Machine learning approaches based on fibroblast morphometry do not predict ALS

Amyotrophic lateral sclerosis (ALS) is a devastating neuromuscular disease with limited therapeutic options. Biomarkers are needed for early disease detection, clinical trial design, and personalized medicine. Early evidence suggests that specific morphometric features in ALS primary skin fibroblasts may be used as biomarkers; however, this hypothesis has not been rigorously tested in conclusively large fibroblast populations. Here, we imaged ALS-relevant organelles (mitochondria, endoplasmic reticulum, lysosomes) and proteins (TAR DNA-binding protein 43, Ras GTPase-activating protein-binding protein 1, heat-shock protein 60) at baseline and under stress perturbations and tested their predictive power on a total set of 443 human fibroblast lines from ALS and healthy individuals. Machine learning approaches were able to confidently predict stress perturbation states (ROC-AUC ∼0.99) but not disease groups or clinical features (ROC-AUC 0.58-0.64). Our findings indicate that multivariate models using patient-derived fibroblast morphometry can accurately predict different stressors but are insufficient to develop viable ALS biomarkers.

Germline breast cancer susceptibility genes, tumor characteristics, and survival

BACKGROUND

Mutations in certain genes are known to increase breast cancer risk. We study the relevance of rare protein-truncating variants (PTVs) that may result in loss-of-function in breast cancer susceptibility genes on tumor characteristics and survival in 8852 breast cancer patients of Asian descent.

METHODS

Gene panel sequencing was performed for 34 known or suspected breast cancer predisposition genes, of which nine genes (ATM, BRCA1, BRCA2, CHEK2, PALB2, BARD1, RAD51C, RAD51D, and TP53) were associated with breast cancer risk. Associations between PTV carriership in one or more genes and tumor characteristics were examined using multinomial logistic regression. Ten-year overall survival was estimated using Cox regression models in 6477 breast cancer patients after excluding older patients (≥75years) and stage 0 and IV disease.

RESULTS

PTV9genes carriership (n = 690) was significantly associated (p < 0.001) with more aggressive tumor characteristics including high grade (poorly vs well-differentiated, odds ratio [95% confidence interval] 3.48 [2.35-5.17], moderately vs well-differentiated 2.33 [1.56-3.49]), as well as luminal B [HER-] and triple-negative subtypes (vs luminal A 2.15 [1.58-2.92] and 2.85 [2.17-3.73], respectively), adjusted for age at diagnosis, study, and ethnicity. Associations with grade and luminal B [HER2-] subtype remained significant after excluding BRCA1/2 carriers. PTV25genes carriership (n = 289, excluding carriers of the nine genes associated with breast cancer) was not associated with tumor characteristics. However, PTV25genes carriership, but not PTV9genes carriership, was suggested to be associated with worse 10-year overall survival (hazard ratio [CI] 1.63 [1.16-2.28]).

CONCLUSIONS

PTV9genes carriership is associated with more aggressive tumors. Variants in other genes might be associated with the survival of breast cancer patients. The finding that PTV carriership is not just associated with higher breast cancer risk, but also more severe and fatal forms of the disease, suggests that genetic testing has the potential to provide additional health information and help healthy individuals make screening decisions.

B-66 The Effect of Bilingualism on Boston Naming Test Performance in Traumatic Brain Injury Survivors and Healthy Adults

Objective

The Boston Naming Test (BNT) is a lexical-retrieval task. It has been documented that those with a history of traumatic brain injury (TBI) have reduced performance on the BNT. Bilingualism is also known to impact BNT performances. We examined the relationship of TBI and bilingualism/monolingualism on BNT performances.

Method

The sample (N = 95) consisted of 36 healthy controls (19 bilingual; 17 monolingual), 32 acute TBI participants (12 bilingual; 20 monolingual), and 27 chronic TBI participants (16 bilingual; 11 monolingual). Acute TBI participants were tested 6 months post-injury and chronic TBI participants were tested 12 months or more post-injury. All participants passed performance validity testing. A 3X2 ANOVA was conducted to determine the effect of TBI and bilingualism/monolingualism on BNT performance.

Results

A main effect was found for group (i.e., control, 6 month TBI, and 12 month TBI), p < .001, ηp² = .21. Pairwise comparisons revealed that acute TBI participants performed worse than the control and chronic TBI groups. A main effect for bilingualism/ monolingualism was found, p < .001, ηp² = .14; monolinguals performed better on the BNT. No interactions were found between TBI and bilingualism/monolingualism.

