Cell-specific extracellular vesicle-encapsulated exogenous GABA controls seizures in epilepsy

BACKGROUND

Epilepsy affects ∼60 million people worldwide. Most antiseizure medications in the market act on voltage-gated sodium or calcium channels, indirectly modulating neurotransmitter GABA or glutamate levels or multiple targets. Earlier studies made significant efforts to directly deliver GABA into the brain with varied success. Herein, we have hypothesized to directly deliver exogenous GABA to the brain with epilepsy through extracellular vesicles (EVs) from human GABA-producing cells and their progenitors as EVs largely mimic their parent cell composition.

METHODS

Human neural stem cells (NSCs), medial ganglionic eminence (MGE) cells, and GABAergic interneurons (INs) were generated from induced pluripotent stem cells (iPSCs) and characterized. EVs were isolated from NSCs, MGE cells, and INs and characterized for size and distribution, morphological features, and molecular markers. Exogenous GABA was passively loaded to the isolated EVs as a zwitterion at physiological pH, and the encapsulated dose of GABA was quantified. Epilepsy was developed through status epilepticus induction in Fisher rats by administration of repeated low doses of kainic acid. The extent of the seizures was measured for 10 h/ day for 3-6 months by video recording and its evaluation for stage III, IV and V seizures as per Racine scale. EVs from INs, MGE cells, and NSCs encapsulated with exogenous GABA were sequentially tested in the 4th, 5th, and 6th months by intranasal administration in the rats with epilepsy for detailed seizure, behavioral and synapse analysis. In separate experiments, several controls including exogenic GABA alone and EVs from INs and MGE cells were evaluated for seizure-controlling ability.

RESULTS

Exogenic GABA could enter the brain through EVs. Treatment with EVs from INs and MGE cells encapsulated with GABA significantly reduced total seizures, stage V seizures, and total time spent in seizure activity. EVs from NSCs encapsulated with GABA demonstrated limited seizure control. Exogenic GABA alone and EVs from INs and MGE cells individually failed to control seizures. Further, exogenic GABA with EVs from MGE cells improved depressive behavior while partially improving memory functions. Co-localization studies confirmed exogenous GABA with presynaptic vesicles in the hippocampus, indicating the interaction of exogenous GABA in the brain with epilepsy.

CONCLUSION

For the first time, the study demonstrated that exogenous GABA could be delivered to the brain through brain cell-derived EVs, which could regulate seizures in temporal lobe epilepsy. It is identified that the cellular origin of EVs plays a vital role in seizure control with exogenous GABA.

Targeted Delivery of 5-Fluorouracil and Sonidegib via Surface-Modified ZIF-8 MOFs for Effective Basal Cell Carcinoma Therapy

The therapeutic effectiveness of the most widely used anticancer drug 5-fluorouracil (5-FU) is constrained by its high metabolism, short half-life, and rapid drug resistance after chemotherapy. Although various nanodrug delivery systems have been reported for skin cancer therapy, their retention, penetration and targeting are still a matter of concern. Hence, in the current study, a topical gel formulation that contains a metal-organic framework (zeolitic imidazole framework; ZIF-8) loaded with 5-FU and a surface modified with sonidegib (SDG; acting as a therapeutic agent as well as a targeting ligand) (5-FU@ZIF-8 MOFs) is developed against DMBA-UV-induced BCC skin cancer in rats. The MOFs were prepared using one-pot synthesis followed by post drug loading and SDG conjugation. The optimized MOFs were incorporated into hyaluronic acid-hydroxypropyl methyl cellulose gel and further subjected to characterization. Enhanced skin deposition of the 5-FU@ZIF-8-SDG MOFs was observed using ex vivo skin permeation studies. Confocal laser microscopy studies showed that 5-FU@ZIF-8-SDG MOFs permeated the skin via the transfollicular pathway. The 5-FU@ZIF-8-SDG MOFs showed stronger cell growth inhibition in A431 cells and good biocompatibility with HaCaT cells. Histopathological studies showed that the efficacy of the optimized MOF gels improved as the epithelial cells manifested modest hyperplasia, nuclear pleomorphism, and dyskeratosis. Additionally, immunohistochemistry and protein expression studies demonstrated the improved effectiveness of the 5-FU@ZIF-8-SDG MOFs, which displayed a considerable reduction in the expression of Bcl-2 protein. Overall, the developed MOF gels showed good potential for the targeted delivery of multifunctional MOFs in topical formulations for treating BCC cancer.

Dirofilariasis mouse models for heartworm preclinical research

Introduction

Dirofilariasis, including heartworm disease, is a major emergent veterinary parasitic infection and a human zoonosis. Currently, experimental infections of cats and dogs are used in veterinary heartworm preclinical drug research.

Methods

As a refined alternative in vivo heartworm preventative drug screen, we assessed lymphopenic mouse strains with ablation of the interleukin-2/7 common gamma chain (γc) as susceptible to the larval development phase of Dirofilaria immitis.

