Selecting a rehabilitation program for people with stroke

This article reviews the 1997 Balanced Budget Act as it pertains to Medicare reimbursement and its consequent impact on medical rehabilitation in general and on persons with stroke in particular. Following a description of the concept and practice of "consumer choice" in health care today, the author frames "choice" in the context of outcomes management wherein the person with stroke may be provided with a report card that describes what outcomes the patient might expect following a course of rehabilitation. Today more than ever, patients are beginning to require information about provider performance that is easy to understand and allows for them to make intelligent purchasing decisions. Literature is reviewed that documents better stroke outcomes in specific types of rehabilitation settings. Finally, a variety of existing consumer tools are reviewed that assist the person with stroke in making an enlightened choice for an optimal setting for stroke rehabilitation. Unfortunately, persons with stroke may not consistently be able to exercise an educated choice because the payer may independently determine placement. An extensive consumer check list of quality indicators is provided to enable the patient's family and provider to evaluate the appropriateness of placing a person with stroke in a given setting.

Inhibition of antigen presentation by the glycine/alanine repeat domain is not conserved in simian homologues of Epstein-Barr virus nuclear antigen 1

Most humans and Old World nonhuman primates are infected for life with Epstein-Barr virus (EBV) or closely related gammaherpesviruses in the same lymphocryptovirus (LCV) subgroup. Several potential strategies for immune evasion and persistence have been proposed based on studies of EBV infection in humans, but it has been difficult to test their actual contribution experimentally. Interest has focused on the EBV nuclear antigen 1 (EBNA1) because of its essential role in the maintenance and replication of the episomal viral genome in latently infected cells and because EBNA1 endogenously expressed in these cells is protected from presentation to the major histocompatibility complex class-I restricted cytotoxic T-lymphocyte (CTL) response through the action of an internal glycine-alanine repeat (GAR). Given the high degree of biologic conservation among LCVs which infect humans and Old World primates, we hypothesized that strategies essential for viral persistence would be well conserved among viruses of this subgroup. We show that the rhesus LCV EBNA1 shares sequence homology with the EBV and baboon LCV EBNA1 and that the rhesus LCV EBNA1 is a functional homologue for EBV EBNA1-dependent plasmid maintenance and replication. Interestingly, all three LCVs possess a GAR domain, but the baboon and rhesus LCV EBNA1 GARs fail to inhibit antigen processing and presentation as determined by using three different in vitro CTL assays. These studies suggest that inhibition of antigen processing and presentation by the EBNA1 GAR may not be an essential mechanism for persistent infection by all LCV and that other mechanisms may be important for immune evasion during LCV infection.

The acute reversal sign: comparison of medical and non-accidental injury patients

OBJECTIVES

(1) To compare the intracranial computed tomography (CT) appearances of patients admitted with various causes of hypoxic ischaemic encephalopathy. Children with known documented accidental trauma were excluded. (2) To compare our results with those in the published literature.

MATERIALS AND METHODS

Seventy-three patients aged between 1 day and 15 years were admitted with clinical features of brain injury and underwent cranial CT. A retrospective review of their medical records and radiology was undertaken. Clinical and radiological data were collected.

RESULTS

On the basis of the combination of the presenting clinical history, progress, outcome, long term follow up and radiology, two groups of patients were identified. Forty-seven children had been the victims of non-accidental injury (NAI). No child in this group had any associated medical condition or any other medical cause for brain injury. All 47 children demonstrated hypoxic ischaemic encephalopathy and had CT signs of cerebral oedema and 'Reversal Sign'. Intracranial haemorrhage was a highly associated feature. Subdural blood was demonstrated in all 47, acute interhemispheric fissure subdural in 42, intracerebral blood in 16 and intraventricular blood in nine. The remaining 26 children were found to have an identifiable 'medical' cause for brain injury. Acute reversal was demonstrated in 21 of this group. Intracranial haemorrhage was uncommon, found in only five and all five had an underlying predisposition to bleeding. No patient in this group demonstrated subdural blood.

