Water Droplet-in-Oil Digestion Method for Single-Cell Proteomics

Recent advances in single-cell proteomics highlight the promise of sensitive analyses in limited cell populations. However, technical challenges remain for sample recovery, throughput, and versatility. Here, we first report a water droplet-in-oil digestion (WinO) method based on carboxyl-coated beads and phase transfer surfactants for proteomic analysis using limited sample amounts. This method was developed to minimize the contact area between the sample solution and the container to reduce the loss of proteins and peptides by adsorption. This method increased protein and peptide recovery 10-fold. The proteome profiles obtained from 100 cells using the WinO method highly correlated with those from 10,000 cells using the in-solution digestion method. We successfully applied the WinO method to single-cell proteomics and quantified 462 proteins. Using the WinO method, samples can be easily prepared in a multi-well plate, making it a widely applicable and suitable method for single-cell proteomics.

1044 Simple echocardiographic scoring in screening for aortic stenosis by emergency physicians in the emergency department

Background; Aortic stenosis (AS) is one of the important critical diseases and may influence hemodynamics in cardiovascular or non-cardiovascular emergency, however, there is no established methodology to diagnose AS in a focused cardiac ultrasound (FOCUS). We have previously reported that our developed visual AS score was a simple index for AS screening using rapid echocardiography and it could successfully diagnose clinically significant AS. The purpose of the present study was to evaluate the diagnostic accuracy of visual AS score assessed by emergency physicians in the emergency department. Methods; Visual AS score was calculated as the sum of the scores of each three aortic cusp’s opening in a short-axis view scored as follows: 0 = not restricted, 1 = restricted, or 2 = severely restricted; and classified in 0 – 6 as we previously reported. Emergency physicians who did not specialize in cardiology or ultrasonography underwent basic 30 minutes training to visualize aortic valve in a short-axis view and to assess visual AS score beforehand. They performed echocardiography and evaluated visual AS score in emergency outpatients with suspected cardiovascular diseases such as chest symptom, consciousness disorder, abnormal vital signs, heart murmur or abnormal electrocardiogram in the emergency department. Then, another assessment of visual AS score and complete echocardiography including quantitative assessment of AS was performed by expert sonographers. Aortic valve area index (AVAI) was calculated using continuity equation and body surface area, and an AVAI > 0.85 cm/m2, 0.6 - 0.85 cm/m2, and < 0.6 cm/m2 were defined as none or mild, moderate and severe AS, respectively. Results: Sixty patients underwent evaluations of visual AS score by emergency physicians. Visual AS score could not be assessed in 5 patients and continuity equation could not be evaluated in 2 patients, both due to poor echocardiographic imaging quality. Visual AS scores assessed by emergency physicians and expert sonographers showed strong positive correlation (R = 0.94, P < 0.0001). Fourteen patients (26 %) including 6 with shock or hypotension, 3 with congestive heart failure, 2 with syncope, 1 with acute myocardial infarction, 1 with suspected cardiac tamponade and 1 with abnormal electrocardiogram had moderate or more degree of AS in complete echocardiography performed by expert sonographers. Visual AS score 3 or more assessed by emergency physicians had 86 %, 100 %, 100 % and 95 % of a diagnostic sensitivity, specificity, positive predictive value and negative predictive value, respectively. Conclusion: Visual AS score in FOCUS is useful to screen for AS for emergency physicians who do not specialize in cardiology.

Involvement of Microglial P2Y12 Signaling in Tongue Cancer Pain

To elucidate if microglial P2Y12 receptor (P2Y12R) mechanisms are involved in the trigeminal spinal subnucleus caudalis (Vc; also known as the medullary dorsal horn) in intraoral cancer pain, we developed a rat model of tongue cancer pain. Squamous cell carcinoma (SCC) cells were inoculated into the tongue of rats; sham control rats received the vehicle instead. Nociceptive behavior was measured as the head-withdrawal reflex threshold (HWRT) to mechanical or heat stimulation applied to the tongue under light anesthesia. On day 14 after the SCC inoculation, activated microglia and P2Y12R expression were examined immunohistochemically in the Vc. The HWRT was also studied in SCC-inoculated rats with successive intra-cisterna magna (i.c.m.) administration of specific P2Y12R antagonist (MRS2395) or intraperitoneal administration of minocycline, a microglial activation inhibitor. Tongue cancer was histologically verified in SCC-inoculated rats, within which the HWRT to mechanical stimulation of the tongue was significantly decreased, as compared with that of vehicle-inoculated rats, although the HWRT to heat stimulation was not. Microglia was strongly activated on day 14, and the administration of MRS2395 or minocycline reversed associated nocifensive behavior and microglial activation in SCC-inoculated rats for 14 d. The activity of Vc wide dynamic range nociceptive neurons was also recorded electrophysiologically in SCC-inoculated and sham rats. Background activity and noxious mechanically evoked responses of wide dynamic range neurons were significantly increased in SCC-inoculated rats versus sham rats, and background activity and mechanically evoked responses were significantly suppressed following i.c.m. administration of MRS2395 in SCC-inoculated rats as compared with sham. The present findings suggest that SCC inoculation that produces tongue cancer results in strong activation of microglia via P2Y12 signaling in the Vc, in association with increased excitability of Vc nociceptive neurons, reflecting central sensitization and resulting in tongue mechanical allodynia.

Immunohistochemical localization of aggresomal proteins in glial cytoplasmic inclusions in multiple system atrophy

AIMS

Multiple system atrophy (MSA) is pathologically characterized by the formation of α-synuclein-containing glial cytoplasmic inclusions (GCIs) in oligodendrocytes. However, the mechanisms of GCI formation are not fully understood. Cellular machinery for the formation of aggresomes has been linked to the biogenesis of the Lewy body, a characteristic α-synuclein-containing inclusion of Parkinson's disease and dementia with Lewy bodies. Here, we examined whether GCIs contain the components of aggresomes by immunohistochemistry.

METHODS

Sections from five patients with MSA were stained immunohistochemically with antibodies against aggresome-related proteins and analysed in comparison with sections from five patients with no neurological disease. We evaluated the presence or absence of aggresome-related proteins in GCIs by double immunofluorescence and immunoelectron microscopy.

