Biomedical subjects

T Iinuma

Publications and source records attributed to T Iinuma.

At least 19 recordsLinked to original sources

PubMed1992

[Preliminary specification of X-ray CT for lung cancer screening (LSCT) and its evaluation on risk-cost-effectiveness].

In Japan mass screening for lung cancer is widely performed by chest X-ray film of 10 x 10 cm, with sputum cytology for high-risk groups. However, the effectiveness of the present mass screening program for lung cancer has been less than expected, although some date have shown improvement of the survival rate as a result of mass screening. We propose a new X-ray CT method of screening for lung cancer called Lung Cancer Screening CT (LSCT). The preliminary specifications for LSCT are as follows: scan speed is within 10 sec for a 40 cm length with a 1 cm slice thickness, and the absorption dose for lung is less than 1 cGy. A computer-assisted diagnostic system is necessary for image reading. The risk-benefit analysis of LSCT indicates that Japanese men and women over 45 years old can be screened in 1992 and thereafter. The cost per person.year of LSCT screening is estimated to be 1.4 x 10(6) yen for a population incidence rate of 50 x 10(-5) person/year and average life expectancy of 30 years. In 1992 the above condition will be satisfied by men aged 55 years old and above, but not by women of any age. We believe that LSCT should be developed further and tested in the high-risk group of men with an incidence rate of 100 x 10(-5) persons/year or more.

Adult↗

PubMed1992

Comparative sequence analysis and expression of bovine PrP gene in mouse L-929 cells.

A cDNA clone encoding bovine scrapie-associated fibril protein, PrP, from a bovine brain cDNA library and six amplified genomic DNA clones of bovine PrP were characterized. These clones possessed specific characteristics observed in other animal PrP genes. However, the bovine PrP was divided into two types by the number of repeats. One possessed four octapeptide repetitive sequences, like other animal PrP genes, and consisted of 256 amino acids; the other had five such repetitive sequences and 264 amino acids. The amino acid sequence of the former bovine PrP agreed with that of sheep PrP up to the 165th amino acid from the N-terminus. Bovine PrP cDNA introduced into mouse L-929 cells were stably expressed. The expression level of recombinant bovine PrP in the cells judged by immunofluorescence was higher than that of authentic mouse PrP. The recombinant PrP comigrated with authentic bovine PrP in SDS-polyacrylamide gel electrophoresis, suggesting that the recombinant product was fully glycosylated in L-929 cells. Distinct bundles of the intermediate filaments were frequently seen at the perinuclear region of the cells.

Amino Acid Sequence↗

PubMed1992

[Ventilation and passages in the middle ear. A study by HRCT in patients with attic cholesteatoma].

Operative records of 75 patients with acquired attic cholesteatoma were evaluated and compared with preoperative HRCT findings. The cholesteatoma extensions were classified into five groups as follows; Group 1 (cholesteatoma limited to the attic, 9 cases), Group 2 (cholesteatoma occupying both the attic and the aditus, 5 cases), Group 3 (cholesteatoma extending down to the posterior tympanum, also occupying an area as in Group 2, 6 cases), Group 4 (cholesteatoma occupying the attic, the aditus and the mastoid antrum, 14 cases), and Group 5 (cholesteatoma extending down to the posterior tympanum, also occupying an area as in Group 4, 41 cases). Ventilatory conditions, or the existence of soft tissue density, were evaluated by HRCT at such locations as the supratubal recess, mesotympanum, anterior and posterior parts of the tympanic isthmus, epitympanum, and mastoid antrum. Results are as follows. In Group 1, all these locations were aerated with the exception of a few cases. In Group 2, complete opacification was observed in almost all of the antrums. Soft tissue masses involved the anterior and/or posterior parts of the tympanic isthmus in both Groups 3 and 5. In Group 3, the posterior part of tympanic isthmus was less aerated than the anterior part of tympanic isthmus. In Group 5, all locations were filled with soft tissue density except the supratubal recess and the mesotympanum, where some degree of aeration was observed. These results indicate that blockage of the ventilatory passages is not essential for formation of an attic cholesteatoma. Soft tissue density in HRCT is not the cause, but rather, the result of extension of a cholesteatoma.

Adolescent↗

PubMed1992

[The effect of endothelin on neurotransmitter regulation of vascular tension in the nasal mucosa].

