Significance of manipulating intratumor hypoxia in the effect on lung metastases in radiotherapy,with reference to its effect on the sensitivity of intratumor quiescent cells

Purpose To evaluate the effect of manipulating intratumor hypoxia during radiotherapy on lung metastasis, referring to its effect on the sensitivity of quiescent tumor cells. Materials and Methods B16-BL6 melanoma tumor-bearing C57BL/6 mice were continuously given 5-bromo-2′-deoxyuridine (BrdU) to label all proliferating (P) cells. They received γ-ray irradiation following loading with the acute hypoxia-releasing agent nicotinamide or local hyperthermia at mild temperatures (MTH). Immediately after the irradiation, cells from some tumors were isolated and incubated with a cytokinesis blocker. The sensitivity of quiescent (Q) cells was assessed in terms of the micronucleus frequency using immunofluorescence staining for BrdU. That of the total (=P + Q) tumor cell population was determined from BrdU non-treated tumors. In other tumor-bearing mice, 17 days after irradiation, macroscopic lung metastases were enumerated. Results In the total cells, a more marked enhancement in sensitivity was observed with nicotinamide than MTH. In Q cells, MTH combination induced a more marked enhancement than nicotinamide. Both nicotinamide and MTH reduced the size of the hypoxic fraction in the two cell populations, especially nicotinamide in the total cells and MTH in Q cells. Without γ-ray irradiation, nicotinamide loading tended to decrease the number of lung metastases. With γ-ray irradiation, nicotinamide loading and MTH, especially the former, reduced the number of metastases more than γ-ray irradiation only. Conclusion Hypoxia manipulation in solid tumors has the potential to influence lung metastases. Notably, acute hypoxia-releasing nicotinamide may be promising for reducing the number of lung metastases.     

Identification of treatment strategies for Mycoplasma genitalium-related urethritis in male patients by culturing and antimicrobial susceptibility testing

Mycoplasma genitalium was first isolated from urethral swab specimens of male patients with non-gonococcal urethritis. However, the isolation of M. genitalium strains from clinical specimens has been difficult. Co-cultivation with Vero cells is one available technique for the isolation of M. genitalium. The strains that can be used for antimicrobial susceptibility testing by broth dilution or agar dilution methods are limited. Macrolides, such as azithromycin (AZM), have the strongest activity against M. genitalium. However, AZM-resistant strains have emerged and spread. Mutations in the 23S rRNA gene contribute to the organism’s macrolide resistance, which is similar to the effects of the mutations in macrolide-resistant Mycoplasma pneumoniae. Of the fluoroquinolones, moxifloxacin (MFLX) and sitafloxacin have the strongest activities against M. genitalium, while levofloxacin and ciprofloxacin are not as effective. Some clinical trials on the treatment of M. genitalium-related urethritis are available in the literature. A doxycycline regimen was microbiologically inferior to an AZM regimen. For cases of treatment failure with AZM regimens, MFLX regimens were effective.     

Pharmacological characterization of α2D-adrenergic receptor-mediated [S]GTPγS binding in rat cerebral cortical membranes

Using the rat cerebral cortical membranes that had once been frozen and stored at -80 degrees C, the stimulation of specific guanosine-5'-O-(3-[(35)S]thio)triphosphate ([(35)S]GTPgammaS) binding mediated through alpha(2)-adrenergic receptors (alpha(2)-ARs) was pharmacologically characterized. The stimulatory effects of (-)-noepinephrine ((-)-NE) and 5-bromo-6-(2-imidazolin-2-ylamino)-quinoxaline (UK-14,304) at maximally effective concentrations were prominent only in the presence of micromolar to submillimolar levels of GDP, with the greatest signal/noise ratio achieved at 100 and 30-100 microM GDP for (-)-NE and UK-14,304, respectively. The alpha(2)-AR-mediated [(35)S]GTPgammaS binding was also critically dependent on the presence of millimolar concentrations of MgCl(2) in assay medium. The maximum stimulation induced by UK-14,304 was equivalent to, or even greater than, that of an endogenous ligand (-)-NE at lower concentrations of NaCl, while it became a partial agonist with higher concentrations of NaCl. Concentration-response curves for several agonists revealed that the omission of NaCl from incubation buffer generally shifted the curves leftward and increased the relative efficacies as compared to the endogenous ligand. The pharmacological profile characterized with a series of adrenergic agonists and antagonists indicated that this response was derived from activation of G proteins coupled with alpha(2)-ARs, in particular alpha(2D)-AR subtype, though the possible involvement of alpha(2C)-ARs was not completely excluded. However, the stimulatory effects of several adrenergic compounds, such as rauwolscine and yohimbine, were ascribed to their agonist properties at 5-HT(1A) receptors. This method serves as a simple but useful strategy for investigating the functional interaction between alpha(2D)-ARs and their coupled G proteins in rat native cerebral cortical membranes, especially in the field of psychopharmacology and biological psychiatry.     

