Significant Reciprocal Correlation Research Articles

Long Sudarshan Kriya Yoga enhances cardiovascular and respiratory synchronization: An observational study

BackgroundSudarshan Kriya Yoga (SKY – a rhythmic cyclic breathing) is known to produce several physiological changes in human body. Earlier it has been reported that SKY improves cardiovascular modulations, namely increase in heart rate variability. ObjectiveTo observe the synchronization in oscillatory modulations in cardiac autonomic tone and ventilatory exchange during Long Sudarshan Kriya Yoga (LSKY). LSKY is a sequential combination of pranayama in ujjayi breath, bhastrika, and cyclic rhythmic breathing followed by yog-nidra. MethodsRegular LSKY practitioners from the Art of Living community with more than two years of experience participated in the study (n = 22; age 40.09 ± 12.68). The Electrocardiogram (ECG), respiration, oxygen saturation, and concentrations of oxygen and carbon-di-oxide from exhaled air were recorded before and during LSKY. The time domain parameters of heart rate variability (HRV) were calculated from ECG. All parameters were compared and correlated at each stage of LSKY. ResultsHighly significant reciprocal correlation was found between HRV parameters and respiration rate during LSKY. Both O2 consumption and CO2 production increased significantly during three stages of pranayama and decreased towards the end of cyclic breathing. We also saw increased SPO2 simultaneously. ConclusionThe autonomic parameters exhibited reciprocal response to respiratory rate and correlated well to the ventilatory parameters. Further during LSKY we observed enhanced synchronization. In conclusion the LSKY has a potential to influence cardiorespiratory parameters for improving the performance of both systems. LSKY - enhances oscillations in HRV that resets the autonomic system, indicative of better cardiac health and prepares body for better metabolic response. Such changes are capable of inducing resilience along with physiological, psychological relaxation and emotional well-being.

Corneal Endothelial Changes by Specular Microscopy after Uncomplicated Phaco-Emulsification of Hard Senile Cataract Graded by Pentacam

Background: Cataract is the most prevalent ophthalmic cause of reversible blindness and it is one of the primary concerns of the public health perspective surgery which is the primary and only treatment method known. Objective: Assessment of corneal endothelial changes by using specular microscopy, after uncomplicated phacoemulsification in moderately hard nuclear 3 senile cataract. Patients and Methods: The present study was performed on 30 eyes of 30 individuals preoperative assessed by pentacam to detect grade 3 nuclear cataract to be selected in our study, then corneal endothelium assessed by specular microscopy to evaluate the corneal endothelium to be reference and to be compared to 1st and 3 rd month. Results: A highly significant decrease in ECD 1st month post-operative and a significant decrease in ECD 3rd month in relation to pre-operative state. Highly significant increase in the coefficient of variation 1st month postoperative and non-significant increase in the 3rd month in relation to preoperative state. Highly significant decrease in the percentage of hexagonality 1st month and 3rd month post operatively. There is a highly significant reciprocal correlation between age and pre-operative endothelial cell density. 3rd month post-operative decrease in ECD is significant correlated to male sex. Conclusion: A major finding of our manuscript is that the harder the senile cataract the more time and surgical manipulation was done in spite of the same surgeon and the same operative condition lead to more endothelium lost and the more variation between the cells and decrease in the percentage of hexagonal post-operative.

Association of homeobox B13 (HOXB13) gene variants with prostate cancer risk in an Iranian population.

Background: Prostate cancer is a complex condition in which both genetic and environmental factors concomitantly contribute to the tumor initiation and progression. Recently, HOXB13 has been proposed as a susceptibility gene for prostate cancer. Objective: The present study was conducted to determine the existence of potential variations in HOXB13 gene in Iranian men with prostate cancer (PCa) compared to benign prostatic hyperplasia (BPH) cases. Methods: HOXB13 genetic status was screened in 51 samples, including 21 blood and tissue of PCa cases, and compared to 30 cases affected by BPH using PCR/sequencing. Then, the existence of potential association was investigated between genomic DNA alterations in blood and tissue PCa specimens. Results: Analysis of BPH tissues showed single nucleotide variations c.366C > T (rs) or c.513T > C (rs9900627) in exon 1, but not in exon 2. Evaluation of PCa tissues revealed 2 cases with both synonymous c.366C > T and c.513T > C variants and 2 cases with the synonymous c.366C > T variant in exon 1. The variants c.366C > T and c.513T > C, simultaneously or separately, were found in blood samples of PCa patients. The novel variant c.127A > G in exon 2 was detected in 1 PCa blood sample. Our analysis indicated a significant reciprocal correlation between HOXB13 mutation in the tissue and blood samples of PCa cases (p= 0.02). Conclusion: The variants in exon 2 of HOXB13 may influence the risk of prostate cancer. Also, evaluation of HOXB13 mutation may be considered as a novel marker for screening PCa. Further investigations are warranted to evaluate the clinical significance of HOXB13 in Iranian population.

