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Biomedical subjects

S Kano

Publications and source records attributed to S Kano.

At least 163 records · Page 9Linked to original sources

Fast versus slow ventilation for neonates.

To investigate the effect of ventilation rate on respiratory mechanics, 21 neonates ventilated in the neonatal period for various reasons were studied while being ventilated at 30 and 80 breaths/min. Dynamic respiratory system elasticity (ERS), dynamic respiratory system resistance (RRS), and alveolar pressure at end expiration (EEP) were calculated by using multilinear regression to fit the equation of motion of a linear single-compartment model. Technically satisfactory data were obtained from 13 neonates. With the fast ventilation rate, tidal volume and RRS decreased by a mean of 41.3% (p < 0.01) and 17.5% (p < 0.01), respectively, ERS and EEP increased by a mean of 8.3% (p < 0.05) and 22.2% (p < 0.01), respectively. Fast ventilation produced a shorter effective time constant during expiration, limiting the changes in EEP and, hence, in end-expiratory lung volume. The same changes in respiratory mechanics were also observed in neonates who did not show an increase in EEP even at high frequency. These neonates had a high elastance and time constant short enough to ensure adequate lung emptying. These results suggest that the respiratory mechanics of ventilated neonates are frequency dependent and that neonates with higher ERS, such as those with hyaline membrane disease, can cope with fast rate ventilation without developing dynamic hyperinflation.

Anthropometry↗

Adult Still's disease with Sjögren's syndrome successfully treated with intravenous pulse methylprednisolone and oral cyclophosphamide.

A patient with adult Still's disease and Sjögren's syndrome failed to respond to conventional doses of corticosteroids. Therefore intravenous pulse methylprednisolone combined with oral cyclophosphamide was given which subsequently resolved the flare of rashes, fevers, and arthritis. This combination therapy may be a useful therapy to consider in patients with adult Still's disease who are resistant to conventional treatment and may allow a reduction in daily corticosteroid requirement.

Administration, Oral↗

A primate model for severe human malaria with cerebral involvement: Plasmodium coatneyi-infected Macaca fuscata.

To develop an animal model for severe human malaria, we carried out clinical and pathologic observations of Japanese monkeys (Macaca fuscata) infected with Plasmodium coatneyi. Two monkeys, eight and nine months of age, were used in this experiment. After inoculation with the parasite, both monkeys developed a fulminating acute infection with high parasitemia (20-28.2%) and became moribund with typical signs of severe malaria. In the splenectomized Japanese monkey, sequestered infected erythrocytes blocked brain capillaries. Electron microscopic studies on brain tissues revealed electron-dense knobs protruding from the membrane of infected erythrocytes that formed focal junctions with the cerebral capillary endothelial cells. These findings were remarkably similar to those seen in human cases. Prominent sequestration of the infected erythrocytes was uniformly distributed in capillaries of the lungs and heart. The nonsplenectomized Japanese monkey developed acute anemia with a packed cell volume of 6%, but blockage of brain capillaries was minimal. However, sequestered, infected erythrocytes were evident in capillaries of the heart and lungs of this animal. Our study showed that the Japanese monkey is highly susceptible to P. coatneyi infection and that this system provides a model for the study of severe human malaria.

Animals↗

Application of seroepidemiology in identification of local foci in a malarious community in Palawan, The Philippines.

The value of seroepidemiology in malaria control programs has long been recognized, but its use in such situations has been limited. We therefore conducted a seroepidemiologic study in a frontier community on Palawan Island, The Philippines, an area where malaria is highly endemic. The first serologic survey was done at the end of the rainy season and the second was done during the dry season. The sera were examined using an indirect fluorescent antibody test. There was a significant difference in the geometric mean reciprocal titer (GMRT) during the rainy season as compared with the GMRT during the dry season. There were seasonal changes in the distribution of high- and low-titer responses, which is suggestive of the occurrence of recent past malaria epidemics. The differences in the geographic distribution of high and low titers were indicative of permanent foci of malaria transmission in this community. Results of a parallel parasitologic study were consistent with those of the serologic study. These findings may be of practical value not only in the proper reorientation of the local malaria control program, but of those of other endemic countries as well.

