PubMed Health⌕ Search

Biomedical subjects

L Landau

Publications and source records attributed to L Landau.

At least 19 recordsLinked to original sources
PubMed2006

Association of haplotypes of beta2-adrenoceptor polymorphisms with lung function and airway responsiveness in a pediatric cohort.

We evaluated the influence of haplotypes of beta(2)-adrenergic receptor (ADRB2) polymorphisms on lung function and airway responsiveness (AR) in a pediatric cohort recruited before birth and followed up to 11 years of age. The subjects (180) were the participants in a prospective study of lung function and AR. They have been assessed five times (at 1 month, 6 months, 12 months, 6 and 11 years of age) for lung function and AR. The two ADRB2 single nucleotide polymorphisms (SNPs): Arg16Gly and Gln27Glu were genotyped by PCR-RLFP and their haplotypes inferred using the program PHASE. An association between the haplotype arg16gln27 and the prevalence of positive AR was found at age 6 years (P = 0.009). The gly16gln27 haplotype was associated with higher FEV1 (P = 0.015) at age 6 and both higher FEV1 and FVC (P = 0.018 and P = 0.001, respectively) at age 11. In contrast, arg16gln27 was associated with both lower FEV1 and FVC (P = 0.028 and P = 0.011, respectively) at age 11. Children with the gly16gln27 haplotype were less likely to have asthma-ever or doctor-diagnosed asthma at age 11 (OR: 0.38; P = 0.019 and OR: 0.31; P = 0.041, respectively). In conclusion, haplotypes of beta(2)-adrenoceptor polymorphisms are associated with lung function, AR, and asthma susceptibility in childhood.

Airway Resistance↗
PubMed2006

The relationship between changes in daily air pollution and hospitalizations in Perth, Australia 1992-1998: a case-crossover study.

A case-crossover study was undertaken to investigate the relationship between daily air pollutant concentrations and daily hospitalizations for selected disease categories in Perth, Western Australia. Daily measurements of particles (measured by nephelometry and PM2.5), photochemical oxidants (measured as ozone), nitrogen dioxide (NO2) and carbon monoxide (CO) concentrations were obtained from 1992 to 1998 via a metropolitan network of monitoring stations. Daily PM2.5 concentrations were estimated using monitored data, modelling and interpolation. Hospital morbidity data for respiratory, cardiovascular (CVD), gastrointestinal (GI) diseases, chronic obstructive pulmonary diseases (COPD) excluding asthma; pneumonia/influenza diseases; and asthma were obtained and categorized into all ages, less than 15 years and greater than 65 years. Gastrointestinal morbidity was used as a control disease. The data were analyzed using conditional logistic regression. The results showed a small number of significant associations for daily changes in particle concentrations, nitrogen dioxide and carbon monoxide for the respiratory diseases, CODP, pneumonia, asthma and CVD hospitalizations. Changes in ozone concentrations were not significantly associated with any disease outcomes. These data provide useful information on the potential health impacts of air pollution in an airshed with very low sulphur dioxide concentrations and lower nitrogen dioxide concentrations commonly found in many other cities.

Air Pollution↗
PubMed1998

Effect of Temperature on Adhesion of Vibrio Strain AK-1 to Oculina patagonica and on Coral Bleaching.

