MR diagnosis of meniscal tears of the knee: value of axial three-dimensional Fourier transformation GRASS images

Axial MR images of 40 knees in 37 patients with clinically suspected meniscal tears were obtained by using a three-dimensional (3-D) Fourier transform, gradient-refocused acquisition in the steady state (GRASS) pulse sequence. All knees also were examined in both coronal and sagittal planes with a two-dimensional (2-D) Fourier transform, spin-echo pulse sequence for T1-weighted images and a multiplanar GRASS pulse sequence for T2*-weighted images (conventional 2-D pulse sequences). Arthroscopic confirmation was available in all cases and was used as the gold standard. In these 40 knees, 32 of 33 meniscal tears and 45 of 47 normal menisci were correctly identified with axial 3-D imaging, yielding a sensitivity of 97% and specificity of 96%. Conversely, the sensitivity was 82% and the specificity was 100% for the 2-D technique in the diagnosis of meniscal tears. A combination of both techniques yielded 100% sensitivity, 100% specificity, and 100% accuracy in the evaluation of the menisci. Seven discrepancies between the findings of the two techniques were found in the evaluation of 33 arthroscopically proved torn menisci; six of the seven represented false-negative 2-D images and one was a false-negative axial 3-D image. Of 47 normal menisci, only two false-positives occurred with axial 3-D imaging and none with 2-D imaging. Despite the lack of a statistically significant difference, these preliminary findings suggest that the sensitivity in the diagnosis of meniscal tears can be improved by adding thin-sliced axial images with the 3-D GRASS pulse sequence to conventional 2-D imaging.

Effects of various inflammatory mediators on eustachian tube patency

The effects of several inflammatory mediators on the patency of the Eustachian tube were evaluated in 15 mongrel dogs. Histamine, leukotriene C4(LTC4) and D4(LTD4), and platelet activating factor (PAF) were perfused through the Eustachian tube of anesthetized dogs at concentrations detected in human middle ear effusion of patients with otitis media. The patency of the Eustachian tube was then evaluated by perfusion pressure and opening pressure. Histamine at concentrations of more than 10(-5) M caused increased tubal resistance and opening pressure rapidly. LTC4 and LTD4 caused a rapid increase of tubal resistance and opening pressure at far lower concentrations, i.e. 10(-12) M. Doses of PAF over 10(-9) M may cause an increase in the opening pressure. These results indicate that various inflammatory mediators are capable of affecting the Eustachian tube function.

[Three-dimensional axial volume acquisition on meniscal lesions of the knee]

Axial three-dimensional volume scans obtained by magnetic resonance (MR) imaging were used to evaluate meniscal lesions of the knee in 28 knees of 26 cases. Axial 0.7 mm thin-sliced images with volume scan outlined the overall meniscal appearance for the first time. Axial volume scan was essential to the diagnosis of discoid lateral meniscus because only it could depict the characteristic elongated appearance of discoid lateral meniscus. Radial meniscal tears were depicted only by this technique: conventional sagittal and coronal views could not detect this type of meniscal tear. Volume scan could detect the precise extent of lesions with horizontal meniscal tears and meniscal degeneration. These MR findings obtained by axial volume scans were confirmed by arthroscopy in all cases. We concluded that volume scans were extremely useful in the evaluation of meniscal lesions because they offered axial views that provided much information on menisci located horizontally in the knee.

[MRI of discoid lateral meniscus]

We retrospectively reviewed the MR examinations of 10 patients (17 knees) with surgically documented discoid lateral meniscus of the knee joint. As MRI of the knee is being used more often, the criteria for diagnosis of this entity with MRI need to be established. We tried to define MRI criteria for the detection of discoid menisci by performing numerical measurements of MR images on a display screen. The transverse diameter of the midbody of a discoid lateral meniscus averaged 21.9 mm (normal control: 8.6 mm), and its proportion to the transverse width of the tibia averaged 29.4% (normal control: 12.0%). The measurable difference in height between the discoid and the medial meniscus was negligible. The number of sagittal sections on which the anterior and posterior horns connected varied from two to five in cases of discoid lateral meniscus, and from zero to two in normal controls. Among these parameters, the transverse diameter and its proportion of the transverse width of the tibia proved to be the most reliable. We concluded that a discoid meniscus is indicated if a transverse diameter of a lateral meniscus exceeds 15 mm (proportion to the tibia: 20%).

