Investigations on the population genetics of the α1-antitrypsin polymorphism

Summary The results of Pi-typing on 2647 individuals from 9 populations are reported. Of the 17 phenotypes and 9 alleles described in literature, we found 12 phenotypes and 8 alleles. The population smaples differ characteristically in their allele frequencies. The allle Pi^M appears constantly in all populations tested with a frequency of more than 0.85. The alleles Pi^F (0.01–0.11), Pi^S (0.01–0.02) and Pi^Z (0.01–0.02) were also relatively frequent in all samples. All the other alleles remain below 0.01. A great increase in the number of Pi-variants was observed in the Central European area. The frequency of ₁-at variants in various populations is discussed.Supported by the Deutsche Forschungsgemeinschaft.Dedicated to Prof. W. Lehmann, Kiel, on his 65th birthday.     

α1-antitrypsin (Pi) phenotypes in a village population from the Gambia,West Africa

Summary A total of 701 individuals from a village in The Gambia, West Africa were tested for serum ₁ ^- antitrypsin phenotypes by isoelectric focusing in thinlayer polyacrylamide gels (pH 4-5). A new variant allele, Pi ^GAM , was discovered at a polymorphic frequency (0.0642), and the inheritance of the variant phenotype was confirmed by family studies. The variant was not found to be associated with any decrease in serum ₁ ^- concentration. The only other allele found within this population was the common allele Pi ^M (0.9358).     

Oxidative DNA damage and influence of genetic polymorphisms among urban and rural schoolchildren exposed to benzene

Traffic related urban air pollution is a major environmental health problem in many large cities. Children living in urban areas are exposed to benzene and other toxic pollutants simultaneously on a regular basis. Assessment of benzene exposure and oxidative DNA damage in schoolchildren in Bangkok compared with the rural schoolchildren was studied through the use of biomarkers.Benzene levels in ambient air at the roadside adjacent to Bangkok schools was 3.95-fold greater than that of rural school areas. Personal exposure to benzene in Bangkok schoolchildren was 3.04-fold higher than that in the rural schoolchildren. Blood benzene, urinary benzene and urinary muconic acid (MA) levels were significantly higher in the Bangkok schoolchildren. A significantly higher level of 8-hydroxy-2′-deoxyguanosine (8-OHdG) in leukocytes and in urine was found in Bangkok children than in the rural children. There was a significant correlation between individual benzene exposure level and blood benzene (r_s = 0.193, P < 0.05), urinary benzene (r_s = 0.298, P < 0.05), urinary MA (r_s = 0.348, P < 0.01), and 8-OHdG in leukocyte (r_s = 0.130, P < 0.05). In addition, a significant correlation between urinary MA and 8-OHdG in leukocytes (r_s = 0.241, P < 0.05) was also found. Polymorphisms of various xenobiotic metabolizing genes responsible for susceptibility to benzene toxicity have been studied; however only the GSTM1 genotypes had a significant effect on urinary MA excretion.Our data indicates that children living in the areas of high traffic density are exposed to a higher level of benzene than those living in rural areas. Exposure to higher level of benzene in urban children may contribute to oxidative DNA damage, suggesting an increased health risk from traffic benzene emission.     

Vitamin D Status among Thai School Children and the Association with 1,25-Dihydroxyvitamin D and Parathyroid Hormone Levels

In several low latitude countries, vitamin D deficiency is emerging as a public health issue. Adequate vitamin D is essential for bone health in rapidly growing children. In the Thai population, little is known about serum 25-hydroxyvitamin D [25(OH)D] status of infants and children. Moreover, the association between 25(OH)D and the biological active form of 1,25-dihydroxyvitamin D [1,25(OH)]₂D is not clear. The specific aims of this study were to characterize circulating serum 25(OH)D, 1,25(OH)₂D and their determinants including parathyroid hormone (PTH), age, sex, height and body mass index (BMI) in 529 school-aged Thai children aged 6–14 y. Adjusted linear regression analysis was performed to examine the impact of age and BMI, and its interaction with sex, on serum 25(OH)D concentrations and 1,25(OH)₂D concentrations. Serum 25(OH)D, 1,25(OH)₂D and PTH concentrations (geometric mean ± geometric SD) were 72.7±1.2 nmol/L, 199.1±1.3 pmol/L and 35.0±1.5 ng/L, respectively. Only 4% (21 of 529) participants had a serum 25(OH)D level below 50 nmol/L. There was statistically significant evidence for an interaction between sex and age with regard to 25(OH)D concentrations. Specifically, 25(OH)D concentrations were 19% higher in males. Moreover, females experienced a statistically significant 4% decline in serum 25(OH)D levels for each increasing year of age (P = 0.001); no decline was seen in male participants with increasing age (P = 0.93). When BMI, age, sex, height and serum 25(OH)D were individually regressed on 1,25(OH)₂D, height and sex were associated with 1,25(OH)₂D with females exhibiting statistically significantly higher serum 1,25(OH)₂D levels compared with males (P<0.001). Serum 1,25(OH)₂D among our sample of children exhibiting fairly sufficient vitamin D status were higher than previous reports suggesting an adaptive mechanism to maximize calcium absorption.     