Results

Non-obese diabetic (NOD) severe combined immunodeficiency (SCID)γc^-/- (NSG and NXG) and recombination-activating gene (RAG)2^-/-γc^-/- mouse strains yielded viable D. immitis larvae at 2-4 weeks post-infection, including the use of different batches of D. immitis infectious larvae, different D. immitis isolates, and at different laboratories. Mice did not display any clinical signs associated with infection for up to 4 weeks. Developing larvae were found in subcutaneous and muscle fascia tissues, which is the natural site of this stage of heartworm in dogs. Compared with in vitro-propagated larvae at day 14, in vivo-derived larvae had completed the L4 molt, were significantly larger, and contained expanded Wolbachia endobacteria titres. We established an ex vivo L4 paralytic screening system whereby assays with moxidectin or levamisole highlighted discrepancies in relative drug sensitivities in comparison with in vitro-reared L4 D. immitis. We demonstrated effective depletion of Wolbachia by 70%-90% in D. immitis L4 following 2- to 7-day oral in vivo exposures of NSG- or NXG-infected mice with doxycycline or the rapid-acting investigational drug, AWZ1066S. We validated NSG and NXG D. immitis mouse models as a filaricide screen by in vivo treatments with single injections of moxidectin, which mediated a 60%-88% reduction in L4 larvae at 14-28 days.

Discussion

Future adoption of these mouse models will benefit end-user laboratories conducting research and development of novel heartworm preventatives via increased access, rapid turnaround, and reduced costs and may simultaneously decrease the need for experimental cat or dog use.

Gastric teratoma presenting as melena in the newborn: A case report

Melena is reported in 1 of 350 to 400 new-borns. Significant upper gastrointestinal bleeding in a neonate with an antenatally diagnosed abdominal mass has not been reported before. This case highlights an unusual presentation of a gastric teratoma and proposes a probable embryological explanation for the site of occurrence.

Age Related Prevalence of Mild Cognitive Impairment in Type 2 Diabetes Mellitus Patients in the Indian Population and Association of Serum Lipids With Cognitive Dysfunction

The magnitude of type 2 diabetes mellitus (T2DM) is ever-increasing in India, and at present, ~77 million people live with diabetes. Studies have established that T2DM increases the risk of neurodegenerative disorders. This study aimed to determine the age-related prevalence of mild cognitive impairment (MCI) in T2DM patients in the Indian population and to identify link between cognitive dysfunction in T2DM patients and serum lipid composition through untargeted and targeted lipidomic studies. Using a cross-sectional study, we evaluated 1278 T2DM patients with Montreal cognitive assessment test (MoCA) and digit symbol substitution test (DSST) for cognitive functions. As per MoCA, the prevalences of MCI in T2DM patients in age groups below 40, 41-50, 51-60, 61-70, 71-80 and 81-90 years were 13.7, 20.5, 33.5, 43.7, 57.1 and 75% with DSST scores of 45.8, 41.7, 34.4, 30.5, 24.2 and 18.8% respectively. Binomial logistic regression analysis revealed serum HbA1c ≥ 7.51, duration of T2DM over 20 years, age above 41 years, and females were independent contributors for cognitive dysfunction in T2DM patients. Preliminary studies with untargeted lipidomics of the serum from 20 T2DM patients, including MCI and normal cognition (NC) group, identified a total of 646 lipids. Among the identified lipids, 33 lipids were significantly different between MCI and NC group, which comprised of triglycerides (TGs, 14), sphingolipids (SL, 11), and phosphatidylcholines (PC, 5). Importantly, 10 TGs and 3 PCs containing long-chain polyunsaturated fatty acids (PUFA) were lower, while 8 sphingolipids were increased in the MCI group. Since brain-derived sphingolipids are known to get enriched in the serum, we further quantified sphingolipids from the same 20 serum samples through targeted lipidomic analysis, which identified a total of 173 lipids. Quantitation revealed elevation of 3 species of ceramides, namely Cer (d18:1_24:1), Hex1Cer (d16:0_22:6), and Hex2Cer (d28:1) in the MCI group compared to the NC group of T2DM patients. Overall, this study demonstrated an age-related prevalence of MCI in T2DM patients and highlighted reduced levels of several species of PUFA containing TGs and PCs and increased levels of specific ceramides in T2DM patients exhibiting MCI. Large-scale lipidomic studies in future could help understand the cognitive dysfunction domain in T2DM patients, while studies with preclinical models are required to understand the functional significance of the identified lipids.

Impella versus intra-aortic balloon pump in cardiogenic shock: a meta-analysis assessing 30-days mortality

Introduction

Cardiogenic shock is linked with eminent morbidity and mortality despite advances in treatment modality. Adjuvant treatment modalities to provide mechanical haemodynamic support in the form of intra-aortic balloon pump (IABP) or Impella are being used among patients with cardiogenic shock. The Impella prunes left ventricular preload, whereas, IABP persuades after load reduction and both contribute to improved cardiac output. A few underpowered randomised control trials (RCTs) and observational studies compared short term mortality benefit of Impella juxtaposed to IABP among patients with cardiogenic shock.

Purpose

A meta-analysis of RCTs and observational studies researching the short-term mortality in cardiogenic shock comparing Impella to IABP was executed.

