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Biomedical subjects

K Aikawa

Publications and source records attributed to K Aikawa.

At least 37 records · Page 2Linked to original sources
PubMed1999

Metastatic cutaneous plasmacytoma: a case report associated with IgA lambda multiple myeloma and a review of the literature of metastatic cutaneous plasmacytomas associated with multiple myeloma and primary cutaneous plasmacytomas.

We present the case of a 67-year-old Japanese woman with immunoglobulin A lambda (IgA lambda) multiple myeloma (MM). She had firm nodular cutaneous lesions on the trunk and scalp without adjacent bone involvement. The patient was diagnosed as having IgA lambda MM of stage IIIA with 52% plasmacytosis in the bone marrow six months before the appearance of the cutaneous lesions. The abnormal plasma cells showed moderate to marked dysplasia in both the bone marrow and skin lesions. The abnormal plasma cells in the bone marrow exhibited abnormal karyotypes: 41, XX, der (1) t (1p; 1q), -4, -10, -14, -16, -17, 17p+, that differed from the "unfavorable" karyotype reported previously. We reviewed the cases of metastatic cutaneous plasmacytoma in MM and cases of primary cutaneous plasmacytoma that have been reported in English or Japanese and identified the Ig class. Among the 83 cases of metastatic cutaneous plasmacytomas in MM, IgG, IgA, IgD, and Bence-Jones protein were found in 52%, 23%, 16%, and 6%, respectively. A disproportionately high frequency of IgD lambda MM was found to have spread to the skin, compared with the frequency of IgD MM itself, which was present in only around 2% of the MM cases. Among the 18 primary cutaneous plasmacytomas, IgG, IgA, and Bence-Jones protein were found in 56%, 11%, and 17%, respectively, but no IgD was found.

Aged↗
PubMed1999

Primary duodenal MALT lymphoma.

Primary duodenal MALT lymphoma (MALToma) is a very rare neoplasm arising from the mucosa-associated lymphoid tissue of the duodenum. We report a 55-year-old woman with MALToma located in the descending duodenum and accompanying Helicobacter pylori infection of the stomach. We performed operative resection due to involvement of the papilla of Vater and submucosal tumor infiltration. Despite wide mucosal spreading, postoperative examination revealed only a small amount of MALToma cells infiltrating into the submucosa. No invasion into the adjacent structure or metastasis to regional lymph nodes was confirmed, suggesting the disease could have been controlled by eradication of Helicobacter pylori.

Duodenal Neoplasms↗
PubMed1998

Morphological and functional changes in coronary vessel evoked by repeated endothelial injury in pigs.

OBJECTIVE: We examined the morphological changes induced by repeated endothelial denudation in coronary artery (CA), as well as functional changes in the endothelium-dependent and smooth muscle responses to various vasoactive agents during the process of intimal thickening. METHODS: We observed vascular responses in denuded and non-denuded portions of pig CA while being fed a normal diet (n = 11, N group) or 2% cholesterol diet (n = 25, C group) to intracoronary acetylcholine (ACh), 5-hydroxytryptamine (5-HT), substance P (SP), and isosorbide dinitrate (ISDN) with and without the nitric oxide synthesis inhibitor N omega-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg i.v.) over a period of 8 weeks. Balloon endothelial denudation of the left anterior descending CA was carried out every 2 weeks. RESULTS: In N group, maximum vasoconstriction was obtained with ACh 2 weeks after the first denudation [26 +/- 5% vs. 1 +/- 1% pre-denudation, p < 0.05]. L-NAME did not affect ACh-induced CA diameter changes. Thereafter, the response to ACh was attenuated by repeated denudation in N groups. However, the degree of 5-HT-induced CA narrowing at the denuded portion increased from 7 +/- 4% (0 week) to 88 +/- 8% (8 weeks) (p < 0.05). The changes resulted in severe myocardial ischaemia, and suggested that endothelium-dependent vasodilation was progressively attenuated while hyperreactivity of vascular smooth muscle simultaneously increased. Vasodilation induced by SP was attenuated somewhat, but ISDN-induced vasodilation was preserved. Although mild hypercholesterolaemia was induced in C group, the vascular responses to these vasoactive agents did not differ from those of N group. CONCLUSIONS: Repeated CA endothelial injury and regeneration induce the change of morphology and vascular reactivity in the denuded portion regardless of atherogenic diet. This study strongly suggests that intimal thickening caused by repeated endothelial injury and regeneration induces specific vascular responses to vasoactive agents. Moreover, it is also suggested that during the progression of intimal thickening, increased vascular smooth muscle contraction and decreased endothelium-dependent dilation appear in a stimulus-dependent manner, often leading to severe coronary vasoconstriction accompanied with definitive ECG ST change.

