Biomedical subjects

J Newman

Publications and source records attributed to J Newman.

At least 19 recordsLinked to original sources

PubMed2006

Comparison of a waterless hand-hygiene preparation and soap-and-water hand washing to reduce coliforms on hands in animal exhibit settings.

Outbreaks of enteric disease associated with exposure to live animals on exhibit have occurred with increasing frequency in recent years. Possibly the most important pathogen causing such outbreaks is Escherichia coli O157:H7, because of the serious illness it can cause. Hand hygiene is consistently protective against disease among persons exposed to animals implicated in these outbreaks. Livestock barns have limited hand-washing facilities, therefore a waterless hand-sanitizing gel would be a potentially preventive measure readily available to visitors and animal exhibitors. This study compared the reduction of bacterial counts on hands of animal exhibitors when soap and water was used or when an ethanol-based hand gel was used after animal handling. Participants were youth and adults involved with showing livestock. The sanitation methods were similar in reducing the total bacteria and coliform counts on the hands of the participants (Wilcoxon rank sum test P values 0.12 and 0.69 respectively).

Animals↗

PubMed2005

Historical and other patterns of monomethyl and inorganic mercury in the Florida panther (Puma concolor coryi).

Since the late 1980s, elevated levels of mercury have been reported in the tissues of the Florida panther (Puma concolor coryi) from the Florida Everglades. The extent, degree, and length of time of mercury contamination in the Florida panther are unknown. The objective of this study was to determine the historical and other patterns of monomethyl and inorganic mercury in the Florida panther by analysis of mercury in panther hair from museum collections. In addition, this study evaluated the effects of preservation of skins on mercury concentrations in hair and the representativeness of museum collections for evaluating historical trends of contamination in the Florida panther. Hair from 42 Florida panther specimens collected from 1896 to 1995 was analyzed for both monomethyl and inorganic mercury. Monomethyl mercury (MMHg) and inorganic mercury (IHg) were found in all specimens. Monomethyl mercury in hair from untanned skins was significantly higher than MMHg in hair from tanned skins. For untanned specimens, the mean MMHg concentration in hair was 1.62 +/- 1.87 mug/g (range 0.11 to 6.68 mug/g, n = 16). Monomethyl mercury accounted for 88% of the total mercury in untanned Florida panther hair. No sexual or geographical differences were found. Although MMHg is generally stable in hair, the tanning process appears to reduce the amount of MMHg in hair. In addition, exogenous IHg contamination of the panther hair was found in museum specimens, especially in older specimens. The implication of these and other factors in interpreting results of museum studies is discussed. The presence of MMHg in panther hair since the 1890s indicates long-term and widespread exposure of the Florida panther to mercury. Levels of MMHg are significantly greater in the 1990s than the 1890s. When combined with field studies of mercury in the Florida panther, considerable individual variability is observed, reflecting short-term changes in exposure of individual panthers to mercury. Although museum specimens showed a significant increase in MMHg over the last 100 years, they did not show the magnitude of increase that field populations of Florida panthers did. A number of Florida panthers appeared to be at risk from mercury over their lifetimes, especially individuals from the early 1990s.

Animals↗

PubMed2005

A randomized controlled trial of an asthma clinical pathway for children in general practice.

AIMS: To evaluate the effect of the implementation of an asthma clinical pathway on asthma in children in general practice. METHODS: A randomized, controlled trial involving 270 general practitioners. One group of general practitioners implemented the asthma clinical pathway for children (intervention group) and the control group continued with their usual asthma medical care management. The main outcome measures were admissions to hospital for asthma and attendance at the Children's Emergency Department. Compliance with the guidelines was assessed by examining asthma drug prescriptions. RESULTS: Admissions to hospital for asthma dropped 40% in the intervention group, by 33% in the control group and by 22% in general practitioners not participating in the trial. The differences between the intervention and control and between the intervention and non-participating general practitioners were not statistically significant. The decrease in attendance at the Children's Emergency Department decreased by 25%, 30% and 19%, respectively, but this was not statistically significant. There was a significant decrease in prescriptions for oral relievers, dry powder relievers in the under 6s, mast cell stabilizers and methylxanthines in both control and intervention groups. However, only for oral relievers was there a significant difference between the intervention group and control, with the decrease larger in the intervention group (p < 0.001). CONCLUSIONS: Admissions to hospital for asthma decreased, as did attendance at the Children's Emergency Department. Prescriptions for asthma medication changed in the direction anticipated with compliance with the asthma clinical pathway. However, we found no evidence within the study that implementation of the asthma clinical pathway by general practitioners resulted in lower morbidity than those general practitioners who did not implement the pathway. Possible explanations are that these general practitioners were already providing care according to the recommendations of the pathway, or that there was contamination of the control group by the intervention, or that the guidelines, although based on currently accepted recommendations, are ineffective.

