SDHC phaeochromocytoma and paraganglioma: A UK-wide case series

OBJECTIVE

Phaeochromocytomas and paragangliomas (PPGL) are rare, but strongly heritable tumours. Variants in succinate dehydrogenase (SDH) subunits are identified in approximately 25% of cases. However, clinical and genetic information of patients with SDHC variants are underreported.

DESIGN

This retrospective case series collated data from 18 UK Genetics and Endocrinology departments.

PATIENTS

Both asymptomatic and disease-affected patients with confirmed SDHC germline variants are included.

MEASUREMENTS

Clinical data including tumour type and location, surveillance outcomes and interventions, SDHC genetic variant assessment, interpretation, and tumour risk calculation.

RESULTS

We report 91 SDHC cases, 46 probands and 45 non-probands. Fifty-one cases were disease-affected. Median age at genetic diagnosis was 43 years (range: 11-79). Twenty-four SDHC germline variants were identified including six novel variants. Head and neck paraganglioma (HNPGL, n = 30, 65.2%), extra-adrenal paraganglioma (EAPGL, n = 13, 28.2%) and phaeochromocytomas (PCC) (n = 3, 6.5%) were present. One case had multiple PPGLs. Malignant disease was reported in 19.6% (9/46). Eight cases had non-PPGL SDHC-associated tumours, six gastrointestinal stromal tumours (GIST) and two renal cell cancers (RCC). Cumulative tumour risk (95% CI) at age 60 years was 0.94 (CI: 0.79-0.99) in probands, and 0.16 (CI: 0-0.31) in non-probands, respectively.

CONCLUSIONS

This study describes the largest cohort of 91 SDHC patients worldwide. We confirm disease-affected SDHC variant cases develop isolated HNPGL disease in nearly 2/3 of patients, EAPGL and PCC in 1/3, with an increased risk of GIST and RCC. One fifth developed malignant disease, requiring comprehensive lifelong tumour screening and surveillance.

Cost benefit analysis of automatic lameness detection systems in dairy herds: A dynamic programming approach

Epidemiological data establish that lameness is second only to mastitis as the dairy industry's most prevalent and costly animal welfare issue. Using an automatic lameness detection (ALD) system in which continuous, accurate detection is coupled with proper treatment, is key for reducing economic losses due to lameness. It is reasonable to assume that the cost of lameness would vary with its severity. Therefore, our first objective was to estimate the cost of different lameness severity levels as a function of milk production, lameness risk, conception probability, and treatment cost using a dynamic programming (DP) model. Our second objective was to conduct a cost benefit analysis for ALD systems which can reduce production losses through early detection and treatment of lameness, when compared to visual-detection (VD; i.e., performed by humans) systems. The default production loss parameters for the VD system used as inputs to the DP model were either sourced from the literature or were estimated based on data from a field trial. The production loss parameters for the ALD system used as inputs to the DP model were based on extrapolations of parameter values used for the VD system. The profit per present cow per year under assumed expenses and revenues decreased from $426.05 (when lameness incidence was assumed to be 0%) to $389.69 when lameness incidence was 19.5 %. Out of the 19.5 % lameness incidence in our default scenario, 9.8 % were moderate cases and 9.7 % were severe cases. Average cost of lameness was $36.36 at 19.5 % incidence. Average cost of lameness increased with increased incidence and was respectively $82.05, $195.05, and $286.87 at the low, medium, and high incidence scenarios. We used an operational framework which compared the lameness costs between the VD and ALD systems with 25 %, 50 % and 75 % net avoided costs (NAC) for the 10 year lifespan of the ALD system, at default, low, medium and high lameness incidence scenarios. The net return per cow per year from using an ALD system over a VD system was $13, at low incidence and 25 % NAC. The net return per cow per year for the ALD system was as high as $99 at high incidence and 75 % NAC. Out of 351 (3 system prices, 3 system efficiencies, 3 levels of lameness incidence and 13 different herd sizes) scenarios tested, 295 resulted in a net profit within the system lifespan of 10 years, thus justifying the investment in ALD systems.

Cancer Care in Small Pacific Island States

Background: Like other LMICs, many Pacific Island countries and territories (PICTs) have fragile and overburdened health systems with which to combat an increasing burden of cancer. Additionally, a combination of small geographically dispersed populations, limited resources, isolation and frequent natural disasters make cancer control in Pacific Islands also significantly different to elsewhere in the world. No prior work has provided a stocktake of current capacity for diagnosis and treatment of cancer across the region to date. Aim: To describe the specialized health services available for cancer control in the Pacific region, and show the complexity associated with accessing cancer care for Pacific Islanders. Methods: A cross-sectional review of medical services and human resources available for cancer control was undertaken for 21 Pacific Community (SPC) member countries and territories in April-May 2018 , specifically diagnosis (pathology and radiology) and treatment (chemotherapy, radiotherapy and surgical modalities and overseas referrals for services not available on-island) by contacting individual countries and territories. Common travel routes were mapped individually for 4 PICTs; Papua New Guinea, Solomon Islands, Kiribati and Tokelau; as examples of the unique challenges faced by rural dwelling Pacific Islanders when accessing the highest level of care available in-country. Results: Capacity for cancer diagnosis and care is extremely limited in the Pacific region. The exceptions are the 2 French territories (French Polynesia and New Caledonia) and Guam where a near full complement of services for diagnosis and treatment are operational. Some pathology services are generally available in the larger PICTs, while specimens are sent to affiliated off island laboratories for the rest. Plain x-ray and ultrasound are available at 1 or more locations in all PICTs. General and gynecologic surgery is the most widespread treatment modality available. Some to full chemotherapy administered in 7 and radiotherapy in 3 (formerly 4) PICTs. Overseas referrals for medical services not available in-country are a common feature to all PICTs health systems. A need to travel long distances to access health care is a challenged faced by Pacific Islanders on outer islands and rural villages. Examples will be presented. Conclusion: Cancer control services are few and far between in the Pacific region, and PICTs will always likely rely on overseas referrals for care not available. Access barriers exist for those on outer islands and in villages, and an unknown number seek treatment late or not at all for these reasons. Governments need to invest into strengthening primary and secondary care services, making them an option that is more easily accessible to remote populations. Collaboration between transport and health sectors to look at ways to improve frequency, regulation and safety of modes of transportation to outer islands to improve current systems.

Constipation-Predominant Irritable Bowel Syndrome Females Have Normal Colonic Barrier and Secretory Function

OBJECTIVES

The objective of this study was to determine whether constipation-predominant irritable bowel syndrome (IBS-C) is associated with changes in intestinal barrier and secretory function.

