Hemodynamic measurement in the femoral head using laser Doppler

The author used a laser Doppler device to measure hemodynamics in the femoral head. Twenty-eight patients with femoral neck fractures, 16 patients with intertrochanteric fractures, and 14 patients with osteoarthritis were studied. Through a lateral approach, a small hole was drilled into the femoral head using a burr, and a probe was inserted to measure intramedullary flow. The flow measurements were high and sinusoidal in shape (corresponding with the heart rate) in all Garden 1, all Garden 2, and in four of six Garden 3 femoral neck fractures. Flow measurements were low and not sinusoidal in two of six Gardens 3 and all Garden 4 fractures. Hemodynamic values were high in all 16 patients with intertrochanteric fractures and all 14 patients with osteoarthritis. Although the posterior column arteries were cut while the intramedullary hemodynamics were being measured in patients with osteoarthritis of the hips, the measured values still were high. The postero-lateral area of the femoral head was fed compensatorily by the inferior retinacular arteries. The laser Doppler is useful in estimating circulatory compromise.

Role of citron kinase as a target of the small GTPase Rho in cytokinesis

During mitosis, a ring containing actin and myosin appears beneath the equatorial surface of animal cells. This ring then contracts, forms a cleavage furrow and divides the cell, a step known as cytokinesis. The two daughter cells often remain connected by an intercellular bridge which contains a refringent structure known as the midbody. How the appearance of this ring is regulated is unclear, although the small GTPase Rho, which controls the formation of actin structures, is known to be essential. Protein kinases are also thought to participate in cytokinesis. We now show that a splice variant of a Rho target protein, named citron, contains a protein kinase domain that is related to the Rho-associated kinases ROCK14 and ROK, which regulate myosin-based contractility. Citron kinase localizes to the cleavage furrow and midbody of HeLa cells; Rho is also localized in the midbody. We find that overexpression of citron mutants results in the production of multinucleate cells and that a kinase-active mutant causes abnormal contraction during cytokinesis. We propose that citron kinase regulates cytokinesis at a step after Rho in the contractile process.

Increased secretion of urokinase-type plasminogen activator by human lung microvascular endothelial cells

Human lung microvascular endothelial cells (HLMECs) secreted 1.5-15 times more urokinase-type plasminogen activator (uPA) antigen than human hepatic microvascular endothelial cells, human umbilical vein endothelial cells (HUVECs), angioma endothelial cells, and lung fibroblasts. All of these cells also secreted a 100-fold greater amount of plasminogen activator inhibitor-1 than of uPA antigen, and uPA activities were not detected in the culture medium. The expression of uPA mRNA in HLMECs was higher (100-fold) compared with HUVECs, angioma endothelial cells, and lung fibroblasts. HLMECs secreted uPA antigen on both the luminal and basal sides of the cells. On the other hand, HLMECs secreted a 10- to 15-fold lower amount of tissue-type plasminogen activator than HUVECs, mostly on the luminal side. After stimulation with interleukin (IL)-1beta, HLMECs secreted a six- to ninefold amount of uPA antigen. In contrast, no stimulatory effect was observed in HUVECs even under high IL-1beta concentrations. The secretion of uPA and plasminogen activator inhibitor-1 from HLMECs was also enhanced by tumor necrosis factor-alpha and IL-2. These results suggest that HLMECs may contribute not only to the patency of lung vessels but also to the maintenance of alveolar functions through the production and secretion of uPA, especially in the presence of inflammatory cytokines.

[Chronic thromboembolic pulmonary hypertension associated with initial pulmonary involvement in Takayasu arteritis]

A 37-year-old non-smoking woman was admitted to our hospital because of nocturnal coughing and exertional dyspnea after using an ultrasonic humidifier. Chest roentgenograms and computed tomography showed many ground-glass opacities in the right upper lobe and left upper lung field. Her symptoms were alleviated and erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels returned to normal following the administration of prednisolone (40 mg/day). The same symptoms subsequently recurred, and ESR and CRP levels increased proportionately to a decreased dosage of prednisolone. In addition, chest computed tomography showed new opacities in the left lower lobe. Transbronchial lung biopsy specimens revealed multiple stenotic or obstructive changes in the small pulmonary arteries by organizing thromboemboli, with no vasculitis. The diagnosis of chronic thromboembolic pulmonary hypertension was made on the basis of multiple defects from lung perfusion scintigraphy, irregular or tapering of the pulmonary arteries detected by pulmonary arteriograms, and increased pulmonary pressure measured by echocardiography. We propose that the pulmonary thromboembolism observed in this case was related to the initial pulmonary involvement of Takayasu arteritis, since the patient's symptoms, ESR and CRP levels all improved markedly following the administration of prednisolone.

