Liposome-encapsulated hemoglobin processing methods

An effective and safe red blood cell substitute is being developed based on double emulsion/evaporation techniques followed by high pressure homogenization to form liposome-encapsulated hemoglobin (LEH). Formulations are made up of hydrogenated phosphatidylcholine (PC, soy or egg), cholesterol, phosphatidylinositol (PI), and alpha-tocopherol in a molar ratio of 1:1:0.2:0.02, respectively. Resulting LEH-encapsulated hemoglobin (Hb) concentrations are greater than 80% of precursor Hb solutions. Met-Hb generation accompanying LEH processing appears to be small with only a 3% increase for encapsulated over precursor. These results correspond to an oxygen content for an LEH suspension sample (50% by volume LEH) of 15 volume% oxygen. Oxygen affinity and cooperativity values for LEH suspensions appear to be near the normal values expected for whole blood. The viscosity of LEH suspension samples (50% by volume LEH in phosphate-buffered saline containing 7.5 wt% albumin) were slightly higher than that of whole blood. The effect of shear rate on leakage of encapsulated Hb from LEH was small, i.e. 0.5% or less. Nearly total isovolemic exchange transfusion using a cannulated rat model demonstrates efficacy of LEH suspension samples. There appears to be no difference in rat internal organ weights between rats exchanged with control compared to rats exchanged with LEH. Circulation half-life following 50% isovolemic exchange-transfusion is about 15 to 18 hours.

Synthesis and Characterization of a Series of Liquid Crystal Monomers Containing a Novel Spacer Group Based on Vinylacetic Acid

A series of liquid crystal monomers with side chains involving a vinylacetic acid unit have been prepared, and their thermal and optical properties compared with those of related compounds containing the same mesogenic unit but a conventional polymethylene spacer group based on a terminal alkene.

[The screening model for early diagnosis of colorectal cancer in general population]

In this study, 75,813 asymptomatic individuals above 30 in Jiashan County of Zhejiang Province were recruited in the screening program. Based on results of risk assessment using a mathematical model (expressed as AD value) and Reverse Passive Hemagglutination Fecal Occult Blood test (RPHA FOB). 62,667 subjects (82.7%) who completed two procedures were divided into 4 groups: 1) AD greater than or equal to 0.3 FOB (+) accounts for 1.2% of total; 2) AD less than 0.3 FOB (+) 3.0%; 3) AD greater than or equal to 0.3 FOB (-) 26.8%; 4) AD less than 0.3 FOB (-) 68.9%. Individuals in groups 1 and 2 were subjected to 60 cm fiberoptic colonoscopic examination; and those of group 3 with AD greater than or equal to 0.5 or with AD less than 0.5 but a positive repeated FOB test was also eligible for 60 cm colonoscopy. Out of 4,299 eligible subjects 3,162 were examined with 60 cm sigmoidoscopy (73.6%). 21 cases of colorectal cancer and 331 cases of polyps (including 75 adenomas) were detected. Among 21 cancers known of Dukes' stages 10 were at early stages (10 Dukes' A and 5 Dukes' B) accounting for 71.5%. According to the screening protocol individuals with negative 60 cm colonoscopic findings and consistently positive FOB results indicate that the lesion may be located above the spleen flexure and require a full fiberoptic colonoscopic examination (150 cm) and/or x-ray air-barium enema.

[Steroidal constituents from Saussurea gossypiphora D. Don]

Four steroids were isolated from the Saussurea gossypiphora for the fist time. They were determined as 3-stigmastanol, beta-sitosterol, stigmast-7-en-3-ol and ergostan-3,24-diol by spectral and chemical methods.

Reproductive factors and colorectal cancer risk among Chinese females

We report results from a population-based case-control study of colorectal cancer among Chinese women in western North America (NA) and the People's Republic of China (China). A common protocol was used to assess reproductive characteristics and hormone use of 395 Chinese women (189 from NA and 206 from China) with cancer of the colon or rectum and of 1112 age-matched Chinese controls (494 from NA and 618 from China). In NA, risks for cancers of both the colon and rectum were lower among parous compared to nulliparous women (odds ratio for colorectal cancer, 0.6, P = 0.08), but the trend in risk was not smooth with increasing number of livebirths. This association with parity was absent for both cancer sites in China. There were no consistent patterns in the relationships between other reproductive factors (including age at menarche, age at first livebirth, menopausal status) and risk of colon and rectal cancer on either continent.

