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Biomedical subjects

D W Shaw

Publications and source records attributed to D W Shaw.

At least 37 records · Page 2Linked to original sources
PubMed1997

CT scan abnormalities in a series of patients with hemorrhagic shock and encephalopathy syndrome.

BACKGROUND: Hemorrhagic shock and encephalopathy syndrome (HSES) affects children under 1 year of age and is characterized by seizures, shock and certain laboratory abnormalities, including coagulation abnormalities. It has a high mortality and many of the survivors are neurologically abnormal. OBJECTIVE: To describe abnormalities observed on initial and follow-up CT scans in a group of patients suffering from HSES. MATERIALS AND METHODS: Retrospective review of records and CT scans of ten patients with HSES who were admitted to the intensive care unit of the Children's Hospital and Medical Center, Seattle. RESULTS: Cerebral edema was seen in all cases when the CT scan was obtained between 1 and 7 days after onset of HSES. The basal ganglia and cerebellum were relatively spared, and no hemorrhage was seen. Patients with moderate or marked cerebral edema usually had a poor prognosis. All survivors had significant neurologic sequelae. CT scans obtained after 7 days often showed encephalomalacia with ex vacuo ventricular enlargement. CT scans obtained between 24 h and 4 days after onset will show the acute changes of HSES. CT scans during the initial and convalescent stages of HSES can provide useful information about cerebral edema and encephalomalacia, which occur frequently with this illness.

Brain↗
PubMed1997

Needle localization for thoracoscopic resection of small pulmonary nodules in children.

BACKGROUND: Children who have malignant disease and pulmonary nodules frequently need a tissue diagnosis to direct therapy. Computed tomography (CT)-guided needle localization and methylene blue marking allow thoracoscopic resection of nonvisible nodules. METHODS: Malignant disease was diagnosed in three patients aged 2, 2.5, and 11 years. Pulmonary nodules seen on chest CT, representing either metastatic disease or infection developed in each patient. All lesions were 1 to 2 cm deep to the pleural surface, precluding thoracoscopic visualization. A Homer mammographic needle was placed near the lesion using CT guidance under general anesthesia. The pleura overlying the lesion was also marked with methylene blue. Under the same anesthetic, patients went to the operating room where the lesions were thoracoscopically resected. RESULTS: Needle localization and methylene blue staining accurately localized the lesion in all cases. Thoracoscopic resection provided a diagnosis of metastatic disease or infection in all cases. There were no complications. CONCLUSION: CT-guided needle localization of pulmonary lesions deep to the pleural surface, is a safe, accurate method for allowing thoracoscopic resection in these children who would otherwise need open thoracotomy for diagnosis.

Biopsy↗
PubMed1997

Gastric outlet obstruction and epidermolysis bullosa.

We describe a case of pyloric atresia coexisting with epidermolysis bullosa, almost certainly of the junctional type. The coexistence of pyloric atresia and junctional epidermolysis bullosa (PA-JEB syndrome) has been repeatedly observed. This syndrome has several clinical features that distinguish it from Herlitz junctional epidermolysis bullosa (JEB). These include a lack of prominent granulation tissue formation and increased frequencies of genitourinary tract involvement and ear anomalies. Aplasia cutis congenita is sometimes present; esophageal atresia is uncommonly present. In all 12 patients examined to date, normal basement membrane zone expression of laminin-5 biochemically distinguishes PA-JEB syndrome from Herlitz JEB. Mutations in the beta 4 integrin gene have been observed in one patient with PA-JEB syndrome. Thus there are both clinical and biochemical reasons to separate the PA-JEB syndrome from Herlitz JEB. This is the second known case of papillary hyperplasia of the amnion to be seen in any setting. The other was a case of JEB without pyloric atresia.

Epidermolysis Bullosa↗
PubMed1997

D-2-hydroxyglutaric aciduria: hypotonia, cortical blindness, seizures, cardiomyopathy, and cylindrical spirals in skeletal muscle.

