Yohimbine Depresses Excitatory Transmission in BNST and Impairs Extinction of Cocaine Place Preference Through Orexin-Dependent,Norepinephrine-Independent Processes

The alpha2 adrenergic receptor (α₂-AR) antagonist yohimbine is a widely used tool for the study of anxiogenesis and stress-induced drug-seeking behavior. We previously demonstrated that yohimbine paradoxically depresses excitatory transmission in the bed nucleus of the stria terminalis (BNST), a region critical to the integration of stress and reward pathways, and produces an impairment of extinction of cocaine-conditioned place preference (cocaine-CPP) independent of α₂-AR signaling. Recent studies show yohimbine-induced drug-seeking behavior is attenuated by orexin receptor 1 (OX₁R) antagonists. Moreover, yohimbine-induced cocaine-seeking behavior is BNST-dependent. Here, we investigated yohimbine-orexin interactions. Our results demonstrate yohimbine-induced depression of excitatory transmission in the BNST is unaffected by alpha1-AR and corticotropin-releasing factor receptor-1 (CRFR₁) antagonists, but is (1) blocked by OxR antagonists and (2) absent in brain slices from orexin knockout mice. Although the actions of yohimbine were not mimicked by the norepinephrine transporter blocker reboxetine, they were by exogenously applied orexin A. We find that, as with yohimbine, orexin A depression of excitatory transmission in BNST is OX₁R–dependent. Finally, we find these ex vivo effects are paralleled in vivo, as yohimbine-induced impairment of cocaine-CPP extinction is blocked by a systemically administered OX₁R antagonist. These data highlight a new mechanism for orexin on excitatory anxiety circuits and demonstrate that some of the actions of yohimbine may be directly dependent upon orexin signaling and independent of norepinephrine and CRF in the BNST.     

Knowledge and Attitudes of Saudi Dental Undergraduates on Oral Cancer

Oral cancer awareness among future dental practitioners may have an impact on the early detection and prevention of oral cancer. A cross-sectional survey was undertaken to assess the current knowledge of future Saudi dentists on oral cancer and their opinions on oral cancer prevention. A pretested questionnaire was sent to 550 undergraduate dental students in the fourth, fifth, and sixth year of the Al-Farabi College for Dentistry and Nursing, Riyadh, Saudi Arabia. Questions relating to knowledge of oral cancer, risk factors, and opinions on oral cancer prevention and practices were posed. Four hundred seventy-nine students returned the questionnaire (87.1 %). Eighty-one percent of respondents correctly answered questions relating to oral cancer awareness. Eighty-seven percent of respondents felt confident in performing a systematic oral examination to detect changes consistent with oral malignancy. Interestingly, 57 % of respondents had seen the use of oral cancer diagnostics aids. Thirty-seven percent of respondents felt inadequately trained to provide tobacco and alcohol cessation advice. There is a need to reinforce the undergraduate dental curriculum with regards to oral cancer education; particularly in its prevention and early detection. Incorporating the use of oral cancer diagnostic aids should be made mandatory.     

Changes in the biochemical composition of fetal fluids and maternal blood serum during different days of gestation in cattle

The aim of this study was to determine the values of some metabolites, ions, and enzymes in maternal blood serum and fetal fluids in relation to gestation day in cattle. Gravid uteri of cattle were collected after slaughter. The allantoic and amniotic fluids as well as maternal blood samples were collected. Fetal ages were determined according to crown–rump length by applying the age estimation formula that previously was presented for cattle. The pregnancies were divided according to gestation days into four groups: 0–50, 51–100, 101–150, and 151–200?days. With the progress of pregnancy, the biochemical levels of fetal fluids and maternal serum changed as follows: there was a rise of total protein, urea, creatinine, and alkaline phosphatase values in fetal fluids and serum; the levels of glucose in maternal serum and potassium in fetal fluids increased; cholesterol, triglyceride, phosphorus, and sodium contents of fetal fluids and serum decreased; the concentrations of glucose and calcium in fetal fluids, lactate dehydrogenase (LDH) in serum and allantoic fluid, potassium in serum, and aspartate aminotransferase (ASAT) in amniotic fluid and serum dropped. The values of LDH in amniotic fluid, ASAT in allantoic fluid, alanine aminotransferase in amniotic and allantoic fluids, and calcium in maternal serum remained unchanged.     

Elevated serum neutrophil elastase is related to prehypertension and airflow limitation in obese women

Background  

Neutrophil elastase level/activity is elevated in a variety of diseases such as atherosclerosis, systolic hypertension and obstructive pulmonary disease. It is unknown whether obese individuals with prehypertension also have elevated neutrophil elastase, and if so, whether it has a deleterious effect on pulmonary function. Objectives: To determine neutrophil elastase levels in obese prehypertensive women and investigate correlations with pulmonary function tests.     

Occult hepatitis C virus infection among haemodialysis patients

Background and study aims

Hepatitis C virus (HCV) infection is a severe problem among patients on maintenance haemodialysis who are at particular risk for blood-borne infections because of prolonged vascular access and potential for exposure to contaminated equipment. Occult hepatitis C virus infection (OCI) is defined as the presence of HCV RNA in liver or peripheral blood mononuclear cells (PBMCs) in the absence of detectable HCV antibody or HCV RNA in the serum. In this study, we aimed to investigate the existence of occult hepatitis C virus infection in PBMCs of haemodialysis (HD) patients in one center. Moreover, we tried to link the condition to risk factors associated with HCV infection in those patients.

Systemic lupus erythematosus with acute pancreatitis and vasculitic rash following COVID-19 vaccine: a case report and literature review

Clinical Rheumatology - Coronavirus disease-19 (COVID-19) is a global pandemic that is caused by COVID-19 virus, which was initially identified in December 2019 in Wuhan, China. Vaccination is one...     

Incidence,efficacy and safety of YAG laser goniopuncture following nonpenetrating deep sclerectomy at a university hospital in Riyadh,Saudi Arabia

Purpose

Assessing the frequency and evaluating the efficacy and safety of Neodymium:Yttrium Aluminum Garnet (Nd:YAG) Laser goniopuncture (LGP) following nonpenetrating deep sclerectomy (NPDS).

Design

Retrospective cohort study.

Patients and methods

We retrospectively reviewed the outcome of 197 eyes of 153 patients with open angle glaucoma who underwent either NPDS or NPDS combined with cataract extraction between January 2005 and September 2010 at King Abdulaziz University Hospital (KAUH). Both demographic and clinical data were retrieved and analysed.

Results

Goniopuncture (GP) was needed in 48 (24.4%) of the eyes which had NPDS or NPDS with cataract extraction after a mean post operative interval of 9.78 (±11.16) months. The mean IOP had significantly decreased from 23.3 (±5.9) mmHg prior to Nd:YAG LGP procedure to 14.6 (±4.4) mmHg at the last post-procedure assessment. At the last follow-up; Nd:YAG LGP was successful in controlling IOP in 27 eyes (56.3%). Mean Nd:YAG LGP failure time was 6.04 (±5.80) months. Young age (<50 years) (p = 0.001); type of glaucoma (secondary versus primary open angle, p = 0.0258) and the use of drainage implant (p = 0.038) were the identified predicting factors for the need of Nd:YAG LGP. Complications following Nd:YAG LGP occurred in 5 eyes (iris touch to TDM (4.2%), Hyphema (2.1%), hypotony maculopathy (2.1%) and choroidal detachment (2.1%).

Conclusions

LGP is an efficient IOP lowering procedure after NPDS, when it is indicated. It is a simple and noninvasive procedure. However, certain precautions should be taken to avoid complications.