Adolescent↗

Morphologic effects of artemether on Plasmodium falciparum in Aotus trivirgatus.

The effects of artemether on the morphology of Plasmodium falciparum were studied in an owl monkey (Aotus trivirgatus) when parasitemia reached 33% and the animal became severely ill. The earliest and the most distinctive ultrastructural changes following the administration of artemether were marked swelling of the mitochondria in the parasites, followed by the appearance of electron-dense chromatin materials in the nuclei and clumping of ribosomes. The initial change was observed within 2 hr of administration of the drug. These findings correlate well with the rapid and effective action of artemether, which has been demonstrated in human clinical trials.

Animals↗

[Giant cell arteritis and polymyalgia rheumatica presenting as subclavian artery obstruction].

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are common diseases in the elderly. The arteritis usually affects medium sized vessels, but large vessel involvement can also occur leading to arm claudication, bruits, loss of pulses and pallor of the upper extremities. The differential diagnosis of large vessel arteritis includes atherosclerosis and Takayasu's disease. Atherosclerosis, which affects patients of similar age to GCA is usually confined to the lower limbs and can be differentiated on the basis of the clinical setting and investigations such as the ESR, arteriography and temporal artery biopsy. Takayasu's arteritis' although histologically and arteriographically indistinguishable from GCA, is predominantly a disease of young women. A patient is described who presented with upper limb ischemia. A clinical examination revealed absence of right radial pulses and presence of murmurs at level of the carotids. The blood pressure was unrecordable in the upper right limb. The ESR was 102 mm/hr and the C-reactive protein was 11.66 mg/dl. A selective arteriography of the aortic arch and its branches revealed a right subclavian artery obstruction with good collateral circulation and a left subclavian artery stenosis. The biopsy of left temporal artery showed a typical GCA in acute stage. Treatment with prednisolone 30 mg/day was started and four weeks later, the ESR had fallen to normal. In addition this case confirms that PMR implies a systemic arteritis.

Arterial Occlusive Diseases↗

Determination of peak expiratory flow.

It is still unknown whether peak expiratory flow (PEF) is determined by "wave speed" flow limitation in the airways. To investigate the influences of airway mechanical properties on PEF, five healthy adults performed maximal forced expiratory effort (MFEE) manoeuvres, in the standard manner and following breathholds at total lung capacity (TLC) of 2 s and 10 s. Oesophageal pressure (Poes) was measured as an index of respiratory effort. Subjects also performed a MFEE following a 10 s breathhold during which intrathoracic pressure was voluntarily raised by a Valsalva manoeuvre, which would increase transmural pressure and cross-sectional area of the extrathoracic airway. Additional MFEEs were performed with the neck fully flexed and extended, to change longitudinal tracheal tension. In separate studies, PEF was measured with a spirometer and with a pneumotachograph. Breathholds at TLC (2 s and 10 s), and neck flexion reduced PEF by a mean of 9.8% (SD 2.9%), 9.6% (SD 1.6%), and 8.7% (SD 2.8%), respectively, when measured with the spirometer. The same pattern of results was seen when measured with the pneumotachograph. These reductions occurred despite similar respiratory effort. Voluntarily raising intrathoracic pressure during a 10 s breathhold did not reverse a fall in PEF. MFEE manoeuvre with neck extension did not result in an increase in PEF, the group mean % changes being -3.0% (SD 5.0%). We conclude that these results do not allow the hypothesis that "wave-speed" (Vws) is reached at PEF to be rejected. A breathhold at TLC could increase airway wall compliance by allowing stress-relaxation of the airway, thus reducing the "Vws" achievable.

Adult↗

[Two cases of pneumococcal septic arthritis complicating rheumatoid arthritis].

