Unveiling the vitamin E profile in rice bran extracellular vesicles: evaluation of extraction and preparation methods

Extracellular vesicles (EVs) are nanoscale entities secreted by various cells, encapsulating various nucleic acids and proteins that play important roles in cellular activities. Although rice bran is known for its richness in phytochemicals such as tocopherol and tocotrienol, the distribution of these compounds within EVs has not been extensively studied. The objective of this study was to detect and analyze the presence of vitamin E in EVs extracted from rice bran. We investigated several EV extraction methods, including rotation, vortex mixing, and ultrasonication, followed by post-extraction techniques such as ultracentrifugation, ultrafiltration, and lyophilization. Vitamin E in the EVs from rice bran was analyzed using LC-FLD. This study is the first to identify tocopherol and tocotrienol in rice bran-derived EVs. Our results indicate that ultracentrifugation followed by rotation is the most effective method for the preparation of rice bran-derived EVs. Notably, the vitamin E profile in EVs varies depending on the preparation method and differs from that in rice bran extracts. The pronounced presence of vitamin E in EVs suggests unique pharmacokinetics and underscores the potential of EVs as carriers for drug delivery systems. This study not only confirms the presence of vitamin E in EVs, but also underscores the potential of EVs and their phytochemical content for therapeutic applications.

The distribution of neuroligin4, an autism-related postsynaptic molecule, in the human brain

NLGN4X was identified as a single causative gene of rare familial nonsyndromic autism for the first time. It encodes the postsynaptic membrane protein Neuroligin4 (NLGN4), the functions and roles of which, however, are not fully understood due to the lack of a closely homologous gene in rodents. It has been confirmed only recently that human NLGN4 is abundantly expressed in the cerebral cortex and is localized mainly to excitatory synapses. However, the detailed histological distribution of NLGN4, which may have important implications regarding the relationships between NLGN4 and autistic phenotypes, has not been clarified. In this study, we raised specific monoclonal and polyclonal antibodies against NLGN4 and examined the distribution of NLGN4 in developing and developed human brains by immunohistochemistry. We found that, in the brain, NLGN4 is expressed almost exclusively in neurons, in which it has a widespread cytoplasmic pattern of distribution. Among various types of neurons with NLGN4 expression, we identified consistently high expression of NLGN4 in hypothalamic oxytocin (OXT)/vasopressin (AVP)-producing cells. Quantitative analyses revealed that the majority of OXT/AVP-producing neurons expressed NLGN4. NLGN4 signals in other large neurons, such as pyramidal cells in the cerebral cortex and hippocampus as well as neurons in the locus coeruleus and the raphe nucleus, were also remarkable, clearly contrasting with no or scarce signals in Purkinje cells. These data suggest that NLGN4 functions in systems involved in intellectual abilities, social abilities, and sleep and wakefulness, impairments of which are commonly seen in autism.

Knockdown of Son, a mouse homologue of the ZTTK syndrome gene, causes neuronal migration defects and dendritic spine abnormalities

Zhu-Tokita-Takenouchi-Kim (ZTTK) syndrome, a rare congenital anomaly syndrome characterized by intellectual disability, brain malformation, facial dysmorphism, musculoskeletal abnormalities, and some visceral malformations is caused by de novo heterozygous mutations of the SON gene. The nuclear protein SON is involved in gene transcription and RNA splicing; however, the roles of SON in neural development remain undetermined. We investigated the effects of Son knockdown on neural development in mice and found that Son knockdown in neural progenitors resulted in defective migration during corticogenesis and reduced spine density on mature cortical neurons. The induction of human wild-type SON expression rescued these neural abnormalities, confirming that the abnormalities were caused by SON insufficiency. We also applied truncated SON proteins encoded by disease-associated mutant SON genes for rescue experiments and found that a truncated SON protein encoded by the most prevalent SON mutant found in ZTTK syndrome rescued the neural abnormalities while another much shorter mutant SON protein did not. These data indicate that SON insufficiency causes neuronal migration defects and dendritic spine abnormalities, which seem neuropathological bases of the neural symptoms of ZTTK syndrome. In addition, the results support that the neural abnormalities in ZTTK syndrome are caused by SON haploinsufficiency independent of the types of mutation that results in functional or dysfunctional proteins.

A Double-blind, Placebo-controlled, Multicenter, Prospective, Randomized Study of Beraprost Sodium Treatment for Cats with Chronic Kidney Disease

Background

Chronic kidney disease (CKD) is a common progressive and irreversible disease in cats. The efficacy and safety of beraprost sodium (BPS) in cats with CKD have not been evaluated.

Hypothesis/Objectives

To evaluate the efficacy and safety of BPS in the treatment of cats with CKD, as compared to placebo.

Animals

Seventy‐four client‐owned cats with naturally occurring CKD.

Methods

Double‐blind, placebo‐controlled, multicenter, prospective, randomized trial. The cats received BPS (55 μg/cat) or a placebo PO q12 h for 180 days. The primary endpoint was prospectively defined as a change in the serum creatinine (sCr), serum phosphorus‐to‐calcium ratio or urine specific gravity (USG).

Results

The sCr increased significantly (P = 0.0030) in the placebo group (mean ± SD: 2.8 ± 0.7 to 3.2 ± 1.3 mg/dL) but not in the BPS group (2.4 ± 0.7 to 2.5 ± 0.7 mg/dL). The difference between the groups at day 180 was significant (0.8 mg/dL, 95% CI: 0.2 to 1.3 mg/dL, P = 0.0071). The serum phosphorus‐to‐calcium ratio was significantly (P = 0.0037) increased in the placebo group (0.46 ± 0.10 to 0.52 ± 0.21 mg/dL) but not in the BPS group (0.50 ± 0.08 to 0.51 ± 0.11 mg/dL). There was no significant change in the USG in either group. An adverse event judged as being treatment‐related included vomiting that occurred in 1 case in the placebo group. No clinically relevant change was observed in the CBC and other blood chemistry tests.

Conclusions and Clinical Importance

Beraprost sodium treatment was well tolerated and safe in cats with CKD. BPS inhibited the reduction in renal filtration function as measured by sCr increase.

Molecular hydrogen attenuates fatty acid uptake and lipid accumulation through downregulating CD36 expression in HepG2 cells

Background

There is accumulating evidence that obesity is closely associated with an impaired free fatty acid metabolism as well as with insulin resistance and inflammation. Excessive fatty acid uptake mediated by fatty acid translocase CD36 plays an important role in hepatic steatosis. Molecular hydrogen has been shown to attenuate oxidative stress and improve lipid, glucose and energy metabolism in patients and animal models of hepatic steatosis and atherosclerosis, but the underlying molecular mechanisms remain largely unknown.