The localization of rDNA in small,nucleolus-like structures in human diplotene oocyte nuclei

Summary Alpha-1-antitrypsin Pi phenotyping was performed by thin-layer isoelectric focusing on samples from 1653 healthy white blood donors. The variants were confirmed by the acid-starch gel technique and crossed immuno-electrophoresis, with complete agreement between the two methods. The allele frequencies in this population were PiM, 0.9019; PiS, 0.0713; PiZ, 0.0142; PiI, 0.0036; PiF, 0.0036; PiV, 0.0024. In addition, some rare phenotypes (MX, IS, LM) were noted. No difference was noted in the distribution of the variant alleles between males and females. The significance of the high frequency of the S allele is related to the ethnic origin of this population. The agreement of the results obtained by our technique and by acid-starch gel electrophoresis confirms the validity of Pi determination by thin-layer isoelectric focusing.     

An excess of the Pi Sallele in dizygotic twins and their mothers

Summary A significant excess of the ₁ (protease inhibitor) Pi ^S allele has been found in 147 pairs of dizygotic (DZ) twins, but frequencies in 170 pairs of monozygotic (MZ) twins do not differ from those in a sample of 1007 blood donors. In 51 mothers of DZ twins the frequency of the Pi ^S allele was double than in the same sample of donors, but there was no corresponding increase in the fathers of DZ twins nor in the parents of MZ twins. In an independent sample of 66 mothers of twins of unknown zygosity, there was also a significant excess of Pi ^M Pi^S and Pi^M Pi^Z phenotypes, and this was particularly marked in the subsample of mothers of opposite-sex twin pairs. We speculate that lowered protease inhibitor levels in women carrying the Pi ^S allele may enhance sperm migration, increase the probability of multiple ovulation, or both.     

Alpha1-antitrypsin levels and electrophoretic patterns of several deficient phenotypes

Summary Two alleles, Pi^Z and Pi^S, are associated with lower than normal alpha₁-antitrypsin concentrations and lower trypsin inhibiting activities in human serum. The phenotypes that result due to heterozygosity or homozygosity for these alleles can be distinguished with electrophoretic procedures. The alpha₁-antitrypsin concentrations of several phenotypes overlap so that the phenotypes can be determined with certainty only by an electrophoretic procedure.

---

Zusammenfassung Die zwei Allele Pi^Z and Pi^S führen zu subnormalen Konzentrationen von Alpha₁-Antitrypsin und niedrigen Trypsinhemmaktivitäten im menschlichen Serum. Die durch Hetero- und Homozygotie für diese Allele entstehenden Phänotypen können durch elektrophoretische Methoden unterschieden werden. Die Alpha₁-Antitrypsin-Konzentrationen der verschiedenen Phänotypen überlappen, so daß eine sichere Erkennung nur durch elektrophoretische Methoden möglich ist.

---

---

This work was supported in part by Deutsche Forschungsgemeinschaft and Joachim Jungius-Gesellschaft der Wissenschaften Hamburg.     

