Early results of a randomized two-by-two factorial phase II trial comparing neoadjuvant chemotherapy with two and four courses of cisplatin/S-1 and docetaxel/cisplatin/S-1 as neoadjuvant chemotherapy for locally advanced gastric cancer.

BACKGROUND: Neoadjuvant chemotherapy (NAC) is a promising method of improving the survival of resectable gastric cancer. Cisplatin/S-1 (CS) and docetaxel/cisplatin/S-1 (DCS) are both effective against metastatic gastric cancer. This report clarified the impact of these regimens on early endpoints, including the pathological responses, chemotherapy-related toxicities, and surgical results. METHODS: Patients with M0 and either T4 or T3 in case of junctional cancer or scirrhous type received two or four courses of cisplatin (60 mg/m2 at day 8)/S-1 (80 mg/m2 for 21 days with 1 week rest) or docetaxel (40 mg/m2 at day 1)/cisplatin (60 mg/m2 at day 1)/S-1 (80 mg/m2 for 14 days with 2 weeks rest) as NAC. Patients then underwent D2 gastrectomy and adjuvant S-1 chemotherapy for 1 year. The primary endpoint was the 3-year overall survival. RESULTS: Between October 2011 and September 2014, 132 patients were assigned to receive CS (n = 66; 33 in 2 courses and 33 in 4 courses) or DCS (n = 66; 33 in 2 courses and 33 in 4 courses). The respective major grade 3 or 4 hematological toxicities (CS/DCS) were leukocytopenia (14.1%/26.2%), neutropenia (29.7%/47.7%), anemia (14.1%/12.3%), and platelet reduction (3.1%/1.5%). The rate of pathological response, defined as a complete response or < 10% residual cancer remaining, was 19.4% in the CS group and 15.4% in the DCS group, and 15.6% in the two-course group and 19.0% in the 4-course group. The R0 resection rate was 72.7% in the CS group and 81.8% in the DCS group and 80.3% in the two-course group and the 74.2% in the four-course group. No treatment-related deaths were observed. CONCLUSIONS: Our results do not support three-drug therapy with a taxane over two-drug therapy, or any further treatment beyond two cycles as an attractive candidate for the test arm of NAC.

Clinical characteristics and outcomes of adenovirus infection of the urinary tract after renal transplantation.

BACKGROUND: Urinary tract infection caused by human adenovirus (HAdV) after renal transplantation (RT) results in graft loss because of concomitant nephropathy and acute rejection and may result in death because of systemic dissemination. METHODS: We assessed the time period between RT and disease onset, symptoms, treatment details, disease duration, renal graft function, outcomes, and complications. RESULTS: HAdV infection of the urinary tract occurred in 8 of 170 renal transplant recipients. Symptoms were macrohematuria in all 8 patients, dysuria in 7, and fever in 5. The median period from RT to disease onset was 367 (range, 7-1763) days, and the median disease duration was 15 (range, 8-42) days. The mean serum creatinine (sCr) level prior to onset was 1.35 ± 0.48 mg/dL and the mean maximum sCr level during disease was 2.34 ± 1.95 mg/dL. These values were increased by ≥25% in 5 patients. The mean sCr levels when symptoms resolved was 1.54 ± 0.67 mg/dL, and no significant difference was seen before, during, or after disease onset (P = 0.069). Two patients were diagnosed with HAdV viremia and 1 with acute tubulointerstitial nephritis revealed on biopsy. In addition to a reduction in immunosuppressant dosage, 2 patients received gammaglobulins and 5 received ganciclovir. CONCLUSION: Symptoms of all patients were alleviated, although some patients developed nephritis or viremia. Hence, the possibility of exacerbation should always be considered. Adequate follow-up observation should be conducted, and diligent and aggressive therapeutic intervention is required to prevent the condition from worsening.

Effect of heat stress soon after muscle injury on the expression of MyoD and myogenin during regeneration process.

