Acute effects of caffeine administration on the ultrastructure of the golden hamster parathyroid gland

This study was conducted to evaluate the acute effects of caffeine on the ultrastructure of the parathyroid glands in golden hamsters. Caffeine was given orally at either 2.5 mg (low dose) or 10 mg (high dose) per 100 g body weight. Caffeine caused a dose dependent decrease of the serum calcium level 2 hours after administration. Transmission electron microscopy of the parathyroid gland revealed that the volume densities occupied by the Golgi complexes and rough endoplasmic reticulum (RER) were found significantly higher 2 hours after receiving high dose of caffeine. Statistical analysis revealed no significant differences regarding to the bone mineral content (BMC) and bone mineral density (BMD). It is considered that the synthesis of parathyroid hormone is stimulated following caffeine administration.

[Estimation of adverse drug reactions by the evaluation scores of subjective symptoms (complaints) and background of patients. V. Drug-induced gastrointestinal system disorders]

OBJECTIVES

The purpose of this study was to develop, implement, and assess an estimation procedure for preventing adverse drug reaction by subjective symptoms (complaints) of patients. This time, we focused and studied on drug-induced gastrointestinal system disorders.

METHODS

We have built a database for CARPIS (Case Reports of Adverse Drug Reaction and Poisoning Information System) since 1987. We studied 224 cases of drug-induced Gastrointestinal System Disorders (stomach or colon disorders: 148, esophagus disorders: 31, pancreas disorders: 45) cumulated in the CARPIS database. The evaluation scores were created based on the subjective symptoms and backgrounds of the patients. We estimated 224 cases using these evaluation scores.

RESULTS

We could estimate 137 cases (92.6%) in 148 cases to be stomach or colon disorders by the use of these evaluation scores. The validity of this evaluation scores was estimated to be as follows: Sensitivity = 92.6%, Specificity = 95.0% and Predictive Value of Positive Test (PVP) = 96.5%. The positive likelihood ratio (LR) was 18.5 and negative likelihood ratio was 0.08. On the other hand, in the case of esophagus disorders, PVP was 84.8% and LR was 18.1. In the case of pancreas disorders, PVP was 90.7% and LR was 21.7.

CONCLUSIONS

In this study, PVP and LR values were good. We thought that these evaluation scores could pick up the drug-induced gastrointestinal system disorders efficiently. We reported previously the evaluation scores about drug-induced liver disorders, extra-pyramidal symptoms, leukopenia and eruption before. In order to apply these evaluation scores onto the clinical practice, we prepared an evaluation form for subjective symptoms and backgrounds of the patients with adverse drug reactions. As a result, the adverse reactions symptoms of each one defined more.

[Estimation of adverse drug reactions by the evaluation scores of subjective symptoms (complaints) and background of patients. IV. Drug eruptions]

OBJECTIVES

The purpose of this study is to develop, implement, and assess an estimation procedure for preventing adverse drug reaction by subjective symptoms (complaints) of patients. This time, we focused and studied on drug eruptions.

METHODS

We have built a database for CARPIS (Case Reports of Adverse Drug Reaction and Poisoning Information System) since 1987, and the case reports of adverse drug reactions accumulated in the CARPIS database to be total about 20,000. We studied 1473 cases of drug eruptions cumulated in CARPIS database. The evaluation scores were created based on the subjective symptoms and backgrounds of the patients. We estimated 1473 cases using this evaluation scores.

RESULTS

We could estimate 1455 cases (98.8%) in 1473 cases to be drug eruptions using this evaluation scores. The validity of this evaluation scores were sensitivity = 98.8%, specificity = 91.0% and predictive value of positive test = 99.4%. The positive likelihood ratio was 11.0 and negative likelihood ratio was 0.01.

CONCLUSIONS

This study confirmed the validity of our evaluation scores. We reported the evaluation scores about drug-induced liver diseases, drug-induced extra-pyramidal symptoms and drug-induced leukopenia before. In order to apply these evaluation scores to the clinical practice, we prepared an evaluation form for subjective symptoms and backgrounds of the patients with adverse drug reactions.

