Ethambutol-induced optic neuropathy with rare bilateral asymmetry onset: A case report

BACKGROUND

Ethambutol-induced optic neuropathy (EON) most commonly manifests as bilateral symmetrical loss of vision and often cause serious and irreversible visual impairment because of the lack of early detection and effective treatment. We followed a case of EON with rare binocular asymmetric clinical manifestations and observed the changes of visual function and retinal structure after drug withdrawal, so as to further understand the clinical characteristics of this disease.

CASE SUMMARY

A 54-year-old man complained of gradual visual decline in the left eye. The patient presented with best-corrected visual acuity of 20/20 in the right eye and 20/50 in the left eye. Color vision examination revealed difficulty in reading green color plates in the left eye. The visual field manifested as concentric contraction in the left eye. After nearly a month of drug withdrawal, the right eye had a similar decline in visual function. At the last visit, 19 mo after drug withdrawal, the visual function significantly recovered in both eyes. During follow-up optical coherence tomography (OCT) examination, both eyes manifested the thickness of the retinal nerve fiber layer from mild thickening to thinning and finally temporal atrophy, and the ganglion cell-inner plexiform layer showed significant thinning. The difference was that a reversible structural disorder in the outer retina of the nasal macula was detected in the left eye by macular high-definition OCT.

CONCLUSION

Nephropathy and high blood pressure, which damage the retinal microcirculation, may cause damage to the outer layer of the retina. Ethambutol may influence photoreceptor as well as retinal ganglion cells.

Analysis of structural injury patterns in peripapillary retinal nerve fibre layer and retinal ganglion cell layer in ethambutol-induced optic neuropathy

BACKGROUND

We investigated structural injury patterns in the peripapillary retinal nerve fibre layer (p-RNFL) and ganglion cell inner plexiform layer (GCIPL) caused by ethambutol treatment.

METHODS

Sixty-four patients undergoing ethambutol treatment at Zhejiang Chinese Medicine and Western Medicine Integrated Hospital were recruited. Fourteen (14) exhibited visual dysfunction (abnormal group), and the remaining 50 had no visual dysfunction (subclinical group). The thickness of the p-RNFL, total macular retina layer and GCIPL were measured using Cirrus-HD Optical coherence tomography (Cirrus-HD OCT, Cirrus high-definition optical coherence tomography), and compared with 60 healthy, age-matched controls.

RESULTS

The p-RNFL thickness was similar in both subclinical and control groups. When compared with the control group, p-RNFL thickness in the abnormal group was significantly increased in the inferior and superior quadrants (GEE, P = 0.040, P = 0.010 respectively). In contrast with the subclinical group, p-RNFL thickness in the inferior quadrant was increased in the abnormal group (GEE, P = 0.047). The GCIPL thickness in the inferonasal and inferior sectors was significantly deceased in the subclinical group when compared with controls (GEE, P = 0.028, P = 0.047, respectively). The average and minimum value of GCIPL thickness, and thickness in the superonasal, inferior, inferotemporal, superotemporal and superior sectors were significantly decreased in the abnormal group when compared with controls (GEE, P = 0.016, P = 0.001, P = 0.028, P = 0.010, P = 0.012, P = 0.015, P = 0.010, respectively). The cube average macular thickness (CAMT) in the abnormal group was significantly thinner than controls (GEE, P = 0.027).

CONCLUSIONS

GCIPL measurements using Cirrus-HD OCT detected retinal ganglion cell layer loss following ethambutol treatment, before visual dysfunction occurred.

A novel role for Livin in the response to ultraviolet B radiation and pterygium development

A pterygium is an inflammatory, invasive and proliferative lesion on the ocular surface, which can decrease visual acuity, damage the ocular surface and affect the appearance of the eye. However, the underlying molecular mechanisms of the pathogenesis remain unclear. In the present study, the role of apoptosis-associated protein Livin in the occurrence and development of pterygium was investigated. Primary samples from quiescent or advanced clinical stages of pterygium and normal human conjunctival tissues were used to assess mRNA and protein expression levels of Livin using reverse transcription-quantitative PCR and immunohistochemistry, respectively. Livin was knocked down in pterygium epithelial cells (PECs) using small interfering RNA (siRNA), to investigate the role of Livin in PEC viability, migration, invasion ability and apoptosis. The cell viability, invasion ability and apoptosis of PECs following ultraviolet B (UVB) radiation alone or in combination with Livin silencing were also analyzed. Expression levels of Livin increased in the pterygium tissues compared with those in the normal conjunctiva at both the mRNA and protein levels. Livin expression levels in advanced pterygium were significantly higher compared with those in quiescent pterygium samples. Knockdown of Livin expression levels significantly reduced cell migration, invasion ability and cell viability, and induced apoptosis of PECs. Inhibition of Livin expression in PECs increased the expression levels of caspase-7, caspase-3 and E-cadherin, whereas expression levels of Snail were downregulated. Cell viability and invasion ability in PECs was enhanced following UVB radiation and Livin expression upregulated. UVB irradiation induced cell invasion ability of PECs and this was attenuated by Livin-silencing. Transfection with Livin siRNA also partially recovered the apoptosis rate of PECs, which was reduced by UVB irradiation. In conclusion, Livin was upregulated in pterygium, and UVB radiation functions in the development of pterygium by inducing Livin expression.

Unilateral inferior oblique anterior transposition for markedly asymmetric dissociated vertical deviation with unilateral inferior oblique over-action

Background

To evaluate the results of unilateral inferior oblique anterior transposition (IOAT) for markedly asymmetric dissociated vertical deviation (DVD) combined with inferior oblique over-action (IOOA).

Methods

Retrospective chart review of the records of all patients with asymmetric DVD combined with unilateral IOOA in the non-dominant eye who received unilateral IOAT on the non-dominant eye. No other muscles were operated on simultaneously. The amount of DVD and IOOA were measured before and after the operation and statistically analysed.

Results

Seventeen patients were included. The mean age at surgery was 23.5 ± 8.4 (range 12–38) years old. The mean postoperative follow-up period was 15.7 ± 7.2 (range 6–32) months. The primary position DVD was 19.6 ± 5.4 (range 14–36) PD preoperatively and decreased significantly to 2.9 ± 2.0 (range 0–8) PD postoperatively (P < 0.01). Preoperatively, there were 2, 7, and 8 patients with + 1, + 2, and + 3 IOOA, respectively, and these were reduced from 2.4 ± 0.7 to 0.3 ± 0.4 postoperatively (P < 0.01). None of the patients were complicated obvious hypotropia, anti-elevation syndrome or IOOA in the contralateral eye.

