Importance of over-dominance as the genetic basis of heterosis in rice

In populations derived from commercial hybrid rice combination Shanyou 10, F(1) heterosis and F(2) inbreeding depression were observed on grain yield (GYD) and number of panicles (NP). Using marker loci evenly distributed on the linkage map as fixing factors, the F(2) population was divided into sub-populations. In a large number of sub-populations, significant correlations were observed between heterozygosity and GYD, and between heterozygosity and NP. This was especially true in type III sub-populations in which the genotype of a fixing factor was heterozygotes. In type III sub-populations, 15 QTL for GYD and 13 QTL for NP were detected, of which the majority exhibited over-dominance effects for increasing the trait values. This study showed that over-dominance played an important role in the genetic control of heterosis in rice.

Confirmation of the X(1835) and observation of the resonances X(2120) and X(2370) in J/ψ→γπ+π-η'

With a sample of (225.2±2.8)×10(6) J/ψ events registered in the BESIII detector, J/ψ→γπ(+)π(-)η(') is studied using two η(') decay modes: η(')→π(+)π(-)η and η(')→γρ(0). The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20σ. In addition, in the π(+)π(-)η(') invariant-mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2σ and 6.4σ, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.

Evidence for ψ' decays into γπ0 and γη

The decays ψ'→γπ(0), γη and γη' are studied using data collected with the BESIII detector at the BEPCII e(+)e(-) collider. The processes ψ'→γπ(0) and ψ'→γη are observed for the first time with signal significances of 4.6σ and 4.3σ, respectively. The branching fractions are determined to be B(ψ'→γπ(0))=(1.58±0.40±0.13)×10(-6), B(ψ'→γη)=(1.38±0.48±0.09)×10(-6), and B(ψ'→γη')=(126±3±8)×10(-6), where the first errors are statistical and the second ones systematic.

Measurements of h(c)(1P(1)) in psi' decays

We present measurements of the charmonium state h(c)(1P(1)) made with 106x10(6) psi' events collected by BESIII at BEPCII. Clear signals are observed for psi'-->pi0 h(c) with and without the subsequent radiative decay h(c)-->gamma eta(c). First measurements of the absolute branching ratios B(psi'-->pi0 h(c)) = (8.4+/-1.3+/-1.0) x 10(-4) and B(h(c)-->gamma eta(c)) = (54.3+/-6.7+/-5.2)% are presented. A statistics-limited determination of the previously unmeasured h(c) width leads to an upper limit Gamma(h(c))<1.44 MeV (90% confidence). Measurements of M(h(c)) = 3525.40+/-0.13+/-0.18 MeV/c2 and B(psi'-->pi0 h(c)) x B(h(c)-->gamma eta(c)) = (4.58+/-0.40+/-0.50) x 10(-4) are consistent with previous results.

Effects of different sleep restriction protocols on sleep architecture and daytime vigilance in healthy men

Sleep is regulated by complex biological systems and environmental influences, neither of which is fully clarified. This study demonstrates differential effects of partial sleep deprivation (SD) on sleep architecture and psychomotor vigilance task (PVT) performance using two different protocols (sequentially) that each restricted daily sleep to 3 hours in healthy adult men. The protocols differed only in the period of sleep restriction; in one, sleep was restricted to a 3-hour block from 12:00 AM to 3:00 AM, and in the other, sleep was restricted to a block from 3:00 AM to 6:00 AM. Subjects in the earlier sleep restriction period showed a significantly lower percentage of rapid-eye-movement (REM) sleep after 4 days (17.0 vs. 25.7 %) and a longer latency to the onset of REM sleep (L-REM) after 1 day (78.8 vs. 45.5 min) than they did in the later sleep restriction period. Reaction times on PVT performance were also better (i.e. shorter) in the earlier SR period on day 4 (249.8 vs. 272 ms). These data support the view that earlier-night sleep may be more beneficial for daytime vigilance than later-night sleep. The study also showed that cumulative declines in daytime vigilance resulted from loss of total sleep time, rather than from specific stages, and underscored the reversibility of SR effects with greater amounts of sleep.

Blunted ventilatory response to hypoxia/hypercapnia in mice with cigarette smoke-induced emphysema

It has been reported that the degree of emphysema induced by chronic cigarette smoke (CS) is greater in female C3H/HeN mice as compared to other mouse strains. We hypothesized that these mice would develop the similar major characteristics seen in hypercapnic patients with chronic obstructive pulmonary disease (COPD), including emphysema, pulmonary inflammation, hypercapnia/hypoxemia, rapid breathing, and attenuated ventilatory response (AVR). Mice were exposed either to CS or filtered air (FA) for 16 weeks. After exposure, arterial blood gases and minute ventilation were measured before and during chemical challenges in anesthetized and spontaneously breathing mice. We found that as compared to FA, CS exposure caused emphysema and pulmonary inflammation associated with: (1) hypercapnia and hypoxemia, (2) rapid breathing, and (3) AVR to 25 breaths of pure N(2), 5% CO(2) alone, and 5% CO(2) coupled with 10% O(2). The similarity of these pathophysiological characteristics between our mouse model and COPD patients suggests that this model could be effectively applied to study COPD pathophysiology, especially central mechanisms of the AVR genesis.

The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer

BACKGROUND

Cutaneous hyperpigmentation occurs in multiple conditions. In addition, many Asian women desire a lighter skin colour. Thus, there is a need for the development of skin lightening agents. Niacinamide is a possible candidate.

OBJECTIVES

To investigate the effects of niacinamide on melanogenesis in vitro and on facial hyperpigmentation and skin colour in vivo in Japanese women.