[A three-dimensional gradient refocussed 3D volume imaging of discoid lateral meniscus]

An axial 3D volume scan with MRI was applied to the evaluation of discoid lateral meniscus of the knee. By 0.7 mm-thick thin-sliced and gapless images with volume scan, characteristically elongated appearance of discoid lateral meniscus was clearly depicted. These MR findings completely accorded with those on arthroscopy. Our conclusion is that an axial 3D volume scan was essential to the diagnosis of discoid lateral meniscus.

Middle ear ventilation mechanism

The ventilation mechanism of the middle ear is very important as regards the pathogenesis of middle ear disease, but its mode of function is still obscure. Therefore, we tried to measure the ventilation and clearance of the middle ear using radio-isotope imaging techniques and 133Xe in order to gain a clearer picture of the ventilation mechanism. In normal Eustachian tube cases, approximately 10% of the initially insufflated gas immediately entered into the middle ear cavity and mastoid air cells. The gas introduced into the middle ear diminished at a rate of 8% of volume per hour in the normal resting state. Two hours after the first procedure, air was insufflated, and gas volume in the middle ear cavity immediately diminished by 30%. In stenotic tube cases, it proved difficult to insufflate the gas into the middle ear, however, its diminishing rate with the passage of time was slightly faster than in normal tube cases. From this data, it was evident that air could easily and quickly enter into even the periphery of the mastoid air cells by insufflation via the Eustachian tube, despite the fact that the middle ear and mastoid air cells form a closed cavity. In the resting state, moreover, the air in the middle ear was thought to be absorbed mainly into the middle ear mucosa at a regular rate. It was confirmed that the insufflation procedure as a therapy for tubal stenosis and OME is very useful for the ventilation of the middle ear.

The tonsillar immune system: its response to exogenous antigens

The palatine tonsil is the only lymphoid organ directly exposed to the outside environment. This characteristic anatomical feature appears to be immunologically significant with the defence activity primarily directed against exogenous antigens. However, the palatine tonsil is also often the site of secondary diseases, such as focal infections. This study investigated how the tonsil responds to horseradish peroxidase (HRP) dropped into the crypts and the effects of this response on the regional lymph node and the kidney as a distant organ. HRP entered through the microcrypts was phagocytosed by macrophages, gathered mostly around the vessels and emigrated to the regional lymph nodes. Anti-HRP antibody-producing cells were observed not only in the tonsil but also in the regional lymph node. In this long-term study with repeated immunization, fusion of the epithelial foot process and reduction of the anionic charge in the glomerulus were often found electron microscopically. This investigation suggests that the tonsil has important roles in the defence activity in relation to the general immune system; otherwise it becomes a primary site for focal infections.

Changes of acetylcholine and choline concentrations in cerebrospinal fluids of normal subjects and patients with dementia of Alzheimer-type

Acetylcholine (ACh) and choline (Ch) in cerebrospinal fluid from 29 normal volunteers and 7 patients with Alzheimer-type dementia (DAT) were examined using high-performance liquid chromatography with electrochemical detector coupled with liquid cation-exchange method. In normal volunteers, ACh concentration was decreased significantly from 40-50 years and Ch concentration was increased significantly from 50-60 years. CSF from patients with DAT revealed high Ch concentration and the increase was statistically significant while ACh concentration in CSF of DAT did not show a significant difference with that of normal volunteers. This Ch augmentation may suggest a disturbance in utilization of Ch for ACh synthesis and may become an useful indicator for organic changes in central cholinergic system.