Body fat composition as predictive factor for treatment response in patients with newly diagnosed multiple myeloma - subgroup analysis of the prospective GMMG MM5 trial.

Introduction/BackgroundObesity is a well-known risk factor for malignant tumors and increased body mass index (BMI) is correlated to the risk of developing multiple myeloma (MM). The correlation of body fat composition with disease activity, adverse events and treatment response of MM patients has not been investigated yet.Patients and MethodsA subgroup of 108 patients from a single institution enrolled in the prospective GMMG-MM5 trial, who received a whole-body low-dose computed tomography (WBLDCT) before induction therapy, were included in this study. Body fat composition was measured in WBLDCT for each patient, divided in the compartments abdomen, pelvis, thigh and further categorized in subcutaneous (SAT) and visceral adipose tissue (VAT). The correlation of these parameters with disease activity (M protein, plasma cell count, LDH, CRAB-criteria), adverse cytogenetics, adverse events and treatment response were evaluated.ResultsSignificant reciprocal correlation was found between adverse cytogenetics and VAT of the abdomen and pelvis, respectively (gain 1q21: p=0.009 and p=0.021; t(4;14): p=0.038 and p=0.042). No correlation of VAT or SAT with adverse events was observed. Significant reciprocal correlation was observed between abdominal (p=0.03) and pelvic (p=0.035) VAT and treatment response. Abdominal VAT remains significant (p=0.034) independently of revised ISS stage and treatment. The BMI did not show a significant correlation with treatment response or investigated cytogenetics.ConclusionBased on the clinically relevant difference in treatment outcome depending on VAT and SAT, excessive body fat of abdomen and pelvis might be a predictive factor for poor treatment response. Further influences in this context should be considered as well, e.g. chemotherapy dosing and body fat metabolism. Further studies are necessary to investigate this hypothesis.

MicroRNA regulation of progesterone receptor in breast cancer.

Hormone receptor status is of significant value when deciding on anti-estrogenic adjuvant therapy for breast cancer tumors. However, while estrogen receptor (ER) regulation was intensively studied, the regulation of progesterone receptor (PR) levels has not been extensively investigated. MicroRNAs (miRNAs, miRs) are post-transcriptional negative regulators of gene expression involved in diverse cellular processes. The aim of this study was to identify miRNAs that regulate PR in breast cancer.We mapped potential miRNA binding sites for miR-181a, miR-23a and miR-26b on PR mRNA and demonstrated a direct regulation of PR by these three miRNAs by in-vitro Luciferase binding assays. Over-expression of each miRNA in MCF-7 cells resulted in a reduction in the expression levels of PR mRNA. Then, expression levels of these miRNAs were measured in Formalin-Fixed, Paraffin-Embedded (FFPE) samples of 29 ER-positive breast cancer tumors and adjacent normal breast tissues. A significant reciprocal correlation between PR mRNA and the miRNA levels were identified suggesting a role for miR-181a, miR-23a and miR-26b in PR regulation in breast cancer. Moreover, the average expression fold-changes of the three miRNAs between cancerous and normal tissues displayed an opposite trend when analyzing according to Immuno-histochemistry(IHC) status. Furthermore, miR-181a and miR-26b were found to be over-expressed in most tumor tissues supporting their role in ER-positive breast cancer development. We conclude that miR-181a, miR-23a and miR-26b act as negative regulators of PR expression in ER-positive breast cancer. The diagnostic and prognostic potential of these miRNAs in breast cancer should be further evaluated.

Co-Expression of Putative Cancer Stem Cell Markers CD44 and CD133 in Prostate Carcinomas.

