[The clinical usefulness of high-dose intravenous immunoglobulin therapy for chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy]

To explore the optimum dose of intravenous immunoglobulin (i.v.Ig) for treating patients with chronic inflammatory demyelinating polyrneuropathy and multifocal motor neuropathy, we compared the usefulness of i.v.Ig among 3 treatment doses. Fifty-nine patients were randomly divided into three treatment dosage groups: 20 patients for Group I using 50 mg/kg/day x 5 days, 19 patients Group II using 200 mg/kg/day x 5 days, and 20 patients Group III using 400 mg/kg/day x 5 days. We assessed clinically and electrophysiologically the effectiveness of the treatment at 5 weeks after the initial infusion. For patients in Group I and II who had not improved (or worsened) with the first treatment, we gave a one-step larger dose in the second treatment (i.e. 200 mg/kg/day x 5 days for those who had been given 50 mg/kg/day x 5 days, 400 mg/kg/day x 5 days for those who had been given 200 mg/kg/day x 5 days) after more than 9 weeks. We found that 15% of the patients in Group I, 21% in Group II and 60% in Group III improved dose-dependently with the first intravenous immunoglobulin treatment. Seven (47%) of 16 patients in Group I and 4 (40%) of 11 patients in Group II improved after the second treatment with larger doses. Adverse reactions including chill sensation, fever, skin eruption and increase in blood GOT and GPT levels were transient and mild. One patient in Group III developed left hemiparesis showing the small infarction in the right thalamus during the course of the treatment, but the symptom was mild. In conclusion, the high-dose intravenous immunoglobulin therapy (400 mg/kg/day x 5 days) is useful for treating patients with CIDP and MMN, although care must be taken of the risk of causing cerebral infarctions.

Ruptured aneurysm of the orbitofrontal artery associated with dural arteriovenous malformation in the anterior cranial fossa--case report

A 27-year-old male presented with a rare association of a ruptured orbitofrontal artery aneurysm and a dural arteriovenous malformation (DAVM) fed by both ethmoidal arteries, manifestation as severe headache, nausea, and vomiting. Computed tomography revealed a hematoma within the right frontal lobe and diffuse subarachnoid hemorrhage. The aneurysm was clipped successfully and the hematoma was evacuated. After an uneventful postoperative course, the patient was referred for gamma knife radiosurgery to treat the DAVM. In this case, the DAVM was asymptomatic and pathogenetically unrelated to the aneurysm, which demanded urgent treatment.

Age-dependent changes in physiological threshold asymmetries for the motor evoked potential and silent period following transcranial magnetic stimulation

OBJECTIVE

To study the effect of age on the physiological threshold asymmetries for the motor evoked potential (MEP) and silent period (SP) following transcranial magnetic stimulation.

METHODS

We studied 63 right-handed subjects and 13 young left-handed subjects (19-39 years). The right-handers were classified into three age groups; 22 young (20-38 years), 20 middle-aged (40-58 years) and 21 old (61-82 years) subjects. We measured the MEP thresholds at rest and during voluntary contraction (VC), and the SP thresholds from the right and left abductor pollicis brevis (APB) muscles. We also measured the side to side differences of the F wave persistency and the F wave/M wave amplitude ratio from the same muscles.

RESULTS

Among young subjects, all of the MEP and SP thresholds for the right APB were significantly lower than those for the left APB in the right-handers, and the reverse was true in the left-handers. The results in the middle-aged right-handers were similar to those in the young right-handers, but in the old right-handers, none of the thresholds were different between the two sides. We did not find any asymmetries of the F wave in the subjects of any age group.

CONCLUSION

We speculate that the age-dependent threshold asymmetries are preferentially related to functional asymmetries at the cortical level.

Effect of nilvadipine on the voltage-dependent Ca2+ channels in rat hippocampal CA1 pyramidal neurons

