Long-term blood pressure control in older Chinese patients with isolated systolic hypertension: a progress report on the Syst-China trial

This report on the ongoing double-blind placebo-controlled Syst-China trial investigated whether antihypertensive drug treatment based mainly on a calcium entry blocker and a converting enzyme inhibitor, would be suitable for maintaining long-term blood pressure (BP) control in older Chinese patients (average age: 67 years) with isolated systolic hypertension (systolic pressure 160-219 mm Hg and diastolic pressure < 95 mm Hg). Active treatment consisted of nitrendipine (10- 40 mg/day) with the possible addition of captopril (12.5- 50 mg/day) and hydrochlorothiazide (12.5-50 mg/day), as necessary to reduce systolic pressure to a level of 150 mm Hg or lower and by at least 20 mm Hg. Matching placebos were used in the control group. This progress analysis was restricted to BP control up to 3 years of follow-up. The placebo (n = 1134) and active treatment n = 1245) groups had similar characteristics at enrolment. The sitting BP averaged 170/86 mm Hg. Systolic pressure fell (P < 0.001) on average 8 mm Hg more on active treatment than on placebo and diastolic pressure 3 mm Hg more. Fewer patients remained on monotherapy in the placebo than in the active treatment group (P < 0.001); on placebo the second and third line medications were started more frequently (P < 0.001). This progress report showed that significant BP reduction can be achieved and maintained in older Chinese patients treated with a calcium antagonist, associated with a converting-enzyme inhibitor and a thiazide, as necessary. Whether this BP reduction would result in a clinically meaningful decrease of cardiovascular complications is still under investigation.

Comparative antimycobacterial activities of rifampin, rifapentine, and KRM-1648 against a collection of rifampin-resistant Mycobacterium tuberculosis isolates with known rpoB mutations

A collection of 24 rifampin-resistant clinical isolates of Mycobacterium tuberculosis with characterized RNA polymerase beta-subunit (rpoB) gene mutations was tested against the antimycobacterial agents rifampin, rifapentine, and KRM-1648 to correlate levels of resistance with specific rpoB genotypes. The results indicate that KRM-1648 is more active in vitro than rifampin and rifapentine, and its ability to overcome rifampin resistance in strains with four different genetic alterations may prove to be useful in understanding structure-function relationships.

[Chemical constituents of Aster albscens Hand.-Mazz]

Four compounds, stigmasterol, D-hurulon-14-en-3-ol, stigma-delta7.22-dien-3beta-palmitate and friedelin were isolated from the root of Aster albscens for the first time. Their structures were elucidated by spectral methods.

Identification of a polymorphic nucleotide in oxyR specific for Mycobacterium bovis

Automated sequence analysis of a 410-bp region of the axyR gene in 105 Mycobacterium tuberculosis complex isolates identified a polymorphic nucleotide that differentiated Mycobacterium bovis isolates from other complex members. All 29 M. bovis isolates sequenced had an adenine residue at nucleotide 285, whereas all 76 other complex isolates had a guanine residue. PCR-restriction fragment length polymorphism analysis of oxyR with restriction endonuclease AluI in an additional 255 complex isolates from widespread intercontinental sources confirmed and extended the unique association of adenine at position 285 with M. bovis isolates.

Prevalence and incidence of NIDDM in Daqing City

OBJECTIVE

To investigate the prevalence and incidence of non-insulin dependent diabetes (NIDDM) in China by WHO criteria.

METHODS

In the prevalence survey of NIDDM all 110660 participants (55391 men, 53269 women) were inhabitants of Daqing City, the largest oil center in northeast China, accounting for 87.3% of the 25 to 74 aged population in this city. They were screened by measuring two-hour plasma glucose concentrations (PG2 h) after a breakfast containing at least 80 g of carbohydrate, then a standard oral glucose tolerance test (OGTT, 75 g glucose load) was performed in 4209 subjects with PG2 h more than 6.67 mmol/L in this screen. NIDDM and impaired glucose tolerance (IGT) were diagnosed using WHO criteria. Incidence survey was made in 36471 non-diabetics identified in the prevalence survey. Two-hour urine-glucose after breakfast was determined during first screen. The urine-glucose trace or positive subjects were then followed by OGTT. Glucose was measured by glucose oxidation method.

