Fasting hepatic insulin clearance reflects postprandial hepatic insulin clearance: a brief report

BACKGROUND

Hepatic insulin clearance (HIC) is an important pathophysiology of type 2 diabetes mellitus (T2DM). HIC was reported to decrease in patients with type 2 diabetes and metabolic syndrome. HIC is originally calculated by post-load insulin and C-peptide from the oral glucose tolerance test (OGTT). However, OGTT or meal tolerance tests are a burden for patients, and OGTT is not suitable for overt diabetes due to the risk of hyperglycemia. If we can calculate the HIC from the fasting state, it is preferable. We hypothesized that fasting HIC correlates with postprandial HIC in both participants with T2DM and without diabetes. We investigated whether fasting HIC correlates with postprandial HIC in overt T2DM and nondiabetes subjects (non-DM) evaluated by using glucose clamp and meal load.

METHODS

We performed a meal tolerance test and hyperinsulinemic-euglycemic clamp in 70 subjects, 31 patients with T2DM and 39 non-DM subjects. We calculated the postprandial C-peptide AUC-to-insulin AUC ratio as the postprandial HIC and the fasting C-peptide-to-insulin ratio as the fasting HIC. We also calculated whole-body insulin clearance from the glucose clamp test.

RESULTS

The fasting HIC significantly correlated with postprandial HIC in T2DM (r_S = 0.82, P < 0.001). Nondiabetes subjects also showed a significant correlation between fasting and postprandial HIC (r_S = 0.71, P < 0.001). Fasting HIC in T2DM was correlated with BMI, HbA1c, gamma-glutamyl transpeptidase, HOMA-IR, HOMA-beta, M/I, and whole-body insulin clearance. Fasting HIC in nondiabetes subjects was correlated with HOMA-IR and HOMA-beta.

CONCLUSIONS

These results suggest that fasting HIC is strongly correlated with postprandial HIC in both overt T2DM and non-DM patients, as evaluated by the meal test and glucose clamp method. Fasting HIC could be a convenient marker of HIC.

Aldehyde dehydrogenase 2 polymorphism is an important gene for insulin resistance in Japanese patients with type 2 diabetes

Background

Aldehyde dehydrogenase 2 (ALDH2) is an important enzyme involved in alcohol metabolism. ALDH2 polymorphism has been reported as a risk factor for type 2 diabetes mellitus (T2DM) and is associated with liver insulin resistance due to alcohol consumption in non-diabetic individuals. Herein, we investigated the association between ALDH2 polymorphisms and insulin resistance in patients with T2DM.

Methods

We performed a meal tolerance test and the hyperinsulinemic-euglycemic clamp on 71 Japanese participants: 34 patients with T2DM, and 37 non-diabetic participants. We analyzed the ALDH2 polymorphism (ALDH2 rs67); GG type was defined as the T2DM high-risk group, compared with the low-risk AG and AA groups.

Results

Glucose levels were similar in the high- and low-risk T2DM groups. The high-risk group for T2DM showed a significantly higher BMI (p < 0.005), insulin resistance in HOMA-IR (p < 0.05), and Insulin sensitivity index (p < 0.05); however, there were no significant differences in insulin resistance in the clamp test (p = 0.10). Alcohol consumption did not differ significantly between groups (p = 0.66). Non-diabetic participants also showed higher HOMA-IR insulin resistance in the high-risk group (p < 0.05), but insulin resistance levels in the glucose clamp tests (p = 0.56) and insulin secretion were not significant.

Conclusion

The results suggest that ALDH2 is an important gene associated with insulin resistance and obesity in Japanese patients with type 2 diabetes.

Retroperitoneal paraganglioma with loss of heterozygosity of the von Hippel-Lindau gene: a case report and review of the literature

