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Biomedical subjects

B Collins

Publications and source records attributed to B Collins.

At least 19 recordsLinked to original sources
PubMed2003

Inherited thrombotic tendency in a pedigree with antithrombin La Rochelle (N405K) and factor V Leiden.

An Irish pedigree with a strong thrombotic tendency, due to the novel association of antithrombin La Rochelle (N405K) and factor V Leiden is described. Thromboses occurred at a median age of 16 years in four family members, carrying both mutant alleles. Molecular diagnosis was facilitated by the creation of an additional restriction enzyme site (Mnl1) in exon 6 of the antithrombin gene. Both the genes for antithrombin and factor V are located at chromosome 1q23. The molecular data and phenotypic behaviour in this family are strongly suggestive of allelic co-segregation of the mutant alleles.

Adolescent↗
PubMed2001

Analyses of micronuclei in exfoliated epithelial cells from individuals chronically exposed to arsenic via drinking water in inner Mongolia, China.

The groundwater in Bayingnormen (Ba Men), located in Central West Inner Mongolia, China, is naturally contaminated with arsenic at concentrations ranging from 50 microg/L to 1.8 mg/L. Various adverse health effects in this region, including cancer, have been linked to arsenic exposure via drinking water. A pilot study was undertaken to evaluate frequencies of micronuclei (MN), as measures of chromosomal alterations, in multiple exfoliated epithelial cell types from residents of Ba Men chronically exposed to arsenic via drinking water. Buccal mucosal cells, airway epithelial cells in sputum, and bladder urothelial cells were collected from 19 residents exposed to high levels of arsenic in drinking water (527.5 +/- 24 microg/l), and from 13 control residents exposed to relatively low levels of arsenic in drinking water (4.4 +/- microg/L). Analytical results from these individuals revealed that MN frequencies in the high-exposure group were significantly elevated to 3.4-fold over control levels for buccal and sputum cells, and to 2.7-fold over control for bladder cells (increases in MN frequency significant at p < .001 for buccal cells; p < .01 for sputum cells; p < .05 for bladder cells). When smokers were excluded from high-exposure and control groups the effects of arsenic were observed to be greater, although only in buccal and sputum cells; approximately 6-fold increases in MN frequency occurred in these tissues. The results indicate that residents of Ba Men chronically exposed to high levels of arsenic in drinking water reveal evidence of genotoxicity in multiple epithelial cell types; higher levels of induced MN were observed in buccal and sputum cells than in bladder cells.

Adult↗
PubMed2001

Selective increases in cytokine expression in the rat brain in response to striatal injection of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate and interleukin-1.

A number of cytokines contribute to acute experimental neurodegeneration. The cytokine response can have detrimental or beneficial effects depending on the temporal profile and balance between pro- and anti-inflammatory molecules. Our recent data suggest that the pro-inflammatory cytokine interleukin-1beta (IL-1beta) acts at specific sites (e.g., the striatum) in the rat brain to cause distant cortical injury, when co-administered with the potent excitotoxin alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (S-AMPA). The objective of the present study was to investigate changes in the expression of several cytokines simultaneously in the rat striatum and cortex after intrastriatal administration of vehicle, S-AMPA or human recombinant (hr) IL-1beta alone or S-AMPA co-injected with hrIL-1beta using reverse transcription-polymerase chain reaction (RT-PCR; Taqman fluorogenic probes) and enzyme-linked immunosorbent assay (ELISA). Injection of S-AMPA alone increased IL-6 mRNA expression in the ipsilateral striatum after 8 h, whilst striatal injection of IL-1beta alone increased local IL-1beta and IL-1ra mRNAs. The levels of mRNA encoding IL-1alpha, IL-1beta, IL-1ra, IL-6, IL-10 and TNFalpha were markedly elevated in the ipsilateral cortex 8 h after co-injection of S-AMPA and hrIL-1beta. Cortical mRNA levels for IL-4, IL-18, TGFbeta and IFNgamma were not significantly different between treatment groups after 2 h or 8 h. A similar pattern of change in the levels of IL-1alpha and IL-6 protein was observed 8 h after treatment. These data demonstrate selective increases in the expression of cytokines in areas of remote cell death in response to administration of hrIL-1beta and S-AMPA. Such cytokines may be involved in the ensuing damage, and further clarification of their actions could aid future therapeutic strategies for several acute neurodegenerative disorders.

Animals↗
PubMed2000

Cortical cell death induced by IL-1 is mediated via actions in the hypothalamus of the rat.

