Expression of activation, adhesion molecules and intracellular cytokines in acute pancreatitis

Adhesion and activation molecules as well as cytokines play an important role in an immune scenario. In acute pancreatitis, we have studied some of these in order to evaluate dysregulation. For this we took peripheral blood mononuclear cells and pancreatitis tissue cells. We analysed activation markers like CD69, CD25 and HLA-DR and found a marked elevation of CD69 as well as CD25 in both peripheral blood cells and tissue mononuclear cells when compared to controls. In PBMC-CD69: P<0.01 and CD25: P<0.01; in tissue-CD69: P<0.001 and CD25: P<0.001. The HLA-DR levels, however, were reduced in the disease state (in acute pancreatitis patient blood (P<0.01) and tissue cells (P<0.001)). The adhesion molecules showed unanimous rise in the blood and the tissue samples. In blood samples, CD11a: P<0.05 and CD11b: P<0.05 and tissue samples CD11a: P<0.01 and CD11b: P<0.01and CD54 in peripheral blood (P<0.05) and tissue (P<0.01) of AP was high as compared to controls. By simultaneous flowcytometric analysis, we determined the co-expression of a surface marker (CD4/CD8/CD14) and intracellular cytokine (TNF-alpha and IFN-gamma) in individual cells. The IFN-gamma producing CD8+T cells were elevated in pancreatic tissue (P<0.01). TNF-alpha producing cell numbers were significantly higher in tissue cells than in blood and also in CD8+ T cells (P<0.001). We conclude that monocyte function is affected in AP as shown by reduced HLA-DR numbers and lowered TNF-alpha producing cells. Moreover, the CD8+T cells appear to play an important role in cytokine synthesis at the effector site.

Generation of ceramide in murine macrophages infected with Leishmania donovani alters macrophage signaling events and aids intracellular parasitic survival

In the present study, we examined the involvement of intracellular ceramide in host pathogen interaction of BALB/c mouse peritoneal macrophages infected with the obligate intracellular protozoan, Leishmania donovani. Our findings indicate that the level of intracellular ceramide was enhanced as a result of the in vitro infection. While the elevated ceramide was largely due to de novo synthesis, activation of the sphingomyelinases was also observed. The enhanced ceramide was responsible for the downregulation of classical PKC activity, upregulation of calcium independent atypical PKC-zeta expression and activity of calcium independent PKC. Ceramide also impaired the phosphorylation of MAPK. Evidently, ceramide suppressed the generation of nitric oxide during leishmanial infection and also facilitated the survival of leishmanial parasites in the intramacrophageal milieu. These data present newer insight to the signaling events in leishmania-infected murine macrophages, which might offer ceramide as a new therapeutic target in the future.

Intracellular cytokines in cells of necrotic tissue from patients with acute pancreatitis

OBJECTIVE

To determine the alterations in intracellular cytokine responses in necrotic pancreatic tissue obtained on debridement from patients with acute pancreatitis.

DESIGN

Laboratory study.

SETTING

Teaching hospital, India.

MATERIAL

Necrotic tissue obtained at necrosectomy from 34 patients with alcohol-induced or biliary pancreatitis (n = 17 in each) and at autopsy from 12 controls.

INTERVENTIONS

Histopathological evaluation; measurement of intracellular content of the cytokines interleukin (IL)-2, IL-4, IL-10 and IFN-gamma in CD4+ and CD8+ T lymphocytes and IL-6 and IL-12 in CD14+ monocytes.

MAIN OUTCOME MEASURES

Intracellular content of the measured cytokines.

RESULTS

CD4+ and CD8+ T cells and CD14+ monocytes responded to in vitro stimulation of mitogens and synthesised cytokines to varying degrees in the three groups. The heterogeneous cytokine response pattern did not show a typical type 1/type 2 polarised model.

CONCLUSIONS

This profile suggests that the cells retain the capacity to modulate their phenotype in response to local conditions at the effector site. These results could be taken into consideration when designing new and specific treatments for modifying the immune inflammatory response.

