A strategy for increasing the brain uptake of a radioligand in animals: use of a drug that inhibits plasma protein binding

A positron-emitter labeled radioligand for the glycine-binding site of the N-methyl-D-aspartate (NMDA) receptor, [(11)C]L-703,717, was examined for its ability to penetrate the brain in animals by simultaneous use with drugs having high-affinity separate binding sites on human serum albumin. [(11)C]L-703,717 has poor blood-brain barrier (BBB) permeability because it binds tightly to plasma proteins. Co-injection of warfarin (50-200 mg/kg), a drug that binds to albumin and resembles L-703,717 in structure, dose-dependently enhanced the penetration by [(11)C]L-703,717 in mice, resulting in a five-fold increase in the brain radioactivity at 1 min after the injection. Drugs structurally unrelated to L-703,717, salicylate, phenol red, and L-tryptophan, were less effective or ineffective in increasing the uptake of [(11)C]L-703,717. These results suggest that the simultaneous use of a drug that inhibits the binding of a radioligand to plasma proteins is a useful way to overcome the poor BBB permeability of the radioligand triggered by its tight binding to plasma proteins. In brain distribution studies in rodents, it was found that, after the increase in brain uptake with warfarin, much of the glycine site antagonist accumulates in the cerebellum but its pharmacological specificity did not match the glycine site of NMDA receptors.

Telomerase activity is down regulated via decreases in hTERT mRNA but not TEP1 mRNA or hTERC during the differentiation of leukemic cells

BACKGROUND

Recent studies have determined several telomerase-associated molecules, but the precise mechanisms regulating telomerase activity by those molecules has not been fully understood.

MATERIALS AND METHODS

The telomerase activity was determined by TRAP assay. Using TaqMan RT-PCR, the quantitative and kinetic values of mRNA expression of the three telomerase-associated molecules were examined in HL60 cells differentiated with tumor necrosis factor mutant and all-transretinoic acid.

RESULTS

The levels of telomerase activity in leukemic cell lines, leukemic cells from patients, and normal peripheral blood cells were distributed over a very wide range. Human telomerase catalytic subunit (hTERT) mRNA expression declined to nearly undetectable levels more rapidly than the inhibition of telomerase activity after treatment with these reagents in HL60 cells. Telomerase-associated protein (TEP1) mRNA increased approximately 6-fold over its level in untreated cells. The levels of human telomerase RNA component (hTERC) also increased approximately 2.7-fold at 5 days after treatment.

CONCLUSIONS

These results suggest that telomerase activity is down-regulated mainly via decreases in hTERT, but not TEP1 and hTERC expression during the differentiation of leukemic cells.

Time-course changes of eosinophil counts in premature infants: no effects of medical manipulation, except erythropoietin treatment, on eosinophilia

In order to determine the factors responsible for eosinophilia during the neonatal period, we counted the eosinophils of premature infants every week and compared the medical profiles of infants with eosinophil counts above the 95th percentile and those below that percentile during the course of study. Medical treatments such as mechanical ventilation, antibiotics administration and intravenous catheterization had no significant effects on the increase of eosinophils. Furthermore, the incidence of eosinophil counts above the 95th percentile was not different between breast-fed and formula-fed infants. The infants treated with erythropoietin had greater eosinophil counts than those with no treatment. It is probable that medical manipulation using foreign bodies such as intratracheal tube, intravenous catheter, antibiotics and artificial formula had no significant effects on the increase of eosinophil counts, except for exogenous erythropoietin.

Detection of human serum tumor necrosis factor-alpha in healthy donors, using a highly sensitive immuno-PCR assay

BACKGROUND

Tumor necrosis factor-alpha (TNFalpha) is an important mediator of inflammatory and autoimmune diseases. Analysis of its pathophysiologic roles has been difficult because low concentrations of TNFalpha, including those in healthy controls, cannot be measured by existing methods.

METHODS

We developed a sensitive immuno-PCR assay for the detection of TNFalpha in human serum. The DNA label was generated by PCR amplification using biotinylated primer and was bound with streptavidin to the biotinylated third antibody. TNFalpha sandwiched by antibodies was detected by amplification of the DNA label using PCR.