Von Hippel-Lindau (VHL) disease is an autosomal dominant disease related to germline mutations in VHL. In VHL disease, pheochromocytoma develops in 10%-20% of patients because of germline mutations and loss of heterozygosity of VHL. However, the rate of paraganglioma associated with VHL is low compared with that of pheochromocytoma, and the reason is unknown. In this study, we performed germline and somatic mutation analyses of retroperitoneal paraganglioma that developed in a patient with clinically diagnosed VHL disease and investigated the tumorigenic mechanism of paraganglioma. The patient was a 25-year-old woman who was considered to have VHL disease on the basis of her family history. She was referred to our clinic to investigate a tumor at the bifurcation of the common iliac artery. The tumor was diagnosed as retroperitoneal paraganglioma by clinical evaluations. A left renal cell carcinoma was also suspected. Polymerase chain reaction direct sequencing analysis and polymorphic microsatellite analysis within the VHL locus suggested that loss of heterozygosity of VHL was associated with paraganglioma and renal cell carcinoma. Multiplex ligation-dependent probe amplification analysis showed a loss of the copy number of VHL exons in paraganglioma. These results suggest that VHL disease contributes to the development of paraganglioma. A literature review showed no reported common missense variants involved in the progression of paraganglioma. The loss of heterozygosity of VHL can be a tumorigenic mechanism of retroperitoneal paraganglioma in VHL disease. However, the low rate of paraganglioma compared with pheochromocytoma is not explained by their genetic background alone.

Significance of pancreatic duodenal homeobox-1 (PDX-1) genetic polymorphism in insulin secretion in Japanese patients with type 2 diabetes

INTRODUCTION

Pancreatic and duodenal homeobox factor-1 (PDX-1) is an imperative gene for insulin secretion in maturity-onset diabetes of the young 4. PDX-1 gene polymorphism was associated with lower first-phase insulin secretion in a genome-wide association study of intravenous glucose tolerance test. It was not associated with type 2 diabetes risk and insulin secretion in a genome-wide oral glucose tolerance test study. However, there have been no reports of overt type 2 diabetes and insulin resistance evaluation using a glucose clamp. We investigated PDX-1 polymorphism, insulin secretion, and insulin resistance in overt type 2 diabetes.

RESEARCH DESIGN AND METHODS

We performed a meal tolerance test (MTT) and hyperinsulinemic-euglycemic clamping on 63 Japanese subjects, 30 with type 2 diabetes and 33 non-diabetic. We analyzed the rs1124607 PDX-1 gene polymorphism and defined A/C and C/C as the high-risk group and A/A as the low-risk group.

RESULTS

HOMA-beta (homeostatic model assessment beta-cell function) was significantly lower in the high-risk group than in the low-risk group for all subjects (72.9±54.2% vs 107.0±63.5%, p<0.05). Glucose levels and glucose area under the curve (AUC) were not significantly different between both the risk groups. The insulin levels at 60 and 120 min and the insulin AUC after MTT were remarkably lower in the high-risk group than those in the low-risk group for all subjects (AUC 75.7±36.7 vs 112.7±59.5, p<0.05). High-risk subjects with type 2 diabetes had significantly lower insulin levels at 30 and 60 min and insulin AUC than low-risk subjects. Non-diabetic high-risk subjects depicted significantly lower insulin levels at 120 and 180 min. There were negligible differences in insulin resistance between the risk groups.

CONCLUSIONS

These results suggest that the PDX-1 genetic polymorphism is crucial for insulin secretion in Japanese patients with type 2 diabetes.

Dipeptidyl peptidase 4 inhibitor improves insulin resistance in Japanese patients with type 2 diabetes: a single-arm study, a brief report

BACKGROUND

Dipeptidyl peptidase 4 inhibitor (DPP4i) is an effective medicine for type 2 diabetes mellitus (T2DM). Some articles reported DPP4i improves insulin secretion and insulin resistance. However, these effects are not well established by glucose clamp test and test meal in Japanese. We investigated the effect of DPP4i on insulin resistance and insulin secretion by using the glucose clamp test and meal tolerance test (MTT).

METHODS

We performed a MTT, and the hyperinsulinemic-euglycemic clamp in 8 Japanese patients with T2DM. This study was a single-arm study. We measured fasting and postprandial glucose, insulin, incretins, and glucagon levels. We also measured serum adiponectin levels.

RESULTS

HbA1c was significantly decreased after 3 months. The fasting and postprandial glucose levels were significantly decreased. Fasting and postprandial insulin levels were not changed. The insulin resistance derived from the glucose clamp test was significantly improved. HOMA-IR was not significantly changed. GLP-1 and GIP were significantly increased but glucagon did not change. Adiponectin was not significantly changed.

CONCLUSIONS

Although the number of patients was very small, these results suggested that DPP4i treatment might improve insulin resistance without changing insulin secretion.

