An improved method for thick film preparation using saponin as a lysing agent.

Thick film examination for malaria is often hampered by the presence of cellular debris obscuring parasites. This is a major problem for diagnostic laboratories that do not have a high exposure to material identification. Films that are relatively free of cellular debris, allowing easier identification of parasites are an obvious advantage. Saponin has been used by researchers to liberate malarial parasites for harvesting from infected erythrocytes. It has also been used for thick film preparations for diagnosis, but has not gained widespread acceptance, possibly due to the persistence of cellular debris inherent in the technique. In the present study the saponin method for thick film examination has been modified by the inclusion of a centrifugation step to remove cellular debris. Thick films were run in parallel with films made using the standard Fields stain technique and the original saponin. Results indicate that the modified saponin technique provides superior preparations free of cellular debris.

Bowel continence for the child with a neurogenic bowel.

For more than 10 years, the Alfred I. duPont Institute's Spinal Dysfunction Clinic in Wilmington, DE, has helped families and their children with myelomeningocele and neurogenic bowels to establish workable, acceptable, physiologically sound bowel programs. The basic bowel management program at the Alfred I. duPont Institute is described here, as is a program by which a child with a neurogenic bowel can obtain continence. The program is based on the child's developmental level, physiological abilities, and any necessary pharmacologic intervention. The program has enabled approximately 75% of its child patients over age 5 with neurogenic bowel to be continent of stool.

Direct pituitary inhibition of prolactin secretion by dopamine and noradrenaline in sheep.

The effects of dopamine, noradrenaline and 3,4-dihydroxyphenylacetic acid (DOPAC) on the release of prolactin were examined in ovariectomized ewes. Infusion of dopamine (0.5 or 1 microgram/kg per min for 2 h i.v.) reduced plasma prolactin concentrations in a dose-dependent manner, whereas DOPAC (5 or 10 micrograms/kg per min for 2 h i.v.) had no effect. In a further series of experiments, ovariectomized hypothalamopituitary disconnected ewes were given dopamine or noradrenaline (each at 0.5 or 1 microgram/kg per min for 2 h i.v.), and both amines reduced mean plasma concentrations of prolactin with similar potency in a dose-dependent manner. These effects were blocked by treatment with pimozide and prazosin respectively. During the infusion of dopamine, the peripheral plasma concentrations of DOPAC and 3,4-dihydroxyphenylethyleneglycol (DHPG) were increased (DOPAC, 22 +/- 7 (S.E.M.) to 131 +/- 11 nmol/l; DHPG, 2.9 +/- 0.3 to 6.4 +/- 0.2 nmol/l), but plasma concentrations of dopamine and noradrenaline did not change. Finally, administration of domperidone, a specific dopamine receptor antagonist that does not cross the blood-brain barrier, resulted in a sustained increase in plasma prolactin concentrations in ovariectomized ewes. We conclude that the secretion of prolactin from the pituitary gland is under dual inhibitory regulation by both dopamine and noradrenaline in the sheep.

Concentrations of dopamine and noradrenaline in hypophysial portal blood in the sheep and the rat.

The concentrations of dopamine, noradrenaline and their respective primary neuronal metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and 3,4-dihydroxyphenylethyleneglycol (DHPG) were measured in the hypophysial portal and peripheral plasma of sheep and rats by combined gas chromatography-mass spectrometry. Hypophysial portal and jugular blood samples were taken at 5- to 10-min intervals for 3-7 h from six conscious ovariectomized ewes. Blood was also collected for 30 min under urethane anaesthesia from the cut pituitary stalk from 16 pro-oestrous female and five intact male rats. In ovariectomized ewes, noradrenaline concentrations were higher in hypophysial portal plasma than in peripheral plasma (6.6 +/- 0.8 vs 2.2 +/- 0.4 nmol/l). In contrast, dopamine was undetectable (less than 1 nmol/l) in the portal and peripheral plasma of all ewes. Plasma levels of DOPAC and DHPG in portal and jugular samples were similar. In all pro-oestrous female rats, plasma concentrations of dopamine were higher in portal blood than in jugular blood (8.0 +/- 1.4 vs 4.8 +/- 0.6 nmol/l). Detectable concentrations of dopamine were measured in the portal plasma of two out of five male rats. Noradrenaline concentrations were higher in portal plasma than in peripheral plasma of both female (8.3 +/- 1.7 vs 3.7 +/- 0.6 nmol/l) and male (14.8 +/- 2.7 vs 6.1 +/- 1.2 nmol/l) rats. These data show that noradrenaline, but not dopamine, is secreted into the long portal vessels in sheep. The results suggest that there are species differences in the secretion of hypothalamic dopamine into hypophysial portal blood.