Association of circulating angiotensin converting enzyme activity with respiratory muscle function in infants

Background

Angiotensin converting enzyme (ACE) gene contains a polymorphism, consisting of either the presence (I) or absence (D) of a 287 base pair fragment. Deletion (D) is associated with increased circulating ACE (cACE) activity. It has been suggested that the D-allele of ACE genotype is associated with power-oriented performance and that cACE activity is correlated with muscle strength. Respiratory muscle function may be similarly influenced. Respiratory muscle strength in infants can be assessed specifically by measurement of the maximum inspiratory pressure during crying (Pi_max). Pressure-time index of the respiratory muscles (PTImus) is a non-invasive method, which assesses the load to capacity ratio of the respiratory muscles.The objective of this study was to determine whether increased cACE activity in infants could be related to greater respiratory muscle strength and to investigate the potential association of cACE with PTImus measurements as well as the association of ACE genotypes with cACE activity and respiratory muscle strength in this population.

Methods

Serum ACE activity was assayed by using a UV-kinetic method. ACE genotyping was performed by polymerase chain reaction amplification, using DNA from peripheral blood. PTImus was calculated as (Pi_mean/Pi_max) × (Ti/Ttot), where Pi_mean was the mean inspiratory pressure estimated from airway pressure, generated 100 milliseconds after an occlusion (P_0.1), Pi_max was the maximum inspiratory pressure and Ti/Ttot was the ratio of the inspiratory time to the total respiratory cycle time. Pi_max was the largest pressure generated during brief airway occlusions performed at the end of a spontaneous crying effort.

Results

A hundred and ten infants were studied. Infants with D/D genotype had significantly higher serum ACE activity than infants with I/I or I/D genotypes. cACE activity was significantly related to Pi_max and inversely related to PTImus. No association between ACE genotypes and Pdi_max measurements was found.

Conclusions

These results suggest that a relation in cACE activity and respiratory muscle function may exist in infants. In addition, an association between ACE genotypes and cACE activity, but not respiratory muscle strength, was demonstrated.     

The effect of pyramiding Phytophthora infestans resistance genes R Pi-mcd1 and R Pi-ber in potato

Despite efforts to control late blight in potatoes by introducing R _pi -genes from wild species into cultivated potato, there are still concerns regarding the durability and level of resistance. Pyramiding R _pi -genes can be a solution to increase both durability and level of resistance. In this study, two resistance genes, R _Pi-mcd1 and R _Pi-ber , introgressed from the wild tuber-bearing potato species Solanum microdontum and S. berthaultii were combined in a diploid S. tuberosum population. Individual genotypes from this population were classified after four groups, carrying no R _pi -gene, with only R _Pi-mcd1 , with only R _Pi-ber , and a group with the pyramided R _Pi-mcd1 and R _Pi-ber by means of tightly linked molecular markers. The levels of resistance between the groups were compared in a field experiment in 2007. The group with R _Pi-mcd1 showed a significant delay to reach 50% infection of the leaf area of 3 days. The group with R _Pi-ber showed a delay of 3 weeks. The resistance level in the pyramid group suggested an additive effect of R _Pi-mcd1 with R _Pi-ber . This suggests that potato breeding can benefit from combining individual R _pi -genes, irrespective of the weak effect of R _Pi-mcd1 or the strong effect of R _Pi-ber .     

Nephelometry determined serum immunoglobulin isotypes in healthy Thai children aged 2-15 years

Knowledge of what constitute normal serum immunoglobulin (Ig) concentrations are important for the diagnosis of immunologic disorders. Data on normal Ig evaluated by nephelometry are limited in healthy Asian children, none being available for Thai children. One hundred and forty-eight healthy Thai children aged 2-15 years were tested for serum immunoglobulins G, A, M, G1, G2, G3, and G4 (Ig G, A, M, G1, G2, G3, and G4) by nephelometry. Sixty-three percent were girls of median interquartile range age 6.9 (4.8-9.7) years. The geometric means for each Ig were summarized and categorized by age. Statistical analyses were used to compare Igs between sexes and age groups, and to compare IgG in this study with data from other published studies. The average ratios of IgG subclasses/IgG for Ig G1:2:3:4 were 66:22:5:7%. IgG, IgA, IgG2, and IgG3 concentrations showed a gradual increase with increasing age. There were no significant sex differences for any immunoglobulin isotype (P= 0.971). Our mean IgG concentration was lower than that measured by the radial diffusion method in healthy Thai children (P < 0.05). In all age groups, the mean IgG concentration in our study was significantly higher than that reported in Turkish and USA children, evaluated by the nephelometric and radial diffusion techniques, respectively (both P < 0.001). This study provides information about normal Ig concentrations measured by nephelometry in healthy Asian children and illustrates the importance of ascertaining normal Ig values for age- and ethnic-matched controls using the same assay to diagnose immunologic disorders correctly.     

