Biomedical subjects

K Takeda

Publications and source records attributed to K Takeda.

At least 1,009 records · Page 56Linked to original sources

PubMed1989

Effects of human recombinant erythropoietin on anaemia, systemic haemodynamics and renal function in predialysis renal failure patients.

Seven anaemic patients with predialysis chronic renal failure were treated with human recombinant erythropoietin. Anaemia was improved, with a 31% increase in haematocrit, but blood pressure increased in all patients with an average of 12% in systolic (P less than 0.01), 14% in diastolic (P less than 0.05) and 13% in mean blood pressure (P less than 0.05). Blood volume was significantly increased by an average of 12%. Cardiac output increased in three of seven patients, and total peripheral resistance in four. GFR, RBF and RPF were not changed but filtration fraction increased significantly (P less than 0.05). It is suggested that blood pressure elevation might be developed as a result of volume expansion, elevated cardiac output, and increased total peripheral resistance.

Anemia↗

PubMed1989

Prediction of arterial oxygen partial pressure from intrapulmonary venous admixture.

A short program was developed to predict the PaO2 at a given FIO2 by using arterial and mixed venous blood gas data obtained at an FIO2 of 1.0. Our program resolves Adair's equation and the shunt equation inversely, on the assumption that intrapulmonary venous admixture and the arteriovenous oxygen content difference remain constant during the study. The study was conducted on 19 patients with respiratory failure who were intubated and mechanically ventilated. According to linear regression analysis, regression coefficients of 0.91 and 0.97 were obtained between the measured PaO2 values and those estimated by the arterial/alveolar oxygen tension ratio (PaO2/PaO2) and our program, respectively (n = 23). The PaO2 values were predicted more accurately by our program than those calculated by PaO2/PaO2. Because our program is simple enough to be carried out with a pocket computer, it may be helpful in a bedside decision of lowering FIO2, especially in patients who require a high FIO2 level to maintain sufficient arterial oxygenation.

Blood Gas Analysis↗

PubMed1989

Postnatal development of cholecystokinin-like immunoreactivity and its mRNA level in rat brain regions.

Developmental changes of preprocholecystokinin mRNA (CCK mRNA) and cholecystokinin-like immunoreactivity (CCK-LI) were examined in rat brain regions (frontal cortex, colliculi, hippocampus, striatum, and cerebellum) using RNA dot blot assays with cholecystokinin (CCK) cDNA and radioimmunoassay, respectively. The CCK-LI levels in all regions examined were very low at birth. Excluding the cerebellum, the levels in these regions increased postnatally and reached adult values at 28 days of age. In contrast to CCK-LI, CCK mRNA levels changed dramatically during development. A considerable amount of CCK mRNA was detected in the frontal cortex and hippocampus at birth. The changes in the level of CCK mRNA in the frontal cortex and colliculi paralleled those of CCK-LI, including a rapid increase from 7 to 14 days of age. The synthesis of CCK mRNA preceded the appearance of CCK-LI. CCK mRNA levels in the hippocampus and striatum exhibited a transient increase, with a peak at 14 days of age. In the adult brain, the CCK mRNA levels were high in the frontal cortex, moderate in the hippocampus and colliculi, and low in the striatum. The cerebellum contained only a negligible amount of CCK mRNA during development. The relatively high level of CCK-LI compared with the low level of CCK mRNA in the striatum supports the idea that most of the striatal CCK-LI is supplied from extrastriatal regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1989

Dual effects of 5-hydroxytryptamine on the release of gamma-aminobutyric acid from myenteric neurones of the guinea-pig ileum.

The effects of 5-hydroxytryptamine (5-HT) on the release of gamma-aminobutyric acid (GABA) were examined in the longitudinal muscle-myenteric plexus (LM-MP) preparation of guinea-pig ileum. 5-HT increased the spontaneous release and inhibited the electrically-evoked release of [3H]-GABA. The 5-HT-evoked release was Ca2+-dependent and tetrodotoxin-sensitive, and was antagonized by (3 alpha-tropanyl)-1H-indole-3-carboxylic acid ester (ICS 205-930), but not by methysergide and ketanserin. The inhibitory effect of 5-HT was antagonized by methysergide, but not by ketanserin and ICS 205-930. 8-Hydroxy-2-(di-n-propylamino)tetralin mimicked the inhibitory effect of 5-HT. Thus, 5-HT may exert an excitatory effect on the enteric GABAergic neurone via the 5-HT3 receptor and an inhibitory effect via the 5-HT1A receptor.

