Retinoic acids up-regulate functional eosinophil-driving receptor CCR3.

Eotaxins and their receptor CCR3 have a definitive role for tissue accumulation of eosinophils both under homeostatic and pathologic conditions. However, physiological stimuli that can up-regulate CCR3 in blood-derived human eosinophils have not been recognized. As a prior gene microarray study revealed up-regulation of CCR3 in eosinophils stimulated with retinoic acids (RAs), the expression of functional CCR3 was examined. We found that 9-cis RA and all-trans RA (ATRA) significantly induced surface CCR3 expression regardless of the presence of IL-3 or IL-5. Pharmacological manipulations with receptor-specific agonists and antagonists indicated that retinoic acid receptor-α activation is critical for CCR3 up-regulation. RA-induced CCR3 was associated with its functional capacity, in terms of the calcium mobilization and chemotactic response to eotaxin-1 (CCL11). Our study suggests an important role of vitamin A derivatives in the tissue accumulation of eosinophils.

Comparative cytotoxicity of gambierol versus other marine neurotoxins.

Many microalgae produce compounds that exhibit potent biological activities. Ingestion of marine organisms contaminated with those toxins results in seafood poisonings. In many cases, the lack of toxic material turns out to be an obstacle to make the toxicological investigations needed. In this study, we evaluate the cytotoxicity of several marine toxins on neuroblastoma cells, focusing on gambierol and its effect on cytosolic calcium levels. In addition, we compared the effects of this toxin with ciguatoxin, brevetoxin, and gymnocin-A, with which gambierol shares a similar ladder-like backbone, as well as with polycavernoside A analogue 5, a glycosidic macrolide toxin. For this purpose, different fluorescent dyes were used: Fura-2 to monitor variations in cytosolic calcium levels, Alamar Blue to detect cytotoxicity, and Oregon Green 514 Phalloidin to quantify and visualize modifications in the actin cytoskeleton. Data showed that, while gambierol and ciguatoxin were successful in producing a calcium influx in neuroblastoma cells, gymnocin-A was unable to modify this parameter. Nevertheless, none of the toxins induced morphological changes or alterations in the actin assembly. Although polycavernoside A analogue 5 evoked a sharp reduction of the cellular metabolism of neuroblastoma cells, gambierol scarcely reduced it, and ciguatoxin, brevetoxin, and gymnocin-A failed to produce any signs of cytotoxicity. According to this, sharing a similar polycyclic ether backbone is not enough to produce the same effects on neuroblastoma cells; therefore, more studies should be carried out with these toxins, whose effects may be being underestimated.

Calcium oscillations induced by gambierol in cerebellar granule cells.

Gambierol is a marine polyether ladder toxin derived from the dinoflagellate Gambierdiscus toxicus. To date, gambierol has been reported to act either as a partial agonist or as an antagonist of sodium channels or as a blocker of voltage-dependent potassium channels. In this work, we examined the cellular effect of gambierol on cytosolic calcium concentration, membrane potential and sodium and potassium membrane currents in primary cultures of cerebellar granule cells. We found that at concentrations ranging from 0.1 to 30 microM, gambierol-evoked [Ca(2+)]c oscillations that were dependent on the presence of extracellular calcium, irreversible and highly synchronous. Gambierol-evoked [Ca(2+)]c oscillations were completely eliminated by the NMDA receptor antagonist APV and by riluzole and delayed by CNQX. In addition, the K(+) channel blocker 4-aminopyridine (4-AP)-evoked cytosolic calcium oscillations in this neuronal system that were blocked by APV and delayed in the presence of CNQX. Electrophysiological recordings indicated that gambierol caused membrane potential oscillations, decreased inward sodium current amplitude and decreased also outward IA and IK current amplitude. The results presented here point to a common mechanism of action for gambierol and 4-AP and indicate that gambierol-induced oscillations in cerebellar neurons are most likely secondary to a blocking action of the toxin on voltage-dependent potassium channels and hyperpolarization of sodium current activation.

Selective up-regulation of type II inosine 5'-monophosphate dehydrogenase messenger RNA expression in human leukemias.