RESULTS AND CONCLUSIONS

In prevalence survey, 630 newly diagnosed NIDDM (296 males, 334 females) and 596 IGT (318 males, 278 females) were found in 110660 (male:female = 55391/53269) studied subjects in addition to 190 previously diagnosed NIDDM. Thus the total prevalence of NIDDM was 7.7/1000, and IGT was 5.5/1000. Standardized to the Chinese population in 1982, the prevalences are 12.6/1000 (95% CI = 12.0/1000-13.3/1000) and 7.7/1000 (95% CI = 7.16/1000-8.19/1000) respectively. In the incidence survey, 191 NIDDM (103 males, 88 females) were diagnosed in the 36471 (male:female = 18801/17670) non-diabetics from 1986 to 1990, thus the annual incidence of NIDDM was 131/100000 (137 males, 125 females). Standardized incidence is 131/100000 (95% CI = 94/100000-168/ 100000). It is estimated that there would be more than 700 thousand new diabetics per year in 24-74 years old Chinese if Chinese population were 1.3 billion in the early 21st century.

Hyperattenuating rim on noncontrast CT of the liver: probable peritumoral sparing of fatty infiltration

CT scans showing a hyperattenuating rim within the liver were retrospectively evaluated in 10 patients to clarify the character, aetiology and clinical significance. All patients had hepatic tumours (7 cavernous haemangiomas in 6 patients, 3 metastatic tumours and 1 hepatocellular carcinoma) as well as fatty infiltration of the liver. Typical features of the hyperattenuating rim on noncontrast CT of the liver included (1) attenuation similar to that of the spleen, (2) a circular or semicircular shape, (3) a width of a few millimeters, (4) peritumoral localization and (5) loss of visualization with contrast enhancement. No such rims were noted around hepatic tumours unassociated with fatty infiltration. Peritumoral sparing of fatty infiltration was inferred. A hyperattenuating rim on noncontrast liver CT, although rare, suggests the presence of a hepatic tumour in fatty liver.

Rat brain cannabinoid receptor modulates N-type Ca2+ channels in a neuronal expression system

Modulation of neuronal ion channels by the cloned rat brain CB1 cannabinoid receptor was investigated with the use of a heterologous neuronal expression system. Transient expression of the rat brain CB1 cannabinoid receptor was accomplished through microinjection of in vitro transcribed cRNA into the cytoplasm of enzymatically dissociated adult rat superior cervical ganglion neurons. The cannabimimetic aminoalkylindole WIN 55,212-2 inhibited whole-cell Ca2+ currents in neurons injected 16-25 hr previously with rat brain CB1 cannabinoid receptor cRNA. Inhibition of the Ca2+ current was voltage and concentration dependent, with a maximal inhibition of 73% and an IC50 value of 47 nM. The synthetic cannabinoid analogue CP55,940 also inhibited Ca2+ currents, with a maximal inhibition of 38% and an IC50 value of 7 nM. Ca2+ current inhibition was blocked by inclusion of guanosine-5'-O-(2-thiodiphosphate) in the intracellular patch pipette solution or by pretreatment with pertussis toxin. Pretreatment with the N-type Ca2+ channel antagonist omega-conotoxin GVIA reduced the inhibition by 100 nM WIN 55,212-2 from 44% to 6%, indicating that N-type Ca2+ channels are a target of cannabinoid action. On washout of WIN 55,212-2, the Ca2+ current amplitude "overrecovered" in 47% of the neurons tested. Anandamide, the endogenous cannabimimetic compound, had an inconsistent effect on the voltage-dependent Ca2+ currents in the majority of neurons microinjected with cannabinoid receptor cRNA. Ca2+ channels were a specific effector target of the cannabinoid receptor, as two different K+ currents, the M current and the A current, were not modulated by the cannabimimetic WIN 55,212-2.

Characterization of rpsL and rrs mutations in streptomycin-resistant Mycobacterium tuberculosis isolates from diverse geographic localities

Two genes (rpsL and rrs) with mutations associated with streptomycin resistance in Mycobacterium tuberculosis were characterized in 78 streptomycin-resistant and 61 streptomycin-susceptible isolates recovered from patients living in the United States, South America, Europe, Africa, and Asia. Fifty-four percent of the 78 resistant organisms had missense mutations in codon 43 of rpsL resulting in a K-43-->R substitution. Mutations in codon 88 of rpsL were also identified in four Asian isolates.

Origin and interstate spread of a New York City multidrug-resistant Mycobacterium tuberculosis clone family

OBJECTIVE

To determine whether isolates of Mycobacterium tuberculosis from New York and elsewhere that are resistant to four or more primary antimicrobial agents and responsible for widespread disease in the 1990s represent a newly emerged clone or a heterogeneous array of unrelated organisms.

SETTING

New York City area and selected locations in the United States.

PATIENTS

M tuberculosis isolates from 1953 patients in New York and multidrug-resistant isolates from six patients from other US communities.

DESIGN

Convenience sample of all M tuberculosis strains (M tuberculosis isolates resistant to rifampin, streptomycin, isoniazid, and ethambutol, and sometimes ethionamide, kanamycin, capreomycin, or ciprofloxacin) submitted to the Public Health Research Institute Tuberculosis Center since 1991 and samples submitted to the Centers for Disease Control and Prevention from throughout the United States. The samples submitted were representative of the New York City strains of M tuberculosis.