Animals↗

PubMed1989

Sibs with tetrasomy 18p born to a mother with trisomy 18p.

We report a family with an 18p trisomic mother and two 18p tetrasomic daughters. The mother is phenotypically normal and healthy, but with an unusual type of trisomy 18p: 47,XX,del(18)(pter----p11.21),+i(18p) de novo. The older sister has microcephaly, mental retardation, an asymmetrical and peculiar face with low set ears, pinched up nose, high arched palate, small mouth, micrognathia, tapering fingers, asymmetrical length of legs, and an asthenic body. The younger sister was stillborn with extensive defects of the skull, congenital hydrocephalus, severe facial anomalies, and lumbosacral meningocele. Both daughters have inherited one normal chromosome 18 and an isochromosome 18p from their mother, and one normal chromosome 18 from their father. Although one quite similar family has been reported, to the best of our knowledge there have been no reports of families in which two daughters with tetrasomy 18p syndrome have been born to a mother with trisomy 18p with isochromosomes.

Abnormalities, Multiple↗

PubMed1989

Sequence of the variant thyroxine-binding globulin of Australian aborigines. Only one of two amino acid replacements is responsible for its altered properties.

A form of thyroxine-binding globulin (TBG) with reduced affinity for hormone and increased susceptibility to heat and acid denaturation has been identified in Australian Aborigines (TBG-A). Results of heat denaturation of TBG established that the TBGA allele is X linked and has a frequency of 50.9% in Western Australian Aborigines. The sequence of an isolated TBGA allele differed at two positions from that of the normal TBG allele (TBGC). One substitution was in codon 191, ACA (threonine) rather than GCA (alanine), and the other was in codon 283, TTT (phenylalanine) instead of TTG (leucine). These nucleotide substitutions resulted in the loss of sites for the enzymes Bgl 1 and Tth 111 II, respectively. The nucleotide substitutions in the TBG-A allele was confirmed by digestion of genomic DNA segments amplified using the polymerase chain reaction. The Bgl 1 and Tth 111 II sites were absent in the genes of two Aboriginal men expressing TBG-A and were present in those of three Aboriginal and six Caucasian males expressing TBG-C. The TBG gene of a seventh Caucasian male possessed the Bgl 1 site but had lost the Tth 111 II site; sequencing of this allele revealed only the substitution in codon 283 identical to that in the TBGA allele. As the biochemical properties of TBGPhe-283 expressed by this individual were indistinguishable from normal TBGLeu-283, we believe that the abnormal properties of TBG-A are due to substitution of alanine for threonine at residue 191.

Adolescent↗

PubMed1989

A mutation causing reduced biological activity and stability of thyroxine-binding globulin probably as a result of abnormal glycosylation of the molecule.

T4-binding globulin (TBG), a 54-kilodalton glycoprotein, is the major thyroid hormone transport protein in man. The exact nature of the mutations causing X chromosome-linked TBG deficiency, which affect about 1 in 2,500 newborn males, is unknown. Here we report the sequence of a unique variant TBG (TBG-Gary) encoding a protein with severely impaired T4 binding as well as decreased stability at 37 C, resulting in its rapid in vivo denaturation. A single nucleotide substitution in the codon for residue 96 of the mature protein replaces isoleucine with asparagine; this replacement creates an additional site for N-linked glycosylation. The anodal shift of TBG-Gary on isoelectric focusing gel electrophoresis suggests that this new site is likely glycosylated. Since glycosylated is required for TBG to assume its correct tertiary structure, but is not subsequently necessary for maintenance of the biological properties or stability of the molecule, we believe that the likely presence of additional carbohydrate probably affects a higher order structure of the molecule and is thus responsible for the reduced stability and hormone binding activity of TBG-Gary (TBGASN-96).