METHODS

Melanin production was measured in a purified mushroom tyrosinase assay, cultured melanocytes, a keratinocyte/melanocyte coculture model, and a pigmented reconstructed epidermis (PREP) model. The clinical trials included 18 subjects with hyperpigmentation who used 5% niacinamide moisturizer and vehicle moisturizer in a paired design, and 120 subjects with facial tanning who were assigned to two of three treatments: vehicle, sunscreen and 2% niacinamide + sunscreen. Changes in facial hyperpigmentation and skin colour were objectively quantified by computer analysis and visual grading of high-resolution digital images of the face.

RESULTS

Niacinamide had no effect on the catalytic activity of mushroom tyrosinase or on melanogenesis in cultured melanocytes. However, niacinamide gave 35-68% inhibition of melanosome transfer in the coculture model and reduced cutaneous pigmentation in the PREP model. In the clinical studies, niacinamide significantly decreased hyperpigmentation and increased skin lightness compared with vehicle alone after 4 weeks of use.

CONCLUSIONS

The data suggest niacinamide is an effective skin lightening compound that works by inhibiting melanosome transfer from melanocytes to keratinocytes.

[A study of millimeter wave's clinical and immunological effects on oral lichen planus patients]

OBJECTIVE

The aim of this study is to observe clinical effects of the millimeter wave on oral lichen planus (OLP) and its immune mechanisms.

METHODS

30 patients with OLP were randomized into the millimeter wave group and the control group. 15 patients in the millimeter wave group were treated with millimeter wave (7.1 mm, 43 GHz, 10 mW/cm2) radiation, while the other 15 patients in the control group were just given soothing treatment. Either before or after the therapy procedure, the clinical manifestations and the T-cell sub-grouping in the peripheral circulation of each patient were double-blindly evaluated.

RESULTS

The pain-soothing effect in the patients treated with millimeter wave was much more obvious than that of the control group (P < 0.01). The peripheral blood CD8+ percent of millimeter wave group decreased greatly (P < 0.05), while no obvious CD8+ change was observed in the control group (P > 0.05). The millimeter wave group's CD4+/CD8+ improvement was also much more obvious than that of the control group (P < 0.05), and its CD4+/CD8+ ratio was completely recovered to the normal level.

CONCLUSION

Millimeter wave can effectively relieve OLP patients' pain, and can regulate OLP patients' cellular immune condition. Millimeter wave might provide a new treatment method for OLP.

[Study on the reaction between 3-amino-6-dimethylamino-2-methlphenazine hydrochloride and deoxyribonucleic acid]

The interaction of deoxyribonucleic acid (DNA) and 3-amino-6-dimethylamino-2-methlphenazine hydrochloride (ZR) was investigated by UV spectrophotometric method in solution (pH 7.4). When DNA was added into ZR solution, the red color was observed, which indicated formation of the DNA-ZR complex. The maximum absorption of the complex was 520 nm with the apparent molar absorptivity of epsilon = 1.5 x 10(6) mol-1.L.cm-1. The maximum absorption of the complex was shifted 70 nm than with ZR. The maximum binding number is n = 303. The basic reaction conditions were investigated. It is found that sodium chloride concentration of the solution has significant effect on the sensitivity of DNA-ZR complex. The Scatchard model is appropriate in the treatment of data obtained here.

[Comprehensive quality appraisal of "maidong"]

According to the contents of 14 kinds of constituents, 6 samples of Maidong from various habitats were comprehensively appraised by the weighted method with factor analysis and fuzzy mathematic method. The results showed that certified Maidong (Ophiopogon japonicus) was superior to its substitute Shanmaidong(Liriope spp.), and the sample from Xiaoshan county was the best in 3 samples of certified goods. Being consistent with the result of the traditional appraisal, the method used in this paper may provide a new means for appraising traditional medicinal materials.

Incoherent-to-Coherent Conversion by Use of the Photorefractive Beam-Fanning Effect and Amplification by Two-Wave Coupling in a Photorefractive Ba(1-x)Sr(x)TiO(3) Crystal

Incoherent-to-coherent conversion by use of the photorefractive beam-fanning effect and amplification by two-wave coupling have been demonstrated experimentally in a photorefractive Ba(1-x)Sr(x)TiO(3) crystal. The converted coherent image is amplified by 60x. The resolution of the amplified coherent image is ~28 line pairs/mm. A notable advantage of the method is that incoherent-to-coherent conversion and coherence amplification of the converted coherent image are realized simultaneously in a photorefractive crystal.

[Calculation of spectroscopic parameters of Ho3+ in Ho:YVO4 crystal]

The intensity parameters omega lambda of Ho3+ in Ho:YVO4 crystal were calculated with J-O theory according to the absorption spectrum. Based on these omega lambda values, the oscillator strength of excited energy state, spontaneous radiation rate, branching ratio and integrated emission cross section were estimated. A discussion on potentiality of application in the infrared laser material is given.

[A multiple-channel system for synchronous acquisition and analysis of neural electrophysiological signals]

The technique for synchronous electrophysiological recording from multiple single cells has been widely applied, but there is still a shortage of suitable data acquisition and analysis systems to fit electrophysiological equipment made in China or Japan. Recently we have developed an acquisition and analysis system for multiple-channel electrophysiological recording. In this paper, we present the pivotal technique of the system and some examples of applications.

