Neonatal screening for glutaric aciduria type I: strategies to proceed

Acute encephalopathic crisis in glutaric aciduria type I results in an unfavourable disease course and poor outcome, dominated by dystonia, feeding problems, seizures and reduced life expectancy. A conditio sine qua non for the prevention of irreversible brain damage is timely diagnosis and start of therapy, i.e. before the onset of neurological disease. As there are no specific clinical signs or symptoms that allow a reliable detection of these patients before the manifestation of encephalopathic crises, neonatal screening programmes for glutaric aciduria type I have been established in some countries using analysis of glutarylcarnitine in dried blood spots by tandem mass spectrometry. This article summarizes recent strategies, pitfalls and shortcomings of mass screening for glutaric aciduria type I, focusing on the relevant risk of missing patients with a mild biochemical phenotype (i.e. low excretors). Furthermore, it evaluates a binary strategy--using glutarylcarnitine as primary variable and glutarylcarnitine/acylcarnitine ratios as secondary variable--to improve the diagnostic sensitivity and specificity of neonatal screening for glutaric aciduria type I. An optimization of diagnostic as well as therapeutic procedures must be achieved before screening for glutaric aciduria type I can be regarded as reliable and beneficial for all patients.

Cell viability effects of triamcinolone acetonide and preservative vehicle formulations

AIM

To assess the effect of triamcinolone acetonide and preservative vehicle formulations on human retinal pigment epithelium (ARPE19) cells over a range of concentrations.

METHODS

Triamcinolone acetonide, in its trade and preservative free formulations, along with the preservative vehicle were added to ARPE19 cell cultures in various concentrations (0.01-1.0 mg/ml). Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at day 5 after exposure. Functionality of the cultured ARPE19 cell line was confirmed by exposure to a previously characterised toxic agent, tamoxifen.

RESULTS

The ARPE19 cell line behaved as predicted with exposure to tamoxifen. All formulations caused significant reductions in ARPE19 cell viability at the highest concentrations (1.0 mg/ml for triamcinolone preparations and undiluted vehicle). Cell viability was reduced to the greatest degree in trade formulation triamcinolone, less so by the vehicle, and least by preservative free triamcinolone. At lower concentrations no significant effect on cell viability was observed, although cell viability was found to be inversely proportional to increasing concentration of all tested reagents

CONCLUSIONS

Both the trade and preservative free formulations of triamcinolone acetonide as well as the vehicle result in cell loss at in vitro concentrations of 1 mg/ml. Although this represents theoretical vitreous concentrations achieved with current widespread therapeutic use it probably does not indicate the actual exposure of cells in their biological milieu. That cell viability was reduced most in the trade formulation suggests a possible potentiated inhibitory toxic effect of triamcinolone acetonide and vehicle at higher concentrations.

Giving them a good start: informatics support of newborn screening and clinical care

Newborns are a vulnerable population: Exposed to dramatically changing environmental conditions, potentially suffering from impairments that cannot realistically be diagnosed during pregnancy, with the risk that unfavorable conditions escalate fast. We have investigated informatics methods and tools to make screening for congenital diseases and containment of critical processes that start in the first days safer and more efficient. This poster present a set of three different methodological approaches that all aim at comprehensive improvement of neonatal care.

High-dose vitamin E supplementation does not diminish ribavirin-associated haemolysis in hepatitis C treatment with combination standard alpha-interferon and ribavirin

BACKGROUND

Ribavirin is associated with haemolytic anaemia. Antioxidants have been reported to decrease severity of this anaemia.

AIM

To determine effect of vitamin E supplementation on ribavirin-associated haemolysis in chronic hepatitis C treated with standard alpha-interferon and ribavirin.

METHODS

Fifty-one naive chronic hepatitis C patients were randomized to receive either alpha-interferon/ribavirin therapy (control) or therapy plus vitamin E 800 IU b.d. with 24-week follow-up. Alanine aminotransferase ALT, haemoglobin and reticulocyte percentage were monitored. Symptoms and health-related quality of life were also monitored at each visit.

RESULTS

Forty-seven subjects were treated (27 vitamin E /20 controls). Thirteen withdrew because of adverse effects or non-compliance. Groups were similar in demographics, genotype and baseline lab indices. Comparison with baseline, treatment and follow-up values showed a significant haemoglobin and ALT reduction in both groups. There was no significant difference in haemoglobin and reticulocyte percentage between groups. Sustained viral response was not significantly different between vitamin E (11/18) and control (6/16) groups. Three patients required ribavirin dose-reduction in the vitamin E group compared with two controls. Health-related quality of life during and end-of-treatment was not different between groups.

CONCLUSIONS

Vitamin E supplementation alone during standard alpha-interferon and ribavirin therapy does not appear to diminish ribavirin-associated haemolysis.

Eclampsia, hippocampal sclerosis, and temporal lobe epilepsy: Accident or association?

BACKGROUND

Up to 30% of patients with temporal lobe epilepsy (TLE) have no identifiable risk factors.

OBJECTIVE

S: To report nine patients with TLE who had a history of eclampsia as the only risk factor for epilepsy and to investigate whether this possible association existed in a larger cohort of women with surgically treated TLE.

METHODS

The clinical data, video-EEG, neuroimaging, and neuropathology of 195 consecutive women undergoing anterior temporal lobectomy (ATL) were reviewed. Risk factors for TLE, age at epilepsy onset, and occurrence of pregnancy were identified in each patient.

