Mapping of a major QTL for pre-harvest sprouting tolerance on chromosome 3A in bread wheat

Quantitative trait loci (QTL) analysis was conducted for pre-harvest sprouting tolerance (PHST) in bread wheat for a solitary chromosome 3A, which was shown to be important for this trait in earlier studies. An inter-varietal mapping population in the form of recombinant inbred lines (RILs) developed from a cross between SPR8198 (a PHS tolerant genotype) and HD2329 (a PHS susceptible cultivar) was used for this purpose. The parents and the RIL population were grown in six different environments and the data on PHS were collected in each case. A framework linkage map of chromosome 3A with 13 markers was prepared and used for QTL analysis. A major QTL (QPhs.ccsu-3A.1) was detected on 3AL at a genetic distance of approximately 183 cM from centromere, the length of the map being 279.1 cM. The QTL explained 24.68% to 35.21% variation in individual environments and 78.03% of the variation across the environments (pooled data). The results of the present study are significant on two counts. Firstly, the detected QTL is a major QTL, explaining up to 78.03% of the variation and, secondly, the QTL showed up in all the six environments and also with the pooled data, which is rather rare in QTL analysis. The positive additive effects in the present study suggest that a superior allele of the QTL is available in the superior parent (SPR8198), which can be used for marker-aided selection for the transfer of this QTL allele to obtain PHS-tolerant progeny. It has also been shown that the red-coloured grain of PHS tolerant parent is not associated with the QTL for PHST identified during the present study, suggesting that PHS tolerant white-grained cultivars can be developed.

Temperature related seasonal changes in Golgi complex of brain, heart and intestine of a teleost

Impact of temperature related seasonal changes in density of Golgi complex were studied in brain, heart and intestine of the freshwater catfish, Clarias batrachus (Linnaeus). The density of Golgi complex was more in these organs of the fish acclimatized to a lower temperature (20 degrees C) than that to a higher temperature (29 degrees C). This suggests that lower temperature induces secretory activity in cells to cope up with the changes in surrounding environment. It could be a kind of histophysiological adaptation in poikilothermic animal.

Expression of HoxA5 in the heart is upregulated during thyroxin-induced metamorphosis of the Mexican axolotl (Ambystoma mexicanum)

Widespread external and internal changes in body morphology have long been known to be hallmarks of the process of metamorphosis. However, more subtle changes, particularly at the molecular level, are only now beginning to be understood. A number of transcription factors have recently been shown to alter expression either in levels of message or in isoforms expressed. In this article, we describe a dramatic increase in the expression of the homeobox gene HoxA5 in the heart and aorta of the Mexican axolotl Ambystoma mexicanum during the process of thyroxin-induced metamorphosis. Immunohistochemical analysis with anti-HoxA5 antibody in thyroxin-induced metamorphosing animals showed a pattern of expression of HoxA5 comparable to that in spontaneously metamorphosing animals. Further, by in situ hybridization, we were able to show significant qualitative differences in the expression of this gene within the heart. Maximum HoxA5 expression occurred at the midpoint of metamorphosis in the myocardium, whereas the hearts of completely metamorphosed animals had the highest levels of expression in the epicardium and endocardium. In the aorta, smooth-muscle cells of the tunica media as well as cells of the tunica adventitia had an increase in expression of HoxA5 with thyroxin-induced metamorphosis. HoxA5 expression significantly changed in cells of the aorta and ventricle with treatment by thyroid hormone. HoxA5, a positive regulator of p53, may be involved with the apoptotic pathway in heart remodeling during amphibian metamorphosis.

Bronchobiliary fistula: an anaesthetic point of view

Bronchobiliary fistula is defined as the passage of bile in the bronchi and in the sputum (bilioptysis). This rare disorder is associated with significant morbidity. Authors review the anaesthetic management of bronchobiliary fistula and recommend the use of double lumen endotracheal tube even in cases with a closed/sealed bronchobiliary fistula.