Acetylcholine↗
PubMed1998

Prolonged release of drug from O/w emulsion and residence in rat nasal cavity.

The present study evaluated the usefulness of an o/w emulsion for slowing the release of chlorpheniramine maleate (CM) and prolonging drug residence in the nasal cavity. O/w emulsion formulations of medium chain triglycerides (MCT) were prepared, and their physicochemical properties and drug release kinetics were evaluated using the in vitro dialysis tube method. Drug disappearance from the rat nasal cavity was determined in in situ nasal experiments. CM partitioned in oil droplets by pH, as predicted by pH partition theory. With higher MCT concentration and pH, slower release of CM was observed. CM disappearance (kapp) from the rat nasal cavity was influenced by the amount of drug partitioned in the oil droplets with both the perfusion and deposit methods, and the kapp of CM decreased with increase in MCT concentration and pH. Moreover, with the deposit method, CM remaining in the nasal cavity exhibited a biphasic profile of disappearance, which complied with a saturated process. Because a very small portion of MCT might be adsorbed and formed a pseudooily layer on the mucous membranes, prolongation of CM residence on the mucous membrane was attained. These findings suggest that emulsion containing 30% MCT at pH 8 may be useful for inclusion in controlled-release formulations of CM for intranasal drug delivery in the treatment of allergy.

Administration, Intranasal↗
PubMed1998

[A clinical study of decreased bone density in the patients treated with long-term luteinizing hormone releasing hormone analogue (LHRH-a)--the risk of iatrogenic osteoporosis due to treatment of carcinoma of prostate].

BACKGROUND: It is well known that androgens play an important role in bone metabolism and male hypogonadism induce osteoporosis. Luteinizing hormone-releasing hormone analogue (LHRH-a) which is essential for conservative therapy of prostatic carcinoma (CaP) ultimately reduces circulating testosterone to castration levels. The purpose of this study was to determine the risk of decrease of bone mineral density in men receiving LHRH-a for CaP. PATIENTS AND METHODS: Fifty-three man with CaP aged 63 to 95 years (mean 75.5 years) were included in this study. Seven patients received LHRH-a with estrogen drug, forty-six patients received LHRH-a with or without anti androgen drug. To estimate patient's bone density we use the second metacarpal bone density using a microdensitometry method. RESULTS: Blood level of sex hormone of the forty-six patients who were received LHRH-a without estrogen, was the same as that of castration. Patients who were treated more than twelve months had less bone density than patients who were treated less than eleven months. As the duration of medical castration period was prolonged, patients bone density were reduced. Whereas seven patients who received estrogen drug did not find a decrease of bone density regardless of duration of treatment period. CONCLUSIONS: Hypogonadism induced LHRH-a also reduce bone density, so there is a risk of iatrogenic osteoporosis caused by therapy for CaP with LHRH-a. Patients with osteoporosis easily suffer from a much complicated and pernicious bone fracture, so we should measure bone density of male patients same as female treated with LHRH-a for a long-term.

Aged↗
PubMed1998

Evaluation of drug disappearance from nasal cavity by the deposit method.