The discovery of isozymes (types I and II) of IMP dehydrogenase (IMPDH; EC 1.1.1.205), the rate-limiting enzyme of de novo GTP biosynthesis, has attracted attention as a possible novel approach to cancer diagnosis and selective tumor cell chemotherapy. To elucidate differences in expression and regulation of the two IMPDH isozymes, we examined the steady-state levels of these mRNAs in various types of leukemic cells from patients. Northern blot analysis revealed that type II IMPDH was more active transcriptionally (1.5- to 5.1-fold) in all the leukemic cells examined than in normal lymphocytes, whereas type I expression was similar. The increased expression of type II mRNA in leukemic cells was closely linked with the increase in total IMPDH activity (r = 0.92). When leukemic cells from a patient with chronic granulocytic leukemia in blast crisis were separated into blast-rich and mature leukocyte-rich fractions, the expression of type II mRNA correlated positively with the population of immature leukemic cells, whereas type I expression was unchanged. Treatment of leukemic blasts with 12-O-tetradecanoyl-phorbol-13-acetate for 5 days resulted in a 90% decrease in the expression of type II mRNA with macrophage-like differentiation, while the expression of type I mRNA was relatively stable. These observations suggest that expression of type II IMPDH is stringently linked with immature characteristics of leukemic cells; thus, it should be a selective target for antileukemic chemotherapy.

2-Methoxy-4-nitroaniline and its isomers induce cytochrome P4501A (CYP1A) enzymes with different selectivities in the rat liver.

We reported previously that 2-methoxy-4-nitroaniline (2-MeO-4-NA) is a selective inducer of cytochrome P4501A2 (CYP1A2) in the rat liver, and its molecular size is the smallest among known CYP1A2-selective inducers. In the present study, a structure-activity relationship on the CYP1A2-selective induction has been investigated using isomeric nitroanisidines and their related chemicals. Western blot analyses revealed that the chemicals removed a substituent (amino, methoxyl or nitro group) from a 2-MeO-4-NA molecule had no capacity for inducing CYP1A enzymes in rat livers. On the other hand, isomeric nitroanisidines such as 2-MeO-4-NA, 2-MeO-5-NA and 4-MeO-2-NA induced both CYP1A2 and CYP1A1 enzymes with different selectivities. As judged from the induced levels of CYP1A proteins, 2-MeO-4-NA (CYP1A2/CYP1A1 ratio; 9.5) and 4-MeO-2-NA (0.3) were the most selective inducers of CYP1A2 and CYP1A1, respectively, among the isomeric nitroanisidines (0.44 mmol/kg) used. The induced level of CYP1A2 protein was in the order 2-MeO-4-NA > 2-MeO-5-NA > 4-MeO-2-NA, although no significant difference was observed on their CYP1A2 mRNA level. On the contrary, increases in the levels of CYP1A1 mRNA and protein were in the order 4-MeO-2-NA > 2-MeO-5-NA > 2-MeO-4-NA. The present findings indicate that all three substituents (amino, methoxyl and nitro groups) are necessary components of nitroanisidines for induction of CYP1A enzymes, and also show that regio-isomeric positions of these substituents determine the selectivity in the induction of CYP1A enzymes.

A carboxy-terminal deletion mutant of protein kinase C beta II inhibits insulin-stimulated 2-deoxyglucose uptake in L6 rat skeletal muscle cells.

Alternative splicing of pre-mRNA encoding the carboxy-terminal (C-terminal) exons of protein kinase C beta (PKC beta) leads to the expression of two protein isoforms, PKC beta 1 and PKC beta II, with the potential for different functions. PKC beta II expression is regulated by insulin via alternative mRNA splicing. A physiological consequence of its activation was investigated in L6 rat skeletal muscle cells expressing GLUT4 transporters, a cell line in which PKC is involved in glucose transport. We examined the contribution of PKC beta II for insulin-stimulated [3H]2-deoxyglucose uptake by constructing three PKC beta II C-terminal deletion mutants designated M216, M217, and M218. When transiently expressed in COS1 cells, M217, with nine amino acids deleted, demonstrated autophosphorylation activity 10-fold less than full-length PKC beta II. The mutants M218, with 13 amino acids deleted, and M216, with 52 amino acids deleted, demonstrated no autophosphorylation activity and are kinase negative. When transiently expressed in L6 myotubes, M217 inhibited insulin-stimulated 2-deoxyglucose uptake by 45% (with a 45% transfection efficiency) whereas M216 and M218, kinase-negative mutants, had no effect compared with cells transfected with control plasmid. Cotransfection of full-length PKC beta II with M217 was able to rescue the inhibition of insulin-stimulated 2-deoxyglucose uptake as compared with cotransfection of M217 with the control plasmid, suggesting that M217 acts as a dominant-negative. In contrast, cotransfection of full-length PKC beta I, the other alternatively spliced form, did not rescue inhibition of insulin-stimulated 2-deoxyglucose uptake by M217. To further demonstrate the involvement of PKC, specifically PKC beta II, in insulin-stimulated 2-deoxyglucose uptake, we used two inhibitors, CG41251 (a specific PKC inhibitor) and CG53353 (a PKC beta II-specific inhibitor at 1 microM). Both inhibited insulin-stimulated 2-deoxyglucose uptake 50-60% in L6 myotubes. We conclude that M217 may act as a specific PKC beta II dominant-negative and that PKC beta II is more specific for insulin-stimulated 2-deoxyglucose uptake in these cells than PKC beta I.

