MRI-derived ventricular volume curves for the assessment of left ventricular function

To assess the utility of double oblique, ECG-gated 1H magnetic resonance (MR) derived volume curves for assessing LV function, cardiac short axis images were acquired with a fast field echo technique. We applied this methodology to assess left ventricular function in three groups: normals, patients with left ventricular hypertrophy, and dilated cardiomyopathy. Six slices with 16-20 phases per RR interval were analyzed, representing the initial 75-80% of the cardiac cycle. For each slice, the endocardial border of the left ventricular (LV) chamber was manually traced. Using Simpson's rule, the total LV volume at a given phase was determined considering the traced area, thickness and position in three-dimensional space of each of the six constituent slices. The calculated volumes were plotted against time and the stroke volume, ejection fraction and cardiac output were determined. The volume vs time plots for the systolic and diastolic portions of the curve were individually fit to third degree polynomials using a least squares approximation. From the fit curves, the following data were extracted: the mean slope (dV/dT) during filling and emptying, and the time to 1/4, 1/3 and 1/2 filling and emptying. These parameters are valuable indices of the functional status of the myocardium; thus, accurate and useful estimates of LV function can be obtained using MRI derived volume curves in normal and abnormal states.     

A mass spectrometric solution to the address problem of combinatorial libraries

The molecular weights of femtomole quantities of small peptides attached to polystyrene beads have been determined with imaging time-of-flight secondary ion mass spectrometry. The analysis is made possible by the selective clipping of the bond linking the peptide to a bead with trifluoroacetic acid vapor before the secondary ion mass spectrometry assay. The approach can be applied to large numbers of 30- to 60-micrometer polystyrene beads for the direct characterization of massive combinatorial libraries.     

Role of vacuolar adenosine triphosphatase in the regulation of cytosolic pH in hepatocytes

The almost exclusive media focus on political violence in South Africa has deflected attention from the high levels of interpersonal violence in areas of socioeconomic deprivation. In order to explore the tension between an at-risk community's perspective and the current reality of violence against women, imaginary constructions of their own violent death produced by 45 African female interview respondents were examined in conjunction with forensic data relating to 73 African female homicide victims in Cape Town, South Africa. The prototypical account of an imagined homicide involved a female commuter being approached by a group of men, taunted and assaulted, raped and then killed. The majority of actual homicides occurred at or in the vicinity of the residence of the victim, with the attacker being known to the deceased. Whilst only 1 of the imagined homicide narratives depicted the use of alcohol by the victim, over half the actual homicides had elevated postmortem blood alcohol levels. These and other disjunctions and convergencies between lay and forensic constructions of violent female death should be viewed in the wider context of enmeshment in social circumstance, and could provide some understanding of how at-risk communities perceive violence against women, thereby providing a foundation for appropriate prevention programmes.     

Bcl-2 protein expression during murine development

Bcl-2 functions as a death repressor molecule in an evolutionarily conserved cell death pathway. To further explore the role of Bcl-2 in development, we assessed its pattern of expression during murine embryogenesis. Immunohistochemical analysis demonstrates that Bcl-2 is widely expressed early in mouse fetal development in tissues derived from all three germ layers and that this expression becomes restricted with maturation. Within epithelium, the E12.5 lung bud demonstrates a proximal to distal gradient of Bcl-2 expression which is enhanced by E18.5. Bcl-2 is expressed throughout the intestinal epithelium through E14.5, but by E18.5 only cells in the crypts and lower villi express Bcl-2. In the mesoderm-derived kidney, Bcl-2 is expressed in both the ureteric bud and metanephric cap tissue at E12.5. Tubular structures also express Bcl-2, although overall levels drop as the kidney matures. Retinal neuroepithelial cells uniformly express Bcl-2 until cells begin to differentiate and then display the topographic distribution maintained into adulthood. The developing limb provides a clear example where Bcl-2 is restricted to zones of cell survival; Bcl-2 is expressed in the digital zones but not in the interdigital zones of cell death. The wide distribution of Bcl-2 in the developing mouse suggests that many immature cells require a death repressor molecule or that Bcl-2 may have roles beyond regulating developmental cell death.     

