Contact allergens responsible for eyelid dermatitis in adults

Allergic contact dermatitis has been established as the most frequent cause of eyelid dermatitis, but it is often misdiagnosed. The purpose of this study was to evaluate the characteristics of patients with eyelid dermatitis who were referred for patch testing. The patients were divided into three subgroups in this retrospective study: patients with only eyelid involvement, patients with involvement of eyelids and other areas, and patients without eyelid involvement. Data was collected on diagnoses, medical history, personal care products and make-up use, occupational dermatitis, and positive allergens. An independent t-test, one-way ANOVA, and chi-squared test were used to analyze the data. A total of 427 patients who referred for patch tests were included in the study. Of these, 139 patients had eyelid dermatitis. Allergic contact dermatitis (ACD) was the most common diagnosis in all three groups referred for patch tests. Use of shaving cream and hair conditioner was significantly higher in patients with only eyelid involvement and nickel sulfate was the most common allergen among them. Patch testing is the gold standard tool in the evaluation of eyelid contact dermatitis, and it is a necessity in the treatment of eyelid dermatitis, for the accurate identification of responsible allergens.

Establishing a Rural General Surgery Residency Program: Identifying Community Stakeholder Perception and Obstacles of a de Novo Residency in Rural Appalachia

BACKGROUND

Rural healthcare has become more challenging over the past several years with increasingly limited access to surgical care in the rural setting. The Accreditation Council for Graduate Medical Education (ACGME) has recently introduced the Rural Track Program (RTP) initiative to combat physician shortage in rural areas. We intend to start the first Rural General Surgery Residency program under the RTP designation in rural Appalachia.

STUDY DESIGN

430 community stakeholders were surveyed regarding the anticipated impact of a new training program. Questions focused on the understanding of a Residency Program, the care provided by residents, impact on availability of local care, current geographical limitation of surgical care, and potential benefits/obstacles of the training program.

RESULTS

Over 90% of all surveyed approved of training surgeons locally, with the local government believing that the program would be a good investment for the community. Several locals had been treated by resident physicians at other facilities and the majority were satisfied with the care they received. Several families frequently travel to larger cities for surgical care, with 96% of all respondents believing that the program would provide better access to care locally.

CONCLUSION

Our study demonstrated that the community is familiar with healthcare in a training facility and welcoming to a local training program, while believing that trainees will have a positive impact on local surgical care in rural Appalachia. We will continue to work with the local community and healthcare personnel while developing the program and tailor our Residency to the rural setting as able.

Gallstone Ileus: A Case Report in a 74-Year-Old Male

Gallstone ileus is a rare complication of complicated gallbladder disease. Typically the result of a cholecystocholeduodenal fistula, a gallstone enters the small bowel and impacts in the ileum causing an obstruction. In this case study, a 74-year-old male presented to the emergency department with nausea, vomiting, and constipation for 2 weeks. CT revealed pneumobilia and a 3.1 cm calcified mass in the terminal ileum. The patient was successfully treated with a robotic-assisted enterotomy alone without complications.

EVALUATION OF THE OBSERVANCE OF RADIATION PROTECTION PRINCIPLES IN KERMANSHAH PROVINCE (WEST OF IRAN) 2020: CROSS-SECTIONAL STUDY

In this descriptive cross-sectional study by census method, the performance of 116 radiographers in the target centers was evaluated in relation to the observance of radiation protection principles with respect to patients, patient companion and radiographers. The data collection tool was a checklist containing 34 principles of radiation protection that were used after confirmation of its continuity and justifiability. The results showed that only in (39.2%) 45 radiographers the observance rate of the principles of radiation protection was acceptable. The highest and lowest levels in which radiographers observed protective principles were observance of protective principles with respect to themselves (60.8%) and protective principles respect of the patient companion (6.3%), respectively. According to the findings, radiation protection principles are not systematically designed, implemented, controlled and monitored by radiographers, and less than half of the radiographers observe the protection principles at the optimal level.

