Effect of sodium molybdate supplementation on high concentrations of Cu in liver of yearling bulls.

AIM: To determine the impact of sodium molybdate treatment, given weekly, on concentrations of Cu in liver, activity of liver enzymes, and weight gain over 4 weeks, in yearling bulls with elevated concentrations of Cu in liver. METHODS: The study was carried on two commercial grazing farms in the Otago region of New Zealand in yearling Friesian bulls (n=150 on Farm A and n=49 on Farm B) with mean concentration of Cu in liver >3,000 µmol/kg fresh weight. On Day 0, all animals were weighed and half were systematically allocated to treatment with sodium molybdate (3 mg/kg liveweight on Farm A and 7 mg/kg liveweight on Farm B); the remainder received no treatment (Control). Sodium molybdate was given as a drench weekly for 4 weeks and all animals were weighed again on Day 28. Ten animals on each farm (five from each treatment group) were systematically selected for blood sampling and liver biopsies on Days 0 and 28. Samples were analysed for concentrations of Cu in plasma, vitamin B12 in serum, activities of γ-glutamyl transferase, aspartate aminotransferase and glutamate dehydrogenase in serum, and concentrations of Cu and vitamin B12 in liver. Separate multivariable linear models were used to compare the change in outcome variables between Days 0 and 28 between bulls that had been drenched with sodium molybdate or not. RESULTS: On Farm A, mean concentrations of Cu in liver on Day 28, as a percentage of concentrations on Day 0, for the control group was 55 (95% CI=40-73)% and for the treatment group was 73 (95% CI=43-111)%. On Farm B, the equivalent mean for the control group was 75 (95% CI=42-131)% and for the treatment group was 85 (95% CI=38-134)%. The multivariable linear models indicated that the changes in concentrations of Cu in liver, activities of liver enzymes and weight gain between Days 0 and 28 did not differ between the bulls treated or not with sodium molybdate (p>0.18). CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with sodium molybdate in one bolus at weekly intervals for 4 weeks did not affect concentrations of Cu in liver, activity of liver enzymes or weight gain in animals with high concentrations of Cu liver on two farms.

Pyoderma gangrenosum: a report of a rare complication after knee arthroplasty requiring muscle flap cover supplemented by negative pressure therapy and hyperbaric oxygen.

Pyoderma gangrenosum (PG) is rare ulcerating skin condition easily confused with wound infection following surgery. We report a complicated case of PG following knee arthroplasty where delayed diagnosis and repeated debridements lead to significant tissue loss. Successful reconstruction was achieved with a muscle flap, but subsequent reactivation of PG and superadded infection placed both the reconstruction and patient's life at risk. Prolonged combined use of negative pressure therapy (NPT), immunosuppression and hyperbaric oxygen (HBO) was successfully used to reduce the wound size, enhance wound granulation, promote re-epithelialisation, and provide pain relief. There is little or no published literature on these treatment modalities for the management of PG, with only one reported case using both NPT and HBO for PG (not following knee arthroplasty). More studies are necessary to determine the role of both modalities in the management of pathergy in large and complex wounds and the rare nature of this complication following knee arthroplasty explains the lack of evidence-based guidance. In conclusion, we suggest a surgical algorithm. This is the first report of PG following knee arthroplasty with the use of both NPT and HBO in order to achieve soft tissue coverage.

The use of a fine-gauge needle to reduce pain in open carpal tunnel decompression: a randomized controlled trial.

This randomized controlled study on 86 patients compared the level of pain experienced by patients on instillation of local anaesthetic into the palm with a 23-gauge and a 27-gauge (dental) needle in open carpal tunnel decompression. Patients were asked to score the amount of pain they experienced during the injection of the local anaesthetic and their level of anxiety about future injections using a visual analogue scale (VAS) and a four-point verbal response scale (VRS). The mean pain and anxiety scores on the VAS were significantly lower in the dental needle group. There was significant correlation between the pain and anxiety VAS scores. When infiltrating local anaesthetic into the palm for open carpal tunnel decompression, the use of a fine (dental) needle can reduce the pain on that occasion and the anxiety concerning future injections likely to be experienced by the patient.