Heat stress could promote skeletal muscle regeneration. But, in the regeneration process, effects of heat stress on myogenic cells and the regulating factors is unknown. Therefore, Influences of heat stress soon after injury on distribution of the myogenic cells and chronological changes in expression of MyoD and myogenin were examined. The first peak of MyoD expression was temporally correlated with the time when proliferating satellite cells began to appear, and the rapid decline of the MyoD expression from the first peak, with the appearance time of myoblasts, respectively in both the non-Heat and Heat groups. The first peak of myogenin expression was temporally correlated with the time when multinuclear cells began to form in the both groups. Due to the heat stress, proliferation and differentiation of myogenic cells and chronological changes in these factors were accelerated one day earlier than in the non-Heat group. As MyoD and myogenin are regulating factor of proliferation and differentiation, heat stress soon after the muscle injury could accelerate the proliferation and differentiation of myogenic cells and the expression of their regulating factors MyoD and myogenin.

Individual differences in prothrombin time-international normalized ratio variation following coadministration of the anticancer agents S-1 and warfarin: 3 case reports.

OBJECTIVE: We report three cases of elevated prothrombin time-international normalized ratios (PT-INR) following the initiation of coadministration of warfarin and S-1, a preparation containing tegafur (FT), gimeracil (CDHP), and oteracil potassium (Oxo). CASE SUMMARIES: The three cases included 2 men and 1 woman aged 79, 71, and 54 y, respectively. PT-INRs were in the range of 2.0 - 3.0 before therapy but were elevated to values in the range of 3.79 - 4.92 within 8 - 17 days after initiating the coadministration of warfarin (1.5 - 3.5 mg/d) and S-1 (80 - 120 mg/d). When the drug interactions in Cases 1 - 3 were evaluated using the Drug Interaction Probability Scale, each of these cases was assessed as "probable". DISCUSSION: The drug interaction between warfarin and S-1 presumably leads to elevated PT-INR because the 5-fluorouracil (5-FU), which is metabolite of FT in S-1, inhibits the metabolic processing of S-warfarin by cytochrome P450 (CYP) 2C9. However, individual differences in the metabolic production of 5-FU from FT because of genetic polymorphisms in CYP2A6 and individual variation in the levels of renal function may lead to complications when 5-FU is coadministered with warfarin as compared to when 5-FU is administered alone. CONCLUSION: It is essential that the dosage level of warfarin is appropriately adjusted by frequent PT-INR measurements when warfarin and S-1 are coadministered.

Warfarin and miconazole oral gel interactions: analysis and therapy recommendations based on clinical data and a pharmacokinetic model.

WHAT IS KNOWN AND OBJECTIVE: Miconazole is a strong inhibitor of CYP2C9, one of the main enzymes involved in the metabolism of warfarin. Concurrent use of the two drugs leads to potentially serious adverse effects. Although it is often assumed that use of the oral miconazole gel is acceptable with concomitant warfarin, because of the low bioavailability following buccal administration, drug-drug interactions have been reported following such use. We aimed to investigate case reports of such interactions and develop a pharmacokinetic model to model such interactions. METHODS: The Medline database from 1966 to October 2010 was used for literature search. Case reports of the potentiation of the anticoagulant effects of warfarin, such as the elevation of prothrombin time (INR), by concomitant administration of warfarin and miconazole oral gel were collected. We quantitatively estimated the extent of inhibition of warfarin metabolism by orally administered miconazole gel and compared our findings with case reports. RESULTS AND DISCUSSION: Metabolism of (S)-warfarin is inhibited potently following administration of a standard dose (200-400 mg/day in Japan) of miconazole gel. This may lead to in an increase in the blood concentration of warfarin and lead to serious adverse effects. The literature reports of clinical interactions with concomitant use of those drugs show that other factors may amplify the effects of any increase in blood concentration. WHAT IS NEW AND CONCLUSION: We summarize all reported, clinically significant, cases of drug interaction between miconazole oral gel and warfarin. Pharmacokinetic modelling shows that concomitant administration of warfarin and miconazole oral gel can lead to substantial increase in warfarin concentration. However, our PK/PD model fails to capture the dramatic increases seen in INR values, and hence bleeding complications, reported in the literature. Taken together, the evidence suggests that concomitant use of miconazole gel and warfarin should be avoided. Even over-the-counter products containing miconazole should be used with caution by patients receiving warfarin.