Operative Rib Fixation at a Rural Trauma Center

INTRODUCTION

Operative rib fixation is becoming more common in the management of rib fractures, with studies showing benefits of surgery in decreasing time on mechanical ventilation, ICU and total hospital length of stay, and mortality. This paper will review the data from our institution to determine if these benefits were seen in our trauma population.

METHODS

A retrospective review of the institution's trauma database was conducted, including operative patients (n = 36), control patients (nonoperative patients from October 2018 to October 2019, n = 207), and selected control patients based on similar injury severity score range as operative patients (n = 181). Data reviewed included time on mechanical ventilation, ICU and total hospital length of stay, and disposition at discharge, including mortalities. Operative complications were also reviewed.

RESULTS

The operative group had a higher ISS compared to both controls, longer average time on mechanical ventilation, longer average ICU and total hospital length of stay, and a higher percentage of patients discharged to inpatient facilities. However, the operative group had lower mortality compared to the control groups. The operative group had 3 surgical site infections requiring readmission and hardware removal.

DISCUSSION

Unlike other studies, our operative patients did not see improvements in time on mechanical ventilation, ICU and total hospital length of stay, or disposition at discharge, but did see a mortality benefit. Confounding factors include higher average ISS in the operative group, and over-sedation in the ICU. Data collection is ongoing, and refinements are being made to perioperative and ICU management to minimize these confounding variables.

The Importance of the Institution of a Robotic Curriculum on Resident Training and Performance

In 2018, general surgery topped the number of robotic cases. Over 90% of residents participate, but only 65% of programs have a formal curriculum, and less than half track progress. Many are insufficient at training due to an observational role. This paper reviews Marshall University General Surgery Residency program's robotic curriculum, which started in 2018. The curriculum consists of a weekend course and simulations, enabling residents obtain certification. Residents participated in Intuitive's Resident Robotic Olympics with first place in 2019 and second and third place in 2020. For the 2021 year, the robotic curriculum was revised into phases based on year. Deadlines and forms help improve and track progress. It is important to develop a curriculum with a protocol for training, monitoring, and credentialing to ensure proficiency. Marshall University General Surgery robotic curriculum has been successful at improving robotic skill, enabling residents to obtain a robotic surgery certification upon graduation.

Effect of self-management program on outcome of adult knee osteoarthritis

BACKGROUND & AIM

Chronic disease is a major concern with an aging population, and arthritis is one of the most prevalent chronic diseases affecting 10% of the population. Self-management can be appropriate to relieve the outcome of osteoarthritis as one of the most suitable approaches in people with chronic diseases. This study aimed to determine the effect of self-management education programs on the outcome of knee osteoarthritis in adult patients.

METHODS

Eighty participants were randomized into either control (40) or intervention (40) groups. Initially, demographic data and outcome of knee osteoarthriti datas were collected. The intervention group was then offered a self-management program. After completing the education, the KOOS questionnaire was completed by both groups. The intervention group practiced the self-management program for 8 weeks at their homes. The outcome of knee osteoarthritis in the two groups was then reassessed and compared.

RESULTS

There was no significant difference in the total score of the outcome of knee osteoarthritis before the training of the self-management education program (P > 0.05) between the two groups. After implementation of the self-management education program, the two groups demonstrated significant differences in scores for pain, symptoms, activities of daily living, sport and recreation function, and quality of life (P < 0.001).

CONCLUSION

Self-management education can improve all outcomes of knee osteoarthritis. Adherence to the proper diet and the use of pain reduction methods along with exercise improve the effects of knee osteoarthritis.

The Effect of Substance Abuse Programs on Positive Drug Screening Tests in Trauma Patients

BACKGROUND

According to the National Institute on Drug Abuse, West Virginia has the highest age-adjusted rate of drug overdose deaths involving opioids. To combat this crisis, comprehensive drug counseling support services were established within the Cabell Huntington Hospital (CHH) system in October 2018 in Huntington, WV, USA. The purpose of this study was to investigate whether these services significantly reduced the number of trauma patients with a positive urine drug screen (UDS) seen at CHH.

