Quantitative assessment of oil palm pollen after 23 years of cryobanking

Cryopreservation of pollen grains is an effective means of conserving desired germplasm of crop plants. Cryoconserved pollen are expected to be long-lived and thus can be suitably retrieved to overcome hybridization constraints imposed by a variety of reasons. We ascertained the performance of oil palm pollen grains (Tenera hybrids) that were cryobanked 23 years ago using liquid nitrogen (-196 degree C). Cryostored pollen were assessed for viability, in-vitro germinability and vigour. Our analysis showed a marginal decline in viability, assessed through fluorochromatic reaction test, of cryopreserved pollen as compared to fresh ones (pre-storage assessment); however, the viability did not decline in the cryostate since it was last tested 15 years back. On the other hand, germinability and vigour of cryopreserved pollen were maintained to the levels of fresh pollen. Our study, for the first time, demonstrates the amenability of pollen grains for cryopreservation of any plant species beyond a period of two decades in general, and that for oil palm in particular. doi.org/10.54680/fr23110110512.

Genomic signatures of protease and reverse transcriptase genes from HIV-1 subtype C isolated from first-line ART patients in India

Genomic signatures of the protease and reverse transcriptase gene of HIV-1 from HIV infected North Indian patients who were under ART from 1 to ≤ 7 years were analyzed. The DNA from plasma samples of 9 patients and RNA from 57 patients were isolated and subjected to amplification for the protease and reverse transcriptase gene of HIV-1 subtype C. Then sequencing was carried out following the WHO dried blood spot protocol. The drug resistance mutation patterns were analyzed using the HIV Drug Resistance Database, Stanford University, USA. Lamivudine-associated drug-resistance mutations such as M184V/M184I, nevirapine-associated drug resistance mutations Y181C and H221Y, and efavirenz-associated drug resistance mutations M230I were observed in reverse transcriptase gene of archived DNA of two HIV-1 infected patients. No mutation was observed in the remaining 7 patients. Various computational tools and websites like viral epidemiological signature pattern analysis (VESPA), hyper mutation, SNAP version 2.1.1, and entropy were utilized for the analysis of the signature pattern of amino acids, hyper mutation, selection pressure, and Shannon entropy in the protease and reverse transcriptase gene sequences of the 9 archived DNA, 56 protease gene and 51 reverse transcriptase gene from the HIV-1 DNA amplified sequences of RNA. The HIV-1 Subtype-C (Gene bank accession number: AB023804) and first isolate HXB2 (Gene bank accession number: K03455.1) was taken as reference sequence. The signature amino acid sequences were identified in the protease and reverse transcriptase gene, no hyper mutation, highest entropy was marked in the amino acid positions and synonymous to non-synonymous nucleotide ratio was calculated in the protease and reverse transcriptase gene of 9 archived DNA sequences, 56 protease and 51 reverse transcriptase gene sequences of HIV-1 Subtype C isolates.

Quantitative assessment of oil palm pollen after 23 years of cryobanking

Cryopreservation of pollen grains is an effective means of conserving desired germplasm of crop plants. Cryoconserved pollen are expected to be long-lived and thus can be suitably retrieved to overcome hybridization constraints imposed by a variety of reasons. We ascertained the performance of oil palm pollen grains (Tenera hybrids) that were cryobanked 23 years ago using liquid nitrogen (-196 degree C). Cryostored pollen were assessed for viability, in-vitro germinability and vigour. Our analysis showed a marginal decline in viability, assessed through fluorochromatic reaction test, of cryopreserved pollen as compared to fresh ones (pre-storage assessment); however, the viability did not decline in the cryostate since it was last tested 15 years back. On the other hand, germinability and vigour of cryopreserved pollen were maintained to the levels of fresh pollen. Our study, for the first time, demonstrates the amenability of pollen grains for cryopreservation of any plant species beyond a period of two decades in general, and that for oil palm in particular. doi.org/10.54680/fr23110110512.

