Moringa oleifera (Lam.): a natural remedy for ageing?

Effect of Moringa oleifera, an age-old ingredient of Indian ayurvedic and traditional medicine, was tested for its effect on age related antioxidant activity in Wistar albino rats of three age groups (6, 12 and 18 months old). Aqueous extract of M. oleifera leaves (MOAE) was administered orally at a dosage of 200 mg/kg body weight for a period of 30 days. MOAE treatment showed significant reduction in lipid peroxidation and lipofuscin pigmentation along with elevated serotonin and antioxidant enzymes in the brains of treated groups of aged rats. LC-MS-MS analysis revealed blood brain barrier permeable secondary metabolites viz., 9,9-bianthracene, 4-Methoxycinnamic acid, Cinnamic acid, (E)-p-coumaric acid pyrogallol and ostruthin from the extract. 9,9-bianthracene and ostruthin showed better binding affinity to Keap-1 and SERT in silico. The present result suggests the protective efficacy of M oleifera against age related oxidative stress in brain.

Plasma Fucosylated Glycans and C-Reactive Protein as Biomarkers of HNF1A-MODY in Young Adult-Onset Nonautoimmune Diabetes

OBJECTIVE

Maturity-onset diabetes of the young (MODY) due to variants in HNF1A is the most common type of monogenic diabetes. Frequent misdiagnosis results in missed opportunity to use sulfonylureas as first-line treatment. A nongenetic biomarker could improve selection of subjects for genetic testing and increase diagnosis rates. We previously reported that plasma levels of antennary fucosylated N-glycans and high-sensitivity C-reactive protein (hs-CRP) are reduced in individuals with HNF1A-MODY. In this study, we examined the potential use of N-glycans and hs-CRP in discriminating individuals with damaging HNF1A alleles from those without HNF1A variants in an unselected population of young adults with nonautoimmune diabetes.

RESEARCH DESIGN AND METHODS

We analyzed the plasma N-glycan profile, measured hs-CRP, and sequenced HNF1A in 989 individuals with diabetes diagnosed when younger than age 45, persistent endogenous insulin production, and absence of pancreatic autoimmunity. Systematic assessment of rare HNF1A variants was performed.

RESULTS

We identified 29 individuals harboring 25 rare HNF1A alleles, of which 3 were novel, and 12 (in 16 probands) were considered pathogenic. Antennary fucosylated N-glycans and hs-CRP were able to differentiate subjects with damaging HNF1A alleles from those without rare HNF1A alleles. Glycan GP30 had a receiver operating characteristic curve area under the curve (AUC) of 0.90 (88% sensitivity, 80% specificity, cutoff 0.70%), whereas hs-CRP had an AUC of 0.83 (88% sensitivity, 69% specificity, cutoff 0.81 mg/L).

CONCLUSIONS

Half of rare HNF1A sequence variants do not cause MODY. N-glycan profile and hs-CRP could both be used as tools, alone or as adjuncts to existing pathways, for identifying individuals at high risk of carrying a damaging HNF1A allele.

Validity of simplified protocols to estimate glomerular filtration rate using iohexol clearance

Background: Iohexol clearance is an accurate and precise exogenous marker of glomerular filtration rate (GFR), but protocols are generally lengthy or require multiple sampling. Shorter or simpler protocols would be more practicable.

Methods: Two clearance estimates, two weeks apart, were undertaken in 11 healthy individuals and 26 diabetic patients with minimal to moderate renal impairment (chronic kidney disease stages 1-3). Blood specimens withdrawn at 60, 90, 120, 150, 180 and 240 min post-iohexol were analysed for iohexol.

Results: Visit 1 demonstrated excellent correlation with visit 2 (slope 1.00, confidence interval [CI] 0.88 to 1.13, intercept 0.94 mL/min/1.73 m2, CI -9.9 to 11.8, P=0.43). The within-individual coefficient of variation (CV) of the 240 min reference method was 5.4% at a mean GFR of 84.1 mL/min/1.73 m2. Single point estimates between 120 and 240 min had CVs of 4.5-7.0%, and did not differ from the reference method CV by more than 2.0 mL/min/1.73 m2. Two and three point estimates in the interval 60-120 min post iohexol injection offered no advantages over these single-point estimates and overestimated at lower GFRs.