METHODS

The trauma registry at CHH was used to obtain data on trauma patients with positive UDS from January 2017 to October 2019, which was divided into groups before and after October 2018. Exclusion criteria were any patients who were prescribed the drug. The percentages of the total number of positive drug screens within each group were calculated, and a t-test analysis was performed to determine the P values.

RESULTS

345 trauma patients with positive UDS were selected. Results showed that there was an overall decrease in the rate of nonprescribed use after October 2018 of benzodiazepines (18.1%-11.5%), cocaine (19.5%-15.3%), opioids (19.1%-12.3%), and oxycodone (10.2%-4.6%). However, none of these changes were statistically significant. There was an increase in the rate of nonprescribed use of amphetamine (20.0%-23.8%) and methamphetamine (14.4%-33.8%).

DISCUSSION

Our hypothesis is that the support systems are relatively new, and may need more time to identify and intervene on patients before a statistically significant effect on drug abuse rates in our region can be seen.

Knowledge of medical professionalism in medical students and physicians at Shahid Beheshti University of Medical Sciences and affiliated hospitals-Iran

Although medical professionalism is a fundamental aspect of competence in medicine and a distinct facet of physicians' competence, evidence suggests that the subject of professionalism is not taught or assessed as part of medical students' curricula in Iran and many other countries. Assessing the knowledge of medical students and physicians about medical professionalism seems to be helpful in identifying the weaknesses of training in the field of professionalism and devise plans for future training on the subject.The present cross-sectional, quantitative, observational, and prevalence study recruited 149 medical interns, clinical residents, physicians, and professors working in hospitals selected through stratified random sampling using a questionnaire designed by the researchers and confirmed for its validity and reliability. The results were analyzed by Stata at a significance level of 0.05.Out of 149 cases, 61.64% were male with the mean age of 30.81 years. A total of 66 participants (44.29%) (95% confidence interval [CI]: 36.44%-52.44%) had heard and 83 (55.70%) (95% CI: 47.55%-63.55%) had not heard the term "medical professionalism" before the study. After adjusting for potential confounders, age and degree did not have statistically significant difference in assessed knowledge of medical professionalism, but sex had (mean difference: 5.88, P = 0.045), and the mean of the female was significantly higher than that of the male participants. The mean percentage of correct answers was 47.67.The present study demonstrated that the medical professionals working in the national healthcare system have an unfavorable theoretical knowledge about medical professionalism in Iran; although this does not indicate that their practices are unethical, it should be noted that one of the prerequisites of possessing a high level of medical professionalism and for establishing a proper relationship between the medical community and the patients is to have a proper knowledge of this concept. Improving behaviors and performances in medical professions requires adequate training on the concepts of medical professionalism and consequently the assessment of the levels of professionalism achieved in medical professionals.

Does vitamin D3 supplementation improve glucose homeostasis in overweight or obese women? A double-blind, randomized, placebo-controlled clinical trial

AIMS

Vitamin D deficiency is considered as a risk factor in cardiometabolic disorders, including cardiovascular diseases, hypertension and Type 2 diabetes mellitus. We have investigated the effect of vitamin D3 supplementation on glucose homeostasis in healthy overweight and obese women.

METHODS

In a double-blind randomized placebo-controlled clinical trial, 77 healthy overweight or obese women (mean age 38 ± 8 years; BMI 29.9 ± 4.2 kg/m(2)) were randomly assigned to the vitamin D3 group (25 μg/day as cholecalciferol tablets) or the placebo group. Selected anthropometric indices, glucose, insulin, HbA(1c) and homeostasis model assessment of insulin resistance at baseline and after 12 weeks were measured. Dietary intakes using 24-h food recall and food frequency questionnaires were assessed. Physical activity was assessed by the International Physical Activity Questionnaire. Adjusted mean differences were calculated using analysis of covariance. Correlation coefficients were calculated by Pearson's analysis.

