Application of indirect linkage analysis and direct genotyping to hemophilia A carrier detection in Sichuan, China.

Hemophilia A (HA) is an inherited X-linked bleeding disorder caused by mutations in the factor VIII gene. Prenatal detection in female carriers from families with HA is important to reduce the number of HA patients. The purpose of this study was to detect carriers in families with HA from Sichuan, China, using linkage analysis and a direct genotyping method. A total of 18 HA families were studied. Using a combination of intron 22 inversion, intron 1 inversion, the BclI polymorphic site in intron 18, the HindIII polymorphic site in intron 19, and dinucleotide CA-repeat markers in introns 1, 13, 22, and 24, we were able to detect HA in 88.9% (16/18) of the families studied. HA was detected in the remaining two families by direct genotyping. This study gave the participants a good understanding of their genetic condition and gave us a preliminary understanding of the prevalence of each mutation in Sichuan HA patients.

Quantitative determination of activated coagulation factor XI as an impurity in therapeutic immunoglobulins from Chinese blood fractionation companies.

Residual activated coagulation factor XI (FXIa) has been suggested to play an important role in thromboembolic events associated with the use of intravenous immunoglobulin (IVIG) lots. This study investigated the predominant plasma proteases in 42 IVIG lots from 4 Chinese manufacturers. In one-stage clotting assays, the procoagulant activities of factors II, VII, IX, X, XI, and XII were quantified. Non-activated partial thromboplastin time and a modified thrombin generation test served as global and FXIa-specific clotting assays, respectively. We found that coagulation factor clotting activities of the 42 IVIG lots were below the detection limit of the assays, except for the products of manufacturer B (lots of 2010), in which 0.030 to 0.032 IU/mL FXI:C were detected. The peak time of thrombin using a thrombin generation test was greater than 35 min, the relevant amount of FXIa was below 0.37 nM, and non-activated partial thromboplastin time was greater than 200 s. Consequently, the 42 IVIG lots showed non-significant procoagulant potential. Further study is required to determine whether a program for FXIa determination in IVIG products should be launched in China.

Variance-components methods for linkage and association analysis of ordinal traits in general pedigrees.

Many complex human diseases such as alcoholism and cancer are rated on ordinal scales. Well-developed statistical methods for the genetic mapping of quantitative traits may not be appropriate for ordinal traits. We propose a class of variance-component models for the joint linkage and association analysis of ordinal traits. The proposed models accommodate arbitrary pedigrees and allow covariates and gene-environment interactions. We develop efficient likelihood-based inference procedures under the proposed models. The maximum likelihood estimators are approximately unbiased, normally distributed, and statistically efficient. Extensive simulation studies demonstrate that the proposed methods perform well in practical situations. An application to data from the Collaborative Study on the Genetics of Alcoholism is provided.

The electrochemical reduction of fullerenes, C60 and C70.

The hexaanion of fullerene, C(60)(6-), was obtained in 1:5 (v/v) acetonitrile-toluene mixture with a mercury hemispherical ultramicroelectrode as a working electrode at a temperature of up to 30 degrees C. The C(70)(6-) ion also can be observed under the same conditions. The differences between the redox potentials of C(60) relative to C(70) indicate that it is easier to add electrons to C(70) and its anions compared to the counterparts of C(60). The results show that the mercury electrode is very suitable for investigation of the properties of the electrochemical reduction for the fullerenes, particularly C(60), at room temperature.

CT-guided stereotactic injection of radionuclide in treatment of brain tumors.

140 patients with brain tumor were treated by CT-guided stereotactic injections of radionuclides, such as Aurum-198 (198 Au), Phosphorus-32 (32 P) and Yttrium-90 (90Y). Of these patients aged from 3 to 67 years (average 37), 64 were male and 76 female. Astrocytoma was found in 75 patients, craniopharyngioma in 46, metastatic carcinoma in 7, meningioma in 5, germinoma in 4 and pituitary adenoma in 3. The tumors were located in the deep part or functionally critical area of the brain. After 267 times of injection of colloidal isotopes, no major adverse effects or complications occurred. Follow-up for 6 to 48 months showed improvement in symptoms in 104 (74.3%) patients and CT scanning showed the diminished tumors.