Modulation of acid secretion in common bile duct ligation-related gastropathy in Wistar rats

BACKGROUND

Portal hypertensive gastropathy is associated with fundic gland atrophy, resulting in a decrease in chief and parietal cells, and diminished acid secretion.

METHODS

Acid secretion by isolated parietal cells was measured (acridine orange retention), along with the levels of various second messengers (intracellular Ca(2+), cyclic adenosine monophosphate and protein kinase C) in the common bile duct, ligated portal hypertensive rats and compared with sham-operated controls.

RESULTS

There was a significant decrease in the response of isolated parietal cells to the secretagogues histamine and carbachol. This resulted in the blunted acid secretion in the common bile duct ligated group. In addition, all the second messengers studied were significantly decreased as compared with the sham-operated controls.

CONCLUSION

These results suggest that the blunted acid secretory response in the portal hypertensive rat is caused by an alteration in the intracellular signal transduction mechanism.

Exacerbations of Bronchitis: bronchial eosinophilia and gene expression for interleukin-4, interleukin-5, and eosinophil chemoattractants

Eosinophilia has been reported during exacerbations of bronchitis, but the mechanisms of tissue recruitment of eosinophils are unclear. We quantified eosinophils and the concurrent expression of cytokines and chemokines probably responsible for the tissue eosinophilia in bronchial biopsies obtained from three groups of nonatopic subjects: (1) healthy nonsmokers (n = 7; FEV1 % predicted = 108 +/- 4 [mean +/- SEM]); (2) nonasthmatic smokers with chronic bronchitis (CB) in a stable phase of their disease (n = 11; FEV1 % predicted: 75 +/- 5); and (3) nonasthmatic subjects with CB who sought medical advice for an exacerbation of their condition (n = 9; FEV(1) % predicted: 61 +/- 8). We applied anti-EG2 antibody and immunostaining to detect and count eosinophils. We performed in situ hybridization to visualize and enumerate cells expressing the genes for interleukin (IL)-4 and IL-5 and the eosinophil chemokines eotaxin, monocyte chemoattractant protein (MCP)-4, or regulated on activation, normal T-cell expressed and secreted (RANTES). We confirmed an increase in EG2-positive eosinophils in patients with CB in exacerbation. We found messenger RNA (mRNA) positivity for IL-4 and IL-5 in CB, but the between-group differences were not statistically significant. However, the numbers of lymphomononuclear cells expressing eotaxin mRNA were significantly greater in the smokers with CB than in the healthy nonsmokers without CB (p < 0.01). Following an exacerbation, RANTES expression was upregulated and this chemokine was strongly expressed in both the surface epithelium and in subepithelial lymphomononuclear cells: only RANTES showed a significant positive correlation with the increasing number of EG2-positive cells (r = 0.51; p < 0.03). In conclusion, an allergic profile of inflammation can also occur in CB: the marked upregulation of RANTES in the epithelium and subepithelium most likely accounts for the increased eosinophilia associated with an exacerbation of bronchitis.

Characterization of a Galactose Specific Adhesin of Enteroaggregative Escherichia coli

A fimbrial adhesin was identified from an enteroaggregative Escherichia coli strain. The adhesin was purified to 740-fold by sequential chromatography on an affinity matrix and gel filtration column in the FPLC system. The homogeneity of the purified protein was established by analytical isoelectrofocussing (pI 7.25). The native adhesin appeared as a high-molecular-weight aggregative protein as revealed by gel filtration chromatography on Superose 12HR10/30 column. However, in sodium dodecyl sulfate-polyacrylamide gel electrophoresis the molecular weight of the adhesin was found to be 18 kDa and this was further confirmed by gel filtration chromatography on Superose 6HR 10/30 column presence of 6 M guanidine hydrochloride. The N-terminal 15-amino-acid sequence of the adhesin did not show homology with any of the previously reported fimbrial adhesins. The purified adhesin showed adhesion to human erythrocytes in the presence of Ca(2+) (5 mM). The optimum temperature and pH for the hemadhesion activity was found to be 25 degrees C and 6.5, respectively. The inhibition study clearly suggested that the binding site of the adhesin could recognize galactose as the specific sugar. The fluorescence of 4-methylumbelliferyl-alpha-D-galactopyranoside was quenched on binding to the adhesin and maximum reversal of fluorescence quenching was observed by competitive substitution titration with raffinose. The adhesin was found to contain one binding site per monomer for its specific sugar residue. The association constant and the free energy of binding were obtained as 3.98 x 10(5) M(-1) and -31.97 kJ/mol, respectively. The adherence of the bacteria to HEp-2 monolayer was inhibited in presence of galactose and this was further supported by a significant reduction in the bacterial adherence to the HEp-2 cells, pretreated with beta-D-galactosidase.