Cancer stem cells (CSCs) are the main players of prostate tumorigenesis thus; characterization of CSCs can pave the way for understanding the early detection, drug resistance, metastasis and relapse. The current study was conducted to evaluate the expression level and clinical significance of the potential CSC markers CD44 and CD133 in a series of prostate tissues. One hundred and forty eight prostate tissues composed of prostate cancer (PCa), high-grade prostatic intraepithelial neoplasia (HGPIN), and benign prostate hyperplasia (BPH) were immunostained for the putative CSC markers CD44 and CD133. Subsequently, the correlation between the expression of these markers and the clinicopathological variables was examined. A higher level of CD44 expression was observed in 42% of PCa, 57% of HGPIN, and 42% BPH tissues. In the case of CD133 expression PCa, HGPIN, and BPH samples demonstrated high immunoreactivity in 46%, 43%, and 42% of cells, respectively. Statistical analysis showed an inverse significant correlation between CD44 expression with Gleason score of PCa (P = 0.02), while no significant correlation was observed between CD133 expression and clinicopathological parameters. A significant reciprocal correlation was observed between the expression of two putative CSC markers CD44 and CD133 in PCa specimens while not indicating clinical significance. Further clinical investigation is required to consider these markers as targets of new therapeutic strategies for PCa.

AWARENESS ON THE INTERNAL STRUCTURE OF MORPHOLOGICALLY-COMPLEX WORDS AND ITS RELATIONSHIP TO VOCABULARY SIZE

The present study examines the relationship between the students' awareness on the internal structure of morphologically-complex words (henceforth MCWs) and English vocabulary size of Indonesian EFL learners. The participants are 111 Indonesian EFL learners who had taken English Morphology subject. Two types of tests are used; Morpheme Identification Test was used to measure the students' awareness on the internal structure of MCWs and the vocabulary size test is used to estimate their vocabulary size. To know the relationship between the two variables, correlational analysis with Kendall-tau formula is then applied. The result shows that both variables have a positive and significant reciprocal correlation.

Serum Sphingolipid Variations Associate with Hepatic Decompensation and Survival in Patients with Cirrhosis.

BackgroundSphingolipids constitute bioactive molecules with functional implications in liver homeostasis. Particularly, ablation of very long chain ceramides in a knockout mouse model has been shown to cause a severe hepatopathy.MethodsWe aimed to evaluate the serum sphingolipid profile of 244 patients with cirrhosis prospectively followed for a median period of 228±217 days via mass spectrometry.ResultsWe thereby observed a significant decrease of long and very long chain ceramides, particularly of C24ceramide, in patients with increasing severity of cirrhosis (p<0.001). Additionally, hydropic decompensation, defined by clinical presentation of ascites formation, was significantly correlated to low C24ceramide levels (p<0.001) while a significant association to hepatic decompensation and poor overall survival was observed for low serum concentrations of C24ceramide (p<0.001) as well. Multivariate analysis further identified low serum C24ceramide to be independently associated to overall survival (standard beta = -0.001, p = 0.022).ConclusionsIn our current analysis serum levels of very long chain ceramides show a significant reciprocal correlation to disease severity and hepatic decompensation and are independently associated with overall survival in patients with cirrhosis. Serum sphingolipid metabolites and particularly C24ceramide may constitute novel molecular targets of disease severity, hepatic decompensation and overall prognosis in cirrhosis and should be further evaluated in basic research studies.

Quantification of Maternal Serum Cell-Free Fetal DNA in Early-Onset Preeclampsia

The aim of this study was to determine whether the increased serum cell-free fetal DNA (cffDNA) level of gravidas developed into early-onset preeclampsia (EOPE) subsequently in the early second trimesters is related to prenatal screening markers. Serum was collected from 1011 gravidas. The level of cffDNA and prenatal screening markers were analyzed in 20 cases with EOPE and 20 controls. All fetuses were male. The maternal serum cffDNA level was assessed by amplification of the Y chromosome specific gene. Correlations between the variables were examined. (Logged) cffDNA in EOPE (median, 3.08; interquartile range, 2.93–3.68) was higher than controls (median, 1.79; interquartile range, 1.46–2.53). The increased level of (logged) cffDNA was correlated significantly with the increased human chorionic gonadotropin (HCG) level (r = 0.628, p < 0.001). Significant reciprocal correlations between cffDNA and babies’ birth weight as well as gestation weeks at delivery were noted (r = −0.516, p = 0.001; r = −0.623, p < 0.001, respectively). The sensitivity and specificity of cffDNA to discriminate between the EOPE cases and the controls were 90% and 85%, respectively. CffDNA is a potential marker for EOPE, which had a significant reciprocal correlation with babies’ birth weight and gestation weeks at delivery. Moreover, it may help in indicating the underlying hypoxic condition in the placenta.

