Determination of [D-Ala2,D-Leu5]enkephalin and the metabolites containing C-terminal D-leucine by high-performance liquid chromatography

A high-performance liquid chromatographic procedure has been developed for the determination of [D-Ala2,D-Leu5]enkephalin (DADLE) and the fragments containing D-leucine in rat blood. The procedure was applied to the determination of blood levels of [3H-D-Leu5]DADLE and the C-terminal fragments after intravenous administration of [3H-D-Leu5]DADLE to a rat. Unlabelled DADLE and the C-terminal fragments were spiked as carriers to rat blood samples and the blood samples were extracted with 1% trifluoroacetic acid in methanol. The recoveries from rat blood were quantitative for all compounds. DADLE and the C-terminal four fragments were well separated on a reversed-phase column with gradient elution using a mobile phase composed of 0.14% HClO4 and acetonitrile.

[A Rathke's cleft cyst with a moving mass in the cyst]

We reported a case of Rathke's cleft cyst (RCC) with a moving mass in the cyst. A fifty-eight-year-old woman complaining of headache was admitted to our hospital. She suffered from hyponatremia, hypothalamic hypopituitarism, but did not show any neurological deficits, nor visual field nor visual acuity disturbance. MRI revealed an intrasellar cyst including a mass shadow and the cyst did not compress the hypothalamus. Interestingly, this mass moved gradually from the floor to the posterior wall of the sella turcica according to changes in position from standing to supine. We operated to remove the cyst partially by transsphenoidal approach. Xanthochromic fluid flowed out from the cyst. In addition, a brownish globular mass, 6 mm in diameter, existed within the cyst without connection to the surrounding tissue. Pathological findings showed that the capsule consisted of cuboid epithelium and was partially stratified, which confirmed the diagnosis of Rathke's cleft cyst. However, the mass was homogeneously stained with H.E., containing no cells, cellular debris, nor connective tissue. PAS stain was negative. Though we could not clarify the material in the cyst, this case is very rarely one of Rathke's cleft cyst. This case demonstrated the possibility of hypothalamic hypopituitarism in spite of the cyst being almost located in the sella turcica. We surmise that a cyst near the stalk of the pituitary gland, even if it is not so large, might compress the portal vein, and thus the function of hypothalamus-pituitary axis.

Primary malignant lymphoma of the rectum with distant metastasis to the stomach: report of a case

Primary extranodal malignant lymphoma frequently occurs in the gastrointestinal tract: however, it is rarely encountered in the rectum. We report herein the case of an 85-year-old man who underwent abdominoperineal resection for primary malignant lymphoma of the rectum, and 1 year later, developed hematemesis caused by gastric metastasis. To our knowledge this is the first case report of such distant metastasis developing from malignant lymphoma of the rectum.

[A case of myeloradiculoneuropathy associated with persistent high titers of anti-GM1 and anti-GD1b antibodies]

A 60-year-old woman was admitted to our hospital with bilateral weakness of the lower limbs. She had been suffering from spastic paraparesis of unknown origin for 12 years since she was 48. Myelopathy with the Th6 level appeared when she was 52 and underwent gradual deterioration. On admission, she showed spastic paraparesis and myelopathy with the Th6 level. A thoracic spinal MRI examination revealed a wholly thin spinal cord. EMG demonstrated that the conduction velocity of the peroneal nerve was 37.8m/sec, and F waves were not evoked on stimulation of the peroneal nerve. Although the anti-GM1 and anti-GD1b antibody titers in the serum were increased on admission, their values decreased transiently after whole plasmapheresis. There was accompanying impairment of the radiculoneuropathy and myelopathy. It is important to measure the titers of anti-ganglioside antibodies in patients with myeloradiculoneuropathy of unknown origin, and whole plasmapheresis is considered to represent a useful treatment for this type of illness.

