A role of interferon-gamma (IFN-gamma) in tumor immunity: T cells with the capacity to reject tumor cells are generated but fail to migrate to tumor sites in IFN-gamma-deficient mice

IFN-gamma-deficient (IFN-gamma-/-) mice induce potent in vitro immune responses such as anti-allo mixed lymphocyte reaction and CTL responses, whereas they often fail to exhibit in vivo immunity. Here, we investigated whether there exists a defect in tumor rejection responses and if so, which process of responses is impaired. IFN-gamma-/- and wild-type (WT) BALB/c mice were immunized with attenuated syngeneic CSA1M tumor cells. The capacity of T cells to mediate tumor protection was examined in Winn assays to assess the growth of tumor cells admixed with tumor-sensitized T cells. Splenic T cells from both groups of mice exhibited comparable levels of tumor-neutralizing activity. When portions of immunized mice were directly challenged with viable tumor cells, tumor rejection was induced only in WT mice. CD4(+) and CD8(+) T-cell infiltration were observed at the site of tumor challenge in WT mice, whereas such a T-cell infiltration did not occur in IFN-gamma-/- mice. Similarly, splenic T cells from interleukin 12-treated CSA1M-bearing IFN-gamma-/- and WT mice neutralized tumor cells at comparable efficacies in Winn assays. However, the migration of these T cells to tumor masses and the resultant interleukin 12-induced tumor regression took place in WT mice, but neither intratumoral T-cell infiltration nor tumor regression occurred in IFN-gamma-/- mice. These results indicate a critical requirement for IFN-gamma in the process of inducing T-cell migration to tumor sites rather than of generating antitumor protective T cells.

Development of a novel immunoradiometric assay exclusively for biologically active whole parathyroid hormone 1-84: implications for improvement of accurate assessment of parathyroid function

We developed a novel immunoradiometric assay (IRMA; whole parathyroid hormone [PTH] IRMA) for PTH, which specifically measures biologically active whole PTH(1-84). The assay is based on a solid phase coated with anti-PTH(39-84) antibody, a tracer of 125I-labeled antibody with a unique specificity to the first N-terminal amino acid of PTH(1-84), and calibrators of diluted synthetic PTH(1-84). In contrast to the Nichols intact PTH IRMA, this new assay does not detect PTH(7-84) fragments and only detects one immunoreactive peak in chromatographically fractionated patient samples. The assay was shown to have an analytical sensitivity of 1.0 pg/ml with a linear measurement range up to 2,300 pg/ml. With this assay, we further identified that the previously described non-(1-84)PTH fragments are aminoterminally truncated with similar hydrophobicity as PTH(7-84), and these PTH fragments are present not only in patients with secondary hyperparathyroidism (2 degrees -HPT) of uremia, but also in patients with primary hyperparathyroidism (1 degrees -HPT) and normal persons. The plasma normal range of the whole PTH(1-84) was 7-36 pg/ml (mean +/- SD: 22.7 +/- 7.2 pg/ml, n = 135), whereas over 93.9% (155/165) of patients with 1 degrees -HPT had whole PTH(1-84) values above the normal cut-off. The percentage of biologically active whole PTH(1-84) (pB%) in the pool of total immunoreactive "intact" PTH is higher in the normal population (median: 67.3%; SD: 15.8%; n = 56) than in uremic patients (median:53.8%; SD: 15.5%; n = 318; p < 0.001), although the whole PTH(1-84) values from uremic patients displayed a more significant heterogeneous distribution when compared with that of 1 degrees -HPT patients and normals. Moreover, the pB% displayed a nearly Gaussian distribution pattern from 20% to over 90% in patients with either 1 degrees-HPT or uremia. The specificity of this newly developed whole PTH(1-84) IRMA is the assurance, for the first time, of being able to measure only the biologically active whole PTH(1-84) without cross-reaction to the high concentrations of the aminoterminally truncated PTH fragments found in both normal subjects and patients. Because of the significant variations of pB% in patients, it is necessary to use the whole PTH assay to determine biologically active PTH levels clinically and, thus, to avoid overestimating the concentration of the true biologically active hormone. This new assay could provide a more meaningful standardization of future PTH measurements with improved accuracy in the clinical assessment of parathyroid function.

IL-12 as well as IL-2 upregulates CCR5 expression on T cell receptor-triggered human CD4+ and CD8+ T cells

The expression of chemokine receptors on leukocytes is related to their activation state. However, the exact mechanism underlying the induction of each chemokine receptor is poorly understood. Here, we investigated how CCR5, a chemokine receptor implicated in T cell trafficking and HIV infection, is induced in human T cells. CCR5 was marginally detected on a freshly prepared human peripheral blood mononuclear cell (PBMC) population. Long-term (8-day) stimulation of PBMC with IL-2 resulted in high levels of CCR5 expression on T cells. IL-12 failed to induce CCR5 on T cells in such a directly stimulated PBMC population. Stimulation of PBMC T cells with anti-CD3 plus anti-CD28 induced detectable albeit very low levels of CCR5 along with the induction of IL-12 receptor. However, these TCR-triggered T cells expressed much higher levels of CCR5 when stimulated with IL-12. Although IL-2 also induced CCR5 expression, CCR5 expression was more potent in IL-12 than IL-2 stimulation. These results indicate that, in addition to IL-2, IL-12 plays an important role in the induction of CCR5 expression on T cells, particularly TCR-triggered T cells.

Activity of the botanical aphicides 1,5-diphenyl-1-pentanone and 1,5-diphenyl-2-penten-1-one on two species of Aphididnae

1,5-Diphenyl-1-pentanone (A) and 1,5-diphenyl-2-penten-1-one (B) are natural products extracted for the first time from Stellera chamaejasme. Laboratory bioassay showed that the two products have strong contact activity and very good anti-feedant activity against Aphis gossypii and Schizaphis graminum. Both products showed dose-dependent relationships for both forms of activity against the two aphids, the contact activity of B being about twice that of A. Both products were inferior to methomyl in contact activity but superior in anti-feedant activity against the two aphids. This is the first report of aphicidal activity in these two compounds, which may represent a new class of aphicide.

[Study of fungus polysaccharides compounds (FPC) in inducing the apoptosis of liver cancer cell Bel-7402]

To observe the influence of fungus polysaccharides compounds (FPC) in inducing human liver cancer cell Bel-7402 apoptosis in cell cultivating in vitro, the authors analyzed tumor inhibitive gene P53 expression in Bel-7402 apoptosis by applying double immuno-marker. The result showed that the multilevel of FPC could all apparently induce Bel-7402 apoptosis. With the enhancement of FPC concentration, the authors observed chromatin condensation in some phases companying with the characteristic apoptosis. In the meantime, it could also greatly reduce the G1 and S, with obviously dose-response relationship. The percentage of cell apoptosis increased with the enhancing of concentration. In the high-level group the authors found typical DNA ladder eletrophoresis stripe. The result showed that the mechanism of the FPC antineoplastic effect had an intimate relation with its induction to apoptosis and that the result of FPC inducing tumor cell apoptosis had the character of P53 independence.

Exposure to silica and silicosis among tin miners in China: exposure-response analyses and risk assessment

OBJECTIVES

To investigate the risk of silicosis among tin miners and to investigate the relation between silicosis and cumulative exposure to dust (Chinese total dust and respirable crystalline silica dust).

METHODS

A cohort study of 3010 miners exposed to silica dust and employed for at least 1 year during 1960-5 in any of four Chinese tin mines was conducted. Historical total dust data from China were used to create a job exposure matrix for facility, job title, and calendar year. The total dust exposure data from China were converted to estimates of exposure to respirable crystalline silica for comparison with findings from other epidemiological studies of silicosis. Each worker's work history was abstracted from the complete employment records in mine files. Diagnoses of silicosis were based on 1986 Chinese pneumoconiosis Roentgen diagnostic criteria, which classified silicosis as stages I-III-similar to an International Labour Organisation (ILO) classification of 1/1 or greater.