Base Sequence↗

PubMed1989

Intestinal absorption of dolichol from emulsions and liposomes in rats.

The intestinal absorption of dolichol from various dosage forms was investigated using the intestinal loop and everted sac methods in the rat. The in situ loop experiments showed that the absorption of dolichol from a triglyceride emulsion was dependent on the chain-length of the triglyceride; the absorption from a tri-n-butyrin emulsion in 1 h was 18.0% of the dose; and the absorption from an HCO-60 suspension was 4.3%. The liposomal preparation enhanced the absorption up to 39.1% of the dose. In in vitro experiments, 25.0% and 13.2% of dolichol were taken up by everted sacs of the jejunum and the ileum, respectively. On the other hand, phospholipids composing liposomes were not absorbed under these conditions. The above results suggest that the absorption mechanism from liposomal preparations may be as follows: dolichol is released from the liposomes into the aqueous phase adjacent to the surface of the intestine and is subsequently partitioned into the intestinal tissue.

Animals↗

PubMed1989

Central baroreflex regulation by the renal nerves in anesthetized rats.

To determine whether the renal nerves affect central baroreflex regulation, the aortic depressor nerve (ADN) was stimulated electrically, while blood pressure, heart rate, and splanchnic nerve activity were recorded in renal denervated and sham-operated rats anesthetized with urethane. Tail cuff systolic pressure fell 6 days after renal denervation, but mean blood pressure recorded after anesthetizing with urethane did not differ between renal denervated and sham-operated rats. Urinary sodium excretion was greater in renal denervated than in sham-operated rats. ADN stimulation produced frequency-dependent falls in blood pressure accompanied by inhibitions of sympathetic nerve activity and heart rate. Depressor and sympathetic inhibitory responses to ADN stimulation were significantly smaller in renal denervated than in sham-operated rats. These findings suggest that the renal nerves can regulate baroreflexes centrally.

Anesthesia↗

PubMed1989

Effect of blood exchange transfusion as an initial treatment of acute hemorrhagic pancreatitis.

The effect of blood exchange transfusion on experimental acute pancreatitis was investigated. Acute hemorrhagic pancreatitis was induced in rats by the injection of sodium taurocholate into the pancreatic duct. One hour after the induction of pancreatitis, blood exchange transfusion was carried out in these rats. The survival rates by 24 hr significantly increased in the exchange transfusion group as compared to those in the non-treated control group. Blood exchange transfusion, though had not significant effect on the macroscopic findings at autopsy, reduced pulmonary edema. These results suggested that blood purification by exchange transfusion may be beneficial for patients with acute pancreatitis, especially at an early stage.

Amylases↗

PubMed1989

Dual regulatory mechanisms of proton transport in rat papillary collecting duct cells in culture.

The regulation of proton transport and cytosolic pH was studied in rat papillary collecting duct (PCD) cells in culture using a pH-sensitive fluorescence probe, 2,7-bis-carboxyethyl-5,6-carboxyfluorescein (BCECF). Data were obtained from confluent monolayers grown on glass coverslips and dipped in a HCO3- -free medium, pH 7.40. The resting intracellular pH (pHi) was 7.16 +/- 0.03 (n = 20). When PCD cells had been acidified by pretreatment with NH4Cl, pHi immediately recovered toward the resting value. Two mechanisms participated in this recovery: a Na+-dependent mechanism which could be inhibited by amiloride (indicative of Na+-H+ exchanger) and a Na+-independent process (a proton ATPase). The pHi recovery from acid loading was inhibited by amiloride to about 55% of the control recovery (half-maximal effect at 100 microM). The rate of pHi recovery after the readdition of Na+ to a sodium-free medium exhibited saturation kinetics (half maximal rate at 28 mM). Dicyclohexylcarbodiimide (DCCD), an inhibitor of a plasma membrane proton ATPase, and the depletion of cellular ATP induced by 2 mM potassium cyanide (KCN) also partially inhibited the rate of pHi recovery after cell acidification with a NH4Cl load. When PCD cells were treated with 1 mM DCCD, amiloride almost completely inhibited pHi recovery. Amiloride and the removal of external Na+ had induced a gradual fall in pHi to a new resting value and rapidly recovered when Na+ was added. We conclude that PCD cells grown in culture have at least two proton transport mechanisms: a Na+-H+ exchanger and a plasma membrane proton ATPase. The kinetics of these processes can be reliably assessed by the pH-sensitive fluorescent probe, BCECF. Both the Na+-H+ exchanger and the plasma membrane proton ATPase may contribute to urinary acidification.

