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Biomedical subjects

W L Smith

Publications and source records attributed to W L Smith.

At least 73 records · Page 4Linked to original sources
PubMed1998

Traumatic brain injury in children and adolescents: psychiatric disorders at one year.

Factors predictive of psychiatric outcome in the second 6 months following traumatic brain injury (TBI) in 43 children and adolescents were assessed prospectively. The outcome measure was the presence of a psychiatric disorder not present before the injury ("novel"). Out of six models tested, four were predictive of novel psychiatric disorder: preinjury family function, family psychiatric history, socioeconomic class/intellectual function, and behavior/adaptive function. Post hoc analyses suggested that preinjury family functioning measured by a structured interview was a significant predictive variable. Severity of injury, when reclassified as severe versus mild/moderate TBI, significantly predicted novel psychiatric disorders. These data suggest that some children, identifiable through clinical assessment, are at increased risk for psychiatric disorders following TBI.

Adolescent↗
PubMed1998

Follow-up of a decentralized colposcopy program for the investigation and management of cervical intraepithelial neoplasia in the central Canadian Arctic.

Cervical intraepithelial neoplasia (CIN) is the second leading cause of cancer in Canadian Inuit women, and the incidence ratio in this population is 3.1 times the Canadian average. In 1993 a program was developed in a regional northern health center (Churchill) to provide colposcopy and loop electrosurgery for women in the Keewatin District of the central Canadian Arctic. Data collected prospectively over the following 2.5 years are presented. One hundred and forty-six women were seen in 341 visits. Indication for referral included CIN I on Pap smear (54.1%), CIN II (34.9%), CIN III (9.6%), and carcinoma of the cervix (1.4%). Large loop excision of the transformation zone was performed at a rate of 9.7 procedures per 100 patient visits. Estimated travel cost-savings attributable to this northern program are $299,200 (Canadian). Use of portable colposcopy in patients' home communities is presently being considered in order to provide enhanced accessibility and further cost-effectiveness.

Arctic Regions↗
PubMed1997

Eicosapentaenoic and docosahexaenoic acids reduce PGH synthase 1 expression in bovine aortic endothelial cells.

To enlighten the mechanism of inhibition of prostacyclin (PGI2) production by n-3 fatty acids, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, cultured endothelial cells were incubated with albumin bound-EPA or -DHA for 22 h. Under these conditions, PGI2 formation in response to bradykinin, calcium ionophore or exogenous arachidonic acid was equally inhibited by 50%, suggesting that the inhibition might occur downstream the phospholipase step, likely at the level of PGH synthase and/or PGI2 synthase activities. Western blot analysis indicated that the mass of the constitutive isoform of PGH synthase (PGH synthase 1), but not PGI2 synthase, was significantly reduced in n-3 fatty acid-enriched cells. In subsequent experiments, PGH synthase 1 mRNA level, measured by northern blotting, was also decreased in n-3 supplemented cells. This reduction was not due to mRNA destabilization. None of these parameters were altered by similar enrichment with oleic acid (OA). These results suggest that EPA and DHA may affect PGH synthase 1 expression, presumably at the transcriptional level.

Animals↗
PubMed1997

Traumatic brain injury in children and adolescents: psychiatric disorders in the first three months.

OBJECTIVE: To assess predictive factors of psychiatric outcome in the first 3 months after traumatic brain injury (TBI) in children and adolescents. METHOD: Subjects were children aged 6 to 14 years at the time they were hospitalized after TBI. The study used a prospective follow-up design. Assessments of preinjury psychiatric, behavioral, adaptive functioning, family functioning, and family psychiatric history status were conducted. Severity of injury was assessed by standard clinical scales and neuroimaging was analyzed. The outcome measure was the development of a psychiatric disorder, never before present ("novel") in a subject during the first 3 months after the TBI. RESULTS: Fifty subjects enrolled, and the analyses focused on 37 subjects followed up at 3 months. Increasing severity of injury, presence of a lifetime psychiatric disorder, family psychiatric history, family dysfunction, and lower socioeconomic class/preinjury intellectual function predicted the development of a "novel" psychiatric disorder in the first 3 months of follow-up. CONCLUSIONS: These data suggest that there are children, identifiable through clinical assessment, at increased risk for development of psychiatric disorders in the first 3 months after TBI.

Adolescent↗
PubMed1997

Traumatic brain injury in children and adolescents: psychiatric disorders at two years.

OBJECTIVE: To extend findings regarding predictive factors of psychiatric outcome from the first to the second year after traumatic brain injury (TBI) in children and adolescents. METHOD: Subjects were children aged 6 to 14 years at the time they were hospitalized after TBI. The study used a prospective follow-up design. Assessments of preinjury psychiatric, behavioral, adaptive functioning, family functioning and family psychiatric history status were conducted. Severity of injury was assessed by standard clinical scales and neuroimaging was analyzed. The outcome measure was the presence of a psychiatric disorder, not present before the injury ("novel"), during the second year after TBI. RESULTS: Fifty subjects enrolled, and the analyses focused on 42 subjects followed at 24 months. Severity of injury, preinjury family function, and preinjury lifetime psychiatric history predicted the development of a "novel" psychiatric disorder present in the second year. CONCLUSION: These data suggest that there are children, identifiable through clinical assessment, at increased risk for "novel" psychiatric disorders in the second year after TBI.

