Estimation of coronary flow reserve with the use of dynamic planar and SPECT images of Tc-99m tetrofosmin

BACKGROUND

We developed a noninvasive method to examine coronary flow reserve with technetium 99m tetrofosmin based on the microsphere model. According to the microsphere model, myocardial blood flow (MBF) can be calculated by MBF = q / integral C(t)dt, where q is myocardial activity and C(t) is tracer concentration in blood. Because the ratio of integral C(t)dt at stress to rest is equal to the ratio of the first transit count in the pulmonary artery (PA) and attenuation factors were canceled out, we calculated the increase ratio of MBF (MBF(IR)).

METHODS AND RESULTS

After injection of dipyridamole, tetrofosmin was injected as a bolus and serial dynamic planar images were obtained to measure the first transit count in PA (PAC). Myocardial single photon emission computed tomography was performed to measure the regional myocardial count (RMC). MBF(IR) was calculated as [(RMCs x PACr)/(RMCr x PACs) - 1] x 100, where r and s denote resting and stress conditions, respectively. In contrast, the increase in the myocardial uptake ratio (MUR(IR)) was defined as (RMCs x SCr/RMCr x SCs - 1) x 100, where SC is syringe count of tracer. The results were as follows: (1) The mean MBF of healthy subjects was 46.9% +/- 22.8%. (2) MBF(IR) of the infarcted region and ischemic region was significantly decreased (8.3% +/- 12.2% and 11.2% +/- 11.9%, respectively; P <.001). (3) MUR(IR) was significantly lower than MBF(IR) (14.1% +/- 21.2%; P <.001). (4) MBF(IR) decreased according to the heart rate at rest (r = 0.47; P <.05).

CONCLUSIONS

MBF(IR) is a potential parameter with which to evaluate coronary flow reserve when the changes of arterial input function during stress are considered.

[Early and late results of composite graft replacement for the aortic root]

From 1985 to 1998, 16 patients underwent composite graft replacement for the aortic root. Ten patients (63%) had Marfan syndrome, 11 (69%) had annulo aortic ectasia (AAE), and 7 (44%) had Stanford A dissection. Two patients (12.5%) underwent emergent operation due to acute aortic dissection. There were 2 (12.5%) operative deaths, and both were Stanford A dissection without Marfan syndrome. Although there was no statistical significance, the operative mortality was higher for the patients with Stanford A dissection (p = 0.087), for those with emergent operation (p = 0.074) and for those without Marfan syndrome (p = 0.051). The overall survival rates were 87.5% at 5 years and 75% at 10 years. The survival rate at 8 years was significantly lower for the patients with Stanford A dissection (35.7%) as compared with non-Stanford A dissection (100%, p = 0.024). Neither Marfan syndrome nor AAE affected the long-term survival. The late results of composite graft replacement for the aortic root were satisfactory except for the patients with Stanford A dissection. It was suggested that the long-term survival for Stanford A dissection was greately affected by the operative deaths for Stanford A dissection without Marfan syndrome.

Galanin-like immunoreactive neural elements in domestic ruminant pancreas

The distribution and ontogeny of the galanin-like immunoreactive (Gal-IR) neural structures in the pancreas of cattle, sheep and goat were investigated immunohistochemically. The present study confirmed the previous findings on the immunolocalization of galanin both in the neural elements and endocrine cells of cattle, and reported for the first time its exclusive localization in the neural elements of sheep and goat. The frequency of Gal-IR nerve fibers and nerve cell bodies was high in cattle and low in sheep and goat. Their first detection was at the first fetal trimester in cattle and third trimester in sheep and goat. In cattle, a marked increase in the frequency of Gal-IR nerve fibers was observed from the third trimester to early neonatal stage followed by a decrease after three months postnatal. In contrast to the non-preferential distribution pattem in sheep, the Gal-IR nerve fibers in cattle and goat pancreas were predominantly associated with the acini, excretory ducts and blood vessels, but rarely detected in the pancreatic islets. The Gal-IR nerve cell bodies were observed as isolated bodies in the intra- and interlobular connective tissues and as a group within the intrapancreatic ganglia. At the vicinity of the nerve cell bodies, Gal-IR nerve fibers were observed. The present findings may suggest that: (1) galanin regulates pancreatic function as neurotransmitter/neuromodulator in ruminants; (2) galanin plays a more important role in large than in small ruminants; and (3) particularly in cattle, it exerts its most dramatic effect during perinatal development.

Immunohistochemical study of the ontogeny of prochymosin--and pepsinogen-producing cells in the abomasum of sheep

The appearance and development of prochymosin- and pepsinogen-producing cells were investigated in the ovine abomasum from fetus to adult using immunohistochemistry. Prochymosin immunoreactivity appeared first in the proper gastric glands of the 100-day-old fetus. The intensity and distribution of prochymosin-immunoreactive cells increased gradually with the progress of gestation, and their most intense immunoreactivities and widest distribution were observed in 3-day-old lambs. They were subsequently reduced throughout postnatal growth. A few prochymosin-immunoreactive cells were scattered in the glands of adult sheep. Pepsinogen immunoreactivity appeared at first in a small number of cells in the base of some proper gastric glands of 120-day-old fetuses. After 130 days, pepsinogen-immunoreactive cells increased their staining intensities and distribution. They reached a peak in area at 21 days, which is comparable to adult sheep. In the pyloric glands, prochymosin- and pepsinogen-immunoreactive cells appeared from 100 and 130 days, respectively. Numbers were reduced in comparison to gastric glands and their occurrence was capricious. The results demonstrated that the ontogeny of prochymosin- and pepsinogen-immunoreactive cells in the abomasum of sheep is more similar to that in cattle than to that in the goat. The present data will contribute to the overall understanding of the development of ruminant gastric proteases.

Left ventricular apex venting during deep hypothermia in a case of difficult re-entry into the mediastinum

The cardiopulmonary bypass techniques of peripheral cannulations and deep hypothermia provide safe and controlled re-entry into the mediastinum, when the thoracic organs are contiguous with the sternum. In such cases, in order to prevent ventricular distention during cooling, left ventricular venting is very important but can be difficult. We made a small (3 cm) left-sided thoracotomy incision and inserted a left ventricular apical venting tube while cooling a patient with a large pseudoaneurysm of the ascending aorta, which was diagnosed 12 years after aortic valve replacement. We found that this technique was easy, safe, and useful to prevent ventricular distention during cooling.

