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Biomedical subjects

R Babu

Publications and source records attributed to R Babu.

At least 19 recordsLinked to original sources
PubMed2006

Mapping QTLs for popping ability in a popcorn x flint corn cross.

Popping expansion volume (PEV) in popcorn (Zea mays L.) is a distinct heritable character and defined as the ratio of the volume after popping to the volume before popping. PEV is quantitatively inherited and 3-4 genes/quantitative trait loci (QTLs) have been implicated. In the present study, we have dissected the quantitative PEV into two component traits, viz., flake volume (FV) and percent unpopped kernels (UPK), and mapped QTLs using SSR markers for all three traits with 194 F3 families derived from a popcorn (A-1-6) x flint corn (V273) cross. Heritability (broad sense) estimates for PEV, FV and UPK based on F3 mean bases were 0.72, 0.54 and 0.68, respectively. The QTL analyses for the three traits based on combined environment data were performed by composite interval mapping using QTL cartographer. Four QTLs were identified for PEV on chromosomes 1, 3, 8 and 10, which together explained 62% of the phenotypic variance (sigma2p). Four QTLs were found on chromosomes 1, 5, 9 and 10 for FV (explaining 44% of sigma2p) and five QTLs for UPK on chromosomes 1, 3, 4, 5 and 9 (explaining 57% of sigma2p). The relative efficiency estimates of marker-based selection in comparison to phenotypic selection for PEV (1.10), FV (1.22) and UPK (1.11) indicated that marker-based selection could be relatively more efficient. The QTL on chromosome 1S for PEV was found to be most significant, where QTLs for hard endosperm starch concentration had been detected earlier.

Alleles↗
PubMed2005

Two-generation marker-aided backcrossing for rapid conversion of normal maize lines to quality protein maize (QPM).

The low nutritive value of maize endosperm protein is genetically corrected in quality protein maize (QPM), which contains the opaque 2 gene along with numerous modifiers for kernel hardness. We report here a two generation marker-based backcross breeding program for incorporation of the opaque 2 gene along with phenotypic selection for kernel modification in the background of an early maturing normal maize inbred line, V25. Using the flanking marker distances from opaque 2 gene in the cross V 25 xCML 176, optimum population size for the BC(2) generation was computed in such a way that at least one double recombinant could be obtained. Whole genome background selection in the BC(2) generation identified three plants with 93 to 96% recurrent parent genome content. The three BC(2)F(2) families derived from marker identified BC(2) individuals were subjected to foreground selection and phenotypic selection for kernel modification. The tryptophan concentration in endosperm protein was significantly enhanced in all the three classes of kernel modification viz., less than 25%, 25--50% and more than 50% opaqueness. BC(2)F(3) lines developed from the hard endosperm kernels were evaluated for desirable agronomic and biochemical traits in replicated trials and the best line was chosen to represent the QPM version of V25, with tryptophan concentration of 0.85% in protein. The integrated breeding strategy reported here can be applied to reduce genetic drag as well as the time involved in a conventional line conversion program, and would prove valuable in rapid development of specialty corn germ plasm.

Crosses, Genetic↗
PubMed2004

H-type tracheo-oesophageal fistula with congenital oesophageal stenosis.

H-type tracheo-oesophageal fistula (H-TOF) and congenital oesophageal stenosis (COS) are both rare anomalies. Only six cases of H-TOF in association with COS have been described in the literature. Characteristically, diagnosis is delayed, often well beyond the neonatal period. We report a patient who was accurately diagnosed on day 12 of life, and outline several of the key clinical dilemmas encountered in managing a neonate with this combination of rare congenital anomalies.

Esophageal Stenosis↗
PubMed2004

A technique to demonstrate external haemorrhoids.

Although uncommon in children, haemorrhoids are one of the causes of a protruding anal lesion and may be confused with rectal prolapse or prolapse of a rectal polyp. The lesions may not be obvious when the child is anaesthetised because of lack of straining. This may prevent accurate diagnosis and impede identification of the lesion if surgery is being attempted. The authors report 3 cases where a 20 F Foley catheter with 30 ml balloon was inserted rectally and gentle traction applied to reproduce the raised venous pressure generated during straining. On each occasion external haemorrhoids could be demonstrated as the underlying pathology.

Catheterization↗
PubMed2004

Surgical risk factors for Hickman catheter sepsis: a prospective study.