RESULTS

Mean fasting blood glucose concentrations declined in the vitamin D3 and placebo groups (-0.28 ± 0.4 vs. -0.65 ± 0.4 mmol/l, P < 0.001) and the mean percentage of HbA(1c) was decreased (-13 ± 18 vs. -19 ± 17 mmol/l, P = 0.06) in both groups, respectively. Mean 25-hydroxyvitamin D concentrations increased in the vitamin D3 and placebo groups (38.2 ± 32 vs. 4.6 ± 14 nmol/l, P < 0.001), respectively. There was a significant correlation between HbA(1c) and 25-hydroxyvitamin D concentrations (r = -0.271; P = 0.018).

CONCLUSIONS

The results indicate that the vitamin D3 supplement of 25 μg/day had no beneficial effect on glycaemic indices in healthy overweight or obese women.

Ground wheat grain for midlactation cows: challenging a common wisdom

The objective was to determine the effects of ground wheat grain (GW) inclusion rate, grinding extent (GE), and their interaction on lactating cow performance. Eight midlactation cows in 3 × 4 m individual boxes were used in a 4 × 4 replicated Latin square design study with 4 21 d periods. GW was fed at either 10% or 20% of diet dry matter (DM), as either finer or coarser particles. DM intake increased and net energy for lactation (NE(L)) intake tended to increase when GW was fed at 10% instead of 20% of diet DM. Milk energy yield, milk solids content and yield, and urine pH were unaffected. Fecal pH tended to increase at 20% versus 10% GW. Total tract apparent NDF, but not DM, digestibility tended to be greater for coarsely than finely GW and tended to be greater at 10% versus 20% GW. GW at 10% versus 20% of diet DM decreased blood BHBA and increased blood concentrations of total proteins and albumin. Data provide novel evidence that both finely and coarsely ground WG can be safely fed up to 20% midlactation cows. Commercial accessibility and cost will determine feeding preference of wheat grain to dairy cows.

Malignant mucosal melanoma of the paranasal sinuses: Two case presentations

Primary mucosal melanoma of the paranasal sinuses is a rare tumor of the head and neck which can be a devastating disease. Cancers arising in the sinonasal cavity are extremely rare, with a poor survival rate. There is inherent difficulty in diagnosing these lesions due to their complex anatomic locations and symptoms which are often confused with more common benign processes. The primary treatment of this rare disease process is resection, except in advanced stages where surgical resection is not an option. Diagnostic accuracy in consideration of size, location, and presence of metastatic disease of these malignant tumors tailors individual patients to different management in order to achieve the longest possible survival.

Bioleaching of tungsten-rich spent hydrocracking catalyst using Penicillium simplicissimum

Adaptation of Penicillium simplicissimum with different heavy metals present in a spent hydrocracking catalyst, as well as one-step, two-step, and spent medium bioleaching of the spent catalyst by the adapted fungus, was examined in batch cultures. Adaptation experiments with the single metal ions Ni, Mo, Fe, and W showed that the fungus could tolerate up to 1500 mg/L Ni, 8000 mg/L Mo, 3000 mg/L Fe, and 8000 mg/L W. In the presence of multi-metals, the fungus was able to tolerate up to 300 mg/L Ni, 200 mg/L Mo, 150 mg/L Fe and 2500 mg/L W. A total of 3% (w/v) spent catalyst generally gave the maximum extraction yields in the two-step bioleaching process (100% of W, 100% of Fe, 92.7% of Mo, 66.43% of Ni, and 25% of Al). The main lixiviant in the bioleaching was shown to be gluconic acid. The red pigment produced by the fungus could also possibly act as an agent in Al leaching.