Randomized trial of buffered versus plain lidocaine for local anaesthesia in open carpal tunnel decompression.

We performed a randomized double-blind case-control study in 64 consecutive patients undergoing open carpal tunnel decompression under local anaesthetic to assess the pain experienced on injection of plain lidocaine (pH 6.4) compared with lidocaine buffered with sodium bicarbonate (pH 7.4). The results showed no statistical difference in the pain scores reported by patients. The mean pain scores for all patients were low, and most patients reported that they were "not at all anxious" about receiving a similar injection in the future.

Basic organization of projections from the oval and fusiform nuclei of the bed nuclei of the stria terminalis in adult rat brain.

The organization of axonal projections from the oval and fusiform nuclei of the bed nuclei of the stria terminalis (BST) was characterized with the Phaseolus vulgaris-leucoagglutinin (PHAL) anterograde tracing method in adult male rats. Within the BST, the oval nucleus (BSTov) projects very densely to the fusiform nucleus (BSTfu) and also innervates the caudal anterolateral area, anterodorsal area, rhomboid nucleus, and subcommissural zone. Outside the BST, its heaviest inputs are to the caudal substantia innominata and adjacent central amygdalar nucleus, retrorubral area, and lateral parabrachial nucleus. It generates moderate inputs to the caudal nucleus accumbens, parasubthalamic nucleus, and medial and ventrolateral divisions of the periaqueductal gray, and it sends a light input to the anterior parvicellular part of the hypothalamic paraventricular nucleus and nucleus of the solitary tract. The BSTfu displays a much more complex projection pattern. Within the BST, it densely innervates the anterodorsal area, dorsomedial nucleus, and caudal anterolateral area, and it moderately innervates the BSTov, subcommissural zone, and rhomboid nucleus. Outside the BST, the BSTfu provides dense inputs to the nucleus accumbens, caudal substantia innominata and central amygdalar nucleus, thalamic paraventricular nucleus, hypothalamic paraventricular and periventricular nuclei, hypothalamic dorsomedial nucleus, perifornical lateral hypothalamic area, and lateral tegmental nucleus. Moderately dense inputs are found in the parastrial, tuberal, dorsal raphé, and parabrachial nuclei and in the retrorubral area, ventrolateral division of the periaqueductal gray, and pontine central gray. Light projections end in the olfactory tubercle, lateral septal nucleus, posterior basolateral amygdalar nucleus, supramammillary nucleus, and nucleus of the solitary tract. These and other results suggest that the BSTov and BSTfu are basal telencephalic parts of a circuit that coordinates autonomic, neuroendocrine, and ingestive behavioral responses during stress.

Indocyanine green enhanced transpupillary thermotherapy of circumscribed choroidal haemangioma.

PURPOSE: To investigate the effect of indocyanine green in enhancing the effect of diode laser for treatment of circumscribed choroidal haemangioma. METHODS: Intravenous indocyanine green was used to enhance uptake of heat energy during transpupillary diode thermotherapy of circumscribed choroidal haemangioma. RESULTS: In a series of 6 patients treated in this manner, response to treatment was much improved compared with results without the use of indocyanine green. All patients retained the same or better visual acuity after treatment, and 67% of eyes improved visual acuity by more than 2 lines on Snellen testing. Ultrasonographic and angiographic evidence of improvement was seen in all patients. Treatment complications were minimal, comprising transient worsening of preexisting cystoid macular oedema in one case, and a small macular branch vein occlusion in the retina overlying the treated area. CONCLUSIONS: The use of indocyanine green as a contrast medium during transpupillary thermotherapy allows consistent uptake of diode laser energy, and shortens the duration of laser burn required. It is a cost-effective, easily performed outpatient procedure, with lower morbidity than other treatment modalities.

Binding properties of the stilbene disulfonate sites on human erythrocyte AE1: kinetic, thermodynamic, and solid state deuterium NMR analyses.

