Migraine associated cerebral hyperperfusion with arterial spin-labeled MR imaging

We present a case series demonstrating abnormal regional cerebral hyperperfusion associated with migraine headache using arterial spin-labeling (ASL). In 3 of 11 patients, regional cortical hyperperfusion was demonstrated during a headache episode that corresponded to previous aura symptoms.

Arterial spin-labeling in routine clinical practice, part 3: hyperperfusion patterns

Arterial spin-labeled (ASL) perfusion imaging can be implemented successfully into a routine clinical neuroimaging protocol and can accurately demonstrate alterations in brain perfusion. We have observed patterns of focal, regional, and global hyperperfusion in a wide variety of disease processes. The causes of hyperperfusion at clinical ASL have not been previously characterized. Focal lesions such as brain tumors and vascular malformations with increased perfusion can be well depicted by ASL. More global causes of hyperperfusion, including postanoxia vasodilation and hypercapnia, may go undetected on conventional MR images, whereas the regional hyperperfusion, which may occur in reversible encephalopathies and luxury perfusion, has been consistently illustrated on ASL cerebral blood flow maps at our institution.

A novel gene-samfR involved in early stage of Streptomyces ansochromogenes differentiation

A 4.6 kb DNA fragment was cloned from the DNA library of Streptomyces ansochromogenes using a partial DNA fragment located in the downstream of promoter-P(TH4) as probe. The experiments revealed that this DNA fragment consists of saw D gene and a 1.4 kb Pvu II fragment which can accelerate mycelium formation o fS. ansochromogenes. The nucleotide sequence of 1.4 kb DNA fragment was determined and analysed; the result indicated that the fragment contains one complete open reading frame (ORF) which encodes a protein with 213 amino acids, and this gene was designated as samfR. The deduced protein has 36% amino acid identities and 52% amino acid similarities in comparison with that encoded by hppR gene, which is involved in the regulation of catabolism for 3-(3-hydroxyphenyl) propionate (3HPP) in Rhodococcus globerulus. The function of samfR gene was studied using strategy of gene disruption, and the resulting samfR mutant failed to form aerial hyphae and spores, its development and differentiation stopped at the stage of substrate mycelium in contrast with wild type strain. The results showed that the samfR gene is closely related to S. ansochromogenes differentiation.

Structure and function of sawB, a gene involved in differentiation of Streptomyces ansochromogenes

A partial DNA library of Streptomyces ansochromogenes 7100 was constructed by using plasmid pl J702 as vector and white mutant W19 as recipient. About 3 000 clones were obtained, two of which gave rise to the grey phenotype as wild type 7100. The plasmids were isolated from two transformants. The result indicated that the 5.2 kb and 5.8 kb DNA fragments were inserted into plJ702. The resulting recombinant plasmids were designated as pNL-1 and pNL-2 respectively. The 1.25 kb Pstl I -Apa I DNA fragment from pNL-1 was recognized as its complementarity to W19 strain. The nucleotide sequence of the 3.0 kb Pst I DNA fragment including 1.25 kb was determined and analyzed. The result indicated that this DNA fragment contains one complete open reading frame (ORF1) which encodes a protein with 295 amino acid residues, and this gene was designated as sawB. The deduced protein has 81% amino acid identities in comparison with that encoded by whiH in Streptomyces coelicolor. The function of sawB gene was studied by using strategy of gene disruption, and the resulting sawB mutant failed to form spores and produced loosely coiled aerial hyphal. The result showed that sawB is closely related to hyphal coiling and sporulation in S. ansochromogenes, and also indicated that the sawB can complement whiH mutant (C119) to restore the grey phenotype of Streptomyces coelicolor J 1501 (wild type).

Anoxic injury-associated cerebral hyperperfusion identified with arterial spin-labeled MR imaging

BACKGROUND AND PURPOSE

Anoxic brain injury is a devastating result of prolonged hypoxia. The goal of this study was to use arterial spin-labeling (ASL) to characterize the perfusion patterns encountered after anoxic injury to the brain.

MATERIALS AND METHODS

Sixteen patients with a history of anoxic or hypoxic-ischemic injury ranging in age from 1.5 to 78.0 years (mean, 50.3 years) were analyzed with conventional MR imaging and pulsed ASL 1.0-13.0 days (mean, 4.6 days) after anoxic insult. The cerebral perfusion in each case was quantified by using pulsed ASL as part of the standard stroke protocol. Correlation was made among perfusion imaging, conventional imaging, clinical history, laboratory values, and outcome.