Conclusions

Unilateral IOAT was recommended in patients with asymmetric DVD coexists with unilateral IOOA.

Prevalence and risk factor analysis of TTV infection in prostitutes

TTV, a DNA virus, has been isolated from patients with non-A to non-E post-transfusion hepatitis. In the past it was assumed that TTV was transmitted parenterally. It is unclear whether sexual contact leads to transmission of this virus. In this study, two sets of TTV-specific polymerase chain reaction primers were used to detect serum TTV DNA in 140 prostitutes and 136 controls. The prevalence of TTV DNA in prostitutes was significantly higher than in the control group (46/140 [32.9%] vs. 29/136 [21.3%]; P = 0.043). There was no significant difference in the prevalence of positive antibody to hepatitis A virus (anti-HAV) in either group (87.8% for prostitutes, 85.3% for controls). No particular risk factor was significantly associated with positive TTV DNA in prostitutes. In summary, TTV is highly prevalent in prostitutes. Transmission of TTV via sexual contact is not as efficient as transmission of hepatitis C and D viruses and GB virus-C hepatitis G virus. The high prevalence of TTV in controls indicates that there are diverse routes of transmission of this virus.

Prevalence and risk factor analysis of TTV infection in prostitutes

TTV, a DNA virus, has been isolated from patients with non-A to non-E post-transfusion hepatitis. In the past it was assumed that TTV was transmitted parenterally. It is unclear whether sexual contact leads to transmission of this virus. In this study, two sets of TTV-specific polymerase chain reaction primers were used to detect serum TTV DNA in 140 prostitutes and 136 controls. The prevalence of TTV DNA in prostitutes was significantly higher than in the control group (46/140 [32.9%] vs. 29/136 [21.3%]; P = 0.043). There was no significant difference in the prevalence of positive antibody to hepatitis A virus (anti-HAV) in either group (87.8% for prostitutes, 85.3% for controls). No particular risk factor was significantly associated with positive TTV DNA in prostitutes. In summary, TTV is highly prevalent in prostitutes. Transmission of TTV via sexual contact is not as efficient as transmission of hepatitis C and D viruses and GB virus-C hepatitis G virus. The high prevalence of TTV in controls indicates that there are diverse routes of transmission of this virus.

Spectral analysis of arterial blood pressure and cerebral blood flow velocity during supine rest and orthostasis

This study evaluates the effect of orthostasis on the low frequency (LF, 0.04 to 0.15 Hz) fluctuations in the blood flow velocity of the middle cerebral artery (MCAFV) in relation to its arterial blood pressure (ABP) equivalent to further define and quantify this relationship in cerebrovascular regulation. Spectral analysis was performed on 22 healthy subjects during supine rest and head-up tilt. The power in the LF range can be used to quantify the LF fluctuations, and four types of LF power data could be obtained for each individual: LF power of supine MCAFV, LF power of supine ABP, LF power of tilt MCAFV, and LF power of tilt ABP. By comparing LF power of MCAFV with LF power of ABP, two power ratios could be generated to describe the flow-pressure relationship during supine rest and head-up tilt, respectively, supine power ratio (LF power of supine MCAFV/ LF power of supine ABP) and tilt power ratio (LF power of tilt MCAFV/ LF power of tilt ABP). In addition, an index for dynamic autoregulation in response to orthostasis can be calculated from these two power ratios (tilt power ratio/supine power ratio). The authors found that this index was dependent on the extent of orthostatic MCAFV changes, and the dependency could be mathematically expressed (r = 0.61, P = .0001), suggesting its involvement in cerebrovascular regulation. Moreover, these data further support the previous observation that the LF fluctuations of MCAFV might result from modulation of its ABP equivalent, and the modulation effect could be quantified as the power ratio (LF power of MCAFV/ LF power of ABP). These observations could be an important step toward further insight into cerebrovascular regulation, which warrants more research in the future.

Transcranial Doppler monitoring with head-upright tilting in patients with syncope

BACKGROUND

The aim of our study was to evaluate the effects of orthostatic stress produced by the head-upright tilt test on human cerebral hemodynamics by transcranial Doppler sonography.

METHODS

We studied 60 subjects who were divided into two groups; one of normal controls (n = 43) and one of patients suffering from syncope (n = 17). A 30-minute head-upright tilt test was conducted on all subjects, and heart rate and blood pressure were monitored by surface electrocardiography and cuff sphygmomanometry, respectively. Cerebral blood flow velocity and cerebral vasoreactivity were continuously monitored using transcranial Doppler sonography.

RESULTS

The maximal decreases in mean blood pressure of controls and patients with syncope were 2.6 +/- 7.8% and 0.5 +/- 7.9% of baseline, respectively. The maximal decreases in mean blood flow velocity in the middle cerebral artery between the two groups reached 19.6 +/- 6.2% and 30.7 +/- 14.1% of baseline, respectively (p < 0.05). The increases in pulsatility index between the two groups were 15.4 +/- 14.3% and 16.9 +/- 21.1% of baseline, respectively.

CONCLUSION

The responses of cerebral blood flow to upright tilting differed significantly between normal controls and patients with syncope, implying that the latter may suffer an impairment of cerebral autoregulation. Further studies are needed to ascertain what clinical implications this finding might have.

A double-blind, placebo-controlled study of tacrine in Chinese patients with Alzheimer's disease

The purpose of the study was to evaluate the efficacy and safety of tacrine over 30 weeks in Chinese patients with probable Alzheimer's disease (AD). A total of 100 patients with mild to moderate AD were recruited and randomly assigned to active or placebo treatment. The active group received 30 mg/day of tacrine for the first 6 weeks, 60 mg/day for the next 6 weeks, 90 mg/day for 6 more weeks and then 120 mg/day for the remaining 12 weeks. Safety evaluations included biweekly determinations of alanine aminotransferase (ALT). The primary outcome measures were Cognitive Abilities Screening Instrument (CASI), Clinical Global Impression of Change (CGIC) by investigator and the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE). Secondary outcome measures were Mini-mental State Examination (MMSE), Alzheimer's Deficit Scale (ADS) and CGIC by caregivers. Sixty-eight patients were included in an intent-to-treat analysis (48 active and 20 placebo); 56 patients had evaluable data at week 30 (36 active and 20 placebo). The results of the complete case analysis revealed a significant improvement in the CASI and MMSE scores of the active group in the 18th week (90 mg/day) and the 30th week (120 mg/day) (p < 0.01). In the intent-to-treat analysis, significant improvement of the active group was noted on CASI at week 30 (p = 0.05), but there was no significant difference in the measures of IQCODE, CGIC and ADS. The primary reasons for withdrawal of tacrine-treated patients (39 patients, 52%) were asymptomatic ALT elevation, anorexia and nausea/vomiting. These patients all recovered from the adverse events on discontinuation of treatment. Tacrine produced a statistically significant improvement in the CASI and MMSE in Chinese patients with mild to moderate AD using a lower dose than in western people.

