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Biomedical subjects

D Selby

Publications and source records attributed to D Selby.

17 recordsLinked to original sources
PubMed1999

Deletion analysis of the adenomatous polyposis coli and PTCH gene loci in patients with sporadic and nevoid basal cell carcinoma syndrome-associated medulloblastoma.

BACKGROUND: Medulloblastomas can occur sporadically or may be associated with hereditary tumor syndromes including familial adenomatous polyposis (FAP) and nevoid basal cell carcinoma syndrome (NBCCS). METHODS: The authors performed a retrospective analysis for allelic deletion of the adenomatous polyposis coli (APC) and PTCH gene loci using paraffin embedded medulloblastoma specimens from patients who were admitted to Children's National Medical Center in Washington, DC, between 1982 and 1997. Thirty-five cases from which tumor and normal tissue could be procured were analyzed. Two of the analyzed cases had a positive family and personal history for NBCCS; in both cases the histology of the medulloblastoma revealed a desmoplastic phenotype. Thirty-three cases were not known to be associated with hereditary disease; 2 of those cases revealed desmoplastic and 31 cases revealed nondesmoplastic "classic" medulloblastoma histology. RESULTS: Although medulloblastoma tumorigenesis has been associated strongly with FAP associated with APC germline mutation, none of the 22 informative sporadic cases revealed loss of heterozygosity of the APC gene locus. PTCH gene deletion was detected in the tumors of both patients with NBCCS. In contrast, only 1 of 33 sporadic medulloblastomas revealed PTCH gene deletion. The sporadic case with PTCH gene deletion did not demonstrate the desmoplastic phenotype. CONCLUSIONS: In conjunction with previous studies, the data from the current study confirm that allelic deletion occurs in NBCCS-associated medulloblastomas, consistent with the role of PTCH as a tumor suppressor gene. However, in sporadic medulloblastomas, allelic deletion of PTCH is an infrequent event. Morphologic examination in conjunction with genetic analysis of PTCH gene deletion in medulloblastoma tissue may prove to be a quick and efficient test with which to screen for NBCCS in patients with medulloblastomas. Although medulloblastoma is a component of Turcot syndrome with demonstrated APC mutations, APC gene deletions appear to be absent or very uncommon in patients with sporadic and NBCCS-associated medulloblastomas.

Adenomatous Polyposis Coli↗
PubMed1998

Bladder distention and pyelectasis in the male fetus: causes, comparisons, and contrasts.

The objective of this paper was to determine if prenatal sonographic findings can accurately differentiate between the causes of bladder distention and pyelectasis in the male fetus. Twenty-one cases were evaluated for the presence of oligohydramnios, posterior urethral dilation, bladder wall thickening, urachal patency, cortical thinning, cortical cysts, and increased renal echogenicity. Postnatal diagnosis included posterior urethral valves (10 cases), prune belly syndrome (four cases), vesicoureteral reflux (four cases), left ureterovesical junction obstruction (one case), and nonrefluxing, nonobstructive megacystis-megaureter (two cases). Oligohydramnios was present in eight of 10 cases of posterior urethral valves and in one of four cases of prune belly syndrome. A dilated posterior urethra was noted in seven of 10 cases of posterior urethral valves and transiently in two of four cases of prune belly syndrome. Bladder wall thickening developed in all cases of posterior urethral valves and was noted in two of four patients with prune belly syndrome. A patent urachus likewise was identified in two of four cases of prune belly syndrome. The presence of oligohydramnios, progressive bladder wall thickening, and dilated posterior urethra was most suggestive of posterior urethral valves, whereas the presence of a patent urachus was most suggestive of prune belly syndrome. The presence of pyelectasis and megacystis without additional amniotic fluid, bladder, urethral, or renal abnormalities was most suggestive of vesicoureteral reflux, ureterovesical junction obstruction, or nonrefluxing, nonobstructive megacystis-megaureter. Owing to the overlap and evolution of these findings, close follow-up evaluation is recommended.

Dilatation, Pathologic↗
PubMed1997

A typical hemolytic uremic syndrome in human immunodeficiency virus-1-infected children.

