Confidence intervals for the log-normal mean

In this paper we conduct a stimulation study to evaluate coverage error, interval width and relative bias of four main methods for the construction of confidence intervals of log-normal means: the naive method; Cox's method; a conservative method; and a parametric bootstrap method. The simulation study finds that the naive method is inappropriate, that Cox's method has the smallest coverage error for moderate and large sample sizes, and that the bootstrap method has the smallest coverage error for small sample sizes. In addition, Cox's method produces the smallest interval width among the three appropriate methods. We also apply the four methods to a real data set to contrast the differences.

[Pedicled omentum graft for improvement of late-blood supply after myocardial revascularization with Nd:YAG laser in the treatment of ischemic heart disease]

26 dogs were devided into 3 groups. Selected left coronary artery branches of all dogs were ligated to make the models of myocardial infarction. The control group of 10 dogs received ligation of selected coronary artery branches(L group) only. Eight dogs were revascularized by Nd:YAG laser (LL group), and 8 dogs were revascularized and covered with pedicled omentum. All dogs were monitored by ECG, cardiac output, fractional 86Rb uptake and histological examination. The results showed that laser channels can perfuse ischemic myocardium and recover myocardial circulation to improve cardiac function immediately. However, the laser channels were closed after 4 weeks by clot, fibrosis and scarring which caused by thermal damage of Nd:YAG laser. The late result of laser myocardial revascularization with pedicled omentum graft is more better in perfusing myocardium and improving cardiac function than sole laser myocardial revascularization.

The evaluation of intra- and extra-cranial circulation in subclavian steal syndrome

OBJECTIVE

To compare the efficacy of transcranial Doppler ultrasound (TCD) and digital subtraction angiography (DSA) in identifying the clinical and hemodynamic relationship between intra- and extra-cranial circulation and subclavian steal syndrome.

METHODS

Sixteen patients were collected. The intra- and extra-cranial arteries were insonated with Doppler ultrasound. DSA and brain CT were performed in all patients. The relationship between the grade of arterial stenosis showing in DSA and the flow direction showing in TCD was studied.

RESULTS

TCD showed reversal flow of the vertebrobasilar artery in 13 patients, normal flow in 3, which was influenced obviously by fist-clenching. In the hyperemia test, the flow velocity and the direction changed significantly in all patients. The steal phenomenon of the middle cerebral artery (MCA) was coincident with that of the arterial cerebral artery (ACA) in 2 cases. Stenosis of MCA or ACA was found in 5 cases (31%). Nine patients were treated with arterial bypass or angioplasty. TCD was performed during the follow-up.

CONCLUSIONS

Reversal flow of the vertebral artery may occur in rest or only in exercise, depending on the grade of subclavian arterial stenosis. Hyperemia test is the most sensitive index. It is necessary to monitor blood flow in the MCA and basilar artery in hyperemia test. The coexistence of intra- and extra-cranial arterial stenosis is common.

[An experimental study on effect of atrial natriuretic peptide on intraocular pressure of white rabbits]

OBJECTIVE

To study the therapeutic effect of atrial natriuretic peptide (ANP) on glaucoma.

METHODS

Various doses of ANP were injected subconjunctivally in albino rabbits, and their effects on intraocular pressures (IOPs) were observed.

RESULTS

The IOPs were significantly decreased by the subconjunctival injection of 20, 30, 40 micrograms of ANP, and with a dose of 40 micrograms, the maximum effect of IOP lowering of 0.88-0.15 kPa maintaining for the longest time 7.5 hours was obtained. Generally, one hour after the injection, the maximum effect could be seen. A dose-effect relationship that is the degree of the reduction of IOP increasing with the dose increase of ANP could be observed.

CONCLUSION

This study indicates that ANP might play an effective therapeutic role in glaucoma.