The sodium-glucose cotransporter 2 inhibitor ipragliflozin improves liver function and insulin resistance in Japanese patients with type 2 diabetes

Sodium–glucose cotransporter 2 inhibitor (SGLT2i) treatment is a therapeutic approach for type 2 diabetes mellitus (T2DM). Some reports have shown that SGLT2i treatment improves insulin resistance; however, few studies have evaluated insulin resistance by the glucose clamp method. Hepatic insulin clearance (HIC) is a new pathophysiological mechanism of T2DM. The effect of SGLT2i treatment on hepatic insulin clearance and insulin resistance is not well known. We investigated the effect of SGLT2i treatment on insulin resistance, insulin secretion, incretin levels, body composition, and hepatic insulin clearance. We conducted a meal tolerance test (MTT) and a hyperinsulinemic-euglycemic clamp test in 9 T2DM patients. Ipragliflozin (50 mg/day) was administered, and the MTT and clamp test were performed after 4 months. We calculated HIC as the postprandial C-peptide AUC-to-insulin AUC ratio. We also measured GLP-1, GIP, and glucagon levels during the MTT. Body weight and HbA1c were decreased, although not significantly, after 4 months of treatment. Postprandial glucose, fasting insulin and postprandial insulin were significantly decreased. Insulin resistance with the glucose clamp was not changed, but the HOMA-IR and insulin sensitivity indices were significantly improved. Incretin and glucagon levels were not changed. Hepatic insulin clearance was significantly increased, but whole-body insulin clearance was not changed. The FIB-4 index and fatty liver index were significantly reduced. The HOMA-beta and insulinogenic indices were not changed, but the C-peptide index was significantly increased. Although the number of patients was small, these results suggested that SGLT2i treatment improved liver function, decreased hepatic insulin resistance, and increased hepatic insulin clearance, despite the small weight reduction.

Hepatic insulin clearance is increased in patients with high HbA1c type 2 diabetes: a preliminary report

INTRODUCTION

Hepatic insulin clearance (HIC) is an important pathophysiology of type 2 diabetes. HIC was reported to decrease in patients with type 2 diabetes and metabolic syndrome. However, hyperglycemia was suggested to enhance HIC, and it is not known whether poorly controlled diabetes increases HIC in patients with type 2 diabetes. We investigated whether HIC was increased in patients with poorly controlled diabetes, and whether HIC was associated with insulin resistance and incretins.

RESEARCH DESIGN AND METHODS

We performed a meal tolerance test and the hyperinsulinemic-euglycemic clamp in 21 patients with type 2 diabetes. We calculated the postprandial C-peptide area under the curve (AUC)-to-insulin AUC ratio as the HIC; measured fasting and postprandial glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon levels and analyzed serum adiponectin and zinc transporter-8 (ZnT8) gene polymorphism.

RESULTS

The HIC significantly correlated with glycated hemoglobin (HbA1c) (r_S=0.58, p<0.01). In patients with high HIC above the median of 6.5, the mean HbA1c was significantly higher compared with low HIC below the median. Homeostatic model assessment (HOMA)-beta (r_S=-0.77, p<0.01) and HOMA-IR (r_S=-0.66, p<0.005) were correlated with HIC. The M/I value in the clamp study was correlated with HIC. GLP-1-AUC and GIP-AUC were not correlated with HIC. Glucagon-AUC was negatively correlated with HIC, but there were no significant differences between the high and low HIC groups. Adiponectin was positively correlated with HIC. The ZnT8 gene polymorphism did not affect HIC.

CONCLUSIONS

These results suggest that HIC was increased in patients with high HbA1c type 2 diabetes, low insulin secretion, low insulin resistance and high adiponectin conditions.

Anti-Ma2 associated paraneoplastic neurological syndrome presenting as encephalitis and progressive muscular atrophy

A 36 year old man with a history of testicular germ cell tumour presented six months after bilateral orchidectomy with progressive amnesia, irritability, vertical gaze palsy, and generalised seizures. Eight months after initial onset of symptoms, he demonstrated a head drop with muscular atrophy of the upper limbs, shoulder girdle, and posterior neck. He reported no sensory disturbances and his sensory examination was normal. The overall clinical presentation was consistent with motor neurone disease. Cerebrospinal fluid analysis revealed mild pleocytosis and increased protein concentration. Serum and cerebrospinal fluid were positive for the anti-Ma2 antibody by western blot analysis and immunostaining. Abnormal high signal in the grey matter was noted in the cervical spinal cord and brain by T2 weighted magnetic resonance imaging (MRI). The patient was treated with corticosteroids, intravenous immunoglobulin, and antiepileptic medication. The patient improved clinically and symptom progression ceased after initiation of treatment. There was complete resolution of the abnormal brain MRI lesions; however, the cervical spinal cord MRI lesion and muscular atrophy remained unchanged. It is suggested that the anti-Ma2 antibody is involved not only in encephalitis, but may also play a role in the cervical spinal cord lesions resulting in a motor neurone disease-like presentation.