Involvement of nitric oxide in the antiaggregatory effect of enalapril

This study was conducted to examine the effects of single dose enalapril (1.6 mg/kg) on platelet aggregation alone and after an intravenous bolus dose of the nitric oxide synthase (NOS) inhibitor N-nitro-L-arginine (L-NNA; 40 mg/kg). Blood samples were collected before and 1, 2 and 6 h after the administration of drugs in rhesus monkeys. Enalapril was administered via a nasogastric tube while L-NNA was administered by the intravenous route. Platelet aggregation was stimulated with adenosine diphosphate (ADP) in platelet rich plasma (PRP). Enalapril significantly inhibited platelet aggregation with a peak effect at 6 h. Upon administration of L-NNA, there was a significant increase in the percentage of platelet aggregation. This effect was partially antagonized by enalapril. The present study demonstrates that enalapril may possess antiaggregatory effects, which may be mediated via nitric oxide mechanisms.

Rapid non-destructive quantitative estimation of urania/thoria in mixed thorium uranium di-oxide pellets by high-resolution gamma-ray spectrometry

A non-destructive technique using high-resolution gamma-ray spectrometry has been standardised for quantitative estimation of uranium/thorium in mixed (ThO2-UO2) fuel pellets of varying composition. Four gamma energies were selected; two each from the uranium and thorium series and the time of counting has been optimised. This technique can be used for rapid estimation of U/Th percentage in a large number of mixed fuel pellets from a production campaign.

Advanced imaging of the macrostructure and microstructure of bone

Noninvasive and/or nondestructive techniques are capable of providing more macro- or microstructural information about bone than standard bone densitometry. Although the latter provides important information about osteoporotic fracture risk, numerous studies indicate that bone strength is only partially explained by bone mineral density. Quantitative assessment of macro- and microstructural features may improve our ability to estimate bone strength. The methods available for quantitatively assessing macrostructure include (besides conventional radiographs) quantitative computed tomography (QCT) and volumetric quantitative computed tomography (vQCT). Methods for assessing microstructure of trabecular bone noninvasively and/or nondestructively include high-resolution computed tomography (hrCT), micro-computed tomography (muCT), high-resolution magnetic resonance (hrMR), and micromagnetic resonance (muMR). vQCT, hrCT and hrMR are generally applicable in vivo; muCT and muMR are principally applicable in vitro. Although considerable progress has been made in the noninvasive and/or nondestructive imaging of the macro- and microstructure of bone, considerable challenges and dilemmas remain. From a technical perspective, the balance between spatial resolution versus sampling size, or between signal-to-noise versus radiation dose or acquisition time, needs further consideration, as do the trade-offs between the complexity and expense of equipment and the availability and accessibility of the methods. The relative merits of in vitro imaging and its ultrahigh resolution but invasiveness versus those of in vivo imaging and its modest resolution but noninvasiveness also deserve careful attention. From a clinical perspective, the challenges for bone imaging include balancing the relative advantages of simple bone densitometry against the more complex architectural features of bone or, similarly, the deeper research requirements against the broader clinical needs. The considerable potential biological differences between the peripheral appendicular skeleton and the central axial skeleton have to be addressed further. Finally, the relative merits of these sophisticated imaging techniques have to be weighed with respect to their applications as diagnostic procedures requiring high accuracy or reliability on one hand and their monitoring applications requiring high precision or reproducibility on the other.

