Expression profile of hepatic drug transporters in patients with hepatocellular carcinoma

e22026

Background: Hepatocellular carcinoma (HCC) does not respond sufficiently to chemotherapy. It has been demonstrated that several transporters can cause drug resistance in tumor cells. In human liver, various drug transporters are expressed and play pivotal roles in hepatic uptake and excretion of drugs. In HCC, the expression profile of hepatic drug transporters may be altered due to pathophysiological changes. However, limited data are available on their expression and regulation in HCC tissues. The aims of this study were to determine the expression levels of hepatic drug transporters in HCC patients and to identify transporter specifically regulated in HCC tissues. Methods: The mRNA expression levels of 17 drug transporters, including 9 solute carrier (SLC) transporters (OAT2, OAT7, OATP1B1, OATP1B3, OATP2B1, OCT1, OCTN2, MATE1 and PEPT1) and 8 ATP-binding cassette (ABC) transporters (R1, MRP1–6 and BCRP), were determined by real-time RT-PCR in cancerous and non-cancerous liver tissues from 57 patients with HCC. Protein expression level was evaluated by Western blot analysis. In addition, DNA methylation status in promoter region of transporter gene was analyzed using bisulfite sequencing. Results: The mRNA expression levels of 11 transporters (OAT7, OCTN2, MATE1, PEPT1, R1, MRP1–6) were significantly increased (1.45 to 4.74-fold, p<0.05) in HCC tissues compared with non-cancerous liver tissues, whereas only OCT1 mRNA was significantly decreased (0.61-fold, p=0.0004). Notably, MRP4 mRNA showed the highest increase, which was consistent with the marked augmentation in the protein level. The frequency of methylation in MRP4 promoter region was comparable between HCC and non-cancerous liver tissues, suggesting other mechanisms than DNA methylation for MRP4 up-regulation. Interestingly, the mRNA expression levels of MRP4 did not change with the differentiation of HCC. Conclusions: It was revealed that most of the hepatic drug transporters were elevated in HCC tissues. Furthermore, we first identified that MRP4 showed remarkable increase in protein as well as mRNA expression levels. These findings suggest that MRP4 is a novel candidate for diagnostic marker and a target molecule to reverse multidrug resistance in chemotherapy for HCC.

No significant financial relationships to disclose.

Long-term effect of tacrolimus therapy in patients with refractory ulcerative colitis

BACKGROUND

Little is known about long-term outcome of tacrolimus therapy for ulcerative colitis. Aim To evaluate long-term efficacy and safety of tacrolimus in Japanese patients with refractory ulcerative colitis.

METHODS

Twenty-seven patients with UC refractory to conventional therapy were administered tacrolimus with trough whole-blood levels of 10-15 ng/mL to induce remission and 5-10 ng/mL to maintain remission. Median treatment duration was 11 months (1-39 months) and median follow-up duration was 17 months (2-65 months). Evaluation of the clinical response was based on a modified Truelove-Witts severity index (MTWSI).

RESULTS

Tacrolimus produced a clinical response in 21 patients (77.8%), and remission was achieved in 19 of these 21 (70.4%) within 30 days. Overall cumulative colectomy-free survival was estimated as 62.3% at 65 months. In 18 of 19 patients treated with corticosteroids at the initiation of tacrolimus therapy, corticosteroids were discontinued or tapered. Adverse events were tremor (25.9%), renal function impairment (18.5%), infectious disease (14.8%), hot flashes (11.1%), hyperkalaemia (7.4%), headache (7.4%), epigastralgia (7.4%) and nausea (3.7%). No mortality occurred.

CONCLUSION

Long-term administration of tacrolimus appears to be an effective and well-tolerated treatment for Japanese patients with refractory ulcerative colitis.