A novel stilbene disulfonate, 4-trimethylammonium-4'-isothiocyanostilbene-2,2'-disulfonic acid (TIDS), has been chemically synthesized, and the interaction of this probe with human erythrocyte anion exchanger (AE1) was characterized. Covalent labeling of intact erythrocytes by [N(+)((14)CH(3))(3)]TIDS revealed that specific modification of AE1 was achieved only after removal of other ligand binding sites by external trypsinization. Following proteolysis, (1.2 +/- 0.4) x 10(6) TIDS binding sites per erythrocyte could be blocked by prior treatment with 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), a highly specific inhibitor of AE1. Inhibition of sulfate equilibrium exchange by TIDS in whole cells was described by a Hill coefficient of 1.10 +/- 0.06, which reduced to 0.51 +/- 0.01 following external trypsinization. The negative cooperativity of TIDS binding following external trypsinization suggests that trypsin-sensitive proteins modulate allosteric coupling between AE1 monomers. Thermodynamic analysis revealed that TIDS binding induces smaller conformational changes in AE1 than is observed following DIDS binding. The similar inhibitory potencies of both TIDS (IC(50) = 0.71 +/- 0.48 microM) and DIDS (IC(50) = 0.2 microM) imply that there is no correlation between the ability of stilbene disulfonates to arrest anion exchange function and the magnitude of ligand-induced conformational changes in AE1. Solid state (2)H NMR analysis of a [N(+)(CD(3))(3)]TIDS-AE1 complex in both unoriented and macroscopically oriented membranes revealed that large amplitude "wobbling" motions describe ligand dynamics. The data are consistent with a model where TIDS bound to AE1 is located exofacially in contact with the bulk aqueous phase.

The provision of services for rural youth with serious emotional and behavioral problems: Virginia's Comprehensive Services Act.

The problems of the delivery of mental health and social services to rural children and adolescents encapsulate many of the problems in the larger health care system. Consequently, many of the principles underlying the President's Health Security Plan are applicable to the reformation of this more specialized service system. The experience of the Commonwealth of Virginia in implementing the Comprehensive Services Act (CSA) highlights the scope of vision needed to transform an existing service delivery system into a coordinated system of care on a state-wide scale.

Physiological regulation of peptide messenger RNA colocalization in rat hypothalamic paraventricular medial parvicellular neurons.

In the present study, we used subcutaneous polyethylene glycol injections to show that a physiologically relevant stimulus, hypovolemia, will selectively increase the expression of neuropeptide genes in a restricted population of parvicellular corticotropin-releasing hormone-containing neurons in the hypothalamic paraventricular nucleus. Our results show that a large reduction in extracellular fluid maintained over approximately 20 hours is associated with a significant increase in the level of corticotropin-releasing hormone mRNA in the medial parvicellular division of the paraventricular nucleus. Additionally, there are concomitant increases in cellular levels of both neurotensin/neuromedin N and proenkephalin mRNAs. Our colocalization results show that the increases in neurotensin/neuromedin N and proenkephalin mRNAs after polyethylene glycol injection occur to a significant degree in cells that also contain corticotropin-releasing hormone mRNA. Furthermore, significant numbers of cells containing proenkephalin mRNA also contain neurotensin/neuromedin N mRNA, raising the possibility that some neurons have increased levels of all three mRNAs. Finally, in the medial parvicellular division of the paraventricular nucleus, the number of identified corticotropin-releasing hormone neurons also containing vasopressin mRNA is very low in control animals and is not increased by polyethylene glycol injections, suggesting that, within this period, activation of the vasopressin gene may not be a critical event in the neuroendocrine response of corticotropin-releasing hormone neurosecretory neurons to extracellular dehydration. Considered together with the effects of adrenalectomy on peptide colocalization, our results suggest the existence of several phenotypically distinct sets of neurons within the medial parvicellular division of the paraventricular nucleus, each characterized by its ability to regulate the expression of neuropeptide genes in a stimulus-specific manner.

Incorporation of fatty acids by concanavalin A-stimulated lymphocytes and the effect on fatty acid composition and membrane fluidity.