The cytokine IL-1 mediates diverse forms of neurodegeneration, but its mechanism of action is unknown. We have demonstrated previously that exogenous and endogenous IL-1 acts specifically in the rat striatum to dramatically enhance ischemic and excitotoxic brain damage and cause extensive cortical injury. Here we tested the hypothesis that this distant effect of IL-1 is mediated through polysynaptic striatal outputs to the cortex via the hypothalamus. We show that IL-1beta injected into the rat striatum with the excitotoxin alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (S-AMPA) caused increased expression of IL-1beta (mRNA and protein) mainly in the cortex where maximum injury occurs. Marked increases in IL-1beta mRNA and protein were also observed in the hypothalamus. S-AMPA, injected alone into the striatum, caused only localized damage, but administration of IL-1beta into either the striatum or the lateral hypothalamus immediately after striatal S-AMPA resulted in widespread cell loss throughout the ipsilateral cortex. Finally we showed that the cortical cell death produced by striatal coinjection of S-AMPA and IL-1beta was significantly reduced by administration of the IL-1 receptor antagonist into the lateral hypothalamus. These data suggest that IL-1beta can act in the hypothalamus to modify cell viability in the cortex. We conclude that IL-1-dependent pathways project from the striatum to the cortex via the hypothalamus and lead to cortical injury, and that these may contribute to a number of human neurological conditions including stroke and head trauma.

Animals↗
PubMed2000

Epidemiologic issues of sexually transmitted diseases in sexual assault victims.

UNLABELLED: The objective of this study was to investigate the epidemiologic aspects of sexually transmitted diseases (STDs) in victims of sexual assault and to discuss the methodological issues in determining risk of STD acquisition. We performed a comprehensive review of the medical literature to determine the prevalence of STDs in victims of sexual assault. A MEDLINE search and a search of bibliographies of published manuscripts was performed to discover relevant articles published in the English language. Studies were included in our review if they provided estimates of the prevalence of infection with Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum, Trichomonas vaginalis, or human papillomavirus (HPV). The main outcome measure was prevalence rates of STDs in victims of sexual assault. It is difficult to determine the rate of newly acquired STDs from sexual assault. In the populations studied the prevalence of STDs can be summarized as follows: N. gonorrhoeae 0.0 to 26.3 percent; C. trachomatis 3.9 to 17 percent; T. pallidum 0.0 to 5.6 percent; T. vaginalis 0.0 to 19.0 percent; and HPV 0.6 to 2.3 percent. We conclude that prevalence estimates vary widely depending on the population studied and known risk factors for STDs. Given the limited follow-up rates in this population, preventive treatment for STDs in addition to emergency contraception should be offered in most instances. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to estimate the prevalence of STD transmission from an act of sexual assault, to describe the various types of STDs that a sexual assault victim is at risk for, and to explain the role of preventive therapy in this setting.

Adolescent↗
PubMed1999

Anti-glomerular basement membrane glomerulonephritis after extracorporeal shock wave lithotripsy.

Extracorporeal shock wave lithotripsy (ESWL) is a common noninvasive procedure for removal of upper urinary tract stones. We present a case of a man who developed anti-glomerular basement membrane (anti-GBM) disease after ESWL and review the two other cases described in the medical literature. In all cases, the affected individuals expressed the HLA DR2/HLA DR15 major histocompatibility antigen and developed a rapidly progressive anti-GBM-induced glomerulonephritis 3 to 7 months after ESWL. Anti-GBM disease may be a rare complication of ESWL in susceptible individuals and should be considered in patients who develop acute renal failure after lithotripsy.

Acute Kidney Injury↗
PubMed1999

The duty of care of the occupational physician in assessing job applicants.

Where an occupational physician carries out a medical assessment of a job applicant, he or she owes a duty to the employer but not to the applicant, unless actual physical harm is caused. If the applicant is unsuccessful as a result of an assessment which is alleged to be negligent, he or she cannot sue the physician. This is essentially because (i) the relationship between the physician and the applicant is insufficiently close, and (ii) the physician might be faced with a conflict of interest since differing duties might be owed to the employer and to the applicant.

Attitude of Health Personnel↗
PubMed1999

The effects of 4-nonylphenol in rats: a multigeneration reproduction study.