Fractal analysis of bone X-ray tomographic microscopy projections

Fractal analysis of bone X-ray images has received much interest recently for the diagnosis of bone disease. In this paper, we propose a fractal analysis of bone X-ray tomographic microscopy (XTM) projections. The aim of the study is to establish whether or not there is a correlation between three-dimensional (3-D) trabecular changes and two-dimensional (2-D) fractal descriptors. Using a highly collimated beam, 3-D bone X-ray tomographic images were obtained. Trabecular bone loss was simulated using a mathematical morphology method. Then, 2-D projections were generated in each of the three orthogonal directions. Finally, the model of fractional Brownian motion (fBm) was used on bone XTM 2-D projections to characterize changes in bone structure that occur during disease, such a simulation of bone loss. Results indicate that fBm is a robust texture model allowing quantification of simulations of trabecular bone changes.

Etiology and management of obscure gastrointestinal bleed--an appraisal from eastern India

OBJECTIVES AND METHOD

Forty patients (mean age 45 years; 24 men) attending a tertiary care hospital in eastern India during the period 1996-2000 were investigated to evaluate the etiology and clinical spectrum of obscure gastrointestinal bleed.

RESULTS

The patients presented to hospital after mean symptom duration of 2.5 years. They had received an average of 15 units of blood transfusion. Most patients presented with recurrent melena (85%); all had iron-deficiency anemia. A total of 230 investigations (89 gastroscopies, 54 colonoscopies, 25 double-contrast meal and follow-through studies, 14 small bowel enemas, 24 radionuclide scans, 16 mesenteric angiographies and 8 intraoperative endoscopies) yielded positive diagnosis in 87.5% of cases. The diseases encountered were small bowel and colonic angiodysplasias (32.5%), ileal Crohn's disease (20%), intestinal tuberculosis (10%), intestinal tumors (10%), nonspecific small bowel ulcers and strictures (7.5%), Meckel's diverticulum (5%) and hemobilia (2.5%). The etiology remained obscure in 5 (12.5%) cases. Overall success of surgery was 63%; in-hospital mortality was 7.5%.

CONCLUSION

Though obscure gastrointestinal bleed is commonly caused by angiodysplasias, it can be an atypical presentation of Crohn's disease.

Does the trabecular bone structure depicted by high-resolution MRI of the calcaneus reflect the true bone structure?

RATIONALE AND OBJECTIVES

The purpose of this study was to compare trabecular bone structure parameters assessed with high-resolution magnetic resonance imaging (HR-MRI) with those determined in specimen sections.

METHODS

High-resolution MR images were obtained for 30 calcaneus specimens with a three-dimensional, T1-weighted spin-echo sequence (spatial in-plane resolution 0.195 mm, slice thicknesses of 0.3 and 0.9 mm). Thirty-eight sections were obtained from the specimens, and contact radiography was performed. In the corresponding sections, structural parameters analogous to bone histomorphometry were determined.

RESULTS

Significant correlations between MRI-derived structural parameters and those derived from macro pathological sections were found: r values of up to 0.75 were obtained (P < 0.01). The highest correlations were found for apparent bone volume/total volume and trabecular thickness. Image thresholding techniques showed a significant impact on these correlations (P < 0.01). The thinner MR sections were less susceptible to the different thresholding algorithms.

CONCLUSIONS

Trabecular bone structure depicted by HR-MR images is significantly correlated with that shown in macro sections (P < 0.01); however, a number of limitations have to be considered, including the substantial impact of thresholding techniques and slice thickness.

Toxico-kinetics, recovery, and metabolism of napropamide in goats following a single high-dose oral administration

Toxicokinetic behavior, recovery and metabolism of napropamide (a pre-emergent herbicide) and its effect on Cytochrome P(450) of liver microsomal pellet were studied following a single high-dose oral administration of 2.5 g kg(-1) and continuous (7 days) oral administration of 500 mg kg(-1) in black Bengal goat. Napropamide was detected in blood at 15 min and the maximum quantity was recovered at 3 h after administration. The absorption rate constant (Ka) value was low indicating poor absorption from the gastrointestinal tract. High elimination half-life (t(1/2) beta) and low body clearance (Cl(B)) values coupled with higher transfer of compound from tissue to central compartment (K(21)) suggest that napropamide persisted in the blood for a long time, i.e., after 72 h of oral administration. The recovery percentage of napropamide, including metabolites, from goats varied from 75.94 to 80.08 and excretion of the parent compound through feces varied from 18.86 to 21.59%, indicating that a major portion of the orally administered napropamide was absorbed from the gastrointestinal tract of goat. Napropamide significantly increased the Cytochrome P(450) content of liver microsomal pellet. The recovery of metabolites from feces, urine, and tissues ranged from 4.2--6.2, 40.81--49.42, and 2.7--11.6%, respectively, during a 4--7 day period. The material balance of napropamide (including metabolites) following a single high-dose oral administration at 2.5 g kg(-1) during 4--7 days after dosing was found to be in the range of 75--80%.