Gravity-dependent atelectasis. Radiologic, physiologic and pathologic correlation in rabbits on high-frequency oscillation ventilation

The authors identify the radiologic features of progressive atelectasis induced under conditions of reduced lung volume. Control (n = 5) and experimental (n = 7) animals were placed on high-frequency oscillation (HFO) ventilation (mean airway pressure: 3 cm H2O) for 6 hours. In the experimental animals, lung volume was artificially reduced by pneumoperitoneum during HFO ventilation. Computed tomography scans and chest radiographs were obtained every hour, and arterial blood gases analyzed. No changes were detected in the control animals. In the experimental animals, in which hypoxemia developed, homogeneous opacity in the dependent lung was found on CT images, and chest radiographs showed a diffuse homogenous shadow with loss of lung volume. Study of pathologic sections from the lung showed that the roentgenographic findings represented atelectasis. The lung was divided into three zones, from dependent to nondependent regions: severe atelectasis, mild atelectasis, and normal lung. Hyperinflations eliminated atelectasis seen on the CT images and alleviated hypoxemia; however an undesirable effect that causes barotrauma also was observed.

Electrocochleographic changes in endolymphatic hydrops induced by type II collagen immunization through the stylomastoid foramen

Changes in action potential (AP) and summating potential (SP) were investigated in guinea pigs immunized with type II collagen through the stylomastoid foramen. Endolymphatic hydrops could be induced in four of 11 guinea pigs. The striking feature of the electrocochleographic waveform in guinea pigs with endolymphatic hydrops was the negative SP recording in response to high frequency tone bursts. Furthermore, abnormal changes in AP were observed in three of four hydropic guinea pigs. Morphologic study of the cochleas in these three guinea pigs with light microscopy revealed spiral ganglion cell degeneration in addition to endolymphatic hydrops and almost normal sensory hair cells. These results suggest that guinea pigs with hydrops as produced by our procedure can serve as a useful model of Meniere's disease, that autoimmune response may play an important role in the etiopathogenesis of Meniere's disease, and that spiral ganglion cell degeneration together with endolymphatic hydrops seems to contribute to abnormal changes in AP.

[Superselective arterial catheterization using a ball tip supple catheter]

We have devised a non torque, supple and flexible catheter with a Ball-tip and have applied this catheter (combined) with the plastic coated guide wire in a superselective angiography to a total of 43 patients, namely, 41 hepatic and 2 renal tumor patients. Since the pulling forces of the arterial blood flow carries the Ball-tip supple catheter to the distal part of the desired artery, the new system seldom causes spastic change and subintimal injury. We have achieved successful catheterization and embolization in all but one cases, even when there are extensive curves in the arteries leading to the affected site. Our conclusion is that cases which cannot be embolized by the conventional method due to the extensive curves of the artery can be safely treated by using this catheter system.

Hepatic arterial catheterization with use of a supple catheter with a ball tip

A new catheter was developed for hepatic angiography and embolization: a non-torque control supple catheter with a ball tip combined with a small guide wire. The catheter was used successfully in 47 of 49 patients with hepatocellular carcinoma or hepatic metastases. It seldom causes spasm or intimal damage of distal arterial branches and is useful even when there are extensive curves in the arteries leading to the affected site.

Microcatheter with a ball tip for hepatic embolization and intra-arterial chemotherapy

A microcatheter used mainly for cranial arterial embolization and chemotherapy was employed for hepatic arterial embolization. The tip of the microcatheter is inflated like a small balloon which then acts as a calibrated-leak balloon. A coaxial system employing a conventional catheter for abdominal angiography combined with a propulsion chamber was used. Successful chemotherapy and embolization by Lipiodol and Spongel was carried out even in cases in whom it has been considered impossible to insert a catheter into the desired arteries.

Histamine content and histamine H1 receptor in experimentally-induced nasal hypersensitivity

Quantitative evaluations of histamine and histamine H1 receptor were carried out in nasal mucosa of toluene diisocyanate (TDI) sensitized guinea-pigs at specific points in time during a pre-determined sensitization period. Histamine content is significantly increased at 1 week and definitely elevated after 2 weeks of sensitization. This increase was maintained throughout the sensitization period. It decreased to normal by four weeks post-sensitization. Also the relatively low histamine content immediately after TDI challenge indicated that a certain amount of histamine was released by TDI challenge. On the other hand, the density and affinity of the histamine H1 receptor was not found to be altered during TDI sensitization. These results suggest that enhanced histamine has a role in the development of nasal allergy, whereas the relevance of quantitative-alteration of the H1 receptor to histamine hypersensitivity observed in nasal allergy has not been demonstrated.

