Photodissociation spectroscopy of N2O+ in the ion storage ring RICE.

The A2Σ+-X2Π electronic transition of the nitrous oxide cation, N2O+, was measured via photodissociation spectroscopy in a cryogenic electrostatic ion storage ring. Rotationally resolved spectra of the N-O stretching vibrational sequence were obtained by detecting neutral N fragments produced via N2O+ → NO+ + N predissociation channels. A new set of molecular constants was determined for the high-lying vibrational levels of the A2Σ+ state.

Cytological features of solid variants of papillary thyroid carcinoma: a fine needle aspiration cytology study of 18 cases.

OBJECTIVE: Solid variants of papillary thyroid carcinoma (SV-PTC) are rare, and there have been few reports describing the cytological findings of such variants. METHODS: The cytological features of cellular specimens aspirated from 18 histologically confirmed SV-PTC cases were evaluated, retrospectively. RESULTS: Solid and small papillary clusters were observed in 14 (77.8%) and 13 (72.2%) cases, respectively. The incidences of large papillary clusters (11.1%) and sheet-like arrangements (11.1%) were low. Nuclear features were consistent with conventional PTC. The background was clean, and there were no colloid materials, foamy histiocytes, multinucleated giant cells, psammoma bodies, or necrotic materials. CONCLUSIONS: Solid clusters and small papillary clusters in conjunction with a clean background are diagnostic clues that indicate SV-PTC cytologically. It is thought that small papillary clusters reflect the micropapillary growth pattern seen within the lumen of middle-sized follicular structures. The presence of nuclear findings typical of conventional PTC and the absence of mitotic figures and necrotic materials are important for distinguishing SV-PTC from poorly differentiated carcinoma.

Clinical outcomes after infrainguinal bypass grafting for critical limb ischaemia in patients with dialysis-dependent end-stage renal failure.

OBJECTIVE: To assess and risk-stratify the medium-term clinical outcomes after infrainguinal bypass grafting (IBG) to treat critical limb ischaemia (CLI) in patients with end-stage renal disease. METHODS: This was a retrospective single-centre study. Between April 2007 and March 2011, 112 limbs from 89 patients were studied. In particular, amputation-free survival (AFS), 30 day mortality, freedom from major adverse limb events (MALE), limb salvage, and overall survival were examined. The aim was to identify outcome predictors. RESULTS: Eight patients (9%) died within 30 days of IBG. The only positive predictor of 30-day mortality was an ejection fraction (EF) < 40% (hazard ratio [HR] 5.57, 95% confidence interval [CI] 1.16-26.83; p = .03). The mean follow-up duration was 14 months. The 1- and 2-year AFS rates were 64% and 43%, respectively, and the rates of freedom from MALE were 81% and 77%, respectively. In addition, the 1- and 2-year limb salvage rates were 89% and 85%, and the survival rates were 68% and 50%, respectively. Non-ambulatory status was negatively associated with AFS (HR 3.04, 95% CI 1.59-5.82; p < .01), freedom from MALE (HR 4.98, 95% CI 1.91-12.96; p < .01), and limb salvage (HR 5.18, 95% CI 1.47-18.30; p = .01). The other negative predictors of overall survival were a serum albumin level <3.0 g/dL (HR 2.26, 95% CI 1.12-4.58; p = .02) and an EF <40% (HR 2.24, 95% CI 1.05-4.79; p = .04). CONCLUSION: Patients with CLI on dialysis enjoyed satisfactory freedom from MALE and limb salvage, but survival and AFS were significantly less than reported for IBG in patients with CLI who did not receive dialysis. In addition, patients with an EF <40%, lower serum albumin (<3.0 g/dL), or non-ambulatory status experienced particularly poor clinical outcomes after IBG.

Diffuse sclerosing variant of papillary thyroid carcinoma: a study of fine needle aspiration cytology in 20 patients.

