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Biomedical subjects

B J Hall

Publications and source records attributed to B J Hall.

At least 19 recordsLinked to original sources
PubMed2003

Osteoarthritis pain and weather.

OBJECTIVE: To evaluate the association between weather (barometric pressure, precipitation and temperature) and pain among individuals with osteoarthritis (OA) (n=154) at the following sites: neck, hand, shoulder, knee and foot. METHODS: This prospective study evaluated men and women, aged 49-90 yr, participating in a community-based, osteoarthritis exercise study (June 1998-January 2002). Weekly self-reported pain scores were collected using a visual analogue scale. Statistical tests, including regression and correlation analyses, were conducted. P values < 0.001 were considered significant. RESULTS: The total number of pain recordings varied by site, ranging from 2269 (feet) to 6061 (hands). The mean temperature was 23 degrees C with a low of 0 degrees C and a high of 36 degrees C. Precipitation levels ranged from 0.00-21.08 cm, with a mean of 0.36 cm. Most associations explored produced non-significant findings. However, among women with hand OA, higher pain was significantly associated with days of rising barometric pressure (P < 0.001). CONCLUSION: Among a population of exercisers aged 49 yr and older, overall these findings did not support the hypothesis that weather is associated with pain. While some associations were suggestive of a relationship, largely these findings indicate that weather is quite modestly, if at all, associated with pain from OA.

Aged↗
PubMed2003

Smoking and osteoarthritis: is there an association? The Clearwater Osteoarthritis Study.

OBJECTIVE: To evaluate the association between cigarette smoking and the subsequent development of osteoarthritis (OA) at four separate sites: knee, hand, foot and cervical spine. METHODS: This cohort study examined 2505 men and women aged 40 years and older participating in the longitudinal Clearwater Osteoarthritis Study (1988-current). Biennial physical exams, including serial radiographs, as well as historical information, were collected. The Lawrence and Kellgren ordinal scale was used to determine radiological evidence of the study outcome, OA. Self-reported history of smoking behavior was used to determine the study exposure. Smoking was classified using four approaches: (1) ever/never, (2) former/never, (3) current/never, and (4) dose. RESULTS: Among the individuals at study entry, radiologically confirmed incident OA was detected during the follow-up period at four sites: knee (32%), hand (49%), foot (28%), and cervical spine (52%). Approximately 11% were self-reported current smokers. Unadjusted analyses indicated that individuals classified as current smokers demonstrated significant levels of protection from OA at all four sites investigated. However, adjusted point estimates ranging from 0.60-1.48 were suggestive of no association between smoking and the development of OA at any of the four sites investigated. CONCLUSION: Based upon the findings of this prospective study, smoking does not appear to convey a clinically significant level of protection against the development of radiologically-confirmed OA. While these findings corroborate previous studies indicating no association between smoking and OA, anecdotal evidence warrants investigation into the role that cigarette smoking may play in the symptomatology of OA.

Cohort Studies↗
PubMed2002

History of acute knee injury and osteoarthritis of the knee: a prospective epidemiological assessment. The Clearwater Osteoarthritis Study.

OBJECTIVE: To evaluate the association between acute joint injury to the knee and knee osteoarthritis (OA). DESIGN: Prospective cohort. Sample size = 1,436. Men and women aged 40 years and older participating in the population-based Clearwater Osteoarthritis Study (1988-current) with biennial physical exams including serial radiographs. Radiologically confirmed knee OA = 27%; self-reported knee injury = 11%. Lawrence and Kellgren ordinal scale was used to determine radiological evidence of the study outcome, knee OA. Self-reported history of knee injury was used to determine the study exposure. RESULTS: Individuals with a history of knee injury were 7.4 (95% C.I. 5.9-9.4) times as likely to develop knee OA than were those individuals who did not have a history of knee injury. CONCLUSION: Acute knee joint injury appears to be a risk factor for the development of knee OA. Prevention strategies for OA should be targeted to those individuals with a history of acute knee injury.

Acute Disease↗
PubMed2001

Adverse events, including death, associated with the use of 1,4-butanediol.

