An action potential-induced and ryanodine sensitive calcium transient dynamically regulates transmitter release at synapses between Lymnaea neurons.

The notion that calcium released through ryanodine receptors effects presynaptic neurotransmitter release is gaining acceptance with the observation that this calcium does indeed contribute to both action potential-evoked and spontaneous transmitter release in a variety of preparations. However, the dynamics of this calcium release and its impact on transmitter release has not yet been fully elucidated. Moreover, in contrast to vertebrate synapses, much less is known about the involvement of ryanodine receptors in the regulation of transmitter release at invertebrate synapses.

Additional chromosomal abnormalities in Philadelphia-positive chronic myeloid leukemia.

Background And Objective: The emergence of non-random chromosomal abnormalities is a well-recognized occurrence in chronic myeloid leukemia (CML) and detection of these abnormalities is important in prognostic stratification. The frequency and types of additional chromosomal abnormalities in CML patients has not been determined in our region.

Patients And Methods: We conducted a descriptive, prospective study of additional chromosomal abnormalities in patients with an established diagnosis of Philadelphia-positive CML from May 2001 to June 2007.

Neuroglobin and cytoglobin distribution in the anterior eye segment: a comparative immunohistochemical study.

This study provides a detailed description of immunolocalization of two oxygen-binding proteins, neuroglobin (Ngb) and cytoglobin (Cygb), in the anterior segment of healthy human and canine eyes. Specific antibodies against Ngb and Cygb were used to examine their distribution patterns in anterior segment structures including the cornea, iris, trabecular meshwork, canal of Schlemm, ciliary body, and lens. Patterns of immunoreactivity (IR) were imaged with confocal scanning laser and conventional microscopy.

Evaluation of iron in serum and urine and their relation with thyroid function in female goitrous patients.

In many developing countries, women are at high risk of goiter and iron deficiency anemia (IDA). Iron deficiency adversely affects thyroid metabolism and may decrease the efficiency of thyroid hormones in areas of endemic goiter. The aim of the present study was to compare the level of iron (Fe) in biological samples (serum and urine) and serum thyroid hormones, thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxin (FT4) of goitrous female patients (GFPs; n = 69) with those of nongoitrous women as control subjects (n = 117), age range 21-45 years.

Surgical training programs in Pakistan.

This paper traces the history and describes the status of surgical training in Pakistan. A key revelation is that excellent surgeons are produced through systems which on formal review might appear to lack standards. Personal characteristics of residents modify outcomes in high volume surgical training units; and consequent variation in quality of outputs is noted.

Sebaceous cell carcinoma of the ocular adnexa: clinical presentations, histopathology, and outcomes.

Purpose: To investigate the clinical features, time to diagnosis, histopathology, treatment, and mortality rates of patients with sebaceous cell carcinoma.

Methods: This was a retrospective, consecutive series of patients with sebaceous cell carcinoma at a tertiary referral medical center. Between January 1984 and January 2006, 31 patients with sebaceous cell carcinoma were evaluated at the Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals and Clinics.

Perisaccadic parietal and occipital gamma power in light and in complete darkness.

Our objective was to determine perisaccadic gamma range oscillations in the EEG during voluntary saccades in humans. We evaluated occipital perisaccadic gamma activity both in the presence and absence of visual input, when the observer was blindfolded. We quantified gamma power in the time periods before, during, and after horizontal saccades.

Silence and the physician executive.

Silence can be an indication that things are running smoothly; on the other hand it can be an ominous sign that there is dissent among your staff.

Promoter hypermethylation of FANCF and outcome in advanced ovarian cancer.

The Fanconi gene family has a role in DNA repair and inactivation of FANCF has been proposed as a mechanism of sensitisation to platinum chemotherapy. This study sought to confirm this hypothesis in cell lines and a large series of ovarian cancer samples. Promoter methylation was assessed by methylation-sensitive polymerase chain reaction of FANCF in nine ovarian cancer cell lines and 74 ovarian cancer samples taken from patients entered on a trial of cisplatin-based chemotherapy.

Postsynaptic expression of an epidermal growth factor receptor regulates cholinergic synapse formation between identified molluscan neurons.

Epidermal growth factor (EGF) family members are conserved in both vertebrates and invertebrates. Recent studies suggest that EGF ligands in invertebrates may have neurotrophic actions that possibly compensate for the apparent absence of neurotrophins in these species. In this study, we have cloned an EGF receptor from the mollusk Lymnaea stagnalis (L-EGFR), and shown that L-EGFR is the receptor for a previously identified EGF-like peptide in Lymnaea, named Lymnaea EGF (L-EGF).

Serotonin modulates transmitter release at central Lymnaea synapses through a G-protein-coupled and cAMP-mediated pathway.

Neuromodulation is central to all nervous system function, although the precise mechanisms by which neurotransmitters affect synaptic efficacy between central neurons remain to be fully elucidated. In this study, we examined the neuromodulatory action of serotonin [5-hydroxytryptamine (5-HT)] at central synapses between identified neurons from the pond snail Lymnaea stagnalis. Using whole-cell voltage-clamp and sharp electrode recording, we show that 5-HT strongly depresses synaptic strength between cultured, cholinergic neuron visceral dorsal 4 (VD4 - presynaptic) and its serotonergic target left pedal dorsal 1 (LPeD1 - postsynaptic).

Mutation in the SLC4A11 gene associated with autosomal recessive congenital hereditary endothelial dystrophy in a large Saudi family.