RESULTS

GCIs were clearly immunolabelled with antibodies against aggresome-related proteins, such as γ-tubulin, histone deacetylase 6 (HDAC6) and 20S proteasome subunits. Neuronal cytoplasmic inclusions (NCIs) were also immunopositive for these aggresome-related proteins. Double immunofluorescence staining and quantitative analysis demonstrated that the majority of GCIs contained these proteins, as well as other aggresome-related proteins, such as Hsp70, Hsp90 and 62-kDa protein/sequestosome 1 (p62/SQSTM1). Immunoelectron microscopy demonstrated immunoreactivities for γ-tubulin and HDAC6 along the fibrils comprising GCIs.

CONCLUSIONS

Our results indicate that GCIs, and probably NCIs, share at least some characteristics with aggresomes in terms of their protein components. Therefore, GCIs and NCIs may be another manifestation of aggresome-related inclusion bodies observed in neurodegenerative diseases.

Transversus abdominis plane block in combination with general anesthesia provides better intraoperative hemodynamic control and quicker recovery than general anesthesia alone in high-risk abdominal surgery patients

BACKGROUND

Patients with severe cardiovascular disease are frequently hemodynamically unstable during abdominal surgery. Improving the safety of such patients by stabilizing intraoperative hemodynamics remains a major concern for anesthesiologists. Transversus abdominis plane (TAP) block in combination with general anesthesia may facilitate optimum anesthetic management of these high-risk patients.

METHODS

Patients with cardiovascular disease classified as American Society of Anesthesiologists (ASA) physical status 3 were enrolled. The patients were undergoing elective abdominal surgery and were randomized to a group receiving general anesthesia and TAP block (Group T, N.=33) or a group receiving general anesthesia alone (Group G, N.=35). We compared the groups for intraoperative hemodynamic stability, anesthesia emergence time, amounts of anesthetics and opioids given, and frequency of emergency treatment with cardiovascular agents. A preliminary study demonstrated that systolic blood pressure and heart rate were maintained stable within 70-110% of their preanesthesia values throughout surgery in ASA 1 elderly patients without cardiovascular disease. Thus, the hemodynamically stable time was defined as the time when systolic blood pressure and heart rate were 70-110% of their preanesthesia values. The ratio of hemodynamically stable time to total operative time was used as an index of hemodynamic stability.

RESULTS

The median (minimum-maximum) percentage of hemodynamically stable time was longer in Group T (91[50-100]%) than Group G (79[40-91]%, P<0.01). The mean sevoflurane concentration, amount of fentanyl given and frequency of vasopressor use were lower in Group T than Group G (P<0.05). Anesthesia emergence time was shorter in Group T (14[4-30] min) than Group G (18[9-52] min, P<0.01). No worsening of cardiovascular complications was observed.

CONCLUSION

For abdominal surgery in patients with severe cardiovascular disease, combining TAP block with general anesthesia promotes intraoperative hemodynamic stability and early emergence from anesthesia.

Defect structures in nematic liquid crystals around charged particles

We numerically study the orientation deformations in nematic liquid crystals around charged particles. We set up a Ginzburg-Landau theory with inhomogeneous electric field. If the dielectric anisotropy epsilon 1 is positive, Saturn-ring defects are formed around the particles. For epsilon 1< 0 , novel "ansa" defects appear, which are disclination lines with their ends on the particle surface. We find unique defect structures around two charged particles. To lower the free energy, oppositely charged particle pairs tend to be aligned in the parallel direction for epsilon 1> 0 and in the perpendicular plane for epsilon 1< 0 with respect to the background director. For identically charged pairs the preferred directions for epsilon 1> 0 and epsilon 1< 0 are exchanged. We also examine competition between the charge-induced anchoring and the short-range anchoring. If the short-range anchoring is sufficiently strong, it can be effective in the vicinity of the surface, while the director orientation is governed by the long-range electrostatic interaction far from the surface.

High maneuverability guidewire with functionally graded properties using new superelastic alloys

Nitinol shape memory alloys (SMAs) are attracting considerable attention as core materials for medical guidewires because of their excellent flexibility and shape retention. However, since Nitinol guidewires possess low rigidity, the pushability and torquability of the guidewires are insufficient. On the other hand, although guidewires made of stainless steel have high pushability, plastic deformation occurs easily. We have developed a new class of superelastic guidewires with functionally graded properties from the tip to the end by using new SMA core materials such as Cu-Al-Mn-based or Ni-free Ti-Mo-Sn SMAs. The tip portion of the guidewire shows excellent superelasticity (SE), while the body portion possesses high rigidity. These functionally graded characteristics can be realized by microstructural control. These guidewires with functionally graded properties show excellent pushability and torquability and are considerably easier to handle than conventional guidewires with Nitinol or stainless steel cores. Moreover, a metallic catheter using a Ni-free Ti-based SMA with high biocompatibility is introduced.

Gastrointestinal tract perforation: CT diagnosis of presence, site, and cause

Gastrointestinal tract perforation is an emergent condition that requires prompt surgery. Diagnosis largely depends on imaging examinations, and correct diagnosis of the presence, level, and cause of perforation is essential for appropriate management and surgical planning. Plain radiography remains the first imaging study and may be followed by intraluminal contrast examination; however, the high clinical efficacy of computed tomographic examination in this field has been well recognized. The advent of spiral and multidetector-row computed tomographic scanners has enabled examination of the entire abdomen in a single breath-hold by using thin-slice sections that allow precise assessment of pathology in the alimentary tract. Extraluminal air that is too small to be detected by conventional radiography can be demonstrated by computed tomography. Indirect findings of bowel perforation such as phlegmon, abscess, peritoneal fluid, or an extraluminal foreign body can also be demonstrated. Gastrointestinal mural pathology and associated adjacent inflammation are precisely assessed with thin-section images and multiplanar reformations that aid in the assessment of the site and cause of perforation.