MAIN OUTCOME MEASURE

Characterization of resistant M tuberculosis strains studied by IS6110 and polymorphic GC-rich repetitive sequence (PGRS) hybridization patterns, multiplex polymerase chain reaction (PCR) analysis, and automated DNA sequencing of genes containing mutations associated with resistance to rifampin (rpoB), isoniazid (katG and inhA locus), and streptomycin (strA and rrs).

RESULTS

Multidrug-resistant M tuberculosis isolates were recovered from 253 New York City patients and had the same or closely allied IS6110 and PGRS patterns, multiplex PCR type, and gene mutations associated with resistance to rifampin, isoniazid, and streptomycin. Isolates with these same molecular characteristics were recovered from patients in Florida and Nevada, health care workers in Atlanta, Ga, and Miami, Fla, and an individual who recently moved from New York City to Denver, Colo, and caused disease or skin test conversion in at least 12 people in a nursing home environment.

CONCLUSIONS

The results document the molecular origin and spread of progeny of a closely related family of multidrug-resistant M tuberculosis strains that have recently shared a common ancestor and undergone clonal expansion. The multidrug-resistant phenotype in these organisms arose by sequential acquisition of resistance-conferring mutations in several genes, most likely as a consequence of antibiotic selection of randomly occurring mutants in concert with inadequately treated infections. Dissemination of these difficult-to-treat bacteria throughout New York City and to at least four additional US cities has adverse implications for tuberculosis control in the 21st century.

Fatty mass in the inferior vena cava at CT: lipoma or normal variant?

Fatty mass in the intrahepatic portion of the inferior vena cava (IVC) is an unusual lesion. We describe two cases of fatty mass appearing in the lumen of the IVC on CT and MRI study. We assume that this can be regarded as a benign process, and is mostly a normal variant.

Detection of human papillomavirus types 16, 18 DNA related sequences in bronchogenic carcinoma by polymerase chain reaction

In studying the relationship between human papillomavirus (HPV) and bronchogenic carcinoma, "high-risk" HPV 16, 18 DNA sequences were detected in samples from 50 lung cancer patients, 18 patients with benign pulmonary diseases and 4 fetal lung tissues by polymerase chain reaction (PCR) and dot-blot hybridization with biotin-labelled probes. The results showed that HPV 16, 18 DNA related sequences were found in 32% of lung cancer specimens, with 10 cases of HPV 16, 5 cases of HPV 18 and 1 case of both types. 48.15% (13/27) of squamous cell carcinomas were shown to be positive for HPV 16, 18 DNA. In addition, two adenocarcinomas and one small cell carcinoma were positive for HPV 16 DNA. No specimens from benign diseases tissues and fetal lung tissues showed positive results. These results suggest that primary bronchogenic carcinoma is related to HPV infection.

A lectin-like peptide isolated from the venom of the Chinese bird spider Selenocosmia huwena

A peptide with haemagglutination activity was isolated from the venom of the Chinese bird spider Selenocosmia huwena by means of ion-exchange and reverse-phase high-performance liquid chromatography. This peptide, named SHLP-I, agglutinates human and mice erythrocytes at a minimum concentration of 125 micrograms/ml and 31 micrograms/ml, respectively. It consists of 32 amino acid residues including 3 Trp and 6 Cys residues, the latter of which form three disulfide bounds. The complete amino acid sequence was determined. The N-terminal and C-terminal residues were Gly and Trp, respectively. SHLP-I shows homology with a fragment of great nettle lectin and with huwentoxin-I from the venom of the same spider.

Genetic diversity and relationships among Streptococcus pyogenes strains expressing serotype M1 protein: recent intercontinental spread of a subclone causing episodes of invasive disease

Chromosomal diversity and relationships among 126 Streptococcus pyogenes strains expressing M1 protein from 13 countries on five continents were analyzed by multilocus enzyme electrophoresis and restriction fragment profiling by pulsed-field gel electrophoresis. All isolates were studied for the presence of the gene encoding streptococcal pyrogenic exotoxin A by PCR. Strain subsets were also examined by automated DNA sequencing for allelic polymorphism in genes encoding M protein (emm), streptococcal pyrogenic exotoxin A (speA), streptokinase (ska), pyrogenic exotoxin B (interleukin-1 beta convertase) (speB), and C5a peptidase (scp). Seven distinct emm1 alleles that encode M proteins differing at one or more amino acids in the N-terminal variable region were identified. Although substantial levels of genetic diversity exist among M1-expressing organisms, most invasive disease episodes are caused by two subclones marked by distinctive multilocus enzyme electrophoretic profiles and pulsed-field gel electrophoresis restriction fragment length polymorphism (RFLP) types. One of these subclones (ET 1/RFLP pattern 1a) has the speA gene and was recovered worldwide. Identity of speA, emm1, speB, and ska alleles in virtually all isolates of ET 1/RFLP type 1a means that these organisms share a common ancestor and that global dispersion of this M1-expressing subclone has occurred very recently. The occurrence of the same emm and ska alleles in strains that are well differentiated in overall chromosomal character demonstrates that horizontal transfer and recombination play a fundamental role in diversifying natural populations of S. pyogenes.

