Role of atypical protein kinase C in activation of sterol regulatory element binding protein-1c and nuclear factor kappa B (NFkappaB) in liver of rodents used as a model of diabetes, and relationships to hyperlipidaemia and insulin resistance.

AIMS/HYPOTHESIS: Previous findings in rodents used as a model of diabetes suggest that insulin activation of atypical protein kinase C (aPKC) is impaired in muscle, but, unexpectedly, conserved in liver, despite impaired hepatic protein kinase B (PKB/Akt) activation. Moreover, aPKC at least partly regulates two major transactivators: (1) hepatic sterol receptor binding protein-1c (SREBP-1c), which controls lipid synthesis; and (2) nuclear factor kappa B (NFkappaB), which promotes inflammation and systemic insulin resistance. METHODS: In Goto-Kakizaki rats used as a model of type 2 diabetes, we examined: (1) whether differences in hepatic aPKC and PKB activation reflect differences in activation of IRS-1- and IRS-2-dependent phosphatidylinositol 3-kinase (PI3K); (2) whether hepatic SREBP-1c and NFkappaB are excessively activated by aPKC; and (3) metabolic consequences of excessive activation of hepatic aPKC, SREBP-1c and NFkappaB. RESULTS: In liver, as well as in muscle, IRS-2/PI3K activation by insulin was intact, whereas IRS-1/PI3K activation by insulin was impaired. Moreover, hepatic IRS-2 is known to control hepatic aPKC during insulin activation. Against this background, selective inhibition of hepatic aPKC by adenoviral-mediated expression of mRNA encoding kinase-inactive aPKC or short hairpin RNA targeting Irs2 mRNA and partially depleting hepatic IRS-2 diminished hepatic SREBP-1c production and NFkappaB activities, concomitantly improving serum lipids and insulin signalling in muscle and liver. Similar improvements in SREBP-1c, NFkappaB and insulin signalling were seen in ob/ob mice following inhibition of hepatic aPKC. CONCLUSIONS/INTERPRETATION: In diabetic rodent liver, diminished PKB activation may largely reflect impaired IRS-1/PI3K activation, while conserved aPKC activation reflects retained IRS-2/PI3K activity. Hepatic aPKC may also contribute importantly to excessive SREPB-1c and NFkappaB activities. Excessive hepatic aPKC-dependent activation of SREBP-1c and NFkappaB may contribute importantly to hyperlipidaemia and systemic insulin resistance.

Human Ca2+/calmodulin-dependent phosphodiesterase PDE1A: novel splice variants, their specific expression, genomic organization, and chromosomal localization.

We report here the identification of novel human PDE1A splice variants, their tissue distribution patterns, genomic structure, and chromosomal localization of the gene. We identified one N-terminus (N3) and one C-terminus (C3) by cDNA library screening and dbEST database search. These N- and C-termini, including the reported N-termini (N1 and N2) and C-termini (C1 and C2), combined to generate nine different PDE1A cDNAs. N1 and N2 are similar to the 5' ends of the bovine PDE1A proteins of 61 kDa and 59 kDa, respectively, and C1 and C2 are the 3' ends of the reported human PDE1A variants. The results of PCR and Southern blot analysis show that nine PDE1A splice variants exhibit distinctive tissue distribution patterns by the difference of the N-terminus. PDE1As with N2 were widely expressed in various tissues, mainly in the kidney, liver, and pancreas. On the other hand, PDE1As with N1 and N3 were particularly expressed at a high level in the brain and testis, respectively. These findings suggest that the distinct expression patterns among PDE1A variants depend on the several promoters situated upstream of exons encoding 5' ends of the variants. The PDE1A gene spans over 120 kb of genomic DNA, and consists of at least 17 exons and 16 introns. The PDE1A gene was located on human chromosome 2q32 by fluorescent in situ hybridization analysis.

Effect of tumor necrosis factor-alpha on insulin signal transduction in rat adipocytes: relation to PKCbeta and zeta translocation.