Hippocampal synthesis of estrogens and androgens which are paracrine modulators of synaptic plasticity: synaptocrinology

Hippocampal pyramidal neurons and granule neurons of adult male rats are equipped with a complete machinery for the synthesis of pregnenolone, dehydroepiandrosterone, testosterone, dihydrotestosterone and 17beta-estradiol. Both estrogens and androgens are synthesized in male hippocampus. These brain steroids are synthesized by cytochrome P450s (P450scc, P45017alpha and P450arom), hydroxysteroid dehydrogenases and reductases from endogenous cholesterol. The expression levels of enzymes are as low as 1/300-1/1000 of those in endocrine organs. Synthesis is dependent on the acute Ca(2+) influx upon neuron-neuron communication via NMDA receptors. Estradiol is particularly important because estradiol rapidly modulates neuronal synaptic transmission such as long-term potentiation via synaptic estrogen receptors. Xenoestrogens may also act via estrogen-driven signaling pathways.

Numerical simulation studies of the convective instability onset in a supercritical fluid

Numerical simulation studies in 2D with the addition of noise are reported for the convection of a supercritical fluid, 3He , in a Rayleigh-Bénard cell. The noise addition is to accelerate the instability growth after starting the heat flow across the fluid, so as to bring simulations into better agreement with published experimental observations. Homogeneous temperature noise and spatial longitudinal periodic temperature variations in either top or bottom plates were programmed into the simulations. The second method was the most effective in speeding up the instability onset. For a small amplitude of the longitudinal perturbations, a semiquantitative agreement with the observations was obtained. The results are discussed in relation to predictions by El Khouri and Carlès.

Arsenic contamination of groundwater in Nawabganj, Bangladesh, focusing on the relationship with other metals and ions

Serious arsenic contamination of groundwater in Bangladesh has been frequently reported and is of great concern. In this research, repeated water sampling from the same 10 tubewells in Nawabganj municipality, Bangladesh, was conducted and analysed, focusing on the seasonal variation of water quality and the relationship among arsenic and other metals and ions. For the seasonal variation of water quality, arsenic and iron concentrations were higher in the rainy season in general although the tendency was not consistent and it depended on the tubewell and the time. Correlation between arsenic and iron could not be observed in this study (r = -0.01) when using all cases. This was because no correlation was observed in the higher arsenic concentration range. Arsenic removal by co-precipitation with coexisting iron is known as one of the locally applicable techniques in Bangladesh, but the result from this study suggests that some additional treatments such as the extra injection of iron should be performed in some cases, especially where the arsenic concentration is high. The correlation between arsenic and other substances was also analysed. As a result, manganese (r = 0.37), molybdenum (r = 0.33) and sulfate ion (r = -0.33) significantly correlated with arsenic (p < 0.05). The negative correlation between arsenic and sulfate ion implies the dissolution of arsenic into groundwater under reductive conditions although there are some exceptional cases.

Isolated dissection of the superior mesenteric artery: CT findings in six cases

Dissection of the superior mesenteric artery (SMA) not associated with aortic dissection is rare. The purpose of this study is to describe the computed tomographic (CT) findings of this condition. We studied the CT findings of six patients with isolated dissection of the SMA. CT demonstrated thrombosis of the false lumen or intramural hematoma (n = 4) and/or intimal flap (n = 4) in all six patients. Other CT findings were enlarged diameter of the SMA (n = 5), increased attenuation of the fat around the SMA (n = 5), and hematoma in the mesentery with hemorrhagic ascites (n = 1). CT is useful for the diagnosis of isolated dissection of the SMA, and increased attenuation of the fat around the artery is considered the key to the diagnosis when no definite findings are evident.

Convection in a very compressible fluid: comparison of simulations with experiments

The time profile DeltaT(t) of the temperature difference, measured across a very compressible fluid layer of supercritical 3He after the start of a heat flow, shows a damped oscillatory behavior before steady-state convection is reached. The results for DeltaT(t) obtained from numerical simulations and from laboratory experiments are compared over a temperature range where the compressibility varies by a factor of approximately 40. First the steady-state convective heat current j(conv) as a function of the Rayleigh number Ra is presented, and the agreement is found to be good. Second, the shape of the time profile and two characteristic times in the transient part of DeltaT(t) from simulations and experiments are compared, namely (1) t(osc), the oscillatory period, and (2) t(p), the time of the first peak after starting the heat flow. These times, scaled by the diffusive time tau(D) versus Ra, are presented. The agreement is good for t(osc)/tau(D), where the results collapse on a single curve showing a power-law behavior. The simulation hence confirms the universal scaling behavior found experimentally. However for t(p)/tau(D), where the experimental data also collapse on a single curve, the simulation results show systematic departures from such a behavior. A possible reason for some of the disagreements, both in the time profile and in t(p), is discussed.

Identification of a novel variant of the human NR2B gene promoter region and its possible association with schizophrenia

N-methyl-D-aspartate (NMDA) receptor dysfunction is involved in the pathogenesis of schizophrenia. We determined the nucleotide sequence of the 5'-upstream region of the human NMDA receptor 2B (NR2B) subunit gene and identified a novel T-200G variant located in one of the Sp1 binding sites. To investigate the effect of this variant on the transcriptional activity of the hNR2B gene, we performed gene reporter assays using PC12 pheochromocytoma cells transiently transfected with luciferase reporter plasmids. In the absence of nerve growth factor (NGF), luciferase activities did not significantly differ between the two alleles and the control plasmid. However, luciferase reporter activity of the T allele was significantly up-regulated compared to that of the G allele in the presence of NGF (P = 0.0013), indicating that this polymorphic site is a critical region for NR2B gene regulation through NGF-induced Sp1-binding. A case control study showed that the frequency of the G allele (P = 0.0164) was significantly higher in 100 schizophrenics than in 100 controls. These findings suggest that the T-200G variant causes dysfunction of NMDA receptors consisting of the NR2B subunit and may be involved in the development of schizophrenia. Replication studies of independent samples and family-based association studies are necessary to further evaluate the significance of our findings.