Methods

The databases PubMed, EMBASE and Cochrane were searched systematically to identify relevant RCTs and observational studies contrasting Impella to IABP and reporting 30-days mortality as outcomes. The search terms used were “Impella”, “IAPB”, “intra-aortic balloon pump” and all word variations were utilised. The search was conducted from the debut of the databases up to January 2020. Two reviewers independently and in tandem performed data screening and extraction from identified articles. Inverse variance method with Paule-Mandel estimator for tau2 and Hartung-Knapp adjustment was used to calculate Risk Ratio with 95% confidence interval. Heterogeneity was assessed using I2 statistics. Furthermore, we calculated the 95% predictive interval for the pooled estimate. All statistical analysis for this meta-analysis was carried out using R statistical software version 3.6.2 using the package meta ( ). Additionally, Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria were used to assess the certainty of evidence.

Results

Five studies constituting 728 patients were included in the final analysis. Two were RCTs (ISAR-SHOCK trial and IMPRESS in Severe Shock trial), one study was a propensity score matched observational study and two were unmatched observational studies. There was no difference in the risk of 30-days mortality in patients treated with Impella as compared to IABP [Risk Ratio: 0.97, 95% confidence interval: 0.66–1.41, I2: 32%]. To account for the heterogeneity, we calculated 95% predictive interval: 0.46–2.02. Thus, very low certainty of evidence concluded no difference in the risk of 30-days mortality among cardiogenic shock patients treated with Impella in opposition to IABP.

Conclusion

This meta-analysis comparing Impella juxtaposed with IABP demonstrated no difference in the risk of 30-days mortality among patients with cardiogenic shock.

30-days Mortality

Funding Acknowledgement

Type of funding source: None

The applicability of the Demirjian, Willems and Chaillet standards to age estimation of 5-15 year old Indian children

BACKGROUND

Demirjian's method of age estimation has been reported to overestimate age and Willems' method to give consistently more accurate results. Not enough, however, is known about the applicability of Chaillet's standards.

AIM

The present study aimed to compare the accuracy of Demirjian's, Willems' and Chaillet's standards in age estimation of 5 to 15 year-old Indian children.

DESIGN

In this cross-sectional observational study, three methods were compared for accuracy in estimating the age of 1200 Indian children aged 5-15 years.

RESULTS

Demirjian's method overestimated age by +0.24 ± 0.80 years, +0.11 ± 0.81years and +0.19 ± 0.80 years in boys, girls and the total sample, respectively. With Willems' method, overestimations of +0.09 ± 0.80 years, +0.08 ± 0.80 years and +0.09 ± 0.80 years were obtained in boys, girls and the total sample, respectively. Chaillet's method underestimated age by -0.12 ± 0.69 years, -0.45 ± 0.88 years and -0.25 ± 0.83 years in boys, girls and the total sample, respectively. Statistically significant differences were observed between dental and chronological ages with all methods (p < 0.001). Significant sex-based differences were observed only with Demirjian's and Chaillet's methods (p < 0.05).

CONCLUSION

Willems' method was the most accurate in age estimation, followed by Demirjian's and Chaillet's methods. While Demirjian's method was more accurate than Chaillet's in females, Chaillet's method better predicted the age of males.

The signaling axis atypical protein kinase C λ/ι-Satb2 mediates leukemic transformation of B-cell progenitors

Epigenetically regulated transcriptional plasticity has been proposed as a mechanism of differentiation arrest and resistance to therapy. BCR-ABL leukemias result from leukemic stem cell/progenitor transformation and represent an opportunity to identify epigenetic progress contributing to lineage leukemogenesis. Primary human and murine BCR-ABL⁺ leukemic progenitors have increased activation of Cdc42 and the downstream atypical protein kinase C (aPKC). While the isoform aPKCζ behaves as a leukemic suppressor, aPKCλ/ι is critically required for oncogenic progenitor proliferation, survival, and B-cell differentiation arrest, but not for normal B-cell lineage differentiation. In vitro and in vivo B-cell transformation by BCR-ABL requires the downregulation of key genes in the B-cell differentiation program through an aPKC λ/ι-Erk dependent Etv5/Satb2 chromatin repressive signaling complex. Genetic or pharmacological targeting of aPKC impairs human oncogenic addicted leukemias. Therefore, the aPKCλ/ι-SATB2 signaling cascade is required for leukemic BCR-ABL⁺ B-cell progenitor transformation and is amenable to non-tyrosine kinase inhibition.

The upstream pathways regulating leukemic transcriptional plasticity for differentiation arrest and resistance to therapy are unclear. Here the authors show that aPKC λ/ι-controls leukemic B-cell precursor differentiation arrest trough RAC/MEK/ERK/SATB2 epigenetic repression

Erb's palsy complicating a case of annular pancreas

We report an unusual presentation of annular pancreas with pneumoperitoneum in a newborn with an associated left sided Erb's palsy. The neurological deficit caused considerable confusion in the diagnosis and unexpected complications after surgery. We highlight the importance of clinical examination and the complications that an Erb's palsy can cause. This unusual triad of Erb's palsy, eventration of diaphragm and annular pancreas has hitherto not been described in literature.