Adenosine Triphosphatases↗

PubMed1989

Inhibitory effect of peptide YY on gastric acid output in rats.

The administration of peptide YY (PYY: 0.8, 1.6 and 3.2 nmol/kg/h, i.v.) to fasting rats inhibited not only baclofen (2 mg/kg, s.c.)-stimulated gastric acid output and gastric mucosal blood flow, but also pentagastrin (8 micrograms/kg/h, i.v.)-stimulated gastric acid output. PYY (3.2 nmol/kg/h) reduced baclofen-induced acid output more than pentagastrin-induced acid output, i.e., by 61.8 +/- 11.5% compared to 35.3 +/- 8.2%. PYY inhibited acetylcholine (ACh) release from cholinergic nerve endings of gastric body evoked by electrical transmural stimulation (ETS: 1 msec, 10 V, 3 Hz, 30 sec) by 47.2 +/- 3.5%. The mechanism of the inhibitory effect of PYY on gastric acid output seems to involve decreased gastric mucosal blood flow and reduced ACh release from cholinergic nerves.

Animals↗

PubMed1989

The mechanism of acute gastric ulcer after induced hemorrhagic shock.

Changes in gastric mucosal blood flow were investigated for their relationship to gastric mucosal prostaglandin E2 (PGE2) and noradrenaline (NA) in rats with hemorrhagic shock. The results were as follows: 1) Gastric mucosal blood flow and NA decreased after hemorrhage. Gastric mucosal PGE2 initially increased after exsanguination and then markedly decreased. 2) Administration of NA before hemorrhage resulted in an increase of PGE2. However, the PGE2 value for animals receiving NA after hemorrhage was not different from that of non-NA-treated group. 3) Pre-treatment with PGE2 suppressed the reduction in both gastric mucosal blood flow and NA and the development of ulcer. These results suggest that the increase in gastric mucosal PGE2 in the early stage of shock might represent a phenomenon of adaptation by the adrenergic activation, and the decrease in PGE2 in the late stage might result from impaired synthesis of PGE2 due to persistent hypoxia and might be one of the possible factors in ulcer formation.

Acute Disease↗

PubMed1989

[Single channel cochlear implant: application to three patients].

Single channel cochlear implant of 3M/House design was implanted to the three patients with profound hearing loss. Before the implantation, use of hearing aid had not afforded serviceable hearing enough for speech recognition in these patients. Postoperative courses were uneventful. Speech rehabilitation was started at 3 weeks after the surgery. The speech tracking scores with the cochlear implant plus lipreading achieved 20-25 bunsetues (the minimum meaningful unit of the Japanese sentence) per minute at three or four months after the operation. All the patients could recognize speech of daily life with help of lipreading. However, speech recognition by the cochlear implant alone was not satisfactory.

Adult↗

PubMed1989

[Modification of speech encoding process of single channel cochlear implant utilizing digital delay circuit].

Speech perception by single channel cochlear implant can be improved to some extent by modifying the encoding process of the speech signals. The principle of our encoding strategy is to present speech signals with appropriate delay time for lower frequency components of the speech sound, while without delay for higher frequency components. This is based on a cochlear physiology that higher frequency sounds are perceived earlier than lower frequency sounds, since the former is perceived at the basal turn and the latter at the apical turn. The following tests were performed without the aid of lip reading in the two patients implanted with a single channel cochlear implant of 3M-House design. Lower frequency components of the speech signals were digitally delayed with a Sony SDP-777 ES surround processor. The results indicated that the optimal delay time for identification of /i/, /e/ and /u/ needed longer delay time, while that of /a/ and /o/ need shorter delay time, corresponding to the difference between the first and second formant of each vowel. Comparison of vowel perception with and without delay coding showed that vowel identification with delay coding was superior to that without it; 30% vs. 16% in case 1, and 48% vs. 30% in case 2.

