Conformational sampling of CDR-H3 in antibodies by multicanonical molecular dynamics simulation

The diversity in the lengths and the amino acid sequences of the third complementarity determining region of the antibody heavy chain (CDR-H3) has made it difficult to establish a relationship between the sequences and the tertiary structures, in contrast to the other CDRs, which are classified by their canonical structures. Enhanced conformational sampling of two different CDR-H3s was performed by multicanonical molecular dynamics (multicanonical MD) simulation while restricting the base structures, with and without the other surrounding CDR segments. The results showed that the multicanonical MD sampled a much larger conformational space than the conventional MD, independent of the initial conformations of the simulations. When the other CDRs surrounding the CDR-H3 segments were included in the calculations, the predominant conformations at 300 K corresponded to the X-ray crystal structures. When only the single CDR-H3 loops were considered with the restricted base structures, a greater number of different conformations were sampled as putative loops, but only a small number of stable conformations appeared at 300 K. Analyses of the resultant conformations revealed a structural role for the glycine, when it is located at position three residues before the last residue of CDR-H3 (Gly-X-X-last residue), coincident with the statistical tendencies of many antibody crystal structures. This reflects the general consistency between the energetically stable conformations and the empirically observed conformations. The current method is expected to be applicable to the structural modeling and the design of antibodies, especially for the inherently flexible loops.

The usefulness of radiation therapy for hepatocellular carcinoma

BACKGROUND/AIMS

The usefulness of radiation therapy (RT) for hepatocellular carcinoma (HCC) is still controversial. To clarify whether RT has its role in the management of HCC as a single modality or in combination with other modalities, we analyzed the clinical features of the patients treated with RT retrospectively.

METHODOLOGY

Twenty-two patients who underwent RT for intrahepatic lesions with total dose ranging from 58 to 68 Gy were studied. Regression rate for 21 of the irradiated lesions was calculated using the computed tomographic scans.

RESULTS

After the size of the irradiated intrahepatic tumor initially decreased, it remained unchanged for a long period. Tumor size at the latest follow-up never exceeded pre-RT tumor size except in one patient who was treated by RT only. In 3 of 20 cancer deaths, the irradiated tumors were the direct cause of death.

CONCLUSION

Local RT for HCC at potentially curative dose can be performed safely in patients with preserved liver function even if they have already been treated with other therapies. Radiation therapy has a role in strengthening the therapeutic efficacy when combined with other therapy.

Hepatic venous hemoglobin oxygen saturation predicts regenerative status of remnant liver after partial hepatectomy in rats

This study was designed to evaluate the use of hepatic venous hemoglobin oxygen saturation (ShVO2) as an indicator of hepatic oxygen supply-demand relation and also regenerative status of the liver after partial hepatectomy in rats. We assessed the ShVO2 levels for 7 days, as well as hepatic hemodynamics, oxygen consumption, DNA synthesis and energy charge of the remnant liver for 3 days after 50% hepatectomy or sham operation. Total hepatic oxygen consumption (HVO2) per liver weight, hepatic oxygen extraction ratio (HO2ER), and DNA synthesis were significantly elevated at days 1 and 3 after hepatectomy, compared with the preoperative levels. Meanwhile, significantly decreased ShVO2 levels were observed at days 1 and 3, and the ShVO2 levels were significantly correlated with the HVO2. Furthermore, the decreased ShVO2 levels were synchronized with the increased DNA synthesis in the remnant liver. Energy charge levels were also significantly decreased at day 1 after hepatectomy. These results suggest that the regenerating liver demands an increased amount of oxygen for mitochondrial oxidative phosphorylation to restore hepatic energy charge. In conclusion, the ShVO2 after hepatectomy may reflect oxygen metabolic status in the remnant liver and could be useful for estimating liver regeneration.

A case of Guillain-Barré syndrome associated with human parvovirus B19 infection

We report a 4-year-old boy who presented with Guillain-Barré Syndrome 11 days after the onset of erythema infectiosum. The illness resolved without gamma globulin therapy.