Effects of nilvadipine on the low- and high-voltage activated Ca2+ currents (LVA and HVA ICa, respectively) were compared with other organic Ca2+ antagonists in acutely dissociated rat hippocampal CA1 pyramidal neurons. The inhibitory effects of nilvadipine, amlodipine and flunarizine on LVA ICa were concentration- and use-dependent. The apparent half-maximum inhibitory concentrations (IC50s) at every 1- and 30-s stimulation were 6.3x10-7 M and 1.8x10-6 M for flunarizine, 1.9x10-6 M and 7.6x10-6 M for nilvadipine, and 4.0x10-6 M and 8.0x10-6 M for amlodipine, respectively. Thus, the strength of the use-dependence was in the sequence of nilvadipine>flunarizine>amlodipine. Nilvadipine also inhibited the HVA ICa in a concentration-dependent manner with an IC50 of 1.5x10-7 M. The hippocampal CA1 neurons were observed to have five pharmacologically distinct HVA Ca2+ channel subtypes consisting of L-, N-, P-, Q- and R-types. Nilvadipine selectively inhibited the L-type Ca2+ channel current which comprised 34% of the total HVA ICa. On the other hand, amlodipine non-selectively inhibited the HVA Ca2+ channel subtypes. These results suggest that the inhibitory effect of nilvadipine on the neuronal Ca2+ influx through both LVA and HVA L-type Ca2+ channels, in combination with the cerebral vasodilatory action, may prevent neuronal damage during ischemia.

Sympathetic skin responses recorded from non-palmar and non-plantar skin sites: their role in the evaluation of thermal sweating

OBJECTIVE

To characterize the sympathetic skin responses (SSRs) recorded from non-palmar and non-plantar (non-Pa/P1) skin sites and to evaluate their clinical usefulness.

METHODS

SSRs were recorded from 6 non-Pa/P1 sites as well as palmar and plantar (Pa/P1) sites using magnetic neck stimulation in 33 normal subjects, 17 neurological patients with dysautonomia and one patient with lumbar sympathectomy. A conventional thermoregulatory sweat test (TST) was also carried out in 3 patients.

RESULTS

Clear and reproducible SSRs were obtained from all recording sites in all of the normal subjects when the skin temperatures of the subjects were maintained above 34 degrees C and the subjects drank 100-200 ml of hot water. The distribution of absent SSRs was closely correlated with that of anhidrosis or a sweating delay shown by the TST in the patients. Nine of the 17 neurological patients (53%) showed normal responses at Pa/P1 sites, and abnormal responses at non-Pa/P1 sites.

CONCLUSIONS

Recording SSRs from multiple skin sites including non-Pa/P1 sites after magnetic stimulation is more sensitive in detecting sudomotor dysfunction than is the conventional method of recording SSRs from only Pa/P1 sites. In addition, this new method is very useful for the objective clinical evaluation of thermal sweating.

Denervation of eccrine glands in patients with familial amyloidotic polyneuropathy type I

OBJECTIVE

To study the alterations in the structure and innervation of eccrine glands in familial amyloidotic polyneuropathy (FAP) type I with Val 30 Met transthyretin mutation.

BACKGROUND

Anhidrosis of the distal lower limbs is a prominent feature of FAP type I.

METHODS

Qualitative and morphometric study of amyloid deposition, eccrine glands, and their innervation in nine patients with FAP type I (duration of sensory symptoms, 8.4 +/- 3.9 years [mean +/- SD]; range, 3 to 15 years) and seven control subjects.

RESULTS

On light microscopy, the endoneurium of cutaneous nerve fascicles had no definite amyloid deposition. Amyloid deposition was observed around eccrine glands in seven of nine patients. On electron microscopy, no focal destruction and degeneration of eccrine glands or ducts and of Schwann cell processes with or without nerve terminals or unmyelinated axons were observed in relation to adjacent amyloid deposition. Secretory vacuoles and granules of dark cells were markedly decreased in some secretory coils. Nerve terminals and unmyelinated axons of eccrine glands were considerably fewer in patients than in control subjects, and denervation was prominent in all patients. A few nerve terminals and unmyelinated axons of eccrine glands were present in patients who had experienced sensory symptoms for 3, 5, and 6 years, but were absent in patients with sensory symptoms for more than 7 years.

CONCLUSIONS

Eccrine glands are markedly to totally denervated in patients with FAP type I and chronic sensory symptoms. The extent of denervation indicates the severity of autonomic denervation and therefore may suggest the timing of liver transplantation.

Nuclear pore changes and absence of apoptosis in lumbar dorsal root ganglion neurons of doxorubicin-intoxicated rats

Doxorubicin (DXR) produces degeneration of neurons in the lumbar dorsal root ganglion (DRG) in rats. Light microscopic studies, which included the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling method, and electron microscopic observation revealed that the moderate nuclear and remarkable cytoplasmic degeneration of DRG neurons of Sprague-Dawley rats after intravenous administration of 8 mg/kg of DXR was cell necrosis, not apoptosis. In some neurons, mostly dark and usually with moderate degrees of nuclear degenerative changes, the nuclear pores were decreased in number and obscure 14 and 20 days after DXR administration. DXR enters presumably the nucleus and is partly removed through the nuclear pores. However, the diameters of nuclear pores were similar in DXR-intoxicated and control rats. The changes in nuclear pores of neurons in DXR intoxication, which to our knowledge has not been previously studied, are considered to be part of the degenerative or necrotic changes of DRG neurons.