Transfer function analysis of cerebral hemodynamics in patients with carotid stenosis

This study evaluates the validity of the transfer function analysis of spontaneous fluctuations of arterial blood pressure (ABP) and blood flow velocity of the middle cerebral artery (MCAFV) as a simple, convenient method to assess human cerebral autoregulation in patients with carotid stenosis. Eighty-three consecutive patients with various degrees of carotid stenosis and 37 healthy controls were enrolled. The carotid stenosis was graded based on the diagnostic criteria of duplex ultrasound. Instantaneous bilateral MCAFV and ABP of all participants were assessed noninvasively using transcranial Doppler sonography and the servocontrolled infrared finger plethysmography, respectively. Spectral analyses of ABP and MCAFV were performed by fast Fourier transform. The fluctuations in ABP as well as in MCAFV were diffracted into three components at specific frequency ranges designated as high-frequency (HF; 0.15 to 0.4 Hz), low-frequency (LF; 0.04 to 0.15 Hz), and very low-frequency (VLF; 0.016 to 0.04 Hz). Cross-spectral analysis was applied to quantify the coherence, transfer phase, and magnitude in individual HF, LF, and VLF components. Transcranial Doppler CO2 vasomotor reactivity was measured with 5% CO2 inhalation. The LF phase angle (r=-0.53, P<0.001); magnitude of VLF (r=-0.29, P=0.002), LF (r=-0.35, P<0.001), and HF (r=-0.47, P<0.001); and CO2 vasomotor reactivity (r=-0.66, P<0.001) were negatively correlated with the severity of stenosis. Patients with unilateral high-grade (greater than 90% stenosis) carotid stenosis demonstrated significant reduction in LF phase angle (P<0.001) and HF magnitude (P=0.018) on the ipsilateral side of the affected vessel compared with their contralateral side. The study also revealed a high sensitivity, specificity, and accuracy using LF phase angle and HF magnitude to detect a high-grade carotid stenosis. A strong correlation existed between the LF phase angle and the CO2 vasomotor reactivity test (r=0.62, P<0.001), and the correlation between the HF magnitude and the CO2 vasomotor reactivity (r=0.44, P<0.001) was statistically significant as well. We conclude that transfer function analysis of spontaneous fluctuations of MCAFV and ABP could be used to identify hemodynamically significant high-grade carotid stenosis with impaired cerebral autoregulation or vasomotor reserve.

Supportive treatment, resection and transcatheter arterial chemoembolization in resectable hepatocellular carcinoma: an analysis of survival in 419 patients

OBJECTIVE AND DESIGN

Both surgical resection and transcatheter arterial chemoembolization (TACE) are effective treatments for hepatocellular carcinoma (HCC). Few reports have compared the different treatment modalities for resectable HCC based on clinically matched groups. The aim of this study was to compare the survival rate after surgery, TACE or supportive treatment in resectable HCC patients, and also in elderly patients (> or = 70 y/o).

METHODS

From 1984 to 1993, 419 consecutive patients with resectable HCC were included in this study. Of these, 311 (74%) underwent resection of tumours and 46 (11%) refused operation, opting instead for TACE. The remaining 62 (15%) who refused both methods of treatment were given supportive care. Univariate and multivariate analyses for prognostic factors and the 5-year survival rate among the groups were studied.

RESULTS

Both surgical resection and TACE groups had a better 5-year survival rate than the supportive treatment group (43% and 34% vs. 7%). There was no difference in survival between the surgery and TACE groups. However, the 5-year survival rate was 11% in TACE and 41% in the surgical group when the patients were > or = 70. In multivariate analysis, female sex (P = 0.0466), tumour size < or = 3 cm (P = 0.0001), alpha-fetoprotein (AFP) < 400 U/l (P = 0.0036), single tumour (P = 0.0474), serum creatinine < or = 1.5 mg/dl (P = 0.0006) and alkaline phosphatase (AP) < or = 100 U/l (P = 0.0007) are associated with good prognosis for resectable HCC.

CONCLUSION

TACE is an alternative for resectable HCC. Tumour size, tumour number, AFP level, renal function, AP level and female sex are prognostic factors. In elderly people, TACE must be used prudently and has a worse prognosis.

Prevalence, implication, and viral nucleotide sequence analysis of GB virus-C/hepatitis G virus infection in acute fulminant and nonfulminant hepatitis

The clinical impact of GB virus-C (GBV-C)/hepatitis G virus (HGV) infection on various causes of acute hepatitis and fulminant hepatitis is controversial. In this study, serum samples from 164 patients with acute hepatitis of various causes, 34 asymptomatic hepatitis B virus (HBV) carriers, and 34 healthy adults were tested for GBV-C/HGV RNA by reverse transcription-nested polymerase chain reaction using primers based on the 5'-untranslated region. Nucleotide sequences of GBV-C/HGV RNA from various groups were compared. The prevalence of GBV-C/HGV RNA was significantly higher in patients with acute hepatitis D virus (HDV) superinfection than in HBV carriers or healthy controls (10/37 vs. 2/34, P < 0.02; 10/37 vs. 1/34, P < 0.005). GBV-C/HGV RNA was detected in 11.1% of acute hepatitis A patients, 9.5% of acute hepatitis B patients, 15.8% of acute hepatitis C patients, 12.5% of acute hepatitis E patients, 11.8% of chronic hepatitis B patients with acute exacerbation, and 11.1% in patients with non-A to -E hepatitis; each was not significantly higher than that in HBV carriers or healthy adults. There were no significant differences in gender, age, serum albumin, bilirubin, and alanine aminotransferase levels nor in the occurrence of fulminant hepatitis (6/28 vs. 36/136) between patients with or without GBV-C/HGV RNA. All six patients with fulminant hepatitis who had GBV-C/HGV RNA were complicated by infection with hepatitis B, C, or D. The GBV-C/HGV clones from 21 patients with or without fulminant hepatitis belonged to group 3. No particular strain of GBV-C/HGV was associated with fulminant hepatitis.

