Genetic and in silico comparative mapping of the polyphenol oxidase gene in bread wheat (Triticum aestivum L.)

Polyphenol oxidases (PPOs) are involved in the time-dependent darkening and discolouration of Asian noodles and other wheat end products. In this study, a doubled haploid (DH) population derived from Chara (moderately high PPO activity)/WW2449 (low PPO activity) was screened for PPO activity based on L-DOPA and L-tyrosine assays using whole seeds. Both these assays were significantly genetically correlated (r = 0.91) in measuring the PPO activity in this DH population. Quantitative trait loci (QTLs) analysis utilising a skeleton map enabled us to identify a major QTL controlling PPO activity based on L-DOPA and L-tyrosine on the long arm of chromosome 2A. The simple sequence repeat (SSR) marker GWM294b explained over 82% of the line mean phenotypic variation from samples collected in both 2000 and 2003. Four SSR markers were validated for PPO linkage in genetically diverse backgrounds and proven to correctly predict the PPO activity in more than 92% of wheat lines. Physical mapping using deletion lines of Chinese Spring has confirmed the location of the GWM294b, GWM312 and WMC170 on chromosome 2AL, between deletion breakpoints 2AL-C to 0.85. In order to identify functional gene markers, data searches for alignments between rice BAC/PAC clones assembled on chromosome 1 and 4, chromosome 7, and (1) the wheat expressed sequence tags mapped in deletion bin (2AL-C to 0.85) and (2) the coding sequence of a previously cloned wheat PPO gene were made and found significant sequence similarities with the PPO gene or common central domain of tyrosinase. Available PPO gene sequences in the National Centre for Biotechnology Information (NCBI) database have revealed that there is a significant molecular diversity at the nucleotide and amino acid level in the wheat PPO genes.

Double-crush syndrome after acetabular fractures. A sign of poor prognosis

Injury to the sciatic nerve is one of the more serious complications of acetabular fracture and traumatic dislocation of the hip, both in the short and long term. We have reviewed prospectively patients, treated in our unit, for acetabular fractures who had concomitant injury to the sciatic nerve, with the aim of predicting the functional outcome after these injuries. Of 136 patients who underwent stabilisation of acetabular fractures, there were 27 (19.9%) with neurological injury. At initial presentation, 13 patients had a complete foot-drop, ten had weakness of the foot and four had burning pain and altered sensation over the dorsum of the foot. Serial electromyography (EMG) studies were performed and the degree of functional recovery was monitored using the grading system of the Medical Research Council. In nine patients with a foot-drop, there was evidence of a proximal acetabular (sciatic) and a distal knee (neck of fibula) nerve lesion, the double-crush syndrome. At the final follow-up, clinical examination and EMG studies showed full recovery in five of the ten patients with initial muscle weakness, and complete resolution in all four patients with sensory symptoms (burning pain and hyperaesthesia). There was improvement of functional capacity (motor and sensory) in two patients who presented initially with complete foot-drop. In the remaining 11 with foot-drop at presentation, including all nine with the double-crush lesion, there was no improvement in function at a mean follow-up of 4.3 years.

Glomus tympanicum: a report of two cases

Two cases of glomus tympanium tumor of the middle ear stage 'type A' according to Fisch classification, are presented due to their rarity in this part of the world. These tumors were excised by end aural tympanotomy approach and there has been no recurrence in both patients to date.

Oropharyngeal flora changes in patients with head and neck malignancy post radiotherapy

Radiotherapy has been recognized as a valuable modality of treatment in the management of head and neck cancers. It can have a direct bactericidal effect on the normal flora of the oropharynx. The objective of this study is to determine the changes in the oropharyngeal flora after external beam radiation. This prospective non randomized control study was performed to aid in identification of organisms involved in sepsis, as well as aid in choosing appropriate antibiotics for surgical procedures in irradiated patient. Forty patients with various head and neck malignancy and thirty control patients were selected. Oropharyngeal swabs were taken prior to radiotherapy, at the end and one month after radiotherapy. A single swab was taken from the control group. A full bacteriological analysis was performed. There was a statistically significant decrease in Alpha Hemolytic Streptococci and Neisseria species post radiotherapy. B Proteus and Candida Albicans showed a statistical significant increase in patients with head and neck cancer post radiotherapy. These changes remained even one month after radiotherapy.

Actinomyces infection of the mastoid: a rare entity

A rare case of mastoid infection caused by actinomyces israelii is presented. This patient underwent exploratory mastoidectomy followed by long term oral pencillin. She responded well to the treatment and has been asymptomatic on follow up to date.