PDE11A negatively regulates lithium responsivity

Lithium responsivity in patients with bipolar disorder has been genetically associated with Phosphodiesterase 11A (PDE11A), and lithium decreases PDE11A mRNA in induced pluripotent stem cell-derived hippocampal neurons originating from lithium-responsive patients. PDE11 is an enzyme uniquely enriched in the hippocampus that breaks down cyclic AMP and cyclic GMP. Here we determined whether decreasing PDE11A expression is sufficient to increase lithium responsivity in mice. In dorsal hippocampus and ventral hippocampus (VHIPP), lithium-responsive C57BL/6J and 129S6/SvEvTac mice show decreased PDE11A4 protein expression relative to lithium-unresponsive BALB/cJ mice. In VHIPP, C57BL/6J mice also show differences in PDE11A4 compartmentalization relative to BALB/cJ mice. In contrast, neither PDE2A nor PDE10A expression differ among the strains. The compartment-specific differences in PDE11A4 protein expression are explained by a coding single-nucleotide polymorphism (SNP) at amino acid 499, which falls within the GAF-B homodimerization domain. Relative to the BALB/cJ 499T, the C57BL/6J 499A decreases PDE11A4 homodimerization, which removes PDE11A4 from the membrane. Consistent with the observation that lower PDE11A4 expression correlates with better lithium responsiveness, we found that Pde11a knockout mice (KO) given 0.4% lithium chow for 3+ weeks exhibit greater lithium responsivity relative to wild-type (WT) littermates in tail suspension, an antidepressant-predictive assay, and amphetamine hyperlocomotion, an anti-manic predictive assay. Reduced PDE11A4 expression may represent a lithium-sensitive pathophysiology, because both C57BL/6J and Pde11a KO mice show increased expression of the pro-inflammatory cytokine interleukin-6 (IL-6) relative to BALB/cJ and PDE11A WT mice, respectively. Our finding that PDE11A4 negatively regulates lithium responsivity in mice suggests that the PDE11A SNPs identified in patients may be functionally relevant.

Bat Hunting and Bat-Human Interactions in Bangladeshi Villages: Implications for Zoonotic Disease Transmission and Bat Conservation

Bats are an important reservoir for emerging zoonotic pathogens. Close human–bat interactions, including the sharing of living spaces and hunting and butchering of bats for food and medicines, may lead to spillover of zoonotic disease into human populations. We used bat exposure and environmental data gathered from 207 Bangladeshi villages to characterize bat exposures and hunting in Bangladesh. Eleven percent of households reported having a bat roost near their homes, 65% reported seeing bats flying over their households at dusk, and 31% reported seeing bats inside their compounds or courtyard areas. Twenty percent of households reported that members had at least daily exposure to bats. Bat hunting occurred in 49% of the villages surveyed and was more likely to occur in households that reported nearby bat roosts (adjusted prevalence ratio [aPR] 2.3, 95% CI 1.1–4.9) and villages located in north‐west (aPR 7.5, 95% CI 2.5–23.0) and south‐west (aPR 6.8, 95% CI 2.1–21.6) regions. Our results suggest high exposure to bats and widespread hunting throughout Bangladesh. This has implications for both zoonotic disease spillover and bat conservation.

A Rare Bilateral Presentation of Multiple Dens Invaginatus, Shovel-Shaped Incisor and Talon Cusp With Mesiodens

The aim of this paper is to describe a unique and unusual case of concomitant appearance of morphological dental anomalies in the maxillary anterior region, along with its management in a patient with no systemic abnormality. This case report describes the clinical and radiographic features of talon cusp, dens invaginatus, shovel-shaped incisors and a supernumerary tooth occurring in a single patient, which is a rare presentation. All 4 permanent maxillary incisors had dens invaginatus, the permanent maxillary canines showed the presence of talon cusps, the permanent maxillary central incisors were shovel-shaped and an erupted mesiodens was also observed. Treatment included restorative, surgical and orthodontic approaches.Kathmandu University Medical Journal Vol.12(4) 2014; 292-295

Differential requirement for P2X7R function in IL-17 dependent vs. IL-17 independent cellular immune responses

IL17-dependent autoimmunity to collagen type V (Col V) has been associated with lung transplant obliterative bronchiolitis. Unlike the T helper 1 (Th1)-dependent immune responses to Tetanus Toxoid (TT), the Th17 response to Col V in lung transplant patients and its Th1/17 variant observed in coronary artery disease patients requires IL-1β, tumor necrosis factor α and CD14(+) cells. Given the involvement of the P2X7 receptor (P2X7R) in monocyte IL-1β responses, we investigated its role in Th17-, Th1/17- and Th1-mediated proinflammatory responses. Transfer of antigen-pulsed peripheral blood mononucleated cells (PBMCs) from Col V-reactive patients into SCID mouse footpads along with P2X7R antagonists revealed a selective inhibition of Col V-, but not TT-specific swelling responses. P2X7R inhibitors blocked IL-1β induction from monocytes, including both Col V-α1 peptide-induced (T-dependent), as well as native Col V-induced (T-independent) responses. Significantly higher P2X7R expression was found on CXCR3(neg) CCR4(+)/6(+) CD4(+) [Th17] versus CXCR3(+)CCR4/6(neg) CD4(+) [Th1] subsets in PBMCs, suggesting that the paradigm of selective dependence on P2X7R might extend beyond Col V autoimmunity. Indeed, P2X7R inhibitors suppressed not only anti-Col V, but also Th1/17-mediated alloimmunity, in a heart transplant patient without affecting anti-viral Epstein-Barr virus responses. These results suggest that agents targeting the P2X7R might effectively treat Th17-related transplant pathologies, while maintaining Th1-immunity to infection.

