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Biomedical subjects

M Nakamoto

Publications and source records attributed to M Nakamoto.

At least 55 records · Page 3Linked to original sources
PubMed1997

Dialysis-related amyloidosis of the tongue in long-term hemodialysis patients.

Dialysis-related amyloidosis (DRA) predominantly occurs in the osteoarticular structures. However, according to studies in the increasing number of long-term hemodialysis patients, DRA has also been systemically found to appear in the other tissues and organs as well. In this study, we investigated lingual amyloidosis in relation to systemic DRA. A total of 472 patients were studied who were on regular hemodialysis for more than 10 years, including 103 patients for more than 20 years. Eight of these patients (7 males and 1 female, mean age 59 +/- 8 years, range 46 to 68 years) developed lingual amyloidosis, seemingly as a result of beta2-microglobulin (beta2m) deposits. All patients demonstrating lingual amyloidosis had been treated with regular hemodialysis for more than 20 years (mean HD duration 23.6 +/- 1.4 years), and its morbidity was 7.8% in the 103 patients and 20% (6 patients) in the 30 patients treated for more than 23 years with hemodialysis. Hemodialysis (HD) duration with bioincompatible unsubstituted cellulose membranes in the 8 patients was longer than that in the control group without lingual amyloidosis (P < 0.05). Lingual amyloid nodules were whitish-yellow in color and varied in size, at least over 1 mm in diameter. Their consistency was firmer than the intact tongue. The location of the amyloid nodules could be classified into two types: (1) diffuse type (diffusely distributed over the tongue), and (2) lateral type (localized only in the lateral side of the tongue). Five of the eight patients with lingual amyloidosis complained of functional disturbances in the tongue, such as abnormal taste, or difficulty in mobility and articulation. No macroglossia was observed in any of these cases. It was thus concluded that DRA of the tongue is a very rare complication, occurring in the late stage of long-term hemodialysis patients, that disturbs their quality of life.

Adult↗
PubMed1997

Response to psychological test in elderly patients with hand-arm vibration syndrome and healthy controls.

We investigated the parasympathetic nervous response to psychological test using heart rate variation (HRV) during deep breathing in elderly patients with hand-arm vibration syndrome and healthy controls. Average age (SD) of 16 patients with vibration-induced white finger (VWF), 13 patients without VWF and 12 healthy controls was 60.1 (2.8), 60.6 (4.2) and 58.8 (3.8), respectively. After an initial supine rest for 40 min, psychological test (Stroop color word test and mirror drawing test) was performed for 20 min. The indexes of HRV (Mean R-R, SD, RMSSD and CV) were calculated. Blood pressure and heart rate were also measured. The indexes of HRV did not differ between the groups before exposure. The SD, RMSSD and CV of the patients without VWF during supine deep breathing after 3 min post-exposure supine rest were significantly lower than those of the control group (p < 0.05). The Mean R-R of the patients without VWF significantly increased (p < 0.05). Blood pressure did not differ in either before or after exposure measurements. The results suggest that the post-exposure response of the parasympathetic nervous system to psychological test reduced in the patients without VWF.

Aged↗
PubMed1997

Acute hemorrhagic gastritis associated with acetazolamide intoxication in a patient with chronic renal failure.

Acetazolamide (Diamox) is a carbonic anhydrase inhibitor commonly used in patients with glaucoma in order to reduce intraocular pressure. Acetazolamide (AZ) is mostly excreted in the urine, therefore, the blood levels of AZ often tend to increase in patients with chronic renal failure. We experienced a case of chronic renal failure in a patient suffering from acute hemorrhagic gastritis associated with AZ intoxication. A 66-year-old female with chronic renal failure was referred to our hospital because of drowsiness and an acute deterioration of renal function. She had been treated with AZ, 500 mg per every day for eleven days for the treatment of glaucoma. Laboratory studies showed leukocyturia, thrombocytopenia, severe anemia, and tarry stools. The serum concentration of AZ was elevated to a maximum of 76.5 mg/ml. She was thus diagnosed as having AZ intoxication. On further examination, acute extensive hemorrhagic gastritis was also found by gastroscopy. Despite of the administration of intensive therapies, she died of disseminated intravascular coagulation (DIC) and septic shock due to bone marrow depression 6 days after admission. It is generally known that excessive blood levels of AZ inhibit not only the gastric juices but also prostaglandin levels and HCO3- excretion in the gastric mucosal barrier. We thus concluded that an excessive dose of AZ had probably destroyed the gastric mucosal barrier or thrombocytopenia due to bone marrow disorder and thus eventually led to the development of hemorrhagic gastritis. As far as we know, this is the first case report of acute hemorrhagic gastritis associated with AZ intoxication. Even though AZ tends to strongly bind to plasma protein and its clearance is generally poor by hemodialysis (HD), in our patient, HD was observed to be rather effective since the clearance of AZ was 45.8 ml/min on HD and 66 ml/min on direct hemoperfusion (DHP). DHP often reduces the number of platelets, also DHP needs a lot of heparin, therefore, we should have performed HD alone instead of DHP. In patients with an impaired renal function, AZ should therefore be administered very carefully in order to avoid an accumulation of the drug. In addition, HD alone should be used to remove any excessive amounts of AZ from the blood.

