Involvement of glucocorticoid receptor on hyperpyrexia induced by methamphetamine administration.

UNLABELLED: We have investigated the involvement of glucocorticoid on methamphetamine (MA) induced hyperpyrexia using a bio-telemetric system. A significant level of hyperpyrexia was observed in MA administered rats. In contrast, increase of body temperature was suppressed by adrenalectomy or by the administration of RU-486, an antagonist of the glucocorticoid receptor. These data suggest that the glucocorticoid receptor may be involved in hyperpyrexia induced by MA. KEYWORDS: methamphetamine - hyperpyrexia - glucocorticoid - corticosterone.

Laser Capture Microdissection of Single Neurons with Morphological Visualization Using Fluorescent Proteins Fused to Transmembrane Proteins.

Gene expression analysis in individual neuronal types helps in understanding brain function. Genetic methods expressing fluorescent proteins are widely used to label specific neuronal populations. However, because cell type specificity of genetic labeling is often limited, it is advantageous to combine genetic labeling with additional methods to select specific cell/neuronal types. Laser capture microdissection is one of such techniques with which one can select a specific cell/neuronal population based on morphological observation. However, a major issue is the disappearance of fluorescence signals during the tissue processing that is required for high-quality sample preparation. Here, we developed a simple, novel method in which fluorescence signals are preserved. We use genetic labeling with fluorescence proteins fused to transmembrane proteins, which shows highly stable fluorescence retention and allows for the selection of fluorescent neurons/cells based on morphology. Using this method in mice, we laser-captured neuronal somata and successfully isolated RNA. We determined that ∼100 cells are sufficient to obtain a sample required for downstream applications such as quantitative PCR. Capability to specifically microdissect targeted neurons was demonstrated by an ∼10-fold increase in mRNA for fluorescent proteins in visually identified neurons expressing the fluorescent proteins compared with neighboring cells not expressing it. We applied this method to validate virus-mediated single-cell knockout, which showed up to 92% reduction in knocked-out gene RNA compared with wild-type neurons. This method using fluorescent proteins fused to transmembrane proteins provides a new, simple solution to perform gene expression analysis in sparsely labeled neuronal/cellular populations, which is especially advantageous when genetic labeling has limited specificity.

Role of NMDA Receptors in Adult Neurogenesis and Normal Development of the Dentate Gyrus.

The NMDA receptors are a type of glutamate receptors, which is involved in neuronal function, plasticity and development in the mammalian brain. However, how the NMDA receptors contribute to adult neurogenesis and development of the dentate gyrus is unclear. In this study, we investigate this question by examining a region-specific knock-out mouse line that lacks the NR1 gene, which encodes the essential subunit of the NMDA receptors, in granule cells of the dentate gyrus (DG-NR1KO mice). We found that the survival of newly-generated granule cells, cell proliferation and the size of the granule cell layer are significantly reduced in the dorsal dentate gyrus of adult DG-NR1KO mice. Our results also show a significant reduction in the number of immature neurons and in the volume of the granule cell layer, starting from three weeks of postnatal age. DG-NR1KO mice also showed impairment in the expression of an immediate early gene, Arc, and behavior during the novelty-suppressed feeding and open field test. These results suggest that the NMDA receptors in granule cells have a role in adult neurogenesis in the adult brain and contributes to the normal development of the dentate gyrus.

Within-Trial Persistence of Learned Behavior as a Dissociable Behavioral Component in Hippocampus-Dependent Memory Tasks: A Potential Postlearning Role of Immature Neurons in the Adult Dentate Gyrus.

The term "memory strength" generally refers to how well one remembers something. But more precisely it contains multiple modalities, such as how easily, how accurately, how confidently and how vividly we remember it. In human, these modalities of memory strength are dissociable. In this study, we asked whether we can isolate a behavioral component that is dissociable from others in hippocampus-dependent memory tasks in mice, which potentially reflect a modality of memory strength. Using a virus-mediated inducible method, we ablated immature neurons in the dentate gyrus in mice after we trained the mice with hippocampus-dependent memory tasks normally. In memory retrieval tests, these ablated mice initially showed intact performance. However, the ablated mice ceased learned behavior prematurely within a trial compared with control mice. In addition, the ablated mice showed shorter duration of individual episodes of learned behavior. Both affected behavioral measurements point to persistence of learned behavior. Thus, the effect of the postlearning manipulation showed dissociation between initial performance and persistence of learned behavior. These two behavioral components are likely to reflect different brain functions and be mediated by separate mechanisms, which might represent different modalities of memory strength. These simple dissociable measurements in widely used behavioral paradigms would be useful to understand detailed mechanisms underlying the expression of learned behavior and potentially different modalities of memory strength in mice. We also discuss a potential role that immature neurons in the dentate gyrus may play in persistence of learned behavior.