Conclusions: An iohexol clearance estimate of GFR derived from a single sample taken between 2 to 4 h after infusion may provide a suitable tool for routine clinical use.

Loss-of-Function Mutations in the Cell-Cycle Control Gene CDKN2A Impact on Glucose Homeostasis in Humans

At the CDKN2A/B locus, three independent signals for type 2 diabetes risk are located in a noncoding region near CDKN2A. The disease-associated alleles have been implicated in reduced β-cell function, but the underlying mechanism remains elusive. In mice, β-cell-specific loss of Cdkn2a causes hyperplasia, while overexpression leads to diabetes, highlighting CDKN2A as a candidate effector transcript. Rare CDKN2A loss-of-function mutations are a cause of familial melanoma and offer the opportunity to determine the impact of CDKN2A haploinsufficiency on glucose homeostasis in humans. To test the hypothesis that such individuals have improved β-cell function, we performed oral and intravenous glucose tolerance tests on mutation carriers and matched control subjects. Compared with control subjects, carriers displayed increased insulin secretion, impaired insulin sensitivity, and reduced hepatic insulin clearance. These results are consistent with a model whereby CDKN2A loss affects a range of different tissues, including pancreatic β-cells and liver. To test for direct effects of CDKN2A-loss on β-cell function, we performed knockdown in a human β-cell line, EndoC-bH1. This revealed increased insulin secretion independent of proliferation. Overall, we demonstrated that CDKN2A is an important regulator of glucose homeostasis in humans, thus supporting its candidacy as an effector transcript for type 2 diabetes-associated alleles in the region.

Blood CEA levels for detecting recurrent colorectal cancer

BACKGROUND

Testing for carcino-embryonic antigen (CEA) in the blood is a recommended part of follow-up to detect recurrence of colorectal cancer following primary curative treatment. There is substantial clinical variation in the cut-off level applied to trigger further investigation.

OBJECTIVES

To determine the diagnostic performance of different blood CEA levels in identifying people with colorectal cancer recurrence in order to inform clinical practice.

SEARCH METHODS

We conducted all searches to January 29 2014. We applied no language limits to the searches, and translated non-English manuscripts. We searched for relevant reviews in the MEDLINE, EMBASE, MEDION and DARE databases. We searched for primary studies (including conference abstracts) in the Cochrane Central Register of Controlled Trials (CENTRAL), in MEDLINE, EMBASE, and the Science Citation Index & Conference Proceedings Citation Index - Science. We identified ongoing studies by searching WHO ICTRP and the ASCO meeting library.

SELECTION CRITERIA

We included cross-sectional diagnostic test accuracy studies, cohort studies, and randomised controlled trials (RCTs) of post-resection colorectal cancer follow-up that compared CEA to a reference standard. We included studies only if we could extract 2 x 2 accuracy data. We excluded case-control studies, as the ratio of cases to controls is determined by the study design, making the data unsuitable for assessing test accuracy.

DATA COLLECTION AND ANALYSIS

Two review authors (BDN, IP) assessed the quality of all articles independently, discussing any disagreements. Where we could not reach consensus, a third author (BS) acted as moderator. We assessed methodological quality against QUADAS-2 criteria. We extracted binary diagnostic accuracy data from all included studies as 2 x 2 tables. We conducted a bivariate meta-analysis. We used the xtmelogit command in Stata to produce the pooled estimates of sensitivity and specificity and we also produced hierarchical summary ROC plots.

MAIN RESULTS

In the 52 included studies, sensitivity ranged from 41% to 97% and specificity from 52% to 100%. In the seven studies reporting the impact of applying a threshold of 2.5 µg/L, pooled sensitivity was 82% (95% confidence interval (CI) 78% to 86%) and pooled specificity 80% (95% CI 59% to 92%). In the 23 studies reporting the impact of applying a threshold of 5 µg/L, pooled sensitivity was 71% (95% CI 64% to 76%) and pooled specificity 88% (95% CI 84% to 92%). In the seven studies reporting the impact of applying a threshold of 10 µg/L, pooled sensitivity was 68% (95% CI 53% to 79%) and pooled specificity 97% (95% CI 90% to 99%).