Acetylcholine modulation of high-voltage-activated calcium channels in the neurones acutely dissociated from rat paratracheal ganglia

1. The modulation of high-voltage-activated (HVA) Ca2+ channels by acetylcholine (ACh) was studied in the paratracheal ganglion cells acutely dissociated from 2-week-old Wistar rats by use of the nystatin perforated patch recording configuration under voltage-clamp conditions. 2. ACh inhibited the HVA Ca2+ currents in a concentration- and voltage-dependent manner. 3. The inhibition was mimicked by a muscarinic agonist, oxotremorine. Pirenzepine and methoctramine produced parallel shifts to the right in the ACh concentration-response curves. Schild analysis of the ACh concentration-ratios yield pA2 values for pirenzepine and methoctramine of 6.85 and 8.57, respectively, suggesting the involvement of an M2 receptor. 4. Nifedipine, omega-conotoxin-GVIA and omega-conotoxin-MVIIC reduced the HVA I(Ca) by 16.8, 59.2 and 6.3%, respectively. A current insensitive to all of these Ca2+ antagonists, namely 'R-type', was also observed. The results indicated the existence of L-, N-, P/Q-, and R-type Ca2+ channels. 5. The ACh-sensitive current component was markedly reduced in the presence of omega-conotoxin-GVIA, but not with both nifedipine and omega-conotoxin-MVIIC. ACh also inhibited the R-type HVA I(Ca) remaining in saturating concentrations of nifedipine, omega-conotoxin-GVIA and omega-conotoxin-MVIIC. 6. The inhibitory effect of ACh was prevented by pretreatment with pertussis toxin. 7. It was concluded that ACh selectively reduces both the N- and R-type Ca2+ channels, by activating pertussis toxin sensitive G-protein through the M2 muscarinic receptor in paratracheal ganglion cells.

Magnetic resonance imaging-documented extravasation as an indicator of acute hypertensive intracerebral hemorrhage

OBJECT

The aim of this study was to determine the usefulness of magnetic resonance (MR) imaging-documented extravasation as an indicator of continued hemorrhage in patients with acute hypertensive intracerebral hemorrhage (ICH).

METHODS

The authors studied 108 patients with acute hyperintensive ICH. Imaging modalities included noncontrast-enhanced computerized tomography (CT) scanning, gadolinium-enhanced MR imaging, and conventional cerebral angiography obtained within 6 hours after the onset of hemorrhage. A repeated CT scan was obtained within 48 hours to evaluate enlargement of the hematoma. Findings on MR imaging indicating extravasation, including any high-intensity signals on T1-weighted postcontrast images, were observed in 39 patients, and 17 of these also showed evidence of extravasation on cerebral angiography. The presence of extravasation on MR imaging was closely correlated with evidence of hematoma enlargement on follow-up CT scans (p < 0.001).

CONCLUSIONS

Evidence of extravasation documented on MR imaging indicates persistent hemorrhage and correlates with enlargement of the hematoma.

Different effect of oxytocin on membrane potential of supraoptic oxytocin neurons in virgin female and male rats in vitro

The effects of oxytocin on membrane potential were investigated in the supraoptic nucleus (SON) neurons of rats using whole-cell patch-clamp technique. SON neurons were electrophysiologically identified as oxytocin (OT) or vasopressin (VP) neurons. Application of OT (1 x 10[-7] M) hyperpolarized membrane potentials of OT neurons in virgin female rats but depolarized membrane potentials of putative OT neurons in male rats. The membrane conductance of SON neurons were increased by treatment of OT in both sexes, suggesting that OT increased the opening of channels on SON neurons. The reversal potential of OT neurons in virgin female rats and putative OT neurons in male rats under OT effective conditions were -66 +/- 1 mV (n = 4) and -46 +/- 2 mV (n = 5), respectively. These data suggest that OT released within the SON suppresses the activity of OT neurons in virgin female rats while it excites putative OT neurons in male rats.