[Staged operation for right isomerism with total anomalous pulmonary venous return: report of a case]

A male infant with right isomerism, single ventricle, severe pulmonary stenosis (PS), and total anomalous pulmonary venous return (TAPVR) underwent successful staged Fontan operation. Pulmonary vein drained into right superior vena cava without a stenotic lesion. Common pulmonary venous chamber was also connected with the atrium by a thin bridging vein. Blalock-Taussig shunt was performed at 2-month-old. Because of progressive pulmonary congestion, an anastomosis between common pulmonary venous chamber and the atrium followed 4 days after the first shunt. Bidirectional cavopulmonary shunt was performed 7 months after the second operation. Because of progressive atrioventricular valve regurgitation, repeated bandings of the shunt were required to regulate the pulmonary flow. Total cavopulmonary connection was completed 9 months after the BCPS. Staged operation is a useful strategy to acquire an appropriate pulmonary blood flow for the isomeric heart with TAPVR and severe PS.

Usefulness of plasma exchange plus continuous hemodiafiltration to reduce adverse effects associated with plasma exchange in patients with acute liver failure

OBJECTIVE

To efficiently remove middle-molecular-weight substances such as hepatic toxins and minimize adverse effects associated with plasma exchange implementation, we have performed plasma exchange slowly in combination with continuous hemodiafiltration. This study was designed to determine the usefulness of plasma exchange with continuous hemodiafiltration in reducing the adverse effects associated with implementation of plasma exchange alone.

DESIGN

A retrospective clinical study.

SETTING

University teaching hospital.

PATIENTS

The study involved 90 patients with liver failure who had been treated with plasma exchange in our department over the past 12 yrs. We examined these patients by dividing them into two groups (48 patients treated with plasma exchange alone and 42 patients treated with plasma exchange plus continuous hemodiafiltration at the time of plasma exchange implementation).

MEASUREMENTS AND MAIN RESULTS

Baseline blood Na+ concentration, HCO3- concentration, and colloid osmotic pressure were followed after implementation of plasma exchange to compare the frequency of development of three adverse effects (hypernatremia, metabolic alkalosis, and sharp decrease in colloid osmotic pressure) in the two groups. Hypernatremia was found in 26.7% of treatments in the group with plasma exchange alone and 3.3% in the group of plasma exchange plus continuous hemodiafiltration, and metabolic alkalosis was found in 30.6% of treatments in the group with plasma exchange alone and 4.9% in the group of plasma exchange plus continuous hemodiafiltration; both percentages were significantly higher in the group with plasma exchange alone (p <.001). A sharp decrease in colloid osmotic pressure occurred in 13.3% of treatments in the group with plasma exchange alone but was not observed at all in the patients treated with plasma exchange plus continuous hemodiafiltration.

CONCLUSIONS

We conclude that adverse effects associated with plasma exchange for artificial liver support for liver failure can be alleviated with use of plasma exchange plus continuous hemodiafiltration instead of plasma exchange alone.

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1999)]

From October 1999 to September 2000, we collected the specimen from 430 patients with lower respiratory tract infections in 17 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and antibiotics and patients' characteristics. Of 515 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in inflammation, 506 strains were investigated. The breakdown of the isolated bacteria were: Staphylococcus aureus 78, Streptococcus pneumoniae 101, Haemophilus influenzae 104, Pseudomonas aeruginosa (non-mucoid) 58, P. aeruginosa (mucoid) 11, Moraxella subgenus Branhamella catarrhalis 41, Klebsiella pneumoniae 18, etc. Of 78 S. aureus strains, those with 4 micrograms/ml or above of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) occupied 57.7%. Vancomycin and arbekacin showed the most potent activities against MRSA without detection of ABK-resistant strain (MIC: 64 micrograms/ml) and decrease of VCM-sensitive strains those were found in 1998. The frequency of S. pneumoniae exhibiting low sensitivity to penicillin (penicillin-intermediate S. pneumoniae: PISP + penicillin-resistant S. pneumoniae: PRSP) decreased to 34.7% from 46.0% in 1998. The frequency of PRSP was 3.0%, being the least number after 1991. Carbapenems showed strong activities against S. pneumoniae. Especially, panipenem inhibited the growth of all 101 strains with MIC of 0.063 microgram/ml. Generally, all drugs showed strong activities against H. influenzae with MIC80s of 4 micrograms/ml or below. MICs of ofloxacin ranged between 0.063 microgram/ml and 4 micrograms/ml in 1998, however, those were 0.125 microgram/ml or below in all H. influenzae in 1999 showing the strongest activity. Tobramycin and ciprofloxacin showed strong activities against P. aeruginosa (both mucoid and non-mucoid) with MIC80s of 1 microgram/ml. Number of isolated P. aeruginosa (mucoid) was little as 11, however, the susceptibilities to all drugs were better than P. aeruginosa (non-mucoid). K. pneumoniae showed good susceptibilities to all drugs except for ampicillin with decreasing of low-sensitive strains compared to those detected in 1998. Also, all drugs generally showed strong activities against M. (B.) catarrhalis. MIC80s of all drugs were 2 micrograms/ml or below. The drug which showed the strongest activity was imipenem inhibiting all 41 strains with MIC of 0.063 microgram/ml. On the patients' characteristics, the number of patients aged 80 years or older who had been increased was decreased in 1999 in the distribution by age. The percentage of the elderly patients aged 70 years or older was 47.0%, which occupied almost a half number of the total patients as in the last year. As for the incidence by disease, bacterial pneumonia and chronic bronchitis were the highest. They were noted in 37.9% and 30.5% of the patients, respectively. In 1999, bronchial asthma was frequently observed as compared in recent years. It was noted in about 10% of the patients which is the same % as in bronchiectasis. We examined the number of strains from these patients with infections before and after administration of antibiotics. In patients with bacterial pneumonia, the number of isolated strains was almost the same between those before and after administration. However, in patients with chronic bronchitis, the number of strains remarkably decreased to less than the half of the total after administration of antibiotics in the last year, but it decreased to 2/3 of the total in 1999. On the administration of antibiotics and isolated bacteria by the day of administration, the bacteria which were isolated more before administration were H. influenzae in 28.4%, S. pneumoniae in 25.7%, M. (B.) catarrhalis in 12.0% and S. aureus in 10.6%. The frequency of S. aureus after administration over 15 days was almost the same as that before administration, but the frequency of P. aeruginosa (both mucoid and non-mucoid) was 36.8% which was higher than that before administration. The frequency of isolated S. pneumoniae was decreased after administration and none of them was isolated after completion of administration. However, that of H. influenzae was decreased to 7.1% after administration within 3 days, and many H. influenzae were isolated after completion of administration as 21.4%.

