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Biomedical subjects

K Ichikawa

Publications and source records attributed to K Ichikawa.

At least 325 records · Page 18Linked to original sources

Nail abrasion: a new treatment for ingrown toe-nails.

A simple new method for the treatment of ingrown toe-nails was devised and applied to 33 toe-nails in 22 patients. The entire nail surface, except for the margin, was abraded until the nail became flexible with a Schreu's skin grinder equipped with a steel bar. When there was infection or granulation of the nail wall, the imbedded nail corner was trimmed before abrasion. The patients underwent additional treatments when one treatment was not enough to achieve cure or when discomfort appeared, which was the first symptom of recurrence. The average number and duration of treatments was 2.9 times and 16 months, respectively. Relief from pain occurred in all patients soon after abrasion was performed. Recurrence of infection and granulation was observed in only one patient. Five patients (23%) remained problem-free for more than one year without any additional treatment, because their incurved nail was gradually improved in shape by repetition of this procedure. This therapy was particularly effective in patients with severely incurved nails.

Adult↗

[Anti-allergic effects of (E)-3-[p-(1H-imidazol-1-ylmethyl)phenyl]-2-propenoic acid (OKY-046), a specific thromboxane (TX) A2 synthetase inhibitor: effect of OKY-046 on II-IV type allergic reactions].

We studied the effects of OKY-046 on types II, III and IV allergic reactions, as classified by Coombs and Gell. In Type II, OKY-046 at 30-100 mg/kg intraduodenally (i.d.) and at 1-30 mg/kg intravenously (i.v.) inhibited the bronchoconstriction in a dose-dependent manner after Forssman antigen injection. Aspirin (3 mg/kg, i.v.) also suppressed it. OKY-046 (30-100 mg/kg, i.d.) suppressed the increase of TXB2 level in the plasma in a dose-dependent manner. However, there was no effect of OKY-046 and aspirin on the decrease in complement activity (CH50), platelets and leukocytes. Additionally, OKY-046 (300 mg/kg, p.o.) prolonged the survival time following Forssman antigen injection. However, the immune hemolysis reaction was not prevented by OKY-046 (10(-6)-10(-3) M). FUT-175 protected against the Forssman shock at 1 mg/kg, i.v. and the in vitro immune hemolysis reaction at 10(-5) M. In Type III, OKY-046 (300 mg/kg, p.o.) significantly suppressed the direct passive Arthus reaction and immune complex nephritis in rats. There was no effect of OKY-046 on the delayed-type hypersensitive response to picryl chloride in mice. We think that OKY-046 should be a beneficial drug for the treatment of types II and III allergic reactions.

Acrylates↗

Effects of beta-hydroxy butyric acid on insulin binding to its receptor and on autophosphorylation of the receptor.

We examined the effects of beta-hydroxy butyric acid (B-OH-butyrate) on insulin binding to its receptor and on autophosphorylation of the receptor in vitro. The affinity of isolated rat adipocyte insulin receptors was significantly increased by B-OH-butyrate at neutral pH. Similar results were obtained with soluble insulin receptors prepared from hepatocytes. Autophosphorylation of insulin receptor, however, was not affected by OH-butyrate at neutral pH. These results suggested insulin resistance in ketoacidosis is not caused by an interaction between B-OH-butyrate and the insulin receptor.

3-Hydroxybutyric Acid↗

Somatostatin analogue (SMS 201-995) decreases plasma levels of corticotropin (ACTH) and corticotropin-releasing hormone in a patient with ectopic ACTH-producing tumors.

Effects of long-acting somatostain analogue (SMS 201-995) on plasma corticotropin (ACTH) and corticotropin-releasing hormone (CRH) levels were studied in a patient (63-year-old woman) with ectopic ACTH-producing tumors associated with type I multiple endocrine neoplasia (MEN-I). The patient had undergone bilateral adrenalectomy. Plasma CRH, as well as plasma ACTH, beta-endorphin and alpha-MSH, increased. The hormone levels were dramatically decreased by acute administration of SMS 201-995. Moderately higher doses of dexamethasone (0.05 or 0.1 mg/kg a day) did not decrease plasma CRH or ACTH. An extremely high dose of dexamethasone (0.2 mg/kg a day), however, decreased plasma ACTH, but failed to decrease plasma CRH. Acute administration of SMS 201-995 further lowered the level of plasma ACTH even in this condition. In addition to the decrease in ACTH, SMS 201-995 decreased plasma CRH. Chronic administration of SMS 201-995 continuously decreased plasma CRH, ACTH and beta-endorphin. The decrease in these hormone concentrations accompanied the disappearance of hyperpigmentation. These results suggested that SMS 201-995 inhibits hypersecretion not only of ACTH but also of CRH, and that the agent is therapeutically useful in normalizing the hypersecretion of these hormones.