The alkylphenol breakdown products of alkylphenol ethoxylates have been shown in in vitro studies to be weakly estrogenic, but few in vivo data address this issue in mammals. Because estrogens have been found to be most potent during developmental/perinatal exposures, this study maximized developmental exposure to nonylphenol (NP) by treating 3.5 generations of Sprague-Dawley rats to NP in diet at 200, 650, and 2000 ppm to determine the range and severity of any toxicity. Dose rate was higher for younger rats; calculated dose ranges were 9-35, 30-100, and 100-350 mg/kg/d for the low (200NP), middle (650NP), and high (2000NP) dose groups, respectively. There were adult (F0, F1, F2) and postnatal day (pnd) 21 (F1, F2, F3) necropsies; the oldest F3 rats were killed on pnd 55-58. Body weight gain was reduced by 8-10% in the 650NP and 2000NP groups. Vaginal opening was accelerated by approximately 2 days (650NP) and approximately 6 days (2000NP) in F1, F2, and F3 generations. Uterine weights at pnd 21 were increased in 650NP (14%) and 2000NP (50%) F1 females, but not in other generations. Testis descent, anogenital distance, and preputial separation were not consistently changed. No consistent changes were seen in pup number, weight or viability, litter indices, or other functional reproductive measures. Relative ovary weight in F2 adults was decreased at 650NP and 2000NP by 12%; relative ovary was unchanged in other generations. Follicle counts were unchanged in F2 adults. Sperm indices, including CASA measures, were unchanged in F0 and F1 males. In F2 rats, epididymal sperm density was reduced by 8% and 13% at 650NP and 2000NP, respectively. Testicular spermatid count was reduced by 13% in 2000NP F2 males; testis and epididymis weights were unchanged. Erosion of gastric and duodenal mucosa was monitored grossly and microscopically, and never found. Kidney weights were increased in 650NP and 2000NP males, and renal medullary tubular dilatation and cyst formation were noted in all generations of males, and often at the lowest dose tested. These data show that NP had limited effects on the reproductive system in the presence of measurable nephrotoxicity. The F2 sperm effects are either statistical/biological "noise," or imply heretofore unknown pharmacokinetics or toxicodynamics. These sperm data should be interpreted cautiously until the findings are repeated.

Animals↗
PubMed1999

An analysis of the suitability of home health visits for telemedicine.

To determine what percentage of traditional home health nursing visits could be done by telemedicine, we carried out a retrospective review of nursing charts (clinical records). Data of two types were recorded. The objective data, which were abstracted from the records, included demographic information, patient assessments, teaching activities and interventions. The subjective data were the opinions of four observers as to whether the visit could have been done using currently available telemedicine technology. Records were sampled randomly for patients who had received home nursing care from three home health agencies in rural and urban areas during the winter and summer of 1996. A 54-item coding instrument was applied to 906 different charted home nursing visits. For 412 (46%) of these, the on-site nursing could reasonably have been replaced by telenursing. Significant factors determining the possible use of telenursing included primary diagnosis, number of interventions and patient age. Among the 10 most common primary diagnoses, the most amenable to telenursing care were chronic airway obstruction and joint disorders; the least amenable were coagulation disorders and anaemia. Telenursing visits could substitute for a substantial fraction of on-site home nursing visits. This has important implications in terms of reducing the cost of home nursing care.

Feasibility Studies↗
PubMed1999

Renal thrombotic microangiopathy associated with anticardiolipin antibodies in hepatitis C-positive renal allograft recipients.

Hepatitis C virus (HCV) infection has been associated with de novo or recurrent membranoproliferative glomerulonephritis and acute transplant glomerulopathy in transplanted kidneys. Recently, anticardiolipin antibodies (ACA) have been linked with chronic HCV infection. A few reports have suggested an association between ACA and renal allograft thrombosis. This study examines the clinical and pathologic features of HCV-positive renal allograft recipients at our institution. From 1990 to 1996, 379 kidney transplants were performed. We identified 18 recipients (4.8%) with HCV-positive serology pretransplant. Determination of IgG and IgM ACA was performed by enzyme-linked immunosorbent assay, using pretransplant sera. Among the 18 patients, five patients presented with biopsy-proven de novo renal thrombotic microangiopathy (RTMA), occurring 5 to 120 d (median, 14 d) after transplant. No differences in pretransplant characteristics were observed between patients with (n = 5) or without (n = 13) RTMA. All five patients had a positive ACA test (either IgG or IgM titer > 2 SD above normal), compared with only one of 13 patients without RTMA. The mean value for IgG ACA was significantly higher in the RTMA patients than in patients without RTMA (22.9 +/- 14.1 versus 6.9 +/- 4.9 IgG phospholipid units, P = 0.02); however, there were no significant differences in IgM ACA titers. Rheumatoid factor and complement C4 levels were normal in pretransplant sera of patients with RTMA. Patients with RTMA had their cyclosporine withdrawn (four of five) or the dose was decreased (one of five), and one of five underwent plasmapheresis. Four of five patients died within 5 yr after transplant, compared with no deaths in the other 13 patients. Finally, as a control group, seven HCV-negative renal allograft recipients who presented with RTMA/hemolytic uremic syndrome during the same time period were found to have normal ACA values (IgG or IgM). RTMA associated with ACA in HCV-positive renal allograft recipients may represent a new clinical entity. The occurrence of this syndrome may have deleterious consequences for patient and graft survival.