Immunohistochemical evaluation of a malignant phecochromocytoma in a wolfdog

A malignant pheochromocytoma with multiple metastases was diagnosed in a 7-year-old male wolfdog that resulted from a cross between an eastern timber wolf (Canis lupus lycaon) and an Alaskan malamute. A yellowish white neoplastic mass approximately 10 cm diameter was found in the right adrenal gland. The neoplasm penetrated through the wall of the caudal vena cava. A diagnosis of pheochromocytoma was established by histopathologic and immunohistochemical procedures. Immunohistochemically, the neoplastic cells expressed chromogranin A, substance P, synaptophysin, Leu-7, protein gene product 9.5, methionine-enkephalin, S100 protein, and galanin. Multiple metastatic tumors were found in the kidneys, spleen, lungs, heart, and liver.

Pretreatment of a Dacron graft with tissue factor pathway inhibitor decreases thrombogenicity and neointimal thickness: a preliminary animal study

The purpose of this study was to evaluate the effects of locally applied TFPI on the reduction of neointimal thickness in Dacron grafts. Seven millimeter internal diameter 5 cm lengths of albumin coated knitted Dacron grafts were interposed in the infrarenal aorta in 14 mongrel dogs. Before implantation, the grafts were immersed in saline solution containing 200 microg/ml of TFPI (TFPI group, n = 7) or 100 IU/ml of heparin (control group, n = 7) for 15 minutes at room temperature. Three months after implantation, neointimal thickness and percentage of graft stenosis were measured by computerized planimetry. All grafts were patent 3 months after implantation. Thrombus was found in one graft in the TFPI group, but observed in three of seven control grafts. Neointimal thickness in the TFPI group was significantly smaller than that in the control group (mean +/- SD, 0.26 +/- 0.1 mm vs. 0.57 +/- 0.15 mm, p < 0.001). Percentage of graft stenosis was significantly lower in the TFPI group than in the control group (13.4 +/- 5.3% vs. 26.9 +/- 7.0%, p < 0.001). Scanning electron micrographs showed that the neointima of TFPI treated grafts were completely covered by endothelial cells. The present results indicate that locally applied TFPI reduces thrombogenicity and neointimal thickness in albumin coated knitted Dacron grafts.

Mutations in the human homologue of the Drosophila segment polarity gene patched in oral squamous cell carcinoma cell lines

In the present study, we have analyzed tumor deoxyribonucleic acid from oral squamous cell carcinoma (OSCC) cells for patched mutations using an exon-by-exon single strand conformation polymorphism assay and direct sequencing. We found two missense mutations which affected the conserved residue in the transmembrane domains of the gene product and in the intracellular loop at the C-terminal residue implicated in regulating the smoothened molecule. In addition, we demonstrated that the N-terminal fragment of sonic hedgehog (Shh-N) stimulates the growth of normal epithelial cells, the OSCC cell line, NA, and the salivary gland adenocarcinoma cell lines, HSG and HSY, which have no detectable mutation in patched. On the other hand, Shh has no effect on human SCC cells (UE, KA, KO, NI, A431 cells) that have mutations in patched. These results strongly suggest that an Shh-patched signaling is involved in the cell growth of oral epithelial cells and in the tumorigenesis of OSCCs.

Topically applied tissue factor pathway inhibitor reduced intimal thickness of small arterial autografts in rabbits

PURPOSE

The purpose of this study was to investigate whether topically applied tissue factor pathway inhibitor (TFPI) reduces intimal thickness and increases long-term patency of small arterial autografts in rabbits.

METHODS

An entire 10-mm long section of the left femoral artery was harvested and immersed in saline solution (control group, n = 10), 100 IU/mL of heparin (heparin group, n = 15), or 40 microg/mL of TFPI (TFPI group, n = 15) for 15 minutes. Then the graft was interposed to the right femoral artery. Patency rates were determined by flow measurements throughout the time course of the study, and the grafts were analyzed for measurement of intimal thickness at 3 months after operation. Immunohistochemical analysis was performed to examine whether topically applied TFPI binds to endothelial cells of the grafts.

RESULTS

Three-month postoperative patency rates were 10% in the control group, 47% in the heparin group, and 73% in the TFPI group. The TFPI group had a significantly higher patency rate than that of the control group (P <.005). Compared with the heparin group, the TFPI group had a significant reduction in intimal area (0.19 +/- 0.05 mm(2) vs 0.30 +/- 0.09 mm(2), P =.0051), in percentage of stenosis (35.7% +/- 7.7% vs 61.4% +/- 15.8%, P <.0001), and in intimal/media areas ratio (0.64 +/- 0.24 vs. 1.04 +/- 0.33, P =.0051). Immunohistologic analyses confirmed that topically applied TFPI bound to endothelial cells.

CONCLUSION

These results indicate that topically applied TFPI reduces intimal thickness and increases long-term patency of small arterial autografts in rabbits.

Functional, metabolic, and histological changes of vascular tissues after warm ischemia

We examined functional, metabolic, and histological changes in the aortic tissue of rats after the period of warm ischemia ranging from 0 to 24 hours to determine the window of time in which grafts can be optimally viable for harvest. Sixty aortas from Brown Norway rats obtained after warm ischemia were used and changes in contraction, endothelial-dependent or -independent vasodilatation, cell viability, and histology were examined. Maximal contraction induced by norepinephrine and potassium chloride decreased time-dependently after exposure to warm ischemia. The warm ischemic period when 50% of the maximal contractile response of freshly isolated arteries was preserved, ranged from 6 to 8 hours. Maximal endothelium-dependent relaxation induced by acetylcholine decreased along with the time of warm ischemia. Endothelium-independent relaxation induced by sodium nitroprusside and forskolin was unaltered for up to 9 hours. Cell viability gradually decreased, and a significant negative correlation was found between warm ischemic period (T: hours) and cell viability (V: %) (V=101.9-2.35T; r(2)=0.96; p<0.0001). Cell viability was greater than 70% within 12 hours postmortem. Histologically, after 9-hour-warm ischemia irreversible changes were detected. Results suggest that the period of warm ischemia for up to 6 hours would be acceptable for preservation of tissue viability.

Time-resolved total internal reflection fluorometry study on polarity at a liquid/liquid interface

The polarity of a water/oil (oil: cyclohexane, carbon tetrachloride, toluene, chlorobenzene, o-dichlorobenzene, or 1,2-dichloroethane) interface was investigated by means of time-resolved total-internal-reflection (TIR) fluorescence spectroscopy of a polarity-sensitive probe: sulforhodamine B (SRB). In bulk solutions, the nonradiative decay rate constant of SRB increased with an increase in a solvent polarity parameter [ET(30)], and this relationship was used to estimate the polarities of water/oil interfaces. For the oil having a relatively low solvent polarity [ET(30) < 35 kcal/mol], the polarity of the water/ oil interface agreed with that of the arithmetic average of the polarities of the two phases [ET(30)calc]. For water/odichlorobenzene and water/1,2-dichloroethane interfaces [ET(30) of the oil > 35 kcal/mol], on the other hand, the interfacial polarity determined by TIR spectroscopy was lower than the ET(30)calc. The results are discussed in terms of thickness/roughness of the water/oil interface.

