Getting back to basics: commentary on McSweeney, Murphy, and Kowal (2005)

The review article "Regulation of Drug Taking by Sensitization and Habituation" by F. K. McSweeney, E. S. Murphy, and B. P. Kowal introduces 2 basic principles of behavior, sensitization and habituation, into a comprehensive model for studying drug intake and drug addiction. A key assumption of the model is that the reinforcing effectiveness of drugs sensitize and/or habituate; however, issues with the measurement of reinforcing effectiveness should be carefully considered. In addition, a multidisciplinary approach might broaden this model and increase its power. Other approaches include, but are not limited to, pharmacokinetic-pharmacodynamic modeling and in vivo measures of brain activity.     

Close mapping of the focal non-epidermolytic palmoplantar keratoderma (PPK) locus associated with oesophageal cancer (TOC)

Focal non-epidermolytic palmoplantar keratoderma (PPK or palmoplantar ectodermal dysplasia type III) is associated with oesophageal cancer in three families: two large pedigrees located in Liverpool, UK and in the midwestern American states and one smaller family from Germany. In these families, the PPK is inherited as autosomal dominant and has a late onset, usually manifesting between 7 and 8 years of age. The disease is characterised by thickening of the pressure areas of the soles, but is not restricted to the feet and also presents with oral leukokeratosis and follicular hyperkeratosis. The disease locus [previously termed the "tylosis oesophageal cancer gene' (TOC) locus] has been mapped to 17q23-qter by linkage analysis. This region is located telomeric to the keratin 16 gene, in which mutations have been identified in focal PPK families who show no increased cancer risk. We describe the close mapping of this locus to the interval between AFMb054zf9 and D17S1603 using haplotype analysis of additional Genethon markers in the region and show that although the American family is unlikely to be related to either of the other two, the UK and German pedigrees may share a common descent. This work provides a basis for positional cloning and candidate gene analysis in order to identify a gene that may be involved in familial oesophageal cancer.      

Spectrum of mutations in the fumarylacetoacetate hydrolase gene of tyrosinemia type 1 patients in northwestern Europe and Mediterranean countries

Hereditary tyrosinemia type 1 (HT1) is a rare metabolic disease caused by a deficient activity of the enzyme fumarylacetoacetase (FAH). To investigate the molecular heterogeneity of tyrosinemia, the geographic distribution and the genotype–phenotype relationship, we have analyzed the FAH genotype of 25 HT1 patients. Mutation screening was performed by PCR amplification of exons 1-14 of the FAH gene, followed by SSCP analysis and direct sequencing of the amplified exons. Fourteen different mutations were found, of which seven were novel, viz. Three missense mutations (G158D, P261L, F405H), a deletion of three nucleotides causing a deletion of serine (DEL366S) and three splice site mutations: IVS2+1(g-t), IVS6-1(g-c), IVS8-1(g-c). The splice site mutations IVS6-1(g-t) and IVS12+5(g-a) were frequently found in countries around the Mediterranean and northerwestern Europe, respectively. No clear correlation between the genotype and the three major HT1 subtypes could be established. Hum Mutat 12:19–26, 1998. © 1998 Wiley-Liss, Inc.     

消旋棉酚拆分的研究——Ⅱ.手性α-甲基苯乙胺及α-甲基苄胺为拆分剂

本文报道用中压柱色谱快速分离S或R-α-甲基苯乙胺及S或R-α-甲基苄胺缩(±)-棉酚的方法,可得光学活性胺缩(+)或(一)-棉酚非对映体,经水解分别得到(+)或(一)-棉酚。并证明胺缩光学活性棉酚非对映体之间有互相转化的性质,此特性可利用于棉酚对映体的转化。     

Blood pressure independent effects of nitrendipine on cardiac structure in patients after renal transplantation

