Biomedical subjects

K Kamitani

Publications and source records attributed to K Kamitani.

At least 19 recordsLinked to original sources

PubMed1999

Covering the head and face maintains intraoperative core temperature.

PURPOSE: To determine the effect of covering the patient's head and face on the prevention of intraoperative hypothermia (<35.5 degrees C). METHODS: This randomized, prospective trial included 44 adults undergoing elective abdominal surgery. After the induction of anesthesia with thiopental, in 44 patients their extremities and trunk were covered with towels and sheets. In addition, 22 patients (covered group) had their face and head fully covered. Anesthesia was maintained with N2O 50-66% (2-3 L x min(-1)) and isoflurane (<IMAC) in oxygen combined with thoracic epidural anesthesia. Core temperature was measured at the tympanic membrane continuously and was recorded at 15 min intervals from the induction of anesthesia. Heat and moisture exchangers were used in their anesthetic circuit. Ambient temperature was maintained near 25 degrees C. RESULTS: Neither group demonstrated intraoperative hypothermia. However, tympanic membrane temperature at 75, 90, 105 min in the covered group were higher than those of control group (36.7+/-0.4 degrees C vs. 36.5+/-0.4 degrees C, 36.8+/-0.5 degrees C vs. 36.4+/-0.5 degrees C, 36.8+/-0.5 degrees C vs. 36.4+/-0.5 degrees C, respectively, P<0.05). CONCLUSION: Covering the patient's head and face maintains intraoperative core temperature.

Adult↗

PubMed1998

[The evaluation of the pre-operative interviews using information sheets].

This investigation deals with patients of more than 15 years of age and family members of children younger than 12 years of age to evaluate the pre-operative interviews using information sheets. The information sheets describe the anesthetic management and complications in a simple style. Sixty% of the patients and 75% of the children's family felt anxiety about the anesthesia and/or the operation (P < 0.05). More than a half of the patients did not want to receive informations about the anesthetic management and the risk of anesthesia. On the other hand, 9% of children's family did not want to know informations about the risk (P < 0.05). More than 80% of patients read the information sheets after the pre-operative interviews and about a half of patients answered that their anxiety before the surgery decreased. In this investigation, the children's family wanted to have information about the anesthesia or the operation more than patients themselves. The pre-anesthetic interviews using information sheets is useful to give information about anesthesia and to relieve anxiety of the patients and the children's family.

Adolescent↗

PubMed1996

Posterior limbus vertebral lesions causing lumbosacral radiculopathy and the cauda equina syndrome.

This report reviews our experience with spinal decompression for posterior limbus vertebral lesions or osteocartilaginous vertebral corner defects in the lumbar spine in 29 children and young adults. There were 19 male and 10 female patients with a mean age of 16.5 years (range, 9 to 24 years). Twenty-four patients were involved with various athletic activities. Clinical presentation included low back pain with a variable degree of radiculopathy in 25 patients and a cauda equina syndrome in four. The level of the affected spinal area was L1-2 in one patient, L2-3 in one, L3-4 in seven, L4-5 in 17, and L5-S1 in three. The preoperative imaging workup showed lateralised "non-calcified' or 'calcified' limbus vertebral defects in 13 patients and centrally displaced lesions in 16 patients. All patients underwent posterior spinal decompression with a slightly extended laminotomy, except for three patients who had a subsequent posterolateral fusion. All of the patients consequently returned to practice their favourite preoperative sport and lifestyle, but five discontinued their previous sports. We suggest that patients with posterior limbus vertebral lesions require careful diagnosis and therapy that are different from those with an ordinary lumbar disc herniation.

Adolescent↗

PubMed1995

Revision surgery for lumbar disc herniation. An analysis of 45 patients.

We reviewed 45 patients who had undergone repeated open operations for lumbar disc herniation. There were 26 men and 19 women with a mean follow up of 4.3 years. Twenty-four patients had had one previous discectomy, 12 had 2, and 9 had 3 or more; 11 needed a fusion without instrumentation. Residual or re-extruded disc hernias, either sub- or transligamentous, were frequently found at revision. Good to excellent results were obtained in 64%. Those who had a first-time revision had earlier improvement and better results. Complete removal and a thorough search for herniated disc material is essential when carrying out the initial operation for extruded or sequestrated herniation. At revision, removal of as much as possible of the remaining nucleus and annulus, but with minimal invasion of the posterior elements, is crucial for improving the outcome.