RESULTS

Twenty-six women had no identifiable risk factors or seizures following a pregnancy. Nine of the 26 women had a history of eclampsia. The median age at the time of eclampsia was 16 years, and the latent period between the occurrence of eclampsia and onset of epilepsy ranged from 1 month to 2 years. The clinical, EEG, MRI, and neuropathologic findings were typical of hippocampal sclerosis (HS) and other than age at onset were no different from those of noneclampsia ATL patients. At mean follow-up of 57 months, seven patients were seizure-free and the other two markedly improved.

CONCLUSION

Eclampsia may be a risk factor for TLE and HS.

Extended experience in the use of laparoscopic ultrasound to detect pelvic nodal metastasis in patients with cervical carcinoma

OBJECTIVE

To evaluate the use of laparoscopic ultrasound (USG) to detect pelvic nodal metastasis in patients with early stage cervical carcinoma.

METHODS

Laparoscopic USG was used to search for pelvic lymph node metastasis in stage Ia2 to IIa cervical carcinoma patients before radical hysterectomy. Suspicious lymph nodes identified by laparoscopic USG were removed laparoscopically for pathological confirmation by frozen section. If nodal metastasis was diagnosed, radical hysterectomy would be cancelled but enlarged lymph nodes were removed preferably by laparoscopic approach before closing the abdomen. These patients were treated with radiotherapy after recovering from the surgery. By comparing the laparoscopic USG and pathological findings of lymph nodes removed with or without radical hysterectomy, diagnostic accuracy of laparoscopic USG was determined.

RESULTS

Ninety-three patients were recruited and the final analysis included 90 patients. Laparoscopic USG found suspicious lymph nodes in 17 patients and nodal metastases were confirmed pathologically in 14 of them. Three patients with macroscopic and five patients with microscopic pelvic nodal metastases were missed by laparoscopic USG. The accuracy, sensitivity, specificity, positive and negative predictive value of laparoscopic USG in detecting pelvic lymph node metastasis were 87.8%, 63.6%, 95.6%, 82.4%, and 89%, respectively. Macroscopic metastatic nodes were successfully removed laparoscopically in 11 out of 14 patients and laparotomy was required for the other three patients.

CONCLUSIONS

Laparoscopic USG can be performed with no major morbidity. This technique is sensitive in detecting macroscopic but not microscopic metastatic pelvic lymph nodes. Removal of macroscopic metastatic nodes identified via laparoscopic USG via laparoscopic approach could be accomplished in majority of patients.

Causes and outcomes of mild traumatic brain injury: an analysis of CIREN data

Approximately one-half of vehicle occupants with traumatic brain injury (TBI) have a mild TBI (admission Glasgow Coma Scale (GCS) score of 13-15 with transient loss of consciousness). However, despite the label of "mild", many of these injuries result in long-term consequences; frequently these sequelae go unrecognized, as the patients are lost to medical follow-up. The Crash Injury Research Engineering Network (CIREN) project affords us the opportunity to examine the crash circumstances, injury sources and outcomes of mild TBI cases in greater detail.

Prevalence of wheeze, bronchial hyper-responsiveness and asthma in the elderly Chinese

BACKGROUND

Asthma is a common health problem affecting patients of all ages. Because of the ease of sampling, epidemiological studies have concentrated mainly on the paediatric and general population.

OBJECTIVE

This study aimed to determine the prevalence of wheeze, bronchial hyper-responsiveness and asthma amongst our elderly population and deduce any clinical and laboratory risk factors that might identify elderly asthmatics at an earlier stage.

METHODS

Two thousand and thirty-two elderly Chinese aged > or = 70 years, randomly selected from a registered list of all recipients of Old Age and Disability Allowances in Hong Kong, were administered a questionnaire on lung health. Two hundred and fifty subjects were invited to attend our laboratory for skin tests and pulmonary function tests and 179 agreed. Of these, 173 (96.6%) and 176 (98.3%) had eosinophil count and serum IgE levels measured, respectively. Two definitions of asthma were used: (1) bronchial hyper-responsiveness (BHR) plus current wheeze, and (2) history of wheezing without previous diagnostic labels of emphysema or chronic bronchitis.

RESULTS

Fifteen patients (out of 179: 8.4%) reported wheezing over the past 1 year. Fifty-one patients (28.5%) demonstrated BHR on spirometry or histamine challenge tests. Seven patients had both symptoms of wheezing and evidence of BHR. The prevalence of asthma using this definition is therefore 3.9% (95% CI 1.6-7.9%). Nine patients had symptoms of wheezing without previous diagnostic labels of chronic bronchitis or emphysema and, using this definition, the prevalence is 5.0% (95% CI 2.3-9.3%). Using multiple logistic regression studies, sex, social class, age, smoking habits, serum IgE levels and eosinophil counts did not predict a diagnosis of asthma using either definition. We found no association between a positive skin test and any respiratory symptoms or illnesses including asthma.

CONCLUSION

Wheeze, bronchial hyper-responsiveness and asthma are prevalent amongst our elderly population. However, there were no identifiable demographic and laboratory risk factors in this study that may help us predict a diagnosis of asthma.

Modulation of cerebral GABA by topiramate, lamotrigine, and gabapentin in healthy adults

BACKGROUND

Anticonvulsant drugs have multiple mechanisms of action. Recent in vivo MRS studies suggest that cerebral gamma-aminobutyric acid (GABA) increases occur with the administration of certain anticonvulsants in humans.

OBJECTIVE

To investigate the effect of topiramate, gabapentin, and lamotrigine on cerebral GABA concentrations in healthy volunteers and correlate the GABA concentrations with serum drug levels.