RESULTS

The limit of detection of the assay was 0. 001 ng/L, an approximately 5 x 10(4)-fold improvement compared with a conventional ELISA. The mean serum TNFalpha concentration (+/- SD) in healthy donors was 0.021 +/- 0.044 ng/L in men (n = 29) and 0.033 +/- 0.065 ng/L in women (n = 25).

CONCLUSION

This method may be useful for analyzing the significance of TNFalpha concentration in various diseases.

Three point mutations of human butyrylcholinesterase in a Japanese family and the alterations of three-dimensional structure

Three different mutations at codons 330 (TTA to ATA), 365 (GGA to AGA) and 515 (CGT to TGT) of human butyrylcholinesterase (hBChE) were identified in a Japanese family. We correlated alterations in in the patient's hBChE activity with possible structural alterations in the three-dimensional structure of hBChE caused by the point mutations. This study was performed using the published computer-generated three-dimensional structure of hBChE based on the structure of acetylcholinesterase. The amino acid substitution at L330I was adjacent to hydrophobic residues that form the channel domain of the active center. This side chain faced the side opposite the active center. The amino acid substitution at G365R was located at the position most remote from the active center, and this substitution site was exposed to the surface of the BChE protein. Alpha-helical structure was present to the active center, and the guanidyl residue of native Arg 515 was hydrogen-bonded to the carboxyl group of Asp 395 in the alpha-helix. These point mutations may cause steric effects on the present patient's hBChE activity. This is the first report of three-dimensional structural analysis performed on the L330I, G365R, and R515C mutations of hBChE.

[The control survey in CD marker analysis of leukemic cells]

Analysis of cell surface antigens is thought to be more objective compared to classification by the morphology. However, it has been indicated that the evaluated data are different each other between institutes. Therefore, we performed a control survey of CD marker analysis in leukemia cells using flow cytometry in six commercial laboratories. The expression of CD2, 4, 5, 7, 8, 10, 13, 14, 19, 20, 33, 34, 38, and 71, HLA-DR in tumor cells from megakaryoblastic leukemia, lymphoblastic crisis of CML, and ALL patients, were examined. There were large differences in the results of CD marker analysis among the six commercial laboratories. One possible reason for this result is the differences in gating condition and monoclonal antibodies used in each laboratory. However, there were the differences in the results even when the same gating condition and antibodies were used. The reasons for the difference in transport or treatment conditions for samples remain a matter of considerable controversy. In the present condition, it was suggested that the exchange of information about the origin of tumor cells between the physician in charge and examination experts is thought to be the best way to analyze proper cell surface antigen expression. Further, no national survey has been carried out, but the establishment of a standard assay is preferred to obtain proper data for the patients and medical parties concerned.

Two optimal prefilter cutoff frequencies needed for SPECT images of myocardial perfusion in a one-day protocol

OBJECTIVE

The purpose of this study was to determine if cutoff frequencies of two-dimensional Butterworth filters need to be changed, depending upon the amount of radiopharmaceutical administered in one-day protocols for reconstructing SPECT images of myocardial perfusion.

METHODS

A scintilation camera and a phantom were used with 2.2 MBq and 10.6 MBq 99mTc. These activities corresponded to the approximate amounts used in our one-day myocardial perfusion imaging protocol. The projection data were collected in 30 positions spread over 180 degrees. Thirty- and 150-sec acquisitions per position were performed to obtain the study and the high-quality reference images. Thirteen cutoff frequencies of the filter were used to reconstruct the SPECT images. Optimal cutoff frequencies were determined by visual assessment and by calculating the normalized mean square error (n.m.s.e). These results were then compared. The same protocol was used to image three volunteers with no heart disease and the images were evaluated visually.

RESULTS

In the phantom study, the optimal cutoff frequencies were 0.225 cycles/pixel for 2.2 MBq, and 0.275 cycles/pixel and 0.25 cycles/pixel for 10.6 MBq by visual inspection, and were 0.225 cycles/pixel and 0.275 cycles/pixel by calculating the n.m.s.e., respectively. In the patient study, the lower cutoff frequency of 0.20 cycles/pixel was optimal for the exercise study (low dose), while the higher cutoff frequencies of 0.275 cycles/pixel was optimal for the resting study (high dose).

