Isoaaptamine increases ROS levels causing autophagy and mitochondria-mediated apoptosis in glioblastoma multiforme cells

Glioblastoma multiforme (GBM) is a common central nervous system disease with a poor prognosis; its five-year survival rate is <5 %, and its median survival of 15 months. Current treatment includes chemotherapy with temozolomide, which is ineffective against GBM, suggesting an urgent need to develop novel therapies. This study evaluated isoaaptamine and aaptamine in the GBM cell lines for cell viability; GBM 8401, U87 MG, U138 MG, and T98G. Our findings showed that isoaaptamine was more potent than its iso-form aaptamine in these four cell lines, and GBM 8401 was most sensitive to isoaaptamine. The study in GBM 8401 cells showed that apoptosis was induced by isoaaptamine with increased cleaved caspase 3 and poly ADP-ribose polymerase (PARP). Moreover, isoaaptamine enhanced oxidative stress by increasing the levels of reactive oxygen species (ROS), inhibiting mitochondrial and cellular superoxidase dismutases (SOD1&2), peroxidase and an anti-apoptotic protein (Bcl-2), and disrupting mitochondrial membrane potential. In addition, the oxygen consumption rates and activities of mitochondrial complexes I-V were significantly reduced. Mitochondrial dynamics were prone to fission instead of fusion after isoaaptamine treatment, and ATP synthesis was ablated. Also, autophagy-related acidic organelle vesicles were formed, indicating autophagy was triggered. Overall, isoaaptamine-induced ROS overproduction in mitochondria could cause mitochondrial dysfunction, apoptosis, and autophagy in the GBM cells.

Contribution of intracranial vertebral artery asymmetry to vestibular neuropathy

OBJECTIVES

To test the hypothesis that vertebral artery hypoplasia (VAH) may affect the lateralisation of vestibular neuropathy (VN), probably through haemodynamic effect on the vestibular labyrinth.

METHODS

69 patients with unilateral VN were examined with a magnetic resonance angiographic (MRA) and caloric test. 50 healthy subjects served as controls. The diagnosis of intracranial VAH was based on MRA if <0.22 cm in VA diameter and a diameter asymmetry index >40%. The authors then correlated the canal paretic side with the VAH side.

RESULTS

MRA study revealed 29 VAH (right/left: 23/6) in VN subjects and six VAH in controls (right/left: 5/1). The RR of VAH in VN subjects compared with controls was elevated (RR=2.2; 95% CI 1.8 to 2.8). There was a high accordance rate between the side of VAH and VN. Among 29 patients with unilateral VAH, 65.5% (N=19) had an ipsilateral VN, in which left VAH showed a higher accordance rate (83.3%) than the right side (60.9%). VN subjects with vascular risk factors also had a higher VAH accordance rate (81%) than those without (25%).

CONCLUSIONS

VAH may serve as a regional haemodynamic negative contributor and impede blood supply to the ipsilateral vestibular labyrinth, contributing to the development of VN, which could be enhanced by atherosclerotic risk factors and the left-sided location.

Cr(VI) removal on fungal biomass of Neurospora crassa: the importance of dissolved organic carbons derived from the biomass to Cr(VI) reduction

Interactions of toxic Cr(VI) with renewable biomaterials are considered an important pathway for Cr(VI) removal in ecosystems. Biomaterials are susceptible to dissolution, and their dissolved derivatives may provide an alternative to surface-involved pathway for scavenging of Cr(VI). In this study, dissolved organic carbon (DOC) derived from Neurospora crassa biomass was investigated. The proportion of Cr(VI) reduction by DOC to that on biomass was determined to evaluate the importance of DOC to Cr(VI) reduction. A rapid increase in DOC concentration from 145.6 to 193.7 mg L(-1) was observed when N. crassa-biomass was immersed in 0.01 M KCl solution at pH of 1-5, and polysaccharides, peptides, and glycoproteins with carboxyl, amide, and -NH functional groups, are the major compositions of DOC. On reaction of 96.2 microM Cr(VI) with N. crassa-biomass or DOC, it was estimated that DOC contributed approximately 53.8-59.5% of the total Cr(VI) reduction on biomass in the dark. Illumination enhanced Cr(VI) reduction via photo-oxidation of biomass/DOC under aeration conditions, which formed superoxide for Cr(VI) reduction. At pH 1, photoinduced Cr(VI) reduction by DOC proceeded more rapidly than reduction on the biomass surface. However, at pH >3, with a decrease in Cr(VI) reduction by DOC, photon-excited biomass may become an important electron source for Cr(VI) photoreduction.

The removal and recovery of Cr(VI) by Li/Al layered double hydroxide (LDH)

Hexavalent Cr has been identified as one of the toxic metals commonly present in industrial effluents. Among the treatment techniques developed for removing Cr(VI) from waste waters, sorption is most commonly applied, due to its simplicity and efficiency. However, few adsorbents can be recycled and reused cost-effectively. In this study, the removal and recovery of Cr(VI) from water using Li/Al LDH was investigated. The removal of Cr(VI) by Li/Al LDH was evaluated in a batch mode. The results demonstrated that Cr(VI) adsorption onto Li/Al LDH occurs by replacing the Cl(-) that originally exists in the interlayer of the adsorbent. The degree of Cr(VI) adsorption observed for Li/Al LDH was relatively high and the process occurred rapidly; however, a portion of adsorbed Cr(VI) was gradually desorbed, due to the Li de-intercalation of Li/Al LDH. Lithium de-intercalation from Li/Al LDH with interlayer Cl(-) and interlayer Cr(VI) follows the first order kinetics and has the activation energies of 76.6 and 41.5 kJ mol(-1), respectively. The properties of thermal unstability and the high adsorption capacity of Li/Al LDH may lead to the development of an innovative technique for the removal of Cr(VI) from Cr(VI)-containing wastewater. That is, Li/Al LDH may be used as an effective adsorbent for the adsorption of Cr(VI) in an ambient environment. Following the adsorptive process, the adsorbed Cr(VI) may be released, using heated water to treat the Cr(VI)-containing Li/Al LDH particles. Through this hydrothermal treatment of the used adsorbent, Cr(VI) can be recovered and the solid product (gibbsite) can be recycled for further use.

Predictors of use of highly active antiretroviral therapy (HAART) among persons with AIDS in San Francisco, 1996-1999

Highly active antiretroviral therapy (HAART) has contributed to a decrease in AIDS-related morbidity and mortality. This study used population-based AIDS surveillance data to evaluate the prevalence and predictors of HAART use among persons with AIDS in San Francisco. Use of HAART among persons living with AIDS increased from 41% in 1996 to 72% in 1999. Fourteen percent of persons diagnosed with AIDS between 1996 and 1999 initiated HAART before their AIDS diagnosis. Use of HAART before an AIDS diagnosis increased from 5% in 1996 to 26% in 1999. In the multivariable analysis, African Americans, injection drug users, and those without insurance at the time of AIDS diagnosis were less likely to use HAART before AIDS diagnosis. Delayed initiation of HAART after AIDS was more likely to occur among African Americans, injection drug users, homeless persons, those with public insurance, and those with higher CD4 counts. Although the overall prevalence of HAART use was high, disparity in use of HAART existed by race and risk group, patient's insurance status, and facility of diagnosis. Barriers in use of treatment should be identified so all persons with AIDS can benefit from improved therapies.

