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Biomedical subjects

S Porat

Publications and source records attributed to S Porat.

At least 19 recordsLinked to original sources
PubMed2005

Fetal intracranial hemorrhage (fetal stroke): does grade matter?

OBJECTIVE: To determine if the severity of antenatally diagnosed hemorrhagic fetal brain insults and fetal stroke detected by ultrasound and magnetic resonance imaging (MRI) predicts postnatal neurodevelopmental prognosis. METHODS: The in-utero presentation and postnatal neurodevelopmental outcome of sonographically detected subdural hematoma or fetal stroke presenting as intraventricular hemorrhage (IVH) or intraparenchymal brain hemorrhage were investigated. RESULTS: Of 33 fetuses diagnosed with hemorrhagic brain lesions, 17 were electively terminated and two suffered intrauterine fetal demise. Thirteen were liveborn, seven by Cesarean delivery and six by spontaneous vaginal delivery. One case was lost to follow-up. Eight neonates had moderate to severe neurological deficit by a mean age of 35 (range, 6-96) months. One died at 2 months of age. These nine were diagnosed with Grade III-IV IVH in utero. Four neonates had normal neurological outcome by a mean age of 41 (range, 30-48) months; these four were diagnosed with subdural hematoma (n = 1) or Grade I-II IVH (n = 3) in utero. Fourteen cases were followed up with MRI, which confirmed ultrasound findings in 10 (71%) cases. In three (21%) cases MRI diagnosis was more accurate and the severity of grading was greater than that obtained on ultrasound imaging. Unilateral left hemispheric lesions were much more common than right-sided lesions (13 vs. 1, respectively). CONCLUSIONS: An antenatal sonographic diagnosis of fetal stroke with IVH Grade III-IV or with brain parenchymal involvement appears to be associated with poor neurological outcome. MRI may contribute to the accuracy of diagnosis, particularly in Grade II and III lesions. Left-sided unilateral lesions are more common than right-sided ones.

Developmental Disabilities↗
PubMed2005

Mild tricuspid regurgitation: a benign fetal finding at various stages of pregnancy.

OBJECTIVE: Tricuspid regurgitation (TR) may accompany various anatomical malformations and/or dysfunction of the fetal right heart. It may also appear in an anatomically healthy heart. With improved ultrasound modalities, more cases than the previously estimated prevalence of fetal TR in the low-risk population are being diagnosed. The objective of this study was to determine the prevalence of mild fetal TR in a low-risk obstetric population. METHODS: In 157 low-risk pregnant women (age range, 18-42 years) undergoing both early second-trimester and mid-trimester targeted organ scanning, including complete fetal echocardiography according to the five transverse planes technique, the apical four-chamber view was visualized using gray-scale, color Doppler and spatiotemporal image correlation (STIC) ultrasound modalities, with optimal acquisition parameters. RESULTS: Mild-to-moderate TR was discovered in the early second-trimester scan in 131/157 (83.4%) fetuses. No cases of cardiac malformation were found. All fetuses showed normal flow in the ductus venosus, including in one case diagnosed with moderate TR. Only in 39 (24.8%) cases was mild TR still evident at the second, mid-trimester scan. Neonatal echocardiography revealed mild TR in eight (5.1%) cases. No cases of chromosomal anomalies were detected. CONCLUSION: Mild TR is a benign finding of a temporal nature in early pregnancy.

Adolescent↗
PubMed2004

Adverse outcome of isolated fetal intra-abdominal umbilical vein varix despite close monitoring.

BACKGROUND AND OBJECTIVES: Fetal intra-abdominal umbilical vein (FIUV) varix-a focal dilatation of the umbilical vein-is an uncommon entity. Outcome varies from spontaneous resolution to fetal death. We describe here the experience of our center with this perplexing entity. METHODS: Case series review of seven cases of isolated FIUV treated in a tertiary care center from 2000 to 2003. RESULTS: We describe seven cases of isolated FIUV varix with varying natural history, follow-up strategies, and fetal outcome. In one of the cases, intrauterine fetal demise occurred despite close follow-up. CONCLUSIONS: We suggest that the course of FIUV is unpredictable, with a high fetal mortality rate. Close fetal monitoring with early delivery at 34 weeks' gestation should be advocated.

Abdomen↗
PubMed2003

Fetal supraventricular tachycardia diagnosed and treated at 13 weeks of gestation: a case report.

