Riffat Mehboob

Substance P/Neurokinin 1 and Trigeminal System: A Possible Link to the Pathogenesis in Sudden Perinatal Deaths

Sudden demise of a healthy fetus or a neonate is a very tragic episode in the life of parents. These deaths have been a mystery since ages but still remain unexplained. This review proposes the involvement of trigeminal nerve, neurotransmitter substance P (SP), and its receptor neurokinin 1 (NK-1R) in regulation of cardiorespiratory control in fetuses and newborns. Anomalies and immaturity of neuroregulatory systems such as trigeminal system in medulla oblongata of brainstem may provide a possible mechanism of sudden perinatal deaths. Vulnerable infants are born with respiratory center immaturity which in combination with any stressor such as cold, hypoxia, and smoking may lead to cessation of breathing and ventilatory response. SP/NK-1R may be involved in regulating the ventilatory control in neonates while it is decreased in fetal and adult life in humans, and any alterations from these may lead to irreversible sleep apnea and fatal breathing, ultimately sudden death. This review summarizes the studies performed to highlight the expression of SP or NK-1R in sudden perinatal deaths and proposes the involvement of trigeminal ganglion along with its nerve and SP/NK-1R expression alteration as one of the possible pathophysiological underlying mechanism. However, further studies are required to explore the role of SP, NK-1R, and trigeminal system in the pathogenesis of sudden infant deaths, sudden intrauterine deaths, stillbirths, and sudden deaths later in human life.

Neurochemical Alterations in Sudden Unexplained Perinatal Deaths—A Review

Sudden unexpected perinatal collapse is a major trauma for the parents of victims. Sudden infant death syndrome (SIDS) is unexpected and mysterious death of an apparently healthy neonate from birth till 1 year of age without any known causes, even after thorough postmortem investigations. However, the incidence of sudden intrauterine unexplained death syndrome (SIUDS) is seven times higher as compared with SIDS. This observation is approximated 40–80%. Stillbirth is defined as death of a fetus after 20th week of gestation or just before delivery at full term without a known reason. Pakistan has the highest burden of stillbirth in the world. This basis of SIDS, SIUDS, and stillbirths eludes specialists. The purpose of this study is to investigate factors behind failure in control of these unexplained deaths and how research may go ahead with improved prospects. Animal models and physiological data demonstrate that sleep, arousal, and cardiorespiratory malfunctioning are abnormal mechanisms in SIUDS risk factors or in newborn children who subsequently die from SIDS. This review focuses on insights in neuropathology and mechanisms of SIDS and SIUDS in terms of different receptors involved in this major perinatal demise. Several studies conducted in the past decade have confirmed neuropathological and neurochemical anomalies related to serotonin transporter, substance P, acetylcholine α7 nicotine receptors, etc., in sudden unexplained fetal and infant deaths. There is need to focus more on research in this area to unveil the major curtain to neuroprotection by underlying mechanisms leading to such deaths.

Characterization and Expression of Sphingosine 1-Phosphate Receptors in Human and Rat Heart

Aim: Sphingosine 1-phosphate (S1P), sphingolipid derivatives are known anti-inflammatory, anti-apoptotic, and anti-oxidant agent. S1P have been demonstrated to have a role in the cardiovascular system. The purpose of this study was to understand the precise expression and distribution of S1P receptors (S1PRs) in human and rat cardiovascular tissues to know the significance and possible implementation of our experimental studies in rat models. Methods and Results: In this study, we investigated the localization of S1PRs in human heart samples from cardiac surgery department, University of Verona Hospital and rat samples. Immunohistochemical investigation of paraffin-embedded sections illustrated diffused staining of the myocardial samples from human and rat. The signals of the human heart were similar to those of the rat heart in all chambers of the heart. The immunohistochemical expression levels correlated well with the results of RT-PCR-based analysis and western blotting. We confirmed by all techniques that S1PR1 expressed strongly as compared to S1PR3, and are uniformly distributed in all chambers of the heart with no significant difference in human and rat myocardial tissue. S1PR2 expression was significantly weak while S1PR4 and S1PR5 were not detectable in RT-PCR results in both human and rat heart. Conclusion: These results indicate that experimental studies using S1PR agonists on rat models are more likely to have a potential for translation into clinical studies, and second important information revealed by this study is, S1P receptor agonist can be used for cardioprotection in global ischemia-reperfusion injury.