RESULTS

There were 1015 (33.7%) miners identified with silicosis, who had a mean age of 48.3 years, with a mean of 21.3 years after first exposure (equivalent to 11.0 net years in a dusty job). Among those who had silicosis, 684 miners (67.4%) developed silicosis after exposure ended (a mean of 3.7 years after). The risk of silicosis was strongly related to cumulative exposure to silica dust and was well fitted by the Weibull distribution, with the risk of silicosis less than 0.1% when the Chinese measure of cumulative exposure to total dust (CTD) was under 10 mg/m(3)-years (or 0.36 mg/m(3)-years of respirable crystalline silica), increasing to 68.7% when CTD exposure was 150 mg/m(3)-years (or 5.4 mg/m(3)-years of respirable crystalline silica). Latency period was not correlated to the risk of silicosis or cumulative dose of exposure. This study predicts about a 36% cumulative risk of silicosis for a 45 year lifetime exposure to these tin mine dusts at the CTD exposure standard of 2 mg/m(3), and a 55% risk at 45 years exposure to the current United States Occupational Safety and Health Administration and Mine Safety and Health Administration standards of 0.1 mg/m(3) 100% respirable crystalline silica dust.

CONCLUSIONS

A clear exposure-response relation was detected for silicosis in Chinese tin miners. The study results were similar to most, but not all, findings from other large scale exposure-response studies.

Tumor vaccination that enhances antitumor T-cell responses does not inhibit the growth of established tumors even in combination with interleukin-12 treatment: the importance of inducing intratumoral T-cell migration

Interleukin-12 (IL-12) treatment is effective in the CSA1M but not in the Meth A and CSA1M-variant tumor models. The authors investigated the cause by which IL-12 treatment fails to induce tumor regression in these two tumor models. T cells from CSA1M-bearing mice have high levels of IL-12 responsiveness, whereas cells from Meth A-bearing mice display marginal levels of responsiveness. Because IL-12 responsiveness in T cells is induced after T-cell receptor stimulation, the lack of IL-12 responsiveness suggests that T cells in Meth A-bearing mice are not sensitized to Meth A tumor antigen. Immunization of normal mice with attenuated Meth A tumor cells resulted in a protective immunity, as shown by the rejection of challenged viable Meth A cells. Such an immunization, when performed in Meth A-bearing mice, induced potent IL-12 responsiveness in T cells. Nevertheless, IL-12 treatment in these mice did not inhibit tumor growth. In another IL-12-incurable (CSA1M-variant) model, IL-12 responsiveness was observed before tumor cell immunization. However, IL-12 treatment was ineffective regardless of whether tumor cell immunization was performed. In these two models, the failure of IL-12 treatment to induce tumor regression was associated with the lack of T-cell migration to tumor sites. These results indicate that the sensitization of T cells to tumor antigens and generation of IL-12 responsiveness are insufficient to induce tumor regression when these sensitized T cells are not allowed to migrate to tumor sites.

Quorum-sensing signal binding results in dimerization of TraR and its release from membranes into the cytoplasm

Promoter binding by TraR and LuxR, the activators of two bacterial quorum-sensing systems, requires their cognate acyl-homoserine lactone (acyl-HSL) signals, but the role the signal plays in activating these transcription factors is not known. Soluble active TraR, when purified from cells grown with the acyl-HSL, contained bound signal and was solely in dimer form. However, genetic and cross-linking studies showed that TraR is almost exclusively in monomer form in cells grown without signal. Adding signal resulted in dimerization of the protein in a concentration-dependent manner. In the absence of signal, monomer TraR localized to the inner membrane while growth with the acyl-HSL resulted in the appearance of dimer TraR in the cytoplasmic compartment. Affinity chromatography indicated that the N-terminus of TraR from cells grown without signal is hidden. Analysis of heterodimers formed between TraR and its deletion mutants localized the dimerization domain to a region between residues 49 and 156. We conclude that binding signal drives dimerization of TraR and its release from membranes into the cytoplasm.

In vitro expression of Penicillium janthinellum cellobiohydrolase I gene in a coupled transcription-translation system

An enzymatically-active fungal cellobiohydrolase I (CBH I) was first synthesized in a coupled reticulocyte lysate system lacking of glycosylation modification by the template DNA(Cbh1) in the presence of T7 RNA polymerase. The synthesized CBH I had the expected size (57 kDa) and catalyzed the substrate of p-nitrophenyl-beta-D-cellobioside (pNPC), and had no activity against carboxymethyl cellulose (CMC-Na). The K(m) and V(max) values of the CBH I for pNPC were 0.82 mmol and 0.067 micromol min(-1) per microg enzyme, respectively. The results indicated that glycosylation may not be necessary for enzymatic activity of fungal cellulases.

Risk factors for development of diabetes mellitus in women with a history of gestational diabetes mellitus

OBJECTIVE

To determine whether diabetes recurs in their later life when women have a history of gestational diabetes mellitus (GDM) or abnormal glucose tolerance test (impaired glucose tolerance, IGT).

METHODS

Three groups of women were investigated at 5-10 years postpartum. GDM group (n = 45) had been diagnosed as having GDM in their previous pregnancy. IGT group (n = 31) had a history of abnormal glucose tolerance test during previous pregnancy. Normal control group (n = 39) was normal previous pregnant population. Their previous obstetric and medical histories were thoroughly reviewed. Fasting plasma glucose (FPG) and oral glucose (75 g) tolerance test (OGTT) were repeated in all women.

RESULTS

Diabetes mellitus (DM) was diagnosed in 33.3% of patients in the GDM group, while in 9.7% in the IGT group and in 2.6% in the normal control group. Incidence of recurring DM in later life was significant higher in the GDM group (P = 0.017). When one or more blood glucose values exceeding WHO criteria for diagnosis of diabetes in their previous pregnancy, the incidence of DM in later life was 60% (3/5, including GDM in women having four abnormal OGTT values), 41.7% (5/12) in women having three, 25% (7/28) in women having two and 9.7% (3/31) in women having one. The women with DM, also with a history of GDM and abnormal OGTT in previous pregnancy, tends to have a high pregnant body mass index (BMI > 25 kg/m2).

CONCLUSION

The women suffering from GDM during previous pregnancy have a high risk of recurrence DM. Two or more abnormal OGTT values during pregnancy, blood glucose level exceeding the maximal values at 1 and 2 hours after oral glucose loading and high pregnant BMI are concluded to be useful factors in predicting the recurring DM in their later life.

[Effect of haidonghua powder(HDHP) on hypothalamic obesity in rats]

OBJECTIVE

To study the effect of HDHP including Laminaria japonica Aresch. and Benincasa hispida(Thunb.) Cogn. etc. on antiobesity in rats with hypothalamic obesity.

METHOD

A rat model of hypothalamic obesity induced by MSG was used and the relative indexes was observed.

RESULT

HDHP(2.5 g.kg-1) could significantly reduce the Lee's index as well as the size of fat cells. HDHP did not influence the serum levels of T3 and T4, insulin and aldosterone, did not inhibited appetite not led to diarrhea.

CONCLUSION

HDHP has the effect of anti-obesity, Without any influencing on the function of thyroid gland and metabolism of water and salt. The mechanism is related to the reduction of fat cell size and the accumulation of fat.

A novel mechanism for skeletal resistance in uremia

BACKGROUND

In treating secondary hyperparathyroidism, the target level of serum intact parathyroid hormone (I-PTH) should be three to five times normal to prevent adynamic bone disease. In circulation, there is a non-(1-84) PTH-truncated fragment, likely 7-84, which, in addition to PTH 1-84, is measured by most I-PTH immunoradiometric (IRMA) assays, giving erroneously high I-PTH values. We have developed a new IRMA assay in which the labeled antibody recognizes only the first six amino acids of the PTH molecule. Thus, this new IRMA assay (Whole PTH) measures only the biologically active 1-84 PTH molecule.

METHODS

Using this new IRMA assay (Whole PTH) and the Nichols "intact" PTH assay, we compared the ability of each assay to recognize human PTH (hPTH) 1-84 and hPTH 7-84 and examined the percentage of non-1-84 PTH in circulation and in parathyroid glands. Possible antagonistic effects of the 7-84 PTH fragment on the biological activity of 1-84 PTH in rats were also tested.

