[A prospective randomized controlled study of the application effect of hydrogel dressings on deep partial-thickness burn wounds after dermabrasion and tangential excision].

Objective: To investigate the clinical effect of applying hydrogel dressings in deep partial-thickness burn wounds after dermabrasion and tangential excision. Methods: A prospective randomized controlled study was conducted. From November 2015 to August 2019, 168 patients with deep partial-thickness burns hospitalized in Zibo Sixth People's Hospital met the inclusion criteria. According to the random number table, the patients were divided into hydrogel dressing+vaseline gauze group (84 cases, 67 males and 17 females) and vaseline gauze only group (84 cases, 65 males and 19 females) who were aged (31±16) and (35±17) years, respectively, and were given corresponding treatment after dermabrasion and tangential excision. The dressings were changed every 3-5 days. Autologous skin grafting was performed with split-thickness or medium-thickness skin grafts taken from trunk or thigh if the wounds failed to heal over 21 days or the wounds were less than 21 days but located in the joints, which might affect the functional activities at later stage. After operation, the general condition of the wounds was observed continuously and dynamically till the wounds were healed. The degree of dressing adhesion was evaluated during the first 4 dressing changes after operation, and the degree of pain was evaluated using Numerical Rating Scale (NRS). The wound healing rate on post operation day (POD) 3, 6, and 15 was calculated. The positive proportion of bacterial culture of wound exudates/cleanout fluid on admission and at dressing change on POD 3, 6, and 15 was calculated. The number of dressing changes were recorded, the rate of skin grafting operation was calculated, and the time of complete wound healing was recorded. Vancouver Scar Scale (VSS) was used in 6 months of follow-up to evaluate the hyperplasia of scar. Data were statistically analyzed with analysis of variance for repeated measurement, independent sample t test, Mann-Whitney U test, chi-square test or Fisher's exact probability test, and Bonferroni correction. Results: During the observation period after operation, the wound was moist with less exudates and the wound healed much faster in patients of hydrogel dressing+vaseline gauze group, with the inner dressing being easier to remove with mild pain, while the wounds showed more exudates and slower healing in patients of vaseline gauze only group with the obvious adhesions of inner dressing, stronger pain, and bleeding in the wounds. Compared with those in vaseline gauze only group, the degree of dressing adhesion and pain NRS score of patients in hydrogel dressing+vaseline gauze group decreased significantly during the first 4 dressing changes after operation (χ2=52.625, Z=-10.854, P<0.01), the wound healing rate increased significantly at dressing change on POD 3, 6, and 15 (t=10.347, 41.150, 167.627, P<0.01), the positive proportion of wound exudates/cleanout fluid bacterial culture did not change significantly on admission or at dressing change on POD 3 (P>0.05) but decreased significantly at dressing change on POD 6 and 15 (χ2=15.616, 15.226, P<0.01), the dressing change times was significantly reduced (t=-11.986, P<0.01), and the rate of skin grafting operation was significantly decreased (χ2=35.850, P<0.01). The complete wound healing time of patients in hydrogel dressing+vaseline gauze group was (17.6±2.8) d, significantly shorter than (27.1±3.0) d in vaseline gauze only group (t=-21.288, P<0.01). During the follow-up of 6 months, the VSS score of scar hyperplasia of patients in hydrogel dressing+vaseline gauze group was significantly lower than that in vaseline gauze only group (Z=-11.287, P<0.01). Conclusions: Compared with the use of vaseline gauze only, the application of vaseline gauze coated with hydrogel dressing in deep partial-thickness burn wounds after dermabrasion and tangential excision is more effective in moisturizing, significantly reducing the degree of dressing adhesion and patients' pain during dressing change, increasing wound healing rate, decreasing wound infection rate and the rate of skin grafting operation, and reducing the number of dressing changes. It shortens the time for complete wound healing, and effectively relieves scar hyperplasia.

[Research on anxiety-like neurobehavior of zebrafish caused by lead exposure and its mechanism].