Somatic mutation theory, DNA repair rates, and the molecular epidemiology of p53 mutations

The theory of somatic mutagenesis predicts that the frequency pattern of induced selectable mutations along a gene is the product of the probability patterns of the several sequential steps of mutagenesis, e.g., damage, repair, polymerase misreading, and selection. Together, the variance of these component steps is propagated to generate a mutagen's induced mutational spectrum along a gene. The step with the greatest component of variance will drive most of the variability of the mutation frequency along a gene. This most variable step, for UV-induced mutations, is the cyclobutyl pyrimidine dimer repair rate. The repair rate of cyclopyrimidine dimers is quite variable from nucleotide position to nucleotide position and we show that this variation along the p53 gene drives the C-->T transition frequency of non-melanocytic skin tumors. On showing that the kinetics of cyclopyrimidine dimer repair at any one nucleotide position are first order, we use this kinetic and the somatic mutation theory to derive Leq, the adduct frequency along a gene as presented to a DNA polymerase after a cell population reaches damage-repair equilibrium from a chronic dose of mutagen. Leq is the product of the first two sequential steps of mutagenesis, damage and repair, and the frequency of this product is experimentally mapped using ligation-mediated PCR. The concept of Leq is applied to mutagenesis theory, chronic dose genetic toxicology, genome evolution, and the practical problems of molecular epidemiology.

Vascular lesions in Chinese patients with transient ischemic attacks

We studied 96 Chinese patients with TIAs using transcranial Doppler and duplex ultrasonography. We found intracranial stenosis or occlusion in 51% of cases and extracranial disease in 19% of cases. The most common intracranial lesion was stenosis of the terminal internal carotid artery or proximal middle cerebral artery, whereas the most common extracranial lesion was stenosis of the carotid bifurcation.

Effect of left ventricular outflow on flow convergence region on the left septal surface in ventricular septal defect

The corrected shunt flow rate (Fc) and corrected defect orifice area (Ac) were calculated by modified equation F = 2 pi R2 (NL-VLVOT x Sin theta) in 23 patients with single membranous ventricular septal defect, in order to correct the effect of left ventricular outflow on flow convergence region on the left septal surface. The results indicated that Fc was closely correlated with Qp-Qs, and Qp/Qs measured by pulsed wave Doppler (r = 0.95 and r = 0.81 respectively, P < 0.001). And the correlation between Ac and the diameter of defect (Dd) measured directly in two-dimensional views was better than that between uncorrected defect orifice area (A) and the Dd (r = 0.98 and 0.69, respectively, P < 0.001). The shunt flow rate calculated by ideal equation F = 2 pi R2 x NL overestimated the actual shunt flow rate in ventricular septal defect, especially in membranous type. Our study concluded that Fc can be used for a more accurate evaluation of the shunt severity of ventricular septal defect.

Color Doppler monitoring of changes of utero-placental-fetal circulation in normal pregnancy and intrauterine growth retardation

The utero-placental-fetal circulation (UPFC) of 150 subjects during second and third trimester was examined by using color Doppler. Of them 89 were normal woman and 58 were patients with intrauterine growth retardation IUGR). Our results showed that UPFC was increased gradually during normal pregnant period. In IUGR patients it was revealed that TAV and Q of UmA, UmV and UtA decreased at 20th week of gestation, especially after 30th week. PI, RI and S/D ratio of UmA were increased, but TAV, Q of UmA and UmV were markly reduced, so was UtA. PI were increased, but the changes of RI, S/D ratio in UtA were not significant. Hemodynamical findings of UmA, UmV and UtA were abnormal in 92.53% of IUGR patients. Only 81.03% present abnormal S/D ratio of UmA (P < 0.01) and the difference was statistically significant. Maternal serum E3, HPL level in IUGR were significantly lower than that of the normal. 6KP level was reduced, TXB2/6KP ratio was significantly increased. TXB2/6KP ratio was markedly related with TAV, Q of UmA, UmV and UtA. Our results suggested that using color doppler ultrasound for examination of hemodynamical changes of UmA, UmV and UtA could revealed UPFC function directly. It is one of the best methods for monitoring IUGR and might be used for early diagnosis of IUGR. The main pathophysiological changes of IUGR were UPFC obstruction and placental disfunction.

[Diagnostic value of endometrial assessment by transvaginal ultrasonography in patients with postmenopausal bleeding]

OBJECTIVE

To assess the value of endometrial transvaginal sonography in diagnosis of patients with postmenopausal bleeding.

METHODS

High resolution transvaginal ultrasonographic examination was performed in 192 patients with postmenopausal bleeding before fractional uterine curettage. The results of endometrial sonogram were compared with endometrial histological findings.

RESULTS

Seventy-seven cases had endometrial thickness < or = 4mm. 74 of them (96.1%) showed physiological changes by pathological examination. Only 3 were endometrial cancer. In contrast, in 115 patients who had endometrial thickness > or = 5mm, 59 (51.3%) had endometrial cancer.