Immunomodulatory role of interleukin-10 in visceral leishmaniasis: defective activation of protein kinase C-mediated signal transduction events

Leishmania donovani, an intracellular protozoan parasite, challenges host defense mechanisms by impairing the signal transduction of macrophages. In this study we investigated whether interleukin-10 (IL-10)-mediated alteration of signaling events in a murine model of visceral leishmaniasis is associated with macrophage deactivation. Primary in vitro cultures of macrophages infected with leishmanial parasites markedly elevated the endogenous release of IL-10. Treatment with either L. donovani or recombinant IL-10 (rIL-10) inhibited both the activity and expression of the Ca2+-dependent protein kinase C (PKC) isoform. However, preincubation with neutralizing anti-IL-10 monoclonal antibody (MAb) restored the PKC activity in the parasitized macrophage. Furthermore, we observed that coincubation of macrophages with rIL-10 and L. donovani increased the intracellular parasite burden, which was abrogated by anti-IL-10 MAb. Consistent with these observations, generation of superoxide (O2-) and nitric oxide and the release of murine tumor necrosis factor-alpha were attenuated in response to L. donovani or rIL-10 treatment. On the other hand, preincubation of the infected macrophages with neutralizing anti-IL-10 MAb significantly blocked the inhibition of nitric oxide and murine tumor necrosis factor-alpha release by the infected macrophages. These findings imply that infection with L. donovani induces endogenous secretion of murine IL-10, which in turn facilitates the intracellular survival of the protozoan and orchestrates several immunomodulatory roles via selective impairment of PKC-mediated signal transduction.

Selective impairment of protein kinase C isotypes in murine macrophage by Leishmania donovani

Leishmania donovani, an obligate intracellular parasite resides and multiplies within macrophage of the reticuloendothelial system. The intracellular signalling mechanism involved in the impaired oxidative response in leishmaniasis has not yet been clearly established. Generation of superoxide anion (O2-) is supposed to be the first line of host defence during microbial invasion. We found a substantial inhibition of superoxide anion generation in parasitized macrophages, which was just the reverse in case of macrophages challenged with Lipophosphoglycan (LPG) deficient attenuated leishmanial parasite UR-6. The generation of O2- essentially needs the prior activation of protein kinase C (PKC) mediated phosphorylation events. Our study proposed that phosphorylation of 67, 54, 47 and 36 kDa proteins was attenuated during infection. This was supported by PKC activity study, where Ca-dependent PKC activity was inhibited but, Ca-independent PKC activity was enhanced. This result was further confirmed by using isotype specific pseudosubstrate inhibitors of Ca-dependent PKC beta and Ca-independent PKC zeta. Application of beta-pseudosubstrate could not alter the Ca-dependent PKC activity but zeta-pseudosubstrate inhibited the Ca-independent PKC activity in infected macrophages. Our immunoblot analysis with specific antibody against PKC beta and PKC zeta isotypes showed down regulation of PKC beta-II expression with concomitant induction of PKC zeta. Such inhibition of Ca-dependent PKC beta was reversed in macrophages treated with UR-6. Taken together, our observations revealed that infection with L. donovani selectively attenuates both the expression and activity of Ca-dependent PKC beta.