Towards Better Understanding of the Pathogenesis of Neuronal Respiratory Network in Sudden Perinatal Death

Sudden perinatal death that includes the victims of sudden infant death syndrome, sudden intrauterine death syndrome, and stillbirth are heartbreaking events in the life of parents. Most of the studies about sudden perinatal death were reported from Italy, highlighting two main etiological factors: prone sleeping position and smoking. Other probable contributory factors are prematurity, male gender, lack of breastfeeding, respiratory tract infections, use of pacifiers, infant botulism, extensive use of pesticides and insecticides, etc. However, extensive studies across the world are required to establish the role of these factors in a different subset of populations. Previous studies confirmed the widely accepted hypothesis that neuropathology of the brainstem is one of the main cause of sudden perinatal death. This study is an effort to summarize the neuropathological evaluation of the brainstems and their association to sudden perinatal death. Brainstem nuclei in vulnerable infants undergo certain changes that may alter the sleep arousal cycle, cardiorespiratory control, and ultimately culminate in death. This review focuses on the roles of different brainstem nuclei, their pathologies, and the established facts in this regard in terms of it’s link to such deaths. This study will also help to understand the role of brainstem nuclei in controlling the cardiorespiratory cycles in sudden perinatal death and may provide a better understanding to resolve the mystery of these deaths in future. It is also found that a global initiative to deal with perinatal death is required to facilitate the diagnosis and prevention in developed and as well as developing countries.

Role of neurotransmitter Substance P in progression of oral squamous cell carcinoma

BACKGROUND Oral squamous cell carcinoma (OSCC) is the most frequent type of head and neck cancers. OBJECTIVES In the present study, we evaluated the expression and distribution of Substance P (SP) in different grades of OSCC and role of SP in its proliferation and progression. SUBJECTS AND METHODS Forty OSCC biopsies were immunohistochemically analyzed by using SP antibody, including 29 male and 11 female cases. 35% were well differentiated, 35% moderately differentiated and 30% poorly differentiated OSCC. The majority of patients were in the age range of 41-80 years. 62% of the cases were positive for SP. SP positivity was expressed in the cytoplasm of the tumor cells. Most of the positive cases were from the tongue region. RESULTS 93% of moderately differentiated, 92% of poorly differentiated and 8% of well-differentiated carcinomas were SP-positive, but SP expression intensity was highest in poorly differentiated cases (+3). More positive patients were males (68.96% of all male patients) with moderately and poorly differentiated OSCC. Among all positive cases, 48% were poorly differentiated, 48% moderately differentiated and 4% well differentiated. CONCLUSION Strong expression of SP in poorly and moderately differentiated cases suggests a role of SP in the progression and development of tumor. Expression of SP in the current study increased as the proliferation of cells increased. Prevalence of oral cancer in males may be due to the fact that they smoke and use pan, chewing gum, beetle nut etc. in this region. SP antagonists can help in the reduction and inhibition of oral cancer. SP has a diagnostic value with sensitivity of 92.5% and specificity of 93.7%. The positive predictive value is 96.2% and the negative predictive value 88.2%.

Genetic analysis of prolactin gene in Pakistani cattle

Prolactin (PRL) is a polypeptide hormone, secreted mainly by the anterior pituitary gland. It is involved in many endocrine activities. The key functions of PRL are related to reproduction and lactation in mammals. To ascertain the presence of polymorphisms in the bovine PRL gene (bPRL), the bPRL gene was sequenced. Five mutations were identified in exonic region and eleven in associated intronic regions in 100 cattle from four Pakistani cattle breeds. Haplotype of predicted amino acid changes represent a common alteration at codon 222 from R-Arginine into K-Lysine in all four breeds. Significant statistical variations were observed in the distribution of single nucleotide polymorphism (SNP) in various cattle populations. However, on basis of present study, an association of these SNPs with milk performance traits in four Pakistani cow breeds cannot be truly replicated but at least can be effective DNA markers for some of the breeds studied. Linkage analysis between these SNPs on larger populations can be useful for the association with milk production traits. Furthermore, present study may be used for marker-assisted selection and management in cattle breeding program in local cattle breeds.

