Juvenile-onset of Dejerine-Sottas disease in a Taiwanese woman

Dejerine-Sottas disease is an uncommon hereditary neuropathy which has not been reported in Taiwan. We describe a 57-year-old woman who had slowly progressive weakness in her four limbs since adolescence. None of her close relatives had the disease and no consanguinity was noted. Neurologic examination showed severe weakness and vibratory sensation loss in the four limbs. The tendon reflexes were generally absent. Electrophysiologic studies suggested a systemic myelinopathic process. Light and electron microscopy of the sural nerve biopsy specimens revealed many onion-bulb shapes formed by the Schwann cell processes or basement membranes without any evidence of myelin sheaths around the axons, which are characteristic features of Dejerine-Sottas disease.

Bacterial meningitis in patients with nasopharyngeal carcinoma

Bacterial meningitis was found in 12 patients with nasopharyngeal carcinoma, accounting for 0.65% of the 1850 patients with the tumour diagnosed between 1981 and 1994 in our hospital. In 11 patients, the time-lag between diagnosis of cancer and the appearance of infection ranged from 9 months to 11 years (mean 57 months) whereas in one patient it was only 5 days. Three patients developed mixed bacterial meningitis. Cerebrospinal fluid culture for bacteria was positive in six patients. Three patients (25%) were bacteraemic. Gram-negative bacilli, especially Pseudomonas aeruginosa, were the most common pathogens. Age, sex and histopathology were not risk factors for infection. Conditions predisposing to meningitis included intracranial invasion of the tumor, neutropenia, otitis media, and neurosurgical procedures. All but two patients had intracranial tumour invasion and erosion of the base of the skull. Local spread of micro-organism to the meninges was more important than haematogenous spread. The overall mortality in our patients was 66.7%, much higher than in patients without cancer.

Tuberculous meningitis in patients with nasopharyngeal carcinoma

Mycobacterial infection has been recognized as a complication in patients with malignancy. Tuberculous (TB) meningitis has not been reported in patients with nasopharyngeal carcinoma (NPC); it may have been overlooked or confused with the underlying malignancy or meningitis caused by other microorganisms. We describe the occurrence of culture-proven TB meningitis in 2 NPC patients. The time lag between the diagnosis of NPC and the occurrence of TB meningitis was 4 years in 1 patient and 6 years in the other. In both patients, the diagnosis of TB meningitis was delayed; they were initially treated for bacterial meningitis. Subsequent antituberculous chemotherapy was successful in 1 patient but failed in the other. Recognition of the infection is important for early diagnosis and proper treatment of this potentially fatal condition in patients with NPC.

Solution conformation of a peptide corresponding to residues 151-172 of HIV-1 integrase using NMR and CD spectroscopy

The solution structure of a synthetic peptide corresponding to residues 151-172 of HIV-1 integrase has been determined by NMR and CD spectroscopy. Residues 151-172 of HIV-1 integrase were predicted to be an alpha-helix and to be responsible for the oligomerization of HIV-1 integrase. Two-dimensional 1H NMR and CD studies indicate that this synthetic peptide adopts an amphipathic alpha-helical conformation in TFE-containing solution. However, concentration-dependent CD studies reveal that this peptide motif does not form dimers or oligomers in solution as predicted. These results are in agreement with the crystal structure of the catalytic domain of HIV-1 integrase reported recently.

Kinetic resolution of amino acid esters catalyzed by lipases

Racemic amino acids were resolved by lipase via hydrolysis of their esters. Lipases (Pseudomonas lipase from Amano PS, Rhizopus lipase from Serva, and porcine pancrease lipase from Sigma) could selectively hydrolyze the L-amino acid esters in aqueous solution with high reactivities and selectivities. The effect of the structural changes in the ester moiety on the stereoselectivity of the lipases was also investigated using D,L-homophenylalanine as a model. Procedures were developed for the resolution of natural and unnatural amino acids.

Rimmed, vacuolar distal myopathy in two Taiwanese siblings

Distal myopathy with rimmed vacuoles (DMRV) is a rare disease that has not previously been reported in Taiwan. This paper reports two siblings with DMRV. Each showed a different pattern of disease progression, one being slowly and the other rapidly progressive. Both patients' initial symptoms appeared in early adulthood, manifesting as muscular wasting and weakness of the legs, especially in the distal muscles. Severe generalized involvement of skeletal muscles, with sparing of the facial, extraocular, bulbar, intercostal and diaphragm muscles was recognized in the advanced stage. The striking finding in their muscle biopsy specimens was the presence of "rimmed" vacuoles. Magnetic resonance imaging showed more severe involvement of the anterior compartment muscles of the lower legs. DMRV is thought to be inherited as an autosomal recessive trait and is distinguishable from other types of distal myopathy on the basis of clinical and pathologic findings. The literature on the subject is reviewed with emphasis on the differences between distal myopathic syndromes.

