Biomedical subjects

K Kitaoka

Publications and source records attributed to K Kitaoka.

At least 19 recordsLinked to original sources

PubMed2005

Total hip arthroplasty with a sliding iliac graft for acetabular dysplasia.

We describe a new technique of reconstruction of the deficient acetabulum in cementless total hip arthroplasty. The outer iliac table just above the deficient acetabulum is osteotomised and slid downwards. We have termed this an iliac sliding graft. Between October 1997 and November 2001, cementless total hip arthroplasty with an iliac sliding graft was performed on 19 patients (19 hips) with acetabular dysplasia. The mean follow-up was 3.4 years (2 to 6). The mean pre-operative Harris hip score was 45.1 which improved significantly to 85.3 at the time of the final follow-up. No patient had post-operative abductor dysfunction. Incorporation of the graft was seen after two to three months in all patients. Resorption of the graft and radiolucencies were infrequent. This technique is a useful alternative to femoral head autografting when the patient's own femoral head cannot be used.

Acetabulum↗

PubMed2001

Focal eosinophilic myositis.

Idiopathic hypereosinophilic syndrome (HES) is a heterogeneous group of disorders with the common features of prolonged eosinophilia of underdetermined cause and multiple organ system dysfunction. Focal eosinophilic myositis is an uncommon manifestation of HES. We report a case of focal eosinophilic myositis with tender muscle swelling followed by proximal weakness, but without non-systemic symptoms and muscle trophism in the lower limbs. Muscle biopsy specimen showed acute myositis with eosinophil infiltration. Electromyographic features were typical of myositis. The clinical and biochemical response to corticosteroids was excellent, and a relapse that occurred because the steroid dose was not lowered, responded well.

Adult↗

PubMed2001

Histologic analysis of the tibial bone tunnel after anterior cruciate ligament reconstruction using solvent-dried and gamma-irradiated fascia lata allograft.

Anterior cruciate ligament (ACL) reconstruction using free tendon graft requires biologic fixation in the bone tunnel. This report describes the intratunnel histology retrieved from a 47-year-old woman who underwent high tibial osteotomy 17 months after ACL reconstruction using a hybrid graft (a solvent-dried and gamma-irradiated fascia lata allograft as a core wrapped with iliotibial autograft). The patient underwent revision because of pain resulting from osteoarthrotic change, and the graft appeared to be taut and healthy on second-look arthroscopy. The sample was taken from the site of the metaphyseal osteotomy site. Histologic examination of the samples was performed with a light microscope (H&E and Masson trichrome stain). Biologic fixation of the graft to the bone was evident from observation of collagen fiber continuities, resembling Sharpey fibers. Integration of the autograft and allograft seemed to have occurred; the junction between the allograft and the autograft could not be determined. However, there was a difference in ligamentization depending on location. In the peripheral region of the graft (the autograft region), the collagen fibers showed a distinct crimped pattern; the fibroblasts were arranged regularly along the major axis of the collagen fiber bundle. In the central part of the graft (the allograft region), remodeling seemed to be delayed. There were acellular, bubbly or myxoid degeneration areas in which the fiber bundles were less oriented and there was increased vascularity.

Anterior Cruciate Ligament↗

PubMed1998

Morphodifferentiation of skeletal muscle fiber ends at the myotendinous junction in the postnatal Chinese hamster: a scanning electron microscopic study.

The postnatal morphodifferentiation of muscle fiber ends at the myotendinous junction was examined by scanning electron microscopy in gastrocnemius muscles of the Chinese hamster. Muscle fiber ends during the first week were simply conical or slightly complex, having a few pit-like invaginations and longitudinal and narrow clefts. By the second week, fiber ends gradually became complicated with an increased number of clefts and finger-like processes. Pits and short clefts linearly arranged towards the fiber tip were visible until the second week. This possibly indicates the linear elongation of the clefts by the fusion of adjacent pits to one another and to preexisting clefts. By the fourth week, the fiber ends had almost fully matured and displayed numerous cytoplasmic processes and lateral grooves.

Animals↗

PubMed1997

Topographic comparison of subneural apparatuses at neuromuscular junctions in normal and dystrophic (mdx) mice: a scanning electron microscope study.