METHODS

A total of 19 IBS-C patients and 18 healthy volunteers (all females) underwent saccharide excretion assay (0.1 g ¹³C mannitol and 1 g lactulose), measurements of duodenal and colonic mucosal barrier (transmucosal resistance (TMR), macromolecular and Escherichia coli Bio-Particle translocation), mucosal secretion (basal and acetylcholine (Ach)-evoked short-circuit current (Isc)), in vivo duodenal mucosal impedance, circulating endotoxins, and colonic tight junction gene expression.

RESULTS

There were no differences in the in vivo measurements of barrier function between IBS-C patients and healthy controls: cumulative excretion of ¹³C mannitol (0-2 h mean (s.e.m.); IBS-C: 12.1 (0.9) mg vs. healthy: 13.2 (0.8) mg) and lactulose (8-24 h; IBS-C: 0.9 (0.5) mg vs. healthy: 0.5 (0.2) mg); duodenal impedance IBS-C: 729 (65) Ω vs. healthy: 706 (43) Ω; plasma mean endotoxin activity level IBS-C: 0.36 (0.03) vs. healthy: 0.35 (0.02); and in colonic mRNA expression of occludin, zonula occludens (ZO) 1-3, and claudins 1-12 and 14-19. The ex vivo findings were consistent, with no group differences: duodenal TMR (IBS-C: 28.2 (1.9) Ω cm² vs. healthy: 29.8 (1.9) Ω cm²) and colonic TMR (IBS-C: 19.1 (1.1) Ω cm² vs. healthy: 17.6 (1.7) Ω cm²); fluorescein isothiocyanate (FITC)-dextran (4 kDa) and E. coli Bio-Particle flux. Colonic basal Isc was similar, but duodenal basal Isc was lower in IBS-C (43.5 (4.5) μA cm^-2) vs. healthy (56.9 (4.9) μA cm^-2), P=0.05. Ach-evoked ΔIsc was similar.

CONCLUSIONS

Females with IBS-C have normal colonic barrier and secretory function. Basal duodenal secretion is decreased in IBS-C.

Improving the detection of environmental enteric dysfunction: a lactulose, rhamnose assay of intestinal permeability in children aged under 5 years exposed to poor sanitation and hygiene

Background

Environmental enteric dysfunction (EED) is an asymptomatic intestinal disorder affecting populations living in conditions of poor sanitation and hygiene. The study tested intestinal barrier function in infants with EED.

Methods

We prospectively studied an advanced high-performance liquid chromatography mass spectrometry assay of urine collected after oral intake of the monosaccharide, L-rhamnose and the disaccharide, lactulose, in 112 children from three continents.

Findings

Compared to the US cohort (n=27), the cohorts of children from Peru (n=19) and Zambia (n=85) were older with evidence of growth impairment. The median (range) of age (months) was 8.0 (2.0 to 13.0), 27.0 (15.0 to 29.0) and 21.0 (12.0 to 36.0), respectively. The median (range) of height for age Z score was −0.1 (−1.8 to 2.4), −1.8 (−3.3 to −0.2) and −2.3 (−8.5 to 1.2), respectively. Among children with valid sugar data (n=22 USA, n=19 Peru, n=73 Zambia), there were no significant differences in the median rhamnose urine concentrations between the three groups. The median (range) lactulose concentration (µg/mL) was 6.78 (0.29 to 31.90), 47.60 (4.23 to 379.00) and 75.40 (0.67 to 873.00) in the US, Peruvian and Zambian cohorts, respectively (p<0.001). The lactulose/rhamnose ratio (LRR) was higher in cohorts from Peru (0.75, 0.15, 5.02) and Zambia (2.26, 0.08, 14.48) compared to the US (0.14, 0.06, 1.00) cohort (p<0.001). In a multivariate effect modification model, higher weight-for-age z scores were associated with lower post-dose lactulose when rhamnose excretion was constant (p=0.003).

Conclusions

This non-invasive two saccharide permeability protocol measures changes in intestinal permeability in children with EED and permits the identification of individuals for interventional trials.

Point-of-Care Clinical Ultrasound for Medical Students

PURPOSE

Our institution has recently implemented a point-of-care (POC) ultrasound training program, consisting of an e-learning course and systematic practical hands-on training. The aim of this prospective study was to evaluate the learning outcome of this curriculum.

MATERIALS AND METHODS

16 medical students with no previous ultrasound experience comprised the study group. The program covered a combination of 4 well-described point-of-care (POC) ultrasound protocols (focus assessed transthoracic echocardiography, focused assessment with sonography in trauma, lung ultrasound, and dynamic needle tip positioning for ultrasound-guided vascular access) and it consisted of an e-learning course followed by 4 h of practical hands-on training. Practical skills and image quality were tested 3 times during the study: at baseline, after e-learning, and after hands-on training.

RESULTS

Practical skills improved for all 4 protocols; after e-learning as well as after hands-on training. The number of students who were able to perform at least one interpretable image of the heart increased from 7 at baseline to 12 after e-learning, p<0.01, and to all 16 students after hands-on-training, p<0.01. The number of students able to cannulate an artificial vessel increased from 3 to 8 after e-learning and to 15 after hands-on training.

CONCLUSION

Medical students with no previous ultrasound experience demonstrated a considerable improvement in practical skill after interactive e-learning and 4 h of hands-on training.

An fMRI investigation of racial paralysis

We explore the existence and underlying neural mechanism of a new norm endorsed by both black and white Americans for managing interracial interactions: "racial paralysis', the tendency to opt out of decisions involving members of different races. We show that people are more willing to make choices--such as who is more intelligent, or who is more polite-between two white individuals (same-race decisions) than between a white and a black individual (cross-race decisions), a tendency which was evident more when judgments involved traits related to black stereotypes. We use functional magnetic resonance imaging to examine the mechanisms underlying racial paralysis, to examine the mechanisms underlying racial paralysis, revealing greater recruitment of brain regions implicated in socially appropriate behavior (ventromedial prefrontal cortex), conflict detection (anterior cingulate cortex), deliberative processing (dorsolateral prefrontal cortex), and inhibition (ventrolateral prefrontal cortex). We also discuss the impact of racial paralysis on the quality of interracial relations.

Abstract PD07-03: A Genomic Predictor of Survival Following Taxane-Anthracycline Chemotherapy for Breast Cancer

Background: There is currently no predictive assay for patients with clinical Stage II-III breast cancer from which predicted sensitivity to treatment is associated with high probability of survival following chemotherapy.