Constant involvement of the Betz cells and pyramidal tract in amyotrophic lateral sclerosis with dementia: a clinicopathological study of eight autopsy cases

We investigated clinicopathologically pyramidal signs, including hyperreflexia, Babinski sign, and spasticity, and the involvement of the primary motor cortex and pyramidal tract, in eight Japanese autopsy cases of amyotrophic lateral sclerosis (ALS) with dementia. Pyramidal signs were observed in seven (88%) of the eight autopsy cases. Hyperreflexia and Babinski sign were evident in seven (88%) and three (38%) patients, respectively, but spasticity was not observed in any of the eight patients. Loss of Betz cells in the primary motor cortex was evident in the seven cases in which this structure was examined. Astrocytosis in the fifth layer of the primary motor cortex was noticed in three cases. In all eight cases, involvement of the pyramidal tract was obvious in the medulla oblongata, but no involvement of the pyramidal tract was found in the midbrain. Involvement of the pyramidal tract in the spinal cord, particularly of large myelinated fibers, was observed in all six cases in which the spinal cord was examined. In ALS with dementia, pyramidal signs were shown to be present more frequently than previously believed, and the clinicopathological correlation between pyramidal signs and involvement of the pyramidal tract was obvious. Constant involvement of Betz cells and the pyramidal tract in ALS with dementia has not been reported. Our clinicopathological findings may make a contribution to the understanding of the clinicopathological hallmarks of this disorder. Furthermore, we believe that this study will also contribute to the elucidation of the nosological status of ALS with dementia.

[Characteristics of hyperacuity sensitivity in normal and cyclovertical deviated subjects]

PURPOSE

To compare the sensitivity of hyperacuity of cyclovertical deviated patients with that of normal subjects.

SUBJECTS AND METHODS

The sensitivity of hyperacuity was measured in 42 normal and 12 cyclovertical deviated patients, using a newly developed computerized device which randomly presents two targets opposed vertically or horizontally on a cathode ray tube(CRT) display.

RESULTS

In normal subjects, lower thresholds were obtained when the targets were aligned either vertically or horizontally. These highly sensitive ranges were defined as "the neutral zone of hyperacuity". An anisotropy of the sensitivity of hyperacuity was observed. i.e., better thresholds were obtained when the offset was set away from the neutral zone, whereas worse thresholds were obtained when the offset as close to the neutral zones. In cyclovertical deviated patients, the thresholds of hyperacuity were high around the neutral zones, which may indicate dysfunction of the central nervous system.

CONCLUSION

This analytical method may be useful to investigate the pathophysiology of the patients with cyclovertical deviations.

SCA17, a novel autosomal dominant cerebellar ataxia caused by an expanded polyglutamine in TATA-binding protein

Genetic etiologies of at least 20% of autosomal dominant cerebellar ataxias (ADCAs) have yet to be clarified. We identified a novel spinocerebellar ataxia (SCA) form in four Japanese pedigrees which is caused by an abnormal CAG expansion in the TATA-binding protein (TBP) gene, a general transcription initiation factor. Consequently, it has been added to the group of polyglutamine diseases. This abnormal expansion of glutamine tracts in TBP bears 47--55 repeats, whereas the normal repeat number ranges from 29 to 42. Immunocytochemical examination of a postmortem brain which carried 48 CAG repeats detected neuronal intranuclear inclusion bodies that stained with anti-ubiquitin antibody, anti-TBP antibody and with the 1C2 antibody that recognizes specifically expanded pathological polyglutamine tracts. We therefore propose that this new disease be called SCA17 (TBP disease).