Differential effects of acrylamide on the degeneration and regeneration of myelinated fibers between C57BL/Ola and C57BL/6J mice after crush injury

To investigate differences in the pathologic processes between mutant C57BL/Ola (Ola) and normal C57BL/6J (6J) mice, the effect of acrylamide (ACR) on the degeneration and regeneration of myelinated fibers after crushing the sciatic nerve was morphometrically evaluated. Both Ola and 6J mice were treated with either ACR (subcutaneous injection of 50 mg/kg every other day for 13 days, n = 6) or physiological saline (n = 6). Morphometric evaluation of myelinated fibers of the sciatic nerve 5 mm distal to the proximal end of the crush site was performed systematically on day 14 of the crushing for each mouse. In Ola mice treated with either saline or ACR, large and small myelinated fibers remained without obvious progression of Wallerian degeneration, and degeneration of myelinated fibers was slower than in 6J mice. On the other hand, in 6J mice treated with either saline or ACR, many small myelinated fibers regenerated after degeneration and loss of both large and small myelinated fibers. In Ola mice, no statistically significant difference in the morphometric parameters was found between saline-treated and ACR-treated groups. Therefore, ACR did not have a significant effect on Wallerian degeneration of myelinated fibers in Ola mice. However, in 6J mice regenerated myelinated fibers were fewer in those receiving ACR than in those receiving saline. Therefore, ACR suppresses regeneration of myelinated fibers after crushing in 6J mice. A delay or partial failure of axonal sprouting and elongation may be responsible for the lower numbers of regenerated myelinated fibers. This study demonstrates the importance of the substrain differences in the degeneration and regeneration of myelinated fibers which may have implications for understanding the different susceptibilities to various neuropathies in man.

[Electrophysiological study of a case of clinically diagnosed corticobasal degeneration with rhythmic myoclonus]

A 66-year-old man with clinically diagnosed corticobasal degeneration was studied electrophysiologically. The patient had bilateral forced grasping, rigidity, bradykinesia and hyperreflexia which were predominant on the right side, motor aphasia, constructional apraxia, forced laughing, dysequilibrium and myoclonus of the right upper extremity. Several anti-parkinsonism drugs were ineffective. Brain MRI revealed cortical atrophy of the fronto-temporo-parietal lobes with left predominance. On single photon emission computed tomography, cerebral blood perfusion was decreased, especially on the left side in the fronto-temporal lobes, basal ganglia and thalamus. Myoclonus was distal dominant, worse on action or posture, and was rhythmic, mimicking a tremor. On surface EMG recording of the myoclonus, agonist and antagonist muscle pairs were activated simultaneously and rhythmic activities with frequencies ranging from 7 to 8 Hz were seen. The patient had an enhanced C reflex with a relatively short latency (41.0 ms) after median nerve stimulation only at the right wrist. Additionally, during voluntary contraction, the time-constant EMG silence lasting for about 80-90 ms followed the C reflexes. On somatosensory evoked potentials (SEPs) to the median nerve stimulation, N20 latencies were normal and P25 and N33 amplitudes were not giant. There was no premovement corticat spike when a jerk-locked averaging method was used. Regarding motor evoked potentials (MEPs) elicited by magnetic brain stimulation, central motor conduction times were normal. The estimated cortical delay between the arrival of a somatosensory volley and the motor cortical discharge responsible for C reflex was 1.0 ms, which was shorter than those (3.1 +/- 0.9 ms) estimated in five patients with typical cortical reflex myoclonus. A conditioning stimulation (C) of the right median nerve produced marked facilitation of MEPs following magnetic stimulation of the left motor cortex, at conditioning-test intervals (C-T intervals) of 20-22 ms, whereas a conditioning stimulation of the left median nerve did not produce the same effect. These C-T intervals were thought to be very short, considering that N20 latency was 19.6 ms in this patient. The duration of the EMG silence following the C reflex corresponded to that of the EMG silence between muscle activities during his rhythmic myoclonus, and also the myoclonus was reset by occurrence of the C reflex. These electrophysiological findings indicate that his myoclonus was based upon the enhancement of direct sensory input from the thalamus to the motor cortex. Moreover, it is suggested that the existence of the time-constant EMG silence following the C reflex was related to the myoclonal rhythm.