Methods

Human hepatoma HepG2 cells were exposed to palmitate-BSA complex after treatment with or without hydrogen for 24 h. The fatty acid uptake was measured by using spectrofluorometry and the lipid content was detected by Oil Red O staining. JNK phosphorylation and CD36 expression were analyzed by Western blot and real-time PCR analyses.

Results

Pretreatment with hydrogen reduced fatty acid uptake and lipid accumulation after palmitate overload in HepG2 cells, which was associated with inhibition of JNK activation. Hydrogen treatment did not alter CD36 mRNA expression but reduced CD36 protein expression.

Conclusion

Hydrogen inhibits fatty acid uptake and lipid accumulation through the downregulation of CD36 at the protein level in hepatic cultured cells, providing insights into the molecular mechanism underlying the hydrogen effects in vivo on lipid metabolism disorders.

Hesperetin upregulates ABCA1 expression and promotes cholesterol efflux from THP-1 macrophages

ABCA1, a member of the ATP-binding cassette transporter family, regulates high-density lipoprotein (HDL) metabolism and cholesterol transport. Its expression is upregulated mainly by the activation of the liver X receptor (LXR). Since ABCA1 plays a pivotal role in cholesterol and HDL metabolism, identification of a compound capable of increasing its expression may be beneficial for the prevention and therapy of atherosclerosis. Firefly luciferase reporter assays were developed for human ABCA1 promoters and LXR enhancers, and an in-house phytochemical library was screened. It was found that a citrus flavonoid, hesperetin (1), increased ABCA1 promoter and LXR enhancer activities in THP-1 macrophages. It was also found that this flavonoid promoted PPAR-enhancing activity. In accordance with these findings, 1 increased mRNA and protein expression of ABCA1 and consequently upregulated ApoA-I-mediated cholesterol efflux. These results provide evidence that 1 promotes ApoA-I-mediated cholesterol efflux from macrophages by increasing ABCA1 expression through the activation of LXRα and PPARγ.

Ethanolic extracts of Brazilian red propolis increase ABCA1 expression and promote cholesterol efflux from THP-1 macrophages

The ATP-binding cassette transporter A1 (ABCA1) is a membrane transporter that directly contributes to high-density lipoprotein (HDL) biogenesis by regulating the cellular efflux of cholesterol. Since ABCA1 plays a pivotal role in cholesterol homeostasis and HDL metabolism, identification of a novel substance that is capable of increasing its expression would be beneficial for the prevention and therapy of atherosclerosis. In the present study, we studied the effects of ethanolic extracts of Brazilian red propolis (EERP) on ABCA1 expression and cholesterol efflux in THP-1 macrophages. EERP enhanced PPARγ and liver X receptor (LXR) transcriptional activity at 5-15μg/ml, which was associated with upregulation of PPARγ and LXRα expression. It was also found that EERP increase the activity of the ABCA1 promoter, which is positively regulated by LXR. Consistent with these findings, treatment with EERP increased both mRNA and protein expression of ABCA1. Finally, EERP upregulated ApoA-I-mediated cholesterol efflux. Our results showed that EERP promote ApoA-I-mediated cholesterol efflux from macrophages by increasing ABCA1 expression via induction of PPARγ/LXR.

Microvesicle-mediated RNA molecule delivery system using monocytes/macrophages

Microvesicles (MVs) and exosomes, which are shed from cells as a cell-to-cell communication tool, are possible vehicles for navigating RNA molecules to body tissues. It is considered that intravenous injection of such MVs or exosomes from patients would not cause severe not-self and toxic reactions. Previously, we found that macrophages take up liposome-entrapped RNA molecules, some of which remain undegraded in the cells. Here, we demonstrate that transfected RNA molecules in human monocytic leukemia THP-1 cells were shed from THP-1 macrophages as contents in MVs during incubation in serum-free medium, which shedding was shown by biochemical analyses such as quantitative reverse transcription (qRT)-PCR, expression of TSG101 (a membrane-associated exosomal protein), and immunoelectron microscopic study. More chemically modified RNA molecules (miR-143BPs) entrapped by MVs (MV-miR-143BPs) were secreted from THP-1 macrophages after miR-143BP transfection compared with the amount after transfection with nonmodified miR-143 transfection. Furthermore, we show that the THP-1 macrophages, which were transfected with the miR-143BP ex vivo, secreted MV-miR-143BPs in xenografted nude mice after intravenous injection, because miR-143 levels were significantly increased in the serum, tumor, and kidney of the host animals. These data suggest that some of the transfected miR-143BPs were secreted from THP-1 macrophages as MV-RNAs both in vitro and in vivo.

Ethanolic extracts of Brazilian red propolis promote adipocyte differentiation through PPARγ activation

AIM OF THE STUDY

The aim of present study was to investigate the effects of ethanolic extracts of red propolis (EERP) on adipogenesis and evaluate the molecular basis for their anti-obesity effects.

MATERIALS AND METHODS

We tested whether EERP alone could induce differentiation of 3T3-L1 cells, regulate the expression of adipocyte-specific genes and reverse inhibitory effects of TNF-α on their differentiation. Next, we performed a luciferase reporter gene assay to test whether EERP could enhance transcriptional activities of PPARγ and adiponectin promoter activities.

RESULTS

EERP strongly induced differentiation of 3T3-L1 preadipocytes into adipocytes, and enhanced the PPARγ transcriptional activity and adiponectin promoter activity. In addition, EERP attenuated the inhibitory effect of TNF-α on adipocyte differentiation and adiponectin production in mature adipocytes.

CONCLUSION

The present study indicates that EERP enhance differentiation of 3T3-L1 adipocytes in part by its potency of PPARγ activation and are capable of reversing inhibitory effects of TNF-α on adipocyte differentiation and adiponectin expression. These results suggest the value of EERP as a diet supplement for prevention and treatment of obesity and obesity-associated disorders.

Identification of non-coding RNAs embracing microRNA-143/145 cluster

In a variety of cancers, altered patterns of microRNA (miRNA) expression are reported and may affect the cell cycle and cell survival. Recent studies suggest that the expression level of miRNAs that act as tumor suppressors is frequently reduced in cancers because of chromosome deletions, epigenetical changes, aberrant transcription and disturbances in miRNA processing. miR-143 and -145, which are located approximately 1.3 kb from each other at chromosome 5q33, are highly expressed in several tissues, but down-regulated in most cancers. However, the mechanism of this down-regulation has not been investigated in detail. Here, we show that both miRNAs were expressed well under the same control program in human tissues, but were down-regulated equally in the most of the cancer cell lines tested. Then we identified the host gene encoding both miRNAs. The transcripts of this gene were approximately 11, 7.5, and 5.5 kb long; and the expression of these transcripts was coordinated with that of its resident miRNAs and down-regulated in the cancer cell lines tested as well as in colorectal cancer tissue samples. These data demonstrate that the host gene can function as a primary miRNA transcript and suggest that the down-regulation of host gene expression caused the low-expression of its encoded microRNAs-143 and -145 in human cancer cell lines and in cancer tissues.

