Midface hypoplasia in syndromic craniosynostosis: predicting craniofacial growth via a novel regression model from anatomical morphometric analysis

Midface hypoplasia in syndromic craniosynostosis (SC) may lead to serious respiratory issues. The aim of this study was to analyse the morphometric correlation between midface and cranial base parameters in paediatric SC patients in order to formulate predictive regression models. The computed tomography scans of 18 SC patients and 20 control were imported into Materialise Mimics Medical version 21.0 software for the measurement of multiple craniofacial landmarks and correlation analysis. The results showed a strong correlation of anterior cranial base (SN), posterior cranial base (SBa), and total cranial base (NBa) (r = 0.935) to maxilla length and width (ZMR-ZML) (r = 0.864). The model of NBa = - 1.554 + 1.021(SN) + 0.753(SBa) with R2 = 0.875 is proposed to demonstrate the development of the cranial base that causes a certain degree of midface hypoplasia in SC patients. The formula is supported using a prediction model of ZMR-ZML = 5.762 + 0.920(NBa), with R2 = 0.746. The mean absolute difference and standard deviation between the predicted and true NBa and ZMR-ZML were 2.08 ± 1.50 mm and 3.11 ± 2.32 mm, respectively. The skeletal growth estimation models provide valuable foundation for further analysis and potential clinical application.

Relationship between various cytokines implicated in asthma

Asthma is a complex disorder involving immunologic, environmental, genetic and other factors. Today, asthma is the most common disease encountered in clinical medicine in both children and adults worldwide. Asthma is characterized by increased responsiveness of the tracheobronchial tree resulting in chronic swelling and inflammation of the airways recognized to be controlled by the T-helper 2 (Th2) lymphocytes, which secrete cytokines to increase the production of IgE by B cells. There are many cytokines implicated in the development of the chronic inflammatory processes that are often observed in asthma. Ultimately, these cytokines cause the release of mediators such as histamine and leukotrienes (LT), which in turn promote airway remodeling, bronchial hyperresponsiveness and bronchoconstriction. The CD4⁺ T-lymphocytes from the airways of asthmatics express a panel of cytokines that represent the Th2 cells. The knowledge derived from numerous experimental and clinical studies have allowed physicians and scientists to understand the normal functions of these cytokines and their roles in the pathogenesis of asthma. The main focus of this review is to accentuate the relationship between various cytokines implicated in human asthma. However, some key findings from animal models will be highlighted to support the discoveries from clinical studies.

Soil-Transmitted Helminths in Malaysia landscape: an aborigines study

Soil-transmitted helminths (STH) is a group of parasitic nematodes, including Trichuris trichiura, Ascaris lumbricoides, Ancylostoma duodenale and Necator americanus, which can cause gastrointestinal disorders in humans. STH is prevalent among neglected communities in both developing and developed countries. This present study aims to determine the current prevalence of STH infections in Aboriginal population after mass delivering of antihelminthic drugs was proposed by WHO in 2005 and a health education learning package (HELP) was initiated in Malaysia in 2012. A total of 235 human fecal samples were collected and a pre-tested questionnaire was given to gather information about the socio-demographic of the Aborigine communities living in Kedah and Selangor, Malaysia. The samples were screened by a direct-fecal smear and confirmed by formalin-ether sedimentation methods. From human faeces, 81.7% was found to be infected with one or more STH species. T. trichiura was the most commonly detected (76.6%), followed by hookworms (26.4%) and A. lumbricoides (19.1%). Triple infections were found in 6.4% of the studied population. Univariate analysis showed that individuals with age group, male, presence of indoor toilet, family size with <7 members and bad living habits (i.e., without antihelminthic drugs) were significantly associated with STH infections. The analysis further showed that walking barefoot was the significant contributing factor to hookworm infections. The high prevalence of human STH infections is alarming. Thus, the urgency in implementing health education related behavioral practice and hygiene to reduce disease burden in these rural communities are a crucial need.

INCREASED OXIDATIVE STRESS AND DOWN REGULATION OF ENDOTHELIAL NITRIC OXIDE SYNTHASE (ENOS) IN THE KIDNEY ATTEN- UATE THE RESPONSIVENESS OF (XlB ADRENERGIC RECEPTORS IN THE KIDNEY OF RATS WITH LEFT VENTRICULAR HYPERTROPHY

Present study explored endothelial nitric oxide synthase/nitric oxide (eNOS/NO) pathway in the kidney and role of αIB adrenergic receptor in the regulation of renal vasculature in the rats with left ventricular hypertrophy (LVH). LVH was induced by administering isoprenaline 5 mg/kg (s.c. 72 h. apart) and caffeine (62 mg/L in drinking water) for 14 days. Quantification of molecular expression of eNOS in kidney was performed by quantitative Real Time Polymerase Chain Reaction (qPCR). Renal vasoconstrictor responses were measured by administering noradrenaline (NA), phenylephrine (PE) and methoxamine (ME) in pre-drug phase, low dose and high dose phases of chloroethylelonidine (CEC), a selective of (αIB adrenergic receptor antagonist. In the kidney of LVH male Wistar Kyoto (WKY) rats eNOS was significantly down regulated (p < 0.05) by 74% relative to Control WKY (taken as 100%). The high dose 5 CEC attenuated the vasoconstrictor responses to NA by 41%, PE by 43% and ME by 33% in the LVH-WKY when compared to the same dose phase in Control WKY group. In LVH, increased oxidative stress in kidney and increased ACE activity in the plasma resulted in down regulation of eNOS/NO in the kidney. The renal vasoconstrictor responses to adrenergic agonist are blunted in LVH and (αIB adrenergic receptor is functional subtype in renal vasculature in LVH.

A critical review of pharmacological significance of Hydrogen Sulfide in hypertension

In the family of gas transmitters, hydrogen sulfide (H2S) is yet not adequately researched. Known for its rotten egg smell and adverse effects on the brain, lungs, and kidneys for more than 300 years, the vasorelaxant effects of H2S on blood vessel was first observed in 1997. Since then, research continued to explore the possible therapeutic effects of H2S in hypertension, inflammation, pancreatitis, different types of shock, diabetes, and heart failure. However, a considerable amount of efforts are yet needed to elucidate the mechanisms involved in the therapeutic effects of H2S, such as nitric oxide-dependent or independent vasodilation in hypertension and regression of left ventricular hypertrophy. More than a decade of good repute among researchers, H2S research has certain results that need to be clarified or reevaluated. H2S produces its response by multiple modes of action, such as opening the ATP-sensitive potassium channel, angiotensin-converting enzyme inhibition, and calcium channel blockade. H2S is endogenously produced from two sulfur-containing amino acids L-cysteine and L-methionine by the two enzymes cystathionine γ lyase and cystathionine β synthase. Recently, the third enzyme, 3-mercaptopyruvate sulfur transferase, along with cysteine aminotransferase, which is similar to aspartate aminotransferase, has been found to produce H2S in the brain. The H2S has interested researchers, and a great deal of information is being generated every year. This review aims to provide an update on the developments in the research of H2S in hypertension amid the ambiguity in defining the exact role of H2S in hypertension because of insufficient number of research results on this area. This critical review on the role of H2S in hypertension will clarify the gray areas and highlight its future prospects.

