5-Aminolevulinic acid induced endogenous porphyrin fluorescence in 9L and C6 brain tumours and in the normal rat brain

A new approach in photodynamic therapy is the use of endogenous porphyrins for sensitisation of tumours to light. The induction of endogenous porphyrins after intravenous injection of 5-aminolevulinic acid (ALA, 200 mg kg-1) was studied in 23 rats, bearing intracranial 9L or C6 tumours. After 0, 2, 4, 6, 8, and 22 hours the rats were sacrificed and the fluorescence distribution of endogenous porphyrins was studied in brain tissue sections with a standard fluorescence microscope and a confocal laser scanning microscope. The role of blood-brain barrier disruption on porphyrin production was studied in 2 rats with a cryo-lesion of the cortex. Additionally, 9L and C6 tumour cell cultures were incubated with ALA for 8 hours in vitro. Fluorescence was measured with a fluorescence spectrophotometer in cell cultures and in the brain sections. Porphyrins were detected in vitro in the tumour cells from 2 hours onwards and ex vivo in the tumour sections mainly from 2 to 8 hours, by 22 hours porphyrin fluorescence had almost disappeared. The contralateral brain showed low fluorescence levels between 2 and 6 hours after ALA administration. At the site of the cryo-lesions low fluorescence was measured 6 hours after ALA administration. The 9L tumours fluoresced homogeneously, with a sharp demarcation towards normal brain tissue. Fluorescence in the C6 tumours was patchy, with a poorly fluorescing edge. In both tumour models fluorescence was also detected in brain surrounding the tumour and sometimes in contralateral white matter and ventricle ependyma and pia mater. The slight increase of porphyrin fluorescence in the normal brain of tumour bearing rats, compared to the absence of this in rats without a tumour, was attributed to transport by bulk flow of porphyrins made in the tumours, and possibly also of circulating porphyrins or ALA leaking from the tumour vessels.     

Growth kinetics and treatment response of the intracerebral rat 9L brain tumor model: a quantitative in vivo study using magnetic resonance imaging

We report the use of magnetic resonance imaging (MRI) for in situ tumor growth rate studies of experimental intracranial 9L tumors. T2-weighted spin-echo coronal magnetic resonance images of rat brains with 9L tumors were obtained every 2 days beginning at 8-11 days postimplantation using a 7 tesla MRI system. Tumors were clearly delineated in the images as a hyperintense region with a relatively well-demarcated border and minimal peritumoral edema. Tumor volumes from individual slices were summed together to yield the total tumor volume. The accuracy of this methodology for volumetric determination was verified by MRI phantom studies. Tumor growth rates determined from sequential MRI measurements of tumor volumes were quantitated in terms of volumetric doubling time. Tumor doubling times were found to range from 50 to 81 h, with an average of 66 +/- 8 h (n = 10). Intracranial 9L tumors were found to grow exponentially over the entire life span of the animal, allowing treated animals to serve as their own controls since the volumetric doubling time could be determined from three to four MRI scans before treatment administration. The intracerebral tumor growth delay following a single injection of 1, 3-bis(2-chloroethyl)-1-nitrosourea (13.3 mg/kg i.p.) allowed for noninvasive determination of in vivo log cell kill. A 2.0 +/- 0.2 (n = 3) log cell kill from 1,3-bis(2-chloroethyl)-1-nitrosourea treatment was found from post-treatment MRI volume measurements. These results demonstrate that MRI provides a powerful and sensitive method for assessing the growth and treatment response of intracranial 9L tumors in the rat.     

