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Biomedical subjects

D Johnson

Publications and source records attributed to D Johnson.

At least 91 records · Page 5Linked to original sources
PubMed2000

The influence of gender and specialty on reporting of abusive and discriminatory behaviour by medical students, residents and physician teachers.

INTRODUCTION: The perception of whether a given behaviour is abusive differs between students and teachers. We speculated that attitudes towards reporting abusive and discriminatory behaviour may vary by specialty as well as by gender. METHODS: We report a cross-sectional survey of incoming medical students, medical students, residents, and teaching faculty at one Canadian medical school. The discrimination and abuse questions were in the following domains: (i) psychological abuse, (ii) sexual abuse, (iii) physical abuse, (iv) gender discrimination, (v) racial discrimination, (vi) disability discrimination, (vii) derogatory remarks regarding homosexuality. The frequency of self-reported witnessed or experienced abusive and discriminatory behaviour was compared by gender, specialty choice and stage of training. RESULTS: The response rates varied by respondent group: 44/56 (79%) of incoming medical students, 177/218 (81%) of medical students, 134/206 (65%) of residents and 215/554 (38%) of physician teachers. The frequency of these behaviours was perceived to be low by both male and female respondents. Abusive and discriminatory behaviour by physician teachers was noted more frequently by residents (P < 0.001) and physician teachers themselves (P < 0.001) compared with incoming medical students. As well, in general, women noted more abusive and discriminatory behaviour by all teachers, compared with men (P < 0. 003). Each response to the abuse/discrimination questions was also modelled as the independent variable using stepwise multiple regression. The area of specialization (surgical versus non-surgical) altered the reporting of abusive and discriminatory behaviour by women. CONCLUSION: We conclude that female surgical residents and medical students undergo a process of acclimatization to the patriarchal surgical culture. As female surgeons become physician teachers they revert to a culture more similar to that of their female non-surgical colleagues. Although a process of deidealization occurs in medical training, these attitudes are not necessarily retained throughout the practising lifetime of physicians as they regain autonomy and more personal control.

Adult↗
PubMed2000

Tension-free vaginal tape for primary genuine stress incontinence: a two-centre follow-up study.

OBJECTIVE: To assess the safety and efficacy of the tension-free vaginal tape procedure in the treatment of primary genuine stress incontinence. PATIENTS AND METHODS: A two-centre follow-up study was conducted on 40 women with urodynamically confirmed primary genuine stress incontinence who had a tension-free vaginal tape inserted under local anaesthesia with sedation. Operative details were recorded and all patients followed up both subjectively, and objectively with repeat urodynamic studies and pad testing. RESULTS: The mean (range) age of the women was 51.1 (33-86) years, the median parity 2 (0-4) and mean body mass index 25.1 (19-35). The mean anaesthesia and operative duration was 42 (25-65) min; 93% of the women resumed immediate spontaneous voiding with no need for catheterization. The mean inpatient stay was 2.2 (2-4) days (where 2 days is equivalent to one night in hospital). The follow-up was conducted at a mean interval of 12.3 (6-24) months. Subjectively, 80% of women were cured and 17.5% significantly improved; objectively, genuine stress incontinence was cured in 95%. Symptomatic postoperative detrusor instability was found in 15% of women and symptoms of voiding dysfunction identified in 5% of women. There were no defects in healing or tape rejection. CONCLUSION: The tension-free vaginal tape procedure is a promising new technique that, in this short-term analysis, appears to be safe and effective. Intra-operative complications are uncommon and both hospital stay and recovery are short. Voiding complications are rare but symptomatic postoperative detrusor instability had an incidence of 15%.

Adult↗
PubMed2000

Is all ventricular fibrillation the same? Influence of mode of induction on characteristics of ventricular fibrillation.

INTRODUCTION: Little information is available on the relationship between the mode of induction of ventricular fibrillation (VF) to VF characteristics. METHODS AND RESULTS: VF was induced from the anterior left ventricle by programmed electrical stimulation, burst pacing, alternating current (AC), high current S2 at a site remote from S1, T wave shock, and intersecting wavefronts in seven normal dogs and seven dogs with chronic myocardial infarction. Using two electrode arrays, 112 electrograms were recorded from the anterior and lateral wall. Cycle lengths were analyzed and activation vectors were created by summing orthogonally recorded bipolar electrograms. The magnitude of the vector loops was integrated over time to produce an "ensemble vector" index (EVI) whose magnitude is high when beat-to-beat activation direction is consistent and low when activation direction is variable. T wave shock-induced VF had a significantly longer cycle length 1 to 5 seconds after VF onset than other modes of induction (P < 0.05). The frequency-corrected EVI was significantly larger for AC current and T wave shock-induced VF as opposed to all other modes of VF induction in early VF (P < 0.0001). After 10 seconds of VF, these differences persisted only on the anterior wall. CONCLUSION: VF induced in animals by T wave shock and AC current had different characteristics than VF induced by other methods. These findings may have implications for our understanding of VF pathophysiology.