CONCLUSION

Transvaginal ultrasonography may be used as a screening procedure in patients with postmenopausal bleeding. Diagnostic uterine curettage may be avoided in patients who had endometrial thickness < or = 4mm.

[Reconstruction of lacrimal passage in repair of oblique facial cleft]

For the reconstruction of lacrimal passage in obligue facial cleft, three methods were performed in 4 cases. According to the difference in local pathology canaliculorhinestomy, transfer of vein or oral mucosa, or modified dacryocystorhinostomy was performed. The patients were followed for 6 to 12 months with satisfacting results.

Distinct roles for two G protein alpha subunits in fungal virulence, morphology, and reproduction revealed by targeted gene disruption

Reduced accumulation of the GTP-binding protein G(i)alpha subunit CPG-1, due either to hypovirus infection or transgenic cosuppression, correlates with virulence attenuation of the chestnut blight fungus, Cryphonectria parasitica. The role of G protein-mediated signal transduction in fungal virulence was further examined by targeted disruption of the gene cpg-1, encoding CPG-1, and a second Galpha gene, cpg-2, encoding the subunit CPG-2. Disruption of cpg-1 resulted in a set of phenotypic changes similar to, but more severe than, those associated with hypovirus infection. Changes included a marked reduction in fungal growth rate and loss of virulence, asexual sporulation, female fertility, and transcriptional induction of the gene lac-1, encoding the enzyme laccase. In contrast, cpg-2 disruption resulted in only slight reductions in growth rate and asexual sporulation and no significant reduction in virulence, female fertility, or lac-1 mRNA inducibility. These results provide definitive confirmation of previous correlative evidence that suggested a requirement of CPG-1-linked signaling for a number of fungal processes, including virulence and reproduction, while demonstrating that a second Galpha, CPG-2, is dispensable for these processes. They also significantly strengthen support for the apparent linkage between hypovirus-mediated disruption of G protein signal transduction and attenuation of fungal virulence.

Plasma endothelin and atrial natriuretic peptide in normal and hypertensive pregnancy

OBJECTIVE

To investigate the possible role of endothelin-1 (ET-1) and atrial natriuretic peptide (ANP) in the pathogenesis of pregnancy-induced hypertension (PIH).

MATERIAL AND METHODS

A total of 110 normal pregnant women (in three trimesters, labour or postpartum) and 30 patients with PIH were studied by measuring plasma ET-1 and ANP levels by radioimmunoassay; 23 normal non-pregnant women were selected as controls.

RESULTS

Compared with normal non-pregnant women, plasma ET-1 levels were significantly decreased in normal pregnant women during all three trimesters. Plasma ET-1 level was significantly increased in the 2nd stage of labour, compared with that in the 3rd trimester. There were significant positive correlation between plasma ET-1 level and mean arterial pressure in normal non-pregnant women and normal pregnant women in all three trimesters. Compared with matched normal pregnant women, plasma ET-1 and ANP levels were significantly increased, while plasma ANP/ET-1 ratio was significantly decreased in PIH patients. Significant positive correlations existed between plasma ET-1 level and mean arterial pressure or the score index of the severity of PIH. After the treatment with magnesium sulfate infusion, plasma ET-1 and ANP levels were significantly decreased, but plasma ANP/ET-1 ratio was significantly increased in PIH patients.

CONCLUSIONS

Augmentation of ET-1 secretion and attenuation of ANP function may be responsible for the development of PIH. ET-1 secretion may be indirectly influenced by magnesium in PIH.

The relationship between alcohol consumption, cognitive performance, and daily functioning in an urban sample of older black Americans

OBJECTIVE

To report on moderate alcohol consumption and measurements of cognitive function and activities of daily living in an older, urban, community-dwelling sample of black Americans.

DESIGN

As part of a community prevalence study of dementia, information on alcohol consumption and cognitive performance was collected on 2040 randomly selected black subjects living in Indianapolis.

MEASUREMENTS

From questions in the screening interview, alcohol consumption was grouped into four categories: lifetime abstainers, regular drinkers less than 4 drinks per week, 4 to 10 drinks per week, and more than 10 drinks per week. Current and past drinkers were analyzed separately. Three measurements were used: (1) a total cognitive score; (2) the delayed recall score from the East Boston Memory Test; (3) a score for daily functioning based upon information from the informant. Multiple regression models were fitted with drinking variables as the major predictor, including covariates of age, gender, education, history of stroke, hypertension, being treated for depression, and a family history of dementia.