Although much evidence has been accumulated suggesting that tumor necrosis factor-alpha (TNF-alpha) is an important mediator of insulin resistance, the precise mechanism involved is still unclear. Recently, it has been reported that insulin-induced glucose uptake is mediated by activation of second messengers such as insulin receptor substrate 1 (IRS-1), phosphatidylinositol 3-kinase (PI3K), and diacylglycerol (DG)-protein kinase C (PKC). We have examined the effect of TNF-alpha on insulin-induced glucose uptake and activations of tyrosine kinase, IRS-1, PI3K and PKC in rat adipocytes. Pretreatment with 0.1-100 nM TNF-alpha for 60 min resulted in a significant decrease in 10 nM insulin- or 1 microM 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced [3H]2-deoxyglucose uptake without affecting basal glucose uptake. 10 nM insulin-stimulated activation of tyrosine kinase, IRS-1 and PI3K was suppressed by preincubation with 0.1-10 nM TNF-alpha for 60 min. 10 nM TNF-alpha pretreatment also suppressed 10 nM insulin- and 1 microM TPA-induced increases in membrane-associated PKCbeta and PKCzeta. Furthermore, 10 nM TNF-alpha, by itself, altered PKCbeta translocation from the membrane to cytosol. These results suggest that TNF-alpha inhibits insulin-stimulated activation of both the tyrosine kinase-IRS-1-PI3K-PKCzeta pathway and DG-PKC pathway. Finally, TNF-alpha contributes to insulin resistance in rat adipocytes.

Differential effect of the antidiabetic thiazolidinediones troglitazone and pioglitazone on human platelet aggregation mechanism.

Troglitazone and pioglitazone, antidiabetic thiazolidinediones, are known to improve insulin resistance. However, the effect of these drugs on platelet aggregation remains unclear. The chemical structure of troglitazone contains vitamin E. Accordingly, we studied the effect of troglitazone, pioglitazone, and vitamin E on thrombin-induced platelet aggregation, metabolism of phosphoinositide, protein phosphorylation, protein kinase C (PKC)-alpha and -beta, and phosphatidylinositol (PI) 3-kinase activation in vitro in human platelets. Maximum platelet aggregation by ADP, collagen, and thrombin decreased in the presence of 0.1-1 micromol/l troglitazone and 500 nmol/l vitamin E for 60 min compared with controls. However, pioglitazone did not inhibit ADP-, collagen-, or thrombin-induced platelet aggregation. Pretreatment with troglitazone and vitamin E, but not with pioglitazone, resulted in decreases in thrombin-induced phosphatidic acid production, hydrolysis of phosphatidylinositol 4,5-bisphosphate by phospholipase C, and 47-kDa protein phosphorylation. Thrombin-induced PKC-alpha and -beta activation in membrane fraction was suppressed by pretreatment with troglitazone and vitamin E, but not with pioglitazone. Separately, troglitazone and pioglitazone stimulated PI 3-kinase activity, but thrombin-induced PI 3-kinase activation was suppressed by pretreatment with troglitazone and pioglitazone for 60 min. These results suggest that troglitazone and vitamin E, but not pioglitazone, have a potent inhibitory effect on platelet aggregation via suppression of the thrombin-induced activation of phosphoinositide signaling in human platelets. Finally, the chemical structure of vitamin E may contribute to the inhibitory effect of troglitazone on platelet aggregation in human platelets.

Glucocorticoid-induced insulin resistance associates with activation of protein kinase C isoforms.

We studied glucocorticoid-induced insulin resistance and possible role of protein kinase C (PKC). Pretreatment with dexamethasone, prednisolone and corticosterone for 60 min decreased insulin-induced [3H] 2-deoxyglucose (DOG) uptake in isolated rat adipocytes. Preincubation with Go6976, LY379196 or myristoylated PKC pseudosubstrate, conventional PKC inhibitor, but not cycloheximide or RU38486, recovered dexamethasone-induced insulin resistance. Dexamethasone activated immunoprecipitates with anti-PKC alpha, beta, and zeta antibodies. PKC zeta activity in adipocytes increased to 163%, and 264% from basal level (100%) with dexamethasone and insulin treatment, respectively. Dexamethasone provoked redistribution of both PKC beta and zeta from the cytosol to the membrane. These results indicate that dexamethasone activates both conventional and atypical PKC. However, conventional PKC is more important in glucocorticoid-induced insulin resistance.

Effect of pertussis toxin on insulin-induced signal transduction in rat adipocytes and soleus muscles.