Hepatorenal syndrome: pathophysiology and treatment

The hepatorenal syndrome (HRS) is a unique form of acute renal failure with entirely normal renal histology in advanced liver disease. Its diagnosis is made by exclusion of all causes of renal failure and by all the five major criteria as set by the International Ascites Club. The presence of hepatomegaly, poor nutritional status, and oesophageal varices at endoscopy are associated with a high risk of HRS. The liver tests, the Child-Pugh score, are of no value in prediction of its occurrence. Contraction of the effective blood volume, which may lead to renal hypoperfusion with preferential renal cortical ischaemia, is proposed pathogenesis of the condition. Because understanding of the pathogenesis of HRS is incomplete, therapy is supportive only. Optimal fluid management is vital as there is almost invariably a reduction in effective arterial blood volume. Dopamine, frusemide and haemofiltration may be helpful in management of fluid overload but do not affect renal function. TIPS has been used successfully in small series of patients. The vasopressin analog also has been used with early excellent response. The treatment of HRS has been discouraging and the only proven cure for HRS is liver transplantation at this point of time.

Microsatellite markers reflect intra-specific relationships between isolates of the vascular wilt pathogen Ceratocystis fimbriata

summary Ceratocystis fimbriata is a serious wilt and canker stain pathogen with a wide geographical distribution and host range that includes both woody and herbaceous plants. Previous studies using hybridization have shown that isolates of C. fimbriata from different hosts and origins differ in colony morphology, pathogenicity and growth rate, as well as conidial state. It has therefore been suggested that distinct strains, linked to host or geographical origin, are encompassed in C. fimbriata. The aim of this study was to develop PCR-based microsatellite markers for population studies on C. fimbriata. ISSR-PCR was used to target specific microsatellite regions of DNA from C. fimbriata. These amplified products were cloned and sequenced. Primer pairs were designed from these sequences to flank the microsatellite regions. From 24 primer pairs, 11 polymorphic primers were selected and tested on a number of C. fimbriata isolates representing a wide host and geographical range. Cluster analyses of the results indicate that these markers clearly distinguish between different geographical and host specific populations of C. fimbriata. The results are concordant with sequence data from the internal transcribed spacer (ITS) region of the rDNA operon of the same isolates. These markers will be useful in future studies of C. fimbriata population structure and diversity.

Suprachoroidal haemorrhage. Secondary management

We report a case of successful management of expulsive suprachoroidal haemorrhage following cataract surgery. This case study highlights the strategy of adequate management.

Effect of a subanesthetic dose of intravenous ketamine and/or local anesthetic infiltration on hemodynamic responses to skull-pin placement: a prospective, placebo-controlled, randomized, double-blind study

Insertion of cranial pins for stabilization of the head can result in a marked hypertensive response, which may adversely affect cerebral hemodynamics. The efficacy of a subanesthetic dose of intravenous ketamine (0.5 mg/kg) and/or lidocaine infiltration (1%) at pin fixation sites before pinning was studied in a prospective, double-blind, placebo-controlled, randomized trial of 40 patients. The subjects were divided into four groups of 10. Patients belonging to the placebo and lidocaine groups received intravenous normal saline (NS), followed by local infiltration with NS at pin insertion sites in the placebo group and 1% lidocaine in the lidocaine group. Patients belonging to the ketamine and ketamine-lidocaine groups received intravenous ketamine followed by local infiltration with NS in the ketamine group, and lidocaine infiltration in the ketamine-lidocaine group. Heart rate (HR) and invasive mean blood pressure (MBP) were recorded before intravenous medication and then at various time intervals until 15 minutes after pin fixation. Intergroup comparison of MBP and HR by 2-way analysis of variance revealed a significant difference between the groups and various time points (P < .05). Post hoc analysis revealed maximum increase in MBP each hour in the placebo group. Mean blood pressure response in the ketamine group was similar to the placebo group. Significant attenuation of MBP and HR was observed in the lidocaine and ketamine-lidocaine groups (P < .05). A minimal increase in HR was observed in the lidocaine-ketamine group. The current study demonstrates maximum attenuation of hemodynamic responses when a subanesthetic dose of intravenous ketamine (0.5 mg/kg) is administered with 1% lidocaine infiltration.