A compact molecular-beam epitaxy apparatus for in situ soft X-ray magnetic circular dichroism experiments

An economical and easily movable molecular-beam epitaxy (MBE) apparatus which prepares magnetic ultrathin films and superlattices with atomically well controlled interfaces has been designed and constructed. Cleaning and characterization of substrates, sample deposition in a layer-by-layer fashion, and characterization of samples both during and after growth can be carried out in a single ultrahigh vacuum (UHV) chamber. This MBE apparatus is combined with UHV high-field magneto-optical instruments for in situ soft X-ray magnetic circular dichroism experiments on two-dimensional magnetic systems.

Morphometry in the cytologic evaluation of thyroid follicular lesions

BACKGROUND

The current study was undertaken to evaluate the quantitative estimation of cytologic features on aspirated smears for the preoperative differential diagnosis of follicular lesions of the thyroid.

METHODS

The subjects were 60 patients with follicular lesions of the thyroid (including 20 follicular carcinomas, 15 follicular adenomas, and 25 adenomatous goiters) whose histopathologic explorations were conducted fully postoperatively. Using a microscope connected to a computerized video system, the mean nuclear area, the mean nuclear perimeter, the circular rate, the largest to the smallest dimension ratio (LS ratio) of the nuclei, and the coefficient of variation of the nuclear area (NACV) were measured and analyzed.

RESULTS

Among the quantitative morphometric parameters of nuclei, the circular rate was significantly higher in the group with adenomatous goiters than those with follicular carcinomas (P < 0.00001) and adenomas (P < 0.005). The group with follicular carcinomas had a higher LS ratio than the group with adenomatous goiters (P < 0.0005). The NACV value increased as the malignant potential of the lesion increased and showed significant differences between the groups. When a NACV of 21.5% was chosen as the cutoff point, the incidence of malignancy was significantly higher in patients with high NACV values than in those with low NACV values (P < 0.00001). Using this borderline value, it was possible to distinguish malignant from benign diseases with a sensitivity of 85.0%, a specificity of 82.5%, and an accuracy of 83.3%.

CONCLUSIONS

Preoperative quantitative estimations of cytologic nuclear features are useful for the preoperative differential diagnosis of follicular lesions of the thyroid.

Surgery for local pelvic recurrence after resection of rectal cancer

This retrospective study evaluated outcome with regard to procedure, local control, and survival after curative surgical resection with and without preoperative radiotherapy for local pelvic recurrence. A total of 58 consecutive patients with local pelvic recurrence of rectal cancer after previous curative resection for primary tumors were reviewed. Of these, 36 underwent both initial resection and follow-up in our department; the remaining 22 had initial surgery and follow-up elsewhere. Of the 58 patients 27 underwent curative re-resection, 9 had palliative resection, and 22 were treated by conservative therapy. Among the 27 patients with curative resection 17 received preoperative radiotherapy (40 Gy) plus surgery and 10 surgery only. No patients were lost to follow-up; median follow-up time was 36.3 months. The overall rate of curative resection was 46.6%: 55.6% in our own follow-up group and 31.8% in the others. With regard to surgical procedure, abdominoperineal resection (APR) with or without sacral resection was standard following previous low anterior resection, and total pelvic exenteration (TPE) with or without sacral resection was common following APR. There was a high incidence of morbidity (71.4%) after TPE. Re-recurrence was observed in 12 (44.4%) after curative re-resection. There was local re-recurrence in 6 (22.2%). The local re-recurrence rate was 11.8% (n = 2) with radiotherapy plus surgery, and 40.0% (n = 4) with surgery alone. The estimated 5-year survival following curative re-resection was 45.6% (61.2% with radiotherapy plus surgery, 29.6% with surgery alone). Both survival and local control with radiotherapy plus surgery tended to be better than with surgery alone. Thus, in selected patients pelvic local recurrence of rectal cancer can be re-resected curably by APR or TPE (with or without sacral resection) combined with preoperative radiotherapy.

