Role of histamine receptor in mesencephalic nucleus dorsalis raphe in cardiovascular regulation

Summary The effects of microinjection of histamine and its antagonists into mesencephalic nucleus dorsalis raphe, were investigated on mean arterial pressure and heart rate in cats to elucidate the nature and role of histaminergic receptors in cardiovascular regulation. Microinjection of histamine (5 and 10 g) into nucleus dorsalis raphe elicited both inhibitory and excitatory cardiovascular responses respectively. On the other hand, microinjection of H₂-receptor blocker, cimetidine (10 g) resulted in hypertension and tachycardia while H₁-receptor antagonist, mepyramine (10 g) microinjection evoked hypotension and bradycardia. Furthermore, local pretreatment with cimetidine and mepyramine blocked the inhibitory and excitatory cardiovascular responses of graded doses of histamine microinjection. These H₁ and H₂ receptors are localized in nucleus dorsalis raphe since microinjection of histamine into adjoining neural structures did not evoke any cardiovascular change. Furthermore, both the inhibitory and excitatory cardiovascular responses to histamine microinjection could not be observed in animals with spinal cord transection and in animals pretreated with p-chlorophenylalanine while they could be observed in bilateral cervical vagotomized animals. Thus, it appears that these cardiovascular responses to microinjection of histamine into nucleus dorsalis raphe, are due to modulation of serotonergic bulbospinal influence on sympathetic preganglionic neurones in the spinal cord. Moreover, the excitatory cardiovascular responses of high dose of histamine (10 g) seem to result from a local release of noradrenaline since they were blocked by prior microinjection of guanethidine and piperoxan into nucleus dorsalis raphe. A release of noradrenaline in turn, modulates the activity of the neurones of the nucleus by acting on adrenoceptors and thereby alters the activity of sympathetic preganglionic neurones. These adrenoceptors appear to be of ₁ type (Saxena et al. 1985, 1987) since phenylephrine microinjection evoked excitatory cardiovascular responses could be blocked by piperoxan. Send offprint requests to K. K. Tangri at the above address     

Optimizing vaccine design for cellular processing,MHC binding and TCR recognition

In this review we describe the methods and processes that our group have developed while aiming to test and design multiepitope vaccines for infectious diseases and cancer. Testing the performance of vaccines composed of epitopes restricted by human leukocyte antigen (HLA) molecules is accomplished by in vitro antigenicity assays, as well as in vivo immunogenicity assays in HLA transgenics. The efficiency by which multiepitope vaccines are processed is optimized by spacer residues, which are designed to facilitate generation by natural processing of the various class I- and class II-restricted epitopes. Methods and strategies to test and optimize HLA binding affinity, patient coverage from the vaccine construct, and TCR recognition of HLA/epitope complexes are also discussed.     

Methylmalonic acidemia mimicking diabetic ketoacidosis and septic shock in infants

Methylmalonic acidemia (MMA) is most common inherited type of organic acidemia. It has diverse presentation in older infants without any initial apparent symptoms. MMA sometimes present with sudden metabolic decompensation, which may mimics common emergencies like septic shock and diabetic ketoacidosis (DKA) without early recognition can be fatal. In born error of metabolism especially organic acidemia should be suspected in any infant presented with severe high anion gap metabolic acidosis. We report two cases of MMA in infants presented acutely mimicking DKA and septic shock.     

Experiences of Urban African Americans with Cancer Pain

The experience of cancer pain is poorly understood from the perspective of African Americans, who experience higher levels of pain, more pain-related distress, and poorer function than Caucasians. Decreased perceived control over pain may play a greater role for African American patients, affecting pain-related distress and function. The purpose of this study was to add to the understanding of cancer pain and perceived control over pain in African Americans, from the patients’ perspective. This qualitative inquiry was part of a larger mixed-methods study testing an intervention to improve pain, pain-related distress, and functional status through increasing perceived control over pain. Participants were recruited from the waiting room of an urban comprehensive cancer and interviewed in their homes. Interviews with 18 adult cancer patients who self-identified as African American and reported experiencing moderate to severe pain (>4 on a 0–10 scale) within the past two weeks were included. Qualitative interviews were audiotaped, transcribed, and analyzed using a constant comparative method. Two major themes emerged from this qualitative inquiry: struggles of the chronic pain experience and benefits of perceived control over pain. Each theme contained several categories. The study unveiled the participants account of both struggles of the chronic pain experience and barriers of perceived control that can be assessed for and targeted in nursing intervention. Benefits to having perceived control over pain were also illustrated in the participants’ narratives.     

Improving the Quality and Efficiency of Conventional In‐center Hemodialysis

There is substantial variability at international, national, and regional levels in how effective dialysis providers are in the implementation of well‐accepted interventions to deliver better health outcomes at reduced costs to payers. The growing number of dialysis patients within a finite pool of resources has led to searches for more efficient methods to provide patient care without compromising or diminishing quality. We review here some contemporary concepts surrounding quality improvement and operations research that may provide clinician administrators to both improve efficiency and quality in facility based hemodialysis units. The creation of balanced scorecards, utilization of process mapping techniques, and the application of LEAN principles may readily improve how hemodialysis care is delivered in an environment of increasing patient volumes and reduced operating resources.