Three candidate genes and angiotensin-converting enzyme inhibitor-related cough: a pharmacogenetic analysis

Unexplained, persistent cough limits the use of angiotensin-converting enzyme (ACE) inhibitors in a significant number of patients. It has been speculated that occurrence of this adverse effect is genetically predetermined; in particular, variants of the genes encoding ACE, chymase, and B2-bradykinin receptor have been implicated. To investigate this question, we determined genotypes for common polymorphisms for these three genes in subjects with a history of ACE inhibitor-related cough. Specificity of the adverse effect was confirmed by a blinded, double-crossover design protocol in which subjects were rechallenged with either lisinopril or placebo. In 99 case subjects and 70 control subjects (who failed to develop cough on rechallenge with ACE inhibitor) thus selected, frequencies for the ACE D and I alleles were 0.56 and 0.44 (cases) and 0.56 and 0.44 (controls), respectively; frequencies for chymase A and B alleles (absence/presence of BstXI site) were 0.56 and 0.44 (cases) and 0.46 and 0.54 (controls), respectively; frequencies for B2-bradykinin receptor + and - alleles (presence/absence of a 21 to 29 nonanucleotide sequence) were 0.52 and 0.48 (cases) and 0.53 and 0.47 (controls), respectively. All observed genotype frequencies were in Hardy-Weinberg equilibrium. There was no evidence for association between genotype at either gene examined and cough (adjusted for gender and age). Our data indicate that common genetic variants of ACE, chymase, and B2-bradykinin receptor do not explain the occurrence of ACE inhibitor-related cough.     

Report of the first workshop on the genetic map of bovine chromosome 1

Allergic bronchopulmonary aspergillosis (ABPA), occurring primarily in patients with asthma or cystic fibrosis (CF), is a hypersensitivity reaction to Aspergillus fumigatus (Af), and is characterized by increased serum IgE levels and peripheral blood and pulmonary eosinophilia. We evaluated the IgE and cytokine profile in ABPA through enzyme-linked immunosorbent assay (ELISA), and evaluated eosinophil activity with the eosinophil peroxidase (EPO) assay. IgE and cytokines were measured in supernatants from cultures of peripheral blood mononuclear cells (PBMC) from three subject groups: ABPA patients, patients with asthma, and healthy individuals. All cultures for the three subject groups were studied in the presence and absence of two purified Af antigens (the 35-kD antigen and heat shock protein 1). We found that increased in vitro levels of IgE in unstimulated PBMC culture supernatants correlated significantly with serum IgE concentrations in ABPA patients. We measured a decrease in IgE levels of up to 75% of baseline values in supernatants from PBMC cultured with Af antigens. Interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) concentrations in cultures with Af were increased in ABPA, whereas concentrations of IL-4 did not differ in the three subject groups. An inverse relation was noted between the changes in IgE and IFN-gamma measured in 4 of 5 ABPA patients. The PBMC supernatants also promoted EPO activity in purified eosinophils from ABPA patients, and to a lesser extent in purified eosinophils from healthy subjects. These results show that the 35-kD antigen and HSP1 from Af downregulate IgE in vitro but are capable of inducing eosinophilia in ABPA. Further studies could result in the characterization of epitopes leading to these disparate effects. An identification of the IgE-down-regulating epitopes in Af antigens might have therapeutic significance.     

Phase I trial of low-dose continuous topotecan infusion in patients with cancer: an active and well-tolerated regimen

PURPOSE: The objective of this trial was to define the maximum-tolerated dose (MTD) of topotecan for a 21-day infusion schedule, repeated every 28 days, in patients with cancer. PATIENTS AND METHODS: Cohorts of four patients received continuous ambulatory infusions of topotecan in escalated duration with doses beginning at 0.20 mg/m2/d for 7 days. Forty-four patients with a histologic diagnosis of cancer refractory to standard therapy were treated with infusions of topotecan for a total of 115 cycles and 1,780 patient-days of infusion. The median number of treatment cycles per patient was two (range, one to eight). All patients were heavily pretreated with chemotherapy and/or radiation. RESULTS: The dose-limiting toxicity (DLT) was myelo-suppression, with thrombocytopenia greater than neutropenia seen at the dose level of 0.70 mg/m2/d for 21 days. At the MTD of 0.53 mg/m2, ten patients were treated for a total of 20 courses, resulting in one episode of grade 4 thrombocytopenia and leukopenia, one grade 3 thrombocytopenia, and two grade 3 leukopenias. This dose regimen was well tolerated, with minimal nonhematologic toxicity. Local infusion port complications developed in two patients and two had bacteremia, including one patient with repeated local skin infections. Objective responses were observed in this heavily pretreated population for patients with ovarian cancer (two partial responses and one mixed response in six patients), breast cancer (one partial response and one mixed response in two patients), and for one patient each with renal and non-small-cell lung cancer (two partial remissions). CONCLUSION: Twenty-one-day topotecan infusion is well tolerated at 0.53 mg/m2, with dose-intensity exceeding other schedules for administration of topotecan. The DLT is hematologic, with thrombocytopenia somewhat exceeding leukopenia. Objective responses were observed in seven patients with breast, ovarian, renal, and non-small-cell lung cancer.     

