A step towards decentralized wastewater management in the Lower Jordan Rift Valley.

In order to address serious concerns over public health, water scarcity and groundwater pollution in Jordan, the expansion of decentralized wastewater treatment and reuse (DWWT&R) systems to small communities is one of the goals defined by the Jordan government in the "Water Strategy 2009-2022". This paper evaluates the general potential of decentralized wastewater system solutions to be applied in a selected area of the Lower Jordan Rift Valley in Jordan. For the study area, the connection degree to sewer systems was calculated as 67% (5% in the rural sector and 75% in the urban sector). The annual wastewater production available for DWWT&R in the rural sector of the investigation area was calculated to be nearly 3.8 million m(3) at the end of 2007. The future need of wastewater treatment and reuse facilities of the rural sector was estimated to be increasing by 0.11 million m(3) year(-1), with an overall potential of new treatment capacity of nearly 15,500 population equivalents (pe) year(-1). The overall potential for implementing DWWT&R systems in the urban sector was estimated as nearly 25 million m(3) of wastewater in 2007. The future need of wastewater treatment and reuse facilities required for the urban sector was estimated to be increasing at a rate of 0.12 million pe year(-1). Together with the decision makers and the stakeholders, a potential map with three regions has been defined: Region 1 with existing central wastewater infrastructure, Region 2 with already planned central infrastructure and Region 3 with the highest potential for implementing DWWT&R systems.

Effects of type of flow, plants and addition of organic carbon in the removal of zinc and chromium in small-scale model wetlands.

Constructed wetlands are used for the treatment of wastewater containing metals. In order to clarify the role of plants, flow and the impact of organic matter, an investigation of three factors, each at two different levels, was carried out in small-scale model wetlands. The evaluated factors and levels were: type of flow (subsurface and surface); presence of plants (planted with Typha latifolia and unplanted) and addition of organic matter (with and without). Eight different experimental units were run for a year. The units were fed with synthetic wastewater containing chromium (VI) (1.5 mg L(-1)), zinc (1.5 mg L(-1)), macro, micronutrients and organic matter (to those units in which this factor was being investigated). Subsurface flow wetlands showed a significantly higher rate of chromium removal in comparison with surface flow systems (97 and 60 mg m(-2) d(-1), respectively). Planted systems removed significantly more chromium compared to unplanted systems (85 and 76 mg m(-2) d(-1), respectively), and the addition of organic matter increased the removal rate in a comparison with the units without it (88 and 69 mg m(-2) d(-1), respectively). Similar results were found for zinc; however, the addition of organic matter made no significant difference to zinc removal.

Differential modulation of GABA- and NMDA-gated currents by ethanol and isoflurane in cultured rat cerebral cortical neurons.

Ethanol and the volatile anesthetics share many features including effects on both GABA and NMDA receptors. To determine the degree of similarity between these compounds, we examined the concentration-response curves for ethanol and isoflurane on currents gated by GABA or NMDA. The effects of isoflurane and ethanol on the righting reflex of rats were also observed. The concentration of ethanol causing loss of the righting reflex of rats was 82.3+/-2.9 mM, whereas median concentration of isoflurane exerting that effect was 0.125 mM. Both isoflurane and ethanol inhibited NMDA-gated currents in cultured cerebral cortical neurons at concentrations well below those associated with loss of the righting reflex or anesthesia. However, the effect of isoflurane was greater than that of ethanol and the slope of the concentration-response curve for isoflurane less steep than that for ethanol. Isoflurane enhanced GABA-gated currents at anesthetic concentrations but there was a sharp concentration-response curve with only minimal effects of isoflurane on GABA-gated currents at concentrations associated with loss of the righting reflex. In contrast, ethanol had no effect on GABA-gated currents even at lethal concentrations, i.e. 300 mM or 1.2%. Comparison of the concentration-response curves for the effects of isoflurane on NMDA- and GABA-gated currents has revealed both EC50 and Hill slope for the potentiation of GABA-gated currents were significantly greater than those for inhibition of NMDA-gated currents. These results support the hypothesis that isoflurane has actions on both the GABA and NMDA systems that are not shared by ethanol.

Increase in rat plasma antioxidant activity after E. coli lipopolysaccharide administration.