BACKGROUND: A diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) is a rare variant and reports describing the cytological findings are few. PATIENTS AND METHODS: We studied 24 cytological samples from thyroid fine needle aspirates of 20 patients with DSV-PTC. The specimens were taken from 14 non-nodular lesions and 10 nodules. RESULTS: All aspirates taken from both non-nodular lesions and nodules had sufficient cellularity. The carcinoma cells frequently (70-100%) appeared as solid cell balls and hollow balls, and showed a hobnail pattern, squamous differentiation, septate cytoplasmic vacuoles and large unilocular vacuoles. Most of the carcinoma cells seem to be taken from the lumen of dilated lymph vessels. Ground glass nuclear chromatin, intranuclear cytoplasmic inclusions and grooved nuclei were infrequent (50% or less). In the background, a large number of lymphocytes and abundant psammoma bodies were almost always seen. CONCLUSIONS: Cytological findings of DSV-PTC are as follows: (1) solid cell balls and/or hollow balls containing lymphocytes; (2) hobnail cells; (3) septate cytoplasmic vacuoles; (4) large unilocular vacuoles; (5) squamous differentiation; (6) abundant psammoma bodies; (7) lymphocytic background; and (8) the absence or relative lack of characteristic nuclear features of papillary carcinoma. When DSV-PTC is suspected by ultrasound examination, the aspiration cytology from a non-nodular area of the thyroid can led us to the diagnosis of the variant.

Influence of grapefruit juice on the pharmacokinetics of diltiazem in Wistar rats upon single and multiple dosage regimens.

Drug efflux by intestinal P-glycoprotein (P-gp) is recognized as a significant biochemical barrier affecting oral absorption for a number of drugs apart from the cytochrome P450 3A enzyme. Various conflicting reports have been published regarding the effects of grapefruit juice (GFJ) on P-gp mediated drug efflux, in which GFJ has been shown to have no effect, as an inhibitor effect or activation of the enzyme. Therefore the present study's objective was to provide clarification of previous findings, adopting a two-way approach, involving both single dose and multiple dosage regimens. Diltiazem (DTZ) 15 mg/kg was administered concomitantly with 5 ml/kg of GFJ to one group (n = 6) of male Wistar rats and another group (n = 6) of animals were provided distilled water with DTZ (the control). A third group of rats was administered GFJ orally for six days and on seventh day GFJ and DTZ were administered concomitantly. The Cmax and AUC of DTZ were decreased significantly in the presence of multiple dose treatment of GFJ. These data were also decreased in presence of simultaneous treatment of single dose GFJ. In vitro metabolism studies and gut sac experiments were conducted in order to understand the mechanism involved. In the liver S9 fraction prepared from the rats treated with multiple doses of GFJ, DTZ metabolism was significantly increased compared to the control. Furthermore, the amount of drug transported from the duodenum was reduced in GFJ treated rats compared to that of the control (1581.0 +/- 7.8 nM vs 1084.81 +/- 6.1 nM, respectively). Grapefruit juice was also reported to inhibit the organic anion transporting polypeptide (OATP), an influx transporter thus reducing the blood levels of OATP substrates which was evident from the in vitro studies. The amount of drug transported from the duodenum was reduced in the presence of pravastatin, a specific OATP inhibitor (1581.0 +/- 7.8 nM to 1265.0 +/- 5.5 nM). Oral single dose exposure to GFJ showed no effect on P-gp, whereas multiple dose administration of GFJ resulted in increased levels of P-gp expression and decreased levels of OATP, thus showing a varied effect on intestinal absorption, and therefore overcoming the inhibition of DTZ metabolism in rats.

Successful and optimized in vivo gene transfer to rabbit carotid artery mediated by electronic pulse.