Effects of long-term treatment with caffeine on the ultrastructure of the golden hamster parathyroid gland and tibia

The ultrastructure of the parathyroid gland and the SEM appearances of the tibia were studied in hamsters with and without administration of caffeine. Caffeine was treated orally each day at either 2.5 mg (low dose) or 10 mg (high dose) per 100 g body weight for a period of 17 or 32 days. Statistical analysis showed no significant differences among all groups examined regarding the serum calcium level. Transmission electron microscopy of the parathyroid gland revealed that the volume densities occupied by the mitochondria, Golgi complexes and rough endoplasmic reticulum of caffeine-treated groups were found significantly higher when compared with controls. The number of secretory granules observed close to the cell membrane per total amount of these granules revealed significant increase in all caffeine-treated animals. The bone mineral content (BMC) values were closely related to body weight. In the high dose caffeine-treated hamsters increment of the mean BMC and body weight values was significantly lower than those of the controls after 32 days. In the scanning electron microscopic studies of the tibia, no alteration in the morphometric parameters was demonstrated. It is considered that the synthesis and release of parathyroid hormone is stimulated following caffeine consumption. Our data suggest that although chronic administration of caffeine in the hamster may slightly increase bone turnover as evidenced by the BMC decrease, bone morphometry was not altered. Thus the osteoporotic changes were not proved in this study.

[Estimation of adverse drug reactions by the evaluation scores of subjective symptoms (complaints) and background of patients. III. Drug-induced leucopenia]

OBJECTIVES

The purpose of this study was to develop, implement, and assess an estimation procedure for preventing adverse drug reaction by subjective symptoms (complaints) of patients. This time, we carried out this study focusing on drug-induced leucopenia.

METHODS

We have built a database for CARPIS (Case Reports of Adverse Drug Reaction and Poisoning Information System) since 1987, and the total number of case reports of adverse drug reaction accumulated in the CARPIS database amounts to about 16,000. Using the date obtained from 139 cases of drug-induced leucopenia accumulated in the CARPIS database, we investigated a relationship between leucopenia and patients. The evaluation scores were created based on the subjective symptoms and backgrounds of the patients.

RESULTS

We could estimate 91 cases (65.5%) in 139 cases to be drug-induced leucopenia by the use of these evaluation scores. The validity of this evaluation scores was estimated to be as follows; sensitivity = 65.5%, specificity = 80.0% and predictive value of positive test (PVP) = 82.0%. The positive likelihood (LR) ratio was 3.3 and negative likelihood ratio 0.43.

CONCLUSIONS

In this study, PVP and LR values were not good, because among the symptoms of leucopenia a very few specific symptoms could be detected. But we reported previous by the evaluation scores about drug-induced liver disorders. Therefore, in order to apply these evaluation scores to the clinical practice, we prepared an evaluation form for subjective symptoms and backgrounds of the patients with adverse drug reactions. In the future, we plan to examine other adverse reactions which adds the data to this form.

Effects of ethanol on the ultrastructure of the hamster thyroid C-cell

The morphology of the thyroid C-cells in golden hamsters after short- and long-term treatment with ethanol was studied. Immunohistochemistry was applied to examine the distribution of the C-cells in the thyroid gland. In the short-term experimental animals, the Golgi complexes and the granular endoplasmic reticulum were well developed and the number of the secretory granules was decreased as compared with those of the control animals. These findings suggest that the cellular activity of the thyroid C-cell is stimulated after short-term treatment with ethanol. The morphology of the thyroid C-cells of the long-term experimental animals was similar to that of the controls. It is conceivable that long-term treatment with ethanol does not affect the function of the C-cell.