Animals↗
PubMed2000

Paternal origin of FGFR2 mutations in sporadic cases of Crouzon syndrome and Pfeiffer syndrome.

Crouzon syndrome and Pfeiffer syndrome are both autosomal dominant craniosynostotic disorders that can be caused by mutations in the fibroblast growth factor receptor 2 (FGFR2) gene. To determine the parental origin of these FGFR2 mutations, the amplification refractory mutation system (ARMS) was used. ARMS PCR primers were developed to recognize polymorphisms that could distinguish maternal and paternal alleles. A total of 4,374 bases between introns IIIa and 11 of the FGFR2 gene were sequenced and were assayed by heteroduplex analysis, to identify polymorphisms. Two polymorphisms (1333TA/TATA and 2710 C/T) were found and were used with two previously described polymorphisms, to screen a total of 41 families. Twenty-two of these families were shown to be informative (11 for Crouzon syndrome and 11 for Pfeiffer syndrome). Eleven different mutations in the 22 families were detected by either restriction digest or allele-specific oligonucleotide hybridization of ARMS PCR products. We molecularly proved the origin of these different mutations to be paternal for all informative cases analyzed (P=2. 4x10-7; 95% confidence limits 87%-100%). Advanced paternal age was noted for the fathers of patients with Crouzon syndrome or Pfeiffer syndrome, compared with the fathers of control individuals (34. 50+/-7.65 years vs. 30.45+/-1.28 years, P<.01). Our data on advanced paternal age corroborates and extends previous clinical evidence based on statistical analyses as well as additional reports of advanced paternal age associated with paternal origin of three sporadic mutations causing Apert syndrome (FGFR2) and achondroplasia (FGFR3). Our results suggest that older men either have accumulated or are more susceptible to a variety of germline mutations.

Acrocephalosyndactylia↗
PubMed2000

Enhanced detection of blood flow in the normal canine prostate using an ultrasound contrast agent.

RATIONALE AND OBJECTIVES: To evaluate the sonographic appearance of normal prostate vascularity in dogs before and after injection of a new ultrasound contrast agent, NC100100. METHODS: Thirty-five intravenous injections of NC100100, in doses ranging from 0.00625 to 0.05 microL microbubbles/kg, were administered to seven anesthetized mongrel male dogs. Transrectal color Doppler imaging and power Doppler imaging were used to perform the assessment. The visibility of the vascular pattern of the prostate was assessed, including dynamics of contrast inflow, blood flow symmetry, and duration times. RESULTS: Before contrast administration, the vascular pattern was poorly visualized in all cases. After contrast injection, the visibility of the vascular architecture improved significantly for both modalities. Independent of the imaging method used, higher doses tended to be more effective than lower doses. Contrast kinetics in the prostate vessels was demonstrated with a mean time from injection of the ultrasound contrast agent to enhancement of the Doppler signals in the subcapsular arteries (+/-1 SD) of 13+/-3 seconds, and the ultrasound contrast agent reached the central periurethral veins 3 to 6 seconds later. A spokelike radial pattern of internal prostatic vessels observed with enhanced ultrasound could also be seen on silicone microfil x-ray images. The Doppler enhancement persisted for a mean time ( +/-1 SD) of 904 seconds (approximately 15 minutes) +/- 225 seconds and tended to increase with increasing dose. CONCLUSIONS: NC100100 significantly improves the detection of blood flow in the normal canine prostate and allows more accurate depiction of the vascular architecture of the prostate.

Animals↗
PubMed2000

Chronic fatigue syndrome: occupation, medical utilization, and subtypes in a community-based sample.