Detection of Drug Resistance Mutations in the Reverse Transcriptase Gene of HIV-1-Infected North Indian Population Failing First-Line Antiretroviral Therapy "A Follow-Up Cohort Study"

We aim to characterize the drug resistance mutations in reverse transcriptase gene of HIV-1 subtype C-infected North Indian population in those who are failing first-line antiretroviral therapy (ART) and if these mutations are associated with mortality. We also attempted the assessment of switch over to second-line antiretroviral therapy in these patients. Based on the immunological marker CD4 count (<350 cubic/mm), 192 HIV/AIDS patients were selected and viral load was estimated in those who were enrolled from December 2009 to November 2016. Based on viral load, genotyping was carried out in 57 HIV-1 isolates (VL ≥1,000 copies/mL) by sequencing and drug resistance mutations were examined through the Stanford HIV Drug Resistance Database, USA. Among them, 21 (36.84%) first-line ART failure patients were shifted to second-line ART. These patients were followed for a period wide ranging from 10 months to 11 years. Drug resistance mutation M184V (ATG to GTA) (63.15%) associated with lamivudine and abacavir and K103N (AAG or AAA to AAU) (36.84%) associated with efavirenz and nevirapine were predominantly identified in first-line ART failure patients. During follow-up, it was observed that 3 out of 21 who were in second-line ART died, whereas 9 out of 36 died who were in the first-line ART. No mutation could be associated with mortality although TAM-2 mutations were absent in patients who died. This study indorses the need for a facility for viral load estimation and resistance monitoring in each treatment failure patient and availability of appropriate antiretroviral therapies.

Identification and differential expression of serotransferrin and apolipoprotein A-I in the plasma of HIV-1 patients treated with first-line antiretroviral therapy

Background

Plasma proteins are known to interfere the drug metabolism during therapy. As limited information is available regarding the role of plasma proteins in HIV drug resistance during ART in HIV/AIDS patients, the present study aimed to identify and characterize the differentially expressed plasma proteins in the drug resistant and drug respondent groups of HIV-1 infected patients with > 6 years of first line ART.

Methods

Four-drug resistant (treatment failure) and four-drug respondent (treatment responder) patients were selected for plasma proteomic analysis based on viral load and drug resistance associated mutations from a cohort study designed on the first line ART patients who were enrolled in the antiretroviral therapy center, Sarojini Naidu Medical College, Agra, India from December 2009 to November 2016.

After depleting high abundant proteins, plasma proteins were resolved using two-dimensional gel electrophoresis on IPG strips, pH range of 3–10. Spots were selected in the gel based on the density of staining which was common in the drug resistant and drug respondent groups separately. The fold change of each spot was calculated using image-J. Each protein spot was identified using the matrix assisted laser desorption/ionization-time of flight/time of flight (MALDI-TOF/TOF) after tryptic digestion. Peptide peaks were identified through flex analysis version 3.3, and a search against a protein data base using the internal Mascot. Gene ontology study was completed through STRING v.11 and Panther15.0.

Results

Out of eight spots from 2D gel samples analyzed by MALDITOF/TOF, two proteins were found to have significant score (> 56) after Flex analysis. These two proteins were identified to be apolipoprotein A1 and serotransferrin. The fold change expression of these two proteins were analyzed in drug resistant and drug respondent group. Apolipoprotein-A1 and serotransferrin were observed to be expressed 1.76 and 1.13-fold more respectively in drug respondent group compared to drug resistant group. The gene ontology analysis revealed the involvement of these two proteins in various important physiological processes.

Conclusion

Apolipoprotein A-I and serotransferrin were found to be expressed more in drug respondent group compared to drug resistant group.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05610-6.

Psychotic Disorders in DSM-5

DSM-5 presents an opportunity to provide greater clarity to constructs involved in classification of psychotic disorders by establishing a meta-structure based on spectra of pathology, giving emphasis to the syndromal nature of current disorders, and to guide ascertainment of psycho-pathology domains to increase understanding of individual cases. There was a need to reduce spurious comorbidity, increase validity, improve reliability, consider possible new disorders, and provide more coherence across chapters in the diagnostic manual. While balancing these objectives, the new information about the nature of these disorders that has been generated since DSM-IV was incorporated into their definition. For example, variations in distinct psychopathological dimensions have been found to better account for the heterogeneity of schizophrenia than traditional subtypes. Resulting changes in DSM-5 include elimination of the classic sub-types of schizophrenia, addition of unique psychopathological dimensions, elimination of special treatment of Schneiderian “first-rank symptoms”, better delineation of schizoaffective disorder, clarification of the nosologic status of catatonia and its consistent treatment across the manual, more precise description of illness course specifiers, and addition of a new category of “attenuated psychosis syndrome” as a condition for further study. The rationale behind and the specific nature of these revisions in the DSM-5 criteria for schizophrenia spectrum and other psychotic disorders are summarized in this article.

