Biochemical separations by continuous-bed chromatography

Innovations in column-packing media for biomolecule purification have progressed from large spherical, porous polysaccharide beads to advanced polymeric supports. Continuous-bed technology is a radical new technology for chromatography based on the polymerization of advanced monomers and ionomers directly in the chromatographic column. The polymer chains form aggregates which coalesce into a dense, homogeneous network of interconnected nodules consisting of microparticles with an average diameter of 3000 A. The voids or channels between the nodules are large enough to permit a high hydrodynamic flow. Due to the high cross-linking of the polymer matrix, the surface of each nodule is nonporous yet the polymeric microparticles provide a very large surface area for high binding capacity. This paper will demonstrate the properties and advantages of using a continuous bed support for high resolution biomolecule separations at high flow-rates without sacrificing capacity.

[Direct vision mitral valve reconstruction: a long-term follow-up of 46 cases]

OBJECTIVE

To improve the long-term results of direct vision mitral valve reconstruction.

METHOD

From July 1983 through July 1995, 46 patients with mitral valve disease were treated by a direct vision reconstructive techniques. Rheumatic valve stenosis and incompetence were noted in 39 (patients), nonrheumatic insufficiencies in 5, and congenital disease in 2. According to leaflet pliability, type I normal leaflet motion was notedin 17 patients, type II leaflet prolapse in 3 and type III restricted leaflet motion in 29. Cardiac function (NYHA classification) showed class II in 2, class in 25 III, and class IV in 19. Valvuloplasty and annuloplasty were performed with various techniques according to the pathanatomical changes of the valve. Prosthetic obturators self made were employed in 29 patients.

RESULT

The operative mortality rate was 6% (3/46). In the mitral valve replacement group it was 10% (27/265). Two to 10 years (mean 65 months) follow-up showed grade I cardiac function in 6 patients, grade II in 17, grade III in 8, and grade IV in 3.

CONCLUSION

Good long-term results can be achieved by valve reconstruction with lower mortality and incidence of thromboembolism than.

[Inhibitor of plasminogen activator 1 (PAI-1) in hepatocellular carcinoma]

OBJECTIVE

To study the expression of the type-1 inhibitor of plasminogen activator (PAI-1) on protein and mRNA in hepatocellular carcinoma (HCC), and the relation between PAI-1 and biological behaviour of HCC.

METHOD

The tumor specimens of HCC (n = 48) and benign liver tumor (contorl n = 12) were tested by immunohistochemistry for the expression of PAI-1 protein. The tumor specimens of HCC (n = 20) and normal liver tissue (contorl n = 5) were evaluated by Northern blot analysis for the expression of PAI-1 mRNA.

RESULT

PAI-1 protein and PAI-1 mRNA were higher in tumor cell than in the marginal tissue of tumor and in control (P < 0.01 and P < 0.05). In deaths 2 years after surgery, PAI-1 was increased as compared to the survival group (P < 0.05). When negative PAI-1 conupared with positive urokinase-type plasminogen activator (uPA) and positive uPA receptor (uPAR). The nambeigs invasion case increased, the difference was more significant than that in the group with negative PAI-1, uPA and uPAR (P = 0.039).

CONCLUSION

The expression of PAI-1 protein and PAI-1 mRNA is increased in HCC. PAI-1 contributes to the invasion, metastasis and prognosis of HCC.

OCI-5/GPC3, a glypican encoded by a gene that is mutated in the Simpson-Golabi-Behmel overgrowth syndrome, induces apoptosis in a cell line-specific manner

OCI-5/GPC3 is a member of the glypican family. Glypicans are heparan sulfate proteoglycans that are bound to the cell surface through a glycosyl-phosphatidylinositol anchor. It has recently been shown that the OCI-5/GPC3 gene is mutated in patients with the Simpson-Golabi-Behmel Syndrome (SGBS), an X-linked disorder characterized by pre- and postnatal overgrowth and various visceral and skeletal dysmorphisms. Some of these dysmorphisms could be the result of deficient growth inhibition or apoptosis in certain cell types during development. Here we present evidence indicating that OCI-5/GPC3 induces apoptosis in cell lines derived from mesothelioma (II14) and breast cancer (MCF-7). This induction, however, is cell line specific since it is not observed in NIH 3T3 fibroblasts or HT-29 colorectal tumor cells. We also show that the apoptosis-inducing activity in II14 and MCF-7 cells requires the anchoring of OCI-5/GPC3 to the cell membrane. The glycosaminoglycan chains, on the other hand, are not required. MCF-7 cells can be rescued from OCI-5/GPC3-induced cell death by insulin-like growth factor 2. This factor has been implicated in Beckwith-Wiedemann, an overgrowth syndrome that has many similarities with SGBS. The discovery that OCI-5/GPC3 is able to induce apoptosis in a cell line- specific manner provides an insight into the mechanism that, at least in part, is responsible for the phenotype of SGBS patients.

[Long-term results of combined splenorenal shunt and porta-azygos devascularization in patients with portal hypertension]

OBJECTIVE

To investigate the long-term effects of combined splenorenal shunt and porta-azygos devascularization in patients with portal hypertension.

METHOD

We analysed retrospectively the follow-up results of 140 portal hypertensive patients undergoing the combined therapy in our hospital from April 1978 to April 1997. Changes of portal hemodynamics were studied by Doppler Flowmeter and DSA pre- and-postoperatively and direct FPP measurement intraoperatively.

RESULT

The operative mortality was 3.6%. No rebleeding was noted in a short period and rebleeding rate was 8.3% in a long term follow-up. The rate of postoperative hepatic encephalopathy was 5.0%. The long-term survival rate of 5-, 10- and 15-years was 83.6%, 64.5% and 54.5%, respectively. After operation FPP and PVP decreased significantly (P < 0.01) and FPP maintained at the level of 3.2 +/- 0.4 kPa.

CONCLUSION

The combined procedure is a rational and practical procedure for the treatment of patients with portal hypertension.

