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Dive into the research topics where David K. Yousefzadeh is active.

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Featured researches published by David K. Yousefzadeh.


The Journal of Pediatrics | 1990

Preserving adult height potential in girls with idiopathic true precocious puberty

Mary Kreiter; Stephen Burstein; Robert L. Rosenfield; George W. Moll; José F. Cara; David K. Yousefzadeh; Leona Cuttler; Lynne L. Levitsky

We designed a prospective study of height potential in girls with idiopathic precocious puberty, comparing the presenting features of girls with and without evidence of reduced adult height potential. The 14 girls with impaired adult height prognoses (group 1) were reexamined after treatment with a gonadotropin releasing hormone agonist, nafarelin. The seven girls with the prognosis of unimpaired height (group 2) were followed without therapy. We found that the group could be distinguished at initial examination by the greater bone age/height age ratio of group 1 (mean +/- SEM: 1.4 +/- 0.06 vs 1.0 +/- 0.05; p less than 0.005) and by the greater difference between predicted height and target height in group 1. The mean predicted height in group 1 was significantly less than the mean target height (150.7 +/- 2.1 vs 165.4 +/- 3.0 cm; p less than 0.005), whereas the mean predicted and target heights in group 2 were similar (165.4 +/- 3.0 vs 164.3 +/- 2.1 cm). Initial estradiol levels were also greater in group 1 than in group 2 (21.6 vs 10.6 pg/ml; p less than 0.05), although this difference was not sustained during follow-up. In group 1, nafarelin therapy suppressed the pituitary-gonadal axis, and although there was a transient reduction in height potential in girls with the youngest bone ages during the first 6 months of therapy, 2 years of treatment slightly improved predicted heights from 150.7 +/- 2.1 to 152.7 +/- 2.0 cm (p less than 0.05). Height predictions also increased without therapy during the 2-year observation period in group 2, from 165.4 +/- 3.0 to 168.7 +/- 4.1 cm (p less than 0.05). Our data indicate that gonadotropin releasing hormone agonist therapy preserves height potential in girls with an initially impaired height prognosis, and that height potential is preserved without therapy in those with a good initial height prognosis.


Pediatric Radiology | 1990

Lenticulostriate vasculopathy in infants with infections of the central nervous system sonographic and Doppler findings

Tamar Ben-Ami; David K. Yousefzadeh; M. Backus; B. Reichman; A. Kessler; C. Hammerman-Rozenberg

Eleven infants had echogenic stripes in the basal ganglia at the location of the lenticulostriate arteries, seen by head ultrasound. Eight patients had proven infection with rubella (2 patients), cytomegalovirus (2 patients), syphilis (1 patient) or bacterial meningitis (3 patients). Two had probable intrauterine infection clinically, but the organism could not be identified; one had trisomy 13. A recent report correlated these echogenic stripes in patients with viral and syphilitic intracranial infection with pathologically proven mineralizing vasculopathy. Our group manifests a wider range of intracerebral infection associated with this finding. Duplex sonography performed in four infants showed these stripesin vivo to be arteries in the basal ganglia. The lenticulostriate arteries are not normally visible by grey scale sonography but their Doppler signal may be elicited in normal children and they are rendered vividly visible by color Doppler. Echogenicity of these vessels is highly suggestive of intracranial infection because it is not encountered normally or in babies with non infectious intracranial disorders except trisomy 13. The prognostic significance of this finding is yet to be determined.


Pediatric Radiology | 2009

The position of the duodenojejunal junction: the wrong horse to bet on in diagnosing or excluding malrotation

