Definition of the surface in the thyroid hormone receptor ligand binding domain for association as homodimers and heterodimers with retinoid X receptor

Thyroid hormone receptors (TRs) bind as homodimers or heterodimers with retinoid X receptors (RXRs) to DNA elements with diverse orientations of AGGTCA half-sites. We performed a comprehensive x-ray crystal structure-guided mutation analysis of the TR ligand binding domain (TR LBD) surface to map the functional interface for TR homodimers and heterodimers with RXR in the absence and/or in the presence of DNA. We also identified the molecular contacts in TR LBDs crystallized as dimers. The results show that crystal dimer contacts differ from those found in the functional studies. We found that identical TR LBD residues found in helices 10 and 11 are involved in TR homodimerization and heterodimerization with RXR. Moreover, the same TR LBD surface is operative for dimerization with direct repeats spaced by 4 base pairs (DR-4) and with the inverted palindrome spaced by 6 base pairs (F2), but not with TREpal (unspaced palindrome), where homodimers appear to be simply two monomers binding independently to DNA. We also demonstrate that interactions between the TR and RXR DNA binding domains stabilize TR-RXR heterodimers on DR-4. The dimer interface can be functional in the cell, because disruption of key residues impairs transcriptional activity of TRs mediated through association with RXR LBD linked to GAL4 DNA-binding domain.

Clinical evaluation of glass ionomers used as fissure sealants: twenty-four-month results

This study evaluated the twenty-four-month retention and effectiveness in dental caries prevention, of Vitremer and Ketac-Bond glass ionomers used as occlusal sealants. The initial sample consisted of 200 school children ages six to eight years whose permanent first molars were sound. The children were divided into two experimental groups (group 1 Vitremer; group 2 Ketac-Bond) and a control group (group 3 unsealed molars). Statistical analysis (Mann-Whitney test) revealed that there were statistically significant differences between the retention levels of the experimental groups A and B in the three evaluation periods (six-, twelve- and twenty-four-month) with Vitremer showing superior results. As to caries incidence, there was a statistically significant difference (chi 2 test) between the experimental groups (A and B) and the control group indicating that glass ionomers are effective for prevention of caries in the occlusal surfaces. Two independent variables were correlated with the presence of caries or that of a restored tooth after twenty-four months (odds ratio) revealing that children who presented white spots (WS) had a probability of presenting caries or restorations that was 5.0, 3.07 and 1.93 times greater at six, twelve, and twenty-four months, respectively than that of children who did not show WS in the experimental groups A and B and in the control group, respectively. The variable represented by the "dmf" index showed a statistically significant correlation (chi 2 test) in the control group, in which there was a 3.26 times greater probability of children presenting a "dmf" index equal to or greater than 1 in the development of caries or who presented a restored tooth in relation to those who did not have a history of caries ("dmf" = 0).

Caries detection methods: can they aid decision making for invasive sealant treatment?

The decision to place sealants is a difficult one, and it has been suggested that in a low risk population it may be efficient to wait until caries is detected in the fissure. An invasive sealant technique with fissure preparation may then be indicated. The diagnostic method used in the indication of such a procedure should accurately detect both dentine caries and sound fissures: high sensitivity for dentine caries (at D3 threshold) with high specificity for enamel caries (at D1 threshold). The aims of this study were to assess the diagnostic performance of selected diagnostic methods at normal cut-offs for traditional dentine caries detection and at reduced cut-offs in relation to the desired performance mentioned above, and to assess whether fissure opening allows for accurate visual detection of dentinal caries. Data were obtained from 230 occlusal sites of 101 extracted human molar teeth. Diagnostic methods used on the entire sample were: visual inspection, electrical conductance measurements and laser fluorescence measurements. The sample was then divided into two groups. Group 1 was subjected to visual inspection after application of a dye. Group 2 was subjected to visual inspection after fissure opening only, and after subsequent dye application. Validation was performed by histological investigation. The results with cut-offs normally used in dentine caries detection were roughly in accordance with the literature, except for laser fluorescence. The sensitivity of visual inspection for dentinal caries (D3) was 17% before and 70% after fissure opening. Using reduced cut-offs, a 100% sensitivity (D3) was achieved with 2 methods, but this also resulted in 63 or 87% false positive diagnoses of sound surfaces. Visual inspection and electrical methods both showed a moderate to high sensitivity (D3) with a higher than 50% specificity (D1). It was concluded that visual inspection and electrical methods at reduced cut-offs may aid the indication of invasive sealant treatment. The visual detection of dentinal caries is substantially increased, but not perfect after fissure opening.