Taxol induces concomitant hyperphosphorylation and reorganization of vimentin intermediate filaments in 9L rat brain tumor cells

Taxol, a microtubule stabilizing agent, has been extensively investigated for its antitumor activity. The cytotoxic effect of taxol is generally attributed to its antimicrotubule activity and is believed to be cell cycle dependent. Herein, we report that taxol induces hyperphosphorylation and reorganization of the vimentin intermediate filament in 9L rat brain tumor cells, in concentration- and time-dependent manner. Phosphorylation of vimentin was maximum at 10(-6) M of taxol treatment for 8 h and diminished at higher (10(-5) M) concentration. Enhanced phosphorylation of vimentin was detectable at 2 h treatment with 10(-6) M taxol and was maximum after 12 h of treatment. Taxol-induced phosphorylation of vimentin was largely abolished in cells pretreated with staurosporine and bisindolymaleimide but was unaffected by H-89, KT-5926, SB203580, genistein, and olomoucine. Thus, protein kinase C may be involved in this process. Hyperphosphorylation of vimentin was accompanied by rounding up of cells as revealed by scanning electron microscopy. Moreover, there was a concomitant reorganization of the vimentin intermediate filament in the taxol-treated cells, whereas the microtubules and the actin microfilaments were less affected. Taken together, our data demonstrate that taxol induces hyperphosphorylation of vimentin with concomitant reorganization of the vimentin intermediate filament and that this process may be mediated via a protein kinase C signaling pathway.     

Altered response to histamine in brain tumor vessels: the selective increase of regional cerebral blood flow in transplanted rat brain tumor

The authors studied the effect of intracarotid administration of histamine on the regional cerebral blood flow (rCBF) in transplanted rat C6 glioma by the hydrogen clearance method. Histamine infusion at doses of 1 and 10 micrograms/kg/min produced an increase of rCBF in the tumor (24.6% +/- 16.4%, p < 0.002, and 37.6% +/- 18.2%, p < 0.0001, respectively) and also in brain surrounding the tumor (26.8% +/- 16.2%, p < 0.002, and 34.9% +/- 9.2%, p < 0.0001, respectively) without any significant changes in the ipsilateral hemisphere. Intravenous administration of pyrilamine (H1 antagonist) and cimetidine (H2 antagonist) reduced blood flow responses to histamine; cimetidine was a more effective blocking agent than pyrilamine. Intracarotid infusion of histamine (1 and 10 micrograms/kg/min) with intravenous injection of Evans blue dye disclosed the selective extravasation of dye in the tumor and the brain surrounding the tumor. These results indicated that brain tumor vessels could respond to histamine differently than normal brain capillaries. The mechanism of selective response to histamine could be explained either by increased permeability or by altered characteristics of histamine receptors in the tumor vessels.     

Effect of defibrination on tumor growth and response to chemotherapy

Other investigators have demonstrated fibrin deposition in tumors. Experiments were therefore designed to test whether systemic defibrination would alter tumor growth or tumor response to chemotherapy with cyclophosphamide. Defibrination with Ancrod, a venom extract of Agkistrodon rhodostoma, did not significantly affect tumor sensitivity to chemotherapy. Similarly, defibrination plus fibrinolytic therapy with streptokinase did not affect responsiveness to cyclophosphamide. Long-term defibrination did not affect tumor growth. These results suggest three possible interpretations: (a) the coagulation system may not be important in tumor growth and response to chemotherapy; (b) adequate clearing of fibrin from the tumor was not accomplished in our experiments; or (c) other factors such as platelet deposition may be involved and platelet function was not inhibited by the therapies used in our experiments.     

The effect of radiation therapy on the kinetics of in vitro lymphocyte response to mitogens

Iridotomies were made in rabbit and human eyes using a continuous wave argon laser. Several of these have been studied histologically to determine the short- and long-term effects on the iris, cornea, lens and retina. Thirty-three eyes of patients with angle-closure glaucoma were treated by argon laser iridotomy and followed for periods of up to twelve months. In two eyes, planned cataract surgery was performed shortly after the laser iridotomy and histologic specimens of the iris were examined. From the experimental and clinical studies, an evaluation was made of the complications and clinical usefulness of the continuous wave argon laser as a means to produce iridotomies for the treatment of angle-closure glaucoma. Further long-term controlled studies are recommended to document the role of laser iridotomy.     