Adolescent↗

PubMed2004

Raised dietary n-6 polyunsaturated fatty acid intake increases 2-series prostaglandin production during labour in the ewe.

Preterm labour is the major cause of perinatal morbidity and mortality in humans. The incidence is around 10% and the causes are often unknown. Consumption of dietary n-6 polyunsaturated fatty acids (PUFAs) in western societies is increasing. These are metabolized to arachidonic acid, the precursor for 2-series prostaglandins (PGs), major signalling molecules during labour. This study investigated the effect of dietary supplementation with linoleic acid (LA, 18: 2, n-6) on parturition. Ewes were fed a control or LA-supplemented diet from 100 days gestation. Labour was induced using a standardized glucocorticoid challenge (dexamethasone, Dex) to the fetus, starting on day 139. Electromyographic (EMG) activity and fetal and maternal circulating PG concentrations were monitored. One third of LA-fed ewes delivered early (pre-Dex) although basal uterine EMG activity preceding Dex was higher in control ewes (P < 0.05). A steep increase in EMG activity occurred 18-38 h after the start of Dex infusion. Twice basal EMG activity (defined as established labour) occurred on average 7 h earlier in the LA-supplemented ewes (P < 0.05). The basal concentrations of maternal and fetal PGFM and fetal PGE(2) were approximately doubled in LA-supplemented ewes before the start of Dex infusion (P < 0.01). The rise in fetal PGE(2) and maternal oestradiol concentrations post-Dex occurred earlier in the LA-supplemented ewes. All PG measurements remained significantly higher in the LA-supplemented ewes during labour onset. This study suggests that consumption of a high LA diet in late pregnancy can enhance placental PG production and may thus increase the risk of preterm labour.

Animals↗

PubMed2003

Outcome of three consecutive inadequate cervical smears.

A retrospective audit of women with three consecutive inadequate cervical smears during 1998-99 was conducted at Birmingham Heartlands Hospital. The commonest reasons were obscured by polymorphs (34.5%) and sparse cellularity (28.9%). Seventy-three per cent (73%) were followed up at colposcopy and 22.1% had histological assessment; 15.9% of women had an abnormality detected, 10.6% with abnormal histology and 5.3% with a cytological abnormality only. Cytological abnormalities were seen in 11.1% of the screening population. This study did not identify a cytological criterion to differentiate those that would or would not have an abnormality on follow-up. It is suggested that all women with three consecutive inadequate smears should have adequate follow-up, although this may place increased demands on colposcopy services.

Cervix Uteri↗

PubMed2002

A phase II study to evaluate the efficacy of dexmedetomidine for sedation in the medical intensive care unit.

OBJECTIVE: To evaluate dexmedetomidine for sedation of patients in the medical ICU. DESIGN AND SETTING: Prospective observational study in an intensive care unit of a university hospital. PATIENTS. Twelve ventilated patients with median APACHE II score 23 (range 10-26). INTERVENTIONS: Patients received a loading dexmedetomidine infusion of 1 microg x kg(-1) over 10 min followed by a maintenance infusion rate of 0.2-0.7 microg x kg(-1) x h(-1) for up to 7 days. After experience with the first four patients this maintenance rate of infusion was increased to a maximum of 2.5 microg kg(-1) x h(-1). If required, propofol and morphine provided rescue sedation and analgesia, respectively. RESULTS: The first four patients with dexmedetomidine infusion at 0.7 microg x kg(-1) x h(-1)all required rescue sedation with a propofol infusion. A protocol amendment allowed the next eight patients to receive higher dexmedetomidine infusions (mean 1.0+/- microg x kg(-1) x h(-1)). Five of the next eight patients did not required propofol, and two patients only required minimal propofol infusions (20-40 mg x h(-1)). A further patient, with hepatic encephalopathy, required a propofol at 50-100 mg x h(-1). Only modest falls in arterial pressure, heart rate and cardiac output were seen, and no rebound sequelae occurred on discontinuation of dexmedetomidine. Adverse cardiovascular events were nearly all confined to the initial loading dose period of dexmedetomidine. CONCLUSIONS: Sedation with dexmedetomidine is efficacious in critically ill medical patients requiring mechanical ventilation in the intensive care unit. A reduction in loading infusion is advised, but higher maintenance infusions may be required to that seen previously in the postoperative ICU patient.

