Characterization of Vibrio cholerae protease activities with peptide digest analysis.

A simple method for the analysis of microbial proteases is described that was used to characterize the proteolytic activities of various Vibrio cholerae isolates. This method utilized the unique peptides generated from the degradation of a standard protein by proteases of various specificities. These peptides were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The unique patterns of peptides seen in gels can be used to type proteases according to their relative specificities. Culture supernatants of V. cholerae isolates from a variety of environmental and human sources were analyzed for the presence of a protease previously isolated and characterized in this laboratory from V. cholerae strain CA401. Supernatants from most isolates showing dimethyl casein proteolytic activity exhibited the presence of enzymes similar to the CA401 protease in their peptide digest patterns against bovine serum albumin and in their immunological reactivities. The probable widespread presence of this virulence-associated protease in V. cholerae isolates is discussed.     

Spectrum of CLN6 mutations in variant late infantile neuronal ceroid lipofuscinosis

The neuronal ceroid lipofuscinoses (NCLs) are a group of autosomal recessive neurodegenerative diseases of childhood. CLN6, the gene mutated in variant late infantile NCL (vLINCL), was recently cloned. We report the identification of eight further mutations in CLN6 making a total of 18 reported mutations. These mutations include missense, nonsense, small deletions or insertions, and two splice-site mutations. Ten mutations affect single amino acids, all of which are conserved across vertebrate species. Minor differences in the pattern of disease symptom evolution can be identified. One patient with a more protracted disease progression was a compound heterozygote for a missense mutation and an unidentified mutation. Fifteen CLN6 mutations occur in one or two families only, and families from the same country do not all share the same mutation. Unlike NCLs caused by mutations in CLN1, CLN3, CLN5, and CLN8, there is no major founder mutation in CLN6. However, one mutation (E72X) is significantly more common in patients from Costa Rica than two other mutations present in that same population. In addition, a 1-bp insertion (c.316insC) is associated with families from Pakistan and I154del may be common in Portugal. A group of Roma Gypsy families from the Czech Republic share two disease-associated haplotypes, one of which is also present in a Pakistani family, consistent with the proposed migration of the Roma from the Indian subcontinent 1,000 years ago. All mutations are recorded in the NCL Mutation Database together with their country of origin for use in the development of rapid screening assays to confirm diagnosis and to facilitate carrier testing appropriate to a population.     

Carnitine deficiency, organic acidemias, and Reye's syndrome

Relative carnitine deficiency is important in the pathophysiology of several disorders, including Reye's syndrome and organic acidemias. In acute clinical crises, carnitine serves as a "buffer," trapping toxic acyl compounds. Mitochondrial failure develops in carnitine deficiency when there is insufficient tissue carnitine available to buffer toxic acyl-CoA metabolites. Toxic levels of acyl-CoA impair the citrate cycle, gluconeogenesis, the urea cycle, and fatty-acid oxidation. Carnitine replacement therapy is safe and induces excretion of toxic acyl groups in the urine.     

An alternate practice sale/retirement arrangement. A way out

Eventually every orthodontist will leave his practice because of illness, death, or retirement. Two widely used methods to accomplish this separation are described. They are "sale of the practice" or "integrating an associate into the practice." This "alternate arrangement" provides that the outgoing orthodontist complete his own cases. The new man gradually, but rapidly, assumes control; the senior man relinquishes control and responsibility. Immediate income is provided for the incoming orthodontist, continuing income for the outgoing orthodontist. The psychologic needs of both individuals are thoroughly addressed.     