Acetazolamide↗
PubMed1997

Systemic lupus erythematosus in a patient with remitting minimal change nephrotic syndrome.

Minimal change nephrotic syndrome (MCNS) developed in a 17-year-old female and spontaneously remitted. One month later the nephrotic syndrome relapsed. Prednisolone therapy, 60 mg/day, was started and resulted in a full remission within a week and the prednisolone dose was subsequently tapered. Seven months later, when 10 mg/day of prednisolone was being administered, she developed erythematous rash with photosensitivity and polyarthralgia without exacerbation of the nephrotic syndrome, and fulfilled four of the American College of Rheumatology criteria for classification of systemic lupus erythematosus (SLE). Avoidance of direct sunlight ameliorated the erythematous rash and the polyarthralgia disappeared even though the prednisolone dose was decreased further. This is the first reported case of SLE developed in a patient with remitting MCNS.

Adolescent↗
PubMed1996

Topographically specific effects of ELF-1 on retinal axon guidance in vitro and retinal axon mapping in vivo.

Topographic maps, which maintain the spatial order of neurons in the order of their axonal connections, are found throughout the nervous system. In the visual retinotectal projection, ELF-1, a ligand in the tectum, and its receptors in the retina show complementary gradients in expression and binding, indicating they may be positional labels for map development. Here we show that ELF-1 acts as a repellent axon guidance factor in vitro. In vivo, when the tectal ELF-1 pattern is modified by retroviral overexpression, retinal axons avoid ectopic ELF-1 patches and map to abnormally anterior positions. All these effects were seen on axons from temporal but not nasal retina, indicating that ELF-1 could determine nasal versus temporal retinotectal specificity, and providing a direct demonstration of a cell recognition molecule with topographically specific effects on neural map development.

Animals↗
PubMed1996

The effects of electrolyte, lactate, high-concentrated glucose, and dialysate on peritoneal mesothelial cells.

In order to investigate which component of dialysate is responsible for mesothelial cell damage, we studied the chronic cytotoxicity to mesothelial cells by using four types of solution. Four different types of solution (Ringer's solution, lactate, high-concentrate glucose, and 4.25% Dianeal) were prepared and injected into the abdominal cavity of five ddY-mice, 5 mL every day for one month. The monolayer of the mesothelial cells was carefully removed from the liver surface by the imprint technique. Then, the mesothelial cell damage was evaluated by using trypan blue staining and comparing the results. Trypan blue-stained cells in 100 mm2 were observed in 7.0% of the control, 15.4% of the Ringer's solution, 18.7% of the lactate, 23.2% of the high-concentrate glucose, and 22.4% of the 4.25% Dianeal group, respectively. The damaged cells were significantly (p < 0.05) greater in the 4.25% Dianeal group than in the control group, and those in the high-concentrate glucose group also appeared to be greater in number compared to the control group It is concluded from these results that damage to the mesothelial cells is induced by chronic exposure to high-glucose dialysate, and its pathogenesis is deeply related to high concentration of glucose.

Animals↗
PubMed1996

[Two cases of the successful treatment of TAPVR with asplenia syndrome in neonates and infants].

Two patients of asplenia syndrome with pulmonary venous obstruction underwent TAPVR repair in the period of neonate (14 days) and infant (49 days). Associated procedures were necessary to adjust pulmonary blood flow (central shunt in 1, PA banding in 1). Both patients required subsequent surgical procedures; right modified BT shunt, due to kinking of central shunt in one patient and rePA banding for reduction of pulmonary blood flow in another patient. One patient died 4 months after the first operation of arrhythmia. Another patient is doing well in 7 months after the first operation. The TAPVR repair in the early period of infant or naonate is necessary to prevent progress of pulmonary venous obstruction. Adjustment of pulmonary blood flow is important for management of patients of asplenia syndrome after TAPVR repair.

Female↗
PubMed1995

Complementary gradients in expression and binding of ELF-1 and Mek4 in development of the topographic retinotectal projection map.

Topographic maps with a defined spatial ordering of neuronal connections are a key feature of brain organization. Such maps are believed to develop in response to complementary position-specific labels in presynaptic and postsynaptic fields. However, the complementary labeling molecules are not known. In the well-studied visual map of retinal axons projecting to the tectum, the labels are hypothesized to be in gradients, without needing large numbers of cell-specific molecules. We recently cloned ELF-1 as a ligand for Eph family receptors. Here, RNA hybridization shows matching expression gradients for ELF-1 in the tectum and its receptor Mek4 in the retina. Binding activity detected with alkaline phosphatase fusions of ELF-1 and Mek4 also reveals gradients and provides direct evidence for molecular complementarity of gradients in reciprocal fields. ELF-1 and Mek4 may therefore play roles in retinotectal development and have properties predicted of topographic mapping labels.