ACTH Syndrome, Ectopic↗

[A morphological study on the mandibular symphysis of cleft lip and palate, anterior crossbite and Angle Class I malocclusions].

Morphological characteristics of the mandibular symphysis among the cleft lip and palate, anterior crossbite and Angle Class I malocclusions were analyzed cephalometrically. 1. In the symphyseal thickness at pogonion, the significant differences among the three groups were not found. In the cleft group, the symphyseal thickness at point B was significantly narrower than that of the Class I group. 2. In the symphyseal height, the cleft group was larger than that of the crossbite group, while the crossbite group was the middle of the two groups. 3. In the symphyseal inclination, the cleft group was significantly large, compared to that of the crossbite and Class I groups. The symphyseal inclination of the cleft group was mostly the alveolar part of mandibular symphysis. 4. The chin formation was the absorption of the around of point B. The chin formation was appeared between the ages of A and B groups.

Cephalometry↗

Hereditary macular dystrophy without visible fundus abnormality.

We found an unusual form of macular dystrophy in three patients from two generations of the same family. The fundi of these patients appeared normal by ophthalmoscopy and fluorescein angiography, even in an older patient and in patients with poor visual acuity. Results of full-field electroretinograms were also normal in both cone and rod components. Focal macular electroretinograms were severely affected, however, indicating retinal impairment in the macular region. Results of Tübingen perimetry were consistent with electroretinographic findings. Since the condition was progressive, this disease is thought to be a hereditary macular dystrophy without visible fundus abnormality.

Adult↗

Possible locations of pH-dependent central chemoreceptors: intramedullary regions with acidic shift of extracellular fluid pH during hypercapnia.

Using liquid membrane pH microelectrodes, we evaluated rapid and transient changes in extracellular fluid (ECF) pH within the medulla during vertebral artery injections of CO2-saturated saline (0.5 ml) in anesthetized (Dial-urethane), spontaneously breathing cats. We found intramedullary regions where ECF pH shifted to the acid side in the time course analogous to respiratory excitation during the CO2 loadings: the acidic shift occurred just before the respiratory excitation. Since most of the tested regions showed no or few changes in ECF pH, the responsive regions are thought to be specific local environments fitting the central chemoreceptors. Forty (85%) out of the 47 responsive regions were found to be scattered in the ventrolateral medulla, i.e. a long narrow zone extending from the ventrolateral surface to the ventral respiratory group (VRG) areas where inspiratory or expiratory activity was frequently recorded. The responsive regions were not necessarily restricted to the superficial ventral layers. We were also able to find the responsive regions in the dorsal area ventral to the nucleus tractus solitarii, though they were fewer in number (7/47). The distributions corresponded rougly to the areas where we had previously identified the tonically firing neurons excited exclusively by stimulation of the central chemoreceptors. These results indicate a possibility that the pH-dependent central chemoreceptors, if any, would be located within the regions demonstrated in this study.

Animals↗

Purification and characterization of NADPH-dependent cytosolic 3,5,3'-triiodo-L-thyronine binding protein in rat kidney.