[Dynamic observation on the incidence and mortality rates of the nasopharyngeal carcinoma (NPC) in Zhongshan City 1970-1984]

The standardized incidence rate of NPC was 14.44/10(5) (male 20.31/10(5), female 8.95/10(5] and the standardized mortality rate was 10.91/10(5) (male 16.00/10(5), female 6.14/10(5] in Zhongshan city during 1970-1984. The fluctuation of incidence and mortality rates were 13.66-18.07/10(5) and 9.02-13.95/10(5) respectively. It was worthy to be mentioned that both the incidence and mortality rate of NPC were relatively stable in 1970-1984.

[Estrogen receptor content in human embryo]

Estrogen receptor (ER) content was measured in 27 human embryos, aged 3 to 7 months, with 17-fluoreceinated estrone (17-FE). ER was demonstrated in a uneven distribution pattern in most human embryonic organs. Most embryonic uteri and livers and a few lungs, stomachs and spleens were ER positive. The ER gradually increased with embryonic development in target organs such as the uterus, ovary and testes, as well as in some non-target areas such as mouth and upper digestive system. The ER decreased with embryonic development in the lower digestive system and were maintained at a low level in the lung, heart, brain and lymphoid organs. In the early embryo (3 to 4 months) the ER positive cells (A, B and C type) accounted for a greater proportion of embryonic cells than they did in the late embryonic period (5 to 7 months). The A and B type cell counts fell to the lowest point in the fifth month and increased again in the sixth month. The C and D type cells reached the lowest point in the fourth month in non-target organs but the D type cells then dramatically increased in the uterus, testes and liver. It was suggested that ER play an important role in human embryonic development and differentiation. The ER may influence proliferative ability of early embryonic organs and the late hormone-specific organ growth.

Diet, physical activity, and colorectal cancer among Chinese in North America and China

In a population-based case-control study of colorectal cancer among Chinese men and women in western North America and the People's Republic of China, a common protocol was used to assess past life-style characteristics of 905 cases diagnosed during 1981-1986 and 2,488 controls. Risks for cancers of both the colon and rectum increased with increased food energy from fat, protein, carbohydrate, and all energy sources combined, for both sexes and on both continents. Yet, in multivariate analysis, colorectal cancer risk was significantly associated only with saturated fat; no relationships were seen with other dietary sources of energy. Colon cancer risk was elevated among men employed in sedentary occupations. On both continents and in both sexes, risks for cancers of both the colon and rectum increased with increasing time spent sitting. Further, the association between colorectal cancer risk and saturated fat was stronger among the sedentary than among the active. Risk among sedentary Chinese Americans of either sex increased more than fourfold from the lowest to the highest category of saturated fat intake. Among migrants to North America, risk increased with increasing years lived in North America. These observations suggest (a) that colorectal cancer risk increases with duration of exposure to a sedentary life-style and a diet rich in saturated fat; (b) that higher incidence among Chinese-American men relative to women is due to longer duration of these habits among men, who have lived longer in North America; and (c) that higher risk among Chinese Americans of both sexes relative to risk among the general population in China is due to differences in such habits. Attributable risk calculations suggest that, if these associations are causal, saturated fat intakes exceeding 10 g/day, particularly in combination with physical inactivity, could account for 60% of colorectal cancer incidence among Chinese-American men and 40% among Chinese-American women.

Secondary structure of pig skin proteodermatan sulfate: a perspective from Raman spectroscopic studies in aqueous solution

Raman spectroscopic studies of pig skin proteodermatan sulfate in H2O are indicative of a well defined secondary structure consisting of alpha-helical, beta-turn, and possibly "random" structures. The above conclusion is surprisingly close to the secondary structure of the "core" protein of pig skin proteodermatan sulfate proposed in the previous paper (V. Renugopalakrishnan et al., Biopolymers 28, 1923-1933, 1989) from FT-IR and CD spectroscopic studies in aqueous solution.

