Alpha-thalassaemia (Hb-Bart's) in Rajasthan (India)

A total of 1,647 cord blood samples (618 of scheduled tribes, 487 of scheduled castes and 542 of general castes) of newborns from the Banswara, Bhilwara, Chittorgarh, Dungarpur, Sirohi and Udaipur districts of the Aravali hilly region of Rajasthan were investigated electrophoretically for evidence of Hb-Bart's (alpha-thalassaemia). Hb-Bart's was encountered in 31 (1.88%) neonates constituting 1.8 to 12.6% of their total haemoglobin. Of these, 24 (1.46%) were of alpha-thalassaemia 1 and 7 (0.42%) of alpha-thalassaemia 2. The incidence of alpha-thalassaemia genes varied from 3.07% in the scheduled tribes, 1.43% in the scheduled castes to 0.77% in the general castes populations giving an overall incidence of 1.88%. Except Hb-Bart's allele, no other mutant haemoglobins were observed.     

Idiopathic talipes equinovarus (ITEV) (clubfeet) in Texas

Idiopathic talipes equinovarus (ITEV) is the most common form of clubfoot with a birth prevalence of 1 per 1,000 births. Serial casting and surgical correction impose a substantial financial burden on families and the health care system. While the etiology of ITEV is considered to be complex, the causes remain elusive. Genetic, maternal, and environmental factors have been suggested to play an etiologic role. This study was undertaken to determine the prevalence of ITEV and define maternal and environmental factors associated with ITEV in Texas from 1996 to 1999. Data on 682 cases of nonsyndromic ITEV were compared with all births (n = 923,543) in Texas during the same period. The overall prevalence and prevalence odds ratios (PORs) were calculated for gender, year of birth, public health region (PHR), race, maternal age, education, folic acid fortification, and parity. The overall prevalence of ITEV was 0.74/1,000 or 1/1,354 live births. Adjusted PORs were similar among blacks and US and foreign-born Hispanics (POR = 0.92, 95% CI = 0.69-1.21; POR = 0.99, 95% CI = 0.79-1.25; and POR = 0.94, 95% CI = 0.74-1.19), respectively, compared to whites. College education and higher parity were significantly associated with a lower risk of giving birth to offspring with ITEV. Babies born after folic acid fortification of grains had a very small decrease in ITEV that may be due to chance.     

Stereocomplex formation in ABA triblock copolymers of poly(lactide) (A) and poly(ethylene glycol) (B)

Two series of triblock copolymers of poly(ethylene glycol) (PEG, number-average molecular weight M _n = 6000) and poly(L -lactide) (PLLA) or poly(D -lactide) (PDLA) were prepared by ring-opening polymerization of lactide initiated by PEG end groups using stannous octoate as a catalyst, either in refluxing toluene or in the melt at 175°C. The weight percentage of PLA in the polymers varied between 15 and 75 wt.-%. Blends of polymers containing blocks of opposite chirality were prepared by co-precipitation from homogeneous solutions. The melting temperatures of the crystalline PEG and PLA phases strongly depended on the composition of the polymers. The melting temperature of the PLA phase in the blends was approximately 40°C higher than that of the single block copolymers. Stereocomplex formation between blocks of enantiomeric poly(lactides) in PEG/PLA block copolymers was established for the first time. Water uptake of polymeric films prepared by solution casting was solely determined by the PEG content of the film.     

Viscometric characterization of poly(oxyethylene)-block-poly(oxypropylene)-block-poly(oxyethylene) in aqueous solution

Viscometric measurements were carried out to characterize poly(oxyethylene)-block-poly-(oxypropy1ene)-block-poly(oxyethy1ene) (POE-POP-POE) in aqueous solution. The results were discussed in terms of a core-shell model of intramolecular phase separation which is based on (i) the selectivity of the solvent water, and (ii) the incompatibility of the POE and POP blocks. The interaction between the two blocks was analysed by vapour pressure osmometry and vapour sorption investigations. The results are:

• 1 The two homopolymer blocks (POE and POP) forming the triblock copolymer are incompatible with each other as vapour pressure osmometry and vapour sorption measurements using ethylbenzene as solvent have shown. This incompatibility of the blocks as well as the selectivity of the solvent water with respect to the different blocks causes the intramolecular (and intermolecular) phase separation of the copolymers in aqueous solution.
• 2 The viscometric data of the aqueous block copolymer solutions can be discussed in terms of the generally accepted core-shell model. This model for the structure of the self-organized molecules includes POP gel core (“melt”) surrounded by solvated POE shell. A quantitative analysis according to this simplified view shows that the hydrodynamic volume of the copolymer molecules is determined by the POE blocks. In the temperature range ? > 30°C, the influence of the POP block on the molecular dimensions is negligible, whereas at ? < 30°C the contributions of the POP and POE to the molecular volume are comparable.
• 3 Kuhn's statistical segment length of POE in the triblock molecules comprises about 4–5 monomeric units. The theta temperature of the triblock copolymer molecules is nearly identical to that of pure POE ((369 ± 3)K).

     

Fra(2) (q13) and inv(9) (p11q12) in autism: causal relationship?

Twenty individuals with autism or related disorders underwent chromosome analysis and physical examinations with documentation of minor anomalies. Chromosome anomalies were identified in 3: 2 had the heritable folate sensitive fra(2) (q13) site and 1 had an inv(9) (p11q12). No heritable chromosome variants or anomalies were seen in 20 age and sex-matched control individuals. When patients with the fra(2) were excluded from analyses, there was no difference in the frequency of chromosome breaks and/or gaps between the study group and control group. The results of this study suggest that heritable folate sensitive fragile sites and other chromosome variants may be more commonly seen in individuals with autism or related disorders in childhood than in the general population.     