METHODS

Seventeen healthy adults were randomly assigned to receive topiramate, gabapentin, and lamotrigine and underwent GABA measurements using a 4.1-T magnet from a 13.5-mL volume over the occipital region. GABA concentrations and serum levels were measured at 3 and 6 hours following administration of an acute single dose of one of the drugs. Thereafter, drugs were titrated over 4 weeks to target doses, with GABA measurements performed at 2 and 4 weeks.

RESULTS

Cerebral GABA concentrations rose 70% in the acute phase compared with baseline for topiramate. GABA rose 48% at 6 hours with gabapentin but not with lamotrigine. With long-term dosing and once target doses were achieved at 4 weeks, significant elevations in GABA were observed compared with baseline for all three drugs (topiramate 46%, gabapentin 25%, lamotrigine 25%).

CONCLUSION

This study demonstrates that single doses of topiramate and gabapentin increase cerebral GABA concentrations acutely (hours) in healthy individuals, but all drugs at clinically utilized doses increase cerebral GABA at 4 weeks. These results suggest that the mechanisms of action of anticonvulsant drugs are more complex and are likely to be multiple in nature.

Effect of light on 5-methoxyindole-3-acetic acid in the rat

This study aims to determine the effects of light on the levels of 5-MIAA to provide further information on this indoleamine, using a sensitive and specific radioimmunoassay (RIA) for immunoreactive 5-methoxyindole-3-acetic acid (5-MIAA) developed in our laboratories using a specific antibody and tritiated label. Significant differences were found in the immunoreactive 5-MIAA levels between mid-light and mid-dark pineal glands in rats adapted to 12/12 hrs light/dark and in constant darkness. Under constant light, the circadian rhythm was abolished. The rat serum displayed no diurnal variations in 5-MIAA levels under aux photic conditions. The persistence of rhythms found in constant darkness but abolished in constant light suggests that the pineal 5-MIAA is endogenous and uses light as an environmental cue. In addition to melatonin, 5-MIAA could possibly be another pineal photoperiodic signal in animals.

The DNA sequence and comparative analysis of human chromosome 20

The finished sequence of human chromosome 20 comprises 59,187,298 base pairs (bp) and represents 99.4% of the euchromatic DNA. A single contig of 26 megabases (Mb) spans the entire short arm, and five contigs separated by gaps totalling 320 kb span the long arm of this metacentric chromosome. An additional 234,339 bp of sequence has been determined within the pericentromeric region of the long arm. We annotated 727 genes and 168 pseudogenes in the sequence. About 64% of these genes have a 5' and a 3' untranslated region and a complete open reading frame. Comparative analysis of the sequence of chromosome 20 to whole-genome shotgun-sequence data of two other vertebrates, the mouse Mus musculus and the puffer fish Tetraodon nigroviridis, provides an independent measure of the efficiency of gene annotation, and indicates that this analysis may account for more than 95% of all coding exons and almost all genes.

Admission angiography for blunt splenic injury: advantages and pitfalls

BACKGROUND

To analyze the use of admission angiography as a nonoperative adjunct for management of blunt splenic injury.

METHODS

Retrospective chart review of all blunt splenic injuries to a Level I trauma center from March 1997 through July 1999.

RESULTS

One hundred twenty-six patients underwent angiography for splenic injury. Eighty-six patients (68%) had a negative angiogram and were treated expectantly. Of these, seven patients (8%) required laparotomy, with a splenic salvage rate of 92%. Embolization was performed on 40 patients (32%) for evidence of vascular injury. Of these, three patients (8%) required laparotomy, for a total salvage of 92%. Repeat angiography was performed for suspicion of bleeding in 12 patients (10%), with 50% requiring embolization. Outcome based on CT grade demonstrated an average grade of 2.9, with a salvage rate of greater than 70% for grade IV and V injuries.

CONCLUSION

Vascular injury increases with splenic injury grade. Embolization improves nonoperative salvage rates to 92%, even with high-grade injuries. Ten percent of patients require additional therapy including "second-look" angiography. A significant portion of patients with negative screening angiograms (10%) required either embolization or laparotomy to control delayed hemorrhage.

Melatonin protects against cardiac toxicity of doxorubicin in rat

Doxorubicin (DOX) is commonly used for the treatment of hematological and solid tumors. However, there are serious toxic effects on the cardiovascular system, which limits the application of the drug. Recently, melatonin has been reported to have immunomodulatory effect in addition to lowering cholesterol levels as well as inhibiting malignant tumors. In this study, the effect of melatonin against the toxicity of doxorubicin was investigated in rats. Hemodynamic function, pathological and biochemical changes were determined in different treated hearts. Our findings showed that a significant protection by melatonin (6 mg kg(-1) for 15 days, cumulative dose of 90 mg kg(-1)) against the DOX-induced toxicity was observed. Cardiac function was improved and lipid peroxidation decreased after melatonin treatment. It is concluded that melatonin provides protection against doxorubicin toxicity via an attenuation of lipid peroxidation.

HLA class II alleles in Chinese patients with hepatocellular carcinoma

BACKGROUND/AIMS

Recent reports of an association between human leucocyte antigens (HLA) and persistence of hepatitis B virus infection, and the familial clustering of hepatocellular carcinoma raise the question of genetic susceptibility. Previous studies have been limited to serological phenotyping of HLA B and DR antigens. The aim of this study was to use molecular genotyping to investigate HLA class II as a risk factor for the development of hepatocellular carcinoma in Hong Kong Chinese.

