Femtosecond-laser-driven photoelectron-gun for time-resolved cathodoluminescence measurement of GaN

A rear-excitation femtosecond-laser-driven photoelectron gun (PE-gun) is developed for measuring time-resolved cathodoluminescence (TRCL) spectrum of wide bandgap materials and structures such as semiconductors and phosphors. The maximum quantum efficiency of a 20-nm-thick Au photocathode excited using a frequency-tripled Al(2)O(3):Ti laser under a rear-excitation configuration is 3.6×10(-6), which is a reasonable value for a PE-gun. When the distance between the front edge of the PE-gun and the observation point is 10 mm, the narrowest electron-beam (e-beam) diameter is 19 μm, which corresponds to one tenth of the laser-beam diameter and is comparable to the initial e-beam diameter of a typical W hair-pin filament of thermionic electron-gun. From the results of TRCL measurements on the freestanding GaN grown by the ammonothermal method and a GaN homoepitaxial film grown by metalorganic vapor phase epitaxy, overall response time for the present TRCL system is estimated to be 8 ps. The value is the same as that of time-resolved photoluminescence measurement using the same excitation laser pulses, meaning that the time-resolution is simply limited by the streak-camera, not by the PE-gun performance. The result of numerical simulation on the temporal e-beam broadening caused by the space-charge-effect suggests that the present PE-gun can be used as a pulsed e-beam source for spatio-time-resolved cathodoluminescence, when equipped in a scanning electron microscope.

Acute generalized exanthematous pustulosis during the puerperal period: a case report

BACKGROUND

Acute generalized exanthematous pustulosis (AGEP) is an uncommon adverse cutaneous reaction, most commonly associated with drugs.

CASE

A 38-year-old primigravida whose labor had been induced developed erythema over her chest and abdomen. She was transferred to our department after a failed vacuum extraction, and delivered a mature infant by forceps. On day three postpartum she developed a 40.4 degrees C fever. Although ceftriaxone was administered, her fever persisted (>38 degreesC). On day six of the puerperium, diffuse non-follicular pustules appeared over her neck and trunk, and AGEP was suspected. Two days after ceftriaxone was withdrawn, the eruptions started to resolve without any medical intervention.

CONCLUSION

Once the diagnosis of AGEP has been made, the antibiotics being administered must be discontinued. If continued treatment is required, pharmacologically distinct antibiotics must be used instead to aid the rapid self-limitation of the disease.

Curative colectomy via minilaparotomy approach without utilizing specific instruments

BACKGROUND

This study evaluated the need for specific instruments when performing a curative resection of colon cancer via a minilaparotomy approach, which has been reported to be a minimally invasive alternative to a laparoscopic approach.

METHODS

The feasibility, safety, and early oncological outcome were compared among 73 patients (first group), in whom a curative resection of colon cancer was performed via a minilaparotomy (skin incision < or =7 cm) utilizing specific instruments (North-bridge retractor system) between September 2002 and March 2005, and 94 patients (second group), in whom a similar procedure was performed without utilizing specific instruments between April 2005 and October 2007.

RESULTS

The two groups did not differ significantly in terms of age, sex, body mass index, site of tumor, level of lymph node dissection, blood loss, UICC stage, number of harvested lymph nodes, incidence of postoperative complications, length of postoperative hospital days, or overall survival, although the frequency of prior abdominal surgery was higher (38.3 vs. 21.9%; P = 0.03) and the median operating time required for a standard lymph node dissection was shorter (120 vs. 135 min; P = 0.03) in the second group.

CONCLUSION

With improved techniques and experience, specific instruments are not necessary for the performance of a curative colectomy via a minilaparotomy approach.

Gene trapping identifies chloride channel 4 as a novel inducer of colon cancer cell migration, invasion and metastases

BACKGROUND

To date, there are few reports on gene products contributing to colon cancer progression.

METHODS

We used a gene trap comprised of an enhanced retroviral mutagen (ERM) cassette that includes a tetracycline-responsive promoter upstream of a haemagglutinin (HA) tag and a splice donor site. Integration of the ERM within an endogenous gene yields a tetracycline-regulated HA-tagged transcript. We transduced RKO colon cancer cells expressing a tetracycline trans-activator-off with the ERM-encoding retrovirus and screened for enhanced migration.