Patients & Methods: We performed Affymetrix gene expression microarrays of prospectively collected tumor biopsies from 508 patients with newly diagnosed HER2-normal invasive breast cancer prior to neoadjuvant taxane-anthracycline chemotherapy followed by adjuvant endocrine therapy (if hormone receptor-positive). The predictor was developed from 310 samples (from MDACC & I-SPY) by combining: 1) a signature to predict sensitivity to endocrine therapy (SET); 2) estrogen receptor (ER)-stratified predictive signatures of resistance to chemotherapy, defined as extensive residual cancer burden (RCB-III) or relapse within 3 years; and 3) ER-stratified predictive signatures of response to chemotherapy, defined as pathologic complete response (pCR) or minimal RCB (RCB-I). The predictor classified tumors as treatment sensitive if high or intermediate SET, or if predicted to be responsive (and not resistant) to chemotherapy. Otherwise, tumors were classified as treatment insensitive. The predictor was then tested on an independent cohort (N= 198, 98% with clinical Stage II-III) who received neoadjuvant (N= 180) or adjuvant (N= 18) taxane-anthracycline chemotherapy (from MDACC, USO, GEICAM, Peru, LBJ). Distant relapse-free survival (DRFS) was evaluated at a 3-year median follow up using negative predictive value (NPV, absence of event if predicted to be sensitive), and absolute risk reduction (ARR) for those predicted to be sensitive (versus insensitive), with 95% confidence interval (CI). The independent predictive value was assessed in multivariate Cox regression analysis based on the likelihood ratio test (P≥0.05). Results: Patients in the independent validation cohort who were predicted to be treatment sensitive (28%) had excellent DRFS, with NPV 92% (CI 85-100) and significant absolute risk reduction (ARR 18%, CI 6-28) at 3 years, compared to those predicted to be insensitive. This was similar to the DRFS observed in patients who achieved pCR after they completed neoadjuvant chemotherapy (NPV 93%, CI 85-100). Predictions were accurate in each phenotypic subset: ER+/HER2- (30% predicted sensitive, NPV 97%, CI 91-100; ARR 11%, CI 0.1-21) and ER-/HER2- (26% predicted sensitive, NPV 83%, CI 68-100; ARR 26%, CI 4-28). Predicted treatment sensitivity (HR 0.20, CI 0.07-0.57), ER+ status (HR 0.32, CI 0.17-0.63), clinical tumor stage T3-4 (HR 2.04, CI 1.07-3.88) and age &gt;50 (HR 0.50, CI 0.25-0.98) were significant in a multivariate model that also included clinical nodal status, grade, and type of taxane used.

Conclusion: We report validation results for the first molecular predictor of sensitivity to neoadjuvant/adjuvant systemic therapy for clinical Stage II-III breast cancer that is independently associated with excellent DRFS in those predicted to be sensitive. Predictions were accurate for both ER+/HER2- and ER-/HER2- invasive breast cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD07-03.

Neospora caninum detected in feral rodents

The role of rodents in the epidemiology of neosporosis was investigated by assaying brain tissue of feral mice (Mus musculus) and rats (Rattus norvegicus) for Neospora caninum. Both mouse and rat brain tissue were extracted for total DNA, and subjected to two different N. caninum-specific nested polymerase chain reaction (PCR) assays. A portion of brain tissue from the mice and rats were also assayed for N. caninum in gerbils or gamma-interferon gene knockout (KO) mice. Of the 105 feral mice tested, 10% were positive in the N. caninum-specific PCR assays. Of the 242 rats tested, 30% were positive in both assays. Although mice and rats had N. caninum by PCR testing, clinical signs of N. caninum infection were not observed nor were N. caninum parasites observed in gerbils or KO mice inoculated with the rodent brain tissue.

Prognostic significance of myeloid associated antigen expression in childhood acute lymphoblastic leukemia in Peru

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Background: The prognostic significance of coexpression of myeloid antigens in pediatric patients with acute lymphoblastic leukemia (ALL) has been reported by several authors, with a frequency that has ranged widely. All of these authors are from developed countries, the aim of this study is to evaluate the prognostic significance of these antigens in childhood ALL in a developing country. Methods: We retrospectively reviewed 729 newly diagnosed patients with ALL under 14 years of age, who had a bone marrow flow cytometry performed at our institution, between 1996–2002. Clinical data and treatment outcomes were reviewed and compared between patients with ALL who expressed myeloid antigens and those who did not using chi-square test. Results: 729 medical charts were studied, 81.6% of them were B-common, 8.2% were pro-B, 8.2% were T-cell and 2.1% were pre-B ALL patients. Overall frequency of myeloid antigen expression was 36.6%. The most frequent specific antigens found were: CD13, 15.5%; CD15, 6.0% and CD33, 4.5%. Evaluating the B-common ALL patients the presence of myeloid antigens rises to 43%. Patients who had coexpression of myeloid antigens had a relapse rate (any site) of 49.2% while 36.3% who had no coexpression had a relapse (p=0.001). There has also been statistical significance in bone marrow response on day 14 of induction with 64.9% having less than 5% blasts in the group without coexpression and 46.4% in the group with coexpression (p<0.0001). Conclusions: The present retrospective review shows the presence of associated myeloid antigens in our ALL patients in 36.6%. We have shown that it is an adverse prognostic factor for childhood ALL in a developing country, unlike reports from other centers in developed countries.

No significant financial relationships to disclose.

Bladder augmentation using PelvicolTM implant for intractable overactive bladder syndrome

The objective of the study was to evaluate the effectiveness of an implant of porcine dermis to augment the bladder in women with refractory overactive bladder syndrome (OAB). Twelve women underwent a Pelvicol bladder augmentation. A visual analogue score for severity of incontinence and a quality of life questionnaire was carried out pre-operatively and at 12 months post-operatively. Follow up cystoscopy was carried out in three women in addition. Three women were dry and cured; five women were significantly improved; two women were slightly improved and the procedure was unsuccessful in the remaining two women. There were no significant complications and voiding was spontaneous in every case. A bladder augmentation using porcine dermis may have a role in the surgical management of non-neuropathic women with OAB that has failed to respond to conservative therapy.