Conclusions

BNT performance improves overtime in TBI and the pattern of improvement post-TBI is not statistically different between bilingual/monolingual groups. Relative to monolinguals, bilingual participants demonstrated worse BNT performance.

B-71 The Effect of Bilingualism on Verbal and Design Fluency Performance in Traumatic Brain Injury Survivors and Healthy Adults

Objective

Traumatic brain injury (TBI) impacts neurocognitive function. Language is also known to influence test performances. We examined the relationship between TBI and monolingualism/bilingualism on verbal and design fluency tests.

Method

The sample (N = 74) consisted of 33 healthy controls (18 bilingual; 15 monolingual), 15 acute TBI participants (6 bilingual; 9 monolingual), and 26 chronic TBI participants (15 bilingual; 11 monolingual). Acute TBI participants were tested 6 months post-injury and chronic TBI participants were tested 12 months or more post-injury. The Delis-Kaplan Executive Function System Letter Fluency (DKEFS-LF), Category Fluency (DKEFS-CF), Category Switching Fluency (DKEFS-CSF), and global verbal fluency composite (DKEFS-GVF) scores assessed verbal fluency; DKEFS fill-dots (DKEFS-FD), empty dots (DFEFS-ED), dot switching (DKEFS-DS), and global design fluency composite (DKEFS-GDF) scores assessed design fluency; and global verbal and non-verbal fluency composite (DKEFS-GF) assessed overall fluency. 3X2 ANOVAs were conducted to evaluate the effect of monolingualism/bilingualism on fluency performance in TBI and controls.

Results

The groups (control and TBI groups) differed for DKEFS-LF, p = .048, ηp² = .09, DKEFS-CF, p = .000, ηp² = .21, DKEFS-GVF, p = .004, ηp² = .15, DKEFS-ED, p = .008, ηp² = .13, DKEFS-GF, p = .001, ηp² = .20, with controls outperforming TBI groups on the DKEFS-CF, DKEFS-GVF, and DKEFS-GF. Furthermore, controls outperformed acute TBI participants on the DKEFS-LF and DKEFS-ED. Main effects were found for bilingualism/monolingualism on DKEFS-CF, p = .035, ηp² = .06, with bilinguals outperforming monolinguals. No interactions were found.

Conclusion

The TBI group had poor verbal and design fluency in contrast controls. Unexpectedly, bilinguals outperformed monolinguals on a task of verbal category fluency. Revealing that in the present study bilinguals have better semantic verbal fluency abilities.

B-69 The Effect of Bilingualism on Symbol Digit Modalities Test Performance in Traumatic Brain Injury Survivors and Healthy Adults

Objective

Traumatic brain injury (TBI) survivors exhibit cognitive deficits. Language factors can also influence neurocognitive performance. We examined the effects of TBI and bilingualism/monolingualism on a test of attention and cognitive speed (i.e., Symbol Digit Modalities Test; SDMT).

Method

The sample (N = 98) consisted of 37 controls (19 bilingual; 18 monolingual), 34 acute TBI participants (12 bilingual; 22 monolingual), and 27 chronic TBI participants (16 bilingual; 11 monolingual). Acute TBI participants were tested 6 months post-injury; chronic TBI participants were tested 12 months or more post-injury. All participants passed performance validity testing. 3X2 ANOVAs were conducted to determine the effect of TBI and language on SDMT written and oral performance.

Results

A main effect was found between groups (control and TBI groups) on SDMT written, p < .001, ηp² = .19 and SDMT oral p < .001, ηp² = .16. Pairwise comparisons revealed a difference between the control group and TBI groups, with TBI groups performing worse. A main effect for bilingualism/monolingualism was not found; interaction effects emerged between TBI and bilingualism/monolingualism on SDMT written, p < .05, ηp² = .07 and SDMT oral p < .05, ηp² = .07.

Conclusion

TBI groups performed worse than controls on the SDMT. Relative to monolinguals with TBI, our findings suggest better cognitive recovery of verbal attention and cognitive speed in bilingual TBI participants.

B-68 The Effect of Bilingualism on Stroop Performance in Traumatic Brain Injury Survivors and Healthy Adults

Objective

Traumatic brain injury (TBI) affects neurocognition. Speaking multiple languages can also influence cognitive test performances. We examined the relationship between TBI and monolingualism/bilingualism on a task of attention and response inhibition (Stroop Color Word Test; SCWT).

