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Biomedical subjects

M L Young

Publications and source records attributed to M L Young.

108 records · Page 6Linked to original sources
PubMedDate not supplied

Focal small bowel perforation: an adverse effect of early postnatal dexamethasone therapy in extremely low birth weight infants.

OBJECTIVE: We tested the hypothesis that early postnatal dexamethasone (EPD) increases the risk of focal small bowel perforation (FSBP) in extremely low birth weight (ELBW) infants. STUDY DESIGN: The techniques of meta-analysis were applied to studies evaluating EPD, which we identified through a systematic literature search. Studies were included if they were randomized, placebo-controlled trials of EPD, enrolled infants with birth weights < or =1000 g, and reported FSBP as an outcome variable. The Breslow-Day test was used to assess for homogeneity and a summary odds ratio was calculated using the Mantel-Haenszel exact method. RESULTS: Four studies, with a pooled sample of 1383 infants, were included in the primary analysis. The Breslow-Day test showed a p-value of 0.61, indicating homogeneity among the studies. FSBP was significantly higher in EPD treated infants [odds ratio 1.91, 95% confidence interval (CI) 1.21, 3.07; p=0.004]. CONCLUSION: EPD increases the risk of FSBP in ELBW infants.

Anti-Inflammatory Agents↗
PubMedDate not supplied

Late events in pediatric patients with Ewing sarcoma/primitive neuroectodermal tumor of bone: the Dana-Farber Cancer Institute/Children's Hospital experience.

The outcome for 82 pediatric patients with Ewing sarcoma (ES) and primitive neuroectodermal tumor (PNET) of bone is reported; the patients were treated at the Dana-Farber Cancer Institute (DFCI) and Children's Hospital (CH) in Boston, MA (USA) from 1971-1988. The charts of all patients with ES/PNET of bone treated during this period were reviewed for disease status, therapy, sites of relapse, information on second malignancies, and survival status. Eighty-two patients with ES/PNET of bone treated at DFCI/CH were identified. The 10-year event-free survival (EFS) rates were 12% (95% confidence interval [CI] 0, 27%) and 38% (95% CI 26, 51%) for patients with and without metastases, respectively (P = 0.002); the overall survival (OS) rates were 17% (95% CI 1, 33%) and 48% (95% CI 35, 61%) for patients with and without metastases (P = 0.001). Median follow-up for surviving patients is 10.2 years. Primary site in the pelvis also was associated with a poor outcome for patients with no metastatic disease (P = 0.006 OS, P = 0.03 EFS). Thirty-one patients survived in first remission at least 5 years from diagnosis, and of these, five experienced relapse of original disease, and five experienced secondary malignancies. Pediatric patients treated for ES/PNET of bone remain at risk for life-threatening events into the second decade of follow-up. After 5 years, the risk of second malignant neoplasm is at least as high as the risk of late relapse. Prolonged follow-up of patients with ES and PNET of bone is indicated.

Adolescent↗
PubMedDate not supplied

Electrophysiologic study and surgical ablation of atrioventricular nodal reentrant tachycardia: report of one case.

A 12 years old boy with frequent episodes of palpitation was found, by the electrophysiologic study, to have an atrioventricular (AV) nodal tachycardia. Endocardial mapping during surgery revealed that the earliest retrograde atrial depolarization of the tachycardia occurred at the posterior part of Koch's triangle. Under normothermic cardiopulmonary bypass, perinodal dissection was performed above the tricuspid annulus at the coronary sinus region. The retrograde VA conduction disappeared. Post-surgery the antegrade conduction had a Mobitz type I block which had returned to normal after the fourth month follow-up.

Child↗
PubMedDate not supplied

Sinus node dysfunction in children.

Seven out of 829 pediatric cardiac patients (0.84%) were found to have sinus node dysfunction (SND) over the past seven years. Of the seven patients, three had structurally normal hearts. One of these three patients had long QT syndrome. In four patients, structural heart disease was noted. In three of these four patients the sinus node dysfunction was attributed to cardiac surgery. The age of onset of SND ranged from four months to eight years. Presenting symptoms and signs included syncope, near-syncope, seizure and congestive heart failure. Two patients were asymptomatic. Five patients had episodic sinus pause. Sinus or junctional bradycardia was noted in four patients. Three had tachy-bradycardia. High grade atrioventricular block was noted in one patient. Treadmill exercise test revealed a nonsustained ventricular tachycardia in two patients. All seven patients were found to have prolonged maximal corrected sinus node recovery time. Prolonged intra-atrial conduction time was found in three, prolonged AV nodal conduction time in one, and prolonged His-Purkinje conduction time in one patient during the electrophysiologic study. All seven patients showed abnormal results in intrinsic heart rate study. Anti-arrhythmic drugs were prescribed. During the follow-up study, no patient died, but two patients received a pacemaker implantation. Because of the extent of their conduction system diseases, it is recommended that patients with SND should be thoroughly investigated.

Child↗
PubMedDate not supplied

Atrial overdrive pacing for conversion of atrial flutter in children.

Atrial flutter (AF) is a potentially dangerous arrhythmia in children, which is difficult to be converted into sinus rhythm by drug therapy alone. In four young patients (3 had history of cardiac surgery, 1 had Ebstein's anomaly), the AF which had failed to medical therapy was converted into sinus rhythm by an intracardiac atrial pacing: In two patients the AF was terminated by atrial pacing alone, and in the other two the AF was converted into sinus rhythm by atrial pacing after procainamide infusion. In all patients an entrainment of AF was observed during the atrial pacing, which favored a reentrant mechanism for the AF in these patients. Evidences of sinus node dysfunction were observed in all three postoperative patients. We conclude that atrial pacing with or without procainamide infusion is an effective method for the conversion of atrial flutter. In addition, for patients with AF and concomitant sinus node dysfunction, this method can ensure the patients' safetiness.