Role of anti-oncomirs miR-143 and -145 in human colorectal tumors

We examined the expression levels of microRNAs (miRNAs (miRs)) in colorectal tumors (63 cancer specimens and 65 adenoma specimens) and paired non-tumorous tissues. Decreased expression of miR-143 and -145 was frequently observed in the adenomas and cancers tested, compared with miR-34a downregulation and miR-21 upregulation. Expression profiles of miR-143 and -145 were not associated with any clinical features. As the downregulation of miR-143 and -145 was observed even in the early phase of adenoma formation, the decreased expression of both miRs would appear to contribute mainly to the initiation step of tumorigenesis, not to the progression stage, and not to clinical prognostic factors. For clinical application, we changed the sequences of the passenger strand in the miR-143 duplex and performed chemical modification at the 3'-overhang portion of miR-143, leading to greater activity and stability to nuclease. The cell growth inhibitory effect of the chemically modified synthetic miR-143 in vitro was greater than that of endogenous miR-143. The miR-143 showed a significant tumor-suppressive effect on xenografted tumors of DLD-1 human colorectal cancer cells. These findings suggest that miR-143 and -145 are important onco-related genes for the initiation step of colorectal tumor development and that the chemically modified synthetic miR-143 may be a hopeful candidate as an RNA medicine for the treatment of colorectal tumors.

Role of microRNA-143 in Fas-mediated apoptosis in human T-cell leukemia Jurkat cells

Treatment of Jurkat T cells with Fas-activating antibody (CH-11) facilitated rapid cell death that was shown to be caspase-dependent apoptosis. The expression of miR-143 was up-regulated during the apoptosis with time. The increased expression of miR-143 emerged from 1 to 2h after the treatment, at which time the caspases-8 and -3 were also activated; and this increase was almost canceled by the pretreatment with an inhibitor of caspase-3 or -8. Furthermore, the transfection of Jurkat cells with mature miR-143 induced a significant growth suppression and enhancement of CH-11-induced apoptosis. On the contrary, an extracellular signal-regulated protein kinase 5 (ERK5), which was determined to be a target of miR-143 in colon cancer DLD-1 cells, was time-dependently down-regulated at the translational level after the treatment. During the apoptosis, the expression level of FasL was maintained and the level of nuclear-Foxo3a was increased in the early phase. These data suggest that the up-regulation of miR-143 could be related to the apoptosis in part by targeting ERK5, which leads to promotion of Foxo3a/FasL positive feedback loop.

Decreased expression of microRNA-143 and -145 in human gastric cancers

OBJECTIVE

Downregulation of specific microRNAs (miRNAs) occurs in human tumors, which suggests a function for miRNAs in tumor suppression. We investigated the role of the miRNAs miR-143 and miR-145 in gastric cancers.

METHODS

The expression levels of miR-143 and miR-145 in the samples from 43 patients with gastric cancer were determined by real-time PCR using TaqMan assay. The growth inhibitory effect was estimated by the transfection of human gastric cancer cells with the miRNA.

RESULTS

The expression levels of miR-143 and -145 were decreased in most human gastric cancers examined, as previously reported to occur in colon tumors. The transfection of human gastric MKN-1 cells with miR-145 resulted in a greater growth inhibitory effect than that with miR-143, results which were contrary to those in colon cancers. In MKN-1 cells, an additive effect on growth inhibition was shown by the combined transfection with miR-143 and miR-145; further, higher sensitivity to 5-fluorouracil was also observed following the transfection with miR-143 or miR-145. The possible candidate target messenger RNAs of miR-145 were identified to be insulin receptor substrate-1 and beta-actin.

CONCLUSION

Taken together, these findings suggest that miR-143 and miR-145 act as anti-oncomirs common to gastrointestinal tumors.

Wnt11 facilitates embryonic stem cell differentiation to Nkx2.5-positive cardiomyocytes

Wnt signaling plays a crucial role in the control of morphogenesis in several tissues. Herein, we describe the role of Wnt11 during cardiac differentiation of embryonic stem cells. First, we examined the expression profile of Wnt11 during the course of differentiation in embryoid bodies, and then compared its expression in retinoic acid-treated embryoid bodies with that in untreated. In differentiating embryoid bodies, Wnt11 expression rose along with that of Nkx2.5 expression and continued to increase. When the embryoid bodies were treated with retinoic acid, Wnt11 expression decreased in parallel with the decreased expression of cardiac genes. Further, treatment of embryoid bodies with medium containing Wnt11 increased the expression of cardiac marker genes. Based on these results, we propose that Wnt11 plays an important role for cardiac development by embryoid bodies, and may be a key regulator of cardiac muscle cell proliferation and differentiation during heart development.

Gene expression of FK506-binding proteins 12.6 and 12 during chicken development

FKBPs are cytosolic receptors for the immunosuppressive drug FK506. FKBP12.6 and FKBP12 associate with cardiac and skeletal muscle isoforms of ryanodine receptors and thereby regulate intracellular Ca(2+) release. The amino acid sequences of FKBP12.6 and FKBP12 are highly conserved among mammals and chicken. The expression profiles of FKBP12.6 and FKBP12 genes during chicken development were compared by Northern blot and in situ hybridization analyses. Transcripts of the FKBP12 gene were abundant throughout the embryo at early stages of development but subsequently underwent gradual down-regulation. Expression of the FKBP12.6 gene was mostly restricted to the heart during early embryogenesis and also underwent subsequent down-regulation, becoming localized to the atrium after hatching. Treatment of early embryos with FK506 had no apparent effect on embryogenesis. Retinoic acid induced marked abnormalities in cardiogenesis, but it did not affect FKBP gene expression. These results suggest that, even though FKBP12.6 and FKBP12 genes are expressed in chick embryos, FK506-sensitive functions of the encoded proteins do not appear to contribute to early embryogenesis or cardiogenesis.