Thrombolysis in acute ischaemic stroke

In conclusion, thrombolysis with rtPA given within six hours of the onset of stroke in carefully selected patients is a safe therapy. However, efficacy has only been demonstrated within three hours after stroke onset. At present, only 6%-12% of all stroke patients are likely to be eligible for thrombolysis. Improved methods for investigating acute stroke, particularly magnetic resonance techniques, may improve the appropriate targeting of this treatment to those patients most likely to benefit. What is certain is that any increasing use of thrombolysis will have major effects on stroke services. The emphasis will have to be on early assessment and referral, if only to reach an imaging facility for a treatment decision to be made.

Two family members with a syndrome of headache and rash caused by human parvovirus B19

Human parvovirus B19 infection can cause erythema infectiosum (EI) and several other clinical presentations. Central nervous system (CNS) involvement is rare, and only a few reports of encephalitis and aseptic meningitis have been published. Here, we describe 2 cases of B19 infection in a family presenting different clinical features. A 30 year old female with a 7-day history of headache, malaise, myalgias, joint pains, and rash was seen. Physical examination revealed a maculopapular rash on the patient's body, and arthritis of the hands. She completely recovered in 1 week. Two days before, her 6 year old son had been admitted to a clinic with a 1-day history of fever, headache, abdominal pain and vomiting. On admission, he was alert, and physical examination revealed neck stiffness, Kerning and Brudzinski signs, and a petechial rash on his trunk and extremities. Cerebrospinal fluid analysis was normal. He completely recovered in 5 days. Acute and convalescent sera of both patients were positive for specific IgM antibody to B19. Human parvovirus B19 should be considered in the differential diagnosis of aseptic meningitis, particularly during outbreaks of erythema infectiosum. The disease may mimic meningococcemia and bacterial meningitis.

Hemochromatosis gene variants in three different ethnic populations: effects of admixture for screening programs

Genetic testing for hemochromatosis may have important implications for diagnosis and screening of the disease. However, the relative importance of mutations in the gene for hereditary hemochromatosis, HFE, may vary among populations, when the mutant allele frequencies and their penetrance in a particular genetic and environmental background are taken into account. We present data on the allele and genotype frequencies and population structure of two HFE genetic variants in three different ethnic groups from a highly mixed urban population (São Paulo, Brazil). Allele frequencies for both the C282Y and H63D HFE mutations showed significant differences among the studied populations (for the C282Y mutation, Euro-Brazilian 3.7%, admixed 0.7%, Afro-Brazilian 0.5%; and for the H63D mutation, Euro-Brazilian 20.3%, admixed 13.0%, Afro-Brazilian 6.4). The data substantiate a European origin for these mutations. Furthermore, they provide a basis for a more rational strategic planning of population screening programs for the disease.

Are Noonan syndrome and Noonan-like/multiple giant cell lesion syndrome distinct entities?

We report on a family with typical clinical findings of Noonan syndrome associated with giant cell lesions in maxilla and mandible. We discuss the obvious clinical overlap between Noonan syndrome and Noonan-like/multiple giant cell lesion syndrome, and we give further clinical and molecular support that these two entities could be allelic conditions.

Survival analysis within one year of first acute myocardial infarction: comparison between non-Q and Q wave myocardial infarction

BACKGROUND

Non-Q wave Myocardial Infarction (non-Q AMI) is related pathophysiologically to Q wave AMI, as each represents different stages of plaque rupture and thrombosis. Post-hospital re-infarction and recurrent angina are more frequent in non-Q AMI than in Q wave AMI, offsetting the higher early risk with Q wave AMI, with one-year survival rates similar in the two types of MI.

OBJECTIVES

1--Evaluation of early (< or = 28 days) and one-year total mortality from first non-Q AMI in comparison to QMI. 2--Analysis of recurrent acute ischaemic events (non-fatal reinfarction and unstable angina) in both types of MI in the same periods of time.

POPULATION AND METHODS

A retrospective study of 1146 patients, mean age 65 +/- 13 years, 65% male, admitted at CCU with a first MI, from January 1988 to December 1997 (minimum follow-up period of one year, mean follow-up 42 +/- 37 months). We compared the baseline demographics and clinical characteristics (coronary risk factors, previous angina, MI evolution, recurrent cardiac events, 28 day mortality and one year mortality) of patients with non-Q AMI (NQ group = 239) and Q wave AMI (Q group = 907).

