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Biomedical subjects

C Singh

Publications and source records attributed to C Singh.

At least 19 recordsLinked to original sources
PubMed2003

In vitro cytotoxic elemanolides from Vernonia lasiopus.

Two new elemanolides, epivernodalol and lasiopulide, were isolated after chromatographic separation of the alcoholic extract of the dried aerial parts of the Vernonia lasiopus. These elemanolides are new C-10 epimers of the sesquiterpene lactones vernodalol and demethylacroylated vernodalol isolated from other species of Vernonia. Both elemanolides showed in vitro cytotoxicity against human cancer cell lines in culture. This is the first report of isolation and cytotoxic activity of the two elemanolides from V. lasiopus.

Antineoplastic Agents, Phytogenic↗
PubMed2003

Implantation metastasis in a 13-year-old girl: a case report.

We report a case of a 13-year-old girl with an osteosarcoma of the right humerus, which had been diagnosed as an aneurysmal bone cyst at our institution. She underwent curettage and bone grafting of the lesion, which resulted in implantation metastasis of the tumour to the ilium. She died 15 months after presentation owing to pulmonary metastases. This report highlights the possibility of metastasis occurring by direct implantation to a graft donor site. We strongly recommend that a biopsy be performed in cases of presumed benign lesions before proceeding with the definitive surgery.

Adolescent↗
PubMed2003

Response of anestrus rural buffaloes (Bubalus bubalis) to intravaginal progesterone implant and PGF2alpha injection in summer.

An investigation was conducted to study the genital condition and response of intravaginal progesterone implant with and without administration of PGF2alpha in anestrus rural buffaloes during summer (April-June, 2001) in tropical climate. The ovarian status of 40 lactating (1st to 4th lactation) noncycling buffaloes and 15 noncycling buffalo heifers (3.5 to 5.0 years of age) maintained under village management condition were examined per rectum. Inactive genitalia with [12] and without [28] palpable corpus luteum (CL) were detected on per rectum examination in buffalo cows. The PGF2alpha-injection caused luteolysis and induction of estrus in 83% buffaloes having distinct corpus luteum. Implantation of progesterone in form of CIDR (Controlled Internal Drug Release device) intravaginally for 10 to 14 days induced resumption of estrus among 83% of anestrus buffaloes within 12 to 120 h after implant removal. Of those detected estrus about 80% of buffaloes conceived following natural service. Implantation of CIDR in combination with intramuscular injection of PGF2alpha was more effective than CIDR alone in terms of exhibition of estrus and conception rate. Long term of 10 to 14 days CIDR implant was superior to short term of 8 days in terms of resumption of estrous cyclicity. The observation suggests that during summer about 30% of rural buffaloes were cycling but due to lack of estrus detection they were declared anestrus, though they were having distinct corpus luteum on ovary. The summer sterility can be overcome by raising progesterone level for 10 to 14 days in buffaloes under rural managemental condition.

Anestrus↗
PubMed2001

Ab initio calculations, FTIR and raman spectra of 2,3-difluorobenzonitrile.

Geometry, vibrational frequencies, atomic charges and several thermodynamic parameters (the total energy, the zero point energy, the rotational constants and the room temperature entropy) were calculated using ab initio quantum chemical methods for 2,3-difluorobenzonitrile molecule. The results were compared with experimental values. With the help of two specific scaling procedures, observed FTIR and Raman vibrational frequencies were analysed and assigned to different normal modes of the molecule. The error obtained was in general very low. Other general conclusions have also been deduced.

Models, Chemical↗
PubMed2000

Role of supravital staining of urine sediment and bright field microscopy in diagnosis of acute renal failure in bedside medicine.

BACKGROUND: An early accurate etiological categorization of acute renal failure (ARF) into acute glomerulonephritis (AGN), acute tubular necrosis (ATN) and acute interstitial nephritis (AIN) is very important in clinical medicine. METHODS: To evaluate the efficacy of a simple, cheap supravital staining method developed in our laboratory, we examined urine of 32 cases of ARF at their initial presentation in oliguric phase, which were later biopsied. The stain consisted of 1% crystal violet and 0.5% safranin in normal saline. The coverslip preparations of coded and stained urine sediments were examined under ordinary bright field microscope (BFM) by two independent observers. RESULTS: The renal biopsy showed 12 cases of AGN, 12 ATN and 8 AIN. The diagnosis could be predicted by supravital staining method in 75% cases with 95% uniformity among two observers with a sensitivity of 85.7% for AGN followed by AIN (80%) and ATN (75%). CONCLUSION: Thus this simple supravital staining technique can be used with ordinary BFM for accurate urine sediment analysis in cases of ARF in bedside medicine.