The differences in the morphodifferentiation of subneural apparatuses (SNAs) at neuromuscular junctions (NMJs) in the extensor digitorum longus muscle of normal and dystrophic (mdx) mice were examined by scanning electron microscopy. In normal mice, primitive shallow cup-like synaptic troughs present at birth had developed to anastomosing grooves containing both pit-like and slit-like junctional folds (JFs) during the 2nd postnatal week. At the 35th day, the SNAs had developed to almost the adult forms, consisting of labyrinthine synaptic grooves with exclusively slit-like JFs. In the mdx mice, the SNAs showed transformation similar to those in the normal mice until the 35th postnatal day. After this period, SNAs with a number of cup-like depressions occurred and increased in number. These morphological changes seemed to be found on regenerating muscle fibers after necrosis, probably indicating the remodelling of their NMJs.

Animals↗

PubMed1997

Massive autoclaved allografts and autografts for limb salvage surgery. A 1-8 year follow-up of 23 patients.

We performed 23 reconstructions with bone grafts autoclaved at 135 degrees C for 10 minutes for extensive bone defects after tumor resection. In 15 cases, the resected specimens were autoclaved and used as autografts. In 7 cases, allografts obtained from amputated extremities or cadavers were autoclaved and immediately stored at -80 degrees C prior to their use. A combination of the two was used in 1 case. The grafts were used in combination with prostheses or other forms of internal fixation. The mean follow-up was 49 (14-98) months. Incorporation of the hostgraft junction was observed radiographically after a mean of 11 (6-17) months in all cases. No recurrence due to the autoclaved bone was observed. However, 10 patients suffered complications, including infection, bone resorption, fracture and loosening of the prosthesis. In terms of Mankin's evaluation of bone grafts, 12 patients were evaluated as good or excellent. We conclude that despite the complications, autoclaved autografts and allografts are viable options for reconstruction in many countries because of the difficulty of obtaining large quantities of fresh frozen allografts.

Adolescent↗

PubMed1997

[The clinical efficacy of imipenem/cilastatin sodium in orthopedic infections and drug levels in the bone tissue].

We evaluated the clinical efficacy of imipenem/cilastatin sodium (IPM/CS--a carbapenem antibiotic) against orthopedic infections, and the drug levels of the bone tissues were determined. The clinical efficacies for 6 patients in the infection group were good in 3 cases, and fair in the other 3; giving an efficacy rate of 50%. Bacteriologically, 8 strains were isolated from patients with the infection and an eradication rate of 87.5% was obtained upon the treatment. In 39 patients that were given the drug prophylactically, no postoperative infections occurred. Mean IPM levels in the bone and the bone marrow at 1 hour after administration in 5 patients of the prophylactic group were 17.3 micrograms/ml and 5.9 micrograms/g, respectively. The ratio of concentrations the bone to those in the bone marrow was 34.6%. The results of this study suggest that IMP/CS reaches to the bone tissue providing sufficient concentrations and that the drug is efficacious for the prophylaxis and the treatment of orthopedic infections.

Adolescent↗

PubMed1995

[A case of rheumatoid arthritis associated with pernicious anemia and bronchiolitis obliterans organizing pneumonia].

A case of rheumateid arthritis (RA) with pernicious anemia (PA) and wandering multiple patchy densities in bilateral lung fields is reported. A 72-year-old woman was hospitalized in February 1994, because of cough. She had already advanced RA (Class IV, Stage IV). She showed macrocytic and hyperchromic anemia as follows ; red-cell count (RBC), 176 x 10(4)/microliters; hemoglobin (Hb),7.2 g/dl; hematocrit (Ht), 21.0% ; MCV, 119.3 fl; and MCH, 40.9 pg. Chest roentgenogram revealed multiple patchy densities in bilateral lung fields and there was no response to the administration of antibiotic agents. From these clinical pictures bronchiolitis obliterans organizing pneumonia (BOOP) was highly suspected. After steroid injection into the joint space, the abnormal lung shadows disappeared. Anemia had been recovering spontaneously, but recurred in July. The results of blood examination were as follows ; RBC, 162 x 10(4)/microliters; Hb, 6.7ng/dl; Ht, 19.1%; MCV, 117.9 fl; and MCH, 41.4 pg. Anti-intrinsic factor antibody was positive. The level of serum vitamin B12 was low, 76 pg/ml. Sternal bone marrow aspiration showed magaloblastic changes with hypersegmentation of granulocytes. PA was diagnosed and improvement was noted after the intramuscular administration of vitamin B12. Subjective symptoms based on RA did not change during the clinical course. It is suggested that the pathogenesis about the combination of RA, BOOP and PA is related to common immunological abnormalities in our patient. A case of RA with PA and BOOP has not been reported previously, thus this case is considered clinically valuable.