Effect of acarbose on postprandial lipid metabolism in type 2 diabetes mellitus

The effect of acarbose, an alpha-glucosidase inhibitor, on postprandial glucose and lipid metabolism was investigated in patients with type 2 diabetes mellitus. Twenty patients (10 men and 10 women) with type 2 diabetes mellitus were studied. A test meal was taken with or without 100 mg of acarbose. The levels of plasma glucose, and serum immunoreactive insulin, lipids, apolipoproteins, and remnant-like particle cholesterol were investigated. Acarbose inhibited the postprandial increase of both plasma glucose and serum immunoreactive insulin. Acarbose also significantly suppressed the increase of serum triglycerides at 60, 90, and 120 min (P < 0.05 to P < 0.01), and the increase of serum remnant-like particle cholesterol at 60 and 120 min (P < 0.05). Acarbose inhibited the postprandial decline of apolipoprotein C-II, and decreased the postprandial serum apolipoprotein C-III level. These results suggest that acarbose may improve postprandial hyperlipidemia as well as postprandial hyperglycemia in patients with type 2 diabetes mellitus.

Changes in tumor marker levels as a predictor of chemotherapeutic effect in patients with gastric carcinoma

BACKGROUND

Evaluating chemotherapeutic effect in patients with gastric carcinoma sometimes is difficult. The authors investigated whether changes in the serum levels of three tumor markers can be used to predict the clinical outcome after chemotherapy.

METHODS

Thirty patients with advanced and recurrent gastric carcinoma were treated with continuous 5-fluorouracil and low dose cisplatin for 4 weeks. Thirteen patients were treated neoadjuvantly prior to gastrectomy. The serum levels of carcinoembryonic antigen, carbohydrate antigen 19-9, and sialyl-Tn antigen were measured prior to and after chemotherapy. Responders were defined as those in whom abnormal serum levels of all three markers decreased to at least 50% of the pretreatment values and remained stable for at least 1 month.

RESULTS

The tumor markers could be evaluated in 27 of 30 patients (90%). The median duration of survival for the 15 responders and 12 nonresponders was 17 months and 6 months, respectively. There was a significant difference in the median duration of survival between the responders and nonresponders using the log rank test (P=0.0005). In the patients who received neoadjuvant therapy, the eight responders had a significantly longer survival period than did the three nonresponders (P=0.018). Seven of the eight responders showed evidence of tumor destruction histologically whereas none of the three nonresponders did.

CONCLUSIONS

Changes in the serum levels of these tumor markers after chemotherapy may be an excellent prognostic indicator for patients with gastric carcinoma.

A case of Kearns-Sayre syndrome showing a constant proportion of deleted mitochondrial DNA in blood cells during 6 years of follow-up

Kearns-Sayre syndrome (KSS) and Pearson syndrome (PS) show quite different phenotypes despite the same underlying genetic defect, i.e. a large deletion of one population of mitochondrial (mt) DNA. The main feature of KSS is progressive encephalomyopathy; on the other hand, PS shows fatal hematological problems in early infancy. Through Southern blot analysis of mtDNA of blood cells, deletion has been consistently found in patients with PS but usually undetectable in KSS patients. Therefore, their different clinical phenotypes have been explained by the different tissue distribution of mutant mtDNA. Recently, a few cases were reported which had features of PS in infancy and later developed KSS. These observations suggest that phenotypes may also be modified by the selection process involving mtDNA within different tissues. We found a case of KSS, who initially presented endocrinological dysfunction such as insulin-dependent diabetes mellitus (IDDM) and growth hormone (GH) deficiency, and had not developed external ophthalmoplegia until the age of 17. Although he did not show any symptoms of PS, a marked proportion of mtDNA was deleted not only in muscle but also in blood cells. Analysis of his blood cells showed an unchanged proportion of deleted mtDNA at three estimations within 6 years of the follow-up period. This case provides evidence that deleted mtDNA in blood cells also has a stable replicative capacity and that a large proportion of deleted mtDNA in blood cells may not accompany hematological problems.

