Absence of host B7 expression is sufficient for long-term murine vascularized heart allograft survival

CD28 antagonists have been shown to promote long-term graft survival and induce donor-specific tolerance. In this study, the role of CD28/B7 costimulation and the relative importance of host versus donor B7 expression in allograft rejection was assessed in a murine abdominal vascularized heterotopic heart transplant model. Wild-type, CD28-deficient, or B7-1/B7-2-deficient C57BL/6 (B6) mice were grafted with allogeneic wild type or B7-1/B7-2-deficient hearts. The results demonstrate allogeneic heart grafts survive long-term in mCTLA4Ig-treated B6 and untreated B7-1/B7-2-deficient B6 recipients but not CD28KO B6 mice. B7-1/B7-2KO B6 recipients treated with anti-CD28 (PV-1) or recombinant human IL-2 rejected the heart transplants indicating that these mice are immunologically competent to reject grafts if costimulatory signals are supplied or bypassed. Finally, there was no difference in rejection between normal animals transplanted with wild-type versus B7-1/B7-2-deficient hearts. These results support a critical role for B7-expressing host antigen presenting cells in the rejection of heart allografts in mice and differences among B7KO and CD28KO animals.

Clinical pharmacokinetics of the prodrug oseltamivir and its active metabolite Ro 64-0802

Oseltamivir is an ethyl ester prodrug of Ro 64-0802, a selective inhibitor of influenza virus neuraminidase. Oral administration of oseltamivir delivers the active antiviral Ro 64-0802 to the bloodstream, and thus all sites of influenza infection (lung, nasal mucosa, middle ear) are accessible. The pharmacokinetic profile of oseltamivir is simple and predictable, and twice daily treatment results in effective antiviral plasma concentrations over the entire administration interval. After oral administration, oseltamivir is readily absorbed from the gastrointestinal tract and extensively converted to the active metabolite. The absolute bioavailability of the active metabolite from orally administered oseltamivir is 80%. The active metabolite is detectable in plasma within 30 minutes and reaches maximal concentrations after 3 to 4 hours. After peak plasma concentrations are attained, the concentration of the active metabolite declines with an apparent half-life of 6 to 10 hours. Oseltamivir is eliminated primarily by conversion to and renal excretion of the active metabolite. Renal clearance of both compounds exceeds glomerular filtration rate, indicating that renal tubular secretion contributes to their elimination via the anionic pathway. Neither compound interacts with cytochrome P450 mixed-function oxidases or glucuronosyltransferases. The pharmacokinetic profile of the active metabolite is linear and dose-proportional, with less than 2-fold accumulation over a dosage range of oseltamivir 50 to 500 mg twice daily. Steady-state plasma concentrations are achieved within 3 days of twice daily administration, and at a dosage of 75mg twice daily the steady-state plasma trough concentrations of active metabolite remain above the minimum inhibitory concentration for all influenza strains tested. Exposure to the active metabolite at steady state is approximately 25% higher in elderly compared with young individuals; however, no dosage adjustment is necessary. In patients with renal impairment, metabolite clearance decreases linearly with creatinine clearance. A dosage reduction to 75mg once daily is recommended for patients with creatinine clearance <30 ml/min (1.8 L/h). The pharmacokinetics in patients with influenza are qualitatively similar to those in healthy young adults. In vitro and in vivo studies indicate no clinically significant drug interactions. Neither paracetamol (acetaminophen) nor cimetidine altered the pharmacokinetics of Ro 64-0802. Coadministration of probenecid resulted in a 2.5-fold increase in exposure to Ro 64-0802; however, this competition is unlikely to result in clinically relevant effects. These properties make oseltamivir a suitable candidate for use in the prevention and treatment of influenza.

Identification of two novel mutations in the hypoglycemic phenotype of very long chain acyl-CoA dehydrogenase deficiency

Very long chain acyl-CoA dehydrogenase (VLCAD) catalyzes the initial step of long chain fatty acid oxidation in the mitochondria. Patients with VLCAD deficiency have recently been observed with two clinical phenotypes. The cardiac form presents with an early onset cardiomyopathy and a high incidence of infant death, while the hypoglycemic form resembles medium chain acyl-CoA dehydrogenase (MCAD) manifesting with hypoketotic hypoglycemia. In our investigation on the molecular basis for these phenotypes, we identified two novel mutations in one VLCAD patient with the hypoglycemic form, a C953T (Pro318Leu) mutation in exon 10 resulting in a substitution of proline 318 by leucine on one allele, and a C1194A (Tyr398Stop) mutation in exon 12 which created a premature stop codon TAA on another allele. The Tyr398Stop mutation may result in a truncated protein or instable messenger RNA.

Cutting edge: blockade of the CD28/B7 costimulatory pathway inhibits intestinal allograft rejection mediated by CD4+ but not CD8+ T cells

The effect of blocking the CD28/B7 costimulatory pathway on intestinal allograft rejection was examined in mice. Murine CTLA4Ig failed to prevent the rejection of allografts transplanted into wild-type or CD4 knockout (KO) mice but did inhibit allograft rejection by CD8 KO recipients. This effect was associated with decreased intragraft mRNA for IFN-gamma and TNF-alpha and increased mRNA for IL-4 and IL-5. This altered pattern of cytokine production was not observed in allografts from murine CTLA4Ig-treated CD4 KO mice. These data demonstrate that blockade of the CD28/B7 pathway has different effects on intestinal allograft rejection mediated by CD4+ and CD8+ T cells and suggest that these T cell subsets have different costimulatory requirements in vivo. The results also suggest that the inhibition of CD4+ T cell-mediated allograft rejection by CTLA4Ig may be related to down-regulation of Th1 cytokines and/or up-regulation of Th2 cytokines.

Angiotensin II stimulates DNA and protein synthesis in vascular smooth muscle cells from human arteries: role of extracellular signal-regulated kinases

OBJECTIVE

This study investigates the growth effects and associated signaling pathways of angiotensin II (Ang II) in human vascular smooth muscle cells.