Actin -related protein 3 (Arp3) is mutated in proteinuric BUF/Mna rats

The BUF/Mna strain of rat is a model of focal and segmental glomerulosclerosis (FSGS) in which a quantitative trait locus (QTL) for proteinuria, Pur1, has been identified. The aim of the present study was to identify candidates for the Pur1 gene. To narrow the Pur1 QTL, we performed fine QTL mapping and single nucleotide polymorphism (SNP) genotyping. To identify candidate genes, sequencing and gene-expression analyses of all genes contained in the narrowed locus were conducted. The narrowed Pur1 region contained 25 genes. Among these genes, only the Arp3 gene was mutated in the BUF/Mna strain; it contained a missense mutation that caused an (L)111(F) substitution. This leucine is conserved across species. Gene-expression analysis failed to identify any other candidate genes for Pur1. Arp3-mediated actin assembly abnormalities were visible in immunohistochemical and electron microscopic examinations of podocytes in old BUF/Mna rats. Taken together, these data suggest that Arp3 is a candidate for the Pur1 gene. This observation is consistent with our growing recognition that abnormal signaling-induced assembly of actin in podocytes leads to the development of FSGS.

Transcription-reverse transcription concerted reaction and minimal residual disease in axillary sentinel nodes of breast cancer

AIMS

To investigate the use of transcription-reverse transcription concerted reaction (TRC) to detect axillary lymph node metastases.

METHODS

Metastases in 423 lymph nodes obtained from 50 breast cancer patients were investigated by routine pathological hematoxylin and eosin (H and E) staining and quantitative analysis of carcinoembryonic antigen (CEA) mRNA by TRC. Enhanced pathological studies, serial sectioning and immunohistochemistry were conducted for cases which were negative by routine pathology, but positive by TRC.

RESULTS

Pathological examination identified metastatic disease in 67 lymph nodes. TRC CEA mRNA results were concordant with 89.8% of these cases at a threshold of 100 copies. TRC identified 30 false negative nodes, which was reduced to 15 by excluding node biopsies yielding less than 40 microg total RNA. Twelve nodes were histologically negative for cancer, but positive according to TRC. Serial sectioning and immunohistochemical analysis of these nodes revealed macrometastatic lesions in three, micrometastasis in one, and isolated tumor cells in two.

CONCLUSION

TRC for the detection of CEA mRNA may complement routine pathological examination by sentinel lymph node biopsy (SNB) in early breast cancer. We have started an enhanced pathological examination with serial sectioning on all excised sentinel nodes to set the best threshold for the TRC method.

Downregulation of organic anion transporters in rat kidney under ischemia/reperfusion-induced qacute renal failure

The effect of acute renal failure (ARF) induced by ischemia/reperfusion (I/R) of rat kidney on the expression of organic anion transporters (OATs) was examined. The level of serum indoxyl sulfate (IS), a uremic toxin and substrate of OATs in renal tubules, shows a marked increase with the progression of ARF. However, this increase was significantly attenuated by ingestion of cobalt. The level of mRNA and protein of both rOAT1 and rOAT3 were markedly depressed in the ischemic kidney. The uptake of p-aminohippuric acid (PAH) and estrone sulfate (ES) by renal slices of ischemic rats was significantly reduced compared to control rats. Renal slices taken from ischemic rats treated with cobalt displayed significantly elevated levels of ES uptake. Cobalt intake did not affect PAH uptake, indicating the functional restoration of rOAT3 but not rOAT1. The expression of Na(+)/K(+)-ATPase was markedly depressed in the ischemic kidney, suggesting that the inward Na(+) gradient in renal tubular cells had collapsed, thereby reducing the outward gradient of alpha-ketoglutarate, a driving force of both rOATs. The decreased expression of Na(+)/K(+)-ATPase was significantly restored by cobalt treatment. Our results suggest that the downregulation of renal rOAT1 and rOAT3 could be responsible for the increase in serum IS level of ischemic rats. Cobalt treatment has a significant protective effect on ischemia-induced ARF, being accompanied by the restoration of rOAT3 and/or Na(+)/K(+)-ATPase function.