Mechanisms of 5-hydroxy-L-tryptophan-induced adrenocorticotropin release: a major role for central noradrenergic drive.

The serotonin (5-hydroxytryptamine, 5-HT) precursor 5-hydroxy-L-tryptophan (5-HTP) and 5-HT antagonists, respectively, are able to stimulate and block pituitary adrenocorticotropin (ACTH) release. However, our previous data do not support a role of central serotoninergic systems in the neural control of ACTH release. We thus examined the hypothesis that 5-HTP given either alone or with uptake-blocking drugs such as fluoxetine caused stimulation of ACTH through activation of central noradrenergic neuronal activity (NNA). The hypothesis was tested in normal adult male rats by correlating medial basal hypothalamic NNA and serotoninergic neuronal activity (SNA) with serum ACTH following administration of 5-HTP (20 and 100 mg/kg, i.p.) in the presence or absence of fluoxetine (10 mg/kg, i.p.) or cyproheptadine (10 mg/kg, i.p.). The alpha 2-adrenergic agonist clonidine (150 micrograms/kg, i.p.) was used to inhibit central NNA and to examine the role of alpha 2-adrenoceptors in the actions of serotoninergic drugs. Computerized mass spectrometry was employed to specifically and precisely assay hypothalamic norepinephrine (NE), 3,4-dihydroxyphenylethyleneglycol (DHPG), 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) to obtain indices of hypothalamic NNA (DHPG/NE) and SNA (5-HIAA/5-HT). The administration of fluoxetine/5-HTP stimulated (p less than 0.01) both hypothalamic NNA and ACTH release.(ABSTRACT TRUNCATED AT 250 WORDS)

Stimulation of the hypothalamic-pituitary-adrenal axis and inhibition of growth hormone release via increased central noradrenaline neuronal activity by urethane anaesthesia in the rat: blockade by clonidine.

Computerized gas chromatography-mass spectrometry was used to measure precisely the hypothalamic levels of noradrenaline (NA), dopamine and serotonin together with those of their major neuronal metabolites 3,4-dihydroxyphenylethyleneglycol (DHPG), 3,4-dihydroxyphenylacetic acid and 5-hydroxyindoleacetic acid in normal male rats 45 min after stimulation of hypothalamic-pituitary-adrenal function by urethane (1.3 g/kg) administration. Urethane treatment resulted in a significant elevation of central noradrenergic neuronal activity (NNA) as assessed from marked rises in hypothalamic DHPG concentrations and the ratio (DHPG/NA). At the same time there was significant stimulation of ACTH and corticosterone release and inhibition of growth hormone release. These hormonal and central effects of urethane (but not anesthesia) were inhibited when the alpha 2-agonist clonidine (150 micrograms/kg) was co-administered. Urethane had no major effect on hypothalamic dopamine or serotonin status. We propose that the release of ACTH and the suppression of growth hormone release following urethane anaesthesia is a result of activation of central NNA and suggest that the hormonal responses are mediated via hypothalamic noradrenergic facilitation of corticotrophin releasing factor and somatostatin release to the anterior pituitary.

Relationship between hypothalamic noradrenergic neuronal activity and serum 3-methoxy-4-hydroxyphenylethylene glycol in the rat.