An infant girl was demonstrated to have D-2-hydroxyglutaric aciduria, the fifth case described and the first with muscle biopsy of this rare organic aciduria that differs clinically and genetically from the more common L-2-hydroxyglutaric aciduria. Her clinical features included mildly dysmorphic facies, developmental delay, generalized hypotonia, myoclonic seizures, cortical blindness, and dilated cardiomyopathy requiring treatment. Muscle biopsy demonstrated only excessive glycogen histochemically, but ultrastructural examination revealed subsarcolemmal cylindrical spirals and normal mitochondria. Because of the metabolism of D-2-hydroxyglutaric aciduria, we regard valproic acid as contraindicated in the treatment of epilepsy in this disease.

Amino Acid Metabolism, Inborn Errors↗
PubMed1997

Asymptomatic recurrence detection with surveillance scanning in children with medulloblastoma.

PURPOSE: To assess the utility of surveillance neuroimaging in detecting recurrent disease in patients treated for medulloblastoma. PATIENTS AND METHODS: Records and scans of 59 consecutive patients treated for medulloblastoma between 1984 and 1993 in one institution were retrospectively reviewed. RESULTS: Nineteen of 59 patients had recurrence of tumor, of which 17 were available for this study. Eleven of the 17 recurrent patients were asymptomatic at the time of detection. The median time to recurrence was 13 months (range, 3 to 90). CONCLUSION: Surveillance scanning detected a majority of recurrences before onset of symptoms. Although the outcome of those with recurrent disease remains poor, early detection with minimum disease provides the best setting in which to test newer therapies. Patients and their parents also were more likely to elect pursuing further treatment when relapse was detected asymptomatically.

Adolescent↗
PubMed1996

Influence of surgery on deglutitive upper oesophageal sphincter mechanics in Zenker's diverticulum.

BACKGROUND/AIMS: To evaluate the role of upper oesophageal sphincter (UOS) compliance in dysphagia, the functional consequences of surgery were evaluated in eight patients with pharyngeal diverticula. The study examined the hypotheses that hypopharyngeal intrabolus pressure is an indicator of UOS compliance and that UOS opening and intrabolus pressure are normalised by surgery. METHODS: In eight patients and nine healthy controls, we measured the timing of swallow events, UOS relaxation, maximal UOS dimensions, intrabolus pressure, and trans-sphincteric bolus flow rates by simultaneous videoradiography and pharyngeal manometry. RESULTS: Bolus flow rates were not changed by surgery. Surgery significantly increased UOS opening (p = 0.0001) and reduced hypopharyngeal intrabolus pressure (p = 0.0001). The slope of the relation between sphincter area and intrabolus pressure was steeper in patients than controls and was normalised by surgery. Surgery had minor effects on basal UOS tone and timing of swallow events. CONCLUSIONS: Upper oesophageal sphincter compliance is poor in Zenker's diverticulum and is normalised by surgery. Hypopharyngeal intrabolus pressure, which correlates with resistance to trans-sphincteric bolus flow, is a useful indicator of UOS compliance. Intrabolus pressure may be a predictor of outcome after myotomy in pharyngeal dysphagia. Cricopharyngeal myotomy is a mandatory component of surgery for Zenker's diverticulum.

Aged↗
PubMed1996

Spinal subdural enhancement after suboccipital craniectomy.

PURPOSE: To characterize transient intraspinal subdural enhancement (potentially mimicking the subarachnoid spread of tumor) seen on MR images in some children after suboccipital craniectomy for posterior fossa tumor resection. METHODS: Radiologic and medical records of 10 consecutive children who had MR imaging for spinal staging after resection of posterior fossa tumor during a 9-month period were reviewed retrospectively. In addition, one case with similar findings of intraspinal enhancement on spinal staging MR images obtained at another institution was included in the review. RESULTS: Intraspinal enhancement thought to be subdural was seen in four of 10 patients undergoing spinal staging MR imaging 6 to 12 days after surgery. In these four patients, MR studies 50 to 18 days later, without intervening treatment, showed resolution of the abnormal enhancement. A fifth patient (from another institution) with similar intraspinal enhancement underwent CT myelography 4 days later, which showed no subarachnoid lesions. No metastases have developed in any of these five patients during the 2.5- to 3.5-year follow-up period. conclusions: From analysis of the MR appearance and on the basis of prior myelographic experience, we suggest an extraarachnoid, probably subdural, location of this enhancement. Awareness of this phenomenon will reduce the rate of false-positive diagnoses of metastatic disease. Preoperative spinal staging should be considered for patients undergoing suboccipital craniectomy.

