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Biomedical subjects

Y Kojima

Publications and source records attributed to Y Kojima.

At least 343 records · Page 19Linked to original sources
PubMed1990

Stomatocytic or discoidal erythrocyte ghosts containing only spectrin.

We extracted Triton-treated erythrocyte ghosts with 2 M KCl (Triton/KCl/ghosts), and then with 1.2 M KBr at pH 5.5 (Triton/KCl/KBr ghosts). Triton/KCl/KBr ghosts were very similar in shape to untreated ghosts, Triton ghosts and Triton/KCl ghosts under a phase-contrast microscope at various pH vales and salt concentrations, despite having lost most of their phospholipids and proteins, except for spectrin. Negatively stained Triton ghosts, Triton/KCl ghosts and Triton/KCl/KBr ghosts appeared similar to each other, but the regularity of the spectrin network structure decreased somewhat in that order. Triton/KCl/KBr ghosts were stabilized by adding both actin and band 4.1, but not by adding either alone. These and previous findings strongly suggest that the spectrin network is visible and the simplest inframembrane structure.

Bromides↗
PubMed1990

CP-82,996, a novel diglycoside polyether antibiotic related to monensin and produced by Actinomadura sp.

A new polyether antibiotic CP-82,996 (C50H86O16) was isolated by solvent extraction from the fermentation broth of Actinomadura sp. (ATCC 53764). Following purification by silica gel column chromatography and crystallization, the structure of CP-82,996 was determined by a single crystal X-ray analysis. The structure is closely related to monensin, but is unique in that it contains two sugar groups, whereas monensin has none. The 1H and 13C NMR chemical shifts and assignments for CP-82,996 were elucidated, and they were compared with those determined previously for monensin. CP-82,996 is active against certain Gram-positive bacteria, and is a very potent anticoccidial agent. It effectively controlled chicken coccidiosis caused by several Eimeria species at 5-10 ppm in feed, and is 10-20 times more potent than monensin.

Animals↗
PubMed1990

CP-60,993, a new dianemycin-like ionophore produced by Streptomyces hygroscopicus ATCC 39305: fermentation, isolation and characterization.

CP-60,993, 19-epi-dianemycin, is a novel polycyclic ether antibiotic produced by Streptomyces hygroscopicus ATCC 39305. Fermentation recovery, purification and crystallization were achieved using standard procedures. CP-60,993 was characterized as a monocarboxylic acid. Elemental analysis suggested a molecular formula of C47H78O14 for the free acid and C47H77O14 Na for the sodium salt. Crystalline from CP-60,993 sodium salt shows the following properties: m.p. 193-205 degrees C, E1%(1 cm) = 157 at 232 nm, [alpha]25 degrees C(D) + 11.0 (c 1, methanol). The structure, determined by MS, PMR and CMR, differs from dianemycin only in the stereochemistry at position 19. This was confirmed by X-ray crystallography carried out on the rubidium salt of CP-60,993. It exhibited activity in vitro against Gram-positive and anaerobic bacteria, efficacy against Eimeria coccidia in vivo in poultry, and stimulation in vitro of rumen propionic acid production.

Aminoglycosides↗
PubMed1990

A comparative study of groups by age for the intra- and postoperative water and electrolyte management of oesophageal carcinoma.

The present study examined the effects of subtotal oesophagectomy through a right thoracal and abdominal approach, on the postoperative water-electrolyte metabolism and cardio-pulmonary function of patients with thoracic oesophageal carcinoma. The primary water balance, total sodium intake, urinary NAG index, free-water clearance (CH2O), oxygen diffusion function of the lungs to aerate blood (DLO2-Index), and alpha-human atrial natriuretic polypeptide (alpha-hANP) were measured perioperatively until the seventh day. Subjects were divided by age according to whether they were older or younger than 70 years into 2 groups. In both groups, no change was observed in the primary water balance, total sodium intake, urinary NAG index or CH2O. However, all of the patients in the older group exhibited significantly higher alpha-hANP values than those in the control group, and the DLO2-Index was also higher in the former subjects during the first 3 days following surgery. It may be concluded that alpha-hANP is a hormone of considerable importance as it is secreted in large amounts in response to increased stress on the cardio-pulmonary system and serves to normalize the water balance causing this extra load.

Acetylglucosaminidase↗
PubMed1990

Convergence patterns of afferent information from the temporomandibular joint and masseter muscle in the trigeminal subnucleus caudalis.

