SPC—A—1肺癌细胞的荧光研究

在３６８ｎｍ光激发下,ＳＰＣ－Ａ－１肺癌细胞在４１０ｎｍ处有一条荧光带,带宽７０ｎｍ。在同样条件激发下,下沉人肺细胞在４６５ｎｍ处有一条荧光带,带宽６５ｎｍ。两者有明显的差别。这说明两者的发光中心结构不同。通过肺细胞对牛血清荧光猝灭的研究,表明两者之间存在能量传递。     

Answering a century old riddle： brachydactyly type A1

In 1903, Farabee analyzed the heredity of the human digital malformation, brachydactyly, the first recorded disorder of the autosomal dominant Mendelian trait. In 1951, Bell classified this type of brachydactyly as type A 1 (BDA 1). Over 100 cases from different ethnic groups have so far been reported. However, the real breakthrough in identifying the cause of BDA 1 has only taken place in the last few years with the progress of the mapping and identification of one of the genes responsible for this disorder, thus providing an answer for a century old riddle. In this article, we attempt to review the current state of knowledge on the genetic features of BDA 1 with its century-old history and signalling pathway of IHH, and also discuss genotype-phenotype correlation not only of BDA 1, but also of all types of brachydactyly.     

Molecular Modeling of PepT1 — Towards a Structure

The proton-coupled uptake of di- and tri-peptides is the major route of dietary nitrogen absorption in the intestine and of reabsorption of filtered protein in the kidney. In addition, the transporters involved, PepT1 (SLC15a1) and PepT2 (SLC15a2), are responsible for the uptake and tissue distribution of a wide range of pharmaceutically important compounds, including β-lactam antibiotics, angiotensin-converting enzyme inhibitors, anti-cancer and anti-viral drugs. PepT1 and PepT2 are large proteins, with over 700 amino acids, and to date there are no reports of their crystal structures, nor of those of related proteins from lower organisms. Therefore there is virtually no information about the protein 3-D structure, although computer-based approaches have been used to both model the transmembrane domain (TM) layout and to produce a substrate binding template. These models will be discussed, and a new one proposed from homology modeling rabbit PepT1 to the recently crystallized bacterial transporters LacY and GlpT. Understanding the mechanism by which PepT1 and PepT2 bind and transport their substrates is of great interest to researchers, both in academia and in the pharmaceutical industries.     

Self-replicating micelles — A chemical version of a minimal autopoietic system

Reverse micelles hosting the internal production of the surfactant are proposed as experimentally feasible models of simple (or minimal) autopoietic systems. We describe the conditions under which these may be formed and their possible biological implications. The micellar systems considered here turn out also to exhibit a capacity for self-reproduction through fragmentation under plausible conditions, thus constituting also a minimal experimental model for prebiotic self-reproduction.     

PHENMETRAZINE HYDROCHLORIDE—A Clinical Evaluation of a New Anoretic Agent

Phenmetrazine hydrochloride appeared to be a safe anoretic agent and was effective in weight control in 80 per cent of a series of 49 obese patients.Tolerance to the drug did not develop in periods up to 18 weeks of continued treatment.Phenmetrazine was most effective in patients under 45 years of age in this series.Side effects were minimal and easily controlled. No allergic or toxic effects were noted.     

Improving the Clinical Diagnosis of Influenza—a Comparative Analysis of New Influenza A (H1N1) Cases

Background

The presentation of new influenza A(H1N1) is broad and evolving as it continues to affect different geographic locations and populations. To improve the accuracy of predicting influenza infection in an outpatient setting, we undertook a comparative analysis of H1N1(2009), seasonal influenza, and persons with acute respiratory illness (ARI) in an outpatient setting.