Chamber-specific differentiation of Nkx2.5-positive cardiac precursor cells from murine embryonic stem cells

Embryonic stem (ES) cells are a useful system to study cardiac differentiation in vitro. It has been difficult, however, to track the fates of chamber-specific cardiac lineages, since differentiation is induced within the embryoid body. We have established an in vitro culture system to track Nkx2.5(+) cell lineages during mouse ES cell differentiation by using green fluorescent protein (GFP) as a reporter. Nkx2.5/GFP(+) cardiomyocytes purified from embryoid bodies express sarcomeric tropomyosin and myosin heavy chain and heterogeneously express cardiac troponin I (cTnI), myosin light chain 2v (MLC2v) and atrial natriuretic peptide (ANP). After 4-week culture, GFP(+) cells exhibited electrophysiological characteristics specific to sinoatrial (SA) node, atrial, or ventricular type. Furthermore, we found that administration of 10(-7) M retinoic acid (RA) to embryoid bodies increased the percentage of MLC2v(-)ANP(+) cells; this also increased the expression of atrial-specific genes in the Nkx2.5/GFP(+) fraction, in a time- and dose-dependent fashion. These results suggest that Nkx2.5(+) lineage cells possess the potential to differentiate into various cardiomyocyte cell types and that RA can modify the differentiation potential of Nkx2.5(+) cardiomyocytes at an early stage.

Heart-selective expression of the chicken FK506-binding protein (FKBP) 12.6 gene during embryonic development

FKBP12.6, a member of the family of FK506-binding proteins, selectively associates with the cardiac isoform of the ryanodine receptor and thereby stabilizes this Ca(2+) release channel. A chicken FKBP12.6 (chFKBP12.6) cDNA was cloned and shown to encode a protein of 108 amino acids. The deduced amino acid sequence of chFKBP12.6 is 91-92% identical to those of mammalian FKBP12.6 proteins. Northern blot analysis revealed that chFKBP12.6 mRNA is largely restricted to the heart during embryonic development and that the abundance of this mRNA in the heart decreases, and it becomes restricted to the atrium during cardiogenesis. In situ hybridization revealed that chFKBP12.6 mRNA is localized to the precardiac mesoderm before formation of the primitive heart tube. Expression of the chFKBP12.6 gene was initially apparent throughout the developing multichambered heart but became restricted to the atria before hatching. Reverse transcription and polymerase chain reaction analysis demonstrated that chFKBP12.6 mRNA is present in the embryo from early gastrulation and is most abundant immediately after the onset of the heartbeat. These observations suggest that the chFKBP12.6 gene is expressed before heart morphogenesis to play a role in excitation-contraction coupling in cardiomyocytes and that the function of the encoded protein becomes increasingly restricted to the atrium during embryonic development.

Expression pattern of novel chick T-box gene, Tbx20

Little is known about the molecular mechanisms involved with the initial specifications of the cardiac mesoderm. In order to identify potential regulatory factors that play important roles in early heart specification, we attempted to isolate the chick H15-related T-box gene and analyze its expression pattern during early development. The chick Tbx20 gene was found to be highly homologous to human, mouse, and zebrafish hrT/Tbx20. Its expression was initially detected in the posterior lateral mesoderm, after which it expanded to the anterior and was intensively co-expressed with a cardiogenic gene, Nkx2.5, in the anterior lateral mesoderm.

Role of FK506-binding protein 12 in development of the chick embryonic heart

A cDNA encoding chicken FK506-binding protein 12 (FKBP12) was isolated and sequenced. The predicted amino acid sequence of the chicken protein shows high homology to those of FKBP12 proteins of other species ranging from human to frog. The possible role of FKBP12 in chick embryonic cardiac development was examined. Northern blot analysis revealed that FKBP12 mRNA is distributed widely in chick embryos, being especially abundant in the heart; the amount of FKBP12 mRNA in the embryonic heart decreased with time. Administration of FK506 to chick embryos at 7 to 9 days resulted in marked cardiac enlargement. FK506 also reduced the expression of myosin, induced a more elongated cell morphology, and impaired network formation in cultured chick embryonic cardiomyocytes. These results suggest that FKBP12 is important in the regulation of contractile function and phenotypic expression in chick cardiomyocytes during embryonic development.

Influence of calcium on proliferation and phenotype alteration of cardiomyocyte in vitro

An accelerated weight gain is noted in the heart of Ca-deficient, hypertensive chick embryos maintained in a shell-less culture in vitro. We previously observed that the Ca handling property of cardiomyocytes isolated from the shell-less embryo is altered, i.e., faster Ca uptake, suggesting a requirement for adequate Ca supply and/or proper Ca handling in embryonic cardiac development. In this study, we have examined the function of Ca on cardiomyocytes by analyzing the effects of 1) various Ca concentration in the culture medium (NCa, 1.8 mmol/ L; HCa, 2.8 mmol/L; LCa, 0.9 mmol/L), and 2) various modulators of Ca handling on cell proliferation and phenotype regulation in chick embryonic cardiomyocytes. The analytical parameters included cell number, DNA content, expression of cell cycle-specific and cardiomyocyte-specific proteins, and creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) enzyme activities. Cell number and total DNA were significantly larger (P < 0.01) in LCa cultures compared with those in NCa. The level of LDH was elevated (P < 0.01), but that of CPK was lowered in LCa. Expression of the G1-S-specific protein PCNA was raised, but that of the contractile proteins myosin and tropomyosin was substantially suppressed in LCa; in HCa, the cells did not proliferate as well, whereas the level of contractile proteins was higher. Thapsigargin, a sarcoplasmic reticulum (SR)-specific, Ca-ATPase inhibitor, simulated the effects of LCa by enhancing cell proliferation and lowering the expression of tropomyosin. These results suggest that culturing in low Ca concentration and inhibition of SR Ca pumping enhance myocardial cell proliferation and suppress sarcomeric protein expression, perhaps by inducing cellular de-differentiation. The in vitro effects of medium Ca concentration and Ca handling modulators on cardiomyocytes also suggest that the in vivo cardiomegaly of the SL embryos is a direct result of Ca-deficiency, and that Ca is important in the phenotype regulation of cardiomyocytes.