METHODS

Cultured vascular smooth muscle cells derived from resistance arteries (< 300 microm diameter) from subcutaneous gluteal biopsies of healthy subjects (n = 6) and human aortic vascular smooth muscle cells were used. Cells were studied between passages 3 and 6. Both 3H-thymidine and 3H-leucine incorporation were measured as indices of vascular smooth muscle cell hyperplasia (DNA synthesis) and cell hypertrophy (protein synthesis), respectively. Growth effects of Ang II (10(-12) - 10(-6) mol/l), in the absence and presence of 10(-5) mol/l losartan (AT1 antagonist) and PD123319 (AT2 antagonist), were determined. Ang II-induced effects were compared to those of endothelin-1. To determine whether extracellular signal-regulated kinase (ERK)-dependent pathways play a role in Ang II-mediated growth, cells were pretreated with the selective ERK kinase (MEK) inhibitor, PD98059 (10(-5) mol/l). ERK activation was determined by Western blot in the absence and presence of PD98059.

RESULTS

Ang II dose-dependently increased 3H-thymidine incorporation in cells from aorta (Emax = 276 +/- 10.4% of control) and resistance arteries (Emax = 284 +/- 5.1% of control). Ang II also stimulated 3H-leucine incorporation in cells from aorta (Emax = 162 +/- 11.6 of control) and resistance arteries (Emax 175 +/- 10% of control). Unlike Ang II, endothelin-1 failed to significantly alter cellular growth, except at high concentrations (> 10(-7) mol/l), where it had a weak stimulatory effect Losartan, but not PD123319, blocked Ang II-stimulated growth responses. Ang II significantly increased phosphorylation of ERK-1 and ERK-2, with maximum responses obtained at 5 min. PD98059 inhibited Ang II-stimulated ERK activity and abrogated agonist-induced DNA and protein synthesis. Losartan, but not PD123319 inhibited Ang II-induced phosphorylation of ERK-1 and ERK-2.

CONCLUSIONS

Ang II stimulates both hyperplasia and hypertrophy in vascular smooth muscle cells from human arteries. These growth effects are mediated via Ang II receptors of the AT1 subtype that are linked to ERK-dependent signaling pathways.

Adsorbed layers and the origin of static friction

Analytic results and experiments in ultrahigh vacuum indicate that the static friction between two clean crystalline surfaces should almost always vanish, yet macroscopic objects always exhibit static friction. A simple and general explanation for the prevalence of static friction is proposed. "Third bodies," such as small hydrocarbon molecules, adsorb on any surface exposed to air and can arrange to lock two contacting surfaces together. The resulting static friction is consistent with experimental behavior, including Amontons' laws.

[Effect of lipopolysaccharide on recombinant human osteogenic protein-1-induced responses in human dental pulp cells]

OBJECTIVE

To investigate the effects of lipopolysaccharide (LPS) on recombinant human osteogenic protein-1 (rhOP-1) induced proliferation and differentiation.

METHODS

Measured MTT, alkaline phosphatase (ALPase) activity and osteocalcin content of human dental pulp cells.

RESULTS

Low-dose LPS (1 microgram/ml) caused co-operative effect with low concentration of rhOP-1 to enhance human dental pulp cell proliferation and ALPase activity, but not to osteocalcin, whereas, high-dose LPS (100 micrograms/ml) significantly inhibited the proliferation, ALPase activity and osteocalcin with or without rhOP-1.

CONCLUSION

The role of LPS in caries-induced reparative dentin might be a significant determinant.

Noninvasive measurement of anatomic structure and intraluminal oxygenation in the gastrointestinal tract of living mice with spatial and spectral EPR imaging

EPR imaging has emerged as an important tool for noninvasive three-dimensional (3D) spatial mapping of free radicals in biological tissues. Spectral-spatial EPR imaging enables mapping of the spectral information at each spatial position, and, from the observed line width, the localized tissue oxygenation can be mapped. We report the development of EPR imaging instrumentation enabling 3D spatial and spectral-spatial EPR imaging of small animals. This instrumentation, along with the use of a biocompatible charcoal oximetry-probe suspension, enabled 3D spatial imaging of the gastrointestinal (GI) tract, along with mapping of oxygenation in living mice. By using these techniques, the oxygen tension was mapped at different levels of the GI tract from the stomach to the rectum. The results clearly show the presence of a marked oxygen gradient from the proximal to the distal GI tract, which decreases after respiratory arrest. This technique for in vivo mapping of oxygenation is a promising method, enabling the noninvasive imaging of oxygen within the normal GI tract. This method should be useful in determining the alterations in oxygenation associated with disease.

[The detection of microsatellite instability in carcinoma and adenoma of large bowel and its significance]

OBJECTIVE

To explore the role of microsatellite instability (MSI) in colorectal carcinogenesis and the relationship between MSI, proliferation activity and prognosis.

METHODS

PCR-SSLP and immunohistochemistry methods were used to detect MSI and the expression of PCNA in 56 cases of carcinomas, 9 cases of adenomas and 6 cases of adenomas with malignant changes.

RESULTS

The total positive rate of MSI were 25/56 cases in colorectal carcinomas. The MSI positive cases were 3/4 in HNPCCs, 22/52 in sporadic colorectal carcinomas, 2/9 in adenomas and 2/6 in adenoma with malignant changes respectively. The PCNA labelling index of MSI positive tumors were significantly lower than that of MSI negative tumors (P < 0.01). The 3 and 5 year survival rates in patients with MSI positive colorectal carcinomas were higher than those of MSI negative tumors.

CONCLUSION

MSI may be an early molecular alteration and another molecular mechanism in colorectal carcinogenesis. The MSI positive tumors have low proliferating activity and a better clinical outcome. The detection of MSI might be useful in predicting prognosis of colorectal carcinomas.

A tunable reentrant resonator with transverse orientation of electric field for in vivo EPR spectroscopy

There has been a need for development of microwave resonator designs optimized to provide high sensitivity and high stability for EPR spectroscopy and imaging measurements of in vivo systems. The design and construction of a novel reentrant resonator with transversely oriented electric field (TERR) and rectangular sample opening cross section for EPR spectroscopy and imaging of in vivo biological samples, such as the whole body of mice and rats, is described. This design with its transversely oriented capacitive element enables wide and simple setting of the center frequency by trimming the dimensions of the capacitive plate over the range 100-900 MHz with unloaded Q values of approximately 1100 at 750 MHz, while the mechanical adjustment mechanism allows smooth continuous frequency tuning in the range +/-50 MHz. This orientation of the capacitive element limits the electric field based loss of resonator Q observed with large lossy samples, and it facilitates the use of capacitive coupling. Both microwave performance data and EPR measurements of aqueous samples demonstrate high sensitivity and stability of the design, which make it well suited for in vivo applications.

