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Biomedical subjects

K Shingu

Publications and source records attributed to K Shingu.

At least 73 records · Page 4Linked to original sources

Microcapsulated parathyroid tissue in vitro.

Ideally, microcapsules will make it possible to transplant parathyroid tissue for allo- and xenotransplantation in hypoparathyroid patients. In this study, parathyroid tissues capsulated by polyelectrolyte complex were evaluated in vitro. Hormone secretion ability was significantly (P < 0.001) greater in sediment than in supernatant. There was no difference in hormone secretion ability between the parathyroid tissue thawed at room temperature and the tissue thawed in a bath at 37 degrees C. Both non-capsulated and capsulated parathyroid tissues were incubated for three weeks. The ability of capsulated parathyroid to secrete hormones in vitro was reduced gradually and disappeared within three weeks. There are still several problems to be solved before the clinical application of parathyroid allotransplantation using microcapsulation.

Cryopreservation↗

Ease of tracheal intubation through the intubating laryngeal mask during manual in-line head and neck stabilisation.

We studied 40 anaesthetised and paralysed patients, in a randomised manner, to compare the ease of tracheal intubation either using a Macintosh laryngoscope and gum elastic bougie (group C) with the ease of tracheal intubation through the intubating laryngeal mask using a fibreoptic bronchoscope (group L), during manual in-line stabilisation of the patient's head and neck. In both groups, a maximum of 120 s was allowed for attempts at tracheal intubation. The ease of placement of the intubating laryngeal mask or tracheal intubation was assessed using a 100-mm visual analogue scale (VAS). In patients in whom tracheal intubation succeeded, time for intubation was measured. The intubating laryngeal mask was placed successfully in 19 of 20 patients, with the median VAS of 18 mm (95% CI: 13-32 mm). The success rate of tracheal intubation in group L (17 patients) was significantly higher than in group C (nine patients) (p < 0.01), tracheal intubation in group L was significantly easier than intubation in group C (p < 0.001; 95% CI for difference in VAS: 18-68 mm) and time taken for tracheal intubation was significantly shorter in group L than in group C (95% CI for difference: 8-50 s).

Adult↗

Efficacy of the laryngeal tube during intermittent positive-pressure ventilation.

We studied the efficacy of the laryngeal tube (VBM, Germany) during intermittent positive-pressure ventilation in 50 patients. After induction of anaesthesia and neuromuscular blockade, a size 4 laryngeal tube was inserted for patients of height 155 cm or greater. After insertion of the laryngeal tube, its pharyngeal and oesophageal balloons were inflated to an intracuff pressure of 60 cmH(2)O. An Ambu self-inflating bag was attached to the laryngeal tube and the lungs were ventilated manually at 15 breath.min(-1). It was possible to ventilate the lungs at the first attempt in 47 patients (94%). The airway pressure at which air leaked around the laryngeal tube exceeded 18 cmH(2)O in 41 patients (82%), and was > 30 cmH(2)O in 25 (50%). Median [interquartile range (range)] leak pressure was 30 [20-30 (6 to > 30)] cmH(2)O. Median [interquartile range (range)] tidal volume was 587 [533-653 (133-800)] ml or 8.8 [8.2-10.6 (1.9-12.6)] ml.kg(-1). We conclude that the laryngeal tube has a potential role in airway management during intermittent positive-pressure ventilation for anaesthesia or cardiopulmonary resuscitation.

Adult↗

Clinicopathological characteristics of atypical cystic duct (ACD) of the breast: assessment of ACD as a precancerous lesion.

To clarify the clinicopathological features of an atypical cystic duct (ACD) as defined by Tsuchiya's criteria as a precancerous lesion of the breast, we used 200 whole mammary gland serial sections of breast cancer. Forty-four (22%) of the 200 breast cancer patients had ACD breast lesions. The frequency of patients with ACD increased in premenopausal women (P = 0.001). There was no correlation between the ACD-present group and the ACD-absent group for immunohistochemical status of the estrogen receptor (ER), progesterone receptor (PgR), p53, or c-erbB2; Ki-67 labeling index of cancer tissues; size of tumor, or lymph node metastases. A number of ACD lesions displayed continuity to cancer lesions. In 500 serial sections of a paraffin-embedded tissue of a ACD case at 3 microm intervals, an apparent transition from ACD into ductal carcinoma in situ was observed. Immunohistochemical analysis using alpha-smooth muscle actin showed that myoepithelial cells of ACD stained strongly, and their nuclei and cytoplasm were thinning. In 16 of the 44 (36%) ACD-present patients, carcinoma cells stained positive for p53. Within those 16 cases, 12 cases (75%) were positive for p53 in ACD lesions. There was a significant correlation between the expression of p53 protein in malignant cells and ACD (P = 0.001). All 44 ACD lesions had no staining of c-erbB2, regardless of staining in malignant lesions. The mean Ki-67 labeling index of ACD lesions was low (0.3%), suggesting that ACD had a low proliferative rate. We suggest that ACD is the precancerous breast lesion because of a histologic continuum between ACD and malignancy, and because of p53 protein expression in ACD.