Nocardia infection of the mastoid in an immunocompromised patient

A rare case of Nocardia infection of mastoid is presented in an immunocompromised patient.

Ocular presentation of sphenoid mucocele

A sphenoid mucocele often presents late due to its deep-seated anatomical site. It has a varied presentation, due to its close relationship to the cavernous sinus and the base of the skull. It can present initially to the ophthalmologist with ocular complaints. In the present paper, the authors present two cases of sphenoid mucocele, one with an isolated third and one with an isolated sixth cranial nerve palsy.

Idiopathic cases of male infertility from a region in India show low incidence of Y-chromosome microdeletion

Chromosomal and Y-chromosomal microdeletion analysis has been done in cases of idiopathic infertility with the objective of evaluating the frequency of chromosomal and molecular anomaly as the causal factor of infertility. Barring a few cases of Klinefelter syndrome (XXY or XY/XXY mosaics), no chromosomal anomaly was encountered. Y-microdeletion was analysed by PCR-screening of STSs from different regions of the AZF (AZFa, AZFb, AZFc) on the long arm of the Y, as well as by using DNA probes of the genes RBM, DAZ (Yq), DAZLA (an autosomal homologue of DAZ) and SRY (Yp; sex determining gene). Out of 177 cases examined, 9 (azoospermia - 8 and oligoasthenospermia - 1) showed partial deletion of AZF. The size of deletion varied among patients but AZFc was either totally or partially removed in all of them. In contrast, no deletion was detected in AZFa. Testis biopsy done on a limited number of cases (50) showed diverse stages of spermatogenic arrest with no specific correlation with the genotype. The frequency of Y-chromosome microdeletion in our samples (approximately 5%) is much lower than the frequency (approximately 10%) reported globally and the two previous reports from India. We contend that the frequency may be affected by population structures in different geographical regions.

Cytological evaluation of global DNA methylation in mouse testicular genome

Global methylation of DNA from different testicular cell types has been studied by DNA end-labeling and nick translation of fixed chromatin (in situ), following digestion with cytosine methylation-sensitive restriction enzymes. Both at the level of chromatic (chromosome) and naked DNA, there is extensive methylation of the genome. Although the extent of methylation was nearly the same among different cell types in the MspI, HpaII, and HhaI digested end-labelled DNA, in the chromosome preparations the digestion patterns varied in cell type-specific manner, pachytene being the most sensitive and spermatids and sperm the most resistant. The differential sensitivity is attributable to the difference in the chromatin organisation in different testicular cell types though no specific region could be identified as particularly more sensitive or resistant to the enzymes. Pachytene bivalents do not reveal a consistent segmental pattern of digestion, but the perichiasmate regions of diplotene/diakinesis and metaphase I chromosomes show hypersensitivity to the enzymes.

Attrition and non-compliance in secondary stroke prevention trials

BACKGROUND

Attrition and non-compliance of subjects in secondary stroke prevention trials due to study drug-induced adverse events and loss to follow-up could lead to bias and loss of information, thus affecting the analysis of study results.

METHODS

We reviewed results from ten antiplatelet stroke prevention clinical trials: CAN TIA, DUTCH TIA, SWED ASA, SALT, UK TIA, CATS, TASS, ESPS, ESPS-2, and CAPRIE to tabulate the frequencies for total subject discontinuation, voluntary withdrawal, and loss to follow-up.

RESULTS

Forty thousand seven hundred and thirty (40,730) subjects participated in the aforementioned secondary stroke prevention trials. The range of outcomes was 11.8-52.0% for subjects discontinued for any reason (n = 9 trials); 3.0-20.9% for study drug-induced adverse events (n = 9 trials), and 4.2-7.8% for voluntary withdrawal (n = 10 trials).

CONCLUSION

There is a substantial discrepancy (up to 20%) between the frequencies of total subject discontinuation for any reason and the sum of study drug-induced adverse events, voluntary withdrawal and loss to follow-up. Underestimation of these important outcomes may limit the ability of clinicians to translate results from clinical trials into medical practice.