RESULTS

In 28 uremic patients, PTH values measured with the Nichols assay, representing a combined measurement of both hPTH 1-84 and hPTH 7-84, were 34% higher than with the Whole assay (hPTH 1-84 only); the median PTH was 523 versus 318 pg/mL (P < 0.001). Similar results were found in 14 renal transplant patients. In osteoblast-like cells, ROS 17.2, 1-84 PTH (10-8 mol/L) increased cAMP from 18.1 +/- 1.25 to 738 +/- 4.13 mmol/well. Conversely, the same concentration of 7-84 PTH had no effect. In parathyroidectomized rats fed a calcium-deficient diet, 7-84 PTH was not only biologically inactive, but had antagonistic effects on 1-84 PTH in bone. Plasma calcium was increased (0.65 mg/dL) two hours after 1-84 PTH treatment, while 7-84 PTH had no effect. When 1-84 PTH and 7-84 PTH were given simultaneously in a 1:1 molar ratio, the calcemic response to 1-84 PTH was decreased by 94%. In normal rats, the administration of 1-84 PTH increased renal fractional excretion of phosphate (11.9 to 27.7%, P < 0.001). However, when 1-84 PTH and 7-84 PTH were given simultaneously, the 7-84 PTH decreased the phosphaturic response by 50.2% (P < 0.005). Finally, in surgically excised parathyroid glands from six uremic patients, we found that 44.1% of the total intracellular PTH was the non-PTH (1-84), most likely PTH 7-84.

CONCLUSION

In patients with chronic renal failure, the presence of high circulating levels of non-1-84 PTH fragments (most likely 7-84 PTH) detected by the "intact" assay and the antagonistic effects of 7-84 PTH on the biological activity of 1-84 PTH explain the need of higher levels of "intact" PTH to prevent adynamic bone disease.

Estimating factors to convert Chinese 'Total Dust' measurements to ACGIH respirable concentrations in metal mines and pottery industries

Historical data on the dust exposures of Chinese workers in metal mines (iron/copper, tin, tungsten) and pottery industries are being used in an ongoing joint Chinese/United States epidemiological study to investigate the exposure-response relationship for the development of silicosis, lung cancer, and other diseases. The historical data include 'total dust' concentrations determined by a Chinese method. Information about particle size distribution and the chemical and mineralogical content of airborne particles is generally not available. In addition, the historical Chinese sampling strategy is different from a typical American eight-hour time-weighted average (TWA) sampling strategy, because the Chinese samples were collected for approximately 15 minutes during production so the sample could be compared to their maximum allowable concentration (MAC) standard. Therefore, in order to assess American respirable dust exposure standards in light of the Chinese experience, factors are needed to convert historical Chinese total dust concentrations to respirable dust concentrations. As a part of the joint study to estimate the conversion factors, airborne dust samples were collected in 20 metal mines and 9 pottery factories in China during 1988 and 1989 using three different samplers: 10mm nylon cyclones, multi-stage 'cassette' impactors, and the traditional Chinese total dust samplers. More than 100 samples were collected and analysed for each of the three samplers. The study yielded two different estimates of the conversion factor from the Chinese total dust concentrations (measured during production processes) to respirable dust concentrations. The multivariate analysis of variance (MANOVA) reveals that, with a fixed sampling/analysis method, conversion factors were not statistically different among the different job titles within each industry. It also indicates that conversion factors among the industries were not statistically different. However, the two estimates consistently showed that conversion factors were the lowest in the pottery industry. Average conversion factors were then calculated for each of the estimates across the industries studied. A pooled mean conversion factor, 0.25+/-0.04, was then derived for all the job titles and industries. Respirable dust levels were estimated from the historical 'total dust' concentrations collected between 1952 and 1992 by adopting the American standard.

[Immunological study on the antitumor effects of fungus polysaccharides compounds]

Fungus polysaccharides compounds (FPC) are the mixture of procyanidins oligomers, glycyrrhetinicacid and polysaccharides of hericium erinaceus, lentinus edodes and poria cocos. The antitumor effects of FPC and its immunity regulating effects as an immunostimulant on the mice burdened with sarcoma 180 (S-180) were studied. FPC (100, 200 and 400 mg/kg BW) was gavaged to mice for 31 days. S-180 was transplanted to these mice on the 21th day. Lentinus edodes group was gavaged 200 mg/kg BW saccharine of lentinus edodes. The results showed that FPC could inhibit the growth of S-180 effectively. The inhibitory rates were 37.74%, 44.73% and 48.32% respectively. The antineoplastic activity of FPC (200 mg/kg. BW) was more effective than polysaccharide of lentinus edodes at the same dose. In S-180 burdened mice, the percentage of L3T4 and the ratio of L3T4/Lyt-2, NK activity and the induced IL-2, IFN-gamma levels were decreased significantly compared with the normal control group. As an immunostimulant, FPC could increase the percentage of L3T4 and the ratio of L3T4/Lyt-2 in S-180 burdened mice, but had no significant effects on the percentage of Lyt-2. Polysaccharide of lentinus edodes alone could also increase the immunity competence of mice burdened with S-180, but was not better than that of FPC at the same dose. It could be concluded that the compound of antineoplastic component could be synergetic.

Interspecies transmission of influenza viruses: H5N1 virus and a Hong Kong SAR perspective

This account takes stock of events and involvements, particularly on the avian side of the influenza H5N1 'bird flu' incident in Hong Kong SAR in 1997. It highlights the role of the chicken in the many live poultry markets as the source of the virus for humans. The slaughter of chicken and other poultry across the SAR seemingly averted an influenza pandemic. This perspective from Hong Kong SAR marks the coming-of-age of acceptance of the role of avian hosts as a source of pandemic human influenza viruses and offers the prospect of providing a good baseline for influenza pandemic preparedness in the future. Improved surveillance is the key. This is illustrated through the H9N2 virus which appears to have provided the 'replicating' genes for the H5N1 virus and which has since been isolated in the SAR from poultry, pigs and humans highlighting its propensity for interspecies transmission.

Differential IL-12 responsiveness of T cells but not of NK cells from tumor-bearing mice in IL-12-responsive versus -unresponsive tumor models

While IL-12 administration induces tumor regression through stimulating T cells in tumor-bearing mice, this IL-12 effect is observed in some but not all tumor models. The present study aimed to compare IL-12 responsiveness of T cells from tumor-bearing mice in IL-12-responsive (CSA1M and OV-HM) and -unresponsive (Meth A) tumor models. Tumor regression in IL-12-responsive tumor models required the participation of T cells, but not of NK1.1(+) cells. Because a NK1.1(+) cell population was the major producer of IFN-gamma, comparable levels of IFN-gamma production were induced in IL-12-responsive and -unresponsive tumor-bearing mice. This indicates that the amount of IFN-gamma produced in tumor-bearing individuals does not correlate with the anti-tumor efficacy of IL-12. In contrast, IL-12 responsiveness of T cells differed between the responsive and unresponsive models: purified T cells from CSA1M/OV-HM-bearing or Meth A-bearing mice exhibited high or low IL-12 responsiveness respectively, when evaluated by the amounts of IFN-gamma produced in response to IL-12. T cells from CSA1M- or OV-HM-bearing but not from Meth A-bearing mice exhibited enhanced levels of mRNA for the IL-12 receptor (IL-12R). These results indicate that a fundamental difference exists in IL-12 responsiveness of T cells between IL-12-responsive and -unresponsive tumor models, and that such a difference is associated with the expression of IL-12R on T cells.

[Effect of hormone replacement therapy on coagulation function in postmenopausal women]

OBJECTIVE

To study the effect of hormone replacement therapy (HRT) on coagulation function in postmenopausal women.

METHODS

Fifty-two postmenopausal women were divided into three groups; placebo group (10 cases), estrogen group (19 cases) and estrogen plus progesterone group (23 cases). Twenty healthy premenopausal women served as control group. The coagulation parameters were determined before and 3, 6 months after initiation of HRT.

RESULTS

The levels of fibrinogen and protein S in postmenopausal women were significantly higher than those in the control group. There was no difference in coagulation parameters before and after placebo administration. After 3-month HRT, the fibrinogen levels in estrogen group and estrogen plus progesterone group significantly decreased and further decreased after 6-month HRT, as compared with before HRT. A significant decrease was also noted in protein S in both groups after 3 month HRT, but returned closely to baseline after 6-month HRT. There was no significant difference in coagulation parameters between estrogen group and estrogen plus progesterone group either before or after HRT.

CONCLUSION

HRT significantly decrease the levels of fibrinogen in postmenopausal women.