Mitogen-activated protein/extracellular signal-regulated kinase inhibition attenuates angiotensin II-mediated signaling and contraction in spontaneously hypertensive rat vascular smooth muscle cells

This study investigates the role of extracellular signal-regulated kinases (ERKs) in angiotensin II (Ang II)-generated intracellular second messengers (cytosolic free Ca2+ concentration, ie, [Ca2+]i, and pHi) and in contraction in isolated vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) and control Wistar Kyoto rats (WKY) using the selective mitogen-activated protein (MAP)/ERK inhibitor, PD98059. VSMCs from mesenteric arteries were cultured on Matrigel basement membrane matrix. These cells, which exhibit a contractile phenotype, were used to measure [Ca2+]i, pHi, and contractile responses to Ang II (10(-12) to 10(-6) mol/L) in the absence and presence of PD98059 (10(-5) mol/L). [Ca2+]i and pHi were measured by fura-2 and BCECF methodology, respectively, and contraction was determined by photomicroscopy. Ang II-stimulated ERK activity was measured by Western blot analysis using a phospho-specific ERK-1/ERK-2 antibody and by an MAPK enzyme assay. Ang II increased [Ca2+]i and pHi and contracted cells in a dose-dependent manner. Maximum Ang II-elicited contraction was greater (P<0.05) in SHR (41.9+/-5.1% reduction in cell length relative to basal length) than in WKY (28.1+/-3.0% reduction in cell length relative to basal length). Basal [Ca2+]i, but not basal pHi, was higher in SHR compared with WKY. [Ca2+]i and pHi effects of Ang II were enhanced (P<0.05) in SHR compared with WKY (maximum Ang II-induced response [Emax] of [Ca2+]i, 576+/-24 versus 413+/-43 nmol/L; Emax of pHi, 7.33+/-0.01 versus 7.27+/-0.03, SHR versus WKY). PD98059 decreased the magnitude of contraction and attenuated the augmented Ang II-elicited contractile responses in SHR (Emax,19. 3+/-3% reduction in cell length relative to basal length). Ang II-stimulated [Ca2+]i (Emax, 294+/-55 nmol/L) and pHi (Emax, 7. 27+/-0.04) effects were significantly reduced by PD98059 in SHR. Ang II-induced ERK activity was significantly greater (P<0.05) in SHR than in WKY. In conclusion, Ang II-stimulated signal transduction and associated VSMC contraction are enhanced in SHR. MAP/ERK inhibition abrogated sustained contraction and normalized Ang II effects in SHR. These data suggest that ERK-dependent signaling pathways influence contraction and that they play a role in vascular hyperresponsiveness in SHR.

[Comparative study on therapeutic effects of gandou tablet I and dimercaptosuccinate acid in treating Wilson disease]

OBJECTIVE

To compare the effects of Gandou I (GD, a Chinese herbal preparation) and dimercaptosuccinate acid (DMSA) in treating Wilson disease (WD).

METHODS

Ninety-four patients with WD were divided into 2 groups, 32 cases in the GD group and 62 in the DMSA group, they were treated with GD and DMSA respectively. The therapeutic course was 4 weeks for both groups. Modified Goldstein's Degree was adopted to evaluate the clinical effect.

RESULTS

The total effective rate of the GD group was 71.9%, which was similar to that of the DMSA group (77.4%, P > 0.05). But the adverse reaction occurred in the latter group was more than that in the former.

CONCLUSION

GD is a low toxic and highly effective drug for long-term treatment of WD.

Role of extracellular signal-regulated kinases in angiotensin II-stimulated contraction of smooth muscle cells from human resistance arteries

BACKGROUND

We assessed the role of extracellular signal-regulated kinases (ERKs) in Ang II-stimulated contraction and associated signaling pathways in vascular smooth muscle cells (VSMCs) from human small arteries.

METHODS AND RESULTS

VSMCs derived from resistance arteries (<300 microm in diameter) from subcutaneous gluteal biopsies of healthy subjects (n=8) were used to assess Ang II-stimulated [Ca2+]i, pHi, and contractile responses. [Ca2+]i and pHi were measured with fura 2-AM and BCECF-AM, respectively, and contraction was measured photomicroscopically in cells grown on Matrigel matrix. To determine whether tyrosine kinases and ERKs influence Ang II-stimulated responses, cells were pretreated with 10(-5) mol/L tyrphostin A-23 (tyrosine kinase inhibitor) and PD98059 (MEK inhibitor). Ang II-stimulated MEK activity was determined by tyrosine phosphorylation of ERKs. The angiotensin receptor subtypes (AT1 and AT2) were assessed with [Sar1,Ile8]Ang II (a nonselective subtype antagonist), losartan (a selective AT1 antagonist), and PD123319 (a selective AT2 antagonist). Ang II dose-dependently increased [Ca2+]i (pD2=8.4+/-0.36, Emax=541+/-55 nmol/L), pHi (pD2=9. 4+/-0.29, Emax=7.19+/-0.01), and contraction (pD2=9.2+/-0.21, Emax=36+/-2.2%). Ang II induced rapid tyrosine phosphorylation of ERKs, which was inhibited by PD98059. Tyrphostin A-23 and PD98059 attenuated (P<0.05) Ang II-stimulated second messengers, and PD98059 reduced Ang II-induced contraction by >50%. [Sar1,Ile8]Ang II and losartan, but not PD123319, blocked Ang II-stimulated responses.

CONCLUSIONS

These data demonstrate that in VSMCs from human peripheral resistance arteries, functional Ang II receptors of the AT1 subtype are coupled to signaling cascades involving Ca2+ and pHi pathways that are partially dependent on tyrosine kinases and ERKs. ERKs, the signaling cascades characteristically associated with cell growth, may play an important role in Ang II-stimulated contraction of human VSMCs.

The role of CD8 and CD4 T cells in intestinal allograft rejection: a comparison of monoclonal antibody-treated and knockout mice

BACKGROUND

The relative contribution of CD8 and CD4 T cells to allograft rejection remains an unresolved issue. Experimental results suggest that the relative importance of these T-cell subsets may vary depending on the model used and the organ studied. We have previously shown that treatment of murine recipients of intestinal allografts with a depleting anti-CD8 or a depleting anti-CD4 monoclonal antibody (mAb) significantly inhibited allograft rejection. This study was undertaken to further examine the contribution of CD8 and CD4 T cells to the rejection of intestinal allografts.