Increased invasive activity of human hepatocellular carcinoma cells is associated with an overexpression of thyroid hormone beta 1 nuclear receptor and low expression of the anti-metastatic nm23 gene

To understand the role of thyroid hormone in metastasis, we studied the expression of the anti-metastatic nm23 gene in eight human hepatocellular carcinoma (HCC) cell lines. These cells differentially expressed the anti-metastatic nm23 gene. A low level of nm23 proteins was found to have a high in vitro invasive activity which correlated closely with an overexpression of the thyroid hormone beta 1 nuclear receptor (h-TR beta 1). Concurrent with the down-regulation of h-TR beta 1, the invasive activity of HCC cells was suppressed by the thyroid hormone, 3,3',5-triiodo-L-thyronine (T3). These results indicate that the invasive activity of HCC cells was regulated by T3, suggesting that T3 could be involved in modulating the functions of nm23.

MRI/myelographic localization of fistulous tract in spinal dural arteriovenous malformations prior to arteriography

OBJECTIVE

Our goal was to use currently available imaging methods to localize the fistulous tract of spinal dural arteriovenous malformations (SDAVMs) prior to arteriography.

MATERIALS AND METHODS

Two middle-aged men showed MR findings indicative of a SDAVM. In the first patient coronal T2-weighted (T2W) imaging identified the engorged draining radiculospinal vein and traced it back to the intervertebral foramen site where the "nidus" was located. Then, axial T2W imaging was performed at the level of the involved intervertebral foramen. In the second patient MRI failed to demonstrate the nidus; myelography was carried out and showed the course of the abnormal intraspinal vein.

RESULTS

Successful MR/myelographic demonstration of the nidus (Case 1) or the abnormal intraspinal vein (Case 2) simplified and abbreviated the later studies.

CONCLUSION

With MRI and/or myelography we were able to localize the site of the fistulous tract in the two cases of SDAVM prior to spinal arteriography.

Alkaline protease catalysis of a secondary amine to form a peptide bond

Procedures for peptide bond formation using esters of L-amino acids as the acyl donor and secondary amines such as derivatives of D- or L-proline, or pyroglutamic acid as the nucleophile in anhydrous 2-methyl-2-propanol catalyzed by alcalase or subtilisin Carlsberg have been developed. Kinetic studies have shown that all secondary amines tested had catalytic efficiencies (kcat/km) in the range 84-423 min-1 M-1. Both enzymes have identical catalytic properties. The selectivity of the enzyme-catalyzed reaction in 2-methyl-2-propanol shows that at the s-1 subsite of the enzyme only L-amino acids are substrates as acyl donors, and at the s-1' subsite both D- and L-amino acids are substrates. Optimal conditions for preparing precursors of the renin inhibitors Z-Ala-Pro-OBzl, Z-Lys(Z)-Pro-OBzl and Z-Lys(TFA)-Pro-OBzl were studied.

Concurrent trigeminal, abducens, and facial nerve palsies presenting as false localizing signs: case report

Multiple cranial nerve dysfunction presenting as false localizing signs is rare. We report a 20-year-old woman who had concurrent trigeminal sensory disturbance, abducens, and peripheral facial nerve palsies in association with a contralateral acoustic neuroma. After surgery, the trigeminal nerve disturbance and the abducens nerve palsy completely recovered, but the peripheral facial nerve palsy persisted. The nature of tumor, the presence of brain stem distortion, the anatomic variation of posterior fossa, and the relationships of cranial nerves and nearby blood vessels, which are factors influencing the occurrence of false localizing, are briefly discussed.