Effects of a newly developed fat emulsion containing eicosapentaenoic acid and docosahexaenoic acid on fatty acid profiles in rats

A new fat emulsion of symmetrical triacylglycerols, containing only eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) was developed. The effects of this preparation on serum and liver fatty acid composition were investigated. Male Sprague-Dawley rats were fed a fat-free oral diet for 2 wk and were then divided into two groups. Seven rats were infused for 7 d with 1 mL of the new fat emulsion, which accounted for 1% of total caloric intake. The other 7 rats received saline. Both groups of rats received a fat-free diet during the infusion. EPA and DHA decreased to one third to one fifth of normal value after 2 wk on a fat-free diet. EPA and DHA of serum and liver remained at a low level in the control group throughout the study. But in the rats administered with the new fat emulsion, EPA and DHA increased rapidly and exceeded normal values in both serum and liver after 7 d of infusion. Decreased arachidonic acid with increased 20:3n-9 resulted in the rise of the triene/tetraene (T/T) ratio to greater than 0.4, indicating an n-6 essential fatty acid deficiency in the control rats. In the group administered the new fat emulsion, however, 20:3n-9 and total content of monounsaturated fatty acids decreased significantly, and the T/T ratio was less than than 0.4 in both serum and liver. In conclusion, the intravenous use of a newly developed fat emulsion containing EPA and DHA is useful in improving the EPA and DHA status of serum and liver without any harmful effects. Beneficial effects are expected in the modulation of inflammatory and stress response.

[N-3 polyunsaturated fatty acids in surgical nutrition]

Recent surgical nutrition includes the management of mediator to induce the stress response and immune function. N-3 polyunsaturated fatty acid (n-3 PUFA) were reported to increase the survival rate, and to improve the nutritional and immune status of septic or burned animals. N-3 PUFA also inhibited the proliferation and metastasis of cancer, and improved the cancer cachexia. N-3 PUFA decreased the production of cytokine and eicosanoid originated from n-6 PUFA, and reduced the inflammatory and stress response. Cell-mediated immunity was suppressed with the reduction of cytokine. But in the stressed state, N-3 PUFA ameliorated the stress induced immunosuppression. Alteration of transcription of cytokine mRNA, changes of membrane fluidity, and reduced expression of adhesion molecule were proposed to interpret these effects. In conclusion, n-3 PUFA can be applied for the surgical patients, especially for the critically ill patients.

Clinical evaluation of nerve-sparing surgery combined with preoperative radiotherapy in advanced rectal cancer patients

BACKGROUND

Since 1984, we have studied nerve-sparing surgery (NSS) combined with preoperative radiotherapy (XRT) in patients with advanced rectal cancer to preserve the genitourinary function without compromising radicality. The present aim was to evaluate the prognosis and the postoperative genitourinary function.

METHODS

A total of 167 patients with advanced rectal cancer underwent curative nerve-sparing surgery. Among them, 60 underwent the preoperative therapy using irradiation (42.6 Gy) and tegafur suppository. Survival, local recurrence, and postoperative genitourinary function were investigated in these patients.

RESULTS

The 5-year survival rate was 80.9% and the local recurrence rate was 6.7% in the NSS+XRT group. Almost all of the patients receiving NSS could micturate spontaneously, but preservation of sexual function was not as successful.

CONCLUSIONS

Better local control and preservation of urinary function were possible in advanced rectal cancer patients by NSS+XRT.

Aggressive surgical approaches to hilar cholangiocarcinoma: hepatic or local resection?

BACKGROUND

It has been reported that surgical excision of hilar cholangiocarcinoma rather than palliative surgical therapy, chemotherapy, or radiotherapy caused prolonged survival in some patients, However, excision is associated with high operative morbidity and mortality rates, particularly when hepatic resection is also performed. The aim of this study was to evaluate the clinical implications of hepatic resection in hilar cholangiocarcinoma.

METHODS

The study involved 76 patients with hilar cholangiocarcinoma who were undergoing surgical resections. Twenty-one patients (28%) underwent a combined resection, with reconstruction of the portal vein in 20 patients and reconstruction of the hepatic artery in 7 patients. Sixty-five patients undergoing seven different types of hepatic resection with extrahepatic bile duct resection (BDR) and 11 patients undergoing BDR only were retrospectively compared for background, operative morbidity and mortality, and survival.