湖南省健康人群血清总蛋白、白蛋白参考值调查

目的：本实验旨在建立湖南省健康人群血清总蛋白（TP）、血清白蛋白（ALB）及A/G比值的参考值区间。方法：收集4543例湖南省城乡健康参考个体,采用全自动生化分析仪测定其血清TP、ALB值,并计算A/G比值,按不同年龄、性别、城乡进行分组统计学分析,建立适合湖南省人群TP、ALB及A/G比值的参考值。结果：湖南省健康人群参考区间为TP：66.51～82.85 g/L,ALB：43.09～50.19g/L,A/G比值为1.05～2.19;TP随年龄增大而稍有升高,中年达到高峰,后随年龄增大而降低,在各年龄组,女性均高于男性（P〈0.05）,乡村地区TP值高于城市地区（P〈0.05）;ALB随年龄增大稍有升高,在青壮年到达高峰而后下降,在儿童青少年、青壮年组血清ALB男性高于女性（P〈0.05）,而在中年、老年组血清ALB无差别,乡村地区ALB值高于城市地区（P〈0.05）;A/G比值随年龄的变化存在一定的差异性,A/G比值随年龄增大稍有增高,在青壮年组达到高峰而后下降,且在各年龄组男性高于女性（P〈0.05）,城市地区A/G值高于乡村地区（P〈0.05）;湖南省健康人群的TP、ALB与全国其他省市的TP、ALB存在差异。结论：湖南省健康人群TP、ALB、A/G比值参考区间与全国其它省份稍有差异,血清TP、Alb、A/G比值存在年龄、性别和地区差异性。     

Estimating PM2.5 concentrations with statistical distribution techniques for health risk assessment in Bangkok

Abstract

Ambient PM_2.5 data in the Central Business District (CBD) of Bangkok monitored by Pollution Control Department and Bangkok Metropolitan Administration were collected over three years in Bangkok from 2015 to 2017. The other air pollutions data were used as the dependent variables to develop mathematic models with statistical distribution technique. Multiple linear regression technique was selected as the main statistical distribution methodology for estimating PM_2.5 concentrations in non-monitored areas. The predicted PM_2.5 concentrations were validated against the measured PM_2.5 concentrations by various statistical techniques. The validation found that the model had strong significant correlations for ambient and roadside area with R ²?=?0.88 and 0.96, respectively. The non-carcinogenic health risk assessment of PM_2.5 was quantified as the hazard quotient (HQ) from both the measured and predicted data. The risk areas and HQ were compared using the inverse distance weighting interpolation technique and illustrated as GIS-based maps. During December to February, the HQ values of PM_2.5 were exceed 1 (HQs?>?1) at all area of CBD; however, the highest HQ was found in the southern part of CBD. The finding could be used for residential health awareness in that area.     

Effect of the rhg1 Gene on Population Development of Heterodera glycines

The effect of the rhg1 gene on equilibrium population densities (E) and reproduction factors (Rf) of Heterodera glycines was studied by comparing the nematode population development on two near-isogenic soybean lines (NIL), differing at the rhg1 locus. The NIL were inoculated with a series of initial egg densities (Pi) in the greenhouse. The relationships between final population densities (Pf = females per plant or eggs per plant) or Rf (final egg density/Pi) on both NIL and Pi were adequately described by quadratic models. The rhg1 gene suppressed Pf and Rf at all Pi of a population of H. glycines race 3 (HG Type 0-); E and maximum Rf were higher on the NIL-S line than on the NIL-R line. After two generations of culture of the race 3 population on the NIL-R line, the population selected by the rhg1 gene (R-eggs) had higher Pf and Rf on the NIL-R line than the population cultured on the NIL-S line (S-eggs) at all Pi. Both R-eggs and S-eggs produced similar egg numbers on the NIL-S line, which was higher than the egg number of either population on the NIL-R line at all Pi. The ratio of E in female numbers on the NIL-R line to E on the NIL-S line increased from 29% for the original race 3 population (S-eggs) to 46% for the rhg1-selected population (R-eggs). Regardless of different egg sources, a trend of increase in the number of eggs per female with the rise of Pi was observed on the NIL-S line. In contrast, female fecundity of both populations declined with the increase of Pi on the NIL-R line. At most inoculum densities, the highest number of eggs per female was observed on the NIL-S line inoculated with the R-eggs, whereas the lowest number of eggs per female was detected on the NIL-R line inoculated with the S-eggs. This study demonstrated that the E and maximum Rf determined by the quadratic models are useful measurements of plant resistance to nematodes.     