168 Cardioprotective role of fingolimod in ischemia-reperfusion injury by activation of akt/erk pathways in rat model

Background and purpose Ischaemic Heart Diseases (IHD) are the most common cause of morbidity and mortality. Incidence and prevalence are continuously growing. There is an escalating risk for revascularisation or resuscitation in patients with IHD. Recently, it has been reported that a sphingosine 1-phosphate receptor agonist play an anti-apoptotic and anti-inflammatory role in the ischemia-reperfusion injury. Objectives The aim of our study is to investigate the cardioprotective effects of sphingosine 1-phosphate receptor agonist fingolimod (FTY720) on global ischemia-reperfusion injury related to the cardiac surgery. Methods In our experimental study, global ischemia-reperfusion was achieved by cardiopulmonary bypass by cardioplegic arrest on ventilated male Sprague-Dawley rats (300–350 g). The global ischaemic period lasted 10 min in the cardioplegic arrest while reperfusion times were maintained for 60 min and 24 hours. ECG monitoring was done using AD instrument and using Millar catheter, heart rate, systolic and diastolic pressures were recorded and mean arterial pressure was calculated. The statistical significance was considered at P 0.05. Results The myocardial protection was observed in the group treated with Fingolimod as compared to control groups. Reduced frequency of apoptotic cells and inflammatory mediators were found in the treated group. The level of adenylates was preserved in the treated group as compared to controls (94%, 61% respectively)(p0.001). Reactive Oxygen Species (ROS) were attenuated in the fingolimod-treated group. Fingolimod treatment improved systolic and diastolic ventricular pressures and contractility strength (p0.005). Conclusions The intravenous administration of fingolimod in global ischemia-reperfusion was cardioprotective. Fingolimod cardioprotection appears to be mediated through preservation of high energy phosphates, reduction in oxidative stress, inhibition of apoptosis and inflammation leading to improved cardiac functions.

233 Anti-arrhythmic role of sphingosine 1-phospahte in post-operative atrial fibrillation by pak1 activation

Background Atrial Fibrillation (AF) is the most common arrhythmia occurring post cardiac surgery. The incidence varies and depends on the type of surgery. Postoperative AF may cause hemodynamically unstable, that increase the risk of stroke and increase mortality. Current management for prophylaxis of postoperative AF is not satisfactory. Objectives The purpose of this study is to investigate the anti-arrhythmic role of sphingosine 1-phosphate to prevent post-cardiac surgery AF. Methods Sprague-Dawley Rats (300-350grams) Obtained from Harlan Laboratories (Udine, Italy). They were fed standard rat chow, which they had access to ad libitum. Randomly categorised into two groups n=10 each group. One group was treated with sphingosine 1-phospahte receptor agonist fingolimod (1 mg/kg, i.v) and the control group was treated with saline. Following 15 min of treatment, cardioplegic arrest with the support of cardiopulmonary bypass. ECG electrodes were attached to limbs and using power lab charts ECG monitored and analysed. Following monitoring of rhythm for 24 hours, all animals were sacrificed and myocardial tissue was collected to analyse Pak1 protein. Results The administration of fingolimod led to significantly better and fast recovery as compared to the control group. The episodes of AF recorded during 24 hours in the treated group was low versus the control group (p0.001). We also investigated Pak1 protein by western blot and immunohistochemistry. Expression of Pak1 observed higher in the fingolimod-treated group(p0.05). Conclusion Sphingosine 1-phosphate receptor agonist fingolimod plays important role in prevention of AF-related to cardiac surgery by activating the Pak1 pathway.Fingolimod is FDA-approved sphingolipid that can be the potential therapeutic drug for post-operative AF prophylaxis.

Hospital-Based Study of Epithelial Malignancies of Endometrial Cancer Frequency in Lahore, Pakistan, and Common Diagnostic Pitfalls

The current study was conducted to see the frequency of epithelial malignancies of endometrium with focus on the common diagnostic pitfalls and identify morphological and immunohistochemical markers helpful in the differential diagnosis between different subtypes. It is a retrospective descriptive study carried out on 52 specimens of endometrial tumors received in Fatima Memorial Hospital, Lahore, Pakistan, during three years (2010–2012). Patients were divided into 5 age groups: <40, 41–50, 51–60, 61–70, and >70 yrs. Tissues were fixed in 10% formalin and processed and stained with haematoxylin-eosin. Stained slides were examined to determine the histological types by WHO classification, and immunohistochemistry for WT1, p53, ER/PR, and MIB1 was done in cases where morphology alone was not helpful in making a confirmed diagnosis. 80% of specimens were of endometrioid adenocarcinomas, 11% of serous tumors, 4% of clear cell carcinoma, and 4% of squamous cell carcinomas involving both cervix and endometrium. Most of the patients (28.84%) with endometrial carcinomas fall in the age range of 51–60 yrs. Endometrioid adenocarcinoma is the most common type of epithelial endometrial malignancies. Morphology is the keystone in the evaluation of these tumors, but immunohistochemistry can also be helpful in establishing the correct diagnosis.