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Biomedical subjects

E Kerem

Publications and source records attributed to E Kerem.

At least 55 records · Page 3Linked to original sources
PubMed1995

Highly variable incidence of cystic fibrosis and different mutation distribution among different Jewish ethnic groups in Israel.

The incidence of cystic fibrosis (CF) and the frequency of disease-causing mutations varies among different ethnic and geographic populations. The Jewish population around the world is comprised of two major ethnic groups; Ashkenazi and non-Ashkenazi. The latter is further classified according to country of origin. In this study, we analyzed the incidence of CF and the distribution of CF mutations in the general Jewish population in Israel and in most of the Jewish ethnic subgroups. The disease frequency varies considerably among the latter. Among Ashkenazi Jews, the frequency of CF is 1:3300, which is similar to the frequency in most Caucasian populations. Among non-Ashkenazi Jews, the disease occurs at a similar frequency among Jews from Libya (1:2700), Georgia (1:2700), Greece and Bulgaria (1:2400), but is rare in Jews from Yemen (1:8800), Morocco (1:15000), Iraq (1:32000), and Iran (1:39000). So far, only 12 mutations have been identified in Israeli Jews, and this enables the identification of 91% of the CF chromosomes in the entire Jewish CF population. However, in each Jewish ethnic group, the disease is caused by a different repertoire of mutations. The frequency of identified mutations is high in Ashkenazi Jews (95%), and in Jews originating from Tunisia (100%), Libya (91%), Turkey (90%), and Georgia (88%). However, a lower frequency of mutations can be identified in Moroccan (85%), Egyptian (50%), and Yemenite (0%) Jews. For genetic counseling of a Jewish individual, it is necessary to calculate the residual risk according to ethnic origin. Carrier screening of healthy Jewish individuals is currently feasible for Ashkenazi Tunisian, Libyan, Turkish, and Georgian Jews. These results provide the required information for genetic counseling of Jewish CF families and screening programs of Jewish populations worldwide.

Africa, Northern↗
PubMed1995

The relationship between genotype and phenotype in cystic fibrosis.

Cystic fibrosis is characterized by a wide variability of clinical expression. The cloning of the cystic fibrosis transmembrane conductance regulator gene and the identification of its mutations has promoted extensive research into the association between genotype and phenotype. Several studies showed that there are mutations, such as delta F508 (the most common mutation worldwide), that are associated with a severe phenotype: early age at diagnosis, pancreatic insufficiency, poor nutritional status, high incidence of meconium ileus, and high sweat chloride levels; lung disease, however, is variable. The milder mutation is dominant over the severe mutation causing a milder phenotype. In vitro studies of cystic fibrosis transmembrane conductance regulator function suggested that different mutations cause different defects of protein production and function. Five mechanisms by which mutations disrupt cystic fibrosis transmembrane conductance regulator function have been suggested: class I mutations cause defective protein production, class II mutations are associated with defective protein processing, class III mutations are associated with defective regulation, class IV mutations are associated with defective conductance, and class V mutations include mutations affecting the level of normal messenger RNA transcript and protein required for normal function. This class might include mutations affecting correct splicing of pre-messenger RNA transcripts by either exon skipping or by inclusion of extra cryptic exons.

Cystic Fibrosis↗
PubMed1995

Maximal expiratory flows generated by rapid chest compression following end-inspiratory occlusion or expiratory clamping in young children.

Partial forced expiratory flow-volume curves obtained by the rapid chest compression technique are being widely used to assess pulmonary function in infants and young children. The aim of this study is to assess whether in this age group flow limitation is achieved with the partial forced expiratory flow-volume curve with rapid chest compression. In eight infants and young children sedated with chloral hydrate, flow-volume curves were obtained by regular rapid chest compression technique, end-inspiratory airway occlusion prior to rapid chest compression, and expiratory clamping prior to rapid chest compression. In each technique, beginning with a cuff pressure of 20 cmH2O, the cuff pressure was increased by 10 cmH2O increments until the compression pressure reached 90 cmH2O. Maximal flow-volume curves were generated by each technique. End-inspiratory occlusion prior to rapid chest compression caused higher flows over the entire phase of expiration than the regular rapid chest compression. This increase could be observed over the entire phase of expiration. Forced expiratory flow at 50% and at 75% of vital capacity (V50 and V75) with regular rapid chest compression were 207 +/- 44 ml.s-1 (mean +/- SD) and 138 +/- 59 ml.sec-1, respectively. When end-inspiratory occlusion preceded rapid chest compression, V50 and V75 increased to 283 +/- 114 and 206 +/- 61 ml.sec-1 respectively, with a mean increase in V50 of 34% and in V75 of 31%. When expiratory clamping preceded the compression, even higher expiratory flows resulted.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1994

Pleural fluid characteristics in pulmonary brucellosis.