David K. Yousefzadeh

AbstractPurposeThe purpose of this communication is to highlight the shortcomings of all currently used imaging criteria in diagnosing or excluding malrotation and offer ultrasound demonstration of the 3rd portion of the duodenum (D3) between the AO and the SMA in transverse and sagittal plains as the most reliable diagnostic method.BackgroundAlthough UGI is currently considered to be the imaging modality of choice in diagnosis of malrotations, numerous publications indicate that in certain patients, false positives and negatives can be encountered.Materials and MethodsThe material consists of more than 10 years experience in university settings, during which the author has used US as the definitive imaging modality for the work-up of malrotation. High resolution linear transducers (5-17 MHz) are the transducers of choice.Imaging Plains:A.TransverseWith gradual grading compression, the following landmarks are illustrated in cehaplocaudad directions in the fallowing order. The junction of splenic vein with the SMV portal vein.The cross sections of SMA and SMV that may either be situated in midline, or to the right or the left of the midline.Left renal vein crossing the spine from left to right between the AO and the SMA.The jejunal vein, often coming from left, transversing between the AO and the SMA.The transverse portion of the duodenum, D3, between the AO & the SMAB.Sagittal D3 between vertically oriented SMA-SMV and the AO.If SMA is not aligned with the AO by slight compression on the right or the left side of the abdomen, it will be aligned (depending on leftward or rightward position of SMA-SMV in axial plain).Vertical orientation of SMA and SMV if they have an anteroposterior orientation.C.Coronal Side by side orientation of SMA and SMV if they don’t have an anteroposterior orientation.ResultsIn overwhelming majority of cases, by illustrating a retromesenteric D3 malrotation and, therefore, midgut volvulus were excluded.DiscussionNone of the current imaging criteria addresses the following most fundamental anatomic and embryologic facts regarding the gut rotation and fixation. In first trimester, the D3 is secured in retroperitoneal space after the embryologic journey comes to an end, making the duodenum immune of midgut volvulus.The surgical pathology of malrotation-midgut volvulus indicates that D3 is always Intraperitoneal and has not reached its final embryologic destination in retroperitoneal space.Demonstrating a retromesenteric D3, therefore, indicates that the embryologic journey is completed and the patient does not have malrotation.Excluding malrotation excludes the likelihood of midgut volvus.ConclusionThe position of the DJJ, the configuration of the duodenal sweep, the orientation of the mesenteric vessels are all wrong horses to bet on because none of them addresses the fundamental anatomic and embryologic facts. Only the cross-sectional imaging, US, CT and MRI can prove that the D3 is retromesenteric, therefore, excluding malrotation and volvulus. Therefore, demonstrating a retromesenteric duodenum is the reference standard of imaging in the work-up of malrotation, not any other previously published criteria. The US imaging is the most acceptable imaging method for malrotation work-up, in the spirit of ALARA principle and “Image Gently” campaign.


Journal of Perinatology | 2005

Antenatal risk factors associated with the development of lenticulostriate vasculopathy (LSV) in neonates.

Robert Mittendorf; Karl Kuban; Peter G. Pryde; John G. Gianopoulos; David K. Yousefzadeh

OBJECTIVE:To determine the antenatal risk factors associated with neonatal lenticulostriate vasculopathy (LSV).STUDY DESIGN:Women in preterm labor were randomized to magnesium sulfate (MgSO4), other tocolytic, or saline control. The surviving babies underwent head ultrasounds (HUS) (weeks of life 1, 2, and 4) and periodic developmental examinations (months 4, 8, 12, and 18).RESULTS:Of 140 infants, 17.1% (24) had neonatal intraventricular hemorrhage (IVH), and 10.0% (14) had LSV (half of the latter (7 of 14) had both IVH and LSV). In a regression model in which other risk factors were controlled for, the association between antenatal exposures to tocolytic MgSO4 ≥50 g and LSV were significant (adjusted odds ratio (OR), 8.3; 95% confidence interval (CI), 1.5 to 45.0; p=0.01).CONCLUSION:Based on our data and their analyses, we infer that antenatal exposure to high-dosage, tocolytic MgSO4 may be associated with LSV.


Pediatric Radiology | 1995

Septic arthritis of the elbow in children: The role of sonography

J. E. Lim-Dunham; Tamar Ben-Ami; David K. Yousefzadeh

Twelve children with suspected septic arthritis of the elbow were prospectively studied with plain-film radiography and ultrasound. Imaging data were correlated with clinical history and final diagnosis. Joint effusion was seen by sonography in six patients, four of whom underwent ultrasound-guided joint aspiration, confirming the diagnosis of septic arthritis in two patients and excluding it in two. Of nine patients whose plain films showed only soft tissue swelling, seven had one or more significant findings with sonography: joint effusion (without fat pad elevation on lateral plain films) in three patients, periosteal reaction in two, and epitrochlear mass in three. Sonography confirmed soft tissue swelling alone in two patients, thus excluding the diagnosis of septic arthritis and obviating unnecessary attempts at joint aspiration. Sonography of the elbow is an informative, easily performed examination, which is capable of showing both intra- and extra-articular abnormalities not apparent by plain radiography. Both the demonstration of pathologic changes and the failure to show joint fluid may affect clinical management.


Digestive Diseases and Sciences | 1989

Isolated granulomatous gastritis in an adolescent

Barry Z. Hirsch; Peter F. Whitington; Barbara S. Kirschner; Dennis D. Black; David G. Bostwick; David K. Yousefzadeh

SummaryThis is a case of a 14 1/2-year-old black male with isolated granulomatous gastritis. The case is unusual in several aspects. For the first time this disorder has been seen in the pediatric age group. The symptoms and signs were more acute and severe than previously reported, and the inflammatory process involved the entire gastric mucosa. Several findings suggested an (auto)immune pathogenesis. The patient had a good clinical and histologic response to prednisone therapy, but the disease recurred after two years when therapy was discontinued.


Pediatric Radiology | 1989

Mastoid abnormalities in Down syndrome.