Sporadic amyotrophic lateral sclerosis with multiple system degeneration: a report of an autopsy case without respirator administration

This report concerns an autopsy case of amyotrophic lateral sclerosis (ALS) with unusual clinical and neuropathological findings. The patient was a Japanese man without hereditary burden who was 49 years old at the time of death. His clinical manifestation included dysarthria at age 48, followed by dysphagia, atrophy and fasciculation of the tongue, muscle weakness in the four extremities, tremor, rigidity, increased deep tendon reflexes in the upper and lower extremities, and incoordination of the four extremities. He died of respiratory failure 12 months after the disease onset. No respirator administration was performed throughout the clinical course. The neuropathological examination revealed not only degeneration of upper and lower motor neuron systems, including the presence of Bunina bodies and ubiquitin-immunoreactive neuronal inclusions in the lower motor neurons, but also prominent degeneration of the substantia nigra and dentate nucleus with slight neuronal loss in the locus ceruleus and pontine nucleus. To our knowledge, this is the first reported case of sporadic ALS without dementia and respirator support, showing degeneration of the substantia nigra and dentate nucleus. This report may contribute to the resolution of the question concerning the neuropathological heterogeneity of sporadic ALS with respiratory support.

Right ventricular infarction with cardiogenic shock treated with percutaneous cardiopulmonary support: a case report

A patient with a right ventricular infarction was resuscitated with percutaneous cardiopulmonary support (PCPS), after attempts at reperfusion, high-dose inotropic support and intra-aortic balloon counterpulsation failed to improve the hemodynamic compromise. Emergency PCPS improved the cardiogenic shock and the reduced right ventricular load, allowing the ischemic right ventricle to recover in the setting of unsuccessful reperfusion. This case demonstrates the use of PCPS as a hemodynamic support device for spontaneous recovery of the ischemic right ventricle. PCPS may be a potential therapy for patients with right ventricular infarction.

[A 40-year-old woman with progressive dementia and abnormal behavior]

We report a 40-year-old Japanese woman who died after 12 years history of progressive dementia and abnormal behaviors. She was well until 1985 at her age of 28 years old, when she had an onset of behavioral change in which she drank much, neglected house-keeping works, and her life style became sloppy. At age 30, she became unable to understand written sentences, and paced up- and down in and out of her house. She was admitted to other hospital where marked dementia with disorientation and memory loss were noted. Slight increase in CSF protein and decrease in the peripheral nerve conduction velocity were also noted at that time. In the next year, she started to have convulsions. These symptoms had progressively become worse and was admitted to Tokyo Metropolital Matsuzawa Hospital in June of 1991 when she was 34 years of age. Despite marked dementia, she was able to walk normally, no motor paralysis, cerebellar ataxia, nor dyskinesia were noted. Deep tendon reflexes were diminished. MRI revealed T-2 high signal intensity lesions involving the white matter of the cerebrum predominantly in the frontal region. In about one year, she started to show difficulty in gait, and she became bed-ridden in July of 1994. She was discharged to home for a while, but required admission again. She expired on February 5, 1998. Her younger brother had an essentially similar dementing disease and he expired at the age of 35 years. The parents were of first cousins. The patient was discussed in a neurological CPC, and the chief discussant arrived at the conclusion that the patient had adult form of metachromatic leukodystrophy, because of white matter change in the frontal lobe, decrease in nerve conduction velocity, convulsion, marked dementia, and consanguineous marriage with a similarly affected brother. Most of the audience agreed with this conclusion, but the differential diagnosis from globoid cell leukodystrophy was felt difficult from the clinical findings alone. Post-mortem examination revealed marked atrophy in the frontal lobe. Cerebellum appeared to be smaller than normal. In the coronal sections, marked atrophy of the white matter with brown discoloration was noted. The lateral ventricles were dilated. Klüver-Barrera staining revealed marked demyelination with relative preservation of the U-fibers. PAS-positive materials were deposited in some astrocytes as well as neurons. Metachromatic deposits were noted not only in the cerebrum but also cerebllum after staining with acid cresyl violet. Pathologic diagnosis was consistent with adult type of metachromatic leukodystrophy.

[Left subclavian artery approach for insertion of IABP]

A 62-year-old man admitted with a complication of chest pain. Cardiac catheterization showed three vessel disease with ventricular dysfunction (EF 40%). And aortagram showed that he had arteriosclerosis obliterans (ASO). While he was waiting for operation, the frequency of chest pain increased. It was considered necessary for him to have IABP catheter inserted. We chose left subclavian artery as an access for the insertion of IABP catheter. The catheter was easily introduced into the descending aorta under the fluoroscopy. Emergency CABG was performed the day after insertion of IABP catheter. IABP removed the next morning of operation. Operation and postoperation course was uneventful. In this case, the insertion and the removal were possible under local anesthesia. Left subclavian approach was useful for emergency case with ASO.