Type II collagen distribution in rodents

The anatomical distribution of type II collagen in animal ears was studied by immunohistochemical techniques, using defined monoclonal antibodies to type II collagen. Type II collagen was observed in the cartilage plate of the auricle and external auditory meatus, tympanic annulus, lamina propria of tympanic membrane (pars tensa), interossicular joints, stapes footplate, eustachian tube cartilage, enchondral layer and globuli interossei of the otic capsule, Rosenthal canal, cribriform base, osseous spiral lamina, spiral ligament, limbus, tectorial membrane, semicircular canal membrane and subepithelial layer of the ampullary crista, utricular and saccular maculae, and the endolymphatic duct and proximal part of the sac.

An anionic charge barrier in the guinea pig cochlea

A charge barrier has been found in the glomerular basement membrane of the kidney and plays an important role in the filtration of solutes. In the present study, we used electron microscopy to localize anionic sites of a similar charge barrier in the guinea pig cochlea. Polyethyleneimine (PEI) was used as a cationic marker to detect anionic sites. Our results showed a localization of PEI with regular interspaces, indicating the anionic sites to the charge in the capillary basement membrane of the stria vascularis and the spiral ligament, and in the basal lamina of Reissner's membrane and the spiral prominence. This charge barrier, as well as structural size barrier, may play an important role in the maintenance of normal inner ear functions.

[Angiosarcoma of the liver and pineal region]

Angiosarcoma is a rare malignant tumor originating from vascular endothelial cells. We have experienced a case of 17-year-old man, who had angiosarcoma in the pineal region and the liver. Patient's initial symptom was headache and CT scan revealed a high density mass in the pineal region with obstructive hydrocephalus. After the radiation therapy, the tumor was disappeared completely on CT scan. One year later, he developed abdominal pain, and CT scan and angiogram revealed multiple angioma like lesions in the liver. The mass in the pineal region showed concomitant regrowth, and finally, the patient was died of abdominal hemorrhage. At autopsy, pineal tumor and hepatic tumor were both angiosarcomas, although it was uncertain which was the original tumor.

Quantitative evaluation of radiotherapy treatment planning using CT image

A method of computerized optimization system of radiotherapy treatment planning is presented. For the optimization of treatment planning, it is highly desirable to evaluate treatment planning quantitatively corresponding to a set of three-dimensional criteria. For this purpose, we introduce a set of criteria using some parameters defined as three-dimensional extension of those of ICRU report 29. The development of computer software has become feasible for clinical use of our criteria. This paper described some preliminary results of our criteria which was applied to some clinical cases. Our method was proved applicable to any type of treatment plannings, and the optimization of treatment plannings will surely be realized through our criteria.

Computed tomography following endoscopic sclerotherapy of esophageal varices

Computed tomography of the chest following endoscopic injection sclerotherapy for esophageal varices was performed in 17 procedures in 13 patients. CT scans were obtained before and within 48 hours after the procedure. CT findings included: esophageal wall thickening; a low-attenuating lesion within the wall of the esophagus with varying appearances, either laminated, localized, or inhomogeneous; a mediastinal lesion; pleural effusion; and various types of pulmonary changes such as atelectasis, pleural-based lesions, dilatation of peripheral pulmonary vessels, and nodular lesions. However, on follow-up CT they had regressed or disappeared. The changes in the mediastinum and pleural space might be caused by direct extension of inflammation from the esophagus, but those in the lungs, especially dilatation of peripheral vessels, may be caused by the sclerosing agent passing to the pulmonary vessels.

Laser surgery for allergic rhinitis

The inferior turbinates of 140 patients with perennial allergic rhinitis were vaporized by a defocused carbon dioxide (CO2) laser beam, using specially designed handpieces. Among these patients, 131 showed improvement in subjective symptoms one month after laser surgery. Excellent or good results were obtained in 27 of 35 patients who were followed up more than one year after laser surgery. The histopathologic changes observed in the nasal mucous membrane after surgery were fibrous proliferation and scar formation in the superficial layer of the submucosa. This surgery can be done under surface anesthesia as an outpatient procedure, and it is painless, with no bleeding.