Ga-67 used to localize the tumor bed for radiation therapy after lumpectomy

The authors present a new method to locate the tumor bed after lumpectomy. The method relies on accumulation of Ga-67 at the surgical site. This technique was useful in identifying the tumor bed in six candidates for breast conserving surgery and radiation therapy. This method may be applicable in other soft tissue malignancies that require postoperative radiation.     

A study on thallium-201 SPECT in brain metastases of lung cancer: with special reference to tumor size and tumor to normal brain thallium uptake ratio

The activity of prolyl endopeptidase (PEP), a serine proteinase, has been found to be significantly lower in the blood of patients with major depression than in normal volunteers. The present study investigates plasma PEP activity in 25 major depressed, 10 manic, and 14 schizophrenic subjects versus 30 normal volunteers. It also examines the effects of antidepressants, valproate, and neuroleptic drugs on plasma PEP activity. PEP activity was significantly lower in major depressed subjects than in normal volunteers and in patients with mania and schizophrenia. In depressed subjects, plasma PEP activity was significantly increased during treatment with antidepressant drugs, such as fluoxetine. Plasma PEP activity was significantly increased in manic and schizophrenic subjects compared with normal volunteers. In manic subjects, short-term treatment with valproate had a significant suppressive effect on PEP activity. No significant effects of neuroleptics on PEP activity could be found in the schizophrenic patients. The results support the hypothesis that lower PEP activity could play a role in the pathophysiology of major depression, while increased PEP activity may be related to psychotic conditions, such as mania and schizophrenia.     

Differential activation of p38 mitogen-activated protein kinase and extracellular signal-regulated protein kinases confers cadmium-induced HSP70 expression in 9L rat brain tumor cells

We have reported that treatment with CdCl2 at 40-100 microM induces the heat shock proteins (HSPs) in 9L rat brain tumor cells, during which the activation of heat shock factor (HSF) is essentially involved. By exploiting protein kinase inhibitors, we further analyzed the possible participation of specific protein kinases in the above processes. It was found that induction of HSP70 in cells treated with a high concentration of cadmium (i.e. 100 microM) is preceded by the phosphorylation and activation of p38 mitogen-activated protein kinase (p38(MAPK)), while that in cells treated with a low concentration (60 microM) is accompanied by the phosphorylation and activation of extracellular-regulated protein kinases 1 and 2 (ERK1/2). In 100 microM cadmium-treated cells, both HSP70 induction and HSF1 activation are eliminated in the presence of SB203580, a specific inhibitor of p38(MAPK). By contrast, in 60 microM cadmium-treated cells, the processes are not affected by SB203580 but are significantly suppressed by PD98059, which indirectly inhibits ERK1/2 by acting on MAPK-ERK kinase. Taken together, we demonstrate that p38(MAPK) and ERK1/2 can be simultaneously or independently activated under different concentrations of cadmium and that the signaling pathways participate in the induction of HSP70 by acting on the inducible phosphorylation of HSF1. We thus provide the first evidence that both p38(MAPK) and ERK signaling pathways can differentially participate in the activation of HSF1, which leads to the induction of HSP70 by cadmium.     

Glial tumor cell proliferation and immune response in the brain

Absence of the maxillary lateral incisor creates an aesthetic problem which can be managed in various ways. The condition requires careful treatment planning and a consideration of the options and outcomes following either space closure or prosthetic replacement. Recent developments in restorative dentistry have warranted a re-evaluation of the approach to this clinical situation. Factors relating both to the patient and to the teeth, including the presenting malocclusion and the effect on the occlusion, are considered. This review considers the possible options: no treatment; orthodontic space closure with canine modification; space maintenance and replacement of the missing tooth with denture, bridge (adhesive and conventional), or implant.     