Long-term expression of the biologically active growth hormone in genetically modified fibroblasts after implantation into a hypophysectomized rat

We employed the hypophysectomized rats as an animal model to explore the feasibility of using genetically engineered fibroblast cells for growth hormone gene therapy. An internal ribosome entry site (IRES)-directed bicistronic retroviral vector, PSN, which contained a porcine growth hormone (pGH) cDNA at the first cistron and a Neo(r) gene at the second cistron was used to infect primary rat embryo fibroblast (REF) cells. The infected cells (5 x 10(6) cells/rat) were injected directly into the peritoneum of syngeneic hypophysectomized rats. We demonstrate that the implanted PSN-infected REF cells could secrete biologically active pGH in vivo, leading to significant growth of the tibia at day 15 and day 57 post-implantation. We also treated the PSN-infected REF cells with collagen to form a tissue-like structure. The skin-like discs were grafted underneath the skin on the back of rats and cells were retrieved at different times. Using two criteria, semiquantitative reverse transcription-polymerase chain reaction on the pGH RNA extracted from the explants and G418 resistance conferred from the explanted cells, we demonstrate that pGH was expressed in the implanted fibroblasts up to 70 days. Despite the fact that the total pGH RNA level was reduced in the explants of long-time post-implantation, which was probably due to the reduction of transduced cells retained in the explants, the specific efficiencies of pGH RNA expression from these explants were maintained as high as the primary PSN-infected REF prior implantation. These results suggest that fibroblast cells are capable of expressing the foreign genes persistently in vivo.

Conformational studies of a synthetic cyclic decapeptide fragment of rat transforming growth factor-alpha

The solution conformation of a synthetic cyclic decapeptide [with sequence mimicking the third disulfide loop of rat transforming growth factor-alpha (rTGF-alpha)] in deuterated dimethyl sulfoxide was studied by 2D NMR. The determination of solution structures was based on NOE interproton distances, using a combination of distance geometry and simulated annealing protocols. The convergence of the selected structures was evident from the small atomic pairwise root-mean-square deviation values among them. Good agreement was noted between the experimental and simulated NOESY spectra, thereby reflecting the accuracy of the calculated solution structures. Analysis of the structures indicates that the residues Tyr5 and Arg9 exhibit similar side chain orientation as that in the corresponding disulfide loop of human transforming growth factor-alpha.

Fabry's disease: report of a case

Fabry's disease is a rare hereditary disorder of glycosphingolipid metabolism. Its clinical features have not been adequately described in Taiwan. This paper reports on a 32-year-old man who had painful acroparesthesia, disseminated skin angiokeratomas, whorled corneal opacity, mitral valve prolapse and renal insufficiency. There was also involvement of the central motor pathways and the autonomic nervous system. A sural nerve biopsy showed loss of small myelinated and unmyelinated fibers. A reduced serum activity of alpha-galactosidase A and a large amount of urinary globotriaosylceramide confirmed the diagnosis of Fabry's disease.

Klebsiella oxytoca meningitis: frequent association with neurosurgical procedures

Klebsiella oxytoca meningitis is a rare condition. Nine patients were diagnosed between 1981 and 1993 at our institution. These accounted for 2.3% of 393 patients with blood and/or cerebrospinal fluid culture-proven bacterial meningitis. K. oxytoca was noted in both community-acquired meningitis and nosocomial meningitis. Eight of the nine cases were patients who had undergone neurosurgical procedures. Four were mixed bacterial meningitis. All K. oxytoca isolates were susceptible to third-generation cephalosporins and all but one to chloramphenicol. Antibiotic therapy was successful in eight patients but failed in one.

Physicochemical properties of alkaline serine proteases in alcohol

The alkaline proteases subtilisin Carlsberg and alcalase possess substantial enzymatic activity even when dissolved in ethanol. The crude enzymes were purified by gel filtration and the main fractions suspended in ethanol to give a translucent suspension. Both the supernatant and the resuspended precipitate after high-speed centrifugation were found to have enzymatic activities. The solubility of subtilisin Carlsberg in anhydrous ethanol was found to be 45.1 micrograms/ml and that of alcalase was 48.1 micrograms/ml by Coomassie blue dye-binding method using bovine serum albumin as a standard. In the presence of water, the solubility of both enzymes increased with water content. The stability of enzymes incubated in ethanol was assayed by their amidase and transesterase activities using Ala-Ala-Pro-Phe-pNA as substrate in phosphate buffer (pH8.2) and Moz-Leu-OBzl as substrate in anhydrous ethanol, respectively. The soluble enzymes have a half-life of about 36 hr and that of suspended enzymes about 50 hr in the amidase activity assay, whereas the same soluble enzymes have a half-life of about several hours and that of suspended enzymes 1 h by the transesterase activity assay. The stability of both enzymes decreased as water concentration increased. The diastereoselectivity of the enzyme-catalyzed hydrolysis of diastereo pairs of tetrapeptide esters, L-Ala-L-Ala-(D- or L-)Pro-L-Phe-OMe and L-Ala-L-Ala-(D- or L-)Ala-L-Phe-OMe, in phosphate is as high as that of the transesterification of these substrates in ethanol. It is concluded that active sites and selectivity of alkaline serine proteases in anhydrous alcohol are probably very similar to those in aqueous solution in spite of the fact that a lower reactivity is usually associated with the enzymes in nonaqueous solvents.