Alpha1-antitrypsin: Physiology,genetics and pathology

Summary Alpha₁-antitrypsin (₁) is a glycoprotein in human serum that inhibits the enzymatic activity of trypsin and other proteolytic enzymes. Its concentration in normal serum is 200–250 mg/100 ml. In certain physiological and pathological situations, such as pregnancy, under contraceptive medication and during inflammation, the level of ₁-at is elevated. The physiological role of ₁ is not known, but the interaction with proteolytic enzymes from white blood cells is probably important. Electrophoretic techniques distinguish several phenotypes, which can be explained by the existence of several codominant alleles at one locus (probably the structural locus). Two alleles Pi^Z and Pi^S cause low concentrations of ₁-at in serum: the approximate concentrations of ₁-at for the different phenotypes are Z/Z 10%, M/Z 50–60%, S/S 60%, M/S 80%, where the level of 212 mg/100 ml found in the M/M phenotype is taken as 100%; thus the effect of these alleles on the ₁-at concentration is additive. Homozygosity for the Pi^Z allele is strongly associated with chronic obstructive lung disease and there is also an association of COPD and heterozygosity for the Pi^Z or Pi^S or both, but to a lesser degree.

---

Zusammenfassung ₁-Antitrypsin (₁-at) ist ein Glykoprotein des menschlichen Serums. Es hemmt die enzymatische Aktivität von Trypsin und anderen proteolytischen Enzymen. Die Konzentration in normalem Serum beträgt etwa 200–250 mg/100 ml. Unter bestimmten physiologischen und pathologischen Bedingungen, z. B. während der Schwangerschaft, nach Verabreichung von Ovulationshemmern und während einer Infektion, ist der Serumspiegel des ₁-at erhöht. Die genaue physiologische Funktion des ₁-at ist unbekannt, wahrscheinlich ist aber die Hemmung von proteolytischen Enzymen aus Leukocyten von Bedeutung. Mit Hilfe elektrophoretischer Methoden kann man einige Phänotypen unterscheiden. Diese Phänotypen können durch mehrere codominante Allele an einem Locus, wahrscheinlich dem Strukturlocus, erklärt werden. Zwei Allele, Pi^Z und Pi^S, verursachen niedrige Konzentrationen von ₁ im Serum: Die ungefähren Serumkonzentrationen von ₁-at der verschiedenen Phänotypen sind: Z/Z 10%, M/Z 50–60%, S/S 60%, M/S 80%; die Konzentration von 212 mg/100 ml des M/M-Phänotyps ist hier gleich 100% gesetzt. Die Wirkung der verschiedenen Allele auf die ₁-at ist also additiv. Homozygotie für das Pi^Z-Allel ist statistisch signifikant mit chronisch obstruktivem Lungenemphysem assoziiert. Eine geringere, aber ebenfalls statistisch signifikante Assoziation mit chronisch obstruktivem Lungenemphysem besteht auch für die Heterozygotie Pi^M/Pi^Z und Pi^M/Pi^S oder nur für eine von beiden Heterozygotien.

---

---

Recipient of a stipendium from Deutsche Forschungsgemeinschaft.     