Immunomodulation of T-cell responses withVibrio choleraeO135 capsular polysaccharide and its protein conjugate, novel cholera vaccine study models

We studied T-cell immune responses to surface capsular polysaccharide (CPS) of Vibrio cholerae O135 and its protein conjugate. CPS and CPS-bovine serum albumin (BSA) activation and presentation are characterized with induced alterations in expression and upregulation of membrane antigens CD25, CD11b, CD16/32, MHCII and CD45 on blood- and spleen-derived T cells. Expression of the early activation marker CD25 revealed efficient CPS-BSA conjugate activation especially of CD4(+) CD3(+) and CD8(+) CD3(+) cells. Specific CPS-BSA-induced CD25(+) T-cell subsets in blood were observed after the first application, i.e. a 4.2-fold increase of CD4(+) CD25(+) and 7.6-fold increase of CD8(+) CD25(+) vs. preimmune levels was determined. The upregulation of surface antigens MHCII and CD45 involved in antigen presentation and cell activation of CD3(+) cells and their significant reciprocal correlation (R(2) =0.92) observed only with CPS-BSA conjugate suggested efficient T-cell dependency and presentation. The pattern of accelerated T-cell activation and engagement of T cells as antigen-presenting cells throughout CPS-BSA immunization contrary to CPS alone was also confirmed in CD4(+) /CD8(+) /CD3(+) splenic cells. The results revealed different T-cell antigen presentation and activation following administration of CPS and CPS-BSA conjugates, as supported also by evaluation of CD45, MHCII and CD25 expression on CD19(+) B cells.

Mycophenolic Acid Predose Concentrations and Renal Function in a Mouse Model for Progressive Renal Fibrosis

Within the scope of this study, the potential antifibrotic effect of mycophenolate mofetil (MMF) on COL4A3-deficient mice as an animal model for progressive renal fibrosis was investigated regarding kidney function and survival. Thirty-five animals were randomly assigned to one of five groups and treated with doses of 0, 10, 50, 100, or 150 mg/kg MMF per day, respectively. When increasing somnolence was observed, indicating end-stage renal disease, the mice were euthanized and blood was obtained. Serum concentrations of creatinine, urea nitrogen, total protein, mycophenolic acid (MPA), and mycophenolic acid glucuronide (MPAG) were quantified. The kidney histology was examined using hematoxylin and eosin as well as trichrome staining. The mean overall survival was 65.9 (+/-6.1) days with no significant difference between the treatment groups (P > 0.05, Mantel-Cox test). Serum predose concentrations of MPA and MPAG showed considerable interindividual variability. There was no correlation between survival time and MPA or MPAG concentrations (P > 0.05, Spearman rank correlation). However, an apparent decrease in serum creatinine and urea nitrogen concentrations was observed at higher doses of MMF, eg, -54% for creatinine in the 150-mg/kg/day group compared with placebo. A highly significant reciprocal correlation between MPA concentrations and serum creatinine was demonstrated (P < 0.01, r = -0.655, Spearman rank correlation). In conclusion, MMF may be a candidate drug for preserving kidney function in progressive renal fibrosis.