It is well recognized that the sensitivity of animals to lipopolysaccharide (LPS) endotoxin varies tremendously. And, it has been recently observed that Sprague-Dawley rats dramatically increase the activity of hepatic endogenous antioxidative enzyme systems after LPS administration. This finding suggests that the relative resistance of rats to LPS may be related to a concomitant increase in the activities of the hepatic antioxidant systems. This study was designed to examine if the above reported hepatic change in rats given LPS could be observed at the systemic level. Male Sprague-Dawley or Wistar rats, weighing 250 - 350 g, were given increasing doses (10 - 100 mg/kg) of LPS i.p. under 1.0% isoflurane anesthesia. Antioxidant capacity (AOC), blood gas analysis, and the cardiovascular parameters of the arterial blood of animals were determined over a 4 hour period following LPS administration. In addition, we studied the effect of pretreatment with the non-specific nitric oxide synthase inhibitor, L-N(G)-Nitroarginine methyl ester hydrochloride (L-NAME), given 50 mg/kg s.c. one and 24 hours before the administration of 20 mg/kg LPS i.p. in Sprague-Dawley rats. Rats given sufficiently high doses of E. coli LPS to produce behavioral effects also showed increased plasma AOCs in the early period after the administration of LPS. Similar changes were noted in Sprague-Dawley and Wistar rat strains, but at different doses that reflect their differential sensitivities to the LPS induced inflammatory response. Also, the resistance of the Sprague-Dawley strain of rats to LPS was not altered by the prior administration of L-NAME, nor was the plasma AOC altered. In conclusion, our study suggests that the rat strains are relatively resistant to develop the toxic signs of LPS in the early period after the administration of LPS, especially in Sprague-Dawley rats. Moreover, endotoxin-induced increases in plasma AOC may contribute to the rats' resistance to LPS intoxication.

Prospective evaluation of Roux-en-Y gastric bypass as primary operation for medically complicated obesity.

OBJECTIVE: To determine prospectively the results of Roux-en-Y gastric bypass (RYGB) used as the primary weight-reducing operation in patients with medically complicated ("morbid") obesity. The RYGB procedure combines the advantages of a restrictive physiology (pouch of 10 mL) and a "dumping physiology" for high-energy liquids without requiring an externally reinforced (banded) stoma. PATIENTS AND METHODS: Between April 1987 and December 1998, a total of 191 consecutive patients with morbid obesity (median weight, 138 kg [range, 91-240 kg]; median body mass index, 49 kg/m2 [range, 36-74 kg/m2]), all of whom had directly weight-related morbidity, underwent RYGB and prospective follow-up. RESULTS: Hospital mortality was 0.5% (1/191), and hospital morbidity occurred in 10.5% (20/191). Good long-term weight loss was achieved, and patients adapted well to the required new eating habits. The mean +/- SD weight loss at 1 year after operation (113 patients) was 52 +/- 1 kg or 68% +/- 2% of initial excess body weight. By 3 years postoperatively (74 patients), weight loss was still 66% +/- 2% of excess body weight. Overall, 53 (72%) of 74 patients had achieved and maintained a weight loss of 50% or more of their preoperative excess body weight 3 years after the operation. In addition, only 1 (1%) of 98 patients had persistent postoperative vomiting 1 or more times per week. CONCLUSION: We believe that RYGB is a safe, effective procedure for most patients with morbid obesity and thus may be the current procedure of choice in patients requiring bariatrics++ surgery for morbid obesity.

Interactive role for neurosteroids in ethanol enhancement of gamma-aminobutyric acid-gated currents from dissociated substantia nigra reticulata neurons.