Lung volume reduction surgery for pulmonary emphysema using dynamic Xenon-133 and Tc-99m-MAA SPECT images

The usefulness of Xe-133 and Tc-99m-MAA single photon emission computed tomography (SPECT) in identifying areas to be resected during video-assisted thoracoscopic lung reduction surgery for emphysema was examined. Twenty-nine patients with advanced emphysema were examined using Xe-133 and Tc-99m-MAA SPECT prior to and following surgery. For the Xe-133 dynamic SPECT, patients inhaled Xe-133 gas for 6 minutes. Equilibrium and subsequent washout SPECT images were acquired every 30 seconds for 6 to 7 minutes during spontaneous breathing. Ventilation was quantified by Xe-133 clearance time (T1/2) in addition to visual assessment. The patients underwent unilateral thoracoscopic volume reduction in the regions with abnormal Xe-133 retention and Tc-99m-MAA defect. All patients demonstrated marked, heterogeneous Xe-133 retention and Tc-99m-MAA defects preoperatively. The worst functioning areas were identified as nonventilated and noflow areas, or areas with air trapping and low perfusion. These changes were found even in patients with diffuse and symmetrical impairments on chest CT. After surgery, most of these "target areas" disappeared and pulmonary function tests demonstrated significant improvement. T1/2 correlated closely with the percent predicted FEV1 (%FEV) and 6-minute walk distance before and after surgery (p<0.0001). Xe-133 and Tc-99m-MAA SPECT imaging was useful in identifying "target areas" in the emphysematous lung. Directed unilateral thoracoscopic volume reduction based on these SPECT images is an effective treatment for emphysema.

SNAP-25 is essential for cortical granule exocytosis in mouse eggs

Synaptosome-associated protein of 25 kDa (SNAP-25) has been shown to play an important role in Ca2+-dependent exocytosis in neurons and endocrine cells. During fertilization, sperm-egg fusion induces cytosolic Ca2+ mobilization and subsequently Ca2+-dependent cortical granule (CG) exocytosis in eggs. However, it is not yet clear whether SNAP-25 is involved in this process. In this study, we determined the expression and function of SNAP-25 in mouse eggs. mRNA and SNAP-25 were detected in metaphase II (MII) mouse eggs by RT-PCR and immunoblot analysis, respectively. Next, to determine the function of SNAP-25, we evaluated the change in CG exocytosis with a membrane dye, tetramethylammonium-1,6-diphenyl-1,3,5-hexatriene, after microinjection of a botulinum neurotoxin A (BoNT/A), which selectively cleaves SNAP-25 in MII eggs. Sperm-induced CG exocytosis was significantly inhibited in the BoNT/A-treated eggs. The inhibition was attenuated by coinjection of SNAP-25. These results suggest that SNAP-25 may be involved in Ca2+-dependent CG exocytosis during fertilization in mouse eggs.

Recombinant human granulocyte colony-stimulating factor attenuates inflammatory responses in septic patients with neutropenia

OBJECTIVE

The objective of this study was to determine the effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) administration in septic patients with neutropenia.

METHODS

Twenty consecutive septic patients were administered rhG-CSF subcutaneously (2 microg x kg(-1) x d(-1)) for 5 days (group G). They were compared with 14 septic patients treated earlier without rhG-CSF (group N). All patients in both groups met the criteria of total leukocyte count (TLC) less than 5,000/mm3 and C-reactive protein (CRP) more than 10 mg/dL. Changes in TLC, absolute neutrophil count (ANC), CRP, respiratory index (RI), Acute Physiology and Chronic Health Evaluation (APACHE) II score, and Goris's Multiple Organ Failure (MOF) index were evaluated. In addition, nucleated cell count (NCC), differentiation in bone marrow aspiration, neutrophil phagocytic and bactericidal activity, serum concentrations of interleukin-6 (IL-6) and IL-8 as inflammatory markers, and plasma concentration of leukocyte elastase (LE) as an indicator of the tissue injury were evaluated in group G.