MAIN RESULTS

In all analyses, there was a very consistent pattern for both current and past drinkers. There was a small but significant dose effect of drinking for the drinkers, with subjects in the heaviest drinking category scoring poorest, i.e., lowest scores in cognitive tests and highest scores in scales of daily functioning indicating more impairment. The scores of abstainers were worse than those of subjects in the lightest drinking category. The pattern of scores for cognitive performance and daily functioning was similar between current and past drinkers. These patterns remained the same even after potential confounders were included.

CONCLUSIONS

Previous research on effects of alcohol on health indices have suggested a J-shaped relationship between amounts of alcohol consumption and measurements of heart disease, stroke, and mortality rates. Our study provides some support for the concept of a similar J-shaped relationship between cognitive performance and alcohol consumption, but the differences between drinking categories were modest and the clinical significance of these findings uncertain.

Association of the epsilon 4 allele of apolipoprotein E with poor performance on a dementia screen in African Americans

In a community-based study of Alzheimer's disease in African Americans age 65 and over, subjects were classified into three levels of performance based on their scores as measured by the Community Screening Instrument for Dementia (CSI"D"), consisting of cognitive and functioning components. In a subset of 268 subjects with apolipoprotein E (APOE) genotype data, we found that the epsilon 4 allele of APOE was associated with intermediate/poor performance (single copy epsilon 4 odds ratio 1.51, 95% CI 1.18 to 1.92; double copy epsilon 4 odds ratio 3.42, 95% CI 2.18 to 5.43). From these data, we believe it would be possible to conduct population screening for the effects of possession of the APOE-epsilon 4 allele using information derived from the CSI"D".

Extensive alteration of fungal gene transcript accumulation and elevation of G-protein-regulated cAMP levels by a virulence-attenuating hypovirus

Persistent infection of the chestnut blight fungus Cryphonectria parasitica with the prototypic hypovirus CHVI-713 results in attenuation of fungal virulence (hypo-virulence) and reduced accumulation of the GTP-binding (G) protein a subunit CPG-1. Transgenic cosuppression of CPG-1 accumulation in the absence of virus infection also confers hypovirulence. We now report the use of mRNA differential display to examine the extent to which virus infection alters fungal gene transcript accumulation and to assess the degree to which modification of CPG-1 signal transduction contributes to this alteration. More than 400 PCR products were identified that either increased (296 products) or decreased (127 products) in abundance as a result of virus infection. Significantly, 65% of these products exhibited similar changes as a result of CPG-1 cosuppression in the absence of virus infection. We also report that both virus infection and CPG-1 cosuppression elevate cAMP levels 3- to 5-fold. Additionally, it was possible to mimic the effect of virus infection and CPG-1 cosuppression on transcript accumulation for representative fungal genes by drug-induced elevation of cAMP levels. These results strengthen and extend previous indications that hypovirus infection causes a significant and persistent alteration of fungal gene expression/transcript accumulation. They further show that this alteration is primarily mediated through modification of the CPG-1 signaling pathway and suggest that, similar to mammalian Gi alpha subunits, CPG-1 functions as a negative modulator of adenylyl cyclase. Finally, these results suggest a role for G-protein-regulated cAMP accumulation in hypovirus-mediated alteration of fungal gene expression.

[Loss of heterozygosity involving DCC gene in human colorectal cancers is correlated with the metastatic potential]

DCC gene located at chromosome 18q21.3 is an important tumor-supressor gene associated with tumorigenesis and progression, especially in colorectal carcinomas. Adopting Southern blot technique and RFLP analysis, 33 primary Chinese colorectal cancer patients were examined for loss of heterozygosity (LOH) of DCC gene. Among 16 informative cases, 6 (38%) showed allelic deletion. 18q LOH was correlated with lymph node and hepatic metastases (P < 0.05). The results indicate that application of molecular genetics is of value in ascertaining the metastatic potential of colorectal carcinomas.