METHODS

We determined HLA DRB1, DQA1, DQB1 and DPB1 alleles in 123 hepatitis B surface antigen positive patients (84 with hepatocellular carcinoma and 39 without) and 124 matched controls.

RESULTS

The alleles DRB1*1501 (36% of HCC patients versus 19% of controls, odds ratio=2.44), DQA1*0102 (42% versus 26%, odds ratio=2.07), and DPB1*0501 (80% versus 63%, odds ratio=2.35) were significantly more common in patients with hepatocellular carcinoma, and DQA1*03 (36% versus 56%, odds ratio=0.53), DQB1*0302 (4.% versus 13%, odds ratio=0.25) and DPB1*0201 (14% versus 29%, odds ratio=0.4) were found at significantly lower frequencies.

CONCLUSIONS

Although none of these associations was significant after correction for multiple testing, this report suggests that further investigations are warranted.

What determines survival duration in hepatocellular carcinoma treated with intraarterial Yttrium-90 microspheres?

BACKGROUND/AIMS

The survival duration of patients with nonresectable hepatocellular carcinoma confined to the liver and treated with intraarterial yttrium-90 microspheres was highly variable.

METHODOLOGY

Eighty-two patients treated by this method were analyzed. Thirty-one patients who lived for one year or longer from the date of first treatment were classified as 'long survivors' and 51 patients who died within 1 year were classified as 'short survivors'.

RESULTS

Comparison between the 2 categories suggested that lower pretreatment level of alpha-fetoprotein and higher tumor-to-normal uptake ratio of yttrium-90 microspheres favored longer survival. Results also indicated that the treatment was effective even for large tumors and for postoperative recurrence. Repeated treatment of viable residual or recurrent tumors offered further palliation and prolongation of survival.

CONCLUSIONS

Pretreatment alpha-fetoprotein level, tumor-to-normal uptake ratio of yttrium-90 microspheres and the number of treatments determine survival duration.

Factors critical to the design and execution of epidemiologic studies and description of an innovative technology to follow the progression from normal to cancer tissue

The results obtained from experimental studies of estrogen carcinogenesis need validation in epidemiologic studies. Such studies present additional challenges, however, because variations in human populations are much greater than those in experimental systems and in animal models. Because epidemiologic studies are often used to evaluate modest differences in risk factors, it is essential to minimize sources of errors and to maximize sensitivity, reproducibility, and specificity. In the first part of this chapter, critical factors in designing and executing epidemiologic studies, as well as the influence of sample collection, processing, and storage on data reliability, are discussed. One of the most important requirements is attaining sufficient statistical power to assess small genetic effects and to evaluate interactions between genetic and environmental factors. The second part of this chapter describes innovative technology, namely, Fourier transform-infrared (FT-IR) spectra of DNA that reveal major structural differences at various stages of the progression from normal to cancer tissue. The structural differences become evident from wavenumber-by-wavenumber statistical comparisons of the mean FT-IR spectra of DNA from normal to cancer tissues. This analysis has allowed distinguishing benign tissues from cancer and metastatic tissues in human breast, prostate, and ovarian cancers. This analysis, which requires less than 1 microg of DNA, is predicted to be used for detecting early cancer-related changes at the level of DNA, rather than at the cellular level.

Sugar coordinately and differentially regulates growth- and stress-related gene expression via a complex signal transduction network and multiple control mechanisms

In plants, sugars are required to sustain growth and regulate gene expression. A large set of genes are either up- or down-regulated by sugars; however, whether there is a common mechanism and signal transduction pathway for differential and coordinated sugar regulation remain unclear. In the present study, the rice (Oryza sativa cv Tainan 5) cell culture was used as a model system to address this question. Sucrose and glucose both played dual functions in gene regulation as exemplified by the up-regulation of growth-related genes and down-regulation of stress-related genes. Sugar coordinately but differentially activated or repressed gene expression, and nuclear run-on transcription and mRNA half-life analyses revealed regulation of both the transcription rate and mRNA stability. Although coordinately regulated by sugars, these growth- and stress-related genes were up-regulated or down-regulated through hexokinase-dependent and/or hexokinase-independent pathways. We also found that the sugar signal transduction pathway may overlap the glycolytic pathway for gene repression. alpha-Amylase and the stress-related genes identified in this study were coordinately expressed under sugar starvation, suggesting a convergence of the nutritional and environmental stress signal transduction pathways. Together, our studies provide a new insight into the complex signal transduction network and mechanisms of sugar regulation of growth and stress-related genes in plants.

The human anti-bullous pemphigoid monoclonal autoantibody P22 is encoded by genes of the IGHV4 and IGLV4 families

We identified, cloned, and biochemically characterized the full-length cDNAs encoding the heavy and light chains of a human monoclonal antibody (mAb) from the Epstein-Barr virus (EBV)-cell line P22. The cell line P22, which originated from a patient with bullous pemphigoid (an autoimmune disease causing skin blistering) expressed immunoglobulin-G (IgG) with a lambda light chain. Although the variable heavy (IGHV) chain gene family could not be assigned by IGHV repertoire analysis, the determination of its nucleotide sequence demonstrated that the heavy chain of P22 belonged to the IGHV4 family. The limited IGHV4 gene usage by memory IgG, IGA and IgE-expressing cells supports the notion of the autoreactivity-associated IGHV4 genes and stresses the strong selection pressure within germinal centres towards IGHV4 family. Alignment of P22 IGHV4 cDNA sequence to germline sequences from gene databases, revealed a remarkable divergence, suggesting that the heavy chain of the P22 mAb encodes a distinct IGHV4 gene. The variable light chain (IGLV) encodes a IGLV4 gene and is 98% similar to a previously reported IGLV gene. Furthermore, fluorescent staining with the recombinant mAb showed the same reactivity to that of the native antibody. The data reported herein, (a) reveal an autoantibody encoding a distinct IGHV4 gene, (b) confirm the notion that autoantibodies preferentially use IGHV4 genes, and (c) hypothesize that somatic hypermutation within GC may be a mechanism by which autoreactive B lymphocytes escape negative selection.