CONCLUSION

Non-accidental injury is strongly associated with the finding on CT of intracranial blood, particularly subdural haematoma and interhemispheric fissure bleeding in the presence of hypoxic ischaemic brain injury. The outlook is extremely poor whatever the underlying cause for hypoxic ischaemic brain injury.

The relation between body size and normalized small solute clearances in continuous ambulatory peritoneal dialysis

The normalized peritoneal clearances of small solutes depend on the ratio of their concentration in dialysate and plasma (D/P) and the drain volume (Dv) corrected for some measure of body size such as body water (V) or body surface area (BSA). The clearance formulas (D/P) x (Dv/V) and (D/ P) x (Dv/BSA) can be used to examine why large individuals tend to be underdialyzed. Large people have low normalized drain volumes (Dv/V, Dv/BSA). It is not known whether size affects the D/P ratios. The purpose of this study was to examine the relationship between normalized peritoneal clearances (Kt/Vurea, CCr per 1.73 m2 BSA) and four size indicators (weight, height, V, BSA) in 301 patients on continuous ambulatory peritoneal dialysis (four daily exchanges with 2-L exchange volume) who underwent 613 clearance studies. Highly significant (P < 0.001) nonlinear relationships were found between Kt/Vurea and weight (r2 = 0.371), height (r2 = 0.289), BSA (r2 = 0.436), and V (r2 = 0.527); and between CCr and weight (r2 = 0.178), height (r2 = 0.115), BSA (r2 = 0.199), and V (r2 = 0.151). There were also significant negative correlations between the normalized drain volumes (Dv/V and Dv/BSA) and all four indicators of body size. Raw (not normalized) peritoneal clearances and drain volumes correlated positively with size. However, D/P(urea) or D/P(creatinine) did not vary with any size indicator except for a weak association between D/P(creatinine) and V (r = 0.089, P = 0.028). This association was not confirmed when V was used to stratify subjects into quartiles, and group differences for D/P(creatinine were tested by one-way ANOVA. This study shows that the exclusive cause of the low normalized peritoneal clearances in large subjects on continuous ambulatory peritoneal dialysis is a low normalized drain volume. No evidence was found to indicate that body size influences the D/P ratio of small solutes. The portion of the variance in normalized clearance explained by size varies by size indicator and solute (urea versus creatinine).

An evaluation of methylated collagen as a substitute for vitreous and aqueous humor

PURPOSE

To evaluate ocular tolerance of methylated collagen gel injected intravitreally and into the anterior chamber.

METHODS

Methylated collagen (type I/III) was tested in New Zealand white rabbits. Vitreous cavity: After pars plana vitrectomy, methylated collagen gel was injected intravitreally. The eyes were examined clinically; electroretinogram recordings were made before and after surgery. Vitreous samples were taken for immunological analysis for the presence of the injected collagen. The rabbits were sacrificed 6 months after surgery; the retina was evaluated by light microscopy. Anterior chamber: In another group of rabbits, methylated collagen gel (0.2 ml, 0.1 ml, or 0.05 ml) was injected into the anterior chamber after paracentesis. The eyes were examined with a slit lamp; intraocular pressure was measured postinjection. The rabbits were sacrificed after 4 months; the corneas were evaluated histologically.

RESULTS

Vitreous cavity: The fundus view was clear for 6 months after intravitreal injection. Scotopic and photopic electroretinograms were normal in 6/7 eyes; one eye experienced a mild decrease one month postoperatively. No abnormal changes were found in the retinal histology. Anterior chamber: Some corneas were hazy and edematous around the injection site for one week. The injected collagen appeared in bundles, patches, and little pieces in the anterior chamber with precipitates on the corneal endothelium, pupillary margin, and the anterior capsule of the lens. The collagen diminished gradually, without causing permanent opacity. Histologically, the corneal endothelium in the eye which received 0.2 ml collagen showed a mild distention of the mitochondriae and vesicle formation between endothelial cells under transmission electron microscope.

CONCLUSION

Methylated collagen gel was tolerated by the eye after intravitreal injection. Localized temporary clinical and mild ultrastructural corneal changes were observed after anterior chamber injection.