Objective: This study aims to explore whether lead exposure could cause anxiety of zebrafish larvae, and to explore its mechanism. Methods: In May 2020, zebrafish embryos 4 hours after fertilization (4 hpf) were collected, E3 culture medium was used as the control group, and different lead exposure concentrations (6, 12, 24, 48 µmol/L) as the poisoned group during the time was 140 h. The mortalities, hatching rates and deformity rates were calculated, the behavioral changes of 144 hpf larvae were observed (moving speed, moving distance, activity, absolute turn angle, the light-evoked startle response, darkness-evoked escape response and thigmotaxis) . The levels of reactive oxygen species (ROS) and malondialdehyde (MDA) were detected in zebrafish larvae in the heads. ELISA kits were used to detect the expression of 5-hydroxytryptamine (5-HT) , dopamine (DA) , noradrenaline (NA) and corticotropin-releasing hormone (CRH) related to anxiety. Results: The mortalities rates of zebrafish embryos in the lead exposure concentration of 12, 24 and 48 µmol/L were higher than the control group, and the embryo hatching rates were lower than control group. The deformity rates of zebrafish larvae in the lead exposure concentration of 24 and 48 µmol/L were higher than control group (P<0.01) . The movement speed, activity and thigmotaxis of zebrafish larvae in the lead exposure concentration of 24 and 48 µmol/L were significantly lower than control group, the absolute turn angle were higher than control group (P<0.01) . The moving distance and darkness-evoked escape response of zebrafish larvae in the lead exposure concentration of 48 µmol/L group were lower than control group (P<0.05) . The light-evoked startle response of zebrafish larvae in the lead exposure concentration of 12, 24 and 48 µmol/L groups were lower than control group (P<0.05) . The ROS levels and MDA concentrations in the heads of larvae in the lead exposure concentration of 24 and 48 µmol/L were higher than control group (P<0.05) . The levels of NA and DA in the heads of the larvae in the lead exposure groups of 12, 24 and 48 µmol/L were lower than control group, and the levels of 5-HT and CRH in the heads of the larvae in the lead exposure groups of 24 and 48 µmol/L were higher than control group (P<0.05) . Conclusion: Lead exposure is toxic to zebrafish embryonic development and may cause anxiety-like neurobehavior changes and oxidative stress in zebrafish.

[Perioperative factors affecting the length of hospital stay after cesarean section of pregnant women with heart disease].

Objective: To explore the related factors influencing the length of hospital stay(LOS) of pregnant women with heart disease (PWHD) after cesarean section. Methods: A total of 306 patients with PWHD who underwent cesarean section from January 2012 to March 2019 were collected. Among them, 203 patients had not undergone heart surgery (uncorrected group) and 103 patients who had undergone heart surgery (corrected group) during the same period. Demographic, perioperative and postoperative data were recorded. Predictors associated with postoperative LOS were determined using univariate and multivariate linear regression analysis models. Results: (1) The median LOS after cesarean section in the uncorrected group was 6 days (5-8 days). The results of univariate linear regression analysis showed that 38 parameters had significant impact on LOS (P<0.05). The results of multivariate linear regression analysis showed that 5 parameters were independent risk factors for prolonged LOS in the uncorrected group; among them, the median LOS in uncorrected group with hypertensive disorders of pregnancy was 3 days longer than that in patients with PWHD alone [7 days (5-8 days) vs 4 days (4-5 days), ß=0.195, P=0.001]; the median LOS in uncorrected group with high serum creatinine was 3 days longer than normal patients [7 days (5-13 days) vs 4 days (4-5 days), ß=0.145, P=0.015]; the LOS of patients who chose general anesthesia was 2 days longer than that of patients who chose spinal anesthesia [6 days (4-8 days) vs 4 days (4-5 days), ß=0.154, P=0.007]; the LOS of patients with postoperative pulmonary infection was 4 days longer than that of patients without pulmonary infection [8 days (5-15 days) vs 4 days (4-5 days), ß=0.269, P<0.01]; the LOS of patients who admitted to ICU after surgery was 2 days longer than that not admitted patients [6 days (5-8 days) vs 4 days (4-5 days), ß=0.268, P<0.01]. (2) The median LOS after cesarean section in corrected group was 4 days (4-5 days). The results of univariate linear regression analysis showed that 8 parameters had significant impact on the LOS (all P<0.05). The results of multivariate linear regression analysis showed that 2 parameters, which were American Society of Anesthesiologists (ASA) grade (ß=0.198, P=0.028) and intraoperative blood loss (ß=0.285, P=0.003), were the independent risk factors for prolonged LOS in corrected group. Conclusion: Preoperative with hypertensive disorders of pregnancy, preoperative creatinine increase, intraoperative general anesthesia, postoperative pulmonary infection, and postoperative admission to ICU are independent predictors of prolonged LOS in uncorrected patients with PWHD; ASA classification and intraoperative bleeding are independent predictor of prolonged postoperative LOS in patients with corrected PWHD.

