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Biomedical subjects

Isaiah D Wexler

Publications and source records attributed to Isaiah D Wexler.

11 recordsLinked to original sources
PubMed2006

Glutaric aciduria type 1: clinical, biochemical and molecular findings in patients from Israel.

Glutaric aciduria type 1 (GA1) is a rare cerebral organic aciduria which typically manifests as an acute encephalopathic crisis followed by profound long-term neurological handicap. We report the diagnosis of 12 new patients from a single laboratory in Israel during a 5-year period. Eleven of the 12 were of Palestinian origin, and only two were related. One patient was asymptomatic whilst one was mildly, one moderately and nine severely affected, two of whom had unusual MRI findings. Two patients had normal glutaric acid excretion and normal blood glutarylcarnitine levels yet glutarylcarnitine excretion was increased, indicating its utility as a diagnostic marker. Four novel GCDH mutations (Thr193_Arg194insHis, Asn329Ser, Thr341Pro, Met405Val) and five previously reported mutations (Ser119Leu, Leu283Pro, Ala293Thr, Gly390Arg and Thr416Ile) were identified. Severely and mildly affected or even asymptomatic patients shared the same genotypes (Thr416Ile/Thre416Ile and Aal293Thr/Thr193_Arg194insHis). Knowledge of the responsible mutation enabled successful prenatal diagnosis on chorionic villous DNA in three families. In conclusion, GA1 is genetically heterogeneous and has a relatively high incidence in the Palestinian population, reflecting the historical tradition of marriages within extended kindreds, particularly in isolated villages. Additional genetic and/or environmental factors must account for the phenotypic heterogeneity in patients with the same genotype. The diagnosis was not suspected in the majority of cases despite typical clinical and/or neuroimaging features, suggesting that glutaric aciduria may be under-diagnosed. Greater awareness of glutaric aciduria amongst pediatricians, neonatologists and radiologists is the key to identifying the disorder in the presymptomatic phase and preventing its catastrophic consequences.

Adolescent↗
PubMed2006

Pregnancy and chronic progressive pulmonary disease.

Progressive pulmonary disease may preclude the option of pregnancy for a number of women in their child-bearing years due to the severity of the disease. For a subset of women with chronic lung disease including cystic fibrosis, pregnancy is possible, but can have a devastating effect both on the prospective mother and fetus. The potential hazards of pregnancy in cystic fibrosis or other progressive pulmonary diseases may trigger a moral conflict between physician and patient. The female patient may argue that her autonomy cannot be circumscribed and that the physician is obliged to assist her reproductive efforts. The physician can counter that his/her participation in potentially harmful interventions is not consistent with professional norms requiring adherence to the principles of beneficence and nonmaleficence. Whenever possible, the ethical conflict between physician and patient should be resolved before initiation of pregnancy. We propose that this best be done through structured negotiations between physician and patient with the goal of constructing an ethical framework for reducing the moral tension between the two. Steps in the negotiating process include defining the therapeutic alliance, information exchange, dialog, and deliberation. As part of the information exchange, it is important to discuss alternatives to pregnancy such as adoption and surrogacy, especially when there are strong contraindications to pregnancy. If negotiations reach a satisfactory conclusion for both sides, there should be a well-delineated consensual agreement to commence the pregnancy with the full support of the medical team.

Chronic Disease↗
PubMed2006

Treatment from birth of nonketotic hyperglycinemia due to a novel GLDC mutation.

OBJECTIVE: To determine whether the devastating outcome of neonatal-onset glycine encephalopathy (NKH) could be improved by instituting treatment immediately at birth rather than after symptoms are already well established. METHODS: A newborn with NKH diagnosed prenatally following the neonatal death of a previous affected sibling was treated from birth with oral sodium benzoate (250 mg/kg/day) and the NMDA receptor antagonist ketamine (15 mg/kg/day) immediately after sampling cord blood and cerebrospinal fluid (CSF) for glycine determination. Glycine cleavage system (CGS) activity was determined in placental tissue. Mutation analysis was performed by sequencing all GLDC, GCSH and AMT exons. RESULTS: CSF glycine (99 micromol/L, reference 3.8-8.0) was already markedly elevated at birth. GCS activity in placental tissue was severely reduced (2.6% of controls). A novel homozygous GLDC c.482A-->G(Y161C) missense mutation was identified. Neonatal hypotonia and apnea did not occur but the long-term outcome was poor, with intractable seizures and severe psychomotor retardation. This contrasts with the favorable outcome with early treatment in variant NKH with mild GCS deficiency (Ann Neuol 2004;56:139-143). INTERPRETATION: Prospective treatment with this regimen can favorably modify the early neonatal course of severe NKH but does not prevent the poor long-term outcome, suggesting glycine-induced prenatal injury and/or ongoing postnatal damage.

Aldehydes↗
PubMed2006

Plastic bronchitis caused by neoplastic infiltrates in a child.

We report on a case of a 7-year-old girl admitted for pneumonia not responding to oral antibiotics. During hospitalization, her pulmonary status deteriorated as a result of significant atelectasis. An extensive workup revealed an anaplastic large-cell lymphoma with neoplastic cells, found in both a biopsied lymph node and pleural fluid aspirate. Bronchoscopic examination showed nearly complete obstruction of the left side by bronchial casts composed of tumor cells, fibrin, and necrotic material, consistent with plastic bronchitis. Neoplastic infiltration of the bronchi should be considered in the differential diagnosis of disease entities causing plastic bronchitis in children.

Bronchitis↗
PubMed2006

Clinical characteristics and outcome of complicated pneumococcal pneumonia in a pediatric population.