Immunohistochemical analyses on serum proteins in nephrons of protein-overload mice by "in vivo cryotechnique"

Immunohistochemical analyses on local distributions of serum proteins in living mouse kidneys are usually difficult to examine with conventional preparation methods. By using our "in vivo cryotechnique" combined with freeze-substitution, we have checked immunolocalizations of the serum proteins in nephrons of bovine serum albumin (BSA)-overload mice, and compared them with those obtained by the conventional preparation methods. In two days of daily BSA-injected mice, the immunolocalization of BSA could be observed in Bowman's space and urinary tubules with their overt proteinuria, where another endogenous mouse albumin was similarly immunolocalized. The leakage of BSA and mouse albumin in Bowman's space and their reabsorption into proximal tubules were detected in 55% of nephrons, where no leakage of immunoglobulin G1 (IgG1) was detected. However, the leakage of IgG1, in addition to BSA and mouse albumin, was detected in the other nephrons. By carefully examining immunolocalizations of BSA and IgG1, they were obviously different from those obtained by the conventional preparation methods without normal blood circulation into the kidneys. The immunolocalizations of both BSA and mouse serum proteins could be directly analyzed with the "in vivo cryotechnique", suggesting that functional damage to glomerular filtration barriers are different at early stages of the BSA-overload mouse model, depending on each nephron of living mice.

Atrophy and hypertrophy of skeletal muscles: structural and functional aspects

This review summarizes current information on structural and functional changes that occur during muscle atrophy and hypertrophy. Most published studies consider an increase in total mass of a muscle as hypertrophy, whereas a decrease in total mass of a muscle is referred to as atrophy. In hypertrophy, the rate of synthesis is much higher than the rate of degradation of muscle contractile proteins, leading to an increase in the size or volume of an organ due to enlargement of existing cells. When a muscle remains in disuse for a long period, the rate of degradation of contractile proteins becomes greater than the rate of replacement, resulting in muscle atrophy. This defect may occur as a result of lack of nutrition, loss of nerve supply, micro-gravity, ageing, systemic disease, prolonged immobilization or disuse. An understanding of the specific modifications that occur during muscle atrophy and hypertrophy may facilitate the development of novel techniques, as well as new therapies for affected muscles.

A longitudinal study to identify constraints to dairy cattle health and production in rural smallholder communities in Northern Vietnam

The objective of the study was to investigate constraints to dairy cattle health and production in rural smallholder communities in northern Vietnam, one of the target areas of the Vietnam government's dairy development programme. A total of 99 dairy farms (11 per commune) were recruited from 9 of 32 communes in Ba Vi District, using random two-stage cluster sampling. After the initial questionnaire interviews were conducted, farms were visited at three monthly intervals over a period of 1 year. Information on several health and production parameters relating to the study cattle was collected. Using multiple indicator modelling, it was found that Fasciola infestation, farmers who had been involved in dairying for longer (not indicative of better management skills), larger herd size, and cattle being kept in a shed were linked to reduced reproductive performances.

The PDZ domain protein PDZK1 interacts with human peptide transporter PEPT2 and enhances its transport activity

The proton-coupled peptide transporter PEPT2 (SLC15A2) mediates the high-affinity low-capacity transport of small peptides as well as various oral peptide-like drugs in the kidney. In contrast to its well-characterized transport properties, there is less information available on its regulatory mechanism, although the interaction of PEPT2 to the PDZ (PSD-95, DglA, and ZO-1)-domain protein PDZK1 has been preliminarily reported. To examine whether PDZK1 is a physiological partner of PEPT2 in kidneys, we started from a yeast two-hybrid screen of a human kidney cDNA library with the C-terminus of PEPT2 (PEPT2 C-terminus (PEPT2-CT)) as bait. We could identify PDZK1 as one of the positive clones. This interaction requires the PDZ motif of PEPT2-CT detected by a yeast two-hybrid assay, in vitro binding assay and co-immunoprecipitation. The binding affinities of second and third PDZ domains of PDZK1 to PEPT2-CT were measured by surface plasmon resonance. Co-immunoprecipitation using human kidney membrane fraction and localization of PEPT2 in renal apical proximal tubules revealed the physiological meaning of this interaction in kidneys. Furthermore, we clarified the mechanism of enhanced glycylsarcosine (Gly-Sar) transport activity in PEPT2-expressing HEK293 cells after the PDZK1 coexpression. This augmentation was accompanied by a significant increase in the V(max) of Gly-Sar transport via PEPT2 and it was also associated with the increased surface expression level of PEPT2. These results indicate that the PEPT2-PDZK1 interaction thus plays a physiologically important role in both oligopeptide handling as well as peptide-like drug transport in the human kidney.