RESULTS

Curative resection was obtained in 5 of 11 (45%) patients undergoing local resection and in 49 of 65 (75%) patients undergoing hepatic resection (p < 0.05). The surgical morbidity rates were 34% and 27% for hepatic and local resection, respectively. The 30-day mortality and hospital mortality rates were 4.6% and 15% for hepatic resection and 0% and 0% for local resection, respectively. The 5-year survival rate was 26% for all resected patients (76 patients); it was 40% versus 0% for curative versus noncurative resections (p < 0.05). No significant difference in surgical resection rates was revealed between hepatic and local resection among resected and curative resected patients.

CONCLUSIONS

Aggressive surgical approaches to obtain curative resections could bring about a better prognosis in hilar cholangiocarcinoma independently of whether hepatic resection or local resection is performed.

Two different reactions involved in the primer/template-independent polymerization of dATP and dTTP by Taq DNA polymerase

Taq and Tth DNA polymerases catalyzed polymerization of dATP and dTTP into poly d(A-T) without requiring added primer/template (Hanaki et al., Biochem. Biophys. Res. Commun. 238, 113-118), while the Stoffel fragment of Taq DNA polymerase and delta Tth DNA polymerase with respective deletions of ca. 290 and 250 N-terminal amino acids did not. The primer/template-independent polymerization appeared to proceed via two reactions, the slow process of formation of 16-19 nt long oligo d(A-T) without primer/template and the rapid process of elongation of the oligo d(A-T) by self-priming. As the former step was more sensitive to N-ethylmaleimide than the elongation reaction, probably the formation of the oligonucleotide preceded the elongation. But when the substrates were depleted, Taq DNA polymerase degraded the high molecular weigh d(A-T) polymer to the oligomers which were resistant to the further digestion by the 5'-->3' exonuclease activity of Taq DNA polymerase. Probably, the elongation and the degradation reactions proceeded simultaneously, the former process being faster than the latter in the presence of enough dATP and dTTP.

[The surgical treatment for acute aortic dissection--a retrospective study from the statistics of affiliated hospitals of a medical school]

A retrospective study was conducted for the surgical treatment on acute aortic dissection among the cardiovascular services of 5 affiliated hospital of medical school. The total of 74 cases were operated for the last 5 years period from Jan., 1991 to Dec., 1995, in which 64 cases were classified as Type A and 10 for Type B. The average age for Type A was 58.4 years old and 10% of patients were consisted of Marfan syndrome. The most frequent complications associated with dissection was aortic regurgitation (37.5%), followed by cardiac tamponade (23.4%). The surgeries were undertaken in less than 24 hours from the onset of symptom in 45.3% of patients. The localization of initial tear as was proved by intraoperative finding was at ascending aorta in 64.0%, whereas it was found at aortic arch in 21.8% of patients. The most frequent application of operative procedure was simultaneous graft replacement of ascending aorta and aortic arch (68.7%) with the use of profound hypothermia and antegrade selective cerebral perfusion (85.4%). The overall mortality rate was 25.0%, however when compared as ascending only vs ascending + arch replacement, the later group demonstrated higher mortality rate (16.6% vs 28.9%). The majority of surgical indication for Type B was hemorrhage from the dissection and 20.0% of mortality was recorded in this group of patients.

Segments I and IV resection as a new approach for hepatic hilar cholangiocarcinoma

Major hepatic resection for biliary tract carcinoma with obstructive jaundice has been reported on as bringing about high surgical morbidity and mortality rates. It has been also revealed that the extent of hepatic resection is closely associated with the occurrence of postoperative complications. Therefore, hepatic resection, limited as much as possible to what is necessary for curative resection, should be performed according to cancer extent. We performed a new surgical approach in 3 patients with hepatic hilar cholangiocarcinoma that included total resection of hepatic segments I and IV (by Couinaud's classification) and bile duct resection with hepaticojejunostomy of 4 to 6 intrahepatic bile duct stumps. All patients underwent curative surgical resections and were discharged within 6 weeks after surgery, without any serious complications. This limited resection of hepatic segments I and IV could be an effective radical surgical procedure for hepatic hilar cholangiocarcinoma, to avoid the occurrence of postoperative liver failure.

