A distinctive effect of CCCP on the transfer of erythromycin to 1-octanol: a possible model in promoting the intracellular antibiotic-accumulation through lipid in a staphylococcal cytoplasmic membrane

Movement of erythromycin (EM), a basic antibiotic solute (pKa 8.6), in an aqueous buffer (pH7.6) at 37 degrees C into 1-octanol was found approximately twofold greater in the presence of another acidic and lipophilic solute, carbonylcyanide m-chlorophenylhydrazone (CCCP), when compared with the EM-movement in the absence of CCCP. CCCP appears to behave just like a carrier of EM, besides being a well-known inhibitor, such as the uncoupling agent of oxidative phosphorylation. The probability is discussed that such an analogous event takes place in the lipid layers of a bacterial-cell membrane.

Different immunosuppressive effects of liposomal FK506 in liver and kidney transplantation

The efficacy of liposomal FK506 was compared between a canine liver transplantation model and a canine kidney transplantation model. The present study revealed that liposomal FK506 increased immunosuppressive efficacy of FK506 in liver transplantation but decreased in kidney transplantation. Because liposomal FK506 increased FK506 levels in the liver and spleen, and decreased FK506 levels in the kidney, it was suggested that enhanced immunosuppressive efficacy in liver transplantation should be attributed to the local immunosuppressive effects in the hepatic allograft rather than effective suppression of splenocyte activity.

[Prognosis of the surgical treatment for non-Hodgkin lymphoma originating from chronic tuberculous empyema--analysis of 11 cases with pleuropneumonectomy]

In total 19 cases of non-Hodgkin lymphoma originating from the wall of chronic tuberculous empyema, pleuropneumonectomeic were performed since 1979, with the aim of total cures for not only lymphoma but empyema in 11 cases. Of these cases extraresections (5 of thoracic cages, 4 of diaphragms, 2 of axillar lymph nodes, each of adventitia of descending aorta and esophagus, of the liver, of the left adrenal grand) were added to extirpate tumors completely. The mean operating time was 6 degrees 55', the mean blood loss during operations was 3090 ml, but in the 3 most recent cases it was less than under 1000 ml using electrocartesy-cutting technique under direct observation. Although preoperative radiations were done to 4 cases to decrease invasive area of tumors and postoperative radiation was done to 1 case, there were no adjuvant chemotherapies. The indicative limitation for resections from the point of ventilatory functions was the same as that of pleuropneumonectomy for ordinary chronic tuberculous empyema. There were 2 cases with serious postoperative complications. One suffered from ARDS and died on the 14th postoperative day, and another developed acute respiratory failure and MOF. But the other 9 cases kept good postoperative courses with a few recurrences of minor empyema. The prognoses for 10 remaining cases is excellent. Only one case died from local recurrence in of lymphoma 27 months later, but all other 9 cases have revealed no recurrence in any places, and the 5 year survival rate based on Kaplan-Meier method of 10 cases is 85.7%. By the way no cases could survive one year later in unresected group. So under the poor prognosis of treatment with radiation or chemotherapy for non-Hodgkin lymphoma originating from chronic tuberculous empyema, we conclude that the complete resection of tumor and empyema, so called pleuropneumonectomy, is the best way to cure this disease.

Evaluation of surgical resection for small hepatocellular carcinomas

BACKGROUND

The surgical results for small hepatocellular carcinomas (HCCs) are not necessarily satisfactory. The resectional therapy for small HCC was evaluated to elucidate its benefits and limitations.

PATIENTS AND METHODS

Data were analyzed concerning 52 patients having small HCC of <3 cm in diameter and <3 nodules, who underwent hepatic resections from 1978 to 1989.

RESULTS

Cumulative and disease-free survival at 5 years after resection were 57% and 37%, respectively. Histologic features, such as differentiation of HCCs, pseudocapsular invasion, and ploidy pattern of nuclear DNA, appeared to be good prognostic indicators. The survival rate of the large-resection group (number of resected segments greater than number of tumor-occupying segments) was significantly better than that in the small-resection group (84% versus 48% at 5 years, P<0.05).