Backward-masking: The effect of the duration of the second stimulus on recognition of the first stimulus

OBJECTIVE

We recorded event-related magnetic fields following a target stimulus followed by a masking stimulus to investigate the visual backward masking effect using a helmet-type magnetoencephalography system in humans.

METHODS

In the target stimulus with masking stimulus conditions, duration of the target stimulus was constant at 16 ms, and duration of the masking stimulus was altered (16, 48 and 144 ms). The target stimulus was masked by the 144-ms masking stimulus, but not by the 16-ms masking stimulus, and was obscured by the 48-ms masking stimulus. For control conditions (Single-condition), event-related magnetic fields were recorded following the sole presentation of the masking stimulus for 32, 64 or 160 ms.

RESULTS

One major response was obtained at 180 ms after the onset of the stimulation in each condition. The equivalent current dipole of one major response was estimated to lie in the occipital lobe, but there was a relatively large inter-individual difference. There was no significant difference in latency between the target stimulus with masking stimulus conditions and Single-conditions. In the target stimulus with masking stimulus conditions with the 48- and 144-ms masking stimulus, the root mean square value did not differ from that in the respective Single-condition, while the root mean square value for the target stimulus with masking stimulus conditions with the 16-ms masking stimulus was significantly smaller than that in the Single-condition with the 32-ms masking stimulus, but not different from that in the Single-condition with the 16-ms masking stimulus.

CONCLUSIONS

The peak latency of one major response depended on the onset of the first stimulus for both the target stimulus with masking stimulus conditions and Single-condition, but the root mean square value depended on the duration of the masking stimulus. We concluded that the temporal information for the target stimulus was preserved during the masking effect, while the figural information was interrupted by the masking stimulus. Our results suggested that temporal factors for the stimulus were processed differently from those responsible for the object's recognition during backward masking.

Blue-dye technique complements four-node sampling for early breast cancer

AIMS

To examine four-node axillary sampling assisted by a blue dye (4NAS/dye) technique as a sentinel node biopsy (SNB) for breast cancer.

METHODS

Lymphatic mapping was performed by injection of patent blue for 33 consecutive cases with breast cancer. Axillary sampling was performed until four nodes were obtained. This was followed by back-up axillary lymph node dissection to examine the feasibility of 4NAS/dye. The same study with 30 cases was conducted at an independent hospital to confirm the feasibility of this method. This method was then applied to 101 consecutive clinically node-negative patients to avoid axillary-node dissection, with intraoperative diagnosis made by frozen section examination.

RESULTS

The median numbers of blue-stained nodes and nodes excised by 4NAS/dye were 1.7 and 3.4, respectively. The identification rate of sentinel lymph nodes (SNs) was 81.8% using the dye alone and 97.0% when the combination was used. Pathological examination revealed that the nodal status was correctly predicted by the dye alone in 62.5% of cases with metastasis, whereas in 100% by 4NAS/dye. The dye alone was not sufficient to identify SNs, especially in cases with prior excisional biopsy. The identification rate of SNs and the accuracy rate in another feasibility study were 100% and 92.5% in 30 consecutive cases, respectively. 4NAS/dye successfully detected SNs in 100 of 101 cases of the subsequent observational study with an acceptable post-operative axillary morbidity and thus succeeded as an SNB.

CONCLUSIONS

The 4NAS/dye method is reliable for the detection of SNs. This method could be applied to observational studies without radio-isotope.

