Detection of mammosomatotroph cells and identification of the coexistence of growth hormone and prolactin within the same secretory granules in these cells using confocal laser scanning microscopy

This study was designed to examine whether mammosomatotroph cells (MS cells) can be easily detected using confocal laser scanning microscopy (CLSM) and whether the coexistence of growth hormone (GH) and prolactin (PRL) within the same secretory granule can be identified in the MS cell using CLSM. Conventional epoxy resin-embedded tissues of mixed GH- and PRL-secreting human pituitary adenomas were used for this double-labelling immunofluorescent study by CLSM. A semithin section of the tissue after plastic removal and bleaching was immunohistochemically double-stained with primary antibodies against GH and PRL, followed by secondary antibodies conjugated with Rhodamine (GH) and FITC (PRL). MS cells simultaneously showing fluorescence of both Rhodamine and FITC were easily detected by CLSM at lower magnification. At higher magnification, the coexistence of Rhodamine and FITC on the same secretory granule was identified by using a superimposed display. This finding was confirmed by immunoelectron microscopy. The CLSM technique may be useful for the study of MS cells.

Reactive antibodies in sera from pubertal and adult gingivitis patients against various Porphyromonas gingivalis antigens

This study was undertaken to determine the immunodominant antigens from Porphyromonas gingivalis which reacted with sera from patients of pubertal and adult gingivitis. The patients with cultivable P. gingivalis and the patients without cultivable P. gingivalis were compared by immunoblots. Fifty subjects participated in this study: 20 with gingivitis, 20 periodontally healthy, and 10 with adult periodontitis. The groups with gingivitis and healthy periodontium each contained 10 pubescent subjects and 10 adult subjects. P. gingivalis was isolated from 9 of 20 patients with gingivitis and from all of 10 with periodontitis by culture study. Approximate molecular weight 43 KDa fimbriae antigen, 57, 53, 46, 28 KDa antigens from outer membrane, and 57, 44, 40, 18.5 KDa antigens from sonicated extracts of P. gingivalis reacted significantly more frequently with sera from the P. gingivalis culture-positive gingivitis patients than with sera from the culture-negative patients by Fisher's exact test. A molecular weight 75, 31 KDa antigen from outer membrane and a 46 KDa antigen from sonicated extract were immunodominant in sera from adult patients with periodontitis. These findings indicate that the specific antigens which reacted with sera from P. gingivalis culture-positive patients are markers of infection with P. gingivalis. Additionally, reactivity to antigens were slightly different between sera from patients with gingivitis and those from patients with periodontitis.

Selective depletion of cyclin-dependent kinases is associated with Fas-mediated apoptosis in human leukemia T-cell lines

The Fas/Apo-1 molecule is a member of tumor necrosis factor/nerve growth factor (TNF/NGF) receptor family and is able to induce apoptosis in various type of malignant cells, including most of the human leukemia T-cells. We previously demonstrated that the Fas-resistant variants may exist in highly Fas-sensitive human leukemia T-cell lines. The surface expression of Fas antigen was unchanged in the variant cells, suggesting the requirement of the cytoplasmic mechanism to exert apoptosis. In the present study, we examined the changes in cytoplasmic proteins of the Fas-sensitive and Fas-resistant cells after stimulation with anti-Fas antibody, 2D1. In Western blotting analysis, we found that the stimulation of Fas-sensitive cells with 2D1, but not resistant variants, induced a repression of cyclin-dependent kinases (cdks), p34cdc2 and p33cdk2, along with apoptosis. There was no alteration in the expression of bcl-2, HSP70, HSP90, and cyclin proteins examined. This observation seemed specific to Fas-mediated apoptosis, because calcium ionophore A23187 or sodium azide failed to repress the expression of cdks. These results indicate that the specific depletion of cdks, most likely due to proteolysis, may play a role in Fas-mediated apoptosis.