Characterization of mass-labeled [13C14]-decabromodiphenylethane and its use as a surrogate standard in the analysis of sewage sludge samples.

Very little data is available about the presence of the brominated flame retardant, DBDPE, in the environment. This study reports the characterization of [(13)C(14)]-decabromodiphenylethane and the use of this surrogate standard to positively identify and quantify the presence of DBDPE in sewage sludge samples. The large difference in response factors between BDE-209 and DBDPE predicates the use of [(13)C(14)]-decabromodiphenylethane as a surrogate standard to improve the accuracy when determining the levels of DBDPE in environmental samples.

Determinants of genital human papillomavirus infection in young women.

Carcinoma of the cervix has several well-established epidemiologic risk factors, including multiple sexual partners and early age at first intercourse. Human papillomavirus (HPV) infection appears to have an etiologic role in the development of cervical neoplasia, but evidence linking HPV infection to known risk factors for cervical cancer has been inconsistent. The lack of expected correlations may be due to the inaccuracy of HPV assays previously used. A polymerase chain reaction DNA amplification method for the detection of HPV was used to investigate the determinants of genital HPV infection in a cross-sectional sample of 467 women attending a university health service. In contrast to studies using less accurate detection methods, the risk factors for HPV infection found here were consistent with those for cervical neoplasia. The risk of HPV infection was strongly and independently associated with increasing numbers of sexual partners in a lifetime, use of oral contraceptives, younger age, and black race. Age at first intercourse, smoking, and history of a prior sexually transmitted disease were correlated with, but not independently predictive of, HPV infection. These results demonstrate that the key risk factors for cervical carcinoma are strongly associated with genital HPV infection. This correlation suggests that HPV has an etiologic role in cervical neoplasia and reaffirms the sexual route of HPV transmission.

Depression of phase-transition temperature by anesthetics: nonzero solid membrane binding.

The anesthetic-induced depression of the main phase-transition temperature of phospholipid membranes is often analyzed according to the van't Hoff model on the freezing point depression. In this procedure, zero interaction between anesthetics and solid-gel membranes is assumed. Nevertheless, anesthetics bind to solid-gel membranes to a significant degree. It is necessary to analyze the difference in the anesthetic binding between the liquid-crystal and solid-gel membranes to probe the anesthetic action on the lipid membranes. This article describes a theory to estimate the anesthetic binding to each state at the phase-transition temperature. The equations derived here reveal the relation between the partition coefficients of anesthetics and the anesthetic effects on the transition characters: the change in the transition temperature, and the broadening of transition. The theory revealed that the width of transition temperature is determined primarily by the membrane/buffer partition coefficients of anesthetics. Our previous data on the local anesthetic action on the transition temperature of the dipalmitoylphosphatidylcholine vesicle membrane (Ueda, I., Tashiro, C. and Arakawa, K. (1977) Anesthesiology 46, 327-332) are analyzed by this method. The numerical values for the partition of local anesthetics into the liquid-crystal and solid-gel dipalmitoyl-phosphatidylcholine vesicle membranes at the phase-transition temperature are: procaine 8.0 x 10(3) and 4.7 x 10(3), lidocaine, 3.7 x 10(3) and 2.3 x 10(3), bupivacaine 4.1 x 10(4), and 2.6 x 10(4), and tetracaine 7.3 x 10(4) and 4.7 x 10(4), respectively.

Capnometry during high-frequency oscillatory ventilation.

We used capnometry during high-frequency oscillatory ventilation (HFOV), and compared CO2 measurements at the distal and proximal ends of an endotracheal tube with arterial CO2 values. Ten white rabbits (mean weight, 2.00 +/- 0.2 [SD] kg) underwent tracheostomy under anesthesia with pentobarbital. The trachea was intubated with an endotracheal tube with a second lumen for sampling respiratory gas at the distal tip. Capnometry was performed through the lumen (CO2d) and the proximal end of the endotracheal tube (CO2p). The internal carotid artery was cannulated to sample blood for measuring arterial blood gases. The differences between CO2d, CO2p, and PaCO2 were measured. Only the relation between CO2d and PaCO2 was good (r = 0.915). We concluded that capnometry can be used during HFOV to estimate PaCO2 provided that respiratory gas is sampled from the distal tip of the endotracheal tube.

