Heat shock modulates prion protein expression in human NT-2 cells.

The pathological hallmarks of Prion disease are cortical spongiform changes and neuronal loss, which are induced by the accumulation of the scrapie-isoform prion protein (PrP(Sc)). PrP(Sc) is derived from a post-translational modification of the cellular form of prion protein (PrP(C)). Heat-shock proteins, a group of molecular chaperones, are involved in the degradation of denatured proteins and post-translational folding of newly synthesized polypeptides. In an attempt to examine any possible relationship between heat shock stress and an induction of prion protein (PrP), human NT-2 cells were treated with heat shock at 42 degrees C for 30 min. After heat-shock treatment, both the level of mRNA and PrP(C) protein were analyzed at various time points by Northern and Western blot, respectively. There was a 1.5- to 2.5-fold increase in PrP mRNA levels 1 and 3h following heat shock. In addition, a two-fold increase in protein level of PrP was found 3 h after heat-shock treatment. These results suggest that cellular stress induces the elevation of both PrP mRNA and protein synthesis. The up-regulation of prion-protein mRNA and protein, implies that PrP may play a role in cellular stress.

Creutzfeldt-Jakob disease: heat shock protein 70 mRNA levels in mononuclear blood cells and clinical study.

Prion diseases such as Creutzfeldt-Jakob disease (CJD) are associated in most cases with the accumulation of an unusual isoform of prion protein (PrPSC). PrPSC is derived from the abnormal folding of the cellular isoform of prion protein (PrPC). On the other hand, heat shock protein is known to ensure proper protein assembly and folding and to facilitate proteolytic digestion of abnormal or denatured proteins. Many studies have therefore hypothesized that heat shock protein is linked to prion disease. We examined the relationship between heat shock protein HSP70 and prion disease in CJD patients. HSP70 mRNA levels in mononuclear blood cells (MBCs) were compared in 14 CJD patients (10 confirmed by histo-pathological study), 12 vascular dementia (VD) patients, 16 patients with Parkinson's disease and dementia (PD) and 14 nondemented control subjects. The possible correlation between HSP70 mRNA expression levels and clinical findings was also evaluated. HSP70 mRNA expression levels in MBCs were measured by northern blotting. HSP70 mRNA levels in MBCs from patients with CJD were significantly higher than those from patients with VD or PD and in nondemented controls. Age at symptom onset, dementia severity, disease duration and neuroimaging grade of CJD patients were not correlated with relative HSP70 mRNA levels. No significant relationship between HSP70 mRNA levels and ageing was found. These results suggest that measurement of HSP70 mRNA in MBCs might provide an auxiliary tool for the diagnosis of CJD.

Application of chromosome 4q35-qter marker (pFR-1) for DNA rearrangement of facioscapulohumeral muscular dystrophy patients in Taiwan.

Facioscapulohumeral muscular dystrophy (FSHD) has been found to be linked to chromosome 4qter. A chromosome 4q35-ter marker, pFR-1 (subclone of the cosmid c51), has been recently isolated and used as a probe for mapping near, or within, the FSHD gene. To examine FSHD-associated DNA rearrangements in the Taiwan population, we used the pFR-1 probe to perform Southern blot analysis on 142 individuals, including 32 FSHD patients within 9 autosomal dominant families, five sporadic FSHD patients from 4 families (include one pair of twins), three sporadic scapuloperoneal syndrome (SPS) patients and two sporadic polymyositis patients with their unaffected parents, and 29 healthy controls. In 29 healthy individuals, 3 SPS and 2 polymyositis patients with their families, probe pFR-1 analysis revealed that all had polymorphic restriction fragments that were larger than 28 kb in length. All but 1 FSHD-affected individual had specific smaller EcoRI fragments (ranging in size from 10.5 to 27 kb). Two point linkage analysis between pFR-1 and the FSHD locus provided significant evidence for FSHD linkage (Z(max)=6.84). A similar smaller fragment was also present in 5 sporadic patients, while this smaller fragment could not be found in one of their parents. Identical EcoRI restriction fragment length polymorphism (RFLP) patterns linked to FSHD were shown in the monozygotic twins, even though they showed extreme variability in the expression of FSHD. We conclude that the pFR-1 probe is a tightly linked marker of FSHD and can be used to detect most DNA rearrangements associated with this disease in the Taiwan population. However, the same RFLP patterns may represent extreme variability in the expression of the FSHD gene.

Blood lactate threshold and type II fibre predominance in patients with exertional heatstroke.

