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P Rathi

Publications and source records attributed to P Rathi.

At least 19 recordsLinked to original sources
PubMed2004

Bacterial lipases: an overview of production, purification and biochemical properties.

Lipases, triacylglycerol hydrolases, are an important group of biotechnologically relevant enzymes and they find immense applications in food, dairy, detergent and pharmaceutical industries. Lipases are by and large produced from microbes and specifically bacterial lipases play a vital role in commercial ventures. Some important lipase-producing bacterial genera include Bacillus, Pseudomonas and Burkholderia. Lipases are generally produced on lipidic carbon, such as oils, fatty acids, glycerol or tweens in the presence of an organic nitrogen source. Bacterial lipases are mostly extracellular and are produced by submerged fermentation. The enzyme is most commonly purified by hydrophobic interaction chromatography, in addition to some modern approaches such as reverse micellar and aqueous two-phase systems. Most lipases can act in a wide range of pH and temperature, though alkaline bacterial lipases are more common. Lipases are serine hydrolases and have high stability in organic solvents. Besides these, some lipases exhibit chemo-, regio- and enantioselectivity. The latest trend in lipase research is the development of novel and improved lipases through molecular approaches such as directed evolution and exploring natural communities by the metagenomic approach.

Bacillus↗
PubMed2002

Statistical medium optimization and production of a hyperthermostable lipase from Burkholderia cepacia in a bioreactor.

AIM: Statistical medium optimization for maximum production of a hyperthermostable lipase from Burkholderia cepacia and its validation in a bioreactor. METHODS AND RESULTS: Burkholderia cepacia was grown in shake flasks containing 1% glucose, 0.1% KH2PO4, 0.5% NH4Cl, 0.24% (NH4)2HPO4, 0.01% MgSO4.7H2O and 1% emulsified palm oil, at 45 degrees C and pH 7.0, agitated at 250 rev min(-1) with 6-h-old inoculum (2% v/v) for 20 h. A fourfold enhancement in lipase production (50 U ml(-1)) and an approximately three fold increase in specific activity (160 U mg(-1)) by B. cepacia was obtained in a 14 litre bioreactor within 15 h after statistical optimization following shake flask culture. The statistical model was obtained using face centred central composite design (FCCCD) with five variables: glucose, palm oil, incubation time, inoculum density and agitation. The model suggested no interactive effect of the five factors, although incubation period, inoculum and carbon concentration were the important variables. CONCLUSIONS: The maximum lipase production was 50 U ml(-1), with specific activity 160 U mg(-1) protein, in a 14 litre bioreactor after 15 h in a medium obtained after statistical optimization in shake flasks. Further, the model predicted reduction in time for lipase production with reduction in total carbon supply. SIGNIFICANCE AND IMPACT OF THE STUDY: Statistical optimization allows quick optimization of a large number of variables. It also provides a deep insight into the regulatory role of various parameters involved in enzyme production.

Bacterial Proteins↗
PubMed2001

Duodenal leiomyoma--a rare cause of haematemesis.

Leiomyoma of the duodenum is a rare tumour. Small intestinal tumours contributing to upper gastrointestinal bleed is still rare. They usually present with malena and anaemia, rarely hematemesis. We report a case of leiomyoma of duodenum diagnosed on endoscopic ultrasound that presented with massive haematemesis.

Adult↗
PubMed2000

Foreign bodies in gut.

BACKGROUND: Foreign body ingestion is common and a frightening experience to the patients and relatives. We report our experience with 102 patients, (78 children and 24 adults), with foreign body ingestion. METHODS: After locating foreign bodies radiologically, 34 (43.6%) foreign bodies in children and 13 (54.2%) foreign bodies in adults were removed endoscopically. General anesthesia was used in 32 children and overtube was used for all sharp foreign bodies. RESULTS: In our study, 78 (76%) patients were below 12 years of age. Coins (79.5%) were commonest foreign bodies in children while dentures (25%) were commonest in adults. Foreign bodies were most commonly sited in stomach (25.6%) in children and esophagus (58.3%) in adults. In 41 (52.6%) children and in three (12.5%) adults, i.e. total 44 out of 102 (43.1%) patients passed foreign bodies spontaneously. The largest foreign body that passed spontaneously was 4-cm long nail in a child. In 34 (43.6%) children and in 13 (54.2%) adults foreign bodies were removed endoscopically. Only 3.8% children and 33.3% adults required surgery. CONCLUSIONS: There was no mortality in our series. Majority of foreign bodies do not require any intervention. Sharp foreign bodies are commonest indication for surgery. However, endoscopic removal is safe, effective and is the method of choice for most patients.

Adolescent↗
PubMed2000

Colonic tuberculosis: colonoscopic appearance and clinico-pathologic analysis.

BACKGROUND: There has been a resurgence of interest in intestinal tuberculosis because of acquired immunodeficiency syndrome (AIDS) epidemic sweeping our country. Role of colonoscopy and colonoscopy directed histology for diagnosing the disease have been emphasised since last few years. AIMS AND OBJECTIVES: To know the colonoscopic features in patients with intestinal tuberculosis and to study the clinicopathological findings in the same. METHODS: We studied twenty-one patients with intestinal tuberculosis referred to us between 1993-1997. Colonoscopy was done in all patients and biopsy specimens were collected from the site of lesion during the procedure. RESULTS: Ileocaecal disease was found in 9 patients, ileocaecal with contiguous ascending colon involvement in eight and segmental colonic tuberculosis in four cases. The colonoscopic findings included nodules in seven patients, nodules with ulcerations in three, ulcerations alone in seven, nodules with strictures in three and polypoidal mass in one patient. Eight cases revealed granuloma on histopathology. CONCLUSIONS: Though bacteriological and histological assessment of tissue is essential to differentiate tuberculosis from other disorders, we stress the importance of colonoscopic appearances in diagnosing tuberculosis. We also recommend antituberculous chemotherapy in patients with high clinical suspicion of tuberculosis on the basis of colonoscopic appearance alone after ruling other causes on histopathological examination.

AIDS-Related Opportunistic Infections↗
PubMed1997

Primary gastric lymphoma in a boy.

Primary gastric lymphoma is an extremely uncommon entity in children, and diffuse large-cell-type lymphoma in this age group is still rarer. An 11-year-old boy with primary gastric lymphoma who responded to CHOP regime is reported.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Esophageal tuberculosis with intramural pseudodiverticulosis.

Esophageal tuberculosis is rare, and its association with intramural pseudodiverticulosis is not widely appreciated. We report a patient with dysphagia who proved to have esophageal narrowing, mediastinal lymphadenopathy, and intramural pseudodiverticulosis. Results of endoscopy and biopsy were nonspecific, but biopsy of the supraclavicular node showed histology consistent with tuberculosis. The patient experienced a dramatic response to antitubercular therapy, with resolution of the esophageal narrowing, mediastinal lymphadenopathy, and esophageal intramural pseudodiverticulosis.

Adult↗
PubMedDate not supplied

Colonic lithobezoar.

We report a four-year-old girl with large number of stones in the colon presenting with subacute intestinal obstruction.

Bezoars↗