Ultrastructural characterization of the tau-immunoreactive tubules in the oligodendroglial perikarya and their inner loop processes in progressive supranuclear palsy

Coiled bodies and interfascicular threads are conspicuous white matter abnormalities of brains of patients with progressive supranuclear palsy (PSP). Both structures are argyrophilic and immunoreactive for the microtubule-binding protein tau. This report concerns the ultrastructural localization of interfascicular threads and their relationship to coiled bodies in five PSP patients. We showed for the first time that abnormal tubules with a 13- to 15-nm diameter and fuzzy outer contours were the common structures of coiled bodies in the oligodendroglial perikarya and of interfascicular threads. Moreover, the tubules were immunolabeled by anti-tau antibodies. The abnormal tau-positive tubules of interfascicular threads were located in the inner loop of the myelin sheath. Our study further indicated that the thread-like structures in the white matter comprised, at least in part, oligodendroglial processes, and that they were also present in gray matter. We consider that the formation of coiled bodies in the perikarya and of interfascicular threads represents a common cytoskeletal abnormality of the oligodendroglia of PSP patients. Moreover, even though the white matter alterations of PSP resemble those of corticobasal degeneration, there are certain ultrastructural differences in the abnormal oligodendroglial tubules of the two diseases.

[A 54-year-old man with progressive proximal muscle atrophy and gynecomastia]

We report a 54-year-old man with progressive proximal muscle atrophy and gynecomastia. The patient had an insidious onset of weakness in his lower extremities at age 14, in that he noted a difficulty in standing up from a chair. Soon after he noted some difficulty in climbing up stairs. At age 35, he noted weakness in his arms; his weakness slowly progressed in that he became unable to walk or stand alone before 40 years of age. He also noted gynecomastia at that age. He was admitted to our hospital for the work up on September 16, 1993, when he was 54-year-old. On admission, he was alert and oriented; his BP was 150/70 mmHg; he had bilateral gynecomastia, however, no other skeletal deformities were found. On neurologic examination, he was mentally sound without dementia, and his higher cerebral functions were normal. Cranial nerves also appeared intact without facial atrophy, dysarthria, or dysphagia; no atrophy was noted in the tongue. He had marked muscle atrophy in both upper and lower extremities more marked in the proximal portions; muscle strength was approximately in the range of 2/5 to 3/5 in the proximal parts, and 4/5 in the distal parts in both upper and lower extremities. No fasciculation was noted; muscle tone was flaccid; no ataxia was present. Deep reflexes were either lost or markedly diminished. No Babinski sign was noted. Sensation was intact. Laboratory examination revealed normal blood counts; serum CK was slightly increased to 131 IU/l; ECG showed complete right bundle branch block; EMG revealed no active units in the right biceps brachii, deltoid, quadriceps femoris, and triceps surae muscles; in other muscles tested, motor unit potentials of low amplitude and short duration were seen; in the right tibialis anterior muscle, however, motor unit potentials with an amplitude up to 6 m V were also seen. Nerve conduction velocities were normal. A diagnostic procedure was performed. He was discussed in the neurological CPC, and the chief discussant arrived at the conclusion that this patient had Becker type of progressive muscular dystrophy. In her differential diagnosis, the possibility of Kennedy-Alter-Sung syndrome was discussed because this patient had gynecomastia. However, the discussant excluded that possibility because of absence of both bulbar symptoms and typical neurogenic changes in his EMG. The diagnostic procedure was a muscle biopsy on the left tibialis anterior muscle. Histologic observation on HE stained specimens revealed marked inequality in the muscle fiber diameters, increase in endomysial nuclei, proliferation of connective tissue, and fiber splitting.(ABSTRACT TRUNCATED AT 400 WORDS)

[An autopsy case of hereditary cerebellar atrophy (Holmes-type) with mental symptoms and rhythmic skeletal myoclonus]