In order to evaluate antiallergic intranasal formulations, the rates of drug disappearance from rat nasal cavity were estimated by the deposit and perfusion methods. The deposit method, which estimates changes in the amount of residual drug in the nasal cavity following washout of the deposited drug over time after application, yielded a good correlation between apparent disappearance rate constant and the combination of lipophilicity and molecular weight. Since the deposit method can be used only with delivery of small amounts of drug to the nasal cavity, the physiological characteristics of the nasal membrane readily affect drug disposition in tests performed with it, and adsorptive drugs such as parabens exhibited rapid disappearance. Doses used clinically for intranasal administration are usually small, and in the case of antiallergic formulations, it is important to maintain the drug concentration in the nasal mucous membrane. The deposit method should be useful for evaluating intranasal antiallergic drug formulations.

Administration, Intranasal↗
PubMed1998

[The effects of sevoflurane, isoflurane or enflurane on the pattern of phrenic nerve discharge in rabbits].

In order to estimate primary action of anesthetic agents on the central neural mechanisms of respiratory control and the ventilatory response to an acute increased ETCO2, the effect of sevoflurane (SEV), isoflurane (ISO) or enflurane (ENF) on the pattern of phrenic nerve discharge (Phr.N.A.) was studied in adult rabbits which had been vagotomized, paralyzed and ventilated artificially with 100% oxygen. Throughout the course of experiment, ETCO2 and the rectal temperature of animals were maintained around physiological values. Depressant effects of these anesthetics on Phr. N.A. which consisted of inspiratory slope (SLO), peak amplitude (AMP), inspiratory (Ti) and expiratory (Te) time, I/E ratio (I/E) and respiratory cycle (Tc) were evaluated and compared with each anesthetic. At 0.5 MAC administration, SEV and ISO reduced SLO and AMP without a remarkable change in Tc, but ENF did with a prolongation in Tc. Inhalation of each anesthetic with 1 MAC caused a marked respiratory slowing with a more reduction of SLO and AMP than those occurred at 0.5 MAC; SEV increased Te more than Ti, but ENF prolonged Ti more than Te, while ISO enhanced both Ti and Te without any change of I/E. An acutely increased ETCO2 after the respiratory arrest (RA test) induced the change of Phr.N.A which was characterized by a marked prolongation in Tc with a prolonged Te, an increased SLO and an augmented AMP. The prolonged Tc induced by RA test was diminished by the inhalation of anesthetics, and a new response, shortening in Ti was produced by ENF and ISO. Based on these results, it might be concluded that there are both quantitative and qualitative differences in these anesthetic effects on the central pattern generator of respiration and the mechanism of CO2 responses at equipotent anesthetic concentrations.

Action Potentials↗
PubMed1997

[Neoadjuvant intra-arterial chemotherapy based on chemosensitivity tests for locally invasive bladder cancer].

We investigated the clinical usefulness of individualization of chemotherapeutic regimen in neoadjuvant intra-arterial chemotherapy for locally invasive bladder cancer. Anticancer drugs were selected according to the results of an in vitro chemosensitivity test (collagen matrix assay or succinic dehydrogenase inhibition test). Nine patients with locally invasive bladder cancer received 1 to 4 courses of neoadjuvant intra-arterial chemotherapy, followed by radical cystectomy. Histopathological responses in the cystectomized specimens were grade 3 in 3 cases, grade 2 in 2, grade 1b in 2 and no response in 2. Pathologically, a complete response and downstaging were observed in 3 and 4 cases, respectively. Seven of the 9 patients were alive no evidence of disease with a mean follow-up period of 38.9 months, whereas 2 patients died of metastasis within 2 years. Six of the 7 patients who showed a complete response or down staging have been free of recurrence. These findings suggest that our chemotherapeutic strategy may improve the prognosis for locally invasive bladder cancer.

Aged↗
PubMed1996

Cepstral representation of speech motivated by time-frequency masking: an application to speech recognition.