OBJECTIVES: Severe damage to skeletal muscle is usually seen in patients with exertional heatstroke. Thirty seven young military recruits with exertional heatstroke in Taiwan from 1992 to 1995 were studied to evaluate changes in muscle pathology and blood lactate with exercise. METHODS: A biopsy sample of the vastus lateralis was taken from recruits within 10 days of the initial presentation. Results were compared with those from 15 controls matched for age and sex. During the recovery period, 90-150 days after exertional heatstroke, 29 patients participated in a constant work load test on the treadmill to assess their blood lactate threshold, and a second biopsy sample was taken. Each biopsy was examined histologically for pathology, distribution of fibre types, and fibre diameter. RESULTS: Twenty four of the 37 patients with exertional heatstroke developed rhabdomyolysis and 18 of these had type II fibre predominance in their muscle biopsy. The patients with type II fibre predominance had a higher tendency to develop rhabdomyolysis (chi 2 = 6.84, P < 0.01). The time required to reach a blood lactate threshold during a constant treadmill work load after recovery was significantly shorter in the patients with exertional heatstroke who had type II fibre predominance (P < 0.01). There was a positive correlation between the highest value of blood lactate and the percentage of type II fibres in all tested subjects (r = 0.82, P < 0.01). CONCLUSION: Patients with type II fibre predominance are more susceptible to exertional heatstroke and tend to have a higher blood lactate concentration and a shorter time to reach blood lactate threshold under a treadmill load test.

Panencephalitic Creutzfeldt-Jakob disease in a Chinese family. Unusual presentation with PrP codon 210 mutation and identification by PCR-SSCP.

A point mutation at codon 210 (GTT to ATT) of the prion protein gene on chromosome 20 was found in a 48-year-old CJD-affected woman of a Chinese family. This affected woman had an early onset and long-duration form of CJD. Serial magnetic resonance image (MRI) analysis of this woman showed severe brain atrophy, prominent diffuse white matter degeneration, and subsequent mineralization of basal ganglia and thalamus. MR spectroscopy (1H) analysis elucidated the absence of peaks of choline, creatine and N-acetylaspartate. Using polymerase chain reaction and single-strand conformational polymorphism (PCR-SSCP) techniques, presymptomatic diagnosis of the second son of this woman showed that he has a similar codon mutation of prion gene as his mother.

Vascular dementia of Binswanger's type: clinical, neuroradiological and 99mTc-HMPAO SPET study.

In 24 patients with vascular dementia of Binswanger's type (VDBT) and 14 age-matched neurologically normal volunteers, we investigated the relationship between clinical features, white matter lesions (leuco-araiosis) and cerebral atrophy on computed tomographic (CT) scan, and regional cerebral blood flow. All subjects underwent the Mini-Mental State Examination of Taiwan, version 1 (MMSE-T1), for assessing the severity of cognitive impairment. The patients were subdivided into two groups, one with mild to moderate (group I, MMSE-T1 scores: 11-24, n=11), and the other with severe dementia (group II, MMSE-T1 scores: below 10, n=13). White matter degeneration was evaluated with densitometric methods. Loss of brain parenchyma was estimated with seven linear measurements (Evan's ratio, third ventricle ratio, width of temporal horn tip, anterior-posterior length of temporal horn, anterior-posterior length of Sylvian fissure and width of frontal interhemispheric fissure) by CT scans. Regional cerebral blood flow was determined with technetium-99m hexamethylpropylene amine oxime (HMPAO) single-photon emission tomography (SPET). In neuroimaging studies, subcortical leuco-araiosis was localized at the frontal region in group I patients and scattered diffusely in group II patients. 99mTc-HMPAO SPET analysis revealed reduction of regional cerebral blood flow in the frontal lobe in group I patients and widespread reduction of regional cerebral blood flow in group II patients. A correlation between frontal leuco-araiosis and perfusion defect of the frontal pole was demonstrated in group I patients, showing findings typical of subcortical dementia. There was no difference in frontal atrophic measurements between group I patients and controls. Ratios of volumes of lost brain parenchyma and leuco-araiosis were significantly higher in group II patients than in the age-matched controls, corresponding to a diffuse cerebral perfusion defect. These results suggest that patients with VDBT have early frontal lobe involvement with posterior progression. Patients with mild VDBT are more likely to show reduction of frontal cerebral blood flow and leuco-araiosis, while those with severe VDBT are more likely to have diffuse leuco-araiosis, cerebral hypoperfusion and brain atrophy.

Panencephalitic Creutzfeldt-Jakob disease. Unusual presentation of magnetic resonance imaging and proton magnetic resonance spectroscopy.