Toward improving human islet isolation from younger donors: rescue purification is efficient for trapped islets.

Several reports suggest that islets isolated from younger donor pancreata are of better quality for clinical islet transplantation. The relative inefficiency of the continuous gradient purification process (CGP) is one of the major obstacles to the utilization of these younger donor pancreata. This study demonstrates the benefits of utilizing an additional purification step, rescue gradient purification (RGP), to recover trapped islets and examines the possible superiority of these rescued islets. Seventy-three human islet isolations purified by RGP following CGP were divided into two groups based on age, and the isolation results were retrospectively analyzed (group I: age < or = 40, group II: age > 40). The quality of islets from both CGP and RGP were assessed by beta-cell fractional viability (beta FV) and ADP/ATP ratio. Significant increases in the percent islet recovery from RGP and the percent trapped islets in group I compared to group II were observed. Donor age correlated negatively to the percent islets recovered from RGP (R = 0.440) and to the percent of trapped islets (R = 0.511). RGP islets had higher beta FV and better ADP/ATP ratio compared to CGP islets. In conclusion, RGP improved the efficiency in the purification of trapped islets, which often come from younger donor pancreata. The better quality of beta-cells in RGP islets encourages us to perform RGP, considering the higher quality as well as the quantity of remaining islets.

In situ quantitative immunoprofiling of regulatory T cells using laser scanning cytometry.

Laser scanning cytometry (iCys; CompuCyte, Cambridge, Mass) has recently been developed to use fluorescence-based quantitative measurements on tissue sections or other cellular preparations at a single-cell level. The purpose of this study was to develop objective, quantitative immunoprofiling of regulatory T cells (T regs) on formalin-fixed/paraffin-embedded (FFPE) biopsy samples from transplanted allografts using iCys. We sought to evaluate the usefulness of iCys to analyzes the population of CD4 (+) Foxp3 (+) T regs among CD4 (+) T-cell and the entire T-cell (the total of CD4 [+] and CD8 [+] populations in human intestinal allograft biopsy samples. Primary antibodies (Foxp3 and CD4) which had been labeled using Alexa Fluoro 488 (Foxp3 Alexa488) and 647 (CD4 Alexa647) with polymer horseradish peroxidase and catalyzed signal amplification were incubated on 1 section. On the other section, CD8 and CD4 were labeled using Alexa488 and Alexa647 using the same protocol. Data acquisition was performed using iCys. The signal intensities of Alexa488 and Alexa647 were sufficient to analyze by iCys. Distribution of the integrals of Alexa488 and Alexa647 to visualize each cell population enabled calculation of the population of T reg among CD4 (+) T cells, CD4 (+) T cells among total T cells, and T reg among entire T cells. iCys and signal amplified immunofluorescent staining allowed objective quantitative immunoprofiling of in situ T reg populations, with precise quantitative analysis at a single-cell level on FFPE sections. This objective method may be applied on biopsy samples from various transplanted organs.

Purification method using iodixanol (OptiPrep)-based density gradient significantly reduces cytokine chemokine production from human islet preparations, leading to prolonged beta-cell survival during pretransplantation culture.