We report on the clinicopathological findings in autosomal recessive hereditary cortical cerebellar atrophy of the Holmes type (H-CCA). Although based on the patient's family tree we cannot rule out the possibility of sex-linked recessive hereditary disease, both clinically and pathologically we differentiated this case from sex-linked recessive hereditary cortical cerebellar atrophy, in which lesions are widely distributed and associated with a variety of symptoms, since the major clinical feature was cerebellar ataxia, and the major lesions were limited to the olivocerebellar system. The patient's initial symptom was a motor disturbance in the upper extremities at the age of 16. This was followed by chronic progression of his symptoms, with cerebellar ataxia becoming the major symptom. The patient died unexpectedly at 40 years of age as a result of choking caused by misswallowing. The total period of observation was 24 years. The clinical features in this case were juvenile onset at age 16 with motor disorders of the upper extremities, followed by cerebellar ataxia, mental symptoms, mainly consisting of personality changes, and associated rhythmic skeletal myoclonus (RSM). Even though the patient died in the middle stage of the disease, pathologically there were extensive lesions in the olivocerebellar system, i.e., extensive degeneration not only of Purkinje cells but of granular cells and the molecular layer, and the distribution of the lesions was characteristic, with more extensive degeneration in the neocerebellum than in the paleocerebellum.(ABSTRACT TRUNCATED AT 250 WORDS)

Mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes with recurrent abdominal symptoms and coenzyme Q10 administration

A male with mitochondrial myopathy, encephalopathy, lactic acidemia, and strokelike episodes is reported. He had also recurrent episodes of ileus. Muscle biopsy revealed ragged-red fibres. The cytochemistry of cytochrome c oxidase (CCO) showed scattered nonstained fibres, while all muscle fibres were heavily stained by immunocytochemistry using CCO antibody. These findings suggest that partical CCO deficiency may be present in the skeletal muscles of the patient. NADH cytochrome c reductase in the patient's muscle mitochondria was low compared with normal controls (about 26%), although succinate cytochrome c reductase was normal. Coenzyme Q10 administration (90 mg/day) did not improve CSF lactate levels, but did decrease plasma lactate levels. His muscle weakness slightly improved.

Effects of paraquat on mitochondria of rat skeletal muscle

The effect of the herbicide paraquat (N,N'-dimethyl 4,4'-bipyridium), known to damage the lipid cellular membrane by peroxidation with superoxide radicals and a singlet oxygen, was investigated on skeletal muscle mitochondria. Minced rat gastrocnemius muscles were incubated in 8 mM paraquat solution. Mitochondrial fractions prepared from the incubated muscles were examined with respect to respiratory function and the enzyme activity of cytochrome c oxidase and succinate-cytochrome c reductase in the electron transport chain. The ADP/O ratio, RCR, and state 3 rates (= oxygen consumption in state 3) decreased gradually. State 4 rates (= oxygen consumption in state 4) increased in the initial stages and decreased after longer incubations. Enzyme activities gradually increased. These results suggested that paraquat damaged the mitochondrial membrane and disrupted oxidative phosphorylation in the early stage of incubation. Also, the electron transport chain was accelerated in the earlier stage and broken following a longer incubation. The inhibitory modality of paraquat on mitochondrial respiration was shown to be different from that of other known inhibitors.

Isolation and characterization of I5B2, a new phosphorus containing inhibitor of angiotensin I converting enzyme produced by Actinomadura sp

A new inhibitor of angiotensin I converting enzyme, I5B2, was isolated from the culture broth of Actinomadura sp. No. 937ZE-1. This compound contains N-methylvaline, tyrosine and 1-amino-2-(4-hydroxyphenyl)ethylphosphonic acid. The microorganism also produced another inhibitor, I5B1, which is identical with K-4 isolated from Actinomadura sp. as an antihypertensive agent.

Isolation and characterization of ancovenin, a new inhibitor of angiotensin I converting enzyme, produced by actinomycetes

Ancovenin, an inhibitor of angiotensin I converting enzyme isolated from the culture broth of a Streptomyces species, is a dialysable peptide composed of sixteen amino acid residues containing unusual amino acids such as threo-beta-methyllanthionine, meso-lanthionine, and dehydroalanine.

Erythrocyte membrane stabilization by plant saponins and sapogenins

Effects of saponins extracted from Bupleuri Radix (saikosaponin) and the corresponding aglycones on hypotonic or hyperthermic hemolysis were investigated. Low concentrations of saikosaponins protect or stabilize rat erythrocytes against both hypotonic and heat-induced hemolysis. Minor modifications of the aglyconic part of the saikosaponin have enormous effects on the membrane stabilizing potency. Saikogenins also protect erythrocytes from hypotonic hemolysis but do not show any prevention of heat-induced hemolysis. It is suggested that saikogenins react with erythrocyte membranes in a quite different manner from saponins and that the existence of the sugar moiety plays an important role in the reaction with membranes as does a slight modification of the molecular structure in the aglyconic part.