Although pulmonary symptoms accompany up to 16% of cases of infection with Brucella melitensis, pleural effusion has rarely been reported. A 12 year old girl had brucellosis with pulmonary disease and a pleural effusion. The pleural fluid was clear and straw coloured with 2700 leucocytes/mm3 (93% lymphocytes), a protein level of 48 g/1, and a glucose concentration of 4.1 mmol/l. Culture of the pleural fluid grew Br melitensis.

Brucella melitensis↗
PubMed1994

Difference in frequencies of the cystic fibrosis alleles, delta F508 and W1282X, between carriers and patients.

One major mutation, delta F508, causing cystic fibrosis (CF) is found in most populations around the world. Among CF patients of Jewish Ashkenazi origin two major mutations, W1282X and delta F508 were found. We compared the relative frequencies of the two major mutations found in this patient population to their relative frequencies in the healthy population. The studied patient population included the entire CF Jewish Ashkenazi patient population in Israel (238 chromosomes), and a small group of Jewish Ashkenazi patients in the USA (57 chromosomes). Among these, 79 (27%) chromosomes carried the delta F508 mutation, and 151 (51%) the W1282X mutation. In addition, we have analyzed the results of screening 1,946 unrelated healthy Jewish Ashkenazi individuals for the delta F508 and the W1282X mutations. Surprisingly, an almost equal number of carriers of the delta F508 (35) and W1282X (36) was found. The difference between the relative proportions of the mutations in the two groups is statistically significant (p = 0.025). A striking manifestation of this difference is revealed in the analysis of patients' genotypes. There were 36 patients homozygous for W1282X, while only 7 patients were homozygous for delta F508, although the number of delta F508 carriers in the general Jewish Ashkenazi population is almost equal to the number of W1282X carriers. This difference in allele frequencies found between healthy carriers and CF patients in the Jewish Ashkenazi population might not be unique to this ethnic group nor to the CF disease. The results indicate that the common practice of inferring general population epidemiologic parameters directly from patients information is liable to introduce biases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Bacteremic necrotizing pneumococcal pneumonia in children.

Necrotizing pneumonia, massive necrosis of lung tissue, is a serious, often fatal, complication of lobar pneumonia. Four children 1.3 to 7.5 yr of age were hospitalized with bacteremic pneumococcal pneumonia. All of them were acutely ill on presentation with arterial desaturation, and they developed anemia and thrombocytosis. Two patients had pleural effusion requiring drainage. A chest CT scan revealed segmental or lobar pulmonary liquification, which led to the diagnosis of necrotizing pneumonia. This finding could be demonstrated early in the course of the disease. Subsequently, all of the patients developed cavitating lesions. With adequate antipneumococcal therapy and/or chest tube drainage, all of the patients recovered completely; however, clinical improvement was prolonged: fever lasted 9 to 20 days, and length of hospitalization was 12 to 26 days. Contrary to that in adults, complete recovery is anticipated in children with bacteremic necrotizing pneumococcal pneumonia, and no invasive investigations are required.

Anti-Bacterial Agents↗
PubMed1994

Similar levels of mRNA from the W1282X and the delta F508 cystic fibrosis alleles, in nasal epithelial cells.

The effect of nonsense mutations on mRNA levels is variable. The levels of some mRNAs are not affected and truncated proteins are produced, while the levels of others are severely decreased and null phenotypes are observed. The effect on mRNA levels is important for the understanding of phenotype-genotype association. Cystic fibrosis (CF) is a lethal autosomal recessive disease with variable clinical presentation. Recently, two CF patients with mild pulmonary disease carrying nonsense mutations (R553X, W1316X) were found to have severe deficiency of mRNA. In the Jewish Ashkenazi CF patient population, 60% of the chromosomes carry a nonsense mutation, W1282X. Patients homozygous for this mutation have severe disease presentation with variable pulmonary disease. The presence of CF transcripts in a group of patients homozygous and heterozygous for this mutation was studied by reverse transcriptase PCR of various regions of the gene. Subsequent hybridization to specific CF PCR probes and densitometry analysis indicated that the CF mRNA levels in patients homozygous for the W1282X mutation are not significantly decreased by the mutation. mRNA levels were compared for patients heterozygous for the W1282X mutation. The relative levels of mRNA with the W1282X, and the delta F508 or the normal alleles, were similar in each patient. These results indicate that the severe clinical phenotype of patients carrying the W1282X mutation is not due to a severe deficiency of mRNA. In addition, the severity, progression, and variability of the pulmonary disease are affected by other, as yet unknown factors.

Alleles↗
PubMed1993

Mild cystic fibrosis and normal or borderline sweat test in patients with the 3849 + 10 kb C-->T mutation.