Acute Kidney Injury↗
PubMed1999

Metal chelators/antioxidants: approaches to protect erythrocytic oxidative stress injury during Plasmodium berghei infection in Mastomys coucha.

Desferal, N-acetyl penicillamine (metal chelators) and propylgallate, catechin, and reduced glutathione (antioxidants) suppressed the erythrocytic oxidative damage generated during Plasmodium berghei infection in Mastomys coucha. Superoxide anion and lipid peroxide levels were increased and on the contrary, superoxide dismutase activity was noticeably decreased in the infected erythrocytes. Metal chelators/antioxidant treatment to infected animals resulted in restoration of O(2)(-), LPO and SOD to near normal levels. Furthermore, treatment of the above mentioned agents displayed a controlled mortality/survival time and parasitaemia. In conclusion, metal chelators/antioxidants were found to be effective against oxidative stress injury and parasite growth resulting in prolonged survival time of the host during experimental malaria.

Animals↗
PubMed1999

Analysis of tea shoot catechins: spectrophotometric quantitation and selective visualization on two-dimensional paper chromatograms using diazotized sulfanilamide.

A highly specific and sensitive diazotized sulfanilamide reagent is synthesized for determination of tea catechins. The reagent is employed both as spray reagent for selective visualization of tea catechins on two-dimensional paper chromatograms (sensitivity <1 microg of d-(+)-catechin) and for their spectrophotometric quantification in the crude extracts of tea polyphenols isolated from fresh or dried tea shoots. The formation of yellow color (lambda(max) = 425 nm) between catechins and diazotized sulfanilamide was investigated and made the basis of a simple and sensitive spectrophotometric method for estimation of the total and individual catechins in different tea cultivars. At 425 nm, the absorbance was linear (r = 0.999) over the (0.4-8.0 microg/mL) concentration range of d-(+)-catechin.

Catechin↗
PubMed1999

Evaluation of the SCOTI device for confirming blind nasal intubation.

The sonomatic confirmation of tracheal intubation (SCOTI) is a new device used to confirm the correct placement of tracheal tubes. It utilises a sonic technique for recognition of a resonating frequency for detection of tracheal intubation. We compared its predictive value with that of the clinical auscultatory method and a capnograph to confirm 132 blind nasal intubations using three different tracheal tubes [red rubber (n = 82), polyvinyl chloride (n = 33) and RAE preformed nasal (n = 17)]. SCOTI correctly identified 70.8% of intubations and chest auscultation did so 99.2% of times. All results were confirmed using a capnograph. The SCOTI device gave a false-negative value in 37 patients (28%) and a false-positive result in two patients (1.5%). The response time for confirming intubations was 2.5 (1.5) s for the SCOTI, 4.1 (1.1) s for a capnograph and 40 (9.4) s for the auscultatory method. The erroneous results shown by the SCOTI device were highest when polyvinyl chloride tubes with a Murphy's eye were used for intubation. This study shows that this device is not very useful for ascertaining the correct placement of tracheal tubes after blind nasal intubation.

Adult↗
PubMed1999

Multiphoton near-infrared femtosecond laser pulse-induced DNA damage with and without the photosensitizer proflavine.

The excitation of pBr322 supercoiled plasmid DNA with intense near-IR 810 nm fs laser pulses by a simultaneous multiphoton absorption mechanism results in single-strand breaks after treatment of the irradiated samples with Micrococcus luteus UV endonuclease. This enzyme cleaves DNA strands at sites of cyclobutane dimers that are formed by the simultaneous absorption of three (or more) 810 nm IR photons (pulse width approximately 140 fs, 76 MHz pulse repetition, average power output focused through 10x microscope objective is approximately 1.2 MW/cm2). Direct single-strand breaks (without treatment with M. luteus) were not observed under these conditions. However, in the presence of 6 microM of the intercalator proflavine (PF), both direct single- and double-strand breaks are observed under conditions where substantial fractions of undamaged supercoiled DNA molecules are still present. The fraction of direct double-strand breaks is 30 +/- 5% of all measurable strand cleavage events, is independent of dosage (up to 6.4 GJ/cm2) and is proportional to In, where I is the average power/area of the 810 nm fs laser pulses, and n = 3 +/- 1. The nicking of two DNA strands in the immediate vicinity of the excited PF molecules gives rise to this double-strand cleavage. In contrast, excitation of the same samples under low-power, single-photon absorption conditions (approximately 400-500 nm) gives rise predominantly to single-strand breaks, but some double-strand breaks are observed at the higher dosages. Thus, single-photon excitation with 400-500 nm light and multiphoton activation of PF by near-IR fs laser pulses produces different distributions of single- and double-strand breaks. These results suggest that DNA strand cleavage originates from unrelaxed, higher excited states when PF is excited by simultaneous IR multiphoton absorption processes.