Identification of a gamma-tubulin-binding domain in BRCA1

We previously reported (L-C. Hsu and R. L. White, Proc. Natl. Acad. Sci. USA, 95: 12983-12988, 1998) that hypophosphorylated BRCA1 is associated with mitotic centrosomes in vivo, perhaps through its interaction with gamma-tubulin. In vitro evidence presented here indicates that full-length BRCA1 protein generated by in vitro translation interacts with gamma-tubulin. A specific domain of BRCA1 protein, BRCA1 fragment no. 3 (BF3; amino acids 504-803), is both necessary and sufficient to bind gamma-tubulin. BF3 and gamma-tubulin coimmunoprecipitated when coexpressed in cells. In addition, expression of BF3 interfered with the interaction between BRCA1 and gamma-tubulin. Stable transformants of COS-7 cells that overexpressed BF3 showed a reduced growth rate partly because of increased apoptosis. Furthermore, overexpression of BF3 in COS-7 cells results in the accumulation of mitotic cells with multiple centrosomes and abnormal spindles. Okadaic acid, an inhibitor of protein phosphatases types 1 and 2A, induces hyperphosphorylation of BRCA1, a reduction of both BRCA1 and gamma-tubulin associated with mitotic centrosomes, and an accumulation of abnormal spindle formation. Thus, attenuating the interaction between BRCA1 and gamma-tubulin, and their association with mitotic centrosomes, may induce an increase of aneuploid cell population and contribute to tumorigenesis.

Heparin-coated cardiopulmonary bypass circuits: current status

Heparin-coated circuits have been subjected to vigorous testing, both experimentally and clinically, for the past decade. When the functions of heparin are preserved on the surface, the heparinized surface plays multiple roles in attenuating the systemic inflammatory response. These include the ability to attenuate contact activation, coagulation activation, complement activation and, directly or indirectly, platelet and leukocyte activation. The heparinized surface also renders the cardiopulmonary bypass (CPB) circuits hydrophilic and protein resistant and augments lipoprotein binding. The multifunctional nature of the heparinized surface contributes to the overall biocompatibility of the surface. Clinically, heparin-coated circuits become most effective in reducing systemic inflammatory response and in improving morbidity, mortality, and other patient outcome related parameters when material-independent blood activation is controlled or minimized through a global biocompatibility strategy. Techniques involved in the global biocompatibility strategy are readily available and are being effectively and safely practiced at several centers. With the global biocompatibility strategy, outstanding and reproducible results have been routinely achieved with conventional CPB techniques. Alternative revascularization procedures should equal or surpass conventional CPB, using best clinically proven strategies with respect to patient outcome and long-term graft patency.

MR perfusion studies of brain for patients with unilateral carotid stenosis or occlusion: evaluation of maps of "time to peak" and "percentage of baseline at peak"

Maps of "time to peak" (TTP) and "percentage of baseline at peak" (PBP) were compared with maps of conventional brain perfusion parameters, namely, mean transit time (MTT) and relative cerebral blood volume (rCBV). We performed MR perfusion studies in 11 patients. All of them had occlusion or high-grade stenosis of the unilateral carotid artery. Three areas of old infarct, 4 areas of new infarct, and 10 areas of brain without infarct were evaluated specifically. In all these cases, the TTP maps appeared similar to the MTT maps. They showed increases, normal values, or decreases at the same time in all areas evaluated. Most areas of abnormally decreased CBV had increased signal in PBP maps. In conclusion, the TTP map provided the same qualitative information as MTT. PBP seemed correlated inversely to CBV and was less sensitive in demonstrating abnormality.

Impact of protease inhibitors and other antiretroviral treatments on acquired immunodeficiency syndrome survival in San Francisco, California, 1987-1996

The authors assessed temporal trends in acquired immunodeficiency syndrome (AIDS) survival for 15,271 persons in San Francisco, California, diagnosed between 1987 and 1996 with an opportunistic illness included in the 1987 AIDS case definition. Predictors of survival were evaluated for 5,686 persons who were diagnosed between 1993 and 1996 and met the 1993 AIDS case definition. Median survival was 19 months for persons diagnosed between 1987 and 1989, 17 months for persons diagnosed between 1990 and 1992, 15 months for persons diagnosed between 1993 and 1994, and 31 months for persons diagnosed between 1995 and 1996. Decreased mortality was associated with use of antiretroviral therapy without protease inhibitors before AIDS (relative hazard (RH) = 0.88, 95% confidence interval (CI): 0.8, 1.0) and after AIDS (RH = 0.83, 95% CI: 0.7, 0.9) and use of antiretroviral agents with protease inhibitors before AIDS (RH = 0.25, 95% CI: 0.2, 0.3) and after AIDS (RH = 0.36, 95% CI: 0.3, 0.4). Increased mortality was found for persons aged > or = 40 years (RH = 1.43, 95% CI: 1.3, 1.6), persons initially diagnosed with an opportunistic illness (RH = 1.97, 95% CI: 1.8, 2.2), and homosexual injection drug users (RH = 1.33, 95% CI: 1.2, 1.5). Survival after AIDS has increased. Treatment with antiretroviral agents, particularly protease inhibitors, strongly predicts improved survival.

Mouse type-2 retinaldehyde dehydrogenase (RALDH2): genomic organization, tissue-dependent expression, chromosome assignment and comparison to other types

Retinaldehyde dehydrogenase (RALDH) isozymes catalyze the formation of an essential developmental modulator, retinoic acid. We determined the structural organization of mouse type-2 Raldh2 by isolation of overlapping genomic DNA clones from a phage library. The gene consists of 14 exons spanning more than 70 kb of genomic DNA. It was localized to mouse chromosome 6. Northern blot analysis revealed testis-specific expression. The RALDH genes belong to the aldehyde dehydrogenase (ALDH) multi-gene family. Three types of RALDH genes (e.g. human ALDH1/mouse Ahd2/rat RalDH(I), human ALDH11/mouse Raldh2/rat RalDH(II) and human ALDH6) are highly conserved during evolution, sharing about 70% identity at the amino acid level between any two gene types and 90% identity between any two mammalian genes of the same type. Different RALDH types show specific tissue and developmental expression patterns, suggesting (i) a regulatory mechanism of retinoic acid synthesis via different promoters of RALDH genes, and (ii) distinctive biological roles of different isozymes in embryogenesis and organogenesis.

Effect of heparin reversal and fresh platelet transfusion on platelet emboli post-cardiopulmonary bypass in a pig model

Heparin reversal by protamine and fresh platelet transfusion may decrease bleeding complications post-cardiopulmonary bypass (CPB) and may increase the level of organ trapped platelet emboli. Platelet emboli were quantified in two groups of 12 Yorkshire pigs (30-35 kg), where 111indium labeled autologous platelets (INPLT: 850-1,200 microCi) were injected intravenously before and after CPB (BCPB, ACPB), and the platelet emboli level in intact organs and their samples (brain, heart, kidneys, lung, liver, and spleen) was quantified with an ion chamber and a gamma counter, respectively. All pigs were systemically heparinized (ACT > 400 sec). CPB was carried out at 2.5-3.5 L/min at 28 degrees C using a centrifugal pump, an oxygenator (OX:Bentley Univox 1.8 m2), an arterial filter (AF:0.25 m2), and a cardiotomy reservoir (CR: BMR 250) for 90 min. Heparin was reversed with an equivalent dose of protamine. The percent of INPLT dose (ID%, mean +/- SD) in organs of BCPB and ACPB pigs was calculated. The sequence of platelet emboli on a unit weight basis (ID%/g) had the following order: Spleen > Liver > Lung > Kidneys > Heart > Brain. The presence of significantly higher levels of emboli in brain, heart, and kidneys in the ACPB than the BCPB group suggest that platelet transfusion after heparin reversal with protamine may increase the risk of platelet emboli. However, it is an acceptable risk for patients having bleeding complications post-CPB.