Method

The sample (N = 96) consisted of 37 healthy controls (19 bilingual; 18 monolingual), 32 acute TBI participants (12 bilingual; 20 monolingual), and 27 chronic TBI participants (16 bilingual; 11 monolingual). Acute TBI participants were tested 6 months post-injury and chronic TBI participants were tested 12 months or more post-injury. The SCWT included the word (SCWT-W), color (SCWT-C), and color-word interference (SCWT-I) conditions. All participants passed performance validity testing. 3X2 ANOVAs were conducted to examine the relationship between TBI and monolingualism/bilingualism on SCWT performances.

Results

Group effects (control and TBI groups) were found for all Stroop measures. We found main effects of TBI on SCWT-W, p = .013, ηp² = .09, SCWT-C, p = .001, ηp² = .14, and SCWT-I, p = .022, ηp² = .08, with the controls outperforming acute TBI survivors on SCWT-I, chronic TBI survivors on SCWT-W, and both TBI groups on SCWT-C. We also observed main effects of language for SCWT-C, p = .012, ηp² = .07, and SCWT-I, p = .003, ηp² = .09, with the monolinguals outperforming bilinguals on SCWT-C and SCWT-I. However, no significant interactions between TBI and language were found.

Conclusion

As expected, the control group outperformed TBI survivors on the SCWT. Monolinguals outperformed bilinguals on all Stroop measures except SCWT-W condition. Our findings seem to suggest that monolingual speakers may have better attention and response inhibition abilities that resulted in better SCWT performance.

B-67 The Effect of Bilingualism on Executive Functioning Performance in Traumatic Brain Injury Survivors and Healthy Adults

Objective

Traumatic brain injury (TBI) survivors often exhibit problems with executive function (EF). Language use can also impact EF test performances. We examined the effects of TBI and bilingualism/monolingualism on several EF tests.

Method

The sample (N = 94) consisted of 37 healthy controls (19 bilingual; 18 monolingual), 30 acute TBI participants (10 bilingual; 20 monolingual), and 27 chronic TBI participants (16 bilingual; 11 monolingual). Acute TBI participants were tested 6 months post-injury and chronic TBI participants were tested 12 months or more post-injury. Stroop Color-Word (SCW), Delis-Kaplan Executive Function System Letter Fluency (DKEFS-LF), Trail Making Test part B (TMT-B) and a EF global composite (EF-GC) were used to assess EF. All participants passed performance validity testing. 3X2 ANOVAs were conducted to determine the effect of TBI and bilingualism/monolingualism on EF performances.

Results

Main effects were found between groups (control and TBI groups) on SCW, p = .046, ηp² = .07, TMT-B, p = .042, ηp² = .07, and EF-GC, p = .005, ηp² = .13; the 6-month TBI group performed worse than controls on TMT-B and EF-GC. Main effects were found for bilingualism/ monolingualism on SCW, p = .012, ηp² = .07, and TMT-B, p = .034, ηp² = .05; monolingual participants performed better than bilingual participants. No significant interactions between TBI and language were found.

Conclusion

The TBI group underperformed on SCW, TMT-B, and EF-GC compared to controls; relative to monolinguals, bilinguals underperformed on the SCW and TMT-B only. In conclusion, our findings seem to suggest that monolinguals have better cognitive flexibility compared to bilinguals that result in better EF performances.

B-70 The Effect of Bilingualism on Trail Making Test Performance in Traumatic Brain Injury Survivors and Healthy Adults

Objective

Traumatic brain injury (TBI) is associated with a number of cognitive deficits. Language factors also impact neurocognitive performance. We examined the effects of TBI and bilingualism/monolingualism on a test of attention and executive functioning (Trail Making Test; TMT).

Method

The sample (N = 96) consisted of 36 healthy controls (19 bilingual; 17 monolingual), 34 acute TBI participants (12 bilingual; 21 monolingual), and 27 chronic TBI participants (16 bilingual; 11 monolingual). Acute TBI participants were tested 6 months post-injury and chronic TBI participants were tested 12 months or more post-injury. 3X2 ANOVAs were conducted to determine the effect of TBI and bilingualism/monolingualism on TMT part A and B.

Results

Main effects were found between groups (i.e., control and TBI groups) on TMT A, p < .001, ηp² = .17 and TMT B, p < .05, ηp² = .09. Pairwise comparisons revealed a difference only between the control group and the 6-month TBI group, with the latter performing worse. Main effects were found for bilingualism/monolingualism on TMT A, p < .05, ηp² = .04 and TMT B, p < .05, ηp² = .05; monolingual participants performed better than bilingual participants. No interactions emerged.

