Serotonin uptake in panic disorder and agoraphobia

Because of reports of reduced serotonin uptake in depression and the frequent association between panic disorder and depression, this study was designed to assess the neurobiologic relationship between panic disorder and depression. Platelet serotonin uptake studies were done on 47 patients with panic disorder, 17 patients with primary major depression, and 15 healthy volunteers. The authors found that the rate of uptake of serotonin to platelets (Bmax) was significantly lower in both the depressed and panic disorder groups than the healthy control group. The panic disorder patients with a present or past history of major depression had slightly higher values than the panic disorder patients without such a history.

Additive hypoglycemic effects of drugs that modify free-fatty acid metabolism by different mechanisms in rats with streptozocin-induced diabetes

In this study the effect of two drugs [etomoxir and nicotinic acid (NA)] on plasma glucose, free-fatty acid (FFA), and triglyceride (TG) concentrations was determined in rats with streptozocin (STZ)-induced diabetes. The two compounds modify FFA metabolism by different mechanisms, etomoxir (ethyl-2-[6-(4-cholorophenoxyl)-hexyl]oxirane-2-carboxylate) by inhibiting hepatic fatty acid oxidation, and NA by inhibiting lipolysis in adipose tissue. Diabetes was induced in male Sprague-Dawley rats, weighing approximately 400 g, by STZ injection (30 mg/kg i.v.), and the metabolic effects of the two drugs were studied 7-10 days later. The acute administration of either etomoxir or NA lowered plasma glucose concentrations in diabetic rats by approximately 150 mg/dl (P less than .001) in 4 h. However, the two drugs differed dramatically in their effects on plasma FFA and TG concentrations. Specifically, etomoxir produced striking increases in plasma FFA and TG concentrations, whereas NA administration caused a marked decrease. However, when NA was given in conjunction with etomoxir, NA prevented the increase in plasma FFA and TG concentration seen with etomoxir; the combination of NA and etomoxir approximately doubled the decrease in plasma glucose concentration produced by NA or etomoxir when given alone. Because plasma insulin concentrations did not change in response to either drug, whether administered singly or in combination, these metabolic effects do not result from a change in insulin secretion. These results suggest that modulation of FFA metabolism at the level of the adipocyte or the liver can have dramatic effects on carbohydrate and lipid metabolism.

Comparison of lorazepam and flurazepam as hypnotic agents in chronic insomniacs

Hypnotic efficacy and safety of 3 weeks of daily doses of 2 mg lorazepam or 30 mg flurazepam were compared in a double-blind cross-over study in eight chronic insomniacs between the ages of 29 and 60 years. Subjects were monitored in the sleep laboratory twice weekly for a total of 25 nights. Also, subjective estimates of sleep, vigilance tests, and adverse effects were recorded throughout the study. Findings indicated lorazepam performed better than flurazepam in most sleep parameters. With lorazepam there was improvement from baseline in percentage of sleep time (P less than .05); in total wake time after sleep onset (P less than .01) and in last third of night (P less than .05); in percentage of stage 2 (P less than .05) (weeks 1, 2, 3) and in percentage of night in stage 4 (weeks 2 and 3). Only total wake time from baseline improved (P less than .05) with flurazepam (week 2). Objective and subjective sleep parameters did not correlate well for either drug. Neither drug impaired REM sleep or vigilance test performance. Side effects (grogginess, lethargy; flurazepam only) were few and none was unexpected; neither rebound insomnia nor early morning insomnia occurred with either drug. In summary, both lorazepam 2 mg at bedtime and flurazepam 30 mg at bedtime were found to be effective and safe for treating chronic insomnia, as measured by parameters of sleep and daytime functioning. Lorazepam had more favorable effects on sleep than did flurazepam.

Lowering of plasma glucose in diabetic rats by antilipolytic agents

Both nicotinic acid (NA) and the adenosine receptor agonist phenylisopropyladenosine (PIA) are potent antilipolytic agents. We have evaluated the ability of these compounds to lower plasma glucose concentration in 450-g male diabetic rats. Diabetes was induced by intravenous streptozotocin, and the rats were studied 7-10 days later. Mean (+/- SE) fasting glucose decreased 4 h after subcutaneous injections of PIA at 0 and 2 h. A similar change in plasma glucose level was also seen in rats injected with NA. The decrease in the concentration of plasma glucose in both instances was preceded by marked sustained reductions in plasma free fatty acid (FFA) concentrations; FFA decreased in PIA-injected rats and in response to NA. With injection of normal saline, neither plasma glucose nor FFA concentrations decreased in diabetic rats. There was no change in the plasma insulin concentration of rats that had hypoglycemic responses to PIA or NA. In vitro glucose uptake was determined in isolated adipocytes, and both PIA and NA were shown to increase basal and maximal insulin-stimulated glucose uptake. The stimulating effect of the two compounds was similar, and the magnitude of the effect was comparable in adipocytes from either normal or diabetic rats. As a result, neither NA nor PIA could restore the defects in glucose transport to normal in adipocytes from diabetic rats. Insulin-stimulated glucose uptake was assessed in vivo by determining the steady-state glucose response of diabetic rats to a continuous infusion of insulin and glucose and was found to be significantly enhanced in response to NA compared with NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)