A number of studies have emphasized that the sympathetic nervous system in vascular smooth muscle plays an important role in the regulation of vascular tension. Recently, however, it has been suggested that several factors produced in endothelial cells may affect this regulatory mechanism. We have previously reported that endothelin-1 (ET), a novel potent endothelium-derived vasoconstrictor peptide, increased the contraction of nasal vascular smooth muscle which was caused by administration of noradrenaline (NA) into the bath solution. In this report, using canine nasal mucosa, we studied for additional effects of ET upon the vasoactivity of NA, and that of neuropeptide Y (NPY), which coexists with NA in the sympathetic nerve terminal. The results are as follows: 1) Pretreatment with alpha-adrenoceptor antagonists did not affect the vasoconstriction induced by ET. 2) With simultaneous administration of 10(-5)M NA and 10(-9)ET, the contraction peak was maintained for at least 2.5 hours. 3) Pretreatment with 10(-10)M ET did not affect the contraction induced by 2.7 x 10(-7)M NPY. 4) Pretreatment with 2.7 x 10(-8)M NPY did not affect the contraction induced by 10(-8)M ET. These results suggest that ET may enhance and prolong the vasocontractile response mediated by alpha-adrenoceptors, but may not affect the response to NPY.

Animals↗

PubMed1992

[Surgical anatomy of the sphenoid sinus--development and intersinus septum].

High-resolution CT images in axial sections obtained from various otologic lesions were used for morphological studies of the sphenoid sinus. 412 subjects, 224 males and 188 females with an average age of 47.5 years, were included in the study. None of the subjects showed any evidence of sinus lesions. By classifying them into four types, the incidences were: conchal type, 1.2%, and postsellar type, 58.2%, respectively. Of surgically important classification of various septae, the incidences were: transverse, 10.9%, medial, 9.4%, frontal lateral, 14.1%, lateral sagittal, 41.5%, and intersinus, 95.1%, respectively. The intersinus septum, seen in 95.1%, pointed toward the carotid canal in 61.1% (right, 33.1; left, 28.0%). In 80% of the subjects, the sphenoid sinus had extended into the bilateral lesser wings and was in contact with the optic canal.

Adult↗

PubMed1992

[Surgical anatomy of the sphenoid sinus--relationship to the internal carotid artery].

HRCT images in axial sections obtained from various otologic lesions were used for morphological studies of the sphenoid sinus. 412 cases including 224 males and 188 females, with an average age of 47.5 years were included in the study. None of the cases showed any evidence of sinus lesions. The internal carotid artery, at its close connection with the sphenoid sinus, was classified into five portions: I, the second turn; II, between the second and third turns; III, the third turn, IV, between the third and fourth turns, and V, ascending portion of the fourth turn. Protrusion into the sphenoid sinus was seen at I in 30.4% of the cases, at II in 39.8%, at III in 34.3%, at IV in 22.3%, and at V in 11.2%. The second turn, where the internal carotid artery emerges from the carotid canal in the petrous bone and turns upward into the cavernous sinus, showed the highest incidence of the carotid eminence. The incidence of protrusion increases as the sinus grows larger. The average distance between the natural orifice and the carotid canal was 19.3mm on the right and 18.9mm on the left. The distance between the posterior end of the nasal septum and the natural orifice was, on average, 3.6mm on the right and 3.6mm on the left.

Adult↗

PubMed1992

[Comparison of CT and MRI in diagnosis of parapharyngeal tumors].

Recently, the usefulness of CT and MRI in diagnosing parapharyngeal tumors has been established. At the same time, several modalities for these imagings, i.e. plane and enhanced CT, T1, 2 weighted MRI and Gadolinium enhanced MRI, have been developed. We compared the image findings of 12 tumors involving the parapharyngeal space with their operative records. T1 was most suited to diagnosing the sites of origins of tumors because of its superior depiction of the internal carotid artery and parapharyngeal fat. Enhanced CT was also superior in depicting these structures, but in cases where the parapharyngeal fat was diminished, or the parapharyngeal fat had been invaded by malignant tumor, enhanced CT was inferior to T1. The spatial resolution of T2 was poor, T2 was thus not useful in diagnosing the sites of origins of tumors. Because tumor intensity tended to be similar to that of fat in Gadolinium enhanced MRI imaging, Gadolinium was not as useful as T1. In diagnosing the extents of tumors, we examined the depiction of both tumor-fat and tumor-muscle interfaces. With regard to the depiction of the tumor-fat interface, enhanced CT and T1 were most useful. In diagnosing the tumor-muscle interface, Gadolinium enhanced MRI was most suitable. The net result is that MRI is superior to CT.

Adipose Tissue↗

PubMed1992

[On the postoperative mucocele of the maxillary sinus and its simulating cases. A clinical treatise].