[Effect of dietary and/or exercise intervention on incidence of diabetes in 530 subjects with impaired glucose tolerance from 1986-1992]

577 subjects with impaired glucose tolerance (IGT) aged from 25 to 74 were identified in Daqing in 1986. They were stratified according to BMI > or = 25 (352 cases) and BMI < 25 (225 cases) and subjects in each BMI group were randomly assigned to four groups: control, diet, exercise and diet plus exercise intervention groups (each group had similar age, BMI, fasting and 2-hour plasma glucose level). A six-year follow up study indicated that incidence of diabetes per 100-person-year was 15.7, 10.0, 8.3 and 9.6 in control, diet, exercise and diet plus exercise groups respectively. Proportional hazards regression analysis controlling for differences in baseline factors (age, sex, BMI and plasma glucose) showed that diet and/or exercise intervention were inversely related to the incidence of diabetes. The better the actual intervention, the less the incidence of diabetes. Therefore, the results strongly indicate that diet and/or exercise intervention treatment are effective methods to reduce the incidence of diabetes.

Analysis of noise properties of a class of exact methods of inverting the 2-D exponential radon transform [SPECT application]

A general approach that the authors proposed elsewhere reveals the intrinsic relationship among methods for inversion of the 2-D exponential Radon transform described by Bellini et al. (1979), by Tretiak and Metz (1980), by Hawkins et al. (1988), and by Inouye et al. (1989). Moreover, the authors' approach provides an infinite class of linear methods for inverting the 2-D exponential Radon transform. In the work reported here, the authors systematically investigated the noise characteristics of the methods in this class, obtaining analytical forms for the autocovariance and the variance of the images reconstructed by use of various methods. The noise properties of a new "quasi-optimal" method were then compared theoretically to those of other methods of the class. The authors' analysis demonstrates that the quasi-optimal method achieves smaller global variance in the reconstructed images than do the other methods of the class. Extensive numerical simulation studies confirm this prediction.

A unified analysis of exact methods of inverting the 2-D exponential radon transform, with implications for noise control in SPECT

Exact methods of inverting the two-dimensional (2-D) exponential Radon transform have been proposed by Bellini et al. (1979) and by Inouye et al. (1989), both of whom worked in the spatial-frequency domain to estimate the 2-D Fourier transform of the unattenuated sinogram; by Hawkins et al. (1988), who worked with circularly harmonic Bessel transforms; and by Tretiak and Metz (1980), who followed filtering of appropriately-modified projections by exponentially-weighted backprojection. With perfect sampling, all four of these methods are exact in the absence of projection-data noise, but empirical studies have shown that they propagate noise differently, and no underlying theoretical relationship among the methods has been evident. Here, an analysis of the 2-D Fourier transform of the modified sinogram reveals that all previously-proposed linear methods can be interpreted as special cases of a broad class of methods, and that each method in the class can be implemented, in principle, by any one of four distinct techniques. Moreover, the analysis suggests a new member of the class that Is predicted to have noise properties better than those of previously-proposed members.

Physical activity and cardiovascular risk factors in rural Shanghai, China

BACKGROUND

Data on the association between physical activity and cardiovascular risk factors among populations with a relatively high level of physical activity such as the Chinese, are sparse.

METHODS

In 1991, as part of the Sino-Shanghai Cardiovascular Disease Registry Project, a cross-sectional survey was performed in a random sample of 1206 residents, aged 35-64 years, living in rural Shanghai, China. Information on physical activity was obtained by questionnaire. The level of physical activity was categorized into low, moderate and high, based on the presence of a weekly frequency (< 1, 1-2, > or = 3) of periods of 20 minutes that cause shortness of breath, increase in pulse rate and perspiration. Body mass index (BMI), systolic (SBP) and diastolic blood pressure (DBP) level, serum lipids levels, smoking status and heart rate were assessed.

RESULTS

Across groups with low, moderate and high levels of physical activity, significant inverse trends were found for hypertension, total cholesterol, BMI and heart rate in men, and for hypertension, SBP and DBP, BMI and heart rate in women. High density lipoprotein cholesterol and current smoking were not related to physical activity. When differences in BMI were allowed for, the association between physical activity and hypertension and serum cholesterol in men, and with hypertension, SBP and DBP in women, were attenuated.