Potassium channel opener reduces extracellular glutamate concentration in rat focal cerebral ischemia

The vasodilatory action of potassium channel openers through a membrane hyperpolarizing action is well known, but little is known about the effect of these drugs on ischemia-induced glutamate release in the brain. We evaluated the effects of a potassium channel opener (Y-26763), given intravenously at 0.03 mg/kg/h from 50 min prior to occlusion until 3 h postocclusion, on cerebral blood flow, extracellular glutamate concentration, and infarct volume in rats with focal ischemia. Y-26763 significantly inhibited the increase in extracellular glutamate concentration at 50 and 60 min of ischemia with a significant reduction of mean arterial blood pressure. However, there was no significant difference in blood flow in the core of infarcted cortex or in infarct volume between Y-26763- and vehicle-treated groups. These results suggest that Y-26763 inhibited presynaptic glutamate release through hyperpolarizing the membrane, but infarct volume was not reduced because of insufficient perfusion owing to its hypotensive effect.

Effect of chronic alcohol intake on energy metabolism in human muscle

We investigated the effect of alcohol on muscle energy metabolism by using 31P magnetic resonance spectroscopy in 12 chronic alcoholics [6 with neurological signs and symptoms (such as cerebellar ataxia or diplopia) and 6 without neurological signs or symptoms], compared with five healthy subjects who also received acute alcohol loading. Intracellular pH and phosphocreatine (PCr) index [PCr/ (PCr + Pi)] were measured during rest, exercise, and recovery in the left flexor digitorum superficialis muscle. In healthy subjects, acute alcohol loading did not influence the changes of muscle pH and PCr index. Alcoholics with neurological signs showed marked decreases in muscle intracellular pH and PCr index during exercise and a marked delay of pH recovery after exercise. There was no delay of PCr index recovery. Alcoholics without neurological signs showed slight decreases in intracellular pH and PCr index, but rapid recovery of both intracellular pH and PCr index was observed. Marked decrease and delayed recovery in pH, but rapid recovery of PCr index, indicate that the muscle of patients with neurological signs produced lactate during and after exercise to maintain the ATP level, which implies that anaerobic metabolism is favored over aerobic metabolism in these patients.

Modulation of extracellular glutamate concentration by nitric oxide synthase inhibitor in rat transient forebrain ischemia

The purpose of the present study was to clarify the effect of topical administration of a nitric oxide synthase inhibitor on extracellular glutamate concentration in transient forebrain ischemia. Two microdialysis probes were inserted into the bilateral striata of Wistar rats. NG-Nitro-L-arginine (L-NNA) with or without L-arginine was topically administered into the unilateral striatum through one of the microdialysis probes, while Ringer's solution was perfused into the contralateral striatum as the control, and 14 minutes of forebrain ischemia was applied. The extracellular glutamate concentration during ischemia and subsequent reperfusion was statistically significantly higher on the 100 microM L-NNA-perfused side than on the control side, but 1 mM L-NNA was ineffective. When 100 microM L-NNA was perfused together with 500 microM L-arginine, the glutamate concentration did not differ from that on the control side. Moreover, administration of 500 microM L-arginine significantly suppressed the glutamate elevation after reperfusion. The fact that the lower dose of L-NNA increased the accumulation of glutamate during ischemia and reperfusion without altering blood flow may indicate that nitric oxide affords protection against ischemia neuronal damage. However, since the higher dose of L-NNA did not affect the glutamate concentration, it appears that the effect of nitric oxide on extracellular glutamate concentration in forebrain ischemia differs, depending on the degree of the inhibition of NOS activity.

Fatal familial insomnia with a mutation at codon 178 of the prion protein gene: first report from Japan

Fatal familial insomnia (FFI), or familial selective thalamic degeneration with a mutation at codon 178 of the prion protein (PrP) gene, is a rapidly progressive autosomal dominant disease characterized by progressive insomnia, dysautonomia, and myoclonus. We report here the clinical and postmortem findings as well as genomic analysis in a first non-Western case with FFI. This patient also clinically had cognitive impairments such as memory disturbance, delirium, and hallucinations, along with insomnia, dysautonomia, and myoclonus. This case implies a worldwide distribution of FFI and also highlights the need for more aggressive clinical application of genomic analysis of the PrP gene and polysomnographic study in patients with insomnia and cognitive impairments.