Immediate response of glenohumeral abduction range of motion to a caudally directed translational mobilization: a fresh cadaver simulation

OBJECTIVE

To investigate the immediate effect of caudal glide translational mobilization on the range of motion (ROM) of passive glenohumeral abduction with a fresh cadaver model to simulate the mobilization movement performed by a physical therapist treating patients with glenohumeral hypomobility.

DESIGN

Mechanical simulation of caudal glide mobilization and abduction torque range of motion (TROM) measurement of the glenohumeral joint with 2 material testing systems. Mobilizations were conducted with the glenohumeral joint positioned at a resting position (IGR) and at the end range of abduction (IGE).

SETTING

Biomechanics laboratory.

CADAVERS

Twenty fresh shoulder specimens from 10 cadavers (mean age, 68 +/- 8 yr).

MAIN OUTCOME MEASURE

Changes in TROM of the glenohumeral abduction in response to 5 bouts of caudal glide mobilization.

RESULTS

At least 3 repetitions of TROM were required to attain consistent measurements on glenohumeral abduction ROM. Significant differences were found among changes in TROM because of rest, IGR, and IGE (Kruskal-Wallis statistics, (chi2 = 14.58, p = .001). A greater increase in glenohumeral abduction TROM was found after IGE (mean +/- standard error of the mean, 4.38 degrees +/- 0.95 degrees) compared with the rest control (0.03 degrees +/- 0.07 degrees; Mann-Whitney test, p = .001, alpha = .017) or its IGR counterpart (0.26 degrees +/- 0.46 degrees, p = .001, alpha = .017).

CONCLUSION

This simulation of caudal glide translational mobilization at the end range using cadaver models improved passive glenohumeral abduction ROM but was ineffective when performed with the shoulder placed in a resting position. The mechanical responses of the glenohumeral joint to translational mobilization in a live patient may be similar, but some caution should be used in generalizing these findings.

Automatic optimization of resting and exercise atrioventricular interval using a peak endocardial acceleration sensor: validation with Doppler echocardiography and direct cardiac output measurements

Peak endocardial acceleration (PEA) measured by an implantable acceleration sensor inside the tip of a pacing lead reflects ventricular filling and myocardial contractility. The contribution of the plateau phase of PEA as an indicator of optimal ventricular filling, hence of the appropriate atrioventricular interval (AVI) at rest and during exercise, was studied in 12 patients (age 69 +/- 6 years) with complete AV block and a PEA sensing DDDR pacemakers (Living 1 Plus, Sorin Biomedica). At a mean resting heart rate of 79 +/- 15 beats/min, the mean AVI optimized by PEA versus Doppler echocardiography (echo) were identical (142 +/- 37 vs 146 +/- 26 ms, P = 0.59). During submaximal exercise at a mean heart rate of 134 +/- 6 beats/min, AVI optimized by PEA was 135 +/- 37 ms. Cardiac output at rest, measured by the CO2 rebreathing method, was comparable with AVI determined by echo versus PEA (4.3 +/- 2.9 and 3.7 +/- 2.4 L/min, respectively), and increased to the same extent (8.0 +/- 3.9 vs 8.3 +/- 5.2 L/min) during submaximal exercise. In patients with AV block, AVI automatically set by PEA was comparable with AVI manually optimized by Doppler echocardiography and was associated with comparable exercise induced hemodynamic changes.

Vegetarianism and ischemic heart disease in older Chinese women

OBJECTIVE

This study compared the risk of ischemic heart disease among older vegetarian Chinese women with that of older non-vegetarian women.

METHODS

90 vegetarian Chinese women over 70 years old in Hong Kong were screened for ischemic heart disease by electrocardiogram (ECG) and cardiovascular questionnaire. They were compared with 90 non-vegetarian women of similar age examined in a previous local survey. The effects of confounding factors were adjusted by stepwise logistic regression analysis.

RESULTS

The percentages of subjects with ischemic heart disease defined by symptoms and ECG or by ECG alone were significantly lower in vegetarian women (p <0.005 and p<0.05 respectively). Vegetarians had lower serum cholesterol levels: more were old age home residents and were less likely to perform regular exercise. On stepwise logistic regression, using probable ischemic heart disease defined by questionnaire and ECG as outcome measure, vegetarianism was the only significant predictor (OR 0.3, 95%CI 0.1-0.6, p<0.005).

CONCLUSIONS

Vegetarian older Chinese women had lower risk of ischemic heart disease when compared with non-vegetarians. Apart from lower serum cholesterol levels, vegetarianism may have other protective factors against ischemic heart disease.

Elevated tumour marker CA19-9: clinical interpretation and influence of obstructive jaundice

AIMS

The tumour marker CA19-9 has been promoted as a reliable test for the detection of pancreatobiliary malignancy, yet its diagnostic role remains poorly defined. In this study the clinical interpretation of a raised serum CA19-9 level has been evaluated, with particular reference to obstructive jaundice.