A Frailty Screening Questionnaire (FSQ) to Rapidly Predict Negative Health Outcomes of Older Adults in Emergency Care Settings.

BACKGROUND: Frailty, at the core of geriatric medicine, is an important concept underpinning health problems but the rapid and valid measurement of frailty for older adults in the Emergency Department (ED) is lacking in China. The Frailty Screening Questionnaire (FSQ), has been shown to be a simple, rapid and practical tool to identify frailty in both community and inpatients settings, yet its utility in acute care settings is not well understood. OBJECTIVE: To determine whether FSQ is useful to identify frailty and predict adverse outcomes in an emergency care setting. DESIGN AND PARTICIPANTS: This prospective study included 350 adults aged 60 and over and admitted to the ED. MEASUREMENTS: The FSQ questionnaire which assessed self-reported slowness, weakness, inactivity, exhaustion, and weight loss was used to rapidly recognize frailty. FRAIL, Clinical frailty score (CFS), activities of daily living (ADL) and nutrition risk screening 2002 were also assessed. Outcome measures included all-cause 28-day mortality, ADL dependency, mechanical ventilation, length of hospital stay, and ICU readmissions 30 and 90 days after discharge. Cox proportional hazard model was used for survival comparison. RESULTS: The prevalence of FSQ frailty and prefrailty in older adults were 44.6% and 30.9% respectively in the emergency setting. FSQ frailty was associated with increasing age, chronic diseases, malnutrition risk, poor physical function and worse outcomes indicated by higher 28-d mortality, ADL dependency, mechanical ventilation, length of hospital stay, and ICU readmissions after discharge. The Kappa coefficient between the FSQ and FRAIL was 0.552. FSQ score was negatively correlated with grip strength and positively correlated with Barthel index, length of hospital stay and CFS score. Cox regression adjusted by epidemiological variables and chronic diseases showed FSQ and all components predicted mortality except weight loss. CONCLUSION: The FSQ is a rapid and useful tool to screen frailty and an effective tool to predict mortality in busy emergency settings.

[Influence of aluminum chloride exposure on embryonic development of zebrafish and neurobehavior of juvenile fish].

Objective: To investigate the influence of aluminum chloride (AlCl(3)) solution on the embryon-ic development of zebrafish and neurobehavior of juvenile fish. Methods: The embryos of zebrafishat 6 hours after fertilization were exposed to AlCl(3) solution at a concentration of 0, 55.0, 60.5, 66.6, 73.5, 80.5, or 100.0 mg/L, and embryonic hatching rates at 48 and 72 hours after fertilization were calculated. The embryos of zebrafishat 6 hours after fertilization were exposed to AlCl(3) solution at a concentration of 0, 60.0, 72.0, 86.4, 103.7, or 124.4 mg/L, and the embryonic mortality rates at 12, 24, 48, 72, and 96 hours after fertilization were calculat-ed. The embryos of zebrafish at 6 hours after fertilization were exposed to AlCl(3) solution at a concentration of 0, 50, 100, 200, 400, or 800 µg/L, and the changes in the neurobehavior of juvenile fish were observed after hatching, including touch-escape reaction at 72 hours after fertilization and autonomic movement and panic es-cape reflex at 7 days after fertilization. Results: Compared with the 0 mg/L group, the≥66.6 mg/L group had a sig-nificant reduction in embryonic hatching rate at 48 and 72 hours after fertilization, and the ≥72.0 mg/L group had a significant increase in embryonic mortality rate at 96 hours after fertilization (P<0.05) . Compared with the 0 µg/L group, the≥100 µg/L group had a significant reduction in the number of times of touch-escape reaction (P<0.05) .Compared with the 0 and 50 µg/L groups, the 100-800 µg/L groups had significant reductions in total movement distance and average speed (P<0.05) . Compared with the dark period before illumination, all groups had a significant increase in movement speed during the light period of the panic escape reflex test (i.e., the third minute) (P<0.05) ; within 2 minutes after the light was turned off, there was no significant change in movement speed in the 0-200 µg/L groups (P>0.05) ; the 400 and 800 µg/L groups had a significant increase in movement speed (P<0.05) . Conclusion: AlCl(3) exposure may cause embryonic developmental disorder in zebrafish and ab-normal neurobehavior in juvenile fish.