[Observation on inhibitory effect of Coptis alone and its combination with Scutellaria and Liquorice on the growth of Staphylococcus aureus]

Using MIC as relative index, an observation was made on the growth inhibition of Staphylococcus aureus by Coptis alone or in combination with Scutellaria and or liquorice. The result shows that when Coptis is combined with Scutellaria, the bacteriostatic effect gets weaker for Scutellaria, but remains unchanged for Coptis, and when Scutellaria takes greater percentages in the combination, the effect of Coptis seems to be stronger. When Coptis is combined with liquorice, whatever the respective percentages may be, the effect tends to get weaker. When the three drugs are used in combination, the effect remains unchanged or even gets stronger for Coptis or liquorice, but tends to decrease for Scutellaria. Coptis used singly or in combination with Scutellaria or liquorice is inferior in bacteriostatic effect to the combination of the three drugs. The mechanism is yet to be further studied.

Apo A-I and apo E concentrations in cerebrospinal fluids of patients with acute meningitis

It has been demonstrated that apolipoproteins found in cerebrospinal fluid (CSF) play an important role in lipid metabolism in the central nervous system (CNS). Previously we reported that CSF apo A-I levels increased with the severity of neurological damage in poliovirus-infected macaques. In the present study, apo A-I was quantitatively analysed in CSF from patients with or without neurological diseases. In controls, CSF apo A-I level was significantly higher in males; 3.83 (0.40) mg/L, mean (SEM) (n = 19) compared with females, 2.42 (0.26) mg/L (n = 23, P < 0.05). CSF apo A-I concentrations in patients with acute meningitis increased at the active stage, 7.74 (1.78) mg/L (n = 10), but returned to basal concentrations at the convalescent stage 2.72 (0.38) mg/L (n = 10), while the CSF apo A-I level in patients with other neurological diseases remained in the same range as in controls. By contrast, CSF apo E was consistently elevated at either stage of acute meningitis. Furthermore, it was found that the levels of CSF apo A-I, but not of apo E, correlated positively with CSF albumin concentrations. These findings suggest that the CSF apo A-I and apo E have different origins and may play different roles in the lipoprotein metabolism in CNS.

Distribution of the receptor for a novel peptide stimulating phosphoinositide hydrolysis in human leukocytes

OBJECTIVES

Previously we reported that a synthetic peptide, WKYMVm, stimulates phosphoinositide (PI) hydrolysis in several hematopoietic cell lines and human neutrophils. In addition, the peptide induces superoxide generation in human neutrophils. The biochemical stimulation appeared to be mediated by specific receptors on leukocytes. In this report we try to find whether the specific receptor(s) exists on specific types of cells in human leukocytes.

DESIGN AND METHODS

To study distribution of the peptide-specific receptors, we prepared a probe, biotin-labeled WKYMVm, and analyzed distribution of the peptide receptor using a biochemical study, cytochemical staining, and flow cytometric analysis.

RESULTS

The peptide-specific receptors are expressed in several human leukocytes including granulocytes, monocytes, and B-lymphocytes but not T-lymphocytes and erythrocytes.

CONCLUSIONS

These data suggest that the receptors for the peptide restricted to certain types of leukocytes and this specificity is probably related to the specific functions of the stimulated leukocytes.

Antibody feedback and somatic mutation in B cells: regulation of mutation by immune complexes with IgG antibody

In response to an appropriate antigenic stimulus, and with help from T lymphocytes, naive B cells differentiate into plasmacytes which produce the primary (germline-encoded) IgM and IgG antibody with low affinity for the antigen. The isotype switch from IgM to IgG coincides with the burst of germinal center reaction and the onset of somatic hypermutation. Here we propose that formation of immune complexes between the residual antigen and the primary IgG antibody, which activate complement and localize specifically in the network of follicular dendritic cells, provides an important signal for triggering the mutation mechanism in germinal center B cells. This hypothesis has been supported by studies on immunogenicity of immune complexes in vivo. The experiments have included an immunization with pre-formed antigen/IgG antibody complex and/or an administration of IgG antibody shortly after the antigen injection. Either of these strategies, which are known to augment the germinal center formation, resulted in earlier onset of somatic mutation and increased mutation frequency in VDJ rearrangements in antigen-reactive B cells, provided that help from T cells was also present. It is presumed that the antigen/antibody/complement complex is able to deliver this important signal by cross-linking of antigen receptor with the CD21/CD19/CD81 molecules on B cells. As a corollary, the signaling by immune complexes may lower the threshold of cell activation determined by receptor affinity for antigen and stimulate diverse V-gene repertoire of B-cell clones in germinal centers.

IL-1 beta and TNF-alpha suppress apolipoprotein (apo) E secretion and apo A-I expression in HepG2 cells

The effect of cytokines on apolipoprotein E (apo E) production and secretion was investigated in a human hepatoma cell line HepG2. Incubation of HepG2 cells with interleukin 1 beta (IL-1 beta) or tumour necrosis factor alpha (TNF-alpha) for 48 h resulted in a significant dose-related decrease of apo E concentration in the culture medium, while intracellular apo E content increased without change in mRNA level. In contrast, IL-1 beta and TNF-alpha decreased both intracellular and medium apo A-I. Elution profiles of cholesterol and apolipoproteins revealed that apo E was present in apo E-rich high density lipoprotein (HDL) fraction and apo A-I was in apo E-rich HDL and small HDL fractions. IL-1 beta and TNF-alpha decreased both apo E and apo A-I in these fractions. The present results suggest that IL-1 beta and TNF-alpha suppress hepatic apo A-I expression and secretion but not expression of apo E, which could contribute to the abnormal lipid metabolism in certain cytokine-mediated inflammatory diseases.

[Studies on hygienic standard for ozone in indoor air]

OBJECTIVE

To formulate a national hygienic standard for ozone in indoor air.

METHODS

Indoor air ozone concentrations at variety of places were detected at its peak level in the daytime. Also, animal experiments exposed to low-level ozone were conducted to study the contents of lipid peroxide in the lungs, the ultrastructure of the bronchial epithelium and the phagocyte function of peritoneal macrophage.

RESULTS

Safety of ozone concentration of 0.1 mg/m3 in indoor air and feasibility to use it as hygienic standard were tested and proved.