Molecular dynamics simulation of a DNA containing a single strand break

Molecular dynamics simulations were performed for a dodecamer DNA containing a single strand break (SSB), which has been represented by a 3'-OH deoxyribose and 5'-OH phosphate in the middle of the strand. Molecular force field parameters of the 5'-OH phosphate region were determined from an ab initio calculation at the HF/6-31G level using the program package GAMESS. The DNA was placed in a periodic boundary box with water molecules and Na+ counter-ions to produce a neutralised system. After minimisation, the system was heated to 300 K, equilibrated and a production run at constant NTP was executed for 1 ns using AMBER 4.1. Snapshots of the SSB-containing DNA and a detailed analysis of the equilibrated average structure revealed surprisingly small conformational changes compared to normal DNA. However, dynamic properties calculated using the essential dynamics method showed some features that may be important for the recognition of this damage by repair enzymes.

Remarkable effect of aluminum reagents on rearrangements of epoxy acylates via stable cation intermediates and its application to the synthesis of (S)-(+)-sporochnol A

A remarkable effect of (C(6)F(5)O)(3)Al for promoting the rearrangement of epoxy acylates via stable cation intermediates was found, and new methods for constructing chiral benzylic, vinylic, and acetylenic quaternary carbon centers were developed. During the study, the importance of the ionic nature of the O-metal bond in the intermediates of such epoxides was addressed. This method was applied to the asymmetric total synthesis of (S)-(+)-sporochnol A.

Analyzing the eye movement of dentists during their reading of CT images

In order to evaluate the eye movements of dentists when they were interpreting radiographs, ten normal computed tomography (CT) images and ten images with pathologic lesions were shown to eight dentists, and the pattern of their eye movement was qualitatively analyzed. Six fixation point parameters were calculated, including the time required to discriminate between normal and pathologic images (X(1)), the total fixation point count (X(2)), the total travel distance between fixation points (X(3)), the average time spent on each fixation point (X(4)), the total gaze fixation time (X(5)), and the maximum gaze fixation time spent on each image (X(6)). When the subjects were interpreting pathologic images, X(2) and X(4) were shorter; however, when they were viewing normal images, time was spent on observing multiple fixation points before the completion of the interpretive process. While pathologic images were recognized through top-down processing, there was a tendency for normal images to be recognized through bottom-up processing. The results of discriminant analysis, using a linear discriminant function, indicated that the independent variables X(2) and X(4) and the dependent variable X(5) were the only variables that contributed significantly to differentiating between normal and pathologic images. The linear discriminant function was Z = 9.0 x 10(-2) x X(2) + 3.0 x X(4) - 2.1 (discriminant score: Z < 0, pathologic image; Z > or = 0, normal image). When the mean value of each individual's gaze fixation data was substituted into the discriminant formula, the hit rate for normal and pathologic images was discriminated at 94% (15 of 16).

Treatment of A-pattern esotropia with marked mongoloid slanting palpebral fissures

BACKGROUND

The association of oblique palpebral fissures and A- or V-pattern has not been clarified. We report two cases of A-pattern esotropia with marked mongoloid slanting palpebral fissures associated with vertical displacement of the horizontal rectus muscle.

CASES

Case 1 was a boy with Prader-Willi syndrome. He showed A-pattern esotropia with upward slanting palpebral fissures. Severe superior oblique muscle overaction was observed. Case 2 was a girl with meningocele. She also showed A-pattern esotropia with upward slanting palpebral fissures.

OBSERVATIONS

In case 1, weakening surgery of the superior oblique muscles did not improve the A-pattern. Coronal images of computed tomography showed one-half-muscle-width upward displacement of both lateral rectus muscles. After downward transposition surgery of the lateral rectus muscles, the preoperative A-pattern of 25 prism diopters (PD) was successfully corrected to 10 PD. In case 2 also, upward displacement of both lateral rectus muscles was shown by computed tomography. The preoperative A-pattern of 26 PD was corrected to 4 PD postoperatively after upward transposition surgery of the medial rectus muscles.

CONCLUSIONS

The vertical displacement of horizontal rectus muscles was considered the principal cause of A-pattern in these cases associated with marked mongoloid slanting palpebral fissures.

Enhanced CT in the diagnosis of acute appendicitis to evaluate the severity of disease: comparison of CT findings and histological diagnosis

PURPOSE

To assess the potential of CT in evaluating the histological severity of acute appendicitis in comparison with surgical and pathological findings.

METHOD

The CT images of 75 patients with surgically proven appendicitis, including 10 cases of catarrhal, 34 of phlegmonous, and 31 of gangrenous appendicitis, were retrospectively analyzed for the following five CT findings: (1) hazy periappendiceal densities, (2) enlarged appendix, (3) increased enhancement of the appendiceal wall, (4) increased enhancement of the periappendiceal intestinal wall, and (5) deficiency of the appendiceal wall. By comparing all the CT findings and the pathological severity of appendicitis (catarrhal, phlegmonous, and gangrenous), the prevalence of the five CT findings was calculated for each pathological category.

RESULTS

Abnormal CT findings were noted in only one case of catarrhal appendicitis. Increased enhancement of the appendiceal wall was observed in all 29 cases of phlegmonous appendicitis (100%), but in only 66.7% (18 cases) of gangrenous appendicitis. Deficiency of the appendiceal wall was more frequently observed in gangrenous (19/27, 70.4%) than phlegmonous appendicitis (4/29, 13.8%).

CONCLUSION

Findings of enhanced CT provide useful information in evaluating the pathological severity of acute appendicitis.

Low synthesis of retinoic acid due to impaired cytochrome P450 1a1 expression in mouse xeroderma pigmentosum fibroblasts

New tumor formation was suppressed by retinoic acid (RA) administration in xeroderma pigmentosum (XP) patients who have a defect in nuclear excision repair. However, the inhibition is not due to enhanced removal of UV-damaged DNA. These results prompted us to investigate whether or not RA metabolism is abnormal in XP fibroblasts and what the underlying mechanism is. Compared with wild type fibroblasts, low activities of RA synthesis were determined on HPLC in mouse fibroblasts lacking XP group A (XPA) gene and UV-induced XPA deficient cancer cells. Moreover, we observed an impaired expression of cytochrome P450 1a1 in XPA deficient fibroblasts by RT-PCR and a decreased expression of retinoic acid receptor gamma in XPA deficient cancer cells by Western blotting. Finally, pre-treatment of RA isoforms significantly protected the XPA deficient fibroblasts from UV-induced death. These results suggest that decreased structure activity of RA synthesis, resulting from impaired mRNA expression of cytochrome P450 1a1 may, at least together with UV irradiation, involve in skin carcinogenesis in XP patients.