Different mutations in the cystic fibrosis (CF) gene appear to contribute to heterogeneity of the CF phenotype. We investigated 15 patients with CF who have the 3849 + 10 kb C-->T mutation. All were Ashkenazi Jews. Their clinical features were compared with those of CF patients with the delta F508/delta F508, W1282X/W1282X, W1282X/delta F508 mutations, which are known to be associated with a severe disease. Patients with the 3849 + 10 kb mutation were older, had been diagnosed as having CF at a more advanced age, and were in a better nutritional state. Sweat chloride values were normal (below 60 mmol/L) in 5 3849 + 10 kb patients (33%). 4 of these patients and 6 others (total 66%) had normal pancreatic function. However, age-adjusted pulmonary function did not differ between the two groups. None of the patients with 3849 + 10 kb C-->T had had meconium ileus or had liver disease or diabetes mellitus. We conclude that this mutation is associated with a mild type of CF.

Age Factors↗
PubMed1993

Lysinuric protein intolerance with chronic interstitial lung disease and pulmonary cholesterol granulomas at onset.

Hyperammonemia and encephalopathy developed in an 11-year-old girl with chronic interstitial lung disease and cholesterol casts in her lung biopsy specimen. She had decreased plasma levels of ornithine, lysine, and arginine and excessive urinary excretion of lysine and arginine, consistent with the diagnosis of lysinuric protein intolerance. Analysis of plasma and urinary amino acids should be considered in the diagnostic evaluation of patients with interstitial lung disease of uncertain origin.

Amino Acid Metabolism, Inborn Errors↗
PubMed1993

Efficacy of albuterol administered by nebulizer versus spacer device in children with acute asthma.

The aim of this study was to compare the response to inhaled albuterol after administration by nebulizer with the response after administration by a metered-dose inhaler and spacer device (MDI-spacer) to children with acute asthma. In a double-blind fashion, 33 children (6 to 14 years of age) with forced expiratory volume in 1 second (FEV1) between 20% and 70% of predicted values, and who were seen in the emergency department with acute asthma, were studied. They were treated with aerosolized albuterol or placebo by MDI-spacer, followed immediately by albuterol or placebo administered by nebulizer with oxygen. The dose ratio for albuterol by MDI-spacer versus nebulizer was 1:5. Outcome measures included a clinical score, respiratory rate, arterial oxygen saturation, and FEV1, measured before and 10, 20, and 40 minutes after treatment. With the exception of heart rate (which increased in the nebulizer group and decreased in the MDI-spacer group (p < 0.05), no difference in the rate of improvement of clinical score, respiratory rate, arterial oxygen saturation, or FEV1 was noted during the 40-minute study period between children who received albuterol by nebulizer and those who received it by MDI-spacer. We conclude that spacers and nebulizers are equally effective means of delivering beta 2-agonists to children with acute asthma.

Acute Disease↗
PubMed1992

Prediction of mortality in patients with cystic fibrosis.

BACKGROUND: The majority of patients with cystic fibrosis die in early adulthood of lung disease. Lung transplantation is a treatment option for patients with advanced pulmonary disease, although the waiting period for organs may be as long as two years. Our purpose was to determine whether the risk of death due to respiratory failure could be predicted one or two years in advance on the basis of pulmonary function, blood gas levels, and nutritional status. METHODS: The study cohort consisted of 673 patients followed between 1977 and 1989. In each patient, pulmonary function, blood gas levels, nutritional status, and vital status were assessed between 1977 and 1987. Cox proportional-hazards regression analysis was used to compute the relative risk of death within one or two years after particular measurements. The effects of age and sex on mortality were also included in the analysis. RESULTS: One hundred ninety patients (28 percent) died during the study period. Overall, patients with a forced expiratory volume in one second (FEV1) less than 30 percent of the predicted value, a partial pressure of arterial oxygen below 55 mm Hg, or a partial pressure of arterial carbon dioxide above 50 mm Hg had two-year mortality rates above 50 percent. Among the laboratory measurements, the FEV1 was the most significant predictor of mortality, but age and sex were also significant in predicting risk. After adjustment for age and sex, the relative risk of death within two years was 2.0 (95 percent confidence interval, 1.9 to 2.2) for each decrement in the FEV1 of 10 percent below the predicted value. Among patients with the same FEV1, the relative risk of death was 2.0 (95 percent confidence interval, 1.5 to 2.6) in patients 10 years younger than other patients, and 2.2 (1.6 to 3.1) in female patients as compared with male patients. CONCLUSIONS: Patients with cystic fibrosis should be considered candidates for lung transplantation when the FEV1 falls below 30 percent of the predicted value. Female patients and younger patients may need to be considered for transplantation at an earlier stage.