CONCLUSION

The national hygienic standard for ozone in indoor air is recommended at 0.1 mg/m3 based on the data and relevant criteria at home and abroad.

A comparative study of transvaginal ultrasonography and pelvic arteriogram in assessment of patients with gestational trophoblastic tumour

OBJECTIVE

To compare the reliability of transvaginal ultrasonography with pelvic arteriography in the assessment of patients with gestational trophoblastic disease.

METHODS

Transvaginal ultrasonography was performed in 24 patients with gestational trophoblastic tumour. Within one week after ultrasound investigation, pelvic arteriography was carried out in each patient. Of 24 cases, 16 patients hadn't been treated by chemical reagent, 5 had accepted 2 to 5 courses of chemotherapy, and 3 had achieved complete remission before both investigations performed.

RESULTS

In 3 patients with complete remission, 2 had no evidence of abnormal findings either on transvaginal ultrasonography or on pelvic arteriography, 1 showed intramyometrial lesions by both methods. In the remaining 21 patients, all demonstrated a abnormal uterine image, and 5 of them accompanied with the finding of parametrium metastatic signs by transvaginal ultrasonography; these abnormal results were confirmed by pelvic arteriographic imaging. However, in two cases without clinical and ultrasonic signs of parametrium metastasis, pelvic arteriography indicated the early metastasis of parametrium vessels.

CONCLUSIONS

Even though it is difficult to predict the early parametrium metastasis in patients with gestational trophoblastic disease by B-ultrasonic investigation, our data would support the introduction of transvaginal ultrasonography in the diagnosis and evaluation of gestational trophoblastic tumour.

[Relationship between T-lymphocyte subpopulation and soluble interleukin-2 receptor (SIL-2R) in recurrent herpetic keratitis]

This article is to study the relationship between T-lymphocyte subpopulation and soluble interleukin-2 receptor (SIL-2R) in recurrent herpetic keratitis. We detected the T-lymphocyte subpopulation of peripheral blood and soluble interleukin-2 receptor(SIL-2R) in 30 cases of recurrent herpetic keratitis, 25 cases of healthy people were set as contrast. The results showed that there were obvious decrease and of CD3, CD4/CD8, and magnificent elevation of soluble interleukin-2 receptor(SIL-2R) in sera of recurrent herpetic keratitis cases when compared with the contrasts, we hold that the lower immune function in recurrent herpetic keratitis cases may attribute to the high level of soluble interleukin-2 receptor (SIL-2R) in the serum. The discovery can provide foundation for immunotherapy.

X-ray crystal structure of the yeast Kar3 motor domain complexed with Mg.ADP to 2.3 A resolution

The kinesin family of motor proteins, which contain a conserved motor domain of approximately 350 amino acids, generate movement against microtubules. Over 90 members of this family have been identified, including motors that move toward the minus or plus end of microtubules. The Kar3 protein from Saccharomyces cerevisiae is a minus end-directed kinesin family member that is involved in both nuclear fusion, or karyogamy, and mitosis. The Kar3 protein is 729 residues in length with the motor domain located in the C-terminal 347 residues. Recently, the three-dimensional structures of two kinesin family members have been reported. These structures include the motor domains of the plus end-directed kinesin heavy chain [Kull, F. J., et al. (1996) Nature 380, 550-555] and the minus end-directed Ncd [Sablin, E. P., et al. (1996) Nature 380, 555-559]. We now report the structure of the Kar3 protein complexed with Mg.ADP obtained from crystallographic data to 2.3 A. The structure is similar to those of the earlier kinesin family members, but shows differences as well, most notably in the length of helix alpha 4, a helix which is believed to be involved in conformational changes during the hydrolysis cycle.

Acetylcholinesterase enhances neurite growth and synapse development through alternative contributions of its hydrolytic capacity, core protein, and variable C termini

Accumulated indirect evidence suggests nerve growth-promoting activities for acetylcholinesterase (AChE). To determine unequivocally whether such activities exist, whether they are related to the capacities of this enzyme to hydrolyze acetylcholine and enhance synapse development, and whether they are associated with alternative splicing variants of AChEmRNA, we used four recombinant human AChEDNA vectors. When Xenopus laevis embryos were injected with a vector expressing the synapse-characteristic human AChE-E6, which contains the exon 6-encoded C terminus, cultured spinal neurons expressing this enzyme grew threefold faster than co-cultured control neurons. Similar enhancement occurred in neurons expressing an insertion-inactivated human AChE-E6-IN protein, containing the same C terminus, and displaying indistinguishable immunochemical and electrophoretic migration properties from AChE-E6, but incapable of hydrolyzing acetylcholine. In contrast, the nonsynaptic secretory human AChE-I4, which contains the pseudointron 4-derived C terminus, did not affect neurite growth. Moreover, no growth promotion occurred in neurons expressing the catalytically active C-terminally truncated human AChE-E4, demonstrating a dominant role for the E6-derived C terminus in neurite extension. Also, AChE-E6 was the only active enzyme variant to be associated with Xenopus membranes. However, postsynaptic length measurements demonstrated that both AChE-E6 and AChE-E4 enhanced the development of neuromuscular junctions in vivo, unlike the catalytically inert AChE-E6-IN and the nonsynaptic AChE-I4. These findings demonstrate an evolutionarily conserved synaptogenic activity for AChE that depends on its hydrolytic capacity but not on its membrane association. Moreover, this synaptogenic effect differs from the growth-promoting activity of AChE, which is unrelated to its hydrolytic capacity yet depends on its exon 6-mediated membrane association.