Floral contrivances and specialised pollination mechanism strongly influence mixed mating in Wrightia tomentosa (Apocynaceae)

Reproductive success of a plant species is largely influenced by the outcome of mating pattern in a population. It is believed that a significantly larger proportion of animal-pollinated plants have evolved a mixed-mating strategy, the extent of which may vary among species. It is thus pertinent to investigate the key contributors to mating success, especially to identify the reproductive constraints in depauperate populations of threatened plant species. We examined the contribution of floral architecture, pollination mechanism and breeding system on the extent of outcrossing rate in a near-threatened tree species, Wrightia tomentosa. The breeding system was ascertained from controlled pollination experiments. In order to determine outcrossing rate, 60 open-pollinated progeny were analysed using an AFLP markers. Although the trees are self-compatible, herkogamy and compartmentalisation of pollen and nectar in different chambers of the floral tube effectively prevent spontaneous autogamy. Pollination is achieved through specialised interaction with moths. Differential foraging behaviour of settling moths and hawkmoths leads to different proportions of geitonogamous and xenogamous pollen on the stigma. However, most open-pollinated progeny were the result of xenogamy (outcrossing rate, tm = 0.68). The study shows that floral contrivances and pollination system have a strong influence on mating pattern. The differential foraging behaviour of the pollinators causes deposition of a mixture of self- and cross-pollen to produce a mixed brood. Inbreeding depression and geitonogamy appear to play a significant role in sustaining mixed mating in this species.

Overexpression of cyclin A in oral dysplasia: An international comparison and literature review

Oral squamous cell carcinoma (OSCC) is one of the most debilitating cancers in the world and while its causes have been heavily researched, the outcome remains grim. Most of these cancers are identified in the late stage and as a result treatment options are limited. Therefore, researchers have focused their efforts on recognizing and identifying dysplastic tissue that has an increased chance of progressing to cancer. Research has begun to look at cell cycle dysfunctions and in particular, aberrant protein functions as a way of identifying the cellular mechanism at fault. The overexpression of a group of regulatory proteins called cyclins has been demonstrated in many types of dysplasia and carcinomas. Although researchers have identified several different types of cyclins as potential culprits, we chose to focus our study primarily on the overexpression of cyclin A. While most research on oral dysplasia and OSCC has been focused on cyclin D, studies have been done on cyclin A. While the etiology of oral dysplasia/SCC appears to be multifactorial, we chose to compare our results with those of similar studies performed across the globe. The social factors, such as the increased use of tobacco that may have contributed to our results, were compared with similar studies performed in Europe and Asia. While our results were remarkably similar and demonstrated a link between the overexpression of cyclin A in oral dysplasia, there exists some differences and thus may require a multicenter, longitudinal study.

Coating doxorubicin-loaded nanocapsules with alginate enhances therapeutic efficacy against Leishmania in hamsters by inducing Th1-type immune responses

BACKGROUND AND PURPOSE

The aim of the present study was to evaluate the immunomodulatory and chemotherapeutic potential of alginate-(SA) coated nanocapsule (NCs) loaded with doxorubicin (SA-NCs-DOX) against visceral leishmaniasis in comparison with nano-emulsions containing doxorubicin (NE-DOX).

EXPERIMENTAL APPROACH

NE-DOX was prepared using low-energy emulsification methods. Stepwise addition of protamine sulphate and SA in a layer-by-layer manner was used to form SA-NCs-DOX. SA-NCs-DOX, NE-DOX and Free DOX were compared for their cytotoxicity against Leishmania donovani-infected macrophages in vitro and generation of T-cell responses in infected hamsters in vivo.

