PubMed Health⌕ Search

Biomedical subjects

M De Silva

Publications and source records attributed to M De Silva.

At least 19 recordsLinked to original sources
PubMed1998

A comparison between digital images viewed on a picture archiving and communication system diagnostic workstation and on a PC-based remote viewing system by emergency physicians.

Picture Archiving and Communication Systems (PACS) make possible the viewing of radiographic images on computer workstations located where clinical care is delivered. By the nature of their work this feature is particularly useful for emergency physicians who view radiographic studies for information and use them to explain results to patients and their families. However, the high cost of PACS diagnostic workstations with fuller functionality places limits on the number of and therefore the accessibility to workstations in the emergency department. This study was undertaken to establish how well less expensive personal computer-based workstations would work to support these needs of emergency physicians. The study compared the outcome of observations by 5 emergency physicians on a series of radiographic studies containing subtle abnormalities displayed on both a PACS diagnostic workstation and on a PC-based workstation. The 73 digitized radiographic studies were randomly arranged on both types of workstation over four separate viewing sessions for each emergency physician. There was no statistical difference between a PACS diagnostic workstation and a PC-based workstation in this trial. The mean correct ratings were 59% on the PACS diagnostic workstations and 61% on the PC-based workstations. These findings also emphasize the need for prompt reporting by a radiologist.

Emergency Service, Hospital↗
PubMed1998

Culturing human embryos with and without glucose.

OBJECTIVE: To review published data and to compare pregnancy rates (PRs) after culturing human embryos with and without glucose and phosphate. DESIGN: Comparison of results from various programs. SETTING: Assisted Reproductive Technology Program. PATIENT(S): Patients were enrolled in various studies. INTERVENTION(S): Human embryos were cultured with and without glucose and phosphate. MAIN OUTCOME MEASURE(S): Pregnancy rates after different techniques of embryo culture. RESULT(S): Some studies reported higher PRs in patients undergoing IVF after embryos were cultured in media without glucose and phosphate versus media with glucose and phosphate. One study showed that PRs were lower when embryos were cultured in media lacking glucose and phosphate compared with media containing glucose and phosphate. Some studies have also shown similar PRs with the two types of culture media. CONCLUSION(S): The PRs in IVF patients will not necessarily be enhanced if the embryos are cultured in media without glucose and phosphate.

Culture Media↗
PubMed1997

Genetic instability in patients with metachronous colorectal cancers.

BACKGROUND: Nearly 7 per cent of patients who undergo resection for colorectal cancer develop metachronous cancers several years later. A molecular marker that could identify patients susceptible to metachronous cancers would be of clinical importance. METHODS: Twenty-four colorectal cancers from 15 individuals with metachronous colorectal cancer were investigated for microsatellite instability at five loci by single stranded conformational polymorphism analysis. A control group of 14 colorectal cancers from individuals who had only developed one sporadic colorectal cancer each was analysed similarly. RESULTS: Microsatellite instability was demonstrated in 17 of 24 cancers from individuals with metachronous cancer compared with one of 14 cancers from individuals with a single colorectal cancer. CONCLUSION: These results suggest that testing for microsatellite instability may be useful in recognizing patients at high risk of developing metachronous colorectal cancers.

Aged↗
PubMed1996

MRI findings in children with neurofibromatosis type 1: a prospective study.

To determine the frequency and nature of MRI lesions in children with neurofibromatosis type I (NF1), 50 patients aged 8 to 16 years were evaluated prospectively with cranial MRI. Forty-one children were asymptomatic with respect to central nervous system pathology, and 50% were macrocephalic. Sixteen patients (32%) had normal MRI examinations. Thirty-two patients (64%) had high intensity lesions on T2-weighted images and 16 patients (32%) had hyperintense lesions on T1-weighted images. Seven patients (14%) had ventricular dilatation (associated with increased intracranial pressure in 2) and 11 patients (22%) had optic pathway lesions (optic glioma in 7). MRI was superior to CT in differentiating optic sheath thickening and optic nerve tortuosity from optic glioma in four patients. An intracranial tumour (ependymoma) and sphenoid wing dysplasia were evident in individual patients. Findings previously unreported in NF1 included an aqueductal web resulting in hydrocephalus, intraocular neurofibroma resulting in retinal detachment, and asymptomatic enlargement of the septum pellucidum. T1 and T2 signal abnormalities in isolation were not associated with neurological deficits or the occurrence of macrocephaly, and all lesions that required intervention were suspected clinically. Macrocephaly in the absence of increased intracranial pressure or accelerated head growth is not an indication for neuroimaging in children with NF1. However, the majority of children (68%) had disease-specific abnormalities and thus MRI may provide a useful adjunct to clinical evaluation in the diagnosis of equivocal cases.

Brain↗
PubMed1996

Chest radiograph abnormalities in very low birthweight survivors of chronic neonatal lung disease.