Clinical and echocardiographic outcomes of aortic intramural hemorrhage compared with acute aortic dissection

Aortic intramural hemorrhage (IMH), which presents clinical manifestations identical to those of acute aortic dissection, is different from aortic dissection in terms of the absence of intimal tear and communication of blood flow between the true and false lumen. This study was conducted for the purpose of diagnosing IMH by transesophageal echocardiography (TEE) prospectively and comparing the clinical and echocardiographic outcome of IMH with aortic dissection. Between August 1991 and November 1996, 27 IMHs and 73 acute aortic dissections were diagnosed using TEE in 202 consecutive patients with suspected aortic dissections. The TEE diagnoses of IMH and aortic dissection were initially compared with computed tomography and magnetic resonance imaging and later confirmed by operative findings (n = 37) or follow-up changes (n = 12). In the 49 patients whose diagnosis was confirmed by operation or follow-up changes, the sensitivity and specificity of TEE for the diagnosis of IMH were 27 of 27 (100%) and 20 of 22 (91%), respectively. There were 11 deaths in 73 patients (15%) from acute aortic dissection and 1 death in 27 patients (4%) from IMH during a follow-up of 1.7+/-1.5 years (p = NS). Stanford classification and types of treatment were not related to death in both groups. Complications developed less often in patients with IMH (3 of 27) than in those with acute aortic dissection (24 of 73), and no death occurred in patients with uncomplicated IMH who were medically treated. A follow-up imaging study of 12 IMH patients showed complete resolution in 8, regression in 3, and progression in 1 patient. TEE is accurate in the diagnosis of IMH and IMH has a lower incidence of complications than aortic dissection because of the absence of intimal tear and communication of blood flow in the false lumen.

Localization of two forms of phospholipase C-beta1, a and b, in C6Bu-1 cells

Phospholipase C-beta1 (PLC-beta1), one of the PLC-beta isozymes, exists as two immunologically distinguishable polypeptides of 150 (PLC-beta1a) and 140 kDa (PLC-beta1b) which are encoded in two distinct transcripts and generated by alternative splicing of a single gene. In this study, the subcellular localization of the two phospholipases C-beta1 proteins was examined in rat C6Bu-1 glioma cells using immunological techniques. Immunoblot analysis revealed that the two forms of PLC-beta1 were detectable in both cytosolic and nuclear fractions. PLC-beta1a appeared to be located preferentially in the cytosol, whereas PLC-beta1b was found predominantly in the nuclei of C6Bu-1 cells. Immunocytochemical experiments confirmed the differential localization of the two PLC-beta1 species in C6Bu-1 cells. These results suggest that the two PLC-beta1 proteins may have different physiological roles in the cell.

Comparison of outcomes of percutaneous mitral valvuloplasty versus mitral valve replacement after resolution of left atrial appendage thrombi by warfarin therapy

This study assesses the efficacy of oral anticoagulation in resolving left atrial appendage (LAA) thrombi and evaluates clinical outcomes of percutaneous mitral valvuloplasty after resolution of LAA thrombi compared with mitral valve replacement. Warfarin therapy is successful in resolving LAA thrombi; percutaneous mitral valvuloplasty after resolution of LAA thrombi is an effective alternative to surgical treatment.

[Comparative study on the retention effect of the inhaled mineral and coal dusts in rat lung]

The pulmonary retention and physico-chemical characteristics of the dust are very important factors in the occurrence of pneumoconiosis. This paper reports a comparative study on the retention characteristics between the inhaled mineral dust and coal dust in rat lung. The dust quantities in the lungs and the mediastinal lymphatic nodes were determined by the formic acid digestion method. The results showed that the pulmonary retention quantities of the coal dust in rats were higher than those of the mineral dust on the third day but lower on the 90th day after exposure for two weeks. The results suggest that the mineral dust can deposit in the lung longer than the coal dust, and the lymphatic system is important for the pulmonary elimination of the dust.

[Effects of low concentration ozone on the respiratory system of mice]

Effects of low concentration of O3 on the respiratory system in mice were studied in the present study. Mice were exposed to 0.1, 0.25 and 1.0 mg/m3 of O3, respectively for 8 h per day for 3 days. Cilia in brochia, Lipid peroxide (LPO) in lung tissue and phagocytic function of macrophage in mice were examined. The results showed that there were cilia damage in the 1.0 mg/m3 group and swelling of mitochondrias as well as endoplasmic reticulums in the 0.25 mg/m3 group. But no damage was found in the group of 0.1 mg/m3. Furthermore, phagocytic rates in the 0.25 and 1.0 mg/m3 groups were significantly lower than that of control group (P < 0.01). No differences in LPO leads were found.

Overexpression of phospholipase C-gamma1 in rat 3Y1 fibroblast cells leads to malignant transformation

Phospholipase C-gamma1 (PLC-gamma1) mediates signals from various extracellular origins to evoke cellular events such as mitogenesis. Previously, we reported that PLC-gamma1 was highly expressed in colorectal cancer and familial adenomatous polyposis, suggesting that PLC-gamma1 might be oncogenic. In this study, we have established rat 3Y1 fibroblasts that overexpress whole PLC-gamma1 and src homology 2 (SH2)-SH2-SH3 domain of PLC-gamma1. These cells showed a transformed phenotype and were tumorigenic when transplanted into nude mice. These results indicate that overexpression of PLC-gamma1 could transform rat fibroblasts, and the transformation is mediated by SH2-SH2-SH3 domain of PLC-gamma1.

Age-related changes in antibody repertoire: contribution from T cells

The immune system of aged mice produces antibodies that are characterized by low affinity, diminished protection against infections and autoreactivity. It has been shown that these antibodies may be encoded by different immunoglobulin V genes and that the mechanism of somatic hypermutation in the V genes is inefficient. Studies on scid mice reconstituted with B and T cells from donors of different ages suggested that both lymphocyte subsets may contribute to the age-related changes in antibody repertoire. With help provided by T cells from young mice, the response to a hapten, nitrophenyl(acetyl), became gradually dominated by B-cell clones that rearranged a particular germline VH gene (V186.2). However, help from the aged T cells resulted in a heterogeneous response of B cells expressing many different V segments. Analysis of discrete foci of primary antibody-forming cells suggested that the aged T-helper cells are unable to govern the normally-occurring competition between the B-cell clones that have different affinities for the hapten. It is proposed that a signaling disequilibrium from the aged T cells, which provide less efficient help in quantitative terms, supports the growth of low-affinity B cells. This process may be exacerbated due to the apparent hyperactivity of aged B cells to CD40-mediated mitogenic signal.