The lost endotracheal tube--a rare complication of accidental esophageal intubation.

Endotracheal intubation is a discreet skill for the management of compromised airway. Various complications associated with this procedure have been described. Here, we would like to present a pediatric patient suffering from cerebellar atrophy, who was intubated in a local clinic due to seizure with cyanosis and loss of consciousness. Unfortunately, due to inadvertent esophageal intubation and bad management, the patient swallowed the endotracheal tube together with two detached loose teeth. This irrational and iatrogenic medical misconduct as exemplified in this accident calls forth the need of educating and disciplining the nonanesthetic physicians for acute management of airway, particularly of those who would likely come across difficult airway problems.

[Study on the surface hydroxyl species of diatomite using DRIFT spectroscopy].

Using DRIFT spectroscopy, we detected surface hydroxyl structure of diatomite in this study. There were either isolated hydroxyl groups or H-bonded hydroxyl groups on the surface of the diatomite. At room temperature, the diatomite surface was predominantly covered by weakly adsorbed water in cavity and water bonded to surface hydroxyl groups via H-bonds. There appeared a broad band with middle wavenumber at 3,400-3,500 cm-1 as a result in the corresponding DRIFT spectra. With driving off adsorbed water by heating the sample from 200 degrees C to 1000 degrees C, the broad band fade away gradually, and a single band at about 3,745 cm-1, which is attributed to both isolated hydroxyl groups and partial H-bonded hydroxyl groups, became more and more intense with increasing temperature. Under the heat treatment conditions of 1,100 degrees C for one hour, the isolated hydroxyl groups were mostly desorbed from the surface, and the H-bonded hydroxyl groups that existed above the inner wall of micropores with diameter of circa 10 nm, however, had not yet condensed thoroughly. The thermal behavior was supposed to be a speciality of diatomite.

Hierarchical model for evaluating pyrantel efficacy against strongyle parasites in horses.

Anthelmintic resistance is an increasing challenge for the control of equine parasites. The fecal egg count reduction test (FECRT) is the practical gold standard method for evaluating reduction in anthelmintic efficacy, but the interpretation is complicated due to high levels of variability. A hierarchical statistical model was described for analysis of FECRT data from multiple farms to evaluate the role of biological factors in determining the strongyle efficacy of pyrantel pamoate in a study performed in Denmark. The model was then used to describe two notions of farm efficacy, namely conditional and marginal efficacy. The median of the lower prediction limits was used to describe a robust classification rule. The performance of the methodology was evaluated using Monte Carlo simulations. The field study was performed on 64 Danish horse farms of different breeds. Of 1644 horses, 614 had egg counts ≥ 200 eggs per gram (EPG) and were treated. Individual coprocultures were performed for identification of Strongylus vulgaris from all horses pre-treatment. Thirty-one farms (48.4%) were positive for S. vulgaris, but pyrantel efficacy was unaffected by the presence of this parasite in the statistical model. Further, there were no significant effects of age, gender, or interactions between these, while the pre-treatment egg count was negatively associated with the egg count reduction. The statistical model classified 81.3%, 10.9%, and 7.8% of farms as no signs of resistance (NR), suspect resistance (SR), and resistance (RE), respectively. In comparison, arithmetic calculations classified 68.8%, 17.2%, and 14.1% in the same categories. Using 10,000 simulated data sets, the methodology provided a classification of farms into different efficacy categories with a false discovery of reduced farm efficacy rate equaling 8.74%. In addition, model-classification was unaffected by presence of single outlier horses in a separate simulation study.

Semiparametric variance-component models for linkage and association analyses of censored trait data.