It has been reported that pertussis toxin (PTX) suppresses the function of trimeric guanine nucleotide binding protein (G-protein). We examined the effect of PTX on insulin-induced glucose uptake, diacylglycerol (DG)-protein kinase C (PKC) signalling, phosphatidylinositol (PI) 3-kinase and PKC zeta activation and insulin-induced tyrosine phosphorylation of Gialpha to clarify the role of G-protein for insulin-mediated signal transduction mechanism in rat adipocytes and soleus muscles. Isolated adipocytes and soleus muscles were preincubated with 0.01 approximately 1 ng/ml PTX for 2 hours, followed by stimulation with 10-100 nM insulin or 1 microM tetradecanoyl phorbol-13-acetate (TPA). Pretreatment with PTX resulted in dose-responsive decreases in insulin-stimulated [3H]2-deoxyglucose (DOG) uptake, and unchanged TPA-stimulated [3H]2-DOG uptake, without affecting basal [3H]2-DOG uptake. In adipocytes, insulin-induced DG-PKC signalling, PI 3-kinase activation and PKC zeta translocation from cytosol to the membrane were suppressed when treated with PTX, despite no changes in [125I]insulin-specific binding and insulin receptor tyrosine kinase activity. Moreover, to elucidate insulin-stimulated tyrosine phosphorylation of 40 kDa alpha-subunit of G-protein (Gialpha-2), adipocytes were stimulated with 10 nM insulin for 10 minutes, homogenized, immunoprecipitated with anti-phosphotyrosine antibody, and immunoblotted with anti-Gialpha-2 antibody. Insulin-induced tyrosine phosphorylation of Gialpha-2 was found by immunoblot analysis with anti-Gialpha-2 antibody. These results suggest that G-protein regulates DG-PKC signalling by binding of Gialpha-2 with GTP and PI 3-kinase-PKC zeta signalling by releasing of Gbetagamma via dissociation of trimeric G-protein after insulin receptor tyrosine phosphorylation in insulin-sensitive tissues.

Rosiglitazone, insulin treatment, and fasting correct defective activation of protein kinase C-zeta/lambda by insulin in vastus lateralis muscles and adipocytes of diabetic rats.

Atypical protein kinases C (PKCs), zeta and lambda, and protein kinase B (PKB) are thought to function downstream of phosphatidylinositol 3-kinase (PI 3-kinase) and regulate glucose transport during insulin action in skeletal muscle and adipocytes. Insulin-stimulated glucose transport is defective in type II diabetes mellitus, and this defect is ameliorated by thiazolidinediones and lowering of blood glucose by chronic insulin therapy or short-term fasting. Presently, we evaluated the effects of these insulin-sensitizing modalities on the activation of insulin receptor substrate-1 (IRS-1)-dependent PI 3-kinase, PKC-zeta/lambda, and PKB in vastus lateralis skeletal muscles and adipocytes of nondiabetic and Goto-Kakizaki (GK) diabetic rats. Insulin provoked rapid increases in the activity of PI 3-kinase, PKC-zeta/lambda, and PKB in muscles and adipocytes of nondiabetic rats, but increases in IRS-1-dependent PI 3-kinase and PKC-zeta/lambda, but not PKB, activity were substantially diminished in GK muscles and adipocytes. Rosiglitazone treatment for 10-14 days, 10-day insulin treatment, and 60-h fasting reversed defects in PKC-zeta/lambda activation in GK muscles and adipocytes and increased glucose transport in GK adipocytes, without necessarily increasing IRS-1-dependent PI 3-kinase or PKB activation. Our findings suggest that insulin-sensitizing modalities, viz. thiazolidinediones, chronic insulin treatment, and short-term fasting, similarly improve defects in insulin-stimulated glucose transport at least partly by correcting defects in insulin-induced activation of PKC-zeta/lambda.

Effects of adenoviral gene transfer of wild-type, constitutively active, and kinase-defective protein kinase C-lambda on insulin-stimulated glucose transport in L6 myotubes.