Impact of a function-based payment model on the financial performance of acute inpatient medical rehabilitation providers: a simulation analysis

OBJECTIVES

To operationalize research findings about a medical rehabilitation classification and payment model by building a prototype of a prospective payment system, and to determine whether this prototype model promotes payment equity. This latter objective is accomplished by identifying whether any facility or payment model characteristics are systematically associated with financial performance.

DESIGN

This study was conducted in two phases. In Phase 1 the components of a diagnosis-related group (DRG)-like payment system, including a base rate, function-related group (FRG) weights, and adjusters, were identified and estimated using hospital cost functions. Phase 2 consisted of a simulation analysis in which each facility's financial performance was modeled, based on its 1990-1991 case mix. A multivariate regression equation was conducted to assess the extent to which characteristics of 42 rehabilitation facilities contribute toward determining financial performance under the present Medicare payment system as well as under the hypothetical model developed.

PARTICIPANTS

Phase 1 (model development) included 61 rehabilitation hospitals. Approximately 59% were rehabilitation units within a general hospital and 48% were teaching facilities. The number of rehabilitation beds averaged 52. Phase 2 of the stimulation analysis included 42 rehabilitation facilities, subscribers to UDS in 1990-1991. Of these, 69% were rehabilitation units and 52% were teaching facilities. The number of rehabilitation beds averaged 48.

MAIN OUTCOME MEASURE

Financial performance, as measured by the ratio of reimbursement to average costs.

RESULTS

Case-mix index is the primary determinant of financial performance under the present Medicare payment system. None of the facility characteristics included in this analysis were associated with financial performance under the hypothetical FRG payment model.

CONCLUSIONS

The most notable impact of an FRG-based payment model would be to create a stronger link between resource intensity and level of reimbursement, resulting in greater equity in the reimbursement of inpatient medical rehabilitation hospitals.

Mutation and downregulation of the transforming growth factor beta type II receptor gene in primary squamous cell carcinomas of the head and neck

In the present study, we analyzed 28 squamous cell carcinomas of the head and neck (SCCHN) for mutations in the coding region of TbetaR-II using 'Cold' SSCP and automatic DNA sequencing analyses. Twenty-one percent (6/28) of the SCCHN examined contained TbetaR-II mutations compared with patient-matched normal tissues. These alterations included five missense mutations (A:T-->G:C transitions in codons 250, 401, 448 and 488, and a G:C-->T:A transversion in codon 373), and a 38-bp deletion between nucleotides 1825 to 1862. In addition to these code-altering mutations, one case exhibited a silent mutation (A:T-->G:C transition in codon 451) and three cases contained one of two potential population polymorphisms (codons 354 and 389). In contrast to colon and gastric cancers exhibiting microsatellite instability (MI) or replication errors (RER+), no 'indirect' frameshift mutations were identified within a 10-bp polyadenine repeat present in the TbetaR-II coding sequence. All of the mutations in the present study occurred within the highly conserved serine/threonine kinase domain and represent the first report of such 'direct' TbetaR-II mutations in primary human tumors. In addition, we analyzed a subset of SCCHN and corresponding normal samples for TbetaR-II mRNA expression using semi-quantitative multiplex RT-PCR. Expression of TbetaR-II was decreased by 24% to 74% in 20 of 23 SCCHN (87%) compared with patient-matched normal tissues. Taken together, the results from this study suggest that alterations in the nucleic acid sequence and mRNA expression of TbetaR-II are prevalent events in the development of SCCHN, which may deregulate cell cycle control.

[The effects of Gu Chi Gao on IL-8 in GCF of periodontitis]

In order to find a new treatment of periodontitis, this paper studied the effects of Gu Chi Gao on IL-8 in gingival crevicular fluid (GCF) of periodontitis. One tooth was selected from every patient in 24 patients with adult periodontitis. After supragingival scaling, the patients were divided into two groups randomly. One group was treated with Gu Chi Gao, while the other group was untreated as control group. All patients were examined after one month. GCF samples were collected with 2 mm x 20 mm Whatman I filter paper stripes and IL-8 in the GCF samples were detected by the method of ELISA. The result demonstrated that the levels of GCF and IL-8 in the treated group were lower than that of control group (P < 0.01), it suggests that Gu Chi Gao may inhibit the production of IL-8 and GCF.

[Evaluation of emergency surgery in gestational trophoblastic tumours]

We retrospectively analyzed 27 cases of gestational trophoblastic neoplasia treated by emergency surgery from 1985-1996 at PUMC hospital. Seventeen cases were diagnosed of choriocarcinoma and 10 were invasive mole. Sixteen out of 27 patients were subjected to hysterectomy because of uterine perforation or severe uterine bleeding; 4 cases received unilateral oophorectomy because of torsion of theca lutein cyst. Emergency open surgery and excision of the metastatic brain tumour were undertaken in 3 patients with elevated intracranial pressure caused by brain edema and haemorrhage; 2 patients showed lifethreatening haemorrhage from vaginal metastatic tumour and were managed by operative intervention. Partial jejunectomy was performed in 2 patients due to rupture of jejunal metastatic mass. Of these 27 cases, 17 hadn't been treated with chemical reagents and 6 cases had received one course of chemotherapy before surgical procedures. After multiple courses of combined chemotherapy postoperatively, 23 patients had achieved complete remission. It is concluded that surgical intervention plays an important role in patients with trophoblastic disease when emergency situations (e.g. life-threatening haemorrhages) occur; early diagnosis and prompt initiation of chemotherapy might have rendered surgery unnecessary.

Cerebrospinal fluid apo E and apo A-I concentrations in early- and late-onset Alzheimer's disease

We compared cerebrospinal fluid (CSF) apolipoprotein (apo) A-I and apo E concentrations in early- and late-onset Alzheimer's disease (EOAD (n = 11), LOAD (n = 15), respectively) with those in control subjects (n = 23). CSF apo A-I levels in both EOAD and LOAD were consistent with control subjects. However, CSF apo E levels were significantly lower in EOAD group (mean +/- SD; 2.65 +/- 1.69 mg/l, P < 0.05) and higher in LOAD group (5.90 +/- 1.94 mg/l, P < 0.01) than those in control group (4.16 +/- 1.69 mg/l). In addition, the epsilon4 allele frequency was not different between EOAD and LOAD groups. Although the reason for the difference in CSF apo E concentrations between two groups is unknown, CSF apo E concentration seems to be associated with the pathogenesis of EOAD and LOAD. The rate of apo E production and/or catabolism in the brain may be different between them.