On the Efficiency of NC Tool Path Planning for Face Milling Operations

Face milling operations are important for producing flat machined surfaces. Existing methodologies to generate NC tool path for face milling are employed everyday by manufacturing industries without considering the impact of tool path selection. A systematic study has been conducted in order to identify those critical control parameters affecting length of cut in face milling operations. Basic polygons, from triangles to heptagons, were planned using both window frame and stair case milling procedures. For each polygon, each vertex was introduced as a possible starting point for a single run in the window frame milling. The cutting orientation was further examined for stair case milling by enumerating the tool sweep angle from 0 to 180 (and 180 to 0 as well) degrees from each vertex. The results are analyzed and important conclusions are drawn noting the efficiency of the cutting process.

Stimulation and inhibition of lipolysis in isolated rat adipocytes: evidence for age-related changes in responses to forskolin and PGE1

The ability of a number of hormones to activate cellular responses in a variety of cells declines with age. The mechanisms responsible for these alterations are complex and incompletely understood. Rat adipocytes have served as an important model to study blunted responses to stimulatory hormones which function by activating cAMP accumulation. We have previously found that the blunted lipolytic response of adipocytes from older rats to the beta adrenergic receptor agonist isoproterenol appeared to be due to a lessened ability of isoproterenol to activate cAMP accumulation. Further, the blunted response to isoproterenol was apparently caused by an accentuated inhibition of lipolysis, mediated by adenosine receptors activated by endogenously released adenosine. The present studies were designed to test and extend those conclusions. We have utilized forskolin to augment the cAMP accumulation that occurs in the presence of isoproterenol. Isoproterenol-activated lipolysis was greater in adipocytes from 2 month old rats compared with those from 12 month old rats (603 +/- 32 vs 450 +/- 29 nmol/10(5) cells/hr, P less than 0.01). However, in the presence of forskolin (10(-6) M), there was no significant difference in the response to isoproterenol between the two groups (646 +/- 23 vs 615 +/- 29 nmoles/10(5) cells/hr). As we had seen previously, the adenosine receptor agonist phenylisopropyladenosine more effectively inhibited lipolysis in the adipocytes from older rats. We now also find that PGE1 more efficaciously inhibits lipolysis in the cells from older rats. These data confirm that diminished cAMP accumulation in adipocytes from older rats appears to be a rate-limiting alteration in the regulation of lipolysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of ubiquinones on spontaneous membrane hyperpolarizations in a cloned monkey kidney cell line

The effects of ubiquinones on spontaneous membrane hyperpolarizations in JTC-12 cells were examined. There were three types of spontaneous hyperpolarizations; rhythmic, sporadic and oscillatory types. The oscillatory type was not observed in the standard medium, whereas it was observed in sodium-free medium or in the medium containing 300 nM coenzyme Q10. The number of the cells showing spontaneous hyperpolarizations significantly increased in the medium containing coenzyme Q10 (47.7%) as compared to the control (18.9%). However, coenzyme Q1 (500 nM) showed no effects.

Age-related changes in rat muscle glycogen synthase activity

This study was designed to evaluate effects of aging on glycogen synthase activity in rat skeletal muscle. Total enzyme activity was shown to be significantly, (p less than .001) lower in tensor fascia latae, biceps femoris, and soleus muscle obtained from 24-month-old compared with 2-month-old rats. Similarly, values for the active form of enzyme were significantly lower, (p less than .001) in all three muscle types of 24-month-old compared with 2-month-old rats. This age-related decline in glycogen synthase activity was not due to a reduction in the affinity of the enzyme for its activator (glucose-6-phosphate) and was independent of the concentration of substrate (UDP-glucose) in the assay system. Because similar age-related changes were seen when enzyme activity was expressed per milligram of muscle protein or per gram of muscle tissue, the fall in enzyme activity was not a simple function of an age-related decline in muscle mass. Glycogen levels also were reduced significantly in tensor fascia latae, biceps femoris, and soleus of 24-month-old rats compared with 2-month-old rats, p less than .001. These results document an age-related change in a key enzyme regulating glycogen metabolism in muscle.