METHODS

Intestinal allografts from B6C3F1/J (C57BL/6 x C3H/HeJ) mice were transplanted into C57BL/6 recipients. Recipient groups included mice with an acquired deficiency in CD8 or CD4 T cells caused by treatment with depleting mAb or mice genetically deficient in CD8 or CD4 T cells as a result of disruption of the genes encoding major histocompatibility complex (MHC) class I, MHC class II, CD8, or CD4. In all cases, rejection was assessed histologically at predetermined time points. In some recipient groups, graft function was also assessed using a maltose absorption assay.

RESULTS

Rejection, assessed between days 10 and 28 after transplantation, was significantly inhibited in mice deficient in CD8 or CD4 T cells after treatment with depleting mAb. In contrast, mice genetically deficient in either CD8 T cells (MHC class I or CD8 knockouts) or CD4 T cells (MHC class II or CD4 knockouts) rejected intestinal allografts promptly. Both histologic and functional evaluation of anti-CD8 mAb-treated mice on day 60 showed that the inhibition of rejection persisted even after the return of a substantial number of CD8 T cells. Although intestinal allografts from anti-CD8 mAb-treated mice displayed little to no evidence of rejection on day 60 after transplantation, these mice were able to reject both donor and third-party skin grafts.

CONCLUSIONS

These results demonstrate that the inhibition of intestinal allograft rejection associated with mAb treatment is not attributable solely to depletion of CD8 or CD4 T cells. Furthermore, anti-CD8 mAb administration did not induce donor-specific tolerance or cause nonspecific immune suppression, as indicated by the skin-grafting experiments. Our findings suggest that at least some depleting mAbs mediate their protective effect on allograft rejection via an alternative mechanism such as the induction of a regulatory cell population(s).

Study on air pollution in Beijing's major industrial areas using multielements in biomonitors and NAA techniques

Three kinds of plant leaves, Chinese white aspen, arborvitae, and pine needles, have been sampled from the Yanshan Oil refinery complex, the Capital Iron and Steel Factory, and Badachu, a control area in Beijing, as biomonitors for air-pollution studies. Each sample was divided into two parts, washed, and unwashed. Thirty-one trace elements (As, Au, Br, Ca, Cd, K, La, Lu, Mo, Na, Sb, Sm, U, W, Yb, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, Hg, Rb, Sc, Se, Sr, Ta, Tb, Th, and Zn) have been determined by using the relative and the K0 methods of instrumental neutron activation analysis (NAA) techniques. The results indicated the following: (1) The concentration of trace elements in unwashed samples are much higher than these in washed samples; (2) the area around Capital Iron and Steel Factory is heavily polluted, and the Yanshan Oil refinery complex area is moderately polluted; (3) Chinese white aspen is a good biomonitor in particular seasons and pine needles are better than arborvitae for yearly monitoring; (4) elements As, Cd, Hg, Co, Rb, Sb, W, and Zn are highly absorbed by Chinese white aspen. Pine needles are sensitive for the absorption the elements Br, Cr, Cd, Fe, Sc, Cs and rare earth elements, but arborvitae is very sensitive for the absorption of Sr.

Role of AT2 receptors in angiotensin II-stimulated contraction of small mesenteric arteries in young SHR

This study assesses the receptor subtype (AT1 and AT2) through which angiotensin II (Ang II) mediates contraction in small arteries of young and adult spontaneously hypertensive rats (SHR). Segments of third-order mesenteric arteries ( approximately 200 microm in lumen diameter) were mounted in a pressurized system. Systolic blood pressure and media:lumen ratio of small arteries were significantly greater (P<0.001) in young SHR and adult SHR than in age-matched Wistar-Kyoto rats (WKY). Ang II-induced contractile effects were significantly increased (P<0.05) in young SHR compared with age-matched WKY. AT1 blockade with losartan, and combined AT1 and AT2 blockade with losartan and PD123319, abolished Ang II-stimulated contraction in young and adult rats. AT2 blockade (PD123319) significantly reduced (P<0.01) Ang II-elicited contraction in young SHR but had no effect in WKY or adult SHR, indicating that AT2 receptors may contribute to Ang II-induced contraction in young SHR. To determine the Ang receptor status in rat mesenteric vessels, AT1 and AT2 receptor mRNA expression was determined by reverse transcription-polymerase chain reaction. AT1 and AT2 receptor protein expression were detected by Western blot analysis. AT1 receptor mRNA was equally expressed in age-matched rats, but expression was significantly lower in young rats compared with adult rats. AT2 receptor mRNA was weakly expressed in WKY and adult SHR. In vessels from young SHR, AT2 receptor mRNA expression was significantly increased compared with the other groups. AT1 receptor protein was equally expressed in adult rats of both strains but was undetectable in young rats. AT2 receptor protein was only detectable in young rats, with the magnitude of expression greater in SHR than WKY. In conclusion, Ang II-stimulated contractile responses are augmented in vessels from young SHR. These effects are reduced by selective AT2 blockade and abolished by AT1 blockade, indicating that both Ang receptor subtypes are involved in contraction in young SHR. In WKY and adult SHR, losartan, but not PD123319, inhibited Ang II-induced contraction, indicating the exclusive involvement of AT1 receptors. Thus, in SHR, in the phase of developing hypertension, enhanced Ang II-stimulated vascular contraction may be associated with changes in Ang II receptor status, as evidenced pharmacologically and by increased vascular AT2 receptor mRNA and protein expression.