Endosteal new bone formation in the long bones of adjuvant treated rats

Histopathological changes were examined mainly in the diaphyseal parts of long bones, especially femur in adjuvant-treated male Lewis-SPF rats, with reference to clinical symptoms of chronic osteoarthritis. The diaphyseal bone marrow of long bones in these rats sequentially showed three different processes of chronic pathological changes, which, however, partly overlapped each other. Initially, multiple epitheloid cell granulomas or granulomatous lesions containing fibrin deposits began to appear in the marrow space about 22 days after adjuvant injection, when the joint score of arthritis reached a peak in severity. Secondly, about a week after appearance of the granulomas, there occurred the intramembranous endosteal new bone formation proceeding from the endosteum towards the granulomatous lesions. The bone formation reached a maximum about 64 days after the treatment, when the redness of joints of feet and hands was already sedated. Finally, about 40 days after occurrence of the second event, the newly growing bone matrix began to be actively resorbed simultaneously. On the other hand, in the bone marrow of metaphyseal parts of long bones in these rats, severe acute osteomyelitis was observed from an early stage, with marked destruction of bone trabeculae and simultaneous new bone formation. In the diaphyseal bone marrow of affected long bones, the epitheloid cell granulomas appear to induce the endosteal new bone formation.

Histopathological studies in the long-term evaluation of Plastipore prostheses

Polyethylene sponge (Plastipore TM) prostheses were clinically implanted in the middle ear for periods varying from 2 weeks to 6 years. Revision surgery allowed removal of 98 of these prostheses for histological examinations. Local foreign body reactions and/or microscopic breakdown of the polyethylene were found to varying degrees in 95 of the 98 prostheses. The remaining 3 prostheses showed only fibrous tissue ingrowth without other changes. We compared the histopathology present with the length of time of implantation, and found that the changes noted were more frequent and marked in those prostheses implanted for long periods of time.

Factors influencing collagen-induced autoimmune ear disease

In 1981, the authors described a type II collagen-induced autoimmune ear disease (CIAED) model. The purpose of this study was to gather further evidence that this is a sound animal model to use in evaluating inner ear diseases. The temporal bone lesions of CIAED in Lewis and Wistar rats were characterized by the presence of sensorineural hearing loss with mild atrophy of the organ of Corti and spiral ganglion degeneration, vestibular dysfunction with vacuolar degeneration of the crista ampullaris, otospongiosis-like lesions in the tympanic annules, cochlear vasculitis, and eustachian tube disease. Both cellular and humoral immune responses to type II collagen were demonstrated. The induction of ear lesions depends on many factors. In general, animals immunized with antigens in complete Freund's adjuvant showed relatively more severe lesions than animals immunized with antigens in incomplete Freund's adjuvant, but the duration of the immunization seems to be a more important factor in reproducing severe lesions. The strain and the source of the animals are also important factors in autoimmune inner ear diseases, as is the condition of the host animals. Subclinical or clinical mycoplasma infection in the rat markedly reduced the incidence and severity of lesions in type II collagen-induced arthritis. Many researchers did not consider sialoductal adenovirus, widely present among laboratory rats, a lesion-producing factor in rats. Although many factors influence the induction and severity of CIAED, these animal models provide an excellent new avenue of inner ear research.

Prognostic determination and submandibular function in Bell's palsy. Dynamic testing with technetium Tc 99m

In 56 patients with Bell's palsy, a submandibular gland function test employing a dynamic technetium Tc 99m scan was performed, to study the relationship between the test results and the prognosis of paralysis. Patients who had no difference in function on the affected facial side compared with the healthy side during the test (performed within ten days after symptomatic onset) had a high rate of early improvement. Patients who showed no response to the salivary secretory stimulant administered had an incomplete recovery and were all considered for surgery. Prognosis within ten days after onset was possible in as many as 37 of the 56 cases.