Adolescent↗

PubMed1995

Osteoporotic vertebral collapse with late neurological complications.

This paper describes 27 patients who had a spinal fracture and underwent an anterior or a posterior spinal decompression, with or without spinal instrumentation, for late neurological compromise secondary to post-traumatic vertebral collapse associated with osteoporosis. Five males and 22 females were studied, with an average follow-up of 3.7 years. The patients developed delayed neurological compromise due to osteoporotic vertebral collapse 1 month to 1.5 years following insignificant spinal fractures. Abnormal hypermobility at the collapsed spinal level with gradual retropulsion of fracture fragments into the spinal canal appeared to contribute to late paralysis. This pathology is treated surgically either anteriorly or posteriorly, but we recommend transpedicular posterolateral decompression and stabilization with a screw-rod construct because of technical ease and minimum invasion.

Age Factors↗

PubMed1995

Effects of propofol on isolated rabbit mesenteric arteries and veins.

We have investigated the effect of propofol on isolated rabbit mesenteric arteries and veins. Isometric tension was measured in rings of arteries (with or without endothelium) or veins in organ chambers. The preparation was stimulated with noradrenaline 10(-6) mol litre-1, K+ 50 mmol litre-1 and caffeine 20 mmol litre-1 in the presence or absence of propofol. Propofol potentiated noradrenaline-induced contractions at lower concentrations (3 x 10(-5) mol litre-1) and attenuated them at greater concentrations (10(-4) and 3 x 10(-4) mol litre-1) in arteries with endothelium. Propofol inhibited noradrenaline-induced contractions in arteries without endothelium. In contrast, propofol produced venodilatation in a concentration-dependent manner (10(-5) to 3 x 10(-4) mol litre-1) of significantly greater magnitude than that in arteries. Propofol inhibited K+-induced contraction of both arteries and veins. It decreased the relaxation induced by acetylcholine (3 x 10(-8), 10(-7) and 3 x 10(-7) mol litre-1) of noradrenaline-induced contractions of arteries. Propofol did not affect caffeine-induced contractions after pretreatment with increased Ca2+. We conclude that propofol has a more potent vasodilator effect on veins than on arteries. Vasoconstriction induced by propofol may be associated with inhibition of endothelium-derived relaxing factor, whereas vasodilatation induced by propofol may be associated with block of voltage-gated influxes of extracellular Ca2+.

Acetylcholine↗

PubMed1995

The vasodilatory effects of ketamine on isolated rabbit portal veins.

The vasodilation mechanism induced by ketamine was investigated in isolated smooth muscle strips of rabbit portal veins. Ketamine inhibited both the phasic and tonic components of K(+)-induced contraction at concentrations greater than 500 microM and 100 microM, respectively. This effect was reversible and concentration-dependent with concentration-dependent with concentrations up to 1 mM. These effects were similar to those produced by verapamil. In the presence of 60 mM K+, application of Ca2+ (2.5 mM) in the perfusing solution caused tonic contraction of the smooth muscle, and ketamine at concentrations larger than 10 microM strongly inhibited this Ca(2+)-induced contraction. Ketamine (100 microM) also inhibited the K(+)-induced contractions significantly in the absence and presence of guanethidine, tetrodotoxin and propranolol. Ketamine produced similar concentration-dependent relaxations in the tissues with and without endothelium. These results indicate that in rabbit portal vein, vasodilation produced by ketamine is not endothelium-dependent but is likely to be due to blockade of the voltage-gated influx of extracellular Ca2+.

Animals↗

PubMed1995

[A transient sinus arrest after right stellate ganglion block--assessment of autonomic function by heart rate spectral analysis].