[Assessment of myocardial fatty acid metabolism in patients with vasospastic angina using 123I-BMIPP myocardial SPECT]

Myocardial perfusion and fatty acid metabolism may be unpaired in the patients of vasospastic angina (VSA), because abnormal regional wall motion of left ventricle has been shown in some cases of VSA without apparent history of myocardial infarction. To study the clinical utility of 123I-BMIPP scintigraphy in diagnosis of myocardial ischemia in VSA, both 123I-BMIPP (rest) and 201T1 (exercise) SPECT were performed in the 20 patients of VSA diagnosed by coronary angiography. Defect scores were calculated visually from the 17 segments of myocardial images and were compared with patient's anginal history, period from last attack, numbers of attack, left ventricular (LV) ejection fraction and severity of regional LV wall motion abnormality. 123I-BMIPP SPECT images showed decreased tracer uptake in 14 cases of 20 (70%) VSA patients. Exercise 201T1 SPECT images showed decreased tracer uptake in 3 cases of 20 (15%) of patients. Severity of regional LV wall motion abnormality was correlated with defect score of BMIPP. Though total defect score of BMIPP did not correlate with patient's anginal history, number of symptoms and LV ejection fraction, correlated inversely with period from last attack. It was suggested that 123I-BMIPP myocardial SPECT images in VSA patients showed "memories" of myocardial ischemic damages induced by vasospasm. In summary, 123I-BMIPP myocardial SPECT images could be a useful test for diagnosis and evaluation of VSA.

Reduced uptake of oxidized low density lipoproteins in monocyte-derived macrophages from CD36-deficient subjects

To clarify the physiological roles of CD36 as an oxidized low density lipoprotein (OxLDL) receptor, we analyzed the monocyte-derived macrophages from normal and two CD36-deficient subjects, since we identified the molecular abnormalities (Kashiwagi, H., Y. Tomiyama, Y. Kosugi, M. Shiraga, R. H. Lipsky, Y. Kanayama, Y. Kurata, and Y. Matsuzawa 1994. Blood. 83:3545-3552; and Kashiwagi, H., Y. Tomiyama, S. Honda, S. Kosugi, M. Shiraga, N. Nagao, S. Sekiguchi, Y. Kanayama, Y. Kurata, and Y. Matsuzawa. 1995. J. Clin. Invest. 95:1040-1046). Scatchard analysis of 125I-OxLDL binding showed a linear plot and the maximum binding was lower by approximately 40% in the macrophages from subjects with CD36 deficiency than those from normal controls. Competition studies showed that the uptake of 125I-OxLDL was suppressed by OKM5, an antibody against CD36, by 53% in normal control macrophages, but not in the CD36-deficient macrophages. After incubation with OxLDL for 24 h, cholesteryl ester mass accumulation was reduced by approximately 40% in the macrophages from CD36-deficient subjects than those from normal controls. These results suggest that CD36 is one of the physiological receptors for OxLDL. Since specific binding of OxLDL was only reduced by approximately 40% in spite of the complete deficiency of CD36, several other receptors also may have some role in OxLDL uptake. Further studies will be needed to assess the quantitative role of CD36 in foam cell formation in vivo.

[Antitumor effect of MX2, a new morpholino anthracycline against C6 glioma cells and its combination effect with photodynamic therapy in vitro]

MX2, a new lipophilic morpholino anthracycline, has been reported to have superior chemotherapeutic effects to adriamycin against murine and human tumor cells. In this study the chemotherapeutic effect of MX2 against C6 glioma cells was examined as well as the photocytotoxicity of MX2 and the combination effect of MX2 and photodynamic therapy (PDT) in vitro. Colony formation is inhibited even with only 2 hour treatment with MX2 in a dose-dependent manner. In this colony forming efficiency assay the drug concentration required for 50% inhibition of colony formation for C6 glioma cells was 24.0 +/- 4.5 ng/ml. Mild photocytotoxicity of MX2 against C6 glioma cells was observed at a high concentration (100 ng/ml) of MX2 following exposure to white light but not red light. In combination, MX2 and the photosensitizer haematoporphyrin derivative (HpD) exhibited an additive cytotoxic effect against C6 glioma cells when the cells were treated with MX2 either immediately after red light illumination following incubation with HpD or at an interval of 24 hours before incubation with HpD. We conclude that MX2 may be clinically useful against malignant glioma alone, and in combination with other therapies such as PDT.