Cultivation and partial characterization of bovine astrovirus

Bovine astrovirus serotype 2 (US2) was adapted to primary neonatal kidney cell (NBK) cultures by the addition of 50 micrograms ml-1 of trypsin in the medium. Infectious virus was released from the cells within 7 days post-infection in early passages and within 3 days in later passages. In the absence of trypsin, neither passage of infected cells nor release of infectious virus occurred. The virus was shown to be similar to the fecal astrovirus by a neutralization test and by ultrastructural studies of infected cells. Primary embryo bovine kidney (EBK) and NBK cell cultures supported infection with both fecal and tissue culture adapted (TCA) astrovirus. The time-related development of infection, as studied by immunofluorescence, was similar for both fecal and TCA astrovirus and for both cell culture types. The first indication of viral infection and expression of viral antigens occurred at 7 h post-infection and was characterized by the appearance of a diffuse faint immunofluorescence (IF) of the cytoplasm. Soon after, two or three brilliant IF granules were observed in the nucleus, which appeared to involve the nucleoli. Subsequently, dense granular IF was seen in the perinuclear region of the cytoplasm, which later extended to involve all the cytoplasmic area. In both EBK and NBK cultures infected with either fecal or tissue culture adapted astrovirus, only a minority of cells became infected, even when the multiplicity of infection exceeded one. Occasionally 10-20% of cells were infected, but in most cultures the proportion did not exceed 2% and in NBK cultures, from 3/9 calves, no infected cells were observed. The virus did not infect bovine cell lines. Infectivity of the virus was not removed by treatment with chloroform, and iododeoxyuridine and actinomycin D when added to the medium, did not block replication. Masses of virions were observed by electron microscopy in discrete areas in the cytoplasm, with similar distributions as the viral antigen foci as seen by IF. The mean diameter of the virions was 34 nm. In conclusion, bovine astrovirus lacks both essential lipids and an envelope, probably has an RNA genome, may have a nuclear phase of replication involving the nucleoli which is not blocked by DNA inhibitors, and has a selective cell tropism.

Studies on rotavirus homologous and heterologous active immunity in infant mice

Homologous and heterologous active immunity was studied in mice with mammalian group A rotaviruses. One day old mice were vaccinated with one of the following rotaviruses: bovine B641 (serotype 6), bovine B223 (untyped), simian SA11 (serotype 3) and murine EDIM (untyped). At 10 days of age they were challenged with EDIM virulent virus or SA11 virus. All the vaccines induced a serological antibody response in the mice but only the homologous immune response was protective.

Radioprotection of DNA by thiols: relationship between the net charge on a thiol and its ability to protect DNA

Release of free bases from calf thymus DNA upon irradiation in aerated 0.1 mol dm-3NaClO4 at pH 7 has been measured by HPLC and shown to be markedly influenced by the presence of thiols during irradiation. The ability of thiols to protect DNA was shown to depend upon the net charge (Z) at pH 7 in the order WR 1065 (Z = +2) greater than cysteamine (Z = +1) greater than 2-mercaptoethanol (Z = 0) approximately equal to dithiothreitol (Z = 0) greater than GSH (Z = -1) approximately equal to 2-mercaptoethanesulfonic acid (Z = -1) approximately equal to 2-mercaptosuccinate (Z = -2). A similar dependence of protection upon net charge was found for disulfides: cystamine (Z = +2) greater than 2-mercaptoethyl disulfide (Z = 0) greater than GSSG (Z = -2). Protection by WR 1065, but not by 2-mercaptoethanol or GSH, was found to decrease significantly with increasing ionic strength. Protection by WR 1065 and GSH was not markedly dependent upon pH between pH 6 and 8. The results are explained in terms of electrostatic interaction of the thiols with DNA, leading to high concentrations of cations near DNA, which allow them to scavenge hydroxyl radicals and repair DNA radicals effectively and to low concentrations of anionic thiols near DNA, which limit their effectiveness as protectors. Poly(dG,dC) and calf thymus DNA exhibited comparable release of G and C upon changing from 0.1 to 0.7 mol dm-3 MgSO4. Since this change causes poly(dG,dC), but not calf thymus DNA, to undergo a change from the B-form to the Z-form of DNA, both forms must have a comparable susceptibility to radiation-induced base release.