RESULTS

The NQ group patients were significantly older (mean age: 67 +/- 12.6 vs 65 +/- 12.5 years; p < 0.05), included fewer smokers (29% vs 43%; p < 0.001) and were more symptomatic before the index infarction (stable angina: 40% vs 30%; p < 0.05; unstable angina: 16% vs 6%; p < 0.001), when compared to the Q group patients. There were no significant differences in MI evolution, in Killip-Kimbal class > or = 2, recurrent angina and in-hospital mortality (Q-12% vs NQ-9%; ns), although there was a higher combined risk of arrhythmias and AV conduction disturbances in patients with QMI (Q-34% vs NQ-26%; p < 0.05). The combined risk of unstable angina and reinfarction at one year was significantly higher in group NQ (NQ-13% vs Q-8.1%; p < 0.05). The NQ group showed no significant difference in 28 day total mortality (NQ-14% vs Q-17%; ns) or at one year follow-up (NQ-24% vs Q-26%; ns) when compared to the Q group.

CONCLUSION

1--Despite a lower severity of non-Q AMI in the acute phase, 28 day and one year total mortality were similar in the two groups. 2--Patients with non-Q AMI showed a higher incidence of recurrent ischemic events at one year follow-up.

Clinical evaluation of a polyacid-modified resin used as a fissure sealant: 48-month results

PURPOSE

To evaluate the incidence of occlusal caries and the rates of retention using Variglass VLC (polyacid-modified resin) as an occlusal sealant.

MATERIALS AND METHODS

The sample consisted of 185 school children (6-8 yr-old), with sound unsealed permanent first molars. Sealants were applied on the upper and lower first molars from a randomly chosen hemiarch (N=370 teeth). The follow-up was conducted at 6, 12 and 48 months examining 343 (93%), 290 (78%) and 187 (51%) teeth, respectively.

RESULTS

After 48 months, total retention of the material was noted in only 5% of the teeth. The presence of sealant in 2/3 and 1/3 of the pit extension was verified in 8% and 14% of the teeth, respectively, while 73% of the sealed teeth had no sealant present on the occlusal surface. Caries incidence, measured by the presence of dental caries and restorations, was 16% representing an annual increase of 4%.

Thrombolytic therapy impact on prognosis after twelve months of first acute myocardial infarction

INTRODUCTION AND OBJECTIVES

Thrombolytic therapy is still widely used to restore antegrade flow in the infarct related artery (IRA), with unquestionable benefits in mortality reduction of such patients. The aim of this study was to evaluate early (< or = 28 days) and one-year mortality of patients with a first Q wave myocardial infarction (Q AMI), comparing those who underwent thrombolytic therapy with those who did not.

POPULATION AND METHODS

A retrospective study was done on 907 patients (median age: 35 +/- 13 years, 66% male) admitted to a Coronary Unit with the diagnosis of first Q AMI, from January 1988 to December 1997, all in the same geographical area (minimum follow-up period of one year, mean follow-up 43 +/- 37 months). We compared demographics and clinical characteristics (coronary risk factors, previous history of angina, MI location and evolution, cardiac events, 28 day and one-year mortality) of patients who underwent thrombolysis (group T = 355) versus those who did not undergo reperfusion therapy (group NT = 552).

RESULTS

Of these patients 39% underwent thrombolytic therapy. Group NT had a greater number of female patients (40% vs 25%; p < 0.001), a significantly higher mean age (67 +/- 12.2 vs 61 +/- 12; p < 0.001), and a higher percentage of diabetics (29% vs 19%; p < 0.001), in comparison to group T. The Q AMI developed into Killip class > or = 2 in 43% of patients in group NT and 23% in group T (p < 0.001). A higher number of AV block (NT-13% vs T-8%; p < 0.05) and higher in-hospital mortality (NT-14% vs T-9%; p < 0.05) was observed in patients not undergoing thrombolysis. The early (NT-22% vs T-12%; p < 0.001) and one-year (NT-33% vs T-16%; p < 0.001) mortalities were significantly higher in group NT than in group T, even after multivariate analysis.

CONCLUSIONS

1--Patients who did not undergo thrombolytic therapy initially had a profile of greater severity, and a higher early and one-year mortality rate. 2--Those who underwent thrombolytic therapy presented a significantly lower mortality, a benefit that was still observed after one year of follow-up and after multivariate correction.