Single fiber electromyography (SFEMG) in mitochondrial diseases (MD)

Conventional EMG, nerve conduction studies and SFEMG were performed in 18 patients with various phenotypes of MD. 14 cases showed findings consistent with mild myopathy, 2 patients signs of sensory-motor axonal neuropathy and 2 cases a mixture of myopathy and axonal neuropathy. Motor unit fiber density was mild increased in 8 out of 13 tested cases. Jitter was abnormal in 10 out of 18 tested patients. Jitter abnormalities were not related to myopathic or neurogenic features in the EMG study, and may be observed in muscles without clinical weakness. The results suggest the existence of neuromuscular transmission disturbances in patients with MD.     

Axonal enlargements (meganeurites) in neuronal ceroid lipofuscinosis (NCL)

Meganeurites have been described by light and electron microscopy in several neuronal lipid storage diseases. In neuronal ceroid lipofuscinosis (NCL), they appear to be less frequent.

We present the first combined Golgi-electron microscopy study of a patient with NCL, which shows that the axons from neurons with meganeurites arise from their distal poles.

Our results reinforce the assumption that neuronal malfunction in this disorder, as in other neuronal storage diseases, is also due to the presence of such meganeurites in the area of the axon hillock-initial axon segment.     

Poly(rI) more important than poly(rC) in the interferon induction process by poly(rI)-poly(rC)

A significantly greater interferon production has been obtained in primary rabbit kidney cell cultures exposed to poly(rI) followed by poly(rC) than in cell cultures exposed to poly(rC) followed by poly(rI). The interferon response in cell cultures exposed to poly(rI) followed by poly(rC) was markedly more resistant to poly-l-lysine and pancreatic ribonuclease treatment than was the interferon response in cell cultures exposed to poly(rC) followed by poly(rI). In addition, poly-l-lysine treatment removed a substantially greater proportion of cell-associated radioactivity from cells exposed to [³H]poly(rC) followed by poly(rI) than from cells exposed to poly(rI) followed by [³H]poly(rC). These findings suggest that the poly(rI) · poly(rC) complex is more tightly and efficiently bound to the cell (surface) when the homopolymers are added in the order poly(rI), poly(rC) than when they are added in the order poly(rC), poly(rI) and that it is more effectively attached to the cell receptor site by its poly(rI) strand rather than by its poly(rC) strand.     

Deletion (2) (q37)

We report on a 5-month-old girl with widely spaced nipples, redundant nuchal skin, coarctation of the aorta, anal atresia with distal fistula, postnatal growth retardation, hypotonia, and sparse scalp hair. Initial clinical assessment suggested the diagnosis of Ullrich-Turner syndrome. Chromosome analysis showed a 46,XX,del(2)(q37) karyotype in peripheral lymphocytes. We compare her findings to those of other reported patients with terminal deletions of 2q. © 1994 Wiley-Liss, Inc.     

可溶性gp130对白血病抑制因子和制瘤素的拮抗作用

在研究可溶性ｇｐ１３０（ｓｇｐ１３０）分子对ＩＬ ６／ＩＬ ６Ｒ作用的基础上,继续研究了ｓｇｐ１３０对ＩＬ ６家族细胞因子白血病抑制因子（ＬＩＦ）和制瘤素（ＯＭ）的生物学作用。结果显示,ｓｇｐ１３０对ＬＩＦ和ＯＭ刺激的人多发性骨髓瘤（ＭＭ）细胞株ＸＧ４ ＣＮＴＦ的增殖有抑制作用。此外,ｓｇｐ１３０对ＬＩＦ和ＯＭ刺激表达ＬＩＦ受体的新鲜ＭＭ细胞的增殖也有抑制作用,提示ｓｇｐ１３０也可为ＬＩＦ和ＯＭ的拮抗剂。     

On the oxygenation-dependent (129)Xe T (1) in blood

The spin-lattice relaxation time, T(1), of hyperpolarized (129)Xe in blood is sensitive to blood oxygenation. In particular, it has been shown that (129)Xe T(1) is shorter in venous blood than in arterial blood. We have studied the T(1) of hyperpolarized (129)Xe dissolved in human blood as a function of blood oxygenation level, sO(2), in the physiological oxygenation range. We show that the (129)Xe relaxation rate, T(1)(-1), varies in a nonlinear fashion as a function of sO(2). This finding suggests that direct interaction of xenon with the paramagnetic heme group of deoxyhemoglobin is not the dominant oxygenation-dependent relaxation mechanism for (129)Xe in blood. These results corroborate the idea that the oxygenation-dependence of (129)Xe T(1) is determined by conformational changes of hemoglobin induced by oxygen binding.     

Theta-behaviour of poly(p-tert-butylstyrene)-block-poly(dimethylsiloxane)-block-poly(p-tert-butylstyrene)

The theta-behaviour of poly(p-tert-butylstyrene)-block-poly(dimethylsiloxane)-block-poly(p-tert-butylstyrene) ABA type triblock copolymers containing ca. 28% by weight tert-butylstyrene was studied in the selective solvents 1-nitropropane and 2-butanone using the phase separation method. The theta-temperatures in these solvents were found to be 157°C and 31°C, respectively. The intrinsic viscosities of the copolymers in 2-butanone (MEK) were obtained at different temperatures. The Mark-Houwink-Sakurada exponent α in MEK at 31°C is greater than 0,5, suggesting that the theta-behaviour of block copolymers is different from that of the homopolymers due to the presence of repulsive interactions between incompatible blocks.