The fatty acid compositions of the neutral lipid and phospholipid fractions of rat lymph node lymphocytes were characterized. Stimulation of rat lymphocytes with the T-cell mitogen concanavalin A resulted in significant changes in the fatty acid composition of both neutral lipids and phospholipids (a decrease in the proportions of stearic, linoleic and arachidonic acids and an increase in the proportion of oleic acid). Membrane fluidity was measured using nitroxide spin-label e.s.r., and increased during culture with concanavalin A. Culturing the lymphocytes in the absence of mitogen did not affect fatty acid composition or membrane fluidity. The uptake and fate of palmitic, oleic, linoleic and arachidonic acids were studied in detail; there was a time-dependent incorporation of each fatty acid into all lipid classes but each fatty acid had a characteristic fate. Palmitic and arachidonic acids were incorporated principally into phospholipids whereas oleic and linoleic acids were incorporated in similar proportions into phospholipids and triacylglycerols. Oleic acid was incorporated mainly into phosphatidylcholine, palmitic and linoleic acids were incorporated equally into phosphatidylcholine and phosphatidylethanolamine, and arachidonic acid was incorporated mainly into phosphatidylethanolamine. Supplementation of the culture medium with particular fatty acids (myristic, palmitic, stearic, oleic, linoleic, alpha-linolenic, arachidonic, eicosapentaenoic or docosahexaenoic acid) led to enrichment of that fatty acid in both neutral lipids and phospholipids. This generated lymphocytes with phospholipids differing in saturated/unsaturated fatty acid ratio, degree of polyunsaturation, index of unsaturation and n - 6/n - 3 ratio. This method allowed the introduction into lymphocyte phospholipids of fatty acids not normally present (e.g. alpha-linolenic) or usually present in low proportions (eicosapentaenoic and docosahexaenoic). These three n - 3 polyunsaturated fatty acids replaced arachidonic acid in lymphocyte phospholipids. Fatty acid incorporation led to an alteration in lymphocyte membrane fluidity: palmitic and stearic acids decreased fluidity whereas the unsaturated fatty acids increased fluidity. It is proposed that the changes in lymphocyte phospholipid fatty acid composition and membrane fluidity brought about by culture in the presence of polyunsaturated fatty acids are responsible for the inhibition of lymphocyte functions caused by these fatty acids.

Effect of bacteriorhodopsin on the orientation of the headgroup of 1,2-dimyristoyl-sn-glycero-3-phosphocholine in bilayers: a 31P- and 2H-NMR study.

Bacteriorhodopsin (BR), purified from the halophilic bacterium, Halobacterium halobium, has been separated from the endogenous purple membrane lipids and reconstituted by detergent dialysis into bilayers of the zwitterionic phospholipid, 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), which was selectively deuterated at the headgroup in the choline alpha- and beta-methylene segments and the choline gamma-methyl groups. Complexes of DMPC/BR contents from 67:1 to 222:1 (mol/mol) were produced under conditions to promote formation of large vesicles (mean diameters 600-700 nm). The magnitudes of the 2H-NMR quadrupole splittings recorded from the deuterium-labelled headgroup segments, and the 31P-NMR chemical shift anisotropy (CSA) of the phosphate group appeared to vary linearly with the BR content in the complexes over the range of DMPC/BR ratios studied. On increasing the proportion of BR in the DMPC-BR complexes, the 2H-NMR quadrupole splittings measured from the choline gamma-methyl groups and the beta-methylene segments and the 31P-NMR CSA increased in magnitude, while the 2H-NMR quadrupole splitting from the alpha-methylene segment decreased. Such opposing changes in the choline alpha- and beta-methylene segment quadrupole splittings are similar to those reported on increasing the proportion of positively charged amphiphile at the bilayer surface (Seelig et al. (1987) Biochemistry 26, 7535-7541). It is suggested that BR presents a net positive charge to the phosphocholine headgroups at the protein/lipid interface.

Reversible unfolding of cytochrome c upon interaction with cardiolipin bilayers. 2. Evidence from phosphorus-31 NMR measurements.