Gender differences in normalized clearances in CAPD: role of body size and normalizing parameters

OBJECTIVE

To compare raw (not normalized) and normalized urea and creatinine clearances between women and men on continuous ambulatory peritoneal dialysis (CAPD). To study whether potential gender differences are due to the normalization process.

DESIGN

Retrospective analysis of clearance studies.

SETTING

Dialysis units of four academic medical centers.

PARTICIPANTS

The study included 302 subjects (135 women and 167 men) on CAPD with four daily exchanges and a 2-L exchange volume.

INTERVENTION

Measurement of urea and creatinine clearances (261 in women, 352 in men) by standard methods. Body water (the volume of distribution, V, for both urea and creatinine) was estimated by the Watson anthropometric formulas.

MAIN OUTCOME MEASURES

Comparison of raw and normalized clearances between women and men. Urea clearance was normalized by V (Kt/Vur), while creatinine clearances was normalized by both V (Kt/Vcr) and body surface area (BSA) (Ccr).

RESULTS

Mean values of weekly total (peritoneal plus renal) raw clearances were higher in men (urea clearance: women 67.1 L, men 77.4 L; Ccr: women 61.7 L, men 78.3 L). Raw renal clearances were higher in men, while raw peritoneal clearances were comparable. Mean weekly total Kt/Vur was higher in women (2.19 vs 1.94 in men), mean weekly total Kt/Vcr did not differ between the genders (women 2.01, men 1.95), while mean weekly Ccr was higher in men (73.0 vs 64.7 L/1.73 m2 in women). When clearances differed, the differences were significant at p < 0.001. Men had greater height and weight, while women had greater body mass index. On the average, V in men exceeded V in women by 31%, while BSA in men exceeded BSA in women by only 12%.

CONCLUSIONS

Normalization of clearances by V creates relatively higher clearance values in women, while normalization by BSA creates relatively higher clearance values in men. Thus the normalization process may create artificial differences in the normalized clearances between genders.

Spontaneous oesophageal perforation due to mediastinal tuberculous lymphadenitis - atypical presentation of tuberculosis

Spontaneous non-traumatic oesophageal perforation secondary to bursting of a mediastinal tuberculous abscess into the oesophagus is rare. The diagnosis is delayed, as perforation remains localised due to mediastinal lymph nodes. Patient can be effectively managed by paraoesophageal drainage of the mediastinal abscess and oesophageal diversion.

Myelolipoma: CT and pathologic features

PURPOSE

To correlate clinical and pathologic patterns of myelolipoma with the computed tomographic (CT) appearance.

MATERIALS AND METHODS

All cases of myelolipoma accessioned by the Armed Forces Institute of Pathology from 1981 through 1997 were reviewed. CT images were scored for the location and size of each myelolipoma and the presence of calcification, hemorrhage, fat, and pseudocapsule. Pathologic findings for the pattern of fat and bone marrow elements were correlated with CT findings.

RESULTS

In 74 patients, 86 myelolipomas were found, of which 72 were in an adrenal gland (eight were bilateral), and 14 extra-adrenal masses were found in 10 patients. Four clinicopathologic patterns emerged: (a) isolated adrenal myelolipoma in 37 patients (fat evident at CT, no other disorders present); (b) myelolipoma with hemorrhage in nine patients (imaging features similar to those of isolated adrenal myelolipomas but larger [mean diameter, 14.2 vs 9.9 cm; P = .01]; (c) extra-adrenal myelolipoma in 10 patients (imaging findings similar to those of adrenal myelolipomas, found most often in the retroperitoneum); and (d) myelolipomatous foci within other adrenal pathologic conditions in 18 patients (smaller, lower fat content, more heavily calcified).

CONCLUSION

Myelolipomas are adrenal or extra-adrenal masses, with hemorrhage more common in larger lesions (diameter, > 10 cm). The CT appearance of myelolipomatous foci, which can be found within other pathologic adrenal conditions, is different from that of isolated adrenal myelolipomas.