Heparan sulfate of perlecan is involved in glomerular filtration

Perlecan is a heparan sulfate proteoglycan and a major component of the glomerular basement membrane. To understand the role of heparan sulfate chains of perlecan in glomerular filtration, detailed analyses were performed of the kidneys of Hspg2(Delta)(3/)(Delta)(3) mice, whose perlecan lacks heparan sulfate attachment sites in N-terminal domain I. Macroscopic, histologic, and electron microscopic observations, as well as immunohistochemical and immunoelectron microscopic analyses using specific antibodies against perlecan and agrin core proteins, revealed no significant abnormalities in these mice under physiologic conditions. Polyethyleneimine staining demonstrated no significant changes in charge density in the glomerular basement membrane. Transcripts of other heparan sulfate proteoglycans, agrin, and collagen type XVIII, as well as perlecan, were expressed at similar levels to those in the wild-type littermates. Approximately 40% of the perlecan synthesized by Hspg2(Delta)(3/)(Delta)(3) fibroblasts was substituted with heparin sulfate and 60% was substituted with chondroitin sulfate. All of the perlecan synthesized by wild-type fibroblasts contained heparin sulfate, indicating an altered substitution of glycosaminoglycans on Hspg2(Delta)(3/)(Delta)(3) perlecan. Immunostaining indicated that the level of chondroitin sulfate was actually increased in the Hspg2(Delta)(3/)(Delta)(3) glomerular basement membrane. When administered intraperitoneally with BSA, Hspg2(Delta)(3/)(Delta)(3) mice exhibited remarkable proteinuria. These findings suggest that heparan sulfate chains of perlecan play an important role in glomerular filtration, especially of a large amount of protein.

Enzyme replacement therapy in Japanese Fabry disease patients: the results of a phase 2 bridging study

Fabry Disease (alpha-galactosidase A deficiency) is an X-linked hereditary disorder leading to the pathological accumulation of globotriaosylceramide (GL-3) in lysosomes, particularly in the vascular endothelium of the kidney, heart and brain. We report the results of an open-label phase 2 study that was undertaken to evaluate whether ethnic differences exist that would affect agalsidase beta (Fabrazyme) treatment of Fabry patients in the Japanese population, relative to safety and efficacy. The study design mirrored the design of the completed phase 3 clinical trial that led to approval of the product agalsidase beta. The 13 Japanese, male Fabry patients enrolled in the study received the enzyme replacement therapy over a period of 20 weeks as biweekly infusions. All selected efficacy end points showed improvements that were comparable with findings from the phase 3 study. These improvements included reductions of GL-3 accumulation in both kidney and skin capillary endothelial cells to (near) normal levels (92% of patients). Kidney and plasma GL-3 levels decreased by 51.9% and 100%, respectively, by ELISA. Renal function remained normal. Fabry-associated pain, and quality of life, showed improvement over baseline in multiple categories. Related adverse events were mild or moderate in intensity and mostly infusion-associated (fever and rigors). As expected, IgG antibody formation was observed in 85% of the patients, but had no effect on treatment response. These results suggest that treatment with agalsidase beta is safe and effective in Japanese patients with Fabry disease. With regard to safety and efficacy, no differences were observed as compared to the caucasian population.

[Mediastinal seminoma difficult to differentiate from thymoma through preoperative biopsy; report of a case]

A case of a 36-year-old male patient with mediastinal seminoma is presented. He consulted a physician with a complaint of back pain and an abnormal shadow was detected on chest X-ray. Chest computed tomography (CT) scan revealed a pulmonary nodule and an anteriormediastinal mass. Preoperative percutaneous needle biopsy suggested that the tumor was similar to thymoma. Complete surgical excision of the mediastinal mass was performed. Immunohistochemical studies showed positive staining of the tumor cells with placental alkaline phosphatase. The final diagnosis was seminoma. Additional postoperative chemotherapy (cisplatin + etoposide) was done. He is alive and well 34 months after the operation.

[Oral sildenafil citrate as an effective alternate in the treatment of postoperative pulmonary hypertensive crisis after congenital heart surgery]

A five-month-old girl of Down syndrome underwent a corrective surgery for complete atrioventricular septal defect. Her postoperative course was complicated with pulmonary hypertensive (PH) crises despite nitroglycerin (NTG) infusion and inhaled nitric oxide (NO). Sildenafil citrate, a phosphodiesterase 5 inhibitor, was administered through a nasogastric tube at a starting dose of 0.3 mg/kg by stepwise increment to the maximum dose of 2 mg/kg 4 hourly. Sildenafil citrate dramatically lowered pulmonary arterial pressure and the patient was weaned from NTG and NO without PH crisis. There was no side effect after sildenafil citrate administration. Oral sildenafil citrate is a safe and potent adjunct to the existing therapies for postoperative PH in infants after open heart surgery.