Objective: To determine the role of the SLC4A11 gene in two pedigrees affected with autosomal recessive congenital hereditary endothelial dystrophy (CHED).

Methods: Nine members of a pedigree from the Kingdom of Saudi Arabia (pedigree 971G) and 2 twins in a pedigree from Bosnia (pedigree GGO413) were diagnosed with autosomal recessive CHED and contributed DNA samples for genetic studies. The proband of each pedigree was tested for disease-causing mutations in the SLC4A11 gene with bi-directional DNA sequencing.

Muscle oxygen uptake differs from consumption dynamics during transients in exercise.

Relating external to internal respiration during exercise requires quantitative modeling analysis for reliable inferences with respect to metabolic rate. Often, oxygen transport and metabolism based on steady-state mass balances (Fick principle) and passive diffusion between blood and tissue are applied to link pulmonary to cellular respiration. Indeed, when the work rate does not change rapidly, a quasi-steady-state analysis based on the Fick principle is sufficient to estimate the rate of O2 consumption in working muscle.

Identification of CDK10 as an important determinant of resistance to endocrine therapy for breast cancer.

Therapies that target estrogen signaling have transformed the treatment of breast cancer. However, the effectiveness of these agents is limited by the development of resistance. Here, an RNAi screen was used to identify modifiers of tamoxifen sensitivity.

A peripheral oxygen sensor provides direct activation of an identified respiratory CPG neuron in Lymnaea.

The mechanisms by which peripheral, hypoxia-sensitive chemosensory cells modulate the output from the respiratory central pattern generator (CPG) remain largely unknown. In order to study this topic at a fundamental level, we have developed a simple invertebrate model system, Lymnaea stagnalis wherein we have identified peripheral chemoreceptor cells (PCRCs) that relay hypoxia-sensitive chemosensory information to a known respiratory CPG neuron, right pedal dorsal 1 (RPeD1). Significance of this chemosensory drive was confirmed via denervation of the peripheral sensory organ containing the PCRCs, and subsequent behavioral observation.

Reasons for migration among medical students from Karachi.

Context: The subject of economic migration among health care professionals has received intense attention. However, the aetiology of this migration has not been rigorously evaluated in Pakistan. Such knowledge can potentially influence health care and academic policies.

Acute vertebrobasilar artery thrombosis: long-term benefit of vertebral artery stenting.

Acute vertebrobasilar artery occlusion is a life-threatening event, even after thrombolytic treatment with local intraarterial (IA) recombinant tissue plasminogen activator. We report a 70-year-old man with acute vertebral artery occlusion in which IA thrombolysis resulted in partial recanalisation and revealed pre-existing severe stenosis as the underlying cause. Stenosis was managed with stenting with excellent long-term clinical as well as angiographical outcomes.

Thrombocytosis: age dependent aetiology and analysis of platelet indices for differential diagnosis.

To identify the etiology of thrombocytosis in various age groups and to evaluate the effectiveness of platelet indices in differentiating reactive and clonal thrombocytosis, an observational, prospective review of patients with platelet count of 600 x 10(9)/L or more performed by using coulter counter STKS (Coulter Electronic, Kerfeld, Germany). Extreme thrombocytosis defined as platelet count of 1000 x 10(9)/L or more. Of 1068 patients, 91.

Arginine vasopressin increases glutamate release and intracellular Ca2+ concentration in hippocampal and cortical astrocytes through two distinct receptors.

Arginine vasopressin (AVP), released from the CNS, plays an important role in regulating several aspects of CNS functions including aggression, anxiety, and cognition. In this study, we report a novel finding that AVP induces glutamate release from astrocytes isolated from the cerebral cortex and hippocampus. We also investigated the types of AVP receptors involved in the AVP-induced increase in glutamate release from astrocytes isolated from the hippocampus and cortex of neonatal rats.

Haemorrhagic manifestations and utility of haematological parameters in dengue fever: a tertiary care centre experience at Karachi.

A retrospective observational study of dengue fever was performed, including 210 patients (male:female ratio 1.6:1, ages 6-74 y, mean 29.7 y) attending the Aga Khan University Hospital, Karachi from January 2001 to December 2006.

Tip60 is a haplo-insufficient tumour suppressor required for an oncogene-induced DNA damage response.

The acetyl-transferase Tip60 might influence tumorigenesis in multiple ways. First, Tip60 is a co-regulator of transcription factors that either promote or suppress tumorigenesis, such as Myc and p53. Second, Tip60 modulates DNA-damage response (DDR) signalling, and a DDR triggered by oncogenes can counteract tumour progression.

Characterization of dextransucrase immobilized on calcium alginate beads from Leuconostoc mesenteroides PCSIR-4.

Immobilization of dextransucrase from Leuconostoc mesenteroides PCSIR-4 on alginate is optimized for application in the production of dextran from sucrose. Dextransucrase was partially purified by ethanol upto 2.5 fold.

Epigenetic inactivation implies independent functions for insulin-like growth factor binding protein (IGFBP)-related protein 1 and the related IGFBPL1 in inhibiting breast cancer phenotypes.

Purpose: To analyze epigenetic regulation of two related genes, insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) and IGFBPL1, and its significance as a determinant of clinical phenotypes in human breast cancer.

Experimental Design: We have investigated the expression and epigenetic regulation of IGFBP-rP1 and IGFBPL1 in human breast cancer cell lines and primary and metastatic carcinomas.

Results: Expression of IGFBP-rP1 and IGFBPL1 is down-regulated in breast cancer cell lines.