Detection of serum hepatitis B, C, and D viral nucleic acids and its implications in hepatocellular carcinoma patients

The association of viremia, elevated serum alanine aminotransferase (ALT) levels, and hepatocyte inflammatory activity in hepatocellular carcinoma (HCC) patients was studied. Serum samples from 114 HCC patients undergoing surgery were assayed for hepatitis B, C, and D viral nucleic acids by polymerase chain reaction (PCR) prior to surgery. Of these patients, 65 had HBV infection alone, 15 had HCV infection alone, 4 had HDV infection, 20 had HBV and HCV superinfection, 1 had triple viral infection, and 9 were negative for HBV and HCV infections. The prevalence of active viral replication was significantly higher in HCV than in HBV (92% versus 70%; P = 0.006) patients, and significantly higher mean serum ALT levels were also noted in the HCV group than in the HBV group (P = 0.02). The incidence of marked ALT elevation (>200 U/l) was highest in the HCV (27%) and the HDV (25%) groups. Patients in the HCV group were 10 years older than those in the HBV group. Viral superinfection did not accelerate the development of HCC. Viral replication persisted in a significant portion of HCC patients and a higher prevalence of hepatic inflammation was noted in patients with HCV- and, possibly, HDV-related HCC.

The impact of traveling to endemic areas on the spread of hepatitis E virus infection: epidemiological and molecular analyses

Traveling to endemic areas carries a risk of hepatitis E virus (HEV) infection, but no molecular analysis to document sources of infection is available. Eighteen (38%) of 47 patients with acute non-A, non-B, non-C hepatitis were positive for antibody to HEV (anti-HEV), and 9 (50%) of these were also positive for serum HEV RNA by polymerase chain reaction following reverse transcription. Only 1 (5%) of the 21 patients with acute hepatitis A was positive for HEV RNA. Travel to endemic areas (mostly to China; odds ratio, 22.2; 95% confidence interval, 4.7-105.8) and deeper jaundice (odds ratio, 5.2; 95% confidence interval, 1.01-27.2) were the only factors associated with HEV infection in multivariate analysis. The two HEV isolates from two patients who had traveled to China and the HEV isolate from a patient whose travel history was obscure formed a monophyletic group with the isolates from Guangzhou. The HEV isolates from our patients show a homology of 72% to 78% in nucleotide sequence with the Burma, Beijing, India, Pakistan, and Xiangjiang strains; a homology of 81% to 91% with the Guangzhou strains; and a homology of 76% with the Mexico strain. The close relationship between the Taiwan isolates and the Guangzhou strains was further supported by the short Kimura's two-parameter distances among them. In summary, HEV infection does occur in this area. Epidemiological and molecular analyses strongly indicate that most cases of HEV infection originated from travel to HEV-endemic areas.

Frequency domain analysis of cerebral blood flow velocity and its correlation with arterial blood pressure

We applied frequency domain analysis to detect and quantify spontaneous fluctuations in the blood flow velocity of the middle cerebral artery (MCAFV). Instantaneous MCAFV of normal volunteers was detected using transcranial Doppler sonography. Spectral and transfer function analyses of MCAFV and arterial blood pressure (ABP) were performed by fast Fourier transform. We found the fluctuations in MCAFV, like ABP, could be diffracted into three components at specific frequency ranges, designated as high-frequency (HF, 0.15 to 0.4 Hz), low-frequency (LF, 0.04 to 0.15 Hz), and very low-frequency (VLF, 0.016 to 0.04 Hz) components. The HF and LF components of MCAFV exhibited high coherence with those of ABP, indicating great similarity of MCAFV and ABP fluctuations within the two frequency ranges. However, it was not the case for the VLF component. Transfer function analysis revealed that the ABP-MCAFV phase angle was frequency-dependent in the LF range (r = -0.79, P < 0.001) but not in the HF range. The time delay between LF fluctuations of ABP and those of MCAFV was evaluated as 2.1 seconds. We conclude that in addition to traditional B-wave equivalents, there are at least two different mechanisms for MCAFV fluctuations: the HF and LF fluctuations of MCAFV are basically secondary to those of ABP, and cerebral autoregulation may operate efficiently in LF rather than HF range. Frequency domain analysis offers an opportunity to explore the nature and underlying mechanism of dynamic regulation in cerebral circulation.

Diagnostic value of anti-hepatitis D virus (HDV) antibodies revisited: a study of total and IgM anti-HDV compared with detection of HDV-RNA by polymerase chain reaction

A high serum titre (> or = 1000 or > or = 5000) of total antibody to hepatitis D virus (anti-HDV) and positive for immunoglobulin (Ig)M anti-HDV have been used to represent HDV replication, while reverse transcription-polymerase chain reaction (RT-PCR) is currently the most sensitive assay for detecting HDV viraemia. The aim of the present study was to re-evaluate the correlation of total anti-HDV and IgM anti-HDV with HDV viraemia based on RT-PCR and to assess the clinical significance of these markers in acute and chronic HDV superinfection. Chronic HDV infection was defined as positive HDV-RNA by RT-PCR for more than 6 months, while total anti-HDV titre was defined by serial dilution. Of 178 hepatitis B virus (HBV) carrier patients studied, 119 cases had been anti-HDV positive for more than 6 months. Two-thirds (79/119) were positive for HDV viraemia by RT-PCR. Only half the chronic HDV viraemic patients had a high titre (> or = 1000) of total anti-HDV, and there was only moderate agreement (kappa = 0.41) between total anti-HDV titre/IgM anti-HDV and HDV-RNA and chronic HDV viraemia. Based on cross-sectional and longitudinal follow-up analyses, serum total anti-HDV titres > or = 100 appeared to be an excellent cut-off titre (kappa = 0.91) in differentiating chronic from acute HDV infection among viraemic patients. In summary, IgM and a high titre total of anti-HDV are not good markers of HDV viraemia, but an anti-HDV titre of > or = 100 appears to be an excellent marker for the differentiation of acute from chronic HDV superinfection.

Decreasing hepatitis D virus infection in Taiwan: an analysis of contributory factors

Superinfection of hepatitis D virus (HDV) among hepatitis B virus (HBV) carriers is mainly through heterosexual contact in Taiwan. This study investigated the change of HDV endemicity and its associated contributory factors. Seventy-seven patients with acute HDV superinfection among 527 consecutive exacerbating hepatitis B surface antigen (HBsAg) carriers were identified over the past 12 years. The prevalence decreased significantly by each 3-year period from June 1983 to May 1995 (23.7, 15.5, 13.1 and 4.2%, respectively, P < 0.001). This trend was more significant in the hepatitis B e antigen (HBeAg)-negative group (P < 0.001) than in the HBeAg-positive group (P = 0.073). Subjects with a history of paid sex and prostitutes were also recruited for analysis both in 1989 and 1996. Although not statistically significant, there was a trend showing a decrease in the prevalence of serum antibody against HDV (anti-HDV) in each risk group: it was lower in 1996 among HBsAg-positive brothel-goers (10.3 vs 6.9%), licensed prostitutes (54.5 vs 50%) and unlicensed prostitutes (36.1 vs 30.8%). Accumulation of anti-HDV-positive subjects in risk groups may mask the actual decrease of new HDV-infected cases. The prevalence of the HBsAg carrier rate among all prostitutes has significantly decreased (18.3 vs 12.2%, P = 0.015). The efficacy of each preventive strategy was examined and mapped with the trend. It was concluded that active preventive measures directed against promiscuity and sexually transmitted disease and the promotion of disposable needles may have contributed to the decrease in HDV endemicity.