Effects of halothane, ketamine and nitrous oxide on dynorphin mRNA expression in dorsal horn neurons after peripheral tissue injury.

Peripheral tissue injury is known to induce changes in gene expression in spinal neurons and result in a prolonged alteration of neuronal excitability. The purpose of this study was to examine the effect of halothane on the dynorphin mRNA expression in spinal dorsal horn neurons after peripheral tissue injury by formalin injection and compare the effect to that of ketamine and nitrous oxide. Male Sprague-Dawley rats were anesthetized with 1.3% halothane, ketamine, or 67% nitrous oxide. Fifteen minutes after induction of anesthesia, rats received an intraplantar injection of 150 microliter 5% formalin into the unilateral hindpaw. General anesthesia was maintained for 8 h, and the expression of preprodynorphin (PPD) and preproenkephalin (PPE) mRNAs in the spinal cord (L4-5) was examined by in situ hybridization. The degree of edema of the inflamed foot was not different among the three anesthesia groups and the control (no anesthesia) group. The number of neurons expressing PPD mRNA dramatically increased in the superficial dorsal horn ipsilateral to the formalin injection in the control group compared to the contralateral side. The number of neurons labeled for PPD mRNA in the halothane group was significantly less than the control group. However, the number of PPD mRNA-expressing neurons in both the ketamine and nitrous oxide groups was significantly less than the halothane group. The expression of PPE mRNA was not influenced by these anesthetics. These data indicate that the suppressive effect of halothane anesthesia on the induction of PPD mRNA in dorsal horn neurons was smaller than those of ketamine and nitrous oxide, suggesting an important supplemental way to control the alteration of gene expression in spinal neurons for clinical settings.

The effects of temperature and pressure on the thermodynamic activity of anesthetics.

Anesthetic potency is often expressed by volume percent or partial pressure in the gas phase, concentrations in the aqueous phase, etc. However. these values do not represent the anesthetic activity at the action sites. Because the activity at the action sites is difficult to obtain. Ferguson (Ferguson, J., 1939. Proc. R. Soc. Lond. B 127 387-404) defined the thermodynamic activity, which is the ratio between the anesthetizing partial pressure and the vapor pressure of the pure anesthetic at the same temperature. This paper discusses the effects of temperature and pressure on the thermodynamic activity of anesthetics. It also discusses the limitations of the Meyer-Overton rule.

Effects of gestational and lactational exposure to Aroclor 1242 on sperm quality and in vitro fertility in early adult and middle-aged mice.

The objective of this study was to examine the effects of gestational and lactational exposure to Aroclor 1242 (0, 10, 25, 50, and 100 mg/kg-bw) on male fertility. Doses were administered to C57BL6 female mice orally every two days from two weeks before mating, during mating, and through gestation until postnatal day 21. Male B6D2F1 offspring were examined for anogenital distance, organ development, epididymal sperm count, sperm motility, and in vitro fertility at 16 and 45 weeks of age. Stomach samples of pups nursing from PCB-treated mothers in the 50 mg/kg dose group were analyzed for PCBs and chlorobiphenylols by high resolution gas chromatography coupled with low resolution mass spectrometry. It was estimated that the nursing pups were exposed to 0.2, 0.6, 1.2, and 2.4 mg/kg/day total PCBs in the 10, 25, 50, and 100 mg/kg dose groups, respectively. This exposure level approaches the maximum FDA recommended levels for PCBs in food and breast milk. The composition of the PCBs in the stomach samples was different from the parent mixture, as there was a higher proportion of heavily chlorinated congeners, as well as chlorobiphenylols. Anogenital distance at weaning, and liver, thymus, and testes weight at 16 and 45 weeks of age were not affected by PCB exposure. Epididymal sperm velocity and linearity were significantly increased in the 25 mg/kg dose group at 16 weeks of age. Sperm count was increased by 36% in this dose group (P = 0.06). By 45 weeks of age, average sperm count in this dose group was similar to that of controls. With the exception of the 50 mg/kg dose group at 16 weeks of age, sperm fertilizing ability in vitro was significantly decreased in all PCB-exposed groups at 16 and 45 weeks of age. These results suggest that fertility in the adult mouse is susceptible to developmental exposure to Aroclor 1242 and is independent of testis weight or epididymal sperm count.