Supraventricular tachycardia (SVT) is the most commonly encountered clinically significant tachycardia in the fetus. When SVT is sustained, congestive heart failure and fetal hydrops may ensue, due to both systolic and diastolic dysfunction. Sonographic diagnosis is usually incidental during the second or third trimester. Treatment goals are cardioversion to sinus rhythm and reversal of cardiac dysfunction. We describe a case of fetal SVT diagnosed at 13 weeks of gestation. Treatment with digoxin and flecainide was successful; the heart rate returned to sinus rhythm within one day, and fetal hydrops resolved within 8 days of treatment. We suspect that as more first-trimester examinations are performed, more cases with SVT will be diagnosed. We discuss the treatment protocol, and suggest that co-administration of two drugs that act synergistically may be more efficient than monotherapy, which is currently used as the first line of treatment. In addition, we discuss the potentially deleterious effect of heart failure encountered at an early developmental stage on the central nervous system. More data need to be collected in order to substantiate a clear recommendation regarding optimal management.

Adult↗
PubMed2001

Dopamine induces phenotypic differentiation or apoptosis in a dose-dependent fashion: involvement of the dopamine transporter and p53.

The effect of dopamine on the growth, phenotypes (morphological and biochemical) and programmed cell death (apoptosis) of the human neuronal NMB cell line was examined. Exposure to 20-50 microM of dopamine decreased cell growth, induced an apparent differentiated cell morphology and increased (3)H-dopamine uptake. At higher concentrations (100-300 microM) dopamine was neurotoxic and induced apoptosis, as reported previously. The observed effects of both low and high doses of dopamine were blocked by cocaine, which suggested involvement of dopamine transporters. Indeed, several experiments demonstrated the relationship between dopamine uptake of cells and their vulnerability to the toxic effect of dopamine. High concentrations of dopamine, which induced apoptosis, also increased p53 levels, detected by RT-PCR analysis and immunoblotting, whereas lower dopamine concentrations, which induced a differentiated phenotype, did not increase p53 immunoblotting. Dibutyryl-cAMP and dimethyl sulfoxide, which induced differentiation but not apoptosis of the NMB cells, did not increase p53 expression. These findings provide an insight into the role of dopamine, dopamine transporters and p53 in the differentiation and apoptosis of dopaminergic neurons, which will further our understanding of neuronal development and neurodegenerative diseases.

Apoptosis↗
PubMed2001

Fractures of the lateral process of the talus in children.

Fractures of the lateral process of the talus are an uncommon injury, which are often misdiagnosed as severe ankle sprain. This error may result in inappropriate treatment of an intraarticular fracture, with subsequent posttraumatic arthrosis. To date, only one fracture of a lateral talar process has been reported in a child, in whom delayed diagnosis and initial mismanagement led to a suboptimal result. The sport of 'snowboarding', which is gaining in popularity, has been significantly associated with fractures of the lateral talar process, leading some authors to dub this fracture 'Snowboarder's Fracture'. This and the ever-increasing incidence of major trauma lead us to believe that this fracture will be encountered more frequently, even in the pediatric population, as the two factors mentioned do not pass over this group. We report lateral talar process fractures in two children: one in a 9-year-old girl and one in an 11-year-old boy, the latter associated with talar neck and body fractures. Timely diagnosis enabled prompt open reduction and internal fixation, preventing subtalar arthrosis. We discuss the pertinent anatomy and mechanism, and present the clinical picture, imaging studies and treatment. Two important points are exemplified by these cases. First, this fracture, although rare, does occur in children, and should be sought in appropriate settings. Second, despite the severe talar injury in the 11 year old, early diagnosis and intervention conserved foot function.

Ankle Injuries↗
PubMed1999

[CT-guided excision of osteoid osteoma].

CT-guided excision of osteoid osteoma is a new surgical technique that enables accurate resection of the nidus during 1-day hospitalization. We present 5-year results in 42 patients (26 males and 16 females, mean age 18 years, range 3-46). In 40 out of 42, complaints disappeared immediately after the procedure. The recovery period was short and the return to normal activity was faster than in the open surgical approach. Complications were minimal and transient.

Adolescent↗
PubMed1999

Do axial dynamic fixators really produce axial dynamization?

The use of dynamic external fixators for the treatment of long bone fracture is widespread and well accepted. It is claimed that dynamization, i.e. small micromovements of compression/distraction at the fracture site, can be produced by allowing sliding of an inner rod within an outer housing. However, as the forces on the fixator are not direct but transferred from the bone via bone pins, there is a bending moment on the fixator. This produces "self-locking" and effectively prevents axial movements. We have studied the effect of this moment on the binding properties of the Orthofix system. The amount of movement at a simulated fracture site allowed before this locking occurs was measured and its implications discussed. It would appear that true axial dynamization does not take place using this system.