RESULTS

One clone showed fivefold enhanced migration with tetracycline withdrawal. Rapid amplification of cDNA ends identified the trapped gene as the chloride channel 4 (CLCN4) exchanger. Stable expression of a CLCN4 cDNA enhanced motility, whereas cells knocked down or null for this transcript showed reduced migration/invasion. CLCN4-overexpressing RKO colon cancer cells were more resistant than controls to proton load-induced cytotoxicity, consistent with the H(+)-extruding function of this antiporter. Intra-splenic delivery of RKO-CLCN4 transfectants, but not controls, yielded liver metastases, and transcript levels were higher in colon cancer metastases to the liver when compared with primary tumours.

CONCLUSIONS

CLCN4 is a novel driver of colon cancer progression.

Intrauterine fetal demise due to streptococcal toxic shock syndrome: a case report

BACKGROUND

Toxic shock syndrome caused by group A streptococci (GAS) is rare around the time of delivery, but it may predispose pregnant women to a life-threatening condition.

CASE

A 32-year-old primigravida at 21 weeks of gestation was taken to our hospital with acute severe abdominal pain following fever. On admission the fetus was found to be dead, and intrauterine fetal demise due to placental abruption was suspected. An emergency cesarean section found no sign of placental abruption. Soon after the surgery, the patient went into shock but was successfully treated with intensive care. Although repeated blood cultures failed to detect microorganisms, the patient was positive for streptococcal pyrogenic toxin A, which is a superantigen of GAS.

CONCLUSION

Once GAS infection is suspected, regardless of negative blood cultures, supportive care in the intensive care unit is mandatory.

[Experience in the treatment for intracranial arteriovenous shunts in children]

PURPOSE

To report our experiences in the treatment for intracranial arteriovenous shunts (AV shunts) in the pediatric population.

MATERIAL AND METHODS

Twelve children with intracranial AV shunts were treated with endovascular embolization between December 1993 and March 2008. These comprised two cases of vein of Galen aneurysmal malformation, three of dural sinus malformation, two of infantile dural AV shunt, five of pial AV fistula including two of vein of Galen aneurysmal dilatation. There were eleven boys and one girl. The age at the first embolization ranged from day 0 to 9 years. We reviewed their clinical features and outcomes.

RESULTS

Six patients including four neonates presented with congestive heart failure, one infant with macrocrania and three children with headache, seizure or ataxia. The number of endovascular embolization ranged from one to five per patient. These included eighteen transarterial embolizations and ten transvenous embolizations. All patients except for one who died eventually from pulmonary hemorrhage showed improvement in their symptoms. Although only five patients achieved complete occlusion of AV shunts, six patients including them developed normally.

CONCLUSION

Intracranial AV shunts in the pediatric population present characteristic clinical features depending on the age of the presentation. Endovascular embolization is currently the treatment of choice for them. It is more important to obtain normal development than to achieve normal morphological appearance. It is also important to understand the difference of pathophysiological features of these diseases in the pediatric and adult population.

Polymorphisms of GSTP1, GSTT1, GSTM1, MTHFR, TS, ERCC1, and ERCC2 in metastatic colorectal cancer treated by first-line mFOLFOX6 chemotherapy

e14628

Background: It was reported that determining functional polymorphisms of genes involved in drug-metabolising pathways and DNA repair may be useful for predicting the response to 5-FU/oxaliplatin chemotherapy in Caucasian patients with metastatic colorectal cancer. This study was performed to examine whether determining these polymorphisms had any clinical value in Asian patients with colorectal cancer receiving 5-FU/oxaliplatin therapy. Methods: Genomic DNA was extracted from peripheral blood lymphocytes (n=25) or colonic mucosa (n=47) in Japanese patients with metastatic colorectal cancer who were receiving first-line therapy with the modified FOLFOX6 regimen followed by FOLFIRI (n=42). Polymorphisms of 5 genes involved in drug metabolism (glutathione S-transferase (GST) P1 (IIe 105 Val), GSTT1 deletion, and GSTM1 deletion, methylenetetrahydrofolate reductase (MTHFR) (Ala 677 Val), and a 6-base pair (bp) deletion in the 3’-untranslated region (UTR) of thymidylate synthase (TS)), and polymorphisms of two DNA repair genes (excision repair cross complementing group 1 (ERCC1): Asp 118 Asn and ERCC2: Lys 751 Gln) were assessed in these patients by PCR-RFLP or the invader technique. Correlations between polymorphisms of these genes and the response to therapy were evaluated. Results: The distribution of the genotypes of GSTP1, GSTT1, TS, ERCC1, and ERCC2 in the present Japanese patients (but not that of GSTM1 or MTHFR), differed significantly from the distribution of these genotypes in a Caucasian population. The response rate and progression-free survival were not correlated with any of the functional polymorphisms investigated. However, patients who had both alleles containing the 6-bp nucleotide fragment in the 3’UTR of TS showed significantly shorter overall survival than those who had at least one allele without the 6-bp nucleotide fragment (p=0.03). Conclusions: These results suggest that 3’UTR polymorphism of TS may be an important predictor of overall survival for Japanese patients with metastatic colorectal cancer receiving first-line 5-FU/oxaliplatin therapy.