Aged↗

PubMed1994

Bioabsorbable osteosynthetic implants of ultra high strength poly-L-lactide. A clinical study.

We have developed reasonably strong but bioabsorbable osteosynthetic screws, pins and nails made of ultra high strength poly-L-lactide (PLLA) and evaluated their use in 143 patients. The PLLA implants have the highest strength among those reported to date. They lose about 10% of their initial strength within 8 weeks, about 40% within 4 weeks and nearly 100% within 20 weeks in vivo. The patients were aged from 9 to 78 years, and the follow up was from 2 to 6 years. The implants were used for fixation of bone grafts in 84 patients, peri- and intra-articular fractures in 49, after osteotomy in 8, and in 2 others. Bony union was not achieved in only one case. In the early stages of the study, breakage of screws occurred in 12 cases (8%), mostly because of an inappropriate size of tap; these problems have not occurred after improvement of the tapping system. There were no cases with abnormal blood tests, infection or foreign body reaction.

Adolescent↗

PubMed1992

The role of limbic-hypothalamic systems in metabolic responses of phenylalanine to repeated cold exposures in rabbits.

In this study we examine the effects of lesions to limbic or hypothalamic structures on the metabolic responses of phenylalanine in liver slices prepared from rabbits exposed to cold stress (-20 degrees C) for 12 hours at a fixed time once a day. The results were as follows: 1. The 1st cold exposure (cold exposure on the 1st day) had marked and various effects on phenylalanine metabolism, and the metabolic responses of phenylalanine to cold exposure gradually decreased and then completely disappeared with repetitions of exposure in intact rabbits. 2. The metabolic patterns and responses of phenylalanine to the 1st cold exposure were altered by lesioning the periventricular arcuate nucleus (ARC), ventromedial hypothalamus (VMH), stria terminalis (ST) or dorsal fornix (FX). 3. The complete abolishment of the metabolic responses to cold exposure by its repetition was observed in rabbits with lesions in the ARC or VMH as well. 4. In contrast, metabolic responses of phenylalanine to cold exposure in rabbits with lesions in the ST or FX remained even after six exposures. These results suggest that the ARC, VMH, amygdala (AMYG)-ST system and dorsal hippocampus (HPC)-FX system played a role in the metabolic regulation of phenylalanine and in the metabolic responses of phenylalanine to the 1st cold exposure and that the AMYG-ST and HPC-FX systems, but not the ARC or VMH, participated in the process of the metabolic adaptation of phenylalanine to cold exposure.

Amygdala↗

PubMed1992

[Multiple cerebral infarction by blood-borne tumor emboli in carcinoma of the mid-pharynx: an autopsy case].

In May, 1989, a-54-year old man was admitted complaining of sore throat and tumor of the neck which had persisted for 2 months. Mid-pharyngeal tumor was diagnosed as poorly differentiated squamous cell carcinoma (stage, T3N2M0) and the patient was treated with radiation (Co 65Gy) from May 30 to July 24 and chemotherapy (UFT), which therapies were effective. On Aug. 16, sudden onset of consciousness disturbance and hemiparesis was revealed, and MRI showed small cerebral infarction. He died on Oct. 23, of pneumonia. Pathological diagnosis revealed a case of carcinoma of the mid-pharynx with wide-spread tumor embolism. Multiple cerebral and myocardial infarctions, thrombus in pulmonary arteries and congestion of kidneys with tumor emboli, due to "disseminated intravascular carcinomatosis" were noticed. A direct cause of death was dyspnea due to multiple lung metastases, pneumonia and tumor embolism in the pulmonary and coronary arteries.

Brain Neoplasms↗

PubMed1992

[Intraoperative monitoring of facial electromyographic responses during neurovascular decompressive surgery for hemifacial spasm].