Evidence for K+ channels involvement in capillary sensing and for bidirectionality in capillary communication

Although the capillary sensing and communication phenomenon has been characterized, its mechanism is not clear. It has been hypothesized that capillary sensing involves a membrane potential change in the capillary endothelium and/or pericyte and that communication represents an electrotonic spread of this change along the capillary. The goal of the present study was to address this hypothesis by examining the presence of K+ channels on the capillary and by determining bidirectionality of communication. Using intravital microscopy, we locally applied K+ (100 mM), acetylcholine (ACh; 3 mM), and norepinephrine (NE; 0.3 mM) on capillaries, 400-500 microns downstream from the arteriole, at the surface of the sartorius muscle in anesthetized frogs. Responses were measured in terms of red blood cell velocity (VRBC) changes in the stimulated capillary (control prestimulation VRBC ranged from 110 to 770 microns/sec). K+ and ACh caused significant 19 and 38% increases in VRBC, while NE caused a -46% decrease, respectively. The K+ response was blocked by local pretreatment with K+ channel blocker BaCl2 (1 microM) and by pretreatment with tetraethyl ammonium chloride (TEA; 5 mM). Responses to ACh and NE were attenuated by pretreatment with 1 microM BaCl2 (to 1%) and with 50 mM TEA (to -25%), respectively. In a separate experiment, NE (3 mM) application on the capillary 500 microns away from the draining venule (capillary occluded) caused a 19% venular constriction (i.e., similar to a reported 21% arteriolar constriction caused by the NE stimulus). We concluded that (i) K+ channels were present on the capillary and (ii) capillary communication was bidirectional. We interpreted these results to be consistent with the above hypothesis of membrane potential change and electrotonic spread.

Expression of a putative vesicular acetylcholine transporter facilitates quantal transmitter packaging

A putative vesicular acetylcholine transporter (VAChT) was overexpressed in developing Xenopus spinal neurons by injection of rat VAChT cDNA or synthetic mRNA into Xenopus embryos. This resulted in a marked increase in the amplitude and frequency of miniature excitatory postsynaptic currents at neuromuscular synapses, reflecting an over 10-fold increase in the vesicular packaging of acetylcholine (ACh). The effect appeared in developing neurons even before synaptogenesis and was blocked by L-vesamicol, a specific blocker of ACh uptake into synaptic vesicles. Mutational studies showed that two highly conserved aspartate residues within putative transmembrane domains 4 and 10 are essential for the transport activity. These results provide direct evidence for the physiological function of a putative VAChT and demonstrate that quantal size can be regulated by changes in vesicular transporter activity.

[Nucleotide sequence of gltB gene encoding the large subunit of Rhodobacter sphaeroides glutamate synthase]

The complete nucleotide sequence of a 5.4-kb chromosomal EcoRI-SalI fragment was determined, which contains the structural gene (gltB) for the large subunit of Rhodobacter sphaeroides glutamate synthase, as well as the 5'- and 3'- flanking regions. A open reading frame of 4636 base pairs was identified as R. sphaeroides gltB gene. The MW of the large subunit, as deduced from the nucleotide sequence, was estimated as 164kD. Comparision of the nucleotide sequences revealed a high similarity among gltB genes of R. sphaeroides, Azospirillum brasilense and Escherichia coli. The deduced amino acid sequence of R. sphaeroides GltB showed a high similarity with that of A. brasilense GltB.

[Effect of Yang-warming and Qi-tonifying natural products on neuroendocrine of deficiency-cold rats]

The rat fed with the compound drug Zhi Mu and Shi Gao was made into an animal model of deficiency cold syndrome. The deficiency cold state was kept for more than 7 days after stopping the drug. So the animal model is good for studing the therapeutic effect of products of heat nature. After 3 therapeutic days with Fu Jiang and Shen Qi compounds, the D beta H activity in serum, cortisone in adrenal gland and NE, DA amount in brain were increased, but serotonin was decreased, and after 7 days the effect was increased significantly. Both compounds could excite the sympathetic nerve and endocrine system in the peripheral and central nervous systems. Shen Qi compound acts quickly, but does not last as long as Fu Jiang. The effect will be better if the two compounds are used together.

[Preparation and characterization of recombinant retroviral vector containing t-PA cDNA]

A recombinant retroviral vector containing tissue-type plasminogen activator (t-PA) cDNA was constructed and transfected into PA317 viral packaging cells, forming intact virus particles. Under electron microscope the recombinant retroviral particles were composed of envelope, capsid and core. These viral particles were spherical with a diameter of 90-180nm, and spread dispersely in the cells. NIH3T3 cell infected by retrovirus particles were screened with G418. The virus titer of 6 x 10(8) CFU/L was verified by counting the positive clones two weeks after screening. The expression of t-PA was demonstrated in the NIH3T3 cells infected with the recombinant virus.

[The expression of IL-1 alpha gene in gingival tissue]

IL-1 is secreted by a variety of cells and plays an important role in the network of cytokines. In this study, the expression of IL-1 alpha in gingival tissue was determined with reverse transcription-polymerase chain reaction (RT-PCR). The PCR-product was confirmed by DNA sequencing. The results showed that IL-1 alpha transcription was detected in all 5 inflammatory gingival tissue samples, but it was not delected in the normal gingival tissue samples and in the samples after treatment. These findings suggested that IL-1 alpha may be a specific indicator of periodontal disease, and a potential mediator in pathogenesis of periodontitis.