Variance-component (VC) models are widely used for linkage and association mapping of quantitative trait loci in general human pedigrees. Traditional VC methods assume that the trait values within a family follow a multivariate normal distribution and are fully observed. These assumptions are violated if the trait data contain censored observations. When the trait pertains to age at onset of disease, censoring is inevitable because of loss to follow-up and limited study duration. Censoring also arises when the trait assay cannot detect values below (or above) certain thresholds. The latent trait values tend to have a complex distribution. Applying traditional VC methods to censored trait data would inflate type I error and reduce power. We present valid and powerful methods for the linkage and association analyses of censored trait data. Our methods are based on a novel class of semiparametric VC models, which allows an arbitrary distribution for the latent trait values. We construct appropriate likelihood for the observed data, which may contain left or right censored observations. The maximum likelihood estimators are approximately unbiased, normally distributed, and statistically efficient. We develop stable and efficient numerical algorithms to implement the corresponding inference procedures. Extensive simulation studies demonstrate that the proposed methods outperform the existing ones in practical situations. We provide an application to the age at onset of alcohol dependence data from the Collaborative Study on the Genetics of Alcoholism. A computer program is freely available.

Improving the power of association tests for quantitative traits in family studies.

Association mapping based on family studies can identify genes that influence complex human traits while providing protection against population stratification. Because no gene is likely to have a very large effect on a complex trait, most family studies have limited power. Among the commonly used family-based tests of association for quantitative traits, the quantitative transmission-disequilibrium tests (QTDT) based on the variance-components model is the most flexible and most powerful. This method assumes that the trait values are normally distributed. Departures from normality can inflate the type I error and reduce the power. Although the family-based association tests (FBAT) and pedigree disequilibrium tests (PDT) do not require normal traits, nonnormality can also result in loss of power. In many cases, approximate normality can be achieved by transforming the trait values. However, the true transformation is unknown, and incorrect transformations may compromise the type I error and power. We propose a novel class of association tests for arbitrarily distributed quantitative traits by allowing the true transformation function to be completely unspecified and empirically estimated from the data. Extensive simulation studies showed that the new methods provide accurate control of the type I error and can be substantially more powerful than the existing methods. We applied the new methods to the Collaborative Study on the Genetics of Alcoholism and discovered significant association of single nucleotide polymorphisms (SNP) tsc0022400 on chromosome 7 with the quantitative electrophysiological phenotype TTTH1, which was not detected by any existing methods. We have implemented the new methods in a freely available computer program.

A powerful and robust method for mapping quantitative trait loci in general pedigrees.

The variance-components model is the method of choice for mapping quantitative trait loci in general human pedigrees. This model assumes normally distributed trait values and includes a major gene effect, random polygenic and environmental effects, and covariate effects. Violation of the normality assumption has detrimental effects on the type I error and power. One possible way of achieving normality is to transform trait values. The true transformation is unknown in practice, and different transformations may yield conflicting results. In addition, the commonly used transformations are ineffective in dealing with outlying trait values. We propose a novel extension of the variance-components model that allows the true transformation function to be completely unspecified. We present efficient likelihood-based procedures to estimate variance components and to test for genetic linkage. Simulation studies demonstrated that the new method is as powerful as the existing variance-components methods when the normality assumption holds; when the normality assumption fails, the new method still provides accurate control of type I error and is substantially more powerful than the existing methods. We performed a genomewide scan of monoamine oxidase B for the Collaborative Study on the Genetics of Alcoholism. In that study, the results that are based on the existing variance-components method changed dramatically when three outlying trait values were excluded from the analysis, whereas our method yielded essentially the same answers with or without those three outliers. The computer program that implements the new method is freely available.

[Quantitative analysis for mast cells in obstructive sialadenitis].

Quantitative analysis for mast cells in 27 cases of obstructive sialadenitis, 12 cases of approximate normal salivary gland tissues and 5 cases of lymphoepithelial lesion of salivary glands shows that the number of mast cells is slightly increased with the increase of gravity-grade of obstructive sialadenitis and this is closely related to fibrosis of salivary glands and infiltration grade of inflammation cells (dominated by lymphocyte cells), whereas not closely relating to the age change of patients. For the cases of benign lymphoepithelial lesion of salivary glands with malignant changes despite of malignant lymphoma or squamous cell carcinoma the numbers of mast cells are obviously decreased.

The specificity of the lymphocyte transformation test in a patient with hypersensitivity reactions to pyrazolone compounds. A 10-week follow-up study before and after rechallenge.