Comparison between porcine dermal implant (Permacol) and silicone injection (Macroplastique) for urodynamic stress incontinence

The objective of this study was to compare the efficacy of porcine dermal implant injection (Permacol) and silicone injection (Macroplastique) in the treatment of female urodynamic stress incontinence (USI) in a prospective randomized trial. Fifty women with urodynamically proven stress incontinence were recruited and randomised to receive either Permacol or Macroplastique injection. Twenty-five patients were enrolled in each case. An International Continence Society (ICS) standard 1-h pad test was carried out prior to the injection and a subjective analysis of incontinence made using a Stamey scoring system. In addition, a Kings College Hospital Quality of Health Questionnaire (KCQ) was completed. The women were followed up at 6 weeks and 6 months and the same methods used to gauge the success or failure of the operation. Preoperatively there were no significant differences in pad losses, Stamey score or King's score between the two groups. The mean age of the women was 61 years (range 28-80 years). At 6 weeks there were significant reductions in the mean and median values in pad losses, Stamey score and King's score in both Permacol and Macroplastique patients but the effects were more pronounced in Permacol patients than Macroplastique patients. Of the Permacol patients, 64% were improved on quantified pad losses out of which 60% were dry whereas 54% of Macroplastique patients were improved on pad losses of which 41.6% were dry. Of the Permacol patients, 64% and 60% had reduction in Stamey and KCQ score, respectively, whereas Macroplastique patients had 46% reduction in one or more grades of Stamey scores and 42% reduction in KCQ scores. At 6 months the results in the Permacol patients appeared to be sustained but not for Macroplastique patients. This study has shown that Permacol injection when used as a urethral bulking agent appears to have a higher cure rate for urodynamic stress incontinence than Macroplastique and these results persist until the follow-up period of 6 months. The use of Permacol injection is an attractive alternative in the treatment of urodynamic stress incontinence.

Modelling the resilience of Australian savanna systems to grazing impacts

Savannas occur across all of northern Australia and are extensively used as rangelands. A recent surge in live cattle exports to Southeast Asia has caused excessive grazing impacts in some areas, especially near watering points. An important ecological and management question is "how resilient are savanna ecosystems to grazing disturbances?" Resilience refers to the ability of an ecosystem to remain in its current state (resist change) and return to this state (recover) if disturbed. Resilience responses can be measured using field data. These responses can then be modelled to predict the likely resistance and recovery of savannas to grazing impacts occurring under different climatic conditions. Two approaches were used to model resilience responses. First, a relatively simple mathematical model based on a sigmoid response function was used. This model proved useful for comparing the relative resilience of different savanna ecosystems, but was limited to ecosystems and conditions for which data were available. Second, a complex process model, SAVANNA, was parameterised to simulate the structure and function of Australian savannas. Simulations were run for 50 years at two levels of grazing to evaluate resistance and then for another 50 years with no grazing to evaluate recovery. These runs predicted that savanna grasslands were more resistant to grazing (changed less) than red-loam woodlands, which recovered relatively slowly from grazing impacts. The SAVANNA model also predicted that these woodlands would recover slightly slower under the climate change scenario projected for northern Australia.

Modelling the trade-off between fire and grazing in a tropical savanna landscape, northern Australia

As savannas are widespread across northern Australia and provide northern rangelands, the sustainable use of this landscape is crucial. Both fire and grazing are known to influence the tree-grass character of tropical savannas. Frequent fires open up the tree layer and change the ground layer from perennials to that dominated by annuals. Annual species in turn produce copious quantities of highly flammable fuel that perpetuates frequent, hot fires. Grazing reduces fuel loads because livestock consumes fuel-forage. This trade-off between fire and grazing was modelled using a spatially explicit, process-orientated model (SAVANNA) and field data from fire experiments performed in the Victoria River District of northern Australia. Results of simulating fire (over 40 years) with minimal or no grazing pressure revealed a reduction in the shrub and woody plants, a reduction in grasses, and no influence on the tree structure given mild fires. While mature trees were resistant to fire, immature trees, which are more likely associated with the shrub layer, were removed by fire. The overall tree density may be reduced with continual burning over longer time periods because of increasing susceptibility of old trees to fire and the lack of recruitment. Increases in stocking rates created additional forage demands until the majority of the fuel load was consumed, thus effectively suppressing fire and reverting to the grazing and suppressed fire scenario where trees and shrubs established.

[Complicated acute appendicitis as intercurrent disease in patient with advanced gastric cancer]

We report a case of a male 64 years old with acute abdomen who was operated with the presumptive diagnosis of complicated acute appendicitis. However the patient had black stools for two months, associated with epigastric pain. Endoscopic diagnosis was: Advanced Gastric Cancer: Borrmann II. Histology was informed as: Infiltrating adenocarcinoma intestinal type middlingly differentiated. Surgery findings were: peritonitis with perforated appendicitis in its base: Free coprolites and carcinomatosis. Histology was reported as: ulcerated mucous in caecal appendix, necrosis and perforation of the muscular wall in the base. Mesentery samples were informed with fat tissue involvement by infiltration of tubular adenocarcinoma.middlingly differentiated, suitable with primary gastric cancer.

Sorption of radioactive contaminants by sediment from the Kara Sea

The purpose of this study is to quantify some of the parameters needed to perform near-field modelling of sites in the Kara Sea that were impacted by the disposal of radioactive waste. The parameters of interest are: the distribution coefficients (Kd) for several important radionuclides, the mineralogy of the sediment, and the relationship of Kd to liquid-to-solid ratio. Sediment from the Kara Sea (location: 73 degrees 00'N, 58 degrees 00'E) was sampled from a depth of 287 m on August 23/24, 1992. Analysis of the material included mineralogy, grain size and total organic carbon (TOC). Uptake kinetics were determined for 85Sr, 137Cs, 241Am, 99Tc, 1251, 232U and 210Pb and distribution coefficients (Kd) were determined for these radionuclides using batch type experiments. Sorption isotherms, developed for 137Cs, 85Sr and 99Tc, were linear in each case. Increasing the liquid-to-solid ratio strongly increased uptake of 137Cs and moderately increased uptake of 99Tc. Analysis for anthropogenic radionuclides indicated the presence only of 239/240Pu in the sediment with the highest activity (at the top section of the core) being 0.420 Bq kg(-1). Other anthropogenic radionuclides were below detection limits.

Function of Rieger syndrome gene in left-right asymmetry and craniofacial development

Rieger syndrome, an autosomal dominant disorder, includes ocular, craniofacial and umbilical abnormalities. The pitx2 homeobox gene, which is mutated in Rieger syndrome, has been proposed to be the effector molecule interpreting left-right axial information from the early embryonic trunk to each organ. Here we have used gene targeting in mice to generate a loss-of-function allele that would be predicted to result in organ randomization or isomerization. Although pitx2-/- embryos had abnormal cardiac morphogenesis, mutant hearts looped in the normal direction. Pitx2-/- embryos had correctly oriented, but arrested, embryonic rotation and right pulmonary isomerism. They also had defective development of the mandibular and maxillary facial prominences, regression of the stomodeum and arrested tooth development. Fgf8 expression was absent, and Bmp4 expression was expanded in the branchial-arch ectoderm. These data reveal a critical role for pitx2 in left-right asymmetry but indicate that pitx2 may function at an intermediate step in cardiac morphogenesis and embryonic rotation.