The development of peritumoral stroma required for IL-12 induced tumor regression depends on the T cell/IFN-gamma-involving host-tumor interaction

T cell migration into tumor masses is a critical process in the scenario of IL-12-induced tumor regression. Our previous study showed that this depends on the development of peritumoral stroma prior to IL-12 therapy. The present study investigated the regulation of the development of peritumoral stroma in comparison with tumor-parenchymal stroma. In the OV-HM and CSA1M tumor models, tumor regression associated with T cell migration was induced following IL-12 treatment. Both OV-HM and CSA1M tumor masses growing in syngeneic mice developed peritumoral stroma before IL-12 treatment. However, peritumoral stroma was not observed in these two types of tumor masses generated in nude mice, T cell-depleted syngeneic mice, anti-IFN-gamma mAb-treated mice or IFN-gamma-deficient mice. In contrast, parenchymal stroma formation did not appear to be affected because tumors generated in these groups of mice exhibited rather higher growth rates than those of tumors in normal syngeneic mice. Importantly, the lack of peritumoral stroma in tumor masses was associated with the failure of T cells to migrate to these tumor masses: splenic T cells prepared from IL-12-treated tumor-bearing mice migrated into the corresponding tumor mass growing in untreated syngeneic recipient mice, whereas portions of the same donor cells failed to migrate into the above stroma-negative tumor masses. These results indicate that the development of peritumoral and parenchymal stroma is differentially regulated; there exist functional differences in the two types of stroma; and the formation of peritumoral stroma requires components of the host's immune system such as IFN-gamma and T cells.

[One of the etiological factors of digestive tract cancers in Chinese: the missense mutation Val384Asp in the hMLH1 gene]

OBJECTIVE

To investigate the etiological role of Val384Asp in the hMLH1 gene, which may be a polymorphism in Chinese, in colorectal, gastric and esophageal cancers.

METHODS

Genomic DNA extracted from normal tissues were subjected to analysis in exon 12 of the hMLH1 gene by single strand conformation polymorphism(SSCP) followed by DNA sequencing of aberrant bands in 101 colorectal, 79 gastric and 76 esophageal cancer patients; in 79 and 76 first degree relatives of gastric cancer and esophageal cancer patients respectively; and in 100 healthy control individuals.

RESULTS

Six percent of Chinese healthy individuals were the carriers of Val3 84Asp in the hMLH1 gene. There were significant differences in the frequencies of Val384Asp in the hMLH1 gene between the patients with colorectal cancer at young age(<45 years) and the control individuals (P<0.05), and between the gastric cancer patients with family history, the first degree relatives and the control group (P<0.05 and P<0.01 respectively). No difference was found between the esophageal cancer patients, their relatives and healthy controls.

CONCLUSION

The alleles frequency of Val384Asp in the hMLH1 gene in Chinese is three percent. This missense mutation may play a part in the etiology of colorectal and gastric cancers in Chinese.

[Bone mineral density and exercises: a cross-sectional study on Chinese athletes]

OBJECTIVES

To evaluate the effect of exercise to osteoporosis by bone mineral density (BMD) measurement of athelets comparing normal individuals in general population.

METHODS

BMD of radium, lumber spine, and femoral neck were measured by single photon absorptiometry (SPA), quantitative CT (QCT), and dual X-ray absorptiometry (DXA) respectively in athletes (n = 162, male 79, female 83) and age matched non-athletes normal population (n = 204, male 91, female 113) in Beijing.

RESULTS

BMD of all sites in all age groups of both male and female athletes are significantly higher comparing with that in non-athletic population. This predominance in athletes is even more distinctive in peak bone mass. Peak bone mass of male athletes is significantly higher than that of female athletes. Bone loss with age is less apparent in athletes than in control. However, there is an accelerated decline of BMD in lumber spine and femoral neck in 30-39 year age group in both male and female athletes, which may be due to the wanting of physical exercise.

CONCLUSIONS

Long term regular proper exercise started in adolescence may play a very important role in the prevention of osteoporosis by improving peak bone mass and decreasing bone loss.

Synthesis and opioid receptor affinity of morphinan and benzomorphan derivatives: mixed kappa agonists and mu agonists/antagonists as potential pharmacotherapeutics for cocaine dependence

This report concerns the synthesis and preliminary pharmacological evaluation of a novel series of kappa agonists related to the morphinan (-)-cyclorphan (3a) and the benzomorphan (-)-cyclazocine (2) as potential agents for the pharmacotherapy of cocaine abuse. Recent evidence suggests that agonists acting at kappa opioid receptors may modulate the activity of dopaminergic neurons and alter the neurochemical and behavioral effects of cocaine. We describe the synthesis and chemical characterization of a series of morphinans 3a-c, structural analogues of cyclorphan [(-)-3-hydroxy-N-cyclopropylmethylmorphinan S(+)-mandelate, 3a], the 10-ketomorphinans 4a,b, and the 8-ketobenzomorphan 1b. Binding experiments demonstrated that the cyclobutyl analogue 3b [(-)-3-hydroxy-N-cyclobutylmethylmorphinan S(+)-mandelate, 3b, MCL-101] of cyclorphan (3a) had a high affinity for mu, delta, and kappa opioid receptors in guinea pig brain membranes. Both 3a,b were approximately 2-fold more selective for the kappa receptor than for the mu receptor. However 3b (the cyclobutyl analogue) was 18-fold more selective for the kappa receptor in comparison to the delta receptor, while cyclorphan (3a) had only 4-fold greater affinity for the kappa receptor in comparison to the delta receptor. These findings were confirmed in the antinociceptive tests (tail-flick and acetic acid writhing) in mice, which demonstrated that cyclorphan (3a) produced antinociception that was mediated by the delta receptor while 3b did not produce agonist or antagonist effects at the delta receptor. Both 3a,b had comparable kappa agonist properties. 3a,b had opposing effects at the mu receptor: 3b was a mu agonist whereas 3a was a mu antagonist.

Tablet dissolution affected by a moisture mediated solid-state interaction between drug and disintegrant

PURPOSE

To investigate the cause for decrease in delavirdine mesylate 200 mg tablet dissolution upon exposure to high humidity.

METHODS

Dissolution testing was performed using the USP 2 (paddle) apparatus. Water in tablets was measured by Karl Fischer titration. 13C CP/MAS NMR was used to identify and quantify delavirdine form changes in tablets. FT-IR spectroscopy was used to monitor delavirdine form change in tablets and component mixes, and to investigate a solid state reaction with the disintegrant.

RESULTS

Dissolution extent of delavirdine mesylate 200 mg tablets was substantially decreased after exposure to high humidity. This effect is related to the amount of water present in the tablet matrix. 13C CP/ MAS NMR detected about 30% conversion from the mesylate salt of delavirdine to its free base form in the tablet matrix. FT-IR spectroscopy demonstrated that a solid state reaction occurs between the freed methanesulfonic acid and the carboxyl sites on the croscarmellose sodium disintegrant.

CONCLUSIONS

Water is thought to act as both a reaction medium and a plasticizer for croscarmellose sodium, facilitating protonation of the carboxyl sites on the disintegrant. This reaction has the potential to occur for any acid salt of a free base. The limiting solubility of delavirdine free base formed in the tablets accounts for much of the decrease in the extent of dissolution. A change in inter-particle bonding can explain the reduction in tablet deaggregation during dissolution.

[Expression of xylose-metabolic key genes of Trichoderma reesei on various carbon sources measured by a series of Northern hybridizations]

The expression of xylose reductase (XR), xylitol dehydrogenase (XDH) and transaldolase (TAL) genes from Trichoderma reesei, measured by Northern hybridization, were studied by adding different carbon sources (20 kinds, including single and mixed carbon sources) separately into the basal medium on which T. reesei QM9414 was grown. The experiment results indicated that the two disaccharides: sophrose and xylibiose act as a strong inducer for the expression of xr and xdh. The lactose and arabinose were identified as inducer also. The presence of glucose repressed the transcription of xr and xdh. When glucose depleted. xr and xdh were expressed at certain level, implying that expression of xr and xdh are controlled by the carbon catabolite repression mechanism and there existed a constitutive base level's expression of xr and xdh when the catabolite repression mechanism was derepressed. On the other hand, transaldolase gene strongly expressed on all the carbon sources used.

