Biomedical subjects

H Azuma

Publications and source records attributed to H Azuma.

At least 55 records · Page 3Linked to original sources

PubMed2000

[Retroperitoneal leiomyosarcoma found 5 cm in size: a case report].

A 76-year-old woman presented with dull pain in left flank. Excretory urogram showed no function of left kidney. Retrograde pyelography, ultrasonography, computed tomography and magnetic resonance imaging demonstrated hydronephrosis of the left kidney and a mass lesion surrounding the ureter. The tumor was removed together with the upper region of the left ureter and kidney. The tumor was 5 x 3 x 2.5 cm in diameter and the pathological diagnosis was a leiomyosarcoma. Although recurrent tumor arose in the pelvis at 14 months after the operation, the patient has been in good general condition without showing any other evidence of recurrent lesion. This case may indicate the importance of early resection of retroperitoneal leiomyosarcoma.

Aged↗

PubMed1999

Aspirin reduces apolipoprotein(a) (apo(a)) production in human hepatocytes by suppression of apo(a) gene transcription.

High serum lipoprotein(a) (Lp(a)) is a risk factor for vascular disorders. Our preliminary observations suggest that, in some patients with coronary heart disease with high serum Lp(a) levels, administration of aspirin reduced Lp(a) levels. Therefore, we aimed to analyze the effects of aspirin on the production of apo(a), the expression of apolipoprotein(a) (apo(a)) mRNA and the transcriptional activity of apo(a) gene promoter. Aspirin (5 mM) reduced the apo(a) levels in culture medium of human hepatocytes and suppressed apo(a) mRNA expression to 73% and 85% of the controls, respectively. Aspirin also reduced the transcriptional activity of apo(a) gene transfected into HepG2 hepatoma cells in a dose-dependent manner, with a maximal effect at 5 mM (44.3 +/- 1.5% of the control). Sodium salicylate (5 mM) also reduced apo(a) gene transcription, whereas indomethacin (10 microM) had no effect. Deletion analysis of apo(a) gene promoter showed that promoter region extending from -30 to +138 is critical for the effect of aspirin. Furthermore, enhanced production, mRNA expression, and gene transcription of apo(a) by interleukin-6 were also inhibited by aspirin. These results demonstrate that aspirin reduces apo(a) production from hepatocytes via reduction of the transcriptional activity of apo(a) gene with suppression of apo(a) mRNA expression. The suppression of apo(a) production by aspirin may at least in part play a role in the anti-atherogenic effect of aspirin in vascular disorders.

Apolipoproteins A↗

PubMed1999

Early induction of apoptosis in androgen-independent prostate cancer cell line by FTY720 requires caspase-3 activation.

BACKGROUND: We previously reported that FTY720, a metabolite from Isaria sinclairii, induced some cancer cells to undergo apoptosis, and that FTY720-induced apoptosis was not related to Fas-antigens. In this study we investigated whether FTY720 was able to induce apoptosis in an androgen-independent prostate cancer cell line, DU145, which is not only resistant to androgen-withdrawal-induced apoptosis but also Fas- and TNF-alpha-mediated apoptosis. METHODS: Cell survival and morphological change were examined and apoptosis was confirmed by DNA isolation and analysis of DNA fragmentation. Caspase activation was studied by using anti-caspase-1 and anti-caspase-3 antibodies. To determine whether caspase activation is central to FTY720-induced apoptosis, caspase inhibitor was added to the media 24 hr prior to the addition of FTY720. RESULTS: We found that FTY720 rapidly induced apoptosis in DU145 cells, and that caspase-3 was activated during FTY720-induced apoptosis. In contrast, normal human prostate stromal cells were resistant to FTY720. Furthermore, FTY720-induced apoptosis was prevented by caspase-3 inhibitor. CONCLUSIONS: The data in this report show that FTY720 is a potential strong antitumor agent for cell line DU145, and provide the first evidence for involvement of caspase-3 in apoptosis of an androgen-independent prostate cancer cell line. Activation of such caspases may provide a means for eliminating androgen-independent prostate cancer in humans.