UNLABELLED: In this paper, we reported our experience of intraoperative facial electromyographic recordings obtained during microvascular decompression for hemifacial spasm. MATERIALS AND METHODS: Intraoperative electromyographic recordings from the mentalis muscle during stimulation of the temporal branch of the facial nerve has been attempted in 31 patients. No muscle relaxants were used except for those before intubation. Of 31 patients, 22 were female and 9 were male. The age on admission ranged from 31 to 60 years with a mean of 54 years. RESULTS: 1. Abnormal response appeared with a latency of about 10 msec after stimulation. This response disappeared in 30 out of 31 patients at the end of operation. In 4 patients, the abnormal response disappeared prior to decompression of the nerve. 2. 30 patients in whom the abnormal response disappeared were free of spasm immediately after surgery. Hemifacial spasm has been relieved in 28 patients with a follow up period of 6 months to 2 years and 7 months. The remaining two patients had mild spasm. The one patient in whom the abnormal response did not disappear had persistent hemifacial spasm. CONCLUSION: The authors think that intraoperative facial electromyographic recording is useful to identify the blood vessel that is causing the spasm and to ensure that decompression of the nerve has been accomplished.

Adult↗

PubMed1990

Scanning electron microscope study of neuromuscular junctions in different muscle fiber types in the zebra finch and rat.

Examination by scanning electron microscopy revealed differences between neuromuscular junctions in the muscle fibers of the zebra finch (bird) and rat. The neuromuscular junctions between the anterior and posterior latissimus dorsi muscles of the zebra finch were compared. The junctions of the former, exclusively slow tonic fibers, were small and numerous along the long axis of a single muscle fiber. The synaptic depressions per junction were few. The junctions of the latter, exclusively fast twitch fibers, were large and consisted of more synaptic depressions than the former. Junctional folds were occasionally found in some depressions. The neuromuscular junctions between the extensor digitorum longus and soleus muscles of the rat were also compared. The former consisted almost entirely of fast twitch muscle fibers, whereas the latter consisted of both slow twitch fibers (75%) and fast twitch fibers (25%). The junctions in the extensor digitorum longus muscle were almost all labyrinthine gutters containing exclusively slit-like junctional folds. In the soleus muscle, two types of junctions were observed. One type was similar to that of the extensor digitorum longus muscle; the other was characterized by labyrinthine gutters containing sparse, narrow slit-like and pit-like junctional folds. We suggest from these structural differences of the subneural apparatuses that the junction of the fast twitch muscle is characterized by the subneural apparatus containing numerous slit-like junctional folds, and that of the slow twitch muscle fiber characterized by the apparatus containing sparse, narrow slit-like and pit-like junctional folds.

Animals↗

PubMed1990

Follow-up study on metastatic cerebellar tumor surgery--characteristic problems of surgical treatment.

Recently, the incidence of metastatic cerebellar tumors has increased. The authors operated on 12 cases of metastatic cerebellar tumors, with total or subtotal removal of nodules in brain metastases. Surgical complications observed as a result of postoperative investigation are presented. 1) Some cases developed carcinomatous meningitis within a short period. During removal of a tumor on the superior cerebellar surface attention should be paid to the prevention of dissemination to the cerebral cisterns adjacent to the tumor. 2) Some cases demonstrated peritoneal metastasis probably due to dissemination via the ventriculoperitoneal shunt tube, suggesting that great care should be taken during a shunt operation after removal. 3) Both carcinomatous meningitis occurring after removal and remote metastasis via the shunt tube were related to recurrence after removal of the cerebellar metastatic lesion, raising the issue of whether or not total macroscopic removal should be included in the indications for surgical treatment of cerebellar metastasis. Those cases in which surgery is indicated should also be routinely treated by postoperative irradiation.

Aged↗

PubMed1990

Clinicopathological study of multiple gliomas--report of three cases.