Direct evidence that the kinase activity of protein kinase C is involved in transcriptional activation through a TPA-responsive element.

In order to examine the involvement of protein kinase C (PKC) in the transcriptional activation of genes by TPA (12-0-tetradecanoyl phorbol 13-acetate) we have constructed a series of PKC expression plasmids. Transient expression of an active fragment of PKC in rat fibroblasts resulted in the transcriptional activation of a TRE (TPA-responsive element)-CAT chimeric gene which contains various repetitions of collagenase TREs. These provide the first direct evidence that kinase activity of PKC is involved in TPA-induced transcriptional activation through TRE.

HLA-B27 subtypes and HLA class II alleles in Japanese patients with anterior uveitis.

PURPOSE: Some patients with anterior uveitis (AU) have ankylosing spondylitis (AS) and are HLA-B27 class I-positive. The purpose of this study was to investigate whether there are differences in HLA at the allele level among each group of patients with AU. METHODS: Seventy-three patients with AU were studied. They were classified into three groups: 31 with AS-associated AU, 14 with HLA-B27-associated AU, and 28 with idiopathic AU. Three control groups without AU were used: 138 random subjects, 33 HLA-B27-positive healthy subjects, and 19 HLA-B27-positive patients with AS. DRB1 and DQB1 genotyping was performed using polymerase chain reaction (PCR)-single-strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism. HLA-B27 subtype was determined by PCR-SSCP. RESULTS: There was no difference in the frequency of any class I antigen except HLA-B27 among the patients studied. The frequencies of HLA-DR12 in AS-associated AU and HLA-DR1 in HLA-B27-associated AU showed an increase. In HLA-B27-associated AU, DRB1*0101 and DQB1*0501 were increased compared with HLA-B27-positive control subjects. When HLA-B27 subtype distribution was compared among the groups, the proportion of B*2704 was significantly lower in HLA-B27-associated AU (P = 0.037), however, such a difference was not present in AS-associated groups. CONCLUSIONS: These results indicated that B*2704 seemed to be less susceptible to AU compared with B*2705 in Japanese subjects. The increase of HLA-DR12 and HLA-DR1 in AU may be caused by linkage disequilibrium with B*2704 and B*2705, respectively.

Heterocyclic amine mixture carcinogenesis and its enhancement by caffeine in F344 rats.

In order to elucidate whether mixed exposure to environmental carcinogens and caffeine increases the risk of cancer induction, we investigated the relationship between preneoplastic lesion development in the liver and colon and drug metabolizing enzyme induction and DNA adduct formation, in rats treated with a mixture of heterocyclic amines (HCAs) and caffeine. In Experiment 1, male F344 rats were administered 3 different HCAs, the food carcinogens, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), alone or in combinations of 2 or 3 at 50 ppm in the diet for 16 weeks. The numbers of hepatic glutathione-S-transferase P form positive (GST-P+) foci and colonic aberrant crypt foci (ACF) were greater in the IQ + MeIQx group than expected from simple summation and increased levels of HCA-DNA adducts were noted. However, no summation was obtained when combined with PhIP, which rather caused inhibition. In Experiment 2, the effects of concurrent caffeine administration on the PhIP carcinogenicity were assessed. Caffeine at 1000 and 500 ppm in the drinking water for 2 weeks significantly increased levels of CYP1A2. Ten weeks concurrent administration of caffeine (1000 ppm) and PhIP (400 ppm) resulted in significant increase of colon ACFs and CYP1A2 expression. Thus, concurrent administration of IQ and MeIQx caused elevation of their carcinogenicity but other mixtures with PhIP did not enhance carcinogenicity. However, a non-carcinogen, caffeine, enhanced PhIP colon carcinogenesis, possibly due to induction of CYP1A2.

Relevance of periglomerular myofibroblasts in progression of human glomerulonephritis.