Isomerism of the right atrial appendages: clinical, anatomical, and microscopic study of a long-surviving case with asplenia and ciliary abnormalities

This study describes a case of isomerism of the right atrial appendages (bilateral morphologically right atrial appendages associated with complex congenital cardiac lesions) with ciliary abnormalities. Detailed investigation included gross anatomic dissection, review of the clinical history, and light, confocal, and electron microscopy. Clinically, this 40-year-old, long-surviving male patient had relatively good health until 4 years before death, which was due to cardiac failure. Surgical intervention consisted only of a Blalock-Taussig shunt (anastomosis of the right subclavian artery to the right pulmonary artery) at 6 years of age. Despite the presence of complex cardiac malformations and asplenia, his longevity may be attributed to the connection of the pulmonary veins to the atrium without pulmonary venous obstruction, pulmonary valvar stenosis rather than atresia, no significant atrioventricular valve regurgitation, and no serious infections during his life. Microscopic examination of bronchial epithelium revealed a narrow, disorganized epithelium with abundant goblet cells and short, angulated cilia with a random orientation and possibly an abnormal central microtubule doublet. These abnormalities were not present in controls, and have been noted in primary ciliary dyskinesia (PCD) or Kartagener's syndrome. Because this syndrome has classically been thought to cause random lateralization resulting in a mirror-imaged arrangement of the organs, the occurrence of truly isomeric patterns is not widely recognized. Whereas polysplenia and left bronchial isomerism have been reported to occur in immotile cilia syndrome, this is the first report to present detailed postmortem anatomic evidence of isomerism of the right atrial appendages, right bronchial isomerism, and asplenia in association with microscopy suggesting ciliary abnormalities.

Demonstration of plasma startup by coaxial helicity injection

The first successful results on the transfer of a coaxial helicity injection (CHI) produced discharge to inductive operation are reported. CHI-assisted plasma startup is more robust than inductive only operation. After hand off for inductive operation, the initial 90 kA of CHI-produced current drops to 40 kA, then ramps up to 170 kA, using only 30 mV s, more than 30% higher than that produced by induction alone. These significant performance enhancing results were obtained on the HIT-II spherical torus experiment (major/minor radius of 0.3/0.2 m).

Awareness, treatment, and control of vascular risk factors in African Americans with stroke

OBJECTIVE

To investigate control of risk factors in African American patients with previous stroke.

METHODS

The baseline history, physical examination, and laboratory data for 1,086 subjects enrolled in the African American Antiplatelet Stroke Prevention Study from 1995 to 1999 were studied. The level of awareness, pharmacologic treatment, and control of diabetes mellitus (casual plasma glucose level > or =200 mg/dL), hypertension (blood pressure > or =140/90 mm Hg), and hypercholesterolemia (serum total cholesterol level > or =240 mg/dL) were determined.

RESULTS

Forty percent of subjects reported a history of diabetes mellitus or use of diabetic medication, and 2% of the remaining subjects had a serum glucose level of > or =200 mg/dL. Of those subjects known to be diabetic, 33% had a serum glucose level of > or =200 mg/dL. A history of hypertension or use of antihypertensive medication was reported in 87% of subjects, and 48% of the remaining subjects were found to have a blood pressure of > or =140/90 mm Hg on exam. Of those subjects known to be hypertensive by history, 73% were on antihypertensive medication, but only 30% of the treated subjects had a blood pressure under 140/90 mm Hg. A history of hypercholesterolemia or use of a lipid-lowering agent was reported in 40% of subjects, and 24% of the remaining subjects had a cholesterol level of > or =240 mg/dL. Use of a lipid-lowering agent was reported in 43% of subjects known to be hypercholesterolemic, and 38% of the hypercholesterolemic subjects had a cholesterol level of > or =240 mg/dL.

CONCLUSION

Inadequate rates of awareness and control of cardiovascular disease and stroke risk factors are seen in a clinical trial of African American stroke patients and are comparable with those of previously published reports.

Mapping and QTL analysis of the barley population Sloop × Halcyon

A genetic linkage map of Hordeum vulgare L. 1280 cM in length, composed of 257 AFLP, RFLP, SNP, and microsatellite markers, has been constructed. The map was based on a doubled haploid population made from the cross Sloop (spring type) × Halcyon (winter type). The genetic map was used to identify qualitative major genes and quantitative trait loci (QTLs) affecting traits related to growth and flowering, grain colour, and disease resistance. Nine QTLs associated with grain colour (brightness, redness, yellowness, blue aleurone colour), plant height, 'intrinsic lateness', awn emergence, response to photoperiod, and spring or winter habit were located on 1H, 2H, 3H, 4H, and 5H. Eight QTLs associated with resistance to scald, net form of net blotch, leaf rust and powdery mildew were identified on chromosomes 1H, 2H, 3H, 4H, 5H, and 7H. The estimated magnitude of the QTL effects ranged from 9 to 85% of the total phenotypic variance. Resistances to leaf scald, net blotch, and leaf rust, and photoperiod and grain colour, were each controlled by at least one major gene.