Up Regulation of cystathione γ lyase and Hydrogen Sulphide in the Myocardium Inhibits the Progression of Isoproterenol-Caffeine Induced Left Ventricular Hypertrophy in Wistar Kyoto Rats

Hydrogen sulphide (H2S) is an emerging molecule in many cardiovascular complications but its role in left ventricular hypertrophy (LVH) is unknown. The present study explored the effect of exogenous H2S administration in the regression of LVH by modulating oxidative stress, arterial stiffness and expression of cystathione γ lyase (CSE) in the myocardium. Animals were divided into four groups: Control, LVH, Control-H2S and LVH-H2S. LVH was induced by administering isoprenaline (5mg/kg, every 72 hours, S/C) and caffeine in drinking water (62mg/L) for 2 weeks. Intraperitoneal NaHS, 56μM/kg/day for 5 weeks, was given as an H2S donor. Myocardial expression of Cystathione γ lyase (CSE) mRNA was quantified using real time polymerase chain reaction (qPCR).There was a 3 fold reduction in the expression of myocardial CSE mRNA in LVH but it was up regulated by 7 and 4 fold in the Control-H2S and LVH-H2S myocardium, respectively. Systolic blood pressure, mean arterial pressure, pulse wave velocity were reduced (all P<0.05) in LVH-H2S when compared to the LVH group. Heart, LV weight, myocardial thickness were reduced while LV internal diameter was increased (all P<0.05) in the LVH-H2S when compared to the LVH group. Exogenous administration of H2S in LVH increased superoxide dismutase, glutathione and total antioxidant capacity but significantly reduced (all P<0.05) plasma malanodialdehyde in the LVH-H2S compared to the LVH group. The renal cortical blood perfusion increased by 40% in LVH-H2S as compared to the LVH group. Exogenous administration of H2S suppressed the progression of LVH which was associated with an up regulation of myocardial CSE mRNA/ H2S and a reduction in pulse wave velocity with a blunting of systemic hemodynamic. This CSE/H2S pathway exhibits an antihypertrophic role by antagonizing the hypertrophic actions of angiotensin II(Ang II) and noradrenaline (NA) but attenuates oxidative stress and improves pulse wave velocity which helps to suppress LVH. Exogenous administration of H2S augmented the reduced renal cortical blood perfusion in the LVH state.

Enhanced expression of endothelial nitric oxide synthase in the myocardium ameliorates the progression of left ventricular hypertrophy in L-arginine treated Wistar-Kyoto rats

The present study investigated the role of endothelial nitric oxide synthase (eNOS) enzyme in the development of left ventricular hypertrophy (LVH) in Wistar-Kyoto rats. The effect of L-arginine administration on cardiac structure, arterial stiffness, renal and systemic hemodynamic parameters was studied and the change in expression of eNOS and cystathione γ lyase (CSE) in the myocardium of LVH rats was evaluated. LVH was induced using isoprenaline (5 mg/kg, S.C.) and caffeine (62 mg/L in drinking water) for 14 days. Following to that, L-arginine (1.25 g/L in drinking water) was given for 5 weeks as a donor of NO. eNOS and CSE gene expressions were down regulated in the LVH group by about 35% and 67% respectively when compared to control. However, in the LVH group treated with L-arginine there was up regulation of eNOS by almost 27% and down regulation in CSE by 24% when compared to control (all P < 0.05). Heart index and H2S plasma levels were reduced by almost 53% in the L-arginine treated LVH group compared to the control (all P < 0.05). Mean arterial pressure, heart rate and pulse wave velocity were reduced while renal blood perfusion increased in L-arginine treated LVH rats compared to their untreated counterparts (all P < 0.05). The enhanced expression of eNOS in L-arginine treated LVH rats resulted in the amelioration of oxidative and haemodynamic parameters suggesting that NO system is an important therapeutic target in cardiac and LV hypertrophies.

IMPACT OF ISOPRENALINE AND CAFFEINE ON DEVELOPMENT OF LEFT VENTRICULAR HYPERTROPHY AND RENAL HEMODYNAMIC IN WISTAR KYOTO RATS

Left ventricular hypertrophy (LVH) is a compensatory mechanism in response to an increased work load on the heart. This study investigated the impact of chronic isoprenaline and caffeine (I/C model) administration on cardiac geometry, systemic hemodynamic and physiological data in rats as LVH develops. LVH was induced by administering isoprenaline (5 mg/kg s.c. every 72 h) and caffeine (62 mg/L) in drinking water for 14 days to Wistar Kyoto (WKY) rats. Mean arterial pressure (MAP), systolic blood pressure (SBP), heart weight, LV weight, LV chamber diameter and thickness of myocardium were observed as LVH indicators. MAP was significantly higher (142 ± 13 vs. 119 ± 2 mmHg, respectively) while heart rate (HR) in LVH was lower (314 ± 9 vs. 264 ± 18 BPM) compared to control WKY. Heart weight, LV weight and kidney weight were 31%, 38% and 7%, respectively, greater in the LVH group as compared to the control WKY (all p < 0.05).The myocardium thickness was 101% greater while LV chamber diameter was 44% smaller in the LVH group as compared to the control WKY (p < 0.05). The superoxide dismutase (SOD), glutathione reductase (GSH) and total antioxidant capacity (T-AOC) levels were significantly reduced while malonodialdehyde (MDA) level increased in LVH as compared to control WKY (all p < 0.05). In conclusion, isoprenaline and caffeine (I/C) induces LVH and cardiac hypertrophy with increases in blood pressure, fluid excretion and reduced renal hemodynamics. Prooxidant mechanism of the body and arterial stiffness are dominant in this disease model. This model of LVH is easily generated and associated with low mortality.

ANTIOXIDANT ACTIVITY AND FREE RADICAL SCAVENGING CAPACITY OF L-ARGININE AND NAHS: A COMPARATIVE IN VITRO STUDY

In the family of gaseous transmitters, hydrogen sulfide (H2S) is considered as third member beside nitric oxide (NO) and carbon monoxide (CO), which can play physiological role in different organs. The present study was designed to elucidate the antioxidant and free radical scavenging potentials of L-arginnine (a source for endogenous production of NO in vivo) and NaHS (a source H2S) individually and in combination. Different assays like 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, percent inhibition of linoleic acid peroxidation and reducing power assays were used to evaluate the free radical scavenging capacity and antioxidant activity of L-arginine and NaHS. Furthermore, study was aimed to know the antioxidant potential of both compounds at their effective doses in human body, which is 56 µM for H2S and 1.2 g/mL for L-arginine. The study also aimed to clear whether either NaHS, L-arginine or the mixture of NaHS and L-arginine in vitio (in the form of new compounds) is responsible for their therapeutic action. Results showed that NaHS, L-arginine and combination of NaHS + L-arginine showed good radical scavenging activity i.e., 55.60%, 52.10% and 52.32%, respectively. Moreover, NaHS was found to have ability to inhibit linoleic acid peroxidation by 53.98% at effective dose while L-arginine did not show inhibition of linoleic acid peroxidation. Combination of NaHS + L-arginine showed 54.15% inhibition of linoleic acid peroxidation, which is similar to that of H2S. Reducing power of NaHS was 0.073 and L-arginine showed 0.037, combination of NaHS + L-arginine showed 0.063. It can be concluded that NaHS showed better antioxidant potential in vitio as compared to L-arginine and the antioxidant activity of the mixture of NaHS + L-arginine is closed to the antioxidant activity of NaHS, which reflects that NaHS is a dominant factor in combination mixture that is responsible for antioxidant activity.