Effects of electrical stimulation of cervical sympathetic trunks on microcirculation in the facial nerve.

This study evaluates the circulatory effects of electrical stimulation of the cervical sympathetic trunks on blood flow in the common carotid artery and facial nerve tissue in dogs. Marked increases in arterial pressure and heart rate were observed due to electrical stimulation of the cervical sympathetic trunks, while blood flow volume in the common carotid artery and in the facial nerve tissue decreased markedly. It was assumed that microcirculation of the facial nerve is definitely impaired by electrical stimulation of the cervical sympathetic trunks, and the tonicity of the sympathetic nervous system appears to be a major factor in changes in the microcirculation of the facial nerve. It is well known that impaired circulation in the nutrient vessels of the facial nerve has an important effect on the pathogenesis of facial palsy. The hypertonicity of the sympathetic nervous system is closely involved in the onset of facial palsy.

Low dose intrathecal morphine and pain relief following caesarean section.

Healthy women who underwent caesarean section under spinal anaesthesia were studied to determine the extent of postoperative analgesia and side-effects produced by low doses of intrathecal morphine. Patients were randomly allocated to receive, in double-blind fashion, 0 mg (group 1: control group), 0.05 mg (group 2), 0.1 mg (group 3), or 0.2 mg (group 4) of morphine, with 10 mg tetracaine in 10% dextrose 2.5 ml. (n = 20 x 4 groups). The effect of intrathecal morphine was examined in terms of the duration until the first supplemental analgesic was needed and the numbers of the doses within the first postoperative 48 h. Pain relief was significantly greater in groups 3 and 4 than in group 1. The incidence of nausea, vomiting and pruritus increased in a dose-dependent manner. No patient developed respiratory depression. Our results suggest that postoperative analgesia lasts more than 24 h with 0.1 mg or 0.2 mg of intrathecal morphine. Since the incidence of side-effects was higher at 0.2 mg, 0.1 mg may be the optimum dose for caesarean section.

Apnea during spinal anesthesia in an unsedated patient with central sleep apnea syndrome.

We describe a case of apnea during spinal anesthesia in an unsedated patient with central sleep apnea syndrome. When spinal anesthesia is planned for a patient who is suspected of having this syndrome, apnea may be induced, even if no sedative was administered and the level of anesthesia is only moderate.

Carboxyhemoglobin and methemoglobin levels in banked blood.

Carboxyhemoglobin and methemoglobin levels in 312 units of banked blood and their relationship to the duration of storage were determined. The carboxyhemoglobin level decreased as the storage time increased, and its mean was 1.4% +/- 2.0% (SD) with a range from 0% to 9.6%. Methemoglobin increased during storage, showing a mean level of 1.6% +/- 0.4% and a range from 0.5% to 4.2%. In a separate study, blood drawn from six volunteers who had smoked two cigarettes each was stored as banked blood for 21 days. The mean initial level of carboxyhemoglobin was 4.4% +/- 1.6%, and the mean half-life of carboxyhemoglobin was approximately 47 days. Methemoglobin increased from an initial 1.3% +/- 0.2% to 2.4% +/- 0.6% at the end of storage. The use of banked blood containing high levels of these abnormal hemoglobins could be a potential risk in critically ill patients.

Effect of preanesthetic rectal famotidine on pH and volume of gastric contents in pediatric outpatients.

STUDY OBJECTIVE: To determine the feasibility and effects of preanesthetic rectal famotidine on gastric fluid pH and volume in pediatric patients. DESIGN: Randomized, prospective, double-blind, controlled study. SETTING: Operating room at a medical center. PATIENTS: Eighty patients undergoing minor surgery under general anesthesia randomly allocated to one of two groups. INTERVENTIONS: Thirty-four patients in Group 1 were given 0.5 mg/kg of diazepam rectally 30 to 120 minutes before anesthesia induction. Thirty-eight patients in Group 2 received 1 mg/kg of famotidine, a new histamine (H2) blocker, and 0.5 mg/kg of diazepam through the same route. Six patients in Group 1 and two patients in Group 2 were excluded from the study due to gastrointestinal (GI) disorders. MEASUREMENTS AND MAIN RESULTS: Patients with gastric pH less than 2.5 or volume of gastric contents greater than 0.4 ml/kg were considered to be at risk for pulmonary aspiration. Thirty-five (92%) of the Group 2 patients had gastric contents with pH greater than 2.5 and gastric volume less than or equal to 0.4 ml/kg. Only 13 (38%) of the patients in Group 1 had similar gastric pH and volume. Rectal administration did not cause the children pain, and no anorectal problems of famotidine were detected. CONCLUSIONS: Famotidine 1.0 mg/kg administered rectally 30 minutes prior to general anesthesia appears to result in a satisfactory increase in gastric pH.