Three months of weekly rifapentine plus isoniazid is less hepatotoxic than nine months of daily isoniazid for LTBI.

SETTING: Nine months of daily isoniazid (9H) and 3 months of once-weekly rifapentine plus isoniazid (3HP) are recommended treatments for latent tuberculous infection (LTBI). The risk profile for 3HP and the contribution of hepatitis C virus (HCV) infection to hepatotoxicity are unclear. OBJECTIVES: To evaluate the hepatotoxicity risk associated with 3HP compared to 9H, and factors associated with hepatotoxicity. DESIGN: Hepatotoxicity was defined as aspartate aminotransferase (AST) >3 times the upper limit of normal (ULN) with symptoms (nausea, vomiting, jaundice, or fatigue), or AST >5 x ULN. We analyzed risk factors among adults who took at least 1 dose of their assigned treatment. A nested case-control study assessed the role of HCV. RESULTS: Of 6862 participants, 77 (1.1%) developed hepatotoxicity; 52 (0.8%) were symptomatic; 1.8% (61/3317) were on 9H and 0.4% (15/3545) were on 3HP (P < 0.0001). Risk factors for hepatotoxicity were age, female sex, white race, non-Hispanic ethnicity, decreased body mass index, elevated baseline AST, and 9H. In the case-control study, HCV infection was associated with hepatotoxicity when controlling for other factors. CONCLUSION: The risk of hepatotoxicity during LTBI treatment with 3HP was lower than the risk with 9H. HCV and elevated baseline AST were risk factors for hepatotoxicity. For persons with these risk factors, 3HP may be preferred.

Cost-effectiveness of a 12-dose regimen for treating latent tuberculous infection in the United States.

SETTING: A large randomized controlled trial recently showed that for treating latent tuberculous infection (LTBI) in persons at high risk of progression to tuberculosis (TB) disease, a 12-dose regimen of weekly rifapentine plus isoniazid (3HP) administered as directly observed treatment (DOT) can be as effective as 9 months of daily self-administered isoniazid (9H). OBJECTIVES: To assess the cost-effectiveness of 3HP compared to 9H. DESIGN: A computational model was designed to simulate individuals with LTBI treated with 9H or 3HP. Costs and health outcomes were estimated to determine the incremental costs per active TB case prevented and per quality-adjusted life year (QALY) gained by 3HP compared to 9H. RESULTS: Over a 20-year period, treatment of LTBI with 3HP rather than 9H resulted in 5.2 fewer cases of TB and 25 fewer lost QALYs per 1000 individuals treated. From the health system and societal perspectives, 3HP would cost respectively US$21,525 and $4294 more per TB case prevented, and respectively $4565 and $911 more per QALY gained. CONCLUSIONS: 3HP may be a cost-effective alternative to 9H, particularly if the cost of rifapentine decreases, the effectiveness of 3HP can be maintained without DOT, and 3HP treatment is limited to those with a high risk of progression to TB disease.

High-rate low-temperature growth of vertically aligned carbon nanotubes.

We report the low-temperature growth of vertically aligned carbon nanotubes (CNTs) at high growth rates by a photo-thermal chemical vapour deposition (PTCVD) technique using a Ti/Fe bilayer film as the catalyst. The bulk growth temperature of the substrate is as low as 370 °C and the growth rate is up to 1.3 µm min(-1), at least eight times faster than the values reported by traditional thermal CVD methods. Transmission electron microscopy observations reveal that as-grown CNTs are uniformly made of highly crystalline 5-6 graphene shells with an approximately 10 nm outer diameter and a 5-6 nm inner diameter. The low-temperature rapid growth of CNTs is strongly related to the unique top-down heating mode of PTCVD and the use of a Ti/Fe bimetallic solid solution catalyst. The present study will advance the development of CNTs as interconnects in nanoelectronics, through a CMOS-compatible low-temperature deposition method suitable for back-end-of-line processes.