The gene for galactosyltransferase maps to mouse chromosome 4

The chromosomal localization of the gene for UDP-galactosyltransferase (glycoprotein 4-B-galactosyltransferase, EC 2.4.1.38) has been determined to be on mouse chromosome 4 by the use of mouse X hamster somatic cell hybrids. It has been proposed that galactosyltransferase is associated with the mouse T/t complex which has been localized to mouse chromosome 17. These results show that galactosyltransferase is not encoded within the T/t complex.

Platelet imipramine binding in patients with panic disorder and major familial depression

Platelet 3H-imipramine binding was investigated in 15 normal subjects, 17 patients with major depressive disorder and 43 patients with panic disorder, to further study the relationship between depressive and anxiety disorders. Whereas patients with major depression had a significantly lower mean Bmax value than healthy volunteers, mean Bmax values in patients with panic disorder did not differ significantly from normal controls. Furthermore, apparently normal Bmax values were observed even in those panic disorder patients who had concurrent major depression or a past history of depression. Thus, despite previous findings of an overlap between panic and depressive disorders, the present results suggest that the two syndromes may have distinct neurochemical substrates.

Suppression of free fatty acids and triglycerides in normal and hypertriglyceridemic rats by the adenosine receptor agonist phenylisopropyladenosine

Activation of adenosine receptors leads to the inhibition of lipolysis in the fat cells of several species including humans. We have examined the effects of the adenosine analog phenylisopropyladenosine (PIA) on lipolysis in vivo in intact rats. PIA suppresses markedly serum-free fatty acid (FFA) concentrations when injected s.c. (-)-PIA is more potent than (+)-PIA in suppressing FFA concentrations; also, this effect of (-)-PIA is blocked by the adenosine receptor antagonist 8-(p-sulfophenyl)theophylline. (-)-PIA also suppressed plasma triglyceride (TG) concentrations by approximately 50% in these rats. Utilizing Triton WR1339 injections, we found that the decrease in serum TG concentrations was associated with a marked fall in very low density lipoprotein secretion rate. We also examined the effects of (-)-PIA on FFA and TG concentrations in two models of hypertriglyceridemia in rats: stretozotocin-induced diabetes and sucrose feeding. Both groups had elevated FFA and TG concentrations compared with controls. An injection of (-)-PIA suppressed markedly FFA concentrations and essentially normalized the serum concentration of TG in these rats. We conclude that (-)-PIA suppresses markedly lipolysis and triglyceride secretion in control and hypertriglyceridemic rats suggesting that the activation of adenosine receptors may have major metabolic effects in vivo.

The human galactosyltransferase gene is on chromosome 9 at band p13

The structural gene for galactosyltransferase (glycoprotein 4-B-galactosyltransferase, EC 2.4.1.38) was localized to human chromosome 9 band p13 by chromosome in situ hybridization using a cloned bovine galactosyltransferase cDNA probe. This chromosomal location is at the same position to which galactose-1-phosphate uridyltransferase, an enzyme which provides the nucleotide sugar substrate (UDP-galactose) for galactosyltransferase, has been mapped.

Desensitization of adenosine receptor-mediated inhibition of lipolysis. The mechanism involves the development of enhanced cyclic adenosine monophosphate accumulation in tolerant adipocytes

Adipocytes contain adenosine receptors, termed A1 receptors, which inhibit lipolysis by decreasing adenylate cyclase activity. The inhibition of lipolysis by adenosine agonists in vivo acutely suppresses the plasma concentrations of free fatty acids (FFA) and triglycerides. We have found that infusions of the adenosine receptor agonist phenylisopropyladenosine (PIA) initially decreases plasma FFA concentrations; however, with prolonged exposure (6 d), rats become very tolerant to the effects of the drug. Adipocytes isolated from epididymal fat pads from PIA-infused rats have altered lipolytic responses. When lipolysis is stimulated with a relatively high concentration of isoproterenol (10(-7) M), PIA does not inhibit lipolysis in adipocytes from the infused animals. However, PIA inhibits isoproterenol-stimulated cyclic AMP (cAMP) accumulation in adipocytes from the infused rats although with decreased sensitivity compared with controls. The explanation for the impaired antilipolytic effect appears to be due to the fact that isoproterenol-stimulated cAMP accumulation is markedly increased in cells from infused rats. Indeed, basal lipolysis and lipolysis stimulated with lower concentrations of isoproterenol (10(-9), 10(-8) M) are effectively inhibited by PIA. cAMP accumulation is greatly increased in adipocytes from infused rats when stimulated by isoproterenol, ACTH, and forskolin. The results have some striking analogies to changes induced in nerve cells by prolonged exposure to narcotics. These data suggest that tolerance to PIA develops in adipocytes as a consequence of enhanced cAMP accumulation.