Convergence patterns of afferent information from the temporomandibular joint (TMJ) and the masseter muscle (Mm) in the trigeminal subnucleus caudalis in response to natural stimulation were examined in anesthetized rats for a better understanding of masticatory pain phenomena. All neurons tested (135) could be placed in one of the following three classes according to their responsiveness to natural stimulation in the TMJ and/or the Mm: Class I neurons, excited by only innocuous stimuli; Class II neurons, excited by only noxious stimuli; Class III neurons, excited by both. Afferent inputs from the TMJ and the Mm converged on 108 (80%) of the 135 neurons. Of these convergent neurons, 79% received nociceptive information from the TMJ and/or the Mm. The results suggest that convergent caudalis neurons that receive nociceptive information from the TMJ and/or the Mm may be important to referred pain associated with dysfunction of the masticatory system.

Action Potentials↗
PubMed1990

Antibody to the capsular polysaccharide/adhesin protects rabbits against catheter-related bacteremia due to coagulase-negative staphylococci.

A rabbit model of catheter-related bacteremia was developed to study immunity to the capsular polysaccharide/adhesin (PS/A) of coagulase-negative staphylococci. Catheters colonized by coagulase-negative staphylococci were inserted into the right jugular vein and attached to a subcutaneous osmotic pump, and blood cultures were obtained over 14 days. Nonimmune rabbits were bacteremic for 6-8 days after infection, hypoglycemic, and hyperlipidemic and had strong immune responses to teichoic acid but not to PS/A. PS/A immunization, but not teichoic acid immunization, reduced the number of bacteremic days by approximately 60%, diminished the hypoglycemia and hyperlipidemia, and ablated the immune responses to teichoic acid. Passive infusion of PS/A-specific polyclonal and monoclonal antibodies using a separate, noninfected catheter-pump combination implanted in the left jugular protected against both bacteremia and hematogenous colonization of this contralateral catheter.

Animals↗
PubMed1990

Mechanism of pharmacodynamic and pharmacokinetic interactions between acetohexamide and phenylbutazone in rabbits.

The interaction of acetohexamide (AH) with phenylbutazone (PBZ) was investigated in rabbits. Orally administered PBZ caused a potentiation of hypoglycaemic action after oral administration of AH. This can be explained by the fact that the co-administration of PBZ significantly increased both the serum concentrations of AH and its pharmacologically active metabolite. (-)-hydroxyhexamide [(-)-HH], after AH administration. The co-administration of PBZ decreased the renal clearance (Clr) and non-renal clearance (Clnr) of AH. PBZ inhibited the in vitro reduction of AH to (-)-HH and decreased the accumulation of (-)-HH by the kidney cortical slices. These results indicate that the mechanism of in vivo interaction of AH with PBZ is complicated.

Acetohexamide↗
PubMed1990

[A case of bacteremia due to Salmonella enteritidis in healthy man].

Although bacteremia caused by non-typhoidal salmonella is frequently observed in immunocompromised hosts, it is rare to find this condition in healthy subjects. In this report, we present a case of bacteremia due to Salmonella enteritidis detected in a healthy man. A 59-year-old man was admitted to our hospital with a fifty-day history of fever on May 18, 1985. On admission, he showed no symptoms except high body temperature (38.8 degrees C). In the laboratory data, C-reactive protein was 3+, white- cell count was 9600, and erythrocyte sedimentation rate was 12 mm/h. Culture in blood and stool yielded Salmonella enteritidis. However, no abnormal findings were found in UGIS, barium enema, OC + DIC, abdominal CT and echography. As soon as Ampicillin was administered, the fever was gone and the blood culture yielded nothing. After six months, the stool culture was negative for pathological intestinal bacterial flora and he was in good physical condition. Generally, bacteremia develops mainly in the immunocompromised hosts, such as patients with neoplastic disease, AIDS, leukemia or collagen disease. The literature provides so far twenty three adult cases of bacteremia due to non-typhoidal salmonella in Japan. Only two of them had no systemic disease as well as our case. Although it is unknown why bacteremia developed in this healthy man, we reported that bacteremia developed rarely in subjects with healthy condition.

Humans↗
PubMed1990

Inactivation of chemotactic activity of C5a by the serratial 56-kilodalton protease.

The effects of the 56-kilodalton protease (56K protease) from Serratia marcescens on complement-derived chemotactic activity were examined. Fresh human serum was incubated with zymosan to produce C5a. This activated serum was then incubated with various concentrations of 56K protease, and the chemotactic activity of mouse peritoneal exudate polymorphonuclear leukocytes (PMN) and macrophages was evaluated. A significant dose-dependent decrease of chemotactic activity was observed after protease treatment. Furthermore, treatment of human recombinant C5a with 56K protease at a dose of 1.0 microgram/ml resulted in a complete loss of chemotactic activity. When the living bacteria of the virulent strain, which produced about 10 times more protease than did the less virulent strain, were injected intraperitoneally into mice, the magnitude of infiltration of polymorphonuclear leukocytes into the peritoneal cavity was much lower than that caused by the less virulent strain. Because complement-dependent chemotactic activity is an initial response to bacterial infection, these results suggest indirect pathogenic functions of serratial proteases that suppress chemotactic activity.