Type II collagen-induced autoimmune salpingitis in rats

Autoimmune salpingitis was induced in 17 (85%) of 20 outbred Wistar rats by immunization with bovine type II collagen; three of those also developed eustachian tube chondritis. The lesions were characterized by infiltrations of a large number of mononuclear cells in the mucosa and submucosa, destruction of cartilaginous structure, and deposition of IgG and complement C3. The animals had high titers of anti-type II collagen antibody. Immunohistochemical examination using monoclonal antibody to type II collagen revealed the presence of type II collagen in the eustachian tube cartilage. These observations suggest a causal relationship between autoimmunity to type II collagen and salpingitis in the rat, and this animal model may be useful in defining the pathogenesis of eustachian tube diseases mediated by immunity to type II collagen.

Type II collagen mediated autoimmune middle ear disease: eustachian tube disease, otitis media with effusion and tympanosclerosis

Intact Eustachian tube and tympanic cavity functions are essential for normal middle ear physiology. Type II collagen is an essential component of ear tissue. Autoimmune response to this type II collagen produces sensorineural hearing loss, vestibular dysfunction, endolymphatic hydrops, otospongiosis-like lesions, Eustachian tube inflammation and Eustachian tube chondritis. In addition, these autoimmune responses occasionally produce otitis media with effusion (not infectious). Tympanosclerosis, which is a frequent sequelae of otitis media with effusions, was also induced by type II collagen immunization together with surgical incision of the tympanic membrane. The exact mechanisms of this type II collagen autoimmune mediated middle ear disease are not clear. However, the animals thus induced have higher antibody titers and cell mediated immune responses to type II collagen. The tympanic membrane showing tympanosclerosis also had C3 and Ig deposits. All the animals with otitis media with effusion induced by type II collagen immunization also had Eustachian tube disease. This could be due to a malfunction of the Eustachian tube. Thus, this model might provide a rational approach for the study of otitis media with effusion associated with vasculitis. Further studies are needed to elucidate the immunologic mechanism involved in the pathogenesis of otitis media with effusion.

Type II collagen induced autoimmune salpingitis in the rat

Previous studies showed type II collagen induced autoimmune salpingitis in Wistar rats. In this study we increased the number of animals and investigated whether or not type II collagen induced salpingitis is transferable by immune sera. Histopathological observations of salpingitis in the serum transferred rats were similar to those observed in the immunized rats but the degree of otopathological changes was less than that of immunized rats. Electronmicroscopic findings indicate an increased permeability in the capillaries and intercellular space and cellular infiltration in the submucosa of the immunized rats.

Synthetic diagnosis of parotid tumor

Computed tomography (CT), ultrasounds, and radioisotope scintigraphy (RI scinti) were applied before operation to 156 patients with parotid tumor, and the result of each test and/or the synthetic study of them were compared with the findings during operation and the pathological diagnosis of isolated tissue. CT was found to be a very effective diagnostic aid in determining the location of the tumor. CT and ultrasounds both provided adequately reliable information regarding the tumor content. For diagnosing the malignancy of the tumor, synthetic diagnosis using CT, ultrasounds and RI scinti had a high diagnostic accuracy. By using the above mentioned methods of diagnosis, an accurate preoperative diagnosis of the tumor could be obtained.

Scanning electron microscopic study of human eustachian tube epithelium: aging and pathologic changes

Scanning electron microscopic study of human Eustachian tube epithelium showed that numerous secretory cells and compound cilia were observed mostly in children while with advancing age squamous or cuboidal cells were largely increased in contrast with decreasing number of ciliated and secretory cells. In the cases of otitis media with effusion, findings were characterized by the mucous hypersecretion and abnormal cilia. Thus, mucociliary function of the tubal epithelium may easily be impaired in children and elderly adults, and the accumulation of fluid may consequently be induced in the middle ear cavity.