APACHE↗

PubMed2002

A primary tumour of the oesophagus with both melanocytic and schwannian differentiation. Melanocytic schwannoma or malignant melanoma?

A 76 year old white woman presented with a four month history of dysphagia and weight loss. Clinical, radiological, and endoscopic examination revealed a pigmented mass in the lower third of the oesophagus. The preoperative diagnosis, including biopsy examination, was that of malignant melanoma. Following oesophageal resection, the mass was found to be a localised, relatively superficial tumour with light, electron microscopic, and immunohistochemical features common to both Schwann cells and melanocytes. The patient survived 46 months after surgery and died of a stroke, with no evidence of tumour recurrence. The tumour is presented as a case of melanocytic schwannoma, with unique features when compared with oesophageal melanotic schwannomas and malignant melanomas described in the literature. The differential diagnosis is discussed and an origin from a common precursor cell of neural crest origin is postulated.

Aged↗

PubMed2001

Effect of combined aspirin and angiotensin-converting enzyme inhibitor therapy versus angiotensin-converting enzyme inhibitor therapy alone on readmission rates in heart failure.

An adverse interaction between aspirin and angiotensin-converting enzyme (ACE) inhibitors is suspected in patients with heart failure, but the effect of combined therapy with these agents on hospital readmission rates is unknown. Our study found that combining aspirin with ACE inhibitors is associated with higher early readmission rates than use of ACE inhibitors alone, particularly in patients with depressed ejection fraction and in those without coronary artery disease.

Aged↗

PubMed2001

The sensitivity of auditory brainstem response testing for the diagnosis of acoustic neuromas.

OBJECTIVES: To determine the sensitivity of auditory brainstem response (ABR) testing for detecting acoustic neuromas and to determine whether the test is less sensitive for detecting small tumors. DESIGN: Retrospective review of the medical charts of 58 patients with acoustic neuroma who had all of the data necessary for inclusion in the study. SETTING: University-affiliated referral practice of one neurotologist. PATIENTS: Patients with acoustic neuromas who had both ABR tracings and magnetic resonance imaging films available for review. MAIN OUTCOME MEASURES: Positive ABR and negative ABR results correlated with tumor size. RESULTS: Tumor size ranged from 0.4 to 7 cm. The overall sensitivity of ABR in diagnosing acoustic neuromas was 90%. However, ABR was progressively less sensitive with decreasing tumor size. Only 7 (58%) of the 12 tumors 1 cm or smaller were detected by ABR. CONCLUSION: Auditory brainstem response testing cannot be relied on for detection of small acoustic neuromas and should not be used as a criterion to determine whether magnetic resonance imaging should be performed when an acoustic neuroma is suspected clinically.

Evoked Potentials, Auditory, Brain Stem↗

PubMed2001

Influence of sample manipulation on contaminant flux and toxicity at the sediment-water interface.

Toxicities of sediments from San Diego and San Francisco Bays were compared in laboratory experiments using sea urchin (Strongylocentrotus purpuratus) embryos exposed to pore water and at the sediment-water interface (SWI). Toxicity was consistently greater to embryos exposed at the SWI to intact (unhomogenized) sediment samples relative to homogenized samples. Measurement of selected trace metals indicated considerably greater fluxes of copper, zinc, and cadmium into overlying waters of intact sediment samples. Inhibition of sea urchin embryo development was generally greater in sediment pore waters relative to SWI exposures. Pore water toxicity may have been due to elevated unionized ammonia concentrations in some samples. The results indicate that invertebrate embryos are amenable to SWI exposures, a more ecologically relevant exposure system, and that sediment homogenization may create artifacts in laboratory toxicity experiments.

Ammonia↗

PubMed2001

Study of Medicare beneficiary complaint procedures.

New procedures for reviewing a sample of Medicare beneficiary complaints about quality of care are compared with traditional procedures at a peer review organization (PRO) for 1998-1999. These new procedures included: (1) expanded communications with complainants and providers, (2) changed data collection methods, (3) integrated concurrent review findings from other agencies, (4) expedited review procedures, and (5) changed the medical review procedures. The findings showed improved beneficiary satisfaction with the new procedures over the traditional procedures and shorter time periods for processing the reviews. Even with the new procedures, beneficiaries continued to be concerned that the review time frames were too lengthy, the reviews generally failed to confirm their complaints, and the PROs generally did not disclose the findings to the beneficiaries.