Sp1-like proteins function in the transcription of human ferredoxin genes

We characterized a regulatory element located in the -76 to -62 region of the human ferredoxin gene. This region bound to Sp1-like proteins with low affinity, as shown using electrophoretic mobility shift, competition, antibody binding, and Southwestern experiments. The similarity of the regulatory element to Sp1 extends beyond its DNA-binding domain, as cloned Sp1 functioned equally well when fused to a peptide that bound to an irrelevant site. The function of these Sp1-binding sites is mediated through the cAMP-dependent protein kinase (PKA) signaling pathway, because reporter genes downstream of the Sp1-binding sites were not activated in a PKA-deficient cell line. Transfection of the catalytic subunit of PKA restored activated transcription. Similar Sp1-binding sites identified in the CYP11A1 and CYP21 genes also controlled cAMP-dependent transcription of the reporter gene. Our finding of the function of Sp1-like proteins in steroidogenic gene transcription adds one more role Sp1 plays in controlling physiological events.

Chronic daily headache in Chinese elderly: prevalence, risk factors, and biannual follow-up

OBJECTIVE

To investigate the prevalence, risk factors, and prognosis of chronic daily headache (CDH) in a population of elderly Chinese subjects.

METHODS

A community-based survey of registered residents > or =65 years old (n = 2,003) in two townships of Kinmen Island in 1993. A neurologist used a structured questionnaire and clinical interview to make the diagnosis of headache. Subjects who had headaches > or =15 days/month for > or =6 months in the previous year were considered to have CDH. CDH was further classified into chronic tension-type headache (CTTH), CDH with migrainous features (CDH/MF), and other CDH. Person-to-person biannual follow-up of the subjects with CDH was done in June 1995 and August 1997.

RESULTS

A total of 1,533 people (77%) participated in our prevalence study. Sixty subjects (3.9%) fulfilled the criteria for CDH, with a higher prevalence in women (F/M: 5.6%/1.8%, p < 0.001). Of these subjects, 42 (70%) had CTTH, 15 (25%) had CDH/MF, and 3 (5%) had other CDH. Only 23% of those with CDH had consulted physicians for their headaches in the previous year. Multivariate logistic regression revealed the significant risk factors for CDH to be analgesic overuse (OR = 79), a history of migraine (OR = 6.6), and a Geriatric Depression Scale-Short Form score of > or =8 (OR = 2.6). The follow-up results in 1995 and 1997 showed that about two-thirds of the subjects still had CDH. Analgesic overuse (relative risk = 1.6) in 1993 was a significant predictor of persistent CDH at follow-up.

CONCLUSIONS

A total of 3.9% of this elderly population had CDH, with CTTH being the most common subtype. Almost two-thirds of those with CDH had persistent frequent headaches at follow-up. Analgesic overuse was a significant predictor of a poor outcome.

Reduction of Platelet Thrombi and Emboli by L-Arginine during Cardiopulmonary Bypass in a Pig Model

We wanted to test the hypothesis that NO generation by L-arginine (LA) infusion will be beneficial in increasing blood flow to all organs to counteract the process of global ischemia during cardiopulmonary bypass (CPB) and to reduce platelet emboli by platelet inhibition. The effect of LA infusion on NO formation, vasodilation, and reduction of thromboembolic burden in organs and tissues after CPB was quantified with In-111-labeled autologous platelets in two major groups: 180 minutes CPB (CPB) and 90 minutes CPB plus 90 minutes reperfusion (RP). Platelets labeled with In-111 tropolone (650-780 µCi) were administered 24 hours before CPB and LA infusion (bolus, 10 mg/kg and infusion at 2 mg/kg/min, 21 pigs for 180 minutes CPB) in 8 groups of 30 Yorkshire pigs (30-35 kg, 6 pigs; LA 2 mg/kg/min, 3 pigs; sham-thoracotomy control, 6 pigs; unoperated control, 6 pigs). Two groups of 9 pigs (control CPB, 6 pigs; LA 2 mg/kg/min, 3 pigs) underwent 90 minutes of CPB and 90 minutes of reperfusion. All pigs were heparinized (ACT > 400 seconds); CPB was instituted with a roller pump, an oxygenator (OX: Bentley Univox, 1.8 m2), and an arterial filter (AF: 0.25 m2, Bentley) at a blood flow of 2.5-3.5 l/min. Radioactive thrombi in OX and AF and emboli in viscera, brain, and connective tissues were imaged with a gamma camera and were finally measured with an ion chamber and a gamma counter. The percent of injected platelets (mean +/- SD) in the organs and tissues of all pigs was calculated. Cerebral emboli were mapped in 25 regions of both hemispheres of pig brain. Flow cytometry with antibodies to CD61 (GPIIIa) and CD62P (GMP-140:control) of porcine platelets was carried out with blood samples taken before, during, and after CPB. Coronary bypass with LA infusion decreased the amount of adherent thrombi in OX and AF (p < 0.07). The embolic burden in brain and lung also decreased. Regional cerebral mapping of In-111 platelets showed reduced emboli in almost all regions, including the medulla, hip pocampus, and posterior cerebral cortex in both LA-treated groups. Flow cytometry of blood samples demonstrated the shift of equilibria from single platelet to platelet-aggregate-microparticle during CPB and steady-state level after the first 5-10 minutes of initiation of CPB. The L-arginine infusion reduced thrombi and emboli during CPB in the pig model.

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.

The impact of the 1993 AIDS case definition on the completeness and timeliness of AIDS surveillance

OBJECTIVE

To assess the impact of the 1993 change in the AIDS case definition on the completeness and timeframe of AIDS case reporting in San Francisco.

DESIGN

Retrospective review of records: billing records, list of selected diagnostic codes, radiology logs, ophthalmology clinic records, and patient registries at a selection of hospitals, clinics, and physician offices.

SETTING

Hospitals, public/community health clinics, and physician offices.

MAIN OUTCOME MEASURES

The completeness of reporting and the median reporting delay was calculated for hospitals, clinics, and physician offices.

RESULTS

Reporting was 97% complete. Reporting from physician offices was less complete (75%) than from other facilities. The median reporting delay was 1 month and was shorter for persons who met the 1993 AIDS case definition (1 month) than for persons who met the 1987 case definition (3 months).

CONCLUSIONS

AIDS case reporting in San Francisco is highly complete but less so for persons diagnosed at physician offices. The 1993 AIDS case definition has resulted in more timely reporting. Health departments should consider efforts to improve reporting from private physician offices and should evaluate the use of laboratory-initiated CD4 reporting.