Adolescent↗
PubMedDate not supplied

Unusual cardiac malformations in Holt-Oram syndrome: report of two cases.

The Holt-Oram syndrome is a hereditary disease which associated with upper limbs anomalies and cardiac defects such as secundum type atrial septal defect. Two cases of this syndrome with unusual cardiac findings are reported: One has an unroofing coronary sinus type atrial septal defect and preexcitation syndrome, the other has pentalogy of Fallot.

Abnormalities, Multiple↗
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An electrophysiologic study of a child with idiopathic sustained left ventricular tachycardia.

A child with congestive heart failure was found to have a paroxysmal ventricular tachycardia (VT) without structural heart disease. This wide QRS tachycardia had an atrioventricular dissociation and a QRS pattern of right bundle branch block and left axis deviation. The tachycardia did not respond to lidocaine or procainamide but instantly responded to verapamil therapy. This VT could be initiated or terminated by either atrial or ventricular pacing during electrophysiologic study. The endocardial biopsy showed that there was myocardial hypertrophy with mild degree of interstitial fibrosis. This entity of ventricular tachycardia often occurs in young people with no overt heart disease but with subclinical endomyocardial changes.

Child↗
PubMedDate not supplied

An historical prospective mortality study of the Sarnia Division of Dow Chemical Canada Inc., Sarnia, Ontario (1950-1984).

We examined the mortality experience of 3,479 male Dow Canada employees who were employed at Sarnia Division for at least 12 continuous months during the years 1945 through 1983, utilizing the Canadian Mortality Data Base maintained by Statistics Canada, covering 1950-1984. We analyzed cause-specific mortality using male, age and calendar-year-adjusted death rates for Canada and Ontario. Total mortality was significantly below expectation whether the entire follow-up period (240 observed vs. 366.9 expected) or a 15-year latency period (171 observed vs. 290.4 expected) was considered. Statistically significant fewer observed deaths were found for all respiratory cancer, cancer of the bronchus and lung, circulatory disease, ischemic heart disease, cerebrovascular disease, digestive disease, cirrhosis and other liver disease and deaths due to accidents, poisonings and violence. The observation of three deaths due to mesothelioma, a rare cancer often associated with asbestos exposure, was a significant finding as was a statistically significant elevation of observed deaths in the category "other forms of heart disease".

Adult↗
PubMedDate not supplied

Rapid identification of color additives, using the C18 cartridge: collaborative study.

Nine laboratories collaboratively studied a method for the separation and identification of the 7 permitted FD&C color additives (Red Nos. 3 and 40; Blue Nos. 1 and 2; Yellow Nos. 5 and 6; Green No. 3) and the banned FD&C Red No. 2 in foods. The method is based on use of a commercial C18 cartridge and spectrophotometry or thin layer chromatography. Collaborators analyzed 5 commercial products (noodles, candy, carbonated soda, flavored gelatin, and powdered drink) and 2 dye mixtures (one containing FD&C Red Nos. 2, 3, and 40; the other containing FD&C Green No. 3 and Red No. 3). All of the colors were identified with little or no difficulty by 8 collaborators. The method has been adopted official first action.

Chromatography, Thin Layer↗
PubMedDate not supplied

Rapid determination of color additives, using the C18 cartridge.

A reliable method has been developed for the rapid separation and identification of the 7 permitted FD&C dyes (Red Nos. 3 and 40; Blue Nos. 1 and 2; Yellow Nos. 5 and 6; Green No. 3) and the recently banned FD&C Red No. 2 in foods. The colors are separated by using the C18 cartridge, and their identity is confirmed by spectrophotometry.

Chromatography, Thin Layer↗
PubMedDate not supplied

Radiofrequency catheter ablation of supraventricular tachycardias in pediatric patients.

Supraventricular tachycardia (SVT) is the most common cardiac arrhythmia in children. Atrioventricular (AV) reciprocating tachycardia utilizing an accessory pathway and AV nodal reentrant tachycardia (AVNRT) constitute a majority of SVTs. Radiofrequency energy ablation has recently become the treatment of choice in adults. Initial experience in pediatric patients in this Institute is reported in this study. Six consecutive patients (aged 5-22 years, mean age 13 years; 3 boys, 3 girls) with narrow-QRS SVT were studied from July to October in 1993. They had experienced symptomatic SVT for a mean period of five years (ranged from 1 to 15 years). Anti-arrhythmic agents, including beta-antagonists and calcium channel blockers, were unable to satisfactorily suppress these SVTs. Four of the six patients were shown to have a left-sided concealed accessory connection as the retrograde limb of the reentrant circuit. After identification of the earliest retrograde activation site, a steerable 7F catheter with a 4-mm-long electrode at the distal tip was placed within the left ventricle and positioned against the atrio-ventricular annulus. Another two patients were proved to have AVNRT. The ablation catheter was placed at the posterior/inferior aspect of the tricuspid annulus and guided by putative slow potential. Radiofrequency current was delivered at a power from 15 to 25W for four to six times with a mean duration of 40 seconds in patients with AV reciprocating tachycardia, and a single time in those with AVNRT. All six SVTs were successfully ablated. No complication was noted in any patient. Follow-up for three to seven months has indicated no recurrence of SVT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