External Fixators↗
PubMed1999

Effect of low-dose treatment with selegiline on dopamine transporter (DAT) expression and amphetamine-induced dopamine release in vivo.

1. Chronic treatment with low doses of the selective monoamine oxidase (MAO) type B inhibitors selegiline [(-)-deprenyl] and rasagiline, causes elevation in extracellular level of 3,4-dihydroxyphenylethylamine (dopamine) in the rat striatum in vivo (Lamensdorf et al., 1996). The present study was carried out to determine whether this effect of selegiline could be the result of an inhibition of the high-affinity dopamine neuronal transport process. 2. Changes in activity of the dopamine transporter (DAT) in vivo following selegiline treatment were evaluated indirectly by microdialysis technique in the rat, from the change in striatal dopamine extracellular concentration following systemic amphetamine administration (4 mg kg(-1), i.p.). Striatal levels of the DAT molecule were determined by immunoblotting. Uptake of [3H]-dopamine was determined in synaptosomes from selegiline-treated animals. 3. Amphetamine-induced increase in striatal extracellular dopamine level was attenuated by one day and by chronic (21 days) treatment with selegiline (0.25 mg kg(-1), s.c.). 4. Striatal levels of DAT were elevated after 1 and 21 days treatment with selegiline, but were not affected by clorgyline, rasagiline, nomifensine or amphetamine. 5. The increase in DAT expression, and attenuation of amphetamine-induced dopamine release, were not accompanied by a change in [3H]-dopamine uptake in synaptosomes of selegiline-treated animals. 6. The results suggest that a reversible inhibition of dopamine uptake occurs following chronic low dose selegiline treatment in vivo which may be mediated by an increase in endogenous MAO-B substrates such as 2-phenylethylamine, rather than by the inhibitor molecule or its metabolites. Increased DAT expression appears to be a special property of the selegiline molecule, since it occurs after one low dose of selegiline, and is not seen with other inhibitors of MAO-A or MAO-B. The new DAT molecules formed following selegiline treatment appear not to be functionally active.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1999

Bcl-2 and p53: role in dopamine-induced apoptosis and differentiation.

The fate of a neuron in the developing brain to multiply, differentiate, or die in an apoptotic manner depends on the expression of genes that are involved in regulating the cell cycle. Recent studies determined the involvement of several genes, including cyclin A and B2, in dopamine-induced apoptosis in cultured chick sympathetic neurons. Another gene that plays a role in apoptosis and differentiation of neurons, oligodendrocytes and PC12 cells is p53. It is also known that DNA damage increases p53 levels, triggering repair or apoptosis in response to moderate or severe damage, respectively. NMB cells express active and inducible forms of p53, thus being particularly suitable to analyze the role of this gene in dopamine-induced apoptosis and differentiation. The main observation of this work is that low concentrations of dopamine induce differentiation while high concentrations induce apoptosis, and that concentrations of dopamine that induce apoptosis increased p53 levels. There peak increase in p53 was within 3-6 h, before cell death. Thus, treatment with a high dopamine concentration may result in oxidation products and/or free radicals that heavily damage DNA, thus increasing p53 levels and initiating a cascade of events leading to apoptosis. Lower concentrations of dopamine apparently have a milder damaging effect on the DNA and induce growth arrest and differentiation. In various systems Bcl-2 inhibits cell death, being apoptotic or necrotic. Bcl-2, and other members of the family, such as Bax, are located downstream to p53 in the apoptotic pathway, and they contain negative or positive p53 response elements. Bcl-2 also protects cells by acting as antioxidant. Neuronal differentiation may be accompanied with an increase in Bcl-2, though it was suggested that the role of Bcl-2 in differentiation is less critical than in apoptosis. Herein, Bcl-2 was found to inhibit dopamine neurotoxicity. Whether the expression of Bcl-2 is regulated by different dopamine concentrations, or by dibutyryl-cAMP and DMSO, remains to be determined.

Apoptosis↗
PubMed1999

The "crushed open pelvis" in children.