The postoperative mucocele of the maxillary sinus typically occurs after 11-15 years after the initial Caldwell-Luc operation with the complaints of swollen and painful cheek. Typical signs and symptoms will be divided into two groups, the one which is associated with expansive lesions and the other with pains along the various branches of the maxillary nerve. In the clinical set-ups, cases with the similar signs and symptoms, and yet lacking definite mucoceles, are often encountered. The present treatise will compare 86 definite cases and 27 simulating cases as to the history, signs and symptoms, various modalities of imaging (CT & MRI), and the possible causes leading to simulating cases. The age at onset, gender, affected side, and period after the initial sinus surgery all showed no differences between the two, i.e., definite and simulating cases. Among signs and symptoms, the definite case showed more of swelling-related matters whereas the simulating case more of pain-related except toothache. The past history of surgeries for the mucoceles on the similar sides to the present lesion is more often seen in the simulating case (64.3%) than in the definite case (18.3%). The findings by imagings in the simulating cases are as follows; obliterated sinus (25.0%), healthy, aerated postop. cavity (35.7%), postop. cavity with mucosal thickening (32.1%), and cyst-like aerated cavity (7.1%). The possible causes leading to the simulating cases are as follows; causes unknown (39.3%), recurrent infection in the postop. cavity (28.6%), dental origin (10.7%), atypical neuralgia (10.7%) and the case shortly after the proceeding sinus surgery (within 12 months, 10.7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

[Quantitative analysis of cholesteatoma using high resolution computed tomography].

Seventy-three cases of adult cholesteatoma, including 52 cases with pars flaccida type cholesteatoma and 21 with pars tensa type cholesteatoma, were examined using high resolution computed tomography, in both axial (lateral semicircular canal plane) and coronal sections (cochlear, vestibular and antral plane). These cases were classified into two subtypes according with the presence of extension of cholesteatoma into the antrum. Sixty cases with chronic otitis media with central perforation (COM) were also examined as controls. The various locations of the middle ear cavity were measured in term of size with comparisons among pars flaccida type cholesteatoma, pars tensa type cholesteatoma and COM. The results were as follows: 1) The width of the attic was significantly larger in both pars flaccida type and pars tensa type cholesteatoma than in COM. 2) With pars flaccida type cholesteatoma there was a significantly larger distance between the malleus and lateral wall of the attic than with COM. In contrast, the distance between the malleus and medial wall of the attic was significantly larger with pars tensa type cholesteatoma than with COM. 3) With cholesteatoma extending into the antrum, regardless of the type of cholesteatoma, there were significantly larger distances than with COM at the following sites; the width and height of the aditus ad antrum, and the width, height and anterior-posterior diameter of the antrum. However, these distances were not significantly different between cholesteatoma without extension into the antrum and COM. The hitherto demonstrated qualitative impressions of bone destruction in cholesteatoma were quantitatively verified in detail using high resolution computed tomography.

Adolescent↗

PubMed1992

[CT rim effects in various head and neck lesions].

The authors evaluated various head and neck lesions seen from April 1988 through March 1990 both by plain and enhanced CT, examined the incidence of rim effect (or rim enhancement), classified these effects, and discussed underlying mechanisms. Materials consisted of 177 cases including primary tumors (28 benign and 49 malignant cases) and lymphadenopathy associated with malignancy (9 cases, metastatic nodes and malignant lymphomas), inflammatory lesions (20 cases), cystic lesions (12 cases), other lesions (7 cases, jugular thrombosis, carotid atheroma and aural lesions), and 22 cases without abnormal findings. Among the 177 cases, rim effects were observed in 22 cases (12%). These effects were analyzed and classified. The incidences of rim effect according lesion type are as follows; cervical lymphadenopathy associated with malignancy 5/9 (56%), primary tumors 8/77 (10%), inflammatory lesions none, cystic lesions 7/12 (58%), and others 3/7 (43%). The highest incidence was seen with cystic lesions including mucoceles of the paranasal sinuses and cervical cysts. Rim effects were classified as follows; Type 1: cystic pattern, Type 2: parenchymatous pattern, Type 3: vascular pattern and Type 4: others. Type 1 was seen in 15 cases (68%), Type 2 in 3 cases (14%), Type 3 in 3 cases (14%), and Type 4 in 1 case (5%). Type 1 included 6 cystic lesions, 3 malignant lymphadenopathies, 3 benign tumors and others. Type 2 included 2 malignant lymphadenopathies and 1 benign tumor, and Type 3, 2 jugular thromboses and 1 carotid atheroma. There was only one Type 4, a cystic lesion. Of interest is the mode of incidences among cervical lymphadenopathies associated with malignancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Cysts↗

PubMed1991

[Blow-out fractures of the orbit--imaging modalities and therapeutic results].