Between a hygiene rock and a hygienic hard place: Avoiding SARS-CoV-2 while needing environmental exposures for immunity

Suboptimal understanding of concepts related to hygiene by the general public, clinicians and researchers is a persistent problem in health and medicine. Although hygiene is necessary to slow or prevent deadly pandemics of infectious disease such as coronavirus disease 2019 (COVID-19), hygiene can have unwanted effects. In particular, some aspects of hygiene cause a loss of biodiversity from the human body, characterized by the almost complete removal of intestinal worms (helminths) and protists. Research spanning more than half a century documents that this loss of biodiversity results in an increased propensity for autoimmune disease, allergic disorders, probably neuropsychiatric problems and adverse reactions to infectious agents. The differences in immune function between communities with and communities without helminths have become so pronounced that the reduced lethality of severe acute respiratory syndrome coronavirus 2 in low-income countries compared to high-income countries was predicted early in the COVID-19 pandemic. This prediction, based on the maladaptive immune responses observed in many cases of COVID-19 in high-income countries, is now supported by emerging data from low-income countries. Herein, hygiene is subdivided into components involving personal choice versus components instituted by community wide systems such as sewage treatment facilities and water treatment plants. The different effects of personal hygiene and systems hygiene are described, and appropriate measures to alleviate the adverse effects of hygiene without losing the benefits of hygiene are discussed. Finally, text boxes are provided to function as stand-alone, public-domain handouts with the goal of informing the public about hygiene and suggesting solutions for biomedical researchers and policy makers.Lay Summary: Hygiene related to sewer systems and other technology can have adverse effects on immune function, and is distinct from personal hygiene practices such as hand washing and social distancing. Dealing with the drawbacks of hygiene must be undertaken without compromising the protection from infectious disease imposed by hygiene.     

Treatment of infants with ureteropelvic junction obstruction: findings from the PURSUIT network

International Urology and Nephrology - Studies based on administrative databases show that infant pyeloplasty is associated with minority race/ethnicity but lack clinical data that may influence...     

Persistent sex disparity in liver transplantation rates

BackgroundStudies have demonstrated that there are sex disparities in the rate of liver transplantation. However, little is known statistically about whether this disparity is caused by liver compartment size, Model for End-Stage Liver Disease adjustments, or regional differences.MethodsWe use retrospective data from the United Network for Organ Sharing Standard Treatment Analysis and Research data files for liver transplantation from 1995 through 2012. The final sample consists of 150,149 patients. These data contain information on all individuals who registered for the liver transplant waiting list as well as updated outcome data. Linear probability and logistic regression models were both used.ResultsWomen were 4.8 percentage points less likely to receive a transplant. Adjustment for race, weight, body mass index, region, education, and other characteristics attenuated the sex difference by roughly 19% (from 4.8 to 3.9 percentage points). The disparity was consistent across the 11 United Network for Organ Sharing allocation regions. Comparing the heaviest women to the lightest men, the disparity flipped. Pairwise comparisons between men and women of various sizes suggest that disparities in favor of men increase with the ratio of male-to-female size.ConclusionOur results document persistent sex disparity in liver transplantation, only 19% of which is explained by size differentials between men and women. Differences in rates of transplantation are increasing in the ratio of male-to-female height and weight, suggesting that some of the disparity is explained by differences in liver compartment size.     

喉癌中EGFR基因扩增、表达及临床意义

目的研究喉癌中表皮生长因子受体(EGFR)基因的扩增、表达,探讨其在喉癌发生、发展中的作用及临床意义。方法采用差异PCR(differential PCR)方法检测40例喉鳞状细胞癌及配对癌旁正常组织中EGFR基因的扩增(即基因拷贝数增加);应用RT-PCR方法检测EGFR mRNA水平;应用SPSS13.0软件对数据进行统计学分析。结果喉癌组织中有13例(占32.5%)EGFR基因拷贝数增加,癌旁对照组中则未检测到(χ2=15.537,P<0.005);喉癌组织中EGFR mRNA平均积分光密度为872.356±62.340,癌旁对照组为346.425±57.380(t=5.959,P<0.001);喉癌组织分化程度越低,病理分期越晚,EGFR基因扩增和mRNA表达水平越高(P<0.05)。结论喉癌中EGFR基因在DNA水平上的扩增是EGFR mRNA过表达的原因之一,EGFR的扩增和过表达在喉癌的发生、进展中发挥一定作用。