To clarify the pathological and clinical significance of periglomerular alpha-smooth muscle actin (alpha-SMA)-positive cells, we examined 51 needle-biopsy specimens from patients with human glomerulonephritis. Immunoelectron microscopy confirmed these cells were myofibroblasts showing characteristic features with abundant alpha-SMA-positive thin myofilaments. Nonsclerotic glomeruli with periglomerular myofibroblasts were larger in the Bowman's capsular planar area than nonsclerotic glomeruli without periglomerular myofibroblasts (24.7 +/- 6.0 x 10(3) microm2 v 19.9 +/- 8.5 x 10(3) microm2; P < 0.01). We studied the correlation between the clinical prognosis and the extent of periglomerular myofibroblasts in 24 patients with IgA nephropathy. Patients were divided into two groups; those with plasma creatinine levels within normal range at biopsy and significantly elevated at follow-up were designated group 1 (poor prognosis), and patients with plasma creatinine levels within normal range at biopsy and not significantly elevated at follow-up were designated group 2 (fair prognosis). In the kidneys of group 1 patients, periglomerular alpha-SMA was expressed more intensively than it was in the kidneys of group 2 patients (alpha-SMA expression score, 1.0 +/- 0.48 v 0.52 +/- 0.54; P < 0.05). These findings indicate that periglomerular myofibroblasts appeared surrounding the nonsclerotic hypertrophic glomeruli, which may lead finally to glomerulosclerosis. This report suggests that interaction between the glomerular cells and the periglomerular myofibroblasts may have a role in the progression of glomerular diseases.

High catalytic activity of human cytochrome P450 co-expressed with human NADPH-cytochrome P450 reductase in Escherichia coli.

Forms of human cytochrome P450 (P450 or CYP), such as CYP1A1, CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4, were expressed or co-expressed together with human NADPH-P450 reductase in Escherichia coli. When P450 was expressed alone in E. coli, the expression level of holo-P450 ranged from 310 to 1620 nmol/L of culture. The expression level of holo-P450 decreased by co-expression with the reductase, and the level ranged from 66 to 381 nmol/L of culture. The expression level of the reductase varied depending on the forms of P450 co-expressed, and ranged from 204 to 937 U/L of culture. We assayed the catalytic activity of P450 using E. coli cells disrupted by freeze-thaw. When co-expressed with the reductase, human P450 catalyzed the oxidation of representative substrates at efficient rates. The rates appeared comparable to the reported activities of P450 in a reconstituted system containing purified preparations of P450 and the reductase.

Enzymatic properties of a novel phorbol ester receptor/protein kinase, nPKC.

A protein kinase C-related cDNA encodes a novel phorbol ester receptor/protein kinase, nPKC epsilon, clearly distinct from the four "conventional" PKCs [Ohno, S., Akita, Y., Konno, Y., Imajoh, S., & Suzuki, K. (1988) Cell 53, 731-741]. We purified nPKC epsilon from COS cells transfected with nPKC cDNA and compared its enzymatic properties with a conventional PKC, PKC alpha. nPKC epsilon was eluted from a hydroxyapatite column at a position coincident with type II PKC and thus was separated from type III PKC (PKC alpha), the only PKC expressed in COS cells. The protein kinase activity of nPKC epsilon is activated by phospholipids and diacylglycerols (or phorbol esters) in a manner similar to conventional PKCs. However, the cofactor dependencies and substrate specificities were clearly different from PKC alpha. A phospholipid, cardiolipin, enhances the kinase activity three- to fourfold compared with phosphatidylserine. The optimum Mg2+ concentration (3 mM) is clearly different from those of conventional PKCs (10-20 mM). The activation of nPKC epsilon by these cofactors is totally independent of Ca2+. Similar to conventional PKCs, nPKC epsilon autophosphorylates serine and threonine residues, indicating the specificity of the kinase to these amino acid residues. However, it shows a clearly different substrate specificity against exogenous substrates in that myelin basic proteins rather than histone are good substrates. These properties of nPKC epsilon permit clear discrimination of nPKC epsilon from conventional PKCs.

Structural and functional diversities of a family of signal transducing protein kinases, protein kinase C family; two distinct classes of PKC, conventional cPKC and novel nPKC.