Synergistic vascular protective effects of combined low doses of PPARalpha and PPARgamma activators in angiotensin II-induced hypertension in rats

BACKGROUND AND PURPOSE

Protective cardiovascular effects of peroxisome proliferator activated receptor (PPAR)alpha and PPARgamma activators have been demonstrated. If used as vasoprotective agents in high risk vascular patients rather than for their metabolic benefits, these agents could be associated with unwanted side effects. As a proof of concept to support the use of combined low doses of PPARalpha and PPARgamma as vascular protective agents in high risk vascular patients, we tested the hypothesis that combined low doses of PPARalpha (fenofibrate) and PPARgamma (rosiglitazone) activators would provide vascular protective benefits similar to full individual doses of these PPAR agonists.

EXPERIMENTAL APPROACH

Male Sprague-Dawley rats infused with Ang II (120 ng kg(-1) min(-1)) were treated with rosiglitazone (1 or 2 mg kg(-1) day(-1)) alone or concomitantly with fenofibrate (30 mg kg(-1) day(-1)) for 7 days. Thereafter, vessels was assessed on a pressurized myograph, while NAD(P)H oxidase activity was determined by lucigenin chemiluminescence. Inflammation was evaluated using ELISA for NFkappaB and Western blotting for adhesion molecules.

KEY RESULTS

Ang II-induced blood pressure increase, impaired acetylcholine-induced vasorelaxation, altered vascular structure, and enhanced vascular NAD(P)H oxidase activity and inflammation were significantly reduced by low dose rosiglitazone+fenofibrate.

CONCLUSIONS AND IMPLICATIONS

Combined low doses of PPARalpha and PPARgamma activators attenuated development of hypertension, corrected vascular structural abnormalities, improved endothelial function, oxidative stress, and vascular inflammation. These agents used in low-dose combination have synergistic vascular protective effects. The clinical effects of combined low-dose PPARalpha and PPARgamma activators as vascular protective therapy, potentially with reduced side-effects and drug interactions, should be assessed.

Renal angiotensin II receptors and protein kinase C in diabetic rats: effects of insulin and ACE inhibition

It has been shown that glomerular ANG II receptors are downregulated and protein kinase C (PKC) activity is enhanced in diabetes mellitus. Therefore, we investigated glomerular and preglomerular vascular ANG II receptors and PKC isoform regulation in streptozotocin (STZ)-diabetic rats treated with insulin and/or captopril. Diabetic rats were prepared by injecting STZ (60 mg/kg). Those that developed diabetes after 48 h were treated with low or high doses of insulin, or with a low dose of insulin as well as captopril, and killed 14 days later. Their glomeruli and preglomerular vessels were purified, competitive binding studies were performed by using the ANG II antagonists losartan and PD-123319, and PKC analysis was carried out by Western blotting. Competitive binding studies showed that the AT(1) receptor was the only ANG II receptor detected on both glomeruli and preglomerular vessels of all groups. Preglomerular vascular AT(1) receptor density (B(max)) was significantly upregulated in low insulin-treated STZ rats, whereas glomerular AT(1) B(max) was downregulated. Furthermore, both the captopril- and high insulin-treated groups had less glomerulosclerosis and vascular damage than the low insulin-treated group. PKCalpha, PKCdelta, PKCepsilon, and PKCmu isoforms found in preglomerular vessels were upregulated by captopril and high insulin doses, respectively, whereas no such regulation occurred in glomeruli. We conclude that in STZ-diabetic rats ANG II receptors and PKC isoforms on preglomerular vessels and glomeruli are differentially regulated by treatment with insulin and/or captopril.

Hyperglycemia enhances angiotensin II-induced janus-activated kinase/STAT signaling in vascular smooth muscle cells