RESULTS

In group G, TLC, ANC, NCC, and neutrophil functions increased significantly, whereas CRP, IL-6, and IL-8 decreased reciprocally. There was no deterioration of LE and RI. Consequently, the APACHE II score and MOF index improved. In group N, however, CRP showed no change concomitant with the APACHE II score and MOF index.

CONCLUSION

Administration of rhG-CSF attenuates inflammatory responses without inducing tissue injury in septic patients with neutropenia.

Modulation of ACh receptor currents by arachidonic acid

The present study investigated the effects of arachidonic acid on Torpedo (alpha beta gamma delta) and neuronal nicotinic acetylcholine (ACh) receptors (chick alpha7; rat alpha7, alpha3 beta2, alpha3 beta4, alpha4 beta2, and alpha4 beta4). Arachidonic acid (10 microM) depressed currents through normal Torpedo ACh receptors during treatment and afterward, persistently (>/=30 min) potentiated the currents. The potentiation was blocked by the selective protein kinase C (PKC) inhibitor, GF109203X or PKC inhibitor peptide (PKCI). The depression was not inhibited by any protein kinase inhibitor examined here, but greater in Ca2+-free extracellular solution. Arachidonic acid also potentiated currents through mutant Torpedo ACh receptors lacking PKC phosphorylation sites at Ser333 on the alpha subunit and Ser377 on the delta subunit without depression, but otherwise, it depressed currents through mutant receptors replacing of each Ser by negatively charged amino acid residue, possibly that mimics PKC phosphorylation of the receptors. These results suggest that the depression was due to the direct blocking effect on Ca2+-modulatory sites, which was accelerated under conditions of the receptors phosphorylated by PKC, and that the potentiation was caused by PKC activation, independently of PKC phosphorylation of the receptors. Arachidonic acid reduced currents through chick alpha7 receptors by a mechanism independent of protein kinase activation. In contrast, arachidonic acid potentiated currents through rat alpha7, alpha3 beta2, alpha4 beta2, and alpha4 beta4 receptors, perhaps by the same mechanism as the potentiation observed in Torpedo ACh receptors, although it had no effect on rat alpha3 beta4 receptors. The results of the present study thus demonstrate that arachidonic acid exerts diverse actions on nicotinic ACh receptors by different mechanisms.

ATP produces potassium currents via P3 purinoceptor in the follicle cell layer of Xenopus oocytes

Purinoceptor agonists produced potassium currents with the order of potency: ATP > adenosine = ADP = AMP > beta,gamma-methylene ATP, while a small response or no response was induced by 2-methylthio ATP, UTP, or alpha,beta-methylene ATP. The response induced by beta,gamma-methylene ATP was completely inhibited in the presence of alpha,beta-methylene ATP, suggesting that the relevant receptor for these agonists was a P3 purinoceptor. ATP induced currents with a latency of 24 s and the currents were not induced in defolliculated oocytes. The currents were not affected by either the Gi/o-protein inhibitor, pertussis toxin (PTX), or the selective cAMP-dependent protein kinase inhibitor, H-89, or the phospholipase C (PLC) inhibitor, neomycin, or the phospholipase A2 (PLA2) inhibitor, 4-bromophenacyl bromide. The currents were enhanced by the selective protein kinase C (PKC) inhibitor, GF109203X, but otherwise, they were reduced by the potent PKC activator, 12-O-tetradecanoylphorbol-13-acetate. The results of the present study suggest that a P3 purinoceptor in the follicle cell layer of oocytes is involved in activation of potassium channels and that the evoked currents are regulated by PLC/PLA2-independent PKC activation.