31P NMR measurements were conducted to determine the structural and chemical environment of beef heart cardiolipin when bound to cytochrome c. 31P NMR line shapes infer that the majority of lipid remains in the bilayer state and that the average conformation of the lipid phosphate is not greatly affected by binding to the protein. An analysis of the spin-lattice (T1) relaxation times of hydrated cardiolipin as a function of temperature describes a T1 minimum at around 25 degrees C which leads to a correlation time for the phosphates in the lipid headgroup of 0.71 ns. The relaxation behavior of the protein-lipid complex was markedly different, showing a pronounced enhancement in the phosphorus spin-lattice relaxation rate. This effect of the protein increased progressively with increasing temperature, giving no indication of a minimum in T1 up to 75 degrees C. The enhancement in lipid phosphorus T1 relaxation was observed with protein in both oxidation states, being somewhat less marked for the reduced form. The characteristics of the T1 effects and the influence of the protein on other relaxation processes determined for the lipid phosphorus (spin-spin relaxation and longitudinal relaxation in the rotating frame) point to a strong paramagnetic interaction from the protein. A comparison with the relaxation behavior of samples spinning at the "magic angle" was also consistent with this mechanism. The results suggest that cytochrome c reversibly denatures on complexation with cardiolipin bilayers, such that the electronic ground state prevailing in the native structure of both oxidized and reduced protein can convert to high-spin states with greater magnetic susceptibility.

The effects of knife cuts in the sub-paraventricular zone of the female rat hypothalamus on oestrogen-induced diurnal surges of plasma prolactin and LH, and circadian wheel-running activity.

To investigate the role of suprachiasmatic efferent connections in the expression of diurnal hormone rhythms, the efferent pathway from the suprachiasmatic nucleus (the putative circadian generator in the rat) to the subparaventricular zone (the main terminal area of suprachiasmatic efferents) was disrupted using bilateral horizontal knife cuts in ovariectomized oestrogen-treated rats. The position of the knife cut was assessed by observing its effect on vasoactive intestinal polypeptide immunoreactivity (a marker for suprachiasmatic efferents into the sub-paraventricular zone). The size of both the diurnal plasma LH and prolactin surges was markedly and consistently reduced over the 3-week period following the lesion in animals with a total deafferentation of the subparaventricular zone, compared with sham-operated animals or lesioned animals with an intact subparaventricular zone. When lesioned animals were grouped according to the presence or absence of damage to the preoptic area, no significant differences were found in the sizes of the plasma hormone surges. When similar knife cuts were given to animals whose activity cycles were observed, no significant effects were noted in the ability of the animals to synchronize to a light/dark regime or to free-run in constant light conditions. These results suggest that the suprachiasmatic nucleus influences the diurnal surges of plasma LH and prolactin in oestrogen-treated ovariectomized rats, initially by an interaction with the subparaventricular zone and not by a direct influence on gonadotrophin-releasing hormone neurones or other more rostral structures.

Congo red birefringent structures in the hypothalamus in senile dementia of the Alzheimer type.

Serial cryostat sections of hypothalamus from four cases of Alzheimer-type dementia and four controls were stained with Congo red and examined for birefringence. Green birefringence and dichroism was associated with (a) neurofibrillary tangles, which were most numerous at the level of the tuberomammillary nucleus where they were found in large acetylcholinesterase-positive neurons; (b) neuropil processes within tangle fields; (c) a few plaque cores in the mammillary body; (d) spicules at the ependyma of the third ventricle, and (e) blood vessels. Birefringence (e) had different properties from (a) to (d) and was considered to be due to collagen. The ependymal spicules did not react with an antibody which recognized the tangles and neuropil processes. Each Alzheimer case had many more tangles than the control cases. Birefringence in (b)-(d) tended to be greater in the Alzheimer than in the control cases. This study confirms previous reports of large numbers of tangles in circumscribed areas of caudal hypothalamus in Alzheimer-type dementia and demonstrates that Congo red staining reveals abnormalities in hypothalamic structures (neuropil processes and ependyma) not demonstrated by other staining techniques.

Gonadal steroids influence neurophysin II distribution in the forebrain of normal and mutant mice.

