云南甘草中新三萜成分的研究

自云南甘草(Clycyrrhiza yunnanensis)根中分离出10个化合物,经化学方法和光谱解析,鉴定9个为五环三萜类化合物:3β,21α,24-三羟基-齐墩果-12-烯-29-羧酸(Ⅰ)、3β,21α-二羟基-齐墩果-12-烯(Ⅱ)、3β,21α,24-三羟基-齐墩果-12-烯(Ⅲ)、桦木酸(Ⅳ)、23-羟基桦木酸(Ⅴ)、齐墩果酸(Ⅵ)、3β-羟基-16-氧-11,13(18)-二烯-3O-羧酸(Ⅶ)、24-羟基甘草内酯(Ⅷ)和21α-乙酰氧基木栓烷-3-酮(Ⅸ);另一个为β-胡萝卜甙(Ⅹ)。其中Ⅰ和Ⅱ为新化合物,分别命名为云南甘草皂甙元B1和B2。其余7个是已知物,但Ⅴ和Ⅸ首次得自甘草属植物,Ⅳ,Ⅵ和Ⅷ首次自云南甘草中分离得到。     

Familial Cushing's disease with severe weight loss occurring in late childhood

We describe a rare case of familial Cushing's disease occurring in a 7-year-old boy, and 19 years of follow up. Our patient first presented soon after his maternal aunt had been treated for Cushing's disease. The clinical presentation was made complicated by the development of an intercurrent eating disorder resembling anorexia nervosa. This resulted in marked weight loss, and even though serum and urinary cortisol levels were elevated, many of the clinical stigmata of Cushing's disease were absent. Eating disorders are relatively uncommon in boys, and in this case there was an organic cause for the abnormal behaviour. This case shows, furthermore, that even the obesity of Cushing's disease can be overcome by the combination of diet and exercise.     

The efficacy of excimer laser (308 nm) for vitiligo at different body sites

BACKGROUND: The treatment with XeCl-excimer laser generated 308-nm UVB radiation has shown promising results in patients with vitiligo. OBJECTIVE: In this controlled, prospective trial we studied the primary efficacy (start and grade of repigmentation) and patient's satisfaction of XeCl-excimer laser for treatment of vitiligo patches at different body sites and re-evaluated the achieved repigmentation 12 months after the end of therapy. METHODS: Twenty-five patients with generalized or localized vitiligo with a total of 85 lesions at different body sites were enrolled in this study. Vitiligo patches were treated with 308-nm XeCl-excimer laser 3 times a week for 6 to 10 weeks. The overall repigmentation grade of each treated lesion was evaluated once a week on a 5 point scale rating from 0 (no repigmentation), 1 (1-5%), 2 (6-25%), 3 (26-50%), 4 (51-75%), to 5 (76-100%). RESULTS: Twenty-four patients completed the study. Within 6 to 10 weeks of treatment 67% of the patients (16/24) developed follicular repigmentation of at least one of their vitiligo lesions. Lesion repigmentation started after a mean of 13 treatments in lesions located on the face, trunk, arm, and/or leg (high-responder location), and after a mean of 22 treatments in lesions located on the elbow, wrist, dorsum of the hand, knee, and/or dorsum of the foot (low-responder location). Untreated control lesions and lesions located on the fingers did not achieve any repigmentation. After 10 weeks of treatment repigmentation of more than 75% was found in 25% (7/28) of lesions of the high-responder location group versus 2% (1/43) of lesions of the low-responder location group. In most cases, laser-induced repigmentation was persistent, as determined 12 months after the end of treatment. CONCLUSIONS: 308-nm excimer laser is an effective modality for the treatment of vitiligo. However, similar to other non-surgical treatment modalities, the therapeutic effect is mainly dependent on the location of vitiligo lesions.     

Homozygous deletion mutations in the plectin gene (PLEC1) in patients with epidermolysis bullosa simplex associated with late-onset muscular dystrophy