It is reported that most of the causative organisms of suppurative arthritis complicating rheumatoid arthritis (RA) is Staphylococcus aureus and that Streptococcus pneumoniae is rare, representing less than 5% of cases of suppurative arthritis complicating RA. We here report two cases of pneumococcal septic arthritis complicating RA. Both were female, and 68 and 64 years old, respectively. They had active, long-standing RA with destructed changes. Infected joints included both knees (case 1) and right knee (case 2). Pain and loss of motion in the septic joints were prominent. On admission, the physical examination showed severe redness, swelling and tenderness of the septic joints and the range of motion of those was markedly decreased. The radiograph of affected joints showed stage III. Laboratory data showed markedly elevated ESR of 127 mm/hr (case 1) and 142 mm/hr (case 2) and C-reactive protein of 49.91 mg/dl (case 1) and 30.36 mg/dl (case 2). Aspirate of the left knee of case 1 showed numerous neutrophils. Cultures of the joint fluid grew S. pneumoniae. Grossly purulent material was aspirated from the right knee of case 2 and cultures also grew S. pneumoniae. They were started on intravenous antibiotics with a good response and the function of involved joints returned to preseptic condition. The source of infection on case 1 was presumed to be otitis media because she had discharge from left ear concurrently with the exacerbation of joint symptoms. Case 2 had productive cough and cultures of sputum also disclosed S. pneumoniae when pain of right knee joint developed. The suggested source of infection was upper respiratory tract.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Anti-type II collagen antibodies in collagen disease].

Using enzyme-linked immunosorbent assay (ELISA), we determined the incidence of serum IgG antibodies to native type II collagen in patients with collagen diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), progressive systemic sclerosis (PSS) and overlap syndrome (OL). Raised serum IgG anti-type II collagen antibody levels were present in 11% of patients with RA, 30% with SLE, 44% with PSS and 42% with OL. There was, however, no correlation with clinical manifestations or other laboratory data.

Adult↗

[Long-term retrospective study of patients with connective tissue diseases accompanied by pulmonary hypertension].

To determine clinical and serological features that are related with the prognosis of connective tissue diseases with pulmonary hypertension (PH), we studied a long-term prognosis of 14 patients (4 SLE, 1 PSS, 3 MCTD, 2 primary Sjögren's syndrome, and 5 OL) accompanied by PH. The patients were divided into three groups; group A (4 cases) that is alive for 5-12 years until present, group B (6 cases) in which PH was the main cause of death, and group C (4 cases) was dead of pulmonary fibrosis and pericardial tamponade. No significant difference was observed in background connective tissue diseases among the three groups. However, the mean ages at the onset of PH was obviously younger in group B (25.7 yrs.) than both in group A (38.3 yrs.) and in group C (42.0 yrs.) (group A vs group B, p < 0.02, and group B vs group C, p < 0.05). Sudden death occurred in 5 of the 6 in group B, whereas it was not observed either in group A or in group C. Also, the interval between onset of PH and death was shorter in group B (1.3 yrs.) than in group C (3.5 yrs.). The incidence of digital necrosis and pericardial effusion was higher in group B (83% and 83%, respectively) than both in group A (0% and 25%, respectively) and in group C (25% and 40%, respectively). A large amount of pericardial effusion was detected in 4 of 5 cases in group B. The incidence of digital necrosis between group A and group B was significantly different (p < 0.05, Fisher's test).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[A case report--pulmonary cryptococcosis associated with systemic lupus erythematosus and review of 44 cases in Japan].