Nonfatal congenital alveolar dysplasia due to abnormalities of NO synthase isoforms

Congenital alveolar dysplasia (CAD) is a rare disorder thought to represent alveolar growth arrest at the canalicular stage of development. An infant with CAD diagnosed on lung biopsy is reported, her respiratory problems resolved spontaneously and she was doing well at follow-up. The infant additionally suffered from systemic hypertension and hypertrophic pyloric stenosis. In conclusion, we speculate that the association of CAD with systemic hypertension and hypertrophic pyloric stenosis might be explained by abnormalities of isoforms of nitric oxide synthase (NOS) resulting in congenital deformities involving smooth muscles.

Using combined x-ray and MR imaging for prostate I-125 post-implant dosimetry: phantom validation and preliminary patient work

Post-implantation dosimetry is an important element of permanent prostate brachytherapy. This process relies on accurate localization of implanted seeds relative to the surrounding organs. Localization is commonly achieved using CT images, which provide suboptimal prostate delineation. On MR images, conversely, prostate visualization is excellent but seed localization is imprecise due to distortion and susceptibility artefacts. This paper presents a method based on fused MR and x-ray images acquired consecutively in a combined x-ray and MRI interventional suite. The method does not rely on any explicit registration step but on a combination of system calibration and tracking. A purpose-built phantom was imaged using MRI and x-rays, and the images were successfully registered. The same protocol was applied to three patients where combining soft tissue information from MRI with stereoscopic seed identification from x-ray imaging facilitated post-implant dosimetry. This technique has the potential to improve on dosimetry using either CT or MR alone.

Simulation of cardiac pathologies using an electromechanical biventricular model and XMR interventional imaging

Simulating cardiac electromechanical activity is of great interest for a better understanding of pathologies and for therapy planning. Design and validation of such models is difficult due to the lack of clinical data. XMR systems are a new type of interventional facility in which patients can be rapidly transferred between X-ray and MR systems. Our goal is to design and validate an electromechanical model of the myocardium using XMR imaging. The proposed model is computationally fast and uses clinically observable parameters. We present the integration of anatomy, electrophysiology, and motion from patient data. Pathologies are introduced in the model and simulations are compared to measured data. Initial qualitative comparison on the two clinical cases presented is encouraging. Once fully validated, these models will make it possible to simulate different interventional strategies.

End stage renal disease due to bilateral renal malakoplakia

Malakoplakia typically affects the bladders of immunocompromised adults who have defective intracellular killing of Escherichia coli. Renal malakoplakia is rare in children and generally has a good outcome. In the case presented, however, it caused end stage renal failure in a 5 year old girl. The management dilemmas surrounding renal transplantation are highlighted.

What can structure tell us about in vivo function? The case of aminoglycoside-resistance genes

Resistance to antibiotics used in the treatment of bacterial infections is an expanding clinical problem. Aminoglycosides, one of the oldest classes of natural product antibiotics, exert their bactericidal effect as the result of inhibiting bacterial protein synthesis by binding to the acceptor site of the 30 S ribosomal subunit. The most common mechanism of clinical resistance to aminoglycosides results from the expression of enzymes that covalently modify the aminoglycoside. We will discuss the enzymology and structure of two representative chromosomally encoded aminoglycoside N-acetyltransferases, Mycobacterium tuberculosis AAC(2')-Ic and Salmonella enterica AAC(6')-Iy, and speculate about their possible physiological function and substrates.

Mapping of electrostatic potential in deep submicron CMOS devices by electron holography

Quantitative two-dimensional maps of electrostatic potential in device structures are obtained using off-axis electron holography with a spatial resolution of 6 nm and a sensitivity of 0.17 V. Estimates of junction depth and variation in electrostatic potential obtained by electron holography, process simulation, and secondary ion mass spectroscopy show close agreement. Measurement artifacts due to sample charging and surface "dead layers" do not need to be considered provided that proper care is taken with sample preparation. The results demonstrate that electron holography could become an effective method for quantitative 2D analysis of dopant diffusion in deep-submicron devices.

Beta-endorphin infusion during exercise in rats does not alter hepatic or muscle glycogen

The aim of this study was to determine whether beta-endorphin infusion influences liver or muscle glycogen concentration during exercise. Thirty-two rats (Harlan Co., IN, USA) with a body mass of 265-290 g were assigned at random to four groups, each of eight rats: (1) beta-endorphin infusion for 90 min at rest; (2) beta-endorphin infusion for 90 min while running on a rodent treadmill at 22 m x min(-1) and 0% grade; (3) saline infusion (0.9% NaCl) for 90 min at rest; and (4) saline infusion for 90 min while running on a rodent treadmill at 22 m x min(-1) and 0% grade. Beta-endorphin infusion elevated plasma beta-endorphin concentration by 2.5-fold at rest compared with saline infusion at rest, and by two-fold after exercise compared with saline infusion after exercise. Beta-endorphin infusion attenuated exercise-induced glucose concentration but did not alter the fasting hepatic glycogen concentration at rest or after exercise compared with saline infusion. Fasting hepatic glycogen decreased significantly as a result of 90 min of exercise independent of treatment. Deep intermedius muscle glycogen concentration at rest was similar after 90 min of both beta-endorphin and saline infusion and decreased significantly as a result of 90 min of exercise independent of treatment. Our results suggest that liver and muscle glycogenolysis is not responsible for the differences in plasma glucose with beta-endorphin infusion during exercise.