The effects of vagotomy on the abomasum in calves: radiography and protein gene product 9.5 immunohistochemistry

Abomasal disorders of calves with total vagotomy, operated on at 1 week old, were investigated with radiography and protein gene product (PGP) 9.5 immunohistochemistry. Radiographic findings indicated abomasal atony with dilatation in all calves 2 weeks after vagotomy, while 4 weeks after vagotomy abomasal dilatation was detected in 2 calves and another 2 calves showed dilatation and impaction. The densities of PGP 9.5-immunoreactive nerves in the tunica muscularis decreased significantly in the corpus region of the greater curvature 2 weeks after vagotomy and in the pyloric region of the lesser curvature 4 weeks after vagotomy, and it was at its lowest 4 weeks after vagotomy in all regions examined. In conclusion, abomasal dilatation and/or impaction in vagotomized calves confirmed by radiography were related with a decreased frequency of nerves in the tunica muscularis of the abomasum.

Mouse hepatocyte growth factor activator inhibitor type 1 (HAI-1) and type 2 (HAI-2)/placental bikunin genes and their promoters

Hepatocyte growth factor (HGF) activator inhibitor type 1 (HAI-1) and type 2 (HAI-2) were recently discovered as specific inhibitors of HGF activator. Each of them contains two Kunitz-type serine protease inhibitor domains and a transmembrane domain, so that their overall structures are similar to each other. In this study, mouse genes encoding HAI-1 and HAI-2 were cloned by screening of a mouse genomic bacterial artificial chromosome library and by polymerase chain reaction of mouse genomic DNA, respectively. The genes (mHAI-1 and mHAI-2) were defined to consist of 11 and eight exons spanning 11 kbp and 9.5 kbp, respectively. Neither a TATA nor CAAT box was found in 5'-flanking regions of both genes and no apparent homologous portion was observed between mHAI-1 and mHAI-2 promoter regions. Promoter assay of mHAI-1 and human HAI-1 revealed that the potential binding sites of a complex of Egr-1-3 and Sp1, which was well-conserved between human (-42 to -58) and mouse (-44 to -57), might be a key portion of its transcriptional regulation to function as not only house-keeping but also early responsive genes.

Incomplete atrioventricular septal defect with hypoplastic left ventricle and left atrioventricular valve stenosis

A 2-month-old male infant with incomplete atrioventricular septal defect associated with a hypoplastic left ventricle and left atrioventricular valve stenosis successfully underwent biventricular repair. Echocardiography showed marked dilatation in the right ventricle and a diminutive left ventricle. However, the left ventricular chamber occupied the apex. Left atrioventricular valve stenosis was due to a solitary papillary muscle. Cardiac catheterization showed pulmonary/systemic flow ratio of 3.61, left ventricular end-diastolic volume of 63% of normal, and right ventricular end-diastolic volume of 324% of normal. During surgical repair, the solitary papillary muscle was divided longitudinally and the ostium primum was closed with a bovine pericardium. Postoperative left ventricular function was appropriate. Even when the preoperative end-diastolic left ventricular volume is small, if the left ventricle chamber is at the apex, then the left ventricular performance can be expected to be appropriate to tolerate the volume load after ostium primum closure.

Signaling pathways leading to transcription and translation cooperatively regulate the transient increase in expression of c-Fos protein

The mechanisms by which growth factors trigger signal transduction pathways leading to the regulation of c-Fos expression are of great interest. In this study we investigated the effect of hepatocyte growth factor (HGF/SF) and epidermal growth factor (EGF) on the expression of c-fos and its product, c-Fos, in human epithelial cell line MKN74. The expression level of c-Fos protein in HGF/SF-stimulated cells was 5--10-fold higher than that in EGF-stimulated cells, whereas the level of c-fos mRNA induced by HGF/SF was similar to that by EGF. The hyperphosphorylation of eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), indicative of an increased number of translation initiation complexes, was detected only in HGF/SF-induced MKN74 cells. Activation of phosphatidylinositol-3'-OH kinase and FKBP12-rapamycin associated mammalian target of rapamycin (FRAP/mTOR) was observed after the treatment with HGF/SF. Pretreatment with an inhibitor of either one, i.e. LY294002 for phosphatidylinositol-3'-OH kinase or rapamycin for FRAP/mTOR, completely inhibited 4E-BP1 phosphorylation and decreased the c-Fos synthesis induced by HGF/SF down to the level found in EGF-induced cells. These results suggest that the phosphorylation of 4E-BP1 is stimulated by HGF/SF in a manner requiring both phosphatidy-linositol-3'-OH kinase-dependent and FRAP/mTOR-dependent pathways, thereby stimulating c-fos mRNA translation. Regulation of the translation process of c-fos mRNA in addition to the immediate activation of c-fos transcription is necessary for the transient increase in the level of c-Fos protein to stimulate cell proliferation.

Antigenicity of Cryopreserved Arterial Allografts: Comparison with Fresh and Glutaraldehyde Treated Grafts

The use of cryopreserved aortic allografts in cardiovascular surgery is widespread and has resulted in excellent outcomes. However, it is controversial whether cryopreservation suppresses the antigenicity of tissue. We designed experimental models to study whether the cryopreservation process alters antigenicity in comparison with that found in fresh and glutaraldehyde treated tissues. Fresh, cryopreserved, and glutaraldehyde treated thoracic aorta from Brown Norway rats were subcutaneously implanted into Lewis rats. Inflammatory cells infiltrating around the grafts were measured on days 7, 14, 28, and 56 after implantation. The glutaraldehyde treated grafts showed significantly less infiltration than the fresh or cryopreserved grafts (p < 0.005). No significant difference was detected between the fresh and cryopreserved grafts. Another study examined the effect of modifications of the aortic allograft on subsequent allogeneic skin graft antigenicity. Subcutaneous implantation of fresh, cryopreserved, and glutaraldehyde treated aortic grafts from Brown Norway into Lewis rats resulted in subsequent skin graft rejection at 4.4+/-0.7, 5.1+/-0.8, and 6.6+/-2.1 days, respectively. There was no significant difference between the fresh and cryopreserved groups; whereas skin grafts in the glutaraldehyde group survived longer than those in the cryopreserved group. These results indicate that cryopreservation had no significant influence on antigenic suppression of arterial allografts.

