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Biomedical subjects

M Ishida

Publications and source records attributed to M Ishida.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Long-term results of vitrectomy for complications of proliferative diabetic retinopathy].

PURPOSE: To evaluate the long-term results of vitrectomy for complications of proliferative diabetic retinopathy. METHODS: Five-year follow-up examinations were obtained on 33 eyes of 24 patients that underwent vitrectomy. The preoperative status of macula was no detachment(group 1, 9 eyes), macular detachment(group 2, 17 eyes), and traction macular fold (group 3, 7 eyes). RESULTS: The retina was successfully reattached in 17 eyes(100%). The final visual acuity obtained was as follows: 75% of the eyes had acuity of 0.1 or better in group 1, 65% in group 2, and 86% in group 3; 44% had acuity of 0.5 or better in group 1, 24% in group 2, and 14% in group 3; and 11% had acuity of 0.05 or worse in group 1, 18% in group 2, and 0% in group 3. 11% of the final visual acuity was worse than the postoperative best visual acuity(three lines or more) in group 1, 29% in group 2, and 14% in group 3. The causes of worsening in vision were optic or macular atrophy. CONCLUSIONS: Vitrectomy for complications of proliferative diabetic retinopathy is valuable in improving the patient's visual acuity.

Adult↗
PubMed2001

Hyperosmotic stimuli induces recruitment of aquaporin-1 to plasma membrane in cultured rat peritoneal mesothelial cells.

Aquaporin-1 (AQP-1) has been reported to play an important role in peritoneal dialysis. To determine the precise mechanism involved, we used cultured rat peritoneal mesothelial cells (RPMCs) to examine the translocation of AQP-1 to the plasma membrane induced by hyperosmotic stimuli. Cultured RPMCs obtained from male Sprague-Dawley rats were incubated at room temperature in Dulbecco modified Eagle medium/F12 (DMEM/F12) with and without glucose or mannitol as the hyperosmotic stimulus. The plasma membrane was then extracted by the Percoll gradient method. Finally, the abundance AQP-1 molecules in the membrane fraction was determined by Western blot analysis. Significant enhancement of AQP-1 abundance (p < 0.05) was observed within 2.5 minutes of the addition of 5% glucose to the medium. The increase was sustained in its abundance through 15 minutes. Abundance of AQP-1 was also increased (p < 0.05) by the addition of 5% mannitol. These results suggest that hyperosmotic stimuli could generate increased AQP-1 abundance in the plasma membrane by translocation of AQP-1 protein from recycling endosomes or early endosomes to the plasma membrane, rather than by protein synthesis via newly expressed mRNA. The latter mechanism would be expected to take more time.

Animals↗
PubMed2001

[A case of fundus albipunctatus with a retinol dehydrogenase 5 gene mutation in a child].

BACKGROUND: We examined a family with fundus albipunctatus in which mutation of the retinol dehydrogenase 5(RDH 5) gene was suspected to be the cause of this disease. CASE: An 8-year-old girl had diffuse multiple white dots in her fundus except for the macula. She had good central vision. The amplitude of her electroretinogram wave was low, but it recovered after three hours of dark adaptation. Dark adaptometry showed an elevated threshold for rod adaptation. No visual field loss was observed. A homozygous missense mutation was found in exon 5 of the RDH 5 gene that substituted histidine for arginine at codon 280(Arg 280 His). Her mother had a normal fundus but was heterozygous for the same mutation. CONCLUSION: A missense mutation of RDH 5(Arg 280 His) was found in a Japanese family with fundus albipunctatus.

Alcohol Oxidoreductases↗
PubMed2001

[An investigation of therapeutic effectiveness and the mechanism of oral appliance therapy on obstructive sleep apnea syndrome].