AUTHORS' CONCLUSIONS

CEA is insufficiently sensitive to be used alone, even with a low threshold. It is therefore essential to augment CEA monitoring with another diagnostic modality in order to avoid missed cases. Trying to improve sensitivity by adopting a low threshold is a poor strategy because of the high numbers of false alarms generated. We therefore recommend monitoring for colorectal cancer recurrence with more than one diagnostic modality but applying the highest CEA cut-off assessed (10 µg/L).

A large multi-centre European study validates high-sensitivity C-reactive protein (hsCRP) as a clinical biomarker for the diagnosis of diabetes subtypes

AIMS/HYPOTHESIS

An accurate molecular diagnosis of diabetes subtype confers clinical benefits; however, many individuals with monogenic diabetes remain undiagnosed. Biomarkers could help to prioritise patients for genetic investigation. We recently demonstrated that high-sensitivity C-reactive protein (hsCRP) levels are lower in UK patients with hepatocyte nuclear factor 1 alpha (HNF1A)-MODY than in other diabetes subtypes. In this large multi-centre study we aimed to assess the clinical validity of hsCRP as a diagnostic biomarker, examine the genotype-phenotype relationship and compare different hsCRP assays.

METHODS

High-sensitivity CRP levels were analysed in individuals with HNF1A-MODY (n = 457), glucokinase (GCK)-MODY (n = 404), hepatocyte nuclear factor 4 alpha (HNF4A)-MODY (n = 54) and type 2 diabetes (n = 582) from seven European centres. Three common assays for hsCRP analysis were evaluated. We excluded 121 participants (8.1%) with hsCRP values >10 mg/l. The discriminative power of hsCRP with respect to diabetes aetiology was assessed by receiver operating characteristic curve-derived C-statistic.

RESULTS

In all centres and irrespective of the assay method, meta-analysis confirmed significantly lower hsCRP levels in those with HNF1A-MODY than in those with other aetiologies (z score -21.8, p < 5 × 10(-105)). HNF1A-MODY cases with missense mutations had lower hsCRP levels than those with truncating mutations (0.03 vs 0.08 mg/l, p < 5 × 10(-5)). High-sensitivity CRP values between assays were strongly correlated (r (2) ≥ 0.91, p ≤ 1 × 10(-5)). Across the seven centres, the C-statistic for distinguishing HNF1A-MODY from young adult-onset type 2 diabetes ranged from 0.79 to 0.97, indicating high discriminative accuracy.

CONCLUSIONS/INTERPRETATION

In the largest study to date, we have established that hsCRP is a clinically valid biomarker for HNF1A-MODY in European populations. Given the modest costs and wide availability, hsCRP could translate rapidly into clinical practice, considerably improving diagnosis rates in monogenic diabetes.

Age-related protective effect of deprenyl on changes in the levels of diagnostic marker enzymes and antioxidant defense enzymes activities in cerebellar tissue in Wistar rats

Antioxidants are free radical scavengers and protect living organisms against oxidative damage to tissues. Experimental evidence implicates oxygen-derived free radicals as important causative agents of aging and the present study was designed to evaluate the age-related effects of deprenyl on the antioxidant defense in the cerebellum of male Wistar rats. Experimental rats of three age groups (6, 12, and 18 months old) were administered with liquid deprenyl (2 mg/kg body weight/day for a period of 15 days i.p) and levels of diagnostic marker enzymes (alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and creatine phosphokinase) in plasma, lipid peroxides, reduced glutathione and activities of glutathione-dependent antioxidant enzymes (glutathione peroxidase and glutathione-S-transferase) and antiperoxidative enzymes (catalase and superoxide dismutase) in the cerebellar tissue were determined. Intraperitonial administration of deprenyl (2 mg/kg body weight/day for a period of 15 days) significantly (p < 0.05) attenuated the age-related alterations noted in the levels of diagnostic marker enzymes plasma of experimental animals. Deprenyl also exerted an antioxidant effect against aging process by hindering lipid peroxidation to an extent. Moderate rise in the levels of reduced glutathione and activities of glutathione-dependent antioxidant enzymes and antiperoxidative enzymes was also observed. The results of the present investigation indicated that the protective potential of deprenyl was probably due to the increase of the activity of the free radical scavenging enzymes or to a counteraction of free radicals by its antioxidant nature or to a strengthening of neuronal membrane by its membrane-stabilizing action. Histopathological observations also confirmed the protective effect of deprenyl against the age-related aberrations in rat cerebellum. These data on the effect of deprenyl on parameters of normal aging provides new additional information concerning the anti-aging potential of deprenyl.