Molecular cloning of rhamnose-binding lectin gene and its promoter region from snakehead Channa argus.

Lectins are sugar-binding proteins that mediate pathogen recognition and cell-cell interactions. A rhamnose-binding lectin (RBL) gene and its promoter region have been cloned and characterized from snakehead Channa argus. From the transcription initiation site, snakehead rhamnose-binding lectin (SHL) gene extends 2,382 bp to the end of the 3' untranslated region (UTR), and contains nine exons and eight introns. The open reading frame (ORF) of the SHL transcript has 675 bp which encodes 224 amino acids. The molecular structure of SHL is composed of two tandem repeat carbohydrate recognition domains (CRD) with 35% internal identity. Analysis of the gene organization of SHL indicates that the ancestral gene of RBL may diverge and evolve by exon shuffling and gene duplication, producing new forms to play their own roles in various organisms. The characteristics of SHL gene 5' flanking region are the presence of consensus nuclear factor of interleukin 6 (NF-IL6) and IFN-gamma activation (GAS) sites. The results provide indirect evidence that up-regulation of SHL expression may be induced in response to inflammatory stimuli, such as lipopolysaccharide (LPS), interleukin 6 (IL-6), and interferon gamma (IFN-gamma). The transcript of SHL mRNA was expressed in the head kidney, posterior kidney, spleen, liver, intestine, heart, muscle, and ovary. No tissue-specific expressive pattern is different from reported STLs, WCLs, and PFLs, suggesting that different types of RBLs exist in species-specific fish that have evolved and adapted to their surroundings.

TST reversion in a BCG-revaccinated population of nursing and medical students, São Paulo, Brazil, 1997-2000.

SETTING: A major university in São Paulo, Brazil, where vaccination against tuberculosis (TB) with bacille Calmette-Guerin (BCG) was routinely offered to first-year medical and nursing students. OBJECTIVES: To estimate the probability of negative tuberculin skin test (TST) results over a 4-year period following BCG revaccination, and to evaluate the effect of factors associated with reversion. DESIGN: Students were enrolled in 1997, initially given a two-step TST, and were retested annually or biannually for the duration of the study. Data on TB exposures and potential risk factors for TST negativity and reversion were collected through annual surveys. A linear mixture survival model was used to estimate the probability of negative TST results over time. RESULTS: Of 159 students, an estimated 20% had a negative TST result despite revaccination, and a further 31% reverted to negative over 4 years of follow-up. No cofactors significantly affected the probability of reversion. CONCLUSION: Overall, in the absence of reported exposure to Mycobacterium tuberculosis, 51% of students revaccinated upon entering nursing or medical school would have a negative TST result by the time they begin their internships. In this recently vaccinated population, reversion was common, suggesting that annual TST screening may remain a useful tool.

Decomposition of 2-naphthalenesulfonate in aqueous solution by ozonation with UV radiation.

This study investigates the ozonation of 2-naphthalenesulfonate (2-NS) combined with ultraviolet (UV) radiation. Naphthalenesulfonic acids are of importance as dye intermediates for the dye and textile auxiliary industries. Its derivatives, such as 2-NS, have been found in rivers and tannery effluents causing pollution problems. Thus, the 2-NS is of concern for the aquatic pollution control especially in the surface and waste waters. Ozonation combined with UV radiation is employed for the removal of 2-NS in the aqueous solution. Semibatch ozonation experiments were proceeded under different reaction conditions to study the effects of ozone dosage and UV radiation on the oxidation of 2-NS. The concentrations of 2-NS and sulfate are analyzed at specified time intervals to elucidate the decomposition of 2-NS. In addition, values of pH and oxidation reduction potential are continuously measured in the course of experiments. Total organic carbon is chosen as a mineralization index of the ozonation of 2-NS. The mineralization of 2-NS via the ozonation is remarkably enhanced by the UV radiation. These results can provide useful information for the proper removal of 2-NS in the aqueous solution by the ozonation with UV radiation.

Toxicity and color formation during ozonation of mono-substituted aromatic compounds.

