Time course and spatial distribution of fMRI signal changes during single-pulse transcranial magnetic stimulation to the primary motor cortex

Simultaneous transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) may advance the understanding of neurophysiological mechanisms of TMS. However, it remains unclear if TMS induces fMRI signal changes consistent with the standard hemodynamic response function (HRF) in both local and remote regions. To address this issue, we delivered single-pulse TMS to the left M1 during simultaneous recoding of electromyography and time-resolved fMRI in 36 healthy participants. First, we examined the time-course of fMRI signals during supra- and subthreshold single-pulse TMS in comparison with those during voluntary right hand movement and electrical stimulation to the right median nerve (MNS). All conditions yielded comparable time-courses of fMRI signals, showing that HRF would generally provide reasonable estimates for TMS-evoked activity in the motor areas. However, a clear undershoot following the signal peak was observed only during subthreshold TMS in the left M1, suggesting a small but meaningful difference between the locally and remotely TMS-evoked activities. Second, we compared the spatial distribution of activity across the conditions. Suprathreshold TMS-evoked activity overlapped not only with voluntary movement-related activity but also partially with MNS-induced activity, yielding overlapped areas of activity around the stimulated M1. The present study has provided the first experimental evidence that motor area activity during suprathreshold TMS likely includes activity for processing of muscle afferents. A method should be developed to control the effects of muscle afferents for fair interpretation of TMS-induced motor area activity during suprathreshold TMS to M1.

Coexistence of narcolepsy and Alzheimer's disease

A recent publication suggested that hypocretin (Hcrt, orexin) may mediate the neuropathological process leading to Alzheimer's disease (AD) and that antagonism of hypocretin receptors decreases this process. Narcoleptics have an approximately 90% loss of Hcrt neurons and commensurate reductions in the levels of Hcrt in their cerebrospinal fluid beginning at disease onset, usually before the age of 30. If Hcrt mediates the disease process, narcoleptics should be protected against AD. We examined the postmortem neuropathology and clinical records of 12 sequentially encountered cases of human narcolepsy. We found that AD was present in 4 of these narcoleptics, a prevalence that is similar to that of the general population.

Process of healing of mucosal defects in the esophagus after endoscopic mucosal resection: histological evaluation in a dog model

BACKGROUND AND STUDY AIMS

Resection of a large amount of the esophageal mucosa often causes esophageal ulcer and postoperative stricture. The aim of this study was to evaluate the process of healing of defects in the esophageal mucosa after endoscopic mucosal resection (EMR).

MATERIALS AND METHODS

Cap-assisted EMR was performed in the thoracic esophagus of six beagle dogs to prepare mucosal defects with a diameter ranging from 15 to 18 mm. The process of mucosal healing was assessed histologically immediately after EMR, and on postoperative day (POD) 2, 4, 7, 14, and 28.

RESULTS

Immediately after EMR, a thin layer of the submucosa remained in the mucosal defect, and no damage to the muscularis propria was evident. Ulcer formation and inflammatory cell invasion were observed in the remaining submucosa on POD 2 and 4. Angiogenesis and collagen fiber hyperplasia were observed after POD 7. Complete epithelialization of the ulcer was observed on POD 28. In the muscularis propria, further destruction and atrophy were evident after POD 7. Fibrosis of the muscularis propria was observed on POD 28.

CONCLUSION

In the esophageal wall after epithelial loss resulting from EMR, atrophy and fibrosis of the muscularis propria remain even after epithelialization.

Doxorubicin, cisplatin, and fluorouracil combination therapy for metastatic esophageal squamous cell carcinoma