Although previous in vivo electrophysiological studies demonstrated a consistent ethanol enhancement of gamma-aminobutyric acid (GABA) responsiveness from substantia nigra reticulata (SNR) neurons, ethanol applied in vitro to dissociated neurons from the SNR had an inconsistent effect on GABA function. One source for the disparity between these contrasting in vivo and in vitro results could be an endogenous factor (acting on an auxiliary site on GABA(A) receptors) that was not available to the isolated SNR neurons. Because neurosteroids are present in vivo and act on an auxiliary site, it was hypothesized that the presence of a neurosteroid was important for a consistent effect of ethanol on GABA responsiveness from neurons studied in vitro. Alone, the neurosteroid analog alphaxalone produced a significant, concentration-related enhancement of GABA responsiveness from isolated SNR neurons. In contrast to an inconsistent action of 100 mM ethanol on GABA responsiveness in the absence of alphaxalone, the presence of 30 and 100 nM alphaxalone resulted in the majority of isolated neurons responding to this ethanol level. At a concentration of alphaxalone as low as 30 nM, ethanol produced a robust concentration-related increase in GABA-gated currents from this cell type. The neurosteroid 3alpha, 5alpha-tetrahydrodeoxycorticosterone (100 nM) also permitted a reliable concentration-dependent ethanol enhancement of responses to GABA from SNR cells, indicative that the effects of alphaxalone were not unique. This consistent neurosteroid-induced ethanol enhancement of GABA responsiveness from dissociated SNR neurons supports the view that neurosteroids may play a key role in the action of ethanol on postsynaptic GABA(A) receptor function.

Antagonism of ketamine-induced anesthesia by an inhibitor of nitric oxide synthesis: a pharmacokinetic explanation.

Because ketamine is an antagonist of NMDA receptors, and because some NMDA receptors activate nitric oxide synthesis in brain, this study examined if nitric oxide synthase (NOS) inhibition by L-NAME altered the course of ketamine-induced behavioral impairment. Rats given progressive doses of L-NAME until NOS activity was inhibited at least 90% displayed reduced depth and duration of behavioral depression after i.m. ketamine. Blood and brain concentrations of ketamine, norketamine, and its dehydrogenated derivative were isolated from rats previously given saline or L-NAME as above, by ether extraction, HPLC separation, and ultraviolet quantitation. The same doses of L-NAME that altered ketamine behavior reduced blood and brain ketamine concentrations 15 min after administration to about three-fourths and one-third of control, respectively. The content of norketamine and its adventitial extraction product were similarly reduced relative to control but the ratio of metabolites to ketamine was not significantly altered (p > 0.05) in brain. The decreased delivery of ketamine into brain, perhaps due to L-NAME-induced alterations in blood flow, may explain the reduced behavioral response to ketamine in these rats.

Metabolic mapping of the rat brain after subanesthetic doses of ketamine: potential relevance to schizophrenia.

Subanesthetic doses of ketamine have been shown to exacerbate symptoms in schizophrenia and to induce positive, negative, and cognitive schizophrenic-like symptoms in normal subjects. The present investigation sought to define brain regions affected by subanesthetic doses of ketamine, using high resolution autoradiographic analysis of 14C-2-deoxyglucose (2-DG) uptake and immunocytochemical staining for Fos-like immunoreactivity (Fos-LI). Both functional mapping approaches were used because distinct and complementary information is often obtained with these two mapping methods. Ketamine, at a subanesthetic dose of 35 mg/kg, substantially increased 2-DG uptake in certain limbic cortical regions, including medial prefrontal, ventrolateral orbital, cingulate, and retrosplenial cortices. In the hippocampal formation, the subanesthetic dose of ketamine induced prominent increases in 2-DG uptake in the dentate gyrus, CA-3 stratum radiatum, stratum lacunosum moleculare, and presubiculum. Increased 2-DG uptake in response to 35 mg/kg ketamine was also observed in select thalamic nuclei and basolateral amygdala. Ketamine induced Fos-LI in the same limbic cortical regions that exhibited increased 2-DG uptake in response to the subanesthetic dose of the drug. However, no Fos was induced in some brain regions that showed increased 2-DG uptake, such as the hippocampal formation, anterioventral thalamic nucleus, and basolateral amygdala. Conversely, ketamine induced Fos in the paraventricular nucleus of the hypothalamus and central amygdala, although no effect of the drug on 2-DG uptake was apparent in these regions. In contrast to the increase in 2-DG uptake observed in select brain regions after the subanesthetic dose, an anesthetic dose of ketamine (100 mg/kg) produced a global suppression of 2-DG uptake. By contrast, a robust induction of Fos-LI was observed after the anesthetic dose of ketamine that was neuroanatomically identical to that produced by the subanesthetic dose. Results of the present investigation show that anesthetic and subanesthetic doses of ketamine have pronounced effects on regional brain 2-DG uptake and induction of Fos-LI. The alterations in regional brain metabolism induced by the subanesthetic dose may be relevant to effects of ketamine to induce schizophrenic-like symptoms.