Blood Bactericidal Activity↗
PubMed1990

Changes in the function of tuberoinfundibular dopaminergic neurons after long-term estradiol treatment in Fischer 344 rats.

The functions of tuberoinfundibular dopaminergic (TIDA) neurons after long-term estradiol treatment were investigated in Fischer 344 (F344) rats which have high susceptibility to estradiol-induced prolactin (PRL)-secreting pituitary tumors. Dopamine synthesis in and release from TIDA neurons were determined in vitro by 3,4-dihydroxyphenylalanine (DOPA) accumulation in the median eminence following incubation with a DOPA decarboxylase inhibitor and endogenous dopamine release from the median eminence, respectively. The concentration of serum PRL and the weight of the anterior pituitary in ovariectomized F344 rats were markedly increased 3 weeks after a single injection of 2 mg estradiol valerate (EV) and decreased thereafter, but still showed higher levels at 15 and 24 weeks than control ovariectomized rats. Dopamine contents in the median eminence were decreased 3 weeks and unchanged 24 weeks after EV treatment. DOPA accumulation and basal dopamine release in the median eminence of F344 rats were decreased 3 weeks and increased 15 and 24 weeks after EV treatment, similarly to those of Wistar rats as reported previously. However, EV treatment, which caused similar increases in the concentrations of serum PRL and estradiol in F344 and Wistar rats, decreased KCl-induced dopamine release in Wistar rats at 3 weeks, but failed to do so in F344 rats. KCl-induced dopamine release 24 weeks after a single EV injection in F344 rats was greater than that in control rats, whereas the dopamine release 24 weeks after the last treatment of 4 injections at 3-week intervals was not different from that in control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Ultrastructure of boar testis: spindle shape body of spermatid.

The fine structure of the spindle shape body (SSB) of boar spermatid was studied using testes samples fixed by perfusion. This structure appeared on the middle piece which served as the upper border of the fibrous sheath of principal piece during the transition period between the late acrosome phase to the maturation phase of spermiogenesis. The formation of this thread-like spindle form coincided with the development of the postnuclear sheath with perinuclear ring just prior to the growth of the equatorial segment of the acrosome. Likewise, the ribs of the fibrous sheath on the principal piece were observed to have already formed but have not yet completed the mitochondrial sheath. The total size of the SSB and its consisting microtubule were measured. The functional meaning of this transitory construction may involve a threshold condition on the sperm middle piece.

Animals↗
PubMed1990

Ultrastructure of goat testes: tubulobulbar complexes between spermatids and Sertoli cells.

The fine structure of tubulobulbar complex (TBC) of goat seminiferous epithelium was studied using testicular samples fixed by perfusion. During the maturation phase of the spermatid, the TBC appeared on the periphery of the head before spermiation, dorsal and ventral parts of the head, both sides of the acrosome and on the postnuclear sheath region. At an early stage of the development of the TBC, a partial loss of smooth endoplasmic reticulum in the ectoplasmic specialization of a neighboring Sertoli cell was observed; filament bundles disappeared and a small fragmented smooth endoplasmic reticulum was left. Subsequently, a spermatid vesicle (coated vesicle) expanded to be in contact with the Sertoli cytoplasm by a small channel. These tubular projections extended to form a bulbous balloon-like structure forming sometimes a bi-balloon appearance, until torn off from the spermatid into the Sertoli cytoplasm and probably digested by the Sertoli cell. The significance of this structural development was morphologically discussed.

Animals↗
PubMed1990

[Analyses of neurotic symptoms and subjective symptoms of fatigue in seamen during a long voyage].