Oxygen transport in tibetan women during pregnancy at 3,658 m

High-altitude reduces infant birth weight as a result of intrauterine growth restriction (IUGR) and is associated with increased neonatal mortality. We hypothesized that babies born to Tibetan compared to Han (Chinese) high-altitude residents were protected from IUGR as the result of increased maternal O(2) transport due, in turn, to increased uterine artery (UA) blood flow. We studied 68 nonpregnant or pregnant Tibetan or Han residents of Lhasa, Tibet Autonomous Region, China (3,658 m). The pregnant women had higher hypoxic ventilatory responses (HVR A) and resting ventilations (V(E)) than their nonpregnant counterparts (Tib HVR = 134 +/- 16 (SEM) vs. 30 +/- 8, Han HVR = 134 +/- 16 vs. 66 +/- 18 A units; Tib V(E) = 11.8 +/- 0.3 vs. 10.1 +/- 0.5, Han V(E) = 10.7 +/- 0.5 vs. 9.4 +/- 0.5 l BTPS/min; all P < 0.05). Pregnancy did not change hemoglobin concentration in the Han but lowered values more than 2 g/dl in the Tibetans, serving to reduce arterial O(2) content below Han values (15.4 +/- 0.3 vs. 17.4 +/- 0.5 ml O(2)/100 ml whole blood, P < 0.05). Compared with the Han, the pregnant Tibetans had higher UA blood flow velocity (58.5 +/- 2.9 vs. 49.1 +/- 3.2, P < 0. 05) and distributed a higher portion of common iliac (CI) blood flow to the UA (4.8 +/- 0.4 vs. 3.3 +/- 0.3, P < 0.05). Birth weights averaged 635 g greater in the Tibetan than Han high-altitude residents (3,280 +/- 78 vs. 2,645 +/- 96 g, P < 0.01), or 694 g more when adjusted for maternal age, parity, height, and near-term body weight. Heavier birth weight babies were born to women with higher V(E) (r = 0.62, P < 0.01) and greater distribution of CI blood flow to the UA (r = 0.42, P < 0.05). We conclude that increased UA blood flow, and not higher arterial O(2) content, permits Tibetan women to increase uteroplacental O(2) delivery and protect their infants from altitude-associated IUGR.

[Construction of plasmids expressing hepatitis E virus antigen fragments and their combinations]

OBJECTIVE

Several different regions of the HEV antigen were expressed in Escherichia coli and their immunological characteristics were simply evaluated.

METHODS

Three coding sequences of immunodominant antigenic regions in structural protein of the hepatitis E virus (ORF2.1: 6287-6403nt, ORF2.2: 6743-7126nt, ORF3: full length of ORF3) were amplified by RT-PCR from the fecal supernatants of macaques experimentally infected with HEV. These three fragments were inserted into the pThioHisC expression vector separately or fused in line by (Gly)n short arms. After identified by DNA sequence analysis, these six recombinant plasmids were transformed into Escherichia coli, and immunology characteristics of expressed antigen fragments were evaluated by Western blotting.

RESULTS

All six genes were successfully expressed in Escherichia coli. Western blotting assay showed that the recombinant proteins specifically reacted with the serum antibody from hepatitis E patient in various degrees.

CONCLUSION

Artificial antigen based on strung epitopes provides a promising strategy for detection and prevention of HEV infection.

Synthesis of SnSe in various alkaline media under mild conditions

The synthesis of SnSe was systematically investigated in various alkaline media and at various temperatures with SnCl2.2H2O and selenium as source materials. The basicity of the alkaline media and the reaction temperature are two key factors considered in our process. The synthesis of SnSe in sodium hydroxide solution and aqueous ammonia is limited to a narrow temperature range, while the synthesis in hydrazine hydrate and ethylenediamine proceeds over a wider range. The final products were characterized by X-ray diffraction pattern (XRD), energy dispersive X-ray (EDX), and transmission electron microscopy (TEM). TEM results showed a variation of crystal morphology of SnSe obtained in different media. Two simple chemical mechanisms for the formation of SnSe are presented.

Synthetic strands of neonatal mouse cardiac myocytes: structural and electrophysiological properties

The aim of the present study was to morphologically and electrically characterize synthetic strands of mouse ventricular myocytes. Linear strands of mouse ventricular myocytes with widths of 34.7+/-4.4 microm (W(1)), 57.9+/-2.5 microm (W(2)), and 86.4+/-3. 6 microm (W(3)) and a length of 10 mm were produced on glass coverslips with a photolithographic technique. Action potentials (APs) were measured from individual cells within the strands with cell-attached microelectrodes. Impulse propagation and AP upstrokes were measured with multisite optical mapping (RH237). Immunostaining was performed to assess cell-cell connections and myofibril arrangement with polyclonal antisera against connexin43 and N-cadherins and monoclonal antibodies against cardiac myosin. Light microscopy and myosin staining showed dense growth of well-developed elongated myocytes with lengths of 34.2+/-4.2 microm (W(1)), 36. 9+/-5.8 microm (W(2)), and 43.7+/-6.9 microm (W(3)), and length/width ratios of 3.9+/-0.2. Gap junctions were distributed around the cell borders (3 to 4 junctions/microm(2) cell area). Each cell was connected by gap junctions to 6.5+/-1.1 neighboring cells. AP duration shortened with time in culture (action potential duration at 50% repolarization: day 4, 103+/-34 ms; day 8, 16+/-3 ms; P:<0.01). Minimum diastolic potential and AP amplitude were 71+/-5 and 97.2+/-7.6 mV, respectively. Conduction velocity and the maximum dV/dt of the AP upstroke were 43.9+/-13.6 cm/s and 196+/-67 V/s, respectively. Thus, neonatal ventricular mouse myocytes can be grown in continuous synthetic strands. Gap junction distribution is similar to the neonatal pattern observed in the hearts of larger mammals. Conduction velocity is in the range observed in adult mice and in the higher range for mammalian species probably due to the higher dV/dt(max). This technique will permit the study of propagation, AP, and structure-function relations at cellular resolution in genetically modified mice.