Aged↗

PubMed2001

Identification of enteropathogenic Escherichia coli in simian immunodeficiency virus-infected infant and adult rhesus macaques.

Enteropathogenic Escherichia coli (EPEC) was recognized as a common opportunistic pathogen of simian immunodeficiency virus-infected rhesus macaques (Macaca mulatta) with AIDS. Retrospective analysis revealed that 27 of 96 (28.1%) animals with AIDS had features of EPEC infection, and EPEC was the most frequent pathogen of the gastrointestinal tract identified morphologically. In 7.3% of animals dying with AIDS, EPEC represented the sole opportunistic agent of the gastrointestinal tract at death. In 20.8% of cases, it was seen in combination with one or more gastrointestinal pathogens, including Cryptosporidium parvum, Enterocytozoon bieneusi, Mycobacterium avium, Entamoeba histolytica, Balantidium coli, Strongyloides stercoralis, cytomegalovirus, and adenovirus. Clinically, infection was associated with persistent diarrhea and wasting and was more frequent in animals that died at under 1 year of age (P < 0.001, Fisher exact test). The organism was associated with the characteristic attaching and effacing lesion in colonic tissue sections and produced a focal adherence pattern on a HEp-2 assay but was negative for Shiga toxin production as assessed by PCR and a HeLa cell cytotoxicity assay. A 2.6-kb fragment encompassing the intimin gene was amplified and sequenced and revealed 99.2% identity to sequences obtained from human isolates (GenBank AF116899) corresponding to the epsilon intimin subtype. Further investigations with rhesus macaques may offer opportunities to study the impact of EPEC on AIDS pathogenesis and gastrointestinal dysfunction.

AIDS-Related Opportunistic Infections↗

PubMed2001

Evaluation and use of sediment toxicity reference sites for statistical comparisons in regional assessments.

Sediment reference sites were used to establish toxicity standards against which to compare results from sites investigated in San Francisco Bay (California, USA) monitoring programs. The reference sites were selected on the basis of low concentrations of anthropogenic chemicals, distance from active contaminant sources, location in representative hydrographic areas of the Bay, and physical features characteristic of depositional areas (e.g., fine grain size and medium total organic carbon [TOC]). Five field-replicated sites in San Francisco Bay were evaluated over three seasons. Samples from each site were tested with nine toxicity test protocols and were analyzed for sediment grain size and concentrations of trace metals, trace organics, ammonia, hydrogen sulfide, and TOC. The candidate sites were found to have relatively low concentrations of measured chemicals and generally exhibited low toxicity. Toxicity data from the reference sites were then used to calculate numerical tolerance limits to be used as threshold values to determine which test sites had significantly higher toxicity than reference sites. Tolerance limits are presented for four standard test protocols, including solid-phase sediment tests with the amphipods Ampelisca abdita and Eohaustorius estuarius and sea urchin Strongylocentrotus purpuratus embryo/larval development tests in pore water and at the sediment-water interface (SWI). Tolerance limits delineating the lowest 10th percentile (0.10 quantile) of the reference site data distribution were 71% of the control response for Ampelisca, 70% for Eohaustorius, 94% for sea urchin embryos in pore water, and 87% for sea urchins embryos exposed at the SWI. The tolerance limits are discussed in terms of the critical values governing their calculation and the management implications arising from their use in determining elevated toxicity relative to reference conditions.

Algorithms↗

PubMed2001

Nonablative laser skin tightening.

This article introduces the reader to the concept of nonablative laser skin tightening with the Cool Touch (Cool Touch Corp., Roseville, CA) laser, a minimally invasive office based procedure. This novel laser system uses dynamic cooling to protect the epidermis while producing a wound healing response in the dermis. Subtle yet positive results have been observed with this laser with minimal down time for patients. The development of this technology and its clinical applications and investigations are discussed.

Animals↗

PubMed2000

BMPR2 haploinsufficiency as the inherited molecular mechanism for primary pulmonary hypertension.