Domains of the Childhood Autism Rating Scale: relevance for diagnosis and treatment

The Childhood Autism Rating Scale (CARS) was factor analyzed. Three factors emerged: Social Impairment (SI), Negative Emotionality (NE), and Distorted Sensory Response (DSR). Unit-weight factor scales showed moderate-to-good internal consistency. Cross-sectional analyses demonstrated that autistic (AUT) subjects were distinguished from subjects with pervasive developmental disorders (PDD) and nonpervasive developmental disorders (NPDD) by higher scores on SI. An SI cutoff score of 26 classified individuals as autistic vs. nonautistic with 78% accuracy. Longitudinal analyses showed that DSR was stable over 6 months of treatment, with little indication of symptom reduction. SI decreased over time across the diagnostic groups, but still showed significant continuity over the period. NE was most malleable and apparently sensitive to the effects of treatment.     

Differential requirements of sodium for coupling of cannabinoid receptors to adenylyl cyclase in rat brain membranes

Sodium is generally required for optimal inhibition of adenylyl cyclase by Gi/o-coupled receptors. Cannabinoids bind to specific receptors that act like other members of the Gi/o-coupled receptor superfamily to inhibit adenylyl cyclase. However, assay of cannabinoid inhibition of adenylyl cyclase in rat cerebellar membranes revealed that concentrations of NaCl ranging from 0 to 150 mM had no effect on agonist inhibition. This lack of effect of sodium was not unique to cannabinoid receptors, because the same results were observed using baclofen as an agonist for GABAB receptors in cerebellar membranes. The lack of sodium dependence was region-specific, because assay of cannabinoid and opioid inhibition of adenylyl cyclase in striatum revealed an expected sodium dependence, with 50 mM NaCl providing maximal inhibition levels by both sets of agonists. This difference in sodium requirements between these two regions was maintained at the G protein level, because agonist-stimulated low Km GTPase activity was maximal at 50 mM NaCl in striatal membranes, but was maximal in the absence of NaCl in cerebellar membranes. Assay of [3H]WIN 55212-2 binding in cerebellar membranes revealed that the binding of this labeled agonist was sensitive to sodium and guanine nucleotides like other Gi/o-coupled receptors, because both NaCl and the nonhydrolyzable GTP analogue Gpp(NH)p significantly inhibited binding. These results suggest that differences in receptor-G protein coupling exist for cannabinoid receptors between these two brain regions.     

Primary small-intestinal lymphomas in Taiwan: immunoproliferative small-intestinal disease and nonimmunoproliferative small-intestinal disease

PURPOSE: The clinicopathologic findings in 45 adult Chinese patients with primary small-intestinal lymphoma (PSIL) are described and compared with those in Western countries and in underdeveloped nations. The efficacy of combination chemotherapy is also assessed. PATIENTS AND METHOD: Six patients had immunoproliferative small-intestinal disease (IPSID) indicated by the presence of alpha-heavy chain protein (alpha-CP) in body fluids or tumor tissues. Thirty-nine patients had non-IPSID, including one with postrenal transplant lymphoma. Thirty-three non-IPSID patients received a minimum of four cycles of combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP). RESULTS: All IPSID patients presented with the clinical and laboratory features of severe intestinal malabsorption, and all had diffuse lymphoplasmacytic infiltration in the mucosa of the small bowel. Lymphomas were localized mainly in the jejunum and mesenteric nodes. The histologic subtypes were diffuse large cell in two, immunoblastic in three, and diffuse mixed in one. All patients responded poorly to chemotherapy, with a median survival duration of 10.5 months. The common presenting symptoms of the 39 non-IPSID patients included abdominal pain (90%), weight loss (31%), abdominal mass (26%), obstruction (26%), and perforation (23%). Diffuse large-cell and immunoblastic lymphomas constituted 82% of cases. Four patients had stage IE, 19 stage II 1E, and 16 stage 112E disease according to the Musshoff's criteria; 22 had bulky tumors and 19 had multiple tumors. The tumors were completely resected in 14 patients. Of 33 patients treated with combination chemotherapy, 73% achieved a complete remission. With a median follow-up duration of 90 months, there have been four relapses, with only one at the primary tumor site. The overall 5-year survival and disease-free survival rates for non-IPSID patients who were treated with chemotherapy were 59% and 54%, respectively. CONCLUSION: Intensive chemotherapy produces long-term disease-free survival in locally advanced non-IPSID PSIL.     