Ectopic inferior vena cava thrombus secondary to a tubo-ovarian abscess

Inferior vena cava (IVC) thrombosis typically arises distally from a thrombophlebitic extension in the pelvis or the lower extremities. It may also occur from propagation of an ovarian vein thrombosis as a result of gynaecological disorders such as pelvic inflammatory disease, endometritis or from pelvic surgeries. In this report, we present an interesting case of a tubo-ovarian abscess with an ectopic IVC thrombus. The approach to management in such cases is also highlighted.

Functional contribution of α1D-adrenoceptors in the renal vasculature of left ventricular hypertrophy induced with isoprenaline and caffeine in Wistar-Kyoto rats

This study investigated the role of α1D-adrenoceptor in the modulation of renal haemodynamics in rats with left ventricular hypertrophy (LVH). LVH was established in Wistar-Kyoto (WKY) rats with isoprenaline (5.0 mg · (kg body mass)(-1), by subcutaneous injection every 72 h) and caffeine (62 mg · L(-1) in drinking water, daily for 14 days). Renal vasoconstrictor responses were measured for noradrenaline (NA), phenylephrine (PE), and methoxamine (ME) before and immediately after low or high dose intrarenal infusions of BMY 7378, a selective α1D-adrenoceptor blocker. The rats with LVH had higher mean arterial blood pressure and circulating NA levels, but lower renal cortical blood perfusion compared with the control group (all P < 0.05). In the LVH group, the magnitude of the renal vasoconstrictor response to ME was blunted, but not the response to NA or PE (P < 0.05), compared with the control group (LVH vs. C, 38% vs. 50%). The magnitude of the drop in the vasoconstrictor responses to NA, PE, and ME in the presence of a higher dose of BMY 7378 was significantly greater in the LVH group compared with the control group (LVH vs. C, 45% vs. 25% for NA, 52% vs. 33% for PE, 66% vs. 53% for ME, all P < 0.05). These findings indicate an impaired renal vasoconstrictor response to adrenergic agonists during LVH. In addition, the α1D-adrenoceptor subtype plays a key role in the modulation of vascular responses in this diseased state.

A preliminary report on ants (Hymenoptera: Formicidae) recovered from forensic entomological studies conducted in different ecological habitats in Malaysia

This study reported the ant species that were recovered from monkey carcasses in three different ecological habitats in Malaysia. The study was conducted from 9 May - 10 October 2007, 6 May - 6 August 2008 and 26 May - 14 July 2009 in forested area (Gombak, Selangor), coastal area (Tanjong Sepat, Selangor) and highland area (Bukit Cincin, Pahang), respectively. Monkey carcass was used as a model for human decomposition in this study. A total of 4 replicates were used in each of the study sites. Ants were observed to prey on eggs, larvae, pupae and newly emerged flies. This study found that ant species could be found at all stages of decomposition, indicating that ants were not a significant indicator for faunal succession. However, different species of ants were obtained from monkey carcasses placed in different ecological habitats. Cardiocondyla sp. was only found on carcasses placed in the coastal area; while Pheidole longipes, Hypoponera sp. and Pachycondyla sp. were solely found on carcasses placed in the highland area. On the other hand, Pheidologeton diversus and Paratrechina longicornis were found in several ecological habitats. These data suggests that specific ant species can act as geographic indicators for different ecological habitats in forensic entomology cases in Malaysia.

Hydrogen sulphide and tempol treatments improve the blood pressure and renal excretory responses in spontaneously hypertensive rats

Oxidative stress and suppressed H2S production lead to increased renal vascular resistance, disturbed glomerular hemodynamics, and abnormal renal sodium and water handling, contribute to the pathogenesis and maintenance of essential hypertension in man and the spontaneously hypertensive rat. This study investigated the impact of H2S and tempol alone and in combination on blood pressure and renal hemodynamics and excretory functions in the SHR. Groups of WKY rats or SHR (n=6) were treated for 4 weeks either as controls or received NaHS (SHR+NaHS), tempol (SHR+Tempol), or NaHS plus tempol (SHR+NaHS +Tempol). Metabolic studies were performed on days 0, 14, and 28, thereafter animals were anaesthetized to measure renal hemodynamics and plasma oxidative and antioxidant markers. SHR control rats had higher mean arterial blood pressure (140.0 ± 2 vs. 100.0 ± 3 mmHg), lower plasma and urinary H2S, creatinine clearance, urine flow rate and urinary sodium excretion, and oxidative stress compared to WKY (all p<0.05). Treatment either with NaHS or with tempol alone decreased blood pressure and oxidative stress and improved renal hemodynamic and excretory function compared to untreated SHR. Combined NaHS and tempol therapy in SHRs caused larger decreases in blood pressure (∼20-22% vs. ∼11-15% and ∼10-14%), increases in creatinine clearance, urinary sodium excretion and fractional sodium excretion and up-regulated the antioxidant status compared to each agent alone (all p<0.05). These findings demonstrated that H2S and tempol together resulted in greater reductions in blood pressure and normalization of kidney function compared with either compound alone.

Antioxidant and cardio protective effect of palm oil leaves extract (standardized ethanolic fraction) in rats' model of saturated fats induced metabolic disorders

Recently, it is suggested to use POLE (palm oil leaf extract) as a nutraceutical health product in food industry due to its newly discovered content of polyphenols and antioxidant vitamins. In the experiment, the antioxidant and anti-lipid-peroxidation activities of the extract were confirmed using; DPPH (1-diphenyl-2-picryl-hydrazil) radical scavenging activity, ferric ion induced lipid peroxidation inhibition, reducing power and hydrogen peroxide scavenging activity assays. The cardio-protective activity was studied in vivo using a model of metabolic syndrome induced by high fat diet. Lipid profile, obesity indices, renal tubular handling of water and electrolytes, blood pressure and arterial stiffness were measured at the end of the treatment period. Sprague Dawley rats weighing 150-200 g were divided into six groups, viz; group C; was treated as a negative control and fed with standard rodents chow, group H; was treated as a positive control and fed with an experimental diet enriched with saturated free fatty acids for 8 weeks, groups HP0.5, HP1 and HP2 which were fed with 0.5,1 and 2 g/kg (body weight) /day of POLE orally during the last 24 days of the high fat diet feeding period and group P; fed with highest dose of POLE. Results revealed that POLE possesses a cardio-protective effect which is ascribed to its content of polyphenols.

Composition and sources of aliphatic lipids and sterols in sediments of a tropical island, southern South China Sea: preliminary assessment

Near-shore surface sediment was collected from five stations off Redang Island located on the eastern coast of Peninsular Malaysia. Freeze-dried sediments were Soxhlet extracted and then fractionated using column chromatography into aliphatic and polar fractions. Determination of these fractions was carried out using gas chromatography mass spectrometry. The concentration of total resolved aliphatic hydrocarbons in sediments ranged from 157 to 308 ng/g. The distribution of aliphatic fraction showed the presence of n-alkanes ranging from nC15 to nC33 with a minor odd-to-even predominance exhibiting carbon maximum, depending on station, at nC17, nC26, nC29 or nC31. Calculation of Carbon Preference Index (CPI) for CPI(15-33) gave values ranging from 1.09 to 1.46. n-Alkanol in all sediment exhibits even-to-odd carbon predominance ranging from nC16 to nC28 and maximising at nC22. n-Fatty acids distribution ranged from nC14 to nC24 with a dominant maximum at nC16 and exhibiting high values of short chain fatty acids (≤nC20) to long chain fatty acids (>nC20) ratios. Unsaturated fatty acids, particularly nC16:1 and nC18:1 is also ubiquitous in all samples. Cholesterol is the most abundant compound amongst the sterol group ranging from 42.8 to 62.6% of the total sterols. β-Sitosterol, brassicasterol and stigmasterol, are also present but of relatively lower amount. These observations suggest that the aliphatic lipids and sterols in the study area originate, mainly, from biogenic sources of marine microbial with minor contribution from epiticular waxes of terrestrial plants.