Clotting and fibrinolytic activity change during the 1 h after a submaximal run

PURPOSE

To determine the changes in clotting and fibrinolytic activity during the 1-h period after an acute submaximal exercise at a specific relative exercise intensity to ascertain whether during this time there is a greater risk for developing a clot formation or thrombus.

METHODS

Ten healthy men reported between 0700 and 1000 h and ran at 70-75% VO2max or walked at 1.2 mph for 30 min in a random counter-balanced order. Venous blood was obtained at rest, immediately after, and every 20 min during the 1-h recovery.

RESULTS

There were no differences in the resting parameters for each treatment. Walking did not alter the activity of any of the measures analyzed compared with rest. Clotting indicators activated partial thromboplastin time (APTT) was significantly decreased by approximately 2 s and remained at this level during the 1-h recovery, and factor VIII activity was elevated 66% immediately after the run and remained elevated at this level during the 1-h recovery period. Fibrinolytic indicators, t-PA, and D-dimers were significantly increased immediately after the run. However, t-PA demonstrated a quadratic negative slope during the 1-h recovery time. D-dimers remained elevated during the 1-h recovery time.

CONCLUSIONS

These results suggest that running at 70-75% VO2max resulted in elevated clotting and fibrinolytic activity. However, the clotting activity was sustained during a time when fibrinolytic activity declined, which suggests a more favorable situation for clot formation during this time after exercise.

Management of an impacted, dilacerated mandibular left permanent first molar: a case report

A case of an unerupted mandibular left permanent first molar, a partially erupted permanent second molar, and a congenitally absent third molar in a 12-year-old girl is described. The permanent first molar, being dilacerated and impacted, required surgical exposure of the crowns of the first and second molars and distalization of the second molar, with the help of a space regainer, to bring the molars into occlusion.

Effects of dopamine beta-hydroxylase inhibition with nepicastat on the progression of left ventricular dysfunction and remodeling in dogs with chronic heart failure

BACKGROUND

Inhibition of dopamine beta-hydroxylase (DBH) results in a decrease in norepinephrine synthesis. The present study was a randomized, blinded, placebo-controlled investigation of the long-term effects of therapy with the DBH inhibitor nepicastat (NCT) on the progression of left ventricular (LV) dysfunction and remodeling in dogs with chronic heart failure (HF).

METHODS AND RESULTS

Moderate HF (LV ejection fraction [LVEF] 30% to 40%) was produced in 30 dogs by intracoronary microembolization. Dogs were randomized to low-dose NCT (0.5 mg/kg twice daily, n=7) (L-NCT), high-dose NCT (2 mg/kg twice daily, n=7) (H-NCT), L-NCT plus enalapril (10 mg twice daily, n=8) (L-NCT+ENA), or placebo (PL, n=8). Transmyocardial (coronary sinus-arterial) plasma norepinephrine (tNEPI), LVEF, end-systolic volume, and end-diastolic volume were measured before and 3 months after initiating therapy. tNEPI levels were higher in PL compared with NL (86+/-20 versus 13+/-14 pg/mL, P:<0.01). L-NCT alone and L-NCT+ENA reduced tNEPI toward normal (28+/-4 and 39+/-17 pg/mL respectively), whereas HD-NCT reduced tNEPI to below normal levels (3+/-10 pg/mL). In PL dogs, LVEF decreased but was unchanged with L-NCT and increased with L-NCT+ENA. L-NCT and L-NCT+ENA prevented progressive LV remodeling, as evidenced by lack of ongoing increase in end-diastolic volume and end-systolic volume, whereas H-NCT did not

CONCLUSIONS

In dogs with HF, therapy with L-NCT prevented progressive LV dysfunction and remodeling. The addition of ENA to L-NCT afforded a greater increase in LV systolic function. NCT at doses that normalize tNEPI may be useful in the treatment of chronic HF.

Inhibition of cholesteryl ester transfer protein by substituted dithiobisnicotinic acid dimethyl ester: involvement Of a critical cysteine

SC-71952, a substituted analog of dithiobisnicotinic acid dimethyl ester, was identified as a potent inhibitor of cholesteryl ester transfer protein (CETP). When tested in an in vitro assay, the concentration of SC-71952 required for half-maximal inhibition was 1 microm. The potency of SC-71952 was enhanced 200-fold by preincubation of the inhibitor with CETP, and was decreased 50-fold by treatment with dithiothreitol. Analogs of SC-71952 that did not contain a disulfide linkage were less potent, did not display time dependency, and were not affected by dithiothreitol treatment. Kinetic and biochemical characterization of the inhibitory process of CETP by SC-71952 suggested that the inhibitor initially binds rapidly and reversibly to a hydrophobic site on CETP. With time, the bound inhibitor irreversibly inactivates CETP, presumably by reacting with one of the free cysteines of CETP. Liquid chromatography/mass spectroscopy (LC/MS) analyses of tryptic digests of untreated or SC-71952-inactivated CETP was used to identify which cysteine(s) were potentially involved in the time-dependent, irreversible component of inactivation by the inhibitor. One disulfide bond, Cys143-Cys184, was unaffected by treatment with the inhibitor. Inactivation of CETP by SC-71952 correlated with a progressive decrease in the abundance of free Cys-13 and Cys-333. Conversion of Cys-13 to alanine had no effect on the rapid reversible component of inactivation by SC-71952. However, it abolished the time-dependent enhancement in potency seen with the inhibitor when using wild-type CETP. These data indicate that Cys-13 is critical for the irreversible inactivation of CETP by SC-71952 and provides support for the structural model that places Cys-13 near the neutral lipid-binding site of CETP.