Supplementation of deprenyl attenuates age associated alterations in rat cerebellum

Aging, a multifactorial process of enormous complexity is characterised by physio-chemical and biological aspects of cellular functions. It is closely associated with changes in metabolism of various biological molecules in the system. In the present study, we have investigated the effect of deprenyl on cerebellum during ageing process in male Wistar rats with respect to the changes in levels of protein, glycoproteins and amino acids in experimental rats of three age groups (6, 12 and 18 months old). Intraperitoneal administration of liquid deprenyl (2 mg/kg body weight/day for a period of 15 days i.p., significantly P < 0.05) attenuated age-associated alterations in the levels of amino acids (taurine, aspartate, glutamate, arginine, hydroxy proline and homocysteine), protein content and glycoprotein components (hexose and hexosamine) in the rat cerebellum. The results of the present investigation indicate that the protective effect of deprenyl is probably related to its ability to strengthen the neuronal membrane by its membrane stabilizing action or to a counteraction of free radicals by its antioxidant property.

Dark neurons in the ageing cerebellum: their mode of formation and effect of Maharishi Amrit Kalash

Dark neurons are considered a manifestation of neuronal injury and although they cover various grades of damage their mode of formation is not yet clear. Age-dependent alterations in a dark purkinje neuronal population of guinea pigs (10 months and 32 months old) and rats (3 months, 6 months, 12 months, 15 months and 28 months) were studied. Light microscopical and electron microscopical observations revealed a significant increase (P < 0.05) in the number of dark purkinje neurons with age in both the guinea pigs and rats. Extraction of lipids from the cerebellum sections before processing for histochemical reaction resulted in a reduction of the dark neuronal population. In an other set of experiments, significant age-dependent increase in the cathepsin-D activity and lipid peroxidation was documented in the guinea pig cerebellum. Treatment of guinea pigs with Maharishi Amrit Kalash (MAK) (500 mg/kg body wt/day, for two months) significantly inhibited (P < 0.05) the activity of cathepsin-D and lipid peroxidation, and decreased the number of dark neurons. These findings suggest that the number of dark neurons increases with age and MAK prevents the conversion of light to dark purkinje neurons due to its inhibitory effects on cathepsin-D activity and antioxidant properties. We suggest that the conformational changes in the normal protein structure due to higher proteolytic activity and peroxidation of lipid in the aging cerebellum endangers a redundant capability for various staining agents and the Osimic acid molecules to react with proteins, lipids and other molecules, leading to an intensified cyto- and karyoplasms electron density.

Evidence of oxidative stress in chronic venous ulcers

Reactive oxygen species have been implicated in the impaired healing of chronic leg ulcers but little direct evidence is available. We have observed a significant (p < 0.01) elevation of the allantoin : uric acid percentage ratio, a marker of oxidative stress, in wound fluid from chronic leg ulcers (median 17, range 8-860) compared to both paired plasma (median 2, range 1-8) and acute surgical wound fluid (median 4, range 3-7). However, the allantoin : uric acid percentage ratio did not differ significantly between chronic wounds that healed and those that failed to heal. Neutrophil elastase was elevated 30- to 1300-fold in chronic wound fluid compared to plasma and there was a correlation (r(2) = 0.742) between wound fluid elastase and the allantoin : uric acid percentage ratio. Total antioxidant capacity of wound fluid, as measured with a chemiluminescence assay, did not show a correlation (r(2) = 0.03) with the observed oxidative stress. These observations suggest that conditions of localized oxidative stress, possibly related to neutrophil-associated production of reactive oxygen species, are present in chronic leg ulcers. It is possible that future therapeutic strategies aimed at reducing oxidative stress, in addition to good standard care, could improve healing rates of chronic wounds.

Optimisation of an enzymatic method for beta-galactosidase

BACKGROUND

The enzyme beta-galactosidase present in the Kupffer cells of the liver has potential as a marker of liver dysfunction prior to transplantation. Spectrophotometric methods have insufficient sensitivity.

METHODS

Fluorimetric methods have the required sensitivity and we have optimised such a method in a microtitre plate format to improve its utility. beta-galactosidase acts on the substrate 4-methylumbelliferyl-galactoside (MUG) to produce 4-methylumbelliferone (4-MU), detected fluorimetrically with excitation wavelength 355 nm and emission wavelength 460 nm.