Purification is one of the most important steps in human islet isolation. Although Ficoll-based density gradients are widely used, OptiPrep-based density gradients are used in few centers. Cytokine/chemokine production from human islet preparations varies widely. Some cytokines/chemokines have been reported to have adverse effects on human islet preparations. Control of cytokine/chemokine production may be a key to improve islet quality and quantity, leading to better transplantation outcomes. The aim of the present study was to investigate the effects on islet preparations of purification methods using various density gradients on viability, cellular composition, and proinflammatory cytokine/chemokine production. After the digestion phase, the extracts were divided into 2 groups for purification using a semiautomated cell processor with Ficoll-based or OptiPrep-based density gradients. Islet preparations cultured for 2 days were assessed regarding islet cell viability (fluorescein diacetate/propidium iodide [FDA/PI]), fractional beta-cell viability by FACS, and beta-cell content using iCys. Cytokine/chemokine production from islet preparations was also measured by Bio-plex. After purification, the purity, islet equivalents (IEQ), and islet recovery rates were comparable between the 2 groups. Although FDA/PI and fractional beta-cell viability showed no significant difference, survival of beta cells during culture was significantly higher in the OptiPrep compared with the Ficoll-based density gradient group. There were significantly lower tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, interferon (IFN)-gamma, IL-6, and MIP-1beta productions from the OptiPrep-based density gradient group. OptiPrep-based density gradients reduced cytokine/chemokine production by islet preparations. In addition, OptiPrep-based density gradient purification significantly reduced the loss of beta-cell mass during pretransplantation culture.

Effect of pituitary adenylate cyclase-activating polypeptide in islet transplantation.

INTRODUCTION: Pituitary adenylate cyclase-activating polypeptide (PACAP) is an islet substance serving as an intra-islet amplifier of glucose-induced insulin secretion similar to exendin-4. It has been reported that systemic administration of PACAP maintained beta-cell mass, delayed the onset of hyperglycemia, and protected beta cells from glucose toxicity. Moreover, PACAP increases glucose-stimulated insulin release in vitro and in vivo. In this study, we investigated the possibility of PACAP use in human islet transplantation. METHODS: Human islets were cultured in the presence or absence of PACAP (10(-12) mol/L) for 48 hours. We assessed beta-cell viability using FACS, cellular composition analysis by iCys/LSC, and glucose-stimulated insulin secretion. In vivo, islets were transplanted beneath the kidney capsule of Streptozotocin-induced diabetic immunodeficient mice. An intravenous glucose tolerance test (IVGTT) was also performed in the presence or absence of PACAP (Peptide International, Louisville, Ky, United States; 1.3 nmol/kg). RESULTS: There were significant improvements in terms of beta-cell viability and cellular composition between islets cultured with or without PACAP, respectively (P < .05). Moreover, glucose-stimulated insulin secretion significantly improved in islets cultured with PACAP compared with controls, respectively (P < .05). Treatment of recipient mice with PACAP resulted in beneficial effects on insulin secretion (PACAP vs control, 13.2 vs 1.9 mU/L), in IVGTT. However, no significant difference was observed in glucose levels between the 2 groups. CONCLUSIONS: Our study indicated that PACAP significantly improved beta-cell viability and survival during culture, and increased insulin secretion in vitro and in vivo. However, blood glucose levels in vivo after an IVGTT did not significantly improve, probably due to increased glucagon secretion from alpha cells. PACAP supplementation to culture medium could be of assistance to improve clinical islet transplantation outcomes.

Laparoscopic and endoscopic cooperative surgery for gastrointestinal stromal tumor dissection.

BACKGROUND: Laparoscopic wedge resections are increasingly applied for gastric submucosal tumors such as gastrointestinal stromal tumor (GIST). Despite this, no defined strategy exists to guide the surgeon in choosing the appropriate laparoscopic technique for an individual case on the basis of tumor characteristics such as location or size. This study aimed to introduce a laparoscopic and endoscopic cooperative surgery (LECS) for gastric wedge resection that is applicable for submucosal tumor resection independent of tumor location and size. METHODS: Seven patients underwent LECS for the resection of gastric submucosal tumors. Both mucosal and submucosal layers around the tumor were circumferentially dissected using endoscopic submucosal dissection via intraluminal endoscopy. Subsequently, the seromusclar layer was laparoscopically dissected on the exact three-fourths cut line around the tumor. The submucosal tumor then was exteriorized to the abdominal cavity and dissected with a standard endoscopic stapling device. RESULTS: In all cases, the LECS procedure was successful for dissecting out the gastric submucosal tumor. In four of seven cases, the tumor was located in the upper gastric portion near the esophagogastric junction. The remaining three tumors were in the posterior gastric wall. In two cases, the tumors were more than 5 cm in diameter, and one was a GIST of the remnant stomach. The mean operation time was 169 +/- 17 min, and the estimated blood loss was 7 +/- 2 ml. The postoperative course was uneventful in all cases. CONCLUSIONS: The LECS procedure for dissection of gastric submucosal tumors such as GIST may be performed safely with reasonable operation times, less bleeding, and adequate cut lines. In addition, the success of the procedure does not depend on the tumor location such as the vicinity of the esophagogastric junction or pyloric ring.