Several gene transfer methods, including viral or nonviral vehicles have been developed, however, efficacy, safety or handling continue to present problems. We developed a nonviral and plasmid-based method for arterial gene transfer by in vivo electronic pulse, using a newly designed T-shaped electrode. Using rabbit carotid arteries, we first optimized gene transfer efficiency, and firefly luciferase gene transfer via electronic pulse under 20 voltage (the pulse length: P(on)time 20 ms, the pulse interval: P(off) time 80 ms, number of pulse: 10 times) showed the highest gene expression. Exogenous gene expression was detectable for at least up to 14 days. Electroporation-mediated gene transfer of E. coli lacZ with nuclear localizing signal revealed successful gene transfer to luminal endothelial cells and to medial cells. Histological damage was recognized as the voltage was increased but neointima formation 4 weeks after gene transfer was not induced. In vivo electroporation-mediated arterial gene transfer is readily facilitated, is safe and may prove to be an alternative form of gene transfer to the vasculature.

In vitro and in vivo evaluations of biodegradable implants for hormone replacement therapy: effect of system design and PK-PD relationship.

This investigation evaluated the feasibility of using subdermally implantable devices fabricated by nonconventional 3-dimensional printing technology for controlled delivery of ethinyl estradiol (EE2). In vitro release kinetics of EE2 and in vivo pharmacokinetics/pharmacodynamics in ovariectomized New Zealand White rabbits were carried out to study 3 implant prototypes: implant I (single-channel EE2 distribution in polycaprolactone polymer core), implant II (homogeneous EE2 distribution in polycaprolactone polymer matrix), and implant III (concentration-gradient EE2 distribution in polycaprolactone and poly(dl-lactide-co-glycolide) (50:50 matrix). EE2 was found to be released from all the implants in a nonlinear pattern with an order of implant III > implant II > implant I. The noncompartmental pharmacokinetic analysis of plasma EE2 profiles in rabbits indicated a significant difference (p < .05) in Cmax, tmax, and mean residence time between implant I and implants II and III, but no difference in the area under the plasma concentration time curves calculated by trapezoidal rule (AUC) among the implants. For pharmacodynamic studies, endogenous follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were observed to be suppressed following implantation of all implants, which demonstrated that a therapeutically effective dose of EE2 had been delivered. Furthermore, the noncompartmental analysis of plasma FSH and LH profiles in rabbits showed a significant difference (p < .05) in AUC and the mean residence time between implant III and implants I and II. A good in vivo/in vitro relationship was observed between daily amounts of EE2 released and plasma profiles of EE2 for all implants. This relationship suggests that plasma profiles of EE2 could be predicted from in vitro measurement of daily amount of EE2 released. Therefore, performing in vitro drug release studies may aid in the development of an EE2 implant with the desired in vivo release rate.

Unilateral surgery supported by germline RET oncogene mutation analysis in patients with sporadic medullary thyroid carcinoma.

Compared to hereditary medullary thyroid carcinoma (MTC), sporadic MTC tends to be unicentric and confined to one lobe. Patients with sporadic MTC usually undergo total thyroidectomy because of a possible hereditary or bilateral process. We evaluated the usefulness of germline RET oncogene mutation analysis in surgery for apparently sporadic MTC and performed unilateral surgery on patients without detectable mutation. In 36 patients with a preoperative diagnosis of apparently sporadic MTC, we performed germline RET oncogene mutation analyses: before surgery in 8 recent patients and after surgery in 28 who had been treated before 1996. Of the latter, 5 had bilateral MTC. DNA samples were extracted from their peripheral blood, and the polymerase chain reaction products of the RET proto-oncogene were analyzed using single-strand conformation polymorphism analysis and the direct sequencing methods. Before 1996 we often performed total thyroidectomy but changed to hemithyroidectomy thereafter, except in one patient with associated Graves' ophthalmopathy. Our minimal standard practice included systematic central and ipsilateral neck dissection. The outcome was assessed in terms of gastrin- and calcium-stimulated plasma calcitonin levels. Germline RET mutations were found in six patients. Five of these patients had bilateral MTC, whereas all 30 patients without mutation had unilateral disease. Hemithyroidectomy in seven of our recent patients resulted in normalization of plasma calcitonin levels in all, although four were found to have microscopic lymph node involvement. In conclusion, hemithyroidectomy with systematic central and ipsilateral neck dissection is an appropriate procedure for patients with sporadic MTC without detectable germline RET mutations.