CONCLUSION

The optimal cutoff frequencies differed for the two activity levels. Cutoff frequencies should be changed according to the amounts of radiopharmaceuticals used for the first and the second examinations in one-day protocols.

[Long-term complete response in two cases of liver metastases from rectal and gastric cancer treated with intra-arterial infusion chemotherapy of leucovorin and 5-fluorouracil]

Intra-arterial infusion chemotherapy combined with leucovorin (LV) and 5-fluorouracil (5-FU) was performed in two patients with multiple metastases from rectal and gastric cancer. In each patient LV 45 mg was infused as a bolus just before and after 5-FU 1,000 mg/4 hrs administration. Thereafter 5-FU dose was decreased gradually. This regimen was principally repeated weekly on an outpatient basis. In both patients PR was detectable 3 and 4 months after the beginning of chemotherapy, and CR was obtained in 21 and 6 months, respectively. Neither patient showed any signs of recurrence and are in good health 35 and 30 months after initiation of chemotherapy. These findings suggest that our protocol has an excellent anti-tumor effect and improves the QOL in some patients for a long time.

Prenatal diagnosis of congenital unilateral hydrocephalus

A case is presented in which fetal unilateral hydrocephalus that had not been definitively diagnosed by ultrasonography was confirmed by means of magnetic resonance imaging. Computed tomography performed in the neonatal period after intraventricular injection of contrast medium showed stenosis of the foramen of Monro.

[Therapeutic effectiveness of combined microsurgery and radiosurgery in a patient with a huge trigeminal neurinoma]

A case of right trigeminal neurinoma extending from the cavernous sinus to the cerebellopontine angle in a 48-year-old male is reported. The patient first noticed right facial numbness in June 1993. Six months later, he experienced headaches with occasional nausea, diplopia, ataxic gait, tinnitus and dysphagia and was referred to our department on January 21, 1994. Neurological examination on admission showed multiple cranial nerve palsy from the 4th to 11th nerve on the right, and the cerebellar sign on the right. Initial CT and MRI revealed a large mass lesion extending from the right cavernous sinus to the right cerebellopontine angle. On February 16, 1994, radical resection of the tumor, except the lesion invading the cavernous sinus, was performed via a combined retroauricular and preauricular transpetrosal transtentorial approach. The histological diagnosis was neurinoma. The patient's postoperative course was uneventful and there was good clinical improvement, although the right facial numbness and mild diplopia persisted. On April 6, 1994, radiosurgery was performed with a maximum dose of 28 Gy and a marginal dose to 14 Gy to the remaining cavernous sinus lesion. Two weeks after radiosurgery, the patient achieved a complete return to his daily routine. Two-year follow-up CT and MRI showed a small residual les on in the right cavernous sinus alone. There was no evidence of tumor growth. No new neurological deficits had developed, and the patient's the double vision had resolved. Thus, the patient has been able to maintain a satisfactory level of activities of daily living. We wound like to emphasize the clinical value of the strategy used to treat this patient which combined microsurgery with subsequent radiosurgery.

[Evaluation of differential media in Helicobacter pylori culture]

Culture is one of the important methods for detecting Helicobacter pylori(Hp). Culture method is generally lower sensitive in comparison with other Hp detection methods. However, culture is necessary for determination of MIC and analysis of bacteriological characteristics. Several culture media are now commercially available for Hp. In this study, we compared commercial media with our original medium. Original medium for Hp culture was most sensitive and showed no false-positive results compared with other commercial media.