The NADPH-dependent cytosolic 3,5,3'-triiodo-L-thyronine(T3)-binding protein (CTBP) has been purified over 30,000-fold from rat kidney by using charcoal extraction, Mono Q-Sepharose, Blue Sepharose CL-6B, and Sephacryl S-200 column chromatography. Purified CTBP had a sedimentation coefficient of 4.7 S, Stokes radius of 32.5A, and calculated molecular weight of 58,000. The apparently homogeneous protein consisted of a single polypeptide chain with Mr of 58,000 as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Scatchard analysis of T3 binding showed that NADPH increases maximal binding capacity without changes in the affinity constant (Ka = 2.43 X 10(9) M-1). Double reciprocal analysis of NADPH and binding capacity gave maximal binding capacity of 16,400 pmol/mg of CTBP, Mr = 58,000. The order of affinity of iodothyronine analogues to purified CTBP was as follows: L-T3 = D-T3 greater than triiodothyroacetic acid greater than L-thyroxine. [125I]T3 bound to purified CTBP spontaneously dissociated from CTBP at 20 degrees C (t 1/2 = 22 min) in the absence of NADPH, whereas the dissociation was not observed in the presence of NADPH. The optimal pH for T3 binding was 7.2-7.5 Na+, K+, Ca2+, and Mg2+ (0-200 mM) did not influence T3 binding to CTBP. The purified CTBP did not bind to DNA and was not adsorbed to concanavalin A-Sepharose.

Animals↗

Evidence for the presence of two active forms of cytosolic 3,5,3'-triiodo-L-thyronine (T3)-binding protein (CTBP) in rat kidney. Specialized functions of two CTBPs in intracellular T3 translocation.

Cytosolic NADPH-dependent 3,5,3'-triiodo-L-thyronine (T3)-binding protein (CTBP) purified from rat kidney was further characterized in its T3 binding and its interaction with nuclei. Pretreatment of the CTBP with NADP induced dithiothreitol (DTT)-dependent T3 binding. The DTT-dependent T3 binding was increased by NADP in a concentration-dependent manner, and the maximal binding was obtained by 0.1 microM NADP. Higher concentrations of NADP (more than 0.1 microM), however, reduced T3 binding. NAD also induced DTT-dependent T3 binding, but was very low compared to that induced by NADP. NADPH and NADH did not produce DTT-dependent T3 binding. This NADP-activated, DTT-dependent T3 binding was characterized as follows: Ka for T3 binding was 1.8 x 10(9) M-1, and the maximal binding capacity was 15,000 pmol/mg of protein in the CTBP activated by 0.1 microM NADP. The molecular weight of the CTBP was 58,000 (4.7 S). A complex of [125I]T3 and CTBP (NADP.DTT.CTBP.[125I]T3), which was made from the CTBP pretreated with NADP and DTT, did not bind to DNA. However, the complex bound to the nuclei prepared from rat kidney. Treatment of the nuclei with 0.38 M KCl and with DNase I did not lead to loss of the binding activity for the complex. Treatment of nuclei with 0.5 M NaCl led to the loss of the activity for binding the complex. A complex of [125I]T3 and NADPH-activated CTBP did not bind these nuclear preparations. These results suggested that the active form of CTBP is present in two different forms: one is NADPH-activated, which plays a role as a reservoir for cytoplasmic T3, and the other is NADP-activated, which plays a role as a T3 carrier protein that transfers T3 from cytoplasm to nucleus.

Animals↗

Yeast mutants with enhanced ability to secrete human lysozyme: isolation and identification of a protease-deficient mutant.

Yeast mutant strains which secrete large amounts of human lysozyme were screened using an agar medium containing bacterial cells. Nine mutants secreted over 10 times more lysozyme than the wild-type parent strain. The mRNA levels for lysozyme in the mutants were not higher than that of the wild-type strain. Three of the mutant strains were deficient in carboxypeptidase Y activity. It was found that the protease deficiency was caused by a deficiency in conversion of proenzyme to mature enzyme in ssl1 mutant cells. The ssl1 gene was found to be closely linked to the centromere and determine both the efficiency of secretion of lysozyme and the processing of carboxypeptidase Y.

Blotting, Northern↗

A case report of transcatheter arterial embolization of cholestatic type of hepatoma.

A 57-year-old man with hepatocellular carcinoma (HCC) invading the hepatic duct was treated with transcatheter arterial embolization (TAE). The dilated hepatic duct was decompressed his jaundice disappeared and he survived for 10 months after the first TAE, succumbing due to bleeding from gastric erosion. Although total bilirubin was 26.7 mg/dl and massive ascites was noted on occasion of the first TAE, hepatic dysfunction did not worsen and both icterus and ascites decreased, disappearing one month after the therapy. Autopsy revealed HCC with trabecular arrangement originating in the left lobe and growing into the left hepatic duct accompanied by liver cirrhosis and follicular carcinoma of the thyroid gland. Severe icterus caused by bile duct obstruction does not correlate with the grade of hepatic failure in HCC with liver cirrhosis, so TAE was effective and should be tried as a first choice therapy in such a poor risk case.