KEY RESULTS

Size and ζ potential of the NE-DOX and SA-NCs-DOX formulations were 310 ± 2.1 nm and (-)32.6 ± 2.1 mV, 342 ± 4.1 nm and (-)29.3 ± 1.2 mV respectively. SA-NCs-DOX was better (1.5 times) taken up by J774A.1 macrophages compared with NE-DOX. SA-NCs -DOX showed greater efficacy than NE-DOX against intramacrophagic amastigotes. SA-NCs-DOX treatment exhibited enhanced apoptotic efficiency than NE-DOX and free DOX as evident by cell cycle analysis, decrease in mitochondrial membrane potential, ROS and NO production. T-cell responses, when assessed through lymphoproliferative responses, NO production along with enhanced levels of iNOS, TNF-α, IFN-γ and IL-12 were found to be up-regulated after SA-NCs-DOX, compared with responses to NE-DOX in vivo. Parasitic burden was decreased in Leishmania-infected hamsters treated with SA-NCs-DOX, compared with NE-DOX.

CONCLUSIONS AND IMPLICATIONS

Our results provide insights into the development of an alternative approach to improved management of leishmaniasis through a combination of chemotherapy with stimulation of the innate immune system.

Phenotypic evaluation of severely damaged ocular surface after reconstruction by cultured limbal epithelial cell transplantation

OBJECTIVE

To report the clinical outcome of autologous cultured limbal epithelial cell transplantation (CLECT) followed by deep anterior lamellar keratoplasty (DALK) in paediatric eyes and to correlate the clinical outcome with the phenotype of rejuvenated corneal epithelium.

METHODS

Four patients with total limbal stem cell deficiency (LSCD) underwent autologous CLECT. Cultivated cell sheets were transplanted onto the damaged ocular surface followed by DALK surgery. Excised corneal buttons were subjected to histopathological analysis. Data recorded included age, sex, laterality, nature of injury, follow-up period, severity of stem cell deficiency, visual acuity, Schirmer's test and impression cytology.

RESULTS

At a mean follow-up period of 19.5 ± 7.4 (range 9-26) months after CLECT, all 4 eyes showed epithelialized and clinically stabilized ocular surface. Manual DALK was performed in all 4 eyes, with a mean follow-up of 9.75 ± 4.5 (range 5-15) months. All eyes exhibited smooth and clear corneal epithelium with improved visual acuity. Excised corneal buttons demonstrated organized corneal epithelial morphology and showed expression of cornea-specific CK3/12 marker.

CONCLUSION

Restoration of severely damaged ocular surface following chemical injury by using 2-stage meticulous approaches offers a new modality for the treatment of severe LSCD. Transplantation of cultivated autologous limbal epithelial cell sheet followed by DALK surgery can efficiently restore the corneal phenotype with improved vision.

Rheumatic fever & rheumatic heart disease: the last 50 years

Rheumatic fever (RF) and rheumatic heart disease (RHD) continue to be a major health hazard in most developing countries as well as sporadically in developed economies. Despite reservations about the utility, echocardiographic and Doppler (E&D) studies have identified a massive burden of RHD suggesting the inadequacy of the Jones' criteria updated by the American Heart Association in 1992. Subclinical carditis has been recognized by E&D in patients with acute RF without clinical carditis as well as by follow up of RHD patients presenting as isolated chorea or those without clinical evidence of carditis. Over the years, the medical management of RF has not changed. Paediatric and juvenile mitral stenosis (MS), upto the age of 12 and 20 yr respectively, severe enough to require operative treatement was documented. These negate the belief that patients of RHD become symptomatic ≥20 years after RF as well as the fact that congestive cardiac failure in childhood indicates active carditis and RF. Non-surgical balloon mitral valvotomy for MS has been initiated. Mitral and/or aortic valve replacement during active RF in patients not responding to medical treatment has been found to be life saving as well as confirming that congestive heart failure in acute RF is due to an acute haemodynamic overload. Pathogenesis as well as susceptibility to RF continue to be elusive. Prevention of RF morbidity depends on secondary prophylaxis which cannot reduce the burden of diseases. Primary prophylaxis is not feasible in the absence of a suitable vaccine. Attempts to design an antistreptococcal vaccine utilizing the M-protein has not succeeded in the last 40 years. Besides pathogenesis many other questions remain unanswered.