METHODS

One hundred and sixty-four patients with a CA19-9 level above 33 U/ml were studied. Serum CA19-9 was compared with clinical diagnosis and correlated with serum bilirubin level. In a subgroup of jaundiced patients (16 benign and 15 malignant cases), follow-up CA19-9 levels were determined 2 weeks after biliary drainage.

RESULTS

The median CA19-9 level was lower in benign cases (102 (IQR 50-264) U/ml) than those with pancreatobiliary tumours (910 (IQR 263-6170) U/ml; P<0.01), although the overlap was substantial. In benign jaundiced cases, a positive correlation was observed between bilirubin and CA19-9 elevation (R=0.41, P<0.01). Relief of jaundice was associated with a fall in CA19-9 level in all benign cases and in nine of the 15 with malignancy.

CONCLUSION

Confident discrimination between benign and malignant disease could not be made on the basis of a solitary elevated CA19-9 measurement. Hyperbilirubinaemia was associated with a further deterioration in specificity and caution is warranted when interpreting the results in jaundiced patients. Overall, only one half of patients with an elevated CA19-9 level ultimately proved to harbour a malignancy.

A GDP-fucose-protected, pyridoxal-5'-Phosphate/NaBH(4)-sensitive lys residue common to human alpha1-->3Fucosyltransferases corresponds to Lys(300) in FucT-IV

Human alpha1-->3/4fucosyltransferases (FucTs) contain a common essential pyridoxal-5'-phosphate(PLP)/NaBH(4) reactive, GDP-fucose-protectable Lys. For identification, site-directed mutants at lysines of FucT-IV and -VII were prepared and tested. Non conserved lysine mutants K119Y and K394Q were similar to wild-type FucT-IV. However, mutants of conserved lysines K228R and K300R were distinct. The specific activity of K228R was 2- to 3-fold lower but retained K(m) values for donor and acceptor substrates as wild-type FucT-IV. The specific activity of K300R was reduced over 400-fold with an apparent K(m) for GDP-fucose over 200 microM. FucT-VII mutants K169R and K240R (equivalent to K228R and K300R for FucT-IV, respectively) were inactive. No change in PLP/NaBH(4) sensitivity occurred with K119Y, K228R, and K394Q compared to wild-type FucT-IV. These and previous results (A. L. Sherwood, A. T. Nguyen, J. M. Whitaker, B. A. Macher, M. R. Stroud, and E. H. Holmes, J. Biol. Chem. 273, 25256-25260, 1998) demonstrate that of three conserved lysines in FucT-IV, two (Lys(228) and Lys(283)) are not involved in substrate binding but perhaps in catalysis. The third site, Lys(300), is involved in GDP-fucose binding and PLP/NaBH(4) inactivation.

Impact of a diagnostic cerebrospinal fluid enterovirus polymerase chain reaction test on patient management

CONTEXT

Enterovirus (EV) infection, the most common cause of aseptic meningitis, can be rapidly diagnosed with an EV-specific reverse transcriptase polymerase chain reaction (EV-PCR) test. However, no studies have examined EV-PCR in a clinical context in which it is routinely used.

OBJECTIVE

To determine the impact of EV-PCR testing on diagnosis and clinical management of suspected aseptic meningitis cases.

DESIGN AND SETTING

Retrospective review of electronic medical records from a 220-bed tertiary care pediatric medical center in San Diego, Calif.

PATIENTS

A total of 276 pediatric patients for whom a diagnostic EV-PCR test was performed during the calendar year 1998.

MAIN OUTCOME MEASURES

Clinical parameters such as length of stay, medication use, and ancillary test use.

RESULTS

One hundred thirty-seven patients (49.6%) had a positive cerebrospinal fluid EV-PCR result. Enterovirus-positive patients with results available before hospital discharge (n=95) had significantly fewer ancillary tests performed (26% vs 72% with at least 1 test performed; P<.001), received intravenous antibiotics for less time (median, 2.0 vs 3.5 days; P<.001), and had shorter hospital stays (median, 42 vs 71.5 hours; P<.001) than EV-negative patients (n=92). A positive EV-PCR result was associated with more rapid hospital discharge (median EV-PCR-to-discharge time, 5.2 hours) compared with a negative result (median EV-PCR-to-discharge time, 27.4 hours; P<.001).

CONCLUSIONS

Our results suggest that a positive EV-PCR result may affect clinical decision making and can promote rapid discharge of patients, and that unnecessary diagnostic and therapeutic interventions can be reduced by use of EV-PCR testing. JAMA. 2000;283:2680-2685.

Joint position during anterior-posterior glide mobilization: its effect on glenohumeral abduction range of motion

OBJECTIVE

To investigate the effect of joint position during an anterior-posterior glide (APG) procedure on the range of motion (ROM) of glenohumeral abduction in cadaver specimens.

DESIGN

Mechanical simulation of APG mobilization and abduction torque ROM measurement of the glenohumeral joint with a material testing system. The immediate mechanical efficacy of APG was compared in two groups of specimens at two different joint positions: midrange (n = 5) and end range (n = 6) of glenohumeral abduction.

SETTING

Biomechanics laboratory.

SPECIMENS

Eleven fresh cadaver shoulder specimens (mean age, 66.9+/-2.5 yrs).

MAIN OUTCOME MEASURE

Improvement in glenohumeral abduction torque ROM obtained before and after APG procedure.