This research investigates the aqueous toxicity occurring during color formation due to ozonation in a semi-batch reactor. The tested mono-substituted aromatic compounds were aniline, phenol (-NH2' -OH, electron-donating group), nitrobenzene and benzoic acid (-NO2' -COOH, electron-withdrawing group). The results revealed that the aqueous toxicity of the Microtox assay from oxidized samples during the early stage of ozonation increased when the color formation was observed, except in the case of nitrobenzene under high pH conditions. Toxicity typically reached a peak at or near the moment of maximum color intensity. Ozonation of these aromatic compounds showed a large increase in toxicity, and the 50% effective concentration (EC50) expressed as chemical oxygen demand (COD) (mg 1(-1)) decreased to 1.4 (aniline), 1.2 (benzoic acid), 0.8 (phenol) and 0.6 (nitrobenzene) orders-of-magnitude. Moreover, the aromatic compounds with an electron-donating group promoted color formation more than did the electron-withdrawing group substituted compounds.

Nanostructure. Epitaxial diamond polytypes on silicon.

Carbon is unique in the variety of configurations it can adopt with itself and other elements. Here we show how ion beams can be used to nanostructure various diamond polytypes, epitaxially aligning them to a silicon substrate. The ready controllability of ion beams, which are already used to manufacture submicrometre-scale devices, means that our findings should enable new carbon and non-carbon materials to be nanostructured for a host of applications.

The biotoxicity and color formation results from ozonation of wastewaters containing phenol and aniline.

This study was undertaken to investigate the color forming phenomena and biotoxicity related problems during the initial stage of ozonation in the wastewater containing phenol or aniline. Experimental results indicate that the phenol under alkaline condition and aniline in all pH conditions cause a serious color problem during the period of early initial ozonation. In addition, the ozonated aniline exhibited more severe color formation than the ozonated phenol did. Both of these compounds revealed that either a high compound concentration or low ozone dosage applied incurred a strong color forming phenomena. Moreover, according to the Microtox test, both ozonated byproducts increased the toxicity during early ozonation when the color formation occurred. The EC50-value as COD decreased from 0.72 (for phenol, pH = 7) to 1.38 (for aniline, pH = 4) orders-of-magnitude. This observation implies that the ozonated color formation would generate new toxicity problems if these colored matters were not further oxidized.

Studies on the genotoxicity of molybdenum salts in human cells in vitro and in mice in vivo.

Molybdenum is an essential element in plants and animals as a cofactor for enzymes. Molybdenum trioxide is used in metallurgical processes, in cosmetics as a pigment, and in contact lens solution, yet limited information is available on molybdenum genotoxicity. In the present study the micronucleus (MN) assay in human lymphocytes and mouse bone marrow and the dominant lethal assay in mice were used to assess the genotoxic effects of molybdenum salts in vitro and in vivo. Two salts of molybdenum were tested in whole blood cultures. Ammonium molybdate was more potent than sodium molybdate in causing a dose-dependent decrease in viability and replicative index and an increase in MN formation in binucleated lymphocytes (P < 0.001). A dose-response in both kinetochore-positive MN (caused by chromosome lagging) and kinetochore-negative MN (associated with chromosome breakage) was observed. Based on the results of a toxicity study of sodium molybdate, two doses, 200 and 400 mg/kg, were assessed in the bone marrow MN assay in mice (two i.p. injections 24 and 48 hr prior to euthanasia). A modest but statistically significant increase in MN frequency in polychromatic erythrocytes was observed (P < 0.05). The same treatment protocol was used to analyze dominant lethality. A dose-dependent increase in postimplantation loss represented mostly by early resorptions was observed the first week after treatment (P = 0.003). These preliminary data suggest that sodium molybdate induces dominant lethality at the postmeiotic stage of spermatogenesis. Overall, molybdenum salts produced moderately positive results both in vitro in human cells and in vivo in mice.

Micronuclei in lymphocytes and exfoliated buccal cells of postmenopausal women with dietary changes in folate.