Contiguous thin multisection MR imaging by two-dimensional Fourier transform techniques

Section thickness in two-dimensional Fourier transform (FT) imaging is dependent on gradient strength and the shape of the radio-frequency pulses used to excite the nuclei. By manipulation of these parameters, it is possible to obtain 2.5-mm-thick sections in contiguous, multisection imaging. Because this method is efficient in imaging with long repetition times (TR), it effectively complements three-dimensional FT thin-section imaging techniques, which require imaging with short TRs. Fifteen double-echo, contiguous images of 0.9 X 0.9 X 2.5-mm resolution were obtained in 17.1 minutes for a TR of 2 seconds.

Identification of three new Ig lambda-like genes in man

Three new human lambda L chain-like Ig genes are identified by restriction enzyme and nucleotide sequence analysis. Two genes, 14.1 and 16.1, have intact J and C regions, and are potentially functional, with open reading frames. A third gene, 18.1, is a pseudogene. The evolutionary lineage of these genes compared to the known functional locus lambda C1-lambda C6 can be surmised from Southern blot and nucleotide homologies. This study demonstrates that the human lambda gene family is more complex than previously recognized.

Hyperpolarizing membrane potential changes in a cloned monkey kidney cell line

Electrophysiological properties of a cloned monkey kidney cell line, JTC-12, were studied. The mean resting potential and input resistance were -15.3 mV and 78 M omega, respectively. Spontaneous hyperpolarizations with increased membrane conductance were observed. Similar hyperpolarization could be elicited by mechanical and electrical stimulations. The mean reversal potential of these hyperpolarizations was -72.7 mV. Hyperpolarization could be also elicited in a chloride-free solution. These data indicate that: JTC-12 cells exhibit spontaneous and induced hyperpolarizations, and occurrence of hyperpolarization is related to an increase in membrane permeability to potassium ions.

In vivo and in vitro resistance to maximal insulin-stimulated glucose disposal in insulin deficiency

The effect of streptozotocin-induced diabetes mellitus on maximal insulin-stimulated glucose uptake in the rat was studied in isolated adipocyte, perfused hindlimb, and the intact organism. Basal glucose transport per fat cell was reduced by approximately two-thirds (P less than 0.001), being associated with a similar decrease in glucose oxidation per fat cell (P less than 0.001). There was also a significant decrease (P less than 0.001) in basal glucose uptake by perfused hindlimb of diabetic rats of approximately 40%. Furthermore, maximal insulin-stimulated glucose transport and oxidation were approximately 50% lower (P less than 0.001) in fat cells of diabetic as compared with control rats. In contrast, maximal insulin-stimulated glucose disposal by perfused hindlimbs from diabetic and control rats was similar, and this was also true of the ability of insulin to maximally stimulate glucose uptake in the intact normal and diabetic rat. These findings indicate that variation exists in the manner in which insulin-sensitive tissues respond to experimentally induced insulin deficiency and support the view that total body glucose disposal is primarily related to insulin action on muscle.

Trimipramine and maprotiline: antidepressant, anxiolytic, and cardiotoxic comparison

A 5-week placebo washout comparison of trimipramine 150 mg/day and maprotiline 150 mg/day was carried out in 15 male and 24 female patients with unipolar major affective disorder. There were no significant differences between the two groups in age, sex, weight, height, or vital signs. Both groups showed significant improvement over time, with no difference between the groups on the Severity and Improvement factors of the Clinical Global Impression scale, on the total and factor subscales of the Hamilton Depression Rating Scale, and on the Anxiety Status Inventory. The maprotiline group showed a greater increase in weight over the study period than did the trimipramine group. There was a significant lowering of systolic blood pressure in the trimipramine group only and a significant and linear increase in pulse rate by Week 3 in the maprotiline group. Analysis of ECG showed that the atrial rates were significantly increased in the maprotiline group (p less than .002) but not in the trimipramine group. Trimipramine had significantly fewer anticholinergic, neurologic, and cardiovascular adverse effects than maprotiline.

Buspirone: anxiolytic?

Sixty (60) out-patients with DSM III generalized anxiety disorder were treated after a 1-week placebo washout in a 4-week double-blind study with buspirone, diazepam and placebo; after which they were withdrawn abruptly from medication or assigned to a 2-week period of placebo. The HAM-A score was significantly lower in the diazepam group at week 2 (p less than .02) and the buspirone group at week 3 (p less than .04) as compared to the placebo group. A similar pattern was evident in the female group, but not in the male group. Dizziness was the most prominent adverse effect in the buspirone group, whereas the diazepam group had more adverse effects including sedation, fatigue, dizziness and impaired concentration. Withdrawal symptoms were more evident in the diazepam group than the buspirone group.