Conclusion

Relative to monolinguals, bilingual participants demonstrated worse attention and executive functioning performances 6 months post-TBI; however, 12 months post-TBI, the difference was negligible.

Outcome after neoadjuvant chemotherapy in Asian breast cancer patients

We aim to identify clinicopathologic predictors for response to neoadjuvant chemotherapy and to evaluate the prognostic value of pathologic complete response (pCR) on survival in Asia. This study included 915 breast cancer patients who underwent neoadjuvant chemotherapy at five public hospitals in Singapore and Malaysia. pCR following neoadjuvant chemotherapy was defined as 1) no residual invasive tumor cells in the breast (ypT0/is) and 2) no residual invasive tumor cells in the breast and axillary lymph nodes (ypT0/is ypN0). Association between pCR and clinicopathologic characteristics and treatment were evaluated using chi-square test and multivariable logistic regression. Kaplan-Meier analysis and log-rank test, stratified by other prognostic factors, were conducted to compare overall survival between patients who achieved pCR and patients who did not. Overall, 4.4% of nonmetastatic patients received neoadjuvant chemotherapy. The median age of preoperatively treated patients was 50 years. pCR rates were 18.1% (pCR ypT0/is) and 14.4% (pCR ypT0/is ypN0), respectively. pCR rate was the highest among women who had higher grade, smaller size, estrogen receptor negative, human epidermal growth factor receptor 2-positive disease or receiving taxane-based neoadjuvant chemotherapy. Patients who achieved pCR had better overall survival than those who did not. In subgroup analysis, the survival advantage was only significant among women with estrogen receptor-negative tumors. Patients with poor prognostic profile are more likely to achieve pCR and particularly when receiving taxane-containing chemotherapy. pCR is a significant prognostic factor for overall survival especially in estrogen receptor-negative breast cancers.

Analysis of resting noise characteristics of three EIT systems in order to compare suitability for time difference imaging with scalp electrodes during epileptic seizures

Electrical impedance tomography measurements in clinical applications are limited by an undesired noise component. We have investigated the noise in three systems suitable for imaging epileptic seizures, the UCH Mark1b, UCH Mark2.5 and KHU Mark1 16 channel, at applied frequencies in three steps from 1 to 100 kHz, by varying load impedance, single terminal or multiplexed measurements, and in test objects of increasing complexity from a resistor to a saline filled tank and human volunteer. The noise was white, and increased from about 0.03% rms on the resistor to 0.08% on the human; it increased with load but was independent of use of the multiplexer. The KHU Mark1 delivered the best performance with noise spectra of about 0.02%, which could be further reduced by averaging to a level where reliable imaging of changes of about 0.1% estimated during epileptic seizures appears plausible.

Magnetic resonance electrical impedance tomography of the breast: a simulation study on basic imaging setup

Magnetic resonance electrical impedance tomography (MREIT) has been developed as a new medical imaging modality providing high-resolution conductivity and current density images. This paper is about MREIT of the breast. To show the feasibility of breast MREIT, we carried numerical simulations and breast phantom experiments. We found that an anomaly with 4 mm diameter can be visualized in a reconstructed conductivity image using 5 mA injection current if the SNR of the corresponding MR magnitude image is at least 150. We propose a desirable electrode configuration and show our first experimental results of the breast MREIT. Developing an RF coil for the breast MREIT, we plan to conduct various experimental studies including tissue phantoms.

Noise Analysis of MREIT at 3T and 11T Field Strength

In Magnetic Resonance Electrical Impedance Tomography (MREIT), we measure the induced magnetic flux density inside an imaging object subject to an external injection current. The magnetic flux density is contaminated with noise and this ultimately limits the quality of reconstructed conductivity and current density images. By using two methods to analyze amounts of noise in 3T and 11T MREIT systems, we found that a carefully designed MREIT study will be able to reduce the noise level below 0.1 nT.

Use of the Extended V-Y Latissimus Dorsi Myocutaneous Flap for Chest Wall Reconstruction in Locally Advanced Breast Cancer

The extended V-Y latissimus dorsi myocutaneous flap described by Micali and Carramaschi provides an innovative method of closing large anterior chest defects after resection of breast cancer. The technique provides robust chest wall coverage that is able to withstand immediate postoperative radiotherapy. The aim of this article is to confirm the usefulness of the flap's design and describe modifications to the technique. The modifications to technique include: a curvilinear design that recruited more skin for closure in patients with wounds extending laterally or superiorly, routine transposition of latissimus dorsi insertion inferio-medially onto the chest wall to maximize pedicle reach, and the use of small split skin grafts or delayed primary closure if there was tension in closing. Twelve patients who underwent resection of locally advanced breast cancer had immediate chest wall reconstruction with the extended V-Y latissimus dorsi musculocutaneous flap. The V to Y design of the flap's cutaneous island allowed primary closure of chest wound and donor defect. There were no instances of chest wound dehiscence. The chest wounds healed, allowing patients to undergo adjuvant radiotherapy in a mean time interval of 6 weeks after surgery.