We used adenoviral gene transfer methods to evaluate the role of atypical protein kinase Cs (PKCs) during insulin stimulation of glucose transport in L6 myotubes. Expression of wild-type PKC-lambda potentiated maximal and half-maximal effects of insulin on 2-deoxyglucose uptake, but did not alter basal uptake. Expression of constitutively active PKC-lambda enhanced basal 2-deoxyglucose uptake to virtually the same extent as that observed during insulin treatment. In contrast, expression of kinase-defective PKC-lambda completely blocked insulin-stimulated, but not basal, 2-deoxyglucose uptake. Similar to alterations in glucose transport, constitutively active PKC-lambda mimicked, and kinase-defective PKC-lambda completely inhibited, insulin effects on GLUT4 glucose transporter translocation to the plasma membrane. Expression of kinase-defective PKC-lambda, in addition to inhibition of atypical PKC enzyme activity, was attended by paradoxical increases in GLUT4 and GLUT1 glucose transporter levels and insulin-stimulated protein kinase B enzyme activity. Our findings suggest that in L6 myotubes, 1) atypical PKCs are required and sufficient for insulin-stimulated GLUT4 translocation and glucose transport; and 2) activation of protein kinase B in the absence of activation of atypical PKCs is insufficient for insulin-induced activation of glucose transport.

Alterations in insulin-induced postreceptor signaling in adipocytes of the Otsuka Long-Evans Tokushima fatty rat strain.

The Otsuka Long-Evans Tokushima fatty (OLETF) rat is a new spontaneous non-insulin-dependent diabetes mellitus (NIDDM) model rat strain developed in Tokushima, Japan. After 18 weeks of age, decreases of 45% and 40% respectively in insulin- and phorbol ester-stimulated [3H]2-deoxyglucose (DOG) uptake were observed, compared with those in Long-Evans Tokushima (LETO) rats (control). Insulin-specific binding and 95 kDa autophosphorylation of insulin receptor in OLETF rats were not different from those in LETO rats. Insulin-induced diacylglycerol (DG) production and Mono Q column-purified protein kinase C (PKC) translocation in adipocytes of OLETF rats were decreased compared with those of LETO rats. Insulin-induced PKC beta translocation from cytosol to membrane was also decreased in adipocytes of OLETF rats. Increases of the PKC beta I, beta II, epsilon and zeta isoforms in membranes of OLETF rats were markedly smaller than those of LETO rats. Analysis of mRNA levels of PKC isoforms in adipocytes of OLETF rats showed decreases of basal level and insulin-induced delayed responses of PKC beta I, beta II, epsilon and zeta mRNA in OLETF rats. On the other hand, insulin- or phorbol ester-induced phosphatidylinositol 3-kinase (PI 3-kinase) activation was decreased in adipocytes of OLETF rats compared with those of LETO rats. These results suggest that insulin resistance in OLETF rats, a spontaneous NIDDM model rat, may be associated with deterioration of insulin-induced DG-PKC signaling and subsequent decrease in PI 3-kinase activation.

Effect of glucocorticoid receptor antagonist RU 38486 on acute glucocorticoid-induced insulin resistance in rat adipocytes.

We examined the mechanism of acute glucocorticoid-induced insulin resistance in rat adipocytes using the glucocorticoid receptor antagonist RU 38486. Pretreatment with dexamethasone (DEX) and prednisolone for 60 minutes resulted in 50% inhibition of insulin-induced [3H]2-deoxyglucose (DOG) uptake at 10(-8) and 10(-7) mol/L, respectively, in rat adipocytes and 20% and 25% inhibition of insulin-induced [3H]2-DOG uptake, respectively, in soleus muscles. Our previous experiments indicated that DEX and prednisolone alone stimulate protein kinase C (PKC) in rat adipocytes. Accordingly, we examined [3H]DEX binding to PKC from MonoQ column-purified rat brain cytosol. Specific [3H]DEX binding to MonoQ column-purified PKC was observed (kd, 56.8 nmol/L; Bmax, 725 fmol/mg protein). Thus, insulin-induced PKC translocation from the cytosol to the membrane was suppressed by pretreatment with 10(-7) mol/L DEX and 10(-6) mol/L prednisolone for 80 minutes. During treatment with RU 38486 for 60 minutes, there was no change in the glucocorticoid-induced inhibitory effect on insulin-induced [3H]2-DOG uptake and PKC translocation from the cytosol to the membrane. Moreover, pretreatment with RU 38486 for 120 minutes slightly prevented the DEX-mediated inhibition of insulin-induced glucose uptake. These results suggest that acute glucocorticoid-induced insulin resistance may be mainly mediated through the other non-glucocorticoid receptor pathway.

Progression of prostate cancer: diagnostic and prognostic utility of prostate-specific antigen, alpha2-macroglobulin, and their complexes.

