Histopathology and Cell Replication Responses in the Respiratory Tract of Rats and Mice Exposed by Inhalation to Glutaraldehyde for up to 13 Weeks

In addition to being a respiratory tract irritant and cross-linkingagent, glutaraldehyde has a number of properties in common withthe rodent nasal carcinogen, formaldehyde. The acute and subchronicresponses to glutaraldehyde in the respiratory tract of ratsand mice were characterized using histopathology and epithelialcell labeling index as end points. Male and female F344 ratsand B6C3F1 mice were whole-body exposed for 1 day, 4 days, 6weeks, or 13 weeks to 0, 62.5, 125, 250, 500, or 1000 ppb glutaraldehydeusing a recycling inhalation chamber. The respiratory tract,with special reference to the nose, was examined by light microscopyand histoautoradiography. Unit length labeling index (ULLI)was determined by nuclear thymidine labeling for selected sites,chosen on the basis of histopathology. A small number of animalsexposed to 1000 ppb (rats and mice) or 500 ppb (mice) died beforethe 6-week time point; these deaths were attributed to glutaraldehydeexposure-associated occlusion of the external nares. Treatment-inducedlesions, including epithelial erosions, inflammation, and squamousmetaplasia, were confined to the anterior third of the noseand were present in both sexes and species. No histopathologicalevidence of glutaraldehyde-induced responses was observed inthe trachea, central airways, or lungs, while the larynx showedminimal changes. There were clear increases in ULLI in associationwith acute and subacute cytotoxic responses, with similar concentration-responserelationships. Neutrophilic infiltration of the squamous epitheliumof the nasal vestibule, present in both rats and mice, becameprogressively more severe with increasing exposure time andwas associated with increased ULLI. The latter responses weregenerally most severe at the higher glutaraldehyde exposureconcentrations, while in female mice they were present at allconcentrations of glutaraldehyde studied. Lesions induced byglutaraldehyde were more anterior in the nose than those reportedfor formaldehyde, they differed in character, and no evidenceof "pre-neoplastic" lesions or karyomegaly, reported for formaldehyde,was observed with glutaraldehyde.     

Morphology and Glycoconjugate Content of Opossum Esophageal Epithelium and Glands: Regional Heterogeneity and Effects of Acid-Induced Mucosal Injury and Recovery

This study examined the regional heterogeneity and site-specific changes in histology and glycoconjugate content following the induction of esophagitis and after recovery in an established animal model. Esophageal samples were excised from five sites in anesthetized opossums 24 hr after 3 consecutive days of 45-min perfusion with saline or 100 mM HCl or 1 week after acid in recovery animals. Controls exhibited significant regional differences in epithelial thickness, gland volume, glycoconjugate composition, and mast cell numbers. Acid perfusion induced erosive esophagitis and significant epithelial denudation throughout the distal 7 cm, combined with significant site-specific increases in gland lumen volume, decreases in mast cell numbers, and changes in glycoconjugate content. No differences from controls were noted in recovery animals, except for a significant increase in epithelial thickness and change in glycoconjugate content in the distal 2 cm. The results of this study highlight the impact of acid exposure on these structural defenses, but further investigation is required to explore the importance of these acid-induced changes in the pathogenesis of reflux esophagitis. This study was supported by Grant MT9978 from the Canadian Institutes of Health Research (CIHR) (W.G.P.), Grant 138239 from the National Science & Engineering Research Council (NSERC) (G.P.M.), and NSERC Postgraduate Scholarship and School of Graduate Studies, Queen’s University (R.J.W.).     

Occupational asthma in Finland

In Finland occupational asthma caused by protein allergens and reactive chemicals present in the air of work environments is increasing. This communication describes provocative challenge tests and methods for measuring exposure under simulated work conditions. The importance of lung function measurements during non-exposure and placebo periods is stressed. Especially late reactions are difficult to assess because of the great circadian variation in the lung function parameters of asthmatics. For a positive challenge test, a decrease in peak flow values of at least 15% and a clear deviation from normal circadian variation and placebo periods is required. The allergens of vegetable or animal origin primarily affect patients with an atopic constitution. Chemical allergens seem to attack all exposed workers in the same way. The report lists the occupations with risk for asthma and refers to the population at risk; bakers seem to be the group with the most risk. The importance of early diagnosis, removal of the worker from exposure and improvement of the hygienic aspects of the work environment are stressed.     

FAMILIAL BLADDER CANCER IN THE NATIONAL SWEDISH FAMILY CANCER DATABASE

PURPOSE: We analyzed the risk of bladder cancer in offspring according to parental and sibling cancer using the national Swedish Family Cancer Database. MATERIALS AND METHODS: Cancer data were obtained from the Swedish Cancer Registry for 1958 to 1996, including 2,105 cases of bladder cancer in offspring. The standardized incidence ratio was used to measure cancer risk in offspring according to familial cancer status. RESULTS: The incidence ratio of bladder cancer increased in Sweden from 1958 to 1996 and it was 3 to 4-fold higher in males than in females. We identified 65 families in which the parents and offspring had bladder cancer with a familial risk of 1.35 (95% confidence interval [CI] 0.97 to 1.79) in sons and 2.29 (95% CI 1.46 to 3.29) in daughters. Discordant cancer sites associated with bladder cancer in the 2 generations were the kidney and thyroid with a standardized incidence ratio of 1.58 (95% CI 1.18 to 2.05) and 1.89 (95% CI 1.00 to 3.05), respectively. Sibling risk was higher compared with offspring risk with a standardized incidence ratio of 2.96 (95% CI 1.41 to 5.08) and in males there was a statistically significant ratio of sibling-to-offspring risk of 2.66 (95% CI 1.29 to 5.45). Patient age at onset modified the familial risk. The highest familial risk of 7.26 (95% CI 2.61 to 14.24) was observed in the brothers of bladder cancer probands diagnosed before age 45 years. CONCLUSIONS: The relatively high ratio of sibling-to-offspring risk as well as observed gender specific effects in bladder cancer may reflect an X linked susceptibility gene.     