The distribution of arginine vasopressin-associated neurophysin (neurophysin II) immunoreactivity was investigated in normal and mutant house mice during development and after various gonadal steroid manipulations. During postnatal development of normal mice dense networks of neurophysin II immunoreactivity in the lateral septal nucleus and lateral habenular nucleus appeared earlier in male than in female mice, with an adult pattern of immunoreactivity being attained by 8 weeks and 12 weeks of age, respectively. The neurophysin II immunoreactivity in the male was denser than that in female mice. After gonadectomy of adult normal mice there was a gradual loss of neurophysin II immunoreactivity in the lateral septum and lateral habenula over a period of 15 weeks. In hypogonadal mice, a mutant in which gonadal development is arrested postnatally due to a deficiency in hypothalamic gonadotrophin releasing hormone, no immunoreactive neurophysin II could be detected in the lateral septum or lateral habenula. A pattern of neurophysin II immunoreactivity similar to that in normal control mice was observed in hypogonadal mice which had been implanted for 4 weeks with silicone elastomer capsules containing testosterone or oestradiol-17 beta, but not 5 alpha-dihydrotestosterone or progesterone. Stimulation of gonadal development and endogenous steroid production in hypogonadal mice by third ventricular grafts of preoptic area tissue from normal neonatal animals also produced a normal pattern of neurophysin II immunoreactivity in the lateral septum and lateral habenula. In the androgen-insensitive testicular feminized mouse immunoreactive neurophysin II was undetectable in the lateral septum and lateral habenula. Treatment of testicular feminized mice with oestradiol-17 beta, but not progesterone, produced a normal pattern of neurophysin II immunoreactivity. The main immunohistological findings were confirmed by radioimmunoassay of tissue extracts which showed that the concentration of arginine vasopressin in lateral septum was far greater in normal males than females and was undetectable in hypogonadal mice; no oxytocin could be detected in the septum of normal or hypogonadal mice. These results show that the expression of neurophysin II immunoreactivity in the lateral septum and lateral habenula of the mouse brain is dependent on the presence of aromatizeable androgens or oestrogens.

A deuterium and phosphorus-31 nuclear magnetic resonance study of the interaction of melittin with dimyristoylphosphatidylcholine bilayers and the effects of contaminating phospholipase A2.

The interaction of bee venom melittin with dimyristolphosphatidylcholine (DMPC) selectively deuteriated in the choline head group has been studied by deuterium and phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy. The action of residual phospholipase A2 in melittin samples resulted in mixtures of DMPC and its hydrolytic products that underwent reversible transitions at temperatures between 30 and 35 degrees C from extended bilayers to micellar particles which gave narrow single-line deuterium and phosphorus-31 NMR spectra. Similar transitions were observed in DMPC-myristoyllysophosphatidylcholine (lysoPC)-myristic acid mixtures containing melittin but not in melittin-free mixtures, indicating that melittin is able to stabilize extended bilayers containing DMPC and its hydrolytic products in the liquid-crystalline phase. Melittin, free of phospholipase A2 activity, and at 3-5 mol% relative to DMPC, induced reversible transitions between extended bilayers and micellar particles on passing through the liquid-crystalline to gel phase transition temperature of the lipid, effects similar to those observed in melittin-acyl chain deuterated dipalmitoylphosphatidylcholine (DPPC) mixtures [Dufourc, E. J., Smith, I. C. P., & Dufourcq, J. (1986) Biochemistry 25, 6448-6455]. LysoPC at concentrations of 20 mol% or greater relative to DMPC induced transitions between extended bilayers and micellar particles with characteristics similar to those induced by melittin. It is proposed that these melittin- and lysoPC-induced transitions share similar mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein-lipid interactions at membrane surfaces: a deuterium and phosphorus nuclear magnetic resonance study of the interaction between bovine rhodopsin and the bilayer head groups of dimyristoylphosphatidylcholine.