We previously reported cases of advanced prostate cancer (PCa) in which serum alpha2-macroglobulin (alpha2M) levels were markedly decreased to less than approximately 50 mg/dl whereas serum prostate-specific antigen (PSA) levels were remarkably increased. These cases were not complicated with disseminated intravascular coagulation (DIC). In this study, we measured serum PSA and alpha2M in 108 patients with either benign prostatic hyperplasia (BPH) or PCa to elucidate the relationship between PSA, i.e. the serum protease derived from the prostatic tissue, and alpha2M, i.e. the protease inhibitor that was the most abundantly contained in serum. alpha2M was determined by ELISA, total PSA and PSA-alpha1-antichymotrypsin (PSA-ACT) by EIA, and free-PSA by RIA in 44 patients with untreated BPH and 64 patients with untreated PCa. The ready association of alpha2M and PSA was assessed using Western blotting to identify complexes of the two. Levels of total serum PSA correlated positively with those of PSA-ACT in PCa (r = 0.99, p < 0.001), and both levels increased with advancing stage of disease. In contrast, the serum-free PSA/total PSA ratio (free/total PSA) and alpha2M levels decreased as the disease progressed. However, only the free/total PSA ratio attained significant difference for localized cancer in stage T1,2 versus BPH (p < 0.05). In stage M1b PCa, in which serum PSA levels were very high, there was a negative correlation between the total PSA and alpha2M values (r = -0.57, p < 0.05). In addition, serum alpha2M levels tended to decrease with progression of PCa. Serum total PSA levels correlated tightly with serum PSA-ACT levels. It is suggested that PSA is usually complexed with ACT in the serum. Free/total PSA was useful for differential diagnosis between early cancer and BPH. Levels of serum alpha2M of less than 50 mg/dl in PCa patients may indicate a possibility of bone metastases.

Insulin regulated PKC isoform mRNA in rat adipocytes.

Insulin and 12-O-tetradecanoyl phorbol-13-acetate (TPA) induce both glucose uptake and translocation of protein kinase C (PKC) from cytosol to membrane in insulin-sensitive tissues as previously reported by several investigators. We examined insulin-mediated PKC beta I, beta II, and epsilon translocation from cytosol to cytoskeleton, and expression of PKC alpha, beta I, beta II, gamma, and epsilon isoforms using the reverse transcription polymerase chain reaction (RT-PCR) method during treatment with insulin for 240 min in rat adipocytes. Insulin-induced increases in PKC beta I, beta II, and epsilon were greater in the cytoskeleton fraction than those in the membrane fraction. Insulin induced time-dependent increases in PKC alpha, gamma, epsilon and zeta mRNA levels for up to 240 min (555%, 117%, 236% and 138% increase, respectively). TPA also induced time-dependent increases in PKC alpha and gamma (34% and 500% increase, respectively) but not in PKC zeta. However, PKC beta I mRNA was decreased for up to 60 min and then maintained at under the basal level during stimulation with insulin and TPA. On the other hand, PKC beta II mRNA was markedly increased for up to 240 min. These results suggest that insulin-regulated PKC alpha, gamma and epsilon mRNA levels and PKC beta mRNA alternative splicing may occur in rat adipocytes.

Acute effects of phorbol ester and insulin on insulin-induced glucose uptake and protein kinase C activation in rat adipocytes.

We examined the acute effect of pretreatment with phorbol ester and insulin on insulin-induced glucose uptake and protein kinase C (PKC) translocation from cytosol to the membrane in rat adipocytes. Adipocytes were preincubated with 1 microM tetradecanoylphorbol 13-acetate (TPA) and 10 nM insulin for 60 min and then stimulated with 10 nM insulin for 10 and 30 min to measure PKC activity in cytosol and membrane fractions using a Mono Q column connected onto an HPLC system and [3H]2-deoxyglucose (DOG) uptake, respectively. Pretreatment with 1 microM TPA and 10 nM insulin for 60 min resulted in the marked decreases of insulin-induced [3H]2-DOG uptake. Translocation of Mono Q column-purified cytosolic PKC enzyme activity and PKC beta immunoreactivity from cytosol to the membrane was suppressed by pretreatment with TPA and insulin for 60 min. These results indicate that acute treatment with TPA and insulin which are PKC activators suppress translocation/activation of PKC, and accordingly inhibit insulin-induced glucose uptake. We suggest that a decrease of cytosolic PKC activity may mainly-contribute to the impaired responsiveness of the glucose transport system after acute TPA and insulin treatment.

