Expression of betaine transporter mRNA: its unique localization and rapid regulation in rat kidney

Betaine is a major compatible osmolyte in the renal medulla. It is taken up into cells via the betaine gamma-amino-n-butyric acid transporter (BGT-1). We investigated the localization of BGT-1 mRNA and its acute regulation by NaCl and furosemide administration. In situ hybridization revealed that BGT-1 mRNA is predominantly present in the outer medulla and papilla. Less intense signals were seen in the inner medulla and no signals were found in the cortex. Microscopic examination suggested that intense signals were present in the medullary thick ascending limbs of Henle's loop (MTAL) and the inner medullary collecting ducts (IMCD). A reverse transcription and polymerase chain reaction assay of individual microdissected segments along the nephron confirmed its localization. Intraperitoneal administration of NaCl rapidly increased the signal in the MTAL, and furosemide prevented the increase in BGT-1 mRNA by NaCl loading. In contrast, BGT-1 mRNA in the IMCD is less sensitive to these kinds of acute regulation. These results suggest that BGT-1 expression in the MTAL is rapidly regulated in response to the magnitude of NaCl absorption, as suggested for the expression of Na+/myo-inositol cotransporter.

Rapid and transient up-regulation of Na+/myo-inositol cotransporter transcription in the brain of acute hypernatremic rats

The osmoregulatory system is well developed in the brain. Osmolytes contribute to maintenance of cell volume and cellular functions without changing intracellular ionic composition. Myo-inositol is regarded as one of the major osmolytes in the brain. In the present study, we investigated the changes in expressions of sodium myo-inositol cotransporter (SMIT) mRNA in the brain of acute hypernatremic rats by in-situ hybridization and Northern blot methods. Under moderate acute hypernatremic conditions, SMIT mRNA level increased markedly at 1 h and returned to almost control levels at 3 h, in accordance with plasma Na+ concentrations. Especially, distinct increases in SMIT mRNA expression were observed in the granule cells and glial cells in the cerebellum. These findings indicate that SMIT plays an important role in osmoregulation, especially in the early stages of acute hypernatremia in the brain.

In vitro-in vivo correlation of pharmacodynamics of felodipine in essential hypertensive patients based on an ion-channel binding model

The relationship between the plasma drug concentration and the antihypertensive effect of felodipine was analyzed by an ion-channel binding model which takes into consideration the slow association/dissociation process of a drug at the calcium channel. The in vitro dissociation constant (Kd) of felodipine to the calcium channel in the heart of rats was determined, and was compared to the in vivo dissociation constant (Kd,calc) estimated by the pharmacodynamic analysis of the concentration-effect data in Japanese essential hypertensive patients obtained from literature. The relative relationship between Kd and Kd,calc of felodipine was substantially identical with eight other calcium channel blocking agents reported previously. This results suggested the possibility that we can predict the pharmacodynamic behavior of newly developed calcium channel blocking agents from the in vitro Kd value and plasma concentration-time profile in human using the ion-channel binding model.

Expression of dopamine transporter mRNA and its binding site in fetal nigral cells transplanted into the striatum of 6-OHDA lesioned rat

Neurological disorders in rat model of hemi-Parkinson's disease can be compensated by the transplantation of fetal nigral cells. However, the role of the dopamine transporter (DAT) in this recovery has not been clarified. To clarify this mechanism, we examined the expression of DAT in the caudate putamen (CPu) by in situ hybridization histochemistry (mRNA) and autoradiography (using the ligand [125I] beta-CIT, which labels DAT) and compared them with the recovery of motor disturbance revealed with methamphetamine-induced rotation. Models were made with the stereotaxic injection of 6-hydroxydopamine into the left side of the substantia nigra pars compacta. Cell suspensions from rat fetus (embryonic day 14-15) were transplanted into the lesioned side of CPu. Methamphetamine-induced rotation, expression of DAT mRNA, and [125I] beta-CIT binding were evaluated 2, 4 and 12 weeks after the transplantation. Methamphetamine-induced rotation recovered partly in the 2nd week and significantly in the 4th week. [125I] beta-CIT binding increased with time and the dense binding was detected 4 and 12 weeks after the transplantation. In all transplanted rats, cells expressing DAT mRNA were found in CPu. These results indicated that transplanted fetal dopaminergic cells maturated in CPu of host animals and extended nerve terminals where high density of DAT binding sites were found.