Catheter-related sepsis (CRS) is a major cause of morbidity in patients receiving chemotherapy and prolonged parenteral nutrition. To determine whether avoiding emergency insertions by using a planned elective list and adopting a 'no-touch' technique has a role in reducing CRS, all cuffed central venous catheters inserted by the open method between 1999 and 2000 were prospectively followed for a total duration of 12 months. The incidence of early sepsis (within 30 catheter days) that could be attributed to surgical factors was studied. CRS was defined as the presence of any two of the following: (1) signs of clinical sepsis without an obvious focus; (2) positive cultures in blood obtained from the catheter; and (3) clinical improvement following removal. A total of 146 catheters were inserted in 130 patients; 15 had a second and 1 had a third catheter inserted. Early CRS was encountered in 13 cases (9%); 95 catheters were inserted on an elective list and 51 on an emergency basis. The distributions of age, sex, number of lumens, neutrophil count, and underlying diagnosis were similar between the groups. There was no significant difference (P = 1) between elective (9/95) and emergency (4/51) insertions. A total of 47 catheters were inserted by the 'no-touch' technique and 48 by the manual technique. There was no significant difference in early sepsis (P = 0.7) between the two techniques (6/47 vs 3/48). Thus avoiding emergency insertion or adopting a 'no-touch' technique does not reduce early CRS. Larger prospective studies are warranted to identify surgical risk factors.

Catheterization, Central Venous↗
PubMed2004

Renal fungal balls and pelvi-ureteric junction obstruction in a very low birth weight infant: treatment with streptokinase.

Renal candidiasis is a rare but well recognised complication of intensive care treatment in neonates. We report a problematic case with obstructing pelvi-ureteric junction (PUJ) fungal balls that was refractory to standard measures of adequate nephrostomy drainage, pelvic irrigation with amphotericin B, and systemic antifungal treatment. In an attempt to avoid potentially difficult open surgery, a novel treatment using a streptokinase solution (3,000 IU/ml) for irrigation was performed. This was successful in clearing the fungal balls, relieving obstruction and rendering the urine sterile. The present case highlights a potential role for streptokinase in cases of renal candidiasis refractory to current treatment protocols.

Antifungal Agents↗
PubMed2002

Implanted vascular access devices (ports) in children: complications and their prevention.

Implanted vascular access devices (ports) play a major role in the management of children with cystic fibrosis (CF) and many haematological conditions. With the expanding use of ports, new and more frequent complications are being encountered. To retrospectively review the complications associated with ports, the case notes of all patients who underwent insertion of a port between 1997 and 2000 were analysed. Details of the underlying disorder, type of vascular device, nature of use, and complications were recorded; 55 ports were inserted in 41 patients (a second port was required in 12, a third port in 2) during this period. Their underlying diagnoses were CF (11), haemophilia (4), haemolytic anaemias (2), immunological disorders (6), solid neoplasms (8), and leukaemia (10). Thirteen ports (24%) were removed and replaced for various complications: infection (2), blockage (4), leak (2), dislodgement (2), and malposition (3). Including four port-related problems managed conservatively (3 access problems managed by change in access technique; 1 blockage managed by urokinase), the over all complication rate was 31%. Ports thus have a high complication rate with long-term use. Selecting the right port system, proper installation of the port chamber, and efficient handling and maintenance by trained staff could prevent the vast majority of port-related complications.

Adolescent↗
PubMed2001

"Cuff-stitch" to prevent inadvertent dislodgement of central venous catheters.

The insertion of central venous catheters (CVCs) is an established practice in the management of children who need long-term total parenteral nutrition or chemotherapy. Inadvertent falling out of CVCs before the cuff becomes incorporated in the tissues is a commonly encountered problem. The technique described involves inserting a circular stitch in the subcutaneous plane before the catheter is placed. Once the CVC is pulled into position, the "cuff-stitch" lays around the catheter distal to the cuff, narrows the tunnel, and prevents accidental dislodgement.

Catheterization, Central Venous↗
PubMed2001

Ectopic intrathoracic liver.

Accessory hepatic tissue, unlike accessory splenic and pancreatic tissue, is rare and has a limited and almost exclusively sub diaphragmatic distribution. Fewer than ten cases of intrathoracic ectopic liver have been reported so far in the literature. This paper reports a case that caused a diagnostic dilemma.

Choristoma↗
PubMed2001

Pneumatic dilatation for childhood achalasia.