Adult↗

Increased chromatid-type chromosomal aberrations in mouse m5S cells exposed to power-line frequency magnetic fields.

PURPOSE: To investigate the induction of chromosomal aberrations in mouse m5S cells after exposure to power-line frequency magnetic fields (extremely low frequency magnetic fields; ELFMF) at high-flux densities. MATERIAL AND METHOD: m5S cells were either untreated or pretreated during the G1 phase with mitomycin C (MMC, 1 microM) for 1 h or 3 Gy X-rays, and then exposed to ELFMF at three different flux densities (5 and 50 mT at 60 Hz, 400 mT at 50 Hz) for 40 h. Unexposed control cells were incubated for the same period in a conventional CO2 incubator. Chromosomal aberrations were analysed in the first post-treatment metaphases. Cell kinetics were assessed by DNA flow cytometry and the mitotic index. RESULTS AND CONCLUSIONS: ELFMF enhanced the formation of spontaneous and MMC- or X-ray-induced chromosomal aberrations, in a flux-density-dependent manner. Statistically significant increases in the frequency of chromosomal aberrations were observed in cells exposed to 400 mT ELFMF with respect to unexposed controls. The aberrations induced by ELFMF were mostly chromatid-type, not chromosome-type. The cells exposed to 400 mT ELFMF exhibited a three-fold higher level of chromatid-type aberrations than did the unexposed cells. Flow cytometric and mitotic index analyses revealed that the S or G2 arrest following MMC or X-irradiation was more profound in ELFMF-exposed cells than in unexposed cells. Our results suggest that ELFMF can interfere with post-replication repair, resulting in increased levels of chromatid-type chromosomal aberrations induced spontaneously and by DNA damaging agents.

Animals↗

Clinical recurrence of papillary thyroid cancer in the remnant lobe.

OBJECTIVE: To find out which factors predict recurrence of cancer in the remnant after unilateral thyroid lobectomy for patients with papillary cancer. DESIGN: Retrospective study. SETTING: Teaching hospital, Japan. SUBJECTS: One hundred thirty-three patients with a clinically solitary papillary thyroid cancer who had unilateral lobectomy for the primary disease between 1966 and 1990 and were followed up for more than 60 months. Twelve patients had developed recurrences in the remnant gland by the time of the second operation and 121 patients had not as judged by a second operation, an ultrasound examination, or by palpation. RESULT: The primary tumour size in those who developed recurrences was significantly larger than in those who did not (p < 0.0001), and clinical signs of regional lymph node involvement or distant metastases were also significantly more common (p = 0.006). No patient died of their cancer. CONCLUSION: Size of the primary tumour is an important prognostic factor for recurrence of solitary papillary thyroid cancer in the remnant after unilateral lobectomy. Such recurrences are unlikely to be lethal.

Adolescent↗

Cricoid pressure applied after placement of laryngeal mask impedes subsequent fibreoptic tracheal intubation through mask.

We studied 70 patients to see if cricoid pressure applied after insertion of the laryngeal mask altered the success rate of tracheal intubation through the mask. After induction of anaesthesia and neuromuscular blockade, patients were randomly allocated to have either cricoid pressure (Group C) or sham pressure (Group S). The view of the glottis through the laryngeal mask was assessed before and after the test pressure, and tracheal intubation through the mask was attempted using a fibreoptic bronchoscope. The test pressure did not alter the view of the glottis in any patient in group S, whereas it narrowed the glottic aperture in 16 out of 35 patients in group C. The fibrescope was inserted into the trachea in all patients in group S and in 25 patients in group C. The success rate of tracheal intubation in group S (31 patients) was significantly higher than in group C (21 patients, P << 0.001; 95% CI for difference: 9-48%). The time for insertion of the fibrescope in group S (median (95% CI): 12 (11-12) s) was significantly faster than in group C (16 (14-17) s, P << 0.001; 95% CI for difference: 3-6 s), and the time for tracheal intubation in group S (16 (15-18) s) was significantly faster than in group C (22 (19-24) s, P < 0.0005; 95% CI for difference: 3-7 s). Cricoid pressure after insertion of the laryngeal mask makes tracheal intubation through the mask significantly more difficult.

Adolescent↗

Pre-operative oral erythromycin reduces residual gastric volume and acidity.