We experienced a case of sinus arrest probably induced by right stellate ganglion block (SGB). A healthy medical student volunteered in our study of the cardiac autonomic nervous system and received the SGB. After the Holter ECG had been attached, the SGB was performed with mepivacaine 8 ml. Horner's sign was observed after about 3 minutes. A transient (15 s) sinus arrest occurred suddenly after about 6 minutes of the tilt test probably due to a vasovagal reflex, and the subject lost consciousness. From spectral analysis of the Holter ECG recording, the right SGB may be closely involved in the induction of the sinus arrest. Our present case suggests that sinus arrest may occur if a patient stands up after right SGB.

Adult↗

PubMed1994

Postoperative bone re-growth in lumbar spinal stenosis. A multivariate analysis of 48 patients.

STUDY DESIGN: Forty-eight patients who underwent posterior decompressive surgery for lumbar spinal stenosis were studied. The effect of bone re-growth after posterior decompression in lumbar spinal stenosis on clinical outcome and the factors promoting the bone re-growth were investigated with a multivariate analysis model. METHODS: Bone re-growth at the sites operated upon was evaluated as a percentage of re-growth of the original laminectomy site based upon plain radiographs. The degree of bone re-growth was classified into four groups: 1) no significant re-growth (Group I, bone regrowth rate 10% or less); mild (Group II, 11% to 40%), moderate (Group III, 41% to 70%), and marked (Group IV, 71% to 100%). The average follow-up period was 4.5 years (range, 2 to 7 years). RESULTS: No significant bone re-growth was shown in 6% of the patients. Mild re-growth was shown in 50%, moderate re-growth in 29%, and marked re-growth in 15%. A multivariate analysis indicated that a total block in the preoperative myelogram, a follow-up period of more than 5 years, decompression at more than three spinal levels, and age under 60 years were associated with moderate or marked bone re-growth. Spinal instability accelerated the bone re-growth mainly in the mid and later follow-up intervals. Spinal levels adjacent to a fusion showed more bone re-growth. Patients with moderate and marked bone re-growth had poorer clinical outcomes than those with no significant and mild bone re-growth. CONCLUSION: Bone re-growth in a surgical defect will occur in most patients after posterior decompression. Moderate and marked postoperative bone re-growth are possibly related to recurrence of neurologic symptoms in the middle of and later on in follow-up periods.

Aged↗

PubMed1994

Effects of halothane and diltiazem on L-type calcium currents in single smooth muscle cells from rabbit portal veins.

We have studied the effects of halothane and diltiazem on L-type voltage-dependent calcium currents (ICa) in single smooth muscle cells from rabbit portal veins using a whole cell voltage clamp technique. The threshold of ICa was -30mV and the peak current was reached at 0mV. Halothane (0.25, 0.5, 1.0, 1.5 and 2.0%) decreased ICa in a concentration-dependent manner and shifted the ICa activation threshold to the depolarizing side. Halothane 2.0% abolished ICa. Diltiazem 10(-8)-10(-6) mol litre-1, a calcium channel antagonist, also depressed ICa in a concentration-dependent manner. Administration of both 0.5% halothane and diltiazem 10(-7) mol litre-1 (concentrations lower than the clinical therapeutic range) abolished ICa; however, halothane did not exhibit use-dependent inhibition of ICa whereas diltiazem showed partial use-dependency. We conclude that the decrease in ICa produced by halothane is associated with a direct vasodilator effect of this anaesthetic, but is not explained by block of Ca2+ channels similar to the action of diltiazem. Furthermore, administration of low concentrations of both halothane and diltiazem decreased ICa and may reduce the contractility of the vascular smooth muscle cells.

Animals↗

PubMed1994

[Anesthesia for modified radical mastectomy with breast reconstruction].

We investigated the factors influencing the amount of intraoperative bleeding, the factors influencing postoperative blood transfusion and the effect of postoperative analgesia retrospectively in 71 patients who underwent modified radical mastectomy with breast reconstruction. The amount of intraoperative bleeding decreased significantly in hypotensive anesthesia using epidural anesthesia compared with that with prostaglandin E1. Patient's weight and body surface area are the factors which influenced the amount of intraoperative bleeding. No patient received intraoperative blood transfusion. The amount of postoperative bleeding was significantly greater in 14 cases with blood transfusion and the amount of intraoperative bleeding was not significantly greater in blood transfusion cases. Fifty-one patients received epidural morphine intraoperatively. The dosage of postoperative analgesic was significantly less in these patients.