CONCLUSIONS

Surgical resection of small HCCs is a safe and effective therapy. A large resection appears to provide better patient survival and tumor-free survival compared to a small resection.

Costimulation of fibronectin receptor promotes Fc gamma R-mediated rescue of IL-3-dependent bone marrow-derived cells from apoptosis

The IL-3-dependent murine bone marrow-derived cell line FDC-P2/185-4 (185-4) undergoes apoptosis when IL-3 is withdrawn from the culture medium. However, a high concentration of aggregated mouse IgG prevents apoptosis of 185-4 cells by an autocrine mechanism, producing IL-3. An analysis of flow cytometry revealed that 185-4 cells expressed Fc gamma RIII on their surface and that these effects of IgG are inhibited by anti-Fc gamma RIII mAb. These results indicated that the effect of IgG is mediated by low affinity Fc gamma RIII. In contrast, a low concentration of mouse IgG cannot prevent the apoptosis of 185-4 cells, but in the presence of fibronectin (FN), cell survival is prolonged. It is generally accepted that the interaction of cells with FN is mediated by several integrins such as alpha 5 beta 1 (VLA-5) or alpha 4 beta 1 (VLA-4), and analysis of flow cytometry showed that 185-4 cells express these integrins on their surface. Furthermore, these effects of FN are blocked specifically by RGD peptide or anti-VLA-4 mAb. These findings indicated that FN induces the costimulatory signal through integrin receptor and enhances the proliferative effect through Fc gamma RIII by a low concentration of IgG. The findings presented here suggested that the engagement of FN-integrin receptors on 185-4 cells increases the sensitivity of the cells for cellular activation of IgG. Since inflammatory cells in the microenvironment are surrounded by extracellular matrix proteins, it is possible that adhesion molecules play important roles in inflammatory states such as autoimmune diseases caused by increased levels of IgG.

Pulmonary hypertension in patients with complete transposition of the great arteries: midterm results after surgery

Postoperative results of surgical repair of complete transposition of the great arteries (TGA) with pulmonary hypertension (PH) in 19 patients in whom mean pulmonary arterial pressure was >50 mmHg or the pulmonary/systemic arterial pressure ratio was >0.8 were examined. TGA with intact ventricular septum was diagnosed in 10 patients and TGA with ventricular septal defect in 9. At the time of corrective surgery (arterial switch 10, atrial switch 9), patients ranged in age from 7 months to 14 years (mean 2.4 years). Seventeen patients (89%) survived with New York Heart Association functional class I. Seven patients in whom calculated pulmonary vascular resistance was 10-20 U m2 after surgery survived with subsequent regression of PH. Residual PH was diagnosed in 36% of survivors. Two patients in whom pulmonary vascular resistance was 26 and 36 U m2, respectively, died after surgery. In patients with TGA, severe PH was not necessarily fatal and was potentially reversible after successful surgery.

Ventriculolumbar perfusion chemotherapy with methotrexate and cytosine arabinoside for meningeal carcinomatosis: a pilot study in 13 patients

Thirteen patients with meningeal carcinomatosis were treated by ventriculolumbar perfusion using methotrexate (MTX) and cytosine arabinoside (Ara-C). MTX (10-30 mg) and Ara-C (40 mg) were infused at 8- to 12-hour intervals on six or nine occasions via an Ommaya reservoir placed in the lateral ventricle. Nine of thirteen patients had evaluable response (69% response rate with a mean survival of 8.8 months among responders) and ventriculolumbar perfusion therapy was effective in improving cerebral, cranial nerve, and spinal root signs and symptoms, especially sensorimotor disturbance in the lower limbs. Three of the six bedridden patients became ambulatory without assistance and two of the four patients who were walking with assistance became ambulatory without assistance. Urinary incontinence also markedly improved, except in one nonresponder. Lumbar cerebrospinal fluid parameters (cytological findings and tumor markers) also improved in association with the clinical improvement. Our pilot results were encouraging, especially the improvement of sensorimotor function in the lower limbs. However, the toxicity was unacceptable when compared with that of standard intrathecal chemotherapy. Thus, this therapy needs to be investigated further to establish the most appropriate drug doses and perfusate volume to reduce toxicity as well as determine its true efficacy in the treatment of meningeal carcinomatosis.