Production of tissue inhibitor of metalloproteinases-1 (TIMP-1) by human astrocytic tumors

Production of tissue inhibitor of metalloproteinases-1 (TIMP-1), a specific inhibitor of matrix metalloproteinases, was investigated in human astrocytic tumors (n = 15) and normal brain tissues (n = 3). Enzyme immunoassay indicated that TIMP-1 levels in the culture media of tumor explants were significantly higher in glioblastomas as compared with anaplastic astrocytomas, astrocytomas, and normal brain tissues. Immunohistochemistry using a monoclonal antibody against TIMP-1 demonstrated that TIMP-1 was detectable mainly in tumor cells, especially in glioblastoma. These results suggest that increased expression of TIMP-1 is associated with the malignant progression of astrocytic tumors.

CT of pulmonary metastases with pathological correlation

CT, including high-resolution CT, has become an essential means of imaging to evaluate pulmonary metastases. The underlying pathological processes of pulmonary metastases can be observed well on CT images, but they are not always specific. Several important CT features correlate with histopathological findings: (1) margin of nodule; (2) hemorrhage accompanying a metastatic nodule; (3) calcification; (4) cavitation; (5) sterilized metastasis; (6) small metastatic nodules in the lobules; (7) lymphangitic carcinomatosis; (8) tumor emboli; and (9) pleural metastases. For reasonable use of CT in pulmonary metastases, these various CT manifestations and their limitations must be understood.

Tenodesis of extensor digitorum in treatment of brachial plexus injuries involving C5, 6, 7 and 8 nerve roots

Restoration of motor function in the hand is difficult in brachial plexus injuries in which the C5, 6, 7 and 8 roots are involved, because there are insufficient motors available for transfer to restore the extensors of the fingers and wrist. We have used extensor digitorum tenodesis in 11 cases and found it effective and simple.

Capillary electrophoresis/frontal analysis for microanalysis of enantioselective protein binding of a basic drug

A new HPCE method was developed for the enantioselective determination of the unbound concentration of a basic drug under plasma protein binding equilibrium. The racemic basic drug verapamil (VER) and human serum albumin mixed solution was used as a model sample solution. The sample solution was introduced into a fused-silica capillary hydrodynamically or electrokinetically. During the electrophoresis following hydrodynamic injection, the unbound drug zone migrated apart from the sample zone and was separated into two zonal peaks with a plateau due to enantiomers by a chiral selector (trimethyl-beta-cyclodextrin) dissolved in the acidic running buffer solution (pH 2.5). By the electrokinetic introduction of the same sample solution from the anodic end, only the unbound drug entered the capillary and was separated into the enantiomers, which also gave the zonal peaks with plateau. The unbound concentration of each enantiomer was determined from the plateau peak height. The results obtained by the different methods for sample introduction agreed well with those determined by conventional ultrafiltration-chiral HPLC, which was employed as a reference method. The unbound concentration of (S)-VER was 1.7 times higher than that of the antipode. The sample size used in the present method was approximately 200 nL, which is about one-thousandth of that in the reference method. The electrokinetic introduction gave a better peak shape than the hydrodynamic introduction.

The antitumor effect of MX2, a new morpholino anthracycline, against malignant glioma cell lines and its subcellular distribution