Analytical survey of human rabies prevalence in the province of Kerman, Iran

In order to determine the frequency rates of domestic and wild animal bites as well as the evaluation of the prevalence rates of rabies disease in human population in the province of Kerman, a retrospective study was designed to analyze statistically the collected recorded data related to this project. The required data such as the numbers of persons who were bitten by animals, the distribution of the studied variables such as geographical locations, age groups of people, jobs and professional relationships, pre-exposure prophylaxis treatment for rabies, and topographical conditions of the injured organs of bodies due to the animal bites, as well as the mortality rates of individuals resulting from rabies, were collected during one decade starting from 21 March 1994 to 21 March 2003 in all 10 cities including the rural areas of the province of Kerman. All data were finally analyzed by SPSS software (Version 11.5). On the basis of recorded statistical analysis, the mortality cases of human rabies in the province of Kerman during one decade was 10 persons (eight males and two females). One-half of them (50%) were bitten by dogs and the others (50%) by foxes. The mean of age of the people who were bitten by dogs was 24.80 years (SD = ± 14.6), while the mean age of the people who were bitten by foxes was 57.25 years (SD = ± 1.50). There was a significant difference between the mean age of these two groups of the people (P < 0.05). The most frequent rate of injured people was reported in the age group of 10–19 years old and the frequency rate of males (76.00%) was more than females (24.00%). There was therefore statistically a significant difference between males and females in this study (P < 0.01). Among the people who were bitten and injured by animals during one decade in the province of Kerman, 85.70% of them have not been treated by a rabies prophylaxis treatment regimen. Among all of them who were bitten by animals, 50% were injured through the hands and feet, 40% of them through heads and faces, and 10% of them through trunks, cervical regions and other organs of the bodies. In the persons who were bitten by animals in the head region, the mean time of the latency period for rabies was 33 days (SD = ± 12.2 days), while the mean time of the latency period in the persons who were bitten through the hands and feet was 77 days (SD = ± 45.8 days). P < 0.1. The results of this study showed that there is a significant reciprocal correlation between the annual raining level and the frequency rate of animal bites in the province of Kerman (r = 0.5, P < 0.01). According to this study, the role of foxes in the epidemiological cycle of human rabies in the province of Kerman, located in the south-east of Iran, seems very important.

Adiponectin and resistin serum levels in women with polycystic ovary syndrome during oral glucose tolerance test: A significant reciprocal correlation between adiponectin and resistin independent of insulin resistance indices

Polycystic ovary syndrome (PCOS) is associated with an increased incidence of insulin resistance (IR), obesity, and type 2 diabetes. Resistin, an adipocytokine, may represent a link between obesity, and these metabolic disorders. There is also evidence that inflammation is a hyperresistinemic state in humans, and cytokine induction of resistin may contribute to insulin resistance in endotoxemia, obesity, and other inflammatory states. In contrast, adiponectin, increases insulin sensitivity, improves glucose tolerance, inhibits inflammatory pathways, while adenovirus-expressed adiponectin reduces atherosclerotic lesions in a mouse model of atherosclerosis. We aimed to assess, in women with PCOS, whether there is a relationship between adiponectin and resistin and the indices of IR, and whether serum levels of these adipocytokines are altered by glucose-induced hyperinsulinaemia. Serum levels of resistin and adiponectin were measured at 0, 60, and 120 min during 75 g oral glucose tolerance test (OGTT), in 19 women with PCOS, age 36.3 ± 11.4 years (mean ± SD), body mass index (BMI) 29.3 ± 7.7 kg/m 2, and correlated with the indices of IR, such as HOMA-IR, QUICKI, and the insulin resistance index calculated from glucose and insulin levels obtained during OGTT. There was no change in resistin concentrations (7.31 ± 4.58, 7.47 ± 5.40, 7.22 ± 5.12 pg/ml, at 0, 60, and 120 min of OGTT, respectively, P = 0.77), but there was an increase in adiponectin from 11.32 ± 4.64 μg/ml at baseline to 14.78 ± 7.41 μg/ml, at 120 min of OGTT ( P < 0.01). The magnitude of the overall rise in adiponectin was greater from 60 to 120 min (from 12.31 ± 5.72 to 14.78 ± 7.41 μg/ml, P < 0.006). Neither resistin, nor adiponectin correlated with the indices of IR, lipids, or other hormonal parameters of the PCOS. There was, however, a significant negative correlation between serum resistin and adiponectin ( P = 0.001). In conclusion, we observed a strong negative correlation between serum adiponectin and resistin, despite the lack of direct correlation with the indices of IR. Given the opposite effects of resistin and adiponectin on the inflammatory process, we speculate that relative proportion of adiponectin-to-resistin might potentially influence cardiometabolic risk in women with the PCOS independently of IR parameters. The observed increase in adiponectin during OGTT requires further study.

CAS (cellular apoptosis susceptibility) gene expression in ovarian carcinoma: Correlation with 20q13.2 copy number and cyclin D1, p53, and Rb protein expression.