CONCLUSIONS

Our findings from a population-based survey in China suggest that a high level of physical activity is associated with favourable levels of some of the established cardiovascular risk factors in men and women.

Synergistic interactions between selective pharmacological inhibitors of phosphodiesterase isozyme families PDE III and PDE IV to attenuate proliferation of rat vascular smooth muscle cells

The interaction between selective inhibitors of 3',5'-cyclic-nucleotide phosphodiesterase (PDE) III (cyclic GMP inhibited phosphodiesterase) and selective inhibitors of PDE IV (Ro 20-1724 inhibited phosphodiesterase) to attenuate fetal bovine serum-stimulated incorporation of [3H]thymidine into DNA and cell proliferation was studied in a line (A10) of vascular smooth muscle cells (VSMC). The nonselective PDE inhibitors 3-isobutyl-1-methylxanthine (IBMX) and papaverine attenuated DNA synthesis with EC50 values (16 and 18 microM, respectively) in the same range as their published IC50 values (2-50 and 2-25 microM, respectively) as PDE inhibitors. The selective PDE III inhibitors CI-930 and cilostamide used alone attenuated DNA synthesis with EC50 values (> 300 and 5.3 microM, respectively) that were much higher than published IC50 values (0.15-0.46 and 0.005-0.064 microM, respectively) for inhibition of PDE III. In the presence of the PDE IV inhibitor rolipram (10 microM), their EC50 values were shifted (0.66 and 0.16 microM, respectively) much closer to their respective IC50 values. When the selective PDE IV inhibitors rolipram and Ro 20-1724 were used alone, they attenuated DNA synthesis with EC50 values (111 and > 100 microM, respectively) much higher than their IC50 values (0.6-2.6 and 2-13 microM, respectively) as inhibitors of PDE IV, but 10 microM CI-930 (PDE III inhibitor) shifted their EC50 values (0.56 and 1.5 microM, respectively) much closer to their IC50 values. In experiments that assessed VSMC proliferation using the MTT [3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] method, IBMX and papaverine attenuated proliferation with EC50 values (27 and 58 microM, respectively) close to their IC50 values. CI-930 and cilostamide used alone did not cause 50% attenuation of proliferation at the highest concentrations tested (100 and 10 microM, respectively). In the presence of 5 microM rolipram, however, their effects were enhanced greatly with EC50 values (0.86 and 0.23 microM, respectively) that were close to their IC50 values as PDE III inhibitors. Similarly, rolipram and Ro 20-1724 attenuated VSMC proliferation with EC50 values close to their IC50 values in the presence (2.1 and 4.6 microM, respectively) but not in the absence (> 100 and > 10 microM, respectively) of 2 microM CI-930. The interactions between PDE III inhibitors and PDE IV inhibitors to attenuate DNA synthesis and VSMC proliferation were synergistic as determined by the combination index. The data demonstrate that the synergistic interactions that attenuate incorporation of [3H]thymidine into DNA are accompanied by synergistic attenuations of VSMC division.(ABSTRACT TRUNCATED AT 400 WORDS)

The application of traditional Chinese medicine to the management of hepatic cancerous pain

The authors summarized the application of traditional Chinese medicine to the management of hepatic cancerous pain in Beijing and Shanghai, and in Jiangsu and Zhejiang Provinces. The therapeutic principle was to invigorate blood circulation and reduce stasis and to soothe the liver and regulate qi, so as to dredge the channels and collaterals. The results were satisfactory.

Stroke incidence and mortality in rural and urban Shanghai from 1984 through 1991. Findings from a community-based registry

BACKGROUND

Mortality from stroke has declined in many countries. This decline may result from a fall in incidence of stroke or a decrease in case fatality from stroke. The present study was conducted to investigate the temporal trends of incidence rate, mortality rate, and case fatality of stroke in an urban and rural Chinese population.

METHODS

A community-based registry study was established in 1983 in defined rural and urban areas of Shanghai with a population aged 35 to 74 years of approximately 86,000 subjects, adhering to the methods and definitions of the World Health Organization MONICA protocol. All stroke events occurring in the population aged 35 to 74 years in these areas were registered by a special three-level case-registration system.

RESULTS

From 1984 through 1991, 1391 stroke cases were identified. No significant change in the incidence rate of stroke was observed from 1984 through 1991 in men and women living in rural and urban areas. Age-standardized mortality rates (per 100,000 person years) of stroke declined significantly during this period, except for rural women. The annual changes and 95% confidence intervals of age-standardized mortality rates were: for rural men -4.6% (-5.4, -3.9), for rural women -0.6% (-1.6, 0.5), for urban men -2.5% (-3.5, -1.6), and for urban women -4.7% (-5.2, -4.2). A significant decrease in case fatality from stroke from 1984 through 1991 was found among men living in rural areas (from 62.4% to 46.0%) and among women living in urban areas (from 48.4% to 33.3%). Overall case fatality, however, showed a nonsignificant decline over time.