Molecular analysis of two closely related mouse aldehyde dehydrogenase genes: identification of a role for Aldh1, but not Aldh-pb, in the biosynthesis of retinoic acid

Mammalian class I aldehyde dehydrogenase (ALDH1) has been implicated as a retinal dehydrogenase in the biosynthesis of retinoic acid, a modulator of gene expression and cell differentiation. As the first step towards studying the regulation of ALDH1 and its physiological role in the biosynthesis of retinoic acid, mouse ALDH1 cDNA and genomic clones have been characterized. During the cloning process, an additional closely related gene was also isolated and named Aldh-pb, owing to its high amino acid sequence identity (92%) with the rat phenobarbitol-inducible ALDH protein (ALDH-PB). Aldh1 spans about 45 kb in length, whereas Aldh-pb spans about 35 kb. Both genes are composed of 13 exons, and the positions of all the exon/intron boundaries are conserved with those of human ALDH1. The promoter regions of Aldh1 and Aldh-pb demonstrate high sequence similarity with those of human ALDH1 and rat ALDH-PB. Expression of Aldh1 and Aldh-pb is tissue-specific, with mRNAs for both genes being found in the liver, lung and testis, but not in the heart, spleen or muscle. Expression of Aldh-pb, but not Aldh1, was also detected at high levels in the kidney. Aldh1 and Aldh-pb encode proteins of 501 amino acids with 90% positional identity. To examine the relative roles of these two enzymes in retinoic acid synthesis in vivo, Xenopus embryos were injected with mRNAs encoding these enzymes to assay the effect on conversion of endogenous retinal into retinoic acid. Injection of ALDH1, but not ALDH-PB, mRNA stimulated retinoic acid synthesis in Xenopus embryos at the blastula stage. Thus our results indicate that Aldh1 can function in retinoic acid synthesis under physiological conditions, but that the closely related Aldh-pb does not share this property.

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.

Characterization of the consequence of a novel Glu-380 to Asp mutation by expression of functional P450c21 in Escherichia coli

P450c21 catalyzes an important step in steroid synthesis. Its deficiency leads to symptoms of steroid imbalance. To obtain enough P450c21 for structure and function studies, we developed a method to express P450c21 in Escherichia coli. The 5'-region of the human P450c21 cDNA was modified to ensure efficient translation and the C terminus of the protein was extended with four His residues for easy purification. Mutant proteins with substitutions at residues 172 and 281 exhibited decreased enzymatic activities similar to those found in mammalian cells. One new mutation changing Glu-380 to Asp (D380) caused 3-fold reduction in enzymatic activity. The amount of apoprotein production detected by immunoblotting and the affinity of the mutant protein towards substrate as measured by Km were normal. The defect lies in the decreased ability of the apoprotein to bind heme, which was measured by CO difference and substrate-binding spectra. The D380 mutant protein had 3-fold reduction in peak heights in both spectra. This reduced heme binding resulted in 3-fold lower enzymatic activity.

BRCA1 is associated with the centrosome during mitosis

Centrosomes and their associated microtubules direct events during mitosis and control the organization of animal cell structures and movement during interphase. The centrosome replicates during the cell cycle, directs the assembly of bipolar mitotic spindles, and plays an important role in maintaining the fidelity of cell division. Recently, tumor suppressors such as p53 and retinoblastoma protein pRB have been localized to the centrosome in a cell cycle-dependent manner. Immunofluorescence microscopy and analysis of isolated centrosomes now provide evidence that BRCA1 protein, a suppressor of tumorigenesis in breast and ovary, also is associated with centrosomes during mitosis. Our results indicate that BRCA1 localizes with the centrosome during mitosis and coimmunoprecipitates with gamma-tubulin, a centrosomal component essential for nucleation of microtubules. Furthermore, gamma-tubulin associates preferentially with a hypophosphorylated form of BRCA1.

Reduction of dimesna to mesna by the isolated perfused rat liver

Mesna is administered with ifosfamide and cyclophosphamide to reduce the incidence of hemorrhagic cystitis. In the present model of mesna metabolism and disposition, mesna is rapidly and irreversibly oxidized to dimesna in the plasma, passes unchanged through the liver, and is then reduced by the kidney and excreted. Our detection of a high ratio of mesna to dimesna in the plasma of clinical samples led us to reinvestigate the hepatic metabolism of mesna and dimesna. We perfused isolated rat livers from female Sprague Dawley rats with protein-free buffered solution containing dimesna at concentrations observed during therapy. In single-pass perfusions, each liver was perfused with up to three dimesna concentrations during consecutive 20-min periods. Recirculating perfusions were used to study single supratherapeutic concentrations of dimesna or mesna. Mesna and dimesna concentrations were measured by specific chromatographic procedures. Dimesna reduction, adjusted by the effluent flow rate and liver weight (0.4-58.5 nmol/min/g liver), correlated closely by linear regression (r = 0.98; n = 36) to the perfused dimesna concentration (4.2-249 microM), indicating a clearance of 0.20 ml/min/g liver. The concentration of dimesna that entered the liver closely matched the summed concentration of mesna and dimesna emerging in the effluent perfusate (single-pass experiments: slope, 0.98; intercept, -0.30; r = 1.00; n = 31). Only trace amounts of unidentified thiols were detected in the bile during recirculation of perfusates with 1 mM mesna or 250 microM dimesna. The effluent mesna concentration correlated inversely with the flow rate, which was consistent with a low extraction ratio in the perfusion model. These data suggested that the dimesna reduction rate was limited by hepatic uptake. Dimesna reduction was decreased by agents that deplete glutathione. Pretreatment of rats with up to 100 mg/kg ifosfamide did not impair hepatic dimesna reduction. In control experiments, dimesna was not reduced during recirculation through the apparatus without a liver. Mesna was oxidized to dimesna during oxygenation of the perfusate in the reservoir, but mesna injected directly into the perfusate just before entry into the liver passed unchanged into the effluent. Extrapolation of the dimesna clearance data from the perfusion model to humans suggests that hepatic dimesna reduction may counterbalance the rapid oxidation of mesna in plasma. The proposed equilibrium is consistent with clinical observations and suggests a new model for mesna metabolism and disposition.

Quantification of device adherent, circulating, and organ pool of thrombin and fibrinogen after cardiopulmonary bypass in a pig model

The pool of thrombin and fibrinogen in circulation, in organs, and on cardiopulmonary bypass devices was quantified during and after cardiopulmonary bypass in four groups of 24 Yorkshire pigs (weight, 30-35 kg); two groups of 10 unoperated pigs were used as controls. Thrombin-alpha and fibrinogen were iodinated with 125iodide using an iodogen transfer technique; 250-300 microCi of these tracers were injected intravenously 1 hr before cardiopulmonary bypass. All pigs were systematically heparinized (activated clotting time > 400 sec); cardiopulmonary bypass was performed at 2.5-3.5 L/min at 28 degrees C using a centrifugal pump, oxygenator (Bentley Univox 1.8 m2; Bentley Inc., Irvine, CA), arterial filter (0.25 m2), and cardiotomy reservoir (BMR 3500) for 90 min, followed by a 90 min reperfusion and 180 min of cardiopulmonary bypass. Iodinated thrombin-alpha and fibrinogen in intact organs and samples of blood, organs, tissues, and oxygenator-arterial filter-cardiotomy reservoir were quantified with an ion chamber and a gamma counter, respectively. The percent of injected iodinated thrombin-alpha and fibrinogen dose (mean +/- SD) in organs and cardiopulmonary bypass devices of all groups of cardiopulmonary bypass pigs was calculated. Thrombin generated at the small area of surgical wounds (0.016-0.038 m2), and fibrin deposited on surfaces of cardiopulmonary bypass devices (2.59 m2), initiate and propagate thrombus formation and embolization. The protein level reached saturation values on all cardiopulmonary bypass devices at 180 min. High levels of thrombin and fibrinogen-fibrin circulate in blood and organs, and are adsorbed on cardiopulmonary bypass devices; this large blood pool of pro-coagulants in the cardiac cradle, tissues, and perfused organs may account for thrombi and emboli during and after cardiopulmonary bypass.