The chemotherapeutic effect of MX2 (3'-deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin), a new lipophilic morpholino anthracycline, against rat C6 and human T98G glioma cells, was examined in vitro and in vivo. The subcellular distribution of MX2 was also studied. The drug concentrations of MX2 required for the 50% inhibition of cell growth (IC50) for C6 and T98G cells were 25.5 +/- 1.3 ng/ml and 70.6 +/- 6.8 ng/ml, respectively, which were much lower than the IC50 values for nimustine (ACNU). A C6 subline resistant to ACNU, C6/ACNU, was established by continuous exposure to graded concentrations of ACNU. The IC50 of MX2 for C6/ACNU was 28.3 +/- 2.2 ng/ml, indicating no cross-resistance to MX2. In the rats bearing the intracerebral C6 tumors, the life span was increased by about 40 to 100% after intravenous administration of MX2 at doses ranging from 1 to 3 mg/kg of body weight. Confocal laser scanning microscopy demonstrated visually the good accumulation of MX2 in the implanted intracerebral C6 tumors, as well as its predominant distribution in the cytoplasm over the nucleus in both cell lines in vitro. Ultrastructural studies also demonstrated the cytotoxic effects of MX2 against glioma cells. Our results suggest that MX2 may be a useful chemotherapeutic agent in the treatment of malignant gliomas and that confocal laser scanning microscopy is useful for the study of the cellular pharmacokinetics of anthracycline derivatives, such as MX2.

Captopril inhibits glioma cell invasion in vitro: involvement of matrix metalloproteinases

We investigated the effects of captopril on the activity of matrix metalloproteinases (MMPs) secreted by T98G glioma cells and their invasiveness in vitro. On gelatin zymography, captopril inhibited gelatinolytic activities in the culture media of T98G cells. This inhibitory effect was reversed by the presence of excess zinc. In an in vitro invasion assay, invasion into the reconstituted basement membrane (Matrigel) by T98G glioma cells was inhibited by captopril in a dose-dependent manner. This inhibitory effect was also reversed by the addition of zinc to the culture media. However, at the effective concentration of captopril for the prevention of tumor cell invasion it did not inhibit the motility, adhesion to Matrigel or proliferation of T98G cells. These findings suggest that captopril inhibits the invasiveness of T98G glioma cells due to its MMP inhibitory activity, chelating zinc ions at the active center of MMPs.

Herpes simplex virus type 2 infections presenting as brainstem encephalitis and recurrent myelitis

We describe here 3 patients with central nervous system infection caused by herpes simplex virus type 2 (HSV-2); one patient with brainstem encephalitis and two with recurrent transverse thoracic myelitis. All three patients showed increased IgG antibodies to HSV in the cerebrospinal fluid (CSF). HSV-2 DNA was demonstrated in the CSF by polymerase chain reaction (PCR) amplification. Upon treatment with acyclovir, one patient with myelitis partially recovered and the others completely recovered. It is important to recognize the wide spectrum of clinical manifestations of HSV-2 infection in the central nervous system (CNS).

[Pharmacokinetics of balofloxacin in the intraocular tissues of pigmented rabbits]

We performed the pharmacokinetics of balofloxacin in plasma and intraocular tissues in pigmented rabbits upon its oral administration. The penetrations of balofloxacin into plasma and aqueous humor of the anterior chamber reached their peaks of 6.46 micrograms/ml and 0.70 microgram/ml, respectively, and the ratio of drug concentration in aqueous humor to that of plasma was 0.12 at 1 hour after an oral administration of 20 mg/kg. Concentrations in plasma and aqueous humor of the anterior chamber reached 0.27 microgram/ml and 0.18 microgram/ml, respectively, at The T 1/2 (alpha) and T 1/2 (beta) of the drug in aqueous humor were longer than those in plasma The T 1/2 (alpha) and T 1/2 (beta) of the drug in aqueous humor were longer than those in plasma at a dose of 20 mg/kg. The concentrations in iris and ciliary body were much higher than in any other intraocular tissue in 24 hours after single administration of 20 mg/kg, and those concentrations remained at high levels for a long time.