We immunohistochemically analyzed cellular apoptosis susceptibility (CAS) protein expression and compared it with 20q13.2 copy number and the expression of cell cycle-associated proteins retinoblastoma (Rb), cyclin D1, and p53 and prognosis on paraffin-embedded tissue from 69 ovarian carcinomas (OCs). CAS protein reactivity was present in 100%, Rb in 54%, cyclin D1 in 47%, and p53 in 49%. Significant reciprocal correlation was observed between high levels of CAS and histologic type, FIGO (International Federation of Obstetrics and Gynecology) stage III and grade 3, residual tumor (>2 cm), 20q13.2 (ZNF217 gene) amplification (>4 copies in >20% cells), and high expression of cyclin D1 (all P < .05). No association was found between cyclin D1, p53, or Rb levels with clinicopathologic factors. In univariate analysis, residual tumor, FIGO stage and grade, ZNF217 amplification, and CAS levels predicted outcome (all P < .05). In multivariate analysis, stage, grade, amount of residual tumor, and ZNF217 amplification showed independent prognostic value (all P < .05). In OC, alteration of CAS and ZNF217 genes, both located at 20q13, is frequent and relevant prognostically. Cyclin D1, Rb, and p53 seem to have a secondary role.

Reciprocal expression of bcl-2 and p53 oncoproteins in urothelial dysplasia and carcinoma of the urinary bladder.

In order to investigate if and when the bcl-2 oncoprotein is activated in bladder tumorigenesis and its relationship with p53 overexpression and patient survival, we studied bcl-2 and p53 expression immunohistochemically in matched normal urothelium, dysplasia and cancer specimens selected by step-sectioning from 54 radically resected bladders for non-metastatic transitional cell carcinoma (TCC). In normal urothelium and mild dysplasia, bcl-2 was restricted to the basal cell compartment, while in moderate and severe dysplasia its expression was detectable also in the upper regions. Excess bcl-2 immunoreactivity was found in 27 (50%) of carcinomas, and a larger proportion of high-grade TCCs showed bcl-2 expression compared with that of low-grade TCCs (P < 0.05). Overexpression of p53 protein showed a increasing trend toward the progression of bladder tumorigenesis (P < 0.01) and a significant reciprocal correlation was found between bcl-2 and p53 expression in either various dysplasias (P < 0.01) or carcinoma (P < 0.05). With the evolution from mild dysplasia to carcinoma in individual cases, loss of bcl-2 expression was more frequently observed in superficial (P < 0.02) or low-grade carcinoma (P < 0.05) than in muscle-invasive or high-grade carcinoma. Furthermore, patients with negative immunostaining for both bcl-2 and p53 in cancer lesions had a significantly more favorable prognosis compared with those with positive immunostaining for the oncoproteins (P < 0.05), although bcl-2 by itself did not predict patient survival. We suggest that aberrant activated bcl-2, which is seen earlier than p53, appears to facilitate bladder tumorigenesis and to enhance tumor aggression in some extent.

Acute phase responses of vasoactive hormones to non pulsatile systemic circulation.

Acute phase responses of vasoactive hormones to the rapid conversion of a systemic flow pattern from pulsatile or non pulsatile mode to the reverse were assessed in 20 goats weighing 45-69 kg. A total left heart bypass was instituted under general anesthesia, with pulsatile and non pulsatile pumps interposed in the circuit in parallel, and the systemic flow mode was rapidly and bidirectionally converted from the pulsatile mode or non pulsatile mode to the reverse. Vasoactive hormone levels and hemodynamics were evaluated before and after 5 min of conversion. No significant difference was observed between the modes either in blood flow or systemic vascular resistance, while the mean aortic pressure was significantly higher in the non pulsatile mode than the pulsatile mode (106.7 +/- 2.4 versus 99.9 +/- 3.5 mmHg). Among various vasoactive hormone levels evaluated, only norepinephrine showed a significant difference between the modes, where concentration in the non pulsatile mode was significantly higher than the pulsatile mode (391.0 +/- 60.7 versus 309.4 +/- 42.5 pg/ml). No correlation was found between the absolute values of mean aortic pressure and norepinephrine level, whereas a significant reciprocal correlation was detected between the magnitude of inter-mode differences in these two parameters. In conclusion, a non pulsatile systemic circulation does not exert significant influence on vasoactive hormone levels, except for slight increase in norepinephrine with a reciprocally correlated increase in mean aortic pressure. It is deduced that activity of the sympathetic nervous system represented by norepinephrine level is higher in the non pulsatile mode than the pulsatile mode, and the baroreceptor reflex functions in an acute phase after flow mode conversion.