Adolescent↗
PubMed1997

Traumatic brain injury in children and adolescents: psychiatric disorders in the second three months.

Psychiatric disorders may be common after traumatic brain injury (TBI) in children, yet there is a death of prospective studies examining this problem. Fifty children aged 6 to 14, hospitalized after TBI, were assessed soon after TBI regarding preinjury psychiatric, behavioral, adaptive, and family functioning, family psychiatric history status and injury severity. The outcome measure was the presence of a "novel" psychiatric disorder (not present before the injury) during the second 3 months after the injury. Forty-two subjects were reassessed at 6 months. Severity of injury, family psychiatric history, and family function predicted a novel psychiatric disorder. Among children suffering a mild/moderate injury, those with preinjury lifetime psychiatric disorders were no longer (as they had been in the first 3 months) at higher risk than those without such a lifetime history. Thus, there appeared to be children, identifiable through clinical assessment, at increased risk for novel psychiatric disorders after TBI.

Adolescent↗
PubMed1997

Preferential activation of HSF-binding activity and hsp70 gene expression in Xenopus heart after mild hyperthermia.

We have examined the effect of mild hyperthermia on the pattern of heat shock transcription factor (HSF) binding activity, heat shock protein 70 (hsp70) and hsp30 gene expression and protein denaturation in selected tissues of adult Xenopus namely, heart, hind limb muscle, eye, liver and spleen. In these studies it was found that heart tissue was the most thermally sensitive of all of the tissues examined since maintenance of adult frogs at 26 degrees C resulted in a preferential activation of HSF binding. Thus, heart has a lowered set point temperature for HSF activation compared to the other tissues examined. At 30 degrees C HSF activation was observed in all of the tissues examined. Heart HSF activation at 26 degrees C was correlated with an increase in hsp70 mRNA and Hsp70 protein accumulation. At 28 degrees C the largest amount of hsp70 and hsp30 mRNA accumulation was detected in heart and skeletal muscle compared to other tissues while hsp70 mRNA accumulation was relatively low in spleen and hsp30 mRNA accumulation was not detectable in eyes, liver and spleen. Incubation of adult frogs at 30 degrees C resulted in enhanced hsp70 and hsp30 mRNA accumulation in all of the tissues. Finally, we have used differential scanning calorimetry (DSC) to compare the temperatures at which protein denaturation occurs in heart and liver tissue. The onset of protein denaturation (T0) occurred approximately 8.5 degrees C lower in heart compared to liver. Also the midpoint of the DSC profile (T1/2) was approximately 10.4 degrees C lower in heart than in liver. Thus, heart proteins are generally more thermolabile than proteins in liver tissue. Taken together these data suggest that heart is more sensitive than the other tissues examined with respect to moderate increases in environmental temperature.

Animals↗
PubMed1997

Pediatric radiology at a rural hospital: value of teleradiology and subspecialty consultation.

OBJECTIVE: We performed a field study and subsequent laboratory investigation of pediatric radiology at a small rural hospital. Our investigation had three components: to describe the characteristics of pediatric radiology in a rural primary care facility, to test the diagnostic accuracy of interpretation of pediatric images transmitted by teleradiology, and to compare relative diagnostic accuracy of general and pediatric radiologists who interpreted pediatric images at a rural institution. MATERIALS AND METHODS: All 196 pediatric radiographs obtained during a 4-month period comprised the database from which we determined practice characteristics. Reports of 153 unselected cases interpreted by general radiologists using teleradiology were compared with interpretation of the same cases by a pediatric radiologist who interpreted the original radiographs. Discrepant cases were further investigated by a receiver-operating-characteristic curve experiment in which general and pediatric radiologists interpreted each case twice: once viewing teleradiologic images and once viewing the original radiographs at another setting. We then compared interpretive accuracy of observers and techniques. RESULTS: The pediatric radiographs were predominantly simple examinations for common acute disease, particularly pneumonia and fractures. Discrepancies of interpretation between teleradiology and original radiographs, which occurred in 13% of images, showed no significant difference in accuracy of interpretation for either teleradiologic images or original radiographs. Likewise, we found no significant advantage for accuracy of interpretation by general or pediatric radiologists. Receiver-operating-characteristic analysis of 18 discrepant cases showed slightly increased accuracy for interpretation of original radiographs by pediatric subspecialists. CONCLUSION: Simple pediatric radiographs obtained at a rural primary care institution and transmitted by teleradiology can be adequately interpreted by general radiologists.

Adolescent↗
PubMed1997

Skeletal injuries in the pediatric patient.

Immature skeleton is different from adult skeleton with unique vulnerability to acute and chronic injuries at the growth plate. Recognition and differential diagnosis of inflicted skeletal injury are important. Familiarity with the dynamic changes of growing skeleton in normal children is key to the recognition of pathologic states.

Acute Disease↗
PubMed1997

Gastrointestinal tumors of childhood.

Tumors of the gastrointestinal tract in children are divided into tumors involving the solid organs that bud from the gastrointestinal tract, principally the liver, and tumors intrinsic to the alimentary tract. This article presents a review of the current state of understanding of solid tissue tumors. The human genome project and better understanding of human genetics have led to remarkable changes in the classification and description of tumors of the alimentary tract. This article attempts to summarize these changes to a current classification of the gastrointestinal polyposis syndromes.

Child↗