Factors that affect human islet isolation.

More than 10,000 IEQ/kg recipient weight of islets is often necessary to achieve insulin independence in patients with type 1 diabetes mellitus. Several studies have identified high donor body mass index (BMI) and pancreas size as important factors for the success of human islet isolation. However, the donor shortage underscores the need to improve isolation outcomes from lower BMI pancreas donors and/or small pancreata. The aim of this study was to identify the critical factors that affect isolation outcome. We analyzed the data from 207 isolations performed from 2002 to 2006 with respect to donor characteristics, pancreas condition, and processing variables. More than 3000 IEQ/g pancreas weight was considered to be an acceptable isolation outcome. This goal was obtained from donors with a BMI >30 kg/m2 (P = .002). The pancreatic surface integrity was also a significant factor (P = .02). Moreover, longer digestion times (P = .04) and a greater proportion of trapped islets negatively affected success rates (P = .004). As previously reported, pancreata from high BMI donors were suitable for islet isolation and transplantation, as they yielded higher total islet particle numbers and higher IEQ/g. Although BMI and pancreas size are not controllable due to the organ donor shortage, factors such as pancreatic surface integrity, shorter digestion time, and lower proportions of trapped islets were found to be significant to obtain higher success rates. The development of better protocols and systematic training of processing/procurement teams will be of assistance to increase the number of successful human islet isolations.

Effect of human islet rescue gradient purification on islet yield and fractional Beta cell viability.

It is difficult to consistently obtain sufficient postpurification islet numbers from younger donors because of the higher proportion of trapped islets after pancreas digestion. Continuous gradient purification (CGP), which is currently used in several islet processing centers, sometimes is not efficient in the purification of trapped islets. Rescue gradient purification (RGP) could improve postpurification islet yields, resulting in an increased number of islet cell products that could be transplanted. Sixty-eight human islet isolations, in which CGP was followed by RGP were analyzed. The quality of islets from CGP and RGP was assessed by beta-cell fractional viability (betaFV) and ADP/ATP ratio. Donor age negatively correlated with the proportion of the islets rescued by RGP (R = -0.52; P < .01) and to the percentage of trapped islets (R = -0.46; P < .01). Age-related differences were observed in pancreas weight, digestion time, and islet yields from CGP, respectively. Importantly, islets from RGP had an 11% higher betaFV compared with islets from CGP. ADP/ATP ratio was also lower in RGP islets versus CGP islets. RGP improved the efficiency of islet purification from younger pancreata and did not affect islet cell viability, which was actually higher in RGP fractions, indicating that rescued trapped islets from the pellet and lower purity layers are not damaged by the extra purification step and may actually be more viable. RGP could be used to rescue high-quality islets from less than 30% pure islet fractions, which are often discarded in the clinical setting.

beta-Cell specific cytoprotection by prolactin on human islets.

