Epithelial cell proliferation in the rat urinary system induced by parenteral injection of lead salts.

In Wistar rats a single intravascular injection of lead nitrate causes substantial cellular proliferation in the proximal tubules of the kidneys and in the epithelium of the renal pelvis, ureters and urinary bladder. The tritiated thymidine labelling index (LI) reaches a peak 18 to 24 h after injection and the mitotic index (MI) increases to a comparable extent 6 to 10 h later. The proliferation is most prominent in the bladder and proximal tubules and is virtually complete at 48 h. After a single intraperitoneal injection the proliferative changes are confined to the ureteric and bladder epithelium. In all affected tissues the proliferation develops without preceding necrosis and appears to be a hyperplastic phenomenon. After intravascular administration the volume of urine and its total protein content are significantly increased and certain proteins were detected which were not present in the urine of saline controls.     

Lower extremity arterial occlusive disease.

The clinician must first understand the natural history of chronic lower extremity ischemia before making a decision regarding therapeutic options. Clearly, mild ischemia as evidenced by claudication does not place the patient at significant risk for limb loss. Initial conservative treatment emphasizing abstinence from tobacco products, control of underlying medical maladies, and an exercise program, along with patient reassurance, will adequately treat the majority of claudicators. When ischemia is present, patient education regarding foot care and avoidance of trauma are beneficial. Limb-threatening ischemia often requires revascularization. Adequate preoperative cardiologic evaluation and intraoperative monitoring have greatly reduced the morbidity and mortality of arterial reconstruction. Selection of the appropriate recipient vessel and bypass conduit enables limb salvage, whereas amputation would have been performed just a few years ago. Continued analysis of treatment outcomes will further define appropriate intervention in the future.     

Coronary artery bypass graft surgery in older women and men.

OBJECTIVE: To compare women and men younger than 70 years of age and 70 years or older undergoing coronary artery bypass surgery. DESIGN: Retrospective chart review, case-control series. SETTING: University medical center. PATIENTS: All women (n = 465) having first-time isolated coronary artery bypass surgery between 1983 and 1988, and 465 men matched for age and year of surgery. Predominantly white; 33% were 70 years or older. MEASURES: Medical record data: demographics, preoperative comorbidities, perioperative and postoperative complications, mortality, length of stay. RESULTS: Preoperatively, women 70 years of age or older had a higher incidence of congestive heart failure, renal disease and hypertension, and a lower incidence of smoking history compared with women less than 70 years old. Men 70 years or older had a higher incidence of congestive heart failure and renal disease, and a lower incidence of smoking history compared with men less than 70 years old. There was no difference in mortality between older and younger women, whereas the mortality rate for older men was higher than that for younger men. There were fewer differences between women younger than 70 and those 70 years or older in incidence of postoperative complications than between men of those same age groups. Among patients 70 years or older, incidence of postoperative congestive heart failure was greater in women than in men. There were no other differences between women and men younger than 70 and those 70 years or older in incidence of postoperative complications. Controlling for the influence of postoperative complications, age was related to length of stay for women and men. CONCLUSIONS: Older women were at no greater risk of mortality or the occurrence of postoperative complications compared with younger women or older men. A functional component influencing recovery and length of hospital stay needs to be considered to provide optimal nursing care after surgery.     

Effects of methylphenidate and behavior modification on the social and academic behavior of children with disruptive behavior disorders: the moderating role of callous/unemotional traits.

This study examined whether response to behavior modification with and without methylphenidate differed for children with attention-deficit/hyperactivity disorder (ADHD) and conduct problems (CP) depending on the presence of callous/unemotional (CU) traits. Participants were 37 children ages 7 to 12, including 19 with ADHD/CP-only and 18 with ADHD/CP-CU, referred to a university-based summer treatment program. Results showed that ADHD/CP-CU children had worse behavior in the behavior-therapy-only (BT-only) condition, especially on measures of CP, noncompliance, and rule violations, but these differences largely disappeared when medication was added to BT. Children with ADHD/CP-CU were also less likely to be normalized by treatment than were children with ADHD/CP-only. These findings, though tentative, suggest that children with ADHD/CP-CU may not show a sufficient positive response to BT alone and that the combination of medication and BT may be especially important for them.     

Neural substrates of semantic memory.

Semantic memory is described as the storage of knowledge, concepts, and information that is common and relatively consistent across individuals (e.g., memory of what is a cup). These memories are stored in multiple sensorimotor modalities and cognitive systems throughout the brain (e.g., how a cup is held and manipulated, the texture of a cup's surface, its shape, its function, that is related to beverages such as coffee, and so on). Our ability to engage in purposeful interactions with our environment is dependent on the ability to understand the meaning and significance of the objects and actions around us that are stored in semantic memory. Theories of the neural basis of the semantic memory of objects have produced sophisticated models that have incorporated to varying degrees the results of cognitive and neural investigations. The models are grouped into those that are (1) cognitive models, where the neural data are used to reveal dissociations in semantic memory after a brain lesion occurs; (2) models that incorporate both cognitive and neuroanatomical information; and (3) models that use cognitive, neuroanatomic, and neurophysiological data. This review highlights the advances and issues that have emerged from these models and points to future directions that provide opportunities to extend these models. The models of object memory generally describe how category and/or feature representations encode for object memory, and the semantic operations engaged in object processing. The incorporation of data derived from multiple modalities of investigation can lead to detailed neural specifications of semantic memory organization. The addition of neurophysiological data can potentially provide further elaboration of models to include semantic neural mechanisms. Future directions should incorporate available and newly developed techniques to better inform the neural underpinning of semantic memory models.