[Epidemiological analysis of Epstein-Barr virus infection]

We analysed the characteristics of 372 Epstein-Barr virus (EBV) infected patients visiting our hospital from 1981 to 1995 classifying the phase I (from 1981 to 1988), the phase II (from 1989 to 1991) and the phase III (from 1992 to 1995). The incidence of infectious mononucleosis (IM) as EBV primary infection increased especially in the patients over 30 years old in the phase II and III. Immunological data on EBV specific antibodies showed twice positivity for anti EBV VCA-Igm antibody and the patients with anti-EBNA antibody decreased in the phase II and III. It is indicative of early diagnosis on primary EBV infection. EBV also causes atypical diseases, non-IM in this report, including hematological or neurological disorders. In hematological ones, one of 4 cases with virus associated hemophagocytic syndrome (VAHS) took fatal courses in the phase I, others had recovered by early diagnosis and adequate therapies (pulse therapy of steroids, exchange transfusion etc.). We indicated here the increased number and advanced age of patients with IM and improvement of the early diagnosis in recent 6 years compared with the previous 8 years.

Visualization of ischemic insult in caudate putamen with beta-CIT

Dopamine (DA) has been considered to play an important role in the development of ischemic neuronal injury in the caudate putamen (CPu). The goal of this study was to examine the change in the dopamine transporter (DAT) after ischemic insult in CPu.

METHODS

Male Mongolian gerbils (n = 10) were exposed to 10-min forebrain ischemia. Animals were decapitated 24 hr (n = 5) and 96 hr (n = 5) after ischemia. The change in the amount of DAT binding sites in CPu was evaluated by in vitro autoradiography with [125I]-beta-CIT (3 beta-(4-iodophenyl)tropan-2 beta-carboxylic acid methyl ester). In addition, the expression of DAT mRNA in CPu and the substantia nigra pars compacta (SNC) was examined.

RESULTS

Iodine-125-beta-CIT specific binding was significantly increased in dorsolateral CPu with ischemic damage both 24 hr and 96 hr after ischemia, with greater increase at 96 hr. DAT mRNA in SNC was also significantly increased 96 hr after ischemia, which corresponded with the increase of [125I] beta-CIT binding. However, DAT mRNA in SNC was decreased 24 hr after ischemia. In the ischemic lesion in CPu, no expression of DAT mRNA could be detected both 24 hr and 96 hr after ischemia.

CONCLUSION

The change in DAT after ischemic insult is clarified with [125I] beta-CIT. This increase of [125I] beta-CIT binding does not come from de novo expression of DAT in glial cells in the damaged area in CPu. This increase of beta-CIT binding reflects increase of DAT synthesis in DA neurons in SNC (96 hr) or other factors such as the impairment of the degradation of DAT in the damaged area in CPu.

Reg gene expression is increased in rat gastric enterochromaffin-like cells following water immersion stress

BACKGROUND & AIMS

Reg gene has been isolated from regenerating rat pancreatic islets, and subsequent studies have shown a trophic effect of Reg protein on islet cells. However, little is known about the role of Reg protein in the stomach. The aim of this study was to clarify the localization of Reg messenger RNA (mRNA) and its product in the stomach and to examine changes in the level of their expression during regeneration of gastric mucosal cells.

METHODS

Gastric lesions were experimentally induced in Sprague-Dawley rats by water immersion stress. Northern blot analysis and in situ hybridization studies were performed to examine changes in mRNA levels. Immunohistochemical studies were performed to identify the cellular localization and to investigate the change in Reg protein level.

RESULTS

Reg mRNA and its product were distributed in the basal part of the oxyntic mucosa and were expressed mainly in enterochromaffin-like cells. Levels of both Reg mRNA and its product were markedly increased in the water immersion-induced gastric lesions.

CONCLUSIONS

Reg mRNA and its product are expressed in gastric enterochromaffin-like cells, and their levels are increased during the healing process of water immersion-induced gastric lesions.

