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Biomedical subjects

U Patel

Publications and source records attributed to U Patel.

At least 73 records · Page 4Linked to original sources
PubMed1994

Effect of electromagnetic stimulation with different waveforms on cultured chick tendon fibroblasts.

An energy efficient electromagnetic stimulator device for fracture healing was compared to a commercially available device in stimulating cell growth in tissue cultures. The energy efficient device, which conserves energy by using a bidirectional time-dependent magnetic wave form, and the commercially available stimulator, which uses a unidirectional time-dependent magnetic wave form, were tested on chick tendon fibroblasts in primary culture. Comparing non-stimulated control and cells electromagnetically stimulated with unidirectional and bidirectional waveforms showed that at the growth phase between days 2 and 3, both electrical stimulation techniques increased cell division as measured by DNA synthesis. When cells were dividing rapidly, collagen synthesis was reduced. When the cells reached the confluence there was no difference among the groups (control, unidirectionally stimulated, and bidirectionally stimulated) in terms of number of cells or collagen produced.

Animals↗
PubMed1994

Sonographic features of renal obstruction mimicked by peripelvic cysts.

Peripelvic cysts can closely mimic the sonographic changes of renal pelvicalyceal dilatation. Three cases are described in which a particular feature was the presence of linear septations extending to the hilum which represented the walls of tubular peripelvic cysts. The cluster of cysts centrally in the renal sinus was originally interpreted as a dilated pelvicalyceal system. Excretion urography is usually necessary to exclude pelvicalyceal dilatation conclusively.

Diagnosis, Differential↗
PubMed1994

The misplaced double J ureteric stent: technique for repositioning using the nitinol 'gooseneck' snare.

An antegrade method for repositioning a prematurely released double J ureteric stent is described. The technique is applicable when the proximal pigtail is still within the renal parenchyma or in the perinephric space. A custom-made Nitinol gooseneck snare was used in this case, but suitable alternatives should be readily available in a standard interventional suite and these are described.

Aged↗
PubMed1994

The diagnostic value of colour Doppler flow in the peripheral zone of the prostate, with histological correlation.

OBJECTIVE: To study the discriminative value of the amount of colour flow on Doppler ultrasound within the peripheral zone of the prostate. PATIENTS AND METHODS: One-hundred and twenty three men were studied using a 7 MHz transrectal probe, and 274 guided biopsies were undertaken. With each biopsy histological outcome was correlated with the grade of colour flow on ultrasound hard copy images. Biopsies with inflammatory cell infiltration, but without carcinoma, were subgraded according to the degree of inflammatory cell infiltration; and these grades were correlated with the corresponding colour flow grade. RESULTS: Normal colour flow was seen with both normal and abnormal prostate biopsy. With increased colour flow the likelihood of abnormal tissue increases; the highest grade of colour flow was seen with either carcinoma or prostatitis (grade 0, 1, 2 and 3 colour flow = 23%, 65%, 74% and 100% respectively of biopsies that were abnormal). In biopsies with inflammatory cell infiltration there was no linear relationship between the grades of colour flow and cellular infiltration (r = 0.52, P > or = 0.05, Kendall rank correlation). The mean grade of cellular infiltration was significantly greater in samples with grade 3 colour flow compared with grades 0-2. CONCLUSION: Grading of the amount of colour flow with Doppler ultrasound is of limited diagnostic discrimination, although with the greatest colour flow specificity for the diagnosis of abnormal prostate (either cancer or prostatitis) is very high. With prostatitis, markedly increased colour flow reflects the severity of inflammatory cellular reaction.

Adult↗
PubMed1994

Comparison of hand injection with mechanical injection for digital subtraction selective cerebral angiography.

100 patients undergoing digital subtraction cerebral angiography were randomized to have contrast delivered by either hand or mechanical injection. We compared the two modes of injection for image quality, the presence of vertebral reflux, possible complications and radiation exposure to the radiologist. There was no statistical difference between the two modes of contrast delivery for image quality and vertebral reflux. Only one definite temporary neurological complication was recorded. However, radiation exposure to the radiologist's hand and body were reduced by up to 70% by using a mechanical injector for contrast delivery during selective cerebral angiography with digital subtraction. We advocate use of the mechanical injector by radiologists who perform regular angiography to reduce their exposure to radiation.

Adolescent↗
PubMed1994

Dinucleotide repeat polymorphisms at nine loci in sporadic colorectal cancer.