Neurocognitive dysfunction in patients with obsessive compulsive disorder

OBJECTIVE

Although a dysfunctional prefrontal-striatal system is presupposed in obsessive-compulsive disorder (OCD), this is not unequivocally supported by neuropsychological studies. This study aims to study the neurocognitive dysfunctions in OCD patients, compared to controls; to study the variations in neurocognitive deficits with the duration of illness, as well as, the severity of the disease.

METHOD

Thirty OCD patients were compared with thirty, age and education matched control subjects on computer based tests measuring executive functions, vigilance and spatial working memory.

RESULTS

OCD patients performed poorly on all the neuro-cognitive parameters as compared to controls. The severity of illness had a positive correlation with poorer performance on CPT. There were no significant correlations between duration of illness and any parameters of cognition.

CONCLUSION

The results suggest that OCD patients perform significantly worse on cognitive measures than controls. This is consistent with their poorer functional outcome. The results further indicate that on the basis of severity OCD patients are qualitatively distinguishable in neuropsychological terms, given their difference in the profiles of cognitive impairment.

Firecracker injuries during Diwali festival: The epidemiology and impact of legislation in Delhi

SETTING AND DESIGN

A hospital-based retrospective study of firecracker-related injuries was carried out at a government sponsored hospital in Delhi.

MATERIALS AND METHODS

1373 patients attended the emergency burn care out-patients clinic during 2002-2010 pre-Diwali, Diwali and post-Diwali days. Every year, a disaster management protocol is revoked during these 3 days under the direct supervision of the Ministry of Health and Family Welfare, Government of India.

RESULTS

There was an increase in the number of patients of firecracker-related injuries in Delhi national capital region from the year 2002 to 2010, based on the hospital statistics. During the study period, the hospital received approximately one patient with firecracker-related injury per 100,000 population of the city. 73.02% of the victims were 5-30 years old. Majority (90.87%) of them sustained <5% total body surface area burn.

CONCLUSIONS

In spite of legislations and court orders, the number of patients is on the rise. The implementation agencies have to analyse the situation to find a way to control this preventable manmade accident. Websites, emails, SMS, social sites, etc. should be used for public education, apart from conventional methods of public awareness.

Apathy, depression, and motor symptoms have distinct and separable resting activity patterns in idiopathic Parkinson disease

Apathy and depression are heterogeneous syndromes with symptoms that overlap clinically. This clinical overlap leads to problems with classification and diagnosis in clinical populations. No functional imaging study has attempted to separate brain regions altered in apathy from those altered in depression in a clinical population. Parkinson disease (PD) is a disorder in which apathy and depression co-exist in a single population. We evaluate the relationship between apathy, depression, and motor severity of disease in PD, focusing on the relationship between these factors and the amplitude of the low frequency fluctuation (ALFF) in the resting state. We first evaluated if the resting ALFF signal is a reliable measure for our clinical question. For this, we develop and introduce a cross validation approach we term the "Regional Mapping of Reliable Differences" (RMRD) method to evaluate reliability of regions of interest deemed "significant" by standard voxel-wise techniques. Using this approach, we show that the apathy score in this sample is best predicted by ALFF signal in the left supplementary motor cortex, the right orbitofrontal cortex, and the right middle frontal cortex, whereas depression score is best predicted by ALFF signal in the right subgenual cingulate. Disease severity was best predicted by ALFF signal in the right putamen. A number of additional regions are also statistically (but not reliably) correlated with our neuropsychological measures and disease severity. Our results support the use of resting fMRI as a means to evaluate neuropsychiatric states and motor disease progression in Parkinson disease, and the clinical and epidemiologic observation that apathy and depression are distinct pathological entities. Our finding that "significance" and "reliability" are dissociated properties of regions of interest identified as significant using standard voxel-wise techniques suggests that including reliability analyses may add useful scientific information in neurobehavioral research.