Ca2+-activated K+ currents in rat locus coeruleus neurons induced by experimental ischemia, anoxia, and hypoglycemia

Ca2+-activated K+ currents in rat locus coeruleus neurons induced by experimental ischemia, anoxia, and hypoglycemia. J. Neurophysiol. 78: 2674-2681, 1997. The effects of metabolic inhibition on membrane currents and N-methyl--aspartic acid (NMDA)-induced currents were investigated in dissociated rat locus coeruleus (LC) neurons by using the nystatin perforated patch recording mode under voltage-clamp conditions. Changes in the intracellular Ca2+ concentration ([Ca2+]i) during the metabolic inhibition were also investigated by using the microfluometry with a fluorescent probe, Indo-1. Removal of both the oxygen and glucose (experimental ischemia), deprivation of glucose (hypoglycemia), and a blockade of electron transport by sodium cyanide (NaCN) or a reduction of the mitochondrial membrane potential with carbonyl cyanide-p-trifluoromethoxyphenyl-hydrazone(FCCP) as experimental anoxia all induced a slowly developing outward current (IOUT) at a holding potential of -40 mV. The application of 10(-4) M NMDA induced a rapid transient peak and a successive steady state inward current and a transient outward current immediately after washout. All treatments related to metabolic inhibition increased the NMDA-induced outward current(INMDA-OUT) and prolonged the one-half recovery time of INMDA-OUT. The reversal potentials of both IOUT and INMDA-OUT were close to the K+ equilibrium potential (EK) of -82 mV. Either charybdotoxin or tolbutamide inhibited the IOUT and INMDA-OUT, suggesting the contribution of Ca2+-activated and ATP-sensitive K+ channels, even though the inhibitory effect of tolbutamide gradually diminished with time. Under the metabolic inhibition, the basal level of [Ca2+]i was increased and the one-half recovery time of the NMDA-induced increase in [Ca2+]i was prolonged. The IOUT induced by NaCN was inhibited by a continuous treatment of thapsigargin but not by ryanodine, indicating the involvement of inositol 1,4, 5-trisphosphate (IP3)-induced Ca2+ release (IICR) store. These findings suggest that energy deficiency causes Ca2+ release from the IICR store and activates continuous Ca2+-activated K+ channels and transient ATP-sensitive K+ channels in acutely dissociated rat LC neurons.

[A case of cortical reflex positive-negative myoclonus--electrophysiological study]

An 11-year-old girl who had the positive-negative myoclonus and the history of the generalized tonic clonic seizure was electrophysiologically studied. She had no siblings with either myoclonus or epilepsy, and her intellectual level was normal. She had no other neurological deficits including ataxia, pyramidal and extrapyramidal signs. Surface EMG showed a brief increase in the EMG activity followed by the silent period associated with positive and negative myoclonus during sustained wrist extension. Giant SEP and C reflex (38.6 ms) following electric stimulation of the median nerve at the wrist were obtained in the resting condition and the silent period (about 180 ms) following C reflex was obtained during voluntary contraction. Jerk-locked back averaging of the EEG time-locked to the onset of the myoclonic discharge recorded from the right biceps muscle showed a cortical spike at the left central region preceding the myoclonus onset by 12.6 ms. The latency of C reflex in this case was very short compared with that of previously reported cortical reflex myoclonus. The estimated cortical delay between the arrival of the somatosensory volley and the motor cortex discharge responsible for the C reflex was -1.0 ms and this value was shorter than that in patients with typical cortical reflex myoclonus (mean 3.7 +/- 1.1 ms). Conditioning stimuli (C) of the right median nerve at the wrist started to facilitate the amplitude of the motor evoked potential recorded from the right abductor pollicis brevis muscle after magnetic test stimuli (T) of the left motor cortex at 20 ms of the C-T interval. This C-T interval was shorter than that (24.6 +/- 1.6 ms) in patients with the typical cortical myoclonus. These electrophysiological findings suggested the shorter reflex pathway of the cortical reflex myoclonus in this case than in typical cortical reflex myoclonus. We speculated that the myoclonus was based upon the direct sensory projection from the thalamus to the motor cortex in this case.

[A case of lumbosacral lipoma-associated adult onset tethered cord syndrome with initial symptoms of sensory disturbance and intractable foot ulcers]

A 63-year-woman who complained of sensorimotor disturbance of the lower extremities and urinary disturbance was presented. She noted loss of superficial sensation in both feet and foot ulcers at the age of 20 years. Her illness was initially diagnosed as hereditary sensory neuropathy type 1 (HSN1). The foot ulcers were so intractable that she had to have her right leg amputated at the age of 48 years. She had a severely impaired superficial sensation in the lower extremities and buttock, distal weakness of the left leg, and dysuria at the age of 60 years. The neurological examination revealed that she had segmental sensorimotor disturbance below the levels of the 5th lumbar segment. MRI demonstrated tethered cord with a lumbosacral lipoma. Adult onset tethered cord syndrome (TCS) that presents with HSN 1-like symptoms as initial clinical features has not yet been reported. Foot ulcers are often seen in child onset TCS in which the degree of tethered cord is severer than adult onset cases. It is reported that release of the tethered cord promotes healing of the foot ulcers. We recommend MRI for the study of the lumbosacral cord of patients with HSN 1-like symptoms, because there is a possibility that such patients may have TCS and early surgical treatment is effective for TCS.