Oral health in pre‐school children with asthma – followed from 3 to 6 years

International Journal of Paediatric Dentistry 2010; 20: 165–172 Objective. The aim of this study was to investigate caries and its determinants in preschool children with and without asthma, followed from 3 to 6 years. Methods and subjects. Caries, plaque, and gingivitis were examined at 3 and 6 years of age in 64 asthmatic children and 50 matched, healthy control children. Furthermore, at 6 years radiographic examination and saliva sampling were conducted. The parents were interviewed about various oral health‐related factors. Results. Initial caries increment between 3 and 6 years of age was statistically significant higher for children with asthma compared with children without asthma (P < 0.05). Asthmatic children had more bleeding gingivitis and a higher consumption of sugary drinks than healthy children at 3 years of age (P < 0.05). At both 3 and 6 years of age, the asthmatic children were more frequently mouth breathers than healthy children, only statistically significant for 6‐year olds (P < 0.05). Conclusion. Preschool children with asthma at 3 years of age run a higher risk of developing caries lesions until 6 years of age compared with children without asthma. Children with asthma have a higher prevalence of bleeding gingivitis, a higher intake of sugary drinks and are more frequently mouth breathers than preschool children without asthma.     

Polytetrapeptide of elastin

High molecular weight polytetrapeptide of elastin, (L-Val¹-L-Pro²-Gly³-Gly⁴)_n, was synthesized using activation of the (GGVP) permutation for polymerization. The temperature-dependence of aggregation was characterized as a function of concentration and the circular dichroism spectra were obtained in the 20° to 70°C temperature range. The latter showed an inverse temperature transition centered near 50°C in which polypeptide order increased on raising the temperature. A concentration of 0.6 g of polytetrapeptide in 1 g of water was Λ irradiation cross-linked (20 Mrad) to form an elastomeric matrix. A study of the temperature-dependence of elastomeric force demonstrated a transition toward increased force on raising the temperature with a midpoint of the transition near 50°C. Thus, there is a correlation between increase in intramolecular order and elastomeric force development. These results are compared to previous results on the polypentapeptide of elastin, (VPGVG)_n and on an analog, (IPGVG)_n, to demonstrate that the temperature of the transition is proportional to the hydrophobicity of the repeating unit. The point is noted that the elastomeric force development correlates better with intramolecular ordering than with intermolecular processes.     

COMPARISON OF THE ANALGESIC EFFECT OF TEN NONSTEROIDAL ANTI-INFLAMMATORY DRUGS

The analgesic effect of 10 anti-inflammatory drugs was comparedusing a single-blind method in 90 patients with rheumatoid arthritis.Each patient received two different drugs, for three days eachand each drug was evaluated in 18 patients. After the trial,the patients considered which of the drugs they preferred. The greatest relief from pain was achieved by diclofenac, indomethacin,naproxen and tolfenamic acid, each of these being preferredby the majority of patients and being significantly (p>0.01)better than the least effective drugs ketoprofen and proquazone.Acetylsalicylic acid, azapropazone, carprofen and ibuprofenwere considered intermediate in efficacy. KEY WORDS: Rheumatoid arthritis, Nonsteroidal drugs     

健儿止泻颗粒联合蒙脱石散治疗小儿腹泻的临床研究

目的探究健儿止泻颗粒联合蒙脱石散治疗小儿腹泻的临床疗效。方法选取2015年6月—2017年3月新疆医科大学第一附属医院收治的腹泻患儿102例为研究对象,采取随机数表法将患儿分为对照组和治疗组,每组各51例。对照组口服蒙脱石散,年龄1岁:1/3袋/次,年龄1~3岁:1/2袋/次,年龄≥3岁:1袋/次,3次/d。治疗组在对照组基础上开水冲服健儿止泻颗粒,年龄1岁:6 g/次,年龄1~5岁:6~12 g/次,年龄≥5岁:12~18 g/次,3次/d。两组患儿均连续治疗7 d。观察两组的临床疗效,比较两组的临床症状改善时间和免疫功能指标。结果治疗后,对照组和治疗组的总有效率分别为92.16%、100.00%,两组比较差异有统计学意义(P0.05)。治疗后,治疗组止泻时间、止吐时间、腹痛改善时间、退热时间、脱水纠正时间均短于对照组,两组比较差异具有统计学意义(P0.05)。治疗后,两组免疫球蛋白A(Ig A)、免疫球蛋白G(Ig G)、CD~(4+)/CD~(8+)水平均显著升高,同组治疗前后比较差异有统计学意义(P0.05);且治疗组这些观察指标明显高于对照组,两组比较差异具有统计学意义(P0.05)。结论健儿止泻颗粒联合蒙脱石散治疗小儿腹泻具有较好的临床疗效,可改善临床症状,调节免疫指标,安全性较好,具有一定的临床推广应用价值。     

A STATISTICAL MODEL OF TRANSMISSION OF Hib BACTERIA IN A FAMILY

The simultaneous estimation of family and community transmission rates as well as cure rates from panel data in a recurrent Hib (Haemophilus influenzae type b bacteria) infection is considered. An individual-based stationary Markov process model with constant hazards in two age groups is applied to describe recurrent asymptomatic Hib infection in a family with small children. The problem of estimation is solved in terms of the Bayesian posterior of the model parameters. The model is used to predict prevalence and incidence of Hib carriage in families as a function of the family size and age structure.