BACKGROUND: 1,4-Butanediol is an industrial solvent that, when ingested, is converted to gamma-hydroxybutyrate, a drug of abuse with depressant effects, primarily on the central nervous system. After reports of toxic effects of gamma-hydroxybutyrate and its resultant regulation by the federal government, 1,4-butanediol and gamma-butyrolactone, another precursor of gamma-hydroxybutyrate and an industrial solvent, began to be marketed as dietary supplements. We investigated reports of toxic effects due to the ingestion of 1,4-butanediol and reviewed the related health risks. METHODS: From June 1999 through December 1999, we identified cases of toxic effects of 1,4-butanediol involving patients who presented to our emergency departments with a clinical syndrome suggesting toxic effects of gamma-hydroxybutyrate and a history of ingesting 1,4-butanediol and patients discovered through public health officials and family members. We used gas chromatography-mass spectrometry to measure 1,4-butanediol or its metabolite, gamma-hydroxybutyrate, in urine, serum, or blood. RESULTS: We identified nine episodes of toxic effects in eight patients who had ingested 1,4-butanediol recreationally, to enhance bodybuilding, or to treat depression or insomnia. One patient presented twice with toxic effects and had withdrawal symptoms after her second presentation. Clinical findings and adverse events included vomiting, urinary and fecal incontinence, agitation, combativeness, a labile level of consciousness, respiratory depression, and death. No additional intoxicants were identified in six patients, including the two who died. The doses of 1,4-butanediol ingested ranged from 5.4 to 20 g in the patients who died and ranged from 1 to 14 g in the nonfatal cases. CONCLUSIONS: The health risks of 1,4-butanediol are similar to those of its counterparts, gamma-hydroxybutyrate and gamma-butyrolactone. These include acute toxic effects, which may be fatal, and addiction and withdrawal.

Adult↗
PubMed1999

Aqueous phase hexylchloroformate derivatization and solid phase microextraction: determination of benzoylecgonine in urine by gas chromatography-quadrupole ion trap mass spectrometry.

A derivatization/solid phase microextraction (SPME) method for the determination of benzoylecgonine in urine was developed. The derivatization is conducted directly in 1 mL of urine while sonicating for 3 min with 12 microL of hexyl chloroformate and 70 microL of a mixture containing acetonitrile:water:hexanol:2-dimethylaminopyridine (5:2:2:1 v/v), yielding benzoylecgonine hexyl ester (BHE) as the product. After the 3 min period, an aliquot of 250 microL is transferred to a vial for SPME. After the desired extraction time the 100 microns polydimethylsiloxane SPME fiber was transferred to the GC-MS for separation and analysis with a quadrupole ion trap mass spectrometer. The hexyl chloroformate derivatization and SPME procedures were optimized for compatibility and sensitivity. The method was found linear for 0.10 to 20.0 micrograms/mL (r2 = 0.999) of benzoylecgonine in urine using benzoylecgonine-d3 as an internal standard (1.5 micrograms/mL). Intra-day precisions were 8.8 and 6.8% RSD for 0.30 microgram/mL and 17 micrograms/mL benzoylecgonine standards in urine (n = 6), respectively. Inter-day precision (n = 3) were < or = 3.3% RSD, indicating good reproducibility. A detection limit of 0.03 microgram/mL (S/N = 3) was achieved, thus making the SPME method a simplified alternative to SPE for GC-MS confirmation after EMIT tests for benzoylecgonine which have a cutoff of 0.30 microgram/mL. Quantitative results by SPME and SPE of two clinical urine specimens known positive for cocaine by EMIT were in excellent agreement. Benzoylecgonine was detected by the derivatization/SPME method in 22 out of 22 other urine specimens known positive for cocaine.

Calibration↗
PubMed1998

Determination of cannabinoids in water and human saliva by solid-phase microextraction and quadrupole ion trap gas chromatography/mass spectrometry.

Solid-phase microextraction (SPME) is applied to the determination of cannabidiol, delta 8-tetrahydrocannabinol (delta 8-THC), delta 9-tetrahydrocannabinol (delta 9-THC), and cannabinol in pure water and human saliva. The inherent extraction behavior of the cannabinoids in pure water is evaluated along with optimization of the method in human saliva. The commercially available poly(dimethylsiloxane) (PDMS) SPME fibers were found to be the best class for the cannabinoid analysis. Partition coefficients were found to be extremely large for all of the cannabinoids (log K > 4.0). Equilibrium times for the 7- and 30-micron PDMS fibers were 50 and 240 min, respectively. A shorter extraction time of 10 min with the 30-micron PDMS fiber may be used for multiple extractions from the same vial, thus conserving the sample necessary for analysis and speeding up the total analysis time. Recoveries for the cannabinoids in saliva, relative to pure water, were dramatically improved by a method developed in our laboratory involving addition of glacial acetic acid to the sample vial prior to performing SPME. Using this method, recoveries relative to SPME in pure water ranged from 21 to 47% depending on the cannabinoid. The linear range for spiked saliva samples was established at 5-500 ng/mL (r2 > 0.994) with precisions between 11 and 20% RSD. The ultimate level of detection by SPME for the cannabinoids in saliva was 1.0 ng/mL, with signal-to-noise values of > or = 12. A saliva sample collected 30 min after marijuana smoking was subject to SPME and traditional liquid-liquid extraction analysis. Internal standard quantitation results for delta 9-THC by both methods yielded comparable results, indicating that the SPME method of analysis is highly accurate and precise. The level of delta 9-THC by SPME was found to be 9.54 ng/mL for the saliva sample.