R. B. J. Glass; David K. Yousefzadeh; N. J. Roizen

Hearing loss and otitis media are commonly associated with Down syndrome. Hypoplasia of the mastoids is seen in many affected children and sclerosis of mastoid bones is not uncommon in Down syndrome. Awareness and early recognition of mastoid abnormality may lead to appropriate and timely therapy, thereby preserving the child’s hearing or compensating for hearing loss; factors which are important for learning and maximum development.


Gastroenterology | 1991

Intestinal obstruction during shigellosis: Incidence, clinical features, risk factors, and outcome

Michael L. Bennish; Abul Kalam Azad; David K. Yousefzadeh

To determine the incidence and outcome of intestinal obstruction during shigellosis, the authors assessed 1211 consecutive patients with shigellosis admitted during a 15-month period to a diarrhea treatment center in Dhaka, Bangladesh. Obstruction was identified in 30 (2.5%) patients. Ten (33.3%) of these patients died, compared with 97 (8.2%) of the 1181 patients without obstructions (P less than 0.001; RR = 4.1). In a case-control study, patients with obstructions were compared with 30 control patients with shigellosis but without obstructions. Case and control patients were similar in age (median, 18 months vs. 24 months; NS). Before admission to the hospital, case patients had less often been breast-fed than control patients (33% vs. 85%; P = 0.006) and had more often received antimicrobial agents (53% vs. 13%; P = 0.001). Case patients more often had abdominal tenderness (73% vs. 13%; P less than 0.001), altered consciousness (50% vs. 17%; P = 0.006), and Shigella dysenteriae type 1 infection (73% vs. 27%, P = 0.001) and had a higher median blood leukocyte count (40 x 10(3)/microL vs. 14 x 10(3)/microL; P = 0.007) and serum potassium concentration (5.0 mmol/L vs. 4.3 mmol/L; P = 0.016), and lower median serum sodium (123 mmol/L vs. 131 mmol/L; P = 0.003) and total protein (52 g/L vs. 60 g/L; P = 0.025) concentrations than did control patients. Eight (27%) patients with obstructions developed the hemolytic-uremic syndrome, compared with none of the control patients (P = 0.003). It was concluded that obstruction is an ominous complication of shigellosis and that therapies in addition to provision of antimicrobial agents need to be evaluated.


Digestive Diseases and Sciences | 1996

Splenic arteriovenous fistula. A rare lesion causing bleeding esophageal varices, ascites, and diarrhea.

Greg Galler; Anthony Yim; Jean C. Emond; Everett Kirch; David K. Yousefzadeh; Alfred L. Baker

SummaryWe report the case of a 39-year-old woman with portal hypertension caused by a splenic arteriovenous fistula that was diagnosed by Doppler ultrasound and splenic arteriography. She presented with esophageal variceal hemorrhage and was initially treated with sclerotherapy. Ascites and secretory diarrhea then developed. At laparotomy portal pressure was 60 cm H2O but fell to 26 cm H2O after the fistula was resected with a splenectomy. All symptoms disappeared shortly thereafter, and the patient has remained well for the past two years.


Journal of Perinatology | 2004

Association between Lenticulostriate Vasculopathy (LSV) and Neonatal Intraventricular Hemorrhage (IVH)

Robert Mittendorf; Robert F. Covert; Peter G. Pryde; Kwang-sun Lee; Tamar Ben-Ami; David K. Yousefzadeh

OBJECTIVES: To determine whether there is an unconfounded association between neonatal intraventricular hemorrhage (IVH) and lenticulostriate vasculopathy (LSV (also known as thalamostriate or mineralizing vasculopathy)).STUDY DESIGN: During the conduct of the Magnesium and Neurologic Endpoints Trial (MagNET), a randomized controlled trial involving maternal, hence fetal, exposure to antenatal magnesium sulfate in the context of preterm labor, head ultrasounds were obtained for each of the surviving neonates. Because of our previous experience in the diagnosis of LSV, when ascertaining the presence of IVH, as called for by the research protocol of our study, the presence or absence of LSV was also determined.RESULTS: We found LSV to be relatively prevalent (10% (14 of 140) among surviving babies). More importantly, it was significantly associated with the occurrence of neonatal IVH, even when controlled for possible confounding (adjusted OR 9.8, 95% confidence interval 1.3 to 73.1; p=0.03).CONCLUSION: Given the known relationships between IVH and neonatal morbidity and mortality, the finding of a statistically significant association between neonatal IVH and LSV may suggest more substantial implications for the latter than previously believed.

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Tamar Ben-Ami

Boston Children's Hospital

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Peter F. Whitington

Children's Memorial Hospital

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Joseph H. Jackson

Boston Children's Hospital

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Robert Mittendorf

Loyola University Medical Center

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Jennifer E. Lim-Dunham

Loyola University Medical Center

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Peter G. Pryde

University of Wisconsin-Madison

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