RESULTS

Reaction conditions in a citrate-phosphate buffer were optimised to give maximal enzyme activity: pH was optimal at 4.4 (range investigated 3.6-5.0) and substrate concentration at 3.33 mmol/l. A small specimen volume (10 microl) in 80 microl of substrate solution produced adequate fluorescent yield after an incubation period of 30 to 60 min at 37 degrees C. Reaction was terminated by addition of 200 microl of glycine-NaOH, pH 12.8. The assay is linear to 3,000 U/ml. The intra-assay coefficient of variation (CV%) at 50, 502, and 2,012 U/ml was 4.7, 3.1, and 3.4, respectively (n=10). Inter-assay CV% at 51, 496, and 1,986 U/ml was 7.0, 4.0, and 3.9, respectively (n=10).

CONCLUSIONS

The assay has greater practical utility and demonstrated significant differences in the perfusate beta-galactosidase between cold-stored and warm-perfused livers in a porcine model of transplantation.

Clinical usefulness of cystatin C for the estimation of glomerular filtration rate in type 1 diabetes: reproducibility and accuracy compared with standard measures and iohexol clearance

OBJECTIVE-Assessment and follow-up of early renal dysfunction is important in diabetic nephropathy. Plasma creatinine is insensitive for a glomerular filtration rate (GFR) >50 ml/min and creatinine clearance is unwieldy and subject to collection inaccuracies. We aimed to assess the reproducibility, reliability, and accuracy of plasma cystatin C as a measure of GFR ranging from normal to moderate impairment due to type 1 diabetes in the presence of a normal plasma creatinine concentration. RESEARCH DESIGN AND METHODS-A sensitive immunoturbidimetric cystatin C assay was examined in 29 subjects with type 1 diabetes and 11 nondiabetic subjects. Duplicate measurements of the following were collected from each subject, 2 weeks apart: cystatin C, enzymatic plasma creatinine, 24-h creatinine clearance, GFR estimated from plasma creatinine by the Cockcroft-Gault equation, and iohexol clearance as a gold standard. RESULTS-Iohexol clearance ranged from 35 to 132 ml. min(-1). 1.73 m(-2). Plasma cystatin C compared well with the other clinically used tests. The reliability of cystatin C, as assessed by the discriminant ratio, was superior to creatinine clearance (3.4 vs. 1.5, P < 0.001) and the correlation of cystatin C with iohexol clearance (Rs -0.80) was similar to that of creatinine clearance (Rs -0.74) and superior to that of plasma creatinine and the Cockcroft-Gault estimate (Rs -0.54 and 0.66, respectively). Duplicate estimations were used to provide an unbiased equation to convert plasma cystatin C to GFR. CONCLUSIONS-Based on this study, cystatin C is a more reliable measure of GFR than creatinine clearance, is more highly correlated with iohexol clearance than plasma creatinine, and is worthy of further investigation as a clinical measure of GFR in type 1 diabetes.

Improved immunoturbidimetric assay for cystatin C

An immunoturbidimetric assay for cystatin C was optimized with respect to assay imprecision. After investigating the optimum pH, polyethylene glycol concentration and specimen volume, two modifications were introduced: an increase in specimen volume to 25 microL; and an extension of the pre-incubation period to 240 s. These modifications produced an assay with between-batch imprecision (coefficient of variation, n = 10 or 11) ranging from 3-9% at 0.72 mg/L to 1.3% at 5.29 mg/L. The assay was susceptible to interference from lipaemia and haemolysis but not bilirubinaemia in both the original and modified protocol. Extending the pre-incubation to 240 s improved tolerance to common interferences and retained assay applicability in the routine clinical setting.