Modified surgical model of paratopic small bowel transplantation in mice

A murine paratopic model of intestinal transplantation was developed and used to study the immune response to allografts in normal C57BL/6 recipients (H2(b)) and C57BL/6 recipients treated with tacrolimus (1 mg/kg, Days 0-7). B6C3F1 mice (C57BL/6 x C3H/HeJ, H2(bxk)) were used as donors. The paratopic model differed from the standard heterotopic model in that continuity of the intestine graft with the recipient intestine was established by anastomosing the graft ileum to the side of the recipient jejunum. The success rate of this modified procedure was 82% (94/114). Major complications included hypovolemic shock and/or anesthetic-related deaths (8%), infection (8%), and vascular thrombosis (2%). Rejection was assessed using both clinical features (i.e., edema and closure of the stoma, mucous discharge, and a palpable mass) and histologic features (apoptosis of crypt cells, crypt destruction, lymphocytic infiltrate, and mucosal ulceration). Syngeneic grafts appeared clinically and histologically normal throughout the study period. Untreated recipients of allografts developed clinical and histologic evidence of rejection by Day 4 which progressed to severe rejection and graft destruction by Day 18. After initially developing evidence of mild to moderate graft rejection on Day 8, the severity of allograft rejection decreased significantly by Days 10 to 14 in tacrolimus-treated mice. By Day 28 evidence of moderate rejection had recurred in mice treated with an 8-day course of tacrolimus. Consistent with these observations, graft function, as assessed by maltose absorption, was impaired in rejecting allografts when compared with syngeneic grafts. Allografts in mice treated with tacrolimus demonstrated improved maltose absorption relative to allografts from untreated mice. These studies describe a modified technique for intestinal transplantation in mice and provide a detailed analysis of complications as well as an assessment of rejection and its functional consequences. Based on these results, we conclude that the paratopic model of intestinal transplantation in mice is a useful tool for studying the host immune response to intestinal allografts.

[Dietary fiber protects intestinal structure and barrier function]

OBJECTIVE

To evaluate the effect of dietary fiber on intestinal structure and barrier function of 5-fluorouracil (5-Fu) challenged rat.

METHOD

Thirty Wistar rats were divided randomly into three groups (10 each group): Chow, enteric nutrition (EN), and EN + Fiber group. Both EN and EN + Fiber group were isonitrogenic and isocaloric. The rats kept their diet respectively for 8 days. 5-Fu was injected intraperitoneally on day 4 postoperatively. Intestinal permeability (L/M) was measured respectively on day 3 and day 7. On day 8, the bacterial translation, wet weight and mucous thickness of both small intestine and colon and the villus height of small intestine were measured. The rats were weighted before and after experiment respectively.

RESULT

The body weight loss of the EN + Fiber group (-3.1 +/- 3.4 g) was less than that of the EN group (-6.6 +/- 5.2 g) (P < 0.05), whereas the Chow group gained body weight (4.9 +/- 4.3 g) (P < 0.01 when compared with EN and EN + Fiber group). The parameters of intestinal structures of the EN + Fiber group was superior to the EN group (P < 0.05). The L/M of both EN + Fiber (from 0.0265 +/- 0.0073 to 0.0274 +/- 0.0068) and the Chow group (from 0.0268 +/- 0.0039 to 0.0281 +/- 0.0044) was unchanged (P > 0.05 for both) after 5-Fu challenged, whereas that of the EN group increased (from 0.0289 +/- 0.0070 to 0.0331 +/- 0.0084) (P < 0.01). The incidence of bacterial translocation to MLN of both EN + Fiber group and the Chow group (20%) was lower than that of the EN group (70%) (P < 0.05).

CONCLUSION

The dietary fiber protects the intestinal structure and barrier function of 5-Fu challenged rats.

Effect of vasopressin antagonism on structure and mechanics of small arteries and vascular expression of endothelin-1 in deoxycorticosterone acetate salt hypertensive rats

The structural and mechanical properties of small arteries are altered in rat models of hypertension. The precise role of humoral factors in these changes has not been determined. In deoxycorticosterone acetate (DOCA) salt hypertension, endothelin-1 (ET-1) peptide content and gene expression are enhanced in mesenteric resistance arteries. These vessels also present augmented vasoconstrictor responsiveness to vasopressin versus control uninephrectomized rats. To determine whether an interaction exists between vasopressin and ET-1 in the pathogenesis of small-artery structural alterations in DOCA-salt rats, we examined the effect of chronic V1 vasopressin receptor antagonism (OPC-21268, 30 mg/kg BID) on the structure and mechanical properties of mesenteric resistance arteries using a pressure myograph and the effect on preproendothelin-1 (preproET-1) gene expression, determined by Northern blot analysis of preproET-1 mRNA. Tail-cuff systolic pressures were elevated in DOCA-salt (200+/-11 mm Hg) versus uninephrectomized rats (109+/-4 mm Hg) and decreased slightly but significantly by OPC-21268 to 187+/-7 mm Hg (P<0.01). Treatment with DOCA-salt increased vascular media-lumen ratios and media cross-sectional areas and reduced both stress and incremental elastic modulus for a given pressure. However, there was no change in distensibility or incremental elastic modulus versus media stress. OPC-21268 partially attenuated the vascular growth in DOCA-salt rats. PreproET-1 mRNA was increased 2-fold in mesenteric arteries of DOCA-salt rats versus uninephrectomized rats, an effect abrogated by OPC-21268. Thus, DOCA-salt hypertension is associated with altered morphology of the small-arterial wall, without altering stiffness of the arterial wall components. OPC-21268 regressed in part these changes, suggesting the involvement of vasopressin. The concomitant attenuation of enhanced ET-1 expression by OPC-21268 suggests that ET-1 may be involved in mediating in part the vascular effects of vasopressin in DOCA-salt hypertensive rats.

[The relationship between different serological types of Pseudomonas aeruginosa strain in lower respiratory tract and its clinical significance]

OBJECTIVE

To explore the relationship between different serological types of pseudomonas aeruginose (PA) in sputum and its clinical significance.

METHOD

PA was detected by Vitek-Ams GNI card and its sensitivity to 12 kinds of antibiotics was measured with GNS-GA, its different serological types were assayed with standard diagnostic serum of type 20.

RESULT

14 different serological types were isolated from 101 strains of PA in sputum (with the typed rate 84.2%). Among them, type 6, type 1, and type 3 were higher with 23.7%, 13.9% and 10.9% respectively. But another 15.8% of strains couldn't be differentiated, so called untyped PA group, among them 10 strains with mucoid-like colony (63% of this untyped group). Patients suffered with this group were older and were very seriously infected with higher mortality (13%). They often suffered from serious COPD and bronchiectasis. The sensitivities of all PA strains to antibiotics in vitro as follows: tobramycin 92.0%, ceftazidine 89.1%, ciprofloxacin 87.1%, ticarcillin 82.2%, and gentamycin 76.2%. Among 12 PA strains tested with imipenem sensitive test, only one strain of mucoid-like colony had been found resistant.