Expression of human aldehyde dehydrogenase-3 associated with hepatocellular carcinoma: promoter regions and nuclear protein factors related to the expression

The human ALDH3 gene is constitutively expressed in stomach, lung, esophagus, and cornea, but hardly detectable in the normal liver. However, it is highly activated in the hepatocellular carcinoma tissues from approximately 50% of patients. The nuclear DNA binding factors exist in both ALDH3-positive cancerous liver and ALDH3-positive HepG2 cells, but not in ALDH3-negative Hep3B cells and normal liver tissues. South-western blot hybridization showed the existence of two nuclear-binding protein components, 35 and 14 kDa, in ALDH3-positive cancerous liver tissues. These two DNA binding proteins were not found in normal stomach tissues and stomach carcinoma KATO III cells. DNaseI footprint analysis identified two protective regions within the ALDH3 promoter. The first protected region has one putative CCAAT-box and one putative Sp1-site. The second protected region contains a putative HiNF-A binding sequence. These findings suggest that a high level of expression of ALDH3 in cancerous liver tissues resulted from the expression or activation of at least two nuclear proteins reacting to the ALDH3 promoter region.

Mapping of 55 new rat microsatellite markers from chromosome-specific libraries

Fifty-five novel rat microsatellite markers were isolated from libraries specific for rat chromosomes (Chrs) 1, 2, and 7. The markers were mapped in three backcross rat populations. Thirty of these markers mapped to Chrs 1, 2, or 7, while the other 25 mapped to other chromosomes. New markers for two genes, liver-specific transporter gene (Livtr) and insulin-responsive glucose transporter (Glut4), were also mapped to rat Chrs 9 and 10, respectively. Three provisionally assigned markers from previous studies were also confirmed. Detailed methodologies for the generation and enrichment of clones containing repeat sequences and for the isolation of chromosome-specific markers are presented, since they represent unique combinations and modifications of previous protocols. Such methods and the newly presented markers should be useful for both specific and general mapping studies in the rat.

Tumor necrosis factor-alpha in plasma during cardiopulmonary bypass in a pig model: correlation with marginated neutrophils and cerebral edema by magnetic resonance imaging

Tumor necrosis factor (TNFalpha) initiates the cytokine cascade via the nuclear factor (NFkappaB), increasing vascular permeability, inflammation, and edema during and after cardiopulmonary bypass (CPB). Cerebral edema before and after thoracotomy and CPB was evaluated by magnetic resonance imaging. TNF-alpha in plasma was measured in 12 Yorkshire pigs with an enzyme linked immunosorbent assay technique using a monoclonal antibody made against porcine TNFalpha. Blood samples were taken 30 min before and 1, 30, 60, 90, 120, 150, and 180 min after initiation of CPB. Plasma was separated from packed cells after centrifugation, and frozen at -80 degrees C. The level of TNFalpha, measured by color intensity, was read with a 96 well microtiter plate reader. Normal values in plasma were low (range, 0-17 pg/ml; mean, 4.7 pg/ml). In sham control pigs undergoing sternotomy, and pigs that had undergone CBP, TNFalpha reached a peak value at 120-150 min, and subsequently declined. TNFalpha in plasma increased in pigs that underwent thoracotomy and CPB. The increase was significantly higher in pigs that underwent CPB. Neutrophil mapping in the pig brain with 111In-labeled autologous neutrophils 180 min after CPB, suggested almost uniform distribution and accounted for the 0.02% of total circulating neutrophils in the brain, corresponding to a total of 8 x 10(5) neutrophils. Magnetic resonance imaging of the pig brain indicated the presence of cerebral edema after CPB, as depicted by the loss of structural details of the sulci, gyri, and ventricles. Activated neutrophils, monocytes, and other inflammatory cells may induce multi-organ edema and injury via TNFalpha and other regional cytokines.

Antigenic characterization of nine wild-type Taiwanese isolates of Japanese encephalitis virus as compared with two vaccine strains

The antigenic properties of nine wild-type Japanese encephalitis viruses isolated in Taiwan during 1990 1994 were investigated by comparison with two inactivated vaccine strains (Beijing-1, Nakayama-NIH). All of the nine Taiwanese isolates were found to induce higher cytopathology in Vero cells but showed similar mouse virulence as the two vaccine strains. Antigenic characterization using six E protein-specific monoclonal antibodies shows two of the nine wild-type isolates (i.e. CH1949 and CH2195) presented different antigenic properties of hemagglutination inhibition and plaque reduction neutralization. The E-protein gene nucleotide sequences of CH1949 and CH2195 were determined and compared with other published sequences of the two vaccine strains and other 19 Asian/Taiwanese isolates. Phylogenetic tree analysis indicates these two wild-type Taiwanese isolates are more distant from the two vaccine strains.

Proton magnetic resonance spectroscopy in deep cerebral venous thrombosis

A 63-year-old man developed a severe left frontal headache followed by an acute change of mentality 6 days later. Magnetic resonance imaging revealed bilateral thalamic ischemia. Angiography confirmed the occlusion of deep cerebral veins. Proton magnetic resonance spectroscopy (1H-MRS) of the thalami showed normal N-acetylaspartate (NAA) peak and the presence of lactate peak, indicating a relatively preserved neuronal viability. The patient improved during the follow-up period, and returned to work 45 days after the onset of the disease. With 1H-MRS, prognosis following venous infarctions may be feasible.

Human aldehyde dehydrogenase gene family

Twelve aldehyde dehydrogenase (ALDH) genes have been identified in humans. These genes, located on different chromosomes, encode a group of enzymes which oxidizes varieties of aliphatic and aromatic aldehydes. Metabolic disorders and clinical problems associated with mutations of ALDH1, ALDH2, ALDH4, ALDH10 and succinic semialdehyde (SSDH) genes have been emerged. Comparison of the human ALDHs indicates a wide range of divergency (> 80 - < 15% identity at the protein sequence level) among them. However, several protein regions, some of which are implicated in functional activities, are conserved in the family members. The phylogenic tree constructed of 56 ALDH sequences of humans, animals, fungi, protozoa and eubacteria, suggests that the present-day human ALDH genes were derived from four ancestral genes that existed prior to the divergence of Eubacteria and Eukaryotes. The neighbor-joining tree derived from 12 human ALDHs and antiquitin indicates that diversification within the ALDH1/2/5/6 gene cluster occurred during the Neoproterozoic period (about 800 million years ago). Duplication in the ALDH 3/10/7/8 gene cluster occurred in Phanerozoic period (about 300 million years ago). Separations of ALDH3/ALDH10 and that of ALDH7/ALDH8 had occurred during the period of appearance and radiation of mammalian species.

Projected incidence of AIDS in San Francisco: the peak and decline of the epidemic

To predict the incidence of AIDS from 1978 through 1998 in San Francisco, we developed a model that combined annual HIV seroconversion rates for homosexual and bisexual men and for heterosexual injecting drug users with estimates of the incubation period distribution between HIV seroconversion and AIDS diagnosis and with estimates of the size of the at-risk populations. Our model assumed the availability of antiretroviral therapy at the efficacy level of zidovudine monotherapy. The annual number of new AIDS cases is estimated to have peaked at 3332 in 1992, and is projected to decline to 1196 annually by 1998. Although the projected number of cases decreased steadily during this period for homosexual and bisexual men, the projected number of cases for injection drug users, women, and persons with other risks increased between 1993 and 1998. The decline in the incidence of AIDS in San Francisco reflects the dramatic reductions in new HIV infections that occurred a decade previously and that were achieved as a result of significant changes in high-risk behaviors, primarily among homosexual and bisexual men. Changes in HIV seroincidence must be factored in before attributing the decrease in AIDS incidence to more effective combination antiretroviral treatment.