The direct effect of injectable cyclosporine and its vehicle, cremophor, on endothelial vascular cell adhesion molecule-1 expression. Ricinoleic acid inhibits coronary artery endothelial activation

As in humans, rabbit coronary artery endothelium basally expresses vascular cell adhesion molecule-1 (VCAM-1). Treatment with parenteral cyclosporine (CsA) to prevent graft rejection in rabbits receiving heterotopic heart transplantation reduced VCAM-1 expression in coronary arteries not only in transplanted, but also in native rabbit hearts. To explore the mechanism of this effect, we co-incubated cultured human saphenous vein endothelial cells for 24 hr with CsA or its vehicle (containing polyoxyethylated castor oil, or Cremophor, and ethanol), at concentrations compatible with those achievable in plasma during administration of parenteral preparations of CsA. Cells were then stimulated with TNF alpha or IL-4 to induce VCAM-1 expression, assessed by a cell-surface enzyme immunoassay. Both CsA and vehicle inhibited IL-4-stimulated VCAM-1 expression in a dose-dependent manner (from [OD mU, mean +/- SEM] 230 +/- 5 to 165 +/- 3 for CsA 50 ng/ml, and to 181 +/- 6 for the corresponding vehicle concentration; P < 0.05 for both comparisons). To investigate whether this vehicle effect also occurs in vivo, we treated 9 New Zealand White rabbits with saline (n = 3), CsA (10 mg/kg/day, n = 3), or vehicle at corresponding doses (n = 3) for 6 weeks. Profiles of coronary arteries (> or = 48 for each group) were semiquantitatively scored (0-5) for VCAM-1 in immunostained heart cross-sections. Administration of both CsA and vehicle significantly reduced VCAM-1 expression compared with saline. Two vehicle components, ethanol and ricinoleic acid, were further evaluated directly on endothelial cells in vitro. While ethanol was ineffective, the monounsaturated fatty acid ricinoleic acid inhibited IL-4-stimulated VCAM-1 expression in a dose-dependent manner (IC50 between 10 and 100 microM). Thus, a fatty acid component of CsA vehicle exerts direct endothelial effects, potentially limiting arterial leukocyte recruitment during parenteral CsA treatment. This observation reveals a novel mechanism for CsA as an inhibitor of leukocyte-endothelial interactions, and furnishes a new potential rationale for the therapeutic action of unsaturated fatty acids in graft coronary disease.

Acute rejection accelerates graft coronary disease in transplanted rabbit hearts

BACKGROUND

The relation between episodes of acute rejection and the development of graft coronary arteriosclerosis remains controversial. We examined the hypothesis that acute rejection episodes accelerate graft coronary arteriosclerosis lesion formation in rabbit allografts.

METHODS AND RESULTS

A control group (n = 5) received cyclosporine 5 mg.kg-1.d-1 for 6 weeks after heterotopic heart transplantation. In a rejection group (n = 5), cyclosporine was omitted for 4 days at 1 and 4 weeks after transplantation. We studied cross sections of grafted hearts at 6 weeks and evaluated myocardial rejection grade, incidence, and severity and cell composition of intimal lesions in multiple coronary artery profiles. Episodic withdrawal of cyclosporine augmented myocardial rejection (International Society for Heart and Lung Transplantation grades 0, 0, 0, 0, and 1A in the control group to grades 1A, 1B, 2, 3A, and 3B in the rejection group). Episodes of acute rejection significantly increased the incidence (7.8 +/- 2.7% to 49.7 +/- 1.9%) and severity (from grade 0.10 +/- 0.04 to 0.79 +/- 0.24) of intimal thickening in graft coronary arteries. Most intimal lesions consisted of smooth muscle cells and contained various degrees of T-lymphocyte infiltration but sparse macrophages.

CONCLUSIONS

In this experimental model, episodes of acute rejection precipitated by cyclosporine withdrawal accelerated the development of graft vascular lesion formation. Activation of vascular cells and leukocyte recruitment during acute rejection may thus contribute to the pathogenesis of graft arteriosclerosis.

