreatic enzymes, epithelial disruption, and by dysfunctional intestinal motility. Octreotide (OCT), a somatostatin analog, has been postulated to protect against BT by influencing one or more of these factors. Twenty-two formula-fed piglets (weight, 3.5 +/- 0.5 kg; age, 20 +/- 5 days) were divided into four groups: control (no drug given; no I/R; n = 6), I/R (no drug given; n = 5), I/R plus low-dose OCT (LD OCT, 0.08 microgram/kg; n = 6), and I/R plus high-dose OCT (HD OCT, 8 micrograms/kg; n = 5). All experimental subjects had nonocclusive mesenteric ischemia induced by reversible pericardial tamponade with mesenteric flow decreased to 25 +/- 5% of baseline for 5 hours followed by 15 +/- 5 hours of reperfusion. Mesenteric lymph nodes (MLN), liver, spleen, blood, and peritoneum were harvested for blind microbial analysis. None of the animals in the control group experienced translocation to the tissues tested. All of the animals in the I/R group experienced BT to the MLN. The subjects in the LD OCT and HD OCT groups experienced BT to the MLN 66% and 80% of the time, respectively. Despite the reported clinical evidence that OCT can protect the intestinal mucosa from injury and increase the clearance of bacteria from the gastrointestinal tract, in this study in which variables other than I/R known to promote bacterial translocation were eliminated, OCT failed to modify or prevent the occurrence of translocation to the MLN after I/R injury.

Animals↗
PubMed1995

Anonymous HIV surveillance with risk factor elicitation at Scotland's largest prison, Barlinnie.

OBJECTIVE: To determine prevalence of HIV infection and risk behaviours among male inmates of Her Majesty's Prison (HMP) Barlinnie, Glasgow, Scotland on 8-9 September 1994. DESIGN: Cross-sectional study: voluntary, anonymous HIV surveillance (using saliva samples) of all inmates and linked self-completion risk-factor questionnaire. SUBJECTS: Of 1073 prisoners available to participate, 985 (92%) completed a risk-factor questionnaire and 982 salivettes were received for testing, of which 978 were tested for HIV antibodies (four were dry samples); 928 questionnaires passed logical checks for consistency. MAIN OUTCOME MEASURES: HIV prevalence on saliva testing, related risk behaviours and ratio of overall-to-disclosed HIV prevalence. Proportion of all inmates who have ever injected drugs, ever injected inside prison, started injecting inside, ever had acute hepatitis, had a recent personal HIV test (since January 1993). RESULTS: Nine saliva samples [eight injecting drug users (IDU), one recognized other risk] out of 978 were HIV-antibody-positive (three presumptively from known HIV-infected inmates). Overall HIV prevalence was estimated at 1% compared with a known prevalence of 0.4%, giving an overall-to-disclosed HIV prevalence ratio of 2.6 in HMP Barlinnie in September 1994. A higher proportion of prisoners from Glasgow (48%) than elsewhere (19%) were IDU. Year of first injection was also different by residence with 23% of Glasgow IDU having first injected after 1988 compared with 45% of IDU from elsewhere, mainly West and South Scotland. Half the IDU inmates reported having injected while incarcerated and 6% had started to inject while incarcerated. Ten per cent of all prisoners and 20% of IDU inmates had had a personal HIV test since January 1993. Logistic regression showed that there was a significant deficit of recent HIV test uptake by Glasgow residents (odds ratio, 0.5; 95% confidence interval, 0.27-0.89), that IDU were more likely to have had treatment for a sexually transmitted disease, and that IDU who had injected inside and those whose injecting career began prior to 1989 were more likely to have had acute hepatitis. CONCLUSION: A consistent harm-reduction policy is needed across prisons in the United Kingdom to avoid transmission of blood-borne viral infections. Drug injecting inside prison is common, a proportion of IDU inmates having first injected drugs while in prison, and much higher rates of hepatitis have been reported in association with injecting while incarcerated compared with that for IDU who only injected outside prison.

Adult↗
PubMed1994

Deaths, HIV infection, abstinence, and other outcomes in a cohort of injecting drug users followed up for 10 years.

