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Biomedical subjects

D M Rosenbaum

Publications and source records attributed to D M Rosenbaum.

At least 37 records · Page 2Linked to original sources
PubMed1995

Fracture of the cuboid in children. A source of leg symptoms.

We report eight cases of fracture of the cuboid in seven children under four years of age, collected during a two-year period. There was no history of trauma in five of the patients. This fracture is rarely diagnosed and has probably been under-reported. Small children are poor historians and difficult to examine, and early radiographs may be normal or have only subtle abnormalities. Cuboid fracture should be considered in the differential diagnosis of limping toddlers, and a bone scan may be needed to confirm the diagnosis earlier than radiography. These fractures heal completely, without sequelae. Treatment in a short-leg walking cast is recommended, primarily for reasons of comfort.

Casts, Surgical↗
PubMed1994

Evidence for hypoxia-induced, programmed cell death of cultured neurons.

Apoptosis, a form of cell death ("programmed" cell death) in which the nucleus and cytoplasm shrink and often fragment, serves to eliminate excessive or unwanted cells during remodeling of embryonic tissues, during organ involution, and in tumor regression. In acute pathological states, such as ischemia, the cells tend to swell and lyse--a process called necrosis. We hypothesize that the delayed neural death clinically associated with hypoxia may, in part, represent apoptosis. A tissue culture model of 24 hours of hypoxia was employed using sympathetic neurons. Pretreatment with an endonuclease inhibitor (aurintricarboxylic acid) decreased cell death by 53%, depolarizing conditions (55 mM potassium chloride) decreased cell death by 33%, and an RNA synthesis inhibitor (actinomycin D) by 26% (all have been shown to prevent apoptosis). Pretreatment with antisense c-myc had no effect. Fluorescent staining with propidium iodide (a DNA marker) demonstrated chromatin condensation and agarose gel electrophoresis demonstrated a DNA "ladder." These data suggest that apoptosis may play a role in hypoxic cell death and that in this paradigm, expression of c-myc is unnecessary. This would suggest a new approach to our understanding of hypoxia and open new strategies to lessen neuronal damage secondary to this process.

Animals↗
PubMed1994

Superoxide dismutase ameliorates neuronal death from hypoxia in culture.

BACKGROUND AND PURPOSE: Studies showing efficacy with free radical scavengers have been conflicting, and when protection was demonstrated it was attributed to action at the level of the vascular endothelium. The purpose of this study was to test the hypotheses that neuronal free radical formation plays a role in the ischemic cascade and occurs intracellularly and that free radical scavengers, if taken up intracellularly, will protect against hypoxic damage. METHODS: A tissue culture model of hypoxia followed by restoration of oxygen was employed, using both superior cervical ganglia and hippocampal neurons. Cells were exposed to an anoxic atmosphere of 95% N2 and 5% CO2 and examined 2 to 24 hours later after restoration of oxygen. Determination of survival was measured by trypan blue exclusion. Nitroblue tetrazolium stain was used to assess free radical formation. RESULTS: Pretreatment with free superoxide dismutase did not decrease cell death after hypoxia as measured by trypan blue exclusion. However, when superoxide dismutase was taken up intracellularly under depolarizing conditions (55 mmol/L KCl in the medium), cell death was decreased significantly compared with hypoxic controls (28.7 +/- 4.34 versus 40.3 +/- 4.33; P < .03). During hypoxia neurons reduced nitroblue tetrazolium to form the blue precipitate formazan, and the color change was blocked in neurons pretreated with superoxide dismutase in depolarizing medium. Similar findings occurred in both superior cervical ganglia and hippocampal neurons. CONCLUSIONS: These findings provide evidence to support the role of neuronal free radical formation in cell death secondary to hypoxia. In addition, free radical scavengers, if taken up intracellularly, may partially ameliorate their deleterious effect.

Animals↗
PubMed1992

Sonographic diagnosis of intestinal malrotation in infants: importance of the relative positions of the superior mesenteric vein and artery.

OBJECTIVE: An abnormal relative position of the superior mesenteric vein and artery can be present in patients with intestinal malrotation. We undertook this retrospective study to see how often we could determine the relative position of these vessels on abdominal sonograms in infants and how often abnormal position of the vessels was associated with malrotation. MATERIALS AND METHODS: We reviewed the radiology files and medical records of 337 infants with vomiting who were referred for sonography because of possible pyloric stenosis. We used sonograms and written reports to determine the position of the superior mesenteric vessels. The position was considered normal when the superior mesenteric vein was to the right of the superior mesenteric artery on transverse sonograms. The position was considered abnormal when the vein was directly ventral to the artery or when the vein was to the left of the artery. Sonographic findings were compared with results of upper gastrointestinal series when possible and with clinical outcome. RESULTS: The relative positions of the superior mesenteric vein and artery were evident in 249 (74%) of the 337 patients. Abnormal orientation of the mesenteric vessels was detected in nine patients. In five patients, the superior mesenteric vein was located to the left of the artery, and all five had intestinal malrotation. In four patients, the superior mesenteric vein was directly ventral to the artery, and one of these had malrotation. CONCLUSION: Sonographic assessment of the relative positions of the mesenteric artery and vein is an important adjunct in the examination of infants with suspected pyloric stenosis. Patients in whom sonograms show an abnormal position of the vessels should have further examination to detect malrotation.