Pulsatile stretch remodels cell-to-cell communication in cultured myocytes

Mechanical stretch is thought to play an important role in remodeling atrial and ventricular myocardium and may produce substrates that promote arrhythmogenesis. In the present work, neonatal rat ventricular myocytes were cultured for 4 days as confluent monolayers on thin silicone membranes and then subjected to linear pulsatile stretch for up to 6 hours. Action potential upstrokes and propagation velocity (theta) were measured with multisite optical recording of transmembrane voltage of the cells stained with the voltage-sensitive dye RH237. Expression of the gap junction protein connexin43 (Cx43) and the fascia adherens junction protein N-cadherin was measured immunohistochemically in the same preparations. Pulsatile stretch caused dramatic upregulation of intercellular junction proteins after only 1 hour and a further increase after 6 hours (Cx43 signal increased from 0.73 to 1.86 and 2.02% cell area, and N-cadherin signal increased from 1.21 to 2.11 and 2.74% cell area after 1 and 6 hours, respectively). This was paralleled by an increase in theta from 27 to 35 cm/s after 1 hour and 37 cm/s after 6 hours. No significant change in the upstroke velocity of the action potential or cell size was observed. Increased theta and protein expression were not reversible after 24 hours of relaxation. Nonpulsatile (static) stretch produced qualitatively similar but significantly smaller changes than pulsatile stretch. Thus, pulsatile linear stretch in vitro causes marked upregulation of proteins that form electrical and mechanical junctions, as well as a concomitant increase in propagation velocity. These changes may contribute to arrhythmogenesis in myocardium exposed to acute stretch.

Two new recurrent nucleotide mutations in the COL1A1 gene in four patients with osteogenesis imperfecta: about one-fifth are recurrent

Previous observations on mutations causing osteogenesis imperfecta (OI) suggested that unrelated patients had private mutations. Here preliminary studies on two patients with type I OI indicated that some mutations in the COL1A1 gene for type I procollagen cannot be detected by analyses of cDNAs. Therefore, we developed a protocol whereby 43 exon and exon flanking sequences of the COL1A1 gene can be amplified by PCR and scanned for mutations by denaturing gradient gel electrophoresis. Two new recurrent nucleotide mutations in the gene were found in four apparently unrelated patients with OI. Analysis of previous publications indicated that up to one-fifth of the mutations causing OI are recurrent in the sense that they were identical in apparently unrelated probands. About 80% of these identical mutations were in CpG dinucleotide sequences.

[Adjustable interatrial communication in management of severe congenital heart disease]

OBJECTIVE

To assess the use of adjustable interatrial communication in patient with severe congenital heart disease undergoing open heart surgery.

METHODS

From February 1998 to June 1999, 13 patients with severe and complex congenital heart disease underwent open heart surgery. Seven patients underwent total cavopulmonary connection, five patients repair of Ebstein's anomaly, and one patient right atrial-pulmonary connection. Adjustable interatrial communication was made in all patients. Four patients had the communication closed at the time of operation, 4 patients had the communication opened at the time of operation, and 5 patients had the communication adjusted and closed postoperatively.

RESULTS

All patients had a smooth postoperative process. There were no postoperative death and no severe postoperative complications.

CONCLUSION

Adjustable interatrial communication for the patients undergoing modified Fontan procedure or correction of Ebstein's anomaly may be advantageous.

Asymmetry of brain functional activation: fMRI study under language and music stimulation

OBJECTIVE

To determine the asymmetry of the human brain functional activation.

METHODS

With the help of GE Signa Horizon MRI system, 14 cases of right-handed volunteers were examined and the blood oxygenation level dependent method was used. The T1-weighted images were obtained with spin echo pulse sequence and the functional imaging (T2*-weighted) was performed using a single shot echo planar imaging pulse sequence. Data analysis was done with Sun Sparc Workstation and by the method of student t test or correlation analysis.

RESULTS

Most of activation areas were in the left hemisphere under language stimulation, while they were in the right side under music stimulation. Besides, a few brain areas in the contralateral cerebral cortex were also activated under both stimulations.

CONCLUSION

The present study supported the hypothesis of the asymmetry of brain functional activation and many brain areas of the cerebral cortex as well as both hemispheres worked in coordination. In addition, it also proved that fMRI is a feasible method in the study of human brain in vivo.

Purification and electron microscopic characterization of the membrane subunit (IICB(Glc)) of the Escherichia coli glucose transporter

The glucose transporter of the bacterial phosphotransferase system mediates sugar transport across the cytoplasmic membrane concomitant with sugar phosphorylation. It consists of a cytoplasmic subunit IIA(Glc) and the transmembrane subunit IICB(Glc). IICB(Glc) was purified to homogeneity by urea/alkali washing of membranes and nickel-chelate affinity chromatography. About 1.5 mg highly pure IICB(Glc) representing 77% of the total activity present in the membranes was obtained from 8g (wet weight) of cells. IICB(Glc) was reconstituted into lipid bilayers by temperature-controlled dialysis to yield small 2D crystals and by a rapid detergent-dilution procedure to yield densely packed vesicles. Electron microscopy and digital image processing of the negatively stained 2D crystals revealed a trigonal lattice with a unit cell size of a = b = 14.5 nm. The unit cell morphology exhibited three dimers of IICB(Glc) surrounding the threefold symmetry center. Single particle analysis of IICB(Glc) in proteoliposomes obtained by detergent dialysis also showed predominantly dimeric structures.