A case of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) associated with pulmonary cryptococcosis which was successfully treated with fluconazole (FCZ) and flucytosine (5-FC) is described. A 63-year-old woman who had been treated with steroid for SLE and low dose methotrexate (MTX) for RA was admitted to Jichi Medical School Hospital because of abnormal shadow in the chest X-ray film. Physical examination revealed no abnormality. A chest CT film showed multiple nodular shadows localized in the right lower lobe. An ultrasonically guided trans-cutaneous lung biopsy performed on 10th hospital day established a diagnosis of pulmonary cryptococcosis. Following the treatment with FCZ and 5-FC for a month, her abnormal lung shadows improved and serum cryptococcal antigen level was decreased. A survey of the literature from 1955 to 1990 revealed 44 cases of SLE associated with cryptococcosis in Japan, in addition to our case, most of whom were on corticosteroid therapy. The majority of patients were young women, representing the usual population of patients with SLE. 34 of these patients had cryptococcal meningitis; 22, pulmonary cryptococcosis; 6, sepsis; 6 cutaneous cryptococcosis. Twenty patients died. Deep fungal infections should be considered whenever patients with SLE have fever of unknown origin, diffuse pulmonary infiltrates, or unexplained CNS symptoms.

Arthritis, Rheumatoid↗

CD3+4-8- alpha beta T cell population with biased T cell receptor V gene usage. Presence in bone marrow and possible involvement of IL-3 for their extrathymic development.

Analysis of TCR of a series of CD4-8- (double negative; DN) alpha beta T cell lines induced with IL-3 revealed that their V gene usage was biased for V alpha 4 and V beta 2. This has been confirmed in the primary short-term cultures. Thus, IL-3 induced the generation of DN alpha beta T cells with predominant V beta 2 gene expression from the CD4+/CD8+ T cell-depleted spleen or bone marrow (BM) cells of both normal and nude BALB/c mice within 10 days. It was further indicated that the V beta 2+ beta-chain genes contained few junctional N regions in both IL-3-induced primary DN alpha beta T cells and continuous lines. Search for the in vivo counterpart of in vitro IL-3-induced DN alpha beta T cells revealed that BM, but not spleens, of normal BALB/c and B6 mice did contain a significant proportion of DN alpha beta T cells, and that the majority of them expressed V beta 2+ beta-chain genes with few junctional N regions. The presence of V beta 2+ DN alpha beta T cells was similarly observed in the BM of BALB/c nude mice, but their proportion varied markedly among various strains of mice, which was not linked to H-2 haplotypes. The results indicated that V beta 2+ DN alpha beta T cells in the BM represented one of the thymus-independent T cell populations, whose development was under the major histocompatibility Ag complex-unlinked genetic control. TCR of these T cells were shown to be functional as judged by the proliferative response to anti-V beta 2 antibody. Taken together, present results suggested that IL-3 could induce differentiation and/or proliferation of DN alpha beta T cells with uniquely limited repertoire, which existed preferentially in BM in vivo, and implied the possible involvement of extrathymic endogenous ligands as a positive selection force.

Animals↗

Soybean phospholipid dependent reductions in triacylglycerol concentration and synthesis in the liver of fasted-refed rats.

The effect of dietary soybean phospholipid on the activities of hepatic triacylglycerol-synthesizing enzymes was compared with soybean oil in fasted-refed rats. Soybean oil at the dietary level corresponding to 20% but not at 5% fatty acid level (21.2 and 5.3% on weight bases, respectively) significantly decreased liver microsomal diacylglycerol acyltransferase activities measured with the endogenous diacylglycerol substrate. Dietary soybean phospholipid even at the dietary level corresponding to 2% fatty acids (3.4% on weight base) significantly decreased the acyltransferase activities measured with endogenous substrate. The dietary phospholipid further decreased the parameter as the dietary level increased, and at the 5% fatty acid level, it was lower than that obtained with soybean oil at 20% fatty acid level. Soybean oil and phospholipid decreased the diacylglycerol acyltransferase activities measured with the saturating concentration of exogenous dioleoylglycerol substrate only when the activities were expressed in terms of total activity (mumol/min per liver) but to much lesser extents. Dietary phospholipid compared to the oil profoundly decreased not only hepatic triacylglycerol but also microsomal diacylglycerol levels. It was indicated that the availability of microsomal diacylglycerol as the substrate for diacylglycerol transferase is the critical determinant in regulating hepatic triacylglycerol synthesis and concentration in this experimental situation. Alterations in the activities of microsomal glycerol 3-phosphate acyltransferase and of the enzymes in fatty acid synthesis could account for the phospholipid-dependent decrease in the microsomal concentration of this intermediate in triacylglycerol synthesis.

