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Biomedical subjects

R P Gandhi

Publications and source records attributed to R P Gandhi.

9 recordsLinked to original sources
PubMed2006

A new synthetic protocol for labeled oligonucleotides, using a chemically cleavable universal linker.

A two-step general method for labeling of synthetic oligonucleotides is described. The protocol employs a cleavable universal linker, 5'-O-(4,4'-dimethoxytrityl)-3'-O-benzoyl-2'-O-(2-cyanoethyl-N,N-diisopropyl)-uridine phosphoramidite, to effect coupling to polymer-bound oligonucleotide chains. Sequentially, coupling with commercially available phosphoramidite reagent of an appropriate label (Biotin, HEX etc.) in an automated DNA synthesizer is carried out. The labeled oligomers, obtained after cleavage and deprotection reactions, are analyzed on RP-HPLC. A distinctive feature of this protocol is the recovery of free oligomers from their labeled analogs under mild conditions. The oligomers obtained are comparable to the corresponding standard oligonucleotides (HPLC).

Biotin↗
PubMed2002

Introduction of functional groups onto polypropylene and polyethylene surfaces for immobilization of enzymes.

Polypropylene and polyethylene surfaces are activated by introducing an active functional group through 1-fluoro-2 nitro-4-azidobenzene by UV irradiation. Horseradish peroxidase and glucose oxidase are immobilized onto the activated surfaces, simply by incubating the enzymes at 37 degrees C. When untreated surfaces are used, insignificant immobilization of the enzymes is observed.

Enzyme Stability↗
PubMed2001

Light-induced activation of an inert surface for covalent immobilization of a protein ligand.

A simple and mild procedure is developed for the preparation of an activated polymer surface, used for immobilization of a protein ligand through a covalent linkage. Activation of the polymer surface is carried out by attaching an active functional group through 1-fluoro-2-nitro-4-azidobenzene (FNAB). UV irradiation of FNAB transforms its azido group into a highly reactive nitrene, which binds with the inert polymer surface, whereas the active fluoro group of FNAB, now part of the polymer, remains intact. Covalent linkage between the ligand and the inert surface is established through this active fluoro group in a thermochemical reaction. The photochemical step is carried out under dry conditions to exclude the possibility of undesirable reactions between the solvent and the highly reactive nitrene. The method can be used for activation of different inert polymer surfaces having carbon hydrogen bonds. The efficacy of our method is demonstrated by immobilizing horseradish peroxidase on an activated polystyrene surface. The enzyme, immobilized through the photolinker, is found to give a twofold increase in absorbance with the substrate as compared to the directly adsorbed enzyme. The method may have many applications in the preparation of bioreactors, biostrips, and biosensors, and in diagnostic tests involving the ELISA technique.

Azides↗
PubMed1989

Successful management of esophageal strictures without resection or replacement.

Esophageal resection or replacement has become the standard therapy for severe esophageal strictures chiefly because less aggressive methods generally have failed. We hereby report our experience with 12 consecutive infants and children who have been managed successfully by means of Stamm gastrostomy and string-guided esophageal dilatation, coupled with endoscopically guided four-quadrant intralesional steroid injection, protected by Nissen fundoplication when gastroesophageal reflux has been demonstrated. In six patients, the stricture(s) were caused by ingestion of lye. In five, they were associated with repair of esophageal atresia. In one, the etiology was never determined. The strictures averaged 3.5 cm in length (range, 1 to 10 cm); the severity of the lesions was indicated by the fact that, in all instances, patients were completely intolerant of solids, and was confirmed fluoroscopically by demonstration of significant luminal narrowing. A mean of 4.3 steroid injections (range, 1 to 8) was required to obtain complete remission of symptoms; there have been no complications except in one lye ingestion patient who developed a tiny perforation following the initial dilatation, which responded to antibiotics alone. All patients remain symptom-free; the mean length of follow-up is 6.2 years (range, 1 to 11 years). We conclude that string-guided esophageal dilatation, when coupled with endoscopically guided steroid injection, is a safe and reliable method for treatment of severe esophageal strictures, which should obviate the need for esophageal resection or replacement in most patients. Moreover, even if treatment should ultimately fail, a procedure of lesser magnitude than esophageal replacement will likely be possible.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1984

Indications and techniques of upper gastrointestinal endoscopy in infants and children.

Review of 98 endoscopies done over a 4-year period demonstrated that these procedures aided in the diagnosis and management of infants and children with upper gastrointestinal disorders. Endoscopic indications included evaluation of the esophagus in gastroesophageal reflux, achlasia, and lye ingestion; and evaluation of biliary and pancreatic diseases. Other indications included diagnosis of the site of upper gastrointestinal bleeding and treatment of esophageal varices with sclerotherapy, esophageal strictures with steroid injection and removal of foreign bodies. The majority of the procedures were done under sedation. There were no complications.

Adolescent↗
PubMed1983

Stab wounds in children.

The Pediatric Surgical Service of Harlem Hospital Center admitted 75 children, 16-years-old and younger, with stab wounds since 1969. Rapid resuscitation and triage of children with major injuries directly to the operating room achieved 100% survival. Review of the circumstance of injury revealed that 75% of the stab wounds were inflicted by children and 66% were known to have been intentional. Social service and psychiatric intervention for troubled children and their families is essential and may decrease the risk of subsequent traumatic injury.

Adolescent↗
PubMed1983

Ten years of experience with falls from a height in children.

Falls from a height are a major cause of accidental death in urban children. The medical and social data on 61 children admitted over the last decade for falls of one or more stories were reviewed. Seventy-seven percent of the children survived. Of the children who fell three stories or less, all survived (100%). Fifty percent mortality occurred between the fifth and sixth floors. Seventy-seven percent of the falls were accidental and 23% of the children jumped or were pushed. The 96% decrease in accidental falls from windows since 1979 demonstrates that the "Children Can't Fly" program in New York City has almost eliminated accidental falls from windows in our hospital population.

Accidents, Home↗
PubMed1982

Ten years' experience with pediatric gunshot wounds.

Gunshot wounds in children have become a significant source of morbidity and mortality in our community in the last 10 yr. One hundred eight children, 16 yr of age and younger, were admitted to the Pediatric Surgical Service for gunshot wounds during this period; only 1 child was admitted for a gunshot wound in the 10 yr preceding this review. Rapid resuscitation and triage of major injuries directly to the operating room achieved a 94% survival. Review of the circumstances of injury revealed that 42% of the gunshot wounds were inflicted by children and 40% were known to have been intentional. Only 20% of the patients had known drug involvement; in general this was involvement in drug selling, not in drug abuse. Social service intervention can offer significant benefit to these children, but ultimately gun control laws with strict enforcement are needed to stop this type of violence toward children.

Accidents↗