In order to investigate the effectiveness and the mechanism of action of oral appliances (OA) on obstructive sleep apnea syndrome (OSAS), a series of studies including overnight polysomnography, both ultrafast MRI and measurement of intraesophageal pressure during daytime naps and cephalometric analysis while awakening were performed on 19 OSAS patients before and during the treatment. In all cases, a significantly decreased apnea hypopnea index (AHI), shortened apnea duration, and a significant elevation in the lowest value of nocturnal arterial oxygen saturation, in comparison with the pretreatment values, were recognized during treatment with OA. The number of patients who responded to OA treatment, i.e., those whose AHI decreased by more than 50% of the pretreatment value, was 13 (68.4%). In cases with an AHI of 30 per hour of sleep or more before treatment, the number of arousals decreased and the percentage in stage 3 + 4 increased significantly during the use of OA. Cephalometric analysis revealed the anteroinferior advancement of the mandible, the anterosuperior movement of the hyoid bone and increase of upper airway area with OA in the cases studied. An MRI of the upper airway during sleep showed that glossopharyngeal obstruction disappeared with the use of OA in all cases, and velopharyngeal obstruction disappeared in nearly half of the cases. Moreover, the fluctuation of the intraesophageal pressure during sleep decreased significantly with OA. There were no differences in clinical background (e.g., age, body mass index, pretreatment value of AHI, and upper airway characteristics) in patients who AHI had decreased to less than 50% and those in whom it remained over 50%. These results confirmed the effectiveness of the treatment with OA. OA can be recommended for OSAS patients with not only glossopharyngeal obstruction, but also velopharyngeal obstruction, which is the most common cause of OSAS.

Adult↗
PubMed2000

Specific labeling of the bovine heart mitochondrial phosphate carrier with fluorescein 5-isothiocyanate: roles of Lys185 and putative adenine nucleotide recognition site in phosphate transport.

The amine/SH-modifying fluorescein 5-isothiocyanate (FITC) specifically labeled Lys(185) in the putative membrane-spanning region of the phosphate carrier from both the cytosolic and matrix sides of bovine heart mitochondria at 0 degrees C and pH 7.2, and the labeling inhibited the phosphate transport. Nonmodifying fluorescein derivatives having similar structural features to those of ADP and ATP (Majima, E., Yamaguchi, N., Chuman, H., Shinohara, Y., Ishida, M., Goto, S., and Terada, H. (1998) Biochemistry 37, 424-432) inhibited the specific FITC labeling and phosphate transport, but the nonfluorescein phenylisothiocyanate did not inhibit FITC labeling, suggesting that there is a region recognizing the adenine nucleotides in the phosphate carrier and that this region is closely associated with the transport activity. The phosphate transport inhibitor pyridoxal 5'-phosphate inhibited the specific FITC labeling, possibly due to competitive modification of Lys(185). In addition, FITC inhibited the ADP transport and specific labeling of the ADP/ATP carrier with the fluorescein SH reagent eosin 5-maleimide. Based on these results, we discuss the structural features of the phosphate carrier in relation to its transport activity.

Adenosine Diphosphate↗
PubMed2000

Entropic stabilization of the tryptophan synthase alpha-subunit from a hyperthermophile, Pyrococcus furiosus. X-ray analysis and calorimetry.

The structure of the tryptophan synthase alpha-subunit from Pyrococcus furiosus was determined by x-ray analysis at 2.0-A resolution, and its stability was examined by differential scanning calorimetry. Although the structure of the tryptophan synthase alpha(2)beta(2) complex from Salmonella typhimurium has been already determined, this is the first report of the structure of the alpha-subunit alone. The alpha-subunit from P. furiosus (Pf-alpha-subunit) lacked 12 and 6 residues at the N and C termini, respectively, and one residue each in two loop regions as compared with that from S. typhimurium (St-alpha-subunit), resulting in the absence of an N-terminal helix and the shortening of a C-terminal helix. The structure of the Pf-alpha-subunit was essentially similar to that of the St-alpha-subunit in the alpha(2)beta(2) complex. The differences between both structures were discussed in connection with the higher stability of the Pf-alpha-subunit and the complex formation of the alpha- and beta-subunits. Calorimetric results indicated that the Pf-alpha-subunit has extremely high thermostability and that its higher stability is caused by an entropic effect. On the basis of structural information of both proteins, we analyzed the contributions of each stabilization factor and could conclude that hydrophobic interactions in the protein interior do not contribute to the higher stability of the Pf-alpha-subunit. Rather, the increase in ion pairs, decrease in cavity volume, and entropic effects due to shortening of the polypeptide chain play important roles in extremely high stability in Pf-alpha-subunit.

Amino Acid Sequence↗
PubMed2000

Vitrectomy for the Treatment of Expulsive Hemorrhage.