In vitro motility of AtKCBP, a calmodulin-binding kinesin protein of Arabidopsis

AtKCBP is a calcium-dependent calmodulin-binding protein from Arabidopsis that contains a conserved kinesin microtubule motor domain. Calmodulin has been shown previously to bind to heavy chains of the unconventional myosins, where it is required for in vitro motility of brush border myosin I, but AtKCBP is the first kinesin-related heavy chain reported to be capable of binding specifically to calmodulin. Other kinesin proteins have been identified in Arabidopsis, but none of these binds to calmodulin, and none has been demonstrated to be a microtubule motor. We have tested bacterially expressed AtKCBP for the ability to bind microtubules to a glass surface and induce gliding of microtubules across the glass surface. We find that AtKCBP is a microtubule motor protein that moves on microtubules toward the minus ends, with the opposite polarity as kinesin. In the presence of calcium and calmodulin, AtKCBP no longer binds microtubules to the coverslip surface. This contrasts strikingly with the requirement of calmodulin for in vitro motility of brush border myosin I. Calmodulin could regulate AtKCBP binding to microtubules in the cell by inhibiting the binding of the motor to microtubules. The ability to bind to calmodulin provides an evolutionary link between the kinesin and myosin motor proteins, but our results indicate that the mechanisms of interaction and regulation of kinesin and myosin heavy chains by calmodulin are likely to differ significantly.

Failure of insulin-like growth factor type I to suppress HIV type 1 in adult or umbilical cord mononuclear blood cells

Insulin-like growth factor type I (IGF-I) has been used as a treatment for cachexia in adults with AIDS and has been reported to show inhibitory activity against HIV-1IIIB in cord blood mononuclear cells (CBMCs) in vitro at low-concentration (1%) fetal bovine serum (FCS). We evaluated the effect of IGF-I on MN, IIIB, and BaL strains, as well as on a patient isolate of HIV-1 in CBMCs and adult peripheral blood mononuclear cells (PBMCs). IGF-I failed to show any inhibitory effect on HIV replication in CBMCs or adult PBMCs under various culture conditions. In contrast to an earlier report of an antiviral effect, IGF-I augmented HIV-1 replication in PHA-stimulated PBMCs maintained in a low concentration of FCS.

Marked increases in concentrations of apolipoprotein in the cerebrospinal fluid of poliovirus-infected macaques: relations between apolipoprotein concentrations and severity of brain injury

Apolipoproteins in cerebrospinal fluid (CSF) might have important functional roles in the pathophysiology of brain and lipid metabolism in the vascular component. The present study examined apolipoprotein A-I (apo-A-I) and apolipoprotein E (apo-E) levels in CSF and serum from poliovirus-infected macaques. Poliovirus-infected macaques developed motor deficits and were classified into three groups: (1) muscle weakness in one or both legs; (2) partial paralysis in one or both legs; (3) complete paralysis in one or both legs. No motor deficits were evident in the control or sham-treated macaques. Apo-A-I concentrations in CSF were markedly elevated in poliovirus-infected macaques with weakness, partial or complete paralysis, in comparison with either control or sham-treated animals, and were proportional to the severity of motor impairment. Apo-E concentrations in CSF were also significantly elevated in poliovirus-infected macaques with complete paralysis. The magnitude of increase in CSF apo-A-I or apo-E concentrations was also closely associated with the degree of histologic neurological damage and inflammation (lesion scores). However, no changes in serum apo-A-I and apo-E concentrations were observed in the poliovirus-infected macaques compared with control macaques. Furthermore there were no significant correlations apo-A-I or apo-E concentrations between serum and CSF. We hypothesize that the elevation of apo-A-I and apo-E concentrations after poliovirus infection is caused by immune stimulation within the central nervous system (CNS). Measures of CSF apo-A-I and apo-E levels might serve as a useful marker for the severity and/or the range of CNS injury.

[Clinical significance of changes of fibrillation potential amplitude following denervation of human skeletal muscle]

To evaluate the value of clinical application of examination of fibrillation potential amplitude, 110 patients, 97 males and 13 females, were examined and only the maximum fibrillation potential amplitudes were recorded in 420 muscles. The results showed that there was no significant difference between sexes, ages and sides. However, significant difference was evident between the groups of different frequency (1+ to 4+). The fibrillation potential amplitude was maximum at 3 to 4 months after denervation and still remained at relatively high level for years in certain patients. No significant difference was showed between the time groups in incomplete nerve injuries. Surgery did not affect the course of fibrillation potential amplitude change. It was suggested that the muscle cells sustained their property for years after denervation in some patients, thus it might explain that satisfactory result could be obtained from operative repair in some late cases. The changes of fibrillation potential amplitude might indicate that the changes from muscle denervation was still reversible and might be more accurate than traditional method of examination.

Fibroblast growth factor 2 can replace ectodermal signaling for feather development

The initiation and morphogenesis of cutaneous appendages depend on a series of reciprocal signaling events between the epithelium and mesenchyme of the embryonic skin. In the development of feather germs, early dermal signals induce the formation of epidermal placodes that in turn signal the mesoderm to form dermal condensations immediately beneath them. We find a spatially and temporally restricted pattern of transcription for the genes that encode fibroblast growth factor (FGF) 2 and FGF receptor (FGFR) 1 in developing feather germs of the chicken embryo. FGF-2 expression is restricted to the epidermal placodes, whereas FGFR-1 expression is limited to the dermal condensations. Transcription of these genes could not be detected in skins of scaleless (sc/sc) embryos that fail to develop feathers as a result of an ectodermal defect. Treatment of sc/sc skins with FGF-2 results in the formation of feathers at the site of application of the growth factor and the induced feathers express FGFR-1 in their dermal condensations. Thus, we have established FGF-2 as an epidermal signal in early feather germ formation. The observation that FGF-2 can rescue the mutant phenotype of sc/sc embryos suggests that FGF-2 either is, or is downstream from, the signal that the sc/sc mutant ectoderm fails to generate.