Anastomotic strictures and delayed gastric emptying after esophagectomy: incidence, risk factors and management

The aim of this study was to report the incidence, risk factors, and management of gastric conduit dysfunction after esophagectomy in 177 patients over a 3-year period in a single center. Patients with anastomotic strictures or delayed gastric emptying (DGE) were identified from a prospective database. Anastomotic strictures occurred in 48 patients (27%). Eighty-three percent of early anastomotic strictures (<1 year) were benign, and all late strictures (>1 year) were malignant. Dilatation was effective in 98% of benign and 64% of malignant strictures. DGE occurred in 21 patients (12%), and was associated with both anastomotic leak (P = 0.001) and anastomotic stricture (P = 0.001). 4/8 patients with late DGE (>3 months postesophagectomy) were tumor-related. Pyloric dilatation was effective in 92% of early and 63% of late DGE. Pyloric stents were inserted in 3 patients with tumor-related DGE. After esophagectomy, early anastomotic strictures (within 1 year) and early delayed gastric emptying (within 3 months) are usually benign and respond to dilatation. However, patients presenting later with tumor-related obstruction are unlikely to respond to anastomotic or pyloric dilatation and should be stented.

Oxidative stress in hypertension: association with antihypertensive treatment

There is growing evidence that oxidative stress contributes to the pathogenesis of hypertension. Our aim was to measure oxidative stress in hypertensive subjects, and assess the potential confounding influences of antihypertensive therapy. Serum malondialdehyde and antioxidant levels were estimated in patients at the time of presentation and also after a antihypertensive therapy for 3 months. During the period of study no antioxidant/s was given to the patients and control subjects. Mean blood pressure values were altered in the hypertensive patients following antihypertensive therapy from their respective values observed at the time of presentation. Serum malondialdehyde levels were significantly higher in the hypertensive patients in comparison to control cases. The antioxidant activity of enzymes super oxide dismutase, glutathione and non enzymatic antioxidant levels of vitamins E and C were significantly lower in patients compared to controls. After 3 months of antihypertensive treatment all the above parameters showed reversal in the respective levels of serum malondialdehyde and antioxidant activity. Antihypertensive medications lower the blood pressure and thereby results in reduced oxidative stress which indicates that oxidative stress is not the cause, but rather a consequence, of hypertension.

"Tuck In" Lamellar Keratoplasty (TILK) for corneal ectasias involving corneal periphery

AIMS

Evaluation of a new surgical technique for the management of corneal ectasia with peripheral corneal involvement.

METHODS

Twelve eyes of 12 patients with corneal ectasias and peripheral corneal thinning requiring surgical intervention, including eight patients with combined keratoconus and PMD and four patients of keratoglobus, were enrolled for the study in a tertiary care hospital. All patients were contact lens intolerant and had a best corrected visual acuity (BCVA) </=20/120 with nine patients (75%) having BCVA </=20/200. "Tuck In" Lamellar Keratoplasty (TILK) that included a central lamellar keratoplasty with intrastromal tucking of the peripheral flange was performed in these patients. The main outcome measures analysed were uncorrected visual acuity (UCVA), BCVA, keratometry, refractive status and time for epithelial healing.

RESULTS

At the last follow-up (mean: 1.7 years (range 13-48 months)), six patients (50.0%) had BCVA >/=20/60, and all patients had BCVA >/=20/80. The mean keratometry decreased from 57.54 (SD 6.89) D preoperatively to 46.36 (2.39) D (p = 0.003), and the mean spherical equivalent (SEQ) refractive error decreased from -7.8 (4.6) D preoperatively to 1.23 (1.88) D (p = 0.007). A significant decrease was also seen in mean refractive astigmatism which decreased from 5.93 (3.06) D preoperatively to 3.23 (1.14) D (p = 0.037).

CONCLUSION

Our technique of TILK is an effective surgical modality for the management of ectatic corneal dystrophies with peripheral corneal thinning.

'Layer by layer' phacoemulsification in posterior polar cataract with pre-existing posterior capsular rent

PURPOSE

To evaluate a new technique of 'Layer by Layer' phacoemulsification in eyes with posterior polar cataract with pre-existing posterior capsular rent (PCR).

METHODS

Layer by layer phacoemulsification was performed in eight eyes of eight patients of posterior polar cataract with pre-existing posterior capsular rent. All the patients had evidence of a posterior capsular defect showing presence of iridescent refractile lens particles in vitreous with onion skinning of central dense plaque.

RESULTS

The mean age of the patients was 43.75+/-2.5 years and six patients were men. All the eyes had vertical posterior capsular defect irrespective of the site of entry of phaco probe. Vitrectomy was not required in any of the eyes. Single piece foldable acrylic intraocular lens was implanted in the bag in all the eyes. The mean preoperative best corrected visual acuity was 0.14+/-0.05, which improved to 0.77+/-0.27.