The chemotherapy regimen currently used for treating esophageal and gastric carcinoma has been either epirubicin, cisplatin, and fluorouracil (5-FU) or docetaxel, cisplatin, and 5-FU. Here, we report the efficacy and toxicity of doxorubicin, cisplatin, and 5-FU for only esophageal squamous cell carcinoma (ESCC). Between January 2000 and October 2008, a total of 41 ESCC patients with a distant metastasis were enrolled. The most common sites of metastasis were liver (26, 63.4%), lung (9, 22.0%), and bone (8, 19.5%). Doxorubicin was administered on day 1 at 30 mg/m(2) , cisplatin on days 1-5 at 14 mg/m(2)/day, and 5-FU on days 1-5 at 700 mg/m(2)/day. The median number of cycles was 2.0 (range 1-8). The dose intensities of doxorubicin, cisplatin, and 5-FU were 92.9, 92.4, and 92.5%, respectively. The overall response rate was 43.9%; one showed complete response, 17 showed partial response, 13 showed a stable disease, and 10 showed progressive disease (PD). The median survival time was 306 days (95% CI = 74-935) and the 1-year survival rate was 37.6%. Grade 3 neutropenia was seen in seven patients and grade 4 in one patient. Grade 3 fatigue, anorexia, mucositis, and diarrhea were observed in three, two, two, and one patient, respectively. This regimen is effective as a first-line therapy for ESCC with distant metastasis.

Intradermal delivery of recombinant vaccinia virus vector DIs induces gut-mucosal immunity

Antigen-specific mucosal immunity is generally induced by the stimulation of inductive mucosal sites. In this study, we found that the replication-deficient vaccinia virus vector, DIs, generates antigen-specific mucosal immunity and systemic responses. Following intradermal injection of recombinant DIs expressing simian immunodeficiency virus gag (rDIsSIVgag), we observed increased levels of SIV p27-specific IgA and IgG antibodies in faecal extracts and plasma samples, and antibody-forming cells in the intestinal mucosa and spleen of C57BL/6 mice. Antibodies against p27 were not detected in nasal washes, saliva, and vaginal washes. The enhanced mucosal and systemic immunity persisted for 1 year of observation. Induction of Gag-specific IFN-gamma spot-forming CD8(+) T cells in the spleen, small intestinal intraepithelial lymphocytes, and submandibular lymph nodes was observed in the intradermally injected mice. Heat-inactivated rDIsSIVgag rarely induced antigen-specific humoral and T-helper immunity. Moreover, rDIsSIVgag was detected in MHC class II IA antigen-positive (IA(+)) cells at the injection site. Consequently, intradermal delivery of rDIs effectively induces antigen-specific humoral and cellular immunity in gut-mucosal tissues of mice. Our data suggest that intradermal injection of an rDIs vaccine may be useful against mucosally transmitted pathogens.

Ensemble and single-molecule fluorescence-based assays to monitor DNA binding, translocation, and unwinding by iron-sulfur cluster containing helicases

Many quantitative approaches for analysis of helicase-nucleic acid interactions require a robust and specific signal, which reports on the presence of the helicase and its position on a nucleic acid lattice. Since 2006, iron-sulfur (FeS) clusters have been found in a number of helicases. They serve as endogenous quenchers of Cy3 and Cy5 fluorescence which can be exploited to characterize FeS cluster containing helicases both in ensemble-based assays and at the single-molecule level. Synthetic oligonucleotides site-specifically labeled with either Cy3 or Cy5 can be used to create a variety of DNA substrates that can be used to characterized DNA binding, as well as helicase translocation and unwinding. Equilibrium binding affinities for ssDNA, duplex and branched DNA substrates can be determined using bulk assays. Identification of preferred cognate substrates, and the orientation and position of the helicase when bound to DNA can also be determined by taking advantage of the intrinsic quencher in the helicase. At the single-molecule level, real-time observation of the helicase translocating along DNA either towards the dye or away from the dye can be used to determine the rate of translocation by the helicase on ssDNA and its orientation when bound to DNA. The use of duplex substrates can reveal the rate of unwinding and processivity of the helicase. Finally, the FeS cluster can be used to visualize protein-protein interactions, and to examine the interplay between helicases and other DNA binding proteins on the same DNA substrate.