Clinical pharmacokinetics of carboplatin and MCNU in malignant brain tumor and normal brain tissues

We measured the concentrations of MCNU and CBDCA in the serum, brain tumor and normal brain tissue. Six patients with malignant glioma were treated with intravenous chemotherapy using 80mg/m2 MCNU and 300mg/m2 CBDCA during surgery. After drug administration, specimens of serum, tumor and normal brain tissue were collected every 30 min and then the drug concentration in each sample was measured. The highest MCNU levels in all samples were obtained immediately after administration which followed by gradual decrease. On the contrary, the mean CBDCA levels in the tumor and normal tissue remained almost at a constant level, although serum CBDCA level declined rapidly as MCNU. As expected, MCNU seemed to have advantages in the treatment of brain tumors as it distributed with higher concentration in the tumor tissue than in the serum and normal brain tissue. On the contrary, CBDCA in the tumor tissue did not exceed the concentration in the serum. Nevertheless, it remained longer in the tumor tissue with a constant level, suggesting that CBDCA can achieve an effective area under the concentration versus time curve (AUC) in the brain tumor tissue to kill tumor cells.     

The response of lymph node metastases of testicular teratoma to radiation therapy

The age-dependent changes in reducible collagen cross-links, Schiff bases and their precursors were followed for human bone and articular cartilage throughout the whole life span from 3 to 89 years of age. With aging, the reduced Schiff bases dihydroxylysinonorleucine remarkable decreased, wheras hexitollysine peaks increased significantly in both collagens. Dihydroxynorleucine, the precursor of the cross-link, was found to increase slightly with age. But the changes in hydroxylysinonorleucine and lysinonorleucine were comparatively small. These changes were discussed in relation to the increased insolubility observed in both collagens at higher age.     

The optimal combination of hyperthermia and carbogen breathing to increase tumor oxygenation and radiation response

PURPOSE: To determine the most effective combination of carbogen breathing with mild temperature hyperthermia (MTH) to increase the oxygenation and radiation response in murine tumors. METHODS AND MATERIALS: MTH at 41.5 degrees C for 60 min was applied by immersion of the tumor in a precisely controlled water bath. The tumor pO2 was measured with a polarographic microelectrode. The radiation response of the tumor was determined using the in vivo/in vitro assay for surviving tumor cells. RESULTS: In the FSaII fibrosarcoma the median pO2 increased from a control value of 6.5 +/- 0.5 mm Hg to 16.6 +/- 1.1 mm Hg immediately after MTH and was 10.9 +/- 1.3 mm Hg 24 h later. Carbogen breathing for 5 min increased the FSaII pO2 to 19.9 +/- 2.1 mm Hg. Carbogen breathing for 5 min beginning immediately after MTH increased the median pO2 more than 5 times to 35.4 +/- 3.8 mm Hg. This combined treatment also substantially increased the response of the tumors to a radiation exposure of 20 Gy. In another tumor model, the SCK mammary carcinoma, MTH treatment increased the median pO2 from the control level of 4.4 +/- 0.2 mm Hg to 12.6 +/- 1.2 mm Hg, and it returned to 4.3 +/- 0.3 mm Hg 24 h later. Carbogen breathing for 5 min increased the SCK tumor pO2 to 17.1 +/- 1.4 mm Hg. The median SCK pO2 was increased about 7 times to 31.2 +/- 4.2 mm Hg when MTH was followed immediately with carbogen breathing for 5 min. The radiation response was also markedly increased by this combination. When the animals breathed carbogen for 15 or 30 min, the pO2 and radiosensitivity in both tumor types either remained the same or was lower than that after 5 min of breathing. In addition, both FSaII and SCK tumors were radiosensitized 24 h after MTH treatment alone or with 5 min of carbogen breathing. CONCLUSIONS: A shorter carbogen breathing time immediately after MTH causes the most tumor radiosensitization. The results of this study also demonstrate that MTH increases radiosensitivity with and without carbogen breathing up to 24 h after the mild hyperthermia treatment.     