Screening of new chemopreventive compounds from Digitalis purpurea

Chemopreventive agents induce a battery of genes whose protein products can protect cells from chemical-induced carcinogenesis. In this study, we isolated four different glycosides (1 acteoside; 2 purpureaside A; 3 calceolarioside B; and 4, plantainoside D) from the leaves of Digitalis purpurea and studied their abilities to induce glutathione S-transferase (GST) and their protective efficiencies against aflatoxin B1-induced cytotoxicity in H4IIE cells. Of these four glycosides, acteoside significantly inhibited the cytotoxicity induced by aflatoxin B1 (AFB1) and also selectively increased GSTalpha protein levels. Reporter gene analysis using an antioxidant response element (ARE) containing construct and subcellular fractionation assays, revealed that GSTalpha induction by acteoside might be associated with Nrf2/ARE activation. The results suggest that acteoside possesses a potent hepatoprotective effect against AFB1 and that it can be applied as a potential chemopreventive agent.

Approaches to stabilization of inter-domain recombination in polyketide synthase gene expression plasmids

Regions of extremely high sequence identity are recurrent in modular polyketide synthase (PKS) genes. Such sequences are potentially detrimental to the stability of PKS expression plasmids used in the combinatorial biosynthesis of polyketide metabolites. We present two different solutions for circumventing intra-plasmid recombination within the megalomicin PKS genes in Streptomyces coelicolor. In one example, a synthetic gene was used in which the codon usage was reengineered without affecting the primary amino acid sequence. The other approach utilized a heterologous subunit complementation strategy to replace one of the problematic regions. Both methods resulted in PKS complexes capable of 6-deoxyerythronolide B analogue biosynthesis in S. coelicolor CH999, permitting reproducible scale-up to at least 5-l stirred-tank fermentation and a comparison of diketide precursor incorporation efficiencies between the erythromycin and megalomicin PKSs.

Enhanced production of heterologous macrolide aglycones by fed-batch cultivation of Streptomyces coelicolor

A media development program for the enhanced production of macrolide aglycones by Streptomyces coelicolor is described. Shake flask studies utilizing a yeast extract and a bakers' yeast increased production by 200% and 80%, respectively. However, ammonia generation and high pH were identified as potential problems in these enriched media. Studies in pH-controlled fermentors revealed that production stage pH significantly affects macrolide titers, with low pH (5.5) being more productive than high pH (6.5). Implementation of glucose feeding in shake flask cultures reduced ammonia generation and controlled production stage pH, resulting in significantly enhanced productivities. The combined effects of media supplementation and glucose feeding resulted in a three to five-fold overall improvement in total macrolide aglycone titers, and is the first reported high-level (>1 g/l) production of recombinant polyketides in a heterologous host.

Precursor-directed biosynthesis of 6-deoxyerythronolide B analogs in Streptomyces coelicolor: understanding precursor effects

A fermentation process employing precursor-directed biosynthesis is being developed for the manufacture of 6-deoxyerythronolide B (6-dEB) analogues. Through a plasmid-based system in Streptomyces coelicolor, 6-dEB synthesis is catalyzed by 6-dEB synthase (DEBS). 6-dEB synthesis is abolished by inactivation of the ketosynthase (KS) 1 domain of DEBS but can be restored by providing synthetic activated diketides. Because of its inherent catalytic flexibility, the KS1-deficient DEBS is capable of utilizing unnatural diketides to form various 13-substituted 6-dEBs. Here we characterize process variables associated with diketide feeding in shake-flask experiments. 13-R-6-dEB production was found to depend strongly on diketide feed concentrations, on the growth phase of cultures at feeding time, and on the R-group present in the diketide moiety. In all cases a major portion of the fed diketides was degraded by the cells.

Homeopathic treatment of mild traumatic brain injury: A randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Mild traumatic brain injury (MTBI) affects 750,000 persons in the United States annually. Five to fifteen percent have persistent dysfunction and disability. No effective, standard pharmacological treatment exists specifically for this problem. We designed a pilot research project to study the clinical effectiveness of homeopathic medicine in the treatment of persistent MTBI.