Abnormal neurochemical asymmetry in the temporal lobe of schizophrenia

Neuroanatomical asymmetries are known to be present in the human brain, and loss of reversal of these asymmetries, particularly through changes in the left temporal lobe, have been found in the brains of patients with schizophrenia. In addition to disturbed neuroanatomical asymmetries, disturbed neurochemical asymmetries have also been reported in the brains of patients with schizophrenia. However, in the temporal lobe, the laterality of most of these neurochemical changes has not been specifically evaluated. Few neurochemical studies have addressed left-right differences in the superior temporal gyrus (STG). A deteriorated serotonin2A receptor-G protein qalpha (Gqalpha)-phosphoinositide-specific phospholipase C beta1(PLC beta1) cascade has been found in the left, but not right, STG of patients with schizophrenia. Not only neuroanatomical but also neurochemical evidence supports the loss or reversal of normal asymmetry of the temporal lobe in schizophrenia, which might be due to a disruption of the neurodevelopmental processes involved in hemispheric lateralization.

[Simultaneous mitral and aortic valvuloplasty using rasping procedure for combined valvular disease: a case report]

We reported a case of successful simultaneous mitral and aortic valvuloplasty using rasping procedure. A 55-year-old woman with combined valvular disease received this operation. Postoperatively, the mitral valve area increased from 1.15 cm2 to 2.03 cm2. Mitral regurgitation improved. Aortic valve pressure gradient decreased from 21 mmHg to 0 mmHg. Aortic regurgitation also improved. Cardiac Index (CI) increased from 1.94 l/min./m2 to 2.59 l/min./m2. Ejection fraction (EF) also increased from 60% to 82%. The postoperative course was uneventful. Excellent postoperative results of this procedure may be expected, not only in single valvular disease but also in combined valvular disease.

Treatment of VX2 carcinoma implanted in the liver with arterial and intraperitoneal administration of oily anticancer agents

PURPOSE

Long-term survival and cure cannot be achieved in patients with unresectable, advanced abdominal cancer, because no chemotherapeutic treatment has definite antitumor activity for malignant solid tumor and its dissemination. In this study, arterial and intraperitoneal administration of oily anticancer agents, which have properties that permit targeted chemotherapy for VX2 carcinoma implanted in the liver, was attempted to achieve long-term survival.

MATERIALS AND METHODS

Rabbits bearing VX2 tumors in the liver measuring 1-2 cm in diameter received an arterial injection of 0.2 ml of nitrogen mustard N-Oxide (HN2-O) dissolved in Lipiodol (7.5 mg/ml), a newly developed oily anticancer agent, for the tumor and an intraperitoneal injection of a cocktail of oily anticancer agents for the prevention of intraperitoneal dissemination.

RESULTS

Twelve out of thirteen rabbits survived and VX2 cancer was not observed in these 12 rabbits. The controls received a sham operation, an intraperitoneal injection of the cocktail of oily anticancer agents alone, or an arterial injection of HN2-O/Lipiodol alone. In these control groups, 27 out of 29 rabbits died of cancer. To examine the dose form for arterial injection, 14 rabbits received an arterial injection of the simple mixture of HN2-O dissolved in physiological saline and Lipiodol, with an additional intraperitoneal injection of the cocktail. Eight of these 14 rabbits died of enlargement of the hepatic tumor and peritoneal dissemination.

CONCLUSION

Long-term survival and cure was achieved in almost all rabbits bearing VX2 tumor in the liver by simultaneous arterial and intraperitoneal injection of oily anticancer agents.

[Indications and results of aortic valve repair]

With the development of prosthetic valves with excellent hemodynamics and durability, aortic valve replacement has become the first choice in the surgical treatment of valve disease. The significant improvement in mortality rates after open-heart surgery has resulted in a demand not only for good hemodynamics but also for a better postoperative quality of life. Because mechanical prosthetic valves are associated with postoperative complications and patients receiving them must remain on anticoagulant therapy for life, and bioprosthetic valves are not sufficiently durable, valve repair techniques are being reevaluated and new ones developed. The indications for valve repair have been extended in mitral valve disease due to the decreased incidence of rheumatic valve disease and increase in degenerative tissue valve disease. Reports indicate that both acute and long-term postoperative results are superior after valve repair compared with valve replacement. Similarly, although some reports on the results of aortic valve repair indicate that the standard techniques do not yield satisfactory long-term results, others suggest that newer techniques may improve the results in both the acute and long-term, chronic phase.

Consumption coagulopathy associated with aneurysms of the abdominal aorta and the bilateral femoral arteries. Report of a case

The authors report a case of a 70-year-old man, with repeating episodes of systemic subdermal hematoma due to consumption coagulopathy associated with abdominal aortic aneurysm and the bilateral femoral arterial aneurysms. Prior to the first operation for abdominal aortic repair, anticoagulation therapy was applied to treat thrombocytopenia and hypofibrinogenemia. Five years following the first surgery, the same treatment was required before resection of the femoral lesions. Consumption coagulopathy is seen in approximately 1-4% population of aortic aneurysms, however, repeated appearance of symptomatic coagulopathy is rarely reported. Anticoagulation therapy was effective to normalize the coagulation and fibrinolytic system and followed by uneventful surgical resection of the aneurysms.

Hrs and hbp: possible regulators of endocytosis and exocytosis

The molecular mechanisms of endocytosis and exocytosis are not yet fully understood. Hrs and Hbp, two tightly associated proteins in eukaryotic cells, have been implicated in these cellular processes. Hrs is homologous to Vps27p, an endosomal protein required for vacuolar and endocytic trafficking in yeast. Hrs is localized to early endosomes and is required for the normal morphology of early endosomes in mammalian cells. Hrs also associates with proteins implicated in endocytosis and exocytosis such as SNAP-25 and Eps15. Hrs treatment inhibits neurotransmitter release in permeabilized neuronal cells and its overexpression inhibits internalization of transferrin. Overexpression of dominant-negative Hbp mutants inhibits ligand-induced downregulation of growth factor/receptor complexes and immunoglobulin E receptor-triggered degranulation of secretory granules in mast cells. These observations suggest an important role for the Hrs/Hbp protein complex in vesicular trafficking during endocytosis and exocytosis.

Interaction between Smad anchor for receptor activation and Smad3 is not essential for TGF-beta/Smad3-mediated signaling

Regulation of subcellular localization of Smad proteins is supposed to be critical for the effective initiation and maintenance of TGF-beta signaling. Recently, Smad anchor for receptor activation (SARA) has been identified as a Smad2 binding protein. SARA regulates the subcellular localization of Smad2 and is required for TGF-beta/Smad2-mediated signaling. In this study, we determined whether the interaction between SARA and Smad3 is essential for TGF-beta/Smad3-mediated signaling. We found that a mutant Smad3 (Smad3NS) that lacked the binding to SARA was phosphorylated by TGF-beta type I receptor at the similar level to that in wild-type Smad3 (Smad3WT). Smad3NS also formed complexes with Smad4 and translocalized into the nucleus. Moreover, Smad3NS and Smad3WT equally enhanced TGF-beta-induced transcription. Therefore, these findings indicate that, in contrast to SARA/Smad2 interaction, SARA/Smad3 interaction is not essential for TGF-beta/Smad3-mediated signaling.