Carcinoma, Hepatocellular↗

Differences in nuclear thyroid hormone receptors among species.

Hepatic nuclear thyroid hormone receptors from rat, dog, chicken, and rainbow trout were compared. Receptor affinities for 3,5,3'-triiodo-L-thyronine (T3) were similar in preparations from rat, dog, and chicken, using isolated nuclei and nuclear extracts. Rainbow trout nuclear receptor showed a lower affinity for T3. Almost half of the receptors were released into the medium with rat and chicken nuclei, and 79.7 +/- 1.1% of the receptors were released with rainbow trout nuclei, when isolated nuclei were incubated with T3 at 22 degrees for 2 hr. The affinity constant of rat liver receptor for calf thymus DNA-cellulose at 0.17 M KCl, pH 7.4, was 3.98 +/- 1.47 x 10(5) M-1, when determined using DNA-cellulose columns. The number of salt bridges involved in DNA binding of the rat receptor was 5.73 +/- 0.38. When receptor-DNA interactions were compared among species, significant differences were found, but the receptors from dog and rainbow trout liver were similar. Sephacryl S-200 column chromatography showed that chicken receptor had a Stokes radius significantly smaller than that of rat receptor. Partial proteolysis of T3-receptor complex using trypsin alpha-chymotrypsin, elastase, and papain produced distinct T3-binding fragments in different species. Our data provide evidence that nuclear thyroid hormone receptors from different species have significant structural dissimilarities.

Animals↗

Allergen-specific induction of interleukin-2 (IL-2) responsiveness in lymphocytes from children with asthma. II. Regulation of IL-2 responsiveness by supernatants of normal lymphocytes.

Induction of interleukin-2 (IL-2) responsiveness by Dermatophagoides farinae (Df)-stimulated lymphocytes from children with asthma was markedly suppressed after the addition of culture supernatants from Df-stimulated normal T cells. Ovalbumin (OVA)-induced IL-2 responsiveness of lymphocytes from patients with hen-egg allergy was not suppressed by the supernatant from Df-stimulated T cells, indicating the antigenic specificity of the effect. Patients' lymphocytes whose IL-2 responsiveness was decreased still expressed Tac antigen (low-affinity IL-2 receptors) but, in contrast to the patients' original lymphocytes, did not absorb or respond to IL-2, suggesting the loss of high-affinity IL-2 receptors (p55/p75) from these cells. The supernatant from Df-stimulated normal T cells from one individual did not necessarily suppress the response of all patients tested, indicating the existence of some allogeneic barrier between the factor(s) and patients' lymphocytes.

Absorption↗

Pressor response and respiratory depression evoked by intravertebral arterial injections of hypoxic saline.

Cardio-respiratory effects of intravertebral arterial injections of hypoxic and/or hypercapnic solutions have been studied in anesthetized (dial-urethane), sino-aortic denervated, vagotomized, artificially ventilated cats. Injection of a small amount (0.8-1.5 ml) of CO2-saturated saline (hypercapnic and hypoxic loading) caused increases in arterial pressure (AP) and heart rate (HR) accompanied by an excitation of phrenic nerve activity (PNA). By contrast, injection of the same amount of N2-saturated saline (hypoxic loading) evoked dissociated cardio-respiratory effects, which were characterized by a transient depression of PNA accompanied by a small but clear increase in AP: the AP rise (18.5 +/- 6.7 mm Hg) was smaller than that (31.3 +/- 7.7 mm Hg) during the aforementioned hypercapnic and hypoxic loading with the CO2-saturated saline. The control injections (normocapnic loading) evoked negligible effects. These differences in cardio-respiratory effects suggest that there may exist hypoxia-sensitive neural substrates, independent of the central chemoreceptors, which would, directly or indirectly, influence the vasomotor center and/or the respiratory center.

Animals↗