No significant financial relationships to disclose.

COX-2 inhibition attenuates cough reflex sensitivity to inhaled capsaicin in patients with asthma

BACKGROUND AND OBJECTIVE

Cyclooxygenase (COX) is an enzyme that converts arachidonic acid to prostanoids. There are two isoforms of COX, namely COX-1 and COX-2. COX-2 is highly inducible by several stimuli and is associated with inflammation. Recent studies have shown that COX-2 is upregulated in the airway epithelium of patients with asthma but little is known about the role it plays in cough, a common symptom of bronchial asthma. This study was designed to investigate the role of COX-2 in cough reflex sensitivity in patients with asthma.

PATIENTS AND METHODS

The effect of etodolac, a potent COX-2 inhibitor, on cough response to inhaled capsaicin was examined in 17 patients with stable asthma in a randomized, placebo-controlled crossover study. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting 5 or more coughs, was measured as an index of airway cough reflex sensitivity.

RESULTS

The geometric mean (geometric SEM) cough threshold was significantly increased after a 2-week treatment program with oral etodolac (200 mg twice a day) compared with placebo (36.7 [1.2] vs 21.6 [1.2] gM, P<.02).

CONCLUSIONS

These findings indicate that COX-2 may be a possible modulator augmenting airway cough reflex sensitivity in asthmatic airways.

The localization of phytate in tofu curd formation and effects of phytate on tofu texture

The localization of phytate on tofu making and its effects on tofu texture were investigated. Thirty-eight percent and 3% of phytate in soymilk were bound to soluble protein and particulate protein, respectively, and the others were in free form. In the early stage of curd formation, phytate bound to particulate proteins and then a large part of phytate was taken into the tofu curd. Increase of phytate contents in soymilk resulted in the increase of coagulant requirement to make firm tofu. Optimal coagulant concentration (OCC) for making tofu was influenced by phytate contents. The increase of phytate in tofu caused decrease of hardness at OCC and resulted in the increase of brittleness and viscosity of tofu. We concluded that the phytate content is one important factor that contributes to tofu texture.

Transventricular hemispherotomy for surgical treatment of intractable epilepsy

Surgical procedures for cerebral hemispherotomy may be broadly divided into those using a lateral and those using a vertical approach. However, careful study of surgical procedures using the lateral approach described in the literature shows differences in the approach to the ventricles. We discuss the application of transventricular hemispherotomy as a technique which provides relatively easy ventricular access for cerebral hemispherotomy. Transventricular hemispherotomy was successfully performed in a 36-year-old woman who was diagnosed with intractable epilepsy due to Sturge-Weber disease, and in a 25-year-old man who had developed intractable post-traumatic seizures after suffering cerebral contusion in a traffic accident as a child. These patients had no seizures or complications after surgery, and both patients have been weaned from antiepileptic drugs. The transventricular approach, as compared with other lateral approaches described in the literature, provides easy access to the ventricular cavity. Transventricular hemispherotomy proved to be a useful approach that allowed the following four common steps in cerebral hemispherotomy to be performed safely: (i) interruption of the internal capsule and corona radiata; (ii) resection of the medial temporal structures; (iii) transventricular corpus callosotomy; and (iv) disruption of the frontal horizontal fibers.

[Detection of unknown primary tumor in a patient with cerebellar metastasis using FDG PET-CT: case report]

Identification of unknown primary tumors in patients with brain metastasis is a continued diagnostic challenge. Several clinical reports have suggested that 18F-flouorodeoxyglucose positron emission tomography (FDG PET) is useful for detecting them. PET has incomparable abilities to determine the metabolic activity of tissues. But it needs the assistance of higher-resolution, anatomic information. CT is the easiest and highest-resolution tomographic modality to be integrated into PET imaging. Because of this, the market for PET devices has shifted so dramatically toward PET-CT. We report a case to show that FDG PET-CT was able to detect an unknown primary tumor. A 75-year-old female underwent resection of a left cerebellar tumor. The histological diagnosis was adenocarcinoma metastasis. Conventional systemic evaluation (chest radiography, chest and abdomen CT, abdominal sonography, and so on) did not show any pathologic image. FDG PET-CT was then carried out. A hypermetabolic focus was revealed in the left hilum. In conclusion, from now on, FDG PET-CT will be considered as the first diagnostic process for patients presenting brain metastasis with an unknown primary tumor.