We investigated whether low-dose erythromycin (200 mg) given as an oral premedicant altered the residual gastric volume and its acidity in fasted patients at induction of anaesthesia in a single-blinded study. Sixty patients were allocated randomly to receive either an erythromycin tablet (200 mg) or nothing with 10 ml water 3 h before induction of anaesthesia, and another 60 patients 1 h before induction of anaesthesia. Oral erythromycin significantly reduced residual gastric volume when it was given approximately 3 h (P<0.05; 95% CI for median difference: 0.1-17 ml) or 1 h (P<0.0005; 95% CI for median difference: 6-24 ml) before induction of anaesthesia. Erythromycin significantly reduced gastric acidity when it was given 1 h before induction of anaesthesia (P<0.02; 95% CI for median pH difference: 0.1-1.7). In contrast, when given 3 h before induction of anaesthesia, erythromycin did not significantly alter acidity.

Adult↗

The anticonvulsant effects of volatile anesthetics on penicillin-induced status epilepticus in cats.

UNLABELLED: Volatile anesthetics may be used to treat status epilepticus when conventional drugs are ineffective. We studied 30 cats to compare the inhibitory effects of sevoflurane, isoflurane, and halothane on penicillin-induced status epilepticus. Anesthesia was induced and maintained with one of the three volatile anesthetics in oxygen. Penicillin G was injected into the cisterna magna, and the volatile anesthetic discontinued. Once status epilepticus was induced (convulsive period), the animal was reanesthetized with 0.6 minimum alveolar anesthetic concentration (MAC) of the volatile anesthetic for 30 min, then with 1.5 MAC for the next 30 min. Electroencephalogram and multiunit activity in the midbrain reticular formation were recorded. At 0.6 MAC, all anesthetics showed anticonvulsant effects. Isoflurane and halothane each abolished the repetitive spike phase in one cat; isoflurane reduced the occupancy of the repetitive spike phase (to 27%+/-22% of the convulsive period (mean +/- SD) significantly more than sevoflurane (60%+/-29%; P < 0.05) and halothane (61%+/-24%; P < 0.05), and the increase of midbrain reticular formation with repetitive spikes was reduced by all volatile anesthetics. The repetitive spikes were abolished by 1.5 MAC of the anesthetics: in 9 of 10 cats by sevoflurane, in 9 of 9 cats by isoflurane, and in 9 of 11 cats by halothane. In conclusion, isoflurane, sevoflurane, and halothane inhibited penicillin-induced status epilepticus, but isoflurane was the most potent. IMPLICATIONS: Convulsive status epilepticus is an emergency state and requires immediate suppression of clinical and electrical seizures, but conventional drugs may be ineffective. In such cases, general anesthesia may be effective. In the present study, we suggest that isoflurane is preferable to halothane and sevoflurane to suppress sustained seizure.

Anesthetics, Inhalation↗

The anticonvulsant effects of volatile anesthetics on lidocaine-induced seizures in cats.

UNLABELLED: Large concentrations of sevoflurane and isoflurane, but not halothane, induce spikes in the electroencephalogram. To elucidate whether these proconvulsant effects affect lidocaine-induced seizures, we compared the effects of sevoflurane, isoflurane, and halothane in cats. Fifty animals were allocated to 1 of 10 groups: 70% nitrous oxide (N2O), 0.6 minimum alveolar anesthetic concentration (MAC) + 70% N2O, 1.5 MAC + 70% N2O, and 1.5 MAC of each volatile agent in oxygen. Lidocaine 4 mg x kg(-1) x min(-1) was infused IV under mechanical ventilation with muscle relaxation. Electroencephalogram in the cortex, amygdala, and hippocampus and multiunit activities in the midbrain reticular formation (R-MUA) were recorded. Lidocaine induced spikes first from the amygdala or hippocampus in the 70% N2O and halothane groups and from the cortex in the sevoflurane and isoflurane groups. Lidocaine induced seizures in all cats in the 70% N2O and 0.6 MAC + N2O groups. Seizure occurrence was reduced in the 1.5 MAC + N2O group (P < 0.05 versus 70% N2O). The onset of seizure was delayed in the 0.6 MAC + N2O and 1.5 MAC groups for sevoflurane and isoflurane, but not for halothane, compared with the 70% N2O group (P < 0.05). Lidocaine increased R-MUA with seizure by 130%+/-56% in the 70% N2O group. The increase of R-MUA with seizure was more suppressed in the volatile anesthetic groups than in the 70% N2O group (P < 0.05). In the present study, sevoflurane and isoflurane attenuated seizure when the blood lidocaine concentration was accidentally increased. IMPLICATIONS: Increasingly, epidural blockade is combined with general anesthesia to achieve stress-free anesthesia and continuous pain relief in the postoperative period. In the present study, sevoflurane and isoflurane attenuated seizure when the blood lidocaine concentration was accidentally increased.

Anesthetics, Inhalation↗