[Synthesis of 2-oxooctahydroimidazo[1,2-alpha]pyridine-3-spiro-4'-piperidine derivatives possessing antiapomorphine activity].

4'-Carbamoyl-1,4'-bipiperidine 1 was dehydrogenated on Pd-C to give 2-oxo-2,3,5,6,7,8-hexahydroimidazo[1,2-alpha]pyridine-3-spiro-4'-p iperidine 2, which was reduced to 2-oxo-1,2,3,5,6,7,8,8a-octahydroimidazo[1,2-alpha]pyridine-3-spiro -4'- piperidine 3 with NaBH4. The iminodibenzyl and similar derivatives of 2 and 3 were synthesized and evaluated by using antiapomorphine test in mice. The derivatives of 3 had more potent antagonistic activity than those of 2 and the order of potency of 3 was: chloriminodibenzyl greater than chlordibenzocycloheptene greater than iminodibenzyl greater than iminostilbene greater than fluorene. Further chemical modification of the most active chloriminodibenzyl derivative 8, such as the substitution of Cl atom to Br atom, N-methylation on amine moiety, the replacement of imidazopyridine ring to imidazopyrrole ring, did not give any positive effect. Therefore, 8 may have potential usefulness as an antipsychotic drug.

[Synthesis of metabolites of mosapramine. II. Synthesis of phenolic metabolites of mosapramine and their pharmacological activities].

Four phenolic metabolites of (+-)-3-chloro-5-[3-(2-oxo-1,2,3,5,6,7,8,8a-octahydroimidazo[1,2- a]pyridine-3-spiro-4'-piperidino)propyl]-10,11-dihydro-5H-dibenz [b,f]azepine (mosapramine), a new antipsychotic drug, were synthesized in order to determine their chemical structures. Pharmacological activities of the three main metabolites were compared with those of mosapramine. The activities of the metabolites were far less potent than those of mosapramine.

[Synthesis of metabolites of mosapramine. I. Synthesis of alcoholic metabolites].

Four alcoholic metabolites of (+-)-3-chloro-5-[3-(2-oxo-1,2,3,5,6,7,8,8a-octahydroimidazo[1,2-a] pyridine-3-spiro-4'-peperidino)propyl]-10,11-dihydro-5'-dibenz[b,f ] azepine(mosapramine), a new antipsychotic drug, were synthesized in order to determine their chemical structures. A mixture of 10-ethoxy-3-chloro-10,11-dihydro-5H-dibenz[b,f]azepine and 11-ethoxy isomer was used as a starting material. Isomeric intermediates, i.e. 10-oxo-3-chloro-5-(3-chloropropyl)-10,11-dihydro-5H-dibenz[b,f]azepine and 11-oxo isomer, were separated by chromatography with silica gel. The metabolites were obtained by NaBH4 reduction of the corresponding 10-oxo or 11-oxo compounds followed by introduction of spiro-piperidine moieties into propyl side chain.

[Dextran-induced anaphylactoid reactions in two patients with gastrointestinal cancer].

We report dextran-induced anaphylactoid reactions (DIAR) subsequent to rapid infusion of Rheomacrodex (dextran 40) in two patients, a 67 year old man with gastric cancer undergoing distal gastrectomy and a 47 year old man with transverse colon cancer undergoing colectomy. Both showed sudden tachycardia, hypotension and skin flush, which were treated with epinephrine or etilephrine administration. Most cases of severe DIAR are immune complex anaphylaxis mediated by dextran-reactive antibodies (DRA) of the IgG class, which are considered to arise mainly in response to immunization with dextran-cross-reactive bacterial polysaccharides in the gastrointestinal tract. High titers of DRA have previously been reported in gastric ulcer patients with pyloric stenosis, suggesting bacterial polysaccharides permeation through the luminal wall which may easily occur in the presence of local inflammation or ulcer. Although serum DRA titers in our patients have not been examined, inflammation or ulcer around the tumor might have played a role in producing high titers of DRA. In patients suspected of gastrointestinal ulcer or inflammation, including cancer, dextran administration is not preferable or should be avoided, unless hapten-dextran preparation is used for the prophylaxis of severe DIAR.