CONCLUSIONS

We observed a decline in stroke mortality rate in a rural and urban Chinese population. No significant changes in stroke incidence were found in this study, whereas case fatality appeared to have decreased, in particular among men living in rural areas and women living in urban areas.

A miniature gamma camera

We have described a mobile miniature-gamma-camera system for use in electrical trauma units and have presented images and imaging characteristics of a prototype system. The system has as its principal component a miniature gamma camera based on a PSPMT. The camera is 92 mm x 92 mm x 190 mm in size, weighs 5 kg, has a 48 mm x 48 mm field of view, and has an intrinsic resolution of approximately 3 mm FWHM and 6 mm FWTM. It is expected that devices of this type will be useful as imaging tools in electrical trauma units and laboratories where imaging studies regarding uptake mechanisms of radiopharmaceuticals for assessing tissue viability are carried out.

The use of mixture models to detect effects of major genes on quantitative characters in a plant breeding experiment

An analysis based on Elston's model of mixed major locus and polygenic inheritance is extended to include populations of progeny testing such as F3, B1s and B2s families derived from F2 and backcrosses in a cross between two inbred lines. Genetic hypotheses that can be validly tested by the likelihood ratio method in the analysis of a breeding experiment include homogeneity of variances due to environment and/or polygenes with transformable scale effect by Box-Cox power function, random and independent segregation of major genes, invariance of the effects of major genes with population types and additive and dominant models for polygenes. Testing hypotheses in the order suggested here can lead to a gradual simplification of the models and increases the feasibility of the subsequent analysis, but caution must be paid to the possible bias in parameter estimation and hypotheses tests. The procedure is applied to a set of data on plant height of rice with the effects of dwarf genes in crosses among three varieties. Two recessive dwarf genes are shown to be nonallelic and unlinked. One dwarf gene is shown to reduce plant height about 36-56 cm, and another 52-61 cm. The effect of polygenes, estimated as the standard deviation among possible inbred lines derived from these crosses, is about 11.7 cm. Interactions between the dwarf genes and the polygenic background are found, especially for one of the two genes. Both the polygenic effects and the interactions are much smaller than the effects of the major dwarf genes.

[A study on PEFV curves in adolescents]

We measured the PEFV curves in 557 adolescents aged from 6 to 19. Among them 200 were measured for MEFV curves additionally. The multiple regression equations of FVC and VFRC were simultaneously set up. The result indicated that the indexes increased with the growth of age. At the beginning stage (6-14 years) there was no difference in the indexes between boys and girls. Later in the age range from 14-16 years there were two cross points. Lastly (after 16 years) the indexes of the boys were much higher than those of the girls. The results suggest that the measurement of VFRC is a possible sensitive index to reflect the lung function variation, because it has not been influenced by the volume history.

Correction for photon attenuation in SPECT: analytical framework, average attenuation factors, and a new hybrid approach

We provide a unified framework for the investigation of convergence properties of the iterative algorithms for photon attenuation correction in SPECT, including the iterative Chang method--a commonly used approach in which an average attenuation factor calculated over all projection angles is employed in a pointwise correction scheme. A new average attenuation factor calculated along the projection line is introduced, which can compensate exactly for the attenuation effect in the case of a uniform activity distribution. We propose a new hybrid approach in which we use this new average attenuation factor initially and then shift to the iterative Chang method in later iterations. This hybrid approach was evaluated in a simulation study by use of a computer-generated phantom with both non-uniform activity and non-uniform attenuation distributions. The results demonstrate that this hybrid approach improves the convergence speed of the iterative Chang method and produces reconstructed images of high quality.

Properties and amino acid sequence of huwentoxin-I, a neurotoxin purified from the venom of the Chinese bird spider Selenocosmia huwena

By means of reverse phase and ion-exchange high performance liquid chromatography, a neurotoxic peptide named huwentoxin-I was purified from the venom of the Chinese bird spider Selenocosmia huwena. The intraperitoneal and intracisternal LD50 in mice of the toxin were 0.70 mg/kg and 9.40 micrograms/kg, respectively. This toxin at the concentration of 1 x 10(-5) g/ml can irreversibly block the neuromuscular transmission of the isolated mouse phrenic nerve-diaphragm preparation in 13.4 +/- 1.3 min (mean +/- S.D., n = 5). The isoelectric point is 8.95 determined by isoelectric focusing electrophoresis. It consists of 33 amino acids including 6 Cys and 6 Lys determined by amino acid analysis. The complete amino sequence of huwentoxin-I was determined. The N-terminal and C-terminal residues were Ala and Leu, respectively. The primary structure showed partial homology with that of mu-agatoxins from the funnel-web spider Agelenopsis aperta.