METHOD

A randomized, double-blind, placebo-controlled trial of 60 patients, with a four-month follow-up (N = 50), was conducted at Spaulding Rehabilitation Hospital (SRH). Patients with persistent MTBI (mean 2.93 years since injury, SD 3.1) were randomly assigned to receive a homeopathic medicine or placebo. The primary outcome measure was the subject-rated SRH-MBTI Functional Assessment, composed of three subtests: a Difficulty with Situations Scale (DSS), a Symptom Rating Scale (SRS), and a Participation in Daily Activities Scale (PDAS). The SRH Cognitive-Linguistic Test Battery was used as the secondary measure.

RESULTS

Analysis of covariance demonstrated that the homeopathic treatment was the only significant or near-significant predictor of improvement on DSS subtests (P =.009; 95% CI -.895 to -.15), SRS (P =.058; 95% CI -.548 to.01) and the Ten Most Common Symptoms of MTBI (P =.027; 95% CI -.766 to -.048). These results indicate a significant improvement from the homeopathic treatment versus the control and translate into clinically significant outcomes.

CONCLUSIONS

This study suggests that homeopathy may have a role in treating persistent MTBI. Our findings require large-scale, independent replication.

Stability of the antiproliferative effect of mitomycin-C after reconstitution

PURPOSE

The purpose of this study was to determine the long-term stability of the antiproliferative effect of mitomycin-C (MMC) following reconstitution.

METHODS

Identical MMC preparations were reconstituted from the crystalline form and then stored at room temperature or 4 degrees C. Cultured human Tenon's fibroblasts were exposed to MMC (0.5 mg/ml) for 2.5 min at 0, 3, 7, 10, 14, 21, 28, 35, and 42 days following reconstitution. After removal of the drug, fibroblast proliferation was measured by tritiated thymidine uptake.

RESULTS

The percentage of inhibition was maintained at > 85% for both the room temperature and the 4 degrees C groups, and this inhibition persisted for the duration of the experiment. There was no statistically significant difference in the results between the storage temperatures.

CONCLUSIONS

These data suggest that MMC retains its antiproliferative effect for at least 6 weeks following reconstitution and that this effect is not changed by storage temperature. Cost savings may be realized by storing MMC in unit-dose reconstituted aliquots for these longer periods, providing sterility can be assured.

Myasthenia gravis in Hong Kong Chinese. 1. Epidemiology and adult disease

A territory-wide study of myasthenia gravis (MG) was conducted in Hong Kong. Two hundred and sixty-two Chinese patients (159 adult and 103 paediatric onset) were identified, corresponding to a point prevalence and period prevalence of 53.5 and 62.2 per million respectively, and an average annual incidence of 4.0 per million population. Nine patients died, 7 from MG, giving a case fatality rate of 0.027. Female predominance was present in the whole group of patients (female to male ratio 1.6:1) and in those with adult disease (ratio 2.1:1), but not in those with onset in childhood (ration 1.1:1). Onset of disease was most common in the first 3 decades of life, and became less common in subsequent decades. Juvenile onset MG occurred in 39.3% of patients and restricted ocular MG in 47.9%. Familial occurrence was found in 5 patients. In the 159 adult onset patients, ocular disease was most common (32.7%), followed by mild generalised (29.6%), moderately severe generalised (24.5%), fulminating (11.9%) and late severe disease (1.3%). The mean age of onset of symptoms was 36.7 years. The symptomatology was similar to that of Caucasoid populations. Autoimmune thyroid disease was the commonest associated disease, and the incidence of thymoma among thymic abnormalities was high at 38%.

High prevalence of undiagnosed diabetes among Chinese patients with ischaemic stroke

We reviewed the prevalence of diabetes mellitus, hypertension and cigarette smoking in 176 Chinese patients with acute stroke, classified, on computed tomographic findings, as intracerebral haemorrhage or cerebral infarction. In all patients with no known history of diabetes, a 75 g OGTT was done 3-6 months after ictus and interpreted using WHO criteria. The overall prevalence of diabetes and impaired glucose tolerance (IGT) was 33.5% and 21.0%, respectively, with a higher prevalence being found in patients with cerebral infarction (P less than 0.05). Forty percent of those with diabetes were previously undiagnosed - all but 2 had ischaemic stroke. Compared to reported findings in the general population, an increased prevalence of hypertension, and possibly also cigarette smoking was found in patients with both stroke categories. On the other hand, significant hypercholesterolaemia was not found in patients of either category. In view of the high prevalence of undiagnosed diabetes among these stroke patients and the increased morbidity and mortality associated with diabetes mellitus, screening for diabetes is recommended especially in those with ischaemic stroke. If a fasting plasma glucose of greater than or equal to 6 mmol/l was used for the initial screening of undiagnosed diabetes in this group of patients, the sensitivity and specificity values would have been 78% and 94%, respectively. Whether this cut-off value can be cost-effectively employed for mass screening remains to be confirmed by studies involving larger numbers of stroke patients.