Cloning and targeted disruption of enpg-1, encoding the major in vitro extracellular endopolygalacturonase of the chestnut blight fungus, Cryphonectria parasitica

The gene enpg-1, encoding the major extracellular endopolygalacturonase (endoPG) purified from culture filtrates of the chestnut blight fungus, Cryphonectria parasitica, was cloned and characterized. The deduced mature enpg-1 protein product, ENPG-1, had a calculated molecular mass of 34.5 kDa and a pI of 7.2, consistent with empirically derived values for the purified enzyme, and had 66% identity with an endoPG from the maize pathogen Cochliobolus carbonum. Targeted disruption of enpg-1 was accomplished by homologous recombination with a cloned copy of the gene that contained the Escherichia coli hygromycin B phosphotransferase gene (hph) inserted into exon 1. enpg-1 disruption resulted in no reduction in canker formation on dormant American chestnut stems. Unexpectedly, the level of polygalacturonase (PG) activity measured in cankered bark tissue infected with enpg-1 disruptants was indistinguishable from that found in canker tissue infected with virulent strain EP155. Isoelectric focusing and activity gel analysis of PG activity extracted from canker bark tissue revealed ENPG-1 to be a minor (less than 5%) activity component in tissue infected with the virulent strain and to be absent in tissue infected with the disruption mutants. The predominant activity in both canker samples consisted of two previously undetected acidic PG forms that appear absent in C. parasitica culture filtrates. We conclude from these results that the major C. parasitica extracellular endoPG produced in culture, ENPG-1, does not play a significant role in fungal virulence. However, the identification of two acidic PG activities expressed predominantly, if not exclusively, in planta provides new opportunities for examining the importance of PGs in C. parasitica pathogenesis.

Psychiatric disorders in African American nursing home residents

OBJECTIVE

High prevalence rates of psychiatric illness and high levels of behavioral disturbance have been reported in studies of nursing home residents; however, the populations evaluated have been predominantly Caucasian. The aims of the present study were to identify prevalence rates of psychiatric disorders and behavioral disturbances in a sample of African American nursing home residents.

METHODS

The authors evaluated 106 African American nursing home residents, aged 65 and over, from a representative sample of nursing homes. The evaluation included informant interview with nursing home staff, cognitive assessment, and a psychiatric interview that included a physical and neurological examination. Consensus diagnoses were reached by using DSM-III-R criteria.

RESULTS

Of the 106 subjects, 90% received at least one primary psychiatric diagnosis, and 71% had at least one behavioral problem; dementia was the most common psychiatric diagnosis (68%). Thirty -one percent of the patients were treated with neuroleptic medication; most of these patients received diagnoses of dementia or schizophrenia. Fifteen percent of the patients had been in physical restraints, which correlated with physical disability.

CONCLUSIONS

The prevalence of psychiatric illness in this sample of African American nursing home residents is similar to that reported in previous studies with predominantly Caucasian populations. Behavioral disturbances, while commonly reported, were somewhat less frequent than reported in previous studies.

[Preparation of huichun zhibao oral liquid (HZOL)]

The formulation, preparing method, quality standards, pharmacodynamic experinents and toxicological experiments of HZOL are described. The content of icariin, which is and effective component of epimedium herb as well as one of the main ingredients in HZOL, was successfully determined through HPLC, with an average recovery of 98.98% and RSD = 1.53%.

[Changes in hematoporphyrin in patients with gastric and hepatic carcinoma and their clinical significance]

The fluorescence spectroscopy of porphyrin molecule in blood was determined with photoluminescence fluorescence spectroscope in 139 patients with gastric carcinoma, 76 with hepatic carcinoma, 110 with gastric ulcer and chronic gastritis, 168 with liver cirrhosis and 33 normals as controls. The results showed that the peaks of Zinc porphyrin and protoporphyrin in patients with cancer were significantly higher than those in patients with benign disease, the peak of protoporphyrin being two to three times higher in the former groups of patients than that in the latter (P < 0.01). Protoporphyrin could be used as a marker to screen and diagnose gastric and hepatic carcinoma.

[Technological studies of effects of inclusion on pericarpium Citri reticulatae volatile oil-beta-cyclodextrin]

The effects of inclusion on Pericarpium Citri Reticulatae volatile oil-beta-cyclodextrin were studied by comparing four methods saturation, grinding, liquid to liquid and liquid to gas. The utilization ratio of oil, the ratio of oil in inclusion complex and the recovery of inclusion complex were used as the criteria in evaluating the inclusion effectiveness. The results showed that the saturation method was the best.