A novel immunoradiometric assay detects full-length human PTH but not amino-terminally truncated fragments: implications for PTH measurements in renal failure

In 8 adolescents with end-stage renal disease (ESRD), basal PTH concentrations measured with a novel immunoradiometric assay (IRMA) (Scantibodies Laboratory, Inc.; S-IRMA) were invariably lower than those estimated with an established assay (Nichols Institute; N-IRMA) (263 +/- 228 versus 645 +/- 442 pg/ml, respectively; p<0.00001). During in vivo dynamic testing, set points for calcium-regulated PTH release were indistinguishable for both IRMAs (1.21 +/- 0.05 versus 1.22 +/- 0.06). However, maximal PTH concentrations were significantly lower when measured by S-IRMA then by N-IRMA (557 +/- 448 and 1114 +/- 606 pg/ml, respectively); minimum PTH concentrations were 41 +/- 65 pg/ml (5.0 +/- 4.2% of maximum) and 189 +/- 137 pg/ml (13.6 +/- 7.2% of maximum), respectively. Correlation between PTH and blood ionized calcium indicated that PTH measured by S-IRMA decreased more readily than the concentrations determined by N-IRMA. The N-IRMA showed indistinguishable cross-reactivity with hPTH(1-84) and hPTH(7-84), while the S-IRMA detected only the full-length peptide. Furthermore, the radiolabeled detection antibody of the N-IRMA interacted equivalently with hPTH(1-34) and hPTH(2-34), while the S-IRMA showed crossreactivity only with hPTH(1-34). These differences in assay specificity could explain the observed differences in ESRD, and suggest that PTH concentrations estimated by the S-IRMA reflect more accurately the amount of biologically active PTH in the circulation. Since low concentrations of PTH are frequently associated with adynamic bone disease, our findings may have significant implications for the treatment of renal osteodystrophy with calcium and/or biologically active vitamin D analogs.

[Cloning whole length cDNA of related genes responsible for smooth muscle cells proliferation in atherogenesis and study on its function]

OBJECTIVE

To clone whole length cDNA of the related genes responsible for vascular smooth muscle cell (SMC) proliferation in atherogenesis, and to study its function.

METHODS

ox-LDL was added as a stimulant to the SMC culture medium. Subtractive library was established using subtractive hybridization technique in order to clone the related genes fragments. With the whole length cDNA library established, the whole length cDNA of the related gene was cloned. The protein expressed was studied.

RESULTS

4 new gene fragments and one whole length cDNA were cloned. The new cloned gene is able to express a protein of about 44000 daltons and closely related to the activity of ox-LDL.

CONCLUSIONS

The new cloned gene is considered responsible for SMC proliferation.

[Clinical study on effect of xianlong capsule on senile vascular dementia]

OBJECTIVE

To assess the efficacy of Xianlong Capsule (XLC) in treating the senile vascular dementia (VD).

METHODS

Forty-six cases of VD were randomly divided into two groups. The XLC group (24 patients) were treated with XLC and the control group (22 patients) were treated with Hydergine. Mini-mental state examination (MMSE), Hamilton depression scale (HDS) marks and clinical symptoms were observed in different groups.

RESULTS

XLC could markedly increase MMSE and HDS marks of VD patients. XLC had the effect of improving balance and gait ability of VD patients.

CONCLUSION

XLC had certain effect on VD and its effect was better than that of Hydergine.

Association between prenatal exposure to methylmercury and developmental outcomes in Seychellois children: effect modification by social and environmental factors

The Seychelles Child Development Study (SCDS) is testing the hypothesis that prenatal exposure to low doses of MeHg from maternal consumption of fish is associated with the child's developmental outcomes. No deleterious relationships between exposure to MeHg and cognitive functions have been identified in the primary analysis of the main cohort through 66 months of age. We performed secondary analyses to determine if effect modification (EM) from social and environmental factors was affecting associations between MeHg and outcomes.

METHODS

MeHg exposure was determined by analysis of maternal hair growing during pregnancy. Children in our Main Study cohort were evaluated at 6.5 months (N = 740) for visual recognition memory and visual attention using the Fagan Infantest, at 19 months (N = 738) and 29 months (N = 736) with the Bayley Scales of Infant Development (BSID). Interactions between MeHg and Caregiver Intelligence, Family Income and Home Environment were examined by multiple regression analysis.

RESULTS

The median prenatal MeHg exposure was 5.9 ppm (Range 0.5-26.7 ppm). No EM occurred for preferential looking or visual attention at 6.5 months, for the BSID Psychomotor Scale at either 19 or 29 months, or for activity level at 29 months as measured by the BSID Infant Behavior Record. Interactions between MeHg level and both caregiver intelligence and family income were statistically significant for the BSID Mental Scale at 19 months but not at 29 months. These showed enhancement of MDI scores with increasing maternal MeHg in higher caregiver IQ groups at several levels of family income.

CONCLUSIONS

In Seychellois children, consistent major EM by social or environmental factors were not identified. The small EM by caregiver intelligence and social factors at 19 months is consistent with the enhanced performance we reported when this cohort was examined at 66 months.

Isolation and identification of xylitol dehydrogenase gene from Trichoderma reesei

A cDNA sub-library from the fungus Trichoderma reesei grown on xylan was constructed in S.cerevisiae recombinant strain H475 harboring a xylose reductase (XR) gene from Pichia stipitis. The xylitol dehydrogenase (XDH) gene was screened from sub-library on a SC selective medium in which xylose was used as a sole carbon source. The length of XDH gene, xdh1, was about 1.3 kb. Southern, Northern and Western blots were carried out, indicating that xdh1 has high affinity with T.reesei and the molecular weight of the xylitol dehydrogenase from T.reesei was about 40 kDa. The strain HX1 harboring both the XR gene from P.stipitis and the XDH gene from T.reesei was able to grow on the xylose medium and converted more than 90% of the xylose into xylitol, ethanol, and other by-products.

[Applied anatomic study on intraorbital and intraethmoidal parts of ethmoidal artery]

OBJECTIVE

In order to provide anatomic data for operation of ethmoidal sinus and optic canal decompression.

METHOD

Using microanatomic method, the intraorbital and intraethmoidal parts of ethmoidal arteries were observed and measured.

RESULT

The length of intraorbital segment of anterior ethmoidal artery was 5.16 +/- 1.24 mm, and its diameter was 0.56 +/- 0.17 mm; the length of intraorbital segment of posterior ethmoidal artery was 9.08 +/- 2.29 mm, with diameter 0.37 +/- 0.14 mm. The ethmoidal artery, nerve and vein were surrounded by fascial sheath which could extend to ethmoidal sinus. Three variants of ethmoidal arteries could be found: It passed through bony canal; It went between the superior wall of ethmoidal cell and ethmoidal mucosa; One part went through bony canal, but the other did not.

CONCLUSION

It was important to find ethmoidal artery in operation of ethmoidal sinus and optic canal decompression.

Generation of influenza A viruses entirely from cloned cDNAs

We describe a new reverse-genetics system that allows one to efficiently generate influenza A viruses entirely from cloned cDNAs. Human embryonic kidney cells (293T) were transfected with eight plasmids, each encoding a viral RNA of the A/WSN/33 (H1N1) or A/PR/8/34 (H1N1) virus, flanked by the human RNA polymerase I promoter and the mouse RNA polymerase I terminator-together with plasmids encoding viral nucleoprotein and the PB2, PB1, and PA viral polymerases. This strategy yielded >1 x 10(3) plaque-forming units (pfu) of virus per ml of supernatant at 48 hr posttransfection. The addition of plasmids expressing all of the remaining viral structural proteins led to a substantial increase in virus production, 3 x 10(4)-5 x 10(7) pfu/ml. We also used reverse genetics to generate a reassortant virus containing the PB1 gene of the A/PR/8/34 virus, with all other genes representing A/WSN/33. Additional viruses produced by this method had mutations in the PA gene or possessed a foreign epitope in the head of the neuraminidase protein. This efficient system, which does not require helper virus infection, should be useful in viral mutagenesis studies and in the production of vaccines and gene therapy vectors.