Mineral phases and some reexamined characteristics of the International Union Against Cancer standard asbestos samples

Standard asbestos samples to be used for biomedical research were first prepared by the International Union Against Cancer (UICC) in 1966 in the United Kingdom and South Africa. Using modern techniques, X-ray diffractometry, analytical transmission electron microscopy, and thermal analysis, we have now analyzed these UICC samples to determine the mineral compositions (mineral phases) and their respective quantities. UICC chrysotile A (from Zimbabwe) contains 2% fibrous anthophyllite as impurity; chrysotile B (from Canada) does not contain any fibrous impurities, only non-fibrous minerals. UICC amosite and crocidolite are almost pure. UICC anthophyllite has 20-30% talc as impurity. The chemical compositions and fiber size distributions of the UICC asbestos samples have also been determined. The mean widths of the fibers of chrysotile A and B are smaller than those of the amphibole fibers. This agrees well with the earlier results which showed the two chrysotile samples to have a larger respirable fraction than the amphiboles.

Treatment of essential and parkinsonian tremor with nipradilol

Nipradilol is a new type of beta-blocker which possesses nitroglycerin-like vasodilating action in addition to beta-blocking action. We investigated the efficacy and safety of nipradilol for treating tremor in 20 patients with essential tremor (ET group) and 20 patients with Parkinson's disease (PD group). All patients received nipradilol (6 mg per day) for more than 8 weeks. Improvement of tremor appeared within 2 or 4 weeks after the start of nipradilol therapy, and the efficacy rate, defined as "moderately effective" or over, was 42.5% in all 40 patients, while that defined as "slightly effective" or over was 87.5%. The efficacy rate tended to be higher in the ET group compared with the PD group. Mean blood pressure was significantly decreased from the 4th week after the start of treatment and heart rate was significantly reduced from the 2nd week of treatment. Laboratory examination showed no significant changes.

Magnetic resonance imaging of herpes simplex virus encephalitis: reversible asymmetric basal ganglia lesions

We report a patient with herpes simplex virus type 1 encephalitis (HSE) who showed abnormal magnetic resonance imaging (MRI) signals in the basal ganglia. The lesions were asymmetric and became apparent with relapse of the neurological symptoms, but they completely disappeared, concomitantly with improvement of the illness.

Reversible magnetic resonance imaging lesions in Wilson's disease: clinical-anatomical correlation

Described herein is a patient with Wilson's disease who had tremor as a prominent neurological manifestation. T2-weighted magnetic resonance imaging showed abnormal high signal intensities in the bilateral lenticular nuclei, thalami, and red nuclei of the midbrain. Improvement of tremor with copper chelating agents was well correlated with a decrease of the abnormal signals in the thalami and the red nuclei.

[A case of medial medullary infarction with prominent deep sensory impairment]

We report a patient with medial medullary infarction who showed deep sensory impairment as his prominent neurological manifestation. A 54-year-old man with a history of hypertension was admitted to our hospital with numbness of the bilateral upper and lower extremities, followed by dysarthria and right hemiparesis. Physical examination revealed no abnormalities except for high blood pressure. He hiccuped continuously. On neurological examination, he exhibited dysarthria, mild dysphagia and right hemiparesis without facial or lingual paresis. Sensitivity to light touch and pinprick was normal, but sensitivity to vibration and joint position was severely decreased in the bilateral upper and lower extremities, predominantly in the lower extremities and on the right side in the upper extremities. He had been treated with antiedema agents and thromboxane synthetase inhibitor. His hiccups stopped within two weeks, and his right hemiparesis gradually improved within one month. However, his deep sensory impairments remained prominent. Blood examinations disclosed positive lupus anticoagulant. MRI showed bilateral infarction at the medial portion of the upper medulla oblongata, extending to both pyramids, especially on the left. Somatosensory evoked potentials (SEP) after median nerve stimulation showed P14 and the later components with prolonged latency. No SEP were recorded after posterior tibial nerve stimulation. The latency of P14 was well correlated with the severity of deep sensory impairments in the upper extremities. Neurological manifestations of our patient are not typical of medial medullary infarction, and are informative about the functional anatomy of the deep sensory tract in the medulla oblongata. We discuss the relation of the intractable hiccups to the bilateral medial medullary lesions, and emphasize the importance of lupus anticoagulant as one of the risk factors in brainstem infarction.