A new spectral representation incorporating time-frequency forward masking is proposed. This masked spectral representation is efficiently represented by a quefrency domain parameter called dynamic-cepstrum (DyC). Automatic speech recognition experiments have demonstrated that DyC powerfully improves performance in phoneme classification and phrase recognition. This new spectral representation simulates a perceived spectrum. It enhances formant transition, which provides relevant cues for phoneme perception, while suppressing temporally stationary spectral properties, such as the effect of microphone frequency characteristics or the speaker-dependent time-invariant spectral feature. These features are advantageous for speaker-independent speech recognition. DyC can efficiently represent both the instantaneous and transitional aspects of a running spectrum with a vector of the same size as a conventional cepstrum. DyC is calculated from a cepstrum time sequence using a matrix lifter. Each column vector of the matrix lifter performs spectral smoothing. Smoothing characteristics are a function of the time interval between a masker and a signal. DyC outperformed a conventional cepstrum parameter obtained through linear predictive coding (LPC) analysis for both phoneme classification and phrase recognition by using hidden Markov models (HMMs). Compared with speaker-dependent recognition, an even greater improvement over the cepstrum parameter was found in speaker-independent speech recognition. Furthermore, DyC with only 16 coefficients exhibited higher speech recognition performance than a combination of the cepstrum and a delta-cepstrum with 32 coefficients for the classification experiment of phonemes contaminated by noises.

Humans↗
PubMed1996

[Efficacy of the chemosensitivity test using collagen gel matrix-supported culture system for urogenital tumors].

BACKGROUND: We evaluated the usefulness of in vitro tumor culture system using a specialized collagen gel matrix (CGM assay) as a chemosensitivity test. PATIENTS AND METHODS: Chemosensitivity results of CGM assay were compared with other in vivo and in vitro assays on an implantable murine bladder tumor cell line (MBT-2). In addition we investigated the possibility of the clinical use of CGM assay using clinical specimens obtained from urogenital malignant tumor patients by comparing the result with that of the other chemosensitivity test, SDI testing using single cells (conventional SDI test). Methods of CGM assay were as follows. Tumor tissues on the collagen gel matrices were incubated under the existence of anticancer drugs following 4 days preculture. Drug sensitivities were evaluated by counting the number of viable cells adjusted to the tumor weight. RESULTS: Inhibition rates in MBT-2 were high in the order of mitomycin C, cisdiamminedichloroplatinum (II), (2"R)-4'-0-tetrahydropyranyl adriamycin. Four of 6 anticancer drugs were decided as chemosensitive drugs. These results corresponded to the results of the antitumor effects on subcutaneously transplanted MBT-2 in vivo, moreover was correlated well with those of the conventional SDI test. Twenty of 22 cases, including 11 of 13 bladder cancer cases, 1 of 3 renal cancer cases, 2 of 3 testicular cancer cases and 1 of 1 adrenal cortical cancer cases, were evaluable in the clinical study of the CGM assay. Corresponding rates between the results of the CGM assay and those of the conventional SDI test performed simultaneously in 12 cases were excellent for each anticancer drug. CONCLUSION: This CGM assay can serve as an effective tool for chemosensitivity testing because of its convenience and high evaluable rate.

Animals↗
PubMed1996

[Aberrations of the p 53 gene in roentgenographically occult squamous cell carcinoma of the lung].

Mutations of one p 53 allele and LOH occur in advanced lung cancers, but in early lung cancer these things were not known well. To make clear carcinogenesis of lung cancer, it is important to study p 53 alterations in early lung cancers. We studied them in 29 roentgenographically occult lung cancers by means of PCR-SSCP and microsatellite marker. PCR-SSCP was performed for exon 7 of the p 53 gene. LOH was found in 6 cases and point mutation was found in 2 cases (codon 234 T-A transversion, codon 245 G-T transition). Frequency of LOH and point mutations was lower than in the cases of advanced lung cancers. These things suggested the clonal expansion of aberrant p 53 gene occurred in the course of cancer development (i.e., roentgenographically occult lung cancer to advanced lung cancer).

Carcinoma, Squamous Cell↗
PubMed1995

Side-chain structure is critical for the transport of sterols from lysosomes to cytoplasm.