Comparative pharmacodynamics of eight calcium channel blocking agents in Japanese essential hypertensive patients

The relationships between plasma drug concentration and antihypertensive effect of eight calcium channel antagonists (nicardipine, nifedipine, nilvadipine, benidipine, manidipine, barnidipine, nitrendipine and efonidipine) in Japanese essential hypertensive patients were analyzed. Based on the effect compartment model, we could explain the long duration of the pharmacological effect, and there was significant correlation (r = 0.876, p < 0.05) between estimated EC50 values and the dissociation constants (Kd) obtained from in vitro binding studies. We also developed the ion-channel binding model to understand the pharmacodynamics of long acting calcium antagonists. The model was also well fitted to antihypertensive effect data. A significant correlation between the apparent in vivo dissociation constants and in vitro Kd values was observed with a slope of 1.45 (r = 0.913), suggesting that the mechanism of long-lasting antihypertensive effect of newer developed calcium antagonists is due to their high binding affinity at ion-channel sites.

Costimulation of fibronectin receptor promotes Fc gamma R-mediated rescue of IL-3-dependent bone marrow-derived cells from apoptosis

The IL-3-dependent murine bone marrow-derived cell line FDC-P2/185-4 (185-4) undergoes apoptosis when IL-3 is withdrawn from the culture medium. However, a high concentration of aggregated mouse IgG prevents apoptosis of 185-4 cells by an autocrine mechanism, producing IL-3. An analysis of flow cytometry revealed that 185-4 cells expressed Fc gamma RIII on their surface and that these effects of IgG are inhibited by anti-Fc gamma RIII mAb. These results indicated that the effect of IgG is mediated by low affinity Fc gamma RIII. In contrast, a low concentration of mouse IgG cannot prevent the apoptosis of 185-4 cells, but in the presence of fibronectin (FN), cell survival is prolonged. It is generally accepted that the interaction of cells with FN is mediated by several integrins such as alpha 5 beta 1 (VLA-5) or alpha 4 beta 1 (VLA-4), and analysis of flow cytometry showed that 185-4 cells express these integrins on their surface. Furthermore, these effects of FN are blocked specifically by RGD peptide or anti-VLA-4 mAb. These findings indicated that FN induces the costimulatory signal through integrin receptor and enhances the proliferative effect through Fc gamma RIII by a low concentration of IgG. The findings presented here suggested that the engagement of FN-integrin receptors on 185-4 cells increases the sensitivity of the cells for cellular activation of IgG. Since inflammatory cells in the microenvironment are surrounded by extracellular matrix proteins, it is possible that adhesion molecules play important roles in inflammatory states such as autoimmune diseases caused by increased levels of IgG.

Inhibition of outflow cushion mesenchyme formation in retinoic acid-induced complete transposition of the great arteries

OBJECTIVE

Endocardial cushion tissue formation, the primordia of valves and septa, is a critical event in cardiac morphogenesis. Maternally administrated all-trans retinoic acid is known to induce complete transposition of the great arteries (TGA) in the mouse embryo. To address the mechanisms of TGA, the effect of retinoic acid on cushion tissue formation was examined.

METHODS

Using a three-dimensional collagen gel culture model, we performed various types of endothelial-mesenchymal transformation assays of co-cultured endocardium with myocardium obtained from 9.5-day mouse embryonic hearts. In vivo immunohistochemical detections of extracellular matrices, fibronectin and type I collagen, were also performed.

RESULTS

Endothelial-to-mesenchymal transformation at the onset of cushion tissue formation was suppressed in the outflow tract of embryos exposed to retinoic acid in culture. This inhibitory effect of retinoic acid was spatially restricted to the outflow tract and reversed by treatment with embryonic myocardial conditioned medium enriched in extracellular inductive molecules. Mesenchyme formation in the outflow tract was inhibited at a lower concentration of retinoic acid (10(-10) mol/l) than that which inhibited the atrio-ventricular canal (10(-7) mol/l) in culture. The fibronectin and type I collagen depositions in pre-migratory outflow tract cardiac jelly in retinoic acid-treated embryonic heart were reduced compared to those in the control.