[Lutembacher's syndrome]

OBJECTIVE

To compare classical and acquired Lutembacher's syndrome (mitral restenosis after percutaneous balloon mitral valvuloplasty) in attempt to know their different in pathophysiology, diagnosis, and surgical treatment.

METHODS

The data from 22 cases of classical and acquired Lutembacher's syndrome who underwent surgical treatment in the same period were analyzed.

RESULTS

No death occurred in the classical group. In the acquired group the mortality however was 42.8% for those highly complicated with pulmonary hypertension and right heart failure.

CONCLUSIONS

Classical Lutembacher's syndrome can be corrected satisfactorily. The acquired one deteriorates rapidly with severe pulmonary hypertension and right heart failure, and needs early surgical intervention reduce the operation mortality.

[Diagnostic value of B-scan in exudative age-related macular degeneration]

PURPOSE

To explore the image features of exudative age-related macular degeneration (AMD) with B-scan.

METHODS

Using NIDEK US-3300 model B-scan to observe 31 patients (54 eyes) with AMD.

RESULTS

The membranous arc echo was found at the posterior polar and there was a shuttle absence of echo between the echo band and the wall of eyeball in the period of retinal pigment epithelium detachment. During the exudation and hemorrhage absorbed not comletely, mixed echo was seen. A small parenchyma body with protrusion was seen with stronger echo in the late phase when the exudation and hemorrhage were replaced by the scar tissues, it was like a convex lens or a triangle and the top pointed to the globe behind, but it was flat towards the vitreous.

CONCLUSION

The B-scan examination is valuable in diagnosis, treatment and follow-up for exudative AMD.

Selective binding of thyrotropin receptor autoantibodies to recombinant extracellular domain of thyrotropin/lutropin-chorionic gonadotropin receptor chimeric proteins

The extracellular domain of the glycosylated human thyrotropin receptor (ET-gp) contains epitopes that can adsorb pathogenic antibodies from sera of patients with Graves' disease (GD). In an attempt to define the regions within the ETSHR with which autoantibodies interact, we expressed extracellular domains of eight thyrotropin receptor/chorionic gonadotropin receptor (TSHR/LH-CGR) chimeric proteins in insect cells. The levels of expression were high and chimeric proteins were glycosylated. Chimeric proteins designated as EMc2+4 and EMc2+3+4, in which amino acids (aa) 90-165 and 261-370, and aa 90-370, respectively, of TSHR were replaced with corresponding aa of LH-CGR, partially reversed the thyrotropin binding inhibitory immunoglobulin (TBII) activity of experimental anti-TSHR antisera (anti-ET-gp). The other six chimeras almost completely reversed the TBII activity of these anti-ET-GP antisera. Next, we tested the ability of these chimeric proteins to reverse the TBII activity of GD patients' sera. Similar to our earlier study, ET-gp protein reversed the TBII activity of all eight GD patients' sera tested. Chimera EMc2, in which aa 90-165 of TSHR has been replaced with corresponding aa of LH-CGR, and EMc2+4 partially reversed the TBII activity of only three of the eight GD patients' sera. However, the other six chimeric proteins failed to neutralize the TBII activity of any of GD patients' sera. These data showed the following: (1) There is considerable heterogeneity amongst autoantibodies in GD patients' sera, (2) The TBII activity of some, but not others, is dependent on aa 90-165 and 261-370, and (3) Most Graves' sera, with TBII activity, failed to react with chimeric proteins in which either N-terminal or C-terminal regions of the extra cellular domain of the TSHR were replaced with corresponding regions of LH-CGR. These results suggest that the TBII activity of GD patients' sera is dependent on conformational epitopes and replacement of certain regions of TSHR with homologous regions of LH-CGR results in sufficient alteration in the conformation of the protein leading to loss of reactivity.

Redistribution of cytochrome c precedes the caspase-dependent formation of ultracondensed mitochondria, with a reduced inner membrane potential, in apoptotic monocytes

Apoptosis was induced in human monocytic THP.1 cells by the use of chemicals with disparate mechanisms of action. Apoptotic cells were characterized by a reduced inner mitochondrial membrane potential, increased cytosolic cytochrome c, ultracondensed mitochondria, condensed chromatin, cytoplasmic inclusions of beta-actin, and fragmentation of the Golgi apparatus. All of these changes, except the release of cytochrome c, were prevented by caspase inhibition. Cells were separated into two populations, with either normal or low inner mitochondrial membrane potential, using fluorescence-activated cell sorting. Ultracondensed mitochondria were observed only in the cells with low inner mitochondrial membrane potential, whereas noncondensed mitochondria were found in the cells with a normal inner mitochondrial membrane potential. We have demonstrated a sequence of related biochemical and ultrastructural changes, commencing with the release of mitochondrial cytochrome c, followed by activation of caspases and a reduction of inner mitochondrial membrane potential. These changes involved the formation of ultracondensed but not swollen mitochondria. Thus the release of mitochondrial cytochrome c was not the result of the mitochondrial permeability transition, reduction of inner mitochondrial membrane potential, or rupture of the outer mitochondrial membrane. Discontinuities in the outer membrane of ultracondensed mitochondria may, however, facilitate the further release of caspase-activating proteins, thereby amplifying the apoptotic process.