[An operative case of primitive neuroectodermal tumor in the posterior mediastinum]

A primitive neuroectodermal tumor (PNET) is very rare and the prognosis of this tumor is poor. A 32-year-old woman complaining of dysphagia and back pain was admitted to our hospital for the posterior mediastinal tumor. The tumor originated from the muscle layer of esophagus and en bloc resection of the tumor combined with the affected part of esophagus was performed. Histopathological diagnosis of the resected tumor was PNET. She received adjuvant chemotherapy. Eight months after the surgery, recurrent tumors in the right mediastinum and the retrooperitoneal space was resected completely. But after the second surgery, dissemination occurred recurrently. These recurrent tumors revealed high sensitivity for radio-therapy. However, she died of rapid recurrence 22 months after the first surgery. In Japan, our case is the second case of PNET in the posterior mediastinum and the first case of PNET arising from the muscle layer of esophagus.

Helicobacter pylori, neutrophils, interleukins, and gastric epithelial proliferation

Infection of Helicobacter pylori causes chronic gastritis and plays an important role in the pathogenesis of gastroduodenal ulceration. H. pylori has also been suggested to be involved in the genesis of adenocarcincoma and MALT lymphoma of the stomach. H. pylori infection is associated with increased gastric epithelial proliferation, which can be reversed by a successful eradication of the organism. Although the mechanisms of increased gastric epithelial proliferation is not known, the enhanced epithelial proliferation is important in developing gastric carcinoma. Whether or not H. pylori de nove stimulates gastric epithelial proliferation is controversial, but gastric infection with H. pylori activates a mucosal inflammatory response by consisting of large numbers of polymorphonuclear and mononuclear cells, that also includes expression of various cytokines including interleukin-8. We review the mechanisms of H. pylori in enhanced gastric epithelial cell proliferation and cytokines in patients with H. pylori infection.

Resection of hepatic and pulmonary metastases in patients with colorectal carcinoma

BACKGROUND

Surgical resection of hepatic or pulmonary metastases has been accepted as appropriate therapy. However, whether aggressive surgery of both hepatic and pulmonary metastases from colorectal carcinoma is of value has not been verified in detail.

METHODS

The authors identified 156 patients who had undergone hepatic resection for colorectal carcinoma metastases. This study reviewed six of these patients who underwent resection of both hepatic and pulmonary metastases from colorectal carcinoma.

RESULTS

Five of the patients included four who underwent pulmonary resection for pulmonary metastases after initial hepatic resection for hepatic metastases and one patient who underwent hepatic metastasis resection after initial pulmonary metastasis resection. One additional patient underwent a simultaneous resection of hepatic and pulmonary metastases. The median interval between the 2 resections was 23 months. The median follow-up was 32 months after the second resection. At the time of last follow-up, 4 patients were alive and free of recurrent disease at 6, 7, 38, and 64 months, respectively, after their second resection. The remaining 2 patients died of disease at 17 and 32 months, respectively, after the second surgery.

CONCLUSIONS

The results of the current study suggest that hepatic and pulmonary resection can result in long term survival in select patients with hepatic and pulmonary metastases from colorectal carcinoma because surgery remains the only potentially curative treatment.

Aneurysm of the left sinus of Valsalva producing aortic valve regurgitation and myocardial ischemia

An aneurysm of the left sinus of Valsalva producing aortic valve regurgitation was treated by excising the aortic root including the aneurysm but leaving the aortic valve leaflets. The aortic valve was reimplanted inside a graft. Postoperative examinations revealed normal aortic valve function. In this case, the cause of aortic valve regurgitation was due to deformity of the aortic annulus. An aortic valve-sparing operation is an appropriate method for such a case.

Aggressive surgical approaches to hilar cholangiocarcinoma: hepatic or local resection?

BACKGROUND

It has been reported that surgical excision of hilar cholangiocarcinoma rather than palliative surgical therapy, chemotherapy, or radiotherapy caused prolonged survival in some patients, However, excision is associated with high operative morbidity and mortality rates, particularly when hepatic resection is also performed. The aim of this study was to evaluate the clinical implications of hepatic resection in hilar cholangiocarcinoma.