Successful treatment of isolated fibular bone metastasis in a uterine endometrial cancer of clear cell carcinoma

Clear cell carcinoma of the endometrium is an uncommon histological subtype and isolated metastasis to bone is rare. The authors present a case of a 61-year-old woman who underwent laparoscopic staging surgery for clear cell carcinoma of uterine endometrium (FIGO Stage IB) and early recurrence with isolated fibular bone metastasis three months later. With salvage radiotherapy (RT), she remains disease-free after 46 months. Curative-intended treatment with RT is possible as in this case.

Sustainable complete remission in recurrence yolk sac tumor patient treated with tandem high-dose chemotherapy and autologous stem cell

A 21-year-old lady diagnosed with Stage 3 ovarian yolk sac tumor (YST) underwent primary cytoreductive fertility sparing surgery, followed by conventional courses of platinum-based chemotherapy and etoposide. Recurrence at cul-da-sac was noted after a short period of remission and secondary debulking performed followed by four cycles of conventional chemotherapy. The patient's disease progressed despite courses of treatments. A joint team management including a hematologist was commenced following the failure of conventional chemotherapies. Two cycles of high-dose chemotherapy (HDCT) with ifosfamide/cisplatin/etoposide (ICE) regimen, followed by autologous stem cell transplantation (ASCT) were given. With this salvage treatment, she remained in complete remission and disease-free for more than 30 months, while maintaining her reproductive function. These approaches appear to be effective as a salvage treatment in selected cases of patients with ovarian germ cell tumor, especially those who failed primary conventional chemotherapy.

Effect of high saturated free fatty acids feeding on progression of renal failure in rat model of experimental nephrotoxicity

The current study evaluates the impact of high saturated fat feeding in rat model of experimental nephrotoxicity induced by gentamicin. Sprague-Dawley rats weighing 200 g were randomized into four groups; the first one received the standard rodents chow for 8 weeks and was treated as control, the second group (HFD)received an experimental high fat diet rich in palm kernel oil (40% of Calories as fat) for the same period. The third group (HFDG) was given 80 mg/kg (body weight)/day gentamicin sulphate intraperitoneally during the last 24 days of the feeding period while the fourth group was given gentamicin as above along with the standard rodents chow. Renal function was assessed through measuring serum creatinine, creatinine clearance and absolute and fractional excretion of both sodium and potassium. At the end, rats underwent a surgical procedure for blood pressure measurement. Renal function study showed a stronger nephrotoxicity for HFDG group. Hypertension was observed in HFD group while the pressure declined after gentamicin co-administration. Overall, changing the feeding behavior toward using more SAFFAs for rats injected with gentamicin promotes the progression of renal failure.

The effect of losartan and carvedilol on renal haemodynamics and altered metabolism in fructose-fed Sprague-Dawley rats

The aim of this study is to assess the effects of losartan and carvedilol on metabolic parameters and renal haemodynamic responses to angiotensin II (Ang II) and adrenergic agonists in the model of fructose-fed rat. Thirty-six Sprague-Dawley rats were fed for 8 weeks either 20% fructose solution (F) or tap water (C) ad libitum. F or C group received either losartan or carvedilol (10 mg/kg p.o.) daily for the last 3 weeks of the study (FL and L) and (FCV and CV), respectively, then in acute studies the renal vasoconstrictor actions of Ang II, noradrenaline (NA), phenylephrine (PE) and methoxamine (ME) were determined. Data, mean±SEM were analysed using ANOVA with significance at P <0.05. Losartan and carvedilol decreased the area under the glucose tolerance curve of the fructose-fed group. The responses (%) to NA, PE, ME and Ang II in F were lower (P <0.05) than C (F vs. C, 17±2 vs. 38±3; 24±2 vs. 48±2; 12±2 vs. 34±2; 17±2 vs. 26±2), respectively. L had higher (P <0.05) responses to NA and PE while CV had blunted (P <0.05) responses to NA, PE and Ang II compared to C (L, CV vs. C, 47±3, 9±2 vs. 38±3; 61±3, 29±3 vs. 48±2; 16±3, 4±3 vs. 26±2), respectively. FL but not FCV group had enhanced (P <0.05) responses to NA, PE and ME compared to F (FL vs. F, 33±3 vs. 17±2; 45±3 vs. 24±2; 26±3 vs. 12±2), respectively. Losartan and carvedilol had an important ameliorating effect on fructose-induced insulin resistance. Losartan treatment could be an effective tool to restore normal vascular reactivity in the renal circulation of the fructose-fed rat.

Effect of dragon fruit extract on oxidative stress and aortic stiffness in streptozotocin-induced diabetes in rats

Cardiovascular complications are consistently observed in diabetic patients across all age groups. The objective of the present study was to investigate the effect of aqueous extract of the fruit pulp of Hylocereus undatus (DFE) on aortic stiffness and oxidative stress in streptozotocin (STZ)-induced diabetes in rats. Twenty-four male, Sprague-Dawley rats were randomized into four groups: I (control), II (diabetic), III (DFE, 250 mg/kg) and IV (DFE 500 mg/kg). Diabetes was induced in groups II, III and IV by intraperitoneal (i.p.) injection of STZ (40 mg/kg). After confirmation of diabetes, group III and IV received DFE for 5 weeks. Pulse wave velocity (PWV) was used as a marker of aortic stiffness and was determined at the end of 5 weeks. DFE significantly decreased (P < 0.05) the fasting blood glucose levels in diabetic rats, but not to normal levels. Systolic blood pressure, pulse pressure and PWV were significantly increased (P < 0.05) in diabetic rats at the end of 5 weeks in comparison with control group. DFE treatment significantly decreased (P < 0.05) these elevations. Oxidative damage was observed in group II after 5 weeks. Plasma malondialdehyde levels significantly decreased (P < 0.05), while superoxide dismutase and total antioxidant capacity significantly increased (P < 0.05) with DFE treatment in comparison with group II. These data demonstrate that DFE treatment was effective in controlling oxidative damage and decreasing the aortic stiffness measured by PWV in STZ-induced diabetes in rats.

Evidence for the role of α1A-adrenoceptor subtype in the control of renal haemodynamics in fructose-fed Sprague-Dawley rat

AIM

To explore the hypothesis that high fructose intake results in a higher functional contribution of α1A-adrenoceptors and blunts the adrenergically and angiotensin II (Ang II)-induced renal vasoconstriction.

METHODS

Twelve Sprague-Dawley rats received either 20% fructose solution [FFR] or tap water [C] to drink ad libitum for 8 weeks. The renal vasoconstrictor response to noradrenaline (NA), phenylephrine (PE), methoxamine (ME) and Ang II was determined in the presence and absence of 5-methylurapidil (5-MU) (α1A-adrenoceptor antagonist) in a three-phase experiment (pre-drug, low- and high-dose 5-MU). Data, mean ± SEM were analysed by ANOVA or Student's unpaired t-test with significance at P < 0.05.

RESULTS

FFR exhibited insulin resistance (HOMA index), hypertension and significant increases in plasma levels of glucose and insulin. All agonists caused dose-related reductions in cortical blood perfusion that were larger in C than in FFR while the magnitudes of the responses were progressively reduced with increasing doses of 5-MU in both C and FFR. The degree of 5-MU attenuation of the renal cortical vasoconstriction due to NA, ME and Ang II was significantly greater in the FFR compared to C.