Mapping of genomic regions associated with net form of netblotch resistance in barley

Quantitative trait loci (QTLs) associated with resistance to net blotch and their chromosomal locations were determined from analyses of doubled haploid progeny of Alexis/Sloop, Arapiles/Franklin, Sloop/Halcyon, and recombinant inbred lines of Sloop-sib/Alexis. Five QTLs on chromosomes 2H, 3H, and 4H were found to be associated with seedling resistance to the net form of net blotch. In Arapiles/Franklin and Alexis/Sloop populations, 4 significant QTLs explaining 9–17% of the variation in net blotch resistance were detected on 2H and 3H. A major locus, QRpts4L accounting for 64% of the variation in infection type, was detected on 4H in the Sloop/Halcyon population. In Sloop/Halcyon, 2 microsatellite markers, EBmac0906 and GMS089, and AFLP marker P13/M50-108, co-segregated and detected maximum variability for net blotch resistance as revealed by bootstrap analysis. EBmac0906 and Bmac0181 were validated in F2 progeny of an Ant29/Halcyon population and reliably predicted phenotypes of 93% of lines resistant and susceptible to net blotch. These markers may be used within breeding programs to select alleles favourable for net blotch resistance derived from Halcyon.

Development and allele diversity of microsatellite markers linked to the aluminium tolerance gene Alp in barley

Aluminium (Al) toxicity is one of the main factors restricting barley production in acidic soils. The utilisation of barley cultivars tolerant to Al is one of the most economic strategies for expanding barley production in these soils. Among barley genotypes, the cultivar Dayton has been reported to exhibit the highest level of Al tolerance. The gene conferring Al tolerance in Dayton, Alp, has been mapped to the long arm of chromosome 4H using RFLP markers. However, such markers are not useful for routine marker-assisted selection in breeding programs due to the cost and labour associated with their use. To increase the ease by which marker-assisted selection can be conducted for Alp, we sought to identify microsatellite markers linked to this gene. Several such markers that flank Alp were identified in a mapping population from a cross between Dayton and Harlan Hybrid. The most tightly linked microsatellite markers, HVM68 and Bmag353, flank Alp and are 5.3 cM and 3.1 cM from this locus, respectively. The linkage between Bmag353 and Alp was validated in a separate F3 population derived from the cross between Dayton and F6ant28B48-16, where this microsatellite marker was found to predict the Al tolerance phenotype with over 95% accuracy. Allele diversity for the 3 most tightly linked microsatellite markers was evaluated among 40 barley genotypes currently used in Australian barley breeding programs. The high levels of polymorphism detected among the genotypes with the markers indicated that the microsatellite markers, especially Bmag353 and Bmac310, will be broadly useful for marker-assisted selection of Alp in breeding programs seeking to improve Al tolerance.

Otological disorders in Down's Syndrome

OBJECTIVE

To assess if children with Down's Syndrome have a higher prevalence of otological abnormality compared to their normal counterparts in Malaysia.

METHODOLOGY

Thirty children with Down's Syndrome and normal children underwent otoscopic ear examination and Impedance test in the ENT outpatients clinic in University Hospital, Kuala Lumpur, Malaysia.

RESULTS

The study showed that children with Down's Syndrome had higher otological disorders. Forty four percent had impacted wax compared to 14.4% in normal children. Twenty one percent of ears in the study group had retracted drums compared to 6.6% of control. Fifteen percent of ears in the study group had middle ear effusion compared to 3.4% in controls, 55% had a type B tympanogram compared to 8.3% in controls and 73.4% had auditory canal stenosis compared to 14.4% in controls.

CONCLUSION

Children with Down's Syndrome, thus have a higher incidence of otological disorders.

Hangman's knot in securing bypass tubes in endonasal dacryocystorhinostomy

We performed 15 cases of dacryocystorhinostomy endoscopically with an 86% success rate. Using a Hangman's knot, the bypass tubes were placed in a secure and lasting way.

Gender and pramipexole effects on levodopa pharmacokinetics and pharmacodynamics

The authors studied the pharmacokinetics of levodopa (LD) with and without pramipexole (PPX) in men and postmenopausal women with PD. Patients on stable dose of carbidopa/LD were randomized to receive escalating doses of placebo or PPX over 7 weeks. LD and PPX pharmacokinetics were performed after a single test dose 25/100 of carbidopa/LD, before initiation of PPX or placebo, at 1.5 mg/d and 4.5 mg/d of PPX or placebo. Compared to men, women had greater LD bioavailability. PPX did not alter LD bioavailability, and PPX pharmacokinetics were equivalent in men and women.