Levels of alpha 2 macroglobulin can predict bone metastases in prostate cancer.

BACKGROUND: In prostate cancer, we previously reported that a marked decrease of serum alpha 2 macroglobulin (alpha 2M) to less than approximately 50 mg/dl was associated with the presence of bone metastases. In order to investigate the relationship between bone metastases and alpha 2M, we assessed these two parameters in 128 patients with prostatic diseases. MATERIALS AND METHODS: 66 patients with untreated benign prostatic hypertrophy and 62 with untreated prostate cancer were included in the study. Measurement of alpha 2M concentration was performed by Laser-Nephelometry, prostate-specific antigen (PSA) by EIA. RESULTS: The serum alpha 2M levels in prostate cancer with bone metastases showed a significantly lower level compared with the group without bone metastases (p < 0.01). Cases with serum alpha 2M levels of less than 50 mg/dl all had bone metastases. Serum alpha 2M levels were inversely related to PSA levels in stage M1b disease. CONCLUSIONS: Measurement of serum alpha 2M levels may be useful for the diagnosis and follow up of bone metastases in prostate cancer.

Dehydroepiandrosterone (DHEA) stimulates glucose uptake in rat adipocytes: activation of phospholipase D.

We examined the effect of dehydroepiandrosterone (DHEA) on glucose uptake and phospholipase D (PLD) activation in rat adipocytes. DHEA (1 microM) provoked a twofold increase in [3H]2-deoxyglucose (DG) uptake for 30 min. Incorporation of [3H]glycerol into diacylglycerol was increased 150% above basal level for 20 min after stimulation with 1 microM DHEA. DHEA increased PLD activity, measured by the incorporation into [3H]phosphatidylethanol in [3H]palmitate labelled rat adipocytes, or by [3H]choline release in [methyl-(3)H]choline labeled rat adipocytes. Our results suggest that DHEA stimulates glucose uptake with activation of PLD in rat adipocytes.

Development of human monoclonal antibodies against human cytomegalovirus.

Human monoclonal antibodies (HMAbs) against human cytomegalovirus (HCMV) have been developed by fusion of human spleen cells and human lymphoblastoid cell lines (NP101 and NP197). The cell line NP101 had great advantages in its high fusion frequency and the stability of the resultant hybridomas. The specificity of HMAbs was confirmed by enzyme-linked immunosorbent assay (ELISA) and immunofluorescence staining. Two of the six HMAbs obtained, which were IgG3 subclass, neutralized viral infectivity in the absence of complement. The neutralizing activity of one of these two HMAbs was enhanced in the presence of human complement, whereas the other was not. Another IgG1 subclass HMAb neutralized viral infection only in the presence of complement. The remaining three HMAbs showed no neutralizing activity. Those HMAbs may provide an important approach to studying human immune responses to HCMV. HMAbs having neutralizing activity may prove to be useful for passive immunotherapy of HCMV diseases.

[Responses in a questionnaire by medical school students who participated in the new curriculum of the clinical learning in clinical pathology].

The clinical learning taken by medical students are an important part of their medical education. To develop a new, effective curriculum for the clinical learning in Clinical Pathology, the instructors defined clear general instructional objectives and specific behavioral objectives, and discussed the learning strategies and evaluation methods. The medical students at our medical school took this new curriculum in Clinical Pathology in 1999. As an evaluation method of this new curriculum, we asked all students to fill out a questionnaire that asked their opinions about the length of each component in the Clinical Pathology rotation, the content of the rotation, etc. Over 80% of the respondents answered that the rotation in Clinical Pathology was useful. Ninety-six percent of the students felt that the experience and knowledge they gained in this Clinical Pathology rotation will be useful in the clinical learning in other departments. Based on the high percentage of favorable responses from the students, we concluded that the new curriculum, which was developed after intensive planning, was successful. In summary, the feedback from students who took the new curriculum in Clinical Pathology showed that this new course was well-accepted by the students and that it created an excellent relationship between the instructors and students. Some of the responses in the questionnaires will be used to improve the Clinical Pathology rotation in the future.

[Concentrations of free form and complex form of prostate-specific antigen in serum of alpha 2 macroglobulin deficient patients with prostatic carcinoma].