Age-related decrement in hormone-stimulated lipolysis

The ability of hormones to activate responses in a variety of tissues decreases with age. The mechanism(s) responsible for these alterations are unclear. We have confirmed that the ability of a beta-adrenergic receptor agonist to activate lipolysis in isolated rat adipocytes decreases with age. Maximum response to isoproterenol was greater in 2-mo-old rats (600 +/- 30 nmol of glycerol released/10(5) cells per h) than 12-mo-old rats (250 +/- 25 nmol/10(5) cells per h), P less than 0.001. Similarly, ACTH is less effective in activating lipolysis in the adipocytes from the older rats. However, the cAMP analogue 8-(4-chlorophenothio)adenosine 3',5'-monophosphate cyclic activated lipolysis equally in the two groups, suggesting that the deficit in adipocytes from the older rats was proximal to cAMP-dependent protein kinase activation. Both isoproterenol and ACTH were significantly less effective in promoting cAMP accumulation in adipocytes isolated from 12-mo-old rats. There was no difference in phosphodiesterase activity of the adipocytes between the two groups. beta-Adrenergic receptors were measured using the antagonist radioligand [125I]cyanopindolol. The number of beta-adrenergic receptors was actually increased in the adipocytes from 12-mo-old rats (26,000 +/- 2,600 receptors/cell) compared with cells from 2-mo-old rats (7,200 +/- 1,300 receptors/cell). The results suggest that diminished cAMP production is responsible for the diminished lipolytic response in the adipocytes of older rats. The mechanism responsible for this change is uncertain but cannot be explained by a loss in beta-adrenergic receptors.

Amelioration of streptozotocin-induced diabetes in the rat by exercise-training: role of muscle glycogenolytic and glycolytic enzyme activity

Streptozotocin-induced insulin deficient rats allowed to run at will had significantly (P less than 0.001) lower mean (+/- SEM) plasma glucose levels (12.1 +/- 0.9 vs 22.6 +/- 1.7 mM/l) than did equally insulin deficient sedentary rats. Muscle glycogen phosphorylase and synthase activities were similar in exercise-trained and sedentary diabetic rats, and were unchanged from control values. In contrast, muscle phosphofructokinase activity was reduced (P less than 0.001) in sedentary rats with insulin deficiency, and the defect was significantly reversed (P less than 0.01) when such rats were allowed to run spontaneously. These results are consistent with the view that the ability of exercise-training to attenuate the magnitude of hyperglycemia in streptozotocin-induced insulin deficiency is associated with an effect on a key regulatory enzyme in the glycolytic pathway.

Inhibition of lipolysis by adenosine is potentiated with age

The ability of a variety of hormones to activate cells declines with age. We have investigated the mechanism for the reduced ability of beta adrenergic stimulation to activate lipolysis in fat cells from older rats. Previously, we have found that these cells have an intact lipolytic response to a cAMP analogue but diminished cAMP accumulation after isoproterenol stimulation, suggesting that the blunted cAMP response is rate limiting. In the present study we have tested the hypothesis that enhanced inhibition of lipolysis by endogenously released adenosine accounts for the diminished lipolysis. Adenosine deaminase was added to media containing the adipocytes from older rats to remove endogenous adenosine. Under these conditions beta adrenergic stimulation of lipolysis is intact in fat cells from older rats. The adenosine analogue N6-phenylisopropyladenosine more effectively inhibited lipolysis in the older group (77 +/- 6%) than in the younger group (46 +/- 5%), suggesting that enhanced efficacy of endogenous adenosine may account for the reduced lipolytic response to catecholamines. When pertussis vaccine was used to functionally inactivate adenosine receptors in adipocytes from the younger and older rats, the ability of isoproterenol to activate lipolysis was restored in the older group. All the data are consistent with the hypothesis that enhanced inhibitory effects of adenosine explain the diminished ability of beta adrenergic agonists to activate lipolysis. It is possible that enhanced inhibitory pathways may be involved in blunting responses to stimulatory hormones in other tissues from older animals.

Magnetic resonance imaging strategies for heart studies

Given a suitable trigger signal, cardiac synchronized magnetic resonance (MR) imaging is simple to implement; however, single section techniques are not efficacious, especially when the heart rate sets the repetition interval. We demonstrate multi-section, double, and single-echo imaging, any of which rapidly covers the cardiac volume; 3-D modes capable of achieving very thin sections; and cycled multi-section imaging capable of efficaciously providing dynamic data on heart motion. These modes form a complementary, powerful set of options for clinical work.