We have shown previously that angiotensin II (Ang II) activates the janus-activated kinase (JAK)/signal transducers and activators of transcription (STAT) pathway in vascular smooth muscle cells (VSMCs) and that activation of the JAK/STAT pathway is required for Ang II induction of VSMC proliferation. In the present study, we examined the effects of hyperglycemia (HG) on Ang II-induced JAK/STAT signaling events in cultured VSMCs. HG increases Ang II-induced JAK2 tyrosine phosphorylation and promotes a partial tyrosine phosphorylation of the enzyme under basal conditions. In addition, HG increases both basal and Ang II-induced complex formation of JAK2 with the Ang II AT(1) receptor. The extent of STAT1 and STAT3 tyrosine and serine phosphorylation are also increased under HG conditions. Furthermore, the tyrosine phosphorylation and activities of the SHP-1 and SHP-2 tyrosine phosphatases, enzymes that regulate Ang II-induced JAK2 tyrosine phosphorylation, are altered by HG. SHP-1, which is responsible for JAK2 tyrosine dephosphorylation in VSMC, is completely deactivated in HG, resulting in a prolonged duration of JAK2 phosphorylation under HG conditions. HG also enhances Ang II induction of VSMC proliferation. Taken together, these data suggest that HG augments Ang II induction of VSMC proliferation by increasing signal transduction through the JAK/STAT pathway.

Regulation of angiotensin II receptors and PKC isoforms by glucose in rat mesangial cells

It has been shown that glomerular angiotensin II (ANG II) receptors are downregulated and protein kinase C (PKC) is activated under diabetic conditions. We, therefore, investigated ANG II receptor and PKC isoform regulation in glomerular mesangial cells (MCs) under normal and elevated glucose concentrations. MCs were isolated from collagenase-treated rat glomeruli and cultured in medium containing normal or high glucose concentrations (5.5 and 25.0 mM, respectively). Competitive binding experiments were performed using the ANG II antagonists losartan and PD-123319, and PKC analysis was conducted by Western blotting. Competitive binding studies showed that the AT1 receptor was the only ANG II receptor detected on MCs grown to either subconfluence or confluence under either glucose concentration. AT1 receptor density was significantly downregulated in cells grown to confluence in high-glucose medium. Furthermore, elevated glucose concentration enhanced the presence of all MC PKC isoforms. In addition, PKCbeta, PKCgamma and PKCepsilon were translocated only in cells cultured in elevated glucose concentrations following 1-min stimulation by ANG II, whereas PKCalpha, PKCtheta, and PKClambda were translocated by ANG II only in cells grown in normal glucose. Moreover, no changes in the translocation of PKCdelta, PKCiota, PKCzeta, and PKCmu were detected in response to ANG II stimulation under euglycemic conditions. We conclude that MCs grown in high glucose concentration show altered ANG II receptor regulation as well as PKC isoform translocation compared with cells grown in normal glucose concentration.

Regulation of natriuretic peptide secretion by the heart

Secreted by the heart, more specifically by atrial cardiomyocytes under normal conditions but also by ventricular myocytes during cardiac hypertrophy, natriuretic peptides are now considered important hormones in the control of blood pressure and salt and water excretion. Studies on natriuretic peptide secretagogues and their mechanisms of action have been complicated by hemodynamic changes and contractions to which the atria are constantly subjected. It now appears that atrial stretch through mechano-sensitive ion channels, adrenergic stimulation via alpha 1A-adrenergic receptors, and endothelin via its ETA receptor subtype are major triggering agents of natriuretic peptide release. With several other stimuli, such as angiotensin II and beta-adrenergic agents, modulation of natriuretic peptide release appears to be linked to local generation of prostaglandins. In all cases, intracellular calcium homeostasis, controlled by several ion channels, is considered a key element in the regulation of natriuretic peptide secretion.

Renal angiotensin II receptor regulation and renin-angiotensin system inhibition in one-kidney, one clip hypertensive rats

OBJECTIVE

To characterize glomerular and preglomerular vascular angiotensin II receptors during the acute phase of nonrenin-dependent one-kidney, one clip hypertension in rats, using the angiotensin II antagonists losartan and PD 123319, and to investigate their regulation after renin-angiotensin system blockade with either an angiotensin converting enzyme inhibitor, captopril, or an angiotensin II receptor antagonist, TCV-116.