Value of the profundapopliteal collateral index for selecting between an in-flow and sequential arterial reconstruction in patients with multisegment arterial occlusive disease.

BACKGROUND: It remains difficult for surgeons to choose between an in-flow and sequential arterial reconstruction in patients with multisegment arterial occlusive disease. In addition, the exact criterion for the proper revascularization procedures of these patients also remains obscure. METHODS: The profundapopliteal collateral index (PPCI) was determined in all patients with occlusions of both the aortoiliac and superficial femoral arteries prior to undergoing an arterial bypass. The PPCI in the inflow bypass (IB) was also compared with the sequential bypass (SB). RESULTS: The symptoms of all patients undergoing either IB or SB improved. Preoperatively, the average PPCI in IB patients was significantly lower than that in SB patients. In addition, no significant difference was observed in the increased average rate of the ankle brachial index (ABI) between IB and SB. CONCLUSIONS: The PPCI is an accurate predictor of the hemodynamic potential of the geniculate collaterals. In cases with a low PPCI, especially in patients with multisegment arterial occlusive disease, in-flow procedures alone may often be sufficient for the successful treatment of such patients. The PPCI is thus considered to be useful for selecting the optimal revascularization procedures.

Factors influencing late survival after abdominal aortic aneurysm repair in Japanese patients.

BACKGROUND: To determine the factors influencing the prognosis of patients with abdominal aortic aneurysms (AAA), the clinical characteristics and long-term survival of 366 consecutive patients were examined and compared with those in previous Western studies. METHODS: During the period from January 1979 to December 1995, 376 patients with AAA were admitted to our hospital. Among these, 332 consecutive patients underwent elective reconstruction of infrarenal AAAs. The remaining 44 patients were not surgically treated. With use of the data from the patients who underwent AAA resection, the relationship of various risk factors, such as cardiac dysfunction, hypertension, renal dysfunction, pulmonary dysfunction, and age, to survival rate was investigated by univariate and multivariate analysis. RESULTS: The operative mortality rate was 0.6%. The survival of the patients who underwent the operation at 5 years was 71.0% and at 10 years 51.8%. The survival rate of the patients who were not surgically treated at 5 years was 26.0% and at 10 years 14.9%. There was a significant difference between the 2 groups. A univariate analysis was performed on each possible risk factor affecting survival rates. In relation to the survival rate of 5 and 10 years, there was no statistical significant difference between patients with or without heart disease or hypertension. By contrast, factors influencing long-term survival were associated with renal dysfunction, pulmonary dysfunction, and age at time of surgery. Multivariate analysis of risk factors affecting survival rates demonstrated that renal dysfunction, pulmonary dysfunction, and age at the time of operation were found to be significant, respectively. The main cause of the death for the long-term survival patients with AAA repair was malignancy, whereas that in the patients without repair was rupture. CONCLUSIONS: Risk factors influencing survival after AAA repair were renal dysfunction, pulmonary dysfunction, and advanced age in Japanese patients. In addition, the main cause of death after aneurysmal resection was malignancy. These results were different from outcomes in Western patients. We need to carefully watch out for malignancy during the follow-up period after AAA resection.

Effects of serotonin and endothelin on the smooth muscle cells of autogenous vein grafts.

