Water-immersion wrinkling is due to vasoconstriction

The underlying mechanism of the water-immersion skin wrinkling test, which is used as a test of sympathetic nerve function, remains elusive. We investigated changes of blood circulation in the hand occurring with water-immersion wrinkling by measuring the velocity of ulnar and digital artery blood flow, and of digit skin blood flow, in healthy subjects before and during wrinkling. Wrinkling was accompanied by significant reduction in blood flow velocity in all vessels, with a maximum in digital vessels. Our data show that water-immersion wrinkling is a function of digit pulp vasoconstriction. This test of sympathetic function can now be quantified using parameters of blood flow velocity, enabling its more widespread and accurate use.     

Photo-induced cytomorphologic changes in an advanced cancer phase I clinical trial

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate whether the application of an Infrared Pulsed Laser Device (IPLD) photo-induced significant cytomorphologic changes during the monitoring of advanced cancer patients participating in a phase I clinical trial. MATERIALS AND METHODS: Patients were irradiated with an IPLD (904 nm pulsed at 3 MHz) under a one-dose, one-schedule, and one-procedure design. Total daily dose consisted of a Radiant Exposure of 4.5x10(5) J/m(2). Thirty-one tissue samples from eleven patients with progressive solid neoplastic diseases (TNM IV, UICC) were obtained at three intervals: Time 0 (15-90 days pre-treatment, n=11); Time I (2-5 months post-treatment; n=11); Time II (6-12 months post-treatment, n=09). Three blinded pathologists evaluated samples; scores were determined by consensus. Data were evaluated by using the Wilcoxon matched-pairs signed-rank test and Spearman rank correlation coefficient. The level of statistical significance was alpha=0.05. RESULTS: Increased apoptosis (Time I, P<0.003; Time II, P<0.007), necrosis (Time I, NS; Time II, P<0.01), cytoplasmic vacuoles (Time I, P<0.03; Time II, P<0.02), and nuclear vacuoles (Time I, NS; Time II, P<0.01), reduced cell size (Time I, P<0.007; Time II, P<0.01) and intercellular adhesion (Time I, P<0.01; Time II, P<0.02) were present in neoplastic cells after IPLD treatment. No apparent changes were noted in non-neoplastic cells. The Spearman rank correlation coefficient between apoptosis, necrosis, nuclear vacuoles, cytoplasmatic vacuoles, intercellular adhesion, and cell size was positive and highly significant (P<0.006). CONCLUSIONS: Although further research is necessary, our preliminary results support the novel possibility that the IPLD photo-induces chaotic dynamics that modulate complex physiologically reparative bioeffects.     

The Belgian PCB/dioxin incident: analysis of the food chain contamination and health risk evaluation