Human Rad52 binds and wraps single-stranded DNA and mediates annealing via two hRad52-ssDNA complexes

Rad52 promotes the annealing of complementary strands of DNA bound by replication protein A (RPA) during discrete repair pathways. Here, we used a fluorescence resonance energy transfer (FRET) between two fluorescent dyes incorporated into DNA substrates to probe the mechanism by which human Rad52 (hRad52) interacts with and mediates annealing of ssDNA–hRPA complexes. Human Rad52 bound ssDNA or ssDNA–hRPA complex in two, concentration-dependent modes. At low hRad52 concentrations, ssDNA was wrapped around the circumference of the protein ring, while at higher protein concentrations, ssDNA was stretched between multiple hRad52 rings. Annealing by hRad52 occurred most efficiently when each complementary DNA strand or each ssDNA–hRPA complex was bound by hRad52 in a wrapped configuration, suggesting homology search and annealing occur via two hRad52–ssDNA complexes. In contrast to the wild type protein, hRad52^RQK/AAA and hRad52^1–212 mutants with impaired ability to bind hRPA protein competed with hRPA for binding to ssDNA and failed to counteract hRPA-mediated duplex destabilization highlighting the importance of hRad52-hRPA interactions in promoting efficient DNA annealing.

Experience with injections of botulinum toxin type A into the detrusor muscle

INTRODUCTION

We evaluated the effects of intra-vesical injection of botulinum toxin type A in the detrusor muscle in patients with neurogenic overactive bladder (OAB), patients with non-neurogenic overactive bladder and patients with interstitial cystitis.

MATERIALS AND METHODS

Between January 2003 and December 2006 we treated 30 patients with 100 I. U. to 300 I. U. of botulinum toxin A in the detrusor muscle. Patients were clinically and urodynamically followed up for 4, 12 and 36 weeks thereafter.

RESULTS

Neurogenic overactive bladder: of the 19 injected doses, 18 (94.7%) in 7 patients were judged as effective, and 1 (5.2%) of 200 U of BTX-A was judged as ineffective. Mean bladder volume increased from 137 to 396 ml. Non-neurogenic overactive bladder: of 7 injections, 6 (85.7%) were judged effective in 5 patients. Mean bladder volume increased from 149 to 322 ml. Interstitial cystitis: in all 4 patients the treatments were deemed ineffective.

CONCLUSIONS

Injecting 300 units of BTX-A into 30 sites in the muscle located in the body of the bladder region is effective for neurogenic bladder patients with intermittent catheterization who have urge and reflective types of incontinence. Injections of 100 and 200 units of BTX-A to treat non-neurogenic overactive bladder with urinary incontinence provided together without retention. The optimal dose of BTX-A requires further investigation. Injection with 200 units of BTX-A was not useful against interstitial cystitis. None of the patients developed any adverse effects after injecting the bladder wall with BTX-A.

Phosphodiesterase isozymes involved in regulating acid secretion in the isolated mouse stomach

The effect of subtype-selective phosphodiesterase (PDE) inhibitors on acid secretion was examined in mouse stomachs to investigate which PDE isozymes are involved in the local regulation of this secretion. Male DDY mice were used after 18 h fasting. An isolated stomach was incubated in an organ bath containing buffered solution gassed with 95% O(2)/5% CO(2), while the lumen was perfused with unbuffered solution gassed with 100% O(2). Acid secretion was measured at pH 5.4 using a pH-stat method. Histamine or pituitary adenylate cyclase activating polypeptide (PACAP) was added to the serosal solution. PDE inhibitors were added to the serosal solution 30 min before histamine or PACAP. The secretion of acid in the isolated stomach was increased by histamine or PACAP, and these responses were totally inhibited by famotidine. IBMX alone increased basal acid secretion and significantly enhanced the acid responses to histamine and PACAP. Among the PDE inhibitors tested, only rolipram (PDE4 inhibitor) significantly increased basal acid secretion and potentiated the acid responses to histamine and PACAP. The latter peptide increased histamine release into the medium, and this response was also enhanced by rolipram. Furthermore, rolipram significantly increased cAMP production induced in the isolated stomach by histamine and PACAP. These results suggest that PDE4 is involved in the local regulation of gastric acid secretion via the degradation of cAMP and that the PDE4 inhibitor rolipram increases the secretion of acid by potentiating acid production in parietal cells and enhancing histamine release from enterochromaffin-like cells.