Treatment of achalasia by pneumatic balloon dilatation (PBD) is well established in adults. Due to limited experience and the rarity of the condition in children, there are relatively few reports in the paediatric literature. Although PBD has been reported as a primary method of treatment, there are no reports of secondary PBD for childhood achalasia. Between 1995 and 1999, five patients underwent treatment for achalasia (age: 9-14 years, M:F = 4:1). The presenting symptoms were dysphagia (5). vomiting episodes (2), aspiration (1), food-bolus obstruction (1), and failure to thrive (1). In all patients a barium swallow and manometry were used to confirm the diagnosis. Three underwent primary PBD. Two who had previously undergone surgical myotomy underwent secondary PBD for recurrence of symptoms. Dilatation was performed using a 35-mm balloon with the child under general anaesthesia. Technical success was defined as demonstration of a waist under screening at lower pressures followed by abolition of the waist at higher pressures. In addition to reviewing our results, a systematic review of the literature was performed (Medline, Cochrane Library, Pubmed, Embase). Three patients (primary dilatation) showed excellent improvement after a single dilatation. In two cases (secondary dilatation) three and five attempts were required. No complications were encountered. The mean follow-up period was 2 years (1-3.5 years) and four patients remained asymptomatic, an overall success rate of 80%. The literature review revealed similar good results in most of the recent reports. Thus, PBD as a primary treatment for childhood achalasia has a success rate of 70%-90% with minimal side effects, short hospital stay, and good patient acceptability over an operation. We have also established the usefulness of this method as a secondary treatment when symptoms recur after surgery.

Adolescent↗
PubMed2001

Glutamine and glutathione counteract the inhibitory effects of mediators of sepsis in neonatal hepatocytes.

BACKGROUND/PURPOSE: Surgical neonates are at risk of sepsis-associated liver dysfunction. Hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) are important mediators of sepsis, which impair neonatal hepatic metabolism. Glutamine has been shown to have beneficial effects on hepatocyte metabolism during neonatal sepsis. However, the molecular basis of these effects are unknown. The aim of this study was to test the hypotheses that (1) glutamine and its dipeptides counteract the inhibitory effect of septic mediators on neonatal hepatocyte oxygen consumption and (2) the effects of glutamine are specific and not shared by other amino acids. In addition, we wished to determine the metabolic pathways and mediators involved in the action of glutamine. METHODS: Hepatocytes were isolated from suckling rats, and O(2) consumption measured polarographically. Study A: the ability of 10 mmol/L glutamine to reverse the inhibitory effects of 1.5 mmol/L H(2)O(2) and 300 micromol/L S-Nitroso-N-acetylpenicillamine (SNAP; a nitric oxide donor) on O(2) consumption was examined. Study B: the ability of other amino acids and dipeptides of glutamine to reverse the effects of H(2)O(2) was examined. Study C: various concentrations of glutamine were tested for their ability to reverse the H(2)O(2) inhibition of O(2) consumption. Study D: the mechanism of action of glutamine was examined by incubating hepatocytes with either an inhibitor of entry into the Krebs cycle or an inhibitor of glutathione synthesis. Study E: the ability of glutathione to reverse the inhibitory effects of H(2)O(2) was examined. RESULTS: Study A: glutamine reversed the inhibition of hepatocyte O(2) consumption exerted by either H(2)O(2) or NO. Study B: glutamine dipeptides reversed the inhibition of hepatocyte O(2) consumption by H(2)O(2), but other amino acids did not. Study C: the counteracting effect of glutamine was proportional to the dose administered. Study D: blocking entry of glutamine into the Krebs cycle did not abolish the effects of glutamine, but blocking glutathione synthesis completely abolished the effect of glutamine. Study E: exogenous glutathione reversed the inhibitory effect of H(2)O(2) on hepatocyte O(2) consumption. CONCLUSIONS: This study found that glutamine and its dipeptides are unique in reversing the effects of septic mediators on neonatal rat liver oxidative metabolism. The effectiveness of glutamine appears to be mediated via glutathione synthesis. Addition of glutamine, glutamine dipeptides, or glutathione to total parenteral nutrition (TPN) may be beneficial in preventing liver damage in neonatal sepsis.

Animals↗
PubMed2001

Congenital segmental dilatation of the duodenum--differential diagnosis for an antenatally-diagnosed intra-abdominal cyst.

We report the third case of segmental dilatation of the duodenum and the first to be diagnosed antenatally. The lesion presented as an intra-abdominal cyst on an antenatal scan at 17 weeks and was followed up with more specific investigations after birth. The final diagnosis was obtained only at laparotomy where the dilated segment was resected. The patient is well at eighteen month follow-up. Segmental dilatation of the gastrointestinal tract, although rare, should be considered in the differential diagnosis of antenatally discovered intra-abdominal cysts.

Cysts↗
PubMed2000

The management of oesophageal atresia in neonates with right-sided aortic arch.