Left ventricular hypertrophy is well established as a blood pressure independent cardiovascular risk factor in patients on renal replacement therapy. The effects of antihypertensive treatment on myocardial structure and function in renal transplant recipients have been so far only rarely investigated. In a double-blind, placebo-controlled study patients were randomized to the calcium channel blocker nitrendipine or placebo if the transplanted kidney had developed a stable phase. Normotensive patients received nitrendipine 2 x 5 mg daily or placebo, hypertensive patients received 2 x 10 mg up to 2 x 20 mg nitrendipine daily or placebo. To achieve adequate blood pressure control, all patients with still elevated blood pressure on study medication received antihypertensive drugs other than calcium channels blockers. Ambulatory blood pressure recording and 2D-guided M-mode echocardiography were performed at baseline and upon completion of the study. In addition, laboratory workup (including serum creatinine and lipids) was done, and serum aldosterone, plasma renin activity, plasma angiotensin II and blood glucose levels were measured in all patients at baseline and after at least 12 months of therapy. Ambulatory blood pressure was almost identical between both groups at study baseline and follow-up. In renal transplant patients on nitrendipine, posterior wall thickness (-0.10 +/- 1.77 mm) and septal wall thickness (-0.83 +/- 2.23 mm) did not change significantly from baseline. In contrast, posterior wall thickness (0.71 +/- 0.92 mm, P < 0.01) and septal wall thickness (0.97 +/- 2.20 mm, P < 0.05) increased in patients on placebo, which differed from the observed changes on nitrendipine (ANOVA: P = 0.093 and P = 0.048, respectively). Relative wall thickness, a parameter for concentric left ventricular hypertrophy, became numerically smaller on nitrendipine therapy from 0.46 +/- 0.07 to 0.44 +/- 0.09 (-0.02 +/- 0.09, NS) but increased from 0.42 +/- 0.08 to 0.48 +/- 0.08 in the placebo arm (+0.04 +/- 0.08, P < 0.02), which was also significant between the two groups (ANOVA: P = 0.036). Endocrine parameters, lipids and blood glucose were not different between the two groups. We conclude from these data that the calcium channel blocker nitrendipine exerted beneficial effects on cardiac structure in patients after renal transplantation independent of blood pressure.      

Anatomy of the perirenal area

The authors comment on the use of the renal bridging septa as a sign in distinguishing compartmentalization of the perinephric space. They also address new concepts regarding the spread of pancreatic effusions and provide information on other anatomic features of the perirenal area.     

Mitogenic properties of a bispecific single-chain Fv-Ig fusion generated from CD2-specific mAb to distinct epitopes [In Process Citation]

The combination of anti-CD2 mAb 9.6 and 9-1, specific for distinct epitopes, induces proliferation of resting human T cells. The mitogenic activity of this mAb mixture depends upon accessory cells and the 9-1 mAb Fc domain. To further study the functional properties of these mAb, their variable regions were cloned and expressed as monospecific single- chain Fv (scFv) proteins fused to the human IgG1 Fc domain (scFvIg). A novel bispecific scFvIg was constructed by cloning the two monospecific scFv binding sites in tandem, with the 9.6 scFv placed N-terminal to the 9-1 scFvIg. Monospecific scFvIg binding to CD2 was comparable to that of the corresponding parental mAb, while the bispecific scFvIg exhibited binding activity similar to that of the 9-1 scFvIg. The combination of 9.6 scFvIg and 9-1 mAb was mitogenic, whereas mixtures including the 9-1 scFvIg were non-stimulatory, confirming the unique properties of the 9-1 IgG3 Fc. Without the IgG3 tail, the bispecific 9.6/9-1 scFvIg was directly mitogenic and was a more potent mitogen than the mAb mixture, but was accessory cell dependent. Unlike the combination of mAb, the bispecific reagent did not directly mobilize calcium in T cells. In comparison to the mAb mixture, bispecific 9.6/9- 1 scFvIg-mediated stimulation of a mixed lymphocyte reaction was significantly more resistant to inhibition of the CD28 co-stimulatory pathway by the inhibitor CTLA-4-Ig. These results show that expression of the 9.6 and 9-1 binding sites together on a bispecific scFvIg increased the mitogenic properties of the mAb and altered the degree of accessory cell signals required for T cell activation.