OBJECTIVE: To trace, follow up, and interview a group of patients known to be injecting drug users in order to establish current drug taking and other features related to drug use over 10 years. DESIGN: Descriptive follow up study of a cohort of injecting drug users established between 1982 and 1985. SETTING: General practice based patient population study initially, with later tracing of subjects throughout the United Kingdom through NHS Central Registries and current general practitioners. SUBJECTS: 203 injecting drug users recruited up to December 1985. MAIN OUTCOME MEASURES: Survival, cause of death, abstinence, or continued drug use; HIV status; and demographic variables. RESULTS: Of the 203 injecting drug users recruited into the study, over half were known to be HIV positive and 42 died of various causes (increasingly AIDS). From the start of follow up in 1990, 163 (91%) of the 180 survivors were traced, of whom 116 (71%) were interviewed. Dramatic changes had occurred in drug taking, with a move away from injecting towards oral drug use. A few patients, however, continued to inject. 90 (78%) of those interviewed had been in prison, of whom 37 (41%) had injected drugs while in prison. CONCLUSIONS: The pattern of deaths had changed from being largely due to overdose in the early 1980s to predominantly AIDS related in later years. The reduction in deaths due to overdose may have been connected with but was not always causally related to a new approach by legal, social, and medical services. Drug use continues in a modified form in a large proportion of patients followed up. As a group, drug users require long term support for a multiplicity of problems.

Adult↗
PubMed1994

Bone marrow transplantation for high risk neuroblastoma at the Children's Hospital of Philadelphia: an update.

A bone marrow transplant (BMT) protocol including surgical excision, local and total body irradiation, and high dose multiagent chemotherapy based on melphalan and bone marrow rescue has been in effect for children with high risk or relapsed neuroblastoma at the Children's Hospital of Philadelphia since 1979. The initial results were reported in 1984 [August et al.: J Clin Oncol 2:609-616, 1984]. This report updates the initial results and those that followed changes in the original conditioning regimen. Forty-two patients were treated between may 1979 and November 1987, and included 27 whose disease had relapsed and 15 who received BMT as part of primary treatment. Allogeneic marrow was given to 12 and autologous marrow to 30; in 7 of these 30, the marrow was purged with monoclonal antibodies and magnetic beads. The 4-year actuarial survival rate is 29%. Ten patients died of early treatment-related complications, 18 died of progressive disease, and 2 died of late complications (1 AIDS and 1 acute myelogenous leukemia). Censoring the two late complications the actuarial 4-year relapse-free survival rate becomes 32%. The longest interval after BMT to relapse was 20 months. There was no significant difference in the survival for patients transplanted following relapse or in first remission. The better survival for patients rescued with autologous marrow (30%) is not statistically significantly different from the result with allogeneic marrow (17%).

Adult↗
PubMed1994

Prevention of radiation enteritis in children, using a pelvic mesh sling.

Between 1986 and 1991, the authors used polyglycolic acid mesh slings (placed at or above the sacral promontory) in eight children with pelvic malignancies to exclude all small bowel from the pelvis during pelvic radiation therapy. The only complications of this treatment were prolonged postoperative ileus (one patient) and temporary, partial small bowel obstruction (one patient). The average amount of radiation administered to the pelvis postoperatively was 5,349 +/- 556 cGy. In one of the eight patients, gastrointestinal symptoms (diarrhea for 24 hours) developed during radiation therapy. Early radiological evaluation confirmed that the small bowel was out of the pelvis in all five of the patients studied. Mesh disruption occurred between 2 and 5 months postoperatively (mean, 3.4 +/- 1.5 months) and was often identified symptomatically by the patient. Seven of the eight survived, with disease remission in six. Pelvic disease was absent at the time of death in the one patient who did not survive. Throughout the follow-up period (mean, 20 months) no survivor has had delayed symptoms of radiation enteritis. In children with pelvic malignancies in whom aggressive application of pelvic irradiation is required, the use of an absorbable pelvic mesh sling appears efficacious in preventing radiation-associated enteritis.

Child↗
PubMed1994

Bacterial translocation in mesenteric ischemia-reperfusion injury: is dysfunctional motility the link?