The Belgian PCB incident occurred at the end of January 1999 when a mixture of polychlorinated biphenyls (PCBs) contaminated with dioxins was accidentally added to a stock of recycled fat used in the production of animal feeds. Although signs of poultry poisoning were noticed by February, 1999, the source and the extent of the contamination were discovered only in May 1999, when it appeared that more than 2500 farms could have been supplied with contaminated feeds. This resulted in a major food crisis, which rapidly extended to the whole country and could be resolved only by the implementation of a large PCB/dioxin food monitoring program. Screening for PCB contamination was based on the determination of the seven PCB markers. When PCB concentrations exceeded the tolerance levels of 0.1 (milk), 0.2 (poultry, bovine, and pig meat), or 1 (animal feed) microg/g fat, dioxins (17 PCDD/Fs congeners) were also determined. At the end of December 1999, the database contained the results of more than 55,000 PCB and 500 dioxin analyses. The study of PCB levels and profiles in contaminated feeds delivered to poultry or pig farms confirmed that the Belgian PCB incident was due to a single source of PCB oil introduced into the food chain at the end of January 1999. This PCB oil had a congeners pattern closely matched to a mixture of Aroclor 1260/1254 in the proportion 75/25. The total amount of PCBs added to recycled fats was estimated at 50 kg (sum of the seven markers) or approximately 150 kg total PCBs, which corresponds to about 100 liters of PCB oil. This PCB mixture contained about 1g TEQ dioxins (more than 90- contributed by PCDFs) and about 2g TEQ dioxin-like PCBs. The proportions of PCB 52 and 101 congeners were fairly constant in animal feeds, excluding the possibility of secondary contamination due to fat recycling from contaminated animals. The highest concentrations of PCBs and dioxins were found in poultry and especially in the reproduction animals (hens and chicks), which showed the classical manifestations of chick edema disease. The pigs were also affected but to a lesser extent and no sign of intoxication was observed. The study of PCB/dioxin patterns and of the PCB:dioxin ratios revealed major differences in the metabolism of these compounds by farm animals. Whereas the PCBs:dioxins ratio was fairly constant in all poultry products with a mean value similar to that found in contaminated feeds (50,000), in pigs this ratio was both much higher and more variable (values up to 10,000,000), reflecting a faster elimination of dioxins than PCBs in these animals. These metabolic differences also emerged from the PCB and dioxin patterns which were altered much more in pigs than in poultry. Although the most contaminated food products (chicken meat) had PCB and dioxin levels more than 100 times above maximal recommended values, it is unlikely that this incident could have caused adverse effects in the general population of Belgium. A doubling of the PCB and dioxin burden of the young adult population would require the consumption of, respectively, 10 and 20 highly contaminated meals. In view of the very limited proportion of the poultry chain effectively contaminated during the incident (around 2%), such an extreme scenario was quite improbable for the general population except perhaps for farmers consuming their own products. But even in that case, it would have meant going back to the levels in the 1980s or attaining the body burden of subjects regularly eating contaminated seafood.     

Impact of water supply and sanitation on diarrheal morbidity among young children in the socioeconomic and cultural context of Rwanda (Africa)

This project studied the frequency and intensity of water contamination at the source, during transportation, and at home to determine the causes of contamination and its impact on the health of children aged 0 to 5 years. The methods used were construction of the infrastructure for three sources of potable water, administration of a questionnaire about socioeconomic status and sanitation behavior, anthropometric measurement of children, and analysis of water and feces. The contamination, first thought to be only a function of rainfall, turned out to be a very complex phenomenon. Water in homes was contaminated (43.4%) with more than 1100 total coliforms/100 ml due to the use of unclean utensils to transport and store water. This socioeconomic and cultural problem should be addressed with health education about sanitation. The latrines (found in 43.8% of families) presented a double-edged problem. The extremely high population density reduced the surface area of land per family, which resulted in a severe nutritional deficit (15% of the children) affecting mainly young children, rendering them more susceptible to diarrhea (three episodes/child/year).     

Genetic determinants of adult hippocampal neurogenesis correlate with acquisition,but not probe trial performance,in the water maze task

A number of reports have indicated that adult neurogenesis might be involved in hippocampal function. While increases in adult neurogenesis are paralleled by improvements on learning tasks and learning itself can promote the survival of newly generated neurons in the hippocampus, a causal link between learning processes and adult hippocampal neurogenesis is difficult to prove. Here, we addressed the related question of whether the baseline level of adult neurogenesis is predictive of performance on the water maze task as a test of hippocampal function. We used ten strains of recombinant inbred mice, based on C57BL/6, which are good learners and show high baseline levels of neurogenesis, and DBA/2, which are known to be poor learners and which exhibit low levels of adult neurogenesis. Two of these strains, BXD-2 and BXD-8, showed a 26-fold difference in the number of newly generated neurons per hippocampus. Over all strains, including the parental strains, there was a significant correlation between the number of new neurons generated in the dentate gyrus and parameters describing the acquisition of the water maze task (slope of the learning curves). Similar results were seen when the parental strains were not included in the analysis. There was no correlation between adult hippocampal neurogenesis and probe trial performance, performance on the rotarod, overall locomotor activity, and baseline serum corticosterone levels. This result supports the hypothesis that adult neurogenesis is involved in specific aspects of hippocampal function, particularly the acquisition of new information.     