Helical CT in the diagnosis of small bowel obstruction

With recent technologic developments, the role of computed tomography (CT) in the diagnosis of bowel obstruction has expanded. CT is recommended when clinical and initial radiographic findings remain indeterminate or strangulation is suspected. This modality clearly demonstrates pathologic processes involving the bowel wall as well as the mesentery, mesenteric vessels, and peritoneal cavity. CT should be performed with intravenous injection of contrast material, and use of thin sections is recommended to evaluate a particular region of interest. CT is reported to have a sensitivity of 78%-100% for the detection of complete or high-grade small bowel obstruction but may not allow accurate diagnosis in cases involving incomplete obstruction. In such cases, the use of adjunct enteroclysis is indicated. Furthermore, multiplanar reformatted imaging may help identify the site, level, and cause of obstruction when axial CT findings are indeterminate. CT can also demonstrate findings that indicate the presence of closed-loop obstruction or strangulation, both of which necessitate emergency exploratory laparotomy. Unfortunately, these pathologic conditions may be missed, and patients with suspected severe obstruction or bowel ischemia in whom CT and clinical findings are widely disparate must also undergo laparotomy. In general, however, CT allows appropriate and timely management of these emergency cases.

Endoscopic transanal decompression with a drainage tube for acute colonic obstruction: clinical aspects of preoperative treatment

PURPOSE

The study was undertaken to evaluate the clinical usefulness of endoscopic transanal decompression with a newly developed drainage tube for the treatment of acute colonic obstruction.

METHODS

Thirty-six patients ranging in age from 46 to 87 years (average age = 69 years) with acute colorectal obstruction secondary to carcinoma were treated by means of intubation with a flexible drainage tube using combined endoscopic and fluoroscopic guidance. After tube placement, the obstructed colon was aspirated, decompressed, and cleaned with a 50 ml syringe and saline solution. The drainage tube was kept inserted and the colon was irrigated two or three times per day using 500 to 1,000 ml of saline until there were no contents in the colon. The colon was almost empty at the time of operation. The success rate, benefits, and complications of this technique were evaluated.

RESULTS

Placement of the drainage tube was successful in 34 (94.4 percent) of 36 patients. Immediately after aspiration and decompression, symptoms related to obstruction were relieved in 21 patients (61.8 percent), within one hour in 9 patients (26.5 percent) and within four hours in 4 patients (11.8 percent). All 34 patients had elective single-stage surgery without severe complications at the anastomotic site such as anastomotic leakage and postanastomotic stenosis that needed treatment a few days after placement of the drainage tube. In the two cases of unsuccessful placement of the drainage tube, emergent colostomy was performed.

CONCLUSION

Decompression with a transanal drainage tube is an easy and safe technique to relieve colonic obstruction effectively without any excess burden to patients. Because the procedure permits single-stage surgery in most cases, it is also cost effective.

Metabolic activation of mitomycin C by NADPH-ferredoxin reductase in vitro

Mammalian NADPH-ferredoxin reductase (EC 1.18.1.2) functions in the mitochondrial electron transport chain for cytochrome P-450-dependent steroid hydroxylation. Significant homology of three-dimensional structure exists in the surroundings of FAD between NADPH-ferredoxin reductase and NADH-cytochrome b5 reductase. The latter is involved in the bioreduction of mitomycin C (MC), a prototype antitumor agent. In this study, we assessed the capacity of NADPH-ferredoxin reductase to activate MC. Mitomycin C increased the NADPH oxidase activity of NADPH-ferredoxin reductase. In the absence of ferredoxin, the Km value of NADPH-ferredoxin reductase for MC was 73.5 +/- 2.3 microM. While in the presence of 500 nM ferredoxin, a Lineweaver-Burk plot exhibited a biphasic curve. NADPH-ferredoxin reductase-mediated reduction of MC resulted in the formation of an alkylated complex of 4-(p-nitrobenzyl) pyridine and an increase in plasmide DNA single-strand breaks under hypoxic conditions. With the addition of 500 nM ferredoxin, the amount of the alkylated complex of 4-(p-nitrobenzyl) pyridine and the plasmide DNA single-strand breaks increased by 40% and 37%, respectively. However, neither alkylated complex of 4-(p-nitrobenzyl) pyridine nor DNA strand breaks was observed in the presence of SOD and catalase under aerobic conditions. These findings demonstrate that NADPH-ferredoxin reductase is capable of catalyzing the bioactivation of mitomycin C under hypoxic conditions in vitro.

The optical interconversion of the P-450 and P-420 forms of neuronal nitric oxide synthase: effects of sodium cholate, mercury chloride and urea

We investigated whether or not neuronal nitric oxide synthase (nNOS) (EC 1.14.13.39) was converted to the P-420 form on exposure to sodium cholate, mercury chloride or urea, and the reconversion of the P-420 to the P-450 form. Sodium cholate and mercury chloride induced the conversion of nNOS from the P-450 to the P-420 form in concentration- and incubation time-dependent manners, and the nNOS activity decreased. In the presence of glycerol, L-arginine and/or tetrahydrobiopterin, the sodium cholate-treated P-420 form could be reconverted to the P-450 form under constant experimental conditions, and the nNOS activity could also be restored. The mercury chloride-treated P-420 form of nNOS could be reconverted to the P-450 form on incubation with reduced glutathione (GSH) or L-cysteine, and the nNOS activity was recovered. However, no reconversion of the mercury chloride-treated P-420 form to the P-450 form was observed in the presence of glycerol, L-arginine, or tetrahydrobiopterin. Urea (4.0 M) dissociated nNOS into its subunits, but nNOS remained in the P-450 form. The nNOS monomer was more susceptible to sodium cholate. After removing the urea by dialysis, and supplementation of the nNOS solution with glycerol, L-arginine or BH(4), the P-420 was reconverted to the P-450 form, and the reassociation of nNOS monomers was also observed. These results suggested that nNOS was more stable as to exposure to sodium cholate, mercury chloride or urea in comparison to microsomal cytochrome P-450, which may be due to the different heme environment and protein structure.