Central respiratory carbon dioxide chemosensitivity does not decrease during sleep.

The ventilatory response to CO2 decreases during slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep compared with awake levels. However, it is not known to what extent this can be attributed to decreased sensitivity of the CO2 chemoreflex. Mechanical factors during sleep may decrease ventilatory output, or PCO2 at the central chemoreceptor may not increase to the same degree as PaCO2, particularly during REM sleep when brain blood flow (BBF) is increased. In 10 goats, we measured the ventilatory (VI), diaphragmatic electromyogram (EMGdI), and BBF responses to CO2 rebreathing during each sleep-wake state. delta VI/delta PaCO2 decreased from wakefulness to SWS (p less than 0.05) and REM sleep (p less than 0.05). In contrast, delta EMGdI/delta PaCO2 was decreased only during REM sleep (p less than 0.05). Concurrently, delta BBF/delta PaCO2 increased during REM sleep (p less than 0.05) compared with the awake state or SWS. A significant reciprocal correlation existed between delta EMGdI/delta PaCO2 and delta BBF/delta PaCO2 across sleep states (r = -0.786). When EMGdI was related to directly measured cerebral venous PCO2 (n = 4), a single linear function (r = 0.894) was found, independent of sleep-wake state. Similar results were obtained during quasi-steady-state hypercapnia. We conclude that central CO2 chemosensitivity is intact during sleep.

Improved method for recovery of enteric viruses from wastewater sludges

Various parameters involved in recovering indigenous enteric viruses from wastewater sludges aided by buffered beef extract elution and subsequent organic flocculation concentration were examined. A statistically significant ( P=0.03) reciprocal correlation was found to exist between the ratio of eluant to sludge solids content used during the elution step, and the efficiency of subsequently concentrating viruses from the produced sludge eluates by means of organic flocculation. A hypothesis is proposed by which to explain the concentration of viruses during beef extract-induced organic flocculation.

Preparation of Parietal Peritoneum for Measurements of In Vitro Permeability

An experimental method for in vitro studies of permeability of parietal peritoneal membrane was developed in rats. Sodium and potassium fluxes across the peritoneum lining two different regions (the diaphragm and the anterior abdominal wall) were estimated and electrical resistance of the isolated membranes were determined. A significant reciprocal correlation was observed between the two indices. Quantitative differences between the two types of membranes were found, the diaphragmatic region being more permeable than the other. It is suggested that a monolayer of mesothelial cells covering the membranes is partially responsible for these differences. The parietal peritoneum was found to be less permeable than visceral peritoneum (mesentery) studied under identical conditions.

Effect of ganglion-blocking agents on renin release in hypertensive patients.

In 18 patients with benign essential hypertension, renin release during reduction of arterial pressure due to sodium nitroprusside infusion was measured before and after administration of ganglion-blocking agents (pentolinium or trimethaphan). In 12 patients, renin release induced by reduction in pressure was significantly reduced but not abolished by ganglion blockade. Simultaneously, ganglion blockade significantly reduced renal vascular resistance (RVR) and almost abolished a decrease in renal blood flow (RBF) due to hypotension. In 6 other patients in whom no significant renin release resulted from hypotension, ganglion blockade caused little changes in renin release, RVR or RBF. The results support the hypothesis that renal sympathetic nerve activity is a factor in variations in renin release in patients with essential hypertension. Following ganglion blockade in the responsive patients, the significant reciprocal correlation between renal venous renin activity and sodium excretion rate shifted but still persisted, suggesting that the renin-releasing mechanism related to sodium excretion may be independent of innervation. On the other hand, the correlation between renin activity and the degree of reduction in pressure was insignificant after ganglion blockade. It is concluded that two intrarenal mechanisms, nerve-dependent and nerve-independent, are involved in renin release due to reduction in pressure. Ganglion blockade also exerted an inhibitory effect on renin release due to hypotension in 4 normotensive subjects and 5 patients with renovascular hypertension.