Roles of neuregulin in synaptogenesis between mossy fibers and cerebellar granule cells

Neuregulins (NRGs), a large group of structurally related signaling proteins, are likely to have important roles in the development, maintenance and repair of the nervous system and other selected tissues. We have demonstrated, by using the major form of NRG cloned from the mouse cerebellum that both the soluble form and the membrane anchored form of NRG may serve different functions in synaptogenesis. The soluble form of NRG was produced by proteolytic cleavage of the membrane anchored form of NRG. The proteolytic cleavage was promoted by protein kinase activation. The cleaved form of NRG trans-synaptically regulated the expression of the NMDA (N-methyl-D-aspartate) receptor subunit NR2C as neurally-derived factors, whereas the membrane anchored form of NRG showed a homophilic binding activity between NRGbeta1s. In adult mice the membrane anchored form of NRG was concentrated in neuro-terminals of both granule cells and pontocerebellar mossy fibers. The fact that NRG can be functionally viewed as cell recognition molecules as well as neurotrophic agents suggests new possibilities for the important class of molecules.

Dynamic changes in glucose metabolism of living rat brain slices induced by hypoxia and neurotoxic chemical-loading revealed by positron autoradiography

Fresh rat brain slices were incubated with 2-deoxy-2-[18F]-fluoro-D-glucose ([18F]FDG) in oxygenated Krebs-Ringer solution at 36 degrees C, and serial two-dimensional time-resolved images of [18F]FDG uptake were obtained from these specimens on imaging plates. The fractional rate constant (= k3*) of [18F]FDG proportional to the cerebral glucose metabolic rate (CMRglc) was evaluated by applying the Gjedde-Patlak graphical method to the image data. With hypoxia loading (oxygen deprivation) or glucose metabolism inhibitors acting on oxidative phosphorylation, the k3* value increased dramatically suggesting enhanced glycolysis. After relieving hypoxia < or = 10-min, the k3* value returned to the pre-loading level. In contrast, with > or = 20-min hypoxia only partial or no recovery was observed, indicating that irreversible neuronal damage had been induced. However, after loading with tetrodotoxin (TTX), the k3* value also decreased but returned to the pre-loading level even after 70-min TTX-loading, reflecting a transient inhibition of neuronal activity. This technique provides a new means of quantifying dynamic changes in the regional CMRglc in living brain slices in response to various interventions such as hypoxia and neurotoxic chemical-loading as well as determining the viability and prognosis of brain tissues.

[Estimation of adverse drug reactions by the evaluation scores of subjective symptoms (complaints) and background of patients. II. Drug-induced extrapyramidal symptoms]

OBJECTIVES

The purpose of this study was to develop, implement, and assess an estimation procedure for preventing adverse drug reaction by subjective symptoms (complaints) of patients. This time, we focused and studied on drug-induced extrapyramidal symptoms.

METHODS

We have built a database for CARPIS (Case Reports of Adverse Drug Reaction and Poisoning Information Systems) since 1987, and the case reports of adverse drug reaction accumulated in the CARPIS database to be total about 16,000. We studied for 180 cases of drug-induced extrapyramidal symptoms cumulated in CARPIS database. The evaluation scores were created based on the subjective symptoms and backgrounds of the patients. We estimated 180 cases using these evaluation scores.

RESULTS

We could estimate 178 cases (98.9%) in 180 cases to be drug-induced extrapyramidal symptoms using these evaluation scores. The validity of these evaluation scores were sensitivity = 98.9%, specificity = 98.0% and predictive value of positive test = 98.9%. The positive likelihood ratio was 49.5 and the negative likelihood ratio was 0.01.

CONCLUSIONS

This study confirmed the validity of our evaluation scores. We reported the evaluation scores about drug-induced liver diseases before. Therefore, to apply these evaluation scores onto the clinical practice, we prepared an evaluation form for subjective symptoms and backgrounds of the patients with adverse drug reactions.

Morphology of the dorsal lingual papillae in the blackbuck, Antilope cervicapra

The dorsal lingual surface of a blackbuck (Antilope cervicapra) was examined by scanning electron microscopy (SEM). The tongue was about 125 mm in length. There were about 30 vallate papillae on both sides. Filiform, conical, fungiform and vallate papillae were found. The filiform papillae were distributed over the entire dorsal surface of the tongue, excepted for the lingual torus where conical papillae were present. The fugiform papillae were present rounded bodies, and more densely distributed on the tip and ventral surface of ligual apex. No foliate papillae were seen on the dorsal surface. The vallate papillae were located on both sides of the midline in the caudal part. Each papilla was surrounded by a groove. These findings indicate that the tongue of the blackbuck is similar to that of the formosan and japanese serow.