Laboratory aquarium experiments demonstrated that Vibrio strain AK-1 caused rapid and extensive bleaching of the coral Oculina patagonica at 29 degrees C, slower and less-complete bleaching at 23 degrees C, and no bleaching at 16 degrees C. At 29 degrees C, the application of approximately 100 Vibrio strain AK-1 cells directly onto the coral caused 50 and 83% bleaching after 10 and 20 days, respectively. At 16 degrees C, there was no bleaching, even with an initial inoculum of 1.2 x 10 bacteria. To begin to understand the effect of seawater temperature on bleaching of O. patagonica by Vibrio strain AK-1, adhesion of the bacteria to the coral as a function of temperature was studied. Inoculation of 10Vibrio strain AK-1 organisms into flasks containing 20 ml of seawater at 25 degrees C and a fragment of O. patagonica resulted in net levels of bacterial adhesion to the coral of 45, 78, and 84% after 2, 6, and 8 h, respectively. The adhesion was inhibited 65% by 0.001% d-galactose and 94% by 0.001% methyl-beta-d-galactopyranoside (beta-M-Gal). After the incubation of Vibrio strain AK-1 with the coral for 6 h, 42% of the input bacteria were released from the coral with 0.01% beta-M-Gal, compared to less than 0.2% when beta-M-Gal was present during the adhesion step. Adhesion did not occur when Vibrio strain AK-1 was grown at 16 degrees C, regardless of whether the corals were maintained at 16 or 25 degrees C, whereas bacteria grown at 25 degrees C adhered to corals maintained at 16 or 25 degrees C. Bacteria grown at 25 degrees C adhered avidly to Sepharose beads containing covalently bound beta-d-galactopyranoside but failed to bind if grown at 16 degrees C. These data suggest that elevated seawater temperatures may cause coral bleaching by allowing for the expression of adhesin genes of Vibrio strain AK-1.

Journal Article↗
PubMed1996

Asthma management in eastern Australia, 1990 and 1993.

OBJECTIVE: To compare the prevalence and management of asthma before and after institution of the National Asthma Campaign. DESIGN: Repeat population-based cross-sectional analytic surveys. SETTING: Eastern Australia (Sydney, Brisbane, Melbourne, and the Hunter Valley, New South Wales) in September 1990 and 1993. SUBJECTS: Primary school children and their parents from 33 schools (8746 children) in 1990 and 40 schools (10 106 children) in 1993. OUTCOME MEASURES: Frequency of respiratory symptoms; diagnoses of asthma; medications; lung function measurements; possession of a peak flow meter and a written action plan. RESULTS: Age and sex distribution of the subjects and the reported prevalence of asthma were similar in 1990 and 1993. The frequency of reported episodes of wheezing and troublesome cough increased significantly in children between 1990 and 1993. Asthma management improved in accordance with current recommendations, with significantly decreased use of regular inhaled bronchodilator medication in children and increased use of preventive medication, monitoring of lung function by doctors and use of peak flow meters and written action plans in both children and adults. CONCLUSION: There is evidence that the National Asthma Campaign may have contributed to increased awareness and improved management of asthma in children and adults in eastern Australia.

Adult↗
PubMed1996

Glandular tumors of the lacrimal sac. Their histopathologic patterns and possible origins.

PURPOSE: To describe and characterize the primary lacrimal sac epithelial tumors of glandular origin, and to describe their possible source from glands in the lacrimal sac and nasolacrimal duct walls. METHODS: The authors conducted a clinicopathologic study on 14 patients with epithelial lacrimal sac tumors of possible glandular origin. In addition, they reviewed 35 surgical specimens of the lacrimal sac and nasolacrimal duct region and 13 cadaver specimens of the lacrimal sac region. RESULTS: Six of the tumors were benign: four were oncocytomas and two were pleomorphic adenomas. Eight of the tumors were malignant: three were oncocytic adenocarcinomas, three were adenoid cystic carcinomas, and two were adenocarcinomas. All tumors were from adults, ranging in age from 38 to 87 years. Twenty-eight of the 47 specimens of lacrimal sac and nasolacrimal duct region showed mixed glands of serous and mucous elements. CONCLUSIONS: Although rare, benign and malignant glandular lacrimal sac tumors should be considered in the differential diagnosis of lacrimal sac obstruction. Their possible origin is from the normal glands that exist under the lacrimal sac and nasolacrimal duct epithelium.

Adenocarcinoma↗
PubMed1995

Gender differences in lung growth.