Androgens↗

PubMed1999

Localization and effects of hepatocyte growth factor on smooth muscle cells during neointimal formation after balloon denudation.

The migration and proliferation of smooth muscle cells (SMCs) may play a key role in tissue remodeling after arterial wall injury. We investigated the localization and effects of hepatocyte growth factor (HGF) in rabbit carotid arteries after balloon denudation. Immunoreactivity for HGF and the c-Met receptor was clearly observed in neointimal SMCs. The immunoreactivity was not restricted to proliferating cells but was seen even in non-dividing cells in the basal layer of the neointima 4 and 6 weeks after balloon denudation. The distribution of platelet-derived growth factor (PDGF)-positive cells paralleled that of proliferating SMCs. The SMCs in the basal layer of the neointima at 4 and 6 weeks were positive for matrix metalloproteinase (MMP)-2 and membrane type 1-MMP which can activate the proform of MMP-2. HGF significantly stimulated the migration but not proliferation of cultured SMCs. Our results suggest that HGF and PDGF act in coordination to promote the proliferation and migration of SMCs in the earlier phases of neointimal formation and that HGF as well as MMP-2 contribute to the later stages by facilitating the migration but not replication of SMCs.

Animals↗

PubMed1999

Encephalopathy associated with haemophagocytic lymphohistiocytosis following rotavirus infection.

UNLABELLED: A 2-year-old Japanese boy with a haemophagocytic lymphohistiocytosis (HLH) associated encephalopathy which developed after rotavirus infection is described. The neurological symptoms consisted of coma, seizures and spastic quadriplegia. On therapy with steroids, etoposide and cyclosporin A, the patient recovered without any neurological deficits. The interferon-gamma levels in serum and CSF were elevated at onset of the disease but had returned to normal at the time of clinical remission. Brain MRI revealed diffuse white matter abnormalities and parenchymal volume loss. Proton magnetic resonance spectroscopy revealed elevated lactate in the abnormal lesions observed on MRI, indicating that macrophages not exhibiting aerobic metabolism had infiltrated the CNS. At the time of clinical remission, the white matter abnormalities and brain lactate had disappeared. These findings suggested that the neurological symptoms resulted from the overproduction of cytokines by activated T-cells and macrophages. The pathophysiology of a HLH associated encephalopathy was considered to be a local immune response within the CNS, because interferon-gamma can induce the expression of major histocompatibility complex class I and II antigens on glial cells in the CNS. CONCLUSION: Haemophagocytic lymphohistiocytosis associated encephalopathy should be considered early in the differential diagnosis of cases with acute onset neuropathy.

Brain Diseases↗

PubMed1999

Expandable metallic stent placement for nutcracker phenomenon.

A 40-year-old woman presented with asymptomatic gross hematuria caused by the nutcracker phenomenon. Despite treatment with hemostatic agents and injection of silver nitrate into the renal pelvis, the hematuria had continued, and severe anemia (hematocrit 17%) had developed. We performed expandable metallic stent (EMS) placement across the left renal vein. Although mild hematuria continued, the anemia resolved after this interventional radiotherapy. EMS placement is a minimally invasive therapy for the nutcracker phenomenon.

Adult↗

PubMed1999

Computerized assessment of the mastoid air cell system.

There have been many arguments on the development of pneumatization of temporal bone. However, a technique for direct volume measurement from high resolution computed tomography has never been reported. The aim of this paper is to develop a technique by using digital image processing to measure the volume of the mastoid air cell system. Forty three ears of 26 healthy subjects (13 males and 13 females) without a history of chronic or exudative otitis media, clear signs of Meniere's disease, severe sensorineural hearing impairment or malformation of temporal bone were eligible for enrolment in this study. Using a digital image processing technique, only the black air cells and tympanic cavity on the CT films are easily selected. Then, after image processing, only areas of these extracted black pneumatized parts are calculated. Consequently, the volume of pneumatized parts of temporal bone could be calculated separately as total volume and as partial volume that divided by several CT planes. The average volume of pneumatization in 43 temporal bones was 5.97 ml. However, since the volume of pneumatization in the temporal bone has traditionally been estimated by analyzing areas on X-ray films, the new method described in this study is significant for its ability to directly measure the volume of pneumatization in the temporal bone.