CONCLUSION

Our technique of 'Layer by layer' phacoemulsification is an effective and safe technique for the management of posterior polar cataract with pre-existing PCR.

Towards a muscarinic hypothesis of schizophrenia

Although the neurotransmitter dopamine plays a prominent role in the pathogenesis and treatment of schizophrenia, the dopamine hypothesis of schizophrenia fails to explain all aspects of this disorder. It is increasingly evident that the pathology of schizophrenia also involves other neurotransmitter systems. Data from many streams of research including pre-clinical and clinical pharmacology, treatment studies, post-mortem studies and neuroimaging suggest an important role for the muscarinic cholinergic system in the pathophysiology of schizophrenia. This review will focus on evidence that supports the hypothesis that the muscarinic system is involved in the pathogenesis of schizophrenia and that muscarinic receptors may represent promising novel targets for the treatment of this disorder.

HIV infection changes glomerular podocyte cytoskeletal composition and results in distinct cellular mechanical properties

In addition to forming the selective filtration barrier for the renal glomerulus, podocytes maintain glomerular capillary architecture by opposing distending hemodynamic forces. To understand the relationship of cytoskeletal properties and the mechanical characteristics of podocytes, we studied filamin expression and distribution and measured cell membrane deformability in conditionally immortalized wild-type (WT) mouse podocytes, and in podocytes derived from a mouse model of HIV-associated nephropathy (HIVAN). In the WT cells, filamin and F-actin were localized at the periphery and in prominent stress fibers. In the HIVAN cells, filamin expression was reduced, and stress fibers were sparse. In a microaspiration assay, HIVAN cells ruptured under minimal negative pressure. Atomic force microscopy demonstrated that the WT cells had a stiffness of 17 kPa, whereas the value for the HIVAN cells was 4 kPa. These results demonstrate that the mechanical properties of WT and HIVAN podocytes are markedly different in a manner that is consistent with differences in the composition and arrangement of their cytoskeletons. The mechanical properties of the WT podocytes suggest that these cells can better maintain capillary integrity than the HIVAN podocytes and implicate pathological assembly of the cytoskeleton as a mechanism of HIVAN.

Increase in weight induced by muraglitazar, a dual PPARalpha/gamma agonist, in db/db mice: adipogenesis/or oedema?

BACKGROUND AND PURPOSE

Muraglitazar, a dual PPARalpha/gamma agonist, caused a robust increase in body weight in db/db mice. The purpose of the study was to see if this increase in weight was due to oedema and/or adipogenesis.

EXPERIMENTAL APPROACH

The affinity of muraglitazar at PPARalpha/gamma receptors was characterized using transactivation assays. Pre-adipocyte differentiation, expression of genes for adipogenesis (aP2), fatty acid oxidation (ACO) and sodium reabsorption (ENaCgamma and Na+, K+-ATPase); haemodilution parameters and serum electrolytes were measured to delineate the role of muraglitazar in causing weight gain vis a vis rosiglitazone.

KEY RESULTS

Treatment with muraglitazar (10 mg kg(-1)) for 14 days significantly reduced plasma glucose and triglycerides. Reduction in plasma glucose was significantly greater than after similar treatment with rosiglitazone (10 mg kg(-1)). A marked increase in weight was also observed with muraglitazar that was significantly greater than with rosiglitazone. Muraglitazar increased aP2 mRNA and caused adipocyte differentiation in 3T3-L1 cells similar to rosiglitazone. It also caused a marked increase in ACO mRNA in the liver of the treated mice. Expression of mRNA for ENaCgamma and Na+, K+-ATPase in kidneys was up-regulated after either treatment. Increased serum electrolytes and decreased RBC count, haemoglobin and haematocrit were observed with both muraglitazar and rosiglitazone.

CONCLUSIONS AND IMPLICATIONS

Although muraglitazar has a better glucose lowering profile, it also has a greater potential for weight gain than rosiglitazone. In conclusion, muraglitazar causes both robust adipogenesis and oedema in a 14-day treatment of db/db mice as observed in humans.