INTRODUCTION: Many cytoprotective agents have been reported to improve islet isolation and transplantation outcomes. However, several of these agents improve all cell subsets within an islet preparation; selection of non-beta-cell components (eg, acinar cells) may have a negative effect on beta-cell function and survival. In this study, we examined the effect of prolactin (PRL) supplementation in the culture medium to determine whether it exerted beta-cell-selective cytoprotection on islet viability and function. MATERIALS AND METHODS: Human islets were precultured with or without recombinant human PRL (500 microg/L) for 48 hours. The fractional viability and cellular composition of non-beta-cell and beta-cell-specific components were assessed using FACS and Laser Scanning Cytometry (LSC). Islet potency was assessed in vivo by transplantation into chemically induced diabetic immunodeficient mice. RESULTS: The relative viable beta-cell mass and the relative islet beta-cell content in the PRL group were 28% higher (P = .018) and 19% higher (P = .029) than the control group, respectively. All transplanted mice achieved normoglycemia in both groups, indicating that PRL treatment did not alter islet function. CONCLUSION: PRL treatment improved beta-cell-specific viability and survival of human islets in vitro. The development of novel beta-cell-specific cytoprotective strategies may be of assistance in improving islet transplantation.

Magnocellular and parvocellular visual pathways have different blood oxygen level-dependent signal time courses in human primary visual cortex.

PURPOSE: The magnocellular and parvocellular pathways (M and P pathways) are the major pathways of the visual system, with distinct histologic and physiologic properties that may also have different metabolic characteristics. We hypothesize that the differences of the 2 visual pathways would also manifest as differences in the signal time course of blood oxygen level-dependent functional MR imaging (BOLD fMRI). The differences in BOLD signal time course may provide insight into the metabolic requirements of the 2 pathways. METHODS: Eleven fMRI sessions on 6 subjects were performed using stimuli that preferentially activated the 2 pathways. Regions commonly activated by both the M and P stimuli in the primary visual cortex (V1) were determined, and the contrast elicited by the stimulus, time-to-peak (TTP), and the full width at half maximum (FWHM) of the BOLD signal time course were measured. RESULTS: The functional stimuli activated cortical regions described previously in the literature, such as V1, V4, and V5. Within V1, the TTP of the signal time course of the 2 stimuli were statistically different, with the P stimulus generating TTPs that were on average 12% faster than the M stimulus (P = .0037). CONCLUSION: We have demonstrated the ability to functionally differentiate the M and P stimuli in a commonly activated anatomic region. Because the BOLD response is dependent on the ratio of oxyhemoglobin and deoxyhemoglobin in the blood, the difference in the BOLD time course between the 2 stimuli suggests that the oxygen demand of the 2 pathways may be different.

Dosage adjustment of quinolone antibiotics and angiotensin-converting enzyme inhibitors in patients with renal dysfunction.

The aim of this study was to verify an approach for calculating pharmacokinetic parameters suitable for adjusting dosage regimens in patients with renal dysfunction. We carried out a retrospective analysis of the pharmacokinetic profiles of 12 new quinolone antibiotics and 11 angiotensin-converting enzyme inhibitors (ACEIs) in patients with normal and impaired renal function to obtain the renal excretion ratio (R(renal)) of each drug. We demonstrated that the pharmacokinetics of each drug in a patient with renal dysfunction can be adequately estimated using the R(renaI) value of each drug together with the creatinine clearance as an index of the individual's renal function. Using the R(renaI) value obtained, we could successfully simulate pharmacokinetic profiles of the drugs in publications other than that used to obtain the R(renal) values. On the other hand, age-related changes in the pharmacokinetics of new quinolone antibiotics are not always adequately predicted using the R(renal) value compared to using creatinine clearance alone as an index, and the reasons for this are not fully understood. These results demonstrate that dosage regimens of quinolone antibiotics and ACEIs in patients with renal dysfunction can be adequately optimized using the R(renal) value for each drug using the present approach.

Living-Donor Liver Transplantation Using Segment 2 Monosegment Graft: A Single-Center Experience.