Angiotensinogen and angiotensin converting enzyme gene polymorphisms and the risk of bipolar affective disorder in humans

A possible participation of the renin-angiotensin system (RAS) components with mood disturbances has been suggested in both animal and pharmacological models. In this cross-sectional study, we examined the association between functional polymorphisms in the angiotensin converting enzyme (ACE) and angiotensinogen (AGT) genes in 115 bipolar affective disorder (BPAD) patients and 323healthy control subjects. The ACE I/D variant did not show any difference in allelic frequencies and genotypic distribution between the groups. In contrast, when studying the AGT M235T polymorphism we found that the M allele was more frequently observed in BPAD patients than in controls (chi(2)=6.766, d.f.=1, P=0.009). Using multivariate logistic models the strongest odds ratio resulted from a dominant genetic model (OR=3.0; CI (95%) 1.7-5.3] Our data suggest an association between the AGT M235 genotype and increased susceptibility for BPAD in these Brazilian patients. These findings are consistent with the hypothesis that the RAS system plays a role in regulating the mood

A single consultation cerebrovascular disease clinic is cost effective in the management of transient ischaemic attack and minor stroke

AIM

We examined the cost effectiveness of a single consultation strategy to manage patients referred with TIA or stroke to our cerebrovascular disease (CVD) clinic, where all relevant investigations (blood tests, CT brain scan and carotid Dopplers) were obtained prior to the clinic appointment.

DESIGN

Retrospective study of patients referred to the CVD clinic at St George's Hospital, London between October 1995 and 1996.

RESULTS

Of 211 new patients seen in the clinic, 73% had CVD; 146 (68%) patients had imaging studies prior to clinic attendance. Of these, 132 (90%) were managed with a single consultation. This strategy cost 5,700 Pounds less than if these patients had been followed up.

CONCLUSION

Performing all relevant investigations prior to clinic attendance allowed a fully informed discussion with the patient at a single consultation and was cost effective.

The influence of dietary nucleotides and long-chain polyunsaturated fatty acids on the incorporation of [3H] arachidonic acid on experimental liver cirrhosis

The purposes of this study were to determine: a) the incorporation of labeled [3H] arachidonic acid on the intestinal mucosa, the liver and plasma, after 1,3 and 5 hours of administration, b) preferential incorporation by different tissues, c) and the effects on experimental rats with thioacetamide-induced cirrhosis, after four weeks of a dietary supplementation with nucleotides and long-chain polyunsaturated fatty acids. 209 female Wistar rats were divided into two groups (control and TAA group). The TAA group was given 300 mg of thioacetamide/L, in their drinking water for four months. After this period, a sample of 6 rats were taken from each group and examined, to evaluate the biochemical and histological changes of the experimental model, and 36 rats were taken to determine the incorporation of radioactivity by the groups. The rest of the animals were divided into four subgroups. Each group, receiving a supplementary diet with only long-chain polyunsaturated fatty acids and/or nucleotides or neither, for 4 weeks. After four months of thioacetamide, the incorporation of the [3H] arachidonic acid showed: a) an increased within 3 h in the intestinal mucosa, b) a decreased in the liver after 3 to 5 h c) and a drastic decrease in the plasma after 3 to 5 h. With a dietary supplementation of long-chain polyunsaturated fatty acids and nucleotides combined, there was a decrease of accumulate [3H] arachidonic acid in the intestine and a increase in the liver and plasma. The simultaneous supply of dietary polyunsaturated fatty acids and nucleotides was beneficial in the reversal of abnormalities of the lipid metabolism, in this experimental model of liver cirrhosis.

Analysis of three dental fluorosis indexes used in epidemiologic trials

The objective of this paper was to compare the DEAN, T-F and TSIF dental fluorosis indexes in relation to prevalence of surfaces, teeth and locality, and to verify the statistical correlation among them. The sample consisted of 461 schoolchildren, ages 12-14 years, born and reared in 3 cities in the State of São Paulo from 2 years of age. A total of 153 were from Cesário Lange with a fluoride concentration in the water supply of 1.4 ppm F, 142 from Piracicaba (0.7 ppm F) and 166 from Iracemápolis (< 0.3 ppm F). The clinical examination was conducted after tooth brushing, using a plane mirror, artificial light and air drying of the teeth for 1 min. Premolars, second molars, and occlusal surfaces were the most severely affected. The three indexes showed similar percentages of children affected in the 3 three cities: 32.7%, 16.9% and 4.2% for the DEAN index, 33.3%, 17.6% and 4.2% for the T-F index and 32.7%, 16.9% and 4.2% for the TSIF index. There were no difficulties in using the three indexes in the field trials; thus the use of any one may be recommended in regions with similar fluoride concentrations to those of this study.