Insulin resistance is not a major determinant of low-density lipoprotein particle size.

The relationship between low-density lipoprotein (LDL) peak particle diameter and insulin sensitivity, very-low-density lipoprotein (VLDL) + intermediate-density lipoprotein (LDL) triglyceride, cholesterol, and apoprotein B, postprandial lipemia, and LDL + high-density lipoprotein (HDL) triglyceride was assessed. The subjects were 101 healthy males aged 15 to 45 years. Sixty-one subjects (60.4%) were offspring of a parent with coronary artery disease before age 60, and 40 subjects (39.6%) had no parental history of coronary artery disease. LDL peak particle diameter was measured following polyacrylamide gradient gel electrophoresis. An insulin sensitivity index (Si) was determined from a frequently sampled intravenous glucose tolerance test using a minimal modeling method. A fat tolerance test was performed with a test meal containing 70 g/m2 fat, with triglyceride concentrations measured hourly for 12 hours. LDL peak particle diameter was significantly correlated with body mass index (BMI) (r = -.282, P < .01), waist to hip ratio (r = -.291, P < .01), fasting triglyceride (logarithmically [log] transformed) (r = -.566, P < .001), area under the postprandial triglyceride curve (log transformed) (r = -.562, P < .001), VLDL + IDL triglyceride (log transformed) (r = -.462, P < .001), VLDL + IDL cholesterol (log transformed) (r = -.477, P < .001), VLDL + IDL apoprotein B (log transformed) (r = -.321, P < .001), LDL + HDL triglyceride (log transformed) (r = .583, P < .001), and HDL cholesterol (r = .347, P < .001), but there was no significant correlation with Si. Using stepwise regression analysis, LDL + HDL triglyceride showed the strongest relationship to LDL peak particle diameter, accounting for 34% of the variation in size. Si was not an independent predictor of LDL particle size. In conclusion, insulin sensitivity appears to have little influence on LDL particle size. The importance of LDL + HDL triglyceride should be considered a preliminary finding warranting verification in this and other populations.

Analysis of 281,797 consecutive blood cultures performed over an eight-year period: trends in microorganisms isolated and the value of anaerobic culture of blood.

The results for 281,797 blood culture sets of specimens collected from adult patients at the Mayo Clinic over an approximately 8-year period (1 November 1984 through 30 November 1992) were analyzed in order to determine whether there were differences in the types of microorganisms isolated over this time and to assess the usefulness of anaerobic culturing of blood. Each blood culture set consisted of two aerobic blood cultures (Septi-Chek [Becton Dickinson, Sparks, MD] and Isolator [Wampole Laboratories, Cranbury, NJ]) and one anaerobic culture (nonvented tryptic or trypticase soy broth [NVTSB; Difco Laboratories, Detroit, or Becton Dickinson]). The relative frequency of isolation of aerobic and facultatively anaerobic gram-positive bacteria and obligately anaerobic bacteria increased over the second half of the 1984-1992 surveillance period. The value of the NVTSB anaerobic blood culture was demonstrated for diagnosing bloodstream infections caused by certain facultatively anaerobic bacteria in addition to obligately anaerobic bacteria and supported the inclusion of the NVTSB anaerobic blood culture as a standard part of the three-component blood culture set used at this institution.

Safety considerations in the use of drug combinations during general anaesthesia.

The most commonly employed technique for providing general anaesthesia uses a balanced approach, where different drugs are used to reach specific desired endpoints. The variety of drugs used can result in a dozen or more different compounds being administered during a 'routine anaesthetic' procedure. Drug interactions are quite common and their clinical effects can be very significant. Clinically, general anaesthesia has 4 goals. These are: unconsciousness/amnesia; analgesia; muscle relaxation and maintenance of homeostasis. The anaesthesiologist tries to select only those drugs that permit a rapid onset of desirable operative conditions so that surgery can be performed properly and rapidly. Such drugs should also minimally disturb the patient's preoperative homeostatic maintenance, and maximise return to a desirable postanaesthetic functional state.