Experience with a bone bank operation and allograft bone infection in recipients at a medical centre in southern Taiwan

To assess the contamination rate of allograft bones at retrieval and the infection rate of the implanted allograft bone, we audited a bone bank retrospectively and reviewed the medical charts of allograft bone recipients between June 1999 and June 2000 at a medical centre in southern Taiwan. The bone bank did its utmost to minimize allograft contamination with hospital-acquired pathogens by adopting purposefully designed criteria for selection of donors. This protocol included sterilization with soaking of the retrieved allograft in a solution of a first-generation cephalosporin before storage and prophylaxis in recipients with first-generation cephalosporin. The contamination rates at allograft retrieval from living and cadaveric donors were 2.7% and 12.4%, respectively (P<0.001). Culture of 262 specimens taken at allograft implant revealed 12 (4.6%) positive for culture. Of the 12 patients implanted with allograft bones positive for culture, nine (75.0%) had allograft bone infection, while three (25.0%) did not. Among the 250 recipients with sterile allograft bones, four (1.6%) were found to have allograft infection. None of the cases of infection required removal of the allograft bones, and all cases were successfully treated with tailored antimicrobial therapy based on susceptibility tests on isolated bacteria. The overall infection rate was 5.0%, which compared favourably with those in other series. A prospective cohort study is needed to determine which of the varied sterilization methodologies gives the best and/or most cost-effective outcome.     

Uranium and other natural radionuclides in drinking water and risk of leukemia: a case-cohort study in Finland

Objective: We assessed the effect of natural uranium and other radionuclides in drinking water on risk of leukemia. Methods: The subjects (n = 144,627) in the base cohort had lived outside the municipal tapwater system during 1967–1980. A subcohort was formed as a stratified random sample of the base cohort and subjects using drinking water from drilled wells prior to 1981 were identified. A case–cohort design was used comparing exposure among cases with leukemia (n = 35) with a stratified random sample (n = 274) from the subcohort. Activity concentrations of uranium, radium-226, and radon in the drinking water were analyzed using radiochemical and alpha-spectrometric methods. Results: The median activity concentration of uranium in well water was 0.08 Bq/L for the leukemia cases and 0.06 Bq/L for the reference group, radon concentrations 80 and 130 Bq/L, respectively, and radium-226 concentrations 0.01 Bq/L for both groups. The hazard ratio of leukemia for uranium was 0.91 (95% confidence interval 0.73–1.13) per Bq/L, for radon 0.79 per Bq/L (95% CI 0.27–2.29), and for radium-226 0.80 (95% CI 0.46–1.39) per Bq/L. Conclusions: Our results do not indicate an increased risk of leukemia from ingestion of natural uranium or other radionuclides through drinking water at these exposure levels.     

Mnemonic deficits in animals depend upon the degree of cholinergic deficit and task complexity