CONCLUSION

Identification of serological type of PA can be used as an important method to make out if the infection comes from the same source, and for surveillance of hospital infection, and to show the main types of PA in some district. But the sensitivity of antibiotics in vitro is no definitive correlation with PA serological types. The disease infected with untyped PA strains have its clinically special characteristics and must be kept attention.

Transcription factor SCL is required for c-kit expression and c-Kit function in hemopoietic cells

In normal hemopoietic cells that are dependent on specific growth factors for cell survival, the expression of the basic helix-loop-helix transcription factor SCL/Tal1 correlates with that of c-Kit, the receptor for Steel factor (SF) or stem cell factor. To address the possibility that SCL may function upstream of c-kit, we sought to modulate endogenous SCL function in the CD34(+) hemopoietic cell line TF-1, which requires SF, granulocyte/macrophage colony-stimulating factor, or interleukin 3 for survival. Ectopic expression of an antisense SCL cDNA (as-SCL) or a dominant negative SCL (dn-SCL) in these cells impaired SCL DNA binding activity, and prevented the suppression of apoptosis by SF only, indicating that SCL is required for c-Kit-dependent cell survival. Consistent with the lack of response to SF, the level of c-kit mRNA and c-Kit protein was significantly and specifically reduced in as-SCL- or dn-SCL- expressing cells. c-kit mRNA, c-kit promoter activity, and the response to SF were rescued by SCL overexpression in the antisense or dn-SCL transfectants. Furthermore, ectopic c-kit expression in as-SCL transfectants is sufficient to restore cell survival in response to SF. Finally, enforced SCL in the pro-B cell line Ba/F3, which is both SCL and c-kit negative is sufficient to induce c-Kit and SF responsiveness. Together, these results indicate that c-kit, a gene that is essential for the survival of primitive hemopoietic cells, is a downstream target of the transcription factor SCL.

Identification of four novel mutations in patients with carnitine palmitoyltransferase II (CPT II) deficiency

Carnitine palmitoyltransferase II (CPT II) deficiency, an autosomal recessive disorder of fatty-acid oxidation, presents as three distinct phenotypes (neonatal, infantile, and adult onset). In order to investigate the molecular basis of these three phenotypes, six patients with CPT II deficiency have been studied. All six unrelated patients in this study experienced the clinical symptoms of CPT II deficiency. Three patients had the neonatal form, one had the milder infantile form, and the remaining two had the adult-onset form with "muscular" symptoms only. Their diagnoses were based upon in vitro analysis of the mitochondrial beta-oxidation pathway in fibroblasts and standard enzyme assays. We devised a method to screen the entire coding sequence and flanking splice junction of the CPT II gene. A total of six different mutations have been identified, including four novel mutations. Among them, the previously reported common mutation, S113L, was only found in 3 of 12 variant alleles. Three of the six mutations have been identified in a few unrelated patients, while the remaining three have been found in single families. This study, as well as those by others, indicates genetic heterogeneity in this disease. In addition to tabulating the mutations, the correlation of mutant genotype to clinical phenotype is briefly discussed.

[Chemical changes of compatibility for shaoyao decoction]

OBJECTIVE

To probe the regular patterns of interactions among chemical components in Chinese medicinal complex prescriptions.

METHOD

The active components of Rhubarb, Coptis root and Baikal skullcap root in different patterns of compatibility were determined by TLC-scanner.

RESULT

The berberine content in Coptis root can be decreased obviously by Rhubarb, Baikai skullcap root and Licorice root, especially by Rhubarb. Coptis root can also decrease the contents of acid components.

CONCLUSION

The acid components can affect each other, thus reducing the contents of effective components.

Vascular endothelin-1 expression and effect of an endothelin ETA antagonist on structure and function of small arteries from stroke-prone spontaneously hypertensive rats

There is some evidence that the endothelin (ET) system may participate in blood pressure elevation and in vascular hypertrophy in stroke-prone spontaneously hypertensive rats (SHR-SP). To further understand the involvement of the ET system in this hypertensive model, we examined preproendothelin-1 (preproET-1) mRNA abundance in blood vessels of 5-week and 18-week SHR-SP in comparison to SHR, and treated 12-week old SHR-SP with the ETA-selective receptor antagonist A-127722.5 (30 mg/kg/day in the drinking water) for 10 weeks. Abundance of preproET-1 mRNA by Northern blot analysis was increased more than twofold in aorta and mesenteric arteries of SHR-SP relative to SHR at 18 weeks but not at 5 weeks of age. SHR-SP treated with A-127722.5 had a tail-cuff systolic blood pressure at 22 weeks of age of 241 +/- 2 mm Hg vs. 251 +/- 3 mm Hg in untreated SHR-SP (p < 0.05). Heart:body weight ratio was no different in both groups, but aortic segment:body weight ratio was slightly but significantly smaller in treated SHR-SP (p < 0.05). Pressurized mesenteric small arteries from treated SHR-SP had a smaller media width (12.6 +/- 0.6 microns vs. 14.9 +/- 0.5 microns; p < 0.05) and media:lumen ratio (5.8 +/- 0.2% vs. 7.3 +/- 0.3%; p < 0.01), whereas media cross-sectional area and lumen diameter tended to decrease and increase, respectively, without achieving statistical significance. Acetylcholine-induced relaxation was improved in treated SHR-SP (99.6 +/- 0.6% vs. 90.0 +/- 3.6%; p < 0.05), whereas relaxation responses to sodium nitroprusside were similar in both groups. These results show increases of preproET-1 expression in blood vessels that appear to be secondary to blood pressure elevation. There is a small ET-dependent component in blood pressure elevation and in conduit and resistance artery changes in adult stroke-prone SHR.

[Detecting coronary artery disease with dobutamine 99mTc-MIBI myocardial perfusion tomography]

OBJECTIVE

To assess the safety and accuracy of dobutamine stress 99mTc-MIBI perfusion tomography (DST) for detecting coronary artery disease(CAD).

METHODS

Seventy nine patients with suspected CAD without previous myocardial infarction underwent DST. Forty eight of the 79 patients had coronary angiography and CAD was defined as greater than 50% reduction in diameter.