Function of FK506 binding protein (FKBP) in chick embryonic cardiac development

FK506 binding protein (BP) 12, an immunophilin of FK506-binding proteins, is involved in intra-cellular signal transduction through the calcineurin-nuclear factor pathway. FKBP12 is reported to be associated with the ryanodine-receptor and IP3 Ca2+ channels, and to regulate cell proliferation via binding transforming growth factor (TGF)-beta receptor and cyclin dependent kinase (CDK). To elucidate the function of FKBP12 in cardiac development, we analyzed the temporal profile and regulation of FKBP12 expression in chick heart and in cultured cardiomyocytes. FKBP12 is expressed in embryos as early as day 4 and is predominantly associated with cardiomyocytes and osteo-chondrocytes. Tissue FKBP level in the heart increases with development. Immunohistochemically, the distribution and levels of FKBP12 appear to be related to sarco-endoplasmic reticulum Ca-ATPase 2 (SERCA2) but not to sarcomeric proteins. In proliferating cells, FKBP12 expression correlates with cellular mitosis, but not with DNA synthesis. In earlier embryos (< day 8), suppressing the activity of FKBP by FK506 administration is lethal, and induces cardiomegaly at later stages. In cultured cardiomyocytes, FK506 reduces the level of contractile proteins and inhibits cell proliferation. These results show that FKBP12 is enriched in cell types involved in dynamic Ca handling, and is likely an important molecule for cardiac development. FKBP12 most likely functions by affecting cellular Ca handling, since its effects are modified by modulators of Ca handling by sarcoplasmic reticulum.

Major risk factors for atherosclerosis are manifested in experimental Ca-deficiency

The eggshell is the major source of Ca required during growth of chick embryos. Therefore, chick embryos placed ex ovo for long-term (SL) are rendered severe systemic calcium deficiency. We report here that SL chick embryos express Ca-deficiency related atherogenic disorders, and that in vitro Ca-deficiency induces dedifferentiation, i.e. loss of cell-type specific features and accelerated proliferative activities, in the various types of cultured cells. Systemic blood pressure is significantly higher and an accelerated weight gain of the heart is noted in SL compared to normal embryos (NL) at the incubation Day-14. Plasma cholesterol was lower, while triglyceride and glucose were higher in SL. Varying Ca in the culture medium (FCa, 1.8 mM; HCa, 2.8 mM; Ca/2, 0.9 mM) clearly affected the phenotype of the cultured cardiomyocytes and vascular cells isolated from the chick embryos. The cell number and total DNA were significantly larger and the level of LDH and proliferating cell nuclear antigen (PCNA) was elevated in Ca/2 compared to FCa. On the contrary, the level of CPK and contractile proteins were lowered in Ca/2. Thus, it is indicated that Ca-deficiency induces atherogenic disorders in vivo, and accelerates cell proliferation and decelerates sarcomeric protein expression in vitro. Taken together, it is suggested that the atherogenic, developmental disorders in SL may be the integrated result of the phenotype alteration in the various cell types directly induced by Ca-deficiency.

Isolation and characterization of a chicken tyrosinase cDNA

Complementary DNA clones coding for chicken tyrosinase were isolated from retinal pigmented epithelium of chicken embryo. Sequence analysis shows that one of the cDNA clones consisting of 1,997 nucleotides has an open reading frame coding for 529 amino acids. The deduced protein has nine N-glycosylation sites and a transmembrane region. A sequence comparison of the deduced chicken tyrosinase with the mouse and human homologues revealed that amino acid sequences are conserved for the entire polypeptides. Seventy-two percent and 73% of amino acids in the chicken sequence are identical to that of the mouse and human tyrosinases, respectively. Histidines neighboring the postulated copper-binding sites and the cysteines are well conserved. RNA blotting analysis showed that a major transcript of 2.5 kb is detected in retinal pigmented epithelium of a 9-day-old chicken embryo.

[A case with delayed-onset radiation pneumonitis suspected to be induced by oral etoposide]

Radiation pneumonitis usually occurs within 1-3 months after the completion of radiation therapy. A 63-year-old male with primary lung cancer treated by radiation therapy developed radiation pneumonitis 5 months after the completion of radiation therapy. He received 60 Gy to the lung tumor in a conventional fractionation schedule, and then two courses of intravenous chemotherapy using cis-diamine-dichloroplatinum (II) (110-140 mg) and etoposide (140-175 mg). Oral etoposide was initiated for bone metastases on the 104th day after the completion of radiation therapy at a daily dose of 20 mg, to a total dose of 1075 mg. He complained of fever and exertional dyspnea 5 months after the completion of radiation therapy. Chest radiography showed homogeneous infiltrates in the irradiated lung. These clinical signs and symptoms were refractory to antibiotic therapy, but steroid therapy resulted in marked improvement. The development of radiation pneumonitis was suspected to be induced by oral etoposide, which was given before the onset of radiation pneumonitis. These data suggest that etoposide induces a recall phenomenon, as has been demonstrated with such drugs as adriamycin and actinomycin-D.

[Temperature distribution and geometry of the electrodes in RF interstitial hyperthermia using circular and interstitial electrodes]

To evaluate the feasibility of clinical application of a newly developed interstitial hyperthermia system, which consists of an 8 MHz radiofrequency generator, interstitial needle electrodes, and a superficial circular electrode, we conducted preclinical experiments using an agar phantom and VX-2 carcinoma in the rabbit. In the experiment with an agar phantom, four 4 cm needle electrodes were placed in a square array at intervals of 1.0, 1.5, and 2.0 cm. Thermography demonstrated homogeneous temperature distribution at electrode intervals of 1.0 and 1.5 cm, but hot spots around the electrodes at an interval of 2.0 cm. When electrode deviation was less than 8 degrees from the parallel plane, no temperature deviation was observed. Using two 2 cm electrodes and two 4 cm electrodes in square array, thermography demonstrated a homogeneous temperature distribution in the area surrounded by the electrodes. Even if the electrodes were located at the periphery of the agar phantom, a homogeneous temperature distribution was obtained in the area surrounded by the electrodes. Using four 4 cm electrodes at intervals of 1.5 cm in VX-2 carcinoma in the rabbit, ideal heating was obtained: 42 degrees C at the periphery of the tumor and 43 degrees C at the center. These data suggest that the newly developed interstitial hyperthermia apparatus provides homogeneous heat distribution at electrode intervals of 1.5 cm or less and can be used in a Phase I study for deep-seated or superficial tumors.

ECG-gated thallium-201 myocardial SPECT in patients with old myocardial infarction compared with ECG-gated blood pool SPECT

We evaluated one of the merits of ECG-gated thallium-201 single photon emission computed tomography (g-T1 SPECT), i.e., the ability to appreciate left ventricular (LV) wall motion. LV wall motion assessed by g-T1 SPECT and by ECG-gated Blood Pool SPECT (g-BP SPECT) was classified into three grades and compared segment by segment. T1-201 uptake by g-T1 SPECT was also classified into three grades and compared with those of wall motion in g-BP SPECT. Fifty patients with prior myocardial infarction were injected intravenously at rest with 111 to 185 M Bq (3 to 5 mCi) of Tl-201. The left ventricular regions were divided into anterior, septal, inferior and lateral segments (50 patients X 4 segments = 200 segments in total). The grades of wall motion and Tl-201 uptake detected by g-Tl SPECT correlated well with those of wall motion in g-BP SPECT (94.5% and 85%, respectively). With g-Tl SPECT it was possible to evaluate left ventricular wall motion, providing clear perfusion images.