[The resolution of racemic sec-phenethyl alcohol on cellulose tribenzoate-based CSP: influence of different alcohols in the mobile phase]

Several primary and secondary alcohols (ethanol, 1-propanol, 2-propanol, 1-butanol) were used as the mobile phase components separately, to investigate their effects on the capacity factor and stereoselectivity of sec-phenethyl alcohol enantiomers on cellulose tribenzoate-based CSP. The chiral recognition mechanism for the enantiomeric aromatic alcohols studied may involve: (1) the aromatic portion of the solute may insert into a chiral cavity of the CSP through a hydrogen bonding interaction between the solute's alcoholic hydrogen and the ester carbonyl group on the CSP; (2) the mobile phase modifiers (various alcohols) compete with the solutes for chiral, as well as achiral, binding sites on the CSP; (3) the structure of the modifier has some effect on stereoselectivity through an alteration of the steric environment of the chiral cavity.

Sequence pattern for the occurrence of N-glycosylation in proteins

To further understand the occurrence of N-glycosylation, 21 nonhomologous proteins with Asn-x-Ser/Thr sequence were investigated. The results showed that some oligopeptides with Gly residues (G-x-y or y-x-G) are adjacent to the N-glycosylated sequences. These oligopeptides are not only essential for the structure and function of the proteins, but they are also found to be often proteolytic processing sites. These properties suggest that these oligopeptides may be a "sequence pattern" for the occurrence of N-glycosylation. The implications of the findings for protein structure and function are discussed.

[CT and MR imaging of germinomas arising in basal ganglia and thalamus]

OBJECTIVE

To evaluate the role of CT and MR imaging in diagnosing germinomas arising in the basal ganglia and thalamus.

METHODS

MR imaging of 11 boys (ranging in age from 3-15 years with a median of 10.7 years) with germinomas arising from the basal ganglia and thalamus was reviewed retrospectively and the imaging findings were compared with the features of 86 germinomas in other regions. The tumors located at basal ganglia in 9 and at thalamus in 2. All diagnosis was proved operatively and pathologyically. Five cases were studied using both CT and MR, 4 were examined with MR and 2 with CT only.

RESULTS

In this series of 11 tumors, 9 were located in the basal ganglia and 2 in the thalamus. The shape of six tumors was global and 5 was lobulated. The cystic components or necrosis were intratumoral in 5 patients and hemorrhage in 4. Patchy enhancement was found in 9 patients and ring-enhancing lesions in 2. Tumor spread oppositely in 4 patients. Five patients demonstrated cortical atrophy ipsilaterally.

CONCLUSION

The germinomas arising from the basal ganglia and thalamus have sex, location and imaging characteristics. Therefore, it is possible to make preoperative diagnosis using CT or MR.

Biological heterogeneity, including systemic replication in mice, of H5N1 influenza A virus isolates from humans in Hong Kong

An H5N1 avian influenza A virus was transmitted to humans in Hong Kong in 1997. Although the virus causes systemic infection and is highly lethal in chickens because of the susceptibility of the hemagglutinin to furin and PC6 proteases, it is not known whether it also causes systemic infection in humans. The clinical outcomes of infection in Hong Kong residents ranged widely, from mild respiratory disease to multiple organ failure leading to death. Therefore, to understand the pathogenesis of influenza due to these H5N1 isolates, we investigated their virulence in mice. The results identified two distinct groups of viruses: group 1, for which the dose lethal for 50% of mice (MLD50) was between 0.3 and 11 PFU, and group 2, for which the MLD50 was more than 10(3) PFU. One day after intranasal inoculation of mice with 100 PFU of group 1 viruses, the virus titer in lungs was 10(7) PFU/g or 3 log units higher than that for group 2 viruses. Both types of viruses had replicated to high titers (>10(6) PFU/g) in the lungs by day 3 and maintained these titers through day 6. More importantly, only the group 1 viruses caused systemic infection, replicating in nonrespiratory organs, including the brain. Immunohistochemical analysis demonstrated the replication of a group 1 virus in brain neurons and glial cells and in cardiac myofibers. Phylogenetic analysis of all viral genes showed that both groups of Hong Kong H5N1 viruses had formed a lineage distinct from those of other viruses and that genetic reassortment between H5N1 and H1 or H3 human viruses had not occurred. Since mice and humans harbor both the furin and the PC6 proteases, we suggest that the virulence mechanism responsible for the lethality of influenza viruses in birds also operates in mammalian hosts. The failure of some H5N1 viruses to produce systemic infection in our model indicates that multiple, still-to-be-identified, factors contribute to the severity of H5N1 infection in mammals. In addition, the ability of these viruses to produce systemic infection in mice and the clear differences in pathogenicity among the isolates studied here indicate that this system provides a useful model for studying the pathogenesis of avian influenza virus infection in mammals.

Human apolipoprotein E N-terminal domain displacement of apolipophorin III from insect low density lipophorin creates a receptor-competent hybrid lipoprotein

The surface of Manduca sexta low density lipophorin (LDLp) particles was employed as a template to examine the relative lipid binding affinity of the 22 kDa receptor binding domain (residues 1-183) of human apolipoprotein E3 (apo E3). Isolated LDLp was incubated with exogenous apolipoprotein and, following re-isolation by density gradient ultracentrifugation, particle apolipoprotein content was determined. Incubation of recombinant human apo E3(1-183) with LDLp resulted in a saturable displacement of apolipophorin III (apo Lp-III) from the particle surface, creating a hybrid apo E3(1-183)-LDLp. Although subsequent incubation with excess exogenous apo Lp-III failed to reverse the process, human apolipoprotein A-I (apo A-I) effectively displaced apo E3(1-183) from the particle surface. We conclude that human apo E N-terminal domain possesses a higher intrinsic lipid binding affinity than apo Lp-III but has a lower affinity than human apo A-I. The apo E3(1-183)-LDLp hybrid was competent to bind to the low density lipoprotein receptor on cultured fibroblasts. The system described is useful for characterizing the relative lipid binding affinities of wild type and mutant exchangeable apolipoproteins and evaluation of their biological properties when associated with the surface of a spherical lipoprotein.

[Purification and characterization of alkaline xylanases from Pseudomonas G6-2]

Pseudomonas G6-2 produced two extracellular xylanases, named XynA and XynB. The enzymes were purified by ammonium sulfate fractionation, Sephadex G-100, DEAE-Sephadex, CM-Sephadex and Bio-gel P-10 chromatographies. Both enzymes were indicated to be endoxylanases, which produced oligomers of xylose from xylan and did not hydrolyze it to xylose. They had same temperature optimum(50 degrees C) and different pH optimum(pH 7.0-9.8 for XynA and pH 7.0-8.0 for XynB). At pH 7.6 and 65 degrees C, XynA and XynB possessed the half life of 6 min and 140 min, respectively. Their activities were strongly inhibited by Cu2+, Fe3+, Pb2+, Zn2+ and Hg2+. The results of chemical modification indicated that tryptophan and carboxy group were related to active center.

Metabolic flux change in hybridoma cells under high osmotic pressure

The effect of high osmotic pressure on the flux changes of two energy metabolisms from glucose and glutamine by AFP-27 hybridoma cells producing monoclonal antibody (MAb) was investigated in batch cultures at various osmotic pressures in the range from 300 to 424 mOsmol/kg. The specific production rate of MAb (q(MAb)) increased monotonically with increasing osmotic pressure. The specific consumption rates of glucose (nu(G)) and glutamine (nu(GLN)) also increased with the osmotic pressure up to 410 mOsmol/kg. However, there were marked changes in the metabolic fluxes when the osmotic pressure was raised further, resulting in a decrease in nu(G) while nu(GLN) continued to increase. These changes in the metabolic fluxes at osmotic pressures higher than 410 mOsmol/kg were associated with an increased yield of lactic acid from glucose (Y (L G )), which indicated the energy yield from glucose declined at osmolarities higher than 410 mOsmol/kg. On the other hand, because of a larger increment in the specific production rate of ammonia under high osmotic pressure, the yield of ammonia from glutamine (Y (A GLN )) increased monotonically with the osmotic pressure throughout the range 300 to 424 mOsmol/kg, signifying a rise in the energy yield from glutamine. Consequently, the higher specific ATP production rates from glucose and glutamine associated with the flux changes under high osmotic pressure could be one of the reasons for the increase in q(MAb) observed at high osmotic pressures.