Correlation of vascular invasion and metastasis in germ cell tumors of testis--a preliminary report

A preliminary study was conducted to correlate vascular invasion with metastasis in testicular tumors. A lectin-immunoperoxidase procedure was used to identify the vessels. Together with standard hematoxylin and eosin staining, the presence of tumor cells in vessels was detected. Primary tumor specimens from 37 cases and retroperitoneal lymph nodes from 10 cases of germ cell tumors were studied. The results showed good correlations between vascular invasion in primary tumors and metastasis to lymph nodes in nonseminomatous germ cell tumors, and between vascular invasion in retroperitoneal lymph nodes and the presence of other metastases. Eight of the 9 nonseminomatous germ cell tumor patients with vascular invasion had metastases, and all 4 patients that had vascular invasion in the lymph nodes had other metastases. However, there seemed to be no correlation between vascular invasion and clinical staging in cases with seminoma in which retroperitoneal lymph node dissection was not performed. These observations, although based on a limited number of cases, warrant more extensive investigations.

Sex difference in insulin-stimulated glucose transport in rat and human adipocytes

In an effort to determine whether differences in basal and maximum insulin-stimulated glucose transport by isolated adipocytes are a function of donor sex, we measured glucose transport rates in the absence and presence of 8 nM insulin in adipocytes isolated from the abdominal subcutaneous fat tissue of nine male and ten female subjects with varying degrees of obesity and in adipocytes isolated from the abdominal subcutaneous and retroperitoneal fat tissue of (180-220 g) male and female rats. Because maximal insulin-stimulated glucose transport rate per cell of adipocytes isolated from subcutaneous abdominal tissue of male and female subjects was constant in each sex, the data have been normalized on the basis of transport per cell. The results demonstrated that basal and maximal insulin-stimulated glucose transport per cell was 53-75% higher per cell in the females versus males in adipocytes from human subcutaneous abdominal adipose tissue (P less than 0.01). A similar difference in glucose transport rate between males and females (P less than 0.001) was also found in rat abdominal subcutaneous adipose tissue. Adipocytes isolated from rat retroperitoneal adipose tissue had higher transport rates (approximately three-fold) and smaller sex differences (35% higher in females) than found in adipocytes from rat and human subcutaneous tissue. These results indicate that basal and maximum insulin-stimulated glucose transport is higher by adipocytes isolated from females and that this difference is independent of adipose cell size and species.

Disparate effects of prazosin and propranolol on lipid metabolism in a rat model

Rats treated with high (3.0 mg/kg) or low (0.3 mg/kg) doses of prazosin had significantly lower (p less than 0.01) plasma triglyceride levels and a lower triglyceride secretion rate than control rats. Propranolol had no effect on triglyceride levels when compared with controls. There was a significant elevation of plasma cholesterol concentrations in propranolol-treated rats when compared with animals given prazosin. The ratio of high-density lipoprotein cholesterol to total cholesterol was significantly greater in prazosin-treated rats than in controls and propranolol-treated rats. Free fatty acid levels were significantly lower in the prazosin-treated group, a finding that may explain reduced very low-density lipoprotein and triglyceride secretion. These data demonstrate that the disparate effects on lipid metabolism of the alpha- and beta-receptor antagonists studied, previously shown to occur in hypertensive man, can be duplicated in the normal rat. This animal model may prove useful for the study of adrenergic mechanisms in lipid metabolism.

A continuous biological process to decolorize bleach plant effluents

Although almost every U.S. pulp mill has a biological wastewater treatment system, these systems based on bacteria, are largely ineffective in the removal of color. For this reason, we have attempted to utilize Phanerochaete chrysosporium, a fungus known to degrade lignin, as the primary organism in a novel waste treatment scheme named the MyCoR Process. Color from bleached Kraft mills originates principally from the first extraction stage of the bleach plant. It is this waste stream which is sent to the MyCoR Process reactor, a rotating biological contactor, for decolorization. We have found that under optimal conditions up to 2,000 color units/L/day can be removed from the waste stream. There is also a concomitant removal of COD and BOD. In addition, chlorolignins originating from the bleaching process were found to be dechlorinated; this is of interest to those concerned with the impact of bleach plant effluents on the environment. The process uses conventional wastewater treatment equipment. However, the use of a pure culture of fungus in a secondary metabolic state has not been attempted previously in a waste treatment scheme. Minor equipment modification and close operator attention may therefore be required. A preliminary economic analysis shows that the MyCoR Process, in its present state, would cost about US$30/metric ton of bleached Kraft pulp produced. This cost will decrease as improved or new strains of fungi are developed for the process.

Surface effects on Raman scattering from Sb deposited on Ag-island films

Surface-enhanced Raman scattering from crystal vibrational modes of a Sb film rather than from vibrational modes of individual molecules has been observed for the first time to our knowledge. A ~20x enhancement of the longitudinal-optical mode (150 cm(-1)) in the Raman spectra of crystalline Sb films deposited on silver-island films was obtained. The excitation profiles, as well as the dependence of Raman intensity on the thickness of Ag films, were studied.