Carbon monoxide, a novel neural messenger, does not modulate extracellular glutamate concentration in forebrain ischemia

We investigated the role of carbon monoxide as a neural modulator of extracellular glutamate concentration in rat hippocampus CA1 in transient forebrain ischemia by using metalloporphyrins, which block the production of carbon monoxide through the inhibition of heme oxygenase (HO) activity. Infusion of 10 and 100 microM zinc protoporphyrin IX, which inhibits nitric oxide synthase activity as well as HO activity, significantly increased glutamate concentration compared with that on the vehicle-treated side. However, infusion of 100 microM tin mesoporphyrin IX, which inhibits only HO activity, did not affect glutamate concentration in ischemia. Our results therefore do not support the hypothesis that carbon monoxide acts as a neural messenger through the modulation of extracellular glutamate concentration in ischemia.

Bifunctional labeling reagent for oligosaccharides to incorporate both chromophore and biotin groups

We have developed a convenient and effective method for biotinylation of oligosaccharides at their reducing ends. A novel biotin hydrazide having a phenyl group produced the biotin adduct of N-acetyllactosamine (LacNAc) by simple incubation at 90 degrees C for 1 h. Although the biotin adduct was obtained as a mixture of several stereoisomers, one of the isomers, cyclic beta-glycoside, became predominant upon letting the reaction mixture stand in a weakly acidic state (pH 3.5). This conversion may be very advantageous for functional analysis of oligosaccharides because natural N-linked oligosaccharides exist in the cyclic beta form. The limit of detection of labeled LacNAc in reversed-phase chromatography was 330 fmol and showed good linearity in the range from 330 fmol to 261 pmol. When this procedure was applied to complex type and high mannose type N-linked oligosaccharides, the labeled oligosaccharides were easily detected and separated by reversed-phase, gel filtration, and anion exchange chromatographies. Furthermore, these labeled oligosaccharides were able to be immobilized onto the solid phase using avidin-biotin technology and were stable enough to allow the binding assay to be performed repeatedly and under the conditions for in situ exoglycosidase digestion. These results suggest that this derivatization technique might be useful for both separation and functional analysis of oligosaccharides.

[Concentration and fiber size of asbestos in lungs of residents living close to the serpentinite area]

Concentrations and fiber size distribution of asbestos in the lung tissue of 16 ( 8 males and 8 females) rural residents living close to the serpentinite area (neighboring group) were analyzed by low temperature ashing-analytical transmission electron microscopy, and were compared with those of 5 (5 males) rural and 53 (34 males and 19 females) urban residents living away from the serpentinite area (reference group). The results are as follows; 1. Pulmonary asbestos fibers were found in all rural residents. The types of asbestos fibers were chrysotile, amosite, crocidolite, actinolite, and tremolite. These findings were very similar to results for urban residents. 2. In males, the geometric mean concentration of actinolite-tremolite in the neighboring group (1.78 x 10(6) fibers/g dry lung) was significantly higher than those in the reference groups (rural: 0.32 x 10(6), urban: 0.31 x 10(6), p < 0.01). In females also, the geometric mean concentration of actinolite-tremolite in the neighboring group (0.59 x 10(6)) was significantly higher than that in the reference group (urban: 0.16 x 10(6), p < 0.05). There were no significant differences in the actinolite-tremolite concentrations between males and females in the neighboring group. 3. The serpentinite in this area have contained not only chrysotile but also both actinolite and tremolite. There was no significant relationship between actinolite-tremolite concentration and occupational history in the neighboring group. It is possible that actinolite and tremolite are liberated from the serpentinite to the atmosphere and inhaled by the residents near the serpentinite area which increases pulmonary actinolite-tremolite concentration. 4. The difference in the geometric mean concentration of chrysotile between the neighboring and the reference group was not statistically significant for both sexes, possibly due to the poor durability of chrysotile in the lung tissue. 5. There were no significant differences in the geometric mean of fiber length and diameter of actinolite-tremolite between the neighboring and the reference group.