CONCLUSIONS

Fructose intake for 8 weeks results in smaller vascular response to adrenergic agonists and Ang II. The α1A-adrenoceptor subtype is the functional subtype that mediates renal cortical vasoconstriction in control rats, and this contribution becomes higher due to fructose feeding.

Effect of renal sympathetic nerve on adrenergically and angiotensin II-induced renal vasoconstriction in normal Wistar-Kyoto rats

BACKGROUND

This study examined the effect of renal sympathetic innervation on adrenergically and angiotensin II (Ang II)-induced renal vasoconstriction in Wistar-Kyoto (WKY) rats.

METHODS

Forty-eight WKY rats were treated with either losartan (10 mg/kg/day p.o.) or carvedilol (5 mg/kg/day p.o.) or a combination of them (10 mg/kg/day + 5 mg/kg/day p.o.) for 7 days. On day 8, the rats were anaesthetized, and renal vasoconstrictor experiments were carried out. A group of rats was subjected to acute unilateral renal denervation during the acute study. Changes in the renal vasoconstrictor responses were determined in terms of reductions in renal blood flow caused by Ang II, noradrenaline (NA), and methoxamine (ME).

RESULTS

In normal animals, losartan decreased (P < 0.05) the renal vasoconstrictor response to Ang II but not to NA or ME. Carvedilol treatment, however, blunted (P < 0.05) the renal vasoconstrictor responses to Ang II and adrenergic agonists. Combination of losartan and carvedilol blunted (P < 0.05) the renal vasoconstrictor response to Ang II but augmented the responses to NA and ME (all P < 0.05). Interestingly, when denervated rats were treated with the same combination, there was a reduction (P < 0.05) in the renal vasoconstrictor responses to Ang II and adrenergic agonists.

CONCLUSIONS

Data suggest that the renal sympathetic nerve contributes to adrenergic agonist-mediated renal vasoconstrictions in normal rats. The data further indicate an interactive relationship between renin-angiotensin and sympathetic nervous systems in modulating adrenergically and Ang II-induced renal vasoconstriction in WKY rats.

Renal sympathetic nervous system hyperactivity in early streptozotocin-induced diabetic kidney disease

AIM

We assessed the role of renal sympathetic nervous system in the deterioration of renal hemodynamic and excretory functions in rats with streptozotocin (STZ)-induced diabetic kidney disease (DKD).

METHODS

Male Sprague-Dawley (SD) rats were induced with diabetes mellitus (DM) using STZ (55 mg/kg, i.p.). The acute studies were conducted on denervated anesthetized rats 7 days after STZ administration. Two sets of experiments were performed: clearance experiments in which six 20-min urine and plasma collections were carried out to measure kidney function parameters, and hemodynamic experiments in which the renal nerves were electrically stimulated and responses in renal vascular resistance (RVR) and renal blood flow (RBF) were recorded.

RESULTS

Renal denervation in STZ-induced diabetic rats produced higher fractional excretion of sodium (FE(Na) ) but lower plasma sodium (P(Na) ), glomerular filtration rate (GFR), and plasma creatinine (P(Cr) ) (all P<0.05 vs. innervated diabetic rats). In innervated diabetic rats, renal nerve stimulation (RNS) caused significant attenuation in the renal vasoconstrictor responses (all P<0.05 vs. innervated control). Renal denervation in diabetic rats significantly blunted these responses (all P<0.05 vs. innervated diabetic rats); however, they were significantly higher (all P<0.05) while compared to denervated control counterparts.

CONCLUSIONS

The data demonstrate an early role for the renal sympathetic innervation in the pathogenesis of DKD. If the kidney is prevented from renal sympathetic nerve action renal functional parameters are markedly improved. The data further suggest an early enhancement in renal sensitivity to intrarenal norepinephrine (NE) upon the removal of renal sympathetic tone in STZ-induced diabetic rats.

The effect of losartan and carvedilol on vasopressor responses to adrenergic agonists and angiotensin II in the systemic circulation of Sprague Dawley rats

1 Interaction between renin-angiotensin (RAS) and sympathetic nervous systems (SNS) was investigated by examining the effect of cumulative blockade of angiotensin II (Ang II) and adrenergic receptors in normal Sprague Dawley rats. 2 Rats were treated with losartan (10 mg/kg), carvedilol (5 mg/kg), or losartan plus carvedilol (10+5 mg/kg) orally for 7 days. On day 8, the animals were anaesthetized with pentobarbitone and prepared for systemic haemodynamic study. Dose-response relationships for the elevation of mean arterial pressure or change in heart rate (HR) in response to intravenous injections of noradrenaline (NA), phenylephrine (PE), methoxamine (ME) and Ang II were determined. 3 Losartan or the combination of losartan with carvedilol blunted vasopressor responses to ME and Ang II. Dose-response relationships for agonist action on HR were significantly inhibited by all treatments except for the combination of losartan and carvedilol on the decrease in HR induced by PE. Carvedilol decreased vasopressor responses to NA, PE and Ang II, and HR responses to NA, ME and Ang II. Combination treatment produced similar effects to losartan on the vasopressor and HR responses but had a greater effect on vasopressor responses to ME and Ang II, and on HR responses to NA and Ang II than carvedilol alone. 4 It is concluded that peripheral vasoconstriction induced by Ang II is partly mediated by adrenergic action and that the vasopressor responses to adrenergic agonists depend on an intact RAS. These observations suggest an interactive relationship between RAS and SNS in determining systemic haemodynamic responses in 'normal' rats.

Role of norepinephrine & angiotensin II in the neural control of renal sodium & water handling in spontaneously hypertensive rats

BACKGROUND & OBJECTIVES

A wealth of information concerning the essential role of renal sympathetic nerve activity (RSNA) in the regulation of renal function and mean arterial blood pressure homeostasis has been established. However, many important parameters with which RSNA interacts are yet to be explicitly characterized. Therefore, the present study aimed to investigate the impact of acute renal denervation (ARD) on sodium and water excretory responses to intravenous (iv) infusions of either norepinephrine (NE) or angiotensin II (Ang II) in anaesthetized spontaneously hypertensive rats (SHR).

METHODS

Anaesthetized SHR were acutely denervated and a continuous iv infusion of NE (200 ng/min/ kg) or Ang II (50 ng/min/kg) was instigated for 1 h. Three 20-min urine clearances were subsequently collected to measure urine flow rate (UV) and absolute sodium excretion (U(Na)V).

RESULTS

Higher UV and U(Na)V (P<0.05) were observed in denervated control SHR as compared to innervated counterparts. The administration of NE or Ang II to innervated SHR produced lower UV and U(Na)V (P<0.05 vs. innervated control SHR). Lower diuresis/natriuresis response to ARD was observed in NE-treated SHR compared to denervated control SHR (P<0.05). Salt and water excretions in denervated NE-treated SHR, however, were significantly higher (P<0.05) relative to the excretion levels in control denervated SHR. Conversely, there was a higher (all P<0.05) diuresis/natriuresis response to ARD when Ang II was administered to SHR compared to denervated control or innervated Ang II-treated SHR.