BACKGROUND: In small infants, left lateral segment grafts are sometimes too large to overcome the problems of large-for-size grafts in the abdominal compartment. To address this problem, we have developed a safe living donor graftectomy for neonates, a so-called "S2 monosegment graft" to minimize graft thickness. We reviewed our single-center experience to evaluate the feasibility of this technique for reducing graft size. METHODS: Eleven living-donor liver transplants using S2 monosegment grafts were performed between October 2008 and September 2014 at our institution. Medical records of both donors and recipients were reviewed and data collected retrospectively. RESULTS: The mean age of recipients at the time of transplantation was 125.3 days, including 3 neonates. The average S2 monosegment graft weight was 127.4 g, and the graft-to-recipient body weight ratio was successfully reduced to 3.5%. The graft livers were reduced to 4.1 cm in thickness. Two recipients with grafts larger than 5 cm could not undergo primary abdominal closure. Portal vein stenosis and biliary stenosis was observed in 1 recipient, and hepatic artery complications were seen in 2 recipients; the clinical course for all donors were uneventful. Liver regeneration was seen in every patient. The graft and patient 1-year survival rate was 100%. CONCLUSIONS: Living-donor liver transplantation using S2 monosegment grafts offers a safe and useful option for treating smaller infants. Here, we introduce our method of S2 monosegment graft emphasizing the donor harvest and graft thickness.

Morphological analysis of selective destruction of pancreatic beta-cells by cytotoxic T lymphocytes in NOD mice.

Interactions of pancreatic islets and islet-associated mononuclear cells (IAMCs) from the nonobese diabetic (NOD) mouse were morphologically investigated. To obtain IAMCs, pancreatic islets isolated from adult NOD mice were cultured for 7 days with interleukin 2. Noted by light microscopy, interactions between IAMCs and freshly isolated islets from young NOD mice began 30 min after the initiation of the coculture, and 6 h later, normal cellular array of the islets was lost. By electron microscopy, most IAMCs had low nucleus-cytoplasm ratio, the nucleus was notched and exhibited condensed chromatin along the nuclear membrane, and well-developed Golgi complexes and several mitochondria were distributed in the cytoplasm. These IAMCs adhered to beta-cells, but not to alpha- or delta-cells, with their pseudopods and caused cytolysis of beta-cells. Immunohistochemical study with antibodies specific for pancreatic hormones demonstrated that only cells reacting with anti-insulin antibody were selectively lost as the incubation time proceeded. Electron immunohistochemistry by immunogold technique showed that effector cells in IAMCs reacted with anti-CD8 (Lyt-2) antibody, but not anti-CD4 (L3T4) or anti-asialogangliosideM1 antibody. In addition, the concentration of pancreatic hormones in the culture medium, used as a marker of cytolysis, also demonstrated that insulin was significantly increased after 6 h of culture, whereas glucagon and somatostatin were not. These results suggest that CD8+ cytotoxic T lymphocytes are involved in the selective destruction of pancreatic beta-cells in the NOD mouse.

Expression of alpha-, beta-, and gamma-subspecies of protein kinase C in the motor neurons in the embryonic and postnatal rat spinal cord.

Using polyclonal antibodies against alpha-, beta- and gamma-subspecies of protein kinase C, developmental changes in expression of these subspecies in the motor neurons in the rat cervical spinal cord were immunohistochemically investigated. On embryonic day-12, the motor neurons began to differentiate from undifferentiated neuroepithelial cells. On embryonic day-13, they began to express weak immunoreactivity for alpha- and beta-protein kinase C and slightly more evident immunoreactivity for gamma-protein kinase C. Immunoreactivity for protein kinase C in these neurons gradually became stronger, as the development progressed. Between embryonic day-18 and postnatal day-7, the motor neurons showed distinct immunoreactivity in the nucleus, perikaryal cytoplasm, axon and dendrites. At these stages, distribution and intensity of immunoreactivity for alpha-, beta- and gamma-protein kinase C were very similar. Thereafter, the expression of this enzyme in the nucleus gradually declined, while in the other structures, expression of each subspecies changed independently. On postnatal day-28 and 35, expression of beta-protein kinase C in the axons was stronger than that of alpha- and gamma-protein kinase C, and immunoreactivity for gamma-protein kinase C in the perikaryal cytoplasm and dendrites was slightly weaker than that for alpha- and beta-protein kinase C. Expression of this enzyme in the motor neurons at these stages was almost the same as in the adult animal. Electron microscopically, immunoreactivity for protein kinase C was randomly distributed in the nucleus, and in the perikaryal cytoplasm, often near the cisterns of the endoplasmic reticulum. Expression of protein kinase C in the growing axons was quite different from that in the mature axons. In the dendrites, immunoreactivity for protein kinase C was distributed randomly in the cytoplasm and at the postsynaptic densities. These findings suggest that protein kinase C might regulate not only the neural functions, but also several aspects of the differentiation process in the motor neurons.