[Evaluation of superior transseptal approach for the removal of left atrial myxoma]

We compared the operative outcomes among 14 patients who underwent the removal of left atrial myxoma with four different approaches; right lateral (n = 2), transseptal bi-atrial (Dubost, n = 4), conventional transseptal (n = 4) and superior transseptal approach (STA, n = 4). Concomitant operations were performed in 4 cases (CABG, two; aortic valvuloplasty, one; mitral valve replacement, one), and two out of 4 cases were in the STA group. The mean operation, cardiopulmonary bypass and aortic cross-clamp times were shorter in the STA group compared to the other three group. The total amount of postoperative drain discharge and the peak value of creatine kinase were also lower in the STA group compared to the other three groups. Among the patients in sinus rhythm before operation, the use of STA was associated with a greater incidence (100%) of postoperative atrial fibrillation or junctional rhythm. These rhythm disturbances were temporary, and all returned to sinus rhythms during hospital stay. We conclude that STA is an excellent approach with a nice surgical view to expose and remove the left atrial myxoma.

XAFS in a single macrophage cell

In this paper, a novel approach using XAFS will be introduced for the study of the problem of cytotoxicity of metal ions. A micro beam from a SR source was used to measure the time-dependent distributions and chemical states of elements in mouse macrophages that were cultured in metallic solutions of different concentration. It is revealed that the concentrations and distributions of calcium, zinc and potassium in a single cell are closely related to the uptake of the metal. Using XAFS analysis, it is shown that metal elements absorbed by the cell interact with the cell and that the chemical state of the metal is changed.

Patch reconstruction of the mitral annulus for active infective endocarditis with annular abscess

Active infective endocarditis is associated with high operative mortality and morbidity. The outcome may be improved by operating at the optimal time using the most appropriate surgical procedure. We describe a 15-year-old man with active infective endocarditis of the mitral valve associated with an annular abscess. Disseminated intravascular coagulation was associated with progressive decrease in the platelet count. The abscess was debrided, the mitral annulus was patch-reconstructed using bovine pericardium treated with glutaraldehyde, then the mitral valve was replaced. The patient was discharged from intensive care unit 3 days after operation with clinical and blood examination improvement. The patient is being observed carefully by periodic follow-up echocardiography, and there is no evidence of PVD, PVE or calcification of the patch during 14 months of follow-up period. Patch reconstruction of the annulus using bovine pericardium treated with glutaraldehyde reinforced the annulus and prevented local reinfection of the prosthesis in this patient.

Water structures in ion-exchange resin particles: solvation dynamics of Nile Blue A

The structures of water, partitioned in cation-exchange resin particles, were studied on the basis of fluorescence dynamics of Nile Blue A (NB). The fluorescence lifetime of NB in the resin was longer than that in water and increased with increasing cross-linking density of the resin (rho). The results demonstrated that the water structures in the resin were significantly different from those in water and dependent on rho. A study on solvation dynamics of NB in the resin, reflecting structured water around the ion-exchange group, revealed the roles of "bound water" molecules in the water structures, since the solvent relaxation time (tauS) in the resin was much longer than that in water and depended on p; tauS increased from 34 to 55 ps with increasing rho from 2 to 8%. The origin of the rho dependence of tauS was discussed in terms of the separation distance between the ion-exchange groups, and the effects of the counterion of the ion-exchange group on the solvation processes were also discussed.

Differentiation-Associated Expression of ß-N-Acetylgalactosaminylated N-Linked Oligosaccharides in Mammary Epithelial Cells

Not only mammalian pituitary glycoprotein hormones but also many glycoproteins from a variety of animal species have been shown to contain N-linked oligosacchardies with the GalNAcbeta1 --> 4GlcNAc structure. Two types of beta-1,4-GalNAcT were found; one transfers N-acetylgalactosamine to acceptor oligosaccharides, which is stimulated by the hormone peptide and the other simply transfers sugar without such activation. In the case of bovine mammary membrane glycoproteins, the expression of beta-N-acetylgalactosaminylated N-linked oligosaccharides was associated with the functional differentiation of the epithelial cells. In contrast, the expression level of such oligosaccharides was much reduced in glycoprotein samples from human breast tumors compared with those from the unaffected regions. These results strongly suggest that the beta-N-acetylgalactosaminylation is one which is regulated under cellular differentiation and dedifferentiation of the mammary gland. Whether or not beta-N-acetylgalactosaminylated N-linked oligosaccharides have unique functions in addition to clearance of the hormone from the circulation remains to be elucidated.

Genome analysis of adenovirus type 7 and adenovirus type 11

PURPOSE

To study the epidemiology of adenovirus type 7 (Ad 7) conjunctivitis and adenovirus type 11 (Ad 11) conjunctivitis in the Japanese population by determining the genome type and sub-genome type.

METHODS

For Ad 7, we used 12 strains from patients with acute viral conjunctivitis and one strain from a patient with pneumonia. For Ad 11, we used 17 strains from patients with acute viral conjunctivitis and 3 strains from patients with cystitis. For Ad 7 genome typing, we used 11 DNA restriction endonucleases (REs) recognizing 6-or 7-base pair sequences, and for Ad 11 genome typing, we used 7 REs. For Ad 7 and Ad 11 sub-genome typing, we used Taq I and Hinf I that recognize 4- or 5-base pair sequences.

RESULTS

The 13 Ad 7 strains all belonged to the same genome type and sub-genome type (Ad 7dH1T1). Adenovirus type 11 strains showed six genome types, with Ad 11p being the most frequent strain. Fifteen Ad 11p strains showed three sub-genome types, but none was the same as the prototype.

CONCLUSIONS

Adenovirus type 7 seemed quite stable and an epidemic may occur again. On the other hand, Ad 11 showed several different types. This finding suggests that Ad 11 did not cause an epidemic in Japan during the first half of the 1990s.