MATERIALS AND METHODS

One-kidney, one clip hypertension was produced in male Sprague-Dawley rats by placing a silver clip (internal diameter 0.2 mm) on the left renal artery and removing the contralateral kidney. After 1, 2 or 4 weeks, the rats were killed, and their glomerular and preglomerular vascular membranes were purified. Competitive binding studies were performed using specific angiotensin II antagonists. Similarly, one-kidney, one clip hypertension was allowed to develop for 2 weeks before treatment with captopril or TCV-116 for 2 weeks.

RESULTS

Competitive binding studies showed that only the angiotensin II type 1 (AT1) receptor was detected on both glomeruli and preglomerular vessels of all groups. The vascular AT1 receptor density was significantly higher in the 1 and 2 week one-kidney, one clip groups, but the glomerular receptor density was not different in these rats compared with age-matched uninephrectomized controls. The glomerular receptor density was significantly higher in captopril-treated rats and significantly lower in TCV-116-treated rats compared with untreated and control rats, but no significant changes were detected in any groups in vascular AT1 receptor density.

CONCLUSIONS

Angiotensin II receptors on preglomerular vessels and glomeruli are differentially regulated during the early phase of hypertension and after renin-angiotensin system blockade. Vascular angiotensin II receptors are upregulated in the early phase of hypertension whereas glomerular angiotensin II receptors are not However, after renin-angiotensin system blockade, glomerular but not vascular angiotensin II receptors were differentially regulated according to the type of blockade.

Vasoactive peptide receptors in the rat kidney

The kidney is composed of different complex structures regulating--among others--renal blood flow and glomerular filtration rate. Several vasoactive peptide systems are involved in that regulation, including atrial natriuretic peptides, the renin-angiotensin system, endothelin and their respective receptors. In this review, we will briefly describe the characteristics, location and regulation of these receptors in the rat kidney.

Renal angiotensin II receptor regulation in two-kidney, one clip hypertensive rats: effect of ACE inhibition

Local renal and plasma renin-angiotensin systems (RAS) both play an important role in blood pressure regulation during the development of two-kidney, one clip Goldblatt hypertension (2K1C) through their vasoactive component, angiotensin II (Ang II). Our goal was to characterize glomerular and preglomerular vascular Ang II receptors during the different stages of development of hypertension in 2K1C rats (2-, 4-, 8-, and 16-weeks postoperative) using Ang II antagonists [Sar1,Ile8]-Ang II, losartan, and PD 123319 and their regulation after angiotensin-converting enzyme (ACE) inhibition by captopril. Competitive binding studies showed that the only Ang II receptor detected on both glomeruli and preglomerular vessels of all groups (2-, 4-, 8-, and 16-week 2K1C rats, control rats, and captopril-treated rats) was the Ang II type 1 receptor (AT1). Vascular AT1 receptor density (Bmax) was significantly lower in only the 16-week 2K1C group, whereas glomerular Bmax was significantly lower in 2K1C rats at 2-, 4-, and 8-weeks. Vascular and glomerular receptor densities were both significantly higher in captopril-treated rats than in nontreated rats. We therefore conclude that in 2K1C rats, Ang II receptors on preglomerular vessels and glomeruli are regulated differentially during the development of hypertension and after ACE inhibition. Our results suggest that glomerular Ang II receptors are regulated by systemic plasma Ang II levels, whereas vascular Ang II receptors are not. However, when renal and systemic RASs are both blocked, these receptors are upregulated but are no longer differentially regulated.