METHODS

The study involved 76 patients with hilar cholangiocarcinoma who were undergoing surgical resections. Twenty-one patients (28%) underwent a combined resection, with reconstruction of the portal vein in 20 patients and reconstruction of the hepatic artery in 7 patients. Sixty-five patients undergoing seven different types of hepatic resection with extrahepatic bile duct resection (BDR) and 11 patients undergoing BDR only were retrospectively compared for background, operative morbidity and mortality, and survival.

RESULTS

Curative resection was obtained in 5 of 11 (45%) patients undergoing local resection and in 49 of 65 (75%) patients undergoing hepatic resection (p < 0.05). The surgical morbidity rates were 34% and 27% for hepatic and local resection, respectively. The 30-day mortality and hospital mortality rates were 4.6% and 15% for hepatic resection and 0% and 0% for local resection, respectively. The 5-year survival rate was 26% for all resected patients (76 patients); it was 40% versus 0% for curative versus noncurative resections (p < 0.05). No significant difference in surgical resection rates was revealed between hepatic and local resection among resected and curative resected patients.

CONCLUSIONS

Aggressive surgical approaches to obtain curative resections could bring about a better prognosis in hilar cholangiocarcinoma independently of whether hepatic resection or local resection is performed.

Resection of hepatic and pulmonary metastases in patients with colorectal carcinoma

BACKGROUND

Surgical resection of hepatic or pulmonary metastases has been accepted as appropriate therapy. However, whether aggressive surgery of both hepatic and pulmonary metastases from colorectal carcinoma is of value has not been verified in detail.

METHODS

The authors identified 156 patients who had undergone hepatic resection for colorectal carcinoma metastases. This study reviewed six of these patients who underwent resection of both hepatic and pulmonary metastases from colorectal carcinoma.

RESULTS

Five of the patients included four who underwent pulmonary resection for pulmonary metastases after initial hepatic resection for hepatic metastases and one patient who underwent hepatic metastasis resection after initial pulmonary metastasis resection. One additional patient underwent a simultaneous resection of hepatic and pulmonary metastases. The median interval between the 2 resections was 23 months. The median follow-up was 32 months after the second resection. At the time of last follow-up, 4 patients were alive and free of recurrent disease at 6, 7, 38, and 64 months, respectively, after their second resection. The remaining 2 patients died of disease at 17 and 32 months, respectively, after the second surgery.

CONCLUSIONS

The results of the current study suggest that hepatic and pulmonary resection can result in long term survival in select patients with hepatic and pulmonary metastases from colorectal carcinoma because surgery remains the only potentially curative treatment.

Selective impairment of HCO3(-)-dependent pHi regulation by lysophosphatidylcholine in guinea pig ventricular myocardium

OBJECTIVE

The aim was to examine the effects of lysophosphatidylcholine (LPC), an amphiphilic lipid metabolite in ischemic myocardium, on intracellular pH (pH(i)) regulatory systems in guinea pig papillary muscles.

METHODS

In CO2/HCO(3-)-buffered Tyrode solution, pH(i), intracellular Na+ activity (aNai) and membrane potential of isolated guinea pig papillary muscles were measured using ion-selective microelectrode and conventional microelectrode. Standard ammonium prepulsing with 20 mM NH4Cl was used to produce an intracellular acid load, and effects of LPC on the pH(i) recovery from acidosis were evaluated in the absence and presence of a transport inhibitor.

RESULTS

LPC acidified the resting pH(i) by 0.03 +/- 0.01 pH units (n = 15, p < 0.01) concomitantly with a slight decrease in resting membrane potential and an increase in aNai in quiescent preparations. The pH(i) recovery rate from an intracellular acid load was decreased to 83 +/- 4% of the control value by 30 microM LPC (n = 8, P < 0.05) but not by 30 microM phosphatidylcholine (PC). In the presence of 10 microM 5-(N,N-hexamethylene) amiloride (HMA), a Na(+)-H+ exchange inhibitor, LPC still slowed pH(i) recovery from an intracellular acid load to 77 +/- 4% of the control (n = 5, P < 0.05). However, LPC failed to alter the pH(i) recovery rate in the presence of 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS, 0.5 mM), a Na(+)-HCO3- symport inhibitor.