Lipid and lipoprotein analysis of cats with lipoprotein lipase deficiency

BACKGROUND

We have previously described a colony of domestic cats with a naturally occurring mutation in the lipoprotein lipase (LPL) gene. We have now further characterized cats homozygous for LPL deficiency (LPL -/-, homozygotes), and have contrasted these with heterozygotes (LPL +/-) and normal cats (LPL +/+).

MATERIALS AND METHODS

Density gradient ultracentrifugation with subsequent lipid analysis, agarose and polyacrylamide gel electrophoresis was used to examine detailed liproprotein differences between the genotypes. Oral fat loading studies and breast milk fatty acid analysis were also performed to further characterize the phenotypic expression of LPL deficiency in this model system.

RESULTS

Several lipid abnormalities associated with homozygosity for LPL deficiency were evident. Triglyceride-rich lipoprotein-triglycerides (TRL-TG) and cholesterol (TRL-C) were higher (TRL-TG 2.09 +/- 1.14 vs. 0.15 +/- 0.04 mmol L-1, P < 0.001; TRL-C 0.42 +/- 0.30 vs. 0.11 +/- 0.16 mmol L-1, P < 0.05) in male -/- than in male +/+ cats, as was HDL-cholesterol (HDL-C, 1.75 +/- 0.24 vs. 1.41 +/- 0.14 mmol L-1, P < 0.05). LDL-C levels were lower in homozygous cats than in control cats, similar to what is seen in human LPL deficiency. Oral fat loading studies revealed that homozygous cats have a marked reduced ability to clear plasma TGs in terms of peak time (7 h vs. 3 h), peak height (9.36 vs. 1.1 mmol L-1), area under the TG clearance curve (AUC, 280.3 vs. 2.2 h mmol L-1) and time to return to baseline. Fasting lipid and lipoprotein levels were not significantly different between heterozygous and normal cats. However, oral fat loading in heterozygotes revealed an intermediate phenotype (peak of 2.35 mmol L-1 at 5 h, AUC 13.1 h mmol L-1), highlighting the impaired TG clearance in these animals.

CONCLUSION

Thus, LPL deficiency in the cat results in a lipid and lipoprotein phenotype that predominantly parallels human LPL deficiency, further validating the use of these animals in studies on the pathobiology of LPL.

Matrix metalloproteinases

Matrix metalloproteinases are a family of highly regulated peptidases that are collectively responsible for the degradation of extracellular matrix during tissue remodeling. Dysregulated activity has long been implicated in the pathologies of cancer and arthritis, and the number of diseases more recently associated with these enzymes has been increasing. In the past year, new transgenic models of matrix metalloproteinase knockouts have been described, allowing the direct assessment of specific enzyme activity in particular disease models. In addition, more selective inhibitors with improved pharmacokinetic profiles have entered clinical trials, allowing the assessment of the safety and efficacy of this strategy.

Sorption/desorption of radioactive contaminants by sediment from the Kara Sea

To understand the long term impact of the disposal of radioactive waste on the Kara Sea, partition coefficients (Kd) for several important radionuclides, the mineralogy of the sediment, and the relationship of Kd to liquid-to-solid ratio were quantified. Sediment was obtained from four locations in the Kara Sea area. Slow sorption kinetics were observed for 85Sr, 232U, 125I and 99Tc, whilst sorption was rapid (less than 50 h to steady-state) for 137Cs, 210Pb, and 241Am. Partition coefficients (Kd) were determined using batch type experiments and sorption isotherms which were developed for 85Sr, 99Tc, 125I, U and 137Cs. Partition coefficients for 137Cs were approx. 350 ml/g for sediment from the Trough and 180 ml/g for Stepovogo Fjord. This difference may be caused by the lower fraction of expandable clay in sediment from the fjord. Uptake of 85Sr, 99Tc, 125I, and U were all similar for both locations, with Kd values averaging 4, 3, 17 and 60 ml/g, respectively. The Kd for 137 Cs varied non-linearly from 40 to 3800 ml/g as the liquid-to-solid ratio varied from 3.4 to 6500, but only when the sorption capacity was high compared to the mass of 137Cs in the closed system of the experiment. Under identical conditions, sediment with lower Kd values showed no effect. Oxidation of sediment effectively desorbed 99Tc from the solid phase, whilst it caused increased uptake of 85Sr and U. In sequential rinses with fresh seawater, desorption was limited to 60% of 137Cs and 85Sr, and 35% of uranium.

Dietary triacylglycerols with palmitic acid (16:0) in the 2-position increase 16:0 in the 2-position of plasma and chylomicron triacylglycerols, but reduce phospholipid arachidonic and docosahexaenoic acids, and alter cholesteryl ester metabolism in formula-Fed piglets

Milk triacylglycerols have an unusual fatty acid distribution, with palmitic acid (16:0) esterified predominately at the center (sn-2) position. Other dietary triacylglycerols contain 16:0 predominantly at the sn-1,3 positions. This study was designed to evaluate the effect of formula triacylglycerol fatty acid distribution on the composition and distribution of plasma lipoprotein fatty acids in piglets fed formula containing synthesized triacylglycerols or palm olein oil with about 32 or 4.2% 16:0, respectively, in fatty acids at the sn-2 position, with comparison to piglets fed sow's milk. Feeding formula with 16:0 at the triglyceride sn-2 position or sow's milk resulted in higher chylomicron triacylglycerol sn-2 16:0 than when palm olein was fed. This suggests that dietary triacylglycerol sn-2 position fatty acids are conserved during digestion, absorption and reassembly to chylomicron triacylglycerols. The increased chylomicron triacylglycerol sn-2 position 16:0 in piglets fed synthesized triacylglycerols was accompanied by lower chylomicron triacylglycerol arachidonic and docosahexaenoic acid than in piglets fed formula with palm olein, suggesting an interaction between dietary triacylglycerol saturated fatty acid distribution and (n-6) and (n-3) fatty acid transport.