Long-term outcome in children and adults with classic focal segmental glomerulosclerosis

A retrospective study was conducted in 93 patients (55 adults and 38 children) with classical focal segmental glomerulosclerosis drawn from the Toronto Glomerulonephritis Registry. The average follow-up period was 11 years, with a cumulative experience of 1,053 patient-years. Both adults and children were similar in profile at the time of entry, except that the nephrotic syndrome was more common in children (55% of adults v 76% of children; P < 0.05). During evolution of the disease, however, the percentages became very similar with 82% of adults and 89% of children developing nephrotic-range proteinuria. At the last observation point, the outcome of patients (adults v children) was complete remission, 22% versus 42%; end-stage renal disease, 42% versus 34%; chronic renal insufficiency, 13% versus 11%; and persisting abnormality, 24% versus 13%. Although there were more children than adults in complete remission, the rate was equal in the treated adults compared with the treated children (44% v 47%). Although optimal duration of steroid therapy cannot be determined by this review, treatment beyond 6 months does not appear to be beneficial. The best guide to prognosis remains complete remission, since long-term renal survival in both age groups with this event was 100%. Those without a complete remission generally progress, although even at 10 years the survival rate is 62% in adults and 58% in children.

Erythrocyte indicators of oxidative stress in gestational diabetes

Foetuses born to mothers with gestational diabetes are at increased risk of developing respiratory distress, foetal macrosomia, foetal anomalies and platelet hyperaggregability. High blood glucose level induces oxidative stress and decreases antioxidant defences. The present study discusses the possibility of lipid peroxidation and protein oxidation in both maternal and foetal erythrocytes as an indicator of oxygen radical activity. The level of lipid peroxidation and protein oxidation in erythrocytes was estimated in 20 mothers with gestational diabetes and their newborns. The maternal age varied between 19 and 42 y and foetal age ranged between 34 and 39 weeks. The proteolytic activities in the erythrocyte lysates obtained from mothers with gestational diabetes and their newborns were significantly greater [(mean +/- SD) 24.41 +/- 9.05 and 16.70 +/- 3.36 microM of amino groups/g haemoglobin, n = 20, respectively] than those from control group (10.18 +/- 4.84 and 14.64 +/- 6.21 microM amino groups/g haemoglobin, n = 15, respectively; p < 0.05 in both cases). Similarly erythrocyte malondialdehyde levels were significantly elevated in babies born to mothers with gestational diabetes (10.11 +/- 2.21 nM/g haemoglobin) when compared to controls (6.8 +/- 3.75 nM/g haemoglobin) (p < 0.05). In the erythrocytes of mothers with gestational diabetes, malondialdehyde levels correlated significantly with glycated haemoglobin levels (p < 0.01). The results of this study indicate that the oxidative stress induced by gestational diabetes manifests as increased lipid peroxidation and protein oxidative damage in the erythrocytes of both mothers with gestational diabetes and their newborn infants.

Systematic analysis of STD control: an operational model

BACKGROUND

Sexually transmitted diseases (STDs) enhance HIV transmission, and improved management of STD in primary health care decreases HIV incidence. In resource poor countries, those responsible for planning and managing STD control programmes need to be able to analyse the STD situation in their setting and the interventions which are therefore likely to be most cost effective. However, the data required for such decision making are often not available in developing countries. This paper presents an operational model, developed as a practical tool to support planning, monitoring, and evaluation of STD intervention strategies in settings where data are unavailable or inadequate.

METHOD

The operational model is based on the approach developed for estimating the effectiveness of control measures in tuberculosis programmes. Using available data, the model takes a step by step approach. It begins with analysis of the total male and female population, the proportion of men and women aged 15-49 years, and the proportion of these who are sexually active. Subsequent steps analyse numbers with STDs, and loss of cases to the health system at each stage between infection and cure. The model was tested in Nairobi, Kenya using available demographic, epidemiological, and public health data; no original data were collected. Data for the total population of Nairobi were not available to illustrate all the steps in the model. For these steps, relevant information was taken where available from a specific study population using a large STD referral centre.