RESULTS

Seventeen of 20 patients with CAD demonstrated perfusion abnormalities by DST (sensitivity 85%), 20 of 24 with normal or non-significant stenosed coronary arteries had normal scan (specificity 83.3%). All 4 patients with coronary ectasia showed abnormalities by DST. Fifty seven percent of the patients experienced some discomfort, but no serious side effects occurred.

CONCLUSIONS

It shows that DST is a safe and accurate alternative to exercise stress perfusion study for detecting CAD in patients unable to perform exercise testing.

CT findings in splenic tuberculosis

Splenic tuberculosis is rare and delay in diagnosis is common. We present two cases of splenic tuberculosis with their appearance on CT. The CT findings were multiple, round or ovoid, low-density lesions without calcification. Except for non-specific lymphadenopathy no abnormality nor history suggestive of tuberculosis was revealed prior to laparotomy. Although CT does not confirm a diagnosis of splenic tuberculosis, it would be a valuable examination to define the extent of disease and guide aspiration biopsy.

BRCA1 up-regulation is associated with repair-mediated resistance to cis-diamminedichloroplatinum(II)

We sought to identify novel genes associated with cis-diamminedichloroplatinum(II) (CDDP) resistance, and by differential display analysis, we found that the human breast and ovarian cancer susceptibility gene BRCA1 was overexpressed in CDDP-resistant MCF-7 cells. A recent report that BRCA1 and human Rad51 colocalize in S-phase cells suggests a role for BRCA1 in DNA damage repair. We hypothesized that BRCA1 plays a role in DNA damage repair-mediated CDDP resistance. In CCDP-resistant variants of breast and ovarian carcinoma cell lines, MCF-7 CDDP/R and SKOV-3 CDDP/R, we found increased levels of BRCA1 protein, and we determined that the SKOV-3 CDDP/R cell line is significantly more proficient at DNA damage repair. Antisense inhibition of BRCA1 in this cell line resulted in an increased sensitivity to CDDP, a decreased proficiency of DNA repair, and an enhanced rate of apoptosis. These data support the hypothesis that BRCA1 is a gene involved in DNA damage repair.

Analysis of genetic diversity in Chinese sweetpotato [Ipomoea batatas (L.) Lam.] germplasm using DNA amplification fingerprinting

The genetic diversity and evolutionary relationships in a representative sample of Chinese sweetpotato collection were assessed using the DNA amplification fingerprinting approach. DNA fingerprint profiles were developed for all 42 accessions tested. There were 19-26 bands for each accession and an average of 20.7 such bands were polymorphic. Chinese sweetpotato germplasm tested exhibited a high degree of genetic diversity. Phenetic analysis revealed five major clusters with the following components: (1) landraces from Guangdong Province, (2) landraces from Fujian province, (3) Chinese cultivars, (4) those closely related to Japanese sweetpotato cultivars, and (5) those closely related to the US sweetpotato cv. Nancy Hall. The genetic association observed between accessions was largely consistent with the known pedigree records. The DNA amplification fingerprinting may provide reliable insights into the domestication history of the sweetpotato crop and may be useful in germplasm enhancement.

[The biological effects of recombinant human osteogenic protein-1 to cultured pulp cells]

The study was to observe the biological effects of rhOP-1 on the proliferation, ALPase activity and osteocalcin of dental pulp cells by cell culture technique, MTT, enzyme kinetic methods and radioimmunoassay. The results indicated rhOP-1 could obviously promote the proliferation and enhanced ALPase activity and osteocalcin secretion of pulp cells with showing dose-dependent relationship in this experimental dose range. Thus, rhOP-1 can induce dental pulp cells to differentiate the cells expressing osteoblast phenotype.

Studies on the comprehensive control of babesiasis in cattle and buffaloes

To obtain a highly effective method for controlling babesiosis in cattle and buffalo, an epidemiological survey was carried out at Zuiyun village in Hubai Province. On the grounds of the epidemiological data, control measures which included preventive drugs and killing the vectors were devised. After two years of control no clinical cases of bovine babesiosis were found. The average number of ticks on cattle or buffalo decreased from 9-282 to 0-11.3. Good results were obtained in another epidemic area using this control method. These results indicated that this technique of controlling babesiosis is highly effective.

Treatment with either anti-CD4 or anti-CD8 monoclonal antibodies blocks alphabeta T cell-mediated rejection of intestinal allografts in mice

BACKGROUND

Rejection is the major barrier preventing the more widespread application of intestinal transplantation as treatment for intestinal failure. For this study, a one-way host-versus-graft murine model was used to investigate the contribution of T cell subsets to the rejection of allogeneic intestinal allografts.

METHODS

Intestinal grafts consisting of the donor jejunum and ileum were procured from C57BL/6J (syngeneic group) and B6C3F1/J (C57BL/6 x C3H/HeJ, allogeneic group) mice. These grafts were then transplanted into (1) normal, (2) antibody-treated, or (3) genetically mutated C57BL/6 mice. Mice were killed at predetermined intervals and the grafts assessed for rejection by a blinded pathologist.

RESULTS

No syngeneic mice demonstrated any evidence of rejection. In contrast, the recipients of allografts experienced progressive rejection. Recipient mice treated with tacrolimus developed significantly less severe allograft rejection. None of the alphabeta T cell-deficient recipient mice (T cell receptor beta chain knockout mice) experienced allograft rejection with follow-up ranging from 8 to 28 days. However, mice deficient in gammadelta T cells (T cell receptor delta chain knockout mice) rejected intestinal allografts in a manner indistinguishable from normal recipients. In order to investigate the role of CD4+ and CD8+ T cells, recipient mice were treated 2 days before transplantation with depleting monoclonal antibodies specific for either CD4+ cells or CD8+ cells. Depletion of either population of cells significantly inhibited allograft rejection.

CONCLUSIONS

These data demonstrate that rejection of intestinal allografts in the murine model was absolutely dependent on alphabeta but not gammadelta T cells. Furthermore, both CD4+ and CD8+ T cells were necessary for small bowel allograft rejection. Additional studies will be required to determine whether the effects of monoclonal antibody treatment were due solely to depletion of T cells or were mediated at least in part through an active process that altered the functional properties of the targeted T cell subset.