Prevalence and risk factor analysis of GBV-C/HGV infection in prostitutes

GB virus-C (GBV-C) and Hepatitis G virus (HGV) are variants of a recently cloned virus transmitted parenterally. It is unclear if sexual contact also transmits this virus. In this study, we detected serum GBV-C/HGV RNA in 140 prostitutes by reverse transcription polymerase chain reaction (RT-PCR) using different primers. Thirty (21%) were found with GBV-C RNA by nested PCR although only 22 (73%) had HGV RNA by single round RT-PCR. Both assays had a nearly perfect agreement (kappa value, 0.812). The prevalence of GBV-C RNA in prostitutes was significantly higher than the control group (30/140 vs. 2/40, P < 0.02). Multivariate analysis revealed that a frequency of paid sex more than 120 times per month was the only factor significantly associated with positive GBV-C RNA in prostitutes (P < 0.003). In summary, prostitutes are a high risk group and reservoir of GBV-C/HGV infection due to high frequency of paid-sex.

Comparison of risk factors for lacunar infarcts and other stroke subtypes

BACKGROUND

Lacunar infarction (LI) is an ischemic stroke subtype with unique clinical, radiological and pathological features. Its relation to other stroke subtypes is unclear. To better understand the underlying pathological process of LI, we compared the risk factors of LI with those of other stroke subtypes.

METHODS

During the study period (from January 1, 1990 to December 31, 1991), 240 consecutive patients with first-ever strokes admitted to the stroke unit of our hospital were enrolled to the study and were classified into one of the four stroke subtypes (52 with LI, 80 atherothrombotic infarcts, 38 cardiogenic embolism and 70 brain hemorrhage) based on their computed tomography (CT) and clinical features using the guideline developed by the National Institute of Neurological Disorders. Eighty outpatients of similar age who had either low back pain or cervical spondylosis were recruited from the clinics of Neurology to serve as non-stroke controls. Data collected included demographics, lifestyle, and other vascular risk factors. Detailed physical and neurological examination, blood biochemistry and Doppler ultrasound on cervical vessels were performed.

RESULTS

Our investigations revealed that LI is a common stroke subtype accounting for 21% of all first-ever strokes in our hospital. Like ischemic stroke patients, those with LI were much more likely to have hypertension, diabetes, heart disease and carotid disease when compared with non-stroke controls. Patients with brain hemorrhage had less history of diabetes and lower levels of cholesterol than LI patients.

CONCLUSIONS

LI patients seemed to share more risk factors with ischemic stroke patients than with brain hemorrhage patients. These shared risk factors suggest a possibly similar underlying pathological process between ischemic strokes and LI patients. Careful screening for those risk factors should be part of the mandatory clinical management for the prevention of LI.

Comparison of clinico-pathological features in hepatitis B virus-associated hepatocellular carcinoma with or without hepatitis D virus superinfection

BACKGROUND/AIMS

Hepatitis D virus superinfection in hepatitis B virus carriers produces additional damage in an already injured liver. Earlier reports noted that the development of hepatocellular carcinoma may be accelerated in hepatitis D virus-superinfected patients. This study aimed to investigate the impact of hepatitis D virus on the clinical course of hepatitis B virus-associated hepatocellular carcinoma.

METHODS

A total of 42 consecutive hepatocellular carcinoma cases seropositive for antibody against hepatitis D virus antigen (anti-HDV) were found from 1986 to 1994; the clinical manifestations, treatment and outcomes were compared with 255 consecutive hepatocellular carcinoma cases seropositive for hepatitis B virus surface antigen but seronegative for anti-HDV.

RESULTS

The mean age was 60 years in both groups of patients. Other features, including sex, duration of follow-up, presence of cirrhosis or ascites, serum biochemistry, status of HBV-e antigen, and gross and microscopic tumor appearance, were not significantly different between the two groups. Though more patients in the anti-HDV-positive group underwent active treatment (operation or transcatheter arterial chemoembolization) than those in the anti-HDV-negative group (54.8% in 42 versus 34.9% in 255 cases, p = 0.02), the cumulative 4-year survival rates (9.5% versus 9.8%) were similar. For the anti-HDV-positive hepatocellular carcinoma patients, tumor size < 5 cm and active treatment were favorable prognostic predictors associated with survival > 18 months.

CONCLUSION

Hepatitis D virus superinfection does not accelerate the development of hepatocellular carcinoma. The clinical manifestations were similar, and the outcome in anti-HDV-positive patients was not worse than in the general HBV-associated hepatocellular carcinoma patients, as long as they were diagnosed at an early stage and actively treated.

Prognostic factor analysis of fulminant and subfulminant hepatic failure in an area endemic for hepatitis B

In order to determine the criteria in selecting candidates for orthotopic liver transplantation (OLT), we assessed the aetiology and prognostic indicators in 61 patients with fulminant or subfulminant hepatitis during the past 13 years. Several previously reported models of high risk predictors were not suitable for a large portion of our patients with different aetiological and ethnic backgrounds. In the present study, serological markers of various hepatitis viruses were tested and clinical parameters were compared between survivors and non-survivors. Multiple virus infection and multifactorial causes were important in the pathogenesis (48%) of acute liver failure. Among the 13 clinical parameters, six were considered significant on univariate analysis: prothrombin time prolongation (P < 0.001), total bilirubin, creatinine and alpha-fetoprotein (P < 0.01), age and cholesterol (P < 0.05). With stepwise logistic regression using most discriminatory cut-off values, an age of > 43 years (P = 0.0001), total bilirubin levels of > 23 mg/dL (P < 0.005) and prothrombin time prolongation > 19 s (P < 0.0001) were independent predictors of non-survival. When applied to determine the index of poor prognosis, the sensitivity, specificity, positive predictive value, negative predictive value and predictive accuracy were 100, 67, 95, 100 and 95%, respectively, in the presence of any one of these prognostic factors. We conclude that these indicators may be useful for selecting patients with acute liver failure indicated for OLT.