Oropharyngeal swelling and macroglossia after cervical spine surgery in the prone position

An unusual case of massive oropharyngeal swelling and macroglossia occurring after cervical spine surgery performed on a patient in the prone position is described. Possible etiological factors are reviewed, and measures to prevent these complications are suggested.

A disease-associated cellular immune response in type 1 diabetics to an immunodominant epitope of insulin

The 9-23 amino acid region of the insulin B chain (B9-23) is a dominant epitope recognized by pathogenic T lymphocytes in nonobese diabetic mice, the animal model for type 1 diabetes. We describe herein similar (B9-23)-specific T-cell responses in peripheral lymphocytes obtained from patients with recent-onset type 1 diabetes and from prediabetic subjects at high risk for disease. Short-term T-cell lines generated from patient peripheral lymphocytes showed significant proliferative responses to (B9-23), whereas lymphocytes isolated from HLA and/or age-matched nondiabetic normal controls were unresponsive. Antibody-mediated blockade demonstrated that the response was HLA class II restricted. Use of the highly sensitive cytokine-detection ELISPOT assay revealed that these (B9-23)-specific cells were present in freshly isolated lymphocytes from only the type 1 diabetics and prediabetics and produced the proinflammatory cytokine IFN-gamma. This study is, to our knowledge, the first demonstration of a cellular response to the (B9-23) insulin epitope in human type 1 diabetes and suggests that the mouse and human diseases have strikingly similar autoantigenic targets, a feature that should facilitate development of antigen-based therapeutics.

Mice lacking myeloperoxidase are more susceptible to experimental autoimmune encephalomyelitis

EAE is a demyelinating disease which serves as an animal model for multiple sclerosis (MS). Myeloperoxidase (MPO) has been implicated in MS through its presence in invading macrophages, and by association of a -463G/A promoter polymorphism with increased risk. Also, MPO at 17q23.1 is within a region identified in genome scans as a MS susceptibility locus. We here examine the incidence of EAE in MPO knockout (KO) mice. MPO is detected in invading macrophages in the CNS of wild-type mice, yet unexpectedly, MPO-KO mice have significantly increased incidence of EAE: Ninety percent of MPO-KO mice developed complete hind limb paralysis as compared to 33% of wildtype (WT) littermates (P<0.0001). This is the first evidence that MPO plays a significant role in EAE, consistent with its postulated role in MS.

Altered activity, social behavior, and spatial memory in mice lacking the NTAN1p amidase and the asparagine branch of the N-end rule pathway

The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. N-terminal asparagine and glutamine are tertiary destabilizing residues, in that they are enzymatically deamidated to yield secondary destabilizing residues aspartate and glutamate, which are conjugated to arginine, a primary destabilizing residue. N-terminal arginine of a substrate protein is bound by the Ubr1-encoded E3alpha, the E3 component of the ubiquitin-proteasome-dependent N-end rule pathway. We describe the construction and analysis of mouse strains lacking the asparagine-specific N-terminal amidase (Nt(N)-amidase), encoded by the Ntan1 gene. In wild-type embryos, Ntan1 was strongly expressed in the branchial arches and in the tail and limb buds. The Ntan1(-/-) mouse strains lacked the Nt(N)-amidase activity but retained glutamine-specific Nt(Q)-amidase, indicating that the two enzymes are encoded by different genes. Among the normally short-lived N-end rule substrates, only those bearing N-terminal asparagine became long-lived in Ntan1(-/-) fibroblasts. The Ntan1(-/-) mice were fertile and outwardly normal but differed from their congenic wild-type counterparts in spontaneous activity, spatial memory, and a socially conditioned exploratory phenotype that has not been previously described with other mouse strains.