Adult↗

PubMed1989

[Assessment of bleomycin-induced pulmonary fibrosis by bronchoalveolar lavage].

To elucidate the pathogenesis of adult respiratory distress syndrome (ARDS), bleomycin is often used to induce lung injury because of is acute inflammatory and late fibrogenic effects on the lung. This study was undertaken to determine if fibroblast growth factors or suppressive factors might exist in bronchoalveolar lavage fluid (BALF) when acute lung injury is induced by bleomycin in rats. In the experimental group, 1.5 U of bleomycin was administered intratracheally, whereas in the control group, saline solution was given. In both groups, rats were sacrificed serially up to 4 wks. In each rat, bronchoalveolar lavage was done three times using an aliquot of 5 ml saline solution. BALF was centrifuged to obtain cells and supernatants which were further fractionated by gel-filtration. Fibroblast stimulatory and inhibitory activities were evaluated by [3H]-thymidine incorporation by fibroblasts. In the experimental group, the recovered cell count increased threefold compared with the control group and most of the increase was attributed to the increase of neutrophil. The fraction whose molecular weight is about 20,000 potentiated the [3H]-thymidine incorporation by fibroblast and its peak activity was found on the 5th day after BLM administration. On the other hand, the fraction of small molecular weight (less than 1,000) showed inhibitory activity which did not change throughout the study period. These results suggest that the imbalance between the fibroblast stimulatory and inhibitory activities after the acute lung injury may have a key role to develop pulmonary fibrosis.

Animals↗

PubMed1989

Vimentin-positive squamous cell carcinoma arising in a burn scar. A highly malignant neoplasm composed of acantholytic round keratinocytes.

Two patients had unusual squamous cell carcinoma (SCC) arising in a burn scar. The SCCs rapidly recurred and metastasized after radical operation, and the patients died of disseminated metastases. Histopathologically, the SCC was poorly differentiated and consisted of acantholytic round cells that diffusely proliferated into the deep dermis. However, small, solid nests composed of squamoid cells were focally observed. Immunohistochemical studies revealed that the acantholytic round neoplastic cells expressed not only keratin but also vimentin, and the coexpression was substantiated with double immunostaining. Vimentin-positive SCC composed of acantholytic round neoplastic cells may be a highly malignant subset of cutaneous SCC.

Burns↗

PubMed1989

Impaired regulation of skin temperature in patients with diabetes mellitus evaluated by the cold exposure test.

This study aimed at evaluating vasomotor response of the hand in patients with diabetes mellitus. A skin temperature of the hand was measured before and after exposure to ice water, and the recovery rates of the skin temperature were determined at 3, 5, and 10 min after the cold exposure. Ninety-two diabetics ranging in age from 25 to 59 years and 43 normal subjects ranging from 23 to 69 years old participated in this study. Since the recovery rate was delayed in normal subjects over the age of 60, comparison was made between the diabetics and the normals under 60 years old. The skin temperature was significantly lower in 26 diabetics with severe peripheral neuropathy (PN) than 40 diabetics without PN. The recovery rate were markedly delayed in the patients with PN, and also delayed in diabetics with severe retinopathy. The recovery rate was not different between the patients with and without ischemic changes in electrocardiogram. The delayed recovery rate was most prominent in the diabetics who had both abnormal heart rate variation (HRV) and orthostatic hypotension, followed by those with abnormal HRV but without orthostatic hypotension. Recovery rates in the diabetics with abnormal HRV alone were within the normal range. Our data suggest that the dysfunction of the regulation of skin temperature in the patients with diabetes mellitus was due to peripheral sympathetic nerve abnormality. The cold exposure test would be useful in the estimation of the sympathetic nerve activity of the diabetics.

Adult↗