RESULTS

Despite the lack of precise data for Nairobi, the model highlighted sex imbalances in population, which has potential implications for STDs. It also showed significant disparities in terms of public health policy--for example, between the number of people infected with STDs and the number who have symptoms, and between the number with symptoms and those who seek treatment from public health facilities. It also showed differences between the numbers who attend a health facility, and those that are correctly diagnosed and treated, and, of these, the proportion that are cured.

CONCLUSION

Even where data are incomplete or not available, the model can be a useful tool for analysis. Application of the model, as the Nairobi example illustrates, provides a useful starting point in terms of determining both general and specific determinants of STDs, identifying problems, highlighting significant sex differences, and indicating where it might be appropriate to focus interventions. The model showed that, in Nairobi, only a small proportion of STD cases are removed from the reservoir of infection in the community through curative services, that cases are lost to the health services at every step, and therefore that interventions are required at every step to achieve comprehensive STD control. It highlights the need for strategies to prevent infections, to identify and treat those with and without symptoms, to motivate those who are aware of their infection to seek treatment, and to improve the effectiveness of partner notification and treatment. Finally, the model points to areas where data are inadequate and where STD control programmes need to concentrate information collection efforts.

Peritoneal urea and creatinine clearances in continuous peritoneal dialysis patients with different types of peritoneal solute transport

We studied whether anuric subjects on continuous ambulatory peritoneal dialysis (CAPD) who achieve the target Kt/V urea of 2.0 weekly will also achieve the target normalized creatinine clearance (NCCr) of 60 liter/1.73 m2 weekly, and the reasons of discrepancy between the two clearances in anuric subjects, by analyzing 476 clearance studies performed in 309 CAPD patients within 12 months of the performance of a peritoneal equilibration test (PET). On the basis of the PET, peritoneal solute transport was classified as low (37 clearance studies), low-average (199 studies), high-average (186 studies) and high (54 studies). We found that weekly values of Kt/V urea in the low transport group (LTG) was 1.74 +/- 0.51, in the low-average transport group (LATG) was 1.66 +/- 0.41, in the high-average transport group (HATG) 1.68 +/- 0.41, and in the high transport group (HTG) 1.73 +/- 0.46 (NS, variance analysis). Weekly values for NCCr, liter/1.73 m2 were: LTG, 37.8 +/- 9.0; LATG, 44.0 +/- 9.2; HATG, 49.2 +/- 10.0; HTG 56.8 +/- 13.3 (P < 0.0001). The ratios of raw (not-normalized) peritoneal creatinine clearance to peritoneal urea clearance were: LTG, 0.65 +/- 0.14; LATG, 0.76 +/- 0.09; HATG, 0.84 +/- 0.09; HTG, 0.91 +/- 0.12 (P < 0.0001). Linear regression with Kt/V urea as x and NCcr as y revealed the following results: LTG, y = 19.486 + 10.500x, r = 0.591 [if x = 2.0, y = 15.004 + confidence interval (95% CI) of y 25.3 to 55.7]; LATG, y = 15.0004 + 17.482x, r = 0.774 (if x = 2.0, y = 50.0, 95% CI of y 38.4 to 61.6); HATG, y = 15.285 + 20.162x, r = 0.829 (if x = 2.0, y = 55.6, 95% CI of y 44.4 to 66.8); HTG, y = 14.945 + 24.134x, r = 0.839 (if x = 2.0, y = 63.2, 95% CI of y 48.4 to 78.1). Peritoneal solute transport type has a major effect on peritoneal creatinine clearance, but an insignificant effect on peritoneal urea clearance. Consequently, the majority of anuric patients who achieve a weekly Kt/V urea of 2.0 will have a weekly NC cr lower than 60 liter/1.73 m2 and will require a Kt/V urea much higher than 2.0 to achieve the target NCcr of 60 liter/1.73 m2 weekly. The current targets of urea and creatinine clearance are not compatible in anuric patients on CAPD.

Fetus in fetu

Fetus in fetu occurs due to aberration of monozygotic twinning. A 16-year-old boy presented with abdominal pain and mass. Laparotomy revealed an anencephalic fetus within an encapsulated retroperitoneal mass. Pathologic examination confirmed rib formation with a primitive vertebral column with bone marrow. There was no other organogenesis.