Phase Transition of KNO3 Monitored by Synchrotron X-ray Powder Diffraction

The solid-state phase transitions of KNO3 were studied at atmospheric pressure in the temperature range 303 to 533 K by synchrotron X-ray powder diffraction. The detectors used were (i) a curved position-sensitive detector and (ii) a moving imaging-plate system built for time-, temperature- and wavelength-dependent powder diffraction. On heating, the transition from α-KNO3 to β-KNO3 occurs at 401 K. On cooling with a cooling rate of 7 K min−1, the transition from β-KNO3 to γ-KNO3 was observed at 388 K. The phase transition from γ-KNO3 to α-KNO3 occurred at temperatures that strongly depended upon the cooling rate. With a high cooling rate of 15 K min−1 from 403 to 303 K, the γ-KNO3 phase was obtained as a pure phase at 303 K, but it was eventually transformed to α-KNO3 at this temperature, and the phase transition at 303 K was complete within 15 min. With a slow cooling rate of 0.5 K min−1 from 403 to 303 K, the γ-KNO3 phase was formed at 391 K and transformed at 370 K to α-KNO3. With a cooling rate of 7 K min−1 from 403 to 303 K, the γ-KNO3 phase transformed to α-KNO3 in a temperature range between 377 and 353 K. The two phases could exist simultaneously in temperature ranges that were apparently dependent upon the thermal history of the sample. The unit-cell parameters of γ-KNO3 from 383 K to room temperature are reported.

Schizosaccharomyces pombe is more sensitive to pressure stress than Saccharomyces cerevisiae

The effects of hydrostatic pressure on ultrastructure, microtubules and microfilaments of Schizosaccharomyces pombe were investigated by fluorescence microscopy, conventional electron microscopy and immunoelectron microscopy. Cells were treated with hydrostatic pressure from 0.1 to 400 MPa for 10 min at room temperature. The nuclear membrane was disrupted at above 100 MPa. At 150 MPa the matrixes of mitochondria had an electron dense area. At 250 MPa the cytoplasmic substances changed dramatically, the cellular organelles could hardly be detected and the fragmented nuclear membrane was barely visible. The fluorescence in alpha-tubulin was lost in most of the cells at 100 MPa. The gold particles for anti alpha-tubulin were not visible in the cells at the same level. Cell cycle specific actin distribution was lost even at 50 MPa, although actin dots localized at the central region remained unchanged. Thick actin cables appeared at 100 MPa. Complete depolymerization of F-actin was observed at 150 MPa. These results suggest that S. pombe cells were more sensitive than Saccharomyces cerevisiae cells. The damage to microtubules and nuclear membrane caused by hydrostatic pressure was though to be followed by breakdown of nuclear division apparatus and the inhibition of nuclear division. This damage might contribute to the frequent formation of polyploidy in S. pombe.

Changes in glutamate/aspartate transporter (GLAST/GluT-1) mRNA expression following facial nerve transection

Expression of glutamate/aspartate transporter (GLAST/GluT-1) was investigated in the axotomized facial nucleus by in-situ hybridization. Hybridization signals for GLAST mRNA were almost undetectable in the facial nucleus of sham-operated animals. However, the hybridization signals were seen from 3 days after facial nerve transection onward in the nucleus of the affected side. These signals lasted at least 5 weeks. Microautoradiograms showed that small non-neuronal cells in the ipsilateral facial nucleus expressed signals of GLAST mRNA after axotomy. These findings suggest that non-neuronal cells, presumably astrocytes, may protect axotomized motor neurons against glutamate toxicity via up-regulation of GLAST in the facial nucleus.

Knee laxity in patients with osteoarthritis and rheumatoid arthritis

Thirty-four patients with osteoarthritis (OA) and 32 patients with rheumatoid arthritis (RA) were studied to determine the effects of OA and RA on the laxity of the knee joints. Laxity was measured with the Genucom Knee Analysis System. The antero-posterior laxity of the OA and RA knees was greater than the control, normal knees in the early stage, and decreased with the severity of disease in OA, but not in RA. Severe OA and RA were associated with a restricted internal-external rotation at the knee joint compared with the control. Internal-external rotation decreased with worsening of both diseases. Varus-valgus laxity tended to increase slightly with the severity of disease. While the morphological changes of the cruciate ligaments in advanced OA and RA were not statistically different, the laxity of OA-afflicted knees was affected slightly by the severity of the damage to the cruciate ligaments.