Patent ductus arteriosus and neonatal death in prostaglandin receptor EP4-deficient mice

The physiological role of the prostaglandin E2 receptor EP4 subtype was investigated by generation of EP4-deficient-mice by gene targeting. Loss of the EP4 receptor was not lethal in utero, but most EP4 (-/-) neonates became pale and lethargic approximately 24 h after birth and died within 72 h. Less than 5% of the EP4 (-/-) mice survived and grew normally more than a year. Histological examination revealed that the ductus arteriosus in dead neonates remained open, while it was partially closed in the survivors. In situ hybridization study showed that EP4 mRNA was strongly expressed in the ductus. These results suggest that neonatal death is at least partly due to patent ductus arteriosus and that the EP4 receptor plays a role in regulation of the patency of this vessel. They also indicate that normal function of the EP4 receptor is essential in neonatal adaptation of the circulatory system.

Correlation between serum cytokeratin 19 fragment and tissue polypeptide antigen levels in patients with non-malignant diseases

It has been reported that cytokeratin 19 fragment (CYFRA 21-1) is superior to tissue polypeptide antigen (TPA) as a tumor marker, although there is a high correlation between CYFRA 21-1 and TPA levels in patients with lung cancer. We investigated correlations between these tumor markers in patients with non-malignant diseases. Marked correlations were found between CYFRA 21-1 and TPA levels in healthy subjects (n = 31), non-insulin-dependent diabetes mellitus (n = 160) and hemodialysis patients (n = 83) (range of r-value = 0.90-0.93, P < 0.0001). However in liver cirrhosis patients (n = 36), only a weak correlation was found (r = 0.39, P < 0.0001) and there were correlations between only TPA and both aspartate aminotransferase and alanine aminotransferase levels (r2 = 0.48 and 0.36, P < 0.0001). The elevated TPA levels in liver cirrhosis patients may be related to the decreased specificity of TPA as a tumor marker.

Pentoxifylline attenuates reperfusion injury in skeletal muscle after partial ischemia

Leukocytes have been shown to contribute to ischemia-reperfusion injury in skeletal muscle. Pentoxifylline (PTXF), a xanthine-derived phosphodiesterase inhibitor, has received recent attention because of its action on leukocytes. To clarify the effects of PTXF in reperfusion injury, we measured the resting transmembrane potential difference (Em) and evaluated postcapillary venule microcirculation using intravital microscopy in rat skeletal muscle during ischemia and reperfusion. The infrarenal aorta was clamped for 90 min and then reperfused for 60 min. Persistent depolarization of the resting Em was observed in an ischemia-reperfusion (IR) group and was significantly repolarized in a PTXF group during the reperfusion period. The tissue water content was significantly reduced in the PTXF group, although no difference was noted in the tissue lactate content. Flowing erythrocyte velocity and wall shear rate in the PTXF group were significantly higher than in the IR group during the reperfusion period but without significant differences in vessel diameter and hemoglobin oxygenation. Blood flow measured by laser-Doppler flowmeter was also significantly improved in the PTXF group. Furthermore, the adherent leukocyte count was significantly reduced in the PTXF group during this same period. These results indicate that PTXF attenuated reperfusion-associated membrane injury and tissue edema and that PTXF suppressed leukocyte adhesion and improved hindlimb blood flow during the reperfusion period.

A triple coaxial catheter system for subselective visceral artery catheterization and embolization: preliminary clinical experience

We developed a triple coaxial catheter system (TCCS) which consists of a 6.1 Fr outer, a 4.1 Fr intermediate, and a 3.0 Fr inner catheter, all coated with a lubricant. The TCCS was used in seven patients with hepatic tumors, after several attempts to access a targeted vessel with conventional catheters and guidewires failed to reach the targeted vessel. No complications were encountered with the use of this system. TCCS may be a useful device for selective abdominal arteriography.