Characterization of avian H5N1 influenza viruses from poultry in Hong Kong

The transmission of avian H5N1 influenza viruses to 18 humans in Hong Kong in 1997 with six deaths established that avian influenza viruses can transmit to and cause lethal infection in humans. This report characterizes the antigenic and biological properties of the H5N1 influenza viruses isolated from chickens, ducks, and geese from farms and poultry markets in Hong Kong during 1997 and compares them with those of virus isolated from the index human case. Each of the H5N1 viruses from Hong Kong poultry markets that were tested were lethal in chickens, possessed polybasic amino acids at the carboxy-terminus of HA1, and by definition were highly pathogenic in poultry. The available nonpathogenic H5 influenza viruses and the pathogenic H5N1 virus from Hong Kong were analyzed with monoclonal antibodies prepared to A/chicken/Pennsylvania/1370/83 (H5N2). The analysis revealed limited antigenic drift in 15 years and established that monoclonal antibodies are useful reagents for identification and antigenic analysis of avian strains that may transmit to humans in the future. One of the monoclonal antibodies permitted separation of the H5N1 influenza viruses from poultry into two groups that correlated with the presence or absence of a carbohydrate at residue 158 adjacent to the receptor binding site on HA. The H5N1 viruses examined replicated in geese, pigs, rats, and mice, but to only a very limited extent in ducks. It is noteworthy that all infected geese shed virus and that the H5N1 viruses caused disease signs and death in a portion (3 of 16) of the geese, with evidence of systemic spread to the brain. The tropism for geese is unusual and may provide insight into the origin of these viruses. In mice, the H5N1 virus caused lethal pneumonia and spread systemically to the brain. Mice would thus provide an ideal model system for studying immune responses and pathogenesis. Transmission experiments in chickens revealed that the H5N1 viruses are spread by fecal-oral transmission rather than by aerosol, and that the viruses are inactivated by drying of feces at ambient temperature. However, infectivity is maintained for at least 4 days in wet feces at 25 degreesC. There were differences in the morphology of the H5N1 viruses isolated from birds and humans. The perpetuation of H5N1 influenza viruses in the poultry markets in Hong Kong and the transmission of these viruses to humans emphasize the importance of these markets in the epidemiology of influenza. The poultry markets are of critical importance in the perpetuation and transmission of influenza viruses to other avian species and to mammals, including humans.

A "pre-satiety sequence" in rats drinking sucrose solutions

Food-deprived rats were given intermittent access or, in a replication, continuous access to a 20% sucrose solution. Both drinking and nondrinking behaviors were recorded. During the ensuing drinking bout, latency of lapping after snout apposition, and duration of lapping bouts, did not change. Approaches to the sipper tube usually eventuated in lapping, though aborted approaches increased in frequency late in the session. Drinking was interrupted by nondrinking behaviors which appeared in a characteristic rostro-caudal sequence: partial head withdrawal from the drinking aperture, then full head withdrawal, then movements of the front paws, then movement of the hind paws with full-body locomotion. All these behavioral changes occurred before there was any appreciable reduction in rate of lapping.

Production of acyl-homoserine lactone quorum-sensing signals by gram-negative plant-associated bacteria

Many gram-negative bacteria regulate expression of specialized gene sets in response to population density. This regulatory mechanism, called autoinduction or quorum-sensing, is based on the production by the bacteria of a small, diffusible signal molecule called the autoinducer. In the most well-studied systems the autoinducers are N-acylated derivatives of L-homoserine lactone (acyl-HSL). Signal specificity is conferred by the length, and the nature of the substitution at C-3, of the acyl side-chain. We evaluated four acyl-HSL bioreporters, based on tra of Agrobacterium tumefaciens, lux of Vibrio fischeri, las of Pseudomonas aeruginosa, and pigment production by Chromobacterium violaceum, for their ability to detect sets of 3-oxo acyl-HSLs, 3-hydroxy acyl-HSLs, and alkanoyl-HSLs with chain lengths ranging from C4 to C12. The traG::lacZ fusion reporter from the A. tumefaciens Ti plasmid was the single most sensitive and versatile detector of the four. Using this reporter, we screened 106 isolates representing seven genera of bacteria that associate with plants. Most of the Agrobacterium, Rhizobium, and Pantoea isolates and about half of the Erwinia and Pseudomonas isolates gave positive reactions. Only a few isolates of Xanthomonas produced a detectable signal. We characterized the acyl-HSLs produced by a subset of the isolates by thin-layer chromatography. Among the pseudomonads and erwinias, most produced a single dominant activity chromatographing with the properties of N-(3-oxo-hexanoyl)-L-HSL. However, a few of the erwinias, and the P. fluorescens and Ralstonia solanacearum isolates, produced quite different signals, including 3-hydroxy forms, as well as active compounds that chromatographed with properties unlike any of our standards. The few positive xanthomonas, and almost all of the agrobacteria, produced small amounts of a compound with the chromatographic properties of N-(3-oxo-octanoyl)-L-HSL. Members of the genus Rhizobium showed the greatest diversity, with some producing as few as one and others producing as many as seven detectable signals. Several isolates produced extremely nonpolar compounds indicative of very long acyl side-chains. Production of these compounds suggests that quorum-sensing is common as a gene regulatory mechanism among gram-negative plant-associated bacteria.

Characterization of three crystalline forms (VIII, XI, and XII) and the amorphous form (V) of delavirdine mesylate using 13C CP/MAS NMR

PURPOSE

The application of solid-state nuclear magnetic resonance (NMR) characterization of three crystalline forms (VIII, XI, XII) and the amorphous form V of delavirdine mesylate (DLV-M) is presented.

METHODS

Conventional 13CCP (cross-polarization)/MAS (magic angle spinning) NMR and related spectral editing methods were employed. NMR relaxation times (T1pH, T1H, and T1C) were also measured.

RESULTS

Distinctly different spectral features among the four solid forms were observed, indicating high sensitivity of 13C NMR to the variations in solid structure. Assessment based on NMR data suggests that both anhydrous forms VIII and XI may contain one molecule per asymmetric unit. DLV may adopt a similar molecular conformation in the two forms. In contrast, form XII is found to consist of two molecules per asymmetric unit. Molecule conformation of DLV in forms VIII, XI, and XII is altered from the dominant conformer in solution. The amorphous form V may contain DLV molecules of a variety of conformations. NMR relaxation times (T1PH, T1H, and T1C) provide valuable information about the motional characteristics in these solids. Values and the rank order of T1pH, T1H, and T1C also reveal significant differences in local environments and the short range order among the four forms.

CONCLUSIONS

Four solid forms of DLV-M (V, VIII, XI, and XII) can be distinctly differentiated by 13C CP/MAS NMR spectroscopy and their structural difference can be partially revealed without obtaining single crystal data. NMR relaxation times reveal motion dynamics and aid structural elucidation for these forms.

Identification of a 374 amino acid protein encoded by RNA segment 6 of influenza C virus

Unspliced mRNA from RNA segment 6 of influenza C virus contains a single open reading frame that potentially encodes a polypeptide of 374 amino acids. This polypeptide, which has not been identified as yet, is predicted to contain the complete amino acid sequence of the matrix protein, M1, as well as that of a small integral membrane protein, CM2. Here, we found that small amounts of two previously unrecognized proteins with apparent molecular masses of 42 (P42) and 44 kDa (P44) were immunoprecipitated with immune serum against CM2. The electrophoretic mobilities of P42 and P44 varied depending on virus strain, indicating that they are virus-coded. Treatment of infected cells with tunicamycin and digestion of immunoprecipitated proteins with various endoglycosidases revealed that P42 is modified by the addition of a high-mannose oligosaccharide chain to generate P44. A monoclonal antibody against M1, like anti-CM2 serum, was able to immunoprecipitate both the P42 and P44 proteins. Furthermore, the tryptic peptide map of either P42 or P44 was indistinguishable from the map of the mixture of M1 and CM2. These results, taken together, suggest strongly that P42 and P44 correspond to the 374 amino acid protein encoded by unspliced RNA segment 6 mRNA and its N-glycosylated form, respectively.