[Detection of common bile duct stones by hepatobiliary scintigraphy]

Hepatobiliary scintigraphy and direct X-ray cholangiography were compared in 29 patients with common bile duct (CBD) stones confirmed at surgery. The scintigraphic findings included no visualization of the biliary system (NV), pooling of bile in the biliary system (PB), prolonged transit time over 60 min (PTT), filling defect in the CBD image (FD), and reflux of bile toward the intrahepatic ducts after gallbladder stimulation (RB). The positive rates of NV, PB, PTT, FD, and RB in patients with CBD stones were 7%, 31%, 17%, 48%, and 14%, respectively. One or more of these five findings was found in 83%. Although the NV was a useful finding suggesting complete obstruction of the CBD, it shared little in the diagnosis of CBD stone. The positive rate of the PB was relatively high and it would be a useful finding as an indication of the presence of passage disturbance of the CBD. The PB was usually accompanied by the FD. The PTT had some usefulness in the detection of incomplete obstruction of the CBD in patients with a visualized gallbladder. In patients with no visualization of the gallbladder, however, the transit time tended to be shorter than that of gallbladder visualized patients. Therefore, the judgment of PTT in patients with no visualized gallbladder needed another criteria. The FD was the most frequent among the five findings and the sites of FD correlated well with CBD stones on direct X-ray cholangiography. The FD would be a reliable finding indicating CBD stone or CBD stenosis. Although the RB was a finding limited in patients with a visualized gallbladder, it seemed to be a helpful findings for the detection of CBD stone in patients with a mildly dilated CBD.

Serum CA125 level is a good prognostic indicator in lung cancer

The serum CA125 level was determined by a one-step immunoradiometric assay method in patients with lung cancer. Increased serum CA125 levels were observed in 37.8% of patients with squamous cell cancer, in 30.0% of those with adenocarcinoma and in 60.0% of those with small call cancer. Most patients with increased serum CA125 levels were in stages 3 or 4. Patients with pleural effusions or ascites showed high serum CA125 levels. The survival time was significantly shorter in patients with increased serum CA125 levels than in those within normal limits. Among patients with advanced disease (stages 3 and 4), an increased serum CA125 level was again a poor prognostic factor (P less than 0.01). The existence of a pleural effusion did not correlate with the survival time. We conclude that CA125 is a good indicator of disease extent and serum levels correlate to the length of survival.

Diffuse gallium-67 uptake in radiation pneumonitis

To evaluate the clinical usefulness of Ga-67 imaging for the assessment of radiation pneumonitis, 12 patients who had developed radiation pneumonitis after receiving radiotherapy alone for non-small-cell lung cancer from 1979 through 1988 were reviewed. Diffuse bilateral Ga-67 uptake occurred in 5 out of the 12 cases; in the other 7 cases, Ga-67 uptake was confined to the irradiation lung. Conversely, chest radiography showed infiltrates only in the irradiated lung. Histopathology of the lung in four out of the five cases that showed diffuse Ga-67 uptake in the lung, however, revealed that the lung outside the radiation field with Ga-67 uptake was consistent with interstitial pneumonitis induced by radiation. These results suggest that radiation pneumonitis could extend beyond the irradiated lung and that Ga-67 imaging is more useful than chest radiography for the assessment of the spatial extent of radiography pneumonitis.

[The role of gallium-67 citrate scintigraphy in gastro-intestinal malignant lymphoma]

To evaluate the clinical usefulness of gallium-67 scintigraphy in the detection of the gastrointestinal (GI) non-Hodgkin's lymphoma (NHL) and in the assessment of the therapeutic effects, gallium-67 scintigraphy was reviewed on 24 cases (25 lesions; stomach in 20, ileum in 2, and terminal ileum and/or cecum in 3). Twenty-three out of the 25 lesions (92.0%) were detected by gallium-67 scintigraphy, while barium study could detect all of the 25 lesions. The sizes of the gallium-67 negative 2 lesions were the smallest of all (2.5 and 3.0 cm). The tumor size was considered to the most important factor in the detection by gallium-67 scintigraphy, while the histological classification and the location of the tumor were not related to its detectability. Findings in follow-up gallium-67 scintigraphy after therapy on 10 cases were correlated well with the therapeutic effects. These data suggest that gallium-67 scintigraphy is useful for the detection of GI involvement of NHL and for the assessment of therapeutic effects.

Single photon emission computed tomography (SPECT) using N-isopropyl-p-(123I) iodoamphetamine (IMP) in the evaluation of patients with epileptic seizures

To evaluate the clinical usefulness of IMP SPECT in the diagnosis of epilepsy, 6 normals and 52 patients in the interictal phase were studied. Thirty min after an intravenous injection of 111 MBq IMP, SPECT was performed using a rotating gamma camera. Of 21 patients with simple partial seizures, a localized decrease of uptake was shown in 16, and an increase in 3. Topologically, these findings corresponded well to the ictal symptoms. Nine of 13 patients with localized epileptic EEG had a good correspondence between the findings on EEG and IMP SPECT. In 20 of 23 with complex partial seizures, the coronal images showed laterality of uptake in the temporal lobes, whereas the CT was normal in 14. However, these findings on IMP SPECT agreed with the EEG in the temporal leads in only 5 cases. Of 8 patients with primary generalized seizures, a diffuse cerebral decrease was shown in 3 of 4 patients with convulsive seizures (grand mal), and a normal uptake in 3 of 4 patients with non-convulsive seizures (petit mal). However, 2 patients showed a localized decrease, therefore, we determined that they suffered from partial seizures evolving to secondarily generalization. From these data, we concluded that IMP SPECT could be a useful method in the diagnosis of epilepsy.