Overview of evacuation and transport of patients following the 1995 Hanshin-Awaji earthquake

We investigated how patients were evacuated and transported from affected hospitals in the disaster area to backup hospitals following the 1995 catastrophic Hanshin-Awaji earthquake. A retrospective review was conducted of medical records of 6107 patients hospitalized during the first 15 days after the earthquake, collected from 48 affected hospitals in the disaster area and 47 backup hospitals in the surrounding area. Of the 6107 patients, a total of 2290 (38%) were transferred to backup hospitals, consisting of 187 patients (50%) with crush syndrome, 702 (26%) with other traumas, and 1401 (41%) with illness. Of those 2290 patients, 1741 (76%) were transferred from affected hospitals to backup hospitals, while 549 patients (24%) were evacuated directly to backup hospitals. The peak in transport came during the first 4 days. The family car was the most frequently used means of transport; ambulance was used in only 26% of cases, and helicopters were used minimally. There was no notable difference in the percentage of intensive care patients and nonintensive care patients transferred to backup hospitals. The mortality rate for patients with trauma and crush syndrome was significantly higher in the affected hospitals. These results suggest that the existing emergency medical service system was not adequate for this urban earthquake. From our vantage point, we are keenly aware of the need for improved communications between hospitals, a well equipped patient transport system, and a well coordinated disaster response mechanism.

Adhesion polypeptides are useful for the prevention of peritoneal dissemination of gastric cancer

We examined the effect of adhesion polypeptides on the adhesion and invasiveness of gastric cancer cell lines. We previously reported the establishment of an extensively peritoneal-seeding cell line, OCUM-2MD3, from a poorly seeding human scirrhous gastric carcinoma cell line, OCUM-2M. Both alpha2beta1 and alpha3beta1 integrin expression was markedly increased on OCUM-2MD3 cells compared with OCUM-2M cells, and the ability of OCUM-2MD3 cells to bind to the extracellular matrix (ECM) was also significantly higher than that of OCUM-2M cells. The adhesion polypeptides, YIGSR and RGD, and two RGD derivatives significantly inhibited the adhesion of OCUM-2MD3 cells to the submesothelial ECM, while not inhibiting the adhesiveness of OCUM-2M cells and two well differentiated human gastric cell lines, MKN-28 and MKN-74. The YIGSR and RGD peptides also significantly inhibited the invasiveness of OCUM-2MD3 cells. The survival of nude mice with peritoneal dissemination given YIGSR sequence intraperitoneally was obviously longer than that of untreated mice. The survival of mice treated with RGD was also improved, and this effect was increased using the RGD derivatives, poly(CEMA-RGDS) and CM-chitin RGDS. These polypeptides appear to block the binding of integrins, which are expressed on OCUM-2MD3 cells, to the submesothelial ECM, and consequently inhibit peritoneal implantation. The peritoneal injection of adhesion polypeptides may be a new therapy against the dissemination of scirrhous gastric cancer, and may be useful for the prevention of dissemination in high-risk patients.

[p53 and Bax protein expression as predictor of chemotherapeutic effect in gastric carcinoma]

This study was performed to estimate p53 and Bax overexpression as a predictor of the response to chemotherapy of patients with gastric cancer. The subjects were 20 patients with stage IV gastric cancer and 3 with locally recurrent lesions treated with 5-fluorouracil (5-FU) and low-dose cisplatin (CDDP) for 4 weeks. Of the total 23 patients, there were 10 responders: 2 showing complete response (CR) and 8, partial response (PR). Carcinoma biopsy specimens of all were obtained endoscopically with anti-p53 and anti-Bax antibodies. Of the 10 responders, 7 were in the negative p53 staining group, while of the 13 non-responders, 11 were in the positive p53 staining group (p = 0.013). But no correlation was demonstrated between the chemotherapeutic effect and Bax staining alone. Moreover, among the p-53-positive cases, the patients with Bax-negative tumors were all chemoresistant. Therefore, immunohistochemical identification of p-53 and Bax prior to chemotherapy may be a useful predictor for choice of non-responders to chemotherapy.