Wandering spleen causing splenic flexure volvulus and obstruction

A 48-year-old woman presented with symptoms of distal bowel obstruction. On examination she had abdominal distension and a lump in the left lumbar and iliac regions. X-ray revealed distension of the colon with dilated small bowel. Exploration revealed an enlarged ptotic spleen whose pedicle caused obstruction of the colon. There was concomitant partial volvulus of the splenic flexure around the splenic pedicle. The splenic vein was thrombosed. Splenectomy was performed.

[An improved method of cholesterol determination in egg yolk by high performance liquid chromatography]

An improved method for cholesterol determination in egg yolk is reported in this paper. Egg yolk was first diluted. Cholesterol was then extracted with ethyl ether and petroleum ether, and quantified by reversed phase liquid chromatography on a Zorbax ODS column (0.46 mm x 15 cm, 5-6 microns) using a mobile phase of acetonitrile and 2-propanol (4:1) with a flow rate of 0.6 mL/min. A linear correlation was observed between 0.05-0.40 g/L of cholesterol. The determination limit was 0.02 g/L. This proposed method of HPLC determination of egg yolk without saponification is superior to colorimetric determination on the sample with saponification, and comparable to HPLC determination with saponification of the egg yolk sample in terms of reliability. No difference in final results was observed between egg yolk sample with saponification and the same sample without saponification. Rapid and reproducible quantification of cholesterol in egg yolk can be completed with this new method. Omission of saponification has made this proposed method more convenient than those ever reported, and can be used in yolk cholesterol study with greater ease.

From the Archives of the AFIP. Mucinous cystic neoplasms of the pancreas: radiologic-pathologic correlation

Mucinous cystic neoplasms of the pancreas are rare primary tumors. They have pathologic and clinical similarities to biliary cystadenomas of the liver and mucinous cystic tumors of the ovary. Mucinous cystic neoplasms of the pancreas typically affect middle-aged women and arise in the tail of the pancreas. Gross pathologic and imaging features usually are those of a large, multilocular cystic mass. There is, however, a spectrum of radiologic findings that overlaps with those of other entities including pancreatic pseudocyst, other primary epithelial and nonepithelial tumors of the pancreas, and metastases. In most cases, ultrasound and computed tomography are the mainstays for radiologic evaluation, with magnetic resonance imaging having a complementary role. All mucinous cystic neoplasms should be considered as mucinous cystadenocarcinomas of low-grade malignant potential. Complete surgical excision alone results in an excellent clinical outcome and disease-free survival, irrespective of histologic or radiologic parameters in over 90% of cases studied.

Expression of Tie2/Tek in breast tumour vasculature provides a new marker for evaluation of tumour angiogenesis

Endothelial receptor tyrosine kinases may play important roles in pathological vascular growth, particularly in tumours. In this study, immunohistochemistry was used to evaluate the expression of a novel endothelial receptor tyrosine kinase, Tie2/Tek, in the endothelium of vascular 'hotspots' in normal breast tissue (n = 10), benign breast lesions (n = 10) and in breast tumours (n = 123). Tie2 expression was detected in the endothelium of all breast tissues examined. However, the strongest expression of Tie-2 was seen in vascular 'hot spots' within the inflammatory infiltrate at the periphery of invasive tumours. Moreover, the proportion of Tie2-positive vessels (Tie2 counts/CD31 counts) was significantly higher in breast tumours than the proportion of Tie2-positive vessels in either normal breast tissue or benign breast lesions (P = 0.004 and 0.0001 respectively). These data are consistent with a role for Tie2 in tumour angiogenesis and demonstrate the potential use of Tie2 expression as a novel marker of the tumour vasculature.