Protective effects of intermittent hypoxic adaptation on myocardium and its mechanisms

Intermittent hypoxic adaptation offers as many beneficial effects in protecting against myocardial injuries as chronic continuous hypoxic adaptation. However, chronic continuous hypoxic adaptation readily causes some adverse effects on the organism, which may be prevented by intermittent hypoxic adaptation. As an approach to potentiate the protective effects, intermittent hypoxic adaptation is also much easier to apply to subjects who are not living at high altitude. The mechanisms underlying the cardioprotective effects of intermittent hypoxic adaptation are less understood, although great similarities exist between chronic continuous and intermittent hypoxic adaptation. The participation of several factors, such as myocardial vascularity, coronary blood flow, and cardiomyoglobin, which comprise the oxygen uptake system is not apparent, while the more efficient energetic metabolism after intermittent hypoxic adaptation may be a mechanism for cardioprotection. The possible roles of several signaling transduction pathways, including adrenoceptors, prostaglandins, and the adenosinergic system, in the beneficial effects of intermittent hypoxia are compared to those of chronic continuous hypoxic adaptation. Antioxidant enzymes and stress proteins may also be part of the mechanisms contributing to the cardioprotection of the intermittent hypoxic adaptation. As the cardioprotective effects of intermittent hypoxic adaptation employ multifold mechanisms, their clear elucidation needs more efforts.

Delivery of 9-Cis retinal to photoreceptors from bovine serum albumin

Retinoids are labile compounds with less than micromolar solubility in aqueous solutions. They are normally associated with a carrier protein, interphotoreceptor retinoid binding protein, in the interstitial spaces of the retina. In the past, experimental retinoids have been delivered to isolated retinas and photoreceptors using either unprotected ethanolic suspensions or phospholipid vesicles that protect but require burdensome preparation. The objective of these experiments was to characterize the protection of retinoids and their delivery to isolated photoreceptor cells at high concentrations using fatty-acid-free bovine serum albumin (BSA) as a convenient vehicle and protectant. Our results confirm that BSA is a useful protectant and vehicle for delivery of retinoids to isolated retinas and photoreceptors.

[Surgical treatment of ventricular septal defect in infants: report of 230 cases]

OBJECTIVE

To review the experience of surgical treatment of ventricular septal defect (VSD) in infants.

METHODS

230 infants with VSD of less than 3 years old underwent surgical repair from Feb. 1990 to Dec. 1997. Their ages ranged from 3 to 36 months. Their weight was 3.2 to 15.5 kg. The number of patients with perimembranous VSD was 192, and that of subpulmonary VSD 36. Two patients had multiple VSDs. 150 patients (65.2%) had moderate or severe pulmonary hypertension before operation.

RESULTS

Thirteen patients died during hospitalization period, with a hospital mortality of 5.65%. The main causes of death were pulmonary hypertensive crisis and arrhythmia. The leading complications were pulmonary infections, arrhythmia and pulmonary hypertensive crisis.

CONCLUSIONS

Surgical treatment of VSD in infancy may have a satisfactory outcome, it standardized surgical techniques and the improved perioperative management are used.

Two-dimensional crystallization of Escherichia coli lactose permease

A chimeric protein consisting of lactose permease with cytochrome b562 in the middle cytoplasmic loop and six His residues at the C terminus (LacY/L6cytb562/417H6 or "red permease") was overexpressed in Escherichia coli and isolated by nickel affinity chromatography after solubilization with dodecyl-beta,d-maltopyranoside. Red permease was then reconstituted in the presence of phospholipids, yielding densely packed vesicles and well-ordered two-dimensional (2D) crystals as shown by electron microscopy of negatively stained specimens. Single-particle analysis of 16 383 protein particles in densely packed vesicles reveals a 5.4-nm-long trapeziform protein of 4.1 to 5.1 nm width, with a central stain-filled indentation. Depending on reconstitution conditions, trigonal and rectangular crystallographic packing arrangements of these elongated particles assembled into trimers are observed. The best ordered 2D crystals exhibit a rectangular unit cell, of dimensions a = 9.9 nm, b = 17.4 nm, that houses two trimeric complexes. Projection maps calculated to a resolution of 2 nm show that these crystals consist of two layers.

Distinct caspase cascades are initiated in receptor-mediated and chemical-induced apoptosis

Release of cytochrome c is important in many forms of apoptosis. Recent studies of CD95 (Fas/APO-1)-induced apoptosis have implicated caspase-8 cleavage of Bid, a BH3 domain-containing proapoptotic member of the Bcl-2 family, in this release. We now demonstrate that both receptor-induced (CD95 and tumor necrosis factor) and chemical-induced apoptosis result in a similar time-dependent activation of caspases-3, -7, -8, and -9 in Jurkat T cells and human leukemic U937 cells. In receptor-mediated apoptosis, the caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone (Z-VAD. FMK), inhibits apoptosis prior to commitment to cell death by inhibiting the upstream activator caspase-8, cleavage of Bid, release of mitochondrial cytochrome c, processing of effector caspases, loss of mitochondrial membrane potential, and externalization of phosphatidylserine. However, Z-VAD.FMK inhibits chemical-induced apoptosis at a stage after commitment to cell death by inhibiting the initiator caspase-9 and the resultant postmitochondrial activation of effector caspases. Cleavage of Bid but not release of cytochrome c is blocked by Z-VAD.FMK demonstrating that in chemical-induced apoptosis cytochrome c release is caspase-independent and is not mediated by activation of Bid. We propose that caspases form an integral part of the cell death-inducing mechanism in receptor-mediated apoptosis, whereas in chemical-induced apoptosis they act solely as executioners of apoptosis.