Effect of sugar type on the efficiency of plant regeneration from protoplasts isolated from shoot tip-derived meristematic nodular cell clumps of Lilium x formolongi hort

Suspension cultures composed of meristematic nodular cell clumps of Lilium x formolongi hort were established from shoot tips placed on MS medium supplemented with 1 mg/l picloram and 30 g/l sucrose, glucose, fructose or sorbitol. Protoplasts isolated from these cultures were embedded in 1 g/l gellan gumsolidified 1/2MS medium with 1 mg/l picloram and the different kinds of sugars at 0.5 M, and cultured at 25 °C in the dark. The highest plating efficiency (13.7%) was obtained when the protoplasts were isolated from the cell clumps which had been subcultured in MS medium containing glucose and were likewise cultured in MS medium supplemented with 0.5 M glucose. Plants were regenerated from the protoplast-derived calli on 1/2MS medium containing 2.5-10 g/l sucrose or 5-10 g/l glucose. These results suggest that the kinds of sugar and concentration are important parameters affecting protoplast isolation, proliferation and plant regeneration in L. x formolomgi hort.

Morphology of a cytochrome c-adsorbed stearic acid monolayer on Brewster angle microscopy

The morphologies of stearic acid and cytochrome c (cyt.c)-adsorbed stearic acid monolayers were investigated by Brewster angle microscopy (BAM) with various molecular areas of stearic acid. With an area of more than 0.38 nm2/molecule, many blight island domains and some bright circles were observed in the BAM image of the stearic acid monolayer. The blight site part became to occupy all the surface with compression, and then became more closely packed with an area of 0.22 nm2/molecule. On the other hand, a different BAM image was obtained for the cyt.c-adsorbed stearic acid monolayer, as follows: (i) a striped pattern was only observed in the presence of cyt.c; (ii) the number of bright circles in the presence of cyt.c was less than that in its absence. Furthermore, when a uniform BAM image was observed for the stearic acid monolayer with cyt.c, the intensity of the absorbance at 409 nm of cyt.c was the highest. By calculating the amount of cyt.c adsorbed on a stearic acid monolayer from the absorbance value, it was shown that cyt.c was most closely packed when an uniform BAM image was observed. These results suggest that the use of BAM and visible absorption spectroscopy together is useful for studying the morphology of a monolayer.

MR imaging of primary intracranial malignant lymphoma

Magnetic resonance imaging (MRI) was performed in ten patients with intracranial lymphoma. Seven were pathologically confirmed and three were clinically diagnosed. Nineteen lesions were found among the ten cases. None had acquired immunodeficiency syndrome (AIDS) or had received immunosuppression therapy. Two lesions were in the lateral and third ventricles, and the others were predominantly in the corpus callosum, deep white matter, or central gray matter. Four patients had multiple lesions. All had mild to severe edema. On T1-weighted images, all lesions showed hypointensity. On T2-weighted images, three lesions showed definite hypointensity to gray matter, and the others showed hyperintensity. The contour of all lesions was well demarcated from the surrounding edema. Eight cases were scanned before and after intravenous administration of 0.1 mmol/kg of gadolinium-dimethylene triaminepentaacetic acid (Gd-DTPA), and all exhibited homogeneous enhancement. Three cases showed blurred enhancement margins. Four cases showed hemorrhage, and the frequency of hemorrhage was higher than in previous reports. Pathological examination was performed in seven cases. All showed dense concentric lymphoma cells without necrosis. There was no pathological difference between the hyperintense and hypointense lesions on T2-weighted images.

Role of vascular nitric oxide synthase in endotoxin shock of Propionibacterium acnes-sensitized rats

The sensitivity of animals to endotoxin differs significantly between species. Thus, factors that determine the susceptibility to endotoxin may play important roles in the pathogenesis of septic shock. In order to determine the mechanism responsible for susceptibility to endotoxin, the effect of lipopolysaccharide (LPS) on the circulatory status of Propionibacterium acnes (PA)-sensitized rats was studied. Following the intravenous administration of a low dose of LPS, the arterial blood pressure of PA-treated rats, but not of normal animals, progressively decreased; the PA-sensitized animals died of circulatory shock within 7 h of LPS administration. N omega-nitro-L-arginine (NA) reduced the depressor effect of LPS by an L-arginine-inhibitable mechanism. Administration of LPS markedly increased the level of the inducible type of nitric oxide (NO) synthase in various tissues, including the aorta, of PA-treated rats but not of control animals. LPS also increased plasma levels of nitrate plus nitrite and aortic levels of cGMP. Dexamethasone inhibited the de novo synthesis of NO synthase in the aorta and other tissues and reduced the depressor effect of LPS. These and other findings suggest that induction of nitric oxide synthase in resistant arteries might underlie the pathogenesis of LPS-induced hypotension in PA-sensitized animals and the mechanism responsible for the susceptibility to endotoxin.