Rat pituitary tumor cells in serum-free culture. II. Serum factor and thyroid hormone requirements for estrogen-responsive growth

Summary The effect of 17β-estradiol (E₂) on growth of GH₄C₁ rat pituitary tumor cells was investigated under serum-free conditions and with medium containing charcoal-extracted serum. Serum-free TRM-1 medium was a 1∶1 (vol/vol) mixture of F12-DME supplemented with 50 μg/ml gentamicin, 15 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, 10 μg/ml insulin, 10 μg/ml transferrin, 10 ng/ml selenous acid, 10 nM 3,5,3′-triiodothyronine (T₃), 50 μM ethanolamine, and 500 μg/ml bovine serum albumin. The cells grew continuously in TRM-1 but were E₂ responsive only when growth was retarded by reducing the T₃ concentration to 10 pM (TRM-MOD). Addition of 1 to 10 nM E₂ to TRM-MOD increased growth by 0.3 to 0.9 cell population doublings over controls in 9 d. By using medium supplemented with charcoal-extracted sera, basal growth became 1 to 1.5 cell population doublings in 9 d. Addition of 0.1 pM E₂ to medium containing charcoal-extracted serum caused a significant increase in cell number whereas pM-nM concentrations stimulated 200 to 570% increases over controls. The effect of steroid hormone was the same in phenol-red-containing and indicator-free medium. The data presented confirm that the major requirements for demonstration of estrogenic effects in culture were optimum concentrations of thyroid hormones and the presence of yet-to-be-characterized serum factors. This work was supported by National Cancer Institute (Bethesda, MD) grants CA-26617 and CA-38024, American Cancer Society grant BC-255, and grant 2225 from The Council for Tobacco Research, U.S.A., Inc.     

Genetic transferrin types and iron-binding: a comparative study of a European and an African population sample

Summary Two population samples, one from Europe and one from Africa, were analyzed for the distribution of genetic transferrin (TF) types, serum concentrations of TF, serum iron concentrations and free iron-binding capacities. In Europeans the distribution of the TF alleles was C1=0.816, C2=0.143, C3=0.037 and B₂=0.004. In black Africans the allele frequencies were: C1, 0.823; C2, 0.104; and D₁=0.073; TF^*C3 was absent. The mean serum concentrations were 362±88 mg/dl in Europeans and 528±176 mg/dl in Africans; this difference was statistically significant. The concentration of serum imunoglobulins was also elevated in black Africans although their health was reported to be normal. The serum iron concentrations in Africans were decreased; the free ironbinding capacity of TF was, thus, increased; the free ironbinding capacity of TF was, thus, increased. In both population samples there was a tendency for slightly higher TF concentrations in the TF C1 subtype than the TF C2 subtype. This correlation was not statistically significant. Analysis of a larger sample is required to establish this relationship.     

Serological response to the 2009 pandemic influenza A (H1N1) virus for disease diagnosis and estimating the infection rate in Thai population

Background

Individuals infected with the 2009 pandemic virus A(H1N1) developed serological response which can be measured by hemagglutination-inhibition (HI) and microneutralization (microNT) assays.

Methodology/Principal Findings

MicroNT and HI assays for specific antibody to the 2009 pandemic virus were conducted in serum samples collected at the end of the first epidemic wave from various groups of Thai people: laboratory confirmed cases, blood donors and health care workers (HCW) in Bangkok and neighboring province, general population in the North and the South, as well as archival sera collected at pre- and post-vaccination from vaccinees who received influenza vaccine of the 2006 season. This study demonstrated that goose erythrocytes yielded comparable HI antibody titer as compared to turkey erythrocytes. In contrast to the standard protocol, our investigation found out the necessity to eliminate nonspecific inhibitor present in the test sera by receptor destroying enzyme (RDE) prior to performing microNT assay. The investigation in pre-pandemic serum samples showed that HI antibody was more specific to the 2009 pandemic virus than NT antibody. Based on data from pre-pandemic sera together with those from the laboratory confirmed cases, HI antibody titers ≥40 for adults and ≥20 for children could be used as the cut-off level to differentiate between the individuals with or without past infection by the 2009 pandemic virus.

Conclusions/Significance

Based on the cut-off criteria, the infection rates of 7 and 12.8% were estimated in blood donors and HCW, respectively after the first wave of the 2009 influenza pandemic. Among general population, the infection rate of 58.6% was found in children versus 3.1% in adults.     