Effects of 5-(4-piperidyl) isoxazol-3-ol (4-PIOL), a GABA(A) receptor partial agonist, on recombinant human GABA(A) receptors

gamma-Aminobutyric acidA (GABA(A)) gated chloride ion channels were expressed from human recombinant cDNA using the baculovirus/Sf-9 insect cell expression system. The electrophysiological effects in whole-cell currents of 5-(4-piperidyl) isoxazol-3-ol (4-PIOL), a GABA(A) receptor partial agonist, were investigated on GABA(A) receptor complexes of alpha1beta2gamma2S subunits as well as a slightly modified construct of alpha1(valine 121)beta2gamma2S subunits. Here we report that (1)4-PIOL induces an inward whole-cell current in a concentration-dependent manner in both alpha1(val 121)beta2gamma2S and alpha1(ile 121)beta2gamma2S receptor subunit combinations. (2) The 4-PIOL induced whole-cell currents were more pronounced in alpha1(val 121)beta2gamma2S than in alpha1(ile 121)beta2gamma2S receptor subunit combinations. (3) 4-PIOL inhibited GABA-induced responses on alpha1(ile 121)beta2gamma2S and alpha1(val 121)beta2gamma2S receptor combinations with similar potency.

Fiber analysis in lungs of residents of a Japanese town with endemic pleural plaques

The authors analyzed various types of fibers in lung-tissue samples, which were obtained from 50 cases (46 surgical resections and 4 autopsies) at Kumamoto-Minami Hospital in Matsubase, where the occurrence of pleural plaques is endemic. Lung cancer necessitated surgical resection in 44 cases. Eleven of the 50 cases were residents of Matsubase; 15 resided in the region around the town, where the frequency of pleural plaques was slightly higher; and 24 cases lived in a region with normal plaque frequency. The number of anthophyllite fibers in the lungs of town residents was significantly higher than in residents of the region with normal plaque frequency. In 6 cases, the authors found accompanying pleural plaques, and the anthophyllite fiber count in the lungs in these cases was significantly higher than in cases without plaques. In addition, the anthophyllite fiber counts in 2 cases with severe plaques were significantly higher in 4 cases with only mild plaques. These results suggested that anthophyllite fiber might be responsible for the increased prevalence of pleural plaques in Matsubase. Even though the anthophyllite fibers were quite long (mean length = 25.1 microm), the width of most anthophyllite fibers were thick (mean diameter = 0.84 microm). Therefore, the aspect ratio of anthophyllite (mean = 38.7) was lower than that of amosite (mean = 81.8), which, in a previous report, was found predominantly in cases of pleural mesothelioma. Perhaps these differences in fiber size are related to the strength of the carcinogenicity to the pleura.

[Length of survival of elderly patients with chronic obstructive pulmonary disease]

We examined survival in 53 patients over 60 years old who had chronic obstructive pulmonary disease, and whose FEV1 was less than 60% of the forced vital capacity and was less than 60% of the predicted value. They comprised 34 men and 19 women. The mean age was 75.2 years. The %FEV1 was 39.0% and the body mass index was 19.0. Neither age %FEV1, nor body mass index differed significantly between men and women. However, the number of cigarettes smoked per day, the number of years of cigarette smoking, and the Brinkman index were higher in men than in women. The Brinkman index was 1255.0 in men and 617.8 in women (p = 0.0001). For the group as a whole, the 5-year survival rate was 65% and the 10-year survival rate was 35%. The survival rate of men did not differ from that of women. Survival and %FEV1 did not differ between men and women, despite the significant difference in Brinkman index, which suggests that women were more susceptible to the effects of cigarette smoking than men. Age, one tenth of %FEV1, and body mass index less than 19 were found to be independent predictors of mortality (proportional hazards analysis, p = 0.044, 0.019, and 0.024, respectively). The 5-year survival rate were as follows: 85% in patients less than 75 years of age, 50% in patients more than 75 years of age, 25% in patients with a %EFV1 less than 30%, 80% in patients with a %FEV1 of 30% to 49%, 62% in patients with a %FEV1 of 50% to 60%, 50% in patients with a body mass index of less than 19, and 83% in patients with a body mass index of more than 19.