We describe the clinical and pathological findings of the hemolytic uremic syndrome (HUS) in two children with human immunodeficiency virus (HIV) infection. Both patients presented with microangiopathic hemolytic anemia, thrombocytopenia, and subsequently developed renal failure. The diagnosis of HUS was confirmed by renal histopathology in both patients. None of these children presented with bloody diarrhea, evidence of circulating antibody response to Escherichia coli O157 lipopolysaccharide, or other known risk factors for HUS, except for the presence of HIV infection. Each patient was treated with intravenous plasma infusion and renal replacement therapy. Their clinical course was characterized by non-oliguria and lack of significant hypertension throughout the acute phase of the disease. Despite these favorable clinical parameters, both patients developed end-stage renal failure. The etiology of this atypical HUS characterized by poor renal survival remains unknown and the role of HIV infection in its pathogenesis, although possible, is unclear.

Brain↗
PubMed1996

Association of a suprasellar mass and intraocular retinoblastoma: a variant of pineal trilateral retinoblastoma?

OBJECTIVE AND IMPORTANCE: 'Trilateral retinoblastoma' designates the association of bilateral retinoblastomas with an ectopic (non-metastatic) intracranial primitive neuroectodermal tumor (PNET). Although the intracranial tumor, usually located in the pineal region, is seen 2-3 years after discovery of the bilateral ocular tumors, variant presentations do occur. The intraocular tumor can be unilateral, and the intracranial tumor can be suprasellar, presenting before the retinal lesions. CLINICAL PRESENTATION: A 4-month-old boy presented with irritability, vomiting and nystagmus. Head CT revealed a large calcified sellar-suprasellar mass. Ocular examination disclosed white macular lesions in the right fundus. He was taken to surgery where subtotal resection of the sellar-suprasellar mass was achieved. Microscopic examination showed a primitive, small, round, blue cell tumor consistent with retinoblastoma. The right ocular lesions, also consistent with retinoblastoma, were treated by cryosurgery. CONCLUSION: The appearance of a suprasellar PNET can precede the appearance of retinal masses in retinoblastoma. The literature suggests that patients with 'sellar' trilateral retinoblastoma have characteristics that differ from patients with a pineal region trilateral retinoblastoma: the intracranial mass more often presents initially; it occurs at a younger age; it is predominant in females, and is more often associated with unilateral ocular lesions. Retinal screening of patients with suprasellar PNET and other atypically located PNETs may disclose more cases of sellar 'trilateral retinoblastoma' and hereditary retinoblastomas. This will have implications on genetic counseling as siblings harboring the disease may be diagnosed and treated at an earlier stage.

Brain Neoplasms↗
PubMed1995

Isolated chloroma: the effect of early antileukemic therapy.

OBJECTIVE: To evaluate the effect of antileukemic chemotherapy administered at diagnosis on the survival of patients with isolated chloroma. DESIGN: Retrospective review of locally identified patients and analysis of cases from the medical literature. PATIENTS: The records of all patients with isolated chloroma identified at three teaching hospitals in Toronto between 1980 and 1994 were reviewed. A MEDLINE search was done to identify all cases of isolated chloroma reported in the English-language medical literature. Patients with a previous known hematologic disorder were excluded. MEASUREMENTS: The effect of therapy on 1) the interval between diagnosis of chloroma and diagnosis of acute myeloid leukemia and 2) survival was determined. RESULTS: 7 local patients and 83 published cases were identified, for a total of 90 evaluable patients. For the entire group, the median time to the diagnosis of acute myeloid leukemia was 9 months, and median survival was 22 months. Chemotherapy was administered to 49 patients (54%) at diagnosis of chloroma. Significantly fewer patients treated with chemotherapy subsequently developed acute myeloid leukemia (41% compared with 71%; P = 0.001). Survival was longer in patients treated with chemotherapy (> 50% alive with a median follow-up of 25 months compared with a median survival of 13 months for those initially untreated; P = 0.001). Multivariate analysis showed that neither local radiotherapy nor surgery had an effect on survival. CONCLUSIONS: Administration of antileukemic chemotherapy at diagnosis of chloroma is associated with a significantly lower probability of developing acute myeloid leukemia and with longer survival.

Acute Disease↗
PubMed1991

Patients avoiding surgery. Pathology and one-year life status follow-up.

Patients were selected for a research study to determine the outcome of patients who had demonstrated enough pathology to have been viewed as surgical candidates and had chosen to avoid surgery. The purpose of the study was to identify the diagnostic categories and to obtain follow-up data on these patients. The patient population consisted of 66 patients with the following pathologies: disc disruption (one and two levels), disc disruption (three levels), stenosis, spondylolisthesis, instability, and herniated nucleus pulposus. The patients were followed for a period of 1 1/2 years and rated on the following lifestyle status categories: Returned to Work, Retired, Retraining, Able to Increase Activity Level, or No Change from Initial Status. Of the nonoperative patients, 18% returned to work. Twelve patients (18%) were retired. Eleven patients (16%) were placed in retraining programs. Twenty patients (29%) were able to increase activity level. Eleven patients (16%) fell under the category of no change.