RESULTS

Glenohumeral abduction improved significantly, as indicated by a significant increase (Kruskal-Wallis statistics, chi2 = 7.50, p = .006) in the torque ROM of the end range group (mean +/- standard error of the mean, 2.02 degrees +/- .20 degrees) over the midrange group (.64 degrees +/- .08 degrees). A significant difference in the magnitude of peak displacement of the humeral head between midrange (14.44+/-3.56 mm) and end range (3.19+/-.81 mm) groups was also found (Mann-Whitney test, p < .030).

CONCLUSION

This study demonstrated that APG technique performed at close to the end of the range of abduction is more effective in improving glenohumeral abduction ROM than that performed at the middle of the range of abduction.

Mucin gene expression in the rat middle ear: an improved method for RNA harvest

Mucins are heavily glycosylated proteins characterized by high molecular weight and heterogeneous structure. Mucin genes are expressed in a tissue- or epithelium-specific manner. Although mucins are known to be important structural components of the mucociliary transport system that protects epithelium against invading microorganisms, very little is known about mucin gene expression unique to the middle ear. This study demonstrated that middle ear messenger RNA specifically hybridized with rat MUC2 and human MUC2 (SMUC-41) complementary DNA probes. MUC3 and MUC5AC mucin genes, dominantly expressed in rodent intestine and trachea, were not detected in the rat middle ears in this study. The middle ear MUC2 messenger RNA harvested by lavage was characterized by a single transcript--unlike its counterpart in intestine and airways, which is characterized by polydispersity--suggestive of a better method for RNA analysis. It was concluded that rat middle ears possess a MUC2 mucin gene or homologue of human MUC2 (SMUC-41).

Phase II studies with DaunoXome in patients with nonresectable hepatocellular carcinoma: clinical and pharmacokinetic outcomes

A total of 14 Chinese patients with inoperable hepatocellular carcinoma received a liposomal formulation of daunorubicin (DaunoXome) at a dose equivalent to 100 mg/m2 of the free drug every 3 weeks. Altogether, 12 patients were assessable for response; 2 patients had stable disease for 8 weeks, but all eventually developed progressive disease and there was no responder. The drug was well tolerated, with no evidence of cardiac toxicity being observed. Deterioration of liver-function tests was attributed to progressive tumors in the terminal stage of the disease. Pharmacokinetics studies revealed a biexponential decay for daunorubicin in association with mean initial and terminal half-lives of 1.8 and 7.4 h, respectively, and a mean total clearance of 15.0+/-5.5 ml/min. The AUC ratio between the metabolite daunorubicinol and daunorubicin was 0.07. These data differ markedly from the pharmacokinetics of the free drug.

The role of Bcl-2 expression in EGF inhibition of TNF-alpha/IFN-gamma-induced villous trophoblast apoptosis

The inflammatory cytokines tumour necrosis factor alpha (TNF-alpha) and immune interferon gamma (IFN-gamma) stimulate villous cytotrophoblast apoptosis while epidermal growth factor (EGF) protects. We hypothesize that TNF-alpha, IFN-gamma and EGF regulate apoptosis in part by modulating cellular expression levels of the anti-death gene bcl-2. While Bcl-2 is reported to be strongly expressed in villous syncytiotrophoblasts, it is not known whether the protein is expressed in cultured villous cytotrophoblasts (CT) and, if so, whether it is functional. We show by Northern blot analysis that bcl-2 mRNA is expressed in cultured CT and by immunoblot analysis that the protein is strongly expressed in highly purified first trimester and term villous cytotrophoblasts. The expression levels of Bcl-2 protein were the same in first trimester and term cytotrophoblasts. Culture with TNF-alpha/IFN-gamma and EGF did not alter expression of either Bcl-2 protein or of the pro-apoptotic Bcl-2 family member Bak. Double label flow cytometric analysis that measured apoptosis and Bcl-2 content simultaneously showed that cells expressing low levels of Bcl-2 underwent TNF-alpha/IFN-gamma-induced apoptosis at a higher frequency than cells expressing lower levels. We conclude that Bcl-2 is expressed in cytotrophoblasts, that its expression is constitutive and that modulation of its expression levels does not mediate cytokine and growth factor regulation of apoptosis in these cells.

The nature of the principal type 1 interferon-producing cells in human blood

Interferons (IFNs) are the most important cytokines in antiviral immune responses. "Natural IFN-producing cells" (IPCs) in human blood express CD4 and major histocompatibility complex class II proteins, but have not been isolated and further characterized because of their rarity, rapid apoptosis, and lack of lineage markers. Purified IPCs are here shown to be the CD4(+)CD11c- type 2 dendritic cell precursors (pDC2s), which produce 200 to 1000 times more IFN than other blood cells after microbial challenge. pDC2s are thus an effector cell type of the immune system, critical for antiviral and antitumor immune responses.

Intraarticular anterior cruciate ligament graft placement on the average most isometric line on the femur. Does it reproducibly restore knee kinematics?

In the past, there has been a plausible hypothesis that anterior cruciate ligament graft placement at isometric sites, such that the tibial and femoral attachment sites remain equidistant from each other throughout knee range of motion, would increase the likelihood of a satisfactory outcome. For a given tibial placement we wanted to determine whether placing the graft on the average of the most isometric femoral line, a fixed distance from the outlet of the intercondylar notch, would return normal laxity to all knees. The three-dimensional kinematics of seven cadaveric knees were measured for angles from full extension to 90 degrees of flexion at 15 degrees increments. Physiologic levels of quadriceps muscle forces were applied to the intact knee, after transection of the anterior cruciate ligament, and after ligament reconstruction with a patellar tendon graft. On average, the reconstruction was found to return anterior-posterior translation, internal-external rotation, and varus-valgus rotation to levels not significantly different from those of the intact knee. However, the ranges of the translation and rotations were large. Placing the graft on the average most isometric femoral line did not restore knee laxity to normal in all knees. This supports the need to customize graft placement in each knee at the time of surgery.