Pharmacokinetics of ceftizoxime in renal failure patients without dialysis

AIM

To investigate the pharmacokinetics of ceftizoxime (Cef) in renal failure patients without any dialysis and supply the basis for a suitable clinical regimen.

METHODS

Cef in plasma and urine was assayed by HPLC.

RESULTS

After injecting Cef 16.7 mg kg-1, Cef concentration in blood was described as a 2-compartment open model. The main pharmacokinetic parameters were Vd 0.55 +/- 0.17 L kg-1; AUC 879 +/- 460 mg L-1 h; Cl 27 +/- 11 mL kg-1 h-1. T1/2 beta was 15 +/- 4 h.

CONCLUSION

T1/2 beta in renal failure patients was about 10 times longer than that in normal volunteers. The clinical regimen should be adjusted in renal failure patients with infection, either prolonging the interval between Cef administration, or decreasing Cef dosage.

A factor in lymph node and spleen induced by restraint stress in mice and rats suppresses lymphocyte proliferation

Extracts from lymph node and spleen in mice and rats subjected to restraint stress significantly suppressed lymphocyte proliferation, but extracts from brain, skeletal muscle, and thymus gland had no effect on lymphocyte proliferation, suggesting that a suppressive factor for lymphocyte proliferation might selectively be induced in lymph node and spleen. Further experiments showed that biochemical properties, molecular weight, correlation between suppressive factors in serum and in extract of the lymph tissue from stressed animals, and control of the generation, all indicated that under the conditions of restraint stress and under the control of central nervous system a suppressive factor was generated in peripheral lymph tissue and then released into the blood-stream, which acted as a strong suppressor of lymphocyte proliferation.

[Copper needle puncturing for the treatment of cavernous hemangioma]

From the beginning of 1990 to Oct. 1993, we have treated 31 patients with cavernous hemangioma using copper needle puncturing. Three months' to one and half years' follow-up showed positive effects in all cases. The paper describes general and local reaction of the treatment, the changes in blood copper concentration and echocardiography and complications.

[Effects of copper needling therapy on cavernous hemangioma assessed by echogram]

Thirty-one patients with subcutaneous cavernous hemangioma were observed by echogram before and after treatment with copper needling. Different characteristics of echogram were found in hemangioma before and after treatment. Color Doppler imaging gave great help in the diagnosis and treatment of this disease and follow-up.

[Intra- and extra-cranial arterial lesions in TIA patients]

Ninety-six patients with transient ischemia attacks were examined by transcranial Doppler (TCD), carotid color-coded ultrasonic imagine, brain computed tomographic scan (CT), compared with digital subtract angiography (DSA), MRI and MRA were done in some cases. The abnormality of CT and MRI was 30.2% and 74.1%, respectively. The most common findings were lacunar infarction or cerebral atrophy. Sixty-two cases fulfilled the TCD criteria of definitive arterial stenosis (64.5%) and three cases of arteriovenous malformation, among whom 27 patients (43.5%) carried out the examination of DSA. There was an excellent coincidence between the DSA and TCD findings, although DSA showed more vessels involved in some patients. Of the 96 cases, the intracranial arterial stenosis or occlusion was in 48.5% and the extracranial in 17.8%. The younger patients (age < 60 years) were subject to involvement of unilateral intracranial artery, but the older had predominantly the bilateral intracranial arterial and extracranial carotid or subclavian arterial lesions.

[Establishment of a new culture system for fetal human tracheobronchus]

Human tracheobronchial tissues were cultured in CMRL 1066 medium containing insulin, hydrocortisone, bovine pituitary extract, and trace elements, with or without fetal bovine serum, in a rocked atmosphere chamber. The morphology of the epithelium remained normal for two months after in organ culture, and then, squamous metaplasia appeared in the epithelium and maintained for more than one year. There were continuous epithelial outgrowths from the human tracheobronchial tissues during the whole duration of organ culture, and the epithelial outgrowth can be subcultured in MCDB 151 medium supplemented with growth factors and grew as a tightly packed monolayer of polygonal cells with the presence of keratin and microvilli. The advantages of organ culture and epithelial cell culture were combined in this new culture system. The new culture model has already been used for the investigation of in vitro transformation of human tracheobronchial epithelial cells by chemical carcinogens in our laboratory.