Simple biochemical markers to assess chronic wounds

We investigated the potential for the biochemical analysis of chronic wound fluid to predict healing using simple and widely available analytes in an out-patient clinic setting. Wound fluid was collected from 12 patients attending a leg ulcer clinic and analyzed for a variety of analytes, including lactate, total protein, and albumin. Twelve weeks after collection the wound was assessed for healing (defined as complete healing or greater than 50% reduction in wound size). The median total protein (44.3 +/- 8.8 g/l) and albumin (25.0 +/- 2.3 g/l) concentrations in exudate collected from four healing wounds were significantly higher (p < 0.05) than in exudate from eight nonhealing wounds (median total protein 29.7 +/- 7.6 g/l, median albumin 17.0 +/- 4.3 g/l). No significant difference was observed for lactate. A second specimen of wound fluid was collected from four of the patients (three nonhealing and one healing). The protein analysis confirmed the pattern observed for the first collection: nonhealing wounds had total protein and albumin which remained low compared to healing wounds. No wound with an exudate albumin of less than 20 g/l healed. Both total protein and albumin are stable analytes which can be easily measured in any laboratory and may offer a simple biomarker of healing in chronic wounds.

Nicotine-induced norepinephrine release in the rat amygdala and hippocampus is mediated through brainstem nicotinic cholinergic receptors

Previous studies have shown that nicotine stimulates norepinephrine (NE) release in the rat hypothalamic paraventricular nucleus, which in turn activates the hypothalamo-pituitary-adrenal axis. In the present study, nicotine induced NE release in the amygdala (AMYG) and the hippocampus (HP) of the same rat in vivo. Nicotine (0.065-0.135 mg/kg i.v. at a rate of 0.09 mg/kg/60 sec) dose-dependently increased NE release at both sites with similar potencies. To determine whether the site of action of nicotine is in the brainstem, which contains the noradrenergic cell bodies projecting to AMYG and HP, nicotinic cholinergic receptor (NAchR) antagonists were injected into the cerebral aqueduct before i.v. nicotine. Use of the following antagonists enabled partial characterization of the NAchRs mediating NE secretion: mecamylamine (Mec), dihydro-beta-erythroidine (DH beta E), methyllycaconitine (MLA) and alpha-bungarotoxin (alpha-BTX). Mec inhibited 80% of NE release in AMYG and 87% in HP (IC50 = 6 nmol for both regions). DH beta E blocked 62% of NE release in AMYG (IC50 = 8 nmol) and 63% in HP (IC50 = 15 nmol). Similar to DH beta E, MLA inhibited 60% of NE release in AMYG and 66% in HP (IC50 = 5 nmol for both regions). In contrast, alpha-BTX had no effect on NE release in either region. These results indicate that brainstem NAchRs accessible from the fourth ventricle mediate nicotine-stimulated NE secretion in AMYG and HP. Taken together with prior investigations showing the brainstem expression of mRNAs encoding NAchR subtypes and the selectivity of antagonists for NAchR subtypes, the present studies suggest that brainstem alpha-3 subunits may be involved.

Enzymatic determination of sodium and chloride in sweat

OBJECTIVE

To develop methods based on enzyme activation for the analysis of sweat sodium and chloride using beta-galactosidase and alpha-amylase, respectively.

METHODS

Both were monitored kinetically on the Cobas Fara centrifugal analyzer. The sweat, collected with the Macroduct system, was diluted no more than five-fold for the volumes obtained of 16 to 80 mu L, median 32.5 mu L. The sodium assay utilized a sodium-binding cryptand to maximize linearity.

RESULTS

Between-run coefficients of variation (%) at 10, 20, and 50 mmol/L were 3.6, 4.5, and 1.3 for sodium and 7.1, 6.1, and 6.0 for chloride, respectively. The sodium method showed excellent agreement with flame photometry (y = 0.997x + 0.742; r = 0.998), and chloride with a mercuric thiocyanate method (y = 0.995x + 0.485; r = 0.996), giving equivalent discrimination between patients with and without cystic fibrosis.

CONCLUSIONS

The methods enable the rapid analysis on the same analyzer of both sodium and chloride in a single dilution of sweat collections of low volume.

Regional and lobular variation in neuronal lipofuscinosis in rat cerebellum: influence of age and protein malnourishment