RESULTS

Fifteen of the 16 patients showed marked global hyperperfusion, and 1 patient showed unilateral marked hyperperfusion. Mean gray matter (GM) cerebral blood flow (CBF) in these patients was 142.6 mL/100 g of tissue per minute (ranging from 79.9 to 204.4 mL/100 g of tissue per minute). Global GM CBF was significantly higher in anoxic injury subjects, compared with age-matched control groups with and without infarction (F(2,39) = 63.11; P < .001). Three patients had global hyperperfusion sparing areas of acute infarction. Conventional imaging showed characteristic restricted diffusion in the basal ganglia (n = 10) and cortex (n = 13). Most patients examined died (n = 12), with only 4 patients surviving at the 4-month follow-up.

CONCLUSION

Pulsed ASL can dramatically demonstrate and quantify the severity of the cerebral hyperperfusion after a global anoxic injury. The global hyperperfusion probably results from loss of autoregulation of cerebral vascular resistance.

Glandular tularemia: Uncommon presentation of the cause of lymphadenopathy in two children

This report details the clinical and histopathological characteristics and course of glandular tularemia, an uncommon but significant cause of cervical lymphadenopathy in two children. Tularemia should be considered in the differential diagnosis of cases with non-tuberculosis, suppurative cervical lymphadenopathy, particularly in those not responding to penicillin treatment.

Arterial spin-labeling in routine clinical practice, part 1: technique and artifacts

The routine use of arterial spin-labeling (ASL) in a clinical population has led to the depiction of diverse brain pathologic features. Unique challenges in the acquisition, postprocessing, and analysis of cerebral blood flow (CBF) maps are encountered in such a population, and high-quality ASL CBF maps can be generated consistently with attention to quality control and with the use of a dedicated postprocessing pipeline. Familiarity with commonly encountered artifacts can help avoid pitfalls in the interpretation of CBF maps. The purpose of this review was to describe our experience with a heterogeneous collection of ASL perfusion cases with an emphasis on methodology and common artifacts encountered with the technique. In a period of 1 year, more than 3000 pulsed ASL cases were performed as a component of routine clinical brain MR evaluation at both 1.5 and 3T. These ASL studies were analyzed with respect to overall image quality and patterns of perfusion on final gray-scale DICOM images and color Joint Photographic Experts Group (JPEG) CBF maps, and common artifacts and their impact on final image quality were categorized.

Arterial spin-labeling in routine clinical practice, part 2: hypoperfusion patterns

Arterial spin-labeling (ASL) is a powerful perfusion imaging technique capable of quickly demonstrating both hypo- and hyperperfusion on a global or localized scale in a wide range of disease states. Knowledge of pathophysiologic changes in blood flow and common artifacts inherent to the sequence allows accurate interpretation of ASL when performed as part of a routine clinical imaging protocol. Patterns of hypoperfusion encountered during routine application of ASL perfusion imaging in a large clinical population have not been described. The objective of this review article is to illustrate our experience with a heterogeneous collection of ASL perfusion cases and describe patterns of hypoperfusion. During a period of 1 year, more than 3000 pulsed ASL procedures were performed as a component of routine clinical brain MR imaging evaluation at both 1.5 and 3T. These images were reviewed with respect to image quality and patterns of hypoperfusion in various normal and disease states.

Association between heat-shock protein 70 gene polymorphisms and DNA damage in peripheral blood lymphocytes among coke-oven workers