Methodology/Principal Findings

Comparative analyses of one hundred non-matched cases each of PCR confirmed H1N1(2009), seasonal influenza, and ARI cases. Multivariate analysis was performed to look for predictors of influenza infection. Receiver operating characteristic curves were constructed for various combinations of clinical and laboratory case definitions. The initial clinical and laboratory features of H1N1(2009) and seasonal influenza were similar. Among ARI cases, fever, cough, headache, rhinorrhea, the absence of leukocytosis, and a normal chest radiograph positively predict for both PCR-confirmed H1N1-2009 and seasonal influenza infection. The sensitivity and specificity of current WHO and CDC influenza-like illness (ILI) criteria were modest in predicting influenza infection. However, the combination of WHO ILI criteria with the absence of leukocytosis greatly improved the accuracy of diagnosing H1N1(2009) and seasonal influenza (positive LR of 7.8 (95%CI 3.5–17.5) and 9.2 (95%CI 4.1–20.3) respectively).

Conclusions/Significance

The clinical presentation of H1N1(2009) infection is largely indistinguishable from that of seasonal influenza. Among patients with acute respiratory illness, features such as a temperature greater than 38°C, rhinorrhea, a normal chest radiograph, and the absence of leukocytosis or significant gastrointestinal symptoms were all positively associated with H1N1(2009) and seasonal influenza infection. An enhanced ILI criteria that combines both a symptom complex with the absence of leukocytosis on testing can improve the accuracy of predicting both seasonal and H1N1-2009 influenza infection.     

A/H1N1流感—世界关注的焦点

2009年4月,A/H1N1流感在墨西哥和美国暴发。随后,疫情迅速蔓延到美洲、欧洲、亚洲多个国家。A/H1N1流感病毒是一种以前在人或动物身上从未观测到的新病毒。遗传进化和抗原特性分析表明该病毒和猪流感病毒密切相关,与人类的季节性流感病毒有明显区别。但是流行病学信息表明A/H1N1流感病毒只攻击人类,并在人与人之间传播,尚未发现动物向人类传播的情况。本文从A/H1N1流感病毒的生物学特性、临床特征、公共卫生意义等方面全面阐述了A/H1N1流感的最新研究进展,为正确认识和科学防控A/H1N1流感提供参考。     

Immune surveillance and neoplasia—1 a minimal mathematical model

A deterministic predator-prey model is presented for describing the dynamics of a solid tumor in the presence of a specifically reactive lymphocyte population which is stimulated by, and antagonistic to, the tumor. The qualitative behavior of the solutions is developed and briefly compared to the results of transplantation experiments. Although the model is primitive, it leads to predictions that are in general agreement with observation and intuitive expectations. In particular, it is found that: (1) very low levels of transplanted tumor will not survive in the recipient. (2) At somewhat higher levels, tumor growth will be uncontrolled in the syngeneic recipient. However, immune intervention if early enough, can lead to control and elimination of the tumor. (3) At still higher levels of transplanted tumor, no amount of immune intervention will be effective in controlling the tumor. (4) If the recipients immune system is suppressed prior to transplantation, or is debilitated for any reason, the chance that the tumor will grow increases. (5) If the recipients immune system is stimulated prior to transplantation, the chance of tumor survival decreases. (6) The survival of the tumor is much more sensitive to changes in tumor parameters (for example, antigenicity) than in lymphocyte parameters. In addition it makes the unintuitive prediction that (7) There areisolated instances under which anincrease in the number of lymphocytes canincrease the chance of tumor survival.     

Diabetic Ketoacidosis—A Review of Cases at a University Medical Center

Twenty-five cases of diabetic ketoacidosis were studied retrospectively with respect to clinical characteristics and results of therapy. In this series (as with all 88 patients admitted in the last five years with a diagnosis of diabetic ketoacidosis) there were no deaths. Infection was found to be the most common precipitating event, documented by physical findings and cultures in one-third of these cases.In about two-thirds of the cases, electrocardiograms which were read as abnormal on admission reverted to normal after therapy.In all patients serum potassium levels decreased from admission values; one patient became symptomatically hypokalemic.Low serum potassium levels on admission and early vigorous bicarbonate therapy are emphasized as major predisposing factors of symptomatic hypokalemia. None of the patients had overt hyperosmolar coma, lactic acidosis or cerebral edema during therapy.     

