Epidermal injury stimulates prenylation in the epidermis of hairless mice

Isoprenylation is the covalent attachment of isoprenyl groups, intermediates of the cholesterol biosynthesis pathway, to carboxy terminal cysteine residues of proteins. Numerous proteins are isoprenylated including small GTP binding proteins, trimeric G proteins, and nuclear lamins, and these prenylated proteins regulate a variety of cell functions, including cell growth, cytokinesis, and differentiation. Here, we quantitated protein prenylation and determined which proteins are prenylated in the epidermis of hairless mice by radiolabeling with ³ H-mevalonolactone following acute or chronic epidermal injury. In normal epidermis, four major radiolabeled bands, with molecular weights of 17–26, 48, 54, and 68 kDa, were observed. The levels of each of these bands increased by 24–63% 16 h following acute epidermal injury induced by topical acetone treatment or tape stripping, returning to normal by 24 h. On 2D gel electrophoresis, there were no major differences between the patterns of labeling following barrier disruption. Subacute epidermal injury induced by either acetone or tape stripping twice a day for 7 days and chronic injury induced by feeding an essential fatty acid-deficient (EFAD) diet, also resulted in a significant increase in protein prenylation. As with acute injury, SDS-PAGE and 2D gel electrophoresis did not reveal marked differences in the pattern of protein prenylation. These results demonstrate that the prenylation of proteins in the epidermis is stimulated by injury, suggesting that one or more of these prenylated species may be important in epidermal proliferation or differentiation. Received: 29 May 1996     

Ultrastructure of the endolymphatic sac in the mongolian gerbil

We describe our findings in an ultrastructural study of the endolymphatic sac of the mongolian gerbil. In conjunction with its specific renal physiology, enabling this animal to withstand long-term water deprivation, we have used our findings to hypothesize the existence of a local monitoring system within the endolymphatic space. The presence of elastic tissue in the subepithelial space of the endolymphatic sac could explain the mechanism through which this structure equilibrates endolymphatic pressure changes. Finally, we propose that a secretion of water-retaining macromolecules may act through osmotic forces to modulate inner ear fluid.     

Conservatively Treated Breast Cancer: Outcome by Histologic Subtype

Abstract: Between 1970 and 1990, 1,008 patients with early-stage breast cancer were treated by conservative surgery without axillary dissection followed by radiation therapy to the intact breast in the Department of Therapeutic Radiology at Yale-New Haven Hospital. The patient population, broken down by histologic subtype, was as follows: 761 patients presented with infiltrating ductal carcinoma, 70 patients with pure intraductal, 38 intraductal with focal invasion, 54 infiltrating lobular, 21 tubular, 17 medullary, 16 mucinous, and 29 with other various histologic subtypes. Patients were followed on a regular basis by the referring physicians and radiation oncologists. Diagnostic studies for distant metastases were performed as clinically indicated. Annual mammography was a routine component of the follow-up program. As of 3/96, with a median follow-up of 10.5 years, 83 patients developed an ipsilateral breast tumor recurrence, and 109 patients developed distant metastases resulting in an overall 10-year breast recurrence-free rate of 84%, and a 10-year distant metastasis-free rate of 78%. There were significant differences in clinical stage, pathological nodal involvement, and administration of systemic therapy between various histologic subtypes. As expected, those patients with histologies of low metastatic potential (such as intraductal, tubular, and mucinous) had significantly superior distant recurrence-free survival rates. With respect to breast relapse rates, there were no statistically significant differences in the 5- and 10-year breast recurrence-free rates between any of the histologic subtypes. Patients with intraductal carcinoma with or without focal invasion had similar breast relapse rates as those with other histologic subtypes. Patients with lobular carcinoma in situ as a histologic component also had a similar overall breast relapse-free recurrence rate. In conclusion, long-term follow-up of conservatively treated breast cancer patients demonstrates no significant differences in ipsilateral breast tumor recurrence rates between various histologic subtypes. There are no histologies which had a statistically significantly higher breast-relapse rate than infiltrating ductal carcinomas and therefore no primary histologic subtype represents a relative contraindication to breast conservation therapy.     

Perceived value of nursing certification--summary of a national survey.

The American Board of Nursing Specialties (ABNS) conducted a survey to determine the value professional nurses place on nursing certification as well as barriers to certification. This article presents an overview of the survey results in general and specifically the views of nephrology nurse participants.     

Subjective work noise: A major risk factor in myocardial infarction

Summary The relationship between subjective work noise exposure and the risk of myocardial infarction (MI) was assessed in a population based casecontrol study. 395 MI patients (31–65 years) were compared to 2148 controls from a random population sample with the same age/sex distribution. The relative risk (RR) for MI—adjusted for control variables (smoking, age, social status, etc.)—was found to increase significantly and steadily with noise category. Subjective work noise exposure was the second greatest risk factor for MI after smoking. Possible bias due to overreporting of subjective noise exposure is discussed. Interdisciplinary studies on the relationship between cardiovascular diseases and workrelated stressors including subjective and objective noise assessment are needed to quantify the risk of MI due to work noise.

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Zusammenfassung In einer bevölkerungsbezogenen Fall-Kontroll-Studie wurde der Zusammenhang zwischen der subjektiven Arbeitslärmbelastung und dem Herzinfarktrisiko untersucht. 395 Herzinfarktpatienten im Alter von 31 bis 65 Jahren wurden mit 2148 Kontrollpersonen aus einer Zufallsstichprobe mit gleicher Alters- und Geschlechtsverteilung verglichen. Das relative Risiko für Herzinfarkt—adjustiert bezüglich mehrerer Einflussvariablen wie Rauchen, Alter, Sozialstatus usw.—stieg signifikant und monoton mit der Arbeitslärmbelastung an. Die subjektive Arbeitslärmbelastung erwies sich als der zweitwichtigste Risikofaktor für Herzinfarkt nach dem Rauchen. Mögliche Fehler wie z.B. Überbewertung der subjektiven Lärmbelastung werden diskutiert. Interdisziplinäre Studien zum Zusammenhang zwischen kardiovaskulären Erkrankungen und arbeitsplatzbezogenen Stressoren mit Erfassung der subjektiven und der objektiven Lärmbelastung sind notwendig, um das Herzinfarktrisiko durch Arbeitslärm zu quantifizieren.

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Résumé Le rapport entre la perception subjective de bruit gênant et le risque d'infarctus du myocarde (IM) fait l'objet d'une étude comparative portant sur 395 malades (IM) âgés de 31 à 65 ans et 2148 cas témoins sortis d'un sondage aléatoire parmi la population générale tout en assurant la même distribution d'âge et de sexe. II s'avère que—après la rectification exigée par les variables telles que consommation de tabac, âge, couche sociale, etc.—le risque relatif (RR) de IM augmente de manière significative et constante avec le gêne causé par le bruit au lieu de travail. Pour le IM, la perception subjective du bruit vécu au lieu de travail est le deuxième facteur de risque, son importance n'étant dépassée que par le tabagisme. Les auteurs discutent l'incidence possible d'une notification exagérée de bruit gênant. Afin de calculer le risque d' IM attributable au bruit perçu au lieu de travail, des études interdisciplinaires devraient être réalisées pour examiner les liens entre les maladies cardiovasculaires et les stresseurs liés au travail, y compris l'évaluation subjective et objective du bruit.