The association of complement activation at a low temperature with hepatitis C virus infection in comparison with cryoglobulin

Complement activation at a low temperature in vitro and cryoglobulinaemia are associated with hepatitis C virus (HCV) infection. The frequency of HCV antibody positivity determined in serum specimens that showed the cold-dependent activation of complement was 100%, whereas it was 48% among sera with cryoglobulin. On the other hand, the frequency of cold activation among HCV-infected sera was 41%, and that of cryoglobulin 48%. Cold activation was not found in any HCV- sera studied, whereas cryoglobulin was found at a frequency of 14% in HCV- sera. Cold activation was also absent among hepatitis B virus (HBV) S antigen or antibody-positive sera, except a few that were both HBV+ and HCV+. Rheumatoid factor was also frequently detected in sera with cold activation or cryoglobulin. Cold activation and cryoglobulin may be generated by common mechanisms in which a low avidity, low temperature-preferring antibody may function. In sera with cold activation, fine particles of immune complexes, which do not form precipitates, may activate the complement system. HCV is a unique virus that coexists with antibody in the serum, therefore the avidity of the antibody for the virus antigen may be low, and occasionally react only at a low temperature. This may be why the in vitro phenomenon related to immune complexes occurs specifically in HCV-infected sera.

Validity and reliability of the Japanese version of the Stress and Coping Inventory

We examined the validity and reliability of the Japanese version of the Stress and Coping Inventory (SCI) among 170 Japanese college students and 234 healthy subjects. The validity and reliability of this version of the SCI in the college student group were supported by significant test-retest correlations, relatively high internal consistency coefficients, and adequate correlations with the Coping Inventory for Stressful Situations (CISS). AS for the healthy subject group, the reliability was supported by relatively high internal consistency coefficients, although further analyses, such as test-retest, are required. The Japanese version of the SCI appears to be suitable for use among college students.

[Evaluation of the polymerase chain reaction for diagnosis of tuberculous meningitis]

Since Shankar et al used polymerase chain reaction (PCR) for detection of Mycobacterium tuberculosis (M. tuberculosis) in cerebrospinal fluid (CSF), there have been numerous reports on PCR assay for diagnosis of tuberculosis meningitis (TBM). The PCR assay have been recognized to be a rapid method for diagnosis of TBM, however there are problems of PCR sensitivity when dealing with CSF samples containing small amount of M. tuberculosis DNA. Comparing direct PCR with nested PCR, we studied on the evaluation of PCR for diagnosis of TBM. In present study the nested PCR were positive in all CSF specimens from 4 patients with TBM, but we could not detect M. tuberculosis DNA by only the direct PCR. Because nested PCR amplification improved the sensitivity and specificity, the nested PCR assay will be necessary for rapid diagnosis of TBM on the clinical laboratory.

Combination assay of urinary beta-core fragment of human chorionic gonadotropin with serum tumor markers in gynecologic cancers

Ectopic production of the immunoreactive beta-subunit of human chorionic gonadotropin (IR-hCG beta) by gynecologic malignancies has been well recognized, but IR-hCG beta has not yet been established as a clinically useful tumor marker, except for germ cell tumors. We measured the concentrations of IR-hCG beta-related molecules, intact hCG, free hCG beta, and beta-CF, in the sera and urine of patients with various gynecologic cancers (cervical, endometrial, and ovarian cancers) to assess their clinical usefulness as a tumor marker in comparison with serum tumor markers such as CEA, SCC, CA125, and CA19-9. The highest incidence of IR-hCG beta was obtained in the assay for beta-CF in the urine, with positive rates of 47.7% (94 of 197) for cervical, 37.8% (14 of 37) for endometrial, and 84.4% (38 of 45) for ovarian cancers with a cut-off value of 0.2 ng/mg of creatinine. In cervical cancer, there was no significant correlation between the concentrations of urinary beta-CF and serum SCC, and 57.9% (114 of 197) of the patients were detected by the combination assay of these tumor markers. Serial determination in 22 cervical cancer patients with elevated urinary beta-CF level prior to therapy showed that its level decreased after successful treatment, but 4 of 5 patients with persistent or recurrent disease had elevated levels of urinary beta-CF. All of the ovarian cancer patients examined were detected by the combination assay of urinary beta-CF and serum CA125. The levels of urinary beta-CF showed little correlation with those of the serum tumor markers, indicating the usefulness of the combination assay of urinary beta-CF with serum tumor markers for detecting cervical and ovarian cancers.