[Home mechanical ventilation for children in Japan]

Children who require prolonged respiratory support often have to spend their whole lives in the hospital. It is important, however, to have time with their families in their own homes. Home mechanical ventilation can make it possible. In Japan, at present, there are probably more than 100 cases in which home mechanical ventilation is being used for children. We have had experience with twelve cases of home mechanical ventilation. By using a transport respirator for these children, there have been excursions 96 times and home stays 123 times. Three of these children could be released for home stay completely. Before taking the patients out of hospital, the patients received training in nursing procedures and in skillful use of the ventilator and equipment. Home mechanical ventilation was, thereby, managed successfully by the family members. Our experience revealed that home mechanical ventilation accelerated social and emotional development of these children, especially patients with neuro-muscular diseases. However, there are also many difficulties such as limitations in regard to social services and support systems, financial and educational problems, etc. Problems related to finances and support systems are the major concerns for the families. It is important to find a way out of these difficulties from the perspective of more human medicine and of quality of life. These problems should be resolved through the government support and social services. In the near future, home mechanical ventilation for children will be probably an important part of pediatrics in Japan.

Cellular localization of Na+/MYO-inositol co-transporter mRNA in the rat brain

The distribution of Na+/MYO-inositol co-transporter (SMIT) mRNA in the rat brain was studied by in situ hybridization histochemistry. The highest levels of SMIT mRNA were observed in the choroid plexus. Intense hybridization signals were found in the pineal gland, the area postrema, the hippocampus, the locus coeruleus, the suprachiasmatic nucleus, the olfactory bulb and the Purkinje cell and granule cell layers of the cerebellum. Low to moderate levels of labelling were detected in almost all neurones and small glia-like cells throughout the brain. These results suggest that almost all cells in the brain possess an SMIT-mediated osmotic and ionic regulatory system, and uneven densities of positive SMIT mRNA signals may reflect the differences in sensitivity of the cells to osmotic and ionic changes and also reflect differences in permeability of capillaries.

Widespread brain distribution of mRNA encoding the orphan neurotransmitter transporter v7-3

Orphan transporter v7-3 is a member of a new subfamily of Na+, Cl- dependent neurotransmitter transporters with two large extracellular loops. Distribution of v7-3 mRNA was investigated in the rat brain. In situ hybridization study revealed that v7-3 mRNA was widely distributed in the rat central nervous system, including the olfactory bulb, the hypothalamus, the cerebral cortex, the hippocampus, and the cerebellum. In addition, intense v7-3 mRNA expression was found in the motor nuclei including the oculomotor nucleus, abducens nucleus, trigeminal motor nucleus, facial nucleus, hypoglossal nucleus and ventral horn of spinal cord. Intense hybridization signals were also observed in the nuclei containing monoaminergic neurons, such as locus coeruleus, the substantia nigra pars compacta, the ventral tegmental area, the dorsal raphe nucleus and the median raphe nucleus. This multifocal and broad nature of the v7-3 distribution suggests widespread roles for this gene product in neurons mediating several important brain function.

Haemodynamic effects of differing blood transfusion rates in infants less than 1500 g

OBJECTIVE

To investigate whether the haemodynamic effects of the standard 2-3 h blood transfusion increases the risk for intraventricular haemorrhage (IVH) and patent ductus arteriosus (PDA) in very low birthweight infants.

METHODOLOGY

In a randomized controlled study, haemodynamic changes using slow and rapid transfusion were compared. Twenty-seven very low birthweight infants were divided between 12h (n = 14) and 3h (n = 13) transfusion groups. Blood pressure, ejection fraction (EF), anterior cerebral artery pulsatility index (PI), blood gases, serum electrolytes and haematocrit were measured pre- and post-transfusion. Infectious status was also monitored.

RESULTS

Blood pressure (48.1/25.5 vs 55.7/30.2 mmHg) and EF (0.68 vs 0.73) increased significantly during rapid transfusion (P<0.01) but remained stable with slow transfusion. Serum potassium, base excess and incidence of infection did not increase in either group.

CONCLUSIONS

Slow transfusion causes less haemodynamic disturbance than rapid transfusion, thereby preventing the potential risk for IVH and PDA.