Release of mitochondrial cytochrome c is upstream of caspase activation in chemical-induced apoptosis in human monocytic tumour cells

Apoptosis, induced in human monocytic THP.1 cells by etoposide and N-tosyl-L-phenylalanyl chloromethyl ketone, was accompanied by the processing/activation of caspases, externalisation of phosphatidylserine (PS) and reduction in mitochondrial membrane potential (delta psi(m)). Activation of caspase(s) occurred prior to both PS exposure and reduction in delta psi(m). The caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethyl ketone (Z-VAD.fmk) blocked the activation of caspases, PS exposure and the reduction in delta psi(m) as well as the morphological changes associated with apoptosis but it did not inhibit the release of mitochondrial cytochrome c. These results suggest that the execution phase of chemical-induced apoptosis in THP.1 cells may be initiated following mitochondrial damage resulting in release of cytochrome c leading to activation of caspase-9 and then activation of effector caspases-3 and -7. This contrasts to receptor-mediated apoptosis, such as Fas, which results in an initial activation of caspase-8.

[The surgical treatment of tetralogy of fallot in 136 adults]

OBJECTIVE

To summarize the experience of surgical treatment of tetralogy of Fallot (TOF) in adults.

METHOD

From April 1975 to December 1997, 136 adult patients underwent total corrective repair of tetralogy of Fallot. The patient age ranged from 14 to 52 years old. The ventricular septal defects were closed with Dacron patch in 112 patients, with pericardial patch in 24 patients. A right ventricular outflow patch was required to eliminate right ventricular outflow tract obstruction in 126 patients.

RESULT

Five patients died during hospitalization, with a hospital mortality of 3.68%. Four early postoperative deaths were due to severe low cardiac output syndrome.

CONCLUSION

In view of current improved and standardized techniques, we conclude that the total corrective repair of TOF may have an excellent result in adult patients.

Apoptosis, in human monocytic THP.1 cells, results in the release of cytochrome c from mitochondria prior to their ultracondensation, formation of outer membrane discontinuities and reduction in inner membrane potential

Induction of apoptosis in human monocytic THP.1 cells by etoposide or N-tosyl-L-phenylalanyl chloromethyl ketone resulted in release of mitochondrial cytochrome c, formation of ultracondensed mitochondria, development of outer mitochondrial membrane discontinuities and a reduction in mitochondrial membrane potential (delta psi m), as well as externalisation of phosphatidylserine, caspase-3 and -7 activation, proteolysis of poly(ADP-ribose) polymerase and lamin B1. The caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethyl ketone inhibited all these ultrastructural and biochemical characteristics of apoptosis except for the release of cytochrome c. Release of mitochondrial cytochrome c was a late event in non-apoptotic cell death occurring after commitment to cell death and without caspase activation. Thus apoptosis is characterised by release of mitochondrial cytochrome c prior to formation of ultracondensed mitochondria and a reduction in delta psi m and by a mechanism independent of rupture of the outer mitochondrial membrane.

[Prediction of cephalopelvic disproportion by ultrasonographic cephalopelic]

OBJECTIVE

To develop a prospective antepartum method of identifying cephalopelvic disproportion by comparing the diameters of fetal head with those of the maternal midpelvis.

METHODS

Transvaginal ultrasound pelvimetry was performed on 190 healthy primigravidas with cephalic presentation at 28-35 weeks of gestation, and the diameters of their fetal heads were meassured within one week prior to delivery. These indices the cephalopelvic indices of diameter, cirumference and area, were calculated and compared.

RESULTS

The cephalopelvic index of diameter (CID), defined as the difference between the mean diameter of the midpelvis and the fetal biparetal diaameter (BPD), showed the highest degree of accuracy (77.9%). Eighty three percent of women with CID less than 15.8 needed operative delivery; 76.2% of those with CId more than 15.8 mm underwent vaginal delivery.

CONCLUSIONS

Transvaginal ultrasound pelvimetry and the CID by and large seems to be able to identify cephalopelvic disproportion before labor and may help obsetricians choose the most appropriate form of delivery in an uncomplicated vertex presentation.

ECG observations in Tibetan and Han residents of Lhasa

In order to compare the prevalence of electrocardiographic (ECG) abnormalities suggestive of right ventricular hypertrophy in native and immigrant populations residing at high altitude, a retrospective review was undertaken of data obtained from a random survey of healthy volunteers and persons with chronic mountain sickness (CMS). All persons included in the survey were ambulatory volunteers from the general community who were evaluated at the Tibet Institute of Medical Science in Lhasa, where the elevation is 3,658 meters. The 74 residents of Lhasa, whose ECGs were studied, included 30 healthy Tibetan natives of Lhasa; 24 healthy Han (Chinese) immigrants, born at or near sea level, who had migrated to high altitude as children or adults; and 20 persons with symptoms of CMS. The ECGs of all subjects were reviewed for predetermined criteria suggestive of right ventricular hypertrophy, which were found to be present in 17% of healthy Tibetan natives, 29% of healthy Han immigrants, and 50% of CMS patients. The Han subjects who had migrated as children presented evidence of right ventricular hypertrophy more commonly than did adult immigrants. The overwhelming majority (90%) of persons with CMS were Han. Thus, the frequency of ECG abnormalities consistent with right ventricular hypertrophy was similar in healthy young Tibetan and Han men, but these abnormalities were less common in Tibetan natives than in Han who had migrated to high altitude as children or in CMS patients. The prevalence of ECG evidence of right ventricular hypertrophy increased with duration of high altitude residence among Han.