[Subcloning and expression of coding region for cellulase binding domain of CBH I from P. janthinellum in E. coli]

The in vitro DNA manipulations, included the nested deletions, of cbh1 from P. janthinellum inserted into pUC18-181 were carried out. The two ends of fragments were modified into blunt ends and the fragments were self-ligated. Then, the encircled plasmids were transformed to E. coli JM109. Utilizing the characterization of CBD binding to crystalline cellulose, one catalytic domain deletion transformant producing active LacZ-CBD fusion protein was isolated from 24 transformants randomly picked from 400 transformants. The molecular weight of the LacZ-CBD fusion protein is 21 kD. The plasmid was designated pUC 18C. The LacZ-CBD fusion protein produced by JM109(pUC18C) was able to be purified by procedure of adsorption-desorption to cellulose. The pNPC activity of crude enzyme solution of JM109(pUC18C) induced by IPTG were zero, identified the JM109(pUC18C) has no CBHI activity.

Molecular mechanisms of serum resistance of human influenza H3N2 virus and their involvement in virus adaptation in a new host

H3N2 human influenza viruses that are resistant to horse, pig, or rabbit serum possess unique amino acid mutations in their hemagglutinin (HA) protein. To determine the molecular mechanisms of this resistance, we characterized the receptor-binding properties of these mutants by measuring their affinity for total serum protein inhibitors and for soluble receptor analogs. Pig serum-resistant variants displayed a markedly decreased affinity for total pig serum sialylglycoproteins (which contain predominantly 2-6 linkage between sialic acid and galactose residues) and for the sialyloligosaccharide 6'-sialyl(N-acetyllactosamine). These properties correlated with the substitution 186S-->I in HA1. The major inhibitory activity in rabbit serum was found to be a beta inhibitor with characteristics of mannose-binding lectins. Rabbit serum-resistant variants exhibited decreased sensitivity to this inhibitor due to the loss of a glycosylation sequon at positions 246 to 248 of the HA. In addition to a somewhat reduced affinity for 6'-sialyl(N-acetyllactosamine)-containing receptors, horse serum-resistant variants lost the ability to bind the viral neuraminidase-resistant 4-O-acetylated sialic acid moieties of equine alpha2-macroglobulin because of the mutation 145N-->K/D in their HA1. These results indicate that influenza viruses become resistant to serum inhibitors because their affinity for these inhibitors is reduced. To determine whether natural inhibitors play a role in viral evolution during interspecies transmission, we compared the receptor-binding properties of H3N8 avian and equine viruses, including two strains isolated during the 1989 to 1990 equine influenza outbreak, which was caused by an avian virus in China. Avian strains bound 4-O-acetylated sialic acid residues of equine alpha2-macroglobulin, whereas equine strains did not. The earliest avian-like isolate from a horse influenza outbreak bound to this sialic acid with an affinity similar to that of avian viruses; a later isolate, however, displayed binding properties more similar to those of classical equine strains. These data suggest that the neuraminidase-resistant sialylglycoconjugates present in horses exert selective pressure on the receptor-binding properties of avian virus HA after its introduction into this host.

Synthesis of 7-arylmorphinans. Probing the "address" requirements for selectivity at opioid delta receptors

Through arylation of 6-keto opiates with diaryliodonium iodide, a series of 7-aryl opiates (3-8) have been prepared in an effort to investigate the effect of conformational mobility of the delta "address" moiety on opioid agonist and antagonist potencies. Evaluation of the ligands in the mouse vas deferens and guinea pig ileum preparations revealed that they were less potent and less selective than the conformationally constrained ligands, naltrindole (1, NTI) and 7-(spiroindanyl)oxymorphone (2, SIOM), at delta opioid receptors. It is concluded that the coplanarity of the address moiety with the C ring of the morphinan structure enhances delta antagonist potency and selectivity.

Prevention of maternal-fetal blood group incompatibility with traditional Chinese herbal medicine

OBJECTIVE

To evaluate the effect of traditional Chinese herbal medicine on the prevention of hemolytic disease caused by maternal-fetal blood group incompatibility.

METHODS

A total of 126 Chinese patients with maternal-fetal blood group incompatibility were studied, including 105 cases of ABO type and 21 cases of Rh type incompatibility. The traditional Chinese herbal medicine was used for preventative treatment in 79 cases, and 47 cases served as controls. The prescription consisted of Herba leonuri 500 g, white peony root 180 g, Banksia rose 12 g, root of Chinese angelica 150 g and Rhizomal ligustica 150 g.

RESULTS

Preventative treatment with traditional Chinese herbal medicine significantly reduced the perinatal mortality rate in cases of Rh type incompatibility, from 50.0% in the control group to 7.7% in the treatment group (P < 0.05). There was no death in the cases of ABO incompatibility. The traditional Chinese herbal medicine also decreased the degree of hemolysis. The percentage of severe cases in the control group was 29.8%, while it was 15.2% in the treatment group (P = 0.05). The duration of treatment was closely related to the outcomes. In patients who used traditional Chinese herbal medicine for more than 10 weeks, the incidence of severe hemolysis was 8.2%, compared with 38.9% in those treated for less than 10 weeks (P < 0.05). The change of serum immune antibody (A and/or B) titers during the treatment was a very important predictive factor for the outcome of the pregnancy.

CONCLUSION

Traditional Chinese herbal medicine is effective not only for ABO type but also for Rh type maternal-fetal blood group incompatibility, with no side effects.

[The intergeneric compatibility of heredity and expression for cellulase genomes between Aspergillus niger and Trichoderma reesei]

By using the developed display techniques of cellulase isozymes and the RAPD-PCR analysis guided by a deduced universal sequence of cellulase genes, the polymorphisms of genomic DNA fingerprints and cellulase isozymes were compared among three typical stable recombinants (3a, 3b, A7-1) and their two parents (Aspergillus niger AMS11, Trichoderma reesei QM9414) in order to provide the molecular evidence of gene recombination, to demonstrate the compatibility of heredity and expression of intergeneric genomes, and to assay on the molecular fundamentals of hybridization dominance. The results showed that in these recombinant strains the recombinantal fingerprints of genomic DNA could be stablly hereditary and the expression of recombinantal CMCase (carboxymethylcellulase) and beta GLase (beta-glucosidase) could be compatibly enhanced. The diversity of molecular fundamentals of cellulase hybridization dominance were (1) the compatible co-existence and enhanced expression of some hereditary beta GLase-coding genes from two parents in recombinant 3b; and (2) the compatibly enhancement of expression between the hereditary genes encoding beta GLase and CMCase from two parents, resulting in the dramatic increase of proteins of corresponding isozymes in recombinants 3a and A7-1. Based on these, a proposal model for the double synergism on cellulase activity in vitro and on its biosynthesis in vivo mediated by beta GLase was suggested. A practical method for assaying on the molecular fundamentals and the stability of hybridization dominance of recombinants was thereby established in this study.

Sample preparation and high-performance liquid chromatographic analysis of deoxyribonucleoside triphosphates in individual rat embryos

A rapid, robust, and sensitive method has been developed to measure concentrations of deoxyribonucleoside triphosphates in individual, day 14 rat embryos by modifying and optimizing existing methods for cellular extracts. Significant changes include: (i) oxidative degradation of ribonucleoside triphosphates using methylamine at lower pH (decreased from 6.5 to 4.0) to improve poor HPLC peak shape of early eluting nucleotides; (ii) glass fiber disc solid-phase extraction of the reaction mixture, which dramatically reduces impurities that interfere with nucleotide measurement, eliminates the necessity of column regeneration, and allows mobile phase recycling; and (iii) lower ionic strength (reduced from 0.4 to 0.26 or 0.12 M ammonium phosphate) and higher pH (increased from 3.25 to 5.55 or 6.98, respectively) mobile phase, conditions which are less destructive to the column's bonded phase and silica support, thereby contributing to longer column life. Enhancements include: (i) filtration of the sample prior to HPLC injection and addition of an in-line filter, guard column, and saturating precolumn of silica in the mobile phase flow, which aids substantially in extending column life and improves chromatographic stability, and (ii) inclusion of an internal standard to correct for mechanical losses. Limits of determination at a signal to noise ratio of 6:1 range from 5.5 to 12 pmol on-column or 0.41 to 0.87 pmol/mg of embryonic tissue depending on the specific nucleotide. Recoveries are quantitative for all nucleotides, and interassay variabilities are between 5 and 7% when quantified by peak height. The method has also been applied successfully to analysis of murine erythroleukemic cell cultures and this, when coupled with the embryo results, suggests its general utility.