Phase transitions of binary alloys with elastic inhomogeneity

In elastically inhomogeneous alloys, in which the shear modulus depends on the composition, coarsening in phase separation can be pinned even without quenched disorder. Here networks in the soft phase enclose the domains in the hard phase. Highly asymmetric strains in the two regions create large free energy barriers that prevent further coarsening. Thus a phase transition occurs between the one-phase and the glassy two-phase states. We numerically obtain the phase diagram and show that this transition is discontinuous at any composition. Therefore there is no critical point.

Effect of isosorbide dinitrate on nitric oxide synthase under hypoxia

Nitric oxide synthase (NOS) catalyzes nitric oxide (NO) formation from L-arginine in the presence of molecular oxygen and NADPH. NO is involved in the regulation of microvasculature. Isosorbide dinitrate (ISDN) and glyceryl trinitrate (GTN) have been widely used as vasodilators to treat acute myocardial ischemia, their biological effects being due to the release of NO. In this investigation, the effects of ISDN and GTN on NOS activity in the presence or absence of oxyhemoglobin under hypoxia and normoxia were studied. The apparent K(m) values for molecular oxygen were 21.6 +/- 1.5 and 9.4 +/- 1.3 micromol/l for nNOS and eNOS, respectively. ISDN liberated NO in a concentration- and pH-dependent manner, but no differences between hypoxia and normoxia were observed. The NO release from ISDN was also measured directly by an electron spin resonance spectral method with N-(dithiocarboxy)sarcosine-Fe complex as a NO-trapping agent. ISDN increased nNOS and eNOS activities in the presence of 30 micromol/l oxyhemoglobin under hypoxia, while it did not affect nNOS and eNOS activities under normoxia. In the absence of oxyhemoglobin, ISDN inhibited nNOS and eNOS activities under both hypoxic and normoxic experimental conditions. The rate of oxygen release from oxyhemoglobin under hypoxia was increased 3 times in the presence of 1 mmol/l ISDN. In contrast to ISDN, GTN could not release NO spontaneously, and it also did not affect nNOS and eNOS activities in the absence or presence of 30 micromol/l oxyhemoglobin under both hypoxic and normoxic conditions. These results indicated that the NO release from ISDN is different from that of GTN, and the increase of NOS activity by ISDN in the presence of oxyhemoglobin under hypoxia is ascribed to the increase in molecular oxygen concentration.

Reductive activation of mitomycin C by neuronal nitric oxide synthase

Mitomycin C (MC) requires bioreduction prior to the generation of alkylating moieties. NADPH-cytochrome P450 reductase is predominant in metabolic activation of MC in hypoxic cancer cells. In this study, neuronal nitric oxide synthase (nNOS), whose reductase domain is structurally similar to that of NADPH-cytochrome P450 reductase, was assessed for its ability to activate MC. nNOS under anaerobic conditions catalyzed the reduction of MC, which was measured as the decrease in absorbance at 375 nm. Neither the heme blocker potassium cyanide (1 mM) nor the nNOS competitive inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME, 1 mM) affected the bioreduction of MC, whereas 0.1 mM diphenyleneiodonium chloride, which binds to the reductase domain of nNOS, inhibited MC reduction completely. The reduction of MC by nNOS was influenced by Ca(2+)/calmodulin. In the absence of Ca(2+)/calmodulin, the rate of MC reduction decreased by 28% at pH 6.6. The formation of an alkylated complex of 4-(p-nitrobenzyl)pyridine occurred in a manner analogous to that observed in MC metabolic experiments. The rate of MC reduction and the formation of the alkylated complex of 4-(p-nitrobenzyl)pyridine at pH 6.6 were increased by 43 and 54%, respectively, as compared with that at pH 7.6. nNOS-activated MC resulted in the consumption of oxygen in air. The rate of oxygen consumption decreased by 50% in the presence of 2000 U/mL of catalase. MC inhibited nNOS activity in a noncompetitive manner. These findings demonstrate that nNOS is capable of catalyzing the bioreduction of MC.

Polyurethane-covered Nitinol Strecker stents as primary palliative treatment of malignant biliary obstruction

PURPOSE

To evaluate the clinical efficacy of the polyurethane-covered Nitinol Strecker stent in the treatment of patients with malignant biliary obstruction.

METHODS

Twenty-three covered stents produced by us were placed in 18 patients with malignant biliary obstruction. Jaundice was caused by cholangiocarcinoma (n = 5), pancreatic cancer (n = 6), gallbladder cancer (n = 4), metastatic lymph nodes (n = 2), and tumor of the papilla (n = 1).

RESULTS

The mean patency period of the stents was 37.5 weeks (5-106 weeks). Recurrent obstructive jaundice occurred in two patients (11%). Adequate biliary drainage over 50 weeks or until death was achieved in 17 of 18 patients (94.4%). Late cholangitis was observed in two patients whose stents bridged the ampulla of Vater. Other late severe complications were not encountered.

CONCLUSION

Although more study is necessary, our results suggest the clinical efficacy of our covered Nitinol Strecker stent in the management of obstructive jaundice caused by malignant diseases.

Blood-brain barrier transport of 125I-labeled basic fibroblast growth factor

PURPOSE

This study was carried out to examine the blood-brain barrier (BBB) transport of human basic fibroblast growth factor (bFGF) and investigate its mechanism.

METHODS

The BBB transport of 125I-bFGF was measured by several in vivo methods including intravenous administration, in situ internal carotid artery perfusion, and intracerebral microinjection. The in vitro binding of 125I-bFGF was characterized using freshly prepared bovine brain capillaries.