Child↗
PubMed1995

Agreement among evaluators of bovine embryos produced in vivo or in vitro.

Six experienced individuals evaluated 40 embryos on videotape for stage of development and quality grade. These 40 observations comprised 15 embryos produced in vivo, 15 embryos produced in vitro, and 10 embryos that were repeated throughout the videotape. Embryos produced in vivo were recovered from uterine flushings of superovulated heifers 7 d after estrus, and embryos produced in vitro were harvested 7 d after insemination of in vitro-matured oocytes. Embryos of various stages (morulae, blastocysts, or degenerated) and quality grades (1 = excellent, 2 = good, 3 = fair, 4 = degenerated) were recorded on videotape for evaluation. After video microscopy, the embryos were stained and the number of nuclei per embryo was counted. Six evaluators reviewed the videotape and the percentage of agreement and kappa (k; agreement beyond chance) among evaluators were determined for classifications of stage and grade. Consistency of each evaluator's responses was estimated using the 10 repeated embryos. Agreement within evaluators was higher for stage of embryo development (89.2%) than quality grade (68.5%). Agreement among evaluators for stage was slightly higher with embryos produced in vivo (85.0%, k = 0.74) than in vitro (72.3%, k = 0.48). Agreement among evaluators for grade was similar with embryos from in vivo (61.0%, k = 0.46) and in vitro (57.7%, k = 0.42) production. For both sources of embryos, agreement was substantially better for Grades 1 and 4 than for Grades 2 and 3. The results of this study suggest that good to excellent agreement exists for classifying Day 7 bovine embryos by stage and by extremes of quality grade (Grades 1 and 4) but not by degree of abnormal morphology (Grades 2 and 3). Simple grading criteria of Grade 1 (highest quality), Grade 2 (morphologic defects), and Grade 3 (degenerated) maximized agreement among evaluators.

Journal Article↗
PubMed1995

Evolution of the cranial computed tomography scan in child abuse.

Computed tomography (CT) scans obtained at the time of clinical presentation have occasionally been reported to be normal in children with history and findings of significant abusive head injury. We have retrospectively observed abnormalities in "normal" scans of some similar children. We have also seen abnormalities develop on serial scanning. To determine how frequently these situations occur, we reviewed charts of 34 children with a final diagnosis of child abuse who also had cranial CT scans performed. Their CT scans were retrospectively reviewed by a pediatric radiologist. Eleven (11/34) CT scans had initially been interpreted as normal. Four (4/11) of these had been reinterpreted during the hospitalization as abnormal, affecting medical (1) and legal (3) outcome. Repeat scanning in three of the remaining seven resulted in surgical drainage of a subdural effusion (1) and affected legal outcome (2). Four of the seven initial scans felt normal throughout the hospitalizations were judged abnormal on retrospective review. This evaluation was confirmed in the two rescanned. Initial CT interpretation most often failed to appreciate changes in parenchymal density and small amounts of falcine or cortical subdural blood. Subsequent scans also showed evolving effusions and infarcts. Changes were noted in 1 1/2 to 5 days. The CT scan frequently shows subtle changes in the immediate posttrauma period. If the child does not recover promptly, subsequent scans frequently result in significant changes in clinical and legal management.

Brain Edema↗
PubMed1995

Concentrations of tumor necrosis factor alpha and progesterone within the bovine corpus luteum sampled by continuous-flow microdialysis during luteolysis in vivo.