Purpose: An evaluation of surgical outcome of vitrectomy in the treatment of expulsive hemorrhage associated with intraocular surgery.Methods: We reviewed 12 eyes from 12 patients with expulsive hemorrhage, occurring after or during cataract extraction (4 eyes), phacoemulsification (2 eyes), glaucoma filtering surgery (4 eyes), or vitrectomy (2 eyes). Mean follow-up period was 21 months.Results: The retina was reattached in 6 eyes (50%) after the initial surgery and ultimately in 9 eyes (75%). Three eyes, which failed to achieve retinal reattachment, resulted in phthisis bulbi. Final visual acuity was 0.1 or better in 4 eyes and 0.01 to 0.09 in 4 eyes. The incidence of expulsive hemorrhage was 0% for cataract surgery, 0.57% for trabeculectomy, and 0.09% for vitrectomy at Toho University Sakura Hospital.Conclusion: In the treatment of expulsive hemorrhage, vitrectomy is an effective surgical procedure to improve the visual function.

Journal Article↗
PubMed2000

Angiotensin II induces transactivation of two different populations of the platelet-derived growth factor beta receptor. Key role for the p66 adaptor protein Shc.

Several signal transduction events induced by angiotensin II (AngII) binding to the angiotensin II type 1 receptor resemble those evoked by platelet-derived growth factor (PDGF) binding to the PDGF-beta receptor (PDGFbeta-R). We report here, in agreement with previous data, that AngII and PDGF-B-chain homodimer (PDGF-BB) stimulate tyrosine phosphorylation of the PDGFbeta-R. Both AngII and PDGF-BB stimulated the phosphorylation of PDGFbeta-R via the binding of tyrosine-phosphorylated Shc to PDGFbeta-R. Both PDGF-BB- and AngII-induced phosphorylation of the Shc.PDGFbeta-R complex was inhibited by antioxidants such as N-acetylcysteine and Tiron, but not by calcium chelation. However, transactivation of PDGFbeta-R by AngII (measured by PDGFbeta-R tyrosine phosphorylation) differed significantly from PDGF-BB. Evidence to support different mechanisms of PDGFbeta-R phosphorylation includes differences in the time course of PDGFbeta-R phosphorylation, differing effects of inhibitors of the endogenous PDGFbeta-R tyrosine kinase and Src family tyrosine kinases, differing results when the PDGFbeta-R was directly immunoprecipitated (PDGFbeta-R-antibody) versus coimmunoprecipitated (Shc-antibody), and cell fractionation studies that suggested that the Shc.PDGFbeta-R complexes phosphorylated by AngII and PDGF-BB were located in separate subcellular compartments. These studies are the first to suggest that transactivation of tyrosine kinase receptors by G protein-coupled receptors involves a unique pathway that regulates a population of tyrosine kinase receptors different from the endogenous tyrosine kinase ligand.

Angiotensin II↗
PubMed2000

The third cytoplasmic loop of the angiotensin II type 1 receptor exerts differential effects on extracellular signal-regulated kinase (ERK1/ERK2) and apoptosis via Ras- and Rap1-dependent pathways.

The third cytoplasmic loop of the angiotensin (Ang) II type 1 receptor (AT(1)) is important for receptor coupling to G proteins and activation of downstream events. Therefore, we determined whether specific AT(1) sequences were required for kinase activation and inhibition of apoptosis by transfecting wild-type (AT1Rwt) and mutated AT(1) into 293 cells. Ang II stimulated a 19.4-fold increase in extracellular signal-regulated kinase (ERK1/ERK2) activity in 293 cells transfected with AT1Rwt. However, in 293 cells that expressed a receptor in which amino acids 221 and 222 were deleted (AT1R[Del221/222]), Ang II-mediated ERK1/ERK2 activation was inhibited by >85%. In contrast, c-Jun NH(2)-terminal protein kinase (JNK) activation was similar in AT1Rwt- and AT1R(Del221/222)-transfected cells. Activation of ERK1/ERK2 by AT1Rwt was independent of Ca(2+), whereas the low level of ERK1/ERK2 activation by AT1R(Del221/222) was completely Ca(2+) dependent. Activation of ERK1/ERK2 in AT1Rwt required Ras, whereas AT1R(Del221/222) required Rap1. These results demonstrate the presence of 2 different pathways for ERK1/ERK2 activation by Ang II, which differ in their requirements for Ca(2+) and small G proteins (Ras versus Rap1). Furthermore, Ang II prevented serum deprivation-induced apoptosis in cells transfected with AT1Rwt but not AT1R(Del221/222). AKT was only phosphorylated by Ang II in AT1Rwt-transfected cells. Overexpression of constitutively active AKT significantly reduced serum deprivation-induced apoptosis in cells transfected with AT1R(Del221/222). This study shows for the first time a direct link between kinase activation and inhibition of apoptosis dependent on amino acids 221 and 222 in the third cytoplasmic loop of the AT(1).