Ruptured hepatocellular carcinoma: treatment strategy and prognostic factor analysis

BACKGROUND

The prognosis of ruptured hepatocellular carcinoma (HCC) is generally poor, but few studies have focused on the analysis of prognostic factors of this catastrophic event.

METHODS

Eighty-four consecutive patients with ruptured HCC were included. Twenty-nine clinical and laboratory variables were correlated to prognosis by using uni- and multivariate analyses.

RESULTS

Epigastralgia and/or right upper quadrant abdominal pain was the most common initial presentation (70%), followed by shock (42%), abdominal distension (27%) and others (17%). Of these 84 patients, 50 patients were treated by supportive measure, 21 by operation and 13 by transcatheter arterial embolization (TAE). The median survival was 13, 30 and 202 days in each group, respectively, and 24 days overall. TAE showed the lowest hemostatic failure rate (20%). Univariate analysis showed that active treatment (operation or TAE), group I tumor with a solitary nodule or single nodule with proliferation into surrounding area, serum creatinine (< or = 1.2 mg/ml), alkaline phosphatase (< or = 95 U/L), alanine aminotransferase (ALT, < or = 40 U/L), total bilirubin (< or = 1.6 mg/ml), initial systolic blood pressure (> or = 90 mmHg), and absence of main portal vein thrombosis were correlated with a survival longer than 90 days (p < 0.05) in univariate analysis. Active treatment, ALT level and initial systolic blood pressure were still significant in multivariate analysis (p < 0.05).

CONCLUSIONS

TAE may help stop the tumor bleeding. Treatment regimen, ALT levels and initial blood pressure are correlated with the prognosis of ruptured HCC.

Clinical significance of the ophthalmic artery in carotid artery disease

A total of 141 subjects with tight stenosis (> or = 75%) or occlusion of internal carotid artery were followed up at intervals 3-6 months regularly for 40 +/- 16 months. The direction of ophthalmic artery flow was used as a parameter of risk indicator on cerebral ischemic events. Eleven patients with bilateral carotid tight stenosis/occlusion were excluded in the analysis. Thus, the 130 carotid arteries were divided into three groups: (1) carotid artery with ipsilateral hemispheric TIA or stroke (85 patients), (2) carotid arteries with contralateral hemispheric TIA/stroke or VBI (15 patients), and (3) carotid arteries of asymptomatic patients (30 patients). The symptomatic carotid artery group (group 1) had significantly more often reversed ophthalmic flow than the other two groups (group 2 and 3, p < 0.001). During follow-up prospectively for four years, 41 patients had cerebral ischemic events, three had cardiac ischemic events and six died of malignancy. Patients with reversed OA flow had more often subsequent cerebral ischemic events than those with forward flow (27 vs 14, p = 0.010). However, the difference remained significant only in the asymptomatic patients (group 3, 4 vs 0, P < 0.001), not for groups 1 and 2, after further analysis. Our work supported that the clinical role of ophthalmic artery collateral varied between asymptomatic and symptomatic patients.

Clinical and radiological pictures of hepatocellular carcinoma with intracranial metastasis

Hepatocellular carcinoma (HCC) with extrahepatic spreading is not uncommon. In order to delineate the clinical and radiological pictures of HCC with intracranial metastasis, 33 documented cases were analysed. Eighteen had brain parenchymal metastasis without skull involvement; the other 15 cases disclosed skull metastasis with brain invasion. The underlying HCC are mainly of expanding (13/33, 39.4%) and multifocal (13/33, 39.4%) types. Eighteen cases (18/33, 54.5%) had mental changes not related to hypoglycaemia or hepatic encephalopathy. Eighteen cases (18/20, 90%) disclosed hyperdense mass lesions by non-contrast computed tomography (CT) scans and 17 cases showed homogeneous enhancement (17/22, 77.3%) by post-contrast CT images. In the non-skull involved group, five cases (5/12, 41.7%) disclosed ring-shape enhancement and 14 cases (14/16, 87.5%) had perifocal oedema, which were not seen in the skull involved group. Eight cases (8/33, 24.2%) presented as intracerebral haemorrhage. Twelve (12/33, 36.4%) died of brain herniation. Most (14/18, 77.8%) non-skull involved cases had simultaneous lung metastasis without bony metastasis, while the skull involved group often (10/15, 66.7%) disclosed extracranial bony metastasis without lung metastasis. The difference in extracranial metastasis was statistically significant (P < 0.05). The multivariate survival analysis disclosed that lower lactate dehydrogenase level (< or = 316 U/L, P = 0.029) and treatments (surgery or radiation, P = 0.001) were positively associated with longer survival. In conclusion, HCC with intracranial metastasis is symptomatic and life-threatening. Half the cases may come from pulmonary metastasis and the other half may be from bony metastasis. Brain irradiation or surgery can prolong their survival.

Injection with nondisposable needles as an important route for transmission of acute community-acquired hepatitis C virus infection in Taiwan

A prospective case-controlled study was conducted in order to determine the transmission route of community-acquired hepatitis C virus (HCV) infection in Taiwan. Thirty-eight consecutive patients (25 men and 13 women) with acute community-acquired HCV infection and 76 age (within 3 years)- and sex-matched healthy control subjects without HCV infection were enrolled. Serum anti-HCV was tested by second generation immunoassay. The sera of 26 family members from 12 families of index patients were also tested for anti-HCV. A questionnaire covering the history of blood transfusion, surgery, intravenous drug abuse, prostitute contact, dental procedures, injection, acupuncture, tattooing, and ear-piercing was conducted among patients and control subjects. Univariate analysis revealed injection with nondisposable needles was an independent risk factor (P = 0.02, odds ratio = 4.17, 95% confidence interval = 1.24-14.47) associated with HCV infection. Other risk factors were not significant. Only 2 (7.7%) family members of index patients had an anti-HCV. In conclusion, more vigorous effort to prohibit the use of nondisposable needles should be promoted to interrupt the spread of community-acquired HCV infection in Taiwan. Of note, a significant number of patients (34.2%) contracted HCV infection without identifiable risk factors. Unidentified routes need to be investigated.

Transorbital color Doppler flow imaging of the carotid siphon and major arteries at the base of the brain

PURPOSE

To describe and evaluate an application of sonography, transorbital color Doppler flow imaging of the carotid siphon and major intracranial arteries, and to compare it with transtemporal color Doppler flow imaging.

METHODS

The carotid siphon and major arteries at the base of the brain of 50 healthy volunteers were screened using the transorbital color Doppler flow sonography. These arteries were also studied by a transtemporal approach for comparison. In 5 volunteers, MR images in special inclination planes were obtained and compared with the transorbital color-coded Doppler flow images.