[The diagnosis of amyotrophic lateral sclerosis supported by motor evoked potential and brain MRI studies]

A 57-year-old man developed severe muscle weakness and atrophy of the upper extremities within a five-month period. Neurological examination revealed severe weakness and atrophy in the scapular muscles and proximal and distal muscles of the upper extremities. Fasciculations were also observed in the various muscles of the upper extremities. There was neither muscle weakness, atrophy nor fasciculation in either his face, neck muscles or lower extremities. He had no pseudobulbar or bulbar signs. Tendon reflexes were mildly hyperactive in the jaw and lower extremities, and normal in the upper extremities. There were no pathological reflexes, spasticity or sensory disturbances. The needle EMG study revealed denervation potentials in all muscles of the upper extremities examined. The nerve conduction study revealed no findings of the conduction block. Cervical spine X-rays revealed the narrowing of the spinal foramens at the left C3/C4 and bilateral C4/C5, C5/C6, and C6/C7 intervertebral levels. In addition, magnetic resonance imaging (MRI) revealed compressions of the cervical cord at C4/C5 and C5/C6 intervertebral levels. These clinical and neuroradiological findings resembled those of the cervical spondylotic amyotrophy (CSA). However, the motor evoked potential (MEP) study revealed the pyramidal tract dysfunction above the levels of the pyramidal decussation. Furthermore, brain MRI revealed abnormal foci in both internal capsules which were characterized by hyperintense relative to cortical gray matter on T2-weighted images and still hyperintense to white matter on proton-density-weighted images. In addition, T2-weighted images demonstrated a low signal within the motor cortex and hyperintense lesions in the white matter of the precentral gyri. These MRI findings indicated the degeneration of the pyramidal tract and corresponded to those found in the patients with amyotrophic lateral sclerosis (ALS) which have been recently reported. It has been difficult to distinguish ALS from CSA. However, MEP and brain MRI studies were useful for distinguishing these two diseases in this patient. In addition, this patient showed typical MRI findings suggesting the degeneration of the pyramidal tract, although this patient had a relatively short course of illness and did not show obvious physical findings suggesting pyramidal tract dysfunction.

[The effect of brain-derived neurotrophic factor on elongation of axons after transection with suture-morphometric evaluation]

Brain-derived neurotrophic factor (BDNF) is considered to play an important role in survival, maintenance, development and repair of the peripheral neuron. In this study, the effect of human recombinant BDNF on sprouting and elongation of axons, the early phase of regeneration of nerve fibers, was morphometrically evaluated 7 days following the sciatic nerve transection and juxtaposition of proximal and distal stumps with suture in Sprague-Dawley rats. In the experimental group (test), 20 mg/kg of BDNF was injected subcutaneously every day for seven days in eight rats, starting 30 minutes after the transection. In the control group (control), phosphate buffered-saline alone was injected in nine rats as in the experimental group. The various morphometric parameters were evaluated in the sciatic nerve of each rat of the control and test, 3 mm distal to the site of the transection on light and electron microscopy of Epon-embedded sections. On both light and electron microscopy only a few myelinated fibers with a very thin myelin sheath were found only in one nerve in each of the control and test. However, significant numbers of unmyelinated axons were found in each nerve of the control and test. There were no statistically significant differences in the total fascicular area per nerve, the numbers of myelinated and unmyelinated axons per mm2 of fascicular area and per nerve, their maximum and median diameters and their size distribution histograms between control and test. In addition, there were no statistically significant differences in the numbers of myelin ovoids per mm2 of the fascicular area and per nerve, their maximum and median diameters and their size distribution histograms between control and test. Therefore, we concluded that there was no definite evidence that BDNF promoted the sprouting and elongation of axons, the early phase of the regeneration of nerve fibers, at least under this experimental conditions.

Granule cell disinhibition in dentate gyrus of genetically seizure susceptible El mice

Paired-pulse inhibition was investigated electrophysiologically in the dentate gyrus using hippocampal slices from epileptic El mice. At short interpulse intervals (IPIs), the inhibition was 30% in the El, and 90% in the control ddY mice at the ages of 10 and 15 weeks. No difference in inhibition was observed at the age of 5 weeks. Bicuculline, a GABAA receptor antagonists, attenuated the inhibition during short IPIs n the ddY mice, while in the El mice, phenobarbital and flunitrazepam, which enhance GABAA receptor function, restored the inhibitory activity comparable to that of the ddY. The disinhibition progressed with growth, closely correlating with seizure development in El mice. These results suggest that decrease in the GABAergic inhibition occurs in the dentate gyrus of the El mice with growth. GABA concentration in the hippocampus was also quantified using HPLC. In El mice, GABA level was significantly lower than that in ddY mice at the ages of 5 and 15 weeks. Thus, the disinhibition observed in the El dentate gyrus at 15 weeks of age does not appear to be directly related to the content of GABA. GABAergic disinhibition suggests possible loss of unknown inhibition control factor(s) in the El dentate gyrus as growth progresses. The growth-dependent disinhibition in the granule cells may be prerequisite for epileptogenesis in El mice.