Free radical and antioxidant status in urban and rural Tirupati men: interaction with nutrient intake, substance abuse, obesity and body fat distribution

Rapid growth in urbanisation and industrialisation causes exposure to toxicant pollution which may contribute to increased incidences of non-communicable diseases. The present study reports on plasma lipid peroxides (LPO), lymphocyte free radicals, antioxidants and DNA damage in relation to life-style, obesity and body fat distribution measures among 56 urban men and 45 age matched rural men. Significant increases in plasma LPO, free radical generation (superoxide anion and hydrogen peroxide), and DNA damage indicated by malondialdehyde (MDA) levels were observed in urban compared to rural men. In vitro assay of DNA damage showed a higher level of MDA in samples of urban men than those of rural men. There were no significant differences in antioxidant enzymes between urban and rural men. Neither body mass index nor fat distribution had a significant influence on free radical generation, while the habits of smoking and alcohol consumption were associated with increased levels of free radicals, plasma LPO and DNA damage and reduced levels of antioxidant enzymes such as glutathione-S-transferase (GST), superoxide dismutase (SOD) and catalase in urban men. Dietary energy and fat intakes were positively correlated with free radical generation. Both superoxide anion and hydrogen peroxide were positively correlated with LPO and DNA damage, and negatively correlated with antioxidant enzymes in urban men. The marked elevation of free radical generation, LPO, DNA damage and depletion in antioxidant levels in urban men may suggest that exposure to environmental toxicant pollution is a risk factor for oxidative damage. It was of interest in this study that, whilst BMI was not greater in urban than rural men, abdominal fatness was. Hypothetically, fat distribution could be altered by the process of oxidative damage if it altered regulation of metabolically active omental fat.

Influence of dietary fat on the activities of subcellular membrane-bound enzymes from different regions of rat brain

The effect of different dietary fats with varying degrees of unsaturation and essential fatty acid composition, which are commonly consumed in India, on the activity of some important membrane-bound enzymes was assessed in different brain regions of rat. Four groups of male CFY weanling rats were fed nutritionally adequate diets containing groundnut, coconut, safflower or mustard oil as fat source at 20% level for 16 weeks. The synaptosomal, microsomal and myelin membranes were prepared from three brain regions, viz., cerebrum, cerebellum and brain stem from each group. The activities of Na+, K(+)-ATPase, Mg(2+)-ATPase and acetylcholinesterase were assayed and the fatty acid composition was determined in these subcellular membrane fractions. The safflower oil-fed group showed higher Na+, K(+)-ATPase activity in most membrane fractions than the coconut or mustard oil-fed groups. The Mg(2+)-ATPase activity was found to be similar amongst all groups in all the brain regions. The synaptosomal acetylcholinesterase activity was distinctly higher in coconut and groundnut oil-fed groups when compared to safflower or mustard oil consuming groups. Alterations in the activities of these subcellular membrane-bound enzymes are expected to exert a significant impact on the electrophysiological and metabolic functions of brain. Results of the present study show that depending on the nature of dietary fat the fatty acid composition of subcellular membranes is altered, which in turn could regulate the activity of membrane-bound enzymes that are vital for brain function.

Estimating the daily dialysate drain volume required in CAPD for a target peritoneal creatinine clearance by body water and peritoneal transport characteristics

Stepwise logistic regression performed in 324 clearance studies in 194 patients identified daily drain volume normalized by body water (DV/V) and peritoneal solute transport type as the predictors of peritoneal creatinine clearance (CCrp) in continuous ambulatory peritoneal dialysis (CAPD). Solution of the regression model for DV/V provided DV/V values predicted to provide a desired CCrp at different probabilities. The ability of the predicted DV/V to detect desired CCrp values was tested in a new set of 359 clearance studies in 217 CAPD patients who had a peritoneal equilibration test within 12 months of the clearance study. No patient with low transport had a CCrp exceeding 54 L/1.73 m2 weekly. The following DV/V values detected CCr > or = 54 L/1.73 m2 weekly with a probability of at least 80%: for low-average transport, 0.406 L/L per 24 hours; for high-average transport, 0.339 L/L per 24 hours; for high transport, 0.241 L/L per 24 hours. Corresponding DV/V values for a CCrp of 60 L/1.73 m2 weekly were as follows: for high-average transport, 0.351 L/L per 24 hours; for high transport, 0.271 L/L per 24 hours. For high-average transport, maximal body surface area (BSA) estimates allowing a CCrp of 60 L/1.73 m2 weekly at a CAPD schedule of four daily exchanges with 3-L exchange volume and 1.5 L/24 hour ultrafiltration volume, and with the specified DV/V values were 2.03 m2 in women and 1.77 m2 in men. Corresponding BSA estimates for high peritoneal solute transport were 2.58 m2 in women and 2.21 m2 in men. The delivered dose of CAPD, expressed as DV/V, required to achieve a target CCrp can be calculated from multivariate statistical models taking into account the peritoneal solute transport type. Multiplication of the required DV/V by V provides an estimate of the required daily exchange volume. Maximal BSA estimates allowing a target CCrp can be calculated for each gender and peritoneal solute transport type.