BACKGROUND: The purpose of this study was to compare the effects of vasoconstrictor substances such as 5-hydroxytryptamine (5-HT) and endothelin on the smooth muscle of canine femoral veins and vein grafts. METHODS: The right canine femoral vein was grafted into the right femoral artery. The left femoral vein was used as a control. In other experiments to examine the effects of surgical procedures such as dissection of the adventitia and the effects of grafting (vein-to-vein bypass), the right femoral vein was dissected out but not removed for grafting and an autogenous vein bypass of the right femoral vein was made using the left femoral vein. In all experiments, the veins were removed 4 weeks after operation and suspended in organ chambers for isometric tension recording. RESULTS: Maximum contractions to endothelin were comparable in control vein and vein grafts. In control vein, the maximum contraction to 5-HT was small, and was inhibited by both methiothepin, a 5-HT, and 5-HT2 antagonist, and sarpogrelate hydrochloride, a 5-HT2 antagonist. In vein grafts 5-HT produced significantly larger contractions than in control veins, which were inhibited by methiothepin but not by the 5-HT2 antagonist. In veins with adventitial dissection alone and vein-to-vein grafts, 5-HT produced small contractions which were comparable to those in control vein. CONCLUSION: The larger contraction response to 5-HT in canine vein grafts may be due to an increased responsiveness of the 5-HT1 receptor caused by grafting into the arterial circulation.

Enhancement of nitric oxide production after arterial reconstruction in patients with arteriosclerosis obliterans.

PURPOSE: Nitric oxide (NO) not only relaxes vascular smooth muscles, but it also reduces platelet adhesion and is itself a potent antiaggregatory substance. Experimental studies have shown that the release of NO is modulated by the blood flow. However, little clinical information is available about the effects of hemodynamic changes after arterial reconstruction on NO production. We therefore examined whether the plasma levels of nitrite (NO2-) and nitrate (NO3-) ions increased after arterial reconstruction in patients with arteriosclerosis obliterans (ASO). METHODS: Blood samples were obtained from the femoral artery in seven patients who underwent arterial reconstruction and seven healthy individuals (control). NO2- and NO3- levels were measured using high-performance liquid chromatography before the operation and 1 hour and 14 days after the operation. In addition, the mean femoral artery blood flow and ankle-brachial pressure index (ABI) were also measured using a duplex and Doppler velocimeter both before and after the operations. RESULTS: In the control subjects, the mean plasma NO2-, NO3-, and NOx (NO2- plus NO3-) levels in the femoral artery were 0.37 +/- 0.15 mumol/L, 45.6 +/- 10.8 mumol/L, and 46.0 +/- 10.9 mumol/L, respectively. Before the operation in the patients with ASO, the mean plasma NO3- (23.8 +/- 2.2 mumol/L) and NOx levels (24.0 +/- 2.3 mumol/L) were significantly lower than those in the control subjects, whereas the plasma NO2- levels (0.27 +/- 0.04 mumol/L) were comparable between the two groups. At 14 days after operation, the mean plasma NO3- and NOx levels in the femoral artery were significantly increased to 42.8 +/- 5.6 mumol/L and 43.4 +/- 5.6 mumol/L compared with those before the operation, whereas the mean plasma NO2- levels (0.50 +/- 0.05 mumol/L) changed significantly. The mean ABI and the mean flow rate before the operation were 0.32 +/- 0.07 and 344 +/- 145 ml/min, respectively. Both the ABI and the mean flow rate significantly increased to 1.04 +/- 0.06 and 627 +/- 141 ml/min after the operation. CONCLUSIONS: In patients who have ASO, the mean plasma level of NO is significantly lower than that of healthy individuals. In patients with ASO, the mean blood flow increased significantly after arterial reconstruction. This hemodynamic improvement may thus enhance NO production and may also help to maintain the patency of the bypass graft or native artery.

The inhibition of canine vein graft intimal thickening using a newly developed antiplatelet agent.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of a newly developed antiplatelet agent, 4-cyano-5, 5-bis[methoxyphenyl]-4-pentenoic acid (E5510) on intimal hyperplasia of experimental autologous vein grafts in a distal poor runoff canine model. METHOD: The femoral vein was implanted into the femoral artery preparing a distal poor runoff model. These animals were divided into three groups consisting of the E5510 group, the Aspirin group, and the Control group. The vein grafts were harvested at either 1 or 4 weeks after implantation. RESULTS: At 4 weeks, the degree of intimal hyperplasia of the graft of E5510 group was significantly less than that of the Aspirin group and the Control group (p < 0.05). No significant difference was observed between the Aspirin group and the Control group. At 1 week, the degree of intimal cell proliferation was determined by bromodeoxyuridine (BrdU) incorporation and was expressed as the BrdU labeling index. The BrdU labeling index of the E5510 group was also significantly lower than that of the Control group (p < 0.05). CONCLUSIONS: These data demonstrate the efficacy of E5510 in reducing intimal hyperplasia of vein grafts under distal poor runoff conditions by reducing the degree of smooth muscle cell proliferation.