Most studies of chronic fatigue syndrome (CFS) have been based on patients recruited from primary or tertiary care settings. Patients from such settings might not be typical of patients in the general population. The present investigation involved examining individuals with CFS from a community-based study. A random sample of 18,675 respondents in Chicago was first interviewed by telephone. A group of individuals with chronic fatigue accompanied by at least four minor symptoms associated with CFS were given medical and psychiatric examinations. From this sample, a physician review group diagnosed individuals with CFS. Those diagnosed with CFS were subclassified based on a variety of categories, including duration of illness, mode of illness onset, and presence or absence of a stressful life event directly preceding onset. In addition, we examined medical utilization among those diagnosed with CFS, as well as whether individuals with CFS were disproportionately represented in health care professions. Important differences emerged on measures of sociodemographics, symptoms, and functional disability. The implications of these findings and others are discussed.

Adult↗
PubMed2000

Social network methods for endemic foci of syphilis: a pilot project.

BACKGROUND: Social network methods have improved our understanding of sexually transmitted disease transmission dynamics, and may be of use in routine field operations for partner notification. GOAL: To augment traditional syphilis-control activities with social network methods in an Atlanta area with high syphilis morbidity. STUDY DESIGN: Disease investigators conducted interviews, used network diagrams to prioritize their work, and relied on network connections for finding hard-to-reach persons. RESULTS: A total of 396 contacts were elicited from 48 infected and 50 uninfected persons. The cumulative prevalence of syphilis was 12.6%, and 24 persons infected with HIV were identified. Network methods disclosed a large, interconnected group (276 persons) characterized by high network centrality and the substantial presence of small, interactive subgroups (microstructures). CONCLUSION: The network approach is a feasible field technique, and can identify core groups involved in the intense transmission of syphilis. The targeted, network-based approach may be useful in attempts to eliminate syphilis.

Adult↗
PubMed2000

The benefit/risk profile of rabeprazole, a new proton-pump inhibitor.

Acid-related diseases such as gastro-oesophageal reflux disease (GORD) and peptic ulcer are a common cause of morbidity and if inadequately treated can lead to serious complications. The proton-pump inhibitor rabeprazole has been extensively evaluated in well-controlled trials in North America and Europe for the acute treatment of erosive or ulcerative GORD and gastric and duodenal ulcers and for the long-term maintenance of GORD healing. The results show that rabeprazole has a favourable benefit/risk profile for each indication. Rabeprazole 10 and 20 mg given once daily in the morning was highly effective in producing and maintaining healing, providing symptom relief, and improving overall well-being. Healing rates for rabeprazole were equivalent to omeprazole in all indications, and superior (GORD healing and duodenal ulcer healing) or equivalent (gastric ulcer healing) to the histamine 2-receptor antagonist ranitidine. Symptom relief provided by rabeprazole was equivalent or superior to comparator drugs. Rabeprazole was well tolerated in both short- and long-term studies. The incidence of treatment-emergent signs and symptoms related to rabeprazole was low, and these were generally mild or moderate in severity. The overall rate of discontinuations due to adverse events was approximately 3%. There were no deaths related to rabeprazole therapy. These findings indicate a favourable benefit/risk profile for each intended use.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Effect of underlying heart disease on the frequency content of ventricular fibrillation in the dog heart.

Although prior studies have examined the frequency content of local electrogram characteristics during fibrillation, little is know about the effects of underlying heart disease on these parameters. This study was designed to compare the frequency content of local electrograms during VF in canine models of acute ischemia, subacute infarction, and chronic myocardial infarction (MI) to those in control animals to test the hypothesis that underlying heart disease can alter the basic characteristics of VF. VF was induced using burst pacing in three groups of mongrel dogs. Five dogs were evaluated 8 weeks after LAD occlusion MI, five were evaluated 5 days after experimental MI, and 5 had VF induced before (control) and immediately after LAD occlusion (ischemia). During VF, unipolar electrograms were recorded from 112 sites on the anterior LV and electrograms were evaluated 15 and 30 seconds after VF initiation in each group. Electrograms were analyzed by fast Fourier transform. No significant time dependent changes in VF characteristics were noted. The peak frequency was highest in control animals and 8-week MI, intermediate in 5-day MI, and lowest in acute ischemia (P < 0.01 for pairwise comparisons). In contrast, the fractional of energy within a bandwidth of 25% peak amplitude was highest in acute ischemia, (P < 0.001) and similar in the other three groups. Infarction decreased total energy by approximately 50%. In conclusion, the pressure of ischemia or infarction alters the frequency content of VF in a complex fashion. In addition to decreasing the peak frequency, the shape of the power spectral curve is altered in models of structural heart disease. These results suggest that the electrophysiological changes produced by infarction or ischemia alter the structural organization of ventricular fibrillation.

Animals↗
PubMed2000

Electrophysiological and anatomic heterogeneity in evolving canine myocardial infarction.