The temporal changes of trabecular architecture in ovariectomized rats assessed by MicroCT

To study the short- and long-term effects of estrogen deficiency on trabecular bone, three-dimensional measurements of proximal tibiae of ovariectomized rats were performed by micro-computed tomography (MicroCT). New three-dimensional (3D) techniques were employed to characterize the trabecular architecture from 0 to 110 days post-ovariectomy (OVX). These new methods no longer assume a plate or rod model of bone, but calculate trabecular thickness, separation, and number and their distribution by placing maximal spheres into the 3D representation of the structure. The model type of bone was quantified with the Structure Model Index (SMI). Utilizing these methods we found a rapid loss of trabecular bone in the first week after OVX. After the first week bone mass declined further, although the rate of loss was lower. In addition there was a complete change in model type from plate-like to rod-like within 7 days post-OVX, and then a very constant SMI after 12 days. After an initial thinning of trabecular structure, further bone loss seems to occur through removal of trabeculae, while the trabecular plate thickness remains constant. The heterogeneity of the network could be quantified by intra-individual standard deviation of local separations, which showed a stair-like progression, with a plateau between 12 and 60 days post-OVX. This study provides new insights into ovariectomy-related changes in cancellous bone structure evaluated by 3D MicroCT. In addition, these data suggest that the rapid change of model from plate-like to rod-like post-OVX may potentially introduce biases in the parameters that are determined using model-based algorithms, and these biases may modify the impact of age-related or therapeutic changes.

Effects of prostaglandin E2 and nitric oxide inhibitors on the expression of interleukin-10, interleukin-12 and MHC class-II molecules in Mycobacterium microti-infected and interferon-gamma-treated mouse peritoneal macrophages

Mycobacterium microti-infected mouse peritoneal macrophages produced high amounts of prostaglandin E2 (PGE2) and nitric oxide (NO) when activated with interferon-gamma (IFN-gamma). In order to understand the relation between PGE2 and NO production and the expression of interleukin-12 (IL-12), interleukin-10 (IL-10) and MHC class-II (Ia) molecules by M. microti-infected and IFN-gamma-stimulated macrophages, we analyzed the level of these molecules in the presence or absence of PGE2 and NO inhibitors. Addition of NG-methyl-L-arginine (L-NMA) and indomethacin (IM) caused a significant increase in IL-12 level (2.6- and 1.9-fold, respectively) whereas IL-10 level decreased by 88 and 56%, respectively, relative to M. microti-infected and IFN-gamma-treated control macrophages. Enhanced PGE2 and NO upregulated IL-10 expression and down-regulated IL-12 and MHC class-II (Ia) expression in M. microti-infected and IFN-gamma-treated mouse peritoneal macrophages.

Changes in calcaneal trabecular bone structure after heart transplantation: an MR imaging study

PURPOSE

To use high-spatial-resolution magnetic resonance (MR) imaging to analyze the trabecular bone structure of the calcaneus in patients before and after heart transplantation and to compare this technique with bone mineral density (BMD) measurement in predicting therapy-induced bone loss and vertebral fracture status.

MATERIALS AND METHODS

High-spatial-resolution 1.5-T MR imaging of the calcaneus was performed in 40 men 11-120 months after heart transplantation, in 11 men before heart transplantation, and in 10 age-matched male volunteers. Sagittal and transverse T1-weighted spin-echo images with a voxel size of 0.195 x 0.195 x 1.000 mm were obtained, and structure measurements analogous to bone histomorphometric values were calculated. In addition, the BMD of the lumbar spine was determined in the transplant recipients pre- and postoperatively by using quantitative computed tomography, and vertebral fracture status was assessed.

RESULTS

Significant differences in structure and BMD measurements were found between patients before and after heart transplantation (P <. 05). In 17 (42%) of 40 transplant recipients, vertebral fractures were found. Although structure measurements were significantly different between patients with and those without fractures (P <.05), BMDs were not. Correlations between time after transplantation and some structure measurements were moderately significant (P <. 05), but such correlations with BMD measurements were not.

CONCLUSION

MR imaging-derived structure measurements in the calcaneus are useful for monitoring bone changes after heart transplantation and assessing vertebral fracture status.