Annual measurements of lung volumes and forced expiratory flows were made in 281 boys and girls from 8 to 12 years and in another cohort of 287 from 12 to 20 years to measure longitudinal lung growth. Gender differences in growth of lung function were documented, with girls generating greater volume-standardized maximal expiratory flows until age 18.5 years. Beyond that age boys generated higher expiratory flows in proportion to total lung capacity (TLC). There was a time lag of up to 1 year between the age of peak growth velocity in lung volume and peak growth velocity in height. Age at peak growth in flow lagged another year behind that in volume. This was noted more in boys than girls. Dysanaptic lung growth was found with differing rates of growth of maximal expiratory flow compared with TLC or vital capacity (VC).

Adolescent↗
PubMed1995

Neonatal chronic lung disease, oxygen dependency, and a family history of asthma.

We examined the relationship between a family history of asthma (FHA), neonatal chronic lung disease (CLD), and oxygen dependency in an inception cohort study of all 24- to 30-week gestation infants admitted to the sole tertiary perinatal center in Western Australia. One hundred and forty-four infants were admitted during the study period; 116 had data analyzed, 112 of whom survived to discharge. Respiratory morbidity was common and the prevalence increased with decreasing gestation. Hyaline membrane disease (HMD) occurred in 92 (79%) and CLD (oxygen dependency at 28 days) in 62 (53%); 35 (30%) were oxygen dependent at 36 weeks corrected age, and 16 (14%) were oxygen dependent at term. Thirty-two infants had an FHA which was equally distributed between those infants with and without CLD. Infants with an FHA were more likely to be oxygen dependent at term (relative risk 4.4; 95% Cl 1.7,11.1). Thirty-eight percent of mothers smoked; 68% of their infants developed HMD compared to 89% of those whose mothers did not smoke. Logistic regression identified GA<28 weeks (OR 7.3; 95% Cl 1.4,39), severe HMD (OR 4.8; 95% Cl 1.1,22), and FHA (OR 11.0; 95% Cl 2.3,53) as the only factors associated with an increased risk of being oxygen dependent at term. The duration of supplemental oxygen in infants with CLD was significantly related to decreasing gestation, greater degree of barotrauma, presence of HMD, pregnancy-induced hypertension in the mother, duration of patent ductus arteriosus, and an FHA. An FHA may worsen chronic lung disease in the neonate, but is not involved as a causal factor. Clinicians should be aware of its influence on duration of oxygen supplementation when counselling parents of very preterm infants.

Asthma↗
PubMed1993

Identification of digitalis-like compounds in human cataractous lenses.

Human cataractous lens nuclei extract inhibited, in a dose-dependent fashion, [3H]ouabain binding to rat brain synaptosomes and microsomal Na(+)- and K(+)-dependent adenosine triphosphate (Na+, K(+)-ATPase) activity and interacted with anti-digoxin antibodies. The compounds responsible for these activities, termed digitalis-like compounds (DLC), were also detected in bovine, rat, cat and rabbit, normal, transparent lenses, but the levels were only 0.7-5.4% of the average levels in the cataractous human lenses. DLC from the human cataractous lenses were purified by a procedure consisting of organic extractions and batch chromatography followed by filtration through a 3000 Da cut-off filter and subsequent separations using reverse-phase high-performance liquid chromatography. The presence of DLC in the different fractions obtained in the chromatograms was monitored by their ability to inhibit [3H]ouabain binding and Na+, K(+)-ATPase activity. Based on chemical ionization mass spectrometry together with ultraviolet spectrometry and biological characterization, it is suggested that new bufodienolides, 19-norbufalin and 19-norbufalin peptide derivatives are responsible for the endogenous DLC activity. It is proposed that these compounds may regulate Na+, K(+)-ATPase activity in the lens under some physiological and pathological conditions.

Animals↗
PubMed1992

The management of acute laryngo-tracheo-bronchitis (croup): a consensus view.