Although the heterogeneity of electrophysiological properties is increased after myocardial infarction, the degree of this heterogeneity has not been well quantitated and its relationship to the histological changes that occur after infarction has not been carefully examined. The purpose of the present study was to test the hypothesis that alterations in electrophysiological properties in healing canine infarction are related to particular histological changes. Experimental infarction was produced by left anterior descending coronary ligation. Six dogs were used as controls, six were studied 5 days following, and six were studied 8 weeks following infarction. Pacing thresholds, effective refractory periods, and activation-recovery times were determined at 112 sites on the anterior left ventricle using a multiple electrode plaque. Conduction velocity, conduction-heterogeneity index--a measure of conduction disturbance--and histology of the epimyocardium underlying the plaque were assessed. The effective refractory periods and activation-recovery times were greater in both infarction groups, most prominently in the subacute group. In subacute infarction, significant postrepolarization refractoriness was present. In healed infarction, conduction velocity was decreased and the conduction-heterogeneity index was increased compared to controls and subacute infarction. Dispersion of excitability and repolarization was associated with more extensive local scarring. Dispersion of myocardial fiber angles was associated with the conduction-heterogeneity index. Some but not all of the electrophysiological changes noted in the animals with infarction were also seen in sham operated animals. Thus, heterogeneity in repolarization and refractoriness is greatest in the subacute phase of myocardial infarction and is associated with the extent of local cell death. In contrast, disturbances in conduction are greatest in healed infarction and associated with disarray of myocardial fibers.

Animals↗
PubMed2000

Assessment of health knowledge after "a healthy adventure".

This study evaluated the general health education program for third graders at Hult Health Education Center (Hult HEC). A quasi-experimental, nonequivalent pretest-posttest control group design with four groups was employed to collect pretest and posttest data from 168 third graders. The four groups included a control group, a traditional classroom health education group, a group that visited Hult HEC, and a group that visited Hult HEC and incorporated center curricular materials in the classroom. Analysis of covariance (ANCOVA) was calculated to test for posttest differences among the four groups, while reducing the effects of initial group pretest score differences. A statistically significant difference occurred in posttest scores among the four groups (F = 120.62, df = 4, 163, p = .0001). Post hoc testing revealed the best results were obtained when combining curricular materials with a visit to the Hult HEC.

Analysis of Variance↗
PubMed2000

Pattern of premature degenerative changes of the cervical spine in patients with spasmodic torticollis and the impact on the outcome of selective peripheral denervation.

OBJECTIVES: To characterise the pattern of and risk factors for degenerative changes of the cervical spine in patients with spasmodic torticollis and to assess whether these changes affect outcome after selective peripheral denervation. METHODS: Preoperative CT of the upper cervical spine of 34 patients with spasmodic torticollis referred for surgery were reviewed by two radiologists blinded to the clinical findings. Degenerative changes were assessed for each joint separately and rated as absent, minimal, moderate, or severe. Patients were clinically assessed before surgery and 3 months postoperatively by an independent examiner using standardised clinical rating scales. For comparison of means a t test was carried out. To determine whether an association exists between the side of degenerative changes and type of spasmodic torticollis a chi(2) test was used. Changes in severity, disability, and pain before and after surgery were calculated using a Wilcoxon matched pairs signed ranks test. RESULTS: Fourteen out of 34 patients had moderate or severe degenerative changes. They were predominantly found at the C2/C3 and C3/C4 level and were significantly more likely to occur on the side of the main direction of the spasmodic torticollis (p = 0.015). There was no significant difference in age, sex, duration of torticollis, overall severity, degree of disability, or pain between the group with either no or minimal changes and the group with moderate or severe changes. However, in the second group the duration of inadequate treatment was longer (10.1 v 4.8 years; p=0.009), head mobility was more restricted (p = 0.015), and head tremor was more severe (p = 0.01). At 3 months postoperatively, patients with n or minimal degenerative changes showed a significant improvement in pain and severity whereas no difference was found in those with moderate or severe changes. CONCLUSIONS: Patients with spasmodic torticollis have an increased risk of developing premature degenerative changes of the upper cervical spine that tend to be on the side towards which the head is turned or tilted and compromise outcome after surgery. Effective early treatment of spasmodic torticollis with botulinum toxin seems to have a protective effect. Patients with spasmodic torticollis and restricted head mobility who do not adequately respond to treatment should undergo imaging of the upper cervical spine. Patients with imaging evidence of moderate or severe degenerative changes seem to respond poorly to selective peripheral denervation.

