Locus heterogeneity for Waardenburg syndrome is predictive of clinical subtypes

Waardenburg syndrome (WS) is a dominantly inherited and clinically variable syndrome of deafness, pigmentary changes, and distinctive facial features. Clinically, WS type I (WS1) is differentiated from WS type II (WS2) by the high frequency of dystopia canthorum in the family. In some families, WS is caused by mutations in the PAX3 gene on chromosome 2q. We have typed microsatellite markers within and flanking PAX3 in 41 WS1 kindreds and 26 WS2 kindreds in order to estimate the proportion of families with probable mutations in PAX3 and to study the relationship between phenotypic and genotypic heterogeneity. Evaluation of heterogeneity in location scores obtained by multilocus analysis indicated that WS is linked to PAX3 in 60% of all WS families and in 100% of WS1 families. None of the WS2 families were linked. In those families in which equivocal lod scores (between -2 and +1) were found, PAX3 mutations have been identified in 5 of the 15 WS1 families but in none of the 4 WS2 families. Although preliminary studies do not suggest any association between the phenotype and the molecular pathology in 20 families with known PAX3 mutations and in four patients with chromosomal abnormalities in the vicinity of PAX3, the presence of dystopia in multiple family members is a reliable indicator for identifying families likely to have a defect in PAX3.     

Choledocholithiasis: percutaneous treatment

The percutaneous approach to retained biliary duct stones is most reasonable in the presence of a T-tube because of the low morbidity and mortality as well as its low cost. We report our experience with 373 patients, emphasizing the technique and the solutions to some frequent problems.     

Effects of green tea and black tea on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone bioactivation, DNA methylation, and lung tumorigenesis in A/J mice

Previous studies in our laboratory showed that decaffeinated green tea and black tea extracts inhibited 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced tumorigenicity in A/J female mice. In order to understand the mechanism of the inhibitory action, we examined the effects of decaffeinated green tea, black tea, and tea components on the metabolic activation of NNK in vitro and in vivo in this animal model. When added to incubation mixtures containing mouse lung microsomes, decaffeinated green tea and black tea extracts and their fractions, at concentrations up to 0.4 mg/ml, inhibited NNK oxidation and NNK-induced DNA methylation. Among the tea components examined, (-)-epigallocatechin-3-gallate was the most potent inhibitor with 50% inhibitory concentrations of about 0.12 mM for both NNK oxidation and DNA methylation. At these concentrations, (-)-epigallocatechin-3-gallate inhibited the catalytic activities of several P450 enzymes and was more potent against P450 1A and 2B1 than 2E1. When decaffeinated green or black tea extracts were given to female A/J mice as the sole source of drinking fluid before an i.p. injection of NNK (100 mg/kg body weight), a statistically significant inhibition of lung DNA methylation, however, was not observed, although a significant reduction in lung tumor multiplicity was observed. The results suggest that, although inhibition of the metabolic activation of NNK and the subsequent DNA alkylation by tea extracts can be demonstrated in vitro, this mechanism may not be important for the inhibitory action of tea against lung tumorigenesis.     

Function of hexameric RNA in packaging of bacteriophage phi 29 DNA in vitro

A methodology based on high-performance gel exclusion chromatography (HPLC-GEC) has been developed to perform permeability studies of vesicles. Encapsulation of two marker isothiocyanate fluorescein (FITC) dextrans of 4400 and 40,500 molecular mass was used as a model system. Combination of two TSK-PW columns, one efficient in vesicle sizing (G6000 PW), the other in that of dextrans (G4000 PW), was required to achieve complete particle separation and to remove entirely the unentrapped dextran after encapsulation into vesicles. Coupling fluorescence and light scattering detection allowed to control the efficiency of the separation, to quantify the vesicle leakage and to follow both the integrity of the vesicles and changes in their size. This methodology can be applied to other fields such as encapsulation of water soluble compounds and drug delivery systems.     

A phase I study of adenovirus-mediated wild-type p53 gene transfer in patients with advanced non-small cell lung cancer

Mutations of the tumor suppressor gene p53 are the most common genetic alterations observed in human cancer. Loss of wild-type p53 function impairs cell cycle arrest as well as repair mechanisms involved in response to DNA damage. Further, apoptotic pathways as induced by radio- or chemotherapy are also abrogated. Gene transfer of wild-type p53 was shown to reverse these deficiencies and to induce apoptosis in vitro and in preclinical in vivo tumor models. A phase I dose escalation study of a single intratumoral injection of a replication-defective adenoviral expression vector encoding wild-type p53 was carried out in patients with incurable non-small cell lung cancer. All patients enrolled had p53 protein overexpression as a marker of mutant p53 status in pretreatment tumor biopsies. Treatment was performed either by bronchoscopic intratumoral injection or by CT-guided percutaneous intratumoral injection of the vector solution. Fifteen patients were enrolled in two centers, and were treated at four different dose levels ranging from 10(7) to 10(10) PFU (7.5 x 10(9) to 7.5 x 10(12) particles). No clinically significant toxicity was observed. Successful transfer of wild-type p53 was achieved only with higher vector doses. Vector-specific wild-type p53 RNA sequences could be demonstrated in posttreatment biopsies of six patients. Transient local disease control by a single intratumoral injection of the vector solution was observed in four of those six successfully transduced patients. There was no evidence of clinical responses at untreated tumor sites. Wild-type p53 gene therapy by intratumoral injection of a replication-defective adenoviral expression vector is safe, feasible, and biologically effective in patients with advanced non-small cell lung cancer.     

Delay from start of symptoms to hospital admission among 5.978 patients with acute myocardial infarction

The aim of this study was to analyse the influence of patient characteristics on delay between onset of symptoms and hospital admission (patient delay) in acute myocardial infarction. A group of 6676 consecutive patients with AMI, admitted alive to 27 Danish hospitals from 1990 to 1992, were studied. Due to missing information on delay or in hospital acute myocardial infarction 698 patients were excluded. Mean patient delay was 9.1 hours, median delay 3.25 hours (5 to 95 percentiles: 0.67-40 hours). In multivariate logistic regression analysis patient delay was independently associated with male gender, increased age, diabetes mellitus, left ventricular systolic function (wall motion index), onset from midnight to 6 a.m., onset on a weekday, history of angina pectoris, chest pain as initial symptom, ventricular fibrillation or-tachycardia, Killip class > or = 3, presence of ST-elevation and ST-depressions. In conclusion, patient delay continues to be disappointingly long. This also applies to patients with a high risk of acute myocardial infarction (notably history of diabetes mellitus and angina pectoris).     

Significance of epidermoid formations in the middle ear in fetuses and children

OBJECTIVE: To determine the incidence, size, and location of epidermoid formations (EFs), which have been suggested to be precursors of congenital cholesteatomas, in temporal bones from fetuses and children. DESIGN: We examined temporal bones from 226 fetuses and children up to the age of 10 years for the incidence, size, and location of EFs. RESULTS: Twenty-five EFs were identified in middle ears of 3 fetuses, 7 neonates, 9 infants, and 2 children aged 2 and 3 years. There was a male-female preponderance of 5:4. Generally, we saw EFs between the anterosuperior edge of the eardrum and the anterior limb of the tympanic ring, but 4 were below the level of the handle of the malleus. Their widths ranged from 25 to 300 microns. Keratinization was not observed in any EF. Contrary to previous reports, we found EFs not only in ears of fetuses, but also in ears of infants and children. CONCLUSION: Although EFs may persist in some ears, possibly developing into congenital cholesteatomas, our findings do not provide direct support for this concept.