Adult↗

PubMed1999

Relationship between HLA-DR antigen and HLA-DRB1 alleles and prostate cancer in Japanese men.

PURPOSE: Human leukocyte antigens (HLA) are cell surface glycoproteins playing a key role in the immune system. In some cancers, changes in major histocompatibility complex (MHC) class I and II expression, usually a reduction or loss of these molecules, appear to provide a mechanism whereby tumour cells may escape host immunity. We investigated the relationship between HLA, especially class II, molecules and prostate cancer in Japanese men using molecular techniques. MATERIALS AND METHODS: HLA class II typing was performed by the polymerase chain reaction-sequence specific primer (PCR-SSP) method of analysis and/or a commercial rapid assay based on the PCR followed by reverse dot-blot hybridization of the PCR products (Inno-LiPA assay). Allele frequencies were calculated. HLA allele frequencies reported in 1216 healthy Japanese individuals were used as the control data. Differences in allele frequency between subjects and the control group were analyzed by the chi-square test. The relationship between HLA antigens/alleles and prostate cancer is expressed in terms of relative risk (RR). RESULTS: The frequencies of HLA-DR4 were significantly higher in Japanese men with prostate cancer than in the healthy control group (gene frequency 36.2% vs. 26.3% in control, p<0.05), although the relative risk of prostate cancer was less than 2. Furthermore, the frequencies of HLA-DRB1-0406, 0410 and 1405 allele were significantly higher in the prostate cancer group than in the control group (allele frequency was 7.3%, 4.5% and 5.4% vs. 3.03%, 1.79% and 2.22%, p<0.05, respectively). RR of those HLA-DRB1 allele for prostate cancer was 2.6 in each allele. CONCLUSIONS: HLA molecules may be useful for the early detection of prostate cancer as a risk factor, and also for recognizing cancer activity by using them as a marker helpful in the choice of appropriate treatment by predicting prognosis.

Alleles↗

PubMed1999

In vitro and in vivo evaluation of the enhancing activity of glycyrrhizin on the intestinal absorption of drugs.

PURPOSE: The enhancing activity of dipotassium glycyrrhizinate (Grz) on the intestinal absorption of drugs has been demonstrated in an in vitro study using Caco-2 cell monolayers and in an in vivo absorption study in rats. METHODS: The hydrolysis of Grz by luminal content and mucosa of the rat colon was investigated. The absorption-enhancing activity of Grz and its hydrolysates was estimated by changes in transepithelial electrical resistance (TEER) and the permeation of sodium fluorescein (Flu-Na) in Caco-2 cell monolayers. It was further evaluated through the absorption of salmon calcitonin (sCT) in the rat colon. RESULTS: Grz was not hydrolyzed to glycyrrhetinylmonoglucuronide (GrMG) and glycyrrhetinic acid (GA) by colonic mucosa, but, rather by the beta-glucuronidase in colonic flora. The hydrolysis of Grz to GrMG was extremely slow and the GrMG produced was rapidly regenerated to GA. Grz and GrMG had no effect on TEER nor on the permeability of Flu-Na across Caco-2 cell monolayers. On the other hand, GA decreased TEER and increased the permeability of Flu-Na in a dose-dependent manner. However, Grz and GrMG enhanced the plasma calcium-lowering effect of sCT after administration in the rat colon. The coadministration of sCT and GA in the rat colon induced the strongest plasma calcium-lowering effect and the highest plasma concentration of sCT. CONCLUSIONS: The in vivo enhancing-activity of Grz in the absorption of drugs is dependent on GA, a hydrolysis product of Grz resulting from the action of beta-glucuronidase in intestinal flora.