The incidence of complicated pneumonia caused by S. pneumoniae is reported to be increasing. This increase may be related to host susceptibility and/or pathogen virulence. The objective of this study was to evaluate clinical and laboratory characteristics associated with complicated pneumococcal pneumonia, and to identify risk factors associated with prolonged fever and hospitalization. The study involved reviewing the records of all children who were hospitalized in four major hospitals in Jerusalem with a confirmed diagnosis of pneumococcal pneumonia during a 12-year period (1986-1997). Demographic, clinical, laboratory, and outcome variables were compared between those with uncomplicated and complicated pneumonia. One hundred and eleven children (median age, 2.2 years) were hospitalized with pneumococcal pneumonia during the study period. Forty-four (39%) of them had complicated pneumonia, characterized by pleural effusion, empyema, pneumothorax, pneumatocele, and/or atelectasis. There was no correlation between the isolation of penicillin-resistant S. pneumonia (16% of cases) and complicated pneumonia. Factors that were significantly associated with complicated pneumonia included weight <or=10% for age, respiratory distress (e.g., tachypnea, dyspnea), anemia, and a white blood cell count (WBC) <15,000/mm(3) at time of admission. Complicated pneumonia and a WBC <15,000/mm(3) on admission increased the risk for prolonged fever and an extended length of hospitalization. Based on these results, it is concluded that host factors such as anemia, low weight, and a low WBC are associated with complicated pneumonia. Both the presence of pulmonary complications and a relatively low WBC in children hospitalized for pneumococcal pneumonia are independent risk factors for protracted fever and extended hospitalization.

Anemia↗
PubMed2005

Association of hereditary hemorrhagic telangiectasia and hereditary nonpolyposis colorectal cancer in the same kindred.

Endoglin (CD105) is a proliferation-associated protein that is strongly expressed in endothelial tissue and has a role in tumor angiogenesis. Mutations in endoglin are also linked to Hereditary Hemorrhagic Telangiectasia type 1 (HHT1), an autosomal dominant disease associated with aberrant angiogenesis. We report an unusual association of HHT1 and Hereditary Nonpolyposis Colorectal Cancer (HNPCC) in the same kindred. Genetic analysis indicates that these 2 syndromes are genetically unrelated and separately segregated within the family. The mutation in the endoglin gene leads to a truncated protein. The mutation in the mismatch repair gene MLH1 causes a splicing defect, giving synthesis to an unstable mRNA from this mutated allele. The potential protective role of an endoglin mutation in patients with HNPCC is discussed.

Adaptor Proteins, Signal Transducing↗
PubMed2003

Cardiovascular disease in type 2 diabetics: epidemiology, risk factors and therapeutic modalities.

Macrovascular complications associated with chronic hyperglycemia in type 2 diabetes mellitus is a major global health problem that is currently on the rise. Accelerated cardiovascular and cerebrovascular atherosclerosis is the major cause of mortality in patients with type 2 diabetes. Many of the risk factors for cardiovascular disease are operative or even exacerbated in diabetic patients, including hypercholesterolemia, hypertriglyceridemia, hypertension, central obesity, and smoking. Other diabetes-specific factors, such as increased levels of plasminogen activator 1 and fibrinogen, chronic inflammation, genetic susceptibility, and accelerated glycosylation end-products-mediated vascular damage, are thought to play a role in the development of CVD among patients with type 2 diabetes. Further studies will hopefully elucidate the clinical relevance of such factors. In addition, recent studies indicate that hyperglycemia is an important and independent risk factor for CVD. Increased risk of CVD is directly related to elevated 1 and 2 hour post-prandial blood glucose averages, as well as to fasting hyperglycemia. Thus, specific treatment regimens designed to reduce the development rate of cardiovascular complications in patients with type 2 diabetes must consider the impact of risk factors and their control, as well as the need for optimal metabolic and glycemic control.

Blood Glucose↗
PubMedDate not supplied

Effect of mild hypoinsulinemia on renal hypertrophy: growth hormone/insulin-like growth factor I system in mild streptozotocin diabetes.

The metabolic aberrations associated with diabetes mellitus profoundly alter the growth hormone/insulin-like growth factor I (GH/IGF-I) system. In severe experimental diabetes, serum IGF-I level is reduced, reflecting altered hepatic expression. On the other hand, increased levels of kidney IGF-I have been implicated in the development of diabetic kidney disease. This study aimed to examine the effect of mild experimental diabetes with hypoinsulinemia on both the systemic and renal GH/IGF-I systems in a low-dose streptozotocin (STZ)-induced diabetic rat. Diabetic animals with mild hypoinsulinemia developed renal hyperfiltration within 3 days of diabetes, whereas the renal size increased significantly only between 30 and 48 days of diabetes. Plasma GH levels were unchanged during the entire course of the study, but a decrease in serum IGF-I, IGF-binding protein 3 (IGFBP-3), and IGF-binding protein 4 (IGFBP-4) occurred after 10, 30, and 48 days. Kidney IGF-I and IGF-binding protein 1 (IGFBP-1) mRNA expression increased after 10 and 30 days of diabetes. A significant increase in kidney IGFBP-1/2, IGFBP-3, and IGFBP-4 proteins was seen after 48 days of diabetes. A positive correlations was found between renal growth and insulin/glucose ratio (r=.57), kidney IGF-I (r=.57), IGFBP-1 mRNA (r=.43), IGFBP-1/2 (r=.41), and IGFBP-4 levels (r=.40). These results demonstrate hyperfiltration within 3 days of diabetes and a similar response in the IGF-I system in mildly and severely hypoinsulinemic rats; however, renomegaly develops slower in mildly diabetic rats at least partly due to delayed changes in the renal IGF and IGF BPs.

Animals↗