Identification of 2-imidazolines as anti-sickling agents

The drugs tolazoline, clonidine, lofexidine, and fenmetozole were found to inhibit the gelation of hemoglobin S in the order of increasing effectiveness. Only the latter, however, reduced the sickling of red cells significantly and normalized the oxygen affinity of SS blood at 5-10 mM concentrations. Since this level of drug is lower than those reported for many other anti-sickling agents to achieve comparable effects, the 2-imidazoline class of compounds may provide important clues for the development of therapy for sickle cell anemia.

Disparate effects of prazosin and propranolol on lipid metabolism in a rat model

The effects of 14 days of daily intraperitoneal injections of prazosin hydrochloride (3.0 or 0.3 mg/kg) or propranolol (5 mg/kg) on various aspects of the lipid metabolism of normal rats was studied. The results indicate that plasma triglyceride and cholesterol concentrations were lower and the ratio of plasma HDL-cholesterol to total cholesterol concentration higher in prazosin-treated rats compared with propranolol-treated rats. The decline in plasma triglyceride levels in prazosin-treated rats was associated with a commensurate reduction in triglyceride secretion rates. Plasma free fatty acid levels were also lower in prazosin-treated rats, and this change may have contributed to the fall in triglyceride secretion rates. These data demonstrate that the disparate effects of alpha and beta receptor antagonists, previously shown to occur in hypertensive humans, can be duplicated in normal rats.

Comparative evaluation of fifteen anti-sickling agents

Fifteen compounds reported to be inhibitors of gelation or sickling were studied by standard methods. These tests included (1) the determination of the solubility of deoxyhemoglobin S or Csat, (2) evaluation of sickling in whole SS blood at various pO2s, (3) measurement of the oxygen affinity of hemoglobin and blood, and (4) examination of red cell indices and morphology. Among the 4 noncovalent agents tested, butylurea was the most potent inhibitor of gelation and sickling in vitro; however, relatively high concentrations were required compared to the covalent agents. In the latter group, bis-(3,5 dibromosalicyl)-fumarate, nitrogen mustard, and dimethyladipimidate were especially effective inhibitors of gelation and/or sickling. All of these compounds require further development before they can be considered for clinical use.

The existence of a highly ordered phase in fully hydrated dilauroylphosphatidylethanolamine

Dilauroylphosphatidylethanolamine dispersion forms a crystalline phase at physiological pH and temperature and in the presence of excess water. This phenomenon was observed and studied by differential scanning calorimetry, scanning densitometry and X-ray diffraction. The crystalline phase is stable at pH 5.5-9.5 and below 40 degrees C. The crystalline phase formed at pH 5.5 and pH 9.5 index according to orthorhombic cells with a = 9.41, b = 8.15, c = 46.0 and a = 9.33, b = 8.05, c = 45.8 (A), respectively. Around 43 degrees C, the crystalline phase is transformed into a multilayer liquid crystal phase. Cooling from 44 degrees C results in the disappearance of the original transition at 43 degrees C and the appearance of a second transition at around 30 degrees C. Below 30 degrees C the lipid forms a gel phase. This gel phase is metastable at pH 5.5 and a crystalline phase may be recovered from it by dispersing or aging methods. Suspensions of dilauroylphosphatidylethanolamine show similar phase transition behaviour at pH 5.5 and pH 9.5, although the transitions are somewhat broader at the higher pH. The thermotropic phase behaviour of dilauroylphosphatidylethanolamine dispersions may be governed by changes in hydration.

Effect of exercise training and sucrose feeding on insulin-stimulated glucose uptake in rats with streptozotocin-induced insulin-deficient diabetes

The effect of exercise training and a sucrose-rich diet on insulin-stimulated glucose disposal was studied in rats with streptozotocin-induced insulin deficiency. Rats were injected with streptozotocin (40 mg/kg), and 3 days later divided into three groups with equal degrees of hyperglycemia. One group of rats was allowed to run spontaneously on exercise wheels, another group remained sedentary but ate a sucrose-rich diet (66% sucrose), and the third also remained sedentary but consumed conventional rat chow. Three weeks later, we determined the effect of these various programs on postabsorptive plasma glucose and insulin levels, as well as on the ability of exogenous insulin to stimulate disposal of a glucose load during a period in which endogenous insulin was suppressed by epinephrine and propanolol. Basal plasma insulin levels were the same in all three groups, but plasma glucose levels were significantly lower (P less than 0.001) in exercise-trained rats, and significantly higher (P less than 0.05) in sucrose-fed rats, than in chow-fed diabetic rats. The inference that exercise training markedly enhanced insulin action in rats with insulin deficiency was borne out by direct estimation of insulin-stimulated glucose disposal. In contrast, sucrose-fed diabetic rats seemed to be more insulin-resistant than chow-fed diabetic rats. These results provide direct evidence that spontaneous exercise can dramatically attenuate the severity of diabetes in insulin-deficient rats by enhancing insulin action. DIABETES 32:165-168, February 1983.