Calcium↗
PubMed2000

Two-dimensional analysis of phospholipids by capillary liquid chromatography/electrospray ionization mass spectrometry.

A phospholipid mixture extracted from cultured cells was directly analyzed by capillary (Cap) liquid chromatography (LC)/electrospray ionization (ESI) mass spectrometry (MS). Using a quadrupole mass spectrometer, we analyzed positive molecular ions, negative molecular ions, positive fragment ions and negative fragment ions under four different functions. In the analysis of the elution patterns of the phospholipids, a two-dimensional map, in which the first dimension is elution time and the second dimension is mass, proved useful. Consequently, four different maps can be obtained by each of four different functions. Among them, from negative fragment ions at high cone voltage in the negative ion mode, ions that originated from acyl fatty acid and phosphorylcholine, phosphorylethanolamine and cyclic inositol phosphate can be detected at specific elution times. The map from positive fragment ions at high cone voltage in the positive ion mode indicated ions such as diradylglycerol and derivatives of 1-alkyl or 1-alkenyl cyclic phosphatidic acid from phosphatidylethanolamine (PE), and phosphorylcholine from choline-containing phospholipids. The map produced from positive molecular ions indicated choline-containing phospholipids such as phosphatidylcholine, sphingomyelin, lysophosphatidylcholine and PE. The map of negative molecular ions effectively indicated acidic phospholipids such as phosphatidylinositol. We were able to obtain more than 500 molecular species of phospholipids by this method within a few hours immediately after extraction from culture cells using a mixture of chloroform and methanol (2:1). In this context, we concluded that the combination of Cap-LC and ESIMS seems to be very effective in the analysis of phospholipid classes and their molecular species.

Animals↗
PubMed2000

Isolation and structures of grammistins, peptide toxins from the skin secretion of the soapfish Grammistes sexlineatus.

Two peptide toxins (named grammistins Gs 1 and Gs 2) with hemolytic and ichthyotoxic activities were isolated from the skin secretion of the soapfish Grammistes sexlineatus. Grammistin Gs 2 showed 6-11 x higher hemolytic activity and 10x higher ichthyotoxicity than grammistin Gs 1. The complete amino acid sequences of Gs 1 comprising 25 residues and Gs 2 comprising 24 residues were determined. Although a search by the database failed to find any homologous toxins from other sources, the grammistins were similar in secondary structures as well as biological activities to the two classes of peptide toxins, melittin from the bee venom and pardaxins from the skin secretion of two species of soles. CD experiments and helical wheel projections showed that the grammistins were randomly coiled in distilled water but formed amphiphilic alpha-helices in the presence of SDS micelles. In addition, they were found to be surface seeking peptides by the Eisenberg plot and assumed to exist as aggregates of 3-4 molecules. Interestingly, grammistin Gs 2 is much more abundant in amphiphilic alpha-helices and much higher in biological activities than melittin and pardaxins as well as grammistin Cs 1.

Amino Acid Sequence↗
PubMed2000

A LIS1/NUDEL/cytoplasmic dynein heavy chain complex in the developing and adult nervous system.

Mutations in mammalian Lis1 (Pafah1b1) result in neuronal migration defects. Several lines of evidence suggest that LIS1 participates in pathways regulating microtubule function, but the molecular mechanisms are unknown. Here, we demonstrate that LIS1 directly interacts with the cytoplasmic dynein heavy chain (CDHC) and NUDEL, a murine homolog of the Aspergillus nidulans nuclear migration mutant NudE. LIS1 and NUDEL colocalize predominantly at the centrosome in early neuroblasts but redistribute to axons in association with retrograde dynein motor proteins. NUDEL is phosphorylated by Cdk5/p35, a complex essential for neuronal migration. NUDEL and LIS1 regulate the distribution of CDHC along microtubules, and establish a direct functional link between LIS1, NUDEL, and microtubule motors. These results suggest that LIS1 and NUDEL regulate CDHC activity during neuronal migration and axonal retrograde transport in a Cdk5/p35-dependent fashion.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2000

Increased plasma fibrinogen level and future risk of coronary artery disease after repair of abdominal aortic aneurysm.