Amino Acid Sequence↗
PubMed1995

Inhibition of TNF-triggering activity of lipopolysaccharide by a proteinaceous factor from normal mouse liver extract.

Recent studies have revealed that animals have evolved a wide range of protective systems against the deleterious effects of LPS, but the molecular mechanisms in the barrier functions of liver against enterobacterial LPS, particularly in mammals, are poorly understood. In this study, we extracted a soluble fraction from the liver of normal mice (normal liver extract, NLE) and examined its effect on biologic activities of LPS. Preincubation of NLE and LPS suppressed serum-dependent TNF induction (TNF-triggering activity) of LPS; the effect was dose-dependent and overcome by increasing LPS concentration, but treatment of macrophages with NLE showed no effect. Separation by ultrafiltration and protease sensitivity demonstrated that the factor(s) in NLE was a protein(s). We tentatively called this liver LPS-inactivating factor (LLIF). LPS inactivation by LLIF was temperature-dependent and required the coexistence of divalent cations. LLIF also suppressed a synthetic lipid A analogue, ONO-4007. Pretreatment of LPS with serum rendered LPS refractory to the action of LLIF. However, LLIF was unable to inhibit limulus amebocyte lysate activation by LPS. Direct interaction of LLIF and lipid A was evident by the method of [1-14C]ONO-4007 binding to solid-phase LLIF, but treatment of [1-14C]ONO-4007 with LLIF generated no degradative products. These results suggest that LLIF probably interacts with the lipid A portion of LPS and interferes with the association of LPS and LBP (LPS-binding protein) in serum, and that LLIF may be one of the protective molecules in liver against the gastrointestine-derived LPS.

Acute-Phase Proteins↗
PubMed1995

Superficial repositioning of the artery for chronic hemodialysis: indications and prognosis.

Superficial repositioning of the artery (SRA) is a modality of the blood access operation for chronic hemodialysis that has been previously used in cases of cardiac failure. We performed 42 SRAs from 1986 to 1993; thereafter, we retrospectively investigated the operative indications, postoperative complications, and long-term results. Superficial repositioning of the artery was indicated for the lack of an appropriate vein (17 cases; 40%), frequent and early access failure due to arteriovenous fistula or polytetrafluoroethylene grafts (six cases; 14%), venous hypertension (five cases; 12%), and cardiac failure (two cases; 5%). The patency rates of the SRAs were 87% at 3 years and 58% at 4.5 years. There was some difficulty in finding the returning veins in five of 28 functioning SRAs (18%). The SRA is thus considered to be a secondary-selected blood access operation; however, it also may be used as an efficient blood access for an extended period of time without any serious complications.

Adult↗
PubMed1995

Carpal tunnel syndrome in patients undergoing CAPD: a collaborative study in 143 centers.

Patients undergoing continuous ambulatory peritoneal dialysis (CAPD) who developed carpal tunnel syndrome (CTS) were retrospectively studied in 143 centers in Japan. Among the total 5,050 patients undergoing CAPD between 1980 and 1993 only 7 patients (0.14%) given CAPD developed CTS. Five of these 7 patients treated solely with CAPD developed CTS 12-108 months after starting CAPD. The remaining 2 patients who were initially treated with HD for 7-9 years and then switched to CAPD developed this complication 9 years after starting CAPD. All 7 patients were women, ranging in age from 32 to 70 (average 52) years. We detected the presence of amyloid deposits in 2 of 5 specimens and beta 2-microglobulin in 2 of 4 specimens from these patients. It was concluded that CAPD minimizes the emergence of CTS although constant surveillance is necessary to detect CTS in patients during CAPD.

Adult↗
PubMed1995

Response to psychological stressors in hand-arm vibration syndrome patients.

We investigated urinary catecholamines' response to acute psychological stress test in hand-arm vibration syndrome patients. Thirteen patients with vibration-induced white finger (VWF) in higher frequency of attack, 7 patients with VWF in lower frequency, 6 patients without VWF and 17 healthy subjects were examined. All subjects were male and their average age (SD) was 59.2 (6.4), 56.3 (2.9), 58.2 (4.7) and 56.8 (4.9), respectively. After an initial rest for 1 hour, acute psychological stress test with stressors--mirror drawing, watching horror video and arithmetic under intermittent noise was performed for 1 hour. Subjective complaints to the stress test were greater in patients with hand-arm vibration syndrome than in the healthy controls. The patient group with VWF in higher frequency indicated significant increases of urinary catecholamines (p < 0.05); average values (SD) at rest period and at stress test were 2.42 (1.17) and 3.71 (1.82) micrograms/h for norepinephrine, and 1.47 (0.73) and 2.66 (1.79) micrograms/h for epinephrine, respectively. Increasing tendency of urinary catecholamines was observed in other three groups, however, they were not statistically significant. The sympathoadrenal medullary response to psychological stressors increased especially in hand-arm vibration syndrome patients with VWF in higher frequency.

Biomarkers↗