Fluctuations of excitability in the monosynaptic reflex pathway to lumbar motoneurons in the cat

1. It is well known that the amplitude of successive monosynaptic reflexes (MSR), elicited by afferent stimuli of constant strength, fluctuate from trial to trial. Previous evidence suggests that such excitability fluctuations within the motor pool can be introduced either pre- and/or postsynaptically. Using unanesthetized decerebrate or decerebrate/spinal cats, we attempted to evaluate the relative importance of pre- and postsynaptic mechanisms to MSR variability and the potential contribution of changes in the identities of responding motoneurons to such variability. 2. Comparisons between the MSR amplitude, measured in a severed ventral root, and the probability of firing of up to three individual motoneurons in fine filaments teased from the same root, confirmed that both correlated and uncorrelated fluctuations of motoneuron excitability are involved in MSR variability. Linear regression analysis from concurrent intracellular recordings from homonymous motoneurons showed that the MSR fluctuations were correlated with the variations in membrane potential baseline, as well as with the fluctuations in the monosynaptic excitatory postsynaptic potential peak amplitude. In all 11 cases tested, the former correlation was stronger than the latter. 3. Stimulation of the caudal cutaneous sural nerve (CCS) was used to alter the postsynaptic potential background on which triceps surae (GS) MSRs were generated. The interval chosen between CCS conditioning and the GS stimulation excluded the involvement of presynaptic inhibition. When conditioned by preceding CCS stimulation, GS population MSRs generally (8/9 cases tested) increased in amplitude without much change in their overall variance. However, the individual motoneurons that contributed to the population responses did show changes in both relative excitability and in the uncorrelated component of their response variance. About half of the concurrently recorded motoneurons (6/13) showed a decrease in relative excitability after CCS conditioning, 5/13 showed an increase, and 2/13 were unchanged. Comparison of unit and population responses indicated that the identities of the motoneurons that responded at any given level of population response were quite different with and without CCS conditioning. 4. High-frequency stimulation of Ia fibers was used to alter the state of presynaptic Group Ia-afferents that produced population MSRs. Post tetanic potentiation following high-frequency stimulation did not greatly alter the variance of population MSRs or ratio of correlated and uncorrelated fluctuations in MSR responses among individual motoneurons within the responding population. However, intratetanic depression and posttetanic potentiation of population MSRs were accompanied by marked shifts in individual motoneuron excitability relative to the population response, again indicated that changes in the identities of responding motoneurons contributes to population response fluctuations.(ABSTRACT TRUNCATED AT 400 WORDS)     

Inferior vena caval thrombosis associated with acute pancreatitis: an unusual vascular complication--its presentation and management

Vascular thrombosis and systemic hypercoagulable states are known complications of acute pancreatitis. They are thought to be secondary to the release of proteolytic enzymes of the pancreas. Inferior vena caval thrombosis is an extremely rare complication of chronic pancreatitis and has, to the authors' knowledge, never been reported in acute pancreatitis. The clinical presentation and radiographic findings are reviewed to illustrate the disease spectrum. Early treatment with intravenous heparin appears to be an effective therapy. Familiarity with this complication will aid physicians in its early diagnosis. However, a high degree of suspicion for this complication is necessary to make a diagnosis.     

Laparoscopic removal of gonads containing on occult seminoma in a woman with complete androgen resistance

Although nomograms to convert readings of resistance (R) and reactance (Xc) into estimates of body composition have begun to emerge for children as well as adults, there has been reluctance to use bioelectrical impedance analysis (BIA) in very young children due to the irritability of children, measurement instability, positioning of electrodes, and, of course, reproducibility of measurements. The precision of completely independent measurements of BIA indices was evaluated by two observers by comparing a series of 40 measurements of R and Xc and 36 measurements for weight in four malnourished children on 10 different days during the course of their nutritional recuperation. For weight, the CV (coefficient of variation) was 3.5% for observer A and 3.8% for observer B. There were no differences in the means across observers with respect to weight, R, and Xc. The results obtained in this study illustrate that properly trained observers following the same standards can produce equivalent data for BIA and weight measurements even in sick children.