Cannabinoids↗
PubMed1997

Determination of barbiturates by solid-phase microextraction (SPME) and ion trap gas chromatography-mass spectrometry.

Solid-phase microextraction (SPME) in conjunction with quadrupole ion trap GC-MS was applied to the determination of a series of barbiturates. A 65 microns Carbowax-divinylbenzene (DVB) SPME fiber was used to successfully extract a series of eight barbiturates from aqueous solution. Absorption kinetics and distribution coefficients for the 65 microns Carbowax-DVB SPME fiber were determined for the compounds. In addition the method was evaluated with respect to linearity, limit of detection, precision, desorption time, and the effect of salt. Limits of detection reached 1 ng/ml for the barbiturates. Linearity was established for the barbiturates over a concentration range of 10-1000 ng/ml, with coefficients of correlation 0.99. Overall, the precision of the method fell between 2.2%-6.5%, depending on the barbiturate. SPME was applied to the identification and quantitation of the barbiturates in a urine matrix. The method was validated by analyzing a reference standard pentobarbital-spiked urine sample. Both standard addition and internal standard with [2H5]-pentobarbital techniques were evaluated, with recoveries found to be 93% and 104%, respectively SPME was then used to rapidly screen a urine specimen tested positive for barbiturates, and butalbital was detected and quantified.

Absorption↗
PubMed1997

Pulmonary lesions in experimental ophidian paramyxovirus pneumonia of Aruba Island rattlesnakes, Crotalus unicolor.

Histologic and ultrastructural changes were observed in the respiratory portions of lung in five 29-40-month-old Aruba Island rattlesnakes, Crotalus unicolor, that were inoculated with an Aruba Island Rattlesnake virus (AIV) strain of ophidian paramyxovirus (OPMV) isolated from an Aruba Island rattlesnake. Lungs from one non-infected and three mock-infected Aruba Island rattlesnakes were examined also. From 4 to 22 days following intratracheal inoculation, progressive microscopic changes were seen in the lung. Initially, increased numbers of heterophils were observed in the interstitium followed by proliferation and vacuolation of epithelial cells lining faveoli. The changes appeared to progress from cranial to caudal portions of the respiratory lung following inoculation. Beginning at 4 days postinoculation, viral antigen was demonstrated in epithelial cells lining faveoli with an immunofluorescent technique using a rabbit anti-AIV polyclonal antibody. Electron microscopy revealed loss of type I cells, hyperplasia of type II cells, and interstitial infiltrates of heterophils and mononuclear cells. Viral nucleocapsid material was seen within the cytoplasm and mature virus was seen budding from cytoplasmic membranes of infected type I and type II cells from 8 to 19 days after infection. A virus consistent with AIV was isolated from lung tissues of infected rattlesnakes, thus fulfilling Koch's postulates.

Animals↗
PubMed1996

An in vitro preparation of frog nose and brain for the study of odour-evoked oscillatory activity.

An in vitro preparation is described that consists of frog brain rostral to the brainstem connected to the nasal epithelium by the olfactory nerves. Field potential and intracellular recordings from various brain structures can be obtained while stimulating the nasal epithelium with air-borne odours for at least 12 h after removal of the brain. Power spectra, amplitude and duration of odour-evoked and spontaneous field potentials in vitro are similar to those obtained from paralyzed, spinal cord pithed frogs. A brief puff of odorant applied to the olfactory epithelium produces a 1-2 s bout of 7-13 Hz oscillations in the field potential recorded from the ipsilateral bulb and various ventral, lateral and medial telencephalic structures. Odour evoked bulbar oscillations are maintained after removal of the telencephalon. Electrical stimulation of the olfactory nerves will not elicit oscillations like those evoked by odour stimulation. High-pressure puffs of non-odorised, moist air, elicit olfactory bulb oscillations similar to those evoked by lower pressure puffs of odorised air. Intracellular recordings from most mitral cells reveal oscillations in membrane potential that are phase-locked to the field potential. The extent to which these phase-locked oscillations produce action potentials varies, apparently as a function of the strength and duration of a long-lasting inhibitory potential that is superimposed upon the 7-13 Hz oscillations. This preparation is well-suited for the study of the cellular basis of oscillatory activity in vertebrate brain, and the function of sensory-evoked oscillatory responses in processing of sensory information.