BACKGROUND/PURPOSE: The management of oesophageal atresia (OA) in association with a right-sided aortic arch (RAA) is challenging. It is controversial whether right or left thoracotomy is the most appropriate surgical approach. The aim of this study was to determine the prevalence of RAA in patients with OA and the most appropriate surgical approach. METHODS: The case records of all the neonates with OA treated over an 18-year period (1980 through 1997) were reviewed. Patients with RAA were analysed with particular reference to the preoperative investigations, operative approach and findings, and postoperative complications. RESULTS: Of the 476 case notes reviewed, 12 (2.5%) had a RAA, and 5 of these infants had major cardiac anomalies. The diagnosis was not suspected on preoperative chest x-ray in any of these infants. In only 1 of the 5 neonates who had a preoperative echocardiogram was RAA suspected. A right thoracic approach was performed in the 11 infants in whom a RAA was not suspected. Immediate conversion to a left thoracotomy with primary anastomosis was carried out in 2 infants. In 2 further infants, fistula ligation alone was performed because of a long gap atresia. Anastomosis via the right thoracotomy was performed in 7 infants. There were 3 anastomotic leaks, 1 intractable stricture, and 1 recurrent fistula. Three patients (25%) had a double aortic arch, and, as a result, a left thoracotomy had to be abandoned in 2. There were 3 deaths, 2 as a result of major cardiac anomalies and 1 related to prematurity and sepsis. CONCLUSIONS: RAA occurs in 2.5% of infants with OA. Preoperative chest x-ray and echocardiogram are unreliable as diagnostic modalities. Anastomosis via a right thoracotomy is associated with a 42% leak rate. The presence of a double aortic arch can make the oesophageal anastomosis via a left thoracotomy as difficult as via a right thoracotomy.

Abnormalities, Multiple↗
PubMed1999

International, collaborative assessment of 146,000 prenatal karyotypes: expected limitations if only chromosome-specific probes and fluorescent in-situ hybridization are used.

The development of chromosome-specific probes (CSP) and fluorescent in-situ hybridization (FISH) has allowed for very rapid identification of selected numerical abnormalities. We attempt here to determine, in principle, what percentage of abnormalities would be detectable if only CSP-FISH were performed without karyotype for prenatal diagnosis. A total of 146 128 consecutive karyotypes for prenatal diagnosis from eight centres in four countries for 5 years were compared with predicted detection if probes for chromosomes 13, 18, 21, X and Y were used, and assuming 100% detection efficiency. A total of 4163 abnormalities (2.85%) were found including 2889 (69. 4%) (trisomy 21, trisomy 18, trisomy 13, numerical sex chromosome abnormalities, and triploidies) which were considered detectable by FISH. Of these, 1274 were mosaics, translocations, deletions, inversions, rings, and markers which would not be considered detectable. CSP-FISH is a useful adjunct to karyotype for high risk situations, and may be appropriate in low risk screening, but should not be seen as a replacement for karyotype as too many structural chromosome abnormalities will be missed.

Chromosome Aberrations↗
PubMed1997

Comparison of balloon angioplasty versus debulking devices versus stenting in right coronary ostial lesions.

Angioplasty of aorto-ostial stenosis is associated with lower procedural success and a higher complication rate. The aim of the present study was to compare the acute and long-term results of balloon and new device angioplasty in 110 consecutive patients with right coronary ostial lesions. Patients were divided into 3 groups according to the angioplasty device used: group I (balloon only, n = 26), group II (debulking devices including excimer laser, directional and rotational atherectomy, n = 26), group III (stent, n = 58). Procedural success was highest in group III (96%) followed by group I (88%), and group II (77%). In-hospital complications were similar among the groups (p = NS). Patients in group III achieved the highest acute gain (2.61 mm) followed by groups II (1.92 mm), and I (1.39 mm, p <0.05). During follow up, target lesion revascularization and/or bypass surgery was required in 24% of patients in group III compared with 47% and 40% in groups I and II, respectively (p <0.05). Cardiac-event free survival was highest in the stent group (74%, p <0.005) and was similar between the balloon (39%) and debulking device groups (45%). Thus, among the currently available technologies, stenting of right coronary ostial lesions appears to provide excellent angiographic and long-term results.

Aged↗
PubMed1997

Mitrofanoff principle for continent urinary diversion.

In 1980 Mitrofanoff described a method to achieve continent urinary diversion by surgically closing the bladder neck and creating a continent catheterizable stoma from the appendix which had been implanted in a nonrefluxing manner into the bladder or from a nonrefluxing distal ureter. The Mitrofanoff principle (MP) serves well as a continence mechanism for either the native bladder or intestinal reservoirs. We review 17 patients, including 10 children, who were treated with the MP and received a continent catheterizable channel. For the MP, appendix was used in 16 patients and ureter in 1. The continuity between the urinary reservoir and urethra was maintained wherever possible. Bladder neck suspension was preferred to bladder neck closure in incontinent females and boys. Complications and their management have been discussed at length. Stable renal functions, ease of catheterization and urinary continence were achieved in 93.8% of the patients.

Adolescent↗