[15O]-water PET and intraoperative brain mapping: a comparison in the localization of eloquent cortex.

[15O]-water PET was performed on 12 patients with structural lesions for localization of the motor (n = 5), language (receptive and expressive; n = 6), and visual cortex (n = 1). All these patients underwent interactive image-guided surgery using an infrared digitizer and intraoperative electrical stimulation mapping for motor, sensory, language, and visual cortex location. MRI-PET coregistration was performed using a surface matching approach that integrated functional information with interactive image guidance during the surgical procedure. An awake craniotomy with motor and sensory intraoperative stimulation was performed using a registered bipolar electrode that was tracked on real-time during the surgical procedure. Intraoperative functional findings were displayed and saved on the registered MRI images. The sites of functional PET activation during the performance of motor, visual and language tasks were then compared to the results of intraoperative cortical stimulation in 11 patients and visual evoked potentials in one. The results of the PET activation studies were concordant with the findings of intraoperative stimulation in all cases. During resection of the structural lesions, intraoperative stimulation was continued in the subcortical pathways, and five patients had positive responses on areas not identified by the functional PET. Furthermore, 3 patients showed transitory changes in function (speech arrest 1, naming difficulty 1, and motor weakness 1) that were reversible after changing the dissection technique or a brain retractor. [15O]-water PET was reliable in identifying the motor, visual, and language cortex. Language-related rCBF increases were highly distributive, although only part of these activations were subjected to intraoperative stimulation. We conclude that [15O]-water PET can be used for preoperative noninvasive identification of functional cortex and may be useful in neurosurgical preplanning. Intraoperative mapping still remains the main means to avoid neurological damage as it can be performed during the entire surgical procedure to avoid damage to cortex, pathways, and damage secondary to ischemia or edema (brain retraction).

Action of zolpidem on responses to GABA in relation to mRNAs for GABA(A) receptor alpha subunits within single cells: evidence for multiple functional GABA(A) isoreceptors on individual neurons.

The relationship between zolpidem sensitivity and GABA(A) receptor alpha subunits was studied in individual dissociated neurons from rat brain. Using whole-cell recording, similar EC50 values were demonstrated for the effect of gamma-aminobutyric acid (GABA) on gated-chloride currents from substantia nigra reticulata (SNR) and lateral septal neurons. Subsequently, many neurons from both the SNR or lateral septum were found to exhibit enhanced GABA-gated chloride currents across concentrations of zolpidem ranging from 10 to 300 nM. Some neurons exhibited a greater than 20% increase in responsiveness to GABA at 30 nM of zolpidem without further increase at higher concentrations of zolpidem. Conversely, zolpidem enhancement of GABA from another group of neurons was not observed at 30 nM zolpidem, but between 100 and 300 nM the response to GABA increased greater than 20%. Finally, a third group of neurons reached both of these criteria for zolpidem enhancement of GABA. This latter spectrum of responses to GABA after varying concentrations of zolpidem was consistent with the presence of either two GABA(A) receptors or a single receptor with differing affinities for zolpidem on an individual neuron. Following determination of the sensitivity of neurons from SNR or lateral septum to zolpidem, cytoplasm was extracted from some individual cells to allow identification of cellular mRNAs for the alpha1, alpha2 and alpha3 GABA(A) receptor subunits with RT-PCR. Those neurons that responded to the 30 nM zolpidem concentration invariably expressed the alpha1-GABA(A) receptor subunit. This result is consistent with the GABA(A) alpha1-receptor subunit being an integral part of a functional high-affinity zolpidem type 1-BZD receptor complex on neurons in brain. Those neurons which showed enhancement of GABA from 100 to 300 nM zolpidem contained mRNAs for the alpha2 and/or the alpha3 receptor subunits, a finding consistent with these alpha subunits forming type 2-BZD receptors. Some individual dissociated SNR neurons were sensitive to both low and high concentrations of zolpidem and contained mRNAs for all three alpha-receptor subunits. These latter individual neurons are proposed to have at least two functional GABA(A) receptor subtypes. Thus, the present investigation emphasizes the importance of characterizing the relationship between endogenous GABA(A) receptor function and the presence of specific structural components forming GABA(A) receptor subtypes on neurons.