Imaging and pathologic features of myelolipoma

Myelolipoma is a benign tumor consisting of mature fat interspersed with hematopoietic elements resembling bone marrow. Imaging findings in a large series of pathologically proved cases of myelolipoma were correlated with the pathologic and histologic features of the lesions. Myelolipoma manifests in four distinct clinicopathologic patterns: isolated adrenal myelolipoma, adrenal myelolipoma with hemorrhage, extraadrenal myelolipoma, and myelolipoma associated with other adrenal disease. Myelolipoma is difficult or impossible to detect at plain radiography unless the lesion is large and predominantly fatty. At ultrasound, myelolipoma often has heterogeneous echogenicity due to its typically nonuniform architecture. Computed tomography (CT) frequently demonstrates large amounts of fat with areas of interspersed higher-attenuation tissue. At magnetic resonance imaging, predominantly fatty areas usually have increased signal intensity on T1-weighted images and moderate hyperintensity complicated by the presence of marrowlike elements in the corresponding regions on T2-weighted images. The imaging appearance of myelolipoma is altered by the presence of hemorrhage. In such cases, CT is the most accurate method for evaluation. Knowledge of the imaging characteristics of myelolipoma usually allows presumptive diagnosis, although percutaneous needle biopsy may be needed to confirm the diagnosis in cases of extraadrenal myelolipoma. Surgical excision is unnecessary unless the diagnosis is unclear or the lesion is symptomatic. Asymptomatic, nonhemorrhagic myelolipomas do not require therapy.

Colchicine down-regulates lipopolysaccharide-induced granulocyte-macrophage colony-stimulating factor production in murine macrophages

Activation of macrophages by LPS and taxol results in production of IL-1, IL-6, TNF-alpha, and granulocyte-macrophage CSF (GM-CSF), which are involved in regulating hemopoiesis, inflammation, and immune responses. Microtubules are proposed as a target site for LPS interaction(s), based on similarities between the effects of the tubulin-binding drug taxol and LPS. To clarify the role of microtubules in LPS-induced GM-CSF expression in macrophages, we examined whether microtubule depolymerizing agents affect GM-CSF production in macrophages. Pretreatment with colchicine impaired LPS induction of GM-CSF in RAW 264 cells, and studies using stable transfectants revealed that colchicine impaired the transcriptional responsiveness of a reporter gene driven by a GM-CSF promoter sequence. Colchicine inhibition of the GM-CSF response correlated with decreases in the mRNA levels of beta-tubulin; maximal inhibition of both events was observed 4 h after addition of colchicine. Microtubule agents inhibited LPS induction of IL-6 and TNF-alpha, while the induction of both IL-1beta and inducible nitric oxide synthase was unaltered, suggesting that LPS activates microtubule-dependent and -independent pathways. Interestingly, LPS stimulation of macrophages down-regulated levels of beta-tubulin transcripts, implying that LPS interacts with an element(s) of the microtubule network in vivo, activating pathways regulating transcription of beta-tubulin. The ability of both colchicine and LPS to modulate transcription of beta-tubulin suggests that this event does not per se underlie the inhibitory effect of colchicine on LPS-induced GM-CSF expression. These data led us to conclude that colchicine inhibits LPS induction of GM-CSF by affecting microtubule-dependent costimulatory signaling pathways that synergize with primary LPS-triggered responses.