Arsenic (V) induces a fluidization of algal cell and liposome membranes

Arsenate is one of the most poisonous elements for living cells. When cells are exposed to arsenate, their life activities are immediately affected by various biochemical reactions, such as the binding of arsenic to membranes and the substitution of arsenic for phosphate or the choline head of phospholipids in the biological membranes. The effects of arsenate on the life activities of algae Chlorella vulgaris were investigated at various concentrations and exposure times. The results demonstrated that the living activities of algal cells (10(10)cells/L) were seriously affected by arsenate at a concentration of more than 7.5mg As/L within 24h. Algal cells and the artificial membranes (liposomes) were exposed to arsenate to evaluate its effects on the membrane fluidization. In the presence of arsenate, the membranes were fluidized due to the binding and substitution of arsenate groups for phosphates or the choline head on the their membrane surface. This fluidization of the biological membranes was considered to enhance the transport of toxicants across the membrane of algal cells.     

Epithelial-cadherin Gene Is Not Mutated in Ductal Carcinomas of the Breast

We investigated mutations of the epithelial (E)-cadherin gene and loss of heterozygosity (LOH) at flanking loci using three microsatellite markers on the long arm of chromosome 16 in 25 ductal carcinomas of the breast. Expression of E-cadherin was also investigated immunohistochemically. No mutations were detected in exons 6 through 9 of the E-cadherin gene. LOH was observed more frequently (42%) at D16S402 (16q-ter) than at D16S421 (16q22.3-q23.1) (17%), which is located near the E-cadherin gene. Expression of E-cadherin was observed at the cell borders in 92% (11/12) of the tumors examined. The absence of mutations in the E-cadherin gene and its conserved expression suggest that inactivation of E-cadherin does not contribute significantly to the invasion or metastatic potential of ductal carcinomas of the breast. Furthermore, the high frequency of LOH at 16q-ter suggests the existence of another tumor suppressor gene which may play a crucial role in the genesis of ductal carcinomas of the breast.     

Endovascular treatment for poorest-grade subarachnoid hemorrhage in the acute stage: has the outcome been improved?

OBJECTIVE: Patients with poor-grade subarachnoid hemorrhage (SAH) have been considered good candidates for endovascular treatment. The results of treatment of Grade V SAH, the poorest grade, however, have not been fully elucidated. METHODS: The clinical characteristics and outcome parameters of 22 World Federation of Neurosurgical Societies Grade V SAH patients treated endovascularly in the acute stage between 1998 and 2000 are summarized and compared with those of 18 Grade V SAH patients treated conservatively between 1995 and 1997. RESULTS: Among the 22 patients treated endovascularly, 8 patients (36.4%) survived. The rate was significantly higher than that of the 18 patients treated conservatively (5.6%), only one of whom survived. The favorable outcome rate, however, was not significantly different between the two groups (4.5% versus 6.0%). Subdivision of both treatment groups according to Glasgow Coma Scale (GCS) score showed that the improved survival among those treated endovascularly was attributable to the improved survival in those with a preprocedural GCS score of 6 but not of 4 or 5. CONCLUSION: Endovascular treatment of the 22 World Federation of Neurosurgical Societies Grade V SAH patients improved their survival rate but not their favorable outcome rate in comparison with conservative treatment. Further accumulation of clinical data is essential to determine whether endovascular treatment can improve the functional outcome of those with GCS scores of 6 and whether there is no role for endovascular treatment in those with GCS scores of 4 or 5.     

Surgery of the liver and pancreas in Japan--message to the special symposium commemorating Dr. Ichio Honjo

About half a century ago, Ichio Honjo performed successful right hepatic lobectomy following ligation of the right hepatic artery and the right branch of the portal vein. That was the world's first successful case of right hepatic lobectomy with preliminary hilar ligation of the right branches of both the hepatic artery and portal vein. In the same year, Honjo carried out a total pancreatectomy for pancreatic cancer for the first time in Japan. Since then, marked progress in the surgical fields of the liver and pancreas has been made and appear to have nearly reached the pinnacle. Surgeons in the late half of the 20th century attempted to extend operative interventions and expand surgical fields while devoting themselves to treating incurable diseases. Therefore the period may be called the "challenging era." We are entering the era of evaluation and selection of the procedures most suitable to both the disease stage and each individual patient.     

Three-dimensional reconstruction of biliary tract using spiral computed tomography for laparoscopic cholecystectomy

To increase the safety of laparoscopic cholecystectomy, we have analyzed the biliary tract in a three-dimensional fashion. The union of the biliary ducts was studied in 50 patients using spiral computed tomography (CT) after intravenous infusion cholangiography. Depending on the union and course of the cystic duct to the common bile duct, cystic duct anatomy was classified into six categories: ipsilateral gallbladder side (type I) and contralateral side with anterior course (type II); contralateral side with posterior course (type III); intrahepatic side (type IV); intrapancreatic side (type V); and unclassified (type VI). The length of the cystic duct was also determined. The cystic duct was identified in 42 cases (84%); 30 cases (60%) were type I, 9 cases (18%) type III, and a single case (2%) of types II, IV and V, respectively. The length of the cystic duct was < or =2 cm in 30 cases that had a shorter operating time compared to 12 cases with a cystic duct <2 cm (p <0.01). In conclusion, three-dimensional reconstruction of the cystic duct anatomy using spiral CT provides simple classification of bile duct anatomy, and this preoperative information may increase the safety of laparoscopic cholecystectomy.