Developmental expression of alpha-, beta- and gamma-subspecies of protein kinase C in the dorsal corticospinal tract in the rat spinal cord.

Developmental expression of alpha-, beta- and gamma-subspecies of protein kinase C in the dorsal corticospinal tract was immunohistochemically investigated at the cervical level of the postnatal rat spinal cord. On postnatal day 0, immunoreactivity for these subspecies was uniformly distributed throughout the posterior funiculus. On postnatal day 7, immunoreactivity for this enzyme in the posterior funiculus began to decline. On postnatal days 14 and 21, the immunoreactivity in the posterior funiculus became weak, while the dorsal corticospinal tract forming in the most ventral portion of the posterior funiculus exhibited strong immunoreactivity for these three subspecies of protein kinase C. Thereafter, immunoreactivity in the corticospinal tract rapidly declined, and on postnatal days 28 and 35, weak immunoreaction was demonstrated as very fine granular deposits in the tract. Expression of this enzyme in the dorsal corticospinal tract at these stages resembled that in the adult rat. Electron microscopically, growth cones and nascent axonal shafts were first noted on postnatal day 2 in the most ventral portion of the posterior funiculus, and thereafter, the axonal shaft gradually thickened and on postnatal day 14 some axons began to be myelinated. The growth cones and thin axonal shafts randomly exhibited weak immunoreactivity in the axoplasm. The thicker unmyelinated axonal shafts showed distinct immunoreactivity uniformly throughout the axoplasm and along the axolemma as granular deposits. In these developing axons, intensity and distribution of immunoreactivity for all three subspecies were principally similar. In the mature myelinated axons, the intensity and distribution of immunoreactivity for each subspecies of protein kinase C were quite different, i.e. immunoreactivity for alpha-subspecies was randomly distributed on some cytoskeletal elements, and that for beta-subspecies was uniformly detected on most of the cytoskeletal elements. In contrast, immunoreactivity for gamma-subspecies was distributed mainly on the endoplasmic reticulum. These findings suggest that in growing corticospinal axons protein kinase C might be involved in several important aspects of axonal development, and that in mature axons this enzyme might participate in different aspects of axonal function.

Cross-axis adaptation of pursuit initiation in humans.

PURPOSE: The initial acceleration of pursuit in the open-loop period is under adaptive control and undergoes motor learning. The current study was undertaken to examine the hypothesis that the direction of pursuit initiation can also be adaptively modified. METHODS: Four neurologically and ophthalmologically normal subjects participated in the experiment. A modified step-ramp paradigm was used to induce cross-axis adaptation, in which a ramp target changed its direction orthogonally just after the target crossed the center. Four direction changes were tested in separate experiments: left to up, left to down, down to left, and up to left. During a 30-minute adaptation session, the target moved in one of two randomly chosen directions (right to left or up to down) at one of two randomly chosen speeds (15.6 or 22.3 deg/sec), but the target changed orthogonally in only one direction. A linear regression fit to the initial 100-msec segment of the pursuit trace was used to determine the direction of pursuit initiation. RESULTS: In all cases, an adaptive change in pursuit initiation was gradually induced in the direction called for by the training paradigm. Adaptation was usually completed (90 degrees shift) within the 30-minute training session but declined quickly to an approximate 30 degrees -shift after training. The latency and vectorial amplitude of the initial acceleration remained unchanged. The adaptation was specific for the direction but not the velocity of the target. CONCLUSIONS: This study showed that the direction of pursuit initiation is under adaptive control, as has been shown for saccadic eye movements and the vestibulo-ocular reflex.