A retrospective analysis was performed in order to review the outcome of open pelvic fractures in children. Medical records, radiographs and CT scans of 15 children with open pelvic fractures admitted to our trauma centre between 1983 and 1995 were reviewed. The minimal follow-up on the survivors was two years. Out of 15 open pelvic fractures ten were vertically unstable. The mechanism of injury was auto-pedestrian collision in 93% (n = 14) of the cases. 86% (n = 13) of the fractures were a result of a "run-over" mechanism, 40% (n = 6) were caused by heavy duty vehicles. All children had injuries in the proximity of the pelvis. Despite the severity of trauma, we found mortality to be 20% (n = 3). Sepsis and deep infection originating from anorectal and genitourinary excretions were found to be the most frequent complications. The improvement in surgical techniques of the pelvis influenced the orthopaedic treatment in these 15 children. External fixation of the pelvis is not always sufficient and to achieve better stabilization of the pelvis, open reduction and internal fixation should be considered. In order to minimize complications, aggressive intervention is needed including irrigation, debridement, intravenous antibiotics, diverging colostomies and cystostomies and fracture fixation. The coordination between trauma teams of different disciplines throughout all stages of the treatment is crucial to achieving better results.

Accidents, Traffic↗
PubMed1998

Traumatic myositis ossificans of the quadriceps in infants.

Acute traumatic myositis ossifications is uncommon and usually occurs in adolescents and young adults after a significant direct blow to the affected muscle. It is extremely rare in infants, and we have been able to find only two other cases in the English literature. We present two cases of traumatic myositis ossificans in infants who, except for the use of diagnostic ultrasonography, would have been misdiagnosed as having osteomyelitis (Patient 1) and a possible malignancy (Patient 2).

Acute Disease↗
PubMed1998

Ultrasonography of the hip in developmental hip dysplasia.

Ultrasonography of the hip was performed sequentially by two different examiners in 75 infants. The ultrasound strips were reviewed twice by three paediatric orthopaedic surgeons and classified by the Graf method. The intraobserver and interobserver agreement between the interpretations was analysed using simple and weighted kappa coefficients calculated for agreement on the Graf classification and for grouping as normal (types 1A to 2A), and abnormal requiring treatment (types 2B to 4). When examining the same ultrasound strip, intraobserver agreement for the Graf classification was substantial (mean kappa 0.61), but interobserver agreement was only moderate (kappa 0.50). For the grouping into normal and abnormal, the mean kappa value for intraobserver agreement was 0.67 and for interobserver agreement 0.57. Because of the significant differences in agreement between normal and abnormal hips, we analysed a subgroup of those with at least one abnormal interpretation. Intraobserver agreement within this subgroup showed moderate reliability (kappa 0.41), but interobserver agreement was only fair (kappa 0.28). Interpretations of two different strips performed sequentially showed significantly lower agreement with an intraobserver kappa value of 0.29 and an interobserver value of 0.28. In the subgroup with at least one abnormal reading, the intraobserver kappa was 0.09 and the interobserver 0.1. Our findings suggest that both the technique of performing ultrasonography and the interpretation of the image may influence the result.

Female↗
PubMed1997

[Treatment of open fractures due to dog bite].

2 patients aged 12 and 19, respectively, sustained open fractures of the wrists due to dog bites. Both were bitten on a wrist by Rotweiller dogs, but with different magnitudes of injury to bone and soft tissue. Treatment, clinical course and recovery are described, together with recommendations for dealing with open fractures due to animal bites. In the presence of considerable injury to soft tissue and bone, and of exposure to canine oral flora, open fractures due to dog bites should be dealt with as high grade open fractures.

Adolescent↗
PubMed1997

Limb amputation in amniotic band syndrome: serial ultrasonographic and Doppler observations.

A 28-year-old woman, gravida 7, para 6, was referred at 21 weeks' gestation to our ultrasound unit because of bilateral fetal lower limb edema diagnosed previously. Ultrasonography showed a constriction ring around both legs, and, with the aid of color Doppler, arterial flow was demonstrated in both legs beneath the constriction ring. Subsequent examinations during the 24th and 28th weeks revealed absence of flow below the constriction ring of the right leg and decreased flow in the left leg. This was followed by the gradual bending, breaking and resorption of the tibia and fibula of the right leg. Between weeks 30 and 34, gradual shrinkage of the remains of the right leg beneath the knee was recorded by serial ultrasonic observations. At the 38th week of gestation, a male infant was born by normal vaginal delivery. Examination at birth revealed amputation of the right leg below the knee, with a denuded end of the stump. There was a partial amputation of the left leg below the knee, with tissue continuity being maintained by the posterior neurovascular bundle, and a posterior strip of skin. The left foot was extremely edematous, with an area of necrosis dorsally. This case afforded us the opportunity of in utero following of natural limb amputation in the amniotic band syndrome.

Adult↗