Prostate-specific antigen (PSA) is present in blood in free form as well as in complex form with various protease inhibitors such as alpha 2 macroglobulin (alpha 2M) and alpha 1 antichymotrypsin (alpha 1 ACT). We had found that alpha 2M is deficient (below approximately 40 mg/dl) in some patients with prostatic carcinoma. Therefore, we investigated the levels of free and complex form of PSA in patients with prostatic disease and obtained the following results. The HPLC study showed that total (free plus complex) PSA level was much higher in the alpha 2M deficient patients with prostatic carcinoma stage D (n = 7, range 1,530-14,746 ng/ml, median value 6,800 ng/ml) than in the non-deficient patients with stage D (n = 16, range 121.6-4,210 ng/ml, median value 851 ng/ml). In the deficient patients, the complex of PSA with alpha 1 ACT increased extraordinarily while free PSA increased to only some extent. In the more severe cases of prostatic carcinoma, the ratio (complex/total PSA) was higher while the ratio (free/total PSA) was lower. The SDS-PAGE Western blotting showed that complex PSA increased extraordinarily and free PSA increased in sera of the deficient patients which was consistent with the HPLC results. Many bands appeared on the blotting at the positions smaller than alpha 2M molecule, which indicated that many fragments of alpha 2M were present in their sera. These bands were more intense than the bands with sera of controls or benign prostatic hypertrophy. The alpha 2M deficiency may be due to the rapid disappearance of the complex with PSA or any other prostate-originated proteases. The complex may undergo accelerated degradation or catabolism of alpha 2M.

[Quantitative levels of serum amyloid A protein and other proteins in cerebrospinal fluid and serum of patients with meningitis].

Serum amyloid A protein (SAA), a putative precursor of the AA protein which constitutes amyloid fibrils in secondary amyloidosis, is evaluated as a sensitive acute-phase reactant in serum. At present, SAA concentration in serum is determined by latex nephelometry, but this assay cannot detect SAA in the low concentration range lower than 10 ng/ml. We have developed a sensitive enzyme immunoassay (EIA) for determining low concentrations of SAA. The assay is reproducible, reliable and requires no pretreatment of specimen prior to assay. We measured levels of SAA by this EIA in both cerebrospinal fluid (CSF) and serum of patients with suspected meningitis, measured also levels of albumin, alpha 2 macroglobulin and C-reactive protein (CRP) to investigate if these protein levels are useful for differential diagnoses of meningitis and for indicators damage of blood-CSF barrier. The SAA reference value in CSF is 3.99 +/- 1.74 ng/ml (mean +/- SD for nonmeningitis patients). The CRP concentration in CSF in bacterial meningitis was much higher than in viral meningitis, but CRP in CSF was also high in bacterial infection other than meningitis. On the other hand, SAA concentration in CSF in these patients with any meningitis are significantly higher than the reference values of SAA (p < 0.001). However, the differences in SAA concentrations among the three types (bacterial, viral and mycotic meningitis) of meningitis were not significant.

[Quantitation and heterogeneity of serum alpha 2-macroglobulin].

alpha 2-Macroglobulin (alpha 2M) is a major protease inhibitor in human plasma. In this study, serum alpha 2M was determined by means of immunoelectrophoresis (IEP), rocket immunoelectrophoresis (R-IEP), laser nephelometry (LN) and single radial immunodiffusion (SRID) in 133 subjects. The values obtained by these methods coincided well in most specimens, but some specimens showed disagreement. The sera of alpha 2M deficiency found by IEP were analyzed by the other methods. We found that R-IEP gave the results of alpha 2M deficiency most frequently while the other methods gave the results of normal alpha 2M level for some specimens. We studied on the presumption that the phenomenon is due to heterogeneity in molecular weight of alpha 2M. After alpha 2M was purified by affinity chromatography and gel filtration chromatography, we further employed gel-filtration on a high-performance liquid chromatography (HPLC) to isolate alpha 2M with different molecular size. Two peaks of immunoreactive alpha 2M were found by the gel-filtration HPLC. When we performed IEP for both portions, the first portion with higher molecular size showed larger rate of migration than the second portion. Serum alpha 2M quantitation with SRID is not appropriate because molecular weight influences on the determination by SRID. We conclude that R-IEP is best suitable for the detection of decrease of serum alpha 2M, although this method requires expertness of manipulation.