Acyltransferases↗

Interleukin 6 gene transcripts are expressed in atherosclerotic lesions of genetically hyperlipidemic rabbits.

We have investigated the involvement of interleukin 6 (IL-6), a growth-regulatory molecule for vascular smooth muscle cells (SMC), in the development of atherosclerotic lesions of Watanabe heritable hyperlipidemic (WHHL) rabbits. In in situ hybridization analysis, quite low levels of IL-6 mRNA were expressed in 'quiescent' SMC cultured from WHHL rabbits; however, high levels of IL-6 mRNA were induced in SMC exposed to 10% fetal bovine serum (FBS), suggesting that growth-stimulated SMC themselves can synthesize IL-6. In in vivo WHHL aortae, transcripts for the IL-6 gene were clearly observed in the fibrous plaques. These findings support the premise that IL-6 is an important autocrine and/or paracrine regulator of SMC proliferation and of pathogenesis of atherosclerosis in this animal model.

Animals↗

Renal potassium wasting in distal renal tubular acidosis: role of aldosterone.

The pathogenesis of renal potassium wasting and hypokalemia in classic renal tubular acidosis (type 1 RTA) remains uncertain. The prevailing theory is that K(+)-Na+ exchange is stimulated due to an inability of the distal tubule to establish a normal steep lumen-peritubular H+ gradient. We encountered a 42-year-old woman with type 1 RTA associated with Sjögren's syndrome, in whom renal potassium wasting and hypokalemia persisted despite sustained correction of systemic acidosis with alkali therapy and increased intake of potassium. In addition, plasma renin activity was markedly increased and the serum aldosterone level was upper-normal despite the hypokalemia. Increased intake of sodium resulted in suppression on the serum aldosterone and correction of renal potassium wasting and hypokalemia. This case shows that secondary hyperaldosteronism, possibly due to an impairment of sodium conservation in the distal tubule, may contribute to the loss of potassium from the distal tubule even after the correction of acidosis.

Acidosis, Renal Tubular↗

[False positive reaction in measurement of allergen-specific IgE--comparison of 3M IgE FAST-Plus Test using polystyrene well as adsorbent with Phadezym RAST].

Irrelevant IgE binding to cellulose discs is known to give false positive results in Phadezym RAST (Pharmacia) for the estimation of allergen-specific IgE in serum. We investigated FAST-Plus Test (3M Diagnostic Systems), an enzyme-linked sandwich type Fluoro-Allergo-Sorbent Test in which a particular allergen was coated to polystyrene well. Phadezym RAST and CAP RAST (Pharmacia) using cellulose-derivative discs as adsorbent were used as reference methods. Patients' sera which gave negative blank reactions to uncoated filter paper disc in the Phadezym RAST system were assayed for specific IgE to 6 allergens using FAST-Plus Test, CAP RAST and Phadezym RAST, and the results of the former two were compared with those of Phadezym RAST using a comparable class system. FAST-Plus Test showed variable correlations with Phadezym RAST, the correlation coefficients ranged from 0.41 to 0.97 (r = 0.462 in house dust 1, r = 0.713 in house dust 2, r = 0.412 in Candida albicans, r = 0.952 in Dermatophagoides peteronyssinus, r = 0.969 in Dermatophagoides farinae and r = 0.682 in Japanese cedar), although most of the results were within one class difference. Similar correlations were obtained between CAP RAST and Phadezym RAST. Of 3004 patients' sera tested in the past two years using Phadezym RAST, 132 (96 cases) displayed positive blank reactions to the uncoated filter paper disc. Of the 96 cases, 80 sera were assayed for binding of IgE to the uncoated cellulose-derivative disc in the CAP RAST system. 18 showed positive results up to 7 IU/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