CONCLUSIONS

Exogenously applied retinoic acid inhibits outflow tract cushion mesenchyme formation in the embryonic heart with TGA. It is suggested that retinoic acid inhibits the expression of extracellular matrices and inductive molecules synthesized by myocardium in the outflow tract.

Effect of cisplatin on the disposition of endogenous serotonin and its main metabolite, 5-hydroxyindole-3-acetic acid, in rats and dogs

Emesis after the administration of cisplatin is a severe complication, and its treatment is an important problem clinically. Cisplatin forces the release of serotonin (5-HT) from enterochromaffin cells in the mucosa, and emesis occurs by the stimulation of 5-HT3 receptors. In this study, we established a simple and simultaneous method of determining 5-HT and its main metabolite, 5-hydroxyindole-3-acetic acid (5-HIAA), in plasma and urine by high performance liquid chromatography with electrochemical detection (HPLC-ECD), and determined the disposition of endogenous 5-HT and 5-HIAA after the administration of cisplatin in rats and dogs. In rats, we found no change in the plasma concentration of 5-HIAA after cisplatin administration, while a distinct increase was shown in the plasma concentration of 5-HT, but it was not significantly different from that of the control rats. The urinary excretion of 5-HIAA was also not different between the two groups. In dogs, we observed intense vomiting in all cisplatin treated dogs. However, we could not detect any change in the 5-HIAA or 5-HT level in the dog plasma. Furthermore, no significant difference in the urinary excretion of 5-HIAA was observed between the cisplatin group and the controls. From these results, the plasma concentration of 5-HT and the urinary excretion of 5-HIAA may not be suitable markers for the evaluation of emesis induced by anticancer drugs in dogs.

EM523L, a nonpeptide motilin agonist, stimulates gastric emptying and pancreatic polypeptide secretion

We investigated the efficacy and the mechanism of action of EM523L, a nonpeptide motilin agonist (motilide), on the stimulation of gastric emptying and on the release of gut peptides after ingestion of a solid meat in normal controls (n = 8) and in diabetic patients (n = 8) with signs of neuropathy. A dose of 2 mg EM523L was administered IV over 15 min just after ingestion of a solid meal (200 kcal Gastric emptying was measured by a radionuclide technique. EM523L accelerated gastric emptying and markedly augmented postprandial pancreatic polypeptide (PP) response in both normal control and diabetic patients. This may suggest the mediation of the Vagal-cholinergic pathway to accelerate gastric emptying. The present study offers a promising therapeutic potential of the motilide in gastrointestinal motility disorders like those observed in diabetics mellitus.

[Functional imaging of the sensorimotor cortex using an ultra-fast MR imaging method]

The aim of this study was to assess changes in brain activity during a motor task and variable sensory stimulation using echo planar imaging, which represents the fastest clinically usefull imaging technique available.

MATERIALS AND METHODS

The subjects of this study were 11 healthy-volunteers, 4 males and 11 females, with an average of 26.4 years. The subjects were instructed to tap the fingers of one hand as the motor task. Compressed air was applied 5 times a second as "simple" sensory stimulation. Simple figures were drawn on the subjects palm as "complex" sensory stimulation. In all cases, functional imaging was performed by T2*-weighted echo planar imaging (TE = 53 msec, TR = 3000 msec, flip angle = 90 degrees, matrix 64 x 64, FOV = 205 mm, slice thickness = 8 mm) alternately at rest and during the task (intervals: 30 sec). A total of 60 images was collected in 3 minutes. Images obtained by subtracting images at rest and during the task were analyzed.

RESULTS AND DISCUSSION

Almost all subjects showed a transient signal increase in the contralateral paracentral region during simple sensory stimulation. Continuous signal increases in the contra- and/or ipsi-lateral para-central region were observed during complex sensory stimulation. Some exhibited signal increases in the parietal or frontal association cortex, but they disappeared when subject's attention was distracted during stimulation. All subjects displayed signal increases in the contralateral para-central region during the motor task. Some of them exhibited signal increases in the medial frontal area (supplementary motor area) and ipsilateral para-central region. These results suggest that the signal increases of functional MRI reflect not only simple reactions to stimulation but higher cerebral function as well.