Thermomechanical study of butyl rubber mastication during compounding

A thermomechanical method was used to study the topological and molecular structure of model rubber compounds. This structure changes because of mastication during compounding. It was found that raw butyl rubber has a diblock structure. The molecular weight distribution of the chains between the junctions of the polymer network, the coefficient of polydispersity, a share of low-temperature and high-temperature blocks, and changes in their glass transition temperatures as a result of the mixing of butyl rubber depend on both the presence of sulfur and the kind of sulfur (polymeric or mineral). © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 2159–2167, 1998     

The relative contributions of scatter and attenuation corrections toward improved brain SPECT quantification

Mounting evidence indicates that scatter and attenuation are major confounds to objective diagnosis of brain disease by quantitative SPECT. There is considerable debate, however, as to the relative importance of scatter correction (SC) and attenuation correction (AC), and how they should be implemented. The efficacy of SC and AC for 99mTc brain SPECT was evaluated using a two-compartment fully tissue-equivalent anthropomorphic head phantom. Four correction schemes were implemented: uniform broad-beam AC, non-uniform broad-beam AC, uniform SC + AC, and non-uniform SC + AC. SC was based on non-stationary deconvolution scatter subtraction, modified to incorporate a priori knowledge of either the head contour (uniform SC) or transmission map (non-uniform SC). The quantitative accuracy of the correction schemes was evaluated in terms of contrast recovery, relative quantification (cortical:cerebellar activity), uniformity ((coefficient of variation of 230 macro-voxels) x 100%), and bias (relative to a calibration scan). Our results were: uniform broad-beam (mu = 0.12 cm(-1)) AC (the most popular correction): 71% contrast recovery, 112% relative quantification, 7.0% uniformity, +23% bias. Non-uniform broad-beam (soft tissue mu = 0.12 cm(-1)) AC: 73%, 114%, 6.0%, +21%, respectively. Uniform SC + AC: 90%, 99%, 4.9%, +12%, respectively. Non-uniform SC + AC: 93%, 101%, 4.0%, +10%, respectively. SC and AC achieved the best quantification; however, non-uniform corrections produce only small improvements over their uniform counterparts. SC + AC was found to be superior to AC; this advantage is distinct and consistent across all four quantification indices.     

New strategies for old problems: tardive dyskinesia (TD). Review and report on severe TD cases treated with clozapine, with 12, 8 and 5 years of video follow-up

Tardive dyskinesia (TD) is the most feared and troublesome extrapyramidal side-effect of prolonged neuroleptic (NL) treatment. We present a review of TD. Its pathophysiology remains elusive, although extrapyramidal symptoms (EPS) increase the liability for TD. Nowadays, therefore, avoidance of all EPS remains the best preventive strategy, as it is not possible to predict which liable patients will develop TD, or of what type or severity. TD frequently includes dystonic features, and is more disabling when these dystonias are present. Clozapine (CLZ) has been reported to be effective in suppressing nearly 60% of TD syndromes, specially those with dystonic features. Based on the few reports in the literature on CLZ and TD by the early 1980s, we started to videotape the first severe TD patient treated with CLZ in 1984. We present the first three case reports of severe TD, with prominent disabling dystonic features, treated with CLZ and videotaped since pretreatment and then periodically for 12, 8 and 5 years of follow-up, respectively. The patients' current diagnosis, gender and age are: Case 1, DSM-IV Schizophrenia Residual Type, male, 39 years; Case 2, DSM-IV Polysubstance Related Disorder, Borderline Personality Disorder, female, 28 years; Case 3, DSM-IV Schizoaffective Disorder, male, 40 years. Two of them presented with a recurrence of TD because of CLZ interruption within the first 2 months of treatment, with no further breakthrough to date. The first two cases have complete remission of TD; the third case is still improving after 5 years of CLZ treatment, with only minor dystonic features persisting that constitute no impairment for work or daily routines at present. All patients, independent of their psychiatric primary diagnosis, have shown significant and progressive improvement in both motor and psychosocial aspects. None of them has been rehospitalized. Long-term treatment and follow-up is required to avoid TD recurrence and to assure full assessment of treatment effectiveness. Ideally, periodic video recording with standardized examination is advisable for long-term follow-up and outcome assessment. At present, CLZ could be regarded as the drug of choice for patients with TD, specially for those with disabling and or dystonic features and who require ongoing NL therapy. The use of novel antipsychotic agents for TD treatment and prevention, with their low EPS liability, is promising, but has yet to be tested.     

Coordination between respiration and deglutition in a preterm infant mammal, Sus scrofa

In adult mammals, the path of a swallowed bolus of solid food crosses the laryngeal opening, so that coordination between respiration and deglutition is critical for airway protection. The nature of such coordination in preterm, low-birth-weight infants with immature nervous systems, is not clear. Using preterm pigs as a model, two measures of respiration were recorded and then coordinated with a high-resolution cineradiographic record of swallowing. Swallows, divided into three distinct events, began before inhalation ended, but expiration did not start until after the milk had passed around the laryngeal opening. These results support the idea that a high degree of coordination between swallowing and respiration exists in preterm infant pigs, although other aspects of the nervous system have not fully matured.