Differential scanning calorimetric study of a homologous series of fully hydrated saturated mixed-chain C(X):C(X + 6) phosphatidylcholines

The successive high-resolution differential scanning calorimetric (DSC) thermograms for aqueous dispersions of a homologous series of mixed-chain phosphatidylcholines, C(X):C(X + 6)PC, have been recorded and analyzed. In this series of saturated mixed-chain phosphatidylcholines, the total number of carbon atoms in the sn-1 acyl chain increases from 11 to 20, and the sn-2 acyl chain is always 6 methylene units longer than the sn-1 acyl chain. In the initial heating DSC thermograms, two prominent endothermic transitions are detected for all the samples prepared from the various C(X):C(X + 6)PCs except C(12):C(18)PC. In contrast, a single exothermic transition is observed on cooling for all the samples except C(13):C(19)PC. The temperature difference between the two endothermic transitions increases linearly as the acyl chain length of C(X):C(X + 6)PC becomes progressively longer. Interestingly, the main phase transition occurs before the subtransition for C(11):C(17)PC dispersions. Our DSC data further demonstrate that the thermodynamic parameters (Tm, delta H, and delta S) associated with the main phase transition for fully hydrated C(13):C(19)PC and other identical MW phosphatidylcholines are inversely related to the corresponding values of the chain-length inequivalence (delta C/CL) for these lipids. This linear relationship can be employed to map the Tm values for aqueous dispersions prepared from a large number of mixed-chain phosphatidylcholines whose values of delta C/CL are within the range of 0.1-0.4.

Differential scanning calorimetry study of mixed-chain phosphatidylcholines with a common molecular weight identical with diheptadecanoylphosphatidylcholine

To examine the thermotropic phase behavior of various mixed-chain phosphatidylcholines in excess water and to compare it with the known behavior of identical-chain phosphatidylcholines, we have carried out high-resolution differential scanning calorimetric (DSC) studies on aqueous dispersions of 10 different mixed-chain phosphatidylcholines. These lipids, C(16):C(18)PC, C(18):C(16)PC, C(15):C(19)PC, C(19):C(15)PC, C(14):C(20)PC, C(20):C(14)PC, C(13):C(21)PC, C(21):C(13)PC, C(12):C(22)PC, and C(22):C(12)PC, have a common molecular weight which is the same as that of C(17):C(17)PC, an identical-chain phosphatidylcholine with a molecular weight of 762.2. When the values of any of the thermodynamic parameters (Tm, delta H, and delta S) of the mixed-chain phosphatidylcholines and C(17):C(17)PC are plotted against the normalized chain-length difference (delta C/CL), a linear function with negative slope is obtained provided that the value of delta C/CL is within the range of 0.09-0.4. The linear relationship suggests that these mixed-chain phospholipids are packed in the gel-state bilayer similar to the bilayer structure of C(17):C(17)PC at T less than Tm; however, the negative slope suggests that the conformational statistics of the hydrocarbon chain and the lateral lipid-lipid interactions of these phosphatidylcholines in the gel-state bilayer are perturbed proportionally by a progressive increase in the chain-length inequivalence between the two acyl chains within each lipid molecule. When the value of delta C/CL for mixed-chain phosphatidylcholines reaches the range of 0.44-0.55, the thermotropic phase behavior deviates markedly from that of less asymmetric phosphatidylcholines, suggesting that these highly asymmetric lipids are packed into mixed interdigitated bilayers at T less than Tm. The heating and cooling pathways of aqueous dispersions prepared from the 10 mixed-chain phospholipids are also discussed.

Antitumor agents. 111. New 4-hydroxylated and 4-halogenated anilino derivatives of 4'-demethylepipodophyllotoxin as potent inhibitors of human DNA topoisomerase II

A series of C-4 hydroxylated and halogenated anilino derivatives of epipodophyllotoxin or 4'-demethylepipodophyllotoxin have been synthesized and evaluated for their inhibitory activity against the human DNA topoisomerase II as well as for their activity in causing cellular protein-linked DNA breakage. Compounds 11-17 and 22 are more potent than etoposide in causing DNA breakage, while compounds 11-13, 15, 16, and 20 are as active or more active than etoposide in their inhibition of the human DNA topoisomerase II. The cytotoxicity in KB cells appears to have no direct correlation with their ability to inhibit DNA topoisomerase II and to cause protein-linked DNA breaks in cells.

Heritability of blood pressure in 7- to 12-year-old Chinese twins, with special reference to body size effects

Systolic and diastolic blood pressures and body-size indices such as body height, body weight, sitting height, chest circumference, skinfold thickness, and body mass index (BMI) were assessed in 110 pairs of like-sex Chinese twins (75 monozygotic and 35 dizygotic) aged 7-12 years. Significant correlations of blood pressure with body-size indices were found. Prior to adjusting for body-size effects, three twin methods yielded low heritability estimates for both systolic (0.32-0.41) and diastolic (0.32-0.51) pressures. Adjusting systolic pressure for body height and BMI via multiple regression nearly halved heritability estimates, but adjusting diastolic pressure for body height and skinfold thickness only changed the estimates slightly.