Aged↗

PubMed1994

[Analgesic effects of the lumbar epidural block with the catheter placed caudad].

In 31 cases of trans-urethral resection of the prostate (TUR-P), the lumbar epidural block was carried out with the catheter placed caudad. In 23 of 31 cases, it was found that the catheters were inserted caudad with coiling, but not so distant from the puncture site. In 3 cases, the catheters were placed caudad beyond a vertebral segment, in 2 cases cephalad, in another 2 cases passed through the intervertebral foramen, and in the other case the position undetectable. However, in 24 of 31 cases, adequate analgesia was obtained by epidural block only. Hypotension during the operation was seen only in 4 cases. In 3 cases, the catheters were successfully placed caudad beyond a vertebral segment and the levels of analgesia 10 minutes after the injection were T11-T10 to S3-S5. In the anesthetic management of TUR-P, it is necessary to obtain complete analgesia in sacral segments and to avoid high thoracic epidural block. We concluded that this method was useful for the anesthetic management of TUR-P.

Aged↗

PubMed1994

[Anesthetic management of a patient with a cryptophthalmos syndactyly syndrome and subglottic stenosis].

We experienced five episodes of anesthesia for a girl with dryptophthalmos syndactyly syndrome and congenital subglottic stenosis from the age of 1.3 year to 4 years. A girl was born at 34 weeks of gestation. The birth weight was 1360 g. The Apgar score was 8 at one minute and there was a hoarseness. She had right cryptophthalmos, syndactyly of hands and left foot, left polydactyly, anomalies of ear and nose, and agenesis of right kidney. The operation was scheduled for syndactyly under general anesthesia when she was 17 days and 5 months. As intubation was unsuccessful in both occasions, the operation was cancelled and subglottic stenosis was pointed out. We decided to postpone the operation until she could cry fully without cyanosis. We evaluated her respiratory ability from the time she became able to cry fully without cyanosis. As a result, we could manage her without any complications such as hypoxia or hypercapnea except mild wheezing.

Abnormalities, Multiple↗

PubMed1993

[Anesthesia for severely burned patients--23 operations in 8 burned patients].

Severely burned patients require repeated debridement or skin grafting soon after the burn injury until the closure of the injury. We retrospectively examined 23 operations in 8 severely burned patients who had undergone debridement or skin grafting more than twice within 30 days. We classified 23 operations into 1st to 4th categories according to days after the burn injury and compared each group regarding intraoperative fluid balance, hypovolemia and perioperative complications. In the 3rd or 4th operation, mean blood loss and fluid administration were more than those of the 1st or 2nd operation. Respiratory dysfunctions or circulatory complications such as hypotension, oliguria occurred more frequently during or after the 3rd or 4th operation. Since patients are in hyperdynamic and hypercatabolic state at the time of the 3rd or 4th operation patients, they will be easily damaged in the peri-operative period. This study suggests that we should bear in mind, in the anesthetic management of burned patients, that they can be in hyperdynamic state as well as in shock state.

Adult↗

PubMed1993

[Electrophysiologic analysis of the lumbosacral radiculopathy using nerve root conduction velocity (NRCV) and cauda equina action potentials (CEAP)].

Nerve root conduction velocity (NRCV) and cauda equina action potential (CEAP) have been measured to assess the severity of lumbosacral radiculopathy, the level-specific diagnosis of the symptomatic roots, and to predict the outcome. This study included 71 patients (40 males, 31 females, average age of 54 years at the time of surgery) who underwent decompressive surgery for lumbar radiculopathy. The NRCV and CEAP were directly measured during the operation. The NRCV decreased significantly with progression of radicular symptoms. The NRCV showed a marked reduction in the nerve roots of the patients with a two years or longer history of radicular symptoms; or those with compression of the nerve roots on the imaging examinations; or nerve roots that were considered to have been subjected to persistent compression over a prolonged period with severe inflammation and adhesions. Multivariative analyses suggested that the NRCV correlated closely to the postoperative neurologic recovery, and the outcome of the lumbosacral radiculopathy could be predicted to some extent by measurements of NRCV. The level-specific diagnosis of the radiculopathy could be determined when the CEAP showed a more than 30% left-right potentials difference.