Decreased plasma C-peptide to insulin molar ratio after oral glucose in elderly subjects

To evaluate the effect of aging on hepatic extraction of insulin, peripheral plasma insulin and C-peptide levels after an oral glucose ingestion were measured in 39 non-obese healthy subjects with normal glucose tolerance test. The subjects were divided into two groups. One age group was below 30 years (n = 17) and another was above 50 years (n = 22). Blood glucose level was significantly higher in elderly subjects than in young at 30 and 60 min, and insulin level was also significantly higher in elderly subjects than in young subjects at 60 min after glucose ingestion. C-peptide response after glucose ingestion was similar in both groups. The molar ratio of C-peptide to insulin after glucose ingestion in elderly subjects was slightly lower than that in young subjects, and the difference between the incremental areas of C-peptide and insulin divided by the incremental area of C-peptide were significantly lower in elderly subjects. These results suggest that hepatic insulin extraction after glucose loading is decreased in elderly subjects and this may partly be responsible for the slightly altered glucose metabolism in elderly subjects with normal glucose tolerance test.

Effect of glucagon on glucose output from bivascularly perfused rat liver

Glucose output was investigated in bivascularly perfused rat liver. Flow rate was 1 ml/min/g from hepatic artery and 2 ml/min/g from portal vein. Basal glucose output (130 +/- 30 microM/min) from bivascularly perfused liver was significantly (p less than 0.02) higher than that (80 +/- 20 microM/min) from usual monovascularly perfused (3 ml/min/g from portal vein) liver. However, glucagon-induced (1 ng/ml) increment in glucose output from bivascularly perfused liver 589 +/- 127 microM/30 min) was not significantly different from that (630 +/- 127 microM/30 min) of monovascularly perfused liver. These results suggest that glucagon-dependent glucose output was similar in monovascularly and bivascularly perfused rat liver, and that arterial blood supply may have some role in glycogenolysis in the perfused rat liver.

Randomized, phase II study comparing interferon combined 5-fluorouracil plus cisplatin hepatic arterial infusion with interferon combined 5-fluorouracil hepatic arterial infusion in patients with advanced hepatocellular carcinoma

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Background: This randomized phase II trial compared the response rate (RR) of interferon (IFN) combined 5-fluorouracil (5FU) plus cisplatin (CDDP) hepatic arterial infusion (HAI) with IFN combined 5FU HAI in advanced hepatocellular carcinoma. Methods: Patients (pts) with measurable histologically or radiologically confirmed advanced hepatocellular carcinoma (major vascular invasion and/or bilobular multiple ≥5 nodules) were randomized into 2 groups. Arm A (n=57): continuous 5FU HAI (300mg/m2 day1–5, day8–12), CDDP HAI (20mg/m2, day 1, day 8 for 1.5 hours). IFN alpha-2b (3M IU/body) was administrated intramuscularly 3 times per week for 4 weeks. The treatment cycles repeated for 6 weeks. Arm B (n=57): IFN combined 5FU HAI with same dose without CDDP infusion. Treatment was continued until disease progression. The primary endpoint was RR. The secondary endpoints were overall survival (OS), time to progression (TTP) and toxicity. Results: Results for responses are presented for 109 pts and toxicity for 114 pts. The best overall response rate (RR) was 46% for group A and 25% for group B. This included 1 (2% of group A) vs. 3 (6% of group B) complete responses, and 25 (44% of group A) vs. 11 (19% of group B) partial responses. Fifteen pts in group A (26%) vs. 19 pts (33%) in group B had stable disease and 13 pts (23%) vs. 22 (39%) in respectively group A and B progressed while on treatment. RR was significantly higher in group A (p=0.02). The median TTP was 6.5 ± 2.0 months (mo) for group A vs. 3.3 ± 2.0 mo for group B (p=0.005). The median OS was 17.6 ± 3.2 mo for group A vs. 10.5 ±2.3 mo for group B (p=0.38). The median OS was 13.7 ± 4.9 mo for both groups. Grade 3/4 toxicity occurred in 65.8% of pts. Hematological toxicity was common and occurred in 53.5%. The thrombocytopenia and infusion port-related toxicity occurred more frequently in group A. Conclusions: IFN combined 5FU plus CDDP HAI shows higher antitumor activity and longer TTP than IFN combined 5FU HAI. Although OS is also longer without significant difference, these results show the clinical efficacy of additional CDDP to IFN combined 5FU HAI.

No significant financial relationships to disclose.