Corpora lutea (CL) of mature, nonlactating Holstein cows (n = 12) each received surgical implants of a microdialysis system between Days 12 and 16 of an estrous cycle (estrus = Day 0). Fractions from dialyzed CL were collected every 30 min for 12 h each day for 7-9 days after surgery. Concurrent sampling of jugular venous blood allowed comparison between luteal dialysate and peripheral serum hormone concentrations. Six cows received no treatment, while 4 cows received prostaglandin F2 alpha (PGF; 25 mg, i.m.) and 2 cows received hCG (5000 IU, i.m.) within 48 h after surgery. Serum progesterone (P4) declined to < 1 ng/ml by Day 20 +/- 0.5 in 4 of 6 nontreated cows and by Day 15 +/- 0.6 in all 4 PGF-treated cows. Both of the hCG-treated cows had increased serum and dialysate P4 after treatment and did not show evidence of luteolysis by the end of their sampling period (Days 22 and 18), and 2 of 6 nontreated cows did not show evidence of luteolysis by the end of their sampling period (Days 22 and 24). All 8 cows undergoing spontaneous or induced luteolysis showed a significant rise (p < 0.01) in dialysate (but not serum) tumor necrosis factor alpha (TNF) after P4 began to decline. From the start of the decline in dialysate P4, intervals to first detectable TNF and to peak TNF, and duration of TNF in the dialysate were 25.8 +/- 8 h, 38.3 +/- 8 h, and 42.3 +/- 7 h, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Nontraumatic pediatric musculoskeletal MR imaging: comparison of conventional and fast-spin-echo short inversion time inversion-recovery technique.

PURPOSE: To compare conventional short inversion time inversion-recovery (STIR) with fast spin-echo (FSE) STIR techniques to evaluate suspected nontraumatic musculoskeletal abnormalities. MATERIALS AND METHODS: Thirty STIR and FSE-STIR examinations in 26 pediatric patients with suspected nontraumatic musculoskeletal abnormalities were prospectively evaluated. Qualitative (subjective) and quantitative (five-point rank score) analyses of the images were performed. RESULTS: FSE-STIR was faster than STIR (mean, 2 minutes 25 seconds and 6 minutes 35 seconds, respectively). Fat suppression was slightly better with STIR. Image degradation due to motion was judged similar. Lesion contrast to muscle was slightly better with STIR than FSE-STIR, and lesion contrast to fat was equivalent. Qualitatively, lesion conspicuity was similar: All lesions were seen with both techniques. CONCLUSION: FSE-STIR can replace STIR when an inversion-recovery fat-suppression sequence is desired. Considerable imaging time is saved.

Adolescent↗
PubMed1995

Influence of normal aging on oral-pharyngeal and upper esophageal sphincter function during swallowing.

The influence of aging on oral-pharyngeal swallowing was assessed by simultaneous manometry and videoradiography in 14 nondysphagic elderly individuals (mean age 76 yr) and 11 healthy, young controls (mean age 21 yr). Sphincter opening was diminished significantly in the elderly (P = 0.0001), but trans-sphincteric bolus flow rates were preserved. The increased impedance to trans-sphincteric bolus flow from reduced sphincter opening in the aged was reflected in a significant increase in hypopharyngeal intrabolus pressure (P = 0.003). Oral transit time was significantly prolonged in the aged (P = 0.01). The timing of upper esophageal sphincter (UES) manometric relaxation and of opening was significantly delayed in the aged (P = 0.0001), and this delay was comparable in magnitude to the prolongation in oral transit. Coordination of UES relaxation and opening with midpharyngeal contraction was not significantly affected by age. Deglutitive hyolaryngeal motion was not affected by age but was delayed by a duration equivalent to the prolongation in oral transit. We conclude that normal aging prolongs the oral-pharyngeal swallow that impairs UES opening but does not influence pharyngo-sphincteric coordination.