Effect of exercise and diet on triglyceride metabolism in rats with moderate insulin deficiency

The ability of exercise and diet to modify the effects of moderate streptozotocin-induced insulin deficiency on triglyceride metabolism has been studied in the rat. Insulin-deficient rats allowed to run spontaneously in exercise wheel cages had significantly lower (P less than 0.001) plasma glucose levels (187 +/- 19 mg/dl) than either sedentary (374 +/- 24 mg/dl) or sucrose-fed (450 +/- 13 mg/dl) diabetic rats, despite the fact that plasma insulin levels were comparable in all these groups. Plasma triglyceride (TG) levels in exercise-trained rats with diabetes (51 +/- 5 mg/dl) were actually lower than in control rats with normal glucose tolerance (90 +/- 14 mg/dl). In contrast, plasma TG levels were higher than control levels in diabetic sedentary rats (128 +/- 11 mg/dl), and severe hypertriglyceridemia developed in sucrose-fed diabetic rats (369 +/- 35 mg/dl). The ability of exercise training to attenuate diabetic hypertriglyceridemia, which was observed in both chow-fed and sucrose-fed rats, was secondary to a decrease in TG secretion, and appeared to be related to lower plasma FFA concentrations. In contrast, the accentuation of diabetic hypertriglyceridemia seen in sucrose-fed rats was related to a defect in TG catabolism. Adipose tissue lipoprotein lipase (LPL) activities were essentially identical in all diabetic rats, suggesting that the observed difference in TG kinetics could not be attributed to concomitant increases or decreases in adipose tissue LPL activity. These results emphasize the powerful impact of exercise and diet on TG metabolism in rats with moderate degrees of insulin deficiency.

SC erythrocytes have an abnormally high intracellular hemoglobin concentration. Pathophysiological consequences

We have examined 20 SC patients on Percoll-Stractan continuous density gradients and find that they have an elevated mean corpuscular hemoglobin concentration (MCHC). Reduction of the MCHC to normal values results in amelioration of four physiologically important blood abnormalities: decreased oxygen affinity, viscosity of deoxygenated erythrocyte suspensions, rate of sickling, and deoxygenation induced K+ efflux. These observations suggest that the rehydration of SC cells to normal values should be considered a potential approach in the therapeutic manipulation of this disease.

Cholinephosphotransferase activities in microsomes and neuronal nuclei isolated from immature rabbit cerebral cortex: the use of endogenously generated diacylglycerols as substrate

A neuronal nuclear fraction (N1) and a microsomal fraction (P3) were isolated from homogenates of cerebral cortices of 15-day-old rabbits. A nuclear envelope fraction (E) was prepared from N1. To assay cholinephosphotransferase, diacylglycerols were first generated in the membranes of these subfractions using a phospholipase C (Bacillus cereus) preincubation. With levels of endogenous diacylglycerols producing maximal specific cholinephosphotransferase activities, an activity ratio of 1:1:5 was found for N1, P3, and E, respectively. An independent neuronal nuclear cholinephosphotransferase, concentrated in nuclear membranes, is indicated. With regard to changes in pH and concentrations of MgCl2 and CDP-choline, N1 and P3 activities responded in a similar manner. However, in contrast to P3, N1 activities we much more profoundly inhibited at low levels of Triton X-100 (0.01-0.02 w/v%) and N1 showed quite significant levels of cholinephosphotransferase activity in the absence of a phospholipase C preincubation. Choline phosphotransferase in N1 and P3 showed Km values for CDP-choline (0.028 and 0.031 mM, respectively) which were much lower than corresponding literature values determined using exogenous diacylglycerols as substrates for this enzyme. The presence of cholinephosphotransferase in neuronal nuclear membranes reflects a rather exceptional nuclear autonomy. This may be related to a need to maintain nuclear phospholipid in the absence of a well-developed endoplasmic reticulum at early stages of neuronal development or to synthesize phospholipid in response to functions unique to the nucleus.

Benzodiazepine withdrawal effects

1. Twenty-nine patients with anxiety neurosis who had completed a one week placebo, three week active drug study on either halazepam or oxazepam were observed for eight weeks for withdrawal effects. Half of the patients received a placebo for the first two weeks of the withdrawal study and half had all medication abruptly stopped. 2. There was no significant difference in the pattern of withdrawal between halazepam, an intermediate range benzodiazepine, and oxazepam, a short acting benzodiazepine. 3. Withdrawal symptoms were apparent, maximally between week 1 and 2 together with possible rebound effects. 4. Patients who received placebo had significantly less severe withdrawal symptoms than those who had their medication abruptly discontinued.