Urethral transitional cell carcinoma in a cat

A 15-year-old, male neutered cat was referred for investigation of dysuria. A retrograde urethrography was performed which showed two space-occupying masses within the lumen of the mid-to-proximal urethra. Exploratory coeliotomy revealed two urethral masses. Segmental urethrectomy was performed to resect the mass, and the lower urinary tract was reconstructed by vesico-urethral anastomosis. Histopathology showed the mass to be a transitional cell carcinoma with incomplete surgical margins. Tumour regrowth was suspected when dysuria was found approximately 318 days after surgery. Clinical signs were palliated by radiation using weekly fractions of 6 Gy for three weeks. The cat died of unknown causes 386 days postoperatively.

Pitfalls during the Embolization and Evaluation after the Embolization for the Skull Base Meningiomas

Pitfall during the embolization and evaluation after the embolization for skull base meningiomas supplied by meningeal arteries of internal carotid artery (ICA) are reported. This study includes 15 cases of skull base meningiomas (two males and 13 females) that supplied by meningeal branches of internal carotid artery. The preoperative embolization was performed by these feeders. MRI findings and serum levels of C-reactive protein (CRP) after the embolization were examined. In ten patients among 15 patients the meningeal branches of ICA were dominant feeders. In ten patients out of 15 patients, the embolization from the meningeal branches of ICA was possible. Eight patients out of these ten patients were suffered from high fever and increase of serum level of CRP after the embolization. During the embolization for skull base meningiomas, the existence of collateral pathways between the ICA system and external carotid artery system were identified. The increase of serum levels of CRP might be recognized in the patients that effective embolization were performed.

Enhanced signal transduction by a directly fused protein of interleukin-6 and its receptor

In order to develop a new type of agonist for the interleukin 6 (IL-6) signal, the gene encoding a directly fused protein (DFP) was constructed by joining the N-terminal portion of IL-6 and the C-terminal (soluble) portion of IL-6R (sIL-6R) without using a flexible polypeptide linker. The biological activity if DFP from a recombinant Pichia pastoris was examined by growth stimulation of IL-6-dependent BAF130 cells expressing human gp130, a membrane receptor. The recombinant DFP exhibited a much stronger growth stimulation (10 times) than the independent IL-6 and sIL-6R (IL-6/sIL-6R), mainly because association of the IL-6 and IL-6R could be maintained even at lower concentrations of DFP. Surface plasmon resonance (SPR) analysis showed that DFP bound to the extracellular portion of gp130 in the biphasic mode, and the dissociation constants of DFP for two phases were the same as those of IL-6/sIL-6R. In cells treated with DFP, stimulation of Stat3 phosphorylation was maintained for a longer period (150 min) than in cells treated with IL6/Il-6R, suggesting that the signal mediated by the DFP was more durable than that mediated by IL-6/sIL-6R, although the signal transduction mechanisms are almost the same for both DFP and IL-6/IL-6R. Therefore, the stronger activity of DFP was attributed to the maintained association of its subunits and/or prolonged phosphorylation of Stat3.

A brainstem cavernoma demonstrating a dramatic, spontaneous decrease in size during follow-up: case report and review of the literature

BACKGROUND

Many reports have demonstrated a worse prognosis for patients whose cavernomas were subtotally removed than for those whose cavernomas were not surgically treated. Therefore, it is better not to touch the cavernoma if a surgeon is not prepared to totally remove it. This report describes a large brainstem cavernoma showing a spontaneous, dramatic reduction in size after removal of only the biopsy specimen of the lesion.

CASE DESCRIPTION

A 42-year-old woman experienced facial numbness, diplopia, and ataxia. A magnetic resonance (MR) study revealed a pontine cavernoma with hemorrhage. Two weeks later, recurrence of the patient's symptoms and consciousness disturbance were noted. An MR study revealed massive hemorrhage from the cavernoma with a ventricle dilatation. An operation on the lesion was conducted 3 months after the initial hemorrhage. However, the operation was aborted when an exploration of the lesion showed a tight adhesion between the lesion and the pons. Removal of only a biopsy specimen and evacuation of the suckable hematoma were done. No neurologic recovery and no decrease in the size of the cavernoma were detected postoperatively. Her family did not wish for further treatments. She was in a bedridden state with severe brainstem dysfunction when she was transferred to a local hospital. Sixteen months after the surgery, her consciousness was clear, and MR imaging confirmed a marked reduction in the size of the cavernoma.

CONCLUSION

A dramatic, spontaneous decrease in size does occur even in the case of a large brainstem cavernoma showing hemorrhages. Conservative therapy may be one of the treatment options for the symptomatic brainstem cavernoma.