Studies of proto-oncogene expression in the chronic and blastic phases of chronic myelogenous leukemia

Chronic and blastic phase chronic myelogenous leukaemia cells have been studied by northern and Southern blot analysis. DNA from matched chronic and blastic phase cells obtained from the same patient demonstrated that the rearrangement site within the breakpoint cluster region did not change at the time of blastic crisis. A search for a mutation in a controlling region of the first exon of c-myc also failed to demonstrate any new abnormality at the time of blastic crisis. While some differences in the transcript levels for several genes (c-myc, p53, histone H3, MRS) were detected, these differences could be ascribed to differences in the proportions of immature cells during the chronic and blastic phases. The data suggested that the c-myc transcripts in blastic phase cells and in immature chronic phase cells differ in that the latter contain some c-myc transcripts that are not polyadenylated. Differences in c-myc transcript half-life could contribute to the differences in the behaviour of chronic phase and blastic phase immature cells.

Proto-oncogene expression in differentiating and non-differentiating chronic myelogenous leukaemia cells

Despite the profound differences between the chronic and blastic phases of chronic myelogenous leukaemia, no differences between chronic and blastic phase cells have been described at the molecular level. Differences have been found in the levels of expression of c-myc, c-myb and p53, which fell when chronic phase cells were cultured, while the levels of expression of the genes were stable when blastic crisis cells were cultured. In contrast c-fms expression increased and MRS expression decreased after culture of chronic or blastic phase cells. The data suggest that the regulation of expression of some genes in blastic crisis cells is unaltered while that of others is disrupted. It is not known whether the failure of c-myc, c-myb and p53 expression to fall during the culture of blastic phase cells is the cause of or a reflection of the failure of these cells to differentiate.

[Changes in histopathology and enzyme histochemistry of thymus in cadmium exposure mice]

The changes in histopathology and enzyme histochemistry of thymus induced by a single intraperitoneal injection of sublethal doses of cadmium chloride into Kunming male mice were examined. The swollen endothelium of capillaries was observed, with an obviously decreased activity of ICDH, LDH and ATPase, which seemed to be due to direct inhibition by cadmium at the 4th hour. The necroses of the cortex thymocytes were found at the 8th hour after injection and reached an extreme at the 16-24th hour, while few necroses of the lymphocytes in the medulla. Beginning 4th to 8th hour after exposure, the activity of enzymes was located in mitochondria of the cortex thymocytes, i.e., SDH, ICDH, CCO and ATPase, was decreased gradually. It suggested that thymic cortex had a marked impairment of blood supply and anoxia. Within 2 days after a single injection the cortex of the gland was mainly populated by epithelial reticular cells except a few lymphocytes. It was noted that there were some bigger cells which were characterized by their large size, basophilic cytoplasma, rough chromatin and high mitotic ability and activity of MDH, LDH, G-6-PD increased in these cells. From above observation the author concluded that the cause of cadmium-induced acute thymic atrophy was lymphocyte necroses within thymic cortex. The mechanism of the cortex thymocytes necrosis was possibly secondary to an anoxia of cortex resulting from capillary damage in the cortex. The ability of thymic regeneration is strong after being damaged. The regenerate cells possessed characteristics of morphology and enzyme histochemistry of immature cells, which probably came from the bone marrow.

Surgical treatment of congenital coronary artery fistula. Report of two cases

Two patients with congenital coronary artery fistula were treated surgically at our hospital in 1987. The fistulae originated from the left coronary artery. One patient was treated by direct ligation and the other by suture from within the left ventricle under cardiopulmonary bypass. The diagnosis and method of surgical treatment were discussed.

[Pharmacodynamics and pharmacokinetics of nifedipine in patients with congestive heart failure]

Twenty-seven cases of congestive heart failure (CHF) were treated with nifedipine (Nif) 20 mg po. Significant improvements in resting hemodynamics were found in 22 cases. The higher the basal systemic vascular resistance (SVR) and pulmonary artery end diastolic pressure (PAEDP) were, the greater the magnitudes of reduction found (r = 0.84 and 0.77, P less than 0.01, respectively). Exercise hemodynamic investigation showed that Nif led to a lowering of SVR, PAEDP and pulmonary vascular resistance (PVR), with increases in SV and concentration of 5-10 ng/ml, with a maximum being observed at the concentration of 20 ng/ml. No further vasodilation was found when the plasma concentration exceeded 20 ng/ml. No remarkable deviations from the normal ranges of Nif pharmacokinetics were found in CHF patients. The plasma norepinephrine level decreased markedly 2 and 7 h after Nif. Thus, it is concluded that oral Nif is beneficial in severe CHF patients having low cardiac output and high SVR.