Folate deficiency is associated with anemia, birth defects, cancer and neuropsychiatric disorders. The purpose of this study was to determine if a moderate folate deficiency during controlled changes in folate intake would affect chromosomal damage in lymphocytes and buccal cells. A study of nine healthy postmenopausal women volunteers (age 49-63 years) was carried out in a metabolic unit (baseline week with folate intake of 195 microg/day, five-week depletion at 56 microg/day, and gradual repletion including four weeks at 111 microg/day, 11 days at 286 microg/day and 9 days at 516 microg/day). Plasma folate, vitamin B-12, and homocysteine were measured weekly. Cytogenetic damage was assessed by scoring micronucleus (MN) frequency in lymphocytes and buccal cells three times: (1) at the beginning of the study, (2) at the end of depletion, and (3) after repletion. The MN frequency increased in binucleated lymphocytes, as well as in all lymphocytes, after depletion (p=0.037), and later decreased following repletion (p=0. 028). Both kinetochore-positive and kinetochore-negative MN were increased after depletion (p=0.015 and 0.028), but after repletion only the change in kinetochore-positive MN was statistically significant (p=0.048). The main variables affecting MN were: (1) vitamin B-12 level, (2) plasma folate level, and (3) baseline frequency of MN. The MN frequency in exfoliated buccal cells was decreased after dietary supplementation of 516 microg/day folate (p=0.010). Thus, low folate, without clinical symptoms of anemia, results in higher levels of cytogenetic damage in both the blood and oral cavity of postmenopausal women.

Micronuclei and developmental abnormalities in 4-day mouse embryos after paternal treatment with acrylamide.

The developmental consequences of paternal exposure to acrylamide (50 mg/kg i.p. for 5 days) were assessed in preimplantation embryos. There was a significant increase in the proportion of morphologically abnormal embryos after postmeiotic treatment during spermatogenesis (88.7% vs. 14.8% in control). Abnormal embryos had an average of 1.8 +/- 3.5 cells and > 80% had at least one fragmented nucleus. In addition, morphologically normal embryos were significantly delayed (34.3 +/- 12.8 cells per embryo vs. 57.6 +/- 15.7 in control, P < 0.001). Acrylamide caused 10- and 20-fold increases in frequencies of cells with micronuclei (MN) in morphologically normal and abnormal embryos, respectively (41 and 93 MN per 1,000 cells). Both centromere-negative (MN-) and centromere-positive (MN+) were induced. Nuclei of abnormal embryos were significantly larger (900 microm2 vs. 250 microm2) than controls. In addition, MN of abnormal embryos were larger than those of normal embryos (21.2 microm2 vs. 6.5 microm2, P < 0.01). Among control embryos, MN+ were significantly larger than MN- (P < 0.05). These findings suggest that the preimplantation embryo is a sensitive indicator of paternally transmitted effects on early development. Multiple mechanisms appear to be involved, including cytogenetic damage, proliferation arrest/delay, and fertilization failure. Future studies are needed to establish how induced cytological defects in preimplantation embryos contribute to birth defects and other postimplantation abnormalities.

Benzene metabolites induce the loss and long arm deletion of chromosomes 5 and 7 in human lymphocytes.

Two of the most common cytogenetic changes in therapy- and chemically-related leukemia are the loss and long (q) arm deletions of chromosomes 5 and 7 (i.e. -5, -7, del(5q) and del(7q)). We have used a novel fluorescence in situ hybridization (FISH) procedure to determine if the benzene metabolites hydroquinone (HQ) and 1,2,4-benzenetriol (BT) can induce these specific changes in human lymphocytes cultured as whole blood. Metaphase spreads were prepared and hybridized with centromeric probes for chromosomes 1, 5 and 7 and sequence specific probes for 5q31 and 7q36-qter. HQ and BT significantly increased monosomy 5 and 7 by 3-5 fold (p < 0.0001). Both HQ and BT also significantly increased the rate of del(5q) and del(7q) by 8-12 fold (p < 0.0001). Chromosome 7 was especially susceptible to aneusomy induction by HQ and BT at low doses. These results show that metabolites of benzene are highly effective in inducing changes in chromosomes 5 and 7 that are involved in the development of myeloid leukemia.

Laparoscopic cholecystectomy in a patient with empyema of the gallbladder and situs inversus.

The successful performance of laparoscopic cholecystectomy in a patient with situs inversus viscerum and empyema of the gallbladder is reported. The 62-year-old man presented with pain in the left upper quadrant associated with fever, chills, nausea and vomiting. The abdomen was tender with guarding and a palpable globular mass in the same region. CT scan demonstrated a distended gallbladder with thick shaggy walls which contained a 2 cm gallstone in the neck and also revealed dextrocardia and situs inversus. The patient's postoperative recovery was uneventful.