Comparative pharmacodynamics of eight calcium channel blocking agents in Japanese essential hypertensive patients

The relationships between plasma drug concentration and antihypertensive effect of eight calcium channel antagonists (nicardipine, nifedipine, nilvadipine, benidipine, manidipine, barnidipine, nitrendipine and efonidipine) in Japanese essential hypertensive patients were analyzed. Based on the effect compartment model, we could explain the long duration of the pharmacological effect, and there was significant correlation (r = 0.876, p < 0.05) between estimated EC50 values and the dissociation constants (Kd) obtained from in vitro binding studies. We also developed the ion-channel binding model to understand the pharmacodynamics of long acting calcium antagonists. The model was also well fitted to antihypertensive effect data. A significant correlation between the apparent in vivo dissociation constants and in vitro Kd values was observed with a slope of 1.45 (r = 0.913), suggesting that the mechanism of long-lasting antihypertensive effect of newer developed calcium antagonists is due to their high binding affinity at ion-channel sites.

[Study of the usefulness of a kit containing imipenem/cilastatin powder with diluent for injection: accuracy of reconstitution]

The usefulness of a kit consisting of non-glass packaging was evaluated in terms of accuracy of reconstitution. The newly developed imipenem/cilastatin powder-and-diluent kit consists of a polyolefin bag with two chambers that contain impenem/cilastatin powder and diluent (0.9% saline, 100 ml), respectively. The accuracy of reconstitution was determined by nurse and pharmacists at the Kitasato University East Hospital by measuring the amount of materials remaining in vials after reconstitution using the syringe dilution method and the transfer-needle dilution method. The mean percent amounts of imipenem and cilastatin remaining after preparation by the syringe dilution method were 5.58 +/- 2.60% and 4.08 +/- 1.77%, respectively. The mean percent amounts of imipenem and cilastatin remaining after preparation by the transfer-needle dilution method were 3.99 +/- 2.28% and 3.71 +/- 2.09%, respectively. The amount of imipenem/cilastatin remaining in the newly developed kit should be negligible, because the kit serves as both a vial and a dosing package. Therefore, greater accuracy in terms of reconstitution is expected with the newly developed kit than with the traditional syringe dilution or transfer-needle dilution methods.

A case of generalized pustular psoriasis followed by bullous disease: an atypical case of bullous pemphigoid or a novel bullous disease?

We describe a 31-year-old Japanese woman with generalized pustular psoriasis treated with PUVA who subsequently developed a bullous disease. Throughout the disease course, there was no phase of psoriasis vulgaris. Although several reports describe coexistence of psoriasis vulgaris and bullous disease such as bullous periphigoid, coexistence of generalized pustular psoriasis without any phase of psoriasis vulgaris and bullous disease is rare. As for the bullous disease, direct immunofluorescence study showed IgG and C3 deposition along the basement membrane zone. Indirect immunofluorescence disclosed IgG antibasement membrane zone antibodies. Indirect immunofluorescence on 1 mol/l sodium chloride-split skin demonstrated linear IgG staining almost exclusively on the dermal side of the split. Western immunoblot analysis revealed that the antibody was directed to neither epidermolysis bullosa acquisita antigen nor bullous pemphigoid antigens. Considering the unusual clinical course, we suspect the possibility of a novel autoimmune blistering disease.

Expression of Na+/myo-inositol cotransporter mRNA in normal and hypertonic stress rat eyes

We studied the localization of Na+/myo-inositol cotransporter (SMIT) mRNA in normal and hypertonic stress rat eyes by in situ hybridization histochemistry using cRNA probes. SMIT mRNA signals were observed in the iris-ciliary body, the lens epithelial cells, and the ganglion cell layer and the inner nuclear layer of the retina. There was a rapid increase on SMIT mRNA in the retina of hypertonic stress rats compared with control rats. These findings suggest that Na+/myo-inositol cotransporter gene expression is osmotically regulated in vivo to protect retinal neuronal function against hypertonic stress.

Clinical observation of spontaneous anginal attacks and multivessel spasm in variant angina pectoris with normal coronary arteries: evaluation by 24-hour 12-lead electrocardiography with computer analysis

OBJECTIVES

Using a new, computerized 24-h 12-lead electrocardiographic (ECG) recording and analysis system (the EAGLE system), we sought to evaluate the clinical manifestations of ischemic episodes in patients with variant angina and normal coronary arteries.

BACKGROUND

Although the prognosis of variant angina without significant organic stenosis is generally good, the incidence of multivessel spasm, a major prognostic factor, is surprisingly high in provocation tests.