Animals↗
PubMed1996

Characterization of paramyxoviruses isolated from three snakes.

Multiple epizootics of pneumonia in captive snakes have been attributed to viruses which have been tentatively placed in the family Paramyxoviridae. Viruses isolated from an ill Neotropical rattlesnake (Crotalus durissus terrificus), from an Aruba Island rattlesnake (Crotalus unicolor), and from a bush viper (Atheris sp.) were propagated in Vero cells and characterized. Viral particles produced in Vero cells were pleomorphic, enveloped, and contained helical nucleocapsids. The viruses were sensitive to ether and to acidic and basic pH. Moreover, they had neuraminidase activity and were able to agglutinate erythrocytes from chicken and a variety of species of mammals. Hemagglutination was inhibited with rabbit antiserum raised against each virus. The buoyant densities of the three isolates ranged from 1.13/cm3 to 1.18/cm3, values consistent with that for an enveloped virus. The nucleic acid in the virion was determined to be RNA by [3H]uridine incorporation. Viral proteins characteristic of paramyxoviruses were immunoprecipitated from cells infected with each of the three isolates using rabbit anti-Neotropical virus serum. The morphologic appearance, physico- and biochemical properties, and cytopathologic effects of these snake viruses were consistent with those of certain members of the family Paramyxoviridae.

Animals↗
PubMed1996

Staining and morphologic features of bone marrow hematopoietic cells in desert tortoises (Gopherus agassizii).

OBJECTIVES: To determine optimal site for collection of bone marrow from desert tortoises, and to characterize cytologic staining and morphologic features of bone marrow hematopoietic cells. ANIMALS: 16 desert tortoises. PROCEDURE: Bone marrow was obtained at necropsy from the pelvis, proximal portion of the humerus, femur, and thickened portions of the cranial to craniolateral and caudal to caudolateral margins of the carapace and plastron for histologic and cytologic examinations. Cytocentrifuged preparations of marrow cells were evaluated for reactivity to cytochemical stains. RESULTS: Histologic sections were adequate for evaluating acidophils, acidophil precursors, and erythrocyte precursors. It was difficult to differentiate among monocytes, lymphocytes, thrombocytes, and blast cells, and eosinophils could not be differentiated from heterophils. Basophils were in rare, small clusters of 3 to 12 cells. A few lymphoid follicles were found in the pelvis and long bones. Use of cytochemical staining accomplished differentiation between agranular heterophil precursors and granulated heterophils, and between granulated eosinophils and basophils. Monocytes, azurophils, and monoblasts had similar staining features. Staining of erythrocyte precursors with Sudan black B differentiated them from lymphocytes. Only a few small cells with periodic acid-Schiff-positive cytoplasm were identified as thrombocytes. Lymphocytes did not stain with any of the cytochemical stains. CONCLUSIONS: For histologic and cytologic evaluation of bone marrow hematopoietic cells, pelvis, proximal portion of the humerus, femur, and thickened portions of the peripheral cranial and caudal regions of the carapace and plastron are suitable sites to collect specimens. There are distinct cytochemical markers for heterophil, monocyte, and erythrocyte precursors, as well as later stage heterophils, eosinophils, basophils, monocytes, and azurophils.

Animals↗
PubMed1995

The effect on diagnostic quality of using dual isotope imaging for 81Krm ventilation and 99Tcm-MAA perfusion lung scanning.