Animals↗

PubMed1999

Accelerated intimal hyperplasia and increased endogenous inhibitors for NO synthesis in rabbits with alloxan-induced hyperglycaemia.

1. We examined whether endogenous inhibitors of NO synthesis are involved in the augmentation of intimal hyperplasia in rabbits with hyperglycaemia induced by alloxan. 2. Four weeks after the endothelial denudation of carotid artery which had been performed 12 weeks after alloxan, the intimal hyperplasia was greatly augmented with hyperglycaemia. The degree of hyperplasia was assessed using three different parameters of histopathological findings as well as changes in luminal area and intima: media ratio. 3. There were positive and significant correlations between intima:media ratio, plasma glucose, and concentrations of N(G)-monomethyl-L-arginine (L-NMMA) and N(G), N(G)-dimethyl-L-arginine (ADMA) in endothelial cells, that is, the intima:media ratio became greater as plasma glucose and endothelial L-NMMA and ADMA were increased. Furthermore, endothelial L-NMMA and ADMA were increased in proportion to the increase in plasma glucose. 4. In contrast, there were inverse and significant correlations between cyclic GMP production by carotid artery strips with endothelium and plasma glucose, between cyclic GMP production and endothelial L-NMMA and ADMA, and between the intima:media ratio and cyclic GMP production. 5. Exogenously applied L-NMMA and ADMA inhibited cyclic GMP production in a concentration-dependent manner. IC50 values were determined to be 12.1 microM for the former and 26.2 microM for the latter. The cyclic GMP production was abolished after the deliberate removal of endothelium from the artery strips. 6. These results suggest that the augmentation of intimal hyperplasia with hyperglycaemia is closely related to increased accumulation of L-NMMA and ADMA with hyperglycaemia, which would result in an accelerated reduction in NO production/release by endothelial cells.

Alloxan↗

PubMed1999

High prevalence of Epstein-Barr virus type A strain with the 30 b.p. deletion of the latent membrane protein-1 gene in a Japanese population.

BACKGROUND: The pathogenic activity of Epstein-Barr virus (EBV) with a characteristic 30 b.p. deletion of the latent membrane protein-1 (LMP-1) gene is controversial. We analyzed the LMP-1 gene and two major strains of EBV, type A and type B, in Japanese patients with EBV-associated disease. METHODS: We directly sequenced the carboxy terminal part of the LMP-1 gene from 15 EBV-infected patients; 10 patients with infectious mononucleosis (IM) and one patient each with Hodgkin's disease, B cell lymphoma, Wiskott-Aldrich syndrome (WAS), AIDS and atypical EBV infection (atEBV). The EBV subtype was studied by determining the 3' divergence of Epstein-Barr virus nuclear antigen (EBNA)-2 using polymerase chain reaction primers. RESULTS: Twelve of 15 patients had EBV with the 30 b.p. deletion and numerous point mutations of the LMP-1 gene, regardless of the disease. Two patients, one with IM and one with WAS, had EBV without the 30 b.p. deletion. One patient with atEBV had two types of LMP-1 gene, one with and one without the 30 b.p. deletion. Thirteen patients had EBV type A, the WAS patient had the type B strain and the atEBV patient had both types A and B. In the patient with atEBV, the two types of LMP-1 gene and two EBV subtypes were detected simultaneously. CONCLUSIONS: The characteristic 30 b.p. deletion of the LMP-1 gene is not an important factor in the pathogenesis of EBV-associated diseases. The EBV type A strain with the 30 b.p. deletion of the LMP-1 gene is prevalent in the Japanese population.

Epstein-Barr Virus Infections↗

PubMed1999

Gestational changes in endothelin-1-induced receptors and myometrial contractions in rat.