CONCLUSION

LPC impairs Na(+)-HCO3- symport but not Na(+)-H+ exchange, and LPC may potentiate its arrhythmogenic action by intensifying the intracellular acidosis in ischemic myocardium.

Routes of hepatic metastasis of gallbladder carcinoma

This clinicopathologic study aims to clarify routes of hepatic metastasis of gallbladder carcinoma. Nineteen liver specimens obtained by extensive hepatectomy performed for the treatment of advanced gallbladder carcinoma were analyzed. We defined hepatic metastasis as a discrete hepatic lesion separate from the primary tumor and paid special attention to portal tracts at the margins of direct hepatic invasion. Eleven early metastatic foci were demonstrated histologically in 6 cases, most commonly in segments adjacent to the gallbladder. All cases with hepatic metastasis had direct hepatic invasion. Nine of the 11 metastatic lesions were located within the portal tracts or accompanied by invasion into the portal tracts. Because they are in continuity with areas of direct hepatic invasion, the portal tracts at the invasive margin often were involved by cancer cells that spread along these tracts. These results suggest that the most important route in development of hepatic metastasis from gallbladder carcinoma is along the portal tracts after direct hepatic invasion.

Dynamic organization of microtubules in guard cells of Vicia faba L. with diurnal cycle

Stomatal movement is regulated by changes in the volume of guard cells, thought to be mainly controlled by an osmo-regulatory system. In the present study, we examined the additional involvement of cytoskeletal events in the regulation of stomatal movement. Microtubules (MTs) in guard cells of Vicia faba L., grown under sunlight, were observed during the day and night by immunofluorescence microscopy. Cortical MTs began to be organized in a radial array at dawn and increased in numbers in the morning following the increase in the stomatal aperture size. Thereafter, MTs became localized near the nucleus and began to be destroyed from the evening to midnight, following the decrease in stomatal aperture size. These diurnal changes in MT organization were observed even two days after transfer from natural light condition to total darkness, and were accompanied by corresponding changes in stomatal aperture. The increase in stomatal aperture size in the early morning was inhibited by 50 microM propyzamide, which destroys cortical MTs in guard cells, whereas the decrease in aperture size in the evening was suppressed by 10 microM taxol, which stabilizes cortical MTs. These results suggest that radially-organized cortical MTs of guard cells may control diurnal stomatal movement.

Enhanced endothelial cell injury by activated neutrophils in patients with obstructive jaundice

BACKGROUND/AIMS

A high incidence of complications has been documented in patients with obstructive jaundice after operations. Recent reports have revealed that neutrophils are involved in the mechanism causing postoperative complications. However, there are few reports investigating the interaction between neutrophils and endothelial cells in obstructive jaundice. The aim of this study was to evaluate neutrophil-mediated endothelial cell injury in patients with obstructive jaundice.

METHODS

Patients were divided into three groups: those with normal liver, obstructive jaundice, and relief of obstructive jaundice. Neutrophils were isolated from patients individually. Human umbilical vein endothelial cells and neutrophils were co-cultured after addition of phorbol myristate acetate. The release of lactate dehydrogenase and thrombomodulin was measured in the medium.

RESULTS

Lactate dehydrogenase and thrombomodulin were released in the co-culture medium, and Eglin C, which is an elastase inhibitor, reduced the release of lactate dehydrogenase and thrombomodulin in a dose-dependent manner. The release of lactate dehydrogenase and thrombomodulin in the group with relief of obstructive jaundice was significantly higher than in the group with normal liver. There was no significant difference between the group with obstructive jaundice and the group with normal liver. The elastase activity in neutrophil suspension was similarly higher in the group with relief of obstructive jaundice than in the group with normal liver.

CONCLUSIONS

This study suggests that neutrophils in patients with obstructive jaundice are not activated before its relief. After relief of obstructive jaundice, neutrophils are strongly primed and have the potential to cause endothelial cell injury. The neutrophil "priming" in patients with obstructive jaundice may be associated with the frequent occurrence of postoperative complications.