[Extraction and sequencing of trace DNA from cornu Cervi pantotrichum]

The trace DNA extraction method was used to extract DNA from the blood, hair, Cornu cervi pantotrichum, hairy antler of the sika deer, Cervus nippon, and penis of Bulbalus bublis and Asinus vulgaris. A 307 bp fragment of mitochondrial DNA cytochrome b gene was amplified with primers L14841 and H15149 for these extractions. The purified PCR products were sequenced by the dideoxy method. DNA sequence obtained from the Cornu cervi pantotrichum is the same as that obtained from the fresh blood and hair of the sika deer, but the sequence of the so-called hairy antler is quite different, implying that it is not from the sika deer. In addition, the phylogenetic relationships among different species are congruent with the traditional known phylogeny.

[Histopathologic and immunochemical changes in Sjögren's syndrome]

To research into the causes of sjögren's syndrome, we investigated the lacrimal gland tissues of 6 cases of sjogren's syndriome by using electronmicroscopy and immunochemical methods. The results revealed that at the early stage the lacrimal gland cells showed degeneration, irregular arrangement and many intracellular vacuoles. At the middle stage, some lymphocytes infliltrated into the gland tissues. And at the advanced stage, lymphocytes and collagenous fibers were there in substitution of gland cells.

[Pharmacological actions of different species form genus Pyrola]

This paper reporst the pharmacological actions and toxicities of the water extracts from Pyrola calliantha, Pyrola decorta and P. forrestiana. The results show that the actions of P. forrestiana on antiventricular fibrillation, strengthening cardiac musicular contraction and antihypoxia abitity are more stronger, but on antiinflammation and antipyretic, effects of P. decorta and P. calliantha are significantly better than that of P. forrestiana. The effects of the three species on immunization and antisepsis are similar.

[Effect of recombinant growth hormone on amino acids metabolism in blood and urine after major operation]

To determine the effects of recombinant human growth hormone (GH) on postoperative amino acids metabolism, we performed a placebo-controlled randomized double-blind trial in 18 patients after elective gastrectomy or colectomy. The same amount of calories and amino acids were administered. Research group was daily injected growth hormone 0.15 IU/(kg.day) and control group was given placebo during the first postoperative week. All urine were analyzed for nitrogen balance and excretion of 3-methylhistidine. On the seventh postoperative day while the parenteral nutrients were being infused, amino acid exchange across the forearm was measured. On the seventh postoperative day all patients' amino acids in plasma were slightly increased by comparing with preoperative day but was not statistical significance. Forearm arterial-venous difference (A-V) measured on POD + 7 was markedly different between groups. There was continued release of amino acids from the forearm in the control subjects, while there was marked amino acid uptake in the GH patients (total amino acid nitrogen exchange was -398 +/- 158 mumol/L vs +165 +/- 61 mumol/L, P < 0.01). Excretion of urinary 3-methylhistidine in control group loss more than in GH group (7.3 +/- 1.0 mumol/(kg.24 h) vs 4.4 +/- 0.3 mumol/(kg.24 h), P < 0.05). The results demonstrated that GH can increase the uptake of amino acid from forearm and decrease the excreation of 3-methylhistidine in urine after operation, but did not disturb the balance of amino acids in plasma.

[Determination of metronidazole in gastric juice by high performance liquid chromatography]

Metronidazole (MTZ) is the first chosen drug of anti-anaerobe which was recommended by World Health Organization. In this paper a high performance liquid chromatographic (HPLC) method has been developed to determine the concertration of MTZ in human gastric juice. Gastric juice was obtained by intubation after taking drug, then the sample was precipitated with ethanol to remove proteins, centrifuged, filtered and finally assayed by HPLC. The operating conditions were reversed phase C18 column (4mm x 150mm), CH3OH:KH2PO4 (5mmol/L, pH 4.0) = 10:90 mobile phase with flow rate of 1.5mL/min and detection wavelength at 320nm. The standard working curve was Y = -1.63 + 1.15X, with r = 0.9999, n = 7. The linear range was 2.5-200mg/L. The detection limit was 0.4mg/L. The average recovery was 96.0% and the coefficient of variation was 3.07%. This method can be applied to guide clinical therapy and pharmaceutical research.

[Studies on biological effects of kappa-selenocarrageenan on human breast cancer cell line BCaP-37]

Proliferation, cell cycle, total amount of DNA, area of cell nucleus, as well as epidermal growth factor receptors (EGFR) and expression of oncogene C-erbB2 mRNA of Chinese breast cancer cell line (BCaP-37) after being treated with kappa-selenocarrageenan were determined by cell culture technique, image cytometry (ICM) and northern blot to explore its anti-tumor mechanism. Results revealed 3.0-120 mg/L selenocarrageenan could inhibit proliferation of BCaP-37, with a response of time and dose dependence. The areas of nuclei were significantly lower with ICM in cells treated with 15 or 60 mg/L selenocarrageenan for four days than those in controls (P < 0.01). Levels of EGFR and expression of C-erbB2 mRNA were significantly inhibited in cells treated with 60 mg/L selenocarrageenan. It suggests that selenocarrageenan can inhibit proliferation of breast cancer cells through regulation of the levels of EGFR and expression of C-erbB2 mRNA.

Radioimmunoimaging of arterial and venous thrombi in canine model using 99mTc labeled monoclonal antifibrin antibody

OBJECTIVE

To evaluate the usefulness of 99mTc labelled monoclonal antifibrin antibody SZ-63 for the detection of vascular thrombi, and to investigate the feasibility of thrombus imaging 99mTc-SZ-63.

METHODS

The monoclonal antibody SZ-63 (Mab SZ-63), which reacts with D-dimer, XLFN and fibrin monomer was produced and labelled with 99mTc using pretinning procedure. After that, the femoral arterial or venous thrombus model was prepared in dogs and injected with 99mTc-SZ-63 intravenously. Both arterial and venous thrombus models were imaged.

RESULTS

Both the arterial and venous thrombi were clearly visible within 2.5 hours after injection of 99mTc-SZ-63. Quantitative imaging analysis showed that the ratios between the thrombus and the opposite vessel increased with time extension. The ratios of thrombus to blood or surrounding muscle were 2. 56 +/- 0.83 and 13.40 +/- 5.10 for arterial thrombi and 3.34 +/- 1.06 and 22.40 +/- 6.40 for venous thrombi after the canines were killed.

CONCLUSION

99mTc-SZ-63 is a useful imaging agent for thrombus detection in vivo.