The role of cytotoxic T lymphocytes in corneal allograft rejection

PURPOSE

Immunologic rejection constitutes a major barrier to the success of allogeneic corneal transplants, but the specific mediators and mechanisms of graft rejection are poorly understood. Several studies have implicated cytotoxic T-lymphocyte (CTL) responses, typically associated with CD8(+) T cells, in promoting corneal graft rejection. This study sought to test the hypothesis that CTLs are essential in promoting corneal graft rejection.

METHODS

BALB/c donor corneas were grafted orthotopically onto C57BL/6, perforin knockout, or CD8(+) T-cell knockout mice. The tempo and incidence of graft rejection were observed for each group. In separate experiments, donor-specific CTL and delayed-type hypersensitivity (DTH) responses were tested at the time of graft rejection by a standard chromium release assay and an ear swelling assay, respectively.

RESULTS

Perforin knockout and CD8(+) T-cell knockout mice were as effective as wild-type C57BL/6 control mice in rejecting BALB/c donor corneas. Furthermore, animals in all three groups were found to develop robust donor-specific DTH, not CTL, responses at the time of graft rejection. Histopathologically, the rejected corneas from all three groups contained a predominantly mononuclear cellular infiltrate.

CONCLUSIONS

This study rejects the hypothesis that CD8(+) CTLs are essential in promoting corneal graft rejection and instead further implicates donor-specific DTH reactions as the relevant immune response during graft failure.

Re-establishment of dislodged percutaneous nephrostomy tube using a ureteroscope

A simple and safe technique for the replacement of a dislodged nephrostomy tube using a ureteroscope is presented.

Beta-endorphin infusion during exercise in rats: blood metabolic effects

Beta-endorphin (betaE) bolus (0.05 mg x kg(-1)) infusion (0.05 mg x kg(-1) x h(-1)) was previously shown in rats to attenuate the decline in plasma glucose during exercise.

PURPOSE

The present investigation compared betaE and saline infusion in rats without a bolus of betaE to determine whether 1) the attenuation in the glucose decline was attributable to the type of administration (bolus betaE + continuous betaE infusion vs continuous betaE infusion), and 2) whether circulating catecholamines or FFAs were in part involved in the glucose decline.

METHODS

Forty untrained Sprague-Dawley rats were randomly assigned to one of four treatments: 1) betaE infusion at rest (betaR), 2) betaE infusion during exercise (betaX), 3) saline infusion at rest (SR), and 4) saline infusion during exercise (SX). Infusions (betaE or saline) with running (22 m x min(-1), 0% grade) lasted 90 min.

RESULTS

A 2 x 2 ANOVA indicated betaE infusion significantly attenuated the decline in plasma glucose due to exercise at 90 min (SX = 4.16 +/- 0.1 vs betaX = 4.61 +/- 0.1 mM). BetaE infusion elevated plasma betaE about 2.5-fold at rest compared with SR and two-fold after exercise (betaX) compared with SX. BetaE infusion had no effect at rest on any of the other variables measured. Exercise significantly increased catecholamines, FFAs and glucagon compared with resting levels. BetaE infusion enhanced the glucagon response to exercise (SX = 577 +/- 67.5 vs betaX = 913 +/- 153 ng x L(-1), P < 0.02). Epinephrine and norepinephrine and FFAs were similar with betaE infusion either at rest or during exercise compared with saline infusion.

CONCLUSION

These results suggest that betaE infusion independent of the betaE bolus can attenuate the decline in glucose during exercise by enhancing glucagon levels and the betaE infusion did not influence circulating catecholamines or FFA's response to exercise.

High-risk corneal allografts are capable of stimulating complement dependent cytolytic antibodies

PURPOSE

To prospectively characterize serum antibody responses in high-risk corneal allografts.

METHODS

Orthotopic and heterotopic C3H (H-2k) corneas were transplanted to CB6F1 (H-2b/d) recipient mice. Individual serum samples were collected at days 7, 14, 21, and 28 from orthotopically and heterotopically grafted mice. Samples were tested for anti-C3H antibodies using an enzyme-linked immunosorbent assay (ELISA). Serum samples were also tested for the ability to lyse target cells in the presence of complement.

RESULTS

In high-risk donor-host combinations, 100% corneal allograft rejection occurs in the absence of IgG1 production. Both orthotopic and heterotopic corneal allografts induced cytolytic complement fixing antibody isotypes.

CONCLUSIONS

Allospecific corneal antibody may be involved in corneal graft rejection in high-risk donor-host combinations.

Bilateral single-session percutaneous nephrolithotomy: a feasible and safe treatment

BACKGROUND AND PURPOSE

The treatment of bilateral urinary calculus disease is often staged, irrespective of the modality of the treatment. Bilateral simultaneous percutaneous nephrolithotomy (PCNL) is still considered by many to be adventurous and risky. We carried out this prospective study of bilateral PCNL under a single anesthesia to study the feasibility, success rate, and complications if any.