Surgical strategy of abdominal aortic aneurysm with preoperative renal failure.

OBJECTIVES: To determine the effect of preoperative renal failure on the outcome of patients suffering from infrarenal abdominal aortic aneurysm (AAA). METHOD: During the period from January 1979 to August 1995, 364 patients with AAA were admitted to our hospital and 323 underwent elective repair. The patients were retrospectively analysed in three groups. Group I was composed of 273 patients with a normal renal function who underwent an aneurysm repair. Group II was composed of 50 patients who demonstrated a preoperative renal dysfunction (creatinine above 2.0 mg/dl or creatinine clearance below 40 ml/min) and underwent an operation, including three patients maintained on chronic haemodialysis. Group III was composed of 18 patients with a renal dysfunction who did not undergo repair, including one patients maintained on chronic haemodialysis. RESULTS: The operative mortality rate of groups I and II were 0.4% and 2.0%, respectively, although no significant difference was observed. The incidence of postoperative cardiac and pulmonary complications were also comparable in two groups. No patients required acute haemodialysis. The 5-year survival rate of group II (44%) was significantly higher than that of group III (20%), and seven of the 18 patients (39%) in group III ultimately died of a rupture of the AAA. CONCLUSIONS: Patients with chronic renal failure can undergo an abdominal aortic aneurysm repair based on the same indications as those without renal failure.

Acceleration of impairment of endothelium-dependent responses under poor runoff conditions in canine autogenous vein grafts.

OBJECTIVES: To assess the effects of changes in shear stress on endothelium-dependent responses. MATERIALS AND METHODS: Autologous vein grafts were implanted in poor or normal distal runoff limbs of 10 mongrel dogs. Six weeks after grafting the vein grafts were removed, cut into rings, and suspended in organ chambers for isometric tension recording. RESULTS: The average value of intimal thickening was 110.7 +/- 45.2 microns in poor runoff limbs and 65.5 +/- 27.9 microns in control limbs, respectively. There was a significant difference between the two groups. Acetylcholine caused comparable endothelium-independent contractions in both groups. In the control group, adenosine diphosphate, thrombin and A23187 caused endothelium-dependent relaxations. In the poor runoff group, the endothelium-dependent relaxations caused by adenosine diphosphate and thrombin were impaired, while A23187 caused comparable endothelium-dependent relaxations. Direct relaxations in response to sodium nitroprusside were comparable between the two groups. CONCLUSIONS: This dysfunction of the endothelium under conditions of abnormal flow may accelerate intimal thickening of the vein graft and result in late graft failure.

The effect of probucol on intimal thickening of autologous vein grafts in hyperlipidemic rabbit.