Macrophages take up and metabolize negatively charged liposomes containing free cholesterol efficiently, resulting in a massive accumulation of cholesteryl esters and triacylglycerols in their cytoplasm (Nishikawa, K., Arai, H. and Inoue, K. (1990) J. Biol. Chem. 265, 5226-5231). This system was used to assess the effects of structural variation of sterol on the intracellular transport and the metabolism of endocytosed sterols by the cells. Liposomes containing phytosterols with an extra one (campesterol) or two (beta-sitosterol, stigmasterol, fucosterol) carbons at the C-24 position of the cholesterol side-chain were endocytosed as efficiently as those containing cholesterol without exhibiting any apparent toxicity on the cells. Esterification of endocyotosed phytosterols was, however, extremely low; campesterol esterification was only 20% that of cholesterol and either beta-sitosterol or stigmasterol was not esterified appreciably. A morphological study showed that the endocytosed phytosterols were accumulated in the phagolysosomes of the cells. Blocking of esterification of endocytosed cholesterol by an acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor did not lead to cholesterol accumulation in the phagolysosomes. These data suggest that accumulation of endocytosed phytosterols in phagolysosomes is not a consequence of the inability of the cell to esterify sterols in the endoplasmic reticulum. In the light of these observations, we conclude that cultured macrophages can discriminate between sterols that differ only by a methyl or ethyl group at the C-24 position at their lysosomal compartment.

Animals↗
PubMed1995

Chronic lymphocytic leukemia associated with nephrotic syndrome and dermatomyositis.

Several types of autoimmune complications of chronic lymphocytic leukemia (CLL) have been previously reported. However, the tendency to develop autoantibodies is usually restricted to the hematopoietic system. We report a 68-year-old man who had developed dermatomyositis after ten years of chemotherapy for CLL. He also had secondary nephrotic syndrome at the onset of CLL. Subsequently, the patient died of perforation of the small intestine. The association of both nephrotic syndrome and dermatomyositis with CLL is very rare. We discuss the possibility of a casual relation.

Aged↗
PubMed1995

[Halothane reduces the inhibition of dorsal horn lamina V type neuronal activity induced by bradykinin injection into the femoral artery contralateral to the recording site].

Effect of halothane (0.2%, 0.5%, and 1.0%) on spinal function were studied in lamina V type cells responding to noxious and light touch applied at their cutaneous receptive field on the foot pad of the left hind paw. Extracellular unit activities of lamina V type cells were recorded at the lumbar level in six cats and thirteen spinal cats. When intra-arterial injection of bradykinin (BK) 10 micrograms into the femoral artery ipsilateral to the recording sites was used as the noxious test stimuli, six of these cells (100%) were found to have inhibitory response in six intact cats and thirteen of these cells (100%) were found to have excitatory response in thirteen spinal cats. On the other hand, when the injection of 10 micrograms into the femoral artery contralateral to the recording sites was used as the noxious test stimuli, six of these cells (100%) were found to have inhibitory response in six intact cats and six of these cells (46%) were found to have inhibitory response in thirteen spinal cats. We studied the effect of halothane on the inhibition induced by BK injection into the femoral artery contralateral to the recording sites in six intact cats and six spinal cats. Halothane 0.2%, 0.5% and 1.0% reduced the inhibition of dorsal horn lamina V type neuronal activity induced by BK injection.

Animals↗
PubMed1995

[Detection of human papillomavirus type 16, 18 and 33 DNA in stage I (pT1N0M0) squamous cell carcinoma of the lung by polymerase chain reaction].

Human papillomavirus (HPV) has been considered one of the important factors of malignant change. To investigate the occurrence of HPV DNA in primary squamous cell carcinoma of the lung, we tried to detect HPV DNA by polymerase chain reaction (PCR). Formalin-fixed paraffin-embedded tissue specimens from 8 cases of stage I (pT1N0M0) squamous cell carcinoma of the lung were examined for the presence of human papillomavirus DNA (type 16, 18 and 33) by polymerase chain reaction. DNA was extracted from double 5 microns sections of each specimen by deparaffinization and proteinase K digestion. Using the primers described previously by Shimada et al, target DNA sequences were selectively amplified through 40 cycles of 94 degrees C for 1 min, 55 degrees C for 2 min, and 72 degrees C for 2 min. When stained band was unclear, second PCR was conducted using product of first PCR as template of second PCR. Human papillomavirus type 18 was present in 1 case (12.5%) in contrast that type 16 and 33 were not detected in these cases.

Adult↗