Enhanced expression of the granulocyte-macrophage colony stimulating factor gene in acute myelocytic leukemia cells following in vitro blast cell enrichment

Expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene in acute myelocytic leukemia (AML) was assayed by Northern blot analysis. GM-CSF messenger RNA (mRNA) was detected in the freshly obtained mononuclear cells of only one of 48 cases of AML, in contrast with recent reports that GM-CSF mRNA might be detected in half of the cases of AML when RNA is prepared from T-cell- and monocyte-depleted leukemic cells. We did find, however, that expression of the GM-CSF gene was detectable in five of ten cases after in vitro T-cell and monocyte depletion steps. Additional studies suggest that expression of GM-CSF in the bone marrow of the one positive case, rather than being autonomous, was under exogenous control, possibly by a paracrine factor secreted by marrow stromal cells. These studies emphasize the potential for altering in vivo patterns of gene expression by in vitro cell manipulation.

Amplitude-compensated matched filtering

A method of amplitude-compensated matched filtering is presented. This yields much better discrimination and a sharper autocorrelation peak compared with the classical matched spatial filter and the phase-only one. By computer simulation in the case of alphanumeric characters, it is concluded that, although the phase information is significantly more important, in the case of a matched filter, the amplitude is important too. Three-dimensional graphs of autocorrelation and cross-correlation are also provided.

Assessment of the glucose tolerance test in unselected pregnancy using 75 g glucose load

A 75 g oral glucose tolerance test (OGTT) was performed in 618 unselected pregnant Chinese women between 24 and 28 weeks gestation. The glucose response at fasting, 1, 2 and 3 h were studied. At 2 h the glucose level at 2-standard deviation and 4-standard deviation above the mean came very close to the criteria of abnormality suggested by the World Health Organization (WHO): 8.3 mmol/l vs. 8.0 mmol/l for impaired glucose tolerance and 10.8 mmol/l vs. 11.0 mmol/l for gestational diabetes mellitus. The area under the glucose response curve also correlates best with the glucose levels at 2 h during the OGTT (y = 2.1x + 4.6, r = 0.885). The 75-g OGTT interpreted with the WHO criteria seems appropriate for pregnant Chinese women. The 75-g test has the added advantages of reducing administration cost and discomfort of the patients.

Color-image correlation with a multiwavelength Fresnel holographic filter

Theoretical and experimental analyses of color-image pattern recognition using a multiwavelength Fresnel holographic filter (FHF) are presented. The FHF technique permits a greatly relaxed spatial-filter alignment requirement, use of a white-light source, negligible color cross talk, and high diffraction efficiency of the spatial filter.

Rainbow holography of 3-D diffuse objects with HOE/MEHL

A new technique of one-step rainbow holography with a multiexposure holographic lens (MEHL) is described. The synthesization of the slitlike function in the object wave can be performed with the specially fabricated holographic lens. The MEHL can also be applied to the oriented speckle encoding of images in white-light optical image processing. Successful experimental results are presented.

[Establishment of epithelial cell line TBC-27 from a human bladder transitional cell carcinoma and its biological characteristics]

The cell line TBC-27, from a human bladder transitional cell carcinoma Grade II, was established and maintained for 8 months through 27 passages. TBC-27 cells have the epithelioid cell morphology during culture. The population doubling time of the 14th generation cells was 27 hours by growth curve. The chromosome karyotype of the 12th generation cells consisted mainly of hypodiploid (mode 40-45). Ultrastructurally, there was a great deal of freeribosome and vesicle in the cytoplasm and a great number of atypical microvilli on the surface of the 21st generation cells. The heterotransplantation test revealed that the xenografted tumor in the immunosuppressed suckling rats was similar to the initial bladder carcinoma in histology.

Propagation of hepatitis A virus in human diploid fibroblast cells

Human hepatitis A virus (HAV) was propagated in human diploid fibroblast cultures (2BS cells) in vitro. Replication of the virus was followed by immunofluorescent staining (IF), indirect ELISA, and by immune electron microscopy. When 2BS cells were inoculated with faecal extracts containing HAV, synthesis of hepatitis A antigen (HAAg) could be detected in the cytoplasm by IF. Its concentration reached a maximum at four weeks post-inoculation. Measured by solid-phase indirect ELISA, the positive/negative (P/N) ratio for HAAg reached values of up to 7.7. The identity of newly synthesized virus particles with HAV was established by immune electron microscopy, IF-blocking, and neutralization with human convalescent serum. Infected cells showed no signs of a specific cytopathic effect. Two of the virus strains propagated in 2BS cells may prove useful as a source of antigen for serologic tests; one of them might be a candidate strain for HAV vaccine.

[Cultivation of urologic and male genital tumor cells]

Thirty specimens from 30 patients with urologic and male genital system tumors were cultured. Eighteen (60%) showed initial cell growth. Four (13%) were successful in primary culture. In a renal cell carcinoma and a bladder transitional cell carcinoma, the subcultures were successful after the primary culture. In eight months, having transferred the former for twelve generations and the latter for twenty-seven generations, these two cell lines are established. The morphological characters of the cultured cells, eradication of fibroblasts, conditions of culture and prevention of contamination are discussed.

White-light image processing using oriented speckle-screen encoding

We present a new technique of spatially oriented speckle-screen encoding to improve on the grating encoding technique for white-light image processing.