RESULTS

The B-mode image of the orbit and intracranial anatomic structures, in addition to the color-coded flow images, provided an unambiguous identification of the carotid siphon and major intracranial arteries. The failure rate was lower when using the transorbital approach than when using the transtemporal approach in identifying the anterior cerebral artery (17% versus 32%). Color Doppler flow imaging using the transtemporal approach was better for the middle cerebral artery, whereas color Doppler flow imaging using the transorbital approach was better for the anterior cerebral artery (contralateral). The Doppler incident angles using the transorbital approach were better for the carotid siphon and anterior cerebral artery (contralateral).

CONCLUSION

Transorbital color Doppler flow imaging, when used in conjunction with the transtemporal examination, can add information concerning the major arteries at the base of the brain.

Natural history of hepatitis D viral superinfection: significance of viremia detected by polymerase chain reaction

BACKGROUND/AIMS

Polymerase chain reaction (PCR) is very sensitive. The aim of the study was to reevaluate viral replication in hepatitis D virus (HDV) superinfection by PCR.

METHODS

HDV and hepatitis B virus (HBV) were detected by PCR in 185 patients.

RESULTS

The acute hepatitis group had the highest detection rate of HDV RNA compared with chronic hepatitis, cirrhosis, hepatocellular carcinoma, and remission groups (63 of 64 vs. 35 of 47, 17 of 23, 19 of 30, and 7 of 21) and the highest alanine aminotransferase (ALT) levels (mean, 1741 U/L vs. 266 to 27 U/L; P < 0.05). The detection rate of HBV DNA was the lowest in the acute group (41%) compared with 66%, 70%, 80%, and 57% in the remaining groups (P < 0.02). At the chronic stage, 13%-25% of cases had HDV RNA, and 30%-48% of cases had HBV DNA detected by PCR but not by traditional method. HDV RNA was associated with ALT levels in horizontal and longitudinal analyses.

CONCLUSIONS

HDV superinfection may be divided into the following three phases: acute phase, active HDV replication and suppression of HBV with high ALT levels; chronic phase, decreasing HDV and reactivating HBV with moderate ALT levels; and late phase, development of cirrhosis and hepatocellular carcinoma caused by replication of either virus or remission resulting from marked reduction of both viruses.

Factors associated with viremia and elevated transaminase levels in asymptomatic hepatitis D virus-infected risk groups

To detect hepatitis D virus (HDV) RNA in asymptomatic HDV-infected risk groups, Northern blot hybridization was carried out using a strand-specific riboprobe. Univariate and multivariate analyses were carried out to evaluate factors associated with HDV viremia and elevated transaminase levels in these subjects. Two (15%) of 13 antibody to HDV (anti-HDV) -positive intravenous drug addicts, 15 (33%) of 45 anti-HDV positive prostitutes, and 6 (40%) of 15 anti-HDV positive brothel goers had detectable serum HDV RNA. Older age (> 31 years old) was negatively associated with HDV RNA (P < .04), while hepatitis B e antigen (HBeAg) was positively associated with it (P < .002) in univariate analysis. Only HBeAg was still significant in multivariate analysis (P < .05). Of the 76 asymptomatic anti-HDV positive case, 28 (37%) had mildly elevated serum ALT levels and only 5 (7%) had ALT levels more than twice normal (> 80 U/L). HBeAg (P < .05) and HDV RNA (P < .02) were two factors associated with ALT elevation in univariate analysis, and HDV RNA was the only significant factor in multivariate analysis (P < .005). In summary, active replication of HBV seemed to be of help for the assembly of HDV and viremia. However, active replication of HDV was associated mostly with mildly elevated ALT levels in these subjects. These cases may represent a particular group in the disease spectrum of HDV infection.

Color Doppler imaging of orbital arteries for detection of carotid occlusive disease

BACKGROUND AND PURPOSE

Distal to a hemodynamically significant stenosis, the Doppler effect becomes dampened. Thus, measuring the flow profile in the ophthalmic artery and the central retinal artery with color Doppler imaging may provide hemodynamic information about the carotid circulation.

METHODS

To validate the flow profile measurement with color Doppler imaging in the ophthalmic and central retinal arteries and to determine the sensitivity and specificity of this examination in the detection of hemodynamically significant carotid stenosis, we compared color Doppler imaging examinations with ocular pneumoplethysmography and ophthalmodynamometry examinations in 66 patients with atherothrombotic ischemic cerebrovascular disease. The degree of carotid stenosis in these patients was determined by a duplex scan with color Doppler imaging, and 57 patients underwent angiography to verify the stenosis.

RESULTS

The flow velocities (systolic peak velocity and end-diastolic velocity) and pulsatility indices (A/B ratio and resistance index) in the ophthalmic and central retinal arteries decreased as the degree of carotid stenosis increased. There is a statistically significant difference in the mean of systolic peak velocity and the mean of end-diastolic velocity of the ophthalmic and central retinal arteries among groups with various degrees of carotid stenosis (P < .02). Using the flow velocities of the ophthalmic and central retinal arteries to diagnose carotid stenosis (> or = 75% stenosis and occlusion), 8 cm/s for systolic peak velocity in the central retinal artery and 29 cm/s for systolic peak velocity plus flow direction reversal in the ophthalmic artery gave the maximum accuracy (sensitivities, 84% and 85.7% and specificities, 89.6% and 81.7%, respectively). The systolic peak velocity in the central retinal artery varied directly with the systolic pressure of the ophthalmic and central retinal arteries.

CONCLUSIONS

The flow velocity and pulsatility in orbital arteries examined by color Doppler imaging provide further hemodynamic information; this test can be used to complement current sonographic examination of carotid disease.

Hepatitis D virus infection among prostitutes in Taiwan

Two hundred and sixty-three adult licensed, 233 adult and 157 teenage unlicensed prostitutes from Taiwan were studied for prevalence and risk factors of hepatitis D virus (HDV) infection. The hepatitis B carrier rate among the three groups was 21, 15 and 20%, respectively, not significantly different from that of the general population in this area. However, the prevalence of HDV infection among carrier prostitutes was 55, 36 and 16%, respectively, much higher than that in general hepatitis B carriers. Univariate analysis revealed that the history of conducting paid sex for more than 12 months (P < 0.03), ear-piercing (P < 0.02), tattooing (P < 0.02), and gonorrhoea or syphilis (P < 0.005) were significant factors associated with HDV infection among these subjects. Multivariate analysis revealed that the history of ear-piercing and venereal diseases (P < 0.001) were still significant. In summary, genital ulcers caused by venereal diseases due to frequent sexual contact with multiple partners, and use of unsterilized needles in ear-piercing or tattooing play important roles in the high prevalence of HDV infection in prostitutes.