OBJECTIVE: To determine whether the neonatal chest radiograph (CXR) at 28 days in very low birthweight (VLBW) infants who develop chronic neonatal lung disease (CNLD) predicts oxygen therapy duration or CXR abnormalities in early childhood. Also, to assess the inter-observer reliability of the radiologists scoring the CXR. METHODOLOGY: Clinically well survivors of CNLD (n = 46) had neonatal CXR scored (mean age 28.5 days) and compared with current CXR (mean age 40 months). The CXR were scored independently and 'blindly' by two paediatric radiologists using a standardized scoring system (range 0-10). RESULTS: There was no correlation between neonatal CXR scores and current CXR scores for either radiologist. There was no association between CXR severity scores and duration of oxygen therapy for either neonatal or current CXR. Radiologist A scored the current CXR significantly more abnormal than radiologist B [medians (range): 3 (1-6) vs 1 (0-5), P < 0.001] with reasonable correlation (r = 0.593, P < 0.005) but worse than chance agreement (kappa = -0.034). The median scores for the neonatal CXR were similar [1.5 (0-8) vs 2 (0-8), P = 0.789] and again there was good correlation (r = 0.760, P < 0.0005) although poor individual agreement (kappa = 0.243) between radiologists. CONCLUSIONS: Follow-up CXR abnormalities in VLBW infants with CNLD are usually minor and are not predictive of the duration of oxygen therapy that will be required nor of the CXR appearance in early childhood. Considerable inter-observer variation exists in the interpretation of the CXR in CNLD.

Bronchopulmonary Dysplasia↗
PubMed1995

Hepatobiliary disease in cystic fibrosis patients with pancreatic sufficiency.

Focal and multilobular biliary cirrhosis are considered pathognomonic of cystic fibrosis (CF) and almost invariably have been reported in patients with steatorrhea. In contrast, patients with pancreatic sufficiency and normal absorption are considered less likely to develop liver or biliary tract problems. The authors report three patients with CF and pancreatic sufficiency, presenting with recurrent abdominal pain (unrelated to pancreatitis). All had common bile duct disease, one with multilobular cirrhosis and portal hypertension. Pancreatic sufficiency was proven by quantitative pancreatic stimulation tests, 3-day fecal fat analyses, and serum pancreatic isoamylases. All three patients had mild lung disease. Two were homozygous for the common delta F508 mutation, and the other, a delta F508 compound heterozygote. Hepatobiliary structure and function were determined by serial hepatobiliary scintigraphy, percutaneous transhepatic cholecystography, and biochemical liver function tests. Patients 1 and 3 had mild hepatomegaly, normal liver biochemistry, and distal common bile duct strictures. Patient 2 had a firm nodular liver with splenomegaly, abnormal liver biochemistry, and a cholangiographic appearance of sclerosing cholangitis. All have undergone operative treatment for persistent abdominal pain. These cases confirm the occurrence of common bile duct pathology and liver disease in patients with CF and pancreatic sufficiency. They demonstrate that liver and biliary tract disease can occur independently of the underlying disease severity and the presence of steatorrhea. Further, they suggest that obstruction of the biliary tract may be an additional factor in the evolution of liver disease in CF.

Biliary Tract Diseases↗
PubMed1994

Thyroid stimulating hormone causes cumulus expansion in mouse oocytes.

The objective of this study was to determine if thyroid stimulating hormone (TSH) could induce cumulus expansion in mouse oocytes in-vitro. The effect of TSH was compared with the effects of LH and FSH. Oocytes were incubated in minimum essential medium (MEM) with and without hormones for 16 h at 37 degrees C under a humidified atmosphere of 5% CO(2) and 95% air. Then LH, FSH or TSH was added into the culture medium at a concentration of 0.25, 0.5, or 1.0 microg/ml, respectively. Cumulus expansion was scored in a subjective manner (O = no expansion; + = slight; ++ = moderate; +++ = maximum expansion) 16 h after addition of the hormones. The percentage of oocytes in the 4 categories of expansion was noted; LH failed (P>0.05) to induce cumulus expansion while TSH and FSH induced cumulus expansion (P<0.05) at all of the doses tested. For FSH, the 0.5 microg/ml dose showed the best response (26% = 0; 18% = +; 10% = ++; 46% = +++). For TSH, the 1.0 microg/ml dose showed the best response (38% = 0; 18% = +; 13% = ++; 31% = +++).

Journal Article↗
PubMed1994

Detection and measurement of thyroid stimulating hormone in human follicular fluid.

The objectives were to measure thyroid stimulating hormone (TSH) levels in human follicular fluid (FF) and compare them with serum levels. Serum and FF samples were obtained from women (n = 41) undergoing in vitro fertilization/embryo transfer, gamete intrafallopian transfer and zygote intrafallopian transfer. Ovulation induction was achieved using human menopausal gonadotropins and human chorionic gonadotropin (hCG) after pituitary suppression with a gonadotropin releasing hormone agonist. Blood samples obtained on the day of hCG injections were assayed for TSH. Follicular fluids were obtained at the time of oocyte retrieval (approximately 34 hours after hCG injection). Serum and FF TSH levels were measured using an enzyme immunoassay. The correlation between serum and FF TSH levels was determined. Comparison between mean serum and FF levels was done using Student's t test after logarithmic transformation of the data. Levels of TSH in FF (1.71 +/- 0.14 microIU/mL, mean +/- SEM) were not different (P > .05) from levels in serum (1.43 +/- 0.10). Serum and FF levels correlated positively (r = .7). TSH appears to be present in human FF, and the levels in FF are similar to those in serum.