Effect of obesity on the response to insulin therapy in noninsulin-dependent diabetes mellitus

An initial improvement in glycemic control is often followed by gradual deterioration of glycemia during insulin treatment of patients with noninsulin-dependent diabetes mellitus (NIDDM). We examined the causes of such worsening in a 12-month follow-up analysis of 100 insulin-treated NIDDM patients in the Finnish Multicenter Insulin Therapy Study who were treated with either combination therapy with insulin or insulin alone. In the entire study group, glycemic control averaged 9.7 +/- 0.2% at 0 months and 8.0 +/- 0.1%, 8.0 +/- 0.1%, 8.2 +/- 0.1%, and 8.5 +/- 0.2% at 3, 6, 9, and 12 months (P < 0.001 for each time point vs. 0 months). Glycemic control at 12 months was significantly worse than that at 3 (P < 0.001), 6 (P < 0.001), and 9 months (P < 0.02). Baseline body mass index was the most significant predictor of deterioration in glycemic control. During 1 yr, hemoglobin A1c decreased almost 3-fold more (by 1.7 +/- 0.2%; P < 0.001 vs. 0 months) in patients whose baseline weight was below the mean baseline body mass index of 28.1 kg/m2 (nonobese patients) than in those whose weight exceeded 28.1 kg/m2 (obese patients; 0.5 +/- 0.2%; P = NS vs. 0 months; P < 0.01 vs. obese patients). Glycemic control improved similarly over 1 yr in the nonobese subjects and deteriorated similarly in the obese patients regardless of their treatment regimen. Insulin doses, per body weight, were similar in the nonobese and obese patients. The nonobese patients consistently gained less weight during 12 months of combination therapy with insulin (3.5 +/- 0.6 kg at 12 months) than during insulin therapy alone (5.1 +/- 0.6 kg; P < 0.05). The treatment regimen did not influence weight gain in the obese group, who gained 4.4 +/- 1.0 kg during combination therapy with insulin and 4.5 +/- 1.1 kg during insulin therapy alone. We reached the following conclusions: 1) after an initial good response, glycemic control deteriorates more in obese than in nonobese patients with NIDDM; 2) in obese patients, weight gain per se cannot explain the poor glycemic response to combination or insulin therapy, but it may induce a disproportionately large increase in insulin requirements because of greater insulin resistance in the obese than in the nonobese; 3) in nonobese patients, glycemic control improves equally during 1 yr with combination therapy with insulin and insulin alone, but combination therapy with insulin is associated with less weight gain than treatment with insulin alone; 4) weight gain appears harmful, as it is associated with increases in blood pressure and low density lipoprotein cholesterol.     

Effect of sulpiride-induced hyperprolactinemia on serum testosterone response to HCG in normal men

In six normal volunteers hyperprolactinemia was induced by sulpiride (150 mg/day) for 10 days. Both before and during sulpiride hCG was injected; the higher testosterone response to hCG, when PRL levels were enhanced, suggests a possible stimulatory role of PRL on Leydig cells.     

The velocities of red cell and plasma flows through parenchymal microvessels of rat brain are decreased by pentobarbital

Local cerebral blood flow is lowered in many brain areas of the rat by high-dose pentobarbital (50 mg/kg). In the present study, the mechanism of this flow change was examined by measuring the distribution of radiolabeled red blood cells (RBCs) and albumin (RISA) in small parenchymal microvessels and calculating the microvascular distribution spaces and mean transit times of RBCs, RISA, and blood. In most brain areas, pentobarbital slightly decreased the RISA space, modestly increased the RBC space, and did not alter the blood space. The mean transit times of RBCs, RISA, and blood through the perfused microvessels were considerably greater in treated rats than in controls. These findings indicate that the mechanism by which high-dose pentobarbital diminishes local cerebral blood flow in rat brain is, in the main, a lowered linear velocity of plasma and RBC flow through small parenchymal microvessels and not decreased percentage of perfused capillaries (capillary retirement). This response is probably driven mainly by lowered local metabolism and may well entail a slight increase in the number of small microvessels that are perfused by RBCs.