Facilitation of A -fiber-mediated acute pain by repetitive transcranial magnetic stimulation

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) of the motor cortex modulates acute and chronic pain perception. The authors previously showed that rTMS over the primary motor cortex (M1) inhibited capsaicin-induced acute pain ascending through C-fibers.

OBJECTIVE

To investigate the effects of 1-Hz rTMS over M1 on acute experimentally induced pain mediated by Adelta-fibers (i.e., another type of acute pain).

METHODS

The authors examined whether rTMS over M1 affected laser evoked potentials (LEPs) in 13 normal subjects using thulium: yttrium-aluminum-garnet laser stimulation. Subjective pain-rating scores and LEPs obtained under three different conditions--rTMS, realistic sham stimulation, and a control condition with no stimulation--were compared.

RESULTS

The authors found that 1-Hz rTMS over M1 significantly aggravated the subjective pain and enhanced the N2-P2 amplitudes compared with the sham or control sessions. Because the pain-rating scores and the N2-P2 amplitudes correlated positively, the N2-P2 amplitudes in the present study can be regarded as the cortical correlate of subjective pain.

CONCLUSIONS

Together with the authors' previous study on C-fiber pain, this facilitatory effect of repetitive transcranial magnetic stimulation on Adelta-fiber-mediated further strengthens the notion of a relationship between repetitive transcranial magnetic stimulation over M1 and pain perception.

Cortical responses to noxious stimuli during sleep

We used magnetoencephalography to study effects of sleep on cortical responses to noxious stimuli and to clarify the mechanisms underlying pain perception. For a noxious stimulus, painful intra-epidermal electrical stimulation, which selectively activates A-delta fibers, was applied to the dorsum of the left hand. While awake, subjects were asked to count the number of stimuli silently (Attention) or ignore the stimuli (Control). During sleep, magnetic fields recorded in stage 1 sleep and stage 2 sleep were analyzed. One main component at a latency around 140-160 ms was identified in the awake condition. Multiple source analysis indicated that this main component was generated by activities in the contralateral primary somatosensory cortex (SI), bilateral secondary somatosensory cortex (SII) and insular cortex. The medial temporal area (MT) and cingulate cortex were activated later than the main component. Cortical responses in the contralateral SI, ipsilateral SII and MT, bilateral insula and cingulate cortex were significantly enhanced in Attention as compared with Control. The main component 1 M as well as later magnetic fields were markedly attenuated during sleep, suggesting that all these cortical areas are involved in pain cognition.

[Successful total arch replacement for a 92-year-old woman with acute Stanford A aortic dissection: report of a case]

We reported a successful case of emergent total arch replacement for a nonagenarian with acute Stanford A aortic dissection. A 92-year-old woman complained of general fatigue, with hypotension. Echocardiography showed moderate pericardial effusion and aortic regurgitation. Computed tomography (CT) scan showed widely extended aortic dissection from the ascending aorta to descending thoracic aorta, and cardiac tamponade. An emergent total arch replacement was performed under hypothermic selective cerebral perfusion with bladder temperature of 22.5 degrees C. Although she suffered from pneumothorax, renal insufficiency and gastrointestinal (GI) bleeding postoperatively, she tolerated the operation and complications, well. She is now leading a good life with the same level of activities of daily living (ADL) as preoperative one.

A comparative magnetoencephalographic study of cortical activations evoked by noxious and innocuous somatosensory stimulations

We recorded somatosensory-evoked magnetic fields and potentials produced by painful intra-epidermal stimulation (ES) and non-painful transcutaneous electrical stimulation (TS) applied to the left hand in 12 healthy volunteers to compare cortical responses to noxious and innocuous somatosensory stimulations. Our results revealed that cortical processing following noxious and innocuous stimulations was strikingly similar except that the former was delayed approximately 60 ms relative to the latter, which was well explained by a difference in peripheral conduction velocity mediating noxious (Adelta fiber) and innocuous (Abeta fiber) inputs. The first cortical activity evoked by both ES and TS was in the primary somatosensory cortex (SI) in the hemisphere contralateral to the stimulated side. The following activities were in the bilateral secondary somatosensory cortex (SII), insular cortex, cingulate cortex, anterior medial temporal area and ipsilateral SI. The source locations did not differ between the two stimulus modalities except that the dipole for insular activity following ES was located more anterior to that following TS. Both ES and TS evoked vertex potentials consisting of a negativity followed by a positivity at a latency of 202 and 304 ms, and 134 and 243 ms, respectively. The time course of the vertex potential corresponded to that of the activity of the medial temporal area. Our results suggested that cortical processing was similar between noxious and innocuous stimulation in SI and SII, but different in insular cortex. Our data also implied that activities in the amygdala/hippocampal formation represented common effects of noxious and tactile stimulations.