Differential side effect profile of triazolam versus flurazepam in elderly patients undergoing rehabilitation therapy

Patients (aged 65 years or older) who were hospitalized for rehabilitation therapy after a cerebrovascular accident or other acute debilitating condition participated in a 6-week controlled clinical trial. After a 2-week period of receiving nightly single-blind placebo, patients were randomly allocated to receive either triazolam (0.125 mg) or flurazepam hydrochloride (15 mg) nightly under double-blind conditions. For the final 2 weeks, patients again received single-blind placebo. The study groups' were comparable in their performance on four psychomotor tests done in the morning during the initial placebo period. Triazolam-treated patients showed subsequent improvement on the tests, consistent with practice effects, whereas flurazepam recipients showed performance impairment during treatment. Triazolam-flurazepam differences were significant in the card-sorting and arithmetic tests, and they approached significance for the Purdue pegboard test. Blind ratings by physical therapists indicated significant impairment among flurazepam recipients in their capacity to cooperate with and participate in the rehabilitation tasks; the impairment persisted into the post-treatment placebo period. Similar flurazepam-triazolam differences, although not significant, were reported by occupational therapy and nursing staff members. The findings suggest that the kinetic differences between flurazepam and triazolam may have clinical implications in elderly patients undergoing rehabilitation therapy.

Red blood cell and adipose tissue fatty acids in mild inactive multiple sclerosis

The fatty acid profiles of phosphatidyl ethanolamine (PE) and phosphatidyl choline (PC) of the red blood cells of 30 patients with mild inactive multiple sclerosis (MS) and 30 healthy controls were studied by gas chromatography. The groups were well matched for factors likely to influence tissue lipid levels, including diet. The MS patients showed a significant reduction in PE eicosapentaenoic acid (p = 0.009) especially in women, and an increase in both PE dihomo-gamma-linolenic acid (p = 0.004) and PC stearic acid (p = 0.04). No reduction in linoleic acid was observed in either the PC or PE fractions of the MS subjects. A similar study of the fatty acid profile in adipose tissue in 26 MS and 35 healthy controls found no detectable eicosapentaenoic acid in either group. However, whereas docosahexaenoic acid was not detectable in any MS patient, 40% of the controls had measurable levels varying from to 0.1 to 0.3% of total estimated fatty acid (p = 0.0003). No reduction in linoleic acid in MS subjects was observed. Supplementation with oral fish body oil demonstrated that n-3 fatty acids were incorporated into red blood cells over 5 weeks and this occurred equally in MS and controls. The effects of oral supplementation on adipose tissue were studied after 1 and 2 years. Whereas many fatty acids such as linoleic acid were raised at 1 year, but did not rise subsequently, eicosapentaenoic acid and docosahexaenoic acid continued to rise through the 2-year period.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic effects of phenytoin on brain-stem auditory evoked potentials in man

The effects of phenytoin (PHT) on brain-stem auditory evoked potentials (BAEPs) were studied in 65 epileptic patients who received long-term PHT monotherapy at therapeutic and supra-therapeutic levels with no clinical evidence of brain-stem toxicity. Abnormal BAEPs were found in 7.5% and 33.3% of patients with therapeutic and supra-therapeutic PHT levels respectively. Serum PHT levels had a trend towards a positive relationship with the I-V interpeak latency (IPL), and a significant negative relationship with the amplitudes of waves I and V. At supra-therapeutic levels, both I-V and I-III IPLs were significantly prolonged while at therapeutic levels only I-III IPLs were prolonged. The absolute latency of wave I was prolonged in both the therapeutic and the supra-therapeutic groups. These results suggest that PHT acts both peripherally on either the auditory nerve or the cochlea, and centrally on brain-stem conduction.

