Spatio-temporal genetic variability in the schistosome intermediate host Biomphalaria pfeifferi

Genetic variation among temporally and spatially defined populations of the schistosome intermediate host, Biomphalaria pfeifferi, was analysed using RAPD markers. Snails were collected from each of eight sites that were 1-20 km apart, on four occasions, over a 2-year period. High levels of genetic variability were found within populations, between populations and between collections. Spatial differentiation and intrapopulation similarity were highest during periods of drought and were lowest following heavy rainfall. Temporal variability, consistent with founder effects, genetic drift and/or differential parasite pressure, was of similar or greater magnitude to that of the spatial variability. The results not only demonstrate that spatio-temporal sampling is necessary to understand the population genetics of short-lived species in variable habitats, but also provide empirical data to support current theoretical models of host-parasite co-evolution.     

Recovery of slow skeletal muscle after injury in the senescent rat

We studied the contractile, histological and biochemical characteristics of regenerating slow (soleus) muscles of aged rats and the effect of IGF-1 treatment on these parameters. Regenerating soleus muscles were studied 21 days after myotoxic injury. In senescent rats (24 month old), the in situ isometric maximal tetanic force (P0), resistance to fatigue (T20%P0) and shortening speed with an afterload of 20%P0 (SS20%P0) were lower (p<0.05) in regenerating soleus muscles as compared to uninjured controlateral soleus muscles. Moreover, the expression of type 1 myosin heavy chain (MHC-1) was decreased by injury in the soleus muscles of senescent rats (p<0.05). Furthermore, a single injection of IGF-1 (3 microg) into the soleus of senescent rats only slightly increased the level of sarcoplasmic reticulum type 2 Ca(2+)-ATPase in regenerating soleus muscles (p<0.01). Contrary to senescent animals, regenerating soleus of adult rats (10 month old) did not present significantly lower P0 and MHC-1 expression than uninjured controlateral muscles (p>0.05). In conclusion, the regeneration of a slow muscle is more uncompleted 3 weeks after myotoxic injury in senescent rats than in adult rats. It cannot be made more effective by a single injection of IGF-1 into the senescent slow muscle.     

Macroscopic Quality Control Improves the Reliability of Blue Dye–Only Sentinel Lymph Node Biopsy in Breast Cancer

Background: One of the problems of sentinel lymph node (SLN) biopsy is the risk of false negatives. At the Institut Curie, to reduce the false-negative rate, we have developed a histological quality control of the SLN performed by blue dye alone, which consists of verification of the SLN blue stain by the pathologist.Methods: A total of 324 patients underwent an SLN biopsy procedure with patent blue dye only followed by an immediate axillary dissection. Initially, SLNs were checked to ensure that they were blue by macroscopic examination. Finally, a search for immunohistochemistry micrometastasis was performed.Results: In 277 (85.5%) of 324 patients, an SLN was identified by the surgeon. After standard examination, the false-negative rate was 11.1% (10 of 90). After macroscopic checking of the 197 negative SLNs, 167 of the 197 were confirmed blue, and there were 5 false negatives, which brought the false-negative rate down to 5.6% (5 of 90). Sixty SLNs out of the 167 confirmed blue SLNs were then proved to be immunohistochemically micrometastatic, and there were 3 false negatives, giving a final false-negative rate of 2.2% (2 of 90; P = .002).Conclusions: In this series, the procedure of pathologic analysis of the SLN has resulted in a significant reduction of the false-negative rate.     

The use of postoperative subcutaneous closed suction drainage after posterior spinal fusion in adolescents with idiopathic scoliosis

BACKGROUND The purpose of this prospective study was to assess the impact of closed suction drainage on transfusion requirements, frequency of dressing changes, and wound healing following posterior spinal fusion in adolescents with idiopathic scoliosis. METHODS Thirty patients were randomly assigned to one of two groups: drain or no drain. Although the group with drains received more postoperative autologous blood transfusions than the group with no drains (0.88 vs 0.5 unit), the difference was not statistically significant (P = 0.2131). In the undrained group, 58% of the patients had moderate to completely saturated dressings on the second postoperative day compared with only 17% of patients in the drained group. Three of 12 patients in the undrained group demonstrated a wound complication rate compared with no complications in the drained group. CONCLUSION In conclusion, subcutaneous closed suction drainage can improve immediate postoperative wound care without significantly increasing blood loss and transfusion requirements for patients undergoing surgery for idiopathic scoliosis.     

Neuromagnetic imaging of cortical oscillations accompanying tactile stimulation

We applied a new method of imaging frequency-specific changes in brain activity in humans during a finger brushing task in order to measure changes in cortical rhythms during tactile stimulation. Neuromagnetic recordings were conducted in five subjects using a whole-head MEG system during tactile stimulation of the right index finger, with or without visual feedback, and while viewing another individual's index finger being stimulated. Volumetric images of changes in source power relative to pre-stimulus baseline levels were computed with 2 mm resolution over the entire brain using a minimum-variance beamforming algorithm (synthetic aperture magnetometry). Onset of tactile stimulation produced a brief (200-300 ms) suppression of mu band (8-15 Hz) and beta band (15-30 Hz) cortical activity in the primary somatosensory and primary motor cortex, respectively, followed by a bilateral increase in beta band activity ('beta rebound') in motor cortex. This pattern of suppression/rebound was absent when subjects observed finger brushing or brushing motions without receiving stimulation. In contrast, these conditions resulted in bilateral increases in beta band activity in sensorimotor areas and decreased power in the alpha (8-12 Hz) band in primary visual areas. These results show that spatially filtered MEG provides a useful method for directly imaging the temporal sequence of changes in cortical rhythms during transient tactile stimulation, and provide evidence that observation of tactile input to another individual's hand, or object motion itself, can influence independent rhythmic activity in visual and sensorimotor cortex.     

One-month stability of depression among elderly home-care patients.

OBJECTIVE: Studies in primary care settings have shown that depression is often chronic and associated with negative outcomes among patients with medical illness. The stability of depression among home care recipients has not been investigated. The authors examined the 1-month stability of major depression in a representative sample of elderly adults shortly after their admission to home care. METHODS: A group of 539 subjects over age 65, newly admitted to home care for skilled nursing, were interviewed with the Structured Clinical Interview for DSM-IV (SCID-IV). Depression severity, medical comorbidity, pain, functional status, cognitive status, and recent life events were also assessed. Of 84 subjects who met criteria for major depression (MDD) at baseline, 74 were available for 1-month follow-up interview. RESULTS: At 1-month follow-up, 31 subjects (42%) continued to meet MDD criteria; 20 (27%) achieved partial remission; and 23 (31%) were in full remission. Fewer instrumental activity limitations at baseline, experiencing "a great deal" of pain, and absence of a recent stressful life event were associated with full remission at 1-month follow-up. CONCLUSION: Nearly one-half of newly admitted elderly home care patients who meet criteria for MDD continue to meet full criteria 1 month later. Functional and psychosocial factors affect the short-term course.