The management of croup relies upon the traditional clinical skills of observation and examination. Parental involvement is essential and the appropriate reassurance of the patient is important. Endotracheal intubation is required only in a small percentage of children whose airway is compromised to such a degree as to produce fatigue and/or near occlusion.

Adrenal Cortex Hormones↗
PubMed1991

Optic disc drusen and hypermetropia.

We report the case of a 41 year old lady with high hypermetropia and optic disc drusen (ODD) in both eyes. A recent study has shown that ODD has a greater tendency to form in eyes with a small scleral canal. It would therefore seem probable to find a higher rate of ODD in hypermetropic eyes. Some of the current literature denies this connection. In this article we discuss the pathogenesis of ODD and the possible connection between this entity and "high" hypermetropia.

Adult↗
PubMed1989

Iodine-131 MIBG scintigraphy in small cell lung cancer.

There is a well documented relationship between small cell carcinoma of the lung and the amine precursor uptake and decarboxylation system of endocrine cells (APUD). We attempted to exploit this association by employing the unique radiopharmaceutical, 131I-MIBG, which is recognized and taken up by the APUD system to monitor disease activity in patients with small cell carcinoma of the lung. A total of eight patients with biopsy proven, metastatic small cell carcinoma of the lung were studied. 131I-MIBG was synthesized in our laboratory by reacting metaiodobenzylamine hydrochloride with cyanamide with subsequent solid phase radioiodination. A dose of 0.5 mCi radiopharmaceutical was injected and images obtained on a large field of view gamma camera with a high energy parallel hole collimator at 2, 24, and either 48 or 72 h. Images were compared with known focal areas of metastatic disease demonstrable on computed tomographic scan, chest roentgenogram or bone scan. We were unable to detect reproducible correlations between the images produced by conventional radiographic techniques and the images produced by our radiopharmaceutical. We conclude that this agent will probably not be useful for localization of metastatic small cell lung carcinoma.

3-Iodobenzylguanidine↗
PubMed1988

Phase II trial of recombinant alpha-2b-interferon and low-dose cyclophosphamide in advanced melanoma and renal cell carcinoma.

The combination of Interferon and low-dose cyclophosphamide synergistically inhibits the growth of human breast cancer xenografts, explanted human non-small cell lung carcinoma, and other experimental tumors. To determine whether this combination would demonstrate clinical efficacy against refractory solid tumors, we used recombinant alpha-2b-Interferon, 10 MU/m2 subcutaneously three times per week, and cyclophosphamide, 25 mg orally twice daily, in 42 patients (25 renal cell carcinoma, 17 melanoma). Two patients were inevaluable due to premature removal from the study. The toxicity profile did not differ substantially from that of Interferon alone with malaise, fatigue, fevers, and chills predominating. Sixteen percent of patients experienced an alteration in mental status. Of 40 patients evaluable for response, there were two partial responders (one renal cell carcinoma, one melanoma) and four minor responders (all renal cell carcinoma). The responder with melanoma had previously failed therapy with dacarbazine (DTIC). Seventeen patients remained stable for a median follow-up of 6 months. We conclude that this regimen is well tolerated; however, the combination of Interferon and low-dose cyclophosphamide used in this way does not appear to be superior to the same dose and schedule of Interferon used alone.

Administration, Oral↗
PubMed1985

Zinc and copper metabolism in patients with senile macular degeneration.

Abnormal zinc and copper metabolism has been described in some retinal disorders affecting the retinal pigment epithelium. Anatomic and functional studies in patients with senile macular degeneration show changes in this retinal layer. We examined the blood and urine of two groups of patients, one consisting of patients with senile macular degeneration and the other a control group, for zinc and copper in serum and urine. In the former group we found elevated values of serum zinc and serum copper that were highly significant when compared with the control group. The significance of these findings and their connection to the retinal pigment epithelium is discussed.

Aged↗