Hsp70 has been shown to act as a chaperone and be associated with cytoprotection against DNA damage caused by environmental stresses. However, it is unknown whether genetic variation in HSP70 plays a role in stress tolerance and cytoprotection against DNA damage. We determined the frequencies of three polymorphisms, HSP70-1 G190C, HSP70-2 G1267A, and HSP70-hom T2437C from 251 steel-plant workers exposed to coke-oven emission and 130 controls. We estimated the association between the HSP70variants/haplotypes and the levels of DNA damage in their peripheral blood lymphocytes detected by single-cell gel electrophoresis assay. Our results showed that overall coke-oven workers had higher levels of the Olive tail moment (Olive TM) (1.27+/-1.12) than that of the controls (0.56+/-0.99, P<0.001). Coke-oven workers with the HSP70-1 C/C genotype had higher levels of Olive TM (2.19+/-0.65), compared with HSP70-1 G/C and G/G carriers (Olive TM=1.34+/-1.09 and 1.14+/-1.08, respectively, P=0.022 and 0.003, respectively). However, the HSP70-2 G1267A and HSP70-hom T2437C polymorphisms were not associated with the levels of Olive TM (P=0.929 and 0.795, respectively). Haplotype analysis showed that carriers of TCG/TCG haplotype pairs had the highest levels of Olive TM among both the exposed subjects (2.04+/-0.59) and the controls (0.81+/-0.59). Our results suggest that the individuals with the homozygous HSP70-1 C/C genotype among the coke-oven workers may be susceptible to DNA damage.

253. Toxic effects of hyperglycaemia arise from induced O-linked glycosylation in early mouse embryos

Glucose flux through the hexosamine biosynthetic pathway (HBP) which is essential for preimplantation development (1) produces uridine 5′-diphospho-N-acetylglucosamine, a donor substrate for multiple glycosylation reactions including O-linked glycosylation. This novel signalling arm of the HBP, known as the hexosamine signalling pathway (HSP) operates via reversible addition of an O-linked β-N-acetylglucosamine (O-GlcNAc) unit to serine and threonine residues of proteins including transcription factors, cytoskeletal components, metabolic enzymes and cellular signalling components. O-linked glycosylation is functionally reciprocal to phosphorylation at the same residues, altering the activity and/or stability of targeted proteins, thus providing a mechanism for modulating cellular physiology in response to glucose availability. The enzymes regulating this O-GlcNAcylation are the β-linked-O-GlcNAc transferase (OGT) and an O-GlcNAc-selective β-N-acetylglucosaminidase (O-GlcNAcase). We hypothesised that the toxicity of hyperglycemia on early embryos arises from increased flux through HBP and increased O-GlcNAcylation of key proteins. Mouse zygotes (18 h post hCG) were cultured under conditions of modified flux through the HSP including hypoglycemia, hyperglycemia or supplemented with glucosamine which feeds exclusively into the HBP to increase downstream O-GlcNAcylation. BADGP was used to inhibit OGT and O-GlcNAcylation. Blastocyst formation, cell proliferation and apoptosis were assessed. Treatments that perturb levels of intracellular protein O-GlcNAcylation inhibited embryo development. Whilst some flux through HBP is required to activate embryonic differentiation (1), excess flux arising from a hyperglycemic environment or glucosamine supplementation reduced cell proliferation and blastocyst formation, confirming the criticality of this novel post-translational signalling pathway. Inhibition of OGT using 2 mM BADGP blocked the negative impact of hyperglycemia on blastocyst formation, cell number and apoptosis supporting our hypothesis that O-GlcNAcylation is a key mechanism used by the embryo to sense and respond to perturbations of glucose in its environment. (1) Pantaleon M, Scott J and Kaye PL (2008) Biol Reprod, 78(4):595–600

Mutation analysis in a family with oculocutaneous albinism manifesting in the same generation of three branches

PURPOSE

To elucidate the molecular basis of oculocutaneous albinism with variable expressivity in a family from The Netherlands in which no consanguinity was reported.

METHODS

Three affected family members were screened for mutations in tyrosinase (TYR) and the pink-eye-dilution gene (P) by using SSCP. The melanocortin receptor gene (MC1R) and amplimers of P showing an aberrant banding pattern in SSCP were analyzed by direct sequencing. All participants underwent ophthalmologic examination including funduscopy, and visually evoked potentials were recorded in two cases.

RESULTS

The pedigree had three branches A, B, and C. We identified three mutations in P (V443I, N476S, C793F) that cause a compound heterozygous situation in cases from branch A (N476S/C793F) and B (V443I/C793F), who showed oculocutaneous albinism. Hair and skin color followed the light Nordic complexion that was also present in other affected and unaffected members of this family. Descendants of branches A and B showed light complexion with iris translucency and peripheral fundus hypopigmentation independent from the genotype identified. A single descendant had red hair, carrying a well known compound MC1R mutation combination for red hair color and a single heterozygous P mutation.