The role of gallium 67 imaging in non-Hodgkin's lymphoma of the gastrointestinal tract

To evaluate the clinical usefulness of gallium 67 imaging in the detection of gastrointestinal (GI) non-Hodgkin's lymphoma (NHL) and in the assessment of the therapeutic effects, images were reviewed in 24 cases (25 lesions: stomach, 20; ileum, 2; and terminal ileum and or cecum, 3) and were compared using barium studies and, in 16 cases, computerized tomography (CT). In all, 23 (92.0%) of the 25 lesions were detected by 67Ga citrate imaging, the barium studies detected all 25, and CT detected 15 of 16 lesions (93.8%). The two lesions not identified by imaging and the one not found by CT were the smallest of all. In 2 (8.7%) of the 23 lesions positively identified by 67Ga-citrate imaging, both CT and imaging revealed the extent of the tumor more accurately than did the barium studies. In all but one of the patients, a close correlation existed between the imaging results and the therapeutic effects. These data suggest that 67Ga imaging is useful in conjunction with CT and barium studies for the detection of GI NHL and for the assessment of both the spatial extent of disease and the therapeutic effects, although a lack of 67Ga uptake after therapy does not always indicate a good therapeutic effect.

Serum albumin metabolism in rheumatic diseases: relationship to corticosteroids and peptic ulcer

Serum albumin concentrations and albumin metabolism were assessed in 150 patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and healthy subjects. Hypoalbuminemia was more marked in RA patients than in SLE patients. There was no correlation in RA patients between albumin levels and either disease activity or glucocorticosteroid administration; however, hypoalbuminemia in RA patients significantly correlated with juxta-articular erosions or with the incidence of peptic ulcer. The incidence of peptic ulcer was higher in RA patients with the combination of hypoalbuminemia and corticoid therapy, and reduced by the injection of anabolic steroid. In contrast, anabolic steroid did not improve hypoalbuminemia and bony erosions in the patients. The fractional catabolic rate of albumin was similarly elevated in both RA and SLE, while the absolute catabolic rate was increased to a greater extent in SLE patients. This explains the differences in serum albumin concentration between the patients with RA and SLE.

Assessment of hepatic excretory function in chronic liver disease by hepatobiliary scintigraphy

Hepatobiliary scintigraphy was performed in 23 normal subjects and 47 patients with chronic liver disease (chronic hepatitis; n = 27, liver cirrhosis; n = 20) to evaluate its availability as a test of liver function. After intravenous administration of Tc-99m N-pyridoxyl-5-methyl-tryptophan, the data were acquired for 60 min and the time-activity curves of ROIs (the heart and liver) were generated. In two compartment model simulation, the early blood clearance rate (kl), late blood clearance rate (km), hepatic uptake rate (ku) hepatic excretion rate (ke), and hepatic excretion T 1/2 were calculated. There was no significant difference in those four k values in normal and chronic hepatitis. However, in liver cirrhosis each of them, except km, was lower than in normal subjects. The kl value correlated closely with the indocyanine green plasma clearance test, whereas the ke and T 1/2 values were closely correlated with the level of serum bilirubins. Only hepatobiliary scintigraphy showed the excretory function of the liver quantitatively and the ke value was helpful in detecting hepatic excretory dysfunction early in chronic liver disease before serum bilirubins increased.

[Evaluation of serum pepsinogen I and II of patients with gastric cancer]

Serum pepsinogen levels were examined by immunoradiometric assay method for evaluating its clinical usefulness in gastric cancer. In patients with gastric cancer, serum PG-I tended to decrease but PG-II stayed normal level, resulting in low PG-I/PG-II ratio. Combination of PG-I and PG-I/PG-II discriminated 53.7% of gastric cancer, 70.6% of scirrhous type gastric cancer, and 66.7-100% of those arisen in the upper portion of the stomach, but 13.7% of normal subjects. As the aged normal subjects tended to show decreased PG-I/PG-II ratio (about 30% of the normal subjects aged over 40 years were discriminated as abnormal), the usefulness for detection of gastric cancer seems to be limited, but some types of gastric cancer such as scirrhous type or one arisen in the upper portion may be discriminated by this method. It is also suggested that this method may detect the recurrence of the cancer in some patients.

A unified design algorithm of two-dimensional digital filters for radioisotope image processing

A unified design algorithm of two-dimensional digital filters for radioisotope image processing based on the Fourier-Bessel transform and the weighted least-squares method is described. The algorithm presented here can treat the various kinds of two-dimensional digital filters in a unified approach. Design examples are presented and several graphs are included to show the relationships between the design parameters as an aid in practical applications. The application of the method in radioisotope image processing is also presented. Several low-pass, Wiener and band-pass filters were designed using the method and applied to some clinical data in nuclear medicine including SPECT images. The digital filter design technique proposed here is considered to provide a powerful tool for extraction of additional qualitative information and improvement of the quality of nuclear medicine images both in research and in routine clinical work.

[Single photon emission computed tomography (SPECT) with N-isopropyl-p-(123I) iodoamphetamine in partial epilepsy--evaluation of delayed image]

Thirty eight patients with partial seizures in the interictal phase were studied using single photon emission computed tomography performed 30 min. (early image) and 4-4.5 hrs. (delayed image) after an injection of 111 MBq (3 mCi) N-isopropyl-p(123I) iodoamphetamine (IMP). Five types of distribution changes were observed on IMP-SPECT between the early and delayed images. Eight patients, Type 1, exhibited an unchanged distribution of IMP between the early and delayed images. Fifteen patients, Type 2, showed a smaller area of low uptake on the IMP-SPECT (delayed image) compared to that on the IMP-SPECT (early image)-redistribution. The Type 3 patients exhibited an initial uptake area on the IMP-SPECT (early image) which later became a lower uptake area on the IMP-SPECT (delayed image)-reversed redistribution. This type was further classified into three categories according to the initial uptake pattern including (a) Type 3A, 3 patients with increased uptake area, (b) Type 3B, 6 patients with normal uptake area, and (c) Type 3C, 6 patients with decreased uptake area. With Type 2, the epileptic findings on the present interictal electroencephalography (EEG) were shown in 11 of 15 patients. However, we could not find any other remarkable correlation among these 5 types and the clinical factors (the types of seizures, the X-CT findings, the present interictal EEG data, the present frequency of seizures, and the intervals from the last seizure). In 2 patients with Type 3B who suffered from simple partial seizures, a region of the normal distribution on the IMP-SPECT (early image) became a lower uptake area on the IMP-SPECT (delayed image), corresponding topologically to the ictal symptoms. In this experience, we determined that the IMP-SPECT (delayed image) could be useful in patients with the epileptic lesions unable to be detected on the IMP-SPECT (early image).