To evaluate the specificity of the lymphocyte transformation test (LTT) in the diagnosis of drug allergy we studied over 71 days an atopic woman with a past history of frequent adverse reactions to pyrazolone drugs. Rechallenge with the incriminated substances aminophenazone (aminopyrine) and propyphenazone was carried out on Days 11 and 31 respectively. An immediate type of hypersensitivity reaction was seen after 100 mg aminophenazone, while 100 mg of propyphanozone led to a serum sickness-like syndrome. We found two specifically sensitized lymphocyte populations using either the pure substance or sera containing metabolite in cell cultures. Stimulatory responses with indices ranging between 3 and 6 were seen 3-4 days after exposure, and the tests remained positive in both instances for 3-4 weeks. Specific sensitization was proven by positive skin tests and by a small but distinct lymphocyte proliferative response before challenge. Several lymphocyte function tests were performed over a period of 53 days and revealed a large fall in pokeweed mitogen-induced immunoglobulin synthesis and an increase in suppressor cell activity after rechallenge with aminophenazone. We conclude that the proliferative response observed in the presence of the offending drug is due to the activation of T memory cells and therefore highly suggestive of a true allergic reaction.

Immunoenhancing effect of flavonoid compounds on lymphocyte proliferation and immunoglobulin synthesis.

Flavonoid compounds are lipophilic agents which can interact with membrane lipids and may affect responsiveness of immune cells. We therefore studied whether cianidanol ((+)-catechin), the O-methyl-derivative (+)-3-methoxy-5,7,3',4'-tetrahydroxyflavan and palmitoyl-derivative (+)-3-palmitoyl-5,7,3',4'-tetrahydroxyflavan influence T and B cell functions. In addition, immunomodulatory property of ubiquinone 50 was also investigated. As controls were used cyclosporin A and inosine which are known to inhibit or enhance immune responses, respectively. The in vitro spontaneous, antigen and mitogen induced proliferation as well as immunoglobulin synthesis of peripheral blood mononuclear cells from healthy individuals was determined in the presence of different concentrations of the agents. All flavonoid compounds and ubiquinone 50 significantly increased (p less than 0.05 - less than 0.01) the spontaneous lymphocyte transformation but hardly affected antigen, alloantigen and mitogen induced proliferative response. Only cianidanol and O-methyl-derivative enhanced significantly (p less than 0.05 - less than 0.01) spontaneous, pokeweedmitogen and Staphylococcus aureus Cowan I induced immunoglobulin synthesis while the palmitoyl-derivative and ubiquinone 50 had only minor influence on B cell function. In contrast, Staphylococcus aureus induced immunoglobulin production was neither increased by inosine nor suppressed by cyclosporin A. These studies show that especially cianidanol and the O-methyl-derivative can exert an immunoenhancing effect on T and B cell functions.

[Lung edema after administration of hydrochlorothiazide. A rare and life-threatening side effect]. / Lungenödem nach Einnahme von Hydrochlorothiazid. Eine seltene, vital bedrohliche Nebenwirkung.

Recurrent pulmonary oedema occurred in a 62-year-old woman after repeated intake of hydrochlorothiazide-triamterene tablets. Eight similar reports in the medical literature suggested it to be a rare case of intolerance to hydrochlorothiazide. The lymphocyte transformation test proved an allergic genesis: there was significant stimulation of patient lymphocytes by active agent/metabolite serum of hydrochlorothiazide but not triamterene.

Serum inhibitory factors (SIF) are of prognostic value in acute viral hepatitis.

Serum inhibitory factors (SIF) were analysed in relation to the natural course of acute viral hepatitis in 81 patients followed over a period of 1 year. 63 patients recovered completely (group 1), and 18 had a protracted course of hepatitis (group 2) as shown by persistent transaminase activity 6 months after onset. 11 patients in group 2 still had signs of liver disease after 1 year. A gradual fall of SIF activity (in 47 patients) heralded resolving hepatitis, whereas persistence of SIF (in 8 patients) correlated with inflammatory activity and failure of hepatitis B viral antigen elimination. Absence of SIF activity was associated with either an uncomplicated or a chronic course of hepatitis in 23 and 3 patients, respectively. Repeated determination of SIF may help to predict the final outcome of hepatitis. Both excessive and failure of SIF production may result in the development of chronic liver disease.