Intrahepatic cholangiocarcinomas associated with nonbiliary cirrhosis. A clinicopathologic study

To determine the prevalence and clinicopathologic features of cholangiocarcinoma (CC) associated with nonbiliary cirrhosis, we performed a clinicopathologic study. Among the 5,563 autopsies in our laboratories during the past 14 years, 85 (1.5%) were CCs. Four (4.7%) were associated with cirrhosis, due to hepatitis B virus in one case and cryptogenic (probably non-A non-B hepatitis virus) in the remaining three. Clinically, patients with CC and cirrhosis were characterized by male preponderance, lower age, past history of liver injury, and elevated values of zinc sulfate and thymol turbidity tests. Pathologically, all CCs with cirrhosis were basically adenocarcinoma; other histologic features included adenocarcinoma resembling bile ductules without mucin (one case), adenocarcinoma with broad areas of signet ring cell carcinoma (one case), adenocarcinoma with extensive sarcomatoid transformation (one case), and adenocarcinoma associated with hepatoliths (one case). Immunohistochemically, immunophenotypes of carcinoma cells of CC with cirrhosis were not different from those of CC without cirrhosis. Carcinoembryonic antigens, CA19-9, DU-PAN-2, and biliary-type cytokeratins were positive and alpha-fetoprotein was negative, suggesting that our CCs are not hepatocellular neoplasms but true CCs. It must be stressed that there are actual CCs arising in nonbiliary cirrhotic livers.

Extrahepatic peribiliary glands express alpha-amylase isozymes, trypsin and pancreatic lipase: an immunohistochemical analysis

We examined expression of alpha-amylase isozymes (pancreatic and salivary), trypsin and pancreatic lipase on the epithelium of extrahepatic peribiliary glands immunohistochemically using 53 autopsied normal extrahepatic bile ducts. Three parts of the extrahepatic bile duct (common bile duct, intrapancreatic bile duct and bile duct at the ampulla of Vater) were examined in each case. Histologically, the extrahepatic bile duct harbored branched tubular glands (extrahepatic peribiliary glands). Extrahepatic peribiliary glands were few in the common bile duct and intrapancreatic bile duct and numerous in the bile duct at the ampulla of Vater. Immunohistochemically, pancreatic alpha-amylase was expressed in the epithelium of extrahepatic peribiliary glands in 42 cases (79%). Salivary alpha-amylase was expressed in the epithelium of the glands in 38 cases (72%). Trypsin was expressed in the epithelium of the glands in 32 cases (60%). Pancreatic lipase was expressed in the epithelium of the glands in 45 cases (85%). The immunoreactivity of these enzymes was granular and located in the supranuclear cytoplasm (corresponding to the Golgi apparatus) of the epithelium of the glands. We confirmed the specificity of the immunoreactivity of these enzymes with various methods. These results suggest that extrahepatic peribiliary glands produce alpha-amylase isozymes, trypsin and pancreatic lipase and secrete these enzymes into lumens of the extrahepatic bile duct. The secreted enzymes may play an important role in the physiology of the extrahepatic bile duct and bile.

Tc-99m-methylene diphosphonate (Tc-99 MDP) and Ga-67 concentration in soft tissue malignant fibrous histiocytoma (MFH): case report

A case of calcifying soft tissue malignant fibrous histiocytoma (MFH) which showed a concentration of Tc-99m MDP and Ga-67 citrate, is presented. Tc-99m MDP and Ga-67 citrate scintigraphies of the thigh mass were correlated with conventional radiography, computed tomography (CT) and angiography.