[Iatrogeny in cardiology]

The word iatrogeny derives from the Greek and concerns any disorder caused to the patient by inaproppriate medical practice. Unfortunately, the rise of an iatrogenic disease is related to the daily handline of cardiac disease. There are two types of iatrogeny: that caused by a medical action and omission iatrogeny, caused by the lack of a medical action. Iatrogeny occurs in all steps of medical practice starting with the patient-doctor relationship including diagnosis treatment and finally prevention of diseases. This article makes a brief commentary about iatrogenic heart disease and mentions some examples of it.

The role of HLA antigens in the development of paracoccidioidomycosis

BACKGROUND

Paracoccidioidomycosis is a systemic granulomatous disease that involves primarily the lungs and may disseminate to other organs and systems. It is caused by Paracoccidioides brasiliensis, a fungus that exhibits reversible thermal dimorphism and whose natural habitat is presently unknown. There are two main clinical forms: the acute (subacute) juvenile form and the chronic adult form. The former runs a more rapid course and is more severe than the latter. This mycosis is found throughout Latin America. Brazil accounts for 80% of reported cases. Presumably P. brasiliensis thrives in humid and hot places, especially near forests or farms. The infection is endemic in certain areas, especially in Brazil, Colombia and Venezuela, where nearly 100% of the population show cutaneous paracoccidioidina positive skin tests, indicating previous contact with the fungus, although a small percentage show clinical manifestations of the disease.

METHODS

We compared the expression of HLA class I antigens in a healthy group (control) and in a group of patients with paracoccidioidomycosis (chronic adult form) using the Terasaki lymphocytotoxicity test modified by Amos for HLA antigen analysis.

AIMS

To discover indications of whether or not individual susceptibility to P. brasiliensis might depend on some specific immunological defect.

RESULTS

There is no evidence of association between a specific HLA antigen and paracoccidioidomycosis in the subjects studied. Further investigations are recommended.

Vascular oxidant stress early after balloon injury: evidence for increased NAD(P)H oxidoreductase activity

Available evidence for oxidative stress after angioplasty is indirect or ambiguous. We sought to characterize the pattern, time course, and possible sources of free radical generation early after arterial balloon injury. Ex vivo injury performed in arterial rings in buffer with lucigenin yielded a massive oxygen-dependent peak of luminescence that decayed exponentially and was proportional to the degree of injury. Signals for injured vs. control arteries were 207. 1 +/- 17.9 (n = 13) vs 4.1 +/- 0.7 (n = 22) cpm x 10(3)/mg/min (p <. 001). Data obtained with 0.25 mmol/l lucigenin were validated with 0. 005-0.05 mmol/l lucigenin or the novel superoxide-sensitive probe coelenterazine (5 micromol/l). Gentle removal of endothelium prior to injury scarcely affected the amount of luminescence. Lucigenin signals were amplified 5- to 20-fold by exogenous NAD(P)H, and were >85% inhibited by diphenyliodonium (DPI, a flavoenzyme inhibitor). Antagonists of several other potential free radical sources, including xanthine oxidase, nitric oxide synthase, and mitochondrial electron transport, were without effect. Overdistension of intact rabbit iliac arteries in vivo (n = 7) induced 72% fall in intracellular reduced glutathione and 68% increase in oxidized glutathione, so that GSH/GSSG ratio changed from 7.93 +/- 2.14 to 0. 81 +/- 0.16 (p <.005). There was also 28.7% loss of the glutathione pool. Further studies were performed with electron paramagnetic resonance spectroscopy. Rabbit aortas submitted to ex vivo overdistension in the presence of the spin trap DEPMPO (5-diethoxy-phosphoryl-5-methyl-1-pyrroline-N-oxide, 100 mmol/l, n = 5) showed formation of radical adduct spectra, abolished by DPI or superoxide dismutase. Computer simulation indicated a mixture of hydroxyl and carbon-centered radical adducts, likely due to decay of superoxide adduct. Electrical mobility shift assays for NF-kappaB activation were performed in nuclear protein extracts from intact or previously injured rabbit aortas. Balloon injury induced early NF-kappaB activation, which was decreased by DPI. In conclusion, our data show unambiguously that arterial injury induces an immediate profound vascular oxidative stress. Such redox imbalance is likely accounted for by activation of vessel wall NAD(P)H oxidoreductase(s), generating radical species potentially involved in tissue repair.