Diet-induced changes in liver and bile but not brain fatty acids can be predicted from differences in plasma phospholipid fatty acids in formula- and milk-fed piglets

The fatty acid composition of plasma phospholipids differs between infants fed formula and infants fed human milk, but the extent to which this is accompanied by differences in tissue phospholipid fatty acids is unclear. This paper describes analysis of plasma, liver and brain fatty acids from piglets fed one of seven formulas, varying in saturated, monounsaturated, (n-6) and (n-3) fatty acids or sow milk from birth for 18 d. Bile fatty acids were analyzed because they are secreted from liver and may be an important source of fatty acids for intestinal lipoprotein synthesis. The results were used to determine the relation between diet-related differences in plasma phospholipid fatty acids and those in brain, liver and bile. Where significant associations were found, prediction limits were constructed to assess the usefulness of analysis of plasma phospholipid fatty acids to predict diet-induced changes in tissue fatty acids. The proportions (g/100 g fatty acids) of 16:0, 18:0, 18:1, 18:2(n-6) and 20:4(n-6) in plasma phospholipids were significantly associated with the proportions of the same fatty acids in liver and bile, but not brain. The results show a reasonably precise, predictable association between plasma and liver, and plasma and bile fatty acids. Brain 20:4(n-6) and 22:6(n-3), in contrast, were not reliably associated with plasma phospholipid 20:4(n-6) and 22:6(n-3) for piglets fed milk or formula providing about 1.5% energy as 18:3(n-3).

Dietary triacylglycerol structure and saturated fat alter plasma and tissue fatty acids in piglets

Human and pig milk triacylglycerols contain a large proportion of palmitic acid (16:0) which is predominately esterified in the 2-position. Other dietary fats contain variable amounts of 16:0, with unsaturated fatty acids predominantly esterified in the 2-position. These studies determined if the amount or position of 16:0 in dietary fat influences the composition or distribution of liver, adipose tissue, lung, or plasma fatty acids in developing piglets. Piglets were fed to 18 d with sow milk or formula with saturated fat from medium-chain triglyceride (MCT), coconut or palm oil, or synthesized triacylglycerols (synthesized to specifically direct 16:0 to the 2-position) with, in total fatty acids, 30.7, 4.3, 6.5, 27.0, and 29.6% 16:0, and in 2-position fatty acids, 55.3, 0.4, 1.3, 4.4, and 69.9% 16:0, respectively. The percentage of 16:0 in the 2-position of adipose fat from piglets fed sow milk, palm oil, and synthesized triacylglycerols were similar and higher than in piglets fed MCT or coconut oil. Thus, the amount, not the position, of dietary 16:0 determines piglet adipose tissue 16:0 content. The effects of the diets on the plasma and liver triacylglycerols were similar, with significantly lower 16:0 in total and 2-position fatty acids of the MCT and coconut oil groups, and significantly higher 16:0 in the plasma and liver triacylglycerol 2-position of piglets fed the synthesized triacylglycerols rather than sow milk or palm oil. The lung phospholipid total and 2-position 16:0 was significantly lower in the MCT, coconut, and palm oil groups, but similar in the synthesized triacylglycerol group and sow milk group. The lung phospholipid total and 2-position percentage of arachidonic acid (20:4n-6) was significantly lower in all of the formula-fed piglets than in milk-fed piglets. The physiological significance of this is not known.

False aneurysm--a complication following an inversion ankle sprain: a case report

Sprains of the lateral ligamentous structures of the ankle joint as a result of inversion are common and frequently result in pain. In most cases, the pain is related to soft-tissue injury and the associated hemorrhage and swelling. This case report describes the complication of posttraumatic false aneurysm of the peroneal artery following an inversion ankle sprain in a 22-year-old athlete, a complication which should be added to the differential diagnosis as a rare, but important possibility. Emphasis of the case report is placed on the rehabilitation of the patient following medical intervention.

One-session management of cervical intraepithelial neoplasia: a solution for developing countries

Six hundred thirty-nine patients with CIN on referral Pap were evaluated cytocolposcopically at the first visit and decided whether to be treated the same day or not. One hundred ninety-two patients (30%) were considered negative. Follow-up evidenced later appearance of CIN in five of them. One hundred fifty-three (24%) were candidates for delayed treatment due to conditions contraindicating same-day treatment. Two hundred ninety-four patients (46%) were randomly allocated in LEEP (149) or excisional laser (145) arms, and treated the same day under local anesthesia. Both arms were comparable. There were three microinvasive carcinomas diagnosed in the surgical specimen. LEEP was faster and produced less bleeding than laser, although required a mean of four slices to remove the lesion. Arterial hypertension after anesthetic infiltration was detected in 26% of cases. Two intraoperative and two delayed bleeders required surgery. The size of lesion and surgical defect were larger than those reported in the literature. Margins were involved in 8 patients (2.7%). Only 4.7% (7/149) of patients randomized to LEEP and 3.4% (5/145) with excisional laser had persistent or recurrent CIN on follow-up. Factors predisposing to failure included depth of surgical defect, grade of lesion, and operator's expertise. With this approach, 69% of patients referred for cytology of CIN were adequately managed in the first visit, which contrasts to classical management that reaches the state of treatment in 30% of patients. LEEP appears to be faster, less costly, and requires less expertise. Its use in conjunction with adequate screening is recommended for developing countries.

Thermocoagulation effect of diode laser radiation in the human prostate: acute and chronic study

OBJECTIVES

To evaluate the safety and efficacy of low-power slow-heating diode laser-induced photocoagulation of prostatic tissue for treatment of benign prostatic hyperplasia, we conducted a series of acute and chronic studies using a diode laser (810 nm) to irradiate human prostate.

METHODS

The study included 6 patients undergoing radical prostatectomy because of malignancy. Laser radiation to the prostate was given transurethrally, in a noncontact mode, at the time of the procedure in 2 patients (acute group): 10 W for 300 seconds on the right side of the prostate and 15 W for 180 seconds on the left. In the remaining 4 patients (chronic group), laser radiation was given at 1, 7, 10, and 12 weeks prior to the prostatectomy.

RESULTS

In the acute group the average depth of coagulation was 8.5 and 9.0 mm for the laser regimens of 15 W for 180 seconds and the 10 W for 300 seconds, respectively. In the chronic group, the average depth of coagulation was 8.9 mm for both laser regimens studied. In the acute group, there was an ill-defined hemorrhagic ring at the periphery of the lesion. At 1 week, an intact necrotic coagulum was present. At 7 weeks, some of the coagulated tissue had already sloughed off. Longer follow-up at 10 and 12 weeks demonstrated formation of a well-defined cavity with mostly re-epithelialized surface.

CONCLUSIONS

Our findings suggest that noncontact diode laser (810 nm) irradiation can induce in the human prostate significant coagulation necrosis followed by sloughing of tissue and cavitation of the prostatic urethra.