DNA↗
PubMed1999

Micronutrient deficiency disorders amongst pregnant women in three urban slum communities of Delhi.

OBJECTIVE: To assess the prevalence of three micronutrient deficiency disorders (MDDs), i.e., iron deficiency, iodine deficiency and vitamin-A deficiency individually and in combination amongst pregnant women. METHODS: A hospital based study was conducted amongst 829 pregnant women of II and III trimester attending antenatal clinic, Rural Health Training Center (RHTC), Najafgarh, New Delhi. Anemia was assessed by the presence of clinical signs and by hemoglobin levels. Iodine deficiency disorders (IDD) were assessed by clinical examination of thyroid gland and by urinary iodine excretion levels. Iodine content of the salt consumed by the pregnant women was also assessed by iodometric titration method. Vitamin A deficiency (VAD) was assessed by the presence of clinical symptoms of nightblindness. Current dietary intake, morbidity conditions on the day of survey and anthropometric measurements of pregnant women were also documented. RESULTS: Prevalence of anemia, IDD and VAD amongst pregnant women was 78.8%, 22.9% and 4.8%, respectively. One per cent of the pregnant women had concomitant presence of all the three MDDs. Pregnant women having combined prevalence of IDD and anemia, IDD and VAD, and VAD and anemia was 15.1%, 0.18% and 2.69%, respecively. Eighty nine per cent of the pregnant women were consuming salt with iodine content of more than 15 ppm which was recommended at household level. Results on dietary intake showed that 18%, 34%, 85% and 57% of the pregnant women were consuming less than 50% of calories, proteins, iron and b-carotene, respectively as compared to their RDA. Forty per cent of the pregnant women were suffering from various morbidity conditions on the day of survey. CONCLUSIONS: The prevalence of micronutrient deficiencies amongst pregnant women of urban slum communities is high.

Adolescent↗
PubMed1997

N-acetyl penicillamine a protector of Plasmodium berghei induced stress organ injury in mice.

N-acetyl penicillamine (NAP), a derivative of penicillamine and copper chelator has been employed as a potential protector of host stress organ injury during Plasmodium berghei infection in mice. Intramuscular injection of NAP (60 mg kg-1 body wt for 10 days) to P. berghei mice was able to restrict the hepato- and splenomegaly. The mortality rate of infected mice was decreased by 50% by NAP. The decreased protein and lipid peroxidation and increased copper contents during P. berghei were almost normalized after NAP treatment. The increased levels of erythrocytic superoxide anion and lipid peroxides due to infection were almost normalized after NAP treatment.

Animals↗
PubMed1997

Diagnosis of glomerular haematuria: role of dysmorphic red cell, G1 cell and bright-field microscopy.

Differentiation between glomerular and non-glomerular haematuria by observation of the changes in red cell morphology using phase-contrast microscopy is a well established technique. However, the method is not widely accepted in clinical practice because of controversy regarding the minimum percentage of dysmorphic red cells required to diagnose glomerular aetiology, as well as the need for specialized microscopes. Recently, a glomerular-specific morphological alteration of red cells has been described, which has the form of a doughnut shape with one or more blebs and which is termed the "G1" cell. In the present double-blind prospective study 250 urine samples were examined without any knowledge of diagnosis. Haematuria was detected in 122 cases. The type of haematuria was characterized by counting dysmorphic cells and G1 cells separately, in each case using a phase-contrast microscope as well as an ordinary bright-field microscope with and without staining of urinary sediments. The results were later correlated with the confirmed diagnosis. The study showed that the G1 cell is more specific than the dysmorphic cell for the diagnosis of glomerular haematuria. Evaluation of both dysmorphic red cells and G1 cells can be done using bright-field microscopy with 100% specificity and sensitivities of 82 and 100%, respectively. It has been concluded that the ordinary bright-field microscope can be used for the diagnosis of glomerular haematuria with an efficiency similar to that of a phase-contrast microscope.

Adolescent↗