Congenital Abnormalities↗
PubMed1990

Baclofen does not protect against cerebral ischemia in rats.

Presynaptic release of glutamate into the extracellular compartment and activation of receptor-operated calcium channels may contribute to ischemic neuronal damage. We evaluated the effect of baclofen, a selective inhibitor of presynaptic glutamate release, on mortality, working memory, and light microscopic hippocampal and cortical damage in the four-vessel occlusion model of cerebral ischemia using 64 male Wistar rats. Baclofen (10 mg/kg i.p.) given 1 hour before and 30-60 minutes after 20 minutes of global ischemia did not lessen mortality, prevent ischemic cellular damage, or significantly improve working memory compared with no treatment. We conclude that preischemic and postischemic administration of baclofen does not protect neurons from ischemic injury.

Animals↗
PubMed1990

Renal involvement in children with lymphoma: comparison of CT with sonography.

In order to determine whether real-time sonography or contrast-enhanced CT was better for detecting renal involvement by lymphoma in children, we retrospectively studied 44 patients (6 months to 19 years of age) in whom lymphoma was diagnosed at our hospital during a 5-year period. In no patient was there any clinical evidence of renal disease at the time of presentation. In 39 patients, sonographic and CT findings were similar (normal in 36 patients and showing extrinsic mass effects on the kidneys in three patients). In five patients with non-Hodgkin lymphoma whose contrast-enhanced CT scans showed low-attenuation renal nodules, renal sonography was normal in two, showed renal enlargement in two, and showed a solitary hypoechoic nodule in one patient with multiple, bilateral nodules on CT. Tissue diagnosis of the renal lesions was not obtained, but in the four patients who had follow-up CT, the renal abnormalities resolved after chemotherapy. Our findings suggest that contrast-enhanced CT is superior to sonography for detection of renal lymphoma in children.

Adolescent↗
PubMed1990

Pilot study of nicardipine for acute ischemic stroke.

The author performed a pilot study of nicardipine (NC), a Ca(+)+ channel blocker, to study its dosing, toxicity, and possible efficacy for hemispheric cerebral infarction within 12 hours (mean 6.9 hr) of onset to determine the advisability of proceeding with a multi-centered controlled trial. NC was administered IV (3 to 7 mg/hr) X 72 hours by titrating dose to mean arterial blood pressure (MABP not less than 10% of baseline), then orally X 30 days. Forty-three patients have been entered; mean age 63 (range 34-89), 25 male and 18 female. Only 3 had CT evidence of infarct on entry. Results have shown improvement in a 100-point (pt) graded exam (40 pts at entry, 68 pts at 3 months). Of 20 patients completing 3 months' evaluation, 17 improved and none worsened. Sixteen out of 20 were at home and 8 had minimal or no impairment. Mean Barthel's index was 72. Mean maximal serum NC level was 75 ng/mL. MABP decreased from 103 (entry) to 83 (72 hours). A larger controlled study is warranted to determine the efficacy of NC for acute cerebral infarct.

Acute Disease↗
PubMed1989

Apraxia of eyelid opening secondary to right hemisphere infarction.

A variety of eyelid movement abnormalities have been attributed to lesions of the central nervous system. Apraxia of lid movements, and especially of lid opening, has received the least attention. We present 2 cases of lid opening apraxia and propose that this abnormality may be due to right hemisphere dysfunction.

Aged↗
PubMed1988

Sonographic diagnosis of hypertrophic pyloric stenosis.

In many pediatric centers, sonography has become the primary imaging method for the diagnosis of hypertrophic pyloric stenosis, but investigators have disagreed about which dimension of the gastric outlet is most useful and accurate. We analyzed 326 consecutive sonograms in 319 infants who presented with vomiting in order to further evaluate the sonographic criteria for the diagnosis of hypertrophic pyloric stenosis. Four observers retrospectively measured three parameters: (1) the thickness of the muscle in the wall of the gastric outlet, (2) the length of that muscle, and (3) the length of the pyloric channel. In the patients with hypertrophic pyloric stenosis, muscle thickness was 4.8 +/- 0.6 mm, muscle length was 2.1 +/- 0.3 cm, and channel length was 1.8 +/- 0.3 cm. In the patients without hypertrophic pyloric stenosis, muscle thickness was 1.8 +/- 0.4 mm, muscle length was 1.3 +/- 0.3 cm, and channel length was 1.1 +/- 0.3 cm. The mean measurement for each parameter was significantly larger in patients who had hypertrophic pyloric stenosis than in those who did not (p less than .01). However, histograms of the three parameters show significant overlap in the measurements of muscle length and channel length between the patients with and those without hypertrophic pyloric stenosis. The thickness of the muscle is the most discriminating and accurate criterion for hypertrophic pyloric stenosis.