Japanese encephalitis virus antigenic variants with characteristic differences in neutralization resistance and mouse virulence

Two different plaque variants of Japanese encephalitis virus were selected from a wild-type Taiwanese isolate using Vero cells. One variant was found to exhibit small plaque morphology with retarded virus replication kinetics in Vero cells, and was demonstrated to be resistant to monoclonal antibody (mAb) E3.3 neutralization. The other variant showed large plaque morphology, was sensitive to mAb E3.3 neutralization, and manifested reduced virulence in mice on both intracranial and intraperitoneal inoculations. These two variants propagated in Vero cells retained high levels of infectivity but had relatively low HA titers as compared with the parent strain. The envelope sequences of these two variants showed four amino acid differences at residues E-85 (Glu/Arg), E-306 (Glu/Gly), E-331 (Ser/Arg), and E-387 (Met/Arg). Our results indicated the neutralizing epitope of Japanese encephalitis virus did not overlap with virus virulence determinant.

A new method for quantitation of platelet microthrombi and microemboli from cardiopulmonary bypass in organs using 111In labeled platelets

During cardiopulmonary bypass (CPB), showers of microemboli (ME) distribute among the organs and connective tissues according to regional blood flow. Post CPB, ME were quantified by subtracting residual platelets (RP) in the organs of a group of unoperated control Yorkshire pigs (n = 6) from those of operated pigs. The RP level was minimized by heparinization (300 IU/kg) before death and exsanguination. The number of adherent microthrombi (MT) and ME from the oxygenator (OX), arterial filter (AF), and thoracotomy site were determined using 111In labeled autologous platelets (INPLT) (525-585 microCi administered 24 hr before CPB) in two CPB groups (ACT > 400 sec) of 12 pigs (30-35 kg). CPB was carried out at a flow of 2.5-3.5 L/min at 28 degrees C with a roller or a centrifugal pump, OX (Bentley Univox 1.8 m2), AF (0.25 m2), and cardiotomy reservoir (CR) (Bentley BR: 3,500), for 90 (n = 6) and 180 (CPB 180, n = 6) min. Six pigs underwent thoracotomy without CPB. L-Arginine was infused at a dose of 2 mg/ kg/min during CPB (n = 6). Flow cytometry was used to estimate the circulating ME in blood. MT and organ trapped ME were imaged with a gamma camera and measured with an ion chamber and a gamma counter. ME values (percent of injected INPLT dose) in six organs and four connective tissues were calculated for all five groups. INPLT distribution indicated a uniform distribution of low level platelet MT in the CR and AF. Circulating ME amounted to 2.5% of total platelets. In the CPB circuit, ME generation in AF was the rate-limiting step (n = 4 x 10(5)). Similar studies in organs and tissues suggested the presence of a uniform distribution of the total events of ME (n = 500 x 10(6)). ME increase in brain, lung, liver, and skeletal muscle following thoracotomy and CPB was significant. The low level of ME in ischemia sensitive organs also indicated the presence of a thrombolytic threshold for cumulative ME. ME disaggregation was activated at an early stage to prevent ischemic damage, specifically in the brain. Measurement of trapped ME provided a novel, reliable, and one step method of evaluation of thrombogenicity of a CPB device and drugs.

[Seroepidemiology of Japanese encephalitis viral infection among 3-6 years old children from mountainous and plains townships located in the northern, central, southern and eastern Taiwan]

In order to evaluate the Japanese encephalitis virus (JEV) vaccination program in rural Taiwan, we conducted a seroepidemiological survey of JEV among rural children 3 to 6 years of age in Taiwan. The children were selected through a systemic sampling following stratification by age of children in 4 selected aboriginal villages and 4 adjacent nonaboriginal villages. The overall vaccine coverage rate for the primary (2 doses) dose was 81.2% (1853/2281) with higher rates (87.7%-87.9%) found among the more recent birth cohort of 3 to 4 years of age. The neutralizing antibody (NT) against JEV was measured with plaque reduction neutralization test (PRNT) using Nakayama strain as the virus. With a positive NT antibody defined as > or = 1:10 dilution of serum yielding more than 50% plaque reduction, the overall JEV NT antibody positive rate among children receiving 3 doses of vaccine was 67%. However, the age-specific positive rates varied significantly with varying ages; the lowest of 47% being among children 4 years of age which was lower than the rates of 68%, 76% and 87% among children of 3, 5 and 6 years of age, respectively. This trend of rising seropositive rates of JEV antibody with increasing age among 4 and 6 years of age was also noted among children who had received no vaccine, suggesting the importance of natural infection among rural Taiwanese children. Despite the high frequency of natural infection, the seropositive rates of JEV antibody still correlated well with the dose of vaccine received, i.e., 67% (1122/1664), 66% (65/97), 33% (4/12) and 40% (19/47) for children receiving 3, 2, 1, and 0 dose of JE vaccines, respectively (P < 0.0001 Chi-square for trend test). When stratified analysis by dose and by type of vaccines was conducted, a significantly higher seropositive rate of JEV NT antibody was noted among children receiving JE vaccine of Beijing type (87%) than children receiving Nakayama type (39%) (p < 0.0001, Chi-square test). Our data indicated that the JEV vaccination, in conjunction with JEV natural infection, has maintained high JEV NT antibody level among rural children of Taiwan.

High rate of hepatitis C virus infection in an isolated community: persistent hyperendemicity or period-related phenomena?

We investigated underlying risks for hyperendemic hepatitis C virus (HCV) infection among the 1853 inhabitants of a mountainous village in Eastern Taiwan with high prevalence of HCV and hepatitis B virus (HBV). Among the 80 selected adults, we found that having resided away from the village before 1985 was protective against HCV infection, while residing in the village after 1985 posed little risk for HCV infection to children and young adults < 30 years of age. Among the 559 school children 7 through 14 years of age, anti-HCV prevalence was 1.9%, and the HBV carrier rate was 29%. Following up 270 children 1 year later, we found that new HCV infection occurred in 0.74% and new or repeated HBV infection occurred in 6.5% of the children, indicating distinct transmission patterns between HBV and HCV. Children of anti-HCV-positive mothers were either anti-HCV-negative or were infected by distinct genotypes of HCV from those infecting their mothers; most married couples in whom both were infected, were infected by HCV of discordant genotypes, indicating negligible importance of sexual or vertical HCV transmission. A case-control study comparing 13 anti-HCV-positive and 53 anti-HCV-negative children showed that having received parenteral medication in local clinics was a significant risk for HCV infection. Our data indicate that, unlike the case of HBV, HCV transmission by vertical or sexual route, or through casual contact are extremely inefficient, and our data further suggest that HCV hyperendemicity is unlikely to persist as a result of the more stringent practice of parenteral precautions in nearly all aspects of daily life.

Prevalence of headaches in a Chinese elderly population in Kinmen: age and gender effect and cross-cultural comparisons

OBJECTIVE

To investigate the prevalence of headaches in a Chinese elderly population.

BACKGROUND

There are few headache surveys in the elderly. Previous studies have shown a low headache prevalence in Chinese.

METHODS

TARGET POPULATION

eligible registered residents > or = 65 years old (N = 2,003) in two townships of Kinmen Island on August 1, 1993. All participants completed a headache questionnaire and underwent clinical evaluation and examination by a neurologist. Headache diagnoses were made according to the International Headache Society, 1988.

RESULTS

1,533 persons (77%) participated in the study, of whom 584 (38%) had at least one episode of headache in the previous year. One-year prevalence of migraine was 3.0%, and tension-type headache, 35%. The prevalence of migraine, but not tension-type headaches, continued to decline with age in the elderly. Life-time prevalence of "incapacitating headache" was 10%, and that of migraine, 5.2%. Forty-two percent of migraineurs stopped having migraine before this survey. In comparison with "10 years ago" 8% participants felt their current headaches were worse, 25% better, and 67%, no change, with a net improvement of 17%.

