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Biomedical subjects

E S Martin

Publications and source records attributed to E S Martin.

At least 19 recordsLinked to original sources
PubMed2005

Common and contrasting genomic profiles among the major human lung cancer subtypes.

Lung cancer is the leading cause of cancer mortality worldwide. With the recent success of molecularly targeted therapies in this disease, a detailed knowledge of the spectrum of genetic lesions in lung cancer represents a critical step in the development of additional effective agents. An integrated high-resolution survey of regional amplifications and deletions and gene expression profiling of non-small-cell lung cancers (NSCLC) identified 93 focal high-confidence copy number alterations (CNAs), with 21 spanning less than 0.5 Mb with a median of five genes. Most CNAs were novel and included high-amplitude amplification and homozygous deletion events. Pathogenic relevance of these genomic alterations was further reinforced by their recurrence and overlap with focal alterations of other tumor types. Additionally, the comparison of the genomic profiles of the two major subtypes of NSCLC, adenocarcinoma (AC) and squamous cell carcinoma (SCC), showed an almost complete overlap with the exception of one amplified region on chromosome 3, specific for SCC. Among the few genes overexpressed within this amplicon was p63, a known regulator of squamous cell differentiation. These findings suggest that the AC and SCC subtypes may arise from a common cell of origin and they are driven to their distinct phenotypic end points by altered expression of a limited number of key genes such as p63.

Adenocarcinoma↗
PubMed2000

Bernard-Soulier syndrome: common ancestry in two African American families with the GP Ib alpha Leu129Pro mutation.

Bernard-Soulier syndrome (BSs) is a rare bleeding disorder characterized by circulating giant platelets, thrombocytopenia, and a prolonged bleeding time. BSs usually has an autosomal recessive inheritance pattern, with a preponderance of Caucasian and Japanese ancestry when the ethnic background has been reported. Underlying this disorder of platelet function is a defect in the platelet glycoprotein (GP) Ib-IX-V complex, composed of four polypeptides, GP Ib alpha, GP Ib beta, GP IX, and GP V. Molecular characterization of individuals with BSs has identified mutations in the GP Ib alpha, GP Ib beta, and GP IX genes responsible for the expressed phenotype. In this study, we report a family of African-American descent, with autosomal recessive BSs showing a point mutation in codon 129 of the GP Ib alpha gene. This mutation, CTC:wild-type to CCC:mutant, is similar to that of another African American family where the resulting leucine to proline substitution in the 5(th) leucine-rich repeat of GP Ib alpha is responsible for the observed BSs phenotype. Comparison of the intragenic polymorphisms of GP Ib alpha, as well as microsatellite markers in a 17.5 cM region of chromosome 17p12 that contains the GP Ib alpha gene, suggests that, although socially unrelated, the Leu129Pro mutation in these two families has a common founder.

Africa↗
PubMed1997

Complex chromosome 4, 9, and 22 rearrangement in a patient presenting with AML-FAB M2.

Fluorescence in situ hybridization (FISH) and the reverse transcription-polymerase chain reaction (RT-PCR) were used to examine a patient presenting with acute myelogenous leukemia (AML) FAB M2, and a complex t(4;9;22)(p14;q34;q11.2). The patient's clinical course was characterized by an aggressive leukemia, resistant to intensive therapy including allogeneic bone marrow transplantation. FISH analysis, using two chromosome painting probes and a BCR/ABL specific probe, confirmed the cytogenetic observation of a 22q11.2-->4p14 and a 4p14-->9q34 exchange, and revealed the presence of a 9q34-->22q11.2, respectively. In addition, RT-PCR demonstrated the presence of a BCR/ABL transcript derived from the major breakpoint cluster region (M-bcr) of the BCR gene. This transcript has been shown to generate an active 210 kDa tyrosine kinase protein more commonly observed in chronic myelogenous leukemia. Because the presentation of AML with this ABL-->BCR fusion product is a rare event, it would seem likely that the additional complex chromosomal rearrangement involving chromosomes 4, 9, and 22 played a role in the aggressive presentation and clinical behavior of this patient's leukemia.

Adult↗
PubMed1997

Studies in a large family with late-onset Alzheimer disease (LOAD).

A large 10-generation family with late-onset Alzheimer disease (LOAD) inherited as an autosomal dominant trait was evaluated historically, clinically, and genetically. The family origin was traced to a founder couple of French ancestry with approximately 3,000 descendants. Although the transmission of a genetic predisposition to LOAD is demonstrated through male individuals, a predominance of affected women is observed. Currently, 14 individuals, 12 of whom are women, are classified as affected with Alzheimer disease (AD). Among the affected, the age of onset ranged from 55 to 78 years. Genotyping of the apolipoprotein E (APOE) locus demonstrated that homozygotes for the E4 allele (APOE4) developed signs of AD in their late 60s, whereas affected heterozygotes presented with the disease in their 70s. A significantly higher APOE4 frequency was observed in affected family members than in those unaffected (0.79 vs. 0.25, chi 2 = 9.919, p = 0.0016, df = 1). Survival for more than 15 years after diagnosed onset was observed in a number of those affected and can be attributed to an improved environment, including excellent care and management during the disabling phase of illness. Alternatively, it may be an example of the genetic heterogeneity in AD. Complete documentation of large families such as the one presented will facilitate the discovery of the multiple genetic factors involved in the pathogenesis of AD.

Aged↗
PubMed1997

Quinine may trigger torsades de pointes during astemizole therapy.