RESULTS

The distribution volume of 125I-bFGF in the postvascular supernatant increased with the perfusion time, and exceeded the space occupied by the brain microvasculature and its trichloroacetic acid (TCA) precipitability was more than 90%. 125I-bFGF avidly bound to isolated bovine brain capillaries with a Bmax of 206 +/- 48 pmol/mg protein, and a Kd of 36.5 +/- 15.7 nM. This binding was significantly inhibited by unlabeled bFGF and heparin in a concentration-dependent manner. The cationic peptides, protamine and poly-L-lysine (each 300 microM), produced over 85% inhibition of 125I-bFGF binding to brain capillaries. Furthermore, glycosaminoglycans with a sulfate residue, chondroitin sulfate B and C (each 10 microg/mL) also inhibited the binding of 125I-bFGF The in vivo transcytosis of 125I-bFGF from the luminal side to the brain was also inhibited by the presence of heparin (10 microg/mL) and poly-L-lysine (300 microM), whereas neither hyaruronic acid (10 microg/mL) nor insulin (10 microM) had any effect. In addition to these results, the brain efflux index method was used to confirm that the transcytosis of 125I-bFGF from brain to blood across the BBB was negligible.

CONCLUSIONS

These results suggest that 125I-bFGF is transported across the BBB, possibly by an adsorptive-mediated transcytosis mechanism that is triggered by binding to negatively charged species on the luminal membrane surface of the brain microvasculature, such as heparan sulfate proteoglycans.

[Recent advances in CT diagnosis of chronic obstructive pulmonary diseases]

With high-resolution CT (HRCT), morphological changes of the lung caused by chronic obstructive pulmonary disease can be evaluated in detail at the level of secondary pulmonary lobule. The location of emphysematous lesions within the lobule can be judged on HRCT images and bronchiolar abnormalities are also demonstrated as thickening of peripheral bronchovascular bundles. In addition to early detection of morphological changes, quantitative evaluation of the severity of the disease is also important. For this purpose, visual assessment with CT scores, quantitative evaluation using "density mask" technique, or histogram analysis are employed. Quantitative parameters provided by these methods correlate well with pathological scores and results of pulmonary function tests. Furthermore, respiratory dynamic CT or paired inspiratory and expiratory CT is also useful to detect air trapping caused by bronchiolar stenosis.

[CT findings of pulmonary infections]

Although many pulmonary infections are diagnosed using chest radiographs in combination with clinical findings and are treated empirically with antibiotics, there are situations in which chemotherapy is not effective and further examinations are necessary. In those cases, CT, especially high-resolution CT (HRCT), can provide additional information about detailed morphological changes of the lung that are sometimes indicative of the causative organisms of pneumonia, such as pulmonary tuberculosis. Although it is true that the same organism can present a wide spectrum of radiological findings, it is also important for differential diagnosis to understand the basic features of pathological changes of the lung and the CT findings caused by each of the various organisms. Such CT information would also be useful in differentiating infectious pneumonia from noninfectious pneumonia. This review article presents the principal CT findings of pulmonary infections and their pathological correlations with various pneumonias, including bacterial, tuberculous, fungal, and viral pneumonias.

Inhibition by retinoids of benzo(A)pyrene metabolism catalyzed by 3-methylcholanthrene-induced rat cytochrome P-450 1A1

Benzo(a)pyrene, a well-known procarcinogen, is believed to be activated by microsomal cytochrome P-450 1A1 (CYP 1A1). We recently reported that rat CYP 1A1 induced by 3-methylcholanthrene (3-MC) catalyzed the conversion of retinal to retinoic acid. In this study, we investigated retinoid inhibition of the metabolism of benzo(a)pyrene and 7-ethoxyresorufin, another specific substrate of CYP 1A1, using liver microsomes prepared from control and 3-MC-pretreated rats as the enzyme source. In 3-MC-treated rats, retinal and retinol, but not retinoic acid, inhibited benzo(a)pyrene metabolism. The 50% inhibitory concentration (IC50) of retinal was about 11.5 micromol/L and the inhibition was competitive, with a Ki value of 5.8 micromol/L. Retinol is a more potent inhibitor than retinal. The IC50 was about 5 micromol/L and the inhibition was mixed, with a Ki value of 19.2 micromol/L and a Ki' value of 4.2 micromol/L. Almost the same results were obtained for the reaction of 7-ethoxyresorufin deethylation. In contrast, the metabolic activity of both benzo(a)pyrene and 7-ethoxyresorufin was much lower in untreated versus 3-MC-treated rats, and only weak inhibition by the retinoids was observed. The results suggest that retinoids inhibit the activation of benzo(a)pyrene and that the substrate specificity of cytochrome P-450 isozymes associated with retinoid metabolism should be taken into account when studying the anticarcinogenic action of retinoids.

Molecular cloning of retinal oxidase/aldehyde oxidase cDNAs from rabbit and mouse livers and functional expression of recombinant mouse retinal oxidase cDNA in Escherichia coli

Retinal oxidase (EC 1.2.3.11) is a molybdenum-containing flavoenzyme with high enzymatic activity as to retinoic acid synthesis. In this study, we provide direct evidence that retinal oxidase is identical to aldehyde oxidase (EC 1.2.3.1) by cDNA cloning. Retinal oxidase and aldehyde oxidase, purified from rabbit liver cytosol using the original methods, showed completely identical HPLC patterns and amino acid sequences for three corresponding polypeptides (103 amino residues). The primary structural information obtained from the cleaved polypeptides permitted molecular cloning of the full-length cDNA of rabbit liver retinal oxidase (aldehyde oxidase). We also cloned and sequenced the full-length cDNA of mouse retinal oxidase. The cDNAs of rabbit and mouse retinal oxidase have a common sequence approximately 4.6 kb long, comprising 4-kb coding regions. The open reading frames of the cDNAs predict single polypeptides of 1334 and 1333 amino acids; the calculated minimum molecular mass of each is approximately 147,000. Northern blot analysis showed that the rabbit retinal oxidase mRNA was widely expressed in tissues. Finally, we successfully constructed a prokaryotic expression system for mouse retinal oxidase. The purified recombinant retinal oxidase from Escherichia coli showed a typical spectrum of aldehyde oxidases and a lower Km (3.8 microM) for retinal and a higher Vmax (807 nmol/min/mg protein) for retinoic acid synthesis than those of rabbit retinal oxidase (8 microM and 496 nmol/min/mg protein). This represents the first eukaryotic molybdenum-containing flavoprotein to be expressed in an active form in a prokaryotic system.