Immunolocalization of gastrin-releasing peptide in the bovine uterus and placenta

Gastrin-releasing peptide (GRP), a mammalian homologue of amphibian bombesin, has been suggested to be a novel regulatory peptide in the reproductive tract during pregnancy. In this study, the localization of GRP in the bovine uterus and placenta was demonstrated by immunohistochemistry. Uterine and placental samples were collected from nonpregnant and pregnant specimens, respectively. Tissue sampling was done from the caruncle and intercaruncle of the uterus, and from the placentome (caruncle and cotyledon) and intercotyledon of the placenta. In all the tissues examined, GRP was detected although its immunoreactivity was observed at various degrees. In the uterus, moderate immunoreactivity for GRP was observed in the uterine gland epithelial cells. In the placenta, strong immunoreactivity for GRP was demonstrated in the uterine gland epithelial cells; moderate in superficial epithelial cells; and weak in the trophoblasts, trophoblastic giant cells and cryptal epithelial hybrid cells. In both nonpregnant and pregnant animals, GRP was immunolocalized in the uterine gland secretions and was found predominantly in the supranuclear region of the uterine gland epithelial cells. These findings may suggest that GRP is secreted into the uterine lumen and regulates the intrauterine environment of both the nonpregnant and pregnant bovine by exocrine, autocrine and/or paracrine manner.

Hepatocyte growth factor activator inhibitor type 1 is a specific cell surface binding protein of hepatocyte growth factor activator (HGFA) and regulates HGFA activity in the pericellular microenvironment

Hepatocyte growth factor activator (HGFA) is responsible for proteolytic activation of the precursor form of hepatocyte growth factor in injured tissues. To date, two specific inhibitors of HGFA have been identified, namely HGFA inhibitor type 1 (HAI-1) and type 2 (HAI-2)/placental bikunin (PB). Both inhibitors are first synthesized as integral membrane proteins having two Kunitz domains and a transmembrane domain, and are subsequently released from cell surface by shedding. Here we show that an active form of HGFA is specifically complexed with membrane-form HAI-1, but not with HAI-2/PB, on the surface of epithelial cells expressing both inhibitors. This binding required the enzyme activity of HGFA. The selective binding of HGFA to the cell surface HAI-1 was further confirmed in an engineered system using Chinese hamster ovary cells, in which only the cells expressing HAI-1 retained exogenous HGFA. The binding of HGFA to HAI-1 was reversible, and no irreversible modifications affecting the enzyme activity occurred during the binding. Importantly, HAI-1 and the HGFA.HAI-1 complex were quickly released from the cell surface by treatment with phorbol 12-myristate 13-acetate or interleukin 1beta accompanying the generation of 58-kDa fragments of HAI-1, which are less potent against HGFA, as well as significant recovery of HGFA activity in the culture supernatant. This regulated shedding was completely inhibited by BB3103, a synthetic zinc-metalloproteinase inhibitor. We conclude that HAI-1 is not only an inhibitor but also a specific acceptor of active HGFA, acting as a reservoir of this enzyme on the cell surface. The latter property appears to ensure the concentrated pericellular HGFA activity in certain cellular conditions, such as tissue injury and inflammation, via the up-regulated shedding of HGFA.HAI-1 complex. These findings shed light on a novel function of the integral membrane Kunitz-type inhibitor in the regulation of pericellular proteinase activity.

Comparison of Sepsis-related Organ Failure Assessment (SOFA) score and CIS (cellular injury score) for scoring of severity for patients with multiple organ dysfunction syndrome (MODS)

OBJECTIVE

To evaluate the usefulness of cellular injury score (CIS) and Sepsis-related Organ Failure Assessment (SOFA) score for determination of the severity of multiple organ dysfunction syndrome (MODS).

DESIGN

A prospective observational study.

SETTING

A medical and surgical intensive care unit (ICU) of a teaching hospital.

PATIENTS

Forty-seven consecutive MODS patients.

MEASUREMENTS AND RESULTS

SOFA score and CIS were measured every day for 12 months for 47 MODS patients. Comparison was made of the SOFA score and CIS for usefulness in the scoring of severity of MODS in 26 survivors and 21 non-survivors. In addition, receiver operating characteristics (ROC) analysis was used to determine the usefulness of these two indexes as predictors of prognosis. No significant differences were found on admission between the survivors and non-survivors, but significant differences between the two subgroups (p < 0.001) were found in maximum value within 1 week after admission and maximum value during the course of treatment for both indexes. Analysis of changes after admission indicated that significant differences between survivors and non-survivors began to appear on day 3 of admission for both indexes; at that time SOFA score began to deteriorate in the non-survivors while CIS began to improve in the survivors. ROC analysis demonstrated that the area under the ROC curve was 0.769 for SOFA scores and 0.760 for CIS.

CONCLUSIONS

Both SOFA score and CIS sequentially reflected the severity of MODS. Furthermore, they were comparable in diagnostic value as predictors of prognosis. These findings may indicate the possibility that MODS is a summation of effects of cellular injury. In addition, sequential evaluation of both SOFA score and CIS would provide a more accurate prediction of prognosis than conventional methods.

A deubiquitinating enzyme UBPY interacts with the Src homology 3 domain of Hrs-binding protein via a novel binding motif PX(V/I)(D/N)RXXKP

Hrs-binding protein (Hbp) is a Src homology 3 (SH3) domain-containing protein that tightly associates with Hrs. Hbp together with Hrs is thought to play a regulatory role in endocytic trafficking of growth factor-receptor complexes through early endosomes. Association of Hbp with a binding partner(s) via the SH3 domain seems to be essential for Hbp to exert its function. In this study, we searched for Hbp-binding proteins by a far Western screening and isolated a mouse cDNA clone encoding a deubiquitinating enzyme mUBPY as an Hbp SH3-binding protein. mUBPY has two Hbp-SH3 domain binding sites. Mutagenic analysis identified a consensus sequence PX(V/I)(D/N)RXXKP as the Hbp-SH3 domain binding motif. It is a novel SH3-binding motif and does not contain the canonical proline-rich consensus binding motif, PXXP. Ubiquitination of growth factor receptors is thought to regulate their intracellular degradation. Thus, UBPY may play a regulatory role in the degradation by interaction with the SH3 domain of Hbp via the novel SH3-binding motif.

Involvement of hrs binding protein in IgE receptor-triggered exocytosis in RBL-2H3 mast cells

Hrs binding protein (Hbp) tightly associated with Hrs is thought to play a regulatory role in vesicular trafficking during endocytosis and exocytosis. In this study, we have expressed dominant-negative mutants of Hbp to evaluate their effects on the degranulation of secretory granules in RBL-2H3 mast cells. The dominant-negative mutants of Hbp significantly inhibited IgE receptor (FcepsilonRI)-triggered secretory response as tested by beta-hexosaminidase release. These results suggest that Hbp functions as a regulator in the FcepsilonRI-triggered degranulation of secretory granules in mast cells.