INTERPRETATION & CONCLUSIONS

NE retains its characteristic antidiuretic/antinatriuretic action following ARD in SHR. Typical action of Ang II on salt and water excretions necessitates the presence of an intact renal innervation. Ang II is likely to facilitate the release of NE from renal sympathetic nerve terminals through a presynaptic site of action. Moreover, there is a lack of an immediate enhancement in the renal sensitivity to the actions of NE and Ang II following ARD in a rat model of essential hypertension.

Role of renal sympathetic nervous system in the control of renal potassium handling

BACKGROUND

It is well established that renal sympathetic nerves are primarily involved in renal sodium and water regulation. However, the relationship between renal sympathetic nerve activity (RSNA) and renal potassium handling is not extensively known. The present study was performed to investigate the role of the renal sympathetic nervous system in the regulation of tubular potassium reabsorption and secretion.

METHODS

Male Sprague Dawley (SD) rats (each group, n=6) were fasted overnight, anesthetized with pentobarbital sodium (60 mg/kg intraperitoneal), denervated by application of phenol to the left renal artery and maintained on an intravenous infusion of saline for 2 hours. During this period, 6 urine and plasma samples were collected at 20-minute intervals to study kidney function parameters.

RESULTS

In denervated rats, there were significantly higher (all p<0.05 vs. innervated control) urine flow rate (UFR), glomerular filtration rate (GFR), absolute sodium excretion (U(Na)V), fractional sodium excretion (FE(N)a), absolute potassium excretion (U(K)V), fractional potassium excretion (FE(K)) and urinary sodium to urinary potassium ratio (U(Na)/U(K)). No appreciable differences were seen in the mean arterial pressure (MAP) and plasma sodium (P(Na)) between denervated and innervated SD rats. However, plasma potassium (P(K)) levels were significantly lower (p<0.05) in denervated rats as compared with innervated counterparts.

CONCLUSIONS

There is a possible involvement of renal nerves in the regulation of renal potassium handling. This effect is largely attributable to a direct action of renal sympathetic nerves on the renal tubular segments.

Renal functional & haemodynamic changes following acute unilateral renal denervation in Sprague Dawley rats

BACKGROUND & OBJECTIVES

Regulation of renal function and haemodynamics are under a direct control from the renal sympathetic nerves and renal denervation produces overt diuresis and natriuresis in several mammalian species. However, the inter-related series of changes in renal function and haemodynamics following acute renal denervation (ARD) is not fully understood. Thus, we aimed to investigate and relate the changes in renal function and haemodynamics following acute unilateral renal denervation in anaesthetized Sprague Dawley (SD) rats.

METHODS

Male SD rats were fasted overnight, anaesthetized with sodium pentobarbitone (60 mg/kg ip), denervated by application of phenol to the left renal artery and maintained on an intravenous (iv) infusion of isotonic saline for 2 h. Throughout this period, six urine and plasma samples were taken at 20-min intervals to study kidney function parameters. In a different set of experiments, renal nerve stimulation (RNS) was carried out to characterize the changes in renal vasoconstrictor responses following ARD.

RESULTS

Denervated animals showed significantly (P<0.05 vs. control innervated rats) higher urine flow rate (UFR), absolute sodium excretion (UNaV), fractional sodium excretion (FENa) and glomerular filtration rate (GFR). The renal vasoconstrictor responses to RNS were significantly (P<0.05) lower in denervated rats as compared to the innervated counterparts. However, no appreciable differences were seen in the mean arterial pressure (MAP), plasma sodium (PNa), basal renal blood flow (RBF) and basal renal vascular resistance (RVR) in both innervated and denervated SD rats.

INTERPRETATION & CONCLUSIONS

Natriuresis, diuresis, enhanced GFR and impaired vasoconstriction in response to RNS are typical and instant responses to ARD in SD rats. Renal sympathetic nerves serve more important role in salt and water conservation than in dynamic autoregulation of RBF under normal sympathetic tone; yet, their effects on renal haemodynamics become more evident in the presence of augmented renal sympathetic nerve activity (RSNA).

Interaction between renin-angiotensin and sympathetic nervous systems in a rat model of pressure overload cardiac hypertrophy

1 A raised cardiac workload activates neurohormones which will increase muscle mass and shift contractility to the right along the Frank-Starling curve. 2 This study examined the interaction between the SNS and RAS in contributing to vascular responsiveness following the development of cardiac hypertrophy due to aortic banding. 3 Sprague Dawley rats (180-200 g) were assigned to one of six groups; Normal, Sham-operated, Aortic Banded (AB), Aortic Banded treated with losartan (ABLOS), Aortic Banded treated with 6-hydroxydopamine (ABSYMP) and Aortic banded treated with both losartan and 6-hydroxydopamine (ABSYMPLOS). A constricting band was placed around the supra renal aorta on day zero with drug treatment from day 37 to day 44. Vasopressor responses to noradrenaline, phenylephrine, methoxamine and angiotensin II were measured on day 45. 4 The magnitudes of the MAP responses to all vasoactive agents, expressed as percentage changes, were similar in Normal and Sham groups, but reduced in the AB group. ABLOS group showed attenuated response to ANGII whereas all responses were enhanced in the ABSYM group. 5 A positive interaction between the two systems was observed with alpha(1A)-adrenoceptors identified as a major component of SNS and AT(1) receptors of RAS to induce vasopressor effects.

Influence of high dietary sodium intake on the functional subtypes of alpha-adrenoceptors in the renal cortical vasculature of Wistar-Kyoto rats

1 Increased renal vascular resistance is one renal functional abnormality that contributes to hypertension, and alpha(1)-adrenoceptors play a pivotal role in modulating this renal vascular resistance. This study investigates the functional contribution of alpha(1)-adrenoceptor subtypes in the renal cortical vasculature of Wistar-Kyoto rats on a normal sodium diet (WKYNNa) compared with those given saline to drink for 6 weeks (WKYHNa). 2 The renal cortical vascular responses to the adrenergic agonists noradrenaline (NA), methoxamine (ME) and phenylephrine (PE) were measured in WKYHNa and WKYNNa rats either in the absence (the control phase) or presence of chloroethylclonidine (CEC), an alpha(1B)-adrenoceptor antagonist, 5-methylurapidil (5-MeU), an alpha(1A) antagonist, or BMY7378, an alpha(1D) antagonist. 3 Results showed a greater renal cortical vascular sensitivity to NA, PE and ME in the WKYHNa compared with WKYNNa rats (P < 0.05). Moreover, 5-MeU and BMY7378 attenuated adrenergically induced renal cortical vasoconstriction in WKYHNa and WKYNNa rats; this response was largely blunted in CEC-treated WKYHNa rats (all P < 0.05) but not in CEC-treated WKYNNa rats. 4 The data suggest that irrespective of dietary sodium content, in Wistar-Kyoto rats alpha(1A)- and alpha(1D)-subtypes are the major alpha(1)-adrenoceptors in renal cortical vasculature; however, there appears to be a functional involvement of alpha(1B)-adrenoceptors in the WKYHNa rats.

Influence of sympathetic and AT-receptor blockade on angiotensin II and adrenergic agonist-induced renal vasoconstrictions in spontaneously hypertensive rats

AIM

This study investigated the influence of angiotensin II (Ang II) receptor and adrenergic blockade on the renal vasoconstrictions caused by Ang II and adrenergic agonists in spontaneously hypertensive rats (SHR).

METHODS

Forty-eight SHR were subjected to 7 days of losartan (10 mg kg(-1) day(-1) p.o.), carvedilol (5 mg kg(-1) day(-1) p.o.) or losartan + carvedilol (10 mg kg(-1) day(-1) + 5 mg kg(-1) day(-1) p.o.). On day 8, the rats were anaesthetized and renal vasoconstrictor experiments performed. One group of rats underwent acute unilateral renal denervation.