Palmitic acid is absorbed as sn-2 monopalmitin from milk and formula with rearranged triacylglycerols and results in increased plasma triglyceride sn-2 and cholesteryl ester palmitate in piglets

Milk fatty acids contain 20-30% palmitic acid (16:0), with approximately 70% of the 16:0 esterified to the sn-2 position of the milk triacylglycerol. Formulae containing vegetable and oleo oils contain different amounts of 16:0, but all have unsaturated fatty acids esterified to the triacylglycerol sn-2 position. Intraluminal triacylglycerol hydrolysis by endogenous lipases produces sn-2 monoacylglycerols and free fatty acids, which are absorbed and re-esterified in the enterocyte for secretion to plasma. The extent of absorption and re-esterification of sn-2 monoacylglycerols from milk or formula fats in infants is unknown. This was studied by feeding piglets sow milk or formulae containing similar total saturated fat, 18:1, 18:2(n-6) and 18:3(n-3) with unsaturated fatty acids at the sn-2 position or with rearranged triacylglycerols containing approximately 30% 16:0, with 70% 16:0 in fatty acids at the sn-2 position. Feeding milk or 16:0 on the sn-2 position of formula with rearranged triacylglycerols resulted in higher 16:0 esterified to the plasma triacylglycerol sn-2 position and in cholesteryl esters than feeding formulae with 0.4 to 4.4% 16:0 in the sn-2 position fatty acids. The absorption of 16:0 as monopalmitin from milk and any metabolic importance in human infants has yet to be determined.

Evidence that palmitic acid is absorbed as sn-2 monoacylglycerol from human milk by breast-fed infants

Milk fatty acids consist of about 20-25% palmitic acid (16:0), with about 70% of 16:0 esterified to the sn-2 position of the milk triacylglycerols. Hydrolysis of dietary triacylglycerols by endogeneous lipases produces sn-2 monoacylglycerols and free fatty acids, which are absorbed, reesterified, and then secreted into plasma. Unesterified 16:0 is not well absorbed and readily forms soaps with calcium in the intestine. The positioning of 16:0 at the sn-2 position of milk triacylglycerols could explain the high coefficient of absorption of milk fat. However, the milk lipase, bile salt-stimulated lipase, has been suggested to complete the hydrolysis of milk fat to free fatty acids and glycerol. These studies determined whether 16:0 is absorbed from human milk as sn-2 monopalmitin by comparison of the plasma triacylglycerol total and sn-2 position fatty acid composition between breast-fed and formula-fed term gestation infants. The human milk and formula had 21.0 and 22.3% of 16:0, respectively, with 54.2 and 4.8% 16:0 in the fatty acids esterified to the 2 position. The plasma triacylglycerol total fatty acids had 26.0 +/- 0.6 and 26.2 +/- 0.6% of 16:0, and the sn-2 position fatty acids had 23.3 +/- 3.3 and 7.4 +/- 0.7% of 16:0 in the three-month-old exclusively breast-fed (n = 17) and formula-fed (n = 18) infants, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary saturated, monounsaturated, n-6 and n-3 fatty acids, and cholesterol influence platelet fatty acids in the exclusively formula-fed piglet

Platelet lipid composition is important to normal platelet morphology and function, and is influenced by dietary fatty acids and cholesterol. The fatty acid composition and cholesterol content of infant formulas differs from those of human milk, but the possible effects on platelet lipids in young infants is not known. This was studied in piglets fed from birth to 18 d of age with one of eight formulas differing in saturated fatty acid chain length, or content of 18:1, 20:5n-3 plus 22:6n-3, or cholesterol. A reference group of piglets fed sow milk was also studied. Sow milk has a fatty acid composition and cholesterol content similar to that of human milk. Piglets fed formulas high in 18:1 (34.9-40.8% wt fatty acids) and low in 16.0 (< or = 6.5% wt fatty acids) had lower platelet counts and greater platelet size than piglets fed sow milk (40.4% 18:1, 30.7% 16:0). Piglets fed formulas high in 16:0 (27-29.6%) and 18:1 (40-40.6%), or low in both 16:0 (5.9-6.1%) and 18:1 (10.8-11.2%), had similar platelet counts and size to piglets fed sow milk. Platelet phospholipid % 20:4n-6 was lower in all the groups of piglets fed formula than in the group fed sow milk. Addition of fish oil with 20:5n-3 plus 22:6n-3 to the formula further decreased platelet phospholipid 20:4n-6. Addition of cholesterol to the formula increased the platelet phospholipid % 20:4n-6 and platelet volume.

Reliability and within subject variability of VE, VO2, heart rate and blood pressure during submaximum cycle ergometry

To assess the reliability and within subject variability of steady-rate ventilation (VE), oxygen uptake (VO2), heart rate, systolic and diastolic blood pressure, 4 subjects exercised for 10 minutes at 3 work rates on a bicycle ergometer: 50 W, 125 W and 55% of maximum work rate (55% max). Each testing session included two work rates and only 2 testing sessions were scheduled per week. The order of the work rates was counterbalanced. In 8 to 10 weeks, 3 of the subjects completed 20 trials at 50 W while the fourth subject completed 11 trials, and all the subjects completed 10 trials at 125 W and 55% max. The within subject variability (S2w) was expressed as a percent of the mean steady-rate response. VO2 ranged from 21.2% to 27.5% of VO2max at 50 W, from 37.7% to 49.7% at 125 W and from 42.9% to 63.7% at 55% max. The S2w averaged 6.8% for VE, 4.3% for VO2, 3.2% for heart rate, 7.3% for systolic blood pressure and 10.5% for diastolic blood pressure. Reliability coefficients were calculated for the steady-rate scores by dividing the between subject variation by the total variation. The reliability was similar for VE, VO2 and heart rate and ranged from r = 0.69 to r = 0.97. Systolic and diastolic blood pressure reliabilities were lower and ranged from r = 0.27 and r = 0.80. In summary, the steady-rate ventilation, oxygen uptake and heart rate responses were reliable and consistent. The reliability of blood pressure was low. It is possible that this low reliability may result from variability in stroke volume or total peripheral resistance.

5-lipoxygenase inhibitory activity of zileuton

Zileuton [N-(1-benzo[b]thien-2-ylethyl)-N-hydroxyure] inhibited 5-hydroxyeicosatetraenoic acid synthesis by rat basophilic leukemia cell 20,000 x g supernatant and rat polymorphonuclear leukocytes (PMNL) (IC50 = 0.5 and 0.3 microM) respectively. It also inhibited leukotriene (LT)B4 biosynthesis by rat PMNL (IC50 = 0.4 microM), human PMNL (IC50 = 0.4 microM) and human whole blood (IC50 = 0.9 microM). Inhibition of human PMNL LTB4 biosynthesis was removed readily by a simple wash procedure. At concentrations up to 100 microM, the compound produced little or no inhibition of several related enzymes, such as platelet 12-lipoxygenase, soybean and rabbit reticulocyte 15-lipoxygenase and sheep seminal vesicle cyclooxygenase. At p.o. doses from 0.5 to 5 mg/kg in the dog, zileuton produced a rapid and sustained inhibition of ex vivo blood LTB4 biosynthesis which correlated with the pharmacokinetic behavior of the compound. In a similar ex vivo study in the rat, the compound displayed an p.o. ED50 of 2 mg/kg. Zileuton was highly effective in preventing 6-sulfidopeptide LT formation in the rat peritoneal cavity triggered by an antigen-antibody reaction with an ED50 of 3 mg/kg. In experimental models of inflammation, zileuton significantly reduced arachidonic-acid induced mouse ear edema (ED50 = 31 mg/kg) and also attenuated inflammatory cell accumulation in the rat pleural Arthus reaction. The effectiveness of this compound for preventing LT formation in vitro, ex vivo and in vivo suggests its utility for preventing the pathophysiological effects of the LTs and other 5-lipoxygenase products in animals and in humans.