In a distinct autosomal recessive variant of epidermolysis bullosa, EB- MD, life-long skin blistering is associated with late-onset muscular dystrophy of unknown etiology. Electron microscopy of these patients' skin suggests that tissue separation occurs intracellularly at the level of the hemidesmosomal inner plaque, which contains plectin, a high molecular weight cytoskeletal associated protein, also expressed in the sarcolemma of the muscle. In this study, we report two patients with EB-MD, each with a homozygous deletion mutation in the plectin gene, PLEC1. In the first case, the proband and her similarly affected sister had a homozygous 9 bp deletion mutation, designated as 2719de19, which resulted in elimination of three amino acids, QEA, in a sequence of 23 amino acids entirely conserved between the mouse and human sequences. The proband in the second family demonstrated a single nucleotide deletion at position 5866, designated as 5866delC, which resulted in frameshift and a premature termination codon for translation 16 bp downstream from the site of deletion. The absence of plectin in the hemidesmosomes, as reflected by negative immunofluorescence with an anti-plectin antibody (HD-1), associated with fragility of basal keratinocytes, implicates plectin as critical for binding of intermediate keratin filament network to hemidesmosomal complexes. The function of plectin as a putative attachment protein also in the muscle would explain the clinical phenotype consisting of cutaneous fragility and muscular dystrophy in EB-MD.      

False-negative results by polymerase chain reaction due to contamination by glove powder

The polymerase chain reaction (PCR) technique has become an important, widely employed method for the detection and quantitation of the nucleic acid sequences used in the diagnosis and monitoring of genetic and infectious diseases. Much attention has been directed at the problem of false-positive PCR results, which are generally attributed to low-level laboratory contamination of amplified sequences ("carryover"). In contrast, few investigators have commented on the somewhat less frequent, but equally problematic, false-negative PCR results. Investigation of the source of sporadic false-negative PCR reactions found that glove powder, inadvertently introduced into tubes when gloves are changed in an effort to reduce false-positive results, can nonspecifically inhibit each of the major steps in the PCR detection process. Methodologic precautions are recommended to minimize this problem.     

CLINICAL AUDIT: IS DAY-CASE ADENOTONSILLECTOMY SAFE?

SUMMARY The trend towards day-case procedures is growing, as a consequence not only of improved medical care but the increasing importance of economic considerations in today's healthcare environment. In the largest worldwide study to date to assess the safety of day-case adenotonsillectomy, we reviewed the records of 4386 patients at the otolaryngology department of the Bradford Royal Infirmary. We found a reactionary haemorrhage rate of 0.57%. All patients who underwent surgery in the morning session had presented with haemorrhage and returned to the operating theatre before the end of the afternoon session. We discuss the implications of these findings, and consider that with careful monitoring day-case tonsillectomy and/or adenoidectomy may safely be introduced.     

Platelet glycoprotein (Gp) IX associates with GpIb alpha in the platelet membrane GpIb complex

The platelet membrane glycoprotein (Gp) Ib complex consists of four polypeptides: the disulfide-linked GpIb alpha and GpIb beta subunits; GpIX, tightly, but noncovalently associated with GpIb alpha-beta; and the more weakly associated GpV. It is not certain whether the association of GpIX to Gplb alpha-beta is via GpIB alpha, GpIb beta, or both subunits, although recently published evidence implicates an interaction with GpIb beta. We have investigated the interaction of GpIX with GpIb alpha-beta using polyclonal rabbit antibodies to GpIb alpha and GpIb beta raised by immunization with purified glycocalicin and with synthetic peptide sequences from GpIb beta, respectively, as well as monoclonal antibodies directed against GpIX (FMC-25) and against GpIb alpha (AP-1). We performed two types of experiments, using either purified GpIb complex or platelets. (1) When wells were coated with nonreduced GpIb complex, the binding of FMC-25 was inhibited 73% by GpIb alpha antibody, but only 30% by the GpIb beta antibody; when wells were coated with reduced complex, FMC-25 binding was inhibited by the same two antibodies by 86% and 13%, respectively. When wells were coated with polyclonal GpIb alpha or GpIb beta antibodies and then incubated with reduced GpIb complex, only wells coated with GpIb alpha antibodies captured GpIX reactivity. When wells were coated with FMC-25 and then incubated with nonreduced GpIb complex, both the GpIb alpha and GpIb beta polyclonal antibodies reacted strongly; in contrast, only GpIb alpha reactivity was retained when wells coated with FMC-25 were incubated with reduced GpIb complex. In the reciprocal experiment, AP-1- coated wells incubated with either nonreduced or reduced GpIb complex bound radiolabeled FMC-25. (2) The ability of polyclonal GpIb alpha and GpIb beta antibodies to inhibit binding of FMC-25 to platelets was studied by ELISA and by flow cytometry. In both systems, FMC-25 binding was inhibited by the GpIb alpha antibody, but not significantly by the GpIb beta antibody. We conclude that GpIX is strongly associated with GpIb alpha in the purified platelet GpIb complex and in the platelet membrane.