TGF-beta1 produced by gastric cancer cells affects mesothelial cell morphology in peritoneal dissemination

In vitro morphologic change of mesothelial cells was observed following the addition of serum-free conditioned medium (SF-CM) from peritoneal dissemination cell line OCUM-2MD3. The same morphologic change of mesothelial cells was observed following the addition of 10 ng/ml TGF-beta1, but not following the addition of b-FGF, IGF-I, VEGF or PDGF-AA. In the in vivo study, mesothelial cells of mice treated with SF-CM from OCUM-2MD3 and TGF- beta1 were separated from one another, resulting in exposure of the submesothelial connective tissue. The molecular size of the mesothelial morphology changing activity was estimated by running the SF-CM from OCUM-2MD3 through a gel filtration column TSK-gel G2000SW. The mesothelial morphology changing activity was recognized at positions equivalent of Mr 6, 500-30,000. 25 kDa TGF-beta1 was detected in the active fraction from the TSK-gel G2000SW column and the SF-CM of OCUM-2MD3 by Western blotting using a monoclonal antibody against TGF-beta1. These findings suggest that TGF-beta1 produced by gastric cancer cells changes the morphology of mesothelial cells and may thus be closely associated with peritoneal dissemination.

Low glucose enhances Na+/glucose transport in bovine brain artery endothelial cells

BACKGROUND AND PURPOSE

Brain arteries are structurally characterized by the tight junctions of the endothelium and by no vasa vasorum that feed arteries themselves. This raises the question of how brain arteries are provided with glucose. A possible explanation is that glucose uptake into arteries may be mediated by both GLUT1, a facilitative glucose transporter, and a Na+/glucose cotransporter (SGLT)-like glucose transporter. The functional role for the SGLT-like glucose transporter, however, is unknown. In the present study we investigated SGLT-like glucose transporter-operated glucose uptake into brain arterial endothelial cells by recording glucose-evoked Na+ currents and monitoring uptake of [3H]-2-deoxy-D-glucose ([3H]-2-DOG).

METHODS

Endothelial cells were cultured from bovine cerebral cortical arteries. Whole-cell patches were made to cells, and glucose-evoked currents were recorded. Cells were incubated with [3H]-2-DOG, and the uptake was determined by a liquid scintillation counter.

RESULTS

Glucose and alpha-methyl-D-glucoside (alphaMeDG), a specific compound for the SGLTs, evoked Na+ currents in a whole-cell voltage-clamp configuration, and the currents were enhanced in cells with over 30 minutes' preincubation in glucose-free media. Glucose-induced currents were inhibited by alphaMeDG, by the selective SGLT inhibitor phlorizin, by dinitrophenol (DNP), an inhibitor of energy metabolism, or by deletion of Na+ from extracellular solution, which indicates that glucose uptake into endothelial cells was mediated by a Na+- and energy-dependent glucose transporter. Notably, the currents were desensitized, reduced in a glucose concentration-dependent manner, and markedly inhibited by either a second application of glucose or the addition of glucose to the patch electrode filling solution; they were potentiated, however, by treatment with cytochalasin B, a GLUT1 to GLUT5 inhibitor. Consistent with the results of patch-clamp recordings, uptake of [3H]-2-DOG into endothelial cells was enhanced by glucose-free insult, and the enhancement was mediated by an SGLT-like glucose transporter.

CONCLUSIONS

The results presented demonstrate that an SGLT-like glucose transporter takes part in glucose uptake into brain artery endothelial cells and that the uptake is regulated by intracellular glucose concentrations; glucose-free insult and the ensuing low cytosolic glucose enhance activity of the SGLT-like glucose transporter. The SGLT-like glucose transporter in the brain arterial endothelium thus may be important in the maintenance of an adequate glucose concentration in the arterial wall under conditions of stress, such as hypoglycemia.

Oxygen transport in conscious newborn dogs during hypoxic hypometabolism

We questioned whether the decrease in O2 consumption (VO2) during hypoxia in newborns is a regulated response or reflects a limitation in O2 availability. Experiments were conducted on previously instrumented conscious newborn dogs. VO2 was measured at a warm ambient temperature (30 degrees C, n = 7) or in the cold (20 degrees C, n = 6), while the animals breathed air or were sequentially exposed to 15 min of fractional inspired O2 (FIO2): 21, 18, 15, 12, 10, 8, and 6%. In normoxia, VO2 averaged 15 +/- 1 (SE) and 25 +/- 1 ml . kg-1 . min-1 in warm and cold conditions, respectively. In the warm condition, hypometabolism (i.e., hypoxic VO2 < normoxic VO2) occurred at FIO2 </=10%, whereas in the cold condition, hypometabolism occurred at FIO2 </=12%. The same results were obtained in a separate group (n = 14) of noninstrumented puppies. For all levels of FIO2 with hypometabolism, the relationships between measures of O2 availability (arterial O2 saturation or content, venous PO2 or saturation, x-axis) vs. VO2 (y-axis) had lower slopes in warm than in cold conditions. Hence, VO2 during hypometabolism in the warm condition was not the maximal attainable for the level of oxygenation. The results do not support the possibility that the hypoxic drop in VO2 in the newborn reflects a limitation in O2 availability. The results are compatible with the idea that the phenomenon is one of "regulated conformism" to hypoxia.