CONCLUSIONS

P mutations underlie oculocutaneous albinism in this family. Two known mutations in MC1R caused red hair color in one family member. No modifier effect of MC1R on P mutations could be deduced from the results of this study.

Evaluation of formocresol versus ferric sulphate primary molar pulpotomy: a systematic review and meta-analysis

AIM

To present a systematic review of the effects of formocresol and ferric sulphate when used as medicaments in pulpotomized primary molar teeth.

METHODOLOGY

The study list was obtained by using MEDLINE, the Cochrane Library, EMBASE and SCI search. Only those papers which met the inclusion criteria were accepted. The quality of studies used for meta-analysis was assessed by a series of validity criteria according to Jadad's scale. A systematic review and meta-analysis were performed.

RESULTS

Eleven clinical studies comprising four randomized-clinical trials (RCTs), four controlled clinical trials (CCTs) and three retrospective studies were included. The results of the meta-analysis of six prospective clinical trials suggested that the two popular pulpotomy medicaments were not significantly different in terms of clinical outcomes, radiographic findings, prevalence of apical and furcal destruction, internal root resorption or pulp canal obliteration. The relative risk (RR) value and 95% CI for those parameters were 0.72 (0.43-1.23), 0.87 (0.59-1.30), 0.67 (0.27-1.66), 1.77 (0.56-5.58) and 1.41 (0.63-3.15), respectively. The overall clinical and radiographic success rates based on the data of treatments with ferric sulphate from the 11 studies included ranged from 78% to 100% (mean 91.6 +/- 8.15%) and from 42% to 97% (mean 73.5 +/- 18.40%), respectively.

CONCLUSIONS

In primary molar teeth with exposure of vital pulps by caries or trauma, pulpotomies performed with either formocresol or ferric sulphate have similar clinical and radiographic success. Ferric sulphate may be recommended as a suitable replacement for formocresol.

Comparison of the Levitan FPS Scope and the single-use bougie for simulated difficult intubation in anaesthetised patients

A randomised cross-over study was performed in 34 patients with no evidence of airway difficulties, following induction of general anaesthesia, to compare the efficacy of the Levitan FPS scope (LFPS) and the single-use bougie for tracheal intubation during simulated grade IIIa laryngoscopy. Success rates for intratracheal placement of the device, and the time required for insertion and tracheal intubation were recorded. Both devices were equally successful (31/34 for the LFPS vs 29/34 for the bougie) for insertion into the glottis. The mean insertion time for the LFPS was statistically longer than that for the bougie (4.4-12.5 s) but this difference was not clinically relevant. Intubation times were similar between the two devices. Major problems hindering successful intubation using the LFPS were the presence of a narrow epiglottic-pharyngeal wall space and copious secretions. An inability to maintain the desired shape was the principal cause of failure with the bougie.

Antisense integrin alphaV and beta3 gene therapy suppresses subcutaneously implanted hepatocellular carcinomas

BACKGROUND

Integrin alphaVbeta3 plays a critical role in tumour angiogenesis and metastasis formation, and is recognized as a key therapeutic target in the treatment of cancer.

AIM

To investigate whether antisense alphaV and beta3 gene therapy has utility in the treatment of hepatocellular carcinomas.

METHODS

Antisense expression plasmids targeting integrin alphaV or beta3 were constructed, and examined by immunohistochemistry and Western blot analyses for their ability to inhibit alphaV and beta3 expression. The antisense alphaV and beta3 expression vectors, either alone or in combination, were injected into HepG2 hepatomas established subcutaneously in nude mice and tumour growth, angiogenesis and apoptosis were monitored.

RESULTS

Antisense alphaV and beta3 downregulated the alphaV and beta3 subunits expressed by human umbilical vein endothelial cells, and the alphaV subunit expressed by HepG2 cells. Gene transfer of antisense alphaV and beta3 expression vectors downregulated alphaV and beta3 in HepG2 tumours established in nude mice, inhibited tumour vascularization and growth, and enhanced tumour cell apoptosis. Antisense alphaV suppressed tumour growth more strongly than antisense beta3; however antisense therapy that simultaneously targeted both integrin subunits was more effective than the respective monotherapies. Antisense alphaV and beta3 inhibited tumour angiogenesis to similar extents, by a process that is independent of vascular endothelial growth factor.