BACKGROUND: Cardiovascular disease such as coronary artery disease is a major cause of late death after repair of abdominal aortic aneurysm (AAA). But risk factors are not well known. So, we investigated the incidence of cardiovascular events after surgery and examined the prognostic factors. STUDY DESIGN: We retrospectively reviewed 270 patients who underwent elective surgery for AAA from 1985 to 1995. Kaplan-Meier survival analysis was used to estimate survival rates and the probability of coronary, cerebrovascular, and cardiovascular events. The risk factors for each endpoint were investigated using multivariate analysis. RESULTS: The overall survival rate was 87.3% at 3 years, 76.4% at 5 years, and 52.3% at 10 years. Current cigarette use, renal insufficiency, advanced age (> or = 70 years old), and higher plasma fibrinogen level (> or = 300 mg/dL) were significant factors influencing survival. The probability of a coronary event was 4.9% at 3 years, 7.1% at 5 years, and 20.7% at 10 years. Plasma fibrinogen level and cerebrovascular disease were significant prognostic factors for coronary events. The probability of a cerebrovascular event was 5.3% at 3 years, 7.6% at 5 years, and 18.0% at 10 years. No significant prognostic factors for cerebrovascular events existed. The probability of a cardiovascular event was 10.3% at 3 years, 14.9% at 5 years, and 33.6% at 10 years. Plasma fibrinogen level was a significant risk factor for cardiovascular events. But the presence of coronary artery disease did not affect survival or the incidence of coronary, cerebrovascular, or cardiovascular events. CONCLUSIONS: Plasma fibrinogen level is an independent risk factor of future coronary events after surgery for AAA, and the increased risk of coronary artery events contributes to the impaired survival. Patients with higher plasma fibrinogen level need careful surveillance for cardiovascular disease after surgery.

Adult↗
PubMed2000

Circulating p53 antibody in patients with colorectal cancer: relation to clinicopathologic features and survival.

The presence of serum anti-p53 antibody has been reported to be associated with survival of patients with breast cancer, ovarian cancer, and hepatocellular carcinoma. To clarify prognostic significance of p53 antibody in colorectal cancer, serum p53 antibody was measured in patients with colorectal cancer. The 89 patients included 71 with colorectal cancer and 18 with colon polyp. An enzyme-linked immunosorbent assay was used to detect p53 antibodies in serum. Clinicopathological parameters such as age, sex, degree of differentiation of cancer, location of tumor, liver metastasis, stage classification, Dukes classification, CEA, CA19-9, and immunostaining of p53 and anti-p53 antibody were evaluated as prognostic factors of colorectal cancer. p53 antibody was positive in 18 of 71 (25%) with colorectal cancer, whereas it was positive in only 1 of 18 (6%) with colon polyp. The patients with p53 antibody had higher CEA and CA19-9 levels, higher positive rates of p53 protein expression in cancer cells, and higher liver metastasis rates. The p53 antibody positivity at stage classification I-IIIb/ Dukes classification A-C was significantly lower than that at stage classification IV/Dukes classification D. Overall survival in colorectal cancer patients with p53 antibody was significantly shorter than in those without p53 antibody. A Cox regression analysis showed that liver metastasis, stage classification, Dukes classification, CA19-9, and p53 antibody were significant prognostic factors in colorectal cancer. Serum anti-p53 antibody could serve as one of the prognostic factors in patients with colorectal cancer.

Aged↗
PubMed2000

Classical QSAR and comparative molecular field analyses of the host-guest interaction of organic molecules with cyclodextrins.

The application of classical QSAR and molecular modeling analysis using Comparative Molecular Field Analysis (CoMFA) to the complexation of some natural and modified cyclodextrins (CDs) with guest molecules was examined. For 1:1 complexation systems between natural beta-CD, modified alpha-, beta-, and gamma-CD that bear one p-(dimethylamino)benzoyl (DMAB) moiety (DMAB-alpha-, beta-, and gamma-CDs) and guest molecules of widely varying chemical structures and properties, the binding constants of the complexes were successfully fitted using multiple linear regression (MLR) with hydrophobic descriptor log P (the partition coefficient between 1-octanol and water phases) and molecular connectivity indices. A non-linear dependency of binding constants on the zero-th and/or first order molecular connectivity index as a measure of size becomes apparent. The modeling performance of the CoMFA models with steric/electrostatic fields to DMAB-alpha- and beta-CD systems was comparable to those of MLR models. However, statistically significant CoMFA models for gamma-CD systems which have higher conformational flexibility of the ring could not be obtained. The CoMFA models obtained for DMAB-alpha- and beta-CD systems showed that the predominant effects were steric for the DMAB-alpha-CD system and electrostatic for the DMAB-beta-CD system, respectively.