[The relationship between visual agnosia and visual pathway for perception]

We report a patient with a unique visual agnosia, who was thought to have lost visual functions except for the primary visual function. The patient was a 71-year-old woman with progressive memory loss and cerebro-cortical atrophy in MRI; her clinical diagnosis was senile dementia of Alzheimer's type. A battery of tests to detect higher visual dysfunctions was performed. First of all, we presented small dots and lines in front of the patient; the patient was able to recognize them. When a triangle, a tetragon, a cube, pieces of paper of different colors and lines of different length were presented, she was unable to recognize those objects. When pictures of her family members or filled circles of different size including small dots and lines were presented, the patient could only detect those small dots and any of lines; she could not recognize the members of her family. The cerebral blood flow was severely reduced in the occipital lobe except for the striate cortex. These data suggested that the visual function of striate cortex was preserved in this patient; the disturbance of higher visual functions was thought to be caused by the dysfunction of extra striate cortex.

Single-channel properties of a G-protein-coupled inward rectifier potassium channel in brain neurons

1. In cultured rat locus coeruleus neurons, somatostatin or met-enkephalin induces an inwardly rectifying K+ conductance. This inward rectifier was analyzed at the single-channel level. 2. Using the inside-out patch-clamp, guanosine 5'-triphosphate (GTP) application to the cytoplasmic side in the presence of somatostatin or met-enkephalin in the pipette produced a large increase in channel activity, which disappeared on switching from GTP to guanosine 5'-diphosphate. 3. The unitary conductance was approximately 30 pS at -95 mV with an extracellular K+ concentration of 156 mM and an intracellular K+ concentration of 124 mM at 23 degrees C. The channel showed burst behavior, and the closed time histogram was fit by two exponentials, with the fast time constant being 0.4 ms. The burst time histogram was also fit by two exponentials, with time constants of 0.24 and 2.0 ms (at 10 nM somatostatin). When the somatostatin concentration was changed from 500 to 1 nM, the kinetic behavior of the channel did not change, except that the open probability of the patch was decreased. 4. The current-voltage relation of the unitary channel current showed inward rectification. The reversal potential coincided with the K+ equilibrium potential, and it shifted according to a change in the K+ equilibrium potential. 5. In the presence of external somatostatin, the application of guanosine 5'-O-(3-thiotriphosphate) to the cytoplasmic side induced an irreversible activation of this channel. 6. These results indicate that this K+ channel is the microscopic counterpart of the somatostatin- or met-enkephalin-induced inwardly rectifying K+ current in whole cell recording, and that the channel is activated by a G protein without a diffusible second messenger. Thus this channel is identified as a neuronal G-protein-coupled inward rectifier K+ channel. 7. Analysis of the burst behavior, based on a close-close-open kinetic model, revealed that there are at least four states in the K+ channel, a short gap, a longer closing, a short opening, and a long opening, and that the neuronal inward rectifier is activated at faster rates than the atrial inward rectifier.

Serum levels of the type IV collagen 7s domain in patients with chronic viral liver diseases

The serum levels of type IV collagen 7s domain (7s collagen) were determined in 80 patients with hepatocellular carcinoma (HCC) and in 105 with chronic liver disease without HCC. Among 86 patients with HCV infection, serum levels of the 7s collagen were significantly higher in those with HCC than-in those without HCC (p<0.05). In contrast, no significant differences were recognized between these two groups in 84 patients with HBV infection. Patients with HCV infection having high serum levels of the 7s collagen exceeding 7.0 ng/ml, were diagnosed as HCC with a sensitivity of 71.8%, a specificity of 74.5%, and a reliability of 77.9%. It was concluded that the progression of hepatic fibrosis plays an important role in the hepatocarcinogenesis of HCV, and that serum levels of the 7s collagen appeared to be useful as a risk factor of the development of HCV-related HCC.

cDNA sequence analysis and characterization of a cytokine-inducing monoclonal antibody derived from autoimmune MRL/MP-lpr/lpr mouse