Genomic instability in the form of microsatellite alterations at nine loci on chromosomes 2p, 8p, 10p, 11p, and nm23-H1 locus on 17q21.3 were studied in sporadic colorectal tumors. Alterations in dinucleotide repeats in tumor DNA as larger allele, smaller allele, or loss of heterozygosity (LOH) were observed. Forty percent of tumor showed an RER+ phenotype. A significantly high number of alterations was detected at loci of chromosome 8p. The markers on chromosomes 2p, 10p, and 11p did not show such significant alteration. LOH was found to be associated with the nm23-H1 locus. No correlation was found between the age, site of tumor occurrence, or metastasis and the microsatellite instability.

Adenocarcinoma↗
PubMed1994

Microsatellite instabilities at five chromosomes in primary breast tumors.

The microsatellite instabilities at nine loci of chromosomes 2p, 8p, 10p and 11p and the nm23-H1 locus on 17q21.3 were studied in primary breast tumors. Alterations in the short interspersed tandem repeats in tumor DNA in the form of either larger allele, smaller allele or LOH were observed. Significantly, a high occurrence of alterations in microsatellite polymorphisms at the ANK1, D8S135 and LPL loci of chromosome 8p (46-54%), the D2S119 locus of chromosome 2p (56%), the D10S197 locus at chromosome 10p (88%), and the nm23-H1 locus of chromosome 17q21.3 (46%) were observed in breast tumors. These results provide the first evidence for genomic instabilities at 2p, 8p and 10p in primary ductal and lobular breast carcinomas. No correlation has been found between the stage of the tumor and microsatellite instability, suggesting that microsatellite instability is an early genetic event in breast carcinogenesis.

Breast Neoplasms↗
PubMed1993

Mutation in the nm23 gene is associated with metastasis in colorectal cancer.

The human nm23 gene, a candidate metastatic suppressor gene, consists of two genes, nm23-H1 and nm23-H2. The potential mutation in the nm23-H1 gene was examined in colorectal cancer using a reverse transcription polymerase chain reaction amplification followed by DNA sequencing analysis. Genomic alterations in the nm23 gene were also examined by Southern hybridization. Genetic alterations either as a deletion in the coding sequence of nm23-H1 or as an allelic deletion were detected in four among eight colorectal adenocarcinomas associated with metastases in lymph nodes, lung, or liver. No alteration was observed in 12 additional colorectal cancer specimens without metastasis. These results provide first evidence for novel mutation in the nm23 gene and demonstrate a correlation between the mutation in the nm23 gene and metastasis in colorectal oncogenesis which suggests that the nm23 gene plays a role in the causation of metastasis.

Alleles↗
PubMed1993

Colour flow and spectral Doppler imaging after papaverine-induced penile erection in 220 impotent men: study of temporal patterns and the importance of repeated sampling, velocity asymmetry and vascular anomalies.

Of 220 impotent men studied, 52 demonstrated venous leakage, 85 had arterial insufficiency and 65 showed normal vascular response. Persistent diastolic velocity > 7 cm/s diagnosed venous leakage with a sensitivity of 94% and a specificity of 69%, using cavernosography as the reference standard. Using clinical response as the reference standard maximal systolic velocity of 30 cm/s identified normal penile arterial response with a sensitivity of 96% and specificity of 82%. There was a good correlation between penile arterial insufficiency and a strong history of arteriopathy. Time to peak systole > 0.1 s was a reliable predictor of arteriogenic impotence and Pulsatility Index (PI) < 300 was discovered only in patients with either venous leakage or arteriogenic impotence. Peak systolic velocity (Tmax) occurred between 5.2 and 6.5 min after injection, and diastolic velocity was minimal at 9 min with only the normal responders showing reversed diastolic flow. However, 22% had a delayed response (Tmax range 1-18 min). Velocity asymmetry was equally common in the three groups and unilateral sampling would have misdiagnosed 6% of patients studied. Vascular anomalies were seen in 13%, particularly a single feeding artery, dorsal vein flow or collateral arterial flow.

Adult↗
PubMed1993

Utility of the instant (unprepared) enema in Crohn's colitis.

Thirty-seven instant (unprepared) barium enemas in 30 patients with proven Crohn's colitis were reviewed. Plain films in 28 indicated that confluence or discontinuity of the colitis did not substantially alter the pattern of faecal residue. In only one patient was residue found overlying active mucosal disease. Aphthoid ulceration was demonstrated in 27%. In five (13%) examinations the colitis was granular and indistinguishable from ulcerative colitis. In 26/37 (70%) typical stigmata of Crohn's colitis were present. There was no complication or clinical deterioration after the instant enema. The instant enema was found to be comparable to a prepared examination for the diagnosis of advanced Crohn's disease, though less accurate for demonstrating early changes.

Barium Sulfate↗
PubMed1993

A randomised dose intensity study in ovarian carcinoma comparing chemotherapy given at four week intervals for six cycles with half dose chemotherapy given for twelve cycles.