Dietary fish oil decreases low-density-lipoprotein clearance in nonhuman primates.

To assess whether fish oil-induced alterations in low-density-lipoprotein (LDL) composition have distinct and important effects on LDL metabolism, we evaluated LDL kinetic behavior in cynomolgus macaques fed an atherogenic diet supplemented with either fish oil (1.6 g n-3 fatty acids; n = 10) or olive oil (n = 9) for > or = 6 mo. LDL from monkeys supplemented with fish oil or olive oil was isolated, labeled with either 125I or 131I, and simultaneously reinjected so that each monkey received its own (autologous injection) and donor (homologous injection) LDL. For LDL injected autologously (monkeys that received their own LDL), the LDL fractional clearance rate (FCR) was reduced in fish oil-supplemented monkeys compared with the olive oil-supplemented controls (0.42 +/- 0.03 compared with 0.56 +/- 0.05 pools/d, P = 0.04). The cholesteryl ester content of fish oil LDL increased compared with olive oil LDL (43 +/- 2% and 36 +/- 3%, respectively, P = 0.03), and the LDL cholesteryl ester content was strongly correlated with autologous LDL clearance (r = -0.76, P = 0.0001). Compared with olive oil LDL, fish oil LDL had a reduced dissociation constant (KD) for binding to the LDL receptor in vitro (KD for fish oil LDL compared with olive oil LDL: 13.9 +/- 1.8 and 7.4 +/- 1.0 mg LDL protein/L, P = 0.03). When both fish oil LDL and olive oil LDL were simultaneously injected into fish oil-supplemented monkeys, the FCR of fish oil LDL was decreased compared with olive oil LDL (0.42 +/- 0.03 and 0.52 +/- 0.04 pools/d, P = 0.006). These data suggest that dietary supplementation with fish oil decreases LDL clearance, and that this effect is mediated, at least in part, by altering LDL structure and reducing the affinity of LDL for its receptor.

Vascular anatomy of the nose and the external rhinoplasty approach.

OBJECTIVE: To characterize the venous, lymphatic, and arterial blood supply of the nose and determine the effect of the external rhinoplasty approach on this vasculature. We hypothesized that dissection in the areolar tissue plane below the musculoaponeurotic layer of the nose will preserve the nasal vasculature and minimize postoperative nasal tip edema. DESIGN: The study included preoperative and postoperative clinical evaluation, cadaver dissection, and histologic examination. In the clinical section, lymphoscintigraphy was performed before and after rhinoplasty using the endonasal (transnostril) or external (open) approach. Additionally, nasal tip edema was subjectively quantified at specified interval after surgery. In the cadaver dissection section, 15 fresh cadavers were dissected to identify the venous and arterial vasculature. In the histology section, fresh nasal tissue was examined by light microscopy to verify the anatomy of arteries, veins, and lymphatic vessels. SETTING: Subjects for the clinical section of the study were volunteers undergoing primary rhinoplasty surgery at the University of Illinois College of Medicine at Chicago. PATIENTS: Lymphoscintigraphy was performed on nine patients who underwent rhinoplasty surgery. Seven of these patients underwent postoperative lymphoscintigraphy. INTERVENTIONS: The rhinoplasty procedures included three different methods of exposure of the nasal structures. Two patients underwent an endonasal (transnostril) nondelivery approach using a transcartilaginous incision. Five patients underwent the external approach with three receiving dissection in the areolar tissue plane below the musculoaponeurotic layer (preserving major nasal vasculature) and two undergoing dissection above the musculoaponeurotic layer (disrupting nasal vasculature). MAIN OUTCOME MEASURES: In the clinical section of the study, the outcome measures were tracer flow as seen on lymphoscintigraphy and tip edema scores subjectively quantitated on a scale from 1 (none) to 4 (maximal). RESULTS: Clinical Section: Lymphoscintigraphy revealed flow of tracer along the lateral aspect of the nose (cephalic to lateral crura) to the preparotid lymph nodes. Postoperative scans revealed preservation of flow of tracer with the endonasal (transnostril) approach and the external approach with submusculoaponeurotic areolar tissue plane dissection. There was loss of normal flow of tracer with the external approach using dissection that disrupted the musculoaponeurotic layer with supratip debulking. The nasal tip edema scores for the transnostril and external approach using areolar plane dissection were significantly lower than the external approach with disruption of the musculoaponeurotic layer. Cadaver Dissection Section: Other than the lateral nasal veins, the major arteries, veins, and lymphatic vessels ran superficial to the musculoaponeurotic layer of the nose. The lateral and dorsal nasal and the columellar arteries comprise an alar arcade that provides the major blood supply to the flap elevated in the external rhinoplasty approach. Histologic Section: Light microscopy of plastic resin sections verified the lymphoscintigraphic and cadaver dissection findings. The lymphatic vessels were located primarily in the reticular dermis above the muscle layer. CONCLUSIONS: The major arterial, venous, and lymphatic vasculature courses in or above the musculoaponeurotic layer of the nose. In the external rhinoplasty approach, dissection in the areolar tissue plane below the musculoaponeurotic layer will minimize tip edema and protect against skin necrosis by preserving the major vascular supply to the nasal tip.