It has been suggested that the circulating levels of 3-methoxy-4-hydroxyphenylethylene glycol (MHPG), a major end metabolite of noradrenaline (NA), may provide an index of central NA neuronal activity. The aim of this study was to examine in the rat the relationship between serum MHPG and hypothalamic NA neuronal activity during basal conditions, and when hypothalamic NA neuronal activity was stimulated or suppressed. Hypothalamic NA neuronal activity was assessed from the concentrations of the primary neuronal NA metabolite 3,4-dihydroxyphenylethyleneglycol (DHPG), MHPG, and the DHPG/NA and MHPG/NA ratios. Following 2-deoxyglucose (2DG) and cysteamine administration, hypothalamic NA neuronal activity and serum MHPG rose significantly. In contrast, hypothalamic NA neuronal activity and serum MHPG fell significantly in gentled rats. Serum MHPG correlated significantly with hypothalamic DHPG and the DHPG/NA ratio in control rats, and with hypothalamic DHPG, MHPG, and the DHPG/NA and MHPG/NA ratios in gentled, 2DG- and cysteamine-treated rats. In the latter two groups, serum MHPG also correlated significantly with serum glucose, which is itself closely related to hypothalamic NA neuronal activity. These studies demonstrate a significant relationship between serum MHPG and hypothalamic NA neuronal activity in the rat, so that serum MHPG provides an index of hypothalamic NA neuronal activity in the rat.

Dopamine-beta-hydroxylase inhibition acutely stimulates rats hypothalamic noradrenaline and dopamine neuronal activity as assessed from metabolic ratios and circulating glucose and ACTH responses.

Because central noradrenaline neuronal activity is tonically inhibited by noradrenaline (NA) itself via an action at prejunctional alpha 2-adrenoceptors, it was hypothesised that the blockade of central NA synthesis following acute dopamine-beta -hydroxylase (DBH) inhibition might primarily deplete prejunctional NA levels and result in an increase in central NA neuronal activity through reduced NA autoinhibition. This hypothesis was tested in the rat following the acute administration of the DBH inhibitors diethyldithiocarbamate (DDC) and cysteamine (CSH). Computerised gas chromatography/mass spectrometry was used to precisely measure the hypothalamic levels of NA and dopamine (DA) together with those of their primary neuronal metabolites dihydroxyphenylethyleneglycol (DHPG) and dihydroxyphenylacetic acid (DOPAC), respectively. Both DDC (at 4 h) and CSH (at 30 min.) caused approximately a 50% reduction of hypothalamic NA concentrations. However this was associated with marked and highly significant increases in hypothalamic DHPG levels (by 50-100%) and in the hypothalamic ratio DHPG/NA. Also, when measured after CSH, the hypothalamic levels of the DHPG metabolite 3-methoxy-4-hydroxyphenylethyleneglycol were highly significantly increased. Consistent with increased DA neuronal activity, both DBH inhibitors raised DA and DOPAC levels and also the ratio DOPAC/DA in the hypothalami of treated rats and markedly suppressed serum prolactin levels (all p less than 0.01). The rise in hypothalamic concentrations of DHPG indicates that an increase in hypothalamic NA neuronal activity occurs following DBH inhibition. Significant elevations of blood glucose, corticosterone and ACTH were also observed after DBH inhibition. As we have previously demonstrated that increased central NA activity is associated with elevations of blood glucose, corticosterone and ACTH, these data provide further evidence for a functional increase in central NA activity caused by acute DBH inhibition. It is proposed that the increase in hypothalamic NA activity after DBH inhibition results from a primary depletion of the prejunctional alpha 2-active autoregulatory pool of NA.

The central vs. peripheral effects of clonidine on ACTH, corticosterone and glucose release.

The role of central vs. peripheral actions of clonidine was investigated in the rat following the separate and combined administration of clonidine and 2-deoxy-D-glucose (2-DG). Clonidine or 2-DG alone stimulated serum glucose and corticosterone but hypothalamic noradrenaline neuronal activity and ACTH release were stimulated by 2-DG only. The stimulation of noradrenaline neuronal activity and ACTH by 2-DG were totally blocked by clonidine. It was concluded that the increases in serum glucose and corticosterone after clonidine administration were not mediated by central effects but that alpha 2-adrenoceptor agonism by clonidine was responsible for inhibition of hypothalamic noradrenaline neuronal activity and pituitary ACTH release.