CONCLUSIONS

We have reported the highest headache prevalence among different Chinese elderly populations, but these were still lower than those reported from Western series. More than half of the elderly life-time migraineurs still had attacks of migraine. Severe headaches, including migraine but not tension-type headaches, declined with age.

Exon/intron structure of aldehyde dehydrogenase genes supports the "introns-late" theory

Whether or not nuclear introns predate the divergence of bacteria and eukaryotes is the central argument between the proponents of the "introns-early" and "introns-late" theories. In this study we compared the goodness-of-fit of each theory with a probabilistic model of exon/intron evolution and multiple nonallelic genes encoding human aldehyde dehydrogenases (ALDHs). Using a reconstructed phylogenetic tree of ALDH genes, we computed the likelihood of obtaining the present-day ALDH sequences under the assumptions of each competing theory. Although on the grounds of its own assumptions each theory accounted for the ALDH data significantly better than its rival, the introns-early model required frequent intron slippage, and the estimated slippage rates were too high to be consistent with reported correlations between the boundaries of ancient protein modules and the ends of ancient exons. Because the molecular mechanisms proposed to explain intron slippage are incapable of providing such high rates and are incompatible with the observed distribution of introns in higher eukaryotes, the ALDH data support the introns-late theory.

Biocompatibility in cardiopulmonary bypass

Recent advances in surgical techniques and perfusion technology allow cardiac operations to be performed routinely with low mortality rates. However, patients undergoing cardiac operations with cardiopulmonary bypass (CPB) are still associated with bleeding disorders, thrombotic complications, massive fluid shifts, and the activation of blood components that are collectively known as the whole body inflammatory response. In this review, the effect of cardiopulmonary bypass on various humoral and cellular components of blood is examined. Blood activation caused by interaction with artificial materials of extracorporeal circuit and by material-independent stimuli is discussed. Methods to control blood activation during and after cardiopulmonary bypass are described. These include surface modification of extracorporeal circuit, control of flow dynamics in the circuit, pharmacological intervention, and the use of extracorporeal devices to remove inflammatory mediators. Recent findings on the effects of heparin-coated circuits on inflammatory response and clinical outcome are reviewed. It appears that the causes of inflammatory response to cardiopulmonary bypass are multifactorial and that an integrated strategy is needed to control and eliminate the negative effects of CPB.

Human aldehyde dehydrogenase genes, ALDH7 and ALDH8: genomic organization and gene structure comparison

The structure of two human aldehyde dehydrogenase genes, ALDH7 and ALDH8, have been determined. The ALDH7 gene spans about 20 kb of the human genomic DNA and is composed of 9 coding exons. The ALDH8 gene is over 10 kb in length and consists of at least 10 exons. The ALDH8 gene contains an in-frame stop codon at the 17th codon position from the first initiator Met. The coding region of the ALDH7 gene shows about 86% nucleotide identity with the corresponding region of the ALDH8 gene. The numbers and positions of the introns of the two genes are conserved, suggesting that gene duplication is involved in the expansion of the ALDH gene family. The human ALDH7 and -8 genes have a closer evolutionary relationship with the human ALDH3.

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.

Emboli from an extraluminal blood flow hollow fiber oxygenator with and without an arterial filter during cardiopulmonary bypass in a pig model

The effect of an arterial filter on visceral emboli was quantified with autologous indium-111 labeled platelets (INPLT) during cardiopulmonary bypass (CPB) in Yorkshire pigs. Biodistribution of INPLT was determined in 12 control pigs (30-35 kg, unoperated control [n = 6] and sham operated control [n = 6]). CPB was carried out with (n = 6) and without (n = 6) an arterial filter in 12 pigs at a flow rate of 2.5-3.5 L/min. Platelets labeled with In-111 tropolone (650-780 microCi) were injected intravenously 24 hr before CPB. All pigs were systemically heparinized (activated coagulation time > 400 sec); CPB was instituted with a roller pump, an extraluminal blood flow oxygenator (Bentley Univox, 1.8 m2), and an arterial filter (0.25 m2) and continued for 3 hr. Platelet kinetics, pooling, and counts were monitored by a Geiger probe and a Coulter counter. The thrombi in the oxygenator and arterial filter and emboli in viscera and brain were imaged with a gamma camera and measured with an ion chamber and gamma counter. Percentage of INPLT (mean +/- SD) in organs, tissues, and components of the circuit in four groups of pigs was calculated. Flow cytometry with antibodies to CD61 (GPIIIa) and CD62P (GMP-140: control) of porcine platelets was carried out with blood samples taken before, during, and after CPB for estimation of circulating platelet aggregates and platelet microparticles. Pulmonary, renal, cardiac, and cerebral emboli in pigs undergoing CPB with and without a filter were similar (p < 0.1). The amount of filter adherent thrombi was small (0.04 +/- 0.01%); oxygenator adherent thrombus in both groups was similar (p < 0.1). Emboli were found in the cerebral medulla, hippocampus, and posterior cerebral cortex in both groups. During CPB, the arterial filter functioned minimally as a trap for platelet thrombi detached from the oxygenator and circulating emboli. Flow cytometry of blood demonstrated the shift of equilibria from single platelets to platelet aggregates and microparticles during CPB and their gradual reversal to single platelets after CPB; the loosely adherent emboli disaggregated and further shifted these equilibria to single platelets and smaller aggregates, probably through the action of endogenous nitric oxide and prostacyclin. The emboli were trapped in organs and tissues and microparticles were sequestered by the reticuloendothelial system.

Allelic imbalance in mammary carcinomas induced by either 7,12-dimethylbenz[a]anthracene or ionizing radiation in rats carrying genes conferring differential susceptibilities to mammary carcinogenesis

To identify and compare the genetic lesions associated with tumorigenesis in rats carrying the mammary carcinoma suppressor (MCS) 1 gene, we induced mammary carcinomas in (Wistar Furth (WF) x Copenhagen (Cop))F1 rats by using either 7,12-dimethylbenz[a]anthracene (DMBA) or radiation. The tumors were screened for allelic imbalances by using polymerase chain reaction and 65 polymorphic microsatellite markers spanning the genome. No allelic imbalance was detected at the mapped location of MCS-1 on chromosome 2; however, a scan of the genome revealed random allelic imbalances in the radiation-induced tumors. In addition, non-random loss of heterozygosity (LOH) on chromosome 1 in the DMBA-induced tumors was documented. We then screened three other subsets of DMBA- and radiation-induced mammary carcinomas from (WF x Fischer (F344))F1, (Wistar Kyoto x F344)F1, and (F344 x Cop)F1 rats for imbalance on chromosomes 1 and 2. No allelic imbalance was detected in the MCS-1 region of chromosome 2 in any of the tumors screened. Nonrandom imbalance on chromosome 1 was detected but only in the DMBA-induced tumors from the (F344 x Cop)F1 rats. Thus, only Cop-derived F1 rats have mammary tumors with the chromosome 1 imbalance; however, the imbalance does not favor the Cop parental allele. We also analyzed the DMBA-induced tumors with LOH at chromosome 1 for Ha-ras codon 61 mutation and found no association. These results suggest that loss of the MCS-1 Cop allele is not required for tumor formation, that the genetic background of the F1 rat appears to influence the type of genetic lesion identified in the mammary tumors, and that there is no association between Ha-ras codon 61 mutation and chromosome 1 imbalance in our model system.

