Lichen sclerosus in 68 patients with squamous cell carcinoma of the penis: frequent atypias and correlation with special carcinoma variants suggests a precancerous role

Lichen sclerosus, an unusual chronic mucocutaneous condition of the penis, has been found in association with invasive penile cancer, and squamous cell carcinoma has been reported in patients with longstanding lichen sclerosus. The aim of this study was to determine the anatomic distribution and prevalence of lichen sclerosus in patients with squamous cell carcinoma of the penis and to search for a correlation with special types of carcinomas. Clinical and pathologic data from 207 penectomy and circumcision specimens with squamous cell carcinomas and giant condylomas were evaluated, and 68 patients with lichen sclerosus were identified. Mean age was 61 years. The preferential anatomic site of lichen sclerosus was the foreskin, but other sites (glans and coronal sulcus) including urethra were also involved. Grossly, the lesions showed white-gray smooth or irregular patches and plaques adjacent to invasive cancers. Microscopically, the lesion was stromal-epithelial with atrophic and hyperplastic epithelium and edematous or densely eosinophilic hyalinized lamina propria. A variable band of lymphocytic infiltration beneath the sclerosis was noted. Lichen sclerosus were preferentially associated with non-human papillomavirus variants of squamous cell carcinoma. When lichen sclerosus was associated with malignancy, it often showed, in addition to the hyperplastic epithelium, a low-grade squamous intraepithelial lesion. These findings suggest that lichen sclerosus may represent preneoplastic condition for at least some types of penile cancers, in particular those not related to human papillomavirus.     

Single multiplex polymerase chain reaction to detect diverse loci associated with diarrheagenic Escherichia coli

We developed and tested a single multiplex polymerase chain reaction (PCR) that detects enterotoxigenic, enteropathogenic, enteroinvasive, and Shiga toxin-producing Escherichia coli. This PCR is specific, sensitive, and rapid in detecting target isolates in stool and food. Because of its simplicity, economy, and efficiency, this protocol warrants further evaluation in large, prospective studies of polymicrobial substances.     

Total parenteral feeding in infants using peripheral veins

Fifteen infants with life-threatening gastrointestinal anomalies received total parenteral feeding for periods ranging from 10 to 54 days; their ages ranged from one day to 5 months. The solutions were administered through peripheral veins. All patients gained weight during the period of observation and no cases of septicaemia were encountered.     

受体介导的凝血酶对成骨细胞增殖及分化的作用

目的 通过凝血酶对成骨细胞的增殖及分化作用的研究来探讨受体介导的凝血酶的功能.方法 原代成骨细胞分别取自于蛋白酶激活受体(protease-activated receptor,PAR)-1敲除鼠和野生对照鼠的头颅骨.并利用凝血酶,人工合成的PAR-1或PAR-4特异性激活短肽对细胞进行处理,通过对5.溴-2-脱氧尿嘧啶的嵌入及细胞碱性磷酸酶活性的测定探讨PAR-1或PAR-4激活对细胞增殖和分化的影响.结果 在野生鼠成骨细胞,凝血酶及PAR-1激活肽均能促进的细胞增殖和降低碱性磷酸酶的活性,但PAR-4激活肽却无这些作用.然而在PAR-1 敲除鼠的成骨细胞无论是凝血酶还是PAR-4激活肽均不能改变细胞的增殖及碱性磷酸酶的活性.结论 本研究结果 表明凝血酶促进成骨细胞增殖及抑制其分化是通过PAR-1介导的.其他凝血酶受体并不具有此作用.     

Excitability and gap junction–mediated mechanisms in nucleus accumbens regulate self-stimulation reward in rats

The nucleus accumbens (Acb) is a part of the striatum which integrates information from cortical and limbic brain structures, and mediates behaviors which reinforce reward. Previous work has suggested that neuronal synchrony mediated by gap junctions in Acb-related areas is involved in brain pleasure and reward. In order to gain insight into functional aspects of the neural information processing at the level of the striatum, we explored the possible role of Acb gap junctional communication and chemical synapses on reward self-stimulation in rats using positive reinforcement. Rats were trained to press a lever that caused an electrical current to be delivered into the hypothalamus, which is recognized to cause pleasure/reward. Intracerebral infusion into the Acb of the gap junctional blocker carbenoxolone (CBX) decreased the lever-pressing activity. Considering that the net effect of blocking gap junctions is a reduced synchronized output of the cellular activities, which at some level represents a decrease in excitability, two other inhibitors of neuronal excitability, carbamazepine (CBZ) and tetrodotoxin (TTX), were infused into the Acb and their effects on lever-pressing assessed. All manipulations that diminished excitability in the Acb resulted in reduced lever-pressing activity. CBX and TTX were also infused into motor cortex mediating forelimb lever-pressing with no effect. However, a manipulation that has the net effect of increasing excitation, the infusion of the opiate antagonist naloxone, also decreased significantly brain self-stimulation. We conclude that reward behaviors depend to a great extent on both excitability and gap junction–mediated mechanisms in Acb neuronal networks. Thus, the Acb provides a site for the study of pleasure/reward, addiction and conscious experience.     

Utilization of screening mammography: comparison of different physician specialties

Data obtained on 426 consecutive patients referred to a breast center by 122 physicians, including family practitioners, general surgeons, and other specialists, showed that the obstetricians-gynecologists referred the greatest average number of patients per physician, with more than 50% of these referrals for screening mammography. Internists referred fewer patients by nearly a factor of ten, with only one-third of these patients referred for screening mammography. Internists may be the weakest link in the utilization of screening mammography.     

Mutagenicity studies on fenitrothion in Drosophila

To extend the data on the possible genotoxic effects of organophosphoruspesticides, the insecticide fenitrothion was tested for theinduction of gene and chromosome mutations in male germ cellsof Drosophila melanogaster. Sex-linked recessive lethals, totaland partial sex-chromosome losses and non-disjunction were studiedfollowing different exposure methods: adult feeding, injectionand larval feeding. In the tests assaying for recessive lethals,we used a MRA strain resistant to malathion. Our results indicatethat fenitrothion, at concentrations ranging from 50 to 150p.p.m., is unable to induce any kind of genetic damage in D.melanogaster, at least under the conditions of testing.