CONCLUSIONS

Antisense gene therapy targeting alphaV integrins warrants consideration as an approach to treat hepatocellular carcinomas.

Electrical properties of neurons in the intact rat major pelvic ganglion

The aim of this investigation was to characterize the electrical properties of neurons in the rat major pelvic ganglia (MPG) using intracellular recording techniques. MPG were dissected from male rats euthanized by isoflurane and thoracotomy. Neurons were classified as "phasic" or "tonic" according to their rate of accommodation during a 500-ms depolarizing current pulse. Phasic cells were further subdivided into rapidly or slowly adapting. The firing pattern of tonic cells was divided into regular high frequency, low frequency or irregular firing. In tonic cells, onset spikes showed TTX-resistant discharges; whereas sustained spikes were TTX sensitive. Changing the current pulse amplitude or the stimulation interval could alter the firing pattern in both types of neurons. Subthreshold membrane potential oscillations (SMPOs) were primarily observed when neurons were depolarized. SMPOs were Na(+) dependent and TTX sensitive. The majority of tonic and phasic neurons generated rebound spikes, most of which were partially Na(+) dependent. A small percentage (<6%) of neurons exhibited spontaneous activity. Taken together these findings are consistent with the concept that neurons in the MPG exhibit heterogeneous electrical properties.

Taurine transporter is expressed in vascular smooth muscle cells

The regulation of vascular smooth muscle cells (VSMCs) function by taurine has been a subject of increasing interest and investigation, and taurine is taken up into cells through a specific transporter system, the taurine transporter (TAUT). In the present study, we examined the expression of TAUT in VSMCs and the kinetic parameters of the uptake process of TAUT in VSMCs. RT-PCR and western blot demonstrated that the mRNA and protein of TAUT was expressed in VSMCs in vitro. Immunohistochemistry using antibody for TAUT revealed the expression of this protein in rat thoracic aorta. The maximal [(3)H]taurine uptake rate in VSMCs was 37.75 +/- 3.13 pmol/min per mg of protein, with a K ( m ) value of 5.42 +/- 0.81 microM. Thus, VSMCs are able to express a functional taurine transporter. The regulation and detailed function of taurine and TAUT in VSMCs remain unclear, but our findings suggest a functional role for them in VSMCs metabolism.

Cardiovascular risk factors and anthropometric measurements of adolescent body composition: a cross-sectional analysis of the Third National Health and Nutrition Examination Survey

OBJECTIVE

To assess the association between certain cardiovascular risk factors that are commonly clustered among individuals with insulin resistance syndrome (IRS) and adolescents' body composition measurements.

METHODS

We examined a total of 1068 adolescents aged 12-16 years from the Third National Health and Nutrition Examination Survey. The sex-specific third tertiles of glucose, triglycerides, systolic blood pressure and first tertile of high-density-lipoprotein (HDL) cholesterol were used to classify the presence of each IRS component. We compared adolescents with none, one, two and three/four IRS components across a series of body composition measurements and lipid profile.

RESULTS

About 18% of the adolescents had three or four IRS components. Overall, IRS among adolescents is more likely to be associated with body weight and measurements related to body girths and less likely to be associated with the measurements related to body lengths. Multivariate analysis results showed that the odds of being at increased risk of obesity (body mass index z-score> 0.85) were significantly greater among those with two (odds ratio (OR)=4.5; 95% CI 2.5-8.2) and three/four (OR=8.9, 95% CI 4.5-17.5) IRS components compared to those without any IRS components. Across sex, the level of non-HDL cholesterol was significantly higher among adolescents with more IRS components (P for trends <0.05).

CONCLUSIONS

The clustered cardiovascular risk factors are strongly associated with an increased risk of obesity and higher levels of non-HDL cholesterol among adolescents.

Debriefing after critical incidents for anaesthetic trainees

This survey investigated the need, and the availability, of debriefing after critical incidents for training anaesthetists. A cross-sectional postal survey of all Australian anaesthetic trainees was conducted in May 2002. Four hundred and nineteen responses were analysed (response rate 64%). Debriefing after a critical incident was perceived by most trainees to be useful, however 36% (n = 149) had never been debriefed. Trainees ranked their preferred content for a debriefing as 'anaesthetic issues' followed by the 'psychological impact of the incident' 'patient issues' and 'surgical issues'. Almost half of respondents reported that they did not feel supported by their anaesthetic department after a negative outcome incident. Trainees who had debriefings were more likely to feel supported by senior colleagues. Debriefing after critical incidents should be an integral part of the supervision of anaesthetic trainees.