The spatial relationship between infant mortality and birth defect rates in a U.S. city

The spatial patterns of infant mortality and birth defect rates in the Des Moines, Iowa, urban region are described as a contoured surface based on the punctual kriging of address-matched vital statistics records from The Iowa Department of Public Health. Areas defined as having high rates are shown to be sensitive to the size of the spatial filtering units. There is no correlation between infant mortality and birth defect rates in the region. The significance of areas with high rates is determined by a Monte Carlo simulation procedure. One area of high infant mortality is found in the region, which contrasts with many smaller areas with high birth defect rates in the region. The observed birth defect rate pattern is consistent with the hypothesis that each birth was equally likely to result in a birth defect, while the infant mortality pattern is unlikely to be the result of such an equal likelihood process.

[Curcuma longa L. tuber yield simulation model and its application under combined agronomic measures for good-quality, high-yield and obvious economic results]

A design of second order orthogonal rotative regression was developed and field tested, and the tuber models for yield, quality and benefit were simulated and built. The effect of agronomic measures on the tuber yield is plant density > phosphorus > sowing date > nitrogen > potassium. There is a clear interrelation effect among agronomic measures. The results of simulation experiment have shown that the optimal combination of farming practices can greatly increase the tuber yield, quality and benefit, and is adjusted according to climate, soil, ferilizer or manure sources, and so on.

A role of PDI in the reductive cleavage of mixed disulfides

We previously reported that protein disulfide isomerase (PDI) can dissociate the glutathione molecule in vitro from the mutant human lysozyme (hLZM) C77A-a, which is modified with glutathione at Cys95; however, it seems structurally difficult for PDI to attack either the disulfide bond or the side chain of the cysteine residue of a mixed disulfide. To investigate the function of PDI, we introduced several glutathione and cysteine derivatives at Cys95, instead of the glutathione of C77A-a. Using thiol compounds modified by 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), we could easily modify the free thiol group of C77A-b (C77A with no glutathionylation), without denaturation. For all of the modifications we tested, a negative correlation was found between the initial rate and the acceleration ratio of the reductive cleavage of mixed disulfides with PDI. A mutant PDI (hPDIM), which has no thiol-disulfide exchange activity, suppressed the reductive cleavage of the mixed disulfide of C77A-a with hPDI, suggesting that hPDI non-covalently interacted with the substrates. Taking account of the results of the structural analysis, we conclude that one of the functions of PDI in vivo lies in relaxing the structure around the disulfide bond, as well as in exchanging the thiol-disulfide bonds.

Binding sites on microtubules of kinesin motors of the same or opposite polarity

The kinesin motor proteins translocate toward either the plus or minus end of microtubules (MTs). Competitive microtubule binding assays were carried out with monomeric motor domains of the minus-end-directed nonclaret disjunctional (Ncd) and Kar3 and the plus-end-directed kinesin heavy chain (KHC) to determine whether motors of the same or opposite polarity compete for binding sites on MTs and to test the idea that motor polarity is determined by differences in binding sites on MTs of the motors. The stoichiometries of binding were approximately 1 motor:1 tubulin heterodimer for all three motors. Ncd and Kar3, both minus-end motors, severely inhibited the binding of one another to MTs, as predicted theoretically for binding of the two motors to the same site on MTs, indicating that the binding sites on MTs of Ncd and Kar3 are the same or overlap extensively. Motors of opposite polarity, KHC and Ncd or KHC and Kar3, showed partial or complete inhibition of binding to MTs under different experimental protocols. The differences in binding behavior could be due to experimental conditions or be inherent in the nature of motor binding to MTs. Alternatively, differences in KHC and Ncd or Kar3 binding sites on MTs may exist such that the motors bind to partially overlapping but nonidentical sites on MTs. These differences in binding sites may be related to the opposite polarity of translocation on MTs of the motors.

[Effects of blood pressure day-nocturnal rhythm and endothelin in patients of sleep apnea syndrome]

OBJECTIVE

To analyse the change of blood pressure and endothelin in sleep apnea syndrome.

METHODS

The ambulatory blood pressure, echocardiogram and plasma endothelin in 164 cases of hypertension and normal controls with or without sleep apnea syndrome (SAS) were examined. The patients were divided into four groups and 41 cases were in each group.

RESULTS

The results showed that in a number of the patients of sleep apnea with or without hypertension blood pressure day nocturnal rhythm disappeared and endothelin increased (18.2 +/- 5.7 ng/L and 13.2 +/- 4.4 ng/L) The difference of nocturnal blood pressure and endothelin between SAS groups and non-SAS groups (11.7 +/- 3.9 ng/L and 4.3 +/- 2.1 ng/L) were statistically significant (P < 0.05 and P < 0.01).

CONCLUSION

It was suggested that the SAS patients might be due to cyclical hypoxemia and nerve-endocrine abnormality activating endothelin, and other vasoactive peptides with increased blood pressure during sleep and enhance the damage to target organs.

A point mutation in the microtubule binding region of the Ncd motor protein reduces motor velocity

Non-claret disjunctional (Ncd) is a kinesin-related microtubule motor protein in Drosophila that functions in meiotic spindle assembly in oocytes and spindle pole maintenance in early embryos. The partial loss-of-function mutant ncdD retains mitotic, but not meiotic, function. The predicted NcdD mutant protein contains a V556-->F mutation in the putative microtubule binding region of the Ncd motor domain. Here we report an analysis of the properties of recombinant Ncd and NcdD proteins. A GST-NcdD fusion protein translocated microtubules approximately 10-fold more slowly than the corresponding wild-type protein in gliding assays. The maximum microtubule-stimulated ATPase activity of an NcdD motor domain protein was reduced approximately 3-fold and an approximately 3-fold greater concentration of microtubules was required for half-maximal stimulation of ATPase activity, compared with the corresponding wild-type protein. The Km for ATP and basal rate of ATP turnover were, in contrast, similar for the NcdD mutant and wild-type Ncd motor domain proteins. Pelleting assays demonstrated that the binding of the mutant NcdD motor protein to microtubules was reduced in the absence of nucleotide, relative to wild-type. The reduced velocity of NcdD translocation on microtubules is therefore correlated with reductions in microtubule-stimulated ATPase activity and affinity of the mutant motor for microtubules. The characteristics of the NcdD motor explain its meiotic loss of function, and are consistent with partial motor activity of Ncd being sufficient for its mitotic, but not its meiotic, role.