Large-scale production of HIV-1 protease from Escherichia coli using selective extraction and membrane fractionation.

Human immunodeficiency virus type 1 (HIV-1) protease was expressed in Escherichia coli as a fusion protein with the N-terminal sequence of IGF-2. The protein accumulated in inclusion bodies as a 40:60 mixture of unprocessed fusion protein and processed protein. A simple purification procedure was developed that yielded 30-40 mg of active protease per liter of fermentation broth with a recovery of 30-40%. The purification process involved the selective extraction of HIV-1 protease from E. coli inclusion bodies with 50% acetic acid and fractional diafiltration to remove impurities and low-molecular-weight protease-related fragments. No chromatographic steps were employed, yet the HIV-1 protease produced by this procedure was greater than 95% pure by SDS-PAGE, reverse-phase HPLC, and N-terminal sequence analysis.

The alpha-glucosidase I inhibitor castanospermine alters endothelial cell glycosylation, prevents angiogenesis, and inhibits tumor growth.

The development of drugs that target the tumor neovasculature may hold promise in inhibiting tumor growth. Experiments in vivo with castanospermine, an inhibitor of the glucosidases that convert protein N-linked high mannose carbohydrates to complex oligosaccharides, resulted in significant inhibition of tumor growth in nude mice. Angiogenesis to basic fibroblast growth factor in castanospermine-treated C57/BL mice was similarly reduced. Endothelial cell proliferation, invasion of basement membrane, and differentiation are crucial steps during neovascularization. In vitro differentiation models using Matrigel and postconfluent cultures of endothelial cells were used to study the effects of glycosidase inhibitors on endothelial cell behavior. FACS analysis of cell surface oligosaccharides using either Concanavalin A or L-phytohemagglutinin lectins confirmed an increase in high mannose groups and a decrease in tri- and tetra antennary beta-linked galactose-N-acetylglucosamine on mannose residues of Asn-linked oligosaccharides upon drug treatment. Castanospermine and the glucosidase inhibitor N-methyldeoxynojirimycin prevented the morphological differentiation of endothelial cells in vitro. These compounds did not alter the proliferation of cultured endothelial cells or their ability to attach to various extracellular matrix molecules. However, the cells showed a reduced ability to migrate and to invade basement membrane gels in vitro and an increased tendency to form aggregates that was inhibitable by D-mannose. These studies suggest that certain cell surface oligosaccharides are required for angiogenesis and that glucosidase inhibitors that alter these structures on endothelial cells are able to inhibit tumor growth.

Estrogen mediates the pregnancy-enhanced cardiotoxicity of cocaine in the isolated perfused rat heart.