[Intraoperative conversion and postoperative complication of video-assisted thoracoscopic surgery lobectomy for primary lung cancer]

By 2002, we had attempted video-assisted thoracoscopic surgery (VATS) lobectomy or segmentectomy for 140 primary lung cancer cases. Four cases (2.9%) were converted to standard posterolateral thoracotomy for oncologic reasons and aortic injury, and 7 cases (5%) were converted to minithoracotomy with a 10 cm incision due to almost injuring the vascular system. Average blood loss in these cases was 379 ml, and there was no blood transfusion required. Seven of these 11 cases had true pleural symphysis in the thoracic cavity. The remaining 129 cases, consisted of 93 lobectomies and 34 segmentectomies, performed with a minithoracotomy of 5 cm using 2 ports. Average surgical duration was 227 minutes, and blood loss was 100 ml. Postoperative complication occurred in 15 patients (11.6%). Major complications included 1 broncho-pleural fistula, 1 pulmonary infarction, 1 cerebral infarction and 1 respiratory failure needed for mechanical ventilation. However, there were no hospital deaths. The mean postoperative hospital stay was 12 days. We recommend that surgeons should pay attention to hilar dissection, particularly in the presences of adhesion and carefully judge whether to convert to thoracotomy at the time of hemorrhage. The VATS procedure has a low mortality and morbidity for lung cancer, but particulaly in high risk patients, requires care and management the same as an open thoracotomy.

Electrical-induced pain diminishes somatosensory evoked magnetic cortical fields

OBJECTIVE

To investigate the effect of conditioning painful stimulation on the early somatosensory magnetic fields (SEF) of test stimulation, in order to clarify the location of the gating effect of pain on tactile response.

METHODS

We used a conditioning stimulus (CS) and test stimulus (TS) paradigm. The CS was applied at the left index finger followed by the TS at the left median nerve. The interstimulus interval between the CS and TS was varied from 100 to 1000 ms. There were two sessions corresponding to two intensities of the CS, painful CS (PCS) and non-painful CS (NPCS). Early components of SEF recorded 20 (1M) and 30 ms (2M) following the TS and the components obtained 20 (1m) and 30 ms (2m) following the CS were analyzed. Each value was compared between the two sessions.

RESULTS

PCS and NPCS attenuated the response of the 2M but not the 1M. The effect of PCS was significantly stronger and lasted longer than that of NPCS. The 1m and 2m components did not differ between PCS and NPCS in terms of amplitude and latency.

CONCLUSIONS

Our data indicated that the early components of the median nerve SEF were affected by a preceding painful stimulation much more than a non-painful stimulus given on the median nerve, and that the sensory gating effect of a painful stimulation on tactile sensation lasted longer than that of a non-painful stimulation. Furthermore, our findings suggested the existence of a 'touch gate' (effect of pain on tactile sensation) at the level of the thalamus or primary somatosensory cortex (SI).

SIGNIFICANCE

The finding suggested that the touch gate might lie in the thalamus or SI.

[Removal of methicillin-resistant staphylococcus aureus infected pacemaker leads under cardiopulmonary bypass: report of a case]

A 71-year-old man, who underwent an intravenous pacemaker implantation previously, suffered from fever and local infection of the generator pocket. A blood culture showed positive for methicillin-resistant staphylococcus aureus (MRSA). He underwent removal of total pacemaker system under cardiopulmonary bypass support successfully. Two leads were tightly adhered to the right atrial free wall, tricuspid valve and right ventricular trabeculation. Postoperative course was uneventful with administration of antibiotics for 5 weeks. Removal under cardiopulmonary bypass is considered to be an effective procedure for treatment of patients with infected pacemaker lead.