It is the practice in some centres to use dual isotope imaging to reduce imaging times in lung ventilation and perfusion studies with 81Krm gas and 99Tcm-macroaggregated albumin (99Tcm-MAA) by simultaneous acquisition of the two images. The resulting loss of image caused by cross-talk between the two energy windows was investigated using two phantoms, one with cold 99Tcm lesions of varying size and contrast, and the other a uniform field of 81Krm. It was found that, under scatter conditions typical of a patient study, the use of dual isotope acquisition and a krypton generator of 470 MBq or greater resulted in a perceptible loss of image quality with lesions up to 4 cm in diameter being missed. On an older camera system, without modern energy and linearity correction facilities, a lower generator activity of only 120 MBq was sufficient to cause image degradation even under very low scatter conditions. Seventy-five patient studies were performed using both single and dual isotope imaging with generator activities ranging from 80 to 282 MBq. At these low generator activities, the studies did not demonstrate any differences between the images that would result in a different diagnosis. We conclude that the use of dual isotope V/Q scanning reduces the diagnostic value of the perfusion image if the activity of the 81Krm generator is too high, although at generator activities of 300 MBq or less no loss of image quality will occur on modern camera systems.

Humans↗
PubMed1994

Physical activity as a risk factor for osteoarthritis of the knee.

A case-control study was conducted to evaluate the association between knee osteoarthritis (OA) and physical activity (PA) among a community group aged 40 years and older. Case patients (85 males, 154 females) had radiologically confirmed knee OA with grade 2+ changes, according to Kellgren and Lawrence criteria. Control subjects (85 males, 154 females) had no radiologic evidence of knee OA. A statistically significant positive association between high PA level and knee OA was observed for women, with an age-adjusted odds ratio (OR) of 1.66 and 95% confidence interval (CI) of 1.01 to 2.72. In men no association was observed (OR = 0.95; 95% CI, 0.49 to 1.83). These associations persisted when controlling simultaneously for potential confounders including age, obesity, history of knee injury, and socioeconomic status, indicating that the OA-PA association is limited to women. One possible explanation is that risk factors for knee OA are influenced by hormones.

Aged↗
PubMed1990

Reported maltreatment in children with multiple disabilities.

This study examined a population of children with multiple disabilities to investigate whether functional, developmental, or perinatal factors could differentiate children reported and substantiated as maltreated from those not so reported. Data were collected from medical records of a cohort of 500 children evaluated between 1973 and 1984 at the Kennedy Institute in Baltimore, Maryland. Maltreatment reporting was documented through the State of Maryland Abuse Registry and the counties of residence of all study children. Results indicated that the profiles of demographic and family characteristics associated with child maltreatment reporting in this population are consistent with the literature, but child functional and developmental characteristics were not confirmed as risk factors for substantiated maltreatment reports. Indeed, contrary to investigator expectations, the more severely disabled children, in terms of functioning, appeared at less risk of maltreatment than did disabled children functioning at more age-appropriate levels.

Activities of Daily Living↗
PubMed1990

Characteristics of canine melanomas and comparison of histology and DNA ploidy to their biologic behavior.

The biologic behavior of 179 formalin-fixed, paraffin-embedded canine melanomas was correlated with their histologic appearance. In addition, flow cytometric analysis of DNA content was performed on 54 of these tumors. Histologic examination accurately predicted clinical course in 89% of the melanomas with known behavior. Flow cytometry accurately predicted behavior in 93% of tumors with diagnostic histograms and demonstrated malignant features in 100% of metastases from malignant oral tumors; histograms were non-diagnostic for 15% of tumors tested. Histologic examination, flow cytometry, and biologic behavior were in agreement for 93% of the tumors with diagnostic histograms. Interpretive problems were encountered in analyzing heavily pigmented melanomas using this flow cytometry technique.

Age Factors↗
PubMed1983

Production of 2,3-butylene glycol from whey by Klebsiella pneumoniae and Enterobacter aerogenes.

Production of 2,3-butylene glycol from whey with Klebsiella pneumoniae and Enterobacter aerogenes was studied. Sterilization of the whey was unnecessary. Acid whey required neutralization, but sweet whey did not. Butylene glycol production was most efficient at 33 degrees C for Klebsiella pneumoniae and at 37 degrees C for Enterobacter aerogenes. Aeration significantly improved yields. Klebsiella pneumoniae produced more butylene glycol than did Enterobacter aerogenes in unsupplemented whey. The addition of 50 mM sodium acetate to whey increased the production of butylene glycol and acetoin by Enterobacter aerogenes; it also increased the production of glycol by Klebsiella pneumoniae, but the increase in this case was offset by a decrease of production of acetoin. Maximal yields of the glycol plus acetoin in whey were obtained in 48 to 64 h, but Enterobacter aerogenes required about 160 h for complete utilization of the lactose. Highest yields were about .3 M butylene glycol plus acetoin, which corresponds to the production of about 10 kg of glycol from 380 liters of whey.

Acetoin↗