Macrophages in the hamster parathyroid gland: immunohistochemical and ultrastructural investigations

The distribution and morphology of the parathyroid macrophages in golden hamsters from neonatal to senile periods were investigated using the monoclonal antibody to ED2 and electron microscopy. The results showed that definite ED2-positive cells were hardly detectable in the parathyroid gland of 1-day-old hamsters. A few ED2-positive cells could be identified in the parathyroid gland of 10-day-old hamsters. The ED2-positive cells were more densely and became conspicuous in 1-, 3-, and 12-month-old hamsters. The number of the cells seems to be increased with aging. Ultrastructurally, we did not find any macrophages in parathyroid glands of 1-day-old hamsters. In the 10-day-old hamster parathyroid gland, a few macrophages existed only in the interstitial tissues. In the parathyroid gland of 1-, 3-, and 12-month-old hamsters, many macrophages were found in the perivascular regions, some cells located among the parenchymal chief cells with no obvious vascular association. These cells showed some physical contacts with chief cells. These results suggest that the parathyroid macrophages exhibit dramatical changes in their distribution and morphology from neonatal to senile periods.

Demonstration of partial erasing of picosecond temporal optical data by use of accumulated photon echoes

We demonstrated partial erasing of temporal optical data on a picosecond time scale by use of accumulated photon echoes. In a photon-echo memory the temporal data at time tau are stored as a frequency grating of period 1/tau in the absorption spectrum of a material. Partial erasing of the temporal data is achieved by irradiation of the material with a pulse pair at time separation tau , but the phase of one of the pulses is shifted 180 degrees . This process does not produce a frequency grating, and no echo is emitted. The experiment was performed with a dye-doped polymer film. The 180 degrees phase shift was obtained by use of a half-wave plate.

Ethanol opens G-protein-activated inwardly rectifying K+ channels

Ethanol affects many functions of the brain and peripheral organs. Here we show that ethanol opens G-protein-activated, inwardly rectifying K + (GIRK) channels, which has important implications for inhibitory regulation of neuronal excitability and heart rate. At pharmacologically relevant concentrations, ethanol activated both brain-type GIRK1/2 and cardiac-type GIRK1/4 channels without interaction with G proteins or second messengers. Moreover, weaver mutant mice, which have a missense mutation in the GIRK2 channel, showed a loss of ethanol-induced analgesia. These results suggest that the GIRK channels in the brain and heart are important target sites for ethanol.

Tailoring of surfaces with ultrathin polymer films for survival and growth of neurons in culture

We have studied the adhesion, growth, and survival of dissociated cells of rat cerebellum onto glass surfaces derivatized with covalently bound ultrathin polymer layers. The surface coatings were prepared by growing polymer chains directly at the surfaces of solid substrates by using self-assembled monolayers of radical chain initiators. Methacrylate and acrylamide polymers with different polarities were covalently attached to the surfaces and the adhesion behaviour of the neuronal cells to these surfaces was studied. Best adhesion and neurite outgrowth properties were found using a positively charged polymer (poly(methacryloyl oxypropyl (trimethyl ammonium) bromide)). This 'grafting from' method for the generation of surface modifications can be used for tailoring the composition of the surface of the substrates. Our experiments demonstrate the potential of these layers for the design of polymeric surface coatings for long term stability of neuronal culture.