METHODS

A total of 122 patients with suspected variant or unstable angina underwent 24-h examination with the EAGLE system and two-channel Holter monitoring. Thirty patients in this group were diagnosed as having variant angina with normal or nearly normal coronary arteries. Twenty-two (73%) of these 30 patients developed anginal attacks with ST segment elevation during monitoring and were enrolled in the study.

RESULTS

The 22 patients had a total of 138 episodes of transient ST segment elevation and 13 episodes of ST segment depression. No arrhythmias were observed during ST segment depression, but 26 episodes of ST segment elevation (19%) were associated with arrhythmias: 7 with premature ventricular contractions, 3 with ventricular bigeminy, 3 with complete atrioventricular (AV) block, 1 with complete AV block and couplets of premature ventricular contractions and 12 with marked sinus bradycardia (< 45 beats/min). Ten (45%) of the 22 patients had multivessel spasm. We observed three different patterns of multivessel spasm: 1) spasm at a different site on different occasions (migratory spasm); 2) spasm that sequentially affected two different sites; 3) simultaneous spasm at more than one site. The duration of ST segment elevation was much longer in patients with sequential and simultaneous spasm than in those with single-vessel spasm, and arrhythmias were more frequent during these two types of multivessel spasm.

CONCLUSIONS

Although the prognosis of multivessel spasm is believed to be poor, this may not necessarily be so. Anginal attacks due to sequential and simultaneous multivessel spasm seem to be more dangerous than those involving single-vessel spasm or migratory multivessel spasm.

Expression of Na+/myo-inositol cotransporter mRNA in the inner ear of the rat

We have demonstrated the cellular localization of Na+/myo-inositol cotransporter (SMIT) mRNA in the rat inner ear by in situ hybridization. In the cochlea, the most intense SMIT mRNA signals were observed in fibrocytes of the spiral ligament, moderate signals were found in the spiral limbus, inner hair cells and spiral ganglion cells, while the hybridization signals were almost undetectable in the marginal cells of the stria vascularis and outer hair cells. In the vestibular system, moderate hybridization signals were found in the sensory epithelium, fibrocytes and vestibular ganglion cells. These findings suggest that SMIT plays an important role in maintenance of intracellular ionic balance and cell volume in the inner ear, especially in the fibrocytes associated with generation of the ion gradients between the endolymph and perilymph.

[The pharmacokinetics of the glycyrrhizin and glycyrrhetic acid after intravenous administration of glycyrrhizin for the patients with chronic liver disease caused by type C hepatitis virus]

Glycyrrhizin had been used widely for the patients with chronic liver disease. We examined the pharmacokinetics of the glycyrrhizin and glycyrrhetic acid in the blood stream after intra-venous administration of glycyrrhizin. The stream concentration of glycyrrhizin in the patients of liver cirrhosis tend to be kept higher than that of chronic hepatitis but there were no significant difference between them except for after a half hour from the administration. There was negative correlation between ICG R15 and the speed of excretion of glycyrrhizin from the serum. On the other hand, the concentration of the glycyrrhetic acid was kept higher in the patients with liver cirrhosis than that of chronic hepatitis, but there were no significant difference between them except for after a half hour from the administration. These findings suggested that the accumulation of glycyrrhizin and glycyrrhetic acid in the patients of liver cirrhosis can be seen by long term administration.

Early detection of pancreatic glucagonoma

Glucagonoma is a rare islet cell tumor of pancreas. Only 122 proven cases have been reported in the English literature so far. Diagnosis of glucagonoma has usually been delayed. The average size of clinically detected glucagonomas was 5.8 cm, and 54.7% of them exhibited metastasis. We describe the case of a 0.7-cm asymptomatic pancreatic glucagonoma. A 45-yr-old female was demonstrated to have a demarcated, small, low echoic mass in the pancreatic head by routine ultrasonography. Table incremental dynamic computed tomography showed a small well-enhanced mass recognized only in an early phase. A 0.7 x 0.7 cm firm nodule on the pancreatic head was excised at operation. Immunohistochemical and ultrastructural studies revealed that this tumor was a glucagon-producing adenoma. This may be the smallest glucagonoma detected by image diagnostics that has been reported in the English literature. Possible early detection of glucagonoma was discussed in this report.