Thirty-four cases of blow-out fracture were evaluated by high-resolution CT, Hess test for red and green color and synoptophore. The results of these tests were compared with the final outcome of the fractures. The fractures were classified on the basis of the location (floor, medial wall or roof), extent (total, partial or linear) and type of fragments (punched-out or trapdoor). The medial wall type included many cases (33%) with no complaint of double vision, and many cases with a combination of disturbances in ocular mobility in both the horizontal and vertical directions. The floor type showed a low incidence of disturbances in ocular movement in the horizontal directions. Regarding the extent of the fracture, all cases with the total type showed disappearance of double vision within three months. Many of the partial and linear types had a poor outcome. With regard to the type of fragments, all of the trapdoor type cases showed a favorable result with disappearance of double vision within three months. Some of the punched-out type cases, however, showed a poor outcome.

Adolescent↗

PubMed1991

[A case report of lymphoepithelial cyst in the parotid gland].

A 57 year-old Japanese male was seen with the chief complaints of left parotid gland swelling, pain, trismus. At the initial visit, a subcutaneous mass, measuring 50 x 70mm, was seen in the left parotid region. The mass was moderately tender and the consistency was soft anteriorly and elastic firm posteriorly. The mobility was restricted with no change in the skin covering the mass. The saliva from the left parotid gland was normal in colour and contents. Various imaging modalities were done preoperatively including CT, MRI, ultrasonography and aspiration biopsy under the ultrasonographic guide. None was thus conclusive for the differential diagnosis and our tentative diagnosis was a cystic lesion in the parotid gland. A partial parotidectomy was performed under general anesthesia and the cystic lesion, measuring 20mm in diameter, was found in the deep lobe. The cyst showed no connection to the external ear canal, and tracts and fistulae were absent. Histopathological report lead to the definite diagnosis of lymphoepithelial cyst. A mild and incomplete facial palsy on the left had been noted for more than 10 years and this, however, improved after the surgery.

Humans↗

PubMed1991

[Isolated medial orbital wall fracture and late fronto-ethmoidal mucocele].

Twenty-one cases of isolated medial orbital wall fractures were reported and CT findings by coronal planes were evaluated as to the effects of fractures upon the ethmoidal cells and nasal meati. Three coronal planes, which respectively contain such structures as Agger nasi, Pars membranacea and superior meatus, were selected for the study. The extent of fracture was evaluated by dividing the medial wall into three equal portions, i.e., superior, middle and inferior. The prolapsed volume was evaluated in three classes of occupying 1/3, 2/3 and 3/3 of the ethmoid. The presence of soft tissue density was recorded at the three surfaces, upper, medial and lower, around the prolapsed orbital content. The extent of the fracture was most often seen in such cases as involving all the three divisions in 41.3%. The prolapsed volume occupying 1/3 was seen in 28, 6%, and 2/3 in 23.8%. The presence of soft tissue density was seen in 38.1% of upper surface, in 36.5% of medial, and 11.1% of lower. Summarizing the total effects of the fractures, the coronal plane containing Pars membranacea was most severely damaged followed by the plane of the superior meatus. Two rare cases of fronto-ethmoidal mucoceles, caused by the traumas of 23 and 14 years before respectively, were also included and reported. The ophthalmological prognosis was favorable in 90.5% of cases by observations extending more than 6 months. Five cases were surgically treated including two cases of mucoceles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[The vasoactivity of endothelin in the nasal mucosa].

Endothelin (ET), a novel endothelium-derived vasoconstrictor peptide with 21 amino acid residues, has recently been isolated from the supernatant of cultured porcine aortic endothelial cells. Several authors reported preliminary results demonstrating that ET has a potent contractile action in vascular smooth muscles, but its effect is slightly different in each target tissue. In the present study, we have examined the vasoactivity of ET in human and canine nasal mucosa with in vitro bioassay. The results are as follows. 1) ET induced a slow, and very sustained contraction from 10(-9) M. This response is stronger than that of noradrenaline (NA) and continued for 6-12 hours. 2) Under the sustained contraction by the administration of alpha 1 adrenoceptor agonist (methoxamine), ET induced an additional contractile response. 3) The response of ET depended on the concentration of Ca2+. 4) ET did not affect the contraction of vascular smooth muscle which was caused by the electrical stimulation. 5) ET increased the contraction of vascular smooth muscle which was caused by the administration of NA into the bath solution.

Amino Acid Sequence↗

PubMed1991

[Anatomical study on the sphenoidal sinus and petrous apex cells].