Unique behavioural phenotypes of recombinant-inbred CXBK mice: partial deficiency of sensitivity to mu- and kappa-agonists

Recombinant-inbred CXBK mice have been used for various studies as putative mu-opioid-receptor deficient mice. However, CXBK mice have never been compared with gene-targeting mice lacking the mu-opioid receptor (muKO) and the K-opioid receptor (kappaKO). Here we report that CXBK mice show distinct behavioural phenotype in opioid-induced analgesia and sedation. Intraperitoneal (i.p.) administration of morphine (3 and 10 mg kg(-1)) induced significantly lower levels of analgesia in CXBK mice than in the control C57BL/6 mice, while higher doses of morphine (30 and 100 mg kg(-1)) induced marked analgesia in CXBK mice. CXBK mice also showed lower analgesia and sedation levels than did C57 mice after i.p. administration of U-50488 (10 and 30 mg kg(-1)). The partial deficiency of sensitivity to morphine and U-50488 of CXBK mice is in sharp contrast to the complete lack of sensitivity to morphine and U-50488 in muKO and kappaKO mice, respectively. Furthermore, CXBK mice showed a lower threshold for nociceptive stimuli when they were not given an opioid, suggesting that CXBK mice could have alterations in the genes related to the nociceptive threshold. These unique behavioural phenotypes of CXBK mice suggest unique genetic alterations in CXBK mice.

Novel neuronal effects of midkine on embryonic cerebellar neurons examined using a defined culture system

1. Midkine (MK) is known to be a member of a family of heparin-binding neurotrophic factors. We used a chemically defined culture system to examine neuronal activities of MK on embryonic rat cerebellar cells. 2. In the culture system, a substrate surface was chemically modified either with amine or with laminin peptide to homogenize substrate conditions for culturing neurons. 3. At the optimal concentration (2.5 ng/ml), MK moderately promoted survivability (1.3-fold) and accelerated neurite outgrowth (1.4-fold) of cerebellar cells, putatively granule neurons, grown on an amine-modified surface. 4. Higher dosages (10 ng/ml or more) of MK, however, caused cellular fragmentation and detachment. Such degenerative effects were diminished by increasing the surface adhesiveness using laminin peptide, suggesting that the cellular degeneration might be caused by changes in the adhesive property of the neuron. 5. Using this culture system, we have found that MK has a novel modulatory activity of neuronal adhesiveness on the cultured cerebellar granule cells. Together with the expression pattern of MK, our study supports the idea that MK may be involved in the developmental events of the cerebellum.

Effects of long-term treatment with ethanol on the ultrastructure of the golden hamster parathyroid gland

The ultrastructure of the parathyroid gland in golden hamsters after long-term treatment with ethanol was studied. Male hamsters of experimental groups were given ethanol at the concentration of 7% for 3 and 5 months with food and water freely available. In the ethanol-treated hamsters, the Golgi complexes associated with many prosecretory granules were well developed and many secretory granules were located near the plasma membrane as compared with those of the control animals. Exocytotic events were observed in 5-month-treated animals. These findings suggest that the secretory activity of the parathyroid gland is stimulated after long-term treatment with ethanol.

A novel type of non-coding RNA expressed in the rat brain

We have characterized a novel type of non-coding RNA which consists of tandem repeats of similar sequences, approximately 0.9 kb in size. This RNA, termed Bsr (brain specific repetitive) RNA, is encoded at a single locus (6 q31-->q32) in the rat genome, where 100 to 150 copies of the 0.9 kb sequences are repeated in tandem. Bsr RNA is preferentially expressed in the rat central nervous system (CNS), especially in phylogenetically old structures, such as the pareo- and archicortex, amygdala, thalamus and hypothalamus. In the developing brains, Bsr RNA is expressed in the subsets of differentiating cells but not in proliferating cells. Despite the finding that Bsr RNA appears to be conserved only among the Rattus species, the specific expression pattern of Bsr RNA suggests that it might have some role in the rat CNS.