Adult↗
PubMed2000

Decreased expression of apM1 in omental and subcutaneous adipose tissue of humans with type 2 diabetes.

We have screened a subtracted cDNA library in order to identify differentially expressed genes in omental adipose tissue of human patients with Type 2 diabetes. One clone (#1738) showed a marked reduction in omental adipose tissue from patients with Type 2 diabetes. Sequencing and BLAST analysis revealed clone #1738 was the adipocyte-specific secreted protein gene apM1 (synonyms ACRP30, AdipoQ, GBP28). Consistent with the murine orthologue, apM1 mRNA was expressed in cultured human adipocytes and not in preadipocytes. Using RT-PCR we confirmed that apM1 mRNA levels were significantly reduced in omental adipose tissue of obese patients with Type 2 diabetes compared with lean and obese normoglycemic subjects. Although less pronounced, apM1 mRNA levels were reduced in subcutaneous adipose tissue of Type 2 diabetic patients. Whereas the biological function of apM1 is presently unknown, the tissue specific expression, structural similarities to TNFalpha, and the dysregulated expression observed in obese Type 2 diabetic patients suggest that this factor may play a role in the pathogenesis of insulin resistance and Type 2 diabetes.

Adiponectin↗
PubMed2000

Comparison of survival and quality of life in advanced non-small-cell lung cancer patients treated with two dose levels of paclitaxel combined with cisplatin versus etoposide with cisplatin: results of an Eastern Cooperative Oncology Group trial.

PURPOSE: Treatment with cisplatin-based chemotherapy provides a modest survival advantage over supportive care alone in advanced non-small-cell lung cancer (NSCLC). To determine whether a new agent, paclitaxel, would further improve survival in NSCLC, the Eastern Cooperative Oncology Group conducted a randomized trial comparing paclitaxel plus cisplatin to a standard chemotherapy regimen consisting of cisplatin and etoposide. PATIENTS AND METHODS: The study was carried out by a multi-institutional cooperative group in chemotherapy-naive stage IIIB to IV NSCLC patients randomized to receive paclitaxel plus cisplatin or etoposide plus cisplatin. Paclitaxel was administered at two different dose levels (135 mg/m(2) and 250 mg/m(2)), and etoposide was given at a dose of 100 mg/m(2) daily on days 1 to 3. Each regimen was repeated every 21 days and each included cisplatin (75 mg/m(2)). RESULTS: The characteristics of the 599 patients were well-balanced across the three treatment groups. Superior survival was observed with the combined paclitaxel regimens (median survival time, 9.9 months; 1-year survival rate, 38.9%) compared with etoposide plus cisplatin (median survival time, 7.6 months; 1-year survival rate, 31.8%; P =. 048). Comparing survival for the two dose levels of paclitaxel revealed no significant difference. The median survival duration for the stage IIIB subgroup was 7.9 months for etoposide plus cisplatin patients versus 13.1 months for all paclitaxel patients (P =.152). For the stage IV subgroup, the median survival time for etoposide plus cisplatin was 7.6 months compared with 8.9 months for paclitaxel (P =.246). With the exceptions of increased granulocytopenia on the low-dose paclitaxel regimen and increased myalgias, neurotoxicity, and, possibly, increased treatment-related cardiac events with high-dose paclitaxel, toxicity was similar across all three arms. Quality of life (QOL) declined significantly over the 6 months. However, QOL scores were not significantly different among the regimens. CONCLUSION: As a result of these observations, paclitaxel (135 mg/m(2)) combined with cisplatin has replaced etoposide plus cisplatin as the reference regimen in our recently completed phase III trial.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Multi-institutional phase I/II trial of paclitaxel, cisplatin, and etoposide with concurrent radiation for limited-stage small-cell lung carcinoma.