The present experiments were performed to characterize the gestational changes in endothelin (ET)-1-induced myometrial contractions and ET receptors in rat. ET-1-induced contractions were composed of two types: increases in resting tone and rhythmic contractions. The increase in resting tone was decreased at 7 days of gestation, but increased at 20 days. The increase in amplitude and frequency of rhythmic contractions remained unchanged during days 7-14 of gestation. Continuous rhythmic contractions were not produced by ET-1 near the term. Both contractions were inhibited by the antagonists BQ 123 and Ro 46-2005 but not by RES 701-1 or BQ 788. In binding studies, total binding sites of [1251]-ET-1 were unchanged, however higher affinity binding sites appeared during pregnancy in addition to the lower affinity sites. The specific [125I]-ET-1 binding in non-pregnant and pregnant myometrium was completely inhibited by unlabelled ET-1 and Ro 46-2005. In contrast, the proportion which was inhibited by BQ 123 was decreased during pregnancy. In conclusion, characteristic gestational changes were the augmentation of ET-1-induced increased resting tone near term, and the appearance of high affinity ET-1 binding sites and an increase in BQ 123-resistant ET-1 binding sites during pregnancy. Further investigations are needed to understand the physiological role of these changes.

Animals↗

PubMed1999

Simultaneous use of sodium deoxycholate and dipotassium glycyrrhizinate enhances the cellular transport of poorly absorbed compounds across Caco-2 cell monolayers.

The absorption-enhancing effect of a combination of sodium deoxycholate and dipotassium glycyrrhizinate in Caco-2 cell monolayers has been compared with that of the enhancers when used alone, and the mechanism of the enhancement was partially elucidated. The effect of the combined compounds was evaluated by measurement of transepithelial electrical resistance (TEER) and the cellular permeability of the water-soluble model compounds sodium fluorescein (MW 376.3) and fluorescein isothiocyanate dextran (MW 4400). The TEER of the monolayers decreased with increasing concentrations of dipotassium glycyrrhizinate in combination with 0.02% (w/v) sodium deoxycholate for 20 min, and reached a minimum at 1% (w/v) dipotassium glycyrrhizinate. Although a combination of 0.02% (w/v) sodium deoxycholate and 1% (w/v) dipotassium glycyrrhizinate enhanced the cellular permeability of sodium fluorescein and fluorescein isothiocyanate dextran, 0.02% (w/v) sodium deoxycholate and 1% (w/v) dipotassium glycyrrhizinate alone had no effect on either the TEER of the monolayers or the cellular transport of the water-soluble compounds. Sequential and separate exposure of the monolayers to each enhancer for 10 min had no effect on the TEER, but a marked decrease in TEER was observed when both compounds were used in combination. The enhancing effect of the combination of sodium deoxycholate and dipotassium glycyrrhizinate was inhibited by H7, a protein kinase C (PKC) inhibitor, suggesting that dipotassium glycyrrhizinate might enhance the activation of PKC via sodium deoxycholate. The combined use of these two enhancers had no toxic effects. These results provide useful, basic information on the action of these absorption enhancers on drugs for which absorption is limited owing to polarity or molecular size, or both.

Absorption↗

PubMed1999

[Role of L-arginine--endogenous NOS inhibitors--endothelin-1 pathway for the vascular remodelling].

Mechanisms of vascular remodelling process are complex and poorly understood. We describe herein the role of L-arginine-endogenous NOS inhibitors-endothelin-1 pathway for the vascular remodelling after endothelial denudation of the rabbit carotid artery. It is reportedly known that NO is a vasodilating substance, an inhibitor of platelet aggregation and adhesion, and an inhibitor of vascular smooth muscle cell proliferation and that endothelin-1, of which production is inhibited by NO, is a potent vasoconstrictor and a potent mitogen. An accumulation of endogenous inhibitors (L-NMMA and ADMA) in regenerated endothelial cells after the endothelial denudation was accompanied by the decreased NO generation, the increased endothelin-1 content within the vessel wall and the occurrence of intimal hyperplasia. Endothelin-1 content within the vessel wall was significantly increased after the exogenous L-NMMA administration for 2 weeks, suggesting that accumulated L-NMMA results in the decreased NO generation and, in turn, increases endothelin-1 content. Endothelin-1 facilitated the [3H]-L-NMMA uptake by endothelial cell and brought about the potentiation of L-NMMA-mediated inhibition of NO generation. These results strongly suggest that the L-arginine--endogenous NOS inhibitors--endothelin-1 pathway plays an active role for vascular remodelling.