Adolescent↗
PubMed1995

MR imaging of bone marrow in children with osteosarcoma: effect of granulocyte colony-stimulating factor.

OBJECTIVE: Granulocyte colony-stimulating factor (GCSF) is used to stimulate myeloid cell production and function in children undergoing chemotherapy for osteosarcoma. We hypothesize that GCSF can cause reconversion of marrow from fatty to hematopoietic and that this change can be detected by MR imaging at sites away from the primary tumor. This benign effect of treatment should not be confused with tumor spread. MATERIALS AND METHODS: MR images of marrow of the affected and contralateral limbs were retrospectively reviewed for 16 patients with osteosarcoma of the femur or tibia; nine of these patients had received GCSF. A grade was assigned to marrow signal intensity at sites away from the tumor, and findings before and after treatment were compared. The validity of MR image interpretation was assessed by comparing the signal intensity of marrow with the histologic appearance of marrow at 19 resection margins. RESULTS: Changes consistent with reconversion were seen on MR images in seven of nine patients who had received GCSF in addition to chemotherapy and in none of seven patients who had received chemotherapy alone. The difference in proportions was statistically significant (p = .006; Fisher's exact test, two tailed). The histologic appearance of marrow at the resection margins agreed with the interpretation of the short-Tl inversion recovery sequence in all cases (100%). CONCLUSION: The findings suggest that GCSF causes changes in the MR imaging appearance of marrow. Histologic correlation supports the hypothesis that these changes are attributable to reconversion from fatty to hematopoietic marrow. Awareness of this finding is important to avoid false-positive diagnosis of marrow metastases.

Adolescent↗
PubMed1995

Hematopoietic marrow regeneration in pediatric patients undergoing spinal irradiation: MR depiction.

PURPOSE: To evaluate changes in vertebral marrow signal intensity that occur over time in children undergoing craniospinal radiation therapy, specifically evaluating for the occurrence and timing of marrow regeneration. METHODS: MR images of nine pediatric patients (ages 4 to 12 years) with posterior fossa medulloblastoma who received total spinal irradiation (24 to 40 Gy) and had at least three MR examinations were reviewed. Signal intensity to vertebral body marrow was graded by two pediatric neuroradiologists who were blinded to patient identity and to the timing of the studies. RESULTS: Eight of nine patients demonstrated increasing signal intensity of the vertebral marrow after irradiation, consistent with conversion of hematopoietic to fatty marrow. In each of these patients, this was followed by subsequent decreasing signal intensity in a mottled or peripheral band pattern indicating recovery of hematopoietic marrow. CONCLUSION: Changes in vertebral body signal intensity consistent with marrow reconversion commonly are seen in pediatric patients 11 to 30 months after they undergo total spinal irradiation.

Bone Marrow↗
PubMed1995

Hypercalciuria and nephrocalcinosis in the oculocerebrorenal syndrome.

The oculocerebrorenal (Lowe) syndrome is an X-linked recessive disorder characterized by congenital cataracts, hypotonia, developmental delay, poor growth and renal tubular dysfunction. Although the disorder has been mapped to chromosome Xq24-26, the underlying metabolic defect remains unknown. The renal component of the Lowe syndrome comprises tubular dysfunction, that is tubular proteinuria and generalized aminoaciduria progressing to the renal Fanconi syndrome, with later glomerular disease. Clinical problems typically include polyuria, acidosis, hypophosphatemia with rickets and eventually end stage renal disease. Hypercalciuria and its sequelae (nephrocalcinosis and nephrolithiasis) have not been described as cardinal features of the untreated disorder although they reportedly complicate vitamin D and calcium therapy of rickets. We discuss 5 boys with congenital cataracts, hypotonia, developmental delay, failure to thrive and the renal Fanconi syndrome who were diagnosed with the Lowe syndrome and in whom hypercalciuria was documented at diagnosis. We conclude that hypercalciuria and its sequelae may occur commonly in patients with the Lowe syndrome as a component of tubular dysfunction or a complication of therapy.

Calcium↗