Because of serious cardiovascular events, warnings against concomitant use of certain medications with the use of antihistamine (HismanalR have been published and added to product labeling. Quinine, the optical isomer to quinidine, is included in these warnings. We present the case of a patient with only mild electrolyte disturbances who experienced an episode of torsades de pointes after a single dose of quinine while taking astemizole.

Adult↗
PubMed1996

Alteration of gonococcal protein expression in acidic culture.

We grew Neisseria gonorrhoeae under acidic, neutral, and alkaline conditions and noted altered expression of at least 12 outer membrane proteins between 31 and 100 kDa in size. One protein whose expression was upregulated under acidic conditions was gonococcal heat shock protein 63. These proteins may contribute to the pathogenesis of gonorrhea in the urogenital tract.

Bacterial Outer Membrane Proteins↗
PubMed1995

Comparison of throat culture methods for the recovery of group A streptococci in a pediatric office setting.

OBJECTIVE: To compare a single-plate method for the recovery of group A streptococci with other methods that have recently been reported as being significantly more sensitive. DESIGN: Throat swabs were allowed to dry for 2 to 6 hours before inoculating 5% sheep blood agar plates. Stabs were made into the agar, bacitracin disks were placed on the primary plates, and the cultures were incubated aerobically. Using duplicate throat swabs, the recovery rates of the above method were compared with the following ones: a carbon dioxide-enhanced incubation atmosphere, an anaerobic atmosphere with a selective blood agar medium, and a Todd-Hewitt broth medium. SETTING: A five-pediatrician office. PATIENTS: A total of 301 pediatric patients with pharyngitis were evaluated using all comparative methods. In addition, duplicate swabs from 590 pediatric patients were compared with each other using the same single-plate method. RESULTS: There were no significant differences between any of the methods. The sensitivity of the single-plate method compared with selective plates incubated anaerobically was 96%. CONCLUSIONS: In a pediatric office setting, a single-plate method using aerobic incubation was adequately sensitive for the recovery of group A beta-hemolytic streptococci. Transport medium, selective medium, carbon dioxide enhancement, and anaerobic incubation did not significantly improve recovery. The present federal regulations that restrict the use of nonselective media and bacitracin disks on primary plates should be reevaluated.

Adolescent↗
PubMed1995

Phenotypic modulation of gonococcal lipooligosaccharide in acidic and alkaline culture.

Neisseria gonorrhoeae infects a diverse array of niches in its human host, which expose the organism to dramatic variations in pH. We examined growth and lipooligosaccharide expression of two gonococcal strains in liquid and solid cultures under acidic, neutral, and alkaline conditions. Growth rates in broth were similar under the three conditions, and the pH remained fairly constant throughout the growth cycle. Altered lipooligosaccharide expression at the different pHs was noted in both plate- and broth-grown organisms.

Bacterial Proteins↗
PubMed1992

Didanosine therapy in patients intolerant of or failing zidovudine therapy.

OBJECTIVE: To examine the effect of didanosine (2',3'-dideoxyinosine, ddI) on surrogate markers of HIV infection (CD4+ lymphocyte count, p24 antigen) and to evaluate the incidence of adverse effects from ddI. DESIGN: This study was performed as a retrospective chart review of patients who were enrolled in Bristol-Myers Squibb's expanded-access program for ddI. SETTING: Patient records were obtained from primary care physicians' offices. PATIENTS: Twenty-five HIV-infected patients diagnosed with AIDS or AIDS-related complex (ARC) who were intolerant of zidovudine (ZDV) therapy or deteriorating clinically despite ZDV therapy and were eligible for inclusion in the ddI expanded-access program. INTERVENTION: ddI was administered orally in a citrate-phosphate buffer every 12 hours. Patients were followed by their private physician on a monthly basis. MAIN OUTCOME MEASURES: Laboratory analysis at each month included CD4+ lymphocyte count, hemoglobin, hematocrit, serum amylase, uric acid, serum triglycerides, and p24 antigen. Mean CD4+ cell count, serum amylase, hemoglobin, and uric acid at each month during ddI therapy were compared with baseline concentrations for nine months. RESULTS: Patients had received prior ZDV therapy for an average of 15.5 months before starting ddI. Mean CD4+ cell counts increased from 53.9/mm3 at baseline to 72.4/mm3 after 4 months of therapy (p = 0.04) but returned to concentrations comparable with those at baseline after 5 months. One case of documented pancreatitis, two cases of suspected pancreatitis, and nine cases of peripheral neuropathy occurred during ddI therapy. The estimated mean cumulative dose for the development of neuropathy was 1.16 g/kg, which is lower than previously reported. CONCLUSIONS: Patients who have received prolonged therapy with ZDV or who have low initial CD4+ counts may not have sustained increases in CD4+ counts from ddI therapy. Also, development of peripheral neuropathy may occur at lower cumulative doses in these patient populations.

AIDS-Related Complex↗
PubMed1991

Protein aggregation and inclusion body formation in Escherichia coli rpoH mutant defective in heat shock protein induction.

Mutations in the rpoH gene, encoding sigma 32, an alternative factor required for transcription of the heat shock genes, result in the extensive aggregation of virtually all cellular proteins and formation of inclusion bodies both under stress and non-stress conditions. Inhibitors of protein synthesis suppress this aggregation, suggesting that newly synthesized proteins preferentially aggregate in rpoH mutants. These data suggest that the heat shock proteins are involved in acquisition of the soluble state (i.e. correct conformation) of the bulk of intracellular proteins after their translation.

Escherichia coli↗