The importance of glucose transport activity as the rate-limiting step of 2-deoxyglucose uptake in tumor cells in vitro

Glucose transporter (GLUT) expression and hexokinase activity are thought to be related to high [18F]-fluorodeoxyglucose (FDG) uptake in tumor cells, but their relative importance is still unknown. To determine which is the predominant factor in FDG uptake in tumor cells, cultured tumor cell lines and a normal cell line were studied in vitro with respect to 2-deoxyglucose (DG) uptake, hexokinase activity, and the initial uptake rate of 3-O-methylglucose (3-O-MG) transport, which is generally accepted as indicating the amount of GLUT expressed on the plasma membrane. In 16 types of tumor cells and one fibroblast cell line, DG uptake was assessed for 60 min, the initial uptake rate of 3-O-MG transport was measured for 1 min, and total hexokinase activity, including that in the mitochondrial fraction, was determined. Across all 16 tumor cell lines, there was a significant correlation between DG uptake and 3-O-MG transport (p = 0.0012, F test), but not between DG uptake and hexokinase activity. Hexokinase activity of the tumor cells was comparable to that of the human fibroblast cells in the exponential growth phase. Most tumor cells showed higher DG uptake and 3-O-MG transport than the human fibroblast cells. The results suggest that DG uptake of cultured tumor cells is governed by GLUT expression, which may be a distinct characteristic of the neoplastic process.

Distribution of prepro-nociceptin/orphanin FQ mRNA and its receptor mRNA in developing and adult mouse central nervous systems

Nociceptin/orphanin FQ (N/OFQ) and its receptor share similarities to opioids and their receptors in terms of the molecular structure and signaling pathway, but the two systems exhibit different actions in vivo. To understand the mechanism of N/OFQ-system actions, we examined, by in situ hybridization analysis, the distribution of preproN/OFQ and N/OFQ receptor mRNAs in the developing and adult mouse central nervous systems (CNS). In most neural regions, preproN/OFQ mRNA was mainly expressed in a small population of middle-sized neurons. These neurons were scattered between large projection-type neurons or within the neuropil, suggestive of interneurons. In some other nuclei (lateral septum, bed nucleus of the stria terminalis, reticular thalamic nucleus, inferior colliculus, and rostral periolivery nucleus), preproN/OFQ mRNA was expressed in a number of large projection-type neurons. By contrast, N/OFQ receptor mRNA was evenly expressed in most neurons of the adult CNS. Considering the inhibitory actions of N/OFQ, the distinct cellular expression pattern of the N/OFQ system suggests that the release of N/OFQ from interneurons may lower neuronal and synaptic activities of neighboring neurons, leading to integration or modulation of local circuits. Furthermore, the cellular expression pattern, distinct from that of the opioid system, may provide a possible molecular/cellular basis for the different in vivo actions of N/OFQ and opioids. In embryonic stages, both preproN/OFQ and N/OFQ receptor mRNAs were highly and widely expressed in the mantle zone, suggesting the possible importance of N/OFQ signaling in CNS development.

[Estimation of adverse drug reactions by the evaluation scores of subjective symptoms (complaints) and background of patients. I. Drug-induced liver disorders]

The purpose of this study was to develop, implement, and assess an estimation procedure for preventing drug-induced liver disorders. We have built a database for CARPIS (case reports of adverse drug reaction and poisoning information services) since 1987, and the case reports of adverse drug reaction accumulated in the CARPIS database to be total about 11,000. We studied the estimation procedure by evaluating the subjective symptoms, backgrounds and laboratory data of patients in 199 cases cumulated in the CARPIS database. The evaluation scores were created on the basis of the subjective symptoms and backgrounds of the patients. Then, we re-estimated 199 cases with the evaluation scores, among which were 165 cases (82.9%) in 199 cases drug-induced liver disorders. For the rest of 34 cases (17.1%) drug-induced liver disorders could not be estimated from our evaluation scores. These 34 cases were either those which the subjective symptoms were not described in their reports, because the patients were hospitalized for other diseases and drug-induced liver disorders were discovered by a clinical examination, or cases of infants for whom it was difficult to confirm the subjective symptoms. The validity of this evaluation scores were sensitivity = 82.9%, specificity = 91.0% and predictive value of positive test = 94.8%. To apply this evaluation scores onto the clinical practice, we prepared an evaluation form for the subjective symptoms and backgrounds of the patients with drug suspecting-induced liver disorders.