Efficient and beta-stereoselective synthesis of 4(5)-methyl-5(4)-(5-amino-5-deoxy-beta-D-ribofuranosyl)imidazole and related compounds exhibiting antiulcer activity

The reaction of 2,3,5-tri-O-benzyl-D-ribose with the lithium salt of an imidazole derivative gave an adduct 17RS. Treatment of 17RS with 1.5N HCl in refluxing tetrahydrofuran gave the beta-4(5)-ribofuranosylimidazole 19 (35%) and the ribosylimidazole 18 (51%). The latter was converted into beta-19 in 86% yield by the Mitsunobu cyclization. This synthetic method produced only the desired beta-anomer. Protection of the imidazole nitrogen of 19 with an ethoxycarbonyl group followed by debenzylation gave 21, which was successively derived to the 5'-amino derivative 1 via the 5'-substituted phthalimide 23, followed by hydrazine degradation in excellent yield. Compound 1 was then converted into the 5'-cyanoguanidine 2 in 79% yield. The 5'-amino derivatives 3-9 lacking a methyl group were efficiently synthesized. Among them, the cyanoguanidine 5 and phenylthiourea 8 exhibited antiulcer activities with half the efficacy of cimetidine. The molecular conformation of 5 was determined by X-ray structure analysis.

[The effect of brain-derived neurotrophic factor on regeneration of nerve fibers after crush injury--morphometric evaluation]

Brain-derived neurotrophic factor (BDNF) is produced in Schwann cells and fibroblasts in the peripheral nerve, and is considered to play an important role in survival, maintenance, development and repair of the peripheral neuron. In this study, the effect of human recombinant BDNF on the regeneration of nerve fibers following a crush injury to the sciatic nerves of Sprague-Dawley rats was evaluated. In the experimental group, 20 mg/kg of BDNF was injected subcutaneously three times a week for 4 weeks in seven rats. In the control group, only the dissolving solution used in the experimental group was injected similarly in seven rats as in the experimental group. The various morphometric parameters were evaluated in the peroneal, sural and tibial nerves and the nerve to soleus muscle distal to the crush site. There were no statistically significant differences in the change of body weight, the improvement of the width between the first and fifth toes on the side of the crush, the density of total myelinated fibers (numbers per mm2), the total number of myelinated fibers (number per nerve), maximum and median diameters of myelinated fibers, the density of unmyelinated fibers, and the electron microscopic parameters of axon and myelin sheath. On the other hand, the number of myelin lamellae in relation to the transverse axonal area was significantly greater in the experimental group than in the control group. Therefore, BDNF may promote the myelination. However, such an effect on myelination seems not to be clinically significant, because such an effect was not demonstrated in other morphometric evaluations reflecting the myelination condition. Therefore, taking all the data obtained in this study into consideration, we concluded that there was no definite evidence that BDNF promoted the regeneration of nerve fibers at least under these experimental conditions.

Regeneration of myelinated fiber after crush injury is retarded in sciatic nerves of mutant Japanese quails deficient in neurofilaments

Regeneration of myelinated fibers in the sciatic nerve 2 weeks after crush injury was studied morphometrically in mutant Japanese quails deficient in neurofilaments and in normal quails (controls). There were fewer regenerated myelinated fibers per nerve at 10 mm (R1) and 20 mm (R2) distal to the crush site in mutants than in controls (P < 0.05). Both median and maximum diameters were smaller (P < 0.01) in mutants than in controls. On electron microscopy, transverse axonal area and axonal circumference were smaller (P < 0.001) at both R1 and R2 in mutants than in controls. The number of myelin lamellae was less (P < 0.01) in mutants than in controls at R1, but was similar at R2. There were fewer myelin lamellae in relation to axonal area in mutants than in controls at R1 (P < 0.0001) and R2 (P = 0.0032). The results indicate a retardation of both radial growth of axons and myelination around axons of the same size in mutants compared with controls. Such retardation may be explained by the deficiency of neurofilaments and the altered relationship between Schwann cell and axon in the mutant.