Dissociation of phagocyte recognition of cells undergoing apoptosis from other features of the apoptotic program

Apoptosis is a programmed form of cell death characterized by biochemical and morphological changes affecting the nucleus, cytoplasm, and plasma membrane. These changes in various cellular compartments are widely regarded as mechanistically linked events in a single "program" in which activation of caspases and proteolysis of intracellular substrates represent a final common pathway leading to cell death. To date there has been very limited exploration of the linkage of this program to the plasma membrane changes, which bring about swift recognition, uptake, and safe degradation of apoptotic cells by phagocytes. Using the mitochondrial inhibitors antimycin A and oligomycin in human monocytic THP.1 cells triggered into apoptosis, we report the uncoupling of plasma membrane changes from other features of apoptosis. These inhibitors blocked increased plasma membrane permeability, externalization of phosphatidylserine, and recognition by two classes of phagocytes but not activation of caspase-3, cleavage of poly(ADP-ribose) polymerase and DNA fragmentation. Externalization of phosphatidylserine in apoptotic human leukemic U937 cells was also dissociated from caspase activation. Thus changes governing safe clearance of apoptotic cells may be regulated by an independent pathway to those bringing about caspase activation. This finding could have important consequences for attempts to manipulate cell death for therapeutic gain in vivo.

Superior exercise performance in lifelong Tibetan residents of 4,400 m compared with Tibetan residents of 3,658 m

Few environments challenge human populations more than high altitude, since the accompanying low oxygen pressures (hypoxia) are pervasive and impervious to cultural modification. Work capacity is an important factor in a population's ability to thrive in such an environment. The performance of work or exercise is a measure of the integrated functioning of the O2 transport system, with maximal O2 uptake (.VO2max) a convenient index of that function. Hypoxia limits the ability to transport oxygen: maximal O2 uptake decreases with ascent to high altitude, and years of high altitude residence do not restore sea level .VO2max values. Since Tibetans live and work at some of the highest altitudes in the world, their ability to exercise at very high altitude (>4,000 m) may define the limits of human adaptation to hypoxia. We transported 20 Tibetan lifelong residents of > or =4,400 m down to 3,658 m in order to compare them with 16 previously studied Tibetan residents of Lhasa (3,658 m). The two groups of Tibetans were matched for age, weight, and height. All studies were performed in Lhasa within 3 days of the 4,400 m Tibetans' arrival. Standard test protocol and criteria were used for attaining .VO2max on a Monark bicycle ergometer, while measuring oxygen uptake (.VO2, ml/kg - min STPD), heart rate (bpm), minute ventilation (VE, 1/min BTPS), and arterial oxygen saturation (SaO2, %). The 4,400 m compared with 3,658 m residents had, at maximal effort, similar .VO2 (48.5 +/- 1.2 vs. 51.2 +/- 1.4 ml/kg - min, P = NS), higher workload attained (211 +/- 6 vs. 177 +/- 7 watts, P < 0.01), lower heart rate(176 +/- 2 vs. 191 +/- 2 bpm, P < 0.01), lower ventilation (127 +/- 5 vs. 149 +/- 5 l/min BTPS, P < 0.01), and similar SaO2(81.9 +/- 1.0 vs. 83.7 +/- 1.2%, P = NS). Furthermore, over the range of submaximal workloads, 4,400 m compared with 3,658 m Tibetans had lower .VO2 (P < 0.01), lower heart rates (P < 0.01), and lower ventilation (P < 0.01) and SaO2 (P < 0.05). We conclude that Tibetans living at 4,400 m compared with those residing at 3,658 m achieve greater work performance for a given .VO2 at submaximal and maximal workloads with less cardiorespiratory effort.

Ventilation and hypoxic ventilatory responsiveness in Chinese-Tibetan residents at 3,658 m

When breathing ambient air at rest at 3,658 m altitude, Tibetan lifelong residents of 3,658 m ventilate as much as newcomers acclimatized to high altitude; they also ventilate more and have greater hypoxic ventilatory responses (HVRs) than do Han ("Chinese") long-term residents at 3,658 m. This suggests that Tibetan ancestry is advantageous in protecting resting ventilation levels during years of hypoxic exposure and is of interest in light of the permissive role of hypoventilation in the development of chronic mountain sickness, which is nearly absent among Tibetans. The existence of individuals with mixed Tibetan-Chinese ancestry (Han-Tibetans) residing at 3,658 m affords an opportunity to test this hypothesis. Eighteen men born in Lhasa, Tibet, China (3,658 m) to Tibetan mothers and Han fathers were compared with 27 Tibetan men and 30 Han men residing at 3,658 m who were previously studied. We used the same study procedures (minute ventilation was measured with a dry-gas flowmeter during room air breathing and hyperoxia and with a 13-liter spirometer-rebreathing system during the hypoxic and hypercapnic tests). During room air breathing at 3,658 m (inspired O2 pressure = 93 Torr), Han-Tibetans resembled Tibetans in ventilation (12.1 +/- 0.6 vs. 11.5+/- 0.5 l/min BTPS, respectively) but had HVR that were blunted (63 +/- 16 vs. 121 +/- 13, respectively, for HVR shape parameter A) and declined with increasing duration of high-altitude residence. During administered hyperoxia (inspired O2 pressure = 310 Torr) at 3,658 m, the paradoxical hyperventilation previously seen in Tibetan but not Han residents at 3,658 m (11.8 +/- 0.5 vs. 10.1 +/- 0.5 l/min BTPS) was absent in these Han-Tibetans (9.8 +/- 0.6 l/min BTPS). Thus, although longer duration of high-altitude residence appears to progressively blunt HVR among Han-Tibetans born and residing at 3, 658 m, their Tibetan ancestry appears protective in their maintenance of high resting ventilation levels despite diminished chemosensitivity.