Prevalence, infectivity, and risk factor analysis of hepatitis C virus infection in prostitutes

A population of 622 prostitutes in Taiwan was tested for antibodies to the hepatitis C virus (anti-HCV) using a synthetic peptide assay composed of representative determinants from capsid and nonstructural (NS) viral proteins. Seventy-four (12%) were positive and the remaining 548 (88%) were negative. Seventy-nine samples were retested by a second-generation anti-HCV assay composed of recombinant capsid and NS proteins of HCV. Both assays had a nearly perfect agreement (Kappa value = 0.91). Of the positive cases, 31% were positive for reactivity to capsid only. Most (60/74, 81%) of the cases positive for synthetic peptide assay were HCV RNA positive, indicating potential infectivity. On the basis of the results of synthetic peptide assay, univariate analysis showed that history of paid sex for longer than 6 months, blood transfusion, acupuncture, intravenous drug abuse, and age over 20 years were significant risk factors of HCV infection (P < 0.01). Elevated alanine aminotransferase levels (> 40 U/L) were positively associated with anti-HCV, while the presence of serum hepatitis B surface antigen was a negatively associated factor. Multivariate analysis revealed that history of paid sex for longer than 6 months and blood transfusion were positively associated with anti-HCV (P < 0.001). The latter only accounted for less than one fifth of the HCV-infected prostitutes. This study indicates strongly that sexual transmission is an important route for HCV infection in prostitutes. This risk group may spread HCV to other populations as a sexually transmitted disease.

Heterosexual transmission as the most common route of acute hepatitis B virus infection among adults in Taiwan--the importance of extending vaccination to susceptible adults

Sixty adult patients with acute viral hepatitis B (AVHB) and 93 controls were interviewed to assess potential risk factors of hepatitis B. Heterosexual contact was the only significant factor, and it was associated with 83% of cases. A history of having new sex partners or multiple sex partners within 6 months before the onset of AVHB or first sexual contact before 20 years of age were significantly associated with HBV infection (P < .005, respectively). There was a dose-response relationship between the number of sex partners and the risk of HBV infection. In multivariate analyses, a history of having new sex partners was the most important factor. Moreover, 18 of 24 sex partners of the patients were serum hepatitis B surface antigen- and HBV DNA-positive. Heterosexual contact is, therefore, the predominant route of HBV transmission among adults in Taiwan. Susceptible adults should receive vaccination.

Incidence of stroke in Taiwan

BACKGROUND AND PURPOSE

Few epidemiological studies concerning the incidence of stroke have been conducted in Taiwan. In an attempt to investigate this common disease, we studied the incidence of stroke in Taiwan in a prospective incidence study.

METHODS

A cohort of 8,562 stroke-free people were followed up for 4 years to observe new stroke occurrence. The methods of sampling the study population have been reported elsewhere. In addition to the help of local doctors, who reported the new stroke cases, we also sent public nurses to visit the study population annually to screen the new cases of stroke.

RESULTS

There were 104 (61 men and 43 women) first-ever stroke cases identified by a neurologist in a period between October 1, 1986 and December 31, 1990. The average annual incidence rate of first-ever stroke for people aged 36 years or older in this study was 330 per 100,000. Incidence rate was higher in eastern Taiwan and in rural communities. Percentages of the major types of stroke were as follows: cerebral infarction, 71%; cerebral hemorrhage, 22%; subarachnoid hemorrhage, 1%; and unclassified, 6%. The significant risk factors for stroke were hypertension and intake of food with a high sodium content.

CONCLUSIONS

The age-specific incidence rates in this study are higher than those reported from the United Kingdom and the United States. The rates are close to those in a report from Japan and a report from a city in mainland China at the same latitude. Cerebral hemorrhages are more common among people in Taiwan than among Occidental people.

Prevalence of stroke in Taiwan

We investigated the prevalence of stroke in Taiwan in an epidemiologic study of stroke, diabetes, and cardiovascular disease that used a two-phase survey design. The study population was drawn by cluster sampling and consisted of both urban and rural communities from four regions of Taiwan. There were 8,705 people 36 years of age or older interviewed during the period of October 1 to December 31, 1986, and 143 cases of completed stroke were later identified by a neurologist. The point prevalence rate for people aged 36 or older in our study was 1,642/100,000 population (95% confidence interval 1,389-1,942/100,000). Prevalence rates differed significantly among the four study regions and between urban and rural communities; prevalence was greater in northern Taiwan and in urban communities. Percentages of the major types of stroke in 143 stroke survivors were as follows: cerebral infarction 67.1% (96 cases), cerebral hemorrhage 14.0% (20 cases), subarachnoid hemorrhage 4.2% (six cases), and unclassified 14.7% (21 cases). Of the stroke survivors, 67.1% were independent in activities of daily living, and 75.5% were independent in ambulation. Hypertension, heart disease, diabetes mellitus, and a family history of stroke were significantly more common in stroke survivors than in strokefree individuals.

Trends in mortality from cerebrovascular disease in Taiwan

The rate of decline in the age-adjusted death rate from cerebrovascular disease (CVD) in Taiwan is not as rapid as in the United States and Japan, and the trends of CVD mortalities have not decreased steadily during the period 1972-1983. A low record of hypertension regulation (5.0%-12.7%), a high proportion (47.1%) of stroke due to cerebral hemorrhage (by clinical assessment), and a high fatality rate (40.1%) for cerebral hemorrhage may account partially for the slower declining rate. A geographic difference in the downward trend of CVD death rate was observed in this period. Districts remote from the major cities have had the lowest decline in CVD death rate.

Prostaglandin endoperoxide E2 isomerase is dissociated from prostaglandin endoperoxide synthetase in the renal cortex

The rate of arachidonic acid metabolism by prostaglandin (PG) endoperoxide synthetase by the rabbit renal cortex (approximately 200 pmol/mg of protein/min) is very slow compared to medulla (approximately 2000 pmol/mg/min). However, by using PGH2 as a substrate and limiting reaction times, we were able to directly measure the endoperoxide-dependent PGE2 isomerase and found that both the cortex and medulla possess high levels of this activity (approximately pmol/mg/min). The PG endoperoxide E2 isomerase is dependent on reduced glutathione, but not cysteine, and is inactivated by p-hydroxymercuribenzoate or boiling. Thus, the renal medulla appears to exhibit an efficient coupling of cyclooxygenase and PG endoperoxide E2 isomerase, whereas the cortex has a vast excess of endoperoxide-dependent enzyme.