PATIENTS AND METHOD

From September 1996 to May 1999, 25 consecutive medically fit patients with bilateral renal calculi needing PCNL were subjected to bilateral PCNL under a single anesthesia.

RESULTS

The PCNL could be accomplished bilaterally in 24 patients (96%). In one patient, the second-side PCNL was abandoned because of excessive bleeding on the first side. A total of 58 tracts and 27 sessions were required for complete treatment of the 48 renal units in the 24 successfully treated patients. The average operating time required for the procedure was 122 minutes. Nineteen patients were rendered stone free in one session, and two more patients were made stone free in a second session. Four renal units in three patients with residual calculi were cleared with double-J stenting and SWL.

CONCLUSION

Bilateral PCNL in a single session is feasible and safe and can be carried out without increased morbidity. We advocate that an endourologist be prepared for bilateral PCNL in the patients in whom it is indicated. The opposite-side PCNL can be done if the first-side treatment is accomplished smoothly and in a reasonable time.

Mandibular talon cusp: report of two rare cases

Two rare cases of talon cusps in the mandibular incisors were observed during a prevalence study on talon cusp. One of them was seen on a mandibular primary lateral incisor. The other one was observed on the mandibular left permanent central incisor, and the right mandibular permanent central incisor was congenitally missing. There were no associated developmental syndromes with either of the cases reported. Of the 4770 children examined, nine cases had talon cusp with only two rare cases of mandibular talon cusp, one in the primary dentition and the other in the permanent dentition.

Structured sedation programme for magnetic resonance imaging examination in children

One thousand, eight hundred and fifty-seven patients underwent magnetic resonance imaging following the establishment of a structured sedation programme. Forty-eight of these patients came from the intensive care unit with a secure airway and were therefore excluded from any further analysis. Oral sedation was to be given to children aged 5 years and below. For children >/= 6 years old, oral sedation could be given only if their level of co-operation was judged to be inadequate by the referring physician. Oral sedation consisted of chloral hydrate 90 mg x kg-1 (maximum 2.0 g) orally with or without rectal paraldehyde 0.3 ml x kg-1. All magnetic resonance imaging requests for children who failed oral sedation as well as those referred for general anaesthesia from the outset were reviewed by a consultant anaesthetist who then allocated patients to undergo the procedure with either general anaesthesia or intravenous sedation. Scans requiring intravenous sedation or general anaesthesia were performed in the presence of a consultant anaesthetist. Intravenous sedation consisted of either a propofol 0.5 mg x kg-1 bolus followed by an infusion (maximum 3 mg x kg-1 x h-1) or midazolam 0.2-0.5 mg x kg-1 boluses. General anaesthesia was given using spontaneous ventilation with a mixture of 66% nitrous oxide in oxygen and isoflurane following either inhalation (sevoflurane) or intravenous (propofol) induction. One thousand and thirty-nine (57.4%) of the scans were done without sedation whereas 93 scans were performed during the consultant anaesthetist supervised sessions. Oral sedation failed in 50 out of 727 patients (6.9%). Eighty-seven per cent of children aged 5 years and below needed sedation compared with 4.5% of those aged over 10 years. Two patients who had only received chloral hydrate developed significant respiratory depression. This structured sedation programme has provided a safe, effective and efficient use of limited resources.

Inhibition of intraocular tumor growth by topical application of the angiostatic steroid anecortave acetate

PURPOSE

This study examined the effect of an angiostatic agent on the growth of a highly vascularized intraocular tumor.

METHODS

A murine uveal melanoma cell line (99E1) was transplanted intracamerally into athymic nude BALB/c mice. Mice were treated topically three times per day beginning on the day of tumor transplantation and continuing through day 28. Groups included (a) 1% anecortave acetate, (b) vehicle control, or (c) no treatment. Tumor growth was scored clinically according to the volume of anterior chamber occupied by tumor. Intraocular tumor weights were determined on days 10, 14, 21, and 28. The effect of the test agents on tumor cell proliferation was examined in vitro by [3H]thymidine incorporation.

RESULTS

Tumors grew progressively in untreated mice and mice treated with the vehicle; tumors filled the entire eye by day 20 and frequently perforated the globe by day 21. By contrast, tumors treated with anecortave acetate grew significantly slower (P < 0.025) and did not perforate the eye. On days 21 and 28 the net tumor weight of the AL-3789-treated animals was 40% to 30% of controls (P < 0.05). Tumor inhibition was presumably due to the angiostatic properties of anecortave acetate because the compound did not affect tumor cell proliferation in vitro.

CONCLUSIONS

The topical ocular administration of anecortave acetate restricted the growth of a highly vascularized angiogenic intraocular tumor.

Muscarinic receptor ligands and their therapeutic potential

Over the past year, the introduction of novel ligands has accelerated the classification of muscarinic receptor subtypes and has led to a better understanding of their physiological role. Important in this respect is the recent recognition of the exquisite selectivity of a series of snake toxins, enabling better definition of the muscarinic subtype 4 receptor. Moreover, several compounds, both agonists and antagonists, are progressing in advanced clinical trials for the treatment of several conditions, including Alzheimer's disease, pain, urinary incontinence and chronic obstructive pulmonary disease.