Animals↗

PubMed1999

ATZ1993, an orally active and novel nonpeptide antagonist for endothelin receptors and inhibition of intimal hyperplasia after balloon denudation of the rabbit carotid artery.

The present experiments were designed to investigate the effect of ATZ1993 [3-carboxy-4,5-dihydro-1-[1-(3-ethoxyphenyl)propyl]-7-(5-pyrimidinyl)met hoxy-[1H]-benz[g]indazole] on the intimal hyperplasia after balloon endothelial denudation of the rabbit carotid artery. ATZ1993 inhibited the specific [125I]endothelin (ET)-1 binding not only to ET-receptor subtype A (ET(A)) with a pKi value of 8.69+/-0.02, but also to ET-receptor subtype B (ET(B)) with a pKi value of 7.20+/-0.03. Counterscreening in the binding assay (30 different receptors) confirmed that ATZ1993 had a high selectivity for ET receptors. Increases in intima:media ratio and DNA content in the vessel wall were significantly (P < 0.005) inhibited by ATZ1993 in a daily dose of 30 mg x 200 ml(-1) x kg(-1) for 1 week before and 6 weeks after balloon denudation. Inhibition of the intimal hyperplasia with ATZ1993 was determined as approximately 77% for increases in intima:media ratio and DNA content. Plasma concentrations of ATZ1993 ranged between 121.6+/-26.6 and 131.7+/-20.9 nM throughout experimental periods. Mean arterial blood pressure, heart rate and body weight gain remained unaffected by administering ATZ1993. These results demonstrate that ATZ1993 is a novel nonpeptide and nonselective ET(A)/ET(B)-receptor antagonist, and the agent when administered orally inhibits effectively intimal hyperplasia after balloon denudation of the rabbit carotid artery.

Administration, Oral↗

PubMed1999

Immunomodulatory functions of low-molecular weight hyaluronate in an acute rat renal allograft rejection model.

Low molecular weight hyaluronate (LMW-HA) blocks interactions between T lymphocyte CD44 and hyaluronate (HA), a heteropolysaccharide that is expressed on the surface of endothelial cells and ubiquitously in the extracellular matrix. This study was undertaken to assess the ability of LMW-HA to modify the course of experimental acute renal allograft rejection. Lewis (LEW) rats were bilaterally nephrectomized and received an orthotopic, fully MHC-mismatched, Wistar-Furth (WF) kidney transplant. Animals received either no treatment, low doses of cyclosporin A (CsA) on days 0 to 5, LMW-HA on days 0 to 5, or CsA plus LMW-HA on days 0 to 5 after transplantation. With no treatment, CsA monotherapy, or HA monotherapy, animals rejected their allografts at a median of 15, 13, and 7.5 d, respectively (P = NS). In contrast, combined CsA plus LMW-HA therapy prevented acute rejection and significantly prolonged graft survival (P = 0.008) to a median of 49.0 d. CsA/LMW-HA-treated grafts also demonstrated better preservation of renal function at day 30 (serum creatinine level, 1.38+/-0.8 mg/dl), compared with surviving animals treated with CsA alone (2.9+/-0.55 mg/dl, P<0.05). Histologic graft analysis of CsA/LMW-HA-treated animals at day 7 after transplantation showed minimal rejection and leukocyte infiltration, compared with all other groups. Intragraft gene expression analysis, using semiquantitative reverse transcription-PCR, at the same time point showed reductions of CD4, CD8, and interferon-gamma transcript levels in the combined-treatment group. This is the first study demonstrating the immunomodulatory functions of LMW-HA in vivo in the setting of organ transplantation. Defining the exact mechanisms that underlie this immunomodulation may provide the rationale to develop novel strategies for use in clinical transplantation.