Probucol is used to treat hypercholesterolemia and also has an anti-atherogenic effect. The effects of probucol on intimal thickening of autologous vein graft in hyperlipidemic rabbits with poor distal run-off were investigated. A poor distal run-off model was prepared in the right hindlimb of 18 rabbits allocated to four groups depending on diet: normolipidemic commercial diet, (NL group, n = 5); hyperlipidemic diet (HL group, n = 5); commercial diet with 1% probucol (NP group, n = 4); and hyperlipidemic diet with 1% probucol (HP group, n = 4). After 4 weeks the femoral vein grafts were implanted into normal (n = 18) or poor (n = 18) runoff limbs. Vein grafts were harvested 4 weeks after implantation. Intimal thickening of the graft was measured and macrophages therein examined immunohistochemically. The serum cholesterol level was not reduced by probucol treatment. The mean flow rate of the graft was significantly reduced in the poor run-off limb. On histological examination intimal thickening in the poor run-off limb was significantly greater than that of controls, while intimal thickening in the HL and HP groups was enhanced compared with that in the NL and NP groups, respectively. Mean intimal thickening in each limb in HP group rabbits was significantly lower than that in HL rabbits (microm): control (HL/HP): 99.4(7.4)/58.8(0.7) (P < 0.05); poor run-off (HL/HP): 155.3(9.6)/130.3(7.3) (P < 0.O5). There was no difference between NL and NP (microm): control (NL/NP): 44.6(24.7)/31.5(12.8); poor run-off (HL/HP): 115.3(13.8)/97.5(34.0). In addition, enhanced intimal thickening due to poor distal run-off was not suppressed. Immunohistochemical staining showed intimal macrophage infiltration in the HL and HP groups; however, macrophage infiltration in grafts in the HP group was less than in the HL group. In conclusion, under hyperlipidemic conditions, probucol decreased intimal thickening enhancement of the vein graft, and suppressed intimal macrophage infiltration. These findings were similar to the anti-atherogenic effect of probucol in the native artery. Hence, probucol administration after vascular reconstruction with vein grafts in patients with hyperlipidemia may be beneficial.

Inhibition of tumor cell proliferation by natural suppressor cells present in murine bone marrow.

Natural suppressor (NS) cells, which are Thy-1-, immunoglobulin-, and nonadherent cells with relatively low density (1.063 to 1.075 g/ml), inhibit not only the proliferation of spleen cells which have been stimulated by allogeneic cells or mitogens but also the proliferation of tumor cell lines. Cell-to-cell contact is not necessary for NS cells to exert NS activity. Being radioresistant, DNA synthesis is not necessary for NS cells to suppress proliferation. However, protein synthesis is necessary, since puromycin blocks NS cell activity. In addition, NS cells were found to secrete a factor which inhibits DNA synthesis. Of the various cytokines tested, interleukin 3 and granulocyte-macrophage colony-stimulating factor enhance NS activity. These results suggest that NS cells play an important role in the suppression of not only immune responses but also tumor growth.

Effect of human recombinant interleukin-6 on the proliferation of mouse hepatocytes in the primary culture.

Effects of various cytokines on the proliferation of mouse hepatocytes were investigated. Human recombinant IL-6 not only enhanced the proliferation of mouse hepatocytes in the presence of epidermal growth factor, but also without epidermal growth factor. However, other human or mouse cytokines such as recombinant IL-1, IL-2, IL-3, IL-4, IFN-beta and IFN-gamma, which are known to regulate immune responses and/or hematopoiesis, had no effect on the proliferation of hepatocytes. These results suggest that IL-6 plays a crucial role in regulating the regeneration of hepatocytes after hepatitis or partial hepatectomy.

Acceptance of murine thyroid allografts by pretreatment of anti-Ia antibody or anti-dendritic cell antibody in vitro.

A new method for thyroid allografts in mice was established. Thyroids of C67BL/6J mice were treated with collagenase, and the follicles were isolated using a Percoll density gradient technique. These follicles were treated with anti-Ia antibody (Ab) or anti-DC Ab plus complement in order to eliminate DCs. The follicles were then mixed with agarose and transplanted under the left renal capsule of BALB/c mice. One hundred days after transplantation, acceptance of the grafts was verified by both histological study and the incorporation of 125I into the grafts. Allografts treated with C were rejected, whereas allografts treated with Ab plus C were accepted. When nontreated thyroids of C57BL/6J mice were grafted under the right renal capsule of BALB/c mice that had accepted DC-depleted thyroids of C57BL/6J mice, the nontreated thyroids were rejected. These findings indicate that DCs play a crucial role in the rejection of mouse thyroid allografts, and that the depletion of DCs permits allografts to be accepted without inducing donor-specific tolerance. Our method presented here may be developed as a viable strategy for the treatment of patients with congenital or acquired hypothyroidism.