We have previously reported that a monoclonal antibody 1D11 derived from an autoimmune MRL/Mp-lpr/lpr (MRL/lpr) mouse induced synthesis or increased production of IL-3, IL-6, and TNF-alpha in the IL-3-dependent bone marrow-derived cell line FDC-P2/185-4. In this report, we analyzed a sequence of cDNA encoding the V region of 1D11, and found that VH and VL segments of 1D11 belonged to the J558 and V kappa 21 family, respectively. The nucleotide sequence of 1D11 in the VH segment was highly homologous to that of AM9, a monoclonal RF derived from MRL/lpr mouse, and the only difference was the replacement of 3 nucleotides in the framework region 1 (FR1). However, the deduced amino acid sequence of 1D11 was identical to that of AM9. In contrast with the VH segment, the sequences of the VL regions of these two antibodies were quite different from each other; 1D11 showed a 3 base deletion in the FR2 and a 24 base insertion in the FR3 compared with AM9. At present, the mechanisms of such insertions or deletions in the FRs of autoantibodies are almost unknown. It is generally accepted that the differences in specificity and affinity of these autoantibodies depend on differences of CDR sequence. However, it is possible that not only CDRs but also FRs of autoantibodies play a critical role in pathogenicity and/or specificity in autoimmune diseases.

G protein-coupled inward rectifier modulated by dopamine agonists in cultured substantia nigra neurons

Dopamine release from dopaminergic neurons in the substantia nigra plays an important role in regulating their activity. In the present experiments the whole-cell clamp technique was used to elucidate the modulatory role of dopamine on K+ conductance in substantia nigra neurons in culture. In pars compacta neurons held near the resting potential, dopamine and quinpirole (a D2 receptor agonist) increased membrane conductance. This response was blocked by S(-)-sulpiride, a D2 receptor antagonist. The current-voltage relation of the quinpirole-induced current showed an inward rectification with a reversal potential that approximately equaled the K+ equilibrium potential. Intracellular application of a non-hydrolysable GTP analogue, guanosine 5'-O-(3-thiotriphosphate; 0.1-0.5 mM) into pars compacta neurons produced an initial spontaneous increase in an inwardly rectifying K+ conductance. Quinpirole markedly accelerated this conductance increase. In cells loaded with a poorly metabolized GDP analogue, guanosine 5'-O-(2-thiodiphosphate), the quinpirole response was diminished. Treatment of pars compacta neurons with pertussis toxin abolished the D2 response. Intracellular application of cyclic AMP (1 mM) neither mimicked nor occluded the D2 response. These results indicate that D2 receptor agonists produce neuronal inhibition by activating an inwardly rectifying K+ current, that this D2 agonist effect is mediated by a pertussis toxin-sensitive G protein, and that cyclic AMP does not mediate the D2 response. Unexpectedly, in cells loaded with guanosine 5'-O-(3-thiotriphosphate) after the inwardly rectifying K+ conductance spontaneously reached a maximum, it started to decline slowly. In cells loaded with guanosine 5'-O-(2-thiodiphosphate), the quinpirole response became diminished at first, but then the membrane conductance slowly increased, together with an increase in the quinpirole response. These results were explained by an interplay of two G proteins, one producing an increase and the other producing a decrease in the K+ conductance. In some pars reticulata neurons, R(+)-SKF-38393 (a D1 receptor agonist) reduced an inwardly rectifying K+ conductance; this would excite the neuron under current clamp conditions. The present study shows that cultured substantia nigra neurons produce functional responses to dopamine agonists. Using these neurons, the ionic mechanisms and signal transduction mechanisms of the responses were elucidated in a more critical manner than in previous studies.

Influence of antemortem medication on the determination of brain death

Post-mortem concentration of pentobarbital in the blood and brain of two deceased neurosurgical patients was determined by gas chromatography/mass spectrometry. Patients treated with barbiturate for elevated intracranial pressure after head injury may incur brain death. In the present two cases of brain death a large amount of barbiturate remained in the brain, even when the blood concentration was not detectable, possibly because the blood flow was stagnant in the brain. It is suggested that a patient under barbiturate coma should be given serious consideration as to the determination of brain death, even if barbiturate is negative in the blood.