Fine mapping and DNA marker-assisted pyramiding of the three major genes for blast resistance in rice

Three major genes (Pi1, Piz-5 and Pita) for blast resistance on chromosomes 11, 6 and 12, respectively, were fine-mapped and closely linked RFLP markers identified. New markers for Pi1 and Pita were found that were flanking the genes. The three genes were pyramided using RFLP markers. A PCR-based SAP (sequence amplified polymorphism) marker was used to identify Piz-5 in the segregating population. The plants carrying the two- and three-gene combinations that were tested for resistance to leaf blast in the Philippines and India indicated that combinations including Piz-5 have enhanced resistance than when it is present alone. The genes from the pyramided lines are at present being deployed into agronomically superior ricevarieties by marker-aided selection (MAS). Received: 20 June 1997 / Accepted: 14 September 1999     

Rat pituitary tumor cells in serum-free culture. I. Selection of thyroid hormone-responsive and autonomous cells

Summary The growth of GH₄C₁, GH₃, GH₁, and GH₃C₁₅ rat pituitary tumor cell lines was studied in a serum-free medium (designated TRM-1) formulated with 1∶1 (vol/vol) mixture of Ham's F12 nutrient mixture and Dulbecco's modified Eagle's medium (F12-DME) containing 15 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), 50 μg/ml gentamicin supplemented with 10 μg/ml bovine insulin, 10 μg/ml human transferrin (Tf), 10 ng/ml selenous acid, 10 nM 3,5,3′-triiodothyronine (T₃), 50 μM ethanolamine (Etn), and 500 μg/ml bovine serum albumin. Of the lines evaluated, only the GH₁ failed to grow in TRM-1. Passage of the GH₄C₁ and GH₃ lines from serum-containing medium into TRM-1 caused an initial selection resulting in cells that grew progressively at higher rates and finally were maintained indefinitely in TRM-1. These populations showed a requirement for supraphysiologic concentrations of T₃ (1.0 to 10 nM). After adaptation of the GH₄C₁ line in TRM-1 for ≤20 generations, removal of components gave a less complex mixture containing 15 mM HEPES, 50 μ/ml gentamicin, 10 μg/ml Tf, 10 nM T₃, and 50 μM Etn (designated TRM-2) that supported serial passage of the cells. Under these conditions, thyroid hormone dependence was lost progressively. When T₃ was removed from TRM-2 adapted cells, a third population was selected that no longer required thyroid hormones and was only slightly stimulated by T₃. These studies demonstrated that the combination of serum-containing and serum-free conditions can be used to select pituitary cell populations that a) required both serum-factor(s) and T₃ for optimum growth, b) required supraphysiologic concentrations of T₃ without serum proteins other than Tf and albumin, and c) were completely autonomous in that they proliferated in medium supplemented only with Tf and nutrients without necessity of other serum factor(s) or T₃. This work was supported by grants CA-26617 and CA-38024 from the National Cancer Institute, Bethesda, MD, American Cancer Society grant BC-255, and grant 2225 from the Council for Tobacco Research, Inc., USA.     

Seasonal variations in the level of immunoglobulins and serum proteins of children differing by exposure to air-borne lead

A semicohort of children, initial age about 11.5 years, from an exposure area near a secondary lead smelting plant (E group children) was examined for some humoral immune response parameters in the blood and saliva and compared to a group of control children matched by age living in a relatively unpolluted rural area (Co group children). All examinations were performed every autumn and spring over a period of 2 successive years, and the data included in the final analysis were only from children who had completed at least 3 of the 4 examination series performed. To sum up, children from area E showed a clearcut elevation of mean blood lead (Pb) levels with marked seasonal fluctuations peaking in spring; Pb levels in the blood of Co group children had no such season-related fluctuation patterns and tended to slightly decline over the two years of observation. Delta-aminolevulinic acid dehydratases (ALAD) levels in area E were of distinctly lower mean values than in area Co, but no correlation with mean blood Pb levels could be observed. Levels of IgG were more or less inversely correlative with Pb levels in both sexes, levels of IgM showed a distinct downward trend in E group children at all samplings. Total serum protein (SP) levels of children from area E showed a reverse correlation with plumbemia, secretory IgA (sIgA) concentrations showed a decrease in E group children of both sexes, but the values tended to converge with control values. Levels of alpha 1-antitrypsin (A 1-AT) showed marked season-related fluctuation patterns in Co children, the curves in E group children turned steeply upward from the third examination series on. Ceruloplasmin (CPL) levels in E group children had a clearcut upward trend at three subsequent blood samplings, the curves in Co group children continued to drop. Children from area E showed markedly higher frequency rates of abnormal values than did children from Co area.