Recent molecular cloning and biochemical experiments on the nature of protein kinase C (PKC) have revealed the existence of two distinct classes of phorbol ester (and diacylglycerol) receptor/protein kinase, conventional PKC (cPKC) and novel PKC (nPKC). Each of these classes contains multiple related molecules expressed in tissues and cells in a type-specific manner. Although nPKC does not show the typical PKC activity ascribable to conventional PKCs and thus was neglected in earlier studies, several lines of evidence suggest that nPKCs are involved in a variety of cell responses to physiological stimuli and phorbol esters. It is possible that in some cases nPKC is the major mediator of the so-called PKC-activators, such as phorbol esters, mezerein, and bryostatins. In addition to the clear difference between cPKC and nPKC, functional diversity among conventional PKCs has also been demonstrated; PKC gamma differs in its competence to mediate the signal toward transcriptional activation through TPA-responsive cis-acting elements from cPKC alpha and nPKC epsilon. The differences between cPKC and nPKC and among the individual members of each of these two classes, and their specific pattern of distribution in tissues and cells, provide a rationale by which to explain the specificity and diversity of cellular responses to external stimuli generating DAG and to phorbol esters. The results presented here also provide a means to dissect the complex signaling pathway in cells and to analyze the molecular basis underlying the signal transduction processes mediated by this family of protein kinases.

Effects of early introduction of intensive insulin therapy on the clinical course in non-obese NIDDM patients.

In order to reconsider the extent of indication of insulin therapy in non-insulin dependent diabetes mellitus (NIDDM), we performed the following trial in a prospective fashion. At the beginning phase of treatment for diabetes, we introduced intensive insulin therapy in 22 non-obese (Body mass index approximately 24 kg/m2) NIDDM patients without proliferative retinopathy, who were selected in a standardized fashion, avoiding any arbitrary choice. None had received oral hypoglycemic agents (OHA) or insulin yet. By administering insulin 3 or 4 times a day, strict glycemic control was attained and maintained, and then the insulin dose was gradually lowered while keeping good glycemic control. In patients whose glycemic control was maintained at an excellent level for more than 7 days under an insulin dosage lower than 8 u/day, insulin therapy was discontinued. As a result, 15 patients (68%) attained good glycemic control both without insulin and OHA almost within a month and 6 patients (27%) shifted to OHA. It is recommended to introduce intensive insulin therapy in non-obese NIDDM patients without proliferative retinopathy and to aim at attaining good glycemic control both without insulin and OHA.

Artificial endocrine pancreas and optimal blood glucose regulation in diabetic patients--from bedside-type to wearable-type.

The artificial endocrine pancreas is a feedback control system regulating insulin delivery on a minute-by-minute basis according to the measured blood glucose levels. The bedside-type artificial endocrine pancreas has been proven to be useful not only as a therapeutic tool for diabetes mellitus but also as an elegant research tool for investigating the pathophysiology of the disease. With significant advances in the development of a subcutaneous tissue glucose monitoring system, the wearable-type artificial endocrine pancreas has been applied to diabetic patients. With this system, perfect glycemic control can be obtained for longer periods in ambulatory diabetic patients. The trend in the development of the artificial endocrine pancreas is now directed to implantable devices. Much efforts have been conducted to realize these devices.

Effect of subconjunctival steroid injection on intraocular inflammation and blood glucose level after cataract surgery in diabetic patients.

PURPOSE: To prospectively evaluate the usefulness of a subconjunctival steroid injection given at the completion of cataract surgery in patients with diabetes mellitus. SETTING: University of Tokyo School of Medicine, Tokyo, Kaiya Eye Clinic, Hamamatsu, and Jyosai Hospital, Tokyo, Japan. METHODS: One hundred four eyes of 104 diabetic patients having routine small incision cataract surgery were randomized into 2 groups. One group received a subconjunctival injection of dexamethasone and the other group did not. Aqueous flare intensity was measured with the laser flare meter preoperatively and 1, 2, 5, 7, and 14 days postoperatively. Another 19 diabetic patients having routine cataract surgery were randomized to receive a subconjunctival steroid injection or not; blood glucose concentration was measured 4 times a day for 3 days postoperatively. RESULTS: There was no significant difference between the 2 groups in aqueous flare values at any postoperative time. The subconjunctival steroid injection induced a transient but significant increase in blood glucose on the day of surgery. CONCLUSION: A subconjunctival steroid injection given at the completion of cataract surgery in diabetic patients had no beneficial effects.

Evaluation of outcome and QOL in patients with craniofacial resection for malignant tumors involving the anterior skull base.