Chemical stability of polyacrylamide-coating on fused silica capillary

The chemical stability of polyacrylamide coatings on a fused silica capillary for capillary electrophoresis was investigated with respect to temperature of capillary and pH as well as salt concentration of running buffer solution by evaluating their effects on electroosmotic mobility. The capillary covalently bonded to linear polyacrylamide through Si-C linkage was stable in buffer solutions of pH 2.3-8.0 at 30 degrees C for 30 days, whereas the capillary bonded through Si-O-Si-C linkage was damaged at pH above 4.6. The electroosmotic mobility observed in both capillaries increased with increasing temperature, though the degree of increase was smaller in the Si-C linked capillary than in the Si-O-Si-C linked capillary. The increase in the buffer concentration resulted in increased electroosmotic mobility in the Si-O-Si-C linked capillary, but no effect was observed for the Si-C linked capillary.

Experimental study of intraoperative local chemotherapy with fibrin glue containing nitrosourea for malignant gliomas

BACKGROUND

Local control of the tumor bed after removal of a tumor is one of the most important points in the treatment of malignant gliomas. This study was designed to examine whether fibrin glue is useful as a vehicle for sustained release of intraoperative local chemotherapy with nitrosourea (ACNU).

METHODS

The growth-inhibiting activity of ACNU on C6 glioma cells and ACNU released into 5-mL supernatant saline from fibrin glue containing 5 mg/mL (10 mg) of ACNU was measured in vitro. C6 tumor inoculated in rat brains was covered with fibrin glue containing either 2 mg/mL or 5 mg/mL of ACNU for 5 days, and the histologic changes were examined.

RESULTS

ACNU inhibited the growth of C6 glioma cells in a dose-dependent manner, and the drug concentration required for 50% inhibition of cell growth (IC50) was about 4 micrograms/mL with 1 hour of treatment. Although about 50% of all ACNU included in the fibrin glue was released in the first hour, an effective concentration over the value of IC50 was sustained even after 12 hours. A histologic examination showed tumor cells damaged within a depth of about 2-3 mm from the tumor surface covered with fibrin glue containing ACNU.

CONCLUSIONS

Fibrin glue may be useful as a vehicle for sustained-release chemotherapy, and intraoperative local chemotherapy with fibrin glue containing anticancer agents such as nitrosourea may be helpful in the local control of malignant gliomas.

Effect of liver intoxication by carbon tetrachloride on hepatic local disposition of oxacillin using moment characteristics as index

The effect of liver intoxication by carbon tetrachloride (CCl4) on the hepatic local disposition using oxacillin as a test drug and bovine serum albumin (BSA) as a reference substance was evaluated by single-pass bolus input method in the isolated perfused rat liver. Oxacillin and BSA were introduced into the liver from the portal vein, and the outflow concentration-time profiles of oxacillin and BSA from the rat liver into the hepatic vein were kinetically assessed by moment analysis. Liver damage was monitored by plasma SGOT, plasma SGPT, and bile flow rate. Hepatic recovery ratio FH of oxacillin increased from 50% to 80%, with an increase in liver intoxication by CCl4; whereas FH of BSA was naturally 100%. Mean transit time tH of oxacillin increased from 6 to 12 sec, with an increase in liver intoxication; whereas tH of BSA increased from 7 to 10 sec. The relative variance sigma 2/tH2 of oxacillin increased from 0.2 to 0.7, with an increase in liver intoxication; whereas sigma 2/tH2 of BSA took the value of approximately 0.4, independent of liver damage. In the relationship between the dispersion model and moments, it was shown that the blood space VB increased from 15 to 20%, the index for distribution (1 + k') of oxacillin from 1.0 to 1.5, the efficiency number RN of oxacillin decreased from 0.7 to 0.3 with the increase in liver damage, and the extent of eddy mixing was predicted to be unaffected by liver damage. The intensive increases in tH and sigma 2/tH2 of oxacillin with the liver intoxication by CCl4 were explained by increases in the extent of distribution and nonequilibrium distribution, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)