PURPOSE: To determine the feasibility of adding paclitaxel to standard cisplatin/etoposide (EP) and thoracic radiotherapy. PATIENTS AND METHODS: Thirty-one patients were enrolled onto this study. During the phase I section of this study, the dose of paclitaxel was escalated in groups of three or more patients. Cycles were repeated every 21 days. For cycles 1 and 2, paclitaxel was administered according to the dose-escalation schema at doses of 100, 135, or 170 mg/m(2) intravenously over 3 hours on day 1. Once the maximum-tolerated dose (MTD) of paclitaxel (for cycles 1 and 2, concurrent with radiation) was determined, that dose was used in all subsequent patients entered onto the phase II section of this study. For cycles 3 and 4, the paclitaxel dose was fixed at 170 mg/m(2) in all patients. On day 2, cisplatin 60 mg/m(2) was administered for all cycles. On days 1, 2, and 3, etoposide 60 mg/m(2)/d (cycles 1 and 2) or 80 mg/m(2)/d (cycles 3 and 4) was administered. Chest radiation was given at 9 Gy/wk in five fractions for 5 weeks beginning on day 1 of cycle 1. Granulocyte colony-stimulating factors were used during cycles 3 and 4 only. RESULTS: Twenty-eight patients were assessable. The MTD of paclitaxel was 135 mg/m(2), with the dose-limiting toxicity being grade 4 neutropenia. Cycles 1 and 2 were associated with grade 4 neutropenia in 32% of courses, with fever occurring in 7% of courses and grade 2/3 esophagitis in 13%. Cycles 3 and 4 were complicated by grade 4 neutropenia in 20% of courses, with fever occurring in 6% of courses and grade 2/3 esophagitis in 16%. The overall response rate was 96% (complete responses, 39%; partial responses, 57%). After a median follow-up period of 23 months (range, 9 to 40 months), the median survival time was 22.3 months (95% confidence interval, 15.1 to 34.3 months) CONCLUSION: The MTD of paclitaxel with radiation and EP treatment is 135 mg/m(2) given over 3 hours. In this schedule of administration, a high response rate and acceptable toxicity can be anticipated.

Adolescent↗
PubMed2000

Differences in circulating concentrations of total, free and bound leptin relate to gender and body composition in adult humans.

We describe a radioimmunoassay (RIA) for total leptin and a gel filtration procedure for the separation of free and bound leptin in human serum. The RIA, based on a locally prepared antibody, has a minimum detection limit of 0.9 ng/mL, a working range (CV < 10%) of 2.5-50 ng/mL, inter-assay precision of 10.2, 7.2 and 8.9%CV at 7.9, 15.4 and 30.0 ng/mL, respectively, 94% recovery of exogenous leptin (range 81.1-120.6%), exhibited parallelism and demonstrated no significant cross-reactivity or interferences. A difference plot of results from this method and those from a commercially available kit (Linco Research) demonstrated satisfactory agreement up to concentrations of 50 ng/mL total leptin, with no significant bias. A gender-dependent correlation was obtained between body mass index (BMI) and total leptin (r = 0.91, P<0.001, n = 75 for men; r = 0.79, P<0.001, n = 72 for women), with women having higher leptin concentrations than men for any given BMI. Gel filtration studies (inter-assay precision: 4.7%CV, n = 18) demonstrated that a variable fraction (between 10% and 40%) of total leptin in serum was bound with high affinity (Keq = 1.0-1.45 x 10(9) L/mol) to a non-albumin, non-lipid macromolecule. Binding affinities were found to be similar irrespective of gender or fat mass. A significant positive correlation between free or bound leptin concentrations and BMI was obtained for both men and women (r = 0.87-0.94); free and bound leptin concentrations were also significantly higher in women (P<0.01) than in men for any given BMI, and higher in obese (P<0.01) than in lean individuals. We conclude that leptin 'resistance' associated with obesity cannot be accounted for by reduced free leptin concentrations in serum and that the methods described are suitable for the investigation of total, free and bound leptin for both clinical and research purposes.

Body Mass Index↗
PubMed2000

Strategies for assessing the implications of malformed frogs for environmental health.

The recent increase in the incidence of deformities among natural frog populations has raised concern about the state of the environment and the possible impact of unidentified causative agents on the health of wildlife and human populations. An open workshop on Strategies for Assessing the Implications of Malformed Frogs for Environmental Health was convened on 4-5 December 1997 at the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina. The purpose of the workshop was to share information among a multidisciplinary group with scientific interest and responsibility for human and environmental health at the federal and state level. Discussions highlighted possible causes and recent findings directly related to frog deformities and provided insight into problems and strategies applicable to continuing investigation in several areas. Possible causes of the deformities were evaluated in terms of diagnostics performed on field amphibians, biologic mechanisms that can lead to the types of malformations observed, and parallel laboratory and field studies. Hydrogeochemistry must be more integrated into environmental toxicology because of the pivotal role of the aquatic environment and the importance of fates and transport relative to any potential exposure. There is no indication of whether there may be a human health factor associated with the deformities. However, the possibility that causal agents may be waterborne indicates a need to identify the relevant factors and establish the relationship between environmental and human health in terms of hazard assessment.

Animals↗