The authors previously reported that mesenteric ischemia and reperfusion (I/R) in a chronic newborn piglet model creates dysfunctional intestinal motility. Whether this leads to inadequate bacterial clearance and translocation (BT) through the gastrointestinal tract remains unclear. To test this hypothesis the authors used their chronic piglet model (weight, 3.5 +/- 0.3 kg; age, 18 +/- 4 days; on formula feeding); nonocclusive mesenteric ischemia was induced via reversible pericardial tamponade. Mesenteric flow (SMA Doppler measurement via the retroperitoneal approach) was decreased to 25% +/- 5% of baseline for 300 minutes in the ischemia group (n = 7) and followed by 14 hours of reperfusion in the I/R group (n = 6). Control subjects had a sham operation (n = 7). Mesenteric lymph nodes (MLN), liver (L), spleen (S), ileum, peritoneum, and blood were harvested for blind quantitative microbial analysis. Subjects in the control group had no cultures positive for growth. Eighty-five percent of animals in the ischemia group had positive MLN cultures only (P < .05 v control). All piglets in the I/R group had positive MLN cultures (P < .05 v control), and one third of them manifested bacteremia. Histological examination did not show mucosal disruption in any group. The validity of this model is confirmed by the negative cultures in the control group and by the presence of normal ileal flora in all animals. In the ischemia and I/R groups, MLN cultures were consistently positive with gram-negative bacilli (Escherichia coli and/or Klebsiella pneumoniae). When subjects of the I/R group had more than 1,000 colonies in the MLN, bacteremia with the translocating organisms was also identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Liquid chromatographic separation of zalcitabine and its stereoisomers.

A liquid chromatographic method capable of separating and quantitating the stereoisomers of zalcitabine has been developed and validated. The separation was achieved with an Astec Cyclobond I--RSP column and a mobile phase of 0.25% triethylamine in water adjusted to a pH of 6.5 with glacial acetic acid. All enantiomers were found to exhibit a linear response in the range of 0.1-10% in the presence of 100% zalcitabine. Precision of analysis was found to be less than 1.5% at a level of 1% relative to zalcitabine. The limit of detection for two of the three enantiomeric impurities was determined to be 0.05% relative to zalcitabine. The detection limit for the third was found to be 0.1%. This method was successfully applied to the analysis of reference standards and several production scale batches. All of these materials were found to be stereochemically pure to a level of 99.8% or better.

Chromatography, High Pressure Liquid↗
PubMed1993

The effects of ischemia and reperfusion on intestinal motility.

The interdigestive migrating motor complex (MMC) has been demonstrated to be a reliable indicator of intestinal motility and function. The effects of low perfusion on the MMC have never been studied. Fourteen newborn Yorkshire piglets (5 to 18 days old, weighing 2.9 +/- 0.4 kg) underwent celiotomy under general anesthesia with placement of four jejunal electrodes (50 cm apart) as well as a superior mesenteric artery (SMA) Doppler flow probe and a pericardial catheter. Group 1 (n = 5) had operation alone. Group 2 (n = 9) had nonocclusive mesenteric ischemia induced by reversible cardiac tamponade for 5 hours between postoperative days 6 to 12. All subjects had MMC phase III electrical activity, cycling time, and propagation velocity recorded daily. In group 2 MMCs were recorded prior to and during ischemia, and during reperfusion. Group 2 animals had 75% +/- 4% decrease in SMA flow during the tamponade period. During the ischemic period, the MMC cycling time (CT) increased from 67 +/- 10 (mean +/- SEM) to 98 +/- 12 minutes (P < .05) and MMC propagation velocity (PV) decreased to 4.2 +/- 2.2 from a baseline value of 10.5 +/- 1.5 cm/min (P < .05). During reperfusion CT and PV values were not significantly different from baseline. The validity of this model is confirmed by the comparable baseline recordings in groups 1 and 2, and by the return of MMC to baseline values within 4 to 7 hours of reperfusion, as seen in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Mesenteric ischemia in hypoplastic left heart syndrome.