Cerebrovascular disease in Hong Kong Chinese

Our prospective study of cerebrovascular disease in Hong Kong confirms a previous clinical impression that stroke in the Chinese has a pattern different from that in Caucasians. We studied 540 patients (aged 20-70 years) with stroke. Computed tomography or autopsy was obtained in 86.1% and showed an increase in the proportion with lacunar infarction, striatocapsular infarction, and parenchymal hemorrhage relative to the frequencies in Caucasians. This increase in the incidence of cerebral hemorrhage occurs not only in semicomatose and comatose patients but also in alert patients (16.9%) and those with a lacunar syndrome (12.5%). Our findings suggest that cerebrovascular disease in the Chinese selectively affects small vessels, causing lacunes and hemorrhages. In future community studies on stroke prevalence, researchers should be cautious about interpreting similar prevalence rates as reflecting similar risk factors or pathologies.

Klinefelter's syndrome and primary central nervous system lymphoma

Klinefelter's syndrome is known to be associated with various malignancies including male breast cancer and germ cell tumour. We report a patient with Klinefelter's syndrome who developed a primary B-cell lymphoma of the central nervous system (CNS). To the best of our knowledge, this is the first case of primary CNS lymphoma in Klinefelter's syndrome.

Multiple sclerosis amongst Chinese in Hong Kong

A territory-wide investigation of southern Chinese patients with multiple sclerosis (MS) was conducted in Hong Kong. There were 47 patients, 35 of whom were clinically definite (CDMS), 6 laboratory-supported definite (LSDMS) and 6 clinically probable (CPMS). The prevalence rate was 0.88 per 10(5) population, which is of the same order as in other Oriental populations but much lower than in Caucasoid populations. Comparisons with major Oriental and Caucasian series showed essentially the same clinical picture with only minor variations. In one autopsy case, the lesions were found mainly in the optic nerves and spinal cord, with marked softening in addition to the classical demyelination features. In contrast to findings in Caucasians, the detection rate of oligoclonal bands in the cerebrospinal fluid was low (33% in CDMS patients) and there was no association with human leucocyte antigens. The possible implications of these findings on the pathogenesis of MS are discussed.

Type I familial amyloid polyneuropathy in a Chinese family

A Chinese family with at least 3 members having the typical clinical picture of type I familial amyloid polyneuropathy is presented. The pathological features, including the immunohistochemical typing of the amyloid deposits, are described and the literature is briefly reviewed.

Cryptococcal infection of the lumbar spine

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Possible evidence for a variant of myasthenia gravis based on HLA and acetylcholine receptor antibody in Chinese patients

A comprehensive study of 194 Chinese patients with myasthenia gravis in Hong Kong has shown distinct differences from the patterns of disease seen in Caucasians. Restricted ocular myasthenia is the predominant disease type in patients presenting in the first two decades of life and is associated with absence or low titres of acetylcholine receptor antibody. Predisposition to this type of disease is strongly associated with HLA-DRw9. Generalized myasthenia gravis occurs predominantly in patients presenting after the age of 20 years and is accompanied by high titres of acetylcholine receptor antibody but is less strongly associated with HLA-DRw9. It is suggested that myasthenia gravis occurring within the first two decades of life and characterized by affected ocular muscles and absence or low titre of acetylcholine receptor antibody is a genetically determined variant of the disease which occurs commonly in Orientals.

Subcortical arteriosclerotic encephalopathy--a controlled psychometric study

Eleven patients with subcortical arteriosclerotic encephalopathy (SAE) were assessed psychometrically, and the results compared with control subjects without neurological disorders and patients with a single cerebral vascular lesion (CVL). The groups were matched for sex, age, years of education, and in addition for the CVL group, the nature, site and size of the discrete vascular lesion. The SAE patients had mild to moderate impairment in intellectual, memory, receptive language and constructional functions, but individual performance ranged from near normality to severe impairment. The differences between the performance of SAE patients and the controls were significant in the majority of tests. The SAE patients had lower scores than CVL patients on all tests, but in many of these the difference was not significant.

A double-blind controlled trial of long chain n-3 polyunsaturated fatty acids in the treatment of multiple sclerosis

A trial of n-3 polyunsaturated fatty acids in the treatment of multiple sclerosis has been conducted over a 5 year period. Ambulant patients (312) with acute remitting disease were randomly allocated to treatment or placebo. Both groups were given dietary advice to increase the intake of n-6 polyunsaturated fatty acids and the treatment group in addition received capsules containing n-3 polyunsaturated fatty acids. Analysis of clinical outcome at the end of 2 years of treatment was made in terms of the duration, frequency and severity of relapses and the number of patients who had improved or remained unchanged. The results showed no significant difference at the usual 95% confidence limits but there was a trend in favour of the group treated with n-3 polyunsaturated fatty acids in all parameters examined.