Morphological relation between the sphenoidal sinus and the petrous apex cell was studied using HRCT images obtained by 339 adults and 43 infants. The adults were classified into normal group (without chronic otitis media or its surgery) 237 cases, and otitis group (chronic otitis media or its post. op.), 102 cases. The posterior extent of the sphenoidal sinus was evaluated in reference to the carotid canal, and the petrous apex cells were evaluated by their mode of distribution in the apex. In the normal adults, no evident relation was seen between the posterior extent and the mode of distribution. Although adult normal female showed statistically significant better development of the posterior extent, sinus-cell relation was similar between both sexes. The adult normal group and otitis group behave similarly by sinus-cell relation, i.e., no evident relation, although inhibited mode of distribution was seen by otitis group. When the adult and infant were compared, the sinus-cell relation was similar and the posterior extent suffered underdevelopment by infant. The distance, between the posterior extension of the sphenoidal sinus and the apex cell at the medial-anterior tip of the petrous bone, is between 8-16 mm and the contact of the both separated by thin bony wall (less than 0.5 mm) was seen in 3 adult cases (0.9%). Both the sphenoidal sinus and the petrous apex cells are under genetic influence of variable degree, separate genes seem to be at work, thus effecting no evident relation between the two. Apart from the internal or genetic influence, environmental or outer influence also affects the development of the two, less than the genetic.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[Measurement of parapharyngeal space using CT images].

Parapharyngeal space can be defined as a potential space surrounded by deglutitional and masticator muscles and their covering, superficial and middle layer of deep cervical fascia. It is easily recognized in images provided by modern scanning devices, such as CT and MRI. Parapharyngeal space has traditionally been divided by styloid process and fascia of tensor veli palatini muscle (nasopharyngeal level) or fascia of stylopharyngeus muscle (oropharyngeal level) into two compartments, prestyloid and postsyloid spaces. The latter is often called as carotid space. Prestyloid portion exclusively contains fat tissue, which yields hypoabsorption area in CT films and high density area in MRI. In most of papers in radiological journals, the term of parapharyngeal space is regarded as its prestyloid portion which is clearly identified. Axial CT images of 144 patients without any naso- or oropharyngeal lesions were analyzed. Two reference levels of nasopharynx were adopted for the study. The upper level passes through the plane of fossa of Rosenmuller, and the lower reference level transects soft palate. The following parameters of the space were measured; Length and width of the whole space, length and width of prestyloid fatty space, and furthermore, width of pre- and poststyloid space, that were divided by a imaginary line parallel to the axis of the whole space (the upper level); Length and width of the whole space, length of base and height of a triangle of the prestyloid part (the lower level). While parapharyngeal space was symmetrical in the upper level, the rate of asymmetry amounted to a fourth in the lower level.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Dentigerous cyst of the maxilla and its image diagnosis.

Dentigerous cysts may grow unnoticed to such extensive sizes as to occupy a considerable portion of the maxillary sinus. As they enlarge, the bony walls overlying the cysts thin out giving rise to an egg shell sensation upon palpation. Three cases of such extensive dentigerous cysts were experienced since 1987. These three cases were used to illustrate the advantages and disadvantages of the following imaging techniques in the preoperative evaluation of these cysts, conventional radiographs, sonography, CT, and MRI.

Adult↗

PubMed1990

[Reevaluation of benefit and risk of mass screening for stomach cancer--comparison between X-ray diagnosis and endoscopy as the screening test].

Mass screening for stomach cancer has been widely performed throughout Japan, since stomach cancer is the most important disease among various malignant diseases in Japan. As a screening test, the X-ray diagnosis with barium contrast medium is used and the risk of X-ray exposure must be considered in order to compare with the benefit of the mass screening. We have reported in the previous article in 1977 that the benefit and risk of stomach cancer mass screening become equal at age of 40 y.o. Since then, various conditions with the mass screening of stomach cancer have changed so that reevaluation of the benefit and risk relationship is necessary. Especially the risk coefficient of radiation-induced stomach cancer has been revised drastically in the report of United Nations Scientific Committee on the effects of radiation in 1988. So, in this report, the benefit of mass screening of stomach cancer is defined as the net elongation of average life expectancy due to the life saved, and the risk of the screening is defined as the net shortage of average life expectancy due to the radiation-induced stomach cancer and leukemia. Since the benefit increases rapidly with age and the risk decreases with age, a certain age at which the benefit and risk become identical should be found and under this age the mass screening is not justified to be performed. Assuming X-ray dose equivalent to stomach of 10 mSv and risk coefficient of stomach cancer of 12.6 X 10(-3) Sv-1 from the United Nations report, the critical age is found to be about 35 y.o. for men and women.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