A randomized comparative clinical evaluation of the Steel Ring, the VCu200 and the TCu220c IUDs

A randomized comparative clinical study of the Steel Ring, VCu200 and TCu220c IUDs was carried out in Beijing. Six-hundred subjects were recruited and each group of 200 was inserted with one of the three devices. The TCu220c and the VCu200 had statistically significantly lower pregnancy and expulsion rates at one and two years of use than the Steel Ring. However, the Steel Ring consistently had the lowest rate of removal for pain and/or bleeding. At two years, the early differences of use-related discontinuation and continuation between the higher rates of the Steel Ring and the lower rates of the VCu200 and TCu220c were significantly reduced. There were no statistically significant differences of net event rates between VCu200 and TCu220c.

[Estrogen receptor (ER) of breast cancer cells. II. Quantitative analysis of breast cancer cells bound with fluoresceinate-ER]

In order to express the quantitative value by the cytochemical method, the breast cancer cells of 41 human and 7 C3H mice were used. The condition of ER was detected by cytochemical (17-fluoresceinated estrone, 17-FE) and biochemical (dextran-coated charcoal, D. C. C.) methods. The relative weight (theta) of each type of cells and the coefficient were obtained by the statistical estimation technique and mathematical modeling. The relative weights of type A, B and C (theta 1, theta 2 and theta 3) were 4.4, 2.8 and 1.8 in human tumor, and 1.9, 0.3 and 1.3 in mouse tumor. The same quantitative unit of value (fmol/mg) can be expressed by the cytochemical method as by the biochemical method. The inadequacies of both methods are presently brought to light. By the D. C. C. method, only about half of the ER in cytosol can be detected and those in the nucleus can not be assayed. By the 17-FE method, it is possible to detect the ER status not only morphologically but also quantitatively.

Colorectal cancer in Chinese and Chinese-Americans

Rationale and plans are described for a collaborative case-control study of large bowel cancer among Chinese-Americans in Los Angeles and the San Francisco Bay Area and among Chinese in Zhejiang Province, People's Republic of China. A common protocol and questionnaire will be used during personal interviews of approximately 400 Chinese and 300 Chinese-American patients with histologically confirmed adenocarcinoma of the colon or rectum and 2,100 Chinese and Chinese-American controls. Controls will be matched to patients on age, sex, and community of residence. The information requested from subjects will permit testing of hypotheses relating colorectal cancer risk to: dietary factors, including intake of fat (saturated and unsaturated), animal protein, fiber, and vitamins A and E and ascorbic acid; physical activity levels and body mass index; reproductive factors among women; history of bowel disease; and family history of cancer. The information requested of Chinese-American subjects will also permit testing of hypotheses relating cancer risk to such migrant factors as United States versus Chinese nativity, duration of residence in the United States, and Chinese province of ancestry. These factors will be tested for associations with cancers of the colon and rectum separately and with cancers of the large intestine as a whole. We will examine sex and geographic differences in relative risks for etiologic factors, location of tumors within the large bowel, histologic subtype of adenocarcinoma, and frequency of accompanying polyps.

[Estrogen receptor (ER) status of breast cancer cells. I. Classification of breast cancer cells bound with fluoresceinate-estrogen]

Based on the location and intensity of fluoresceinate-estradiol or 17-fluoresceinate-estrone bound to breast cancer cells, the estrogen receptor (ER) status of breast cancer cells were classified into A. B. C. D and E types. The type A was the entire cell marked with fluorescent brightness, B was nucleus marked with fluorescence but not the cytoplasm, C was cytoplasm but not the nucleus, D was only the nucleolus concentrated with fluorescence and type E was very faint fluorescence presented in the entire cell. Types A, B and C were taken as positive, and the others negative. Twenty human breast cancer cells bound with fluoresceinate-estradiol were evaluated by computer image processing technique and it was demonstrated that each of the five types of cells could be identified. The instant and contiguous observation after dropped the 17-fluoresceinate-estrone demonstrated the simultaneous presence of all these five types of cells. The breast cancer cells bound with fluorescence light the distribution of ER within a cell and, hence, the possibility of morphologic and biologic investigation of ER.