Dental caries and fluorosis prevalence study in a nonfluoridated Brazilian community: trend analysis and toothpaste association

The main purpose of this study is to compare data from previous surveys to current prevalence rates of dental caries and dental fluorosis in eleven- and twelve-year-olds in a non-fluoridated Brazilian community (< 0.2 ppm F). This study also assesses the possible association between use of fluoride toothpaste and the prevalence of dental caries and dental fluorosis. The sample subjects are randomly selected schoolchildren who were examined with a dental probe and buccal mirror under natural light. The intra-examiner error was calculated, using Kappa statistics (K tau 0.85). The results showed that between 1991 and 1997 there was a 56.7 percent decrease in the prevalence of dental caries and an 80.1 percent increase in dental fluorosis. Children with dental fluorosis were 1.75 times more likely to be free of caries (OR = 1.75-CI:0.43, 6.68). Children who started using fluoride toothpaste before the age of three were 4.43 times more likely to have dental fluorosis than those who started using it after the age of three (OR = 4.43-CI:0.51, 99.61). The results of the cross-sectional surveys conducted with schoolchildren in 1991, 1995, and 1997 suggest a continuing decrease in the prevalence of dental caries and an increase in the prevalence of dental fluorosis in this nonfluoridated Brazilian town.

Cost-effectiveness study of a school-based sealant program

A nonprofit private dental clinic provides free dental treatment for children up to the age of eighteen years. In order to expand its services to reach more children, a school-based sealant program using dental auxiliary personnel was organized. This paper evaluated the performance of the school-based program during 1991 by comparing the costs of the school-based program with the costs of the sealants placed in the clinic in twelve months. Costs were calculated based on 1991 expenditures, and effectiveness rates were estimated from dental literature on sealants. The cost of saving one tooth-surface from decaying within a six-year period at the school and the clinic was $65 and $42 with an average sealing time per tooth surface of 18 and 12.5 minutes, respectively. Despite the relatively lower cost of personnel, the school program cost was 35 percent higher than at the clinic. Nevertheless, if hidden costs, such as transportation, time off work, and waiting time for those attending the clinic were considered, costs could be comparable or even higher for the clinic. The main goal of this paper is to explore a methodology to compare programs of different nature, and critically evaluate the results.

Cloning and characterization of a putative human d-2-hydroxyacid dehydrogenase in chromosome 9q

There is little information on d-isomer-specific dehydrogenases in humans. Identification of d-2-hydroxyglutaric aciduria, an inherited metabolic disorder associated with severe neurological dysfunction, highlights the role of d-isomers in human metabolism. The possibility of a defect in d-2-hydroxyglutarate dehydrogenation prompted us to employ E. coli d-2-hydroxyacid dehydrogenase cDNA to search the human expressed sequence tags database. Two human EST homologues were retrieved and sequenced. Analysis showed the two clones were identical with 1258 nucleotides encoding 248 amino acids of the putative human d-2-hydroxyacid dehydrogenase. It was highly homologous to bacterial d-2-hydroxyacid dehydrogenases (46%), d-phosphoglycerate dehydrogenase (38%), and formate dehydrogenase (36%) at the amino acid level. The gene is expressed ubiquitously in tissue, most abundantly in liver, and was mapped to chromosome 9q between markers WI-3028 and WI-93330. To our knowledge this is the first cloning and characterization of the cDNA for a human d-isomer specific NAD(+)-dependent 2-hydroxyacid dehydrogenase.

Aspirin or heparin in acute stroke

Acute stroke treatment using aspirin and/or heparin was studied in the International Stroke Trial (IST) and Chinese Acute Stroke Trial (CAST) which randomised over 40,000 patients altogether. Combining the results demonstrated that aspirin (150-300 mg) given within 48 h of the onset of stroke produced a small but significant improvement in outcome (death or dependency) 4 weeks to 6 months after stroke of about 1 patient per 100 treated. There was a significant reduction in recurrent ischaemic stroke of similar degree, which was not associated with significant increase in cerebral haemorrhage. Therefore, aspirin should be used as early secondary prevention against recurrent stroke, after excluding cerebral haemorrhage by scanning the patient. Heparin does not improve clinical outcome after stroke even in patients in atrial fibrillation. It decreased recurrent ischaemic stroke significantly in IST, but at the cost of a significant increase in cerebral haemorrhage. Low molecular weight heparins and heparinoids have not proved any more beneficial. Therefore, heparin does not appear to be a useful routine therapy in acute stroke. The use of heparin should, therefore, be limited to patients at high risk of deep vein thrombosis or early recurrence.