Adolescent↗
PubMed1992

Association of a nonsense mutation (W1282X), the most common mutation in the Ashkenazi Jewish cystic fibrosis patients in Israel, with presentation of severe disease.

Only about 30% of the cystic fibrosis chromosomes in the Israeli cystic fibrosis patient populations carry the major CF mutation (delta F508). Since different Jewish ethnic groups tended to live as closed isolates until recent times, high frequencies of specific mutations are expected among the remainder cystic fibrosis chromosomes of these ethnic groups. Genetic factors appear to influence the severity of the disease. It is therefore expected that different mutations will be associated with either severe or mild phenotype. Direct genomic sequencing of exons included in the two nucleotide-binding folds of the putative CFTR protein was performed on 119 Israeli cystic fibrosis patients from 97 families. One sequence alteration which is expected to create a termination at residue 1282 (W1282X) was found in 63 chromosomes. Of 95 chromosomes, 57 (60%) are of Ashkenazi origin. Together with the delta F508 (23% in this group), G542X, N1303K, and 1717-1G----A mutations, the identification of 92% of cystic fibrosis chromosomes of Ashkenazi origin becomes possible. Patients homozygous for the W1282X mutation (n = 16) and patients heterozygous for the delta F508 and W1282X mutations (n = 22) had similarly severe disease, reflected by pancreatic insufficiency, high incidence of meconium ileus (37% and 27%, respectively), early age at diagnosis, poor nutritional status, and variable pulmonary function. In conclusion, the W1282X mutation is the most common cystic fibrosis mutation in the Ashkenazi Jewish patient population in Israel. This nonsense mutation is associated with presentation of severe disease.

Cystic Fibrosis↗
PubMed1992

Wheezing in infants with cystic fibrosis: clinical course, pulmonary function, and survival analysis.

Wheezing is a common finding in infants with cystic fibrosis (CF). This study was undertaken to determine the prevalence of wheezing in infants with CF and to compare the clinical outcome of those who wheezed in infancy with that of those who did not. The study cohort included 229 CF patients born between 1965 and 1979 with CF diagnosed before 2 years of age. Fifty-seven (25%) had physician-documented wheezing during the first 2 years of life. Wheezing had resolved by the age of 2 years in 50% of the patients and by the age of 4 years in 75%. Although wheezing seemed to be linked to a family history of allergy and asthma, the frequency of the delta F508 mutation was similar to that of the non-wheezers. There was no significant difference in survival at the age of 13 years between the two groups. At the age of 7 years, patients who had wheezed had significantly lower forced expiratory flow rate at mid-expiratory phase (85 +/- 34% predicted) compared with those with no wheezing history (101 +/- 34% predicted). At the age of 13 years, forced expiratory volume in 1 second values was lower in the wheezing group (69 +/- 24% predicted vs 78 +/- 21% predicted), as was forced expiratory flow rate at mid-expiratory phase (56 +/- 33% predicted vs 69 +/- 30% predicted). In conclusion, although wheezing in infants with CF seems to have diminished with age, pulmonary function abnormalities were more evident at 7 and 13 years of age in the group that wheezed than in the group that did not.

Cohort Studies↗
PubMed1992

Efficacy of adding nebulized ipratropium bromide to nebulized albuterol therapy in acute bronchiolitis.

Nebulized ipratropium bromide is though to be synergistic with albuterol in therapy for acute childhood asthma. Because the efficacy of ipratropium in bronchiolitis is uncertain and some infants with bronchiolitis do not respond to nebulized albuterol alone, the following study was undertaken. In this double-blind, placebo-controlled trial, 69 infants between 6 weeks and 24 months of age who exhibited the first episode of acute bronchiolitis were randomly assigned to receive either nebulized albuterol (0.15 mg/kg per dose) and ipratropium bromide (250 micrograms per dose) (group A, n = 36) or nebulized albuterol and normal saline (placebo) (group B, n = 33) for two doses, 1 hour apart. The two groups were comparable at baseline. Both therapies resulted in clinically significant improvement. However, the addition of ipratropium resulted in no additional benefit with respect to decrease in the respiratory rate (mean decreases 10.6/min vs decreases 8.6/min, P = .86), accessory muscle score (range 0 through 3) (decreases 0.92 vs decreases 0.82, z = -0.44), wheeze score (range 0 through 3) (decreases 0.94 vs 0.85, z = -0.20), oxygen saturation (increases 0.25% vs increases -0.33%, P = .86), or hospitalization rate (17 vs 10). The number of "nonresponders" and "clear responders" was also very similar in both groups. No toxicity was noted. The increase in heart rate was mild and similar in both groups (increases 6.7 vs increases 11.1). The power of the study to detect a difference between the two treatment groups in the respiratory rate change > or = 8/min is greater than 90%.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