Isolation and characterization of endophytic Streptomyces strains from surface-sterilized tomato (Lycopersicon esculentum) roots

AIMS

To isolate endophytic Streptomyces strains from tomato and examine their antimicrobial activity.

METHODS

Endophytic Streptomyces strains were isolated using surface-sterilization methods and identified by morphological characteristics. Antimicrobial activities were measured by the agar plate sensitivity method. Antifungal activity in vivo was measured by seedling mortality in infested soils.

RESULTS

Twenty-one per cent of endophytic streptomycete isolates produced antibacterial metabolites and 41% produced antifungal metabolites in S medium. Sixty-five per cent of the most frequently isolated strains inhibited the growth of Rhizoctonia solani by the antibiosis assay but only 32% produced metabolites active against R. solani in S medium. Growth promotion and enhanced disease resistance of seedlings inoculated with Streptomyces sp. strain S30 were observed in tomato but not in cucumber seedlings.

CONCLUSIONS

Endophytic Streptomyces spp. strains were successfully isolated using stringent methods and strain S30 promoted growth and enhanced resistance to R. solani in tomato seedlings.

SIGNIFICANCE AND IMPACT OF THE STUDY

Endophytic streptomycetes showing antifungal activity in vitro and in vivo may indicate the potential for their use as biocontrol agents particularly of R. solani disease of tomato seedlings.

Thrombolytic therapy with tissue plasminogen activator for superior vena cava thrombosis in an infant with sepsis

Superior vena cava syndrome is rare in infants, and rarely responds to conservative treatment. We report a 22-mo-old girl with superior vena cava syndrome due to the use of a central venous line and/or sepsis. Doppler study and computed tomography angiography of the neck showed thrombosis within the superior vena cava and jugular veins. She was admitted to a monitored setting and received recombinant tissue plasminogen activator for 2 d. The clinical features of superior vena cava syndrome disappeared completely 3 d after treatment. No complications were observed and radiological investigations showed blood flow through the thrombus after treatment. Systemic recombinant tissue plasminogen activator may be useful in the treatment of superior vena cava syndrome in children.

A whistling face syndrome case with bilateral skin dimples

The whistling face syndrome (Freeman-Sheldon Syndrome) is a rare disorder characterized by typical face and limb abnormalities. A wide range of clinical findings have been reported. We report unusual skin dimples in a sporadic case with the whistling face syndrome.

Clostridium difficile colitis in patients after kidney and pancreas-kidney transplantation

Limited data exist about Clostridium difficile colitis (CDC) in solid organ transplant patients. Between 1/1/99 and 12/31/02, 600 kidney and 102 pancreas-kidney allograft recipients were transplanted. Thirty-nine (5.5%) of these patients had CDC on the basis of clinical and laboratory findings. Of these 39 patients, 35 have information available for review. CDC developed at a median of 30 days after transplantation, and the patients undergoing pancreas-kidney transplantation had a slightly higher incidence of CDC than recipients of kidney alone (7.8% vs. 4.5%, P>0.05). All but one patient presented with diarrhea. Twenty-four patients (64.9%) were diagnosed in the hospital, and CDC occurred during first hospitalization in 14 patients (40%). Treatment was with oral metronidazole (M) in 33 patients (94%) and M+oral vancomycin (M+V) in 2 patients. Eight patients had recurrent CDC, which occurred at a median of 30 days (range 15-314) after the first episode. Two patients (5.7%) developed fulminant CDC, presented with toxic megacolon, and underwent colectomy. One of them died; the other patient survived after colectomy. CDC should be considered as a diagnosis in transplant patients with history of diarrhea after antibiotic use, and should be treated aggressively before the infection becomes complicated.

One to one, one to two, two to one? What is the rhythm?

Images

Cloning and characterization of sanO, a gene involved in nikkomycin biosynthesis in Streptomyces ansochromogenes

AIMS

To clone and characterize sanO, a gene involved in the biosynthesis of nikkomycins in Streptomyces ansochromogenes.