Hypoplastic left heart syndrome (HLHS) has been widely viewed as a uniformly fatal form of congenital heart disease. Between January 1984 and December 1990, 387 patients with the diagnosis of HLHS were treated at this institution. Mesenteric ischemia was clinically diagnosed in 31 patients (8% incidence) and confirmed by pathology or surgery in 25 of those patients. The mean age at the time of onset was 17.5 +/- 5.4 weeks and only 13% were premature newborns. In 80% of the patients a low perfusion state and significant hypotension were documented within 48 hours prior to the diagnosis of bowel ischemia. Nine patients (29%) required operative intervention (bowel resection 4, diffuse ischemia 3, and simple drainage 2). Overall, at operation or at autopsy, nine patients (29%) had diffuse gastrointestinal ischemia. Of 31 patients with mesenteric ischemia, 26 children (84%) died shortly after onset of the gastrointestinal symptoms regardless of means of management. Five patients (10%) initially improved with aggressive medical and/or surgical management; however, 4 subsequently died secondary to complications of their primary cardiac disease. Therefore, the overall mortality of patients with mesenteric ischemia was 97%. Previous reports have estimated that up to 7% of full-term newborns with symptomatic congenital heart disease may develop necrotizing enterocolitis (NEC). Our unique group of patients with HLHS is comprised mostly of full-term infants who developed onset of mesenteric ischemia at a mean age of 4 months associated with an underlying low perfusion state. This mesenteric ischemia has been erroneously identified as NEC.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis, Differential↗
PubMed1993

Ovarian masses in children: a review of 91 cases of malignant and benign masses.

Ovarian masses in children are uncommon. We reviewed all cases of ovarian masses presenting to this hospital from 1979 to 1990. Ninety-one patients fulfilled the criteria and had medical records available. All patients were less than 18 years old. Four were diagnosed antenatally. Thirty-four tumors presented prior to 8 years of age and 1 (2.9%) was malignant. Fifty-eight tumors presented after 8 years of age and 18 (33%) were malignant. Seventy-two patients had benign disease and 19 had malignant tumors. Of those with benign disease 22 had simple or epithelial cysts, 25 had teratomas, 13 had torsion with cyst formation, 3 had granulosa cell tumors, and 9 had other less common lesions. Analysis of symptoms could not distinguish between benign and malignant lesions; however, age was less (P < .03) and tumor size smaller (P < .001) in patients with benign lesions. Benign lesions presented at a mean age of 8.8 years. Fifty-four patients had an ultrasound, all were diagnostic: simple mass (14), complex mass (8), or cyst (32). Mean size of the masses was 9.5 x 7.7 cm. Fourteen patients had a contralateral ovarian cyst. The malignant lesions included 14 germ cell tumors (4 endodermal sinus, 4 teratoma, 2 choriocarcinoma, 2 dysgerminoma, 1 embryonal, and 1 mixed), 4 epithelial tumors (1 mucinous cystadenocarcinoma, papillary cystadenocarcinoma, papillary serous cystadenocarcinoma, and endometrioid adenocarcinoma), and one patient with leukemic infiltration (ALL). Germ cell tumors presented at a mean age of 11.8 years. Eight of these patients had an ultrasound and all showed a mass (7) or cyst (1).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Comparison of workshop CD45R monoclonal antibodies with OvCD45R monoclonal antibodies in sheep.

The reactivity of the antibovine monoclonal antibodies (mAbs) comprising temporary cluster TC1 was compared with that of two OvCD45R mAbs on sheep cells. Three of the mAbs--CC31, CC99 and CC103--did not cross-react with sheep cells. All the workshop mAbs precipitated two molecules of apparent molecular weight (MW) 200 kDa and 220 kDa while the antisheep CD45R mAb 20-96 precipitated a single band of 220 kDa. Cell surface expression was examined by single colour FACS (fluorescence activated cell sorting) analysis of efferent and afferent lymph cells and peripheral blood lymphocytes and the distribution of the antigens on CD4+, CD8+ and T19+ (WC1) and B cells was determined by two colour fluorescence staining. By cellular distribution and immunohistology the TC1 mAbs could be divided into four distinct groups which differed from a fifth group comprising the two OvCD45R antibodies.

Animals↗