RESULTS

There were significant (P < 0.05) reductions in the renal vasoconstrictor responses to noradrenaline, phenylephrine, methoxamine and Ang II after losartan and carvedilol treatments compared with that in untreated rats (all P < 0.05). However, in renally denervated SHR treated with carvedilol, the vasoconstrictor responses to all the vasoactive agents were enhanced compared with those in SHR with intact renal nerves treated with carvedilol. Intact SHR given both losartan and carvedilol showed greater renal vasoconstrictor responses to the vasoactive agents than when given either losartan or carvedilol alone (all P < 0.05).

CONCLUSION

Carvedilol reduced the vasoconstrictor response to Ang II and all the adrenergic agonists in the presence of the renal nerves, but, following the removal of renal sympathetic activity, carvedilol enhanced the sensitivity of both renal alpha(1)-adrenoceptors and AT(1) receptors to the vasoactive agents. Co-treatment with losartan and carvedilol reduced the renal vasoconstrictor responses to exogenously administered vasoactive agents but to a lesser extent than losartan or carvedilol alone. The results obtained demonstrate an interaction between Ang II receptors and adrenergic neurotransmission in the SHR.

Clonidine and a novel clonidine analog AL-12 cause sympathoinhibition in spontaneously hypertensive and diabetic spontaneously hypertensive rats

This study examined the sympathoinhibitory effects of clonidine and a novel clonidine analog, AL-12, in rat models of genetic hypertension and a combined state of genetic hypertension and diabetes. Rats in the treatment groups were given either clonidine or AL-12 while the respective control groups received either saline or Tween 80 for 6 days. Physiological data were collected during this period, which was followed by acute studies on day 7 when bolus administrations (i.v.) of graded doses of noradrenaline, phenylephrine and methoxamine were carried out. It was observed that in AL-12-treated nondiabetic spontaneously hypertensive rats (SHR), the pressure responses to all adrenergic agonists were greater (p < 0.05) in the treated group, while in the diabetic SHR rats a larger pressure response was observed only to noradrenaline (p < 0.05). In nondiabetic SHR rats treated with clonidine, a greater (p < 0.05) pressure response was observed only in the case of phenylephrine. In the diabetic SHR rats treated with clonidine, the pressure responses to the adrenergic agonists were similar (p > 0.05) in the treated and its control animals except that methoxamine caused a greater (p < 0.05) pressure response in the control group. The data obtained suggest that clonidine and AL-12 act possibly via vascular alpha1 and alpha2 adrenoceptors present at both pre- and postsynaptic locations.

Influence of cisplatin-induced renal failure on the α1-adrenoceptor subtype causing vasoconstriction in the kidney of the rat

This study investigated whether the alpha(1)-adrenoceptor subtype(s) mediating the vasoconstrictor actions of the renal sympathetic nerves were altered in rats with cisplatin-induced renal failure. Male Wistar Kyoto rats were used and half received cisplatin (5 mg/kg i.p.) to induce renal failure and were taken for study 7 days later. The renal blood flow reductions caused by electrical renal nerve stimulation and close intra-renal administration of noradrenaline, phenylephrine and methoxamine were determined before and after amlodopine (AMP), 5-methylurapidil (MeU), chloroethylclonidine (CEC) or BMY 7378. Water intake and creatinine clearance were decreased (P<0.05) by 40-50% while fractional excretion of sodium was increased two-fold in the cisplatin treated rats. Mean arterial pressure was higher, 110+/-2 versus 102+/-3 mmHg and renal blood flow was lower, 10.7+/-0.9 versus 18.9+/-0.1 ml/min/kg in the renal failure rats (both P<0.05). AMP, MeU and BMY 7378 decreased (all P<0.05) the adrenergically induced renal vasoconstrictor responses in the renal failure groups by 30 to 50% and in normal rats by 20 to 40%. In the presence of CEC, renal nerve stimulation and noradrenaline and methoxamine induced renal vasoconstrictor responses were enhanced (all P<0.05) in the renal failure but not in the normal rats. These data showed that alpha(1A)- and alpha(1D)-adrenoceptors were the major subtypes in mediating adrenergically induced renal vasoconstriction but there was no substantial shift in subtype in renal failure. The contribution of alpha(1B)-adrenoceptor subtypes either pre- or post-synaptic appeared to be raised in the renal failure rats.

Evidence of an environmental contribution to the aetiology of cryptorchidism and hypospadias?

OBJECTIVES

Evidence suggests that there is geographical variation in the birth prevalence of both cryptorchidism and hypospadias. The aim was to determine if there is evidence of spatial heterogeneity in the prevalence of these conditions and to test the hypothesis that environmental factors may contribute to aetiology.

METHODS

A population-based dataset of cryptorchidism and hypospadias cases was constructed from the hospital episodes statistics that covered the Northern Region of England and assigned to a small area based on the residential address at time of admission. Expected numbers of cases for each small area were computed. The ratio of observed to expected cases was determined for each small area and analysed with respect to both geographical heterogeneity and small area level socio-economic deprivation. The Potthoff-Whittinghill method was used to determine if there was localized spatial clustering of cases.

RESULTS

There was statistically significant spatial clustering for cases of both cryptorchidism [estimated Extra-Poisson Variation (EPV) = 0.14; 95% CI, 0.03-0.25] and hypospadias (EPV = 0.17; 95% CI, 0.05-0.28). In addition, increased prevalence was associated with lower levels of deprivation for hypospadias (P = 0.06), but there was no such relationship for cryptorchidism (P = 0.61).

CONCLUSIONS

The finding of localized spatial heterogeneity in the prevalence of cryptorchidism and hypospadias is consistent with the involvement of a spatially varying environmental risk factor. The apparent social patterning of hypospadias is likely to reflect an association with lifestyle and other factors which underpin social variation in health. However, there also remains a possibility that these findings may be due to variability in ascertainment of cases.

Birth prevalence of cryptorchidism and hypospadias in northern England, 1993-2000

AIM

There is much debate as to whether the prevalence rates of cryptorchidism and hypospadias are increasing. To address this issue we investigated the birth prevalence of cryptorchidism and hypospadias in the northern region of England during the period 1993-2000.

METHODS

Cases of cryptorchidism and hypospadias were identified from northern region hospital episodes statistics (HES). Trends in birth prevalence, based on the number of male live births, were assessed using linear regression.

RESULTS

Prevalence was 7.6 per 1000 male live births for cryptorchidism and 3.1 per 1000 male live births for hypospadias. The orchidopexy rates for 0-4 year olds and 5-14 year olds were 1.8 and 0.8 per 1000 male population, respectively. The rates for hypospadias repair for 0-4 year olds and 5-14 year olds were 0.6 and 0.1 per 1000 male population, respectively. There was a statistically significant decreasing temporal trend for the corrective procedure in cryptorchidism of 0.1 per 1000 male population aged under 5 years per annum (95% confidence interval: -0.01 to -0.05, p<0.001), but no temporal change for the corrective procedure in hypospadias (p = 0.60).

CONCLUSION

HES data were of high quality for the study period. There was no significant change in the prevalence of surgically corrected hypospadias. However, there was an apparent decline in the prevalence of surgically corrected cryptorchidism that may reflect a decrease in the prevalence of the condition or may be due to a decrease in the rate of surgical intervention.