Primary pulmonary hypertension (PPH) is a potentially lethal disorder, because the elevation of the pulmonary arterial pressure may result in right-heart failure. Histologically, the disorder is characterized by proliferation of pulmonary-artery smooth muscle and endothelial cells, by intimal hyperplasia, and by in situ thrombus formation. Heterozygous mutations within the bone morphogenetic protein type II receptor (BMPR-II) gene (BMPR2), of the transforming growth factor beta (TGF-beta) cell-signaling superfamily, have been identified in familial and sporadic cases of PPH. We report the molecular spectrum of BMPR2 mutations in 47 additional families with PPH and in three patients with sporadic PPH. Among the cohort of patients, we have identified 22 novel mutations, including 4 partial deletions, distributed throughout the BMPR2 gene. The majority (58%) of mutations are predicted to lead to a premature termination codon. We have also investigated the functional impact and genotype-phenotype relationships, to elucidate the mechanisms contributing to pathogenesis of this important vascular disease. In vitro expression analysis demonstrated loss of BMPR-II function for a number of the identified mutations. These data support the suggestion that haploinsufficiency represents the common molecular mechanism in PPH. Marked variability of the age at onset of disease was observed both within and between families. Taken together, these studies illustrate the considerable heterogeneity of BMPR2 mutations that cause PPH, and they strongly suggest that additional factors, genetic and/or environmental, may be required for the development of the clinical phenotype.

Adolescent↗

PubMed2000

Crystal structure of the haloalkane dehalogenase from Sphingomonas paucimobilis UT26.

The haloalkane dehalogenase from Sphingomonas paucimobilis UT26 (LinB) is the enzyme involved in the degradation of the important environmental pollutant gamma-hexachlorocyclohexane. The enzyme hydrolyzes a broad range of halogenated cyclic and aliphatic compounds. Here, we present the 1.58 A crystal structure of LinB and the 2.0 A structure of LinB with 1,3-propanediol, a product of debromination of 1,3-dibromopropane, in the active site of the enzyme. The enzyme belongs to the alpha/beta hydrolase family and contains a catalytic triad (Asp108, His272, and Glu132) in the lipase-like topological arrangement previously proposed from mutagenesis experiments. The LinB structure was compared with the structures of haloalkane dehalogenase from Xanthobacter autotrophicus GJ10 and from Rhodococcus sp. and the structural features involved in the adaptation toward xenobiotic substrates were identified. The arrangement and composition of the alpha-helices in the cap domain results in the differences in the size and shape of the active-site cavity and the entrance tunnel. This is the major determinant of the substrate specificity of this haloalkane dehalogenase.

Binding Sites↗

PubMed2000

Involvement of an FtsH homologue in the assembly of functional photosystem I in the cyanobacterium Synechocystis sp. PCC 6803.

The Synechocystis sp. PCC 6803 genome encodes four putative homologues of the AAA protease FtsH, two of which (slr0228 and sll1463) have been subjected to insertional mutagenesis in this study. Disruption of sll1463 had no discernible effect but disruption of slr0228 caused a 60% reduction in the abundance of functional photosystem I, without affecting the cellular content of photosystem II or phycobilisomes. Fluorescence and immunoblotting analyses show reductions in PS I polypeptides and possible structural alterations in the residual PS I, indicating an important role for slr0228 in PS I biogenesis.

ATP-Dependent Proteases↗

PubMed2000

Is screening mammography effective in elderly women?

PURPOSE: Screening mammography is effective in reducing breast cancer mortality in women between the ages of 50 and 69 years. We sought to determine whether older women who undergo screening mammography have a decreased risk of metastatic breast cancer. SUBJECTS AND METHODS: We studied 690,993 women aged 66 to 79 years who were California Medicare beneficiaries from January 1992 to December 1993, and who chose the fee-for-service plan. Health Care Financing Administration part B billing records were used to determine the use of screening mammography. The extent of breast cancer (in situ, local, regional, or metastatic) was ascertained for the 6,767 women who were diagnosed with the disease in 1993, using data from the California State Cancer Registry. For each type (extent) of breast cancer, the relative risk (RR) and 95% confidence (CI) of developing breast cancer was estimated by dividing the risk of its development in screened women by the risk in women who were not screened. RESULTS: A total of 46% of women had mammography during the 2-year study period. In situ, local, and regional breast cancer were more likely to be detected among women who underwent screening mammography. For example, the relative risk of detecting local breast cancer in screened women was 3.3 (95% CI: 3.1 to 3.5). The risk of detecting metastatic breast cancer, on the other hand, was significantly reduced among women aged 66 to 79 years who underwent screening mammography (RR = 0.57, 95% CI: 0.45 to 0.72). CONCLUSION: Screening mammography is associated with a decreased risk of detecting metastatic breast cancer among elderly women. Public health recommendations need to weigh the benefit of screening elderly women against the cost and potential harm from screening and treating early lesions that may have no effect on mortality.

Black or African American↗