Various factors other than ageing influence lipofuscinosis in neurons and other cells. Protein malnutrition is one such factor that has been studied. In the present study 3 months old rats were subjected to protein malnutrition (PM) for 3, 6 and 12 months by feeding them with low protein diet (4% protein). An age matched control group of rats was also maintained on a normal diet with high protein content (20% protein). The cerebella from the PM and control group rats were processed for histochemical, biochemical and fluorescent microscopic studies. Quantitative analysis of lipofuscin revealed that PM caused an increase in lipofuscin accumulation in the Purkinje neurons. A similar study on the Purkinje neurons of rats belonging to various age groups i.e. 6, 9 and 15 months, showed an increase in lipofuscin accumulation with age. Further, the increase in lipofuscinosis in ageing and PM rats was found to be varying. The maximum lipofuscin accumulation with PM was in the neurons of the 5th and 7th (75% and 71%, respectively) lobule of vermian region. The maximum increase in lipofuscin accumulation with age was found to be in lobule III (105.8%) of vermian region. Such a variation occurred in the hemisphere region also. Moreover, taking the two regions of cerebellum as a whole, neurons of the hemisphere region accumulated more amount of lipofuscin than those of the vermis region. The authors feel that the regional specificity of lipofuscin accumulation is to be studied in terms of the functional role of the various regions of a particular tissue in question.

Lipofuscin accumulation in neurons with restraint stress

Stress induced lipofuscinosis was studied in rat cerebellum. 3 month old wistar rats were subjected to restraint stress by keeping them immobile for 24, 48 and 72 hours duration. This was achieved in specially prepared cages which allowed no space for the rats to move; giving a stress to the animal. The cerebella from the stressed groups rats were removed after the experiment and were processed for fluorescent microscopical, histochemical and fluorimetric study of lipofuscin. The lipofuscin content in the Purkinje neurons was compared with that of the control rats which were of the same age, size and weight as of the experimental rats. The results showed that the lipofuscin content in the neurons of the experimental rats was more than that of the control ones. In gist, while 24 hrs. stress caused a 28.9% increase in lipofuscin content, 48 hrs. stress resulted in a 38.3% increase. This shows that restraint stress can be a good experimental model for lipofuscinogenesis and ageing studies.

The in vivo and in vitro effects of antibodies against rabbit beta 2-integrins

Beta 2-integrins play a crucial role in the development of an inflammatory response. In ours study, Abs have been used to investigate the role of individual members of this family of adhesion molecules in both in vivo and in vitro assays. An Ab against rabbit LFA-1 effectively inhibited the adhesion of rabbit polymorphonuclear leukocytes to rabbit endothelial cells in culture and was also effective in blocking cell recruitment to the peritoneum and vascular leakage at dermal sites of inflammation. An Ab that inhibited rabbit complement receptor type 3 function in vitro failed to inhibit cell recruitment to the peritoneum or vascular leakage in response to intradermal FMLP. Histologic studies suggested that the anti-complement receptor type 3 Ab may have modified the cell migration process.

The in vivo and in vitro effects of antibodies against rabbit beta 2-integrins

Beta 2-integrins play a crucial role in the development of an inflammatory response. In ours study, Abs have been used to investigate the role of individual members of this family of adhesion molecules in both in vivo and in vitro assays. An Ab against rabbit LFA-1 effectively inhibited the adhesion of rabbit polymorphonuclear leukocytes to rabbit endothelial cells in culture and was also effective in blocking cell recruitment to the peritoneum and vascular leakage at dermal sites of inflammation. An Ab that inhibited rabbit complement receptor type 3 function in vitro failed to inhibit cell recruitment to the peritoneum or vascular leakage in response to intradermal FMLP. Histologic studies suggested that the anti-complement receptor type 3 Ab may have modified the cell migration process.

An adaptable computer interface for radioimmunoassay

To assist data handling of results derived from radioimmunoassay the RIACalc Multigamma counter package was interfaced to a laboratory information system. The interface was bidirectional and allowed transfer of worklists and results. A suite of programs was written for the laboratory information system that enabled flexible data processing to meet a range of laboratory requirements. One utility within the suite contained a simple user definable rule based routine for automatically requesting additional tests. Use of the interface and new software improved laboratory efficiency and illustrated the potential benefits of decision making systems.

'Dark' cell formation under protein malnutrition: process of conversion and concept of 'semi-dark' type Purkinje cells

This paper deals with some deleterious effects of protein malnourishment in rat cerebellum. Severe protein deprivation enhanced the formation of 'dark' cells in white rats. It is postulated that abnormal changes in the neuronal contents induced by nutritional stress play a vital role in the formation of the 'dark' cells through an intermediary stage, 'semi-dark' cells. Centrophenoxine a lipofuscinolytic agent, however, seems to interfere with the process of formation of 'dark' cells and/or helps reconversion of the 'dark' cells into the normal or 'light' type Purkinje cells.