The contribution of adrenoceptor subtype(s) in the renal vasculature of diabetic spontaneously hypertensive rats

1. Diabetes and hypertension are both associated with an increased risk of renal disease and are associated with neuropathies, which can cause defective autonomic control of major organs including the kidney. This study aimed to examine the alpha(1)-adrenoceptor subtype(s) involved in mediating adrenergically induced renal vasoconstriction in a rat model of diabetes and hypertension. 2. Male spontaneously hypertensive rats (SHR), 220-280 g, were anaesthetized with sodium pentobarbitone 7-day poststreptozotocin (55 mg x kg(-1) i.p.) treatment. The reductions in renal blood flow (RBF) induced by increasing frequencies of electrical renal nerve stimulation (RNS), close intrarenal bolus doses of noradrenaline (NA), phenylephrine (PE) or methoxamine were determined before and after administration of nitrendipine (Nit), 5-methylurapidil (5-MeU), chloroethylclonidine (CEC) and BMY 7378. 3. In the nondiabetic SHR group, mean arterial pressure (MAP) was 146+/-6 mmHg, RBF was 28.0+/-1.4 ml x min(-1) x kg(-1) and blood glucose was 112.3+/-4.7 mg x dl(-1), and in the diabetic SHR Group, MAP was 144+/-3 mmHg, RBF 26.9+/-1.3 ml(-1) min x kg(-1) and blood glucose 316.2+/-10.5 mg x dl(-1). Nit, 5-MeU and BMY 7378 blunted all the adrenergically induced renal vasoconstrictor responses in SHR and diabetic SHR by 25-35% (all P<0.05), but in diabetic rats the responses induced by RNS and NA treated with 5-MeU were not changed. By contrast, during the administration of CEC, vasoconstrictor responses to all agonists were enhanced by 20-25% (all P<0.05) in both the SHR and diabetic SHR. 4. These findings suggest that alpha(1A) and alpha(1D)-adrenoceptor subtypes contribute in mediating the adrenergically induced constriction of the renal vasculature in both the SHR and diabetic SHR. There was also an indication of a greater contribution of presynaptic adrenoceptors, that is, alpha(1B)-, and/or alpha(2)-subtypes.

Current perspectives and opportunities for international cooperation for development of polymer based drug delivery systems

The present paper is devoted to: Analysis of significant endeavours directed to polymer base drug delivery systems, elucidating addressing priority problems and biopolymer development, significant R & D needs and priorities and the framework as well as the requirements for international networking in the area of drug delivery system. Such organized collaboration will enable promotion of knowledge among interested parties and cultures. Concerned pharmaceutical institutional and scientific associations e.g. International Pharmaceutical Federation FIP and American Association of Pharmaceutical Sciences AAPS should adopt and initiate planned activities for developing and activation of appropriate drug network encompassing active members from the academic, professional centres and drug industry. The proposed network should be established on a self-sustained basis.

Electrophysiological characterization of a motilin agonist, GM611, on rabbit duodenal smooth muscle

Effects of motilin and a newly synthesized erythromycin derivative, GM611, on membrane potential and currents of rabbit duodenal smooth muscle have been investigated by intracellular potential recording and whole cell patch-clamp technique and compared with results from contractile experiments. Motilin and GM611 (0.01-100 nM) dose dependently produced slowly sustained depolarizations (half-maximal effective dose = 0.15 and 3.9 nM for motilin and GM611, respectively) but exhibited biphasic effects on spike activities superimposed on slow waves. With small depolarizations, the number of spike discharges increased, whereas larger depolarizations markedly reduced spike amplitude. Motilin-induced (or GM611-induced) depolarization appeared to be associated with the activation of monovalent cation-selective channels, and the reduction in the spike amplitude appeared mainly to be associated with inhibition of voltage-dependent Ca2+ channels. Furthermore, data from patch-clamp experiments suggested that Ca2+ release occurred from heparin-sensitive internal stores upon stimulation of motilin receptors by these agonists. Possible implications of these electrophysiological effects in motilin- or GM611-induced tonic and phasic contractions have been discussed.

Contraction and depolarization induced by fetal bovine serum in airway smooth muscle

We investigated the effects of fetal bovine serum (FBS) on the resting membrane potential and muscle tone of canine airway smooth muscles using tension recording and microelectrode methods. At concentrations > 0.1%, FBS induced a sustained increase in muscle tone. At concentrations > 1%, FBS depolarized the resting membrane potential of dog trachea in a dose-dependent manner. When FBS was dialyzed, it failed to induce a sustained increase in muscle tone or to depolarize the membrane, indicating that FBS contained factor(s) that induced contraction of dog airway smooth muscles. When FBS was dialyzed against distilled water, the outer solution which was freeze dried and then reconstituted (> 1% in original vol) induced a sustained increase in muscle tone, indicating that FBS contained dialyzable factor(s) that increased muscle tone and depolarized the resting membrane potential of dog airway smooth muscles. Methysergide (10(-6) M) or cyproheptadine (10(-6) M), nonspecific antagonists to serotonin receptors, 5-hydroxytryptamines (5-HT1 and 5-HT2), markedly reduced the FBS-induced increase in the muscle tone to approximately 20% of the original value but did not abolish the response. On the other hand, methysergide (10(-6) M) completely suppressed the increase in the muscle tone evoked by peak fractions obtained by application of the dialysate of FBS or 5-HT to a C18 reverse-phase column, indicating the peak fractions contained only 5-HT. These observations indicate that FBS contained 5-HT and an unknown factor(s) responsible for increase in the muscle tone of the airway smooth muscle induced by FBS.

Ischaemia and mediator release: interrelationship in antigen-challenged sensitized guinea-pig kidney

Renal vasoconstriction and ischaemia that follow in vitro antigen challenge of isolated perfused kidney of sensitized guinea-pig appears to be a self-perpetuating process, starting with a primary peak of release of vasoconstrictor mediators and followed by secondary peaks (particularly of arachidonic acid metabolites) which are probably initiated by ischaemia/reperfusion damage.

Differential effects of epidermal growth factor, transforming growth factor-alpha, and vaccinia virus growth factor in the positive regulation of IFN-gamma production

We have recently shown that epidermal growth factor (EGF) is capable of positive regulation of IFN-gamma production, thus establishing a functional relationship between nonhemopoietic growth factors and the immune system. In order to study this relationship further, EGF and the EGF-related growth factors transforming growth factor-alpha (TGF-alpha) and vaccinia virus growth factor (VGF), which stimulate cellular proliferation via binding to the EGF receptor, were studied for their functional and physicochemical effects on IFN-gamma production. In contrast to the positive signal of purified murine EGF and recombinant human EGF (both at 1 nM), neither synthetic TGF alpha nor recombinant VGF were capable of restoring competence for IFN-gamma production by Th cell-depleted spleen cell cultures. TGF-alpha and VGF, in molar excess, also failed to block the helper signal of EGF for IFN-gamma production. Thus TGF-alpha and VGF failed to functionally compete for the EGF receptor in the murine spleen cell system. Both TGF-alpha and VGF stimulated murine 3T3 cell proliferation at concentrations similar to those of EGF, and thus their failure to provide help for IFN-gamma production was not due to a general lack of biologic activity. Binding studies with 125I-EGF suggest that the EGF receptor on murine lymphocytes is not constitutively expressed, but inducible by the T cell mitogen staphylococcal enterotoxin A. TGF-alpha did not compete with 125I-EGF for the induced receptor. The data suggest that lymphocytes express a novel inducible EGF receptor that differs from that expressed on cells such as 3T3 fibroblasts.