A unified computer program for assessment of attenuation correction and data acquisition methods in single photon emission computed tomography (SPECT)

A computer based simulation program was developed to assess the usefulness of various attenuation correction algorithms and data acquisition methods in single photon emission computed tomography (SPECT) in a unified approach. The program analytically calculated projection ray sums from a mathematical model with various distributions of activities and either uniform or non uniform attenuation coefficients by using the line integrals including the effect of attenuation. Data acquisition starting at arbitrary angles, various acquisition angles, including a 180 degree scan and a non circular orbit of a gamma camera, including an elliptical orbit can readily be taken into consideration in our simulation program. To simulate non circular orbit data acquisition, the resolution dependence on the object distance from the collimator surface was incorporated into the simulation. This computer based simulation program allows various combinations of attenuation correction algorithms such as hybrid methods, and data acquisition methods can be evaluated under a large number of study conditions. The usefulness of this computer based simulation program is shown with several representative examples.

[Diagnostic value of the reflux sign in cholescintigraphy after administration of a gallbladder contracting agent--a comparison with X-ray cholangiography]

This study reviewed 25 patients with the reflux sign in cholescintigraphy to assess its diagnostic value in evaluating biliary passage. After at least 4-hour fasting 5 mCi of 99mTcPMT or p-butyl IDA was injected intravenously and serial images were recorded before and after intramuscular injection of 10 micrograms of ceruletide diethylamine (caerulein). The reflux sign was determined positive when increased radioactivities in the left hepatic duct (minor reflux; MIR) or more peripheral intrahepatic ducts (major reflux; MAR) were recognized after injection of caerulein. The reflux sign was found in 28 of 237 (12%) studies. Direct and/or indirect X-ray cholangiograms were available in 25 (MIR; 15, MAR; 10). They included common bile duct (CBD) stone in 4, dilated CBD in 4, biliary dyskinesia (BD) in 4, chronic pancreatitis (CP) in 4, gallbladder (GB) stone in 3, duodenal ulcer (DU) in 2, CBD adenoma, pancreatic pseudocyst (PP), duodenal diverticle (DD), and acute cholangitis (AC) in 1 each. Their serum bilirubin levels were within normal limit in all but 2 at the time of cholescintigraphy. Transit time of radionuclides to the duodenum was found prolonged more than 60 min in 17 (68%) patients and persistent pooling in the CBD was found in 8 (28%) patients on scintigrams. The diameter of the CBD on X-ray cholangiogram was ranged 4 to 17 mm. Dilated CBD of more than 10 mm was found in 13 (52%) patients and apparent stenosis of the CBD in 6 (24%) patients. MAR seemed to correspond to increased diameter of the common hepatic more than 2 mm after caerulein injection in DIC. No abnormal findings in X-ray cholangiography was found in 10 (40%) patients including 3 with BD, 2 with GB stone, 2 with DU, 1 each with CP, PP, and AC. All those patients demonstrated MIR. We concluded that major reflux (MAR) sign was helpful in detecting an incomplete obstruction of the CBD, especially in patients with slightly to mildly dilated CBD.

SPECT volume measurement using an automatic threshold selection method combined with a V filter

The volume measurement of various organs by single photon emission computed tomography (SPECT) has generally been performed by summing up the voxels lying within the outer edge of the organ determined by thresholding as a function of the maximum reconstructed counts within a volume of interest. The optimum threshold level, however, is influenced by various factors. To eliminate this problem, Mortelmans et al. (1986) proposed to use an automatic threshold selection method (ATSM) based on discriminant criteria and to correct the errors induced by the imperfect system response using the method based on linear regression analysis, which has some problems in practical application. We tried to use ATSM combined with a V filter. The correlation coefficient (r) and the regression equation between the true (x) and the calculated volume (y) obtained by experimentation using 22 phantoms with a volume ranging between 26 ml and 380 ml were as follows: r = 0.994 and y(ml) = 1.015 x +1.09 using ATSM combined with a V filter, while r = 0.993 and y(ml) = 1.110 x +30.55 using only ATSM. The relative error between the true and the calculated volumes decreased significantly (P less than 0.01) from 37.7% +/- 26.9% to 5.5% +/- 4.2%. The results suggest that ATSM combined with a V filter is useful for correcting the errors caused by an imperfect system response, and is available and reliable for SPECT volume determination even when the organ volume is small.

Availability of tumor-antigen 4 as a marker of squamous cell carcinoma of the lung and other organs

The serum level of tumor-antigen 4 (TA-4) was measured in 401 patients with squamous cell carcinoma (SCC) of various organs (76 lung, 82 esophagus, and 234 head and neck). The mean serum level of TA-4 in patients with lung SCC was 3.6 times higher than that in healthy controls and even higher in the advanced stages of disease (III, IV). In patients with benign diseases or other types of lung cancer, however, the TA-4 serum level was not different from the controls regardless of the clinical stage. During radiation therapy, the TA-4 levels in patients with lung SCC decreased with reduction in tumor size. It increased again markedly during recurrence. Similarly, patients with SCC of the esophagus and head and neck also showed elevated TA-4 levels but only at advanced stages and in recurrence. It was concluded that TA-4 is highly related to SCC not only of the uterine cervix but also of other organs and that serum level determinations are useful for monitoring therapeutic effects and recurrence of these diseases, despite some limitations.

[An immunoradiometric assay of serum SCC antigen using a monoclonal antibody--a comparison with the conventional double antibody method]

The serum level of the squamous cell carcinoma-related antigen (SCC-Ag) has been measured by a new immunoradiometric assay (IRMA) method that has been recently developed by using a monoclonal antibody, and compared with the results obtained by the conventional double-antibody method using a polyclonal antibody. Both methods gave essentially the same results, that the serum SCC-Ag level was high in patients with squamous cell carcinoma of various organs when compared with other types of lung cancer or benign diseases. However, the percentages of the serum SCC-Ag level over the normal range were found to be higher by the new IRMA method than by the conventional method. This may be due to the improvement in sensitivity and accuracy of this newer method of assay, which also results in a considerable decrease in the normal range estimated in healthy subjects. Therefore, it has been concluded that this new method is more suitable than the conventional method for an early diagnosis of squamous cell carcinoma in all organs.

Simulation and experimental study of respiratory motion effect on image quality of single photon emission computed tomography (SPECT)

The effect of respiratory motion on the image quality of single photon emission computed tomography (SPECT) was investigated by computer simulation and experimentation. In the computer simulation, the phantom was assumed to be cylindrical with a uniform background and a spherical cold or hot spot. To simulate respiratory motion, a cyclic linear motion parallel to the axis of rotation of a gamma camera was assumed. The contrast in the transaxial images was calculated for various respiratory amplitudes and its dependence on lesion size and object contrast was investigated. In the experiments, a moving phantom was used to simulate respiratory motion. The simulation and the experimental results were in good agreement within the range of statistical error. The effect on the lesion detectability was investigated using receiver operating characteristics (ROC) analysis, and a method for correcting respiratory motion was devised.