Morphometric analysis of spinous cell in oral submucous fibrosis. Comparison with normal mucosa, leukoplakia and squamous cell carcinoma

The morphometric analysis of the spinous cell in 16 specimens of oral submucous fibrosis (OSF) was made by using interactive image analysis system (IBAS-II). 19 parameters of the size and shape were chosen, and compared with normal mucosa, leukoplakia, dysplasia and carcinoma. The results indicated that the cell dimensions (area, perimeter, all kinds of diameter) and nuclear cytoplasmic ratio in OSF were between normal mucosa and dysplasia as well as carcinoma. The former showed a progressive decrease (P < 0.01), and the latter showed a progressive increase (P < 0.01). The dimensions of the nuclei did not show considerable differences among the groups (P < 0.05). A series of discriminant functions had been developed with stepwise discriminant analysis, the agreement ratio for OSF was 93.75%. The decrease of cell area and the increase of nuclear cytoplasmic ratio could reflect a malignant progress. The cell morphometric model could discriminate OSF well from other groups, suggesting that the change of the epithelium in OSF appearing in the spinous cell is specific itself.

Three-dimensional uniform grid modeling of electrical defibrillation on a data parallel computer

Finite element modeling has played an increasingly important role in the study of defibrillation. In order to model well the complex anatomical details, a large number of elements are required in the finite element grid, leading to a large set of equations that often cannot be solved effectively with the computational power of conventional computers. In this paper, we describe the use of a data parallel computer to provide the memory and reduction in solution time for solving these large finite element problems. Using a uniform grid and a nodal assembly technique, the discretized problem domain can be mapped efficiently to the parallel computer, allowing the solution of problems with over two million unknowns. The finite element algorithm for a three-dimensional inhomogeneous anisotropic body is described together with its parallel implementation. Test results for a canine torso model constructed from CT images are also presented.

[Anatomical study on the Riolan's anastomosis arch]

The Riolan's anastomosis arch is discussed on the basis of colon vessel constructions in 162 operations of the colonic interposition for esophageal substitution, and the materials reported in some journals. The Riolan's arch is not the marginal vessels of the flexura lienalis, because of its lower incidence (< 10%). We believe that the integrity of the arch is not responsible for the blood supply of the colon.

Platinum binding to metallothionein. Analysis of circular dichroism spectra of complexes formed between metallothionein and platinum from cis- and trans-diamminedichloroplatinum

The first observation of the circular dichroism (CD) spectral features of platinum-saturated metallothionein, Pt7MT, is presented. It is characterized by two intensive bands with maxima at 235 nm (-) and 255 nm (+). Properties of the reactions of cis- and trans-diamminedichloroplatinum (DDP) with rabbit liver MT have been studied by monitoring the CD spectral changes. The overall rate of the reaction between trans-DDP and MT is determined to be significantly faster than that for cis-DDP and MT. The stepwise incorporation of Pt into Zn7MT resulted in a nonsystemic changes in the CD spectral envelope. These data argue that Pt(II) replaces Zn(II) in ZnMT in a nonspecific, "distributed" manner across both domains, because the onset of clustering was observed after 5 mol equiv of Pt was bound. A dynamic mechanism has been proposed in which the reaction proceeds via the formation of an intermediate, RS-Pt (NH3)2-SR. As it is converted to the product, the ammine ligands are lost very slowly, especially in the case of cis-DDP, because of the strong requirement of Pt for square planar coordination, which comprises the rate-limiting step.

[Limb-salvage surgery in 60 patients with osteosarcoma]

Limb-salvage surgery plays an important role in the treatment of osteosarcoma. From 1974 to 1993, 104 patients with osteosarcoma were treated in our department. Sixty of them were treated with limb-salvage procedures. In fourty-four patients of stage II B receiving adjuvant chemotherapy, the five-year survival rate was 46.69%. The overall local recurrence rate was 15%. The infection rate was 12.9%, and mechanical complication occurred in 14.8% of the patients. The functional result was generally good. Improved concepts of en bloc resection and better reconstructive techniques suggest that limb-salvage procedures are not only possible but can provide excellent functional result in patients with osteosarcoma. Further work must be directed to reducing local recurrence and improving reconstructive techniques.