Transient hepatic attenuation difference (THAD) in patients without neoplasm: frequency, shape, distribution, and causes

Transient hepatic attenuation difference (THAD) is a valuable finding in detecting hypervascular lesions. However, similar findings are also observed in patients even without known hepatic diseases. We elucidate the characteristic findings and the causes of THAD in patients without hepatic neoplasm in this article. Dual-phased contrast-enhanced CT studies performed in 450 patients were reviewed, and THAD was observed in 42 (9.3%). THAD was linear or wedge-shaped and was seen contiguous to the liver surface with a relatively obscure margin in 40 of the 42 cases. The most common cause of THAD was chronic cholecystitis followed by previous biliary surgery. THAD was also seen in 30 patients with no hepatic diseases in whom it had a tendency to locate around the gallbladder fossa or in the periphery of the liver particularly in the left lobe. The knowledge of the prevalence, shape, distribution and causes of THAD is essential for the evaluation of contrast-enhanced CT images obtained during the arterial phase.

Steroidogenic acute regulatory protein (StAR) transcripts constitutively expressed in the adult rat central nervous system: colocalization of StAR, cytochrome P-450SCC (CYP XIA1), and 3beta-hydroxysteroid dehydrogenase in the rat brain

Steroidogenic acute regulatory protein (StAR) is a 30-kDa protein involved in the transport of cholesterol to the inner mitochondrial membrane and thus plays a key role in steroid biosynthesis. To clarify the implications of this protein in neurosteroid biosynthesis, we examined the possible expression of a StAR transcript in the adult rat CNS and detected it. cDNA cloning and sequencing analysis revealed that two forms of StAR mRNAs are expressed in the brain in the same manner as in the adrenal gland, indicating that they are fully functional and not minor gene transcripts. An RNase protection assay quantitatively revealed that the amount of the rat StAR transcript in brain was two to three orders of magnitude lower than that in the adrenal gland. An in situ hybridization study, involving antisense riboprobes, revealed that StAR transcripts were abundant in the cerebral cortex, hippocampus, dentate gyrus, olfactory bulb, cerebellar granular layer, and Purkinje cells. Furthermore, other steroidogenic enzymes, side-chain cleavage cytochrome P-450SCC (CYP XIA1) and 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase (EC 1.1.1.145), were found to be coexpressed in the hippocampus, dentate gyrus, cerebellar granular layer, and Purkinje cells. These findings strongly indicate that neurosteroids are synthesized in a region-specific manner in the brain.

Immunoradiometric assay for the N-terminal fragment of proatrial natriuretic peptide in human plasma

Recently, the N-terminal fragment of proatrial natriuretic peptide (N-terminal proANP) has been proposed as a marker of chronic congestive heart failure. In this study, we established a two-step immunoradiometric assay using monoclonal antibodies and synthetic N-terminal proANP (1-67) as a standard. It allows us to measure plasma N-terminal proANP in only 4 h without prior extraction. The detection limit of this assay was 15 pmol/L for a 100 microL sample of plasma. Within-run CVs ranged from 1.7% to 2.9% and between-run CVs ranged from 4.2% to 5.1%. The dilution curves of plasma samples showed good linearity and analytical recovery was 89-104%. The mean (+/-SD) N-terminal proANP in plasma of 33 healthy subjects was 188 (+/-71) pmol/L and 1030 (+/-411) pmol/L in 25 patients with heart failure. Our immunoradiometric assay is rapid and precise enough for routine determination of N-terminal proANP in human plasma.

Non-fluorescent chromosome painting using the peroxidase/diaminobenzidine (DAB) reaction

PURPOSE

To develop and validate non-fluorescent chromosome painting for bright-field microscopy using the peroxidase/diaminobenzidine (DAB) reaction.

MATERIALS AND METHODS

Peripheral blood lymphocytes were taken from patients with uterine cancer who had received heavy-ion radiation therapy. Chromosome slides were treated with RNase and pepsin, denatured mildly, hybridized with a biotinylated DNA probe specific for whole-chromosome 4 and stained using the peroxidase/DAB reaction with an avidin-biotin amplification. The slides were analysed under a bright-field microscope and an atomic force microscope. The detection rate of chromosome aberrations by DAB painting was compared with that obtained by dual analysis of Giemsa staining and FISH painting.

RESULTS

When chromosomes 4 were painted, 11.5% of unstable aberrations were detected by DAB painting, while 10.8% of them were found by dual analysis of Giemsa staining and FISH painting.

CONCLUSION

A DAB painting method that can effectively detect rearranged aberrations was established. It has advantages over FISH painting: the preparations can be analysed by bright-field microscope, can be preserved permanently and are suitable for analysis by an automated system.

Role of the matrix metalloproteinase and tissue inhibitors of metalloproteinase families in noninvasive and invasive tumors transplanted in mice with severe combined immunodeficiency

OBJECTIVES

To elucidate the role of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human urothelial cancers, we studied gene expressions of MMPs, TIMPs, and membrane-type 1 matrix metalloproteinase (MT1-MMP) in noninvasive or invasive tumor lines transplanted in mice with severe combined immunodeficiency (SCID).

METHODS

The UCT-1 tumor line, derived from bladder cancer, is a noninvasive transplantable tumor with no evidence of metastasis. The UCT-2 tumor line, derived from a renal pelvic tumor, extensively invades without metastasis. We examined gene expressions of MMPs-1, 2, 3, 7, 8, 9, 10, and 11, TIMPs-1, 2, and 3, and MT1-MMP in UCT-1 and 2 by semiquantitative polymerase chain reaction analysis.

RESULTS

Significantly higher gene expression of MMP-2 was detected in the invasive UCT-2 tumor line than in the noninvasive UCT-1 tumor line. Although both tumor lines expressed TIMP-1 and MT1-MMP, stronger gene expression of MT1-MMP was observed in the UCT-2 tumor line than in the UCT-1 tumor line. The other MMPs or TIMPs were not detected in either of the lines.

CONCLUSIONS

MMP-2 and MT1-MMP may have an important role in the invasion mechanism of urothelial cancers.