OBJECTIVE: To determine whether pregnancy enhances cocaine toxicity in the isolated perfused whole rat heart model and whether this enhanced toxicity can be simulated by pre-treatment with either estrogen or progesterone. METHODS: Hearts excised from 65 female Sprague-Dawley rats were attached to a Langendorff apparatus for measurement of left ventricular systolic pressure, heart rate, and contractility. Before excision, the animals were assigned to one of five groups: 1) nonpregnant, 2) pregnant, 3) nonpregnant pretreated with progesterone, 4) nonpregnant pretreated with estrogen, and 5) nonpregnant pretreated with estrogen and progesterone. Each group was exposed serially to the following cocaine concentrations: 5 x 10(-6), 1 x 10(-5), and 6 x 10(-5) mol/L. RESULTS: Heart rate declined at all doses of cocaine (9.2, 6.9, and 31.0%, respectively). The lowest dose of cocaine had positive inotropic effects, with a 23.2% increase in left ventricular pressure and a 15.3% increase in contractility. Exposure to the two higher doses resulted in negative inotropic effects (a 24.8% decrease in left ventricular pressure and a 39.7% decrease in contractility for the highest dose). Although pre-treatment with estrogen, alone or with progesterone, resulted in responses similar to those seen in pregnant animals, progesterone pre-treatment alone failed to do so. CONCLUSIONS: Cocaine displayed cardiotoxicity in isolated rat hearts similar to that in other animal models. This toxicity was enhanced by pregnancy. We were able to simulate changes by pretreating the animals with estrogen. Perhaps the enhanced cardiotoxicity of cocaine in pregnancy is partially mediated by estrogen.

Splanchnic insulin dynamics and secretion pulsatilities in abdominal obesity.

Insulin secretion, clearance dynamics, and their relationship to peripheral plasma insulin and glucose levels were monitored during three 12-h periods of overnight rest, intake of three meals, and continuous enteral feeding of mixed nutrients. The low-frequency ultradian and the high-frequency insulin secretion pulsatility characteristics during the steady-states of overnight rest and continuous enteral feeding were also examined. In abdominally obese subjects, the insulin secretion rate was consistently higher than normal by 2.3-fold. Peripheral plasma insulin levels were increased by 3.4-fold during the overnight period and by 4- to 5-fold during the two fed states. Endogenous insulin clearance was significantly reduced during feeding. Both low- and high-frequency insulin secretory pulsatilities were detected in the abdominally obese subjects. Pulse periods were within the normal range. Pulse maxima, nadirs, and absolute amplitudes were increased concomitant with the increase in insulin secretion. Ultradian relative pulse amplitudes, however, were blunted. A significantly higher pulse-to-pulse variability was observed in the abdominally obese subjects compared with normal subjects. Furthermore, a significantly higher level of interindividual variability in the nutrient-stimulated insulin secretion and in the ultradian pulse characteristics was observed. Thus in abdominal obesity, the increase in pancreatic insulin output is limited and the secretory pulsatilities are aberrant, suggesting a defect in the insulin secretory process. Diminished insulin clearance contributes to the degree of peripheral hyperinsulinemia compensating for the insulin resistance characteristic of this form of obesity.

Contrasting effects of two arachidonate 5-lipoxygenase inhibitors on formyl-methionyl-leucyl-phenylalanine (fMLP) and complement fragment 5a induced human neutrophil superoxide generation.

SC-45662 and SC-41661A, selective arachidonate 5-lipoxygenase (5-LO) inhibitors, had markedly different effects on formyl-methionyl-leucyl-phenylalanine (fMLP) and complement fragment 5a (C5a) induced superoxide release from human neutrophils (PMNs). SC-45662 inhibited superoxide generation induced by fMLP and C5a with IC50 values of 12 and 5 microM, respectively. Furthermore, SC-45662 was capable of inhibiting fMLP and C5a induced superoxide release in PMNs primed with bacterial lipopolysaccharide, tumor necrosis factor-alpha and other priming agents. SC-41661A, a compound from the same chemical series as SC-45662, did not inhibit or induce superoxide generation, but instead primed PMNs for fMLP and C5a induced superoxide generation. The induced superoxide release was concentration dependently enhanced 2 to 4-fold at 5-50 microM. Superoxide release induced by phorbol myristate acetate or serum-activated zymosan was unaffected by either SC-45662 or SC-41661A. The regulation of superoxide generation by these compounds, both of which have the identical oxidation-reduction pharmacophore, was clearly independent of their effects on 5-LO activity. Furthermore, the mechanism by which SC-45662 and SC-41661A alter superoxide generation did not appear to depend on inhibition of xanthine oxidase, catalase or superoxide dismutase. These new compounds provide effective tools for further investigation of the relationship of these two biochemical oxidative systems.