BACKGROUND: The importance of dose intensity has not been clearly defined in ovarian cancer and we present a prospectively randomised trial of dose intensity in patients with ovarian cancer. PATIENTS AND METHODS: Ninety-nine patients with FIGO stage Ic, II, III and IV epithelial ovarian cancer were randomised to receive cycles of standard dose cyclophosphamide (600 mg/m2) and carboplatin (300 mg/m2) alternating with adriamycin (50 mg/m2) and ifosfamide (5 G/m2) for 6 cycles at monthly intervals (49 patients) or cycles of half dose cyclophosphamide (300 mg/m2) and carboplatin (150 mg/m2) alternating with adriamycin (25 mg/m2) and ifosfamide (2.5 G/m2) for 12 cycles at monthly intervals (50 patients). Patients in each arm were well balanced for major prognostic factors. RESULTS: The combined clinical response rate (complete response and partial response) on the 6 month arm was 76% compared with 48% on the low dose intensity arm (p = 0.009). With a median follow up of 25.7 months the median survival on the low dose intensity arm is 20.9 months. The median survival point on the 6 month arm has not yet been reached. The median progression free interval on the 12 month arm was 19.8 months, the median value has not yet been reached on the standard arm. The amount of residual tumour following initial laparotomy was the only significant independent variable affecting survival (p = 0.0001). The mean received dose intensity of each drug was greater than 80% of the planned dose intensity. More patients had clinical disease progression during treatment on the low dose intensity arm (42%) when compared to the standard dose intensity arm (8%) (p = 0.0003). Fifteen patients on the standard dose arm experienced a total of 18 delays and 5 patients on the low dose arm experienced 17 delays. Nausea, vomiting and diarrhoea were similar for both standard and low dose cycles of chemotherapy with a consequent benefit for patients receiving fewer cycles even though these were of higher dose. CONCLUSIONS: The combination studied was more effective when given at the higher dose intensity and the improved response and survival was not accompanied by a significant increase in toxicity.

Adenocarcinoma↗
PubMed1993

Thyrotropin-releasing hormone stimulation tests in infants.

The TSH response to TRH administration (7 micrograms/kg) was measured in 68 infants (22 premature) who had abnormal thyroid screening tests by the filter paper method and whose serum thyroid function tests were only mildly abnormal. Twenty-eight infants (12 premature) had peak TSH values of 35 mU/L or less and were considered normal (group I). Forty infants (10 premature) had peak TSH values above 35 mU/L and were considered hyperresponsive (group II). The mean age at testing, screening T4, TSH levels that prompted the testing, as well as baseline T4, T3, and free T4 at the time of TRH testing were not different between the groups. The mean (+/- SD) baseline TSH value was greater in group II (6.8 +/- 2.3 mU/L) than in group I (4.4 +/- 2.2 mU/L; P < 0.001). However, there was a great deal of overlap in the individual TSH values (group I, 0.9-10 mU/L; group II, 1.9-10.6 mU/L). Mean peak TSH levels were significantly different in the two groups (group I, 24 +/- 7.7 mU/L; group II, 60.3 +/- 26.1 mU/L; P < 0.001). During long term follow-up, all 25 group I infants available for evaluation have been confirmed as clinically and biochemically normal. No infant diagnosed as normal was later found to have evidence of hypothyroidism. Fourteen infants in group II have had evidence of thyroid dysfunction. We conclude that the TSH response to TRH stimulation is a useful tool for the evaluation of infants suspected of having primary hypothyroidism. Whether hyperresponsiveness to TRH represents a form of neonatal hypothyroidism requiring treatment remains to be determined.

Congenital Hypothyroidism↗
PubMed1993

Colour Doppler and duplex ultrasound assessment of Peyronie's disease in impotent men.

280 patients (aged 28 to 74 years, mean 57) with erectile failure (EF) underwent colour Doppler and duplex ultrasound imaging (CDI) following intracorporeal papaverine. After achieving a full, or nearly full, erection visual inspection and palpation revealed plaques and/or constriction or deformity of the penis in 55 (20%) cases. 10 (4%) were known to have Peyronie's plaques prior to referral. Of these 55 patients ultrasound showed focal echogenic plaques in 14 (25%) and diffuse thickening of the tunica albuginea in 41 (75%). CDI diagnosed arteriogenic EF in 20 (36%) of these patients, venous leak in 10 (18%), arterial and venous in two (4%) and a normal response in 23 (42%). In 11 (20%) patients (seven with arteriogenic EF and four with venous leak) the plaque was seen to be affecting vessels. These results indicate that abnormalities of the tunica albuginea are far more common in patients presenting with erectile failure than previously thought. We believe that the diffuse thickening is a form of Peyronie's which is only recognized after pharmacological induction of penile erection.

Adult↗