Activation of hepatocyte growth factor/scatter factor in colorectal carcinoma

Activation of hepatocyte growth factor/scatter factor (HGF/SF) in the extracellular milieu is a critical limiting step in the HGF/SF-induced signaling pathway mediated by Met receptor tyrosine kinase, which has potentially important roles in tumor biology and progression. However, little is known concerning the regulation of HGF/SF activation in tumors. Immunoblot analysis revealed that the activation of HGF/SF was enhanced significantly in colorectal carcinoma tissues compared with the corresponding normal mucosa. Serum-free conditioned media of cultured human colorectal carcinoma cell lines contained HGF/SF-activating activity, and the addition of a single-chain precursor form of HGF/SF to the serum-free culture of these cells resulted in HGF/SF-dependent modulation of cellular phenotypes, such as increased scattering and enhanced secretion of vascular endothelial growth factor. This processing activity was enhanced by thrombin treatment but was inhibited significantly by a neutralizing antibody against HGF activator (HGFA), a factor XIIa-like serine proteinase believed to be expressed mainly in the liver. The activity was also inhibited by recombinant HGFA inhibitor type 1 (HAI-1). The presence of HGFA mRNA and secretion of HGFA protein were confirmed in the cell lines. Therefore, extrahepatic expression of HGFA in the colorectal carcinoma cells could be responsible for the single-chain HGF/SF-processing activity of the cells. We examined the expression of HGFA and HAI-1 in human colorectal mucosa and adenoma-carcinoma sequence. Immunohistochemically, HGFA was stained weakly in the normal enterocytes, and immunoreactivity was increased modestly in the neoplastic differentiation. The subcellular localization of HGFA immunoreactivity was altered in carcinoma cells showing basal or cell-stroma interface staining patterns, compared with normal and adenoma cells with a supranuclear or apical staining pattern. In contrast to HGFA, the expression of HAI-1 decreased significantly in carcinoma cells relative to the adjacent normal or adenoma cells, indicating that the net balance between HGFA and HAI-1 shifts in favor of HGFA in carcinomas. In fact, pro-HGFA and the active form of HGFA proteins increased in carcinoma tissue compared with the corresponding normal mucosa. It was concluded that HGFA is expressed in colorectal mucosa and tumors and could be involved in the activation of HGF/SF in colorectal carcinomas. Therefore, the balance between HGFA and HAI-1 could play an important role in the regulation of HGF/SF activity in colorectal carcinomas.

[Vascular anastomoses in free jejunal reconstruction to the neck vessels: an experience of consecutive 20 cases without using surgical microscope]

Twenty consecutive cases of pharyngoesophageal cancer who underwent free jejunal reconstruction were reported. The common carotid or external carotid artery was used for a feeder of the free graft. The internal jugular vein were served as a drainage vein. All anastomoses were performed in an end-to-side fashion without using surgical microscopes. Mean carotid artery clamping time was 16 minutes and no neurological complications were noticed postoperatively. Graft failure was occurred in 1 patient. The presenting technique, showing 95% success rate, is recommended as a simple option for vascular anastomosis in free jejunal reconstructive surgery.

Augmentation of mitochondrial reduced glutathione by S-adenosyl-L-methionine administration in ischemia-reperfusion injury of the rat steatotic liver induced by choline-methionine-deficient diet

We examined whether warm ischemia-reperfusion (I/R) damage of the rat steatotic liver can be reduced by administration of S-adenosyl-L-methionine (SAMe). We examined the effect of SAMe on the mitochondrial reduced-glutathione (GSH) pool. Sixty minutes of partial left lobar vascular clamping followed by 2 h of reperfusion were employed for a model of hepatic warm ischemia. Either 5% dextrose or SAMe was injected intraperitoneally 2 h before I/R in steatotic rats (S-D5% or S-SAMe group). Serum liver enzyme concentrations 2 h after reperfusion were significantly lower in the S-SAMe group than in the S-D5% group. The cytosolic and mitochondrial GSH concentrations after I/R were significantly higher in the S-SAMe group than in the S-D5% group (p < 0.05). The cytosolic and mitochondrial oxidized-glutathione/GSH ratios after I/R were significantly greater in the S-D5% group than in the S-SAMe group (p < 0.01). The adenosine triphosphate concentration was higher in the S-SAMe group than in the S-D5% group (p = 0.0515). These results show that hepatocellular and mitochondrial oxidative stress after I/R in the steatotic liver can be reduced by administration of SAMe. The results also show that mitochondrial function and hepatocellular integrity can be restored by administration of SAMe in steatotic rats.

Is upper mediastinal lymphadenectomy necessary in squamous carcinoma of the lower thoracic oesophagus?

AIM

We examined the indication of upper mediastinal lymphadenectomy for a squamous cell carcinoma of the lower thoracic oesophagus.

METHODS

49 patients underwent a curative oesophagectomy with upper mediastinal lymphadenectomy for a squamous cell carcinoma of the lower thoracic oesophagus. Node status and clinicopathological characteristics of these patients were reviewed retrospectively.

RESULTS

16 (94.1%) of 17 patients with superficial tumours had no positive node in the upper mediastinum. Nine (29.0%) of 31 patients with transmural tumours had positive nodes in the upper mediastinum (P = 0.04). Ten (20.4%) of 49 patients had many positive nodes in the upper mediastinum. Of these 10 patients, 6 patients had 5 or more positive nodes in all. The 5-year survival rate for patients with 5 or more positive nodes was 7.7%, which was significantly poorer than patients with 4 or fewer positive nodes.

CONCLUSIONS

Upper mediastinal lymphadenectomy is unnecessary in most of the superficial squamous carcinomas of the lower thoracic oesophagus.

Endosomal localization and receptor dynamics determine tyrosine phosphorylation of hepatocyte growth factor-regulated tyrosine kinase substrate

Hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) is a prominent substrate for activated tyrosine kinase receptors that has been proposed to play a role in endosomal membrane trafficking. The protein contains a FYVE domain, which specifically binds to the lipid phosphatidylinositol (PI) 3-phosphate (PI 3-P). We show that this interaction is required both for correct localization of the protein to endosomes that only partially coincides with early endosomal autoantigen 1 and for efficient tyrosine phosphorylation of the protein in response to epidermal growth factor stimulation. Treatment with wortmannin reveals that Hrs phosphorylation also requires PI 3-kinase activity, which is necessary to generate the PI 3-P required for localization. We have used both hypertonic media and expression of a dominant-negative form of dynamin (K44A) to inhibit endocytosis; under which conditions, receptor stimulation fails to elicit phosphorylation of Hrs. Our results provide a clear example of the coupling of a signal transduction pathway to endocytosis, from which we propose that activated receptor (or associated factor) must be delivered to the appropriate endocytic compartment in order for Hrs phosphorylation to occur.