Action Potentials↗

PubMed1992

[Pneumothorax during laparoscopy].

A 28-year-old female was scheduled for laparoscopy under general anesthesia. Her history and physical examination were unremarkable. Trachea was intubated uneventfully following intravenous administration of thiopental 200 mg and vecuronium 8 mg. Anesthesia was maintained with 40% O2, 60% N2O and sevoflurane. Shortly after pneumoperitoneum was introduced, airway resistance increased and breathing sounds were hardly audible over the right side of the chest. A chest radiograph showed the right pneumothorax. Immediately after evacuating the peritoneal gas, the chest radiograph and a blood gas analysis showed that the pneumothorax had improved. Pneumothorax can occur subsequently to pneumoperitoneum due to passage of gas through weak points or defects in the diaphragm. Breathing sound should be monitored carefully during the laparoscopic surgery. Anesthetic gas analyzer and capnometer are considered to be useful to confirm the cause of the pneumothorax.

Adult↗

PubMed1991

[Anti-inflammatory effects of methylprednisolone aceponate in animals].

In the case of dermal application of the drugs to croton oil-induced ear edema in rats and picryl chloride-induced delayed type hypersensitivity in mice, the anti-inflammatory effect of methylprednisolone aceponate (MPA) was slightly weaker than those of clobetasol 17-propionate and diflucortolone 21-valerate, but stronger than those of hydrocortisone 17-butyrate and hydrocortisone 17-butyrate 21-propionate. Betamethasone 17-valerate applied dermally was less and more effective than MPA to ear edema in rats and delayed type hypersensitivity in mice, respectively. The anti-inflammatory effect of MPA was weaker in subcutaneous administration than in topical application to the two inflammatory models. It was suggested that MPA has strong anti-inflammatory effects and weak systemic effects by topical application. Methylprednisolone 17-propionate (MP-17P) and methylprednisolone (MP), unesterified in only the C-21 position and in both the C-17 and 21 positions of MPA, respectively, showed weaker anti-inflammatory activities than MPA by topical application to croton oil-induced ear edema. The ratio of the anti-inflammatory effects by topical application to subcutaneous administration of MPA was higher than those of MP-17P and MP. The excellent characteristics of MPA as a dermal anti-inflammatory drug are suggested to be derived from di-esterification of MP, which has a weak activity intrinsically.

Administration, Topical↗

PubMed1989

Purification and characterization of hen oviduct N alpha-acetyltransferase.

Hen oviduct N alpha-acetyltransferase was purified to homogeneity by ammonium sulfate fractionation and DEAE-cellulose, Sepharose 6B, hydroxylapatite, and CoA affinity chromatography. The molecular weights of the native N alpha-acetyltransferase and its protein subunit were estimated as 240,000 and 79,000, respectively. The purified enzyme exhibited a narrow pH optimum centered at 7.8. The enzyme was activated by dithiothreitol, cysteine, glutathione, and beta-mercaptoethanol, but inhibited by Fe2+, Mn2+, Zn2+, Ca2+, Mg2+, and all thiol-specific reagents tested. These findings suggest that a thiol group(s) is essential to the enzyme activity. Substrate specificity experiments of the purified enzyme revealed that (i) the minimal length of a peptide chain required for N alpha-acetylation is 10 residues, (ii) the amino acids, Ala, Ser, Met, and Gly, which are predominantly found in the N termini of N alpha-acetylated proteins, are not the sole determinant of N alpha-acetylation for 10 and more residue peptides, and (iii) N alpha-acetyltransferase recognizes a minute difference in the side chain structure at the N termini of ACTH1-18-NH2 and [Gly1]ACTH1-18-NH2, a productive and a nonproductive substrate, respectively.

Acetyltransferases↗