L-pipecolic acid oxidation in rat: subcellular localization and developmental study

By using a sensitive radioactive assay method, we present here evidence that L-pipecolic acid oxidase is localized in both mitochondria and peroxisomes of rat liver. Brain white matter contained a more than 2-fold higher activity of L-pipecolic acid oxidation than the brain cortex. Suborganellar fractionation studies indicate that while the enzyme is a matrix protein in mitochondria, it is membrane-associated in peroxisomes. Both rotenone and antimycin A completely inhibited the enzyme activity in mitochondria but not in peroxisomes. The enzyme was shown to be inducible in mitochondria and peroxisomes of rat liver and brain tissues by glucagon and di-(2-ethylhexyl)phthalate, respectively. We report here for the first time the developmental aspects of L-pipecolic acid oxidation activity in rat liver and brain tissues. L-Pipecolic acid oxidase activity was detectable in whole rat embryo at 10 days of gestation, suggesting active L-pipecolic acid metabolism early during development. In both liver and brain tissues L-pipecolic acid oxidation activity was highest at 15 days of gestation and decreased with age in prenatal and postnatal conditions.

[A study of accuracy of multiple-unit one-piece castings of fixed bridge]

We studied how the accuracy of the three-unit and four-unit bridges is affected by the three different sprue programmes and heat-treatment. The results of experiments are as follows. 1. In the two types of fixed bridge the accuracy of the lateral pouring sprue programme is greater than that of the top-pouring and bottom-pouring sprue programmes. 2. After the heat-treatment of the casting, the stresses are distributed again, so the accuracy of the casting becomes lesser. 3. The change in the measurement of the total and pontic lengths of multiple-unit fixed bridges generally causes a "fork shape" deformity.

Evaluation of brain function in acute carbon monoxide poisoning with multimodality evoked potentials

The median nerve somatosensory evoked potentials (SEP), pattern reversal visual evoked potentials (VEP), and brain stem auditory evoked potentials (BAEP) were studied in 109 healthy adults and in 88 patients with acute carbon monoxide (CO) poisoning. The upper limits for normal values of peak and interpeak latencies of multimodalities of evoked potentials in the reference group were established by a stepwise multiple regression analysis. SEP changes selectively affecting N32 and N60 were found in 78.8% of patients. There was prolonged P100 latency of VEP in 58.2% of the cases examined. The prevalence of BAEP abnormalities in comatose patients (36%) was significantly higher than that (8.6%) in conscious patients. BAEP abnormalities were most frequently seen in comatose patients who had diminished brain stem reflexes (77.8%). It has been found that a consistent abnormality involving N20 and subsequent peaks in SEP, a remarkable prolongation of P100 latency in VEP, or a prolongation of III-V interpeak latency in BAEP as well as the reoccurrence of evoked potential abnormalities after initial recovery all indicate unfavorable outcomes in patients with acute CO poisoning. The multimodality evoked potentials have proved to be sensitive indicators in the evaluation of brain dysfunction and in the prediction of prognosis of acute CO poisoning and the development of delayed encephalopathy.

Developmental changes of L-lysine-ketoglutarate reductase in rat brain and liver

1. Developmental aspects of L-lysine-ketoglutarate reductase, the first enzyme in saccharopine pathway of L-lysine degradation in rat liver and brain tissues were studied. 2. Although the adult rat brain shows negligible activity, the enzyme activity was shown to be highly active during the early stages of development. 3. The enzyme activity gradually decreased through development in the brain, whereas it gradually increased in the liver, establishing the fact that the saccharopine pathway is the major pathway in liver. 4. Our results also show that glucagon stimulated the induction of this enzyme by 2-3-fold in both adult liver and brain tissues.

[Pharmacokinetics of sinomenine by HPLC]

Pharmacokinetics of sinomenine in rabbit was studied by reverse-phase HPLC method. After i.v. injection of 20 mg/kg of sinomenine to rabbits, the pharmacokinetic characteristics were found to fit a two-compartment open model.

Highly polymorphic XbaI RFLPs of the human 21-hydroxylase genes among Chinese

A highly polymorphic XbaI restriction site flanking the human 21-hydroxylase genes (21-OHA and 21-OHB) was found with the probe pC21/3c, the cDNA of the 21-hydroxylase gene. From the results of RFLP analysis of 10 subjects with congenital adrenal hyperplasia (CAH) owing to 21-hydroxylase deficiency and their parents, at least four polymorphic fragments (30 kb, 27 kb, 25 kb, and 15 kb) resulting from cleavage at the polymorphic endonuclease sites outside the genes were found, and at least 10 different polymorphic patterns were observed among Chinese. These results indicate that these polymorphic loci are very informative for prenatal diagnosis of 21-hydroxylase deficiency.