The role of cholinergic basal forebrain (CBF) neurons in mnemonic behaviors was investigated using the immunotoxin 192IgG-saporin. We assessed two routes of immunotoxin administration: intracerebroventricular (ICV) and intraparenchymal (INTRA). INTRA lesions of the medial septum (MS) and/or the nucleus basalis magnocellularis (NBM) were compared with ICV-lesions, INTRA-phosphate-buffered saline injected, and naive controls. The INTRA-NBM/MS and ICV NBM/MS lesions produced a similar depletion of choline acetyltransferase activity of 80% across all CBF projections. Water maze performance was similarly impaired for ICV- and INTRA-NBM/MS animals during various phases of testing, whereas animals with individual lesions of the NBM or MS performed at the level of controls. In contrast to the allocentric demands of water maze performance, the egocentric-based T-maze task revealed a vast group difference between the ICV- and the INTRA-NBM/MS animals. INTRA-NBM/MS animals showed a severe deficit in the non-match- and match-to-position version, whereas again, animals with single lesions were unimpaired. In addition, a dichotomy between animals with complete cholinergic deafferentation was observed in the inhibitory avoidance task. ICV-NBM/MS showed a diminished retention for the aversive stimulus while the INTRA-NBM/MS animals remembered well. During plus maze testing, only the INTRA-NBM/MS animals had a reduced level of anxiety. Although non-CBF regions may have been differently affected by the two routes of immunotoxin administration, global measures of arousal, motivation, and motor initiation did not reveal a different behavioral pattern. Our findings suggest that a dynamic interplay exists between the degree of cholinergic deficit and task demands revealing different types of mnemonic impairments.     

Contact allergy to the monomers in p-tert-butylphenol-formaldehyde resin

In many adhesive formulations p-tert-butylphenol-formaldehyde resin (PTBP-F-R) is used as a binder. Contact allergy to this resin is not rare. In patients hypersensitive to PTBP-F-R, and butylphenol derivatives therein, it is for diagnostic and preventive reasons necessary to know the nature of the primary sensitizing substances, as well as the cross-reaction patterns for these. The aim of this study was to investigate contact allergy to monomers in PTBP-F-R and potential cross-reacting substances. 12 patients hypersensitive to PTBP-F-R were patch tested with 2 monomers, the raw materials formaldehyde and p-tert-butylphenol, and 3 closely related substances. High pressure liquid chromatography (HPLC) was used to investigate the purity of the test substances. It was shown that the monomers 2-methylol p-tert-butylphenol and 2,6-dimethylol p-tert-butylphenol could elicit allergic reactions in humans hypersensitive to PTBP-F-R. No simultaneous reactions or cross-reactions were shown to formaldehyde, p-tert-butylphenol, p-tert-butylcatechol, 2(3)-tert-butyl-4-hydroxyanisole (BHA) or 3,5-di-tert-butyl-4-hydroxytoluene (BHT). It was also shown that low amounts of contaminants in the test substances, if not taken into account, could influence the conclusions drawn from the test results obtained.     

Implicit and explicit alcohol-related cognitions

This article presents the proceedings of a symposium at the 2001 RSA Meeting in Montreal, Canada organized by Reinout W. Wiers and Alan W. Stacy. The purpose of the symposium was to present recent applications of implicit cognitive processing theory to alcohol research. Basic cognitive research has demonstrated that implicit cognition influences memory and behavior without explicit recall or introspection. The presentations from this symposium show that implicit cognition approaches yield new insights into understanding drinking motivation. The presentations were: (1) An introduction by Alan W. Stacy; (2) Implicit cognition and alcohol use. Involvement of other variables? (Susan L. Ames); (3) Alcohol expectancies and the art of implicit priming (Jane A. Noll); (4) Parental alcoholism and the effects of alcohol on semantic priming (Michael A. Sayette); (5) Implicit arousal and explicit liking of alcohol in heavy drinkers (Reinout W. Wiers); and (6) Negative affective cues and associative cognition in problem drinkers (Martin Zack). Comments were provided by the discussant Marvin Krank. The presented studies demonstrated that: (1) implicit memories of alcohol associations are powerful predictors and cross‐sectional correlates of alcohol use; (2) implicit retrieval processes influence alcohol outcome expectancies and alcohol consumption; (3) alcohol consumption influences implicit memory processing; (4) heavy drinkers reveal different affective responses in implicit and explicit tasks; and (5) negative affect exerts an implicit priming effect for alcohol associations in problem drinkers. These findings illustrate the importance of implicit cognition in understanding alcohol abuse and demonstrate the potential of the theoretical framework for more widespread application across a variety of areas of alcohol research, including diagnostics for the risk of alcohol abuse, treatment, and prevention.