Activities of Daily Living↗
PubMed1989

Pain provocation and disc deterioration by age. A CT/discography study in a low-back pain population.

The computed tomography (CT)/discograms and discographic pain provocation reports of 291 clinical patients, 790 discs (mean age, 38; range, 17-79) were collected. The CT/discograms were classified separating anular disruption and degeneration and recording the pain provoked during discography as no pain, dissimilar, similar, or exact reproduction of the patient's clinical pain. Nondegenerated discs usually were found to be painless, and deteriorated discs painful. The proportion of severely degenerated but painless discs increased with age, as did the discs producing dissimilar pain. This may help explain the poor correlation of low-back pain with radiographic degenerative changes reported in previous epidemiologic studies.

Adult↗
PubMed1989

The development of the Dallas Pain Questionnaire. An assessment of the impact of spinal pain on behavior.

The Dallas Pain Questionnaire (DPQ) was developed to assess the amount of chronic spinal pain that affects four aspects (daily and work-leisure activities, anxiety-depression, and social interest) of the patients' lives. Results of the DPQ's statistical properties suggest that the DPQ is an externally reliable instrument as well as internally consistent. Two factors emerged from factor structure analysis. Factor 1 represents functional activities and Factor 2 represents emotional capacities. A correlation analysis suggests the concurrent validity of the psychological functional factors of the DPQ. A t test demonstrated that chronic pain patients have significantly higher DPQ scores than normals. Because these findings support its statistical properties, the DPQ appears to have utility for clinical and research purposes. The findings, limitations, and implications of this study are detailed, as are suggestions for future research.

Activities of Daily Living↗
PubMed1986

Internal fixation with Knodt's rods.

Knodt's rods are an effective distraction internal fixator for promoting fusion for lumbar spine surgery. The chief disadvantage in 92 cases was a removal rate of about one third. The 93% fusion rate, and instant mobilization of the patient are reasonable trade-offs for the disadvantages of a second operation for removal of the rods.

Humans↗
PubMed1985

Reduction of postoperative pain parameters by presurgical relaxation instructions for spinal pain patients.

This study investigated the effects of a relaxation instruction session conducted presurgically with postsurgical pain parameters for patients undergoing spinal surgery. Results indicated that the relaxation group (n = 50) as compared with an equivalent group (n = 50) matched to type of surgery and sex type, workers compensation status had significant reduction of days of hospitalization, complaints noted by nurses, and medications (primarily demerol and phenaphen). Sex type, age, and workers compensation status were not significant factors regarding these outcome measures. The results were considered in light of the anxiety/pain explanation of pain sensitivities with implications for health care with spinal pain surgical candidates.

Adult↗
PubMed1983

The relationship of Minnesota Multiphasic Personality Inventory (MMPI) profile clusters to pain behaviors.

Previous research involving cluster analysis of Minnesota Multiphasic Personality Inventory (MMPI) profiles among persons with chronic low back pain has suggested the existence of four distinct profile clusters. The present study had two goals: (1) to replicate the previous finding independently and (2) to investigate the relationship of the profiles to the subjects' self-reported pain history and response to treatment. Subjects were 92 patients in a multimodal inpatient low back-pain treatment program. A cluster analysis of the MMPI profiles was performed and the resultant clusters were compared in terms of histories and treatment outcome. The four clusters were successfully replicated for the total sample and for males and females separately. The profiles were significantly related to subjects' pain histories, but only one outcome difference was found. It was inferred that the MMPI is of value in understanding patients' pain coping behaviors but that further research is needed to explore the utility of the MMPI in understanding their response to treatment.

Back Pain↗
PubMedDate not supplied

Orthogonal acceleration time-of-flight mass spectrometry.

The principles and applications of time-of-flight mass spectrometry involving instruments with independent (orthogonal) axes for ion generation and mass analysis are reviewed. This approach, generally referred to as orthogonal acceleration time-of-flight mass spectrometry, has proved particularly advantageous for the combination of continuous ionization sources with time-of-flight mass spectrometry. The history of the technique is briefly discussed along with the instrumental principles pertaining to all the stages of the instrumentation from ion source to detector. The applications of commercial and customized instruments are discussed for several ionization methods including electrospray, matrix assisted laser desorption/ionization, electron ionization, and plasma ionization.

Albumins↗