Female↗
PubMed1993

Infantile myofibromatosis: a radiological review.

Infantile myofibromatosis is an unusual condition generally presenting in the newborn period. It may be solitary or multicentric. Sites involved include skin and subcutaneous tissues, muscle, bones and viscera. Nine cases are presented, including one case in an identical twin whose co-twin remained asymptomatic. The radiological features and differential diagnosis are discussed.

Bone Neoplasms↗
PubMed1992

Partial sacral agenesis with constipation: a report of one family.

Seven first degree relatives in three generations of a family with partial sacral agenesis are reported. Anterior sacral meningoceles were found in five cases, four of whom had severe constipation, one with urinary voiding dysfunction, and another without constipation who had low pressure headaches and dyspareunia. The anomalad was transmitted in an autosomal dominant fashion with incomplete penetrance and variable expression. This entity should be considered in all children and adults with severe constipation from birth, a family history of constipation and/or where constipation is refractory to medical therapy.

Abnormalities, Multiple↗
PubMed1992

Aggressive surgical management of craniopharyngiomas in children.

The cases of 50 patients with craniopharyngioma operated on at The Hospital for Sick Children in Toronto between January, 1975, and December, 1989, are reviewed. All patients were under 18 years of age (mean 9.39 years). Headaches, endocrine deficiencies, and visual deficits were the most common symptoms on admission. Forty-five patients underwent what was considered by the surgeon to be total excision of their tumor, and five had subtotal excision. Tumors recurred in 17 patients (mean time of recurrence 32.6 months after surgery). One patient died in the postoperative period and three have been lost to follow-up study. Of the remaining 46 patients, 28 are leading a normal or nearly normal life, although all are receiving endocrine replacement and some have required help to overcome mild deficits in memory or visual acuity. Twelve patients are able to function reasonably well and attend school despite being hampered by intellectual or visual deficits or problems with weight control; four have a significant handicap, and two have died.

Actuarial Analysis↗
PubMed1990

Effect of removal of cumulus cells from one-cell mouse embryos on in vitro development.

The effects of the removal of cumulus cells from fertilized mouse oocytes (one-cell embryos) and the presence of streptomycin in culture medium on in vitro development were studied. Ham's F-10 medium with (0.075 g/liter) or without streptomycin was supplemented with human serum (15%). Cumulus-intact embryos were harvested from oviducts after mice were superovulated with pregnant mare's serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Hyaluronidase (300 IU/ml) was used to remove the cumuli. Embryos were cultured (i) with cumulus/without streptomycin (n = 238), (ii) with cumulus/with streptomycin (n = 185), (iii) without cumulus/with streptomycin (n = 210), and (iv) without cumulus/without streptomycin (n = 218). Embryonic development was assessed 24, 96, and 120 hr after initiation of culture. Percentage two cells and percentage small or expanded blastocysts were not different (P greater than 0.05) among experimental groups. Percentages (mean +/- SE) hatched blastocysts for the four groups were (i) 36 +/- 8 and 54 +/- 7, (ii) 35 +/- 8 and 55 +/- 6, (iii) 19 +/- 5 and 42 +/- 6, (iv) 23 +/- 5 and 47 +/- 5 at 96 and 120 hr, respectively. Percentages all (small, expanded, and hatched combined) blastocysts were (i) 74 +/- 5 and 74 +/- 5, (ii) 74 +/- 9 and 72 +/- 5, (iii) 56 +/- 6 and 63 +/- 5, and (iv) 61 +/- 5 and 63 +/- 5 at 96 and 120 hr, respectively. A greater (P less than 0.05) percentage of embryos developed to blastocysts and hatched by 96 and 120 hr, when they were cultured with the cumulus intact.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Imaging paediatric endocrine disorders.

Disorders of growth and development, including delayed and precocious puberty may be idiopathic, constitutional or due to a disorder of one of several endocrine systems including the hypothalamic-pituitary system, the adrenal and the thyroid. Sonography is of great importance in the classification of precocious puberty in children. Skeletal maturation assessment is useful to evaluate the severity of the growth disorder and to monitor subsequent therapy. Magnetic resonance imaging and computed tomography are essential in the study of the pituitary and central nervous system. MRI has special advantages in the imaging of the hypothalamic-pituitary region. The thyroid gland and its function are still best imaged with radionuclide scintigraphy. Sonography can play a complementary though less important role. Hypoparathyroidism, pseudohypoparathyroidism and pseudopseudohypoparathyroidism although rare are more common in children than primary hyperparathyroidism. Valuable clues as to the presence of these conditions can be gained by examination of the plain radiographs. Confirmation of their diagnosis still rests with the biochemical and endocrine profile.

Diagnostic Imaging↗