Female↗
PubMed1987

Sonographic evaluation of abdominal lymphangiomas in children.

Sonography provided an accurate diagnosis in 10 preoperative studies and correctly showed the extent of the lesions in two postoperative examinations in a group of 12 children with surgically proven intraabdominal lymphangiomas. These masses typically contained anechoic fluid in one or more contiguous cystic loculations bounded by or containing one or more 1- to 2-mm thick septa. Thicker septa occurred in several cases with inflammation and/or accumulations of fatty tissue. Chylous or creamy fluid displayed fine diffuse echoes, whereas hemorrhage resulted in coarse echoes and/or solid masses. In two patients unusual renal involvement mimicked polycystic kidney disease. Typical sonographic appearances of lymphangioma may be radically altered by hemorrhage, inflammation, and unusual sites of involvement.

Abdominal Neoplasms↗
PubMed1986

Atlantooccipital instability in Down syndrome.

Atlantooccipital instability is an uncommon and usually lethal result of major trauma. Nontraumatic cases of instability at this site are rare. We report the findings in two children with Down syndrome who have striking atlantooccipital subluxation demonstrated on flexion and extension radiographs. Since there is increasing radiologic evaluation of cervical spine stability in patients with Down syndrome who wish to participate in athletic activities, the status of the atlantooccipital joint needs careful assessment, especially after cervical fusion for C1-C2 instability.

Adolescent↗
PubMed1985

Acute epiphyseal osteomyelitis in children.

Nine children over 20 months of age had acute osteomyelitis of the epiphysis of a long bone. The clinical features varied, but all of the patients had pain at the infected site and an elevated erythrocyte sedimentation rate. The distal femur was involved in seven cases, the proximal tibia in two, and the proximal humerus in one. In two patients there was a contiguous metaphyseal lesion, while the other seven patients (eight sites) had lesions limited to the epiphysis. Bone scintigraphy clearly identified the infected sites in all seven patients in whom it was performed, and allowed an early diagnosis in four cases. Radiographs showed a lytic lesion of the epiphysis that corresponded to the scintigraphic findings in all cases. The vascular supply to the epiphysis and the microscopic structure of the epiphyseal venous sinusoids provide locations that favor lodgement of blood-borne organisms. The epiphysis of the child should be recognized as another site of hematogenous osteomyelitis.

Acute Disease↗
PubMed1984

Sonographic assessment of renal length in normal children.

Renal length was measured from normal real-time sonograms of 203 pediatric patients and graphed to provide a "growth chart" of normal renal size vs. age. Mean renal lengths are reported for each year of age. For children older than 1 year, the regression equation is: renal length (cm) = 6.79 + 0.22 X age (years). For babies younger than 1 year, the equation is: renal length (cm) = 4.98 + 0.155 X age (months).

Adolescent↗
PubMed1984

Empyema in children: clinical course and long-term follow-up.

Sixteen patients, aged 1 month to 15 years, were studied to determine the clinical course and long-term outcome of empyema in previously healthy children. The pathogens responsible were Haemophilus influenzae type b (seven patients), Staphylococcus aureus (five patients), Streptococcus pneumoniae (three patients), and viridans group Streptococcus (one patient). All patients had loculated fluid showing on chest roentgenographs. Chest tube drainage yielded 20 to 1,495 mL (mean 293 mL) during the first three days, accounting for 83% of total drainage. Chest tubes were removed after three to 17 days (mean ten days). Only slight roentgenographic improvement showed during chest tube drainage. Three patients required an open thoracotomy because of an unsatisfactory clinical response. Hospitalization ranged from eight to 77 days (mean 25 days). All patients had residual pleural thickening shown on chest roentgenographs taken at discharge. Thirteen patients were seen 5 to 140 months (mean 66 months) after discharge. Findings from physical examination were normal in 12 of the 13 patients. Pulmonary function tests in ten of the 13 patients revealed (mean percent predicted +/- 1 SD): vital capacity 92 +/- 12, residual volume 85 +/- 31, total lung capacity 92 +/- 13, peak flow rate 96 +/- 17, forced expiratory volume in 1 second 90 +/- 13, and maximal mid-expiratory flow rate 93 +/- 25. In all but one patient, findings on chest roentgenograms were normal or showed slight pleural thickening. Children with loculated empyema can be treated successfully with antibiotics and chest tube drainage. Few patients require open drainage, and further surgery is rarely required. The long-term outcome is excellent.

Adolescent↗