Numerical analysis of electrical defibrillation. The parallel approach

Numerical modeling offers a viable tool for studying electrical defibrillation, allowing the behavior of field quantities to be observed easily as the different system parameters are varied. One numerical technique, namely the finite-element method, has been found particularly effective for modeling complex thoracic anatomies. However, an accurate finite-element model of the thorax often requires a large number of elements and nodes, leading to a large set of equations that cannot be solved effectively with the computational power of conventional computers. This is especially true if many finite-element solutions need to be achieved within a reasonable time period (eg, electrode configuration optimization). In this study, the use of massively parallel computers to provide the memory and reduction in solution time for solving these large finite-element problems is discussed. Both the uniform and unstructured grid approaches are considered. Algorithms that allow efficient mapping of uniform and unstructured grids to data-parallel and message-passing parallel computers are discussed. An automatic iterative procedure for electrode configuration optimization is presented. The procedure is based on the minimization of an objective function using the parallel direct search technique. Computational performance results are presented together with simulation results.

Coaxial architecture of an optical neural network with a lenslet array

A theoretical limitation on the neuron numbers (N x N) of a spatial interconnection system based on a lenslet array is analyzed. To improve the limitation, we propose a submatrix coaxial interconnection architecture. Off-axial aberration is decreased, and high light efficiency is achieved. A detailed analysis is given.

[A study on the boundary value of hemoglobin concentration for screening iron deficiency anemia in pregnant women]

To evaluate whether a pregnant woman is in anemia or there exist the needs to replenish iron is usually based on the measurement of hemoglobin (HB) concentration, because the evaluation of iron nutritional status has not yet been used widely in our country. Blood specimens were collected from 258 pregnant women, and concentrations of Hb, serum ferritin (SF) and free erythrocyte protoporphyrin (FEP) were determined to find out a reasonably boundary value of Hb concentration from the two different ones set by our country and WHO, respectively, and the one averaged the former two, i.e, 100g/L, 110g/L and 105g/L. False positivity and false negativity in diagnosis of iron deficiency anemia (IDA) for pregnant women were evaluated based on the measurement of SF and FEP concentrations as gold standards. Results showed that the optimal Hb concentration for preliminary diagnosis of IDA was 105g/L with maximizing Yorden index.

[Both 987P and F41 fimbriae produced by the same enterotoxigenic Escherichia coli strain isolated from a piglet with diarrhea]

An enterotoxigenic Escherichia coli strain isolated from a piglet with diarrhea was examined for the presence of fimbriea 987P and F41 by a direct agglutination (with MAbs), an indirect immunofluorescence technique (MAbs as first antibodies), SDS-PAGE and Western blots (antisera IgG as probes). Results of these techniques revealed that both 987P and F41 fimbrial adhesins were produced by the same strain, not by separate ones.

The G gamma:A gamma ratios in the fetal hemoglobin of newborns of the Man ethnic group and their gamma-globin gene arrangements

The G gamma:A gamma ratios of Hb F were determined in 331 newborn babies of the Man ethnic group in Liaoning Province, P.R. China, using polyacrylamide gel electrophoresis; in 27 cases they were also determined by reversed phase high performance liquid chromatography. The results showed that a high G gamma value (> 80%) was present in four cases (1.21%) and low G gamma values (30-48%) in six cases (1.81%); not a single case with the A gamma T [A gamma 75(E19)Ile->Thr] chain was found. Gene mapping analysis demonstrated that two babies with high G gamma values had the -G gamma-G gamma-/-G gamma-A gamma- (0.60%), and two others the -G gamma-AG gamma-A gamma-/-G gamma-A gamma- (0.60%) arrangements. Two of the four babies with low G gamma values were identified as -A gamma-A gamma-/-G gamma-A gamma- (0.60%) and the other two as -GA gamma-/-G gamma-A gamma- (0.60%). The genotype -A gamma-A gamma- has not been reported before in Chinese.

DNA repair rates mapped along the human PGK1 gene at nucleotide resolution

The repair of cyclobutane pyrimidine dimers (CPDs), DNA lesions induced by ultraviolet light, was studied at nucleotide resolution. Human fibroblasts were irradiated with ultraviolet light and allowed to repair. The DNA was enzymatically cleaved at the CPDs, and the induced breaks along the promoter and exon 1 of the PGK1 gene were mapped by ligation-mediated polymerase chain reaction. Repair rates within the nontranscribed strand varied as much as 15-fold, depending on nucleotide position. Preferential repair of the transcribed strand began just downstream of the transcription start site but was most pronounced beginning at nucleotide +140 in exon 1. The promoter contained two slowly repaired regions that coincided with two transcription factor binding sites.