Fluid production by in vitro lungs from fetal guinea pigs

Lungs from fetal guinea pigs (54-67 days of gestation) were supported in vitro, and lung liquid secretion rates were measured by a dye-dilution technique. The average secretion rate in the first hour was 2.14 +/- 0.08 (SE) mL x kg-1 body weight.h-1 (0.21 +/- 0.01 mL/h) (n = 450); this was comparable to intact preparations. In an independent study of 30 lungs, secretion continued unchanged for 3 h, with no significant change in fluid composition. Between 54 days and term, production appeared to fall in terms of millilitres per kilogram per hour. The following agents were placed in the supporting saline during the middle hour of incubation. (i) Sodium iodoacetate: at 10(-4) M this produced a fall in secretion (fall, succeeding hours; 55.4 +/- 23.0 and 64.9 +/- 17.5%; n = 6); at 10(-3) M it stopped secretion (fall, succeeding hours; 87.2 +/- 10.3 and 100%, n = 6). (ii) Ouabain: at 10(-5) M there was no change in production (n = 6); at 10(-4) M, four preparations were unaffected, two reduced production. (iii) Epinephrine (10(-7) M) produced a significant fall in production in all cases (n = 6); in four preparations secretion reduced (average fall, 64.4 +/- 10.8%); in two preparations there was reabsorption (average rate, -1.03 mL.kg-1.h-1). This extends the effect of epinephrine to the guinea pig, and suggests that the in vitro preparation is a useful model for studies of the fetal lung.

A single and multiple dose pharmacokinetic and metabolism study of meclofenamate sodium

A single and multiple oral dose administration study of meclofenamate sodium (Meclomen) was conducted in ten healthy male volunteers. An initial 300 mg oral dose on day 1 was followed by a 100 mg every 8 h dosage regimen on study days 4 through 18. Intensive plasma and urine sample collection was carried out over the first three study days, and for 120 h following administration of the final dose on day 18. Plasma and urine specimens were analyzed by a specific HPLC assay for unconjugated meclofenamic acid and metabolites I and II of meclofenamic acid before and after sample incubation with beta-glucuronidase. Meclofenamic acid was rapidly absorbed following oral dose administration. Concentrations of meclofenamic acid existed primarily as unconjugated drug in plasma, with only a small amount present in the conjugated form. Meclofenamic acid was rapidly eliminated, with an elimination half-life of approximately 1.3 h. This resulted in no detectable accumulation upon multiple dose administration. Metabolite I, which is one-fifth as active as meclofenamic acid in in vitro inhibition of cyclooxygenase, was present in unconjugated form at steady state in concentrations approximately 50 per cent of those of meclofenamic acid, as unconjugated drug. The majority of metabolite I in plasma existed as glucuronide conjugate. Metabolite II, which is inactive, was present in very significant concentrations in unconjugated form. Plasma protein binding determinations conducted on meclofenamic acid and metabolite I indicated that the free fraction of metabolite I was 8.7 to 10.9 times higher than that of meclofenamic acid. When the lower activity and lower steady state concentrations, but higher free fraction, are considered, it would appear that metabolite I may contribute significantly to the in vivo inhibition of cyclooxygenase activity seen after administration of meclofenamic acid.

Electrophysiological measures of visual and auditory function as indices of neurotoxicity

The application of auditory and visual evoked potentials (VEP) to neurotoxicity testing of humans and animals is reviewed. VEPs elicited by flash, reversing-checkerboard patterns, and sine wave grating are described. The flask evoked potential in rats is altered by exposure to many heavy metals, pesticides and solvents. The brainstem auditory evoked potential also appears to be sensitive to neurotoxic chemicals, but the evidence available is limited. The homology of auditory and visual evoked potentials in rats and humans is useful for cross-species extrapolation in neurotoxicology research.

Radiation exposure to patients during extracorporeal shock wave lithotripsy

Extracorporeal shock wave lithotripsy is rapidly becoming an accepted treatment of renal calculi. Since fluoroscopy is involved to image the stones it is important to know how much radiation the patient receives during this proCedure. Surface radiation exposure to the patient was measured in more than 300 fluoroscopic and radiographic procedures using thermoluminescent dosimeters. Initial results showed an average skin exposure of 10.1 rad per procedure for each x-ray unit, comparing favorably with exposure rates for percutaneous nephrostolithotomy and other routine radiological procedures. Factors influencing exposure levels include stone characteristics (location, size and opacity), physician experience and number of shocks required. Suggestions are given that may result in a 50 per cent reduction of radiation exposure.

Experiential factors in the expression of hypermotility produced by intradentate colchicine: lack of effect of GM1 ganglioside on colchicine-induced loss of granule cells and mossy fibers

Adult male Fischer-344 rats were given bilateral injections of 2.5 micrograms colchicine or artificial cerebrospinal fluid into caudal and rostral sites of the dentate gyrus of the hippocampus. One group of rats received 21 consecutive daily injections of 20 mg/kg GM1 gangliosides, i.p., beginning the day prior to surgery. Another group received saline. Colchicine-induced hypermotility was not seen in animals repeatedly handled 21 d after surgery, in spite of significant decreases in granule cell number and decreases in the volume of hippocampal mossy fibers. Pretreatment with GM1 had no effect on behavior and it did not protect against the hippocampal damage produced by colchicine. Rats given colchicine, but not handled for 21 d, showed significant hypermotility, which was associated with decreases in hippocampal granule cells. These data underscore the importance of handling in postlesion functional recovery.

Acute pernicious or fulminating beriberi with severe lactic acidosis. A case report

This report describes a case of severe acidosis with cardiac failure due to alcohol in a black man. Treatment with parenteral thiamine produced a prompt response. Thiamine deficiency should be recognized as an important cause of lactic acidosis.