Inhibition of protein kinase C by snake venom toxins: comparison of enzyme inhibition, lethality and hemolysis among different cardiotoxin isoforms

Cardiotoxins, neurotoxins and phospholipase A2 (PLA2) are three major classes of toxic components present in the Taiwan cobra, Naja naja atra of the Elapidae family. Cardiotoxins (or called cytotoxins), a group of major polypeptides of around 60 amino-acid residues present abundantly in the elapid family of snakes, comprise about 45-55% of the crude venom of Taiwan cobra. In contrast to another prominent group of structurally similar neurotoxins with well-established acetylcholine receptors and modes of action, cardiotoxins showed no defined cellular targets and very diverse pharmacological functions. A systematic structure/function comparison of these toxins was made by their relative inhibitory effects on protein kinase C (PKC) isolated from mouse brains. Lethality and hemolysis of various cardiotoxin isoforms were also compared in order to shed some insight on the biological targets and mechanisms of these surface-active amphiphilic polypeptides. A structure comparison of these cardiotoxins based on computer model-building revealed that some defined and subtle differences can be detected upon the superposition of these three-dimensional polypeptide chains, which may reflect the intrinsic differences in the hydrophobic peptide segments present on the surface loops of toxin molecules. The differences seem to correlate with different inhibitory activities exhibited by cardiotoxins in contrast to the lack of activity by cobrotoxin and PLA2 on PKC.

Brain abscess as a complication of stroke

BACKGROUND

Systemic infection is a common complication of stroke. However, brain abscess as a complication of stroke has never been reported.

CASE DESCRIPTIONS

We report two patients, one with a hypertensive intracerebral hemorrhage and the other with nonseptic cerebral infarction. In both patients, brain abscess developed at the stroke lesion site after an infectious complication. After surgical aspiration and antibiotic treatment, one patient recovered and the other died.

CONCLUSIONS

These two cases demonstrate that brain abscess may occur in a previous hemorrhage or infarction area as a complication of systemic infection. Recognition of the risk is important for early diagnosis and proper treatment of this potentially fatal complication of stroke.

Recurrent hypertensive intracerebral hemorrhage

Hypertensive intracerebral hemorrhage has been considered as a one-time event with rare recurrence. This observation is quite different from our experience in Taiwan. We, therefore, conducted a systematic review of our series of consecutive patients with recurrent bleeding. During a 2-year period, we encountered 47 patients with recurrent hypertensive intracerebral hemorrhage from a total of 892 consecutive patients with hypertensive hemorrhage (5.3%). There were 25 men and 22 women with a mean age of 59 +/- 10 (range: 36-78) years at the onset of the first hemorrhage and 62 +/- 9 (range: 39-80) years at the second hemorrhage. The median interval between 2 hemorrhages was 2 years and 4 months (range: 1 month to 8.5 years). All except one recurrent hemorrhages occurred at a site different from the previous one. Of the 38 patients admitted to our hospital for both hemorrhages only 5 were regularly treated with antihypertensive therapy. The outcome for the recurrent bleeding was grave: 26% died and 51% became totally dependent or vegetative. Recurrent hypertensive hemorrhage is not as rare as previously thought; it comprises 5.3% of our patients with hypertensive intracerebral hemorrhage. The recurrent hemorrhage, however, rarely occurs at the same location as the previous one. Uncontrolled hypertension appears to be an important risk factor for the recurrence. Control of blood pressure after the first bleeding should be attempted to prevent recurrent hemorrhage.

Sequence comparison and computer modelling of cardiotoxins and cobrotoxin isolated from Taiwan cobra

Six cardiotoxins and one neurotoxin isolated and purified from the Taiwan cobra venom (Naja naja atra) possess distinct pharmacological and biochemical properties despite the existence of a grossly similar tertiary structure among these toxins, i. e., a core consisting of a series of short loops and four disulfide bridges. A systematic structure comparison of these major toxin isoforms was made by the secondary-structure predictions together with computer model-building based on the primary sequences and the established X-ray and NMR structures of one published cardiotoxin isoform and cobrotoxin. It is of interest to find that some defined and subtle differences can be detected upon the superposition of these three-dimensional polypeptide chains, which may reflect the intrinsic differences in the surface hydrophobicity of cardiotoxins and cobrotoxin as revealed by hydropathy profiles of these toxins in one of three major loops. The differences seem to correlate with different inhibitory activities exhibited by cardiotoxins in contrast to the lack of activity by cobrotoxin on protein kinase C (PKC).