Adjuvants, Immunologic↗

PubMed1999

In vitro and in vivo immunomodulatory effects of RDP1258, a novel synthetic peptide.

Peptides derived from certain regions of human class I MHC molecules are known to have immunomodulatory effects. In particular, amino acid residues 75-84 of the HLA-B7 and HLA-B2702 molecules have demonstrated allele nonspecific immunosuppression in several animal transplant models. There is evidence that these effects are mediated by binding to intracellular heat shock proteins, including heme oxygenase-1. A new derivative of these peptides, RDP1258, was developed using a novel computer-assisted rational design technique. In vitro, RDP1258 peptide inhibited rat heme oxygenase activity in a dose-dependent manner. Similar to observations made with other in vitro heme oxygenase inhibitors, in vivo administration of RDP1258 peptide to naive rats resulted in upregulation of splenic heme oxygenase activity. The effects of the peptide on alloimmune responses were then tested. Addition of RDP1258 to rat and human mixed leukocyte reactions inhibited proliferation in a dose-dependent manner. In a rat renal transplantation model, peptide therapy combined with a sub-therapeutic dose of cyclosporin A significantly prolonged allograft survival. These data provide further evidence that modulation of the heat shock protein heme oxygenase by rationally designed peptides affects immune effector functions and may allow the development of novel immunomodulatory strategies in organ transplantation.

Adjuvants, Immunologic↗

PubMed1999

FDG PET to evaluate combined intra-arterial chemotherapy and radiotherapy of head and neck neoplasms.

UNLABELLED: We evaluated the effectiveness of combined intra-arterial chemotherapy and radiotherapy on head and neck squamous cell carcinomas using fluorodeoxyglucose (FDG) PET. METHODS: Fifteen patients with squamous cell carcinoma of the head and neck were included in the study. Fourteen patients completed the treatment regimen and underwent FDG PET before and 4 wk after chemoradiotherapy. One patient underwent pretreatment FDG PET only. The pretreatment and post-treatment PET images were compared with clinical and histopathologic evaluations of the effects of chemoradiotherapy. For the quantitative evaluation of regional radioactivity, standardized uptake values (SUVs) with an uptake period of 50 min were used. RESULTS: Before treatment, FDG PET detected neoplasms in all 15 patients. The overall clinical response rate to chemoradiotherapy in the 14 patients who were imaged before and after treatment was 100%. Before treatment, the neoplastic lesions showed high SUVs (mean 7.77 mg/mL), which significantly decreased after therapy (3.62 mg/mL, P < 0.01). Lesions with higher pretreatment SUVs (> 7 mg/mL) showed residual viable tumor cells after the treatment in 3 of 8 patients, whereas those with lower SUVs (< 7 mg/mL, 6 patients) were successfully treated. Three of seven tumors with post-treatment SUVs > 4 mg/mL had viable tumor cells, whereas all tumors (7/7) with post-treatment SUVs < 4 mg/mL showed no viable cells. With concomitant chemoradiotherapy monitored by FDG PET, 5 patients avoided surgery entirely, and the remaining 9 patients underwent a reduced form of surgery. CONCLUSION: FDG PET is useful in evaluating the effects of combined chemotherapy and radiotherapy in patients with head and neck carcinoma. Pretreatment FDG PET is useful in predicting the response to treatment, and post-treatment FDG PET can evaluate residual viable cells. Hence, FDG PET is a valuable tool in the treatment of head and neck tumors.

Antineoplastic Combined Chemotherapy Protocols↗