Rhodopsin, isolated from bovine retinal rod outer segment disk membranes, has been reconstituted into bilayers of 1,2-dimyristoyl-sn-glycero-3-phosphocholine which was deuterated in the terminal methyl groups of the choline polar head group. By use of a mixed detergent system of cholate and octyl glucoside to solubilize the phospholipid and rhodopsin, 15 membrane complexes of predetermined phospholipid to rhodopsin mole ratios of between 350:1 and 65:1 have been produced by exhaustive dialysis and studied by a variety of techniques. Electron micrographs of replicas from freeze-fractured membrane complexes showed that the majority of the lipid, for all rhodopsin:phospholipid ratios, was contained in large bilayer vesicles with diameters in excess of 400 nm. Complexes produced with rhodopsin from frozen retina produced an absorption maximum at 478 nm after photobleaching whereas rhodopsin from fresh retina could be bleached more completely to an absorption maximum at 380 nm. Deuterium nuclear magnetic resonance (NMR) spectra from the lipid head groups of bilayers above the gel to liquid-crystalline phase transition temperature were shown to be sensitive in a systematic way to the presence of rhodopsin which could be bleached to 380 nm. The measured quadrupole splittings, taken as the separation of the turning points of the recorded NMR spectra, decreased from a value of 1.28 kHz for protein-free bilayers to approximately 0.40 kHz for bilayers containing 65 molecules of phospholipid for each rhodopsin at 32 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

A glycophospholipid tail at the carboxyl terminus of the Thy-1 glycoprotein of neurons and thymocytes.

Cell surface molecules of eukaryotic cells have been considered to be integrated into the membrane bilayer by a transmembrane protein sequence. The Thy-1 antigen of rodent thymocytes and brain was the first eukaryotic membrane molecule for which biochemical data clearly suggested membrane integration via a nonprotein tail. Direct evidence is now presented showing that a glycophospholipid structure is attached to the carboxyl-terminal cysteine residue and that 31 carboxyl-terminal amino acids predicted from the Thy-1 complementary DNA sequence are not present in the mature glycoprotein. These experimental results raise questions concerning signaling across a cell membrane since antibodies to Thy-1 can stimulate T lymphocytes to release lymphokines and undergo cell division.

Changes in catecholamine concentrations in the hypothalamus and region of the midbrain raphe in male and female rats during postnatal development.

To investigate possible sex differences in central catecholaminergic systems, the concentrations of dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were measured by high-performance liquid chromatography with electrochemical detection in the hypothalamus-preoptic area (H-POA) and midbrain raphe (MR) region of male and female rats throughout postnatal development. Other than a small but significant sex difference in DA concentration in the MR at 36 h (higher in females), the results showed that there were no sex differences in the concentrations of DA or DOPAC at any age in either brain region. The developmental profiles of the concentrations of DA and DOPAC showed that DAergic systems in the H-POA are immature at birth, with concentrations increasing steadily until 80 days of age, but in the MR concentrations reach a maximum at 20 days of age; a situation which is perhaps a reflection of differing monoamine metabolism in the two areas.

Effects of 5-hydroxytryptamine uptake blockers on the concentration in brain of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid in male rats, pro-oestrous rats and ovariectomized rats treated with oestrogen and progesterone.

The aim of this study was to determine the effect of 5-hydroxytryptamine (5-HT) uptake blockade on 5-HT turnover by measuring the concentrations of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) in brain with the aid of high performance liquid chromatography and electrochemical detection. The indoleamines were measured in the anterior hypothalamus (AH), posterior hypothalamus (PH) and raphe nuclei 30 min after the i.v. injection of either alaproclate (30 mg/kg) or zimelidine (20 mg/kg). The effect of alaproclate was studied in male rats, pro-oestrous female rats, rats ovariectomized and injected s.c. with 20 micrograms oestradiol benzoate (OB) on dioestrus and at 12.00 h of the next day (presumptive pro-oestrus) with 2 mg progesterone (model 1) and rats ovariectomized 3-4 weeks before an s.c. injection of 20 micrograms OB followed 72 h later by an s.c. injection of 2 mg progesterone (model 2). Alaproclate caused a significant decrease in the 5-HIAA/5-HT ratio in the AH and PH of the brain of male rats, in the PH and raphe nuclei in pro-oestrous rats and model 1, and in the raphe nuclei alone in model 2. Zimelidine had no effect on the 5-HIAA/5-HT ratio in any area in model 2. In male rats the injection of parachlorophenylalanine produced a marked reduction in the brain concentrations of 5-HT and 5-HIAA, but the 5-HIAA/5-HT ratio was unchanged by a subsequent injection of alaproclate. None of the pharmacological agents affected significantly the brain concentrations of noradrenaline, dopamine or dihydroxyphenylacetic acid.(ABSTRACT TRUNCATED AT 250 WORDS)