Distinctive serial magnetic resonance changes in a young woman with rapidly evolved neurocysticercosis, with positron emission tomography results

A woman aged 21 years noticed numbness of the left hand, dysarthria, and right hemiparesis. Magnetic resonance imaging (MRI) showed homogeneously enhanced lesions in the bilateral cerebral white matter; these enlarged within 2 weeks, showing ring-like enhancement, and then spontaneously decreased in size and enhancement. Neurocysticercosis was confirmed by repeated, significantly positive serology results and the dramatic response to praziquantel. Subsequently, positron emission tomography (PET) revealed persisting regions of possibly decreased cerebral uptake of [18F]2-fluoro-2-deoxyglucose. This is the first documentation of such distinctive serial MRI changes and the results of PET in neurocysticercosis.

Magnetic resonance imaging in Avellis' syndrome

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Limb lengthening and correction of angulation deformity: immediate correction by using a unilateral fixator

We performed limb lengthening (callus distraction) with immediate correction of the angulation deformity in 11 patients (16 long-bone segments) in Chiba Children's Hospital. The operated segments were 14 tibias and two femurs. The average age at operation was 12.0 years (range, 4.8-15.3). All had varus deformities and limb shortening. We used the Orthofix unilateral fixator in all cases. The following two types of osteotomy were selected, depending on the degree of the varus deformity: opening wedge osteotomy if it was < 20 degrees or dome osteotomy if > 20 degrees. The average amounts of the leg lengthening and the correction angle were 32.4 mm (range, 20-50) and 23.8 degrees (range, 15-40 degrees). The average of the healing index was 32.6 days/cm (range, 28.5-36.8 days/cm). There was also no difference in healing index between the two osteotomies groups, despite the greater angular correction in the dome osteotomy group. We concluded that our method of lengthening with immediate correction of deformity was a very simple and effective method.

Alteration of enzyme function of the type II hexokinase C-terminal half on replacements of restricted regions by corresponding regions of glucokinase

To know the structural properties responsible for the enzymic activity of the 50-kDa C-terminal half of type II hexokinase (HKII-C) derived from rat hepatoma cell line AH130, we constructed cDNAs of HKII-C and its recombinants in which restricted regions containing highly conserved sequences, referred to as regions 2 and 3, were replaced by the corresponding regions of glucokinase. The binding domains of ATP and glucose were proposed to exist in these regions, respectively. Then, the HKII-C and chimera HKII-Cs were overexpressed in Escherichia coli BL21(DE3)pLysS. They all exhibited hexokinase activity, and their activities were inhibited by glucose-6-phosphate (Glc-6-P) competitively for ATP and uncompetitively for glucose. The replacement of region 2 of HKII-C by the corresponding region of glucokinase increased the affinity for glucose and decreased the affinity for Glc-6-P, but it did not significantly affect the affinity for ATP. In contrast, the replacement of region 3 did not cause an appreciable change in hexokinase activity. These findings suggest that region 2 is associated with the binding of ATP and Glc-6-P, and that the latter binding site is located close to the ATP binding site. In addition, region 2 was suggested to be directly related with the binding of glucose and other hexoses.

Isolation and characterization of cDNA and genomic clones encoding human muscle type carnitine palmitoyltransferase I

With a cDNA probe encoding rat muscle type carnitine palmitoyltransferase I (CPTI), we isolated cDNA and genomic clones encoding the human homologue and deduced the primary structure of human muscle type CPTI. By Northern analysis, we confirmed the dominant expression of this isoform in heart and skeletal muscle.