Cyclodextrins↗
PubMed2000

Significance of lung resistance-related protein in the clinical outcome of acute leukaemic patients with reference to P-glycoprotein.

Lung resistance-related protein (LRP) overexpression in leukaemic blast cells from acute leukaemia patients and the effect of LRP or P-glycoprotein (P-gp) on the clinical outcome of acute leukaemia were investigated individually by dividing patients into four groups. The complete remission rate of group I (LRP and P-gp both negative) was 81.7%, group II (only LRP positive) 87.5%, group III (only P-gp positive) 87.1% and group IV (LRP and P-gp both positive) 40.0%. There were no statistical differences between group I and groups II or III, but a significant difference was observed between groups I, II or III and group IV. Median overall survival in group IV was significantly shorter (4.6 months) than in groups I, II or III, although no significant differences were observed between group I and groups II or III (18.9, 20.5 and 31.8 months). There was a tendency for disease-free survival in group III to be longer than that in groups I, II or IV. The reasons for these findings are discussed. Our present results indicate that the co-existence of LRP and P-gp strongly influenced the effectiveness of induction chemotherapy and long-term prognosis, whereas the isolated presence of LRP or P-gp did not.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed2000

Stimulatory effect of procaine on the growth of several microalgae and cyanobacteria.

Procaine has been used to stimulate plant growth and it has been noted that it also promotes growth of microorganisms. The effect of procaine hydrochloride concentration on the growth rates of several species of microalgae and cyanobacteria was studied under both photoautotropic and heterotrophic growth conditions. Procaine hydrochloride was added to cultures at concentrations over the range 0.01-1000 mg L(-1). A stimulating effect of procaine hydrochloride on photoautotrophic growth was observed for the cyanobacteria Anabaena cylindrica and Anabaena variabilis, and for the salt-tolerant green algae Dunaliella primolecta and Dunaliella parva. During active growth in batch culture an increase in growth rate (compared with control culture without procaine hydrochloride) of about 25% was observed at 0.1 mgL(-1) of procaine hydrochloride for A. cylindrica. However, procaine hydrochloride was toxic at concentrations of > 10 mgL(-1). Simultaneous administration of hydrolysis products of procaine, p-aminobenzoic acid and diethyl aminoethanol, in lieu of procaine hydrochloride, was as effective as procaine in stimulating growth of A. cylindrica. Heterotrophic growth of Chlorella ellipsoidea and Prototheca zopfii was not stimulated by procaine hydrochloride over the concentration range studied (0.1-10 mg L(-1)). The combined effects of procaine hydrochloride concentration and four other environmental factors (temperature, light intensity, CO2 concentration in the flushing gas and NaCl concentration) on growth rate of D. primolecta was modelled using both a neural network approach and a response surface method. These results indicate that procaine hydrochloride exerts different effects on the growth of microalgal and cyanobacterial cells as functions of dosage, species and culture conditions.

Anesthetics, Local↗
PubMed2000

Analyses of structure of photoreceptor organelle and blepharismin-associated protein in unicellular eukaryote Blepharisma.

In the ciliated protozoan Blepharisma, step-up photophobic response is believed to be mediated by a novel type of photosensory pigment known as "blepharismins" (BL) that are contained in the pigment granules located just beneath the plasma membrane. We examined the ultrastructure of the pigment granules by freeze-fracture and thin-section electron microscopy and proposed a schematic diagram showing the granules' three-dimensional inner membranous structure. Some of the BL are suggested to be associated with 200 kDa membrane protein. High-pressure liquid chromatography analysis of pigment species associated with 200 kDa protein obtained from blue forms of Blepharisma (oxyblepharisma) revealed that the 200 kDa protein was associated with five types of oxyblepharismin. The fluorescence intensity was increased when the pigments were dissociated from the 200 kDa protein. The result supports the hypothesis that the pigment-200 kDa complex is able to transduce light energy into signals mediating the photobehavior of Blepharisma.

Animals↗