THE SCOPE AND RESPONSIBILITY OF MEDICINE—A Forum with a Purpose

To engender discussion of what the scope and responsibility of medicine ought to be in today''s society, California Medicine printed in its June issue six essays by authors known to have keen if various interest in the subject.In presenting the essays the editors expressed hope that they would be the beginning of a forum from which a definition of our profession''s responsibilities may be distilled. Readers were invited to take part in a continuation of the forum in succeeding issues. Following are three contributions selected from those received to date. Others will be published in the months ahead.If you have thoughts on the subject, just address them to the editors of California Medicine, 693 Sutter Street, San Francisco, California 94102. Keep your essays short, please.     

THE SCOPE AND RESPONSIBILITY OF MEDICINE—A Forum with a Purpose

To engender discussion of what the scope and responsibility of medicine ought to be in today''s society, California Medicine printed in its June issue six essays by authors known to have keen if various interest in the subject.In presenting the essays the editors expressed hope that they would be the beginning of a forum from which a definition of our profession''s responsibilities may be distilled. Readers were invited to take part in a continuation of the forum in succeeding issues. Following are four contributions selected from those received to date. Others will be published in the months ahead.If you have thoughts on the subject, just address them to the editors of California Medicine, 693 Sutter Street, San Francisco, California 94102. Keep your essays short, please.     

Accelerated nitrogen inputs — A new problem or a new perspective?

This paper considers whether new problems are arising in forest ecosystems due to increased levels of inorganic N deposition from the atmosphere, or whether there are no new problems, just a change of perception. Deposition of N has indeed increased. Wet deposition rates are reasonably quantified, but the rates of dry deposition to forests are largely unknown. Current transport and deposition models are probably under-estimating N deposition to forests. Consideration of possible effects of enhanced N deposition reveals with varying degrees of certainty that there may be effects due to high N in biomass, high uptake rates, leaching of nitrate and consequent acidification, and an overall increase in N availability. Forest ecosystems are not well-enough understood to set a critical load for N deposition, but enough is known to define some upper limits.     

THE SCOPE AND RESPONSIBILITY OF MEDICINE—A Forum with a Purpose

To engender discussion of what the scope and responsibility of medicine ought to be in today''s society, California Medicine printed in its June issue six essays by authors known to have keen if various interest in the subject.In presenting the essays the editors expressed hope that they would be the beginning of a forum from which a definition of our profession''s responsibilities may be distilled. Readers were invited to take part in a continuation of the forum in succeeding issues. Following are three contributions selected from those received to date. Others will be published in the months ahead.If you have thoughts on the subject, just address them to the editors of California Medicine, 693 Sutter Street, San Francisco, California 94102. Keep your essays short, please.     

A molecular insight into papaya leaf curl—a severe viral disease

Papaya leaf curl disease (PaLCuD) caused by papaya leaf curl virus (PaLCuV) not only affects yield but also plant growth and fruit size and quality of papaya and is one of the most damaging and economically important disease. Management of PaLCuV is a challenging task due to diversity of viral strains, the alternate hosts, and the genomic complexities of the viruses. Several management strategies currently used by plant virologists to broadly control or eliminate the viruses have been discussed. In the absence of such strategies in the case of PaLCuV at present, the few available options to control the disease include methods like removal of affected plants from the field, insecticide treatments against the insect vector (Bemisia tabaci), and gene-specific control through transgenic constructs. This review presents the current understanding of papaya leaf curl disease, genomic components including satellite DNA associated with the virus, wide host and vector range, and management of the disease and suggests possible generic resistance strategies.     

THE SCOPE AND RESPONSIBILITY OF MEDICINE—A Forum with a Purpose

To engender discussion of what the scope and responsibility of medicine ought to be in today''s society, California Medicine printed in its June issue six essays by authors known to have keen if various interest in the subject.In presenting the essays the editors expressed hope that they would be the beginning of a forum from which a definition of our profession''s responsibilities may be distilled. Readers were invited to take part in a continuation of the forum in succeeding issues. Following are three contributions selected from those received to date. Others will be published in the months ahead.If you have thoughts on the subject, just address them to the editors of California Medicine, 693 Sutter Street, San Francisco, California 94102. Keep your essays short, please.