In vivo assessment of trabecular bone structure using fractal analysis of distal radius radiographs

Our purpose in this study was (i) to measure trabecular bone structure using fractal analysis of distal radius radiographs in subjects with and without osteoporotic hip fractures, and (ii) to compare these measures with bone mineral density (BMD) as well as with measures of trabecular bone structure derived from high resolution magnetic resonance (MR) images. Distal radius radiographs were obtained using semi-industrial films (55 kVp, 400 mAs) in 30 postmenopausal patients, who had suffered osteoporotic hip fractures (74.8+/-8.2 years) in the last 24 months and 27 postmenopausal age-matched (74.6+/-6.6 yr) normal volunteers. Radiographs were digitized at 50 microm. A Fourier power spectrum-based fractal dimension (FD) characterizing the trabecular pattern was measured in a region of interest proximal to the joint line. The fractal dimension was calculated over two spatial frequency (f) ranges: FD1 was calculated over 0.5<log(f)<l.0, FD2 over the higher range 1.0<log(f)<1.5. Trabecular BMD in the radius was obtained using peripheral quantitative computed tomography (pQCT) (Stratec GmbH, Germany). In addition BMD of the proximal femur was determined using dual x-ray absorptiometry (DXA) (QDR 2000, Hologic, MA). In a subset of patients (16 controls and 18 with hip fractures), high resolution MR imaging of the distal radius (spatial resolution of 156 x 156 x 500 microm) was used to obtain measures analogous to bone histomorphometry. There were significant differences (p<0.05) between the fracture and nonfracture groups in the total femur BMD (13%), trabecular BMD in the distal radius (4%), and the fractal dimension in the radiographs (FD2) (3%). The correlations between FD2 and the total femur BMD as well as trabecular bone BMD in the distal radius were -0.48 (p<0.006) and -0.22 (p<0.33); respectively; FD1 increased with BMD and showed lower correlations. FD2 showed good correlations with App. Tb.N (-0.71) and App. Tb.Sp (0.69) (p<0.01), moderate correlation with App BV/TV (-0.53) (p<0.05), and no significant correlation with App. Tb.Th. The correlations between structural measures and FD1 showed the inverse trend and were typically lower. The odds ratios for a hip fracture were 2.44 for total femur BMD, 1.5 for trabecular BMD (radius), and 1.5 for FD2, respectively. In summary, the fractal measures derived from radiographs of the radius show differences between subjects with and without hip fractures, the predictive power of measures in the distal radius are comparable to radial trabecular BMD but lower than that of total hip BMD.

Effect of nimodipine on male reproductive functions in rats

Nimodipine, a dihydropyridine calcium channel blocker, was administered orally using two different doses (40 mg and 60 mg/kg/day) to rats. Both short term (2 weeks) and long term (6 weeks) effects of the drug were observed. The drug administration resulted in a marked decrease in sperm density, sperm motility and acrozomal reaction. Zona-pellucida penetration by the sperm obtained from drug-treated animals was significantly lower when compared with sperm from normal animals. Nimodipine stimulated Ca2+ ATPase activity in isolated plasma membrane of rate spermatozoa. In conclusion, short term and long term administration of nimodipine has deleterious effect on male reproductive functions in rats.

A longitudinal study of ventricular volume in early relapsing-remitting multiple sclerosis

The specific aim of this study was to determine whether progressive brain atrophy could be detected within 18 months of establishing a diagnosis of relapsing-remitting multiple sclerosis (RRMS). Fifteen patients with clinically definite RRMS (mean disease duration from first symptom=6 months, mean EDSS=1.2) completed 6 - 14 monthly quantitative MRI sessions. The volume of the lateral ventricles was determined each month using a semi-automated thresholding technique from T1-weighted axial images. The number of new monthly gadolinium-enhancing (Gd+) lesions and EDSS scores were also recorded. Lateral ventricular volumes increased significantly during this study. When individual data were examined, statistically significant changes were observed in six of 15 patients. Monthly change in ventricular volume was related to baseline EDSS and total number of new Gd(+) lesions. These observations indicate brain atrophy, a putative imaging marker of diffuse demyelination and axonal loss, can occur as early as 18 months after first symptoms of RRMS, and is related to the baseline level of disability and to the number of new Gd+ lesions. Multiple Sclerosis (2000) 6 332 - 337