Three cases of multiple gliomas with postmortem findings including a rare case of multicentric glioma are presented. A 59-year-old female was hospitalized with decreased mental activity and gait disturbance. Computed tomographic (CT) scans and magnetic resonance (MR) images showed two independent mass lesions in the left frontal and the right temporal lobes, shown by postmortem to have no communication. Histologically, they were a gemistocytic astrocytoma and an anaplastic astrocytoma, respectively. Therefore, multicentric glioma was diagnosed. A 66-year-old male was admitted with slow mentation and gait disturbance. CT scans and MR images demonstrated two mass lesions; one overriding the bilateral frontal lobes through the corpus callosum and the other in the left temporal lobe. Postmortem examination showed that both lesions were glioblastoma and the left temporal tumor was accompanied by subarachnoid dissemination. A 29-year-old male was hospitalized with gustatory hallucination and convulsions of the right upper extremity. CT scans revealed two mass lesions in the right frontal and the left temporal lobes. MR images demonstrated communication between the two lesions through the corpus callosum. The left temporal tumor developed into the occipital lobe and another new lesion appeared in the right temporal lobe despite chemotherapy and irradiation. Postmortem examination revealed communication between the three masses through the corpus callosum. Histologically, all three tumors were glioblastoma. Multicentric gliomas have been reported at various incidences from 2.3 to 9.1%. However, multicentric gliomas with multiple tumors of different histologies are very rare and only 16 cases have been reported. MR imaging is more valuable than CT scanning to detect communication between two or more lesions.

Aged↗

PubMed1989

Avian spinal cord chimeras. Further studies on the neurological syndrome affecting the chimeras after birth.

These experiments bring new information concerning the immunological status after birth of quail----chick spinal cord chimeras. Such birds have been produced using recipient flocks of chickens different from those in our previous experiments. The breakdown of tolerance after hatching has been recorded and found to vary with the origin of the embryos. Chickens of broiler JA 657 strain and of a white leghorn strain raised in Japan started to exhibit signs of neural graft rejection later in life than the white leghorn chickens from a French breeder used in our previous studies. As previously described, in two animals, long-term tolerance was observed only for allogeneic chick----chick neural tube grafts. In one chimera the neurological syndrome resulting from rejection was reversible, and no signs of immune attack of the grafted central nervous tissue could be detected at sacrifice. This and other observations reported in this article strongly support the contention that the host immune response to foreign neural tissues starts in peripheral nerves and ganglia where no blood-brain barrier exists rather than in the spinal cord. A humoral response of the host against non-polymorphic quail antigens present on fibroblasts was observed in all birds at the time of rejection.

Animals↗

PubMed1989

Influence of microinjection of glucagon into the amygdala on hepatic acetate metabolism in rabbits.

Glucagon was injected directly into the medial amygdala (AMYG) of rabbits, and changes in hepatic acetate metabolism were studied. The injection of 3 ng glucagon into the AMYG of intact rabbits increased the rates of 14C transfer from 14C-1-acetate into CO2, glucose, ketone bodies, cholesterol ester, free fatty acids and phospholipids but decreased those of 14C transfer into triglyceride. However, the glucagon injection into the AMYG of rabbits with lesions of stria terminals or into the parietal cortex of intact rabbits had no effects on the hepatic acetate metabolism. These observations support the hypothesis that the AMYG is a part of the glucagon-sensitive brain regulator system in the hepatic acetate metabolism.

Acetates↗

PubMed1989

[Evaluation of recurrent metastatic brain tumor of lung cancer origin].

The authors examined numerous clinical features in 15 patients in whom brain metastases from lung cancer recurred after total or subtotal removal. The incidence of recurrence after initial removal of brain nodules was 46.9% (15 of 32 cases). There was no significant correlation between the incidence of recurrence and the histology of the lung cancer, the site of brain nodules, or age. Recurrent brain nodules were the cause of or contributed to death in 60% of recurrent cases. Recurrence was within 3 months of initial removal of brain nodules in 10 of the 15 patients. Brain metastasis recurred only at the initial site in 11 cases (73.3%). Three patients developed carcinomatous meningitis and one had multiple metastases in addition to recurrence or regrowth at the original site. The primary lung cancer was relatively stable at the time of recurrence of brain nodules in 60% of the patients. Tumor removal and radiotherapy are highly recommended for prevention of early recurrence following initial removal of brain metastases. Removal of metastatic tumor is advised in the event of recurrence after 1 year from initial surgery, since the outcome after second surgery tends to be fair. However, tumor removal and radiotherapy are sometimes capable of inducing recurrence of brain nodules. Therefore, it is hoped that more effective cancer chemotherapy will be developed in the near future.

Adenocarcinoma↗