Activity patterns and synaptic organization of ventrally located interneurons in the embryonic chick spinal cord

To investigate the origin of spontaneous activity in developing spinal networks, we examined the activity patterns and synaptic organization of ventrally located lumbosacral interneurons, including those whose axons project into the ventrolateral funiculus (VLF), in embryonic day 9 (E9)-E12 chick embryos. During spontaneous episodes, rhythmic synaptic potentials were recorded from the VLF and from spinal interneurons that were synchronized, cycle by cycle, with rhythmic ventral root potentials. At the beginning of an episode, ventral root potentials started before the VLF discharge and the firing of individual interneurons. However, pharmacological blockade of recurrent motoneuron collaterals did not prevent or substantially delay interneuron recruitment during spontaneous episodes. The synaptic connections of interneurons were examined by stimulating the VLF and recording the potentials evoked in the ventral roots, in the VLF, or in individual interneurons. Low-intensity stimulation of the VLF evoked a short-latency depolarizing potential in the ventral roots, or in interneurons, that was probably mediated mono- or disynaptically. At higher intensities, long-latency responses were recruited in a highly nonlinear manner, eventually culminating in the activation of an episode. VLF-evoked potentials were reversibly blocked by extracellular Co2+, indicating that they were mediated by chemical synaptic transmission. Collectively, these findings indicate that ventral interneurons are rhythmically active, project to motoneurons, and are likely to be interconnected by recurrent excitatory synaptic connections. This pattern of organization may explain the synchronous activation of spinal neurons and the regenerative activation of spinal networks when provided with a suprathreshold stimulus.

Spontaneous network activity transiently depresses synaptic transmission in the embryonic chick spinal cord

We examined the effects of spontaneous or evoked episodes of rhythmic activity on synaptic transmission in several spinal pathways of embryonic day 9-12 chick embryos. We compared the amplitude of synaptic potentials evoked by stimulation of the ventrolateral funiculus (VLF), the dorsal or ventral roots, before and after episodes of activity. With the exception of the short-latency responses evoked by dorsal root stimulation, the potentials were briefly potentiated and then reduced for several minutes after an episode of rhythmic activity. Their amplitude progressively recovered in the interval between successive episodes. The lack of post-episode depression in the short-latency component of the dorsal root evoked responses is probably attributable to the absence of firing in cut muscle afferents during an episode of activity. The post-episode depression of VLF-evoked potentials was mimicked by prolonged stimulation of the VLF, subthreshold for an episode of activity. By contrast, antidromically induced motoneuron firing and the accompanying calcium entry did not depress VLF-evoked potentials recorded from the stimulated ventral root. In addition, post-episode depression of VLF-evoked synaptic currents was observed in voltage-clamped spinal neurons. Collectively, these findings suggest that somatic postsynaptic activity and calcium entry are not required for the depression. We propose instead that the mechanism may involve a form of long-lasting activity-induced synaptic depression, possibly a combination of transmitter depletion and ligand-induced changes in the postsynaptic current accompanying transmitter release. This activity-dependent depression appears to be an important mechanism underlying the occurrence of spontaneous activity in developing spinal networks.

Cognitive effects of topiramate, gabapentin, and lamotrigine in healthy young adults

OBJECTIVE

To study the acute and steady-state cognitive effects of three new antiepileptic drugs (AEDs): gabapentin, lamotrigine, and topiramate.

BACKGROUND

Several newer antiepileptic medications approved recently by the Food and Drug Administration are gaining attention as efficacious alternatives to established AEDs. Greater tolerability with fewer side effects are reported in some. However, the potential cognitive effects of these newer AEDs have received limited attention.

METHODS

Healthy young adults randomized to either of the three drugs were administered tests of attention, psychomotor speed, language, memory, and mood at baseline (predrug), acute single-dose period, and after 2 and 4 weeks on the drug.

RESULTS

Compared with baseline, the topiramate group had selective, statistically significant declines on measures of attention and word fluency at acute doses, whereas the other two AED groups had no performance changes. At the 2- and 4-week test periods, only the topiramate subjects continued to display neurocognitive effects from drug administration.

CONCLUSIONS

Results demonstrate potential acute and steady-state adverse cognitive effects for topiramate, whereas minimal effects were displayed for either gabapentin or lamotrigine in young healthy adults.

Combating hepatocellular carcinoma with an integrated approach

This short review summarizes an integrated approach to new methods of managing hepatocellular carcinoma (HCC) developed at our centre. HCC-specific isoforms of alpha-fetoprotein were detected by isoelectric focusing and their value in the differential diagnosis of early HCC on a background of chronic liver disease has been shown. Selective internal radiation therapy using yttrium-90 (90 Y) microspheres has been shown to be an effective treatment for inoperable HCC in a phase I and II study. A partition model for estimating the radiation doses from the 90 Y microspheres to the tumour and the non-tumorous liver during the therapy was then formulated, verified by correlating with intraoperative dosimetry, and evaluated in clinical settings. This permits 90 Y microspheres to be administered safely without the need of an open surgery and a randomized therapeutic controlled trial is in progress. Another randomized controlled trial using iodine-131 Lipiodol as a post-operative adjuvant therapy, aiming at reducing the recurrence rate is also on-going. HCC may be more effectively combated with a better understanding of its pathogenesis from chronic liver disease.