Adult↗
PubMed1998

Perineural invasion in squamous cell carcinoma of the head and neck.

OBJECTIVE: To determine if perineural invasion (PNI) of small nerves affects the outcome of patients with squamous cell carcinoma (SCC) of the upper aerodigestive tract. DESIGN: Retrospective clinicopathological study of patients with at least 2 years of follow-up and with negative margins and no prior, synchronous, or metachronous SCC. SETTING: Academic otolaryngology department. PATIENTS: One hundred forty-two patients who had SCC of the oral cavity, oropharynx and hypopharynx, or larynx resected between 1981 and 1991. INTERVENTION: Surgery with or without adjuvant therapy. MAIN OUTCOME MEASURES: Local recurrence was examined with respect to PNI, nerve diameter, and microvascular or microlymphatic invasion. Perineural invasion was correlated with lymph node metastasis, extracapsular spread, and survival. RESULTS: Perineural invasion of nerves less than 1 mm in diameter was present in 74 patients, lymphatic invasion in 53, and vascular invasion in 9. Perineural invasion was significantly associated with local recurrence (23% for PNI vs 9% for no PNI; P=. 02), and disease-specific mortality (54% mortality for PNI vs 25% for no PNI; P<.001). With extralaryngeal tumors, PNI was associated with nodal metastasis (73% vs 46%; P=.03). Perineural invasion was not associated with extracapsular spread (P=.47). Microvascular invasion, lymphatic invasion, and nerve diameter were not significantly related to local recurrence. CONCLUSIONS: Perineural invasion of small nerves is associated with an increased risk of local recurrence and cervical metastasis and is, independent of extracapsular spread, a predictor of survival for patients with SCC of the upper aerodigestive tract.

Carcinoma, Squamous Cell↗
PubMed1998

Secondary pleural involvement by an AIDS-related anaplastic large cell (CD30+) lymphoma simulating metastatic adenocarcinoma.

We report a patient with acquired immunodeficiency syndrome with secondary pleural and pulmonary involvement by a CD30+ anaplastic large cell lymphoma (ALCL) that morphologically simulated metastatic adenocarcinoma. We describe the morphologic findings in order to heighten awareness that CD30+ ALCL may mimic metastatic adenocarcinoma in a body fluid or bronchial brushing and should be considered in the differential diagnosis. Primary body cavity based (PCBC) AIDS-related lymphoma is a relatively newly described disease entity with morphologic features bridging ALCL and large cell immunoblastic lymphoma with a CD30+ null immunophenotype. A morphology mimicking adenocarcinoma has not been previously described in this entity but should be considered in a patient with AIDS presenting exclusively with a serous effusion. Appropriate immunoperoxidase staining should aid in these differential diagnoses.

Adenocarcinoma↗
PubMed1998

Nurse reactions to a prototype home telemedicine system.

We have studied nurse reactions to a prototype home health telemedicine system. The system used interactive video through the local cable television network. Six nurses were directly involved with telecare video-visits. There were 54 patients. The average age of the patients was 76 years (range 21-101). Thirty-six (67%) patients were female and 18 (33%) were male. The patients had an average of 4.6 different diagnoses (range 1-16). They were also on a very wide range of medications (mean 9.9, range 2-23). Nurses overwhelmingly felt the system was effective for what this particular project was trying to accomplish. They were enthusiastic about the prospects of practising nursing by telemedicine, even though they had reservations about aspects of the particular system being used. Their main complaints were about limitations of the software and limitations of the telecommunication system that linked them to the patients.

Adult↗
PubMed1998

Nurse and patient reactions to a developmental home telecare system.

Pilot studies have suggested that telemedicine is a satisfactory means of delivering nursing services into the home. A home telecare programme in Kansas provided nursing services to homes in four towns in Kansas. The present study examined patients' and nurses' perceptions of a variety of issues related to home telecare. Data-collection methods included in-depth interviews, observation and analyses of archival data from patient records. Patients suffered an average of 4.6 concurrent illnesses. On the whole, patients perceived the system as a valuable resource that offered great potential, although many saw no immediate health benefits for themselves. Nurses were enthusiastic about the prospect of practising in this way, although they did have strong opinions about what types of nurses, patients and illnesses were suited to telemedicine.

Adult↗