The purpose of this study was to retrospectively evaluate the effectiveness of anterior craniofacial resection in the treatment of nasal and paranasal malignant tumors involving anterior skull base. Between 1992 and 1998, 13 patients with nasal or paranasal malignant tumors underwent this surgical procedure. The site and time of metastasis or recurrence, and survival outcome were retrospectively surveyed. Current status of long-surviving patients and their subjective assessment of the surgical treatment were also evaluated through questionnaires. Median follow-up period was 52 months. Nine patients (69%) were alive with no evidence of disease. Of these patients, eight had survived for more than three years. Recurrence or metastasis occurred in four patients (31%). The mean time interval between surgery and recurrence or metastasis was 11 months. According to the results of questionnaires to long-surviving patients, 89% patients had some complaints. In particular, complaints of unsightly appearance were manifested by all these patients. When the patients themselves evaluated their current conditions resulting from this surgical treatment, 63% were dissatisfied. These results suggest that this surgical treatment is valid for selected patients in regard to survival outcome. When the effectiveness of this treatment is evaluated, however, psychological and functional issues should not be taken lightly.

Electroresponsive pulsatile depot delivery of insulin from poly(dimethylaminopropylacrylamide) gel in rats.

We describe a model for pulsatile drug delivery with an electroresponsive polymer that is stimulated by an externally applied electrical field. Insulin loaded in an electroresponsive poly(dimethylaminopropylacrylamide) (PDMAPAA) gel was administered as a subcutaneous depot in rats. The gel induced a pulsatile plasma glucose decrease in correspondence to stimulation with a constant current of 1.0 mA (0.36 mA/cm2). The first drop occurred at 0.5 h after a 1-min application of current at 0 h and the second drop occurred at 3 h after a 10-min application of current at 2 h. Calculation of pharmacological bioavailability showed that the gel released 0.12% of the loaded insulin after these two stimuli. This in vivo study demonstrates the feasibility of this pulsatile delivery system. The mechanism of insulin release from the electroresponsive PDMAPAA gel is associated with electrokinetic flow of solvated insulin with water; that is, transportation process of counterions (electrophoresis) and water molecules (electroosmosis) in the crosslinked polyelectrolyte gel network.

In vivo fate of folate-BSA in non-tumor- and tumor-bearing mice.

KB tumor cells exhibit an increased number of folate receptors on their membrane. This receptor has been proposed as a promising target for tumor drug targeting. Therefore, the disposition of folate-conjugated bovine serum albumin (folate-BSA) was examined as a model system for drug targeting. Nude mice which had received KB tumor cell transplants were given bolus intravenous administration of either 111In-labeled folate-BSA (111In-folate-BSA; 1 mg/kg) or unmodified 111In-BSA (111In-BSA; 1 mg/kg). The disposition characteristics and pharmacokinetics of 111In-folate-BSA were compared with those of the 111In-BSA as a control. The half-life of the beta-phase of 111ln-folate-BSA in plasma was 140 min. The tumor uptake rate index for 111In-folate-BSA was 0.46 microL/min/g, and that for 111In-BSA was 0.32 microL/min/g. This index of 111In-folate-BSA was slightly higher than that of 111In-BSA in vivo, by a factor of 1.4. In vivo experiments showed folate-BSA has a relatively long plasma duration. 111In-folate-BSA also showed selective distribution to tumors, but not as great as recent results from in vitro experiments. Therefore, the low vascular permeability of BSA into solid tumor tissue and inhibition of folate-mediated 111In-folate-BSA uptake by tumor cells from the blood may be the rate-limiting factor of distribution.

Differential localization of s and e antigens in hepatitis B virus-associated glomerulonephritis.

We report here a case of membranous glomerulonephritis associated with chronic hepatitis B (HB) virus infection and describe differential localization of HB antigens in glomeruli. The patient showed mild proteinuria and was positive for hepatitis B surface (HBs) antigen, hepatitis B envelope (HBe) antigen, and antibody to hepatitis B core (HBc) antigen in the serum. The antibody against hepatitis C was negative. A renal biopsy revealed membranous glomerulonephritis with mesangial proliferation. The immunohistochemical studies using monoclonal antibodies localized the HBe antigen along the capillary wall and the HBs antigen in the mesangial area. The immunoelectron microscopic study confirmed the localization of HB antigens: HBe antigen was located in the subepithelial and intramembranous electron dense deposits and HBs antigen in the mesangial deposits. Our present results provide the first report of the differential localization of HB antigens in glomeruli at both the light and electron microscopic levels. The differential localization of HB antigens will provide insight into the pathogenesis of membranous glomerulonephritis.