[Neuroanatomical study of the internal structures of the brain based on brain fiber dissection]

From the beginning of the 17th Century, anatomists started to elucidate numerous tracts and fasciculi of the brain using fiber dissection techniques. Due to the complexities associated with tissue preparation and the time-consuming nature of traditional techniques the popularity of this method has gradually declined with the advent of modern neuroimaging techniques such as MRI. Many novel approaches to deep brain lesions have recently been devised following the development of skull base surgery. In comparison, the study of functional neuroanatomy has been relatively neglected. Understanding how neuronal fibers in the brain interconnect and communicate neuronal functions is critical when performing surgery for malignant glioma and epilepsy, as brain parenchyma has to be resected and neuronal fibers are interrupted. In the preoperative planning process we have applied anatomical studies using brain fiber dissection techniques. Brain fiber dissection offers the advantage of exposing association, commissural and projection fibers of cerebral white matter in three dimensions. Brain fiber dissection appears useful for assisting neurosurgeons to acquire neurosurgical skills and become familiar with neuroanatomical features. The techniques and significance of brain fiber dissection are described herein.

Serial antenatal sonographic observation of cerebral dural sinus malformation

Dural sinus malformation is an extremely rare congenital cerebrovascular malformation. We report serial antenatal sonographic findings in two patients with dural sinus malformation. Sonography can reveal dural sinus malformation at 24 weeks' gestation. Correct and early diagnosis may help determine the appropriate place, timing, and mode of delivery, which may result in a better therapeutic course and patient outcome.

Endovascular Treatment of Dural Sinus Malformation With Arteriovenous Shunt in a Low Birth Weight Neonate-Case Report-

A boy was born at 36 weeks gestation weighing 2,135 g, with a prenatal diagnosis of dural sinus malformation with arteriovenous shunts. Congestive heart failure and anuria at birth prompted emergency intervention. Transfemoral-transvenous coil embolization was performed on day 1, resulting in partial occlusion of the huge venous pouch with a total length of 2,355 cm of detachable coils. Transarterial glue embolization on days 7, 23, and 42 was required due to persistent heart failure. Transarterial embolization was performed by common carotid puncture because the transfemoral route could not be used due to the small size and compromised blood flow of the femoral artery. Transarterial embolization reduced the arteriovenous shunts markedly and resulted in clinical improvement. Early treatment of a high flow dural arteriovenous fistula in a low birth weight neonate can achieve an excellent result with an acceptable neurological outcome.

Regrowth and Fatal Rerupture Despite Proximal Occlusion After Coil Embolization of a Ruptured Large Basilar Bifurcation Aneurysm-Case Report-

A 40-year-old man suffered chronic progressive symptoms of brainstem compression after undergoing endosaccular coil placement in a ruptured large basilar bifurcation aneurysm. Radiographical examinations showed coil compaction and regrowth of the aneurysmal mass with perifocal mesencephalic edema. The symptoms did not resolve even after additional clip occlusion of the upper basilar artery and the patient died of rerupture. At present, direct surgical clipping using a skull base technique with or without hypothermic circulatory arrest or upper basilar artery occlusion with or without bypass surgery may be a better choice as an initial treatment for giant or large basilar bifurcation aneurysm with a wide neck.

Homogenous simultaneous detection of HCV RNA and internal control by two-color fluorescence real-time monitoring of isothermal sequence amplification with INAF probes

We demonstrated the homogenous simultaneous detection of HCV RNA and internal control by two-color fluorescence real-time monitoring of isothermal sequence amplification with INAF probes.

Biological Properties of Allogenic Articular Chondrocytes on the Surface of Bovine Cartilage Explants in vitro

Bovine cartilage explants were co-cultured with or without allogenic chondrocytes for 4 weeks. The attachment of the applied chondrocytes to cartilage after labelling with fluorescence was assessed using a confocal laser microscope. Morphological changes and the production of extracellular matrix (ECM) of co-cultured chondrocytes on intact and damaged surfaces of cartilage were evaluated by histological and immunohistochemical methods. Co-cultured chondrocytes attached to and proliferated on the intact and damaged areas of cartilage, and a new layer was created there. The defects were also filled with ECM produced by the co-cultured chondrocytes. Glycosaminoglycans and collagen type II were detected in the newly formed ECM, and large numbers of rounded chondrocytes were observed at primitive lacunae in this matrix at 4 weeks of culture. The results suggest that chondrocytes have the ability to attach to, to proliferate on and to establish a new matrix on the intact and damaged surfaces of cartilage explants.