The variations of neurotic symptoms and subjective symptoms of fatigue were studied in relation to circumstances aboard ship in subsamples of the crew (N = 24) and students and researchers (N = 24) of a training ship belonging to a university during a summer voyage of the North Pacific route in 1987. The data were obtained by a self-administered questionnaire administered seven times before and during the voyage. The present study analysed the data collected during the 40 d voyage (the first four questionnaires including that before departure). Complaints of neurotic symptoms and fatigue were reported to be much greater in the present sample than those in a general occupational setting. Although the complaints reported by students and researchers decreased at landing, complaints of physical fatigue reported by the crew increased at landing but those of mental fatigue hardly changed. With regard to correlation between the values of the responses to circumstances aboard ship and the values of neurotic symptoms and fatigue, "quality of sleep" was significantly correlated with these symptoms for the crew. For the students and researchers, significant correlations were demonstrated between such items as "boredom toward work" and "quality of sleep", and physical fatigue, between the "anxiety over disease" and mental fatigue and "anxiety over disease", "risk of injury" and "fear of death" and neurotic symptoms in the first survey after departure (13th day).

Adult↗
PubMed1990

[Chronic subdural hematoma with a markedly fibrous hypertrophic membrane. Case report].

A 40-year-old female, who had taken low-dose oral contraceptives for 2 months before onset, developed transient dysarthria, left hemiparesis, and left hemihypesthesia. One month later, a computed tomography (CT) scan revealed a uniformly enhanced, convex-shaped, hypertrophic membrane with a lobulated lumen in the subdural space of the right parietal region. A right parietal craniotomy was performed. The membrane, consisting of elastic-hard, hypertrophic granulation tissue and yellowish, sticky fluid in the lumen, was readily freed and totally extirpated. Subsequently, the patient recovered without persistent symptoms. Light microscopic examination detected the sinusoidal channel layer and the fibrous layer in an alternating configuration, along with intramembranous hemorrhagic foci. Such hypertrophy must have been caused by repeated intramembranous hemorrhages and reactive granulation. Such findings of hematoma membrane have never previously been reported. Thus, this is an interesting case, clearly distinguished from typical chronic subdural hematoma.

Adult↗
PubMed1990

Massive hemorrhage in acoustic neurinoma after minor head trauma--case report.

Massive hemorrhage within an intracranial neurinoma occurs rarely. The authors describe a 62-year-old female with intratumoral bleeding which led to the discovery of an acoustic neurinoma. She developed a gait disturbance after a minor head injury. A computed tomographic scan obtained 2 months later demonstrated multiple high-density areas in the anterior portion of the left cerebellopontine angle. Preoperative diagnosis was acoustic neurinoma. The tumor had multiple cysts which contained a mixture of xanthochromic fluid and old, brownish hematomas, and was successfully removed. The intratumoral hemorrhage is thought to have resulted from traumatic rupture of the dilated vessels, although the trauma was slight. This is the first reported case of an acoustic neurinoma discovered through treatment for intratumoral hemorrhage occurring after a minor head injury.

Brain Injuries↗
PubMed1990

[Course of recovery from motor aphasia in four patients with localized lesions in the vicinity of Broca's area].

The neuropsychological signs and prognosis of patients with localized lesions in the vicinity of Broca's area of the left inferior frontal gyrus have been controversial. We studied periodic changes in the neuropsychological signs of four patients who had relatively localized lesions in the vicinity of Broca's area and manifested aphasia of the non-fluent type. The ages of the four patients at the onset were 62, 66, 30 and 37 years. The localized lesions in their brains were the result of brain infarctions revealed by CT scans, and included so-called Broca's center in the left inferior frontal gyrus along with adjacent brain tissue. The neuropsychological signs of the four patients were periodically assessed by means of the standard language test of aphasia (SLTA). In the early stage of aphasia, they had moderate difficulties in speaking to explain test materials or recall words and mild difficulties in reading aloud, repeating and writing words. One year later, most of their neuropsychological signs disappeared except for mild difficulties in speaking fluently and recalling words. It should be noted, however, that all four patients were able to return to their previous occupations one or two years later, because they had recovered from aphasia. Based on the results of this study, we conclude that the neuropsychological signs of Broca's aphasia caused by relatively localized lesions in the left inferior frontal gyrus are mild and largely disappear within one or two years.

Adult↗
PubMed1990

CP-84,657, a potent polyether anticoccidial related to portmicin and produced by Actinomadura sp.

A new polyether antibiotic CP-84,657 (C45H78O14) was isolated by solvent extraction from the fermentation broth of Actinomadura sp. (ATCC 53708). Following purification by column chromatography and crystallization, the structure of CP-84,657 was elucidated by spectroscopic (NMR and MS) methods. The absolute stereochemistry was determined by a single crystal X-ray analysis of the corresponding rubidium salt. CP-84,657 is among the most potent anticoccidal agents known, effectively controlling the Eimeria species that are the major causative agents of chicken coccidiosis at doses of 5 mg/kg or less in feed. It is also active in vitro against certain Gram-positive bacteria, as well as the spirochete, Treponema hyodysenteriae.

Actinomycetales↗