Air or nitrous oxide for loss-of-resistance epidural technique?

PURPOSE

To compare the spinal-epidural spread of gas following loss of resistance (LOR) technique for detection of the epidural space using air or nitrous oxide (N2O).

METHODS

Comparison of the spread of air and N2O in the epidural space following LOR technique was performed by using Magnetic Resonance Imaging (MRI). Ten adult patients ASA grade I served as their own control in this prospective study. A control MRI (MRI Contr-1) of the dorsolumbar spine was performed. Then, an 18 gauge epidural needle was introduced at the L3-4 intervertebral space using 0.14 ml x kg(-1) N2O for LOR and the MRI (MRI-N2O) was repeated. Forty eight hours later, an MRI scan (Contr-2 MRI) was performed and, subsequently, an 18 gauge epidural needle was introduced, using 0.14 ml x kg(-1) air for LOR followed by an MRI (MRI-Air) scan. The volumetric measurements of gas pockets were done using a formula.

RESULTS

Gas bubbles after N2O were few and small compared with larger gas pockets occupying up to three vertebral segments after the use of air for LOR. The volume of air in the epidural space was 2.96+/-0.93 ml compared with 0.35+/-0.32 ml N2O.

CONCLUSION

The use of N2O for LOR technique of detecting the epidural space produced very small bubbles detected by MRI compared with the use of air under similar conditions.

Acupressure wristbands do not prevent postoperative nausea and vomiting after urological endoscopic surgery

PURPOSE

To evaluate the efficacy of acupressure wristbands in the prevention of postoperative nausea and vomiting (PONV).

METHODS

Two hundred ASA I-II patients undergoing elective endoscopic urological procedures were included in a randomized, prospective, double blind, placebo-controlled study. Spherical beads of acupressure wristbands were placed at the P6 points in the anterior surface of both forearms in Group I patients (acupressure group, n = 100) whereas, in Group 2 (control group, n = 100) they were placed inappropriately on the posterior surface. The acupressure wristbands were applied 30 min before induction of anesthesia and were removed six hours postoperatively. Anesthesia was induced with thiopental and maintained with nitrous oxide and oxygen, fentanyl, isoflurane and vecuronium. The tracheas were extubated on the operation table after patients received neostigmine and atropine. Post operative nausea and vomiting were evaluated separately as none, mild, moderate or severe at the time of patient's arrival in PACU, then at six hours and twenty-four hours after surgery by a blinded observer.

RESULTS

In the acupressure group, 25 patients had PONV compared with 29 patients in the control group (P = NS).

CONCLUSION

Application of acupressure wristbands at the P6 of both forearms 30 min before induction of anesthesia did not decrease the incidence of PONV in patients undergoing endoscopic urological procedures.

Expression of axolotl RNA-binding protein during development of the Mexican axolotl

Amphibians occupy a central position in phylogeny between aquatic and terrestrial vertebrates and are widely used as model systems for studying vertebrate development. We have undertaken a comprehensive molecular approach to understand the early events related to embryonic development in the Mexican axolotl, Ambystoma mexicanum, which is an exquisite animal model for such explorations. Axolotl RBP is a RNA-binding protein which was isolated from the embryonic Mexican axolotl by subtraction hybridization and was found to show highest similarity with human, mouse, and Xenopus cold-inducible RNA-binding protein (CIRP). The reverse transcriptase polymerase chain reaction (RT-PCR) analysis suggests that it is expressed in most of the axolotl tissues except liver; the expression level appears to be highest in adult brain. We have also determined the temporal and spatial pattern of its expression at various stages of development. RT-PCR and in situ hybridization analyses indicate that expression of the AxRBP gene starts at stage 10-12 (gastrula), reaches a maxima around stage 15-20 (early tailbud), and then gradually declines through stage 40 (hatching). In situ hybridization suggests that the expression is at a maximum in neural plate and neural fold at stage 15 (neurula) of embryonic development.