Extensive portal tumor thrombi with portal hypertension in an autopsy case of intrahepatic cholangiocarcinoma

Vascular invasion is not a prominent feature of cholangiocarcinoma (CCC), in contrast to hepatocellular carcinoma (HCC), which frequently shows extensive vascular tumor thrombi. We report an autopsy case of CCC with extensive portal tumor thrombi and portal hypertension. A 57-yr-old man presented with abdominal pain. Liver imaging revealed no tumors, but showed intrahepatic portal venous obstruction. HCC with portal tumor thrombi was suspected clinically. His clinical course was rapid; he died of hepatic failure 50 days after admission. At autopsy, the liver (2,700 g) was studded with diffuse whitish yellow granular areas with flecks of coalescent granules. Intrahepatic portal veins were diffusely occluded by tumor thrombi. Microscopically, the tumor was poorly differentiated adenocarcinoma with mucin; tumor cells were immunohistochemically positive for carcinoembryonic antigen, CA 19-9, DU-PAN-2, and biliary type cytokeratins, but negative for alpha-fetoprotein. Tumor cells were diffuse in the liver, and there were numerous tumor thrombi in the small portal veins. Hepatic veins and small arteries were occasionally occluded by tumor thrombi. There was ascites, splenomegaly and tumor thrombi in the gastric and esophageal veins, suggesting that portal hypertension had been present. This tumor seemed to have marked affinity to invade portal veins. It must be stressed that there are CCCs with extensive portal tumor thrombi and resultant portal hypertension.

Production of basic fetoprotein in human peripheral lymphocytes during blastic transformation

To clarify the significance of basic fetoprotein (BFP) in lymphocytes, we investigated whether BFP is produced in lymphocytes during blastic transformation. Peripheral blood lymphocytes obtained from 14 adults were cultured under the stimulation of lectins. The concentration of BFP in the culture medium (extracellular BFP) was estimated serially. The incorporation of [6-3H]-thymidine was assayed simultaneously. The intracellular BFP was measured by dual flow cytometry for DNA and BFP. A lymph node was studied immunohistochemically. Serum BFP was measured in four cases of lymphocytic leukaemia. In two cases, dual staining was performed. The intracellular BFP of the mitogen-stimulated lymphocytes was increased within 24 h. The extracellular BFP was increased exponentially from 72 h. The extracellular BFP at 96 h did not correlate with the [3H]-thymidine incorporation. The intracellular BFP increase began in G1 phase. Immunostaining showed that the B cells also produced BFP. The serum BFP level in leukaemia was high in 1 of 4 cases and the leukaemic cells in two cases showed high intracellular BFP content. These observations indicate that BFP is produced in activated human lymphocytes and in lymphocytic leukaemic cells. The production of BFP during blastic transformation will be a useful new in vitro model for studying the biological role of BFP, and BFP labelling may offer some new possibilities for the study of lymphocytes.

Cystic dilatation of peribiliary glands in livers with adult polycystic disease and livers with solitary nonparasitic cysts: an autopsy study

Cystic dilatation of peribiliary glands of intrahepatic and extrahepatic bile ducts was investigated in autopsied livers with adult polycystic disease (n = 8), in autopsied livers with solitary nonparasitic cysts (n = 18) and in normal autopsied livers (n = 23). In normal livers, cystic dilatation of intrahepatic peribiliary glands was absent or slight, when present. In livers with solitary nonparasitic cysts, cystic dilatation of intrahepatic peribiliary glands was present in varying degrees. In livers with adult polycystic disease, intrahepatic peribiliary glands showed frequent and severe cystic dilatation so marked that it was grossly recognizable. In contrast, peribiliary glands of the extrahepatic bile ducts showed no cystic dilatation in most cases, regardless of the three conditions examined. Liver parenchymal cysts were numerous in livers with adult polycystic disease, few in livers with solitary nonparasitic cysts and nonexistent in normal livers. Von Meyenburg complexes were present in 87.5% of livers with adult polycystic disease, in 16.7% of livers with solitary nonparasitic cysts and in 4.3% of normal livers. These findings suggest that intrahepatic peribiliary glands undergo cystic dilatation in livers with adult polycystic disease-and, to a lesser degree and frequency in livers with solitary nonparasitic cysts, probably because of congenital or genetic factors-and that these cystic changes may comprise a part of numerous cysts of adult polycystic disease.