Systematic lymph node dissection for clinically diagnosed peripheral non-small-cell lung cancer less than 2 cm in diameter

The value of radical systematic lymphadenectomy for treatment of early-stage bronchial carcinoma is controversial. We performed a prospective randomized study to address this question. Altogether 115 patients with peripheral non-small-cell lung cancers smaller than 2 cm in diameter were enrolled in this study. They were randomly assigned into a lobectomy with lymph node sampling group (sampling group, n = 56) or a lobectomy with radical systematic lymph node dissection group (dissection group, n = 59). Inclusion criteria were based only on preoperative clinical studies. Four tumors were larger than 2 cm postoperatively. One patient had disseminated disease, and two had intrapulmonary metastases discovered at surgery. Two patients had small-cell carcinoma. There were four with pathologic N1 disease and seven with N2 disease in the dissection group and three with N1 and eight with N2 disease in the sampling group. The numbers of local and distant recurrences were two and six, respectively, in the dissection group and two and five in the sampling group. The overall 5-year survival was 81% in the dissection group and 84% in the sampling group. No significant differences in the recurrence rate or survival was seen between the groups. Our results demonstrate that clinically evaluated peripheral non-small-cell carcinomas smaller than 2 cm in diameter do not require radical systematic mediastinal and hilar lymph node dissection.

Pyoderma gangrenosum following cytosine arabinoside, aclarubicin and granulocyte colony-stimulating factor combination therapy in myelodysplastic syndrome

Pyoderma gangrenosum (PG) is a neutrophilic dermatosis, which may be associated with systemic conditions such as hematologic disorders. We present a patient who had been diagnosed as having myelodysplastic syndrome associated with PG at onset, in whom a febrile ulcerative skin lesion developed following cytosine arabinoside, aclarubicin and granulocyte colony-stimulating factor (G-CSF) combination chemotherapy in the course of the disease. Skin biopsy revealed dense neutrophilic infiltrate in the dermis with central epidermal ulceration, consistent with the diagnosis of PG. Oral prednisolone was effective for the skin lesion. In this case, G-CSF application may participate in the recurrence of PG.

Na+-dependent and phlorizin-inhibitable transport of glucose and cycasin in brain endothelial cells

Although cycasin (methylazoxymethanol beta-D-glucoside) is proposed to be a significant etiological factor for the prototypical neurodegenerative disorder Western Pacific amyotrophic lateral sclerosis and parkinsonism-dementia complex, the mechanism underlying transport of cycasin across the blood-brain barrier (BBB) is unknown. We examined cycasin transport in cultured bovine brain endothelial cells, a major element of the BBB. Cycasin was taken up into endothelial cells in a dose-dependent manner with maximal uptake observed at a concentration of 10 microM. Cycasin uptake was significantly inhibited by alpha-methyl-D-glucoside, a specific analogue for the Na+-dependent glucose transporter (SGLT), by the SGLT inhibitor phlorizin, by replacement of extracellular NaCl with LiCl, and by dinitrophenol (DNP), an inhibitor of energy metabolism. In addition, cycasin produced inward currents in a whole-cell voltage clamp configuration. Peak currents were observed at 10 microM with a trend toward reduction at higher concentrations, and currents were clearly blocked by alpha-methyl-D-glucoside, phlorizin, and DNP. In addition, cycasin never evoked currents in Na+-free extracellular solution. These results suggest that cycasin is selectively transported across brain endothelial cells, possibly across the BBB by a Na+/energy-dependent glucose transporter.