METHODS AND RESULTS

A 4.5-kb BamHI-KpnI fragment was cloned and sequenced. Sequence analysis revealed that this fragment contains three complete open reading frames. The largest one with 2034 bp was designated sanO, which encodes a protein consisting of 667 amino acids with high similarity to module of peptide synthetase. sanO disruption mutants produced no nikkomycin X, but formed nikkomycin Z at almost the same level of the wild-type strain. The production of nikkomycin X can be recovered by genetic complementation of sanO disruption mutants. Primer extension also revealed that transcription start point(tsp) of sanO was localized 87 bp upstream of the potential start codon (GTG).

CONCLUSIONS

sanO was essential for the biosynthesis of nikkomycin X.

SIGNIFICANCE AND IMPACT OF THE STUDY

Nikkomycins have received increased interest of study because of their prospective application in agriculture and medicine. Cloning and characterization of genes involved in the nikkomycin biosynthesis will help to elucidate the whole biosynthetic pathway of nikkomycins.

Acute disseminated encephalomyelitis in children: outcome and prognosis

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) is the most common demyelinating disorder of childhood. Its clinical features, prognosis and treatment vary in different reports.

OBJECTIVES

To examine a series of children with ADEM for clinical findings, course, recurrences, and possible variables affecting outcome.

METHODS

Multicentric data collected from 7 tertiary referral centers were registered and evaluated in a central database in 1990 - 2001 for clinical, laboratory, and MRI features. Course and prognosis were assessed in patients with at least 12 months' follow-up.

RESULTS

Forty-six patients were evaluated. Median age at onset was 8 years, M/F ratio, 1.7/1. Most common symptoms and signs pertained to the motor system and consciousness. Of 39 children with 12 months' follow-up, 71 % recovered completely. Thirteen (33 %) children had relapses. Patients who had more than one relapse (n = 4) presented with new symptoms at each attack. Treatment with high-dose methylprednisolone was associated with complete recovery, and tapering over more than 3 weeks, with a lower rate of relapses. MRI lesions could persist even in asymptomatic patients; in particular, periventricular lesions tended to disappear later than others.

CONCLUSIONS

Complete clinical recovery is common and serious complications are rare in childhood ADEM, but the rate of relapses is considerable. Clinical picture at first relapse may help to identify patients likely to experience multiple relapses. The timing and duration of steroid treatment affects outcome.

Lipids and coronary heart disease in Asia

In Western countries, it has been shown that coronary heart disease (CHD) is related to high serum total cholesterol (TC) levels. In less developed continents such as Asia and Africa, serum lipid levels are low and CHD incidence is much lower as compared with Western countries. With growing urbanization and industrialization in Asia, it has been shown that there is a concomitant rise in the level of serum TC and with it a rise in CHD. In all the Asian countries, serum TC levels are also higher in the urban compared with the rural population. Singapore, the only Asian country which is 100% urbanized since 1980, showed a rise of serum TC similar to that seen in the US and UK from the 1950s to the 1980s followed thereafter by a fall. This is reflected in the trend (rise followed by a fall) of CHD morbidity and mortality as well. In spite of a declining trend in serum TC level, CHD morbidity and mortality are still high in Singapore and comparable to the Western countries. The rest of the Asian countries show a different pattern from Singapore. In general, there is still a rising trend in serum TC level and in CHD mortality in most Asian countries. However, Japan is considered an exception in having a decreasing CHD mortality in spite of an increasing trend in serum TC. This may be attributed to a better control of other CHD risk factors such as hypertension and smoking. The rising trend in serum TC level remains a cause for concern, as this will emerge as a major problem for CHD morbidity and mortality in the future.

sanC--a novel gene involved in nikkomycin biosynthesis in Streptomyces ansochromogenes

AIMS

To investigate the genes involved in the nikkomycin biosynthesis and their molecular mechanism.

METHODS AND RESULTS

A 0.9 kbp SmaI fragment was cloned and sequenced which contains a complete open reading frame designated sanC (GenBank accession no. AF228522). In search of database, the deduced product of sanC was not homologous with any known proteins. The disruption and complementation of sanC showed that sanC is essential for nikkomycin biosynthesis in Streptomyces ansochromogenes.

CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY

sanC is a novel and essential gene involved in nikkomycin biosynthesis in S. ansochromogenes.