Modulation of renal glomerular angiotensin II receptors by ace inhibition and AT1 receptor antagonism

Angiotensin-converting enzyme inhibitors (ACE-I) and specific nonpeptide angiotensin II (ANG II) receptor antagonists have been used extensively to treat a variety of cardiovascular disorders in experimental animals and humans. Despite their widespread use, only a limited amount of data has been published regarding the effect that renin-angiotensin system (RAS) blockade may have on ANG II receptors, and very often this information is contradictory. The present study was designed to investigate whether changes in plasma ANG II levels induced by RAS blockade could alter glomerular ANG II receptor characteristics. Captopril was employed as an ACE-I with losartan and TCV-116, two AT1 receptor antagonists of different chemical structure. Two experimental protocols were established. Protocol 1 contained 3 experimental groups: controls (Sprague-Dawley rats, 250-300 g BW), and animals treated with either captopril (0.5 g/l via drinking water) or losartan (10 mg/kg BW p.o.). In protocol 2, the animals were treated as in protocol 1 except that losartan was replaced by TCV-116 (1 mg/kg BW p.o.). At the end of treatment (3 days), all groups were killed by decapitation, blood was collected for plasma renin activity (PRA) measurement, and hearts and kidneys were excised. ANG II receptors were assessed by radioligand binding assays on membrane preparations of purified glomeruli, by displacement of 125I-[Sar1, Ile8]-ANG II with specific nonpeptide antagonists of AT1 (losartan) and AT2 (PD 123319) receptor subtypes. RAS blockade by either ACE-I or AT1 antagonists increased PRA. The binding assays showed that renal glomeruli from treated rats and controls expressed a single population (AT1) of ANG II receptors. The density of glomerular AT1 receptors was not modulated by captopril, but was significantly lower in animals treated with either losartan (Bmax: 854 +/- 169 vs. 379 +/- 79 fmol/mg protein and Kd: 59 +/- 6 vs. 45 +/- 6 nM for controls and losartan, respectively) or TCV-116 (480 +/- 72 vs. 188 +/- 16 fmol/mg protein and Kd: 45 +/- 9 vs. 37 +/- 18 nM for controls and TCV-116, respectively) than in their controls. No changes in receptor affinity (Kd) were detected. Previous membrane "acid-wash" did not modify the results. We conclude that short-term RAS blockade by AT1 antagonists, but not by ACE-I, induces true downregulation of renal glomerular ANG II receptors. No AT2 receptor subtype was detected.

An artificial intelligence program for the radiologic diagnosis of brain lesions

A software program has been developed that uses a frame-based expert system for differential diagnosis in neuroradiology. A frame-based expert system is used to store the magnetic resonance (MR) and computed tomographic (CT) imaging characteristics of over 100 known brain disorders in object-like entities. The frames are organized in a hierarchic structure in which lower order frames inherit attributes from higher order frames, with the highest frame containing information that applies to all the other frames. Program execution follows a consultation paradigm with a dynamic database. A decision tree menu provides a user-friendly interface with which to navigate through the network, based on features of the lesion as depicted on MR and CT images. The system can provide a differential diagnosis based on the MR imaging findings alone with information criteria including the signal intensity of the lesion on T1- and T2-weighted images, the location of the lesion, and the presence or absence of mass effect. The differential diagnosis may be further refined by adding CT-related information, including CT attenuation and the presence or absence of calcification and contrast enhancement.

Differential regulation of renal glomerular and preglomerular vascular angiotensin II receptors

The activity of the renin-angiotensin system (RAS) can be influenced by sodium intake and angiotensin II (ANG II) infusion. It has been shown that ANG II can regulate the density of its receptors. Therefore, we investigated the regulation of glomerular and preglomerular vascular ANG II receptors by changes in RAS activity. Sprague-Dawley rats were fed a low- or high-sodium diet or were infused with nonpressor or pressor doses of ANG II for 7 days. ANG II receptor characteristics were determined by radioligand binding assays with use of ANG II antagonists losartan and PD-123319. AT1 was the only receptor type found in membrane preparations from all groups. Glomerular ANG II receptor characteristics in all groups were unchanged compared with their controls, whereas vascular receptor density was significantly downregulated by sodium restriction. We conclude that glomerular and preglomerular vascular ANG II receptors are differentially regulated such that AT1 receptors in preglomerular vessels can be regulated by changes in endogenous RAS. ANG II infusion did not induce any modification of either glomerular or vascular AT1 receptors, suggesting a predominant role of the endogenous local renal RAS.