Prognosis of deeply comatose patients on ventilators

Although the concept of brain death has been widely accepted, the criteria required for making the diagnosis remain controversial. This prospective study was undertaken to examine the reliability of a set of clinical criteria adopted in Taiwan. One hundred and forty deeply comatose patients (101 men, 39 women; mean age 49.5 (SD 17.6) years) requiring ventilation were studied. Seventy three patients met the clinical criteria for brainstem death; all developed cardiac asystole (97% within seven days) despite continued full cardiorespiratory support. Brainstem death was diagnosed in only two of the 21 patients with hypoxic or ischaemic insults. This stresses the rarity of hypoxic or ischaemic encephalopathy as a cause of brainstem death. The results show that if strict attention is paid to preconditions and exclusions, brainstem death can be reliably diagnosed on clinical grounds alone.

Elucidation of the insurmountable nature of an angiotensin receptor antagonist, SC-54629

SC-54628 [1-(2-methylphenyl)-4-butyl-1,3-dihydro-3-[[6-[2-(1H- tetrazol-5-yl)phenyl]-3-pyridinyl]methyl]-2H-imidazol-2-one] and its 1-(2,6-dimethylphenyl)-2H-imidazol-2-one derivative SC-54629 were potent inhibitors of 125I-angiotensin II (125I-AII) binding to rat adrenal cortex angiotensin type 1 (AT1) receptors. SC-54628 and SC-54629 antagonized AII-induced contraction of rabbit vascular smooth muscle in a surmountable fashion and an insurmountable fashion, respectively. Binding experiments with SC-54629 were undertaken to determine the nature of receptor interaction, which might explain the insurmountable mode of antagonism of SC-54629. The presence of a high concentration of SC-54629 did not affect the dissociation of membrane-bound 125I-AII induced by an excess of unlabeled AII, indicating that the antagonist binds to the agonist binding site and not an allosteric domain. Incubation of adrenal cortex membranes with SC-54629 decreased the density of 125I-AII binding sites. When incubation of the SC-54629-treated membranes with radiolabeled AII was prolonged, the SC-54629-induced decrease in AT1 receptor density was attenuated, suggesting that binding of the antagonist is slowly reversible. Furthermore, the dissociation of [3H]SC-54629 was 5-fold slower than that of 125I-AII bound to AT1 receptors. These results suggest that the insurmountable antagonism of AII by SC-54629 is most likely due to the slow reversibility of SC-54629 binding to the AT1 receptor.

Acute transverse myelopathy and cutaneous vasculopathy in primary Sjögren's syndrome

Neurologic complications of primary Sjögren's syndrome (SS) may be under-estimated. Here, we report a patient with primary SS, who developed acute transverse myelopathy (ATM) and skin purpuric lesions simultaneously. In the first episode of myelopathy, the patient's neurologic deficits improved after steroid therapy. However, she died of recurrent myelopathy with systemic complications 4 months later. Review of the English-language literature revealed only 3 cases of primary SS associated with ATM, none of the 3 patients had skin lesions. Anti-Ro(SS-A) antibodies, and ATM in our patient suggests that immune-mediated vasculopathy may play a role in the pathogenesis of acute myelopathy in primary SS.

POEMS syndrome in Chinese

POEMS (polyneuropathy, organomegaly, endocrine disturbance, M-protein and skin hyperpigmentation) syndrome occurring in Chinese has been inadequately described. Here we report our experience of 12 Chinese patients with the syndrome. This series is similar to those reported from Japan and from the Western world by the predominance of middle-aged males. Diabetic mellitus, a common feature in POEMS syndrome, was not present in our patients. M-protein of the lambda type was demonstrated in 7 patients by immunoelectrophoresis or by immunofixation electrophoresis. Osteosclerosis in Chinese patients is not as common as in patients reported from Japan or from the Western world; a common radiographic finding in our patients was a compression fracture of the thoraco-lumbar spine with or without sclerotic and lytic lesions. The condition has a grave prognosis; 9 patients die within 4 years after onset of the disease despite various kinds of treatment.

Polymerase chain reaction in the diagnosis of chromosomal breakpoints

Polymerase chain reaction-based methods for the detection of translocation-induced gene rearrangements are now widely used for diagnostics and patient monitoring. This article concentrates on two of the best studied chromosome translocations resulting in specific gene rearrangements and oncogene activation: the Philadelphia translocation of chronic myelogenous leukemia and acute leukemias, and the t(14;18) translocation of follicular lymphomas.