We present serial magnetic resonance imaging (MRI) scans on a biopsy-verified case of Creutzfeldt-Jakob disease (CJD). The initial MRI scan demonstrated increased T2 signal-intensity within the basal ganglia and thalami. Subsequent MRI scans demonstrated a thin cortex, increased T2 signals diffusely within the white matter including U-fibers, and hypointense T2 signals within the basal ganglia, and thalami. Proton magnetic resonance spectroscopy (1H-MRS) study showed an absence of creatine, choline and N-acetylaspartate signals. By these characteristic findings, serial MRI and MRS studies may be helpful in differentiating CJD from other dementing illnesses.

Mitochondrial alterations of skeletal muscle in a heat stress rat model.

The morphological and ultrastructural alterations of skeletal muscle in experimental rats with heat stress were investigated. Fifteen male Sprague-Dawley rats were exposed in a 42 degrees C constant temperature oven, resulting in a heat stress state; ten rats were used as controls. All treated rats had weakness of the 4 limbs associated with increased serum creatine kinase levels (p < 0.01). Soleus muscles were submitted to histological, histochemical, ultrastructural and quantitative-morphometric analysis. The group receiving heat stress showed many ragged-red fibers in Gomori trichrome stain and appeared hyper-reactive in succinate dehydrogenase and cytochrome C oxidase stains. The ultrastructure of ragged-red fibers showed increased mitochondrial aggregation as multiple small nests, which were particularly located in the subsarcolemmal space. The mitochondrial area was significantly increased in heat stress rats (p < 0.001). The consistently increased mitochondrial area and histochemical alterations of mitochondria are early pathological abnormalities in muscles with heat stress and indicate fundamental impairment of energy metabolism.

A young adult with tuberculous meningitis diagnosed by polymerase chain reaction on serial CSF samples: a case report.

A polymerase chain reaction (PCR) assay was used to diagnose a young adult with tuberculous meningitis who presented with unusual clinical symptoms of an acute illness. He had repeated cerebrospinal fluid (CSF) samples taken, and the PCR assay for detecting mycobacterial deoxyribonucleic acid was negative for the first two CSF specimens, but was positive in the third. He was then treated with antituberculous drugs and had complete restoration three months later. A follow-up PCR of the CSF was still positive after one month of therapy using antituberculous drugs, but converted to a negative result one month later. It is concluded that it is valuable to repeatedly sample CSF specimens for PCR study in patients with clinically suspected tuberculous meningitis.

Rapid diagnosis of tuberculous meningitis by polymerase chain reaction assay of cerebrospinal fluid.

A polymerase chain reaction (PCR) method for the rapid diagnosis of tuberculous meningitis (TBM) was used to study prospectively 47 cerebrospinal fluid (CSF) samples from 45 patients. Twenty CSF samples were from patients with clinically suspected TBM and another 27 samples came from patients without clinically suspected TBM. Mycobacterial DNA was detected in 15 CSF samples (14 from patients with clinically suspected TBM and 1 from a patient not suspected of having TBM). Of the PCR-positive samples, 4 were also positive for mycobacterial culture. However, 32 PCR-negative samples were all culture-negative. All samples were negative for the acid-fast bacillus by direct smear. The single PCR-positive patient in the clinically unsuspected TBM group was initially diagnosed as suffering from aseptic meningitis on the basis of his clinical features. The mycobacterial culture of his CSF specimen was also positive and a revised diagnosis of an aseptic type of TBM was made. The estimations of specificity and sensitivity in this study were 100% and 70% respectively. The results showed that using a PCR to detect mycobacterial DNA in CSF for the early diagnosis of TBM is not only a rapid but also an accurate method.

Essential tremor: clinical, electromyographical and pharmacological studies in 146 Chinese patients.

From February 1984 to February 1988, 258 cases of various kinds of tremor were seen in our movement disorder clinic. Among them, 146 cases (57%) were diagnosed as essential tremor, and of these, 96 (65.8%) were males and 50 (34.2%) were females, ranging in age from 14 to 89 years (mean: 36 years). The main tremor occurred in the hands (100%), and in a few cases were combined with head, leg, lip, voice and neck tremors. A familial tendency was obvious in 47 cases (32%). The surface electromyographic (EMG) study of essential tremor revealed two patterns, one of synchronous type (73%) and the other of alternating type (27%). Its frequency was between 5 and 9Hz. The burst duration was short (50-100 msec) and the amplitude was low (less than 200 mu v). All cases were divided into two groups to received propranolol therapy, 78 cases with high dosages (120-240 mg/day) and 68 with low dosages (60-80 mg/day). The higher dose was better in effect than the lower one (p less than 0.01). Propranolol also had effect on tremors of alternating type (p less than 0.01), which is different from previous reports.