The effect of age on the change in deformity after anterior débridement surgery for tuberculosis of the spine

STUDY DESIGN

This article evaluates how an immature spine responds to anterior débridement surgery (without bone grafting) for spinal tuberculosis during growth and development. Sixty-three patients were studied, 29 of whom were children aged 10 years or less at the time of surgery, whereas the remaining 34 subjects were adults. These patients were the subject of the Medical Research Council Working Party's prospective study, started in Hong Kong in the mid-1960s.

OBJECTIVES

To evaluate how an immature spine responds to débridement surgery for tuberculosis, during growth and development, to determine whether there are differences in the longitudinal pattern of deformity between children and adults, and to determine the influence of disproportionate spinal growth on the progression of deformity in children.

SUMMARY OF BACKGROUND DATA

All patients were followed prospectively for a mean period of 19.6 years after débridement surgery. The mean age at surgery for children (n = 29) was 4.3 years and for adults (n = 34) 35.3 years.

METHODS

The kyphos and deformity angles were measured from lateral spinal radiographs obtained at preoperative evaluation and postoperatively at 6 months, 1 year, 5 years, and at final follow-up evaluation using an electronic digitizer.

RESULTS

The results showed that the longitudinal pattern of changes in the mean kyphos and deformity angles in young children presented a picture slightly different from that in adults. The mean angles were increased at the 6-month and at 1-year evaluations after débridement surgery in both groups. Afterward, in children there was some spontaneous correction in these mean angles, whereas in adults these angles showed variation according to the site of lesion during the follow-up years. Statistical analysis according to the site of spinal lesion showed that in thoracic tuberculosis, there was an increase in kyphos and deformity angles at the 6-months postoperative evaluation (more in children than in adults). There were no significant changes in these angles from the 1-year to the final follow-up evaluations. In thoracolumbar tuberculosis, there were significant increases in kyphos and deformity angles at the 6-month postoperative evaluation, and thereafter adults did not show any significant change until final follow-up examination, whereas children showed a tendency toward spontaneous correction, although this finding was not statistically significant. In lumbar tuberculosis, there was an equal tendency toward spontaneous correction in children and adults from 1 postoperative year onward.

CONCLUSIONS

The authors could find no evidence of disproportionate posterior spinal growth, which has been suspected in the past to be a factor involved in contributing to progression of kyphotic deformity after anterior débridement surgery for spinal tuberculosis.

Sequencing and expression of the human ALDH8 encoding a new member of the aldehyde dehydrogenase family

The human aldehyde dehydrogenase gene (ALDH) family is characterized by two major conserved DNA sequences encoding residues which are possibly involved in the catalytic function and the maintenance of the functional conformation of the ALDH enzyme. This property is the basis for synthesizing the degenerate primers to clone several cDNAs of the ALDH isozymes. In this report, we describe the cDNA sequence and the expression of a new member of this family, ALDH8. The human ALDH8 gene was identified during the process of the screening for the human ALDH7 genomic clones. Overlapping ALDH8 cDNA clones were isolated by polymerase chain reaction (PCR) amplification of human salivary gland total RNA or lambda gt11 cDNA library. When the ALDH8 cDNA sequence was aligned with that of the ALDH7 which encodes a polypeptide chain of 468 amino acid (aa) residues, it was found that a termination codon (TGA) is placed in frame at the ALDH8 sequence corresponding to the codon GCG for the seventeenth aa position of the ALDH7. Therefore, the human ALDH8 gene is a potential nonprocessed pseudogene in the ALDH multigene family which has no other pseudogenes reported so far. Alternatively, the ALDH8 gene is a functional gene if the premature stop codon is suppressed, or if the first downstream in-frame ATG serves as the initiator codon. This longest putative open reading frame (ORF) encodes a polypeptide chain of 385 aa residues, includes the two ALDH conserved regions, and demonstrates 86% identity with the corresponding ORF region of the human ALDH7. The expression of the ALDH8 transcripts is restricted to the salivary gland among the human tissues examined.

Reduction of neutrophil margination by L-arginine during hypothermic cardiopulmonary bypass in a pig model

Nitric oxide generation by L-arginine (2 mg/kg/min) infusion during cardiopulmonary bypass (CPB) increases blood flow to all organs and reduces cytokine induced organ damage by reducing the level of marginating neutrophils (Ns). The N-trapping in the oxygenator (OX), arterial filter (AF), cardiotomy reservoir (CR), and N-margination were quantified with indium 111 labeled autologous neutrophils (INN) in nine groups of 40 Yorkshire pigs (30-35 kg). Cardiopulmonary bypass (180 min or 90 min CPB, 90 min reperfusion) was carried out at 2.5-3.5 L/min and at two temperatures (18 degrees C, 28 degrees C). The INN (650-780 microCi) was administered intravenously 15 mins before CPB. All pigs received heparin systemically (activated coagulation time > 400 secs); CPB was instituted with a roller pump, OX (Univox 1.8 m2), AF (0.25 m2), and CR (BCR-3500, Bentley Lab, Irvine, CA). The INN distribution in the device (OX, AF, CR) and organs was imaged with a gamma camera and measured with an ion chamber and a gamma counter. The LA infusion decreased N-trapping, estimated as the percent of injected INN (mean +/- standard deviation), in OX from control (2.7 +/- 2.02)% to (0.94 +/- 0.29)%, and margination in lung from control (48 +/- 4)% to minimal levels (23 +/- 2)% (p < 0.01). In the CPB reperfusion group, a beneficial effect was observed at LA low dose and toxicity of higher N-margination at 15 mg/ kg/min. Neither CPB temperature nor Leumedin affected N-margination significantly.

Human gamma-aminobutyraldehyde dehydrogenase (ALDH9): cDNA sequence, genomic organization, polymorphism, chromosomal localization, and tissue expression

The cDNA and the gene (ALDH9) for a human aldehyde dehydrogenase isozyme, which has a high activity for oxidation of gamma-aminobutyraldehyde and other amino aldehydes, were cloned and characterized. The cDNA has an open reading frame of 1479 bp encoding 493 amino acid residues. The gene is about 45 kb and consists of 10 coding exons interrupted by nine introns. The gene was assigned to chromosome 1q22-q23, using fluorescence in situ hybridization. Northern blot hybridization indicated that the size of the mRNA is about 2.4 kb and that the gene is expressed at high levels in adult liver, skeletal muscle, and kidney and low levels in heart, pancreas, lung, and brain. The gene is polymorphic, i.e., C or T at nt 327 and C or G at nt 344.

Function and membrane topology of wild-type and mutated cytochrome P-450c21

We have studied membrane topology of cytochrome P-450c21 (P450c21) using the approaches of mutagenesis and protease digestion. P450c21 is located at the cytoplasm with an N-terminal hydrophobic domain integrated into microsomal membranes. When this hydrophobic domain was replaced by a secretory signal peptide, P450c21 was translocated into the lumen and lost enzymic activity. No other topogenic sequence was detected in the bulk of the P450c21 peptide. A mutant protein with Pro-30 replaced by Leu (L30) corresponding to the mutation found in the diseased state was created. L30 protein lost 90% of enzymic activity, while a double mutant (L30R32) with an additional Leu-32 to Arg mutation had slightly higher residual enzymic activity. Apart from lower activity, L30 was also present in the cell at a lower level than wild-type P450c21. This lower level is probably due to increased degradation, as L30 is synthesized at a normal rate. Both L30 and L30R32 proteins, however, were integrated into membranes normally. Therefore the Pro-30 --> Leu mutation did not affect membrane integration, but affected the abundance and enzymic activity of P450c21.