Phase I clinical and pharmacologic study of chronic oral administration of the farnesyl protein transferase inhibitor R115777 in advanced cancer

PURPOSE

To determine the maximum-tolerated dose, toxicities, and pharmacokinetics of R115777, a farnesyl transferase inhibitor, when administered continuously via the oral route.

PATIENTS AND METHODS

Patients with advanced solid malignancies were treated with R115777 using an interpatient dose escalation scheme starting at 50 mg bid. Pharmacokinetics were assessed on days 1, 28, and 56.

RESULTS

Twenty-eight patients were entered onto the study and the median duration of treatment was 55 days. The dose-limiting toxicities were myelosuppression and neurotoxicity. At a dose of 400 mg bid, grade 4 leukocytopenia and neutropenia were seen in two of four patients. Neurotoxicity grade 3 developed in one of five patients at 500 mg bid and in one of 13 at 300 mg bid after 8 weeks of treatment. Common nonhematologic toxicities were nausea, vomiting, and fatigue. The recommended dose for phase II/III testing in this scheme is 300 mg bid. The pharmacokinetic studies indicated dose proportionality. Little accumulation occurred and steady-state levels were reached within 2 to 3 days. Analyses of historic tumor material showed that five of 15 of patients had a K-ras mutation in codon 12. Three patients with pancreatic, colon, and cervix carcinomas had stable disease and one patient with a colon carcinoma had a minor response accompanied by a more than 50% decrease in carcinoembryonic antigen tumor marker. A fifth patient, with platinum-refractory non-small-cell lung cancer, showed a partial response that lasted for 5 months.

CONCLUSION

Continuous dosing of R115777 is feasible with an acceptable toxicity profile at a dose of 300 mg bid.

Treatment of murine breast cancer cells with antisense RNA to the type I insulin-like growth factor receptor decreases the level of plasminogen activator transcripts, inhibits cell growth in vitro, and reduces tumorigenesis in vivo

AIMS

To establish that cells from the murine mammary carcinoma cell line, EMT6, express type I insulin-like growth factor receptor (IGF-IR), tissue-type plasminogen activator (tPA), and urokinase-type plasminogen activator (uPA). To investigate the role of IGF-IR in growth, transformation, and tumorigenesis in addition to its relation to tPA and uPA in EMT6 cells. To assess the suitability of the EMT6/syngeneic mouse model for studying the role of IGF-IR in tumorigenesis.

METHODS

The presence of transcripts for IGF-IR, tPA, and uPA was determined by northern blot analysis using poly (A(+)) RNA derived from EMT6 cells transfected with an antisense IGF-IR construct or a construct lacking the antisense IGF-IR insert. Flow cytometry was used to measure IGF-IR protein. Assays were performed to determine cell proliferation, transformation, and the tumorigenicity of antisense IGF-IR transfected EMT6 cells and control transfected EMT6 cells.

RESULTS

There was strong expression of IGF-IR, tPA, and uPA in EMT6 cells. EMT6 cells from clones carrying antisense IGF-IR displayed a significant decrease in cell proliferation and lost the ability to form colonies in soft agar. A decrease in tumour size occurred when cells carrying the antisense IGF-IR were injected into syngeneic mice. Reduced expression of tPA and uPA was seen in EMT6 cells carrying the antisense IGF-IR construct.

CONCLUSIONS

The IGF-IR plays a role in the progression, transformation, and tumorigenesis of EMT6 murine mammary carcinoma cells. The suppression of IGF-IR mRNA in EMT6 cells decreases tPA and uPA expression. EMT6 cells and the syngeneic mouse provide a suitable model for studying the role of IGF-IR in breast tumour progression.

Application of disposable plastic microfluidic device arrays with customized chemistries to multiplexed biochemical assays

Plastic microfluidic array platforms and synergistic multiplexed assay chemistries are under development for a variety of applications, including assays of gene expression, proteomics, genotyping, DNA sequencing and fragment analysis, sample preparation and high-throughput pharmaceutical discovery. The low production costs of plastic substrates makes possible economical single-use device arrays, eliminating cleaning and sample-to-sample carryover contamination. Hundreds of microchannels and reservoirs are readily included on a single microtitre-plate-size substrate, enabling the manufacture of highly parallel fluidic array systems to increase throughput and speed.