Cultural conditions on the production of extracellular enzymes by Trichoderma isolates from tobacco rhizosphere

Abstract Twelve isolates of Trichoderma spp. isolated from tobacco rhizosphere were evaluated for their ability to produce chitinase and β-1,3-glucanase extracellular hydrolytic enzymes. Isolates ThJt1 and TvHt2, out of 12 isolates, produced maximum activities of chitinase and β-1,3-glucanase, respectively. In vitro production of chitinase and β-1,3-glucanase by isolates ThJt1 and TvHt2 was tested under different cultural conditions. The enzyme activities were significantly influenced by acidic pH and the optimum temperature was 30 °C. The chitin and cell walls of Sclerotium rolfsii, as carbon sources, supported the maximum and significantly higher chitinase activity by both isolates. The chitinase activity of isolate ThJt1 was suppressed significantly by fructose (80.28%), followed by glucose (77.42%), whereas the β-1,3-glucanase activity of ThJt1 and both enzymes of isolate TvHt2 were significantly suppressed by fructose, followed by sucrose. Ammonium nitrate as nitrogen source supported the maximum activity of chitinase in both isolates, whereas urea was a poor nitrogen source. Production of both enzymes by the isolates was significantly influenced by the cultural conditions. Thus, the isolates ThJt1 and TvHt2 showed higher levels of chitinase and β-1,3-glucanase activities and were capable of hydrolyzing the mycelium of S. rolfsii infecting tobacco. These organisms can be used therefore for assessment of their synergism in biomass production and biocontrol efficacy and for their field biocontrol ability against S. rolfsii and Pythium aphanidermatum infecting tobacco.

Etiological Spectrum of Acute Intestinal Obstruction.

Gastrointestinal obstruction in children may be due to a variety of conditions. 150 cases of acute intestinal obstructions seen over a period of 180 months were reviewed. Intestinal atresia was the comonest cause (34, 22.4%).

Esophageal surgery in newborns, infants and children.

The most common surgery on the esophagus by pediatric surgeons the world over is performed in the newborn period in babies with congenital esophageal atresia with tracheo-esophageal fistula. Post-operative complications like recurrent fistula, anastomotic stricture and some patients with gastroesophageal reflux would also require surgical intervention. Apart from esophageal dilatation, gastrostomy and feeding jejunostomy, children with strictures secondary to caustic ingestion, reflux or previous esophageal anastomosis may require esophageal substitution. This operation may also be required in babies with pure esophageal atresia as well as those with a long gap esophageal atresia with fistula. The entire stomach, stomach tubes, colon or jejunum are often used but techniques preserving as much of the original esophagus as possible are preferable and more physiological. Surgery is also required in children with congenital esophageal stenosis and duplication cyst.

CT virtual bronchoscopy: new non invasive tool in pediatric patients with foreign body aspiration.

A 2-year-old girl presented with recurrent cough, wheese and breathing difficulty. Her imaging (CT and virtual bronchoscopy) revealed a foreign body in tracheobronchial tree, that was removed by rigid bronchoscopy.

Profile and outcome of neuroblastoma with convertional chemotherapy in children older than one year: a 15-years experience.

The clinical profile and outcome of neuroblastoma in 103 children, older than one-year is presented. 74 had Stage IV, 27 Stage III and one patient each had Stage I or II disease. Treatment included chemotherapy followed by surgical resection/debulking. Radiotherapy was administered to those with residual tumor. Chemotherapy consisted of OPEC (vincristine, cyclophosphamide, cisplatin and etoposide). The caretakers of 54 (52.4%) children either did not opt for or defaulted therapy, whilst 3 patients died before chemotherapy could be initiated. Of the remaining 46 patients, the tumor progressed during therapy in 19 (41.3%). Relapse of disease was documented in 22 (47.8%) cases. Merely 4 (8.7%) children are disease free for a period of 16.5+/-6.7 months. Majority of children presented with advanced disease and the outcome was dismal with conventional non-myloablative chemotherapy.

Current status of fetal surgery.

The allure of fetal surgery is the possibility of interrupting in utero progression of an otherwise treatable condition. In spite of advances in prenatal diagnosis and refinements in surgical techniques, this field has not yet got off the ground because the risks to the mother and fetus, during and after the procedure far outweigh the benefits, and the infrastructure required to support such activity is prohibitively expensive. The various surgical conditions in which fetal surgery has been attempted and the present status of this specialty are discussed.

Primary vesicoureteral reflux: progress of disease, somatic growth and renal parameters.

Thirty children (45 units) in the age group 1 day-12 yrs with primary vesicoureteral reflux were studied prospectively and periodically assessed for renal function, scarring, grade of reflux and somatic growth parameters. Four children (6 units) with grade IV reflux underwent ureteric reimplantation. Complete resolution with medical management was seen in all 12 units of grade I-III reflux and in 5 of the remaining 27 units of grade IV-V reflux over 6 months-6 yrs. This group showed highly significant improvement in height . The weight gain of the above 2 groups was statistically significant compared to those with persistent reflux. Focal defects were seen initially in 62 percent refluxing units. None of the patients showed deterioration in renal function or formation of new scars over the next 1-7 years. Three children on conservative management showed persistent growth retardation with associated breakthrough infection, hypertension, multiple renal scars and poor renal functional volume.

Fetal rhabdomyoma in a neonate.

Rhabdomyoma is a rare benign tumour, majority arising from the cardiac muscle. Seventy to 90 percent of extra cardiac rhabdomyomas are found in the head and neck region, usually within the upper aero digestive tract. We report a case of rhabdomyoma of anterior neck in a neonate. Although rhabdomyomas of posterior neck have been reported, those reported in anterior triangle are infrequent. The lesion has not recurred one year after complete excision. There are no similar reports in Indian literature.

Bronchial transection: delayed diagnosis and successful repair.

Traumatic bronchial transection is usually recognized and repaired immediately after injury. Bronchial transection has a variety of clinical presentations due to air leak into the pleural cavity and it is very rare to have total absence of air leak from the transected bronchus at presentation. We present one such case of main right bronchus injury with total absence of initial clinical signs and symptoms, leading to a delay in the diagnosis. However, the surgical repair eight months after injury showed excellent recovery of the chronically collapsed lung.

Paraesophageal hernia in the neonatal period: suspicion on chest X-ray.

The paraesophageal hernia is rarely seen in the neonatal period. Presentation in neonatal period can be confused with the possibility of esophageal atresia or esophageal web. The upper gastrointestinal tract contrast study is diagnostic in this disease, but careful viewing of the plain X-ray of the chest can also lead to suspicion of the diagnosis. Two neonates with para-esophageal hernia are reported, one with the mesenterico-axial volvulus and the second neonate without volvulus.

Conservative management of giant hepatic mesenchymal hamartoma.

We report a six-month-old male infant with mesenchymal hamartoma of the liver which was left untreated. Repeat CT scan 1 year later showed regression and calcification of the tumor. The child is well 3 years later.

Preoperative aspiration for anterior mediastinal cyst with respiratory distress.

We report a 5-month-old boy who presented with an anterior mediastinal cystic teratoma. Pre-operative symptoms of respiratory distress secondary to airway obstruction were markedly reduced by percutaneous aspiration. Aspiration was also beneficial in easily ventilating the baby during the surgical procedure.