Assessment of carotid artery stenosis by MR angiography: comparison with x-ray angiography and color-coded Doppler ultrasound

PURPOSE

To compare magnetic resonance angiography (MRA) with duplex Doppler ultrasound (US) and x-ray angiography (XRA) in the evaluation of the carotid bifurcation.

METHODS

The carotid arteries of 61 patients were studied using MRA, US, or XRA; 31 of the patients underwent all three examinations. MRA included both 2D and 3D time-of-flight sequences. Internal and external carotid artery origins were graded normal, mild, moderate, severe, or critical stenosis, or complete occlusion by each of the three studies.

RESULTS

Spearman rank correlations of both internal and external carotid artery grades were 0.85 (MRA and XRA), 0.69 (MRA and US), and 0.73 (XRA and US). For internal carotid artery origins only, the correlations were 0.94 (MRA and XRA), 0.85 (MRA and US), and 0.82 (XRA and US). Of discrepancies in internal carotid artery interpretation greater than one grade, seven resulted from US error, three from MRA error, and one from XRA error. A 2-cm partially thrombosed aneurysm detected by US and MRA was missed by XRA. Of 16 possible ulcers on XRA, 11 were noted by MRA, none by US.

CONCLUSIONS

MRA and XRA are similar in assessment of carotid bifurcation stenosis. MRA, like US, permits direct visualization of plaque. This preliminary study suggests that MRA may be used to clarify equivocal findings of US, or replace XRA in presurgical planning.

[Evaluation of a logistic regression model in predicting the prognosis of Graves' disease treated by antithyroid drugs]

One hundred and twelve new cases of Graves' disease were treated by tapazole for 6 months and followed up for another 12 months. The initial dose was 30 mg/d. Clinical and biochemical euthyroidism was achieved within 1 to 3 months, then a maintenance was given until cessation of drugs at 6 months. One hundred and eleven cases completed the study. Remission and relapse were defined at the end of follow-up for 1 year according to the presence or absence of clinical manifestation of hyperthyroidism and the levels of T3 and T4. The results of the 12-month follow-up showed that 46 of 111 cases were in remission, and the remaining 65 cases suffered relapse. A logistic regression model with 4 variables was established, which included thyroid suppression rate and goitre size by palpation at the end of drug treatment, the level of T3 before therapy, and the patients' age. The model had 81.5% sensitivity, 84.8% specificity and 82.9% (92/111) accuracy in predicting the outcome of Graves' disease after withdrawal of drug for 1 year. The results were much better than any other univariate analysis in this study.

[Detection of steroid 21-hydroxylase gene variation among normal Chinese and patients with congenital adrenal hyperplasia]

Genomic DNA from 40 unrelated healthy individuals and 16 families affected with 21-hydroxylase deficiency were digested with restriction enzyme Taq I followed by Southern blot and hybridization using a 21-hydroxylase (21-OH) gene cDNA probe. In healthy individuals the number of copies of 21-OHB gene was constant while that of 21-OHA gene was variable including deletion and duplication. In addition, we found an extra 5.6 kb band in one normal person and in one CAH family. Among the 16 affected families, 19% of 21-OHB gene were deleted. No homologous deletion was found. The frequency of deletion is lower than that reported in the literature. There was variation in the copy-number of 21-OHA gene among patients with CAH, yet no difference was found between the patients and normal persons. The information on prenatal diagnosis of CAH is briefly discussed.

[Investigation on the distribution and serotyping of V. parahaemolyticus isolated from marine products and environment in Zhoushan archipelago]

Isolation for V. parahaemolyticus from 1003 samples of marine products and environment was attempted in Zhoushan archipelago in 1986-1987. The results showed that V. parahaemolyticus could be detected from all kinds of marine products, the positive rate was between 40%-100%. The V. parahaemolyticus was detected in all samples from the environment. The main O groups were O2, O5, O1, O4, O3 and O12, the O9 groups was not detected. Although 103 serotypes have been detected, the main serotypes were O1K32, O5K17, O5K15, O2K28, O2K3 and O12K51(52), 17.9% of the strains could not be typed.

Identification of aortic thrombus by magnetic resonance imaging

The unique properties of magnetic resonance imaging result in the potential to differentiate various components of the diseased arterial wall. In this article four cases are presented in which magnetic resonance imaging showed mural aortic thrombus and its anatomic relationship to the visceral and renal arteries. Once thrombus is identified and localized specific operative strategies can be undertaken to prevent recurrent embolic events and/or avoid perioperative thromboembolic complications.