Effects of chronic lithium, amitriptyline and mianserin on glucoregulation, corticosterone and energy balance in the rat.

Major negative side-effects reported for mood-stabilizing and antidepressant drugs in humans are excess weight gain and carbohydrate craving. The aim of the present study was to establish whether the rat could usefully be employed in investigation of these phenomena. Three experiments investigated the effects of chronic lithium (40 mg/kg LiCl), amitriptyline (2.5 mg/kg), mianserin (2.5 mg/kg) and saline administration (15-20 days, one subcutaneous injection/day) on body weight, food intake and fluid intake. Water and food cubes were provided in all experiments. Additionally available, as separate fluid sources, in Experiment 2 were 24% sucrose and 0.6% saccharin and in Experiment 3, 0.6% saccharin. Blood was collected for plasma glucose and insulin determinations 20-24 hours after the final injections. Lithium administration resulted in a marked increase in weight gain but only if both sucrose and saccharin were available (Experiment 2). Saccharin intake was increased with lithium treatment as was total caloric intake with sucrose available. Amitriptyline induced a sweetness craving; however, weight gain was somewhat depressed with just cubes available (Experiment 1) and only normalised by the additional availability of sucrose and saccharin (Experiment 2). With amitriptyline, total caloric intake was never different from controls. Weight gain was slightly suppressed and caloric intake slightly elevated by mianserin but importantly the two effects combined for a decrease in metabolic efficiency which was particularly exaggerated under the condition of carbohydrate availability (Experiment 2). Lithium and amitriptyline both produced hyperinsulinemia with normoglycemia whether or not the rate of weight gain was changed and whether or not intake was increased. Corticosterone levels were elevated by all drug treatments in Experiment 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Chlorpromazine hyperalgesia antagonizes clonidine analgesia, but enhances morphine analgesia in rats tested in a hot-water tail-flick paradigm.

Seventy-six male Sprague-Dawley rats were tested in a hot-water (55 degrees +/- 0.5 degrees C) tail-flick paradigm. Tail-flick latencies (TFL) were obtained at 30 and 15 min before intraperitoneal injection of either morphine (2.5, 5.0 and 10.0 mg/kg) clonidine (25, 50, 100 and 200 microgram/kg), chlorpromazine (CPZ, 2.5 and 5.0 mg/kg), dual injections of these drug combinations, or a saline control injection. Further TFL measures were taken immediately following drug administration and thereafter at 15 min intervals. The mean of the pre-drug TFL's served as each rat's baseline. All other TFL's were calculated as percentage changes from that baseline. Mean changes were determined for each treatment group and differences between groups, at each test time, were analysed. Our results demonstrated morphine and clonidine analgesia but CPZ hyperalgesia. The drug interaction studies revealed that morphine analgesia is enhanced by co-administration of either clinidine or CPZ but that clonidine analgesia is antagonized by chlorpromazine. These data suggest that morphine and clonidine exert their analgesic effects through different neurochemical mechanisms. It is particularly interesting that the clonidine-CPZ combination should result in TFL's similar to baseline levels, even though both drugs are sedatives. The investigation emphasizes the value of chlorpromazine as a pharmacological tool in analgesic research because of its ability to induce hyperalgesia even though it is a sedating agent.

Cervicofacial actinomycosis.

Cervicofacial actinomycosis is a disease that is currently encountered as a pseudotumor entity or cold abscess. The frequent use of antibiotics in treatment of masses in the cervicofacial region may either delay its appearance or disguise the diagnosis. The surgeon must be highly suspicious when making the diagnosis since precautions in handling the biopsy specimens are necessary. Treatment consists of incision biopsy and drainage or aspiration to establish the diagnosis, followed by prolonged penicillin therapy. In those patients allergic to penicillin, clindamycin should be the initial drug of choice. Either medication must be administered for a prolonged period of time, even after the disease is clinically controlled.