Serratia protease. Amino acid sequences of both termini, the 53 residues in the middle region containing the sole methionine residue, and a probable zinc-binding region

Reexamination of the molecular mass and the amino acid composition of Serratia protease revealed the presence of 1 mol of methionine per mol of protein (about 46K daltons), and this was confirmed by BrCN cleavage followed by separation of the two fragments. The sole methionine residue was located near the middle region of the molecule. The amino(N)-terminal sequence was determined by Edman degradation of the protein and studies of several proteolytic peptides, establishing a sequence of 18 residues with a heterogeneous N-terminus. The carboxyl(C)-terminal sequence was determined by carboxypeptidase A digestion and tritium-labeling of the citraconylated C-terminal half segment to be -Phe-Ile-Val. The sequences of a total of 53 residues containing the methionine residue and a total of 38 residues containing two histidine residues were established by the application of various conventional methods to a BrCN peptide and several proteolytic peptides. The segment containing the histidine residues was homologous with that containing the two histidine residues chelating the zinc atom of thermolysin. The 38-residue segment may be directly connected to the 53-residue segment.

Antibody activity in perilymph from rats with type II collagen-induced autoimmune inner ear disease

Rats were immunized with native type II bovine collagen to induce autoimmune inner ear disease, and the antibody activity in the inner ear fluid was measured. Antibody activity against type II collagen was detected in the perilymph at about 10% to 20% of serum level. Thus, the presence of antibody against type II collagen in inner ear fluid may imply an immune injury mechanism in inner ear diseases.

Type II collagen-induced autoimmune inner ear lesions in guinea pigs

Guinea pigs immunized with type II collagen developed histologic changes resembling those observed in patients with sensorineural hearing loss associated with connective tissue diseases. The histologic changes observed in the inner ears of these guinea pigs included spiral ganglion cell degeneration, atrophied organ of Corti, atrophy of stria vascularis, and mild extension of Reissner's membrane. These pathologic changes were accompanied by both humoral and cell-mediated immune responses directed against type II collagen--a collagen found in the subepithelial layer of the endolymphatic duct and spiral ligament. These findings suggest that an immune response directed against type II collagen can induce inner ear lesions.

CO2 laser stapedotomy: is it practical?

The argon laser has been described as an instrument capable of performing stapedotomy for otosclerosis. Because of the possibility of cost ineffectiveness and damage to the saccule using the argon laser, this study was undertaken to ascertain the possibility of using the CO2 laser for stapedotomy. the operation was done on seven cats, and the resulting histopathologic findings were studied. Stapedotomy was also performed with the CO2 laser on human cadaver temporal bones to measure temperature changes in the vestibule and to develop guidelines for the laser's use in humans. The authors' results indicated that the CO2 laser can be used effectively and safely in cats and should be considered for human use.

Autonomic nervous system in human palatine tonsil

The autonomic nervous system in the human palatine tonsil was studied systematically as follows: 1) Using the radio binding assay method, the presence of beta-adrenergic receptors and muscarinic-cholinergic receptors was demonstrated in the tonsil. 2) Using high performance liquid chromatography, the quantity of catecholamines in the tonsillar tissue was determined for the first time. 3) The distributions of sympathetic and parasympathetic nerves in the tonsillar tissue were demonstrated by fluorescence- or enzyme-histochemistry. 4) Cases of habitual tonsillitis were compared with cases of simple tonsillitis concerning the quantities of beta-adrenergic receptors and catecholamines. As a result, the difference in quantity of beta-adrenergic receptors between the two was insignificant, but the quantity of catecholamine was greater in the former.

Closure of dural defects with proplast

Defects of the dura mater, which are a source of cerebral spinal fluid leakage, may be produced by trauma and otologic and neurosurgical operations. Proplast was evaluated as a graft material to close dural defects in three animal models (cats). For comparison, temporalis fascia was similarly evaluated in an additional three cats. Microsurgical techniques were utilized to close the defects, and both materials successfully prevented cerebral spinal fluid leakage. Proplast, however, was judged superior when studied microscopically at three months. There was ingrowth of living dura into the Proplast and no evidence of inflammatory reaction.

Histology of human eustachian tube muscles: effect of aging

Forty-eight specimens of human eustachian tube tensor and levator muscles were examined histologically in order to study their functions and the effect of aging. The muscle fibers reach their maximum growth in the third decade with a narrow short diameter: tensor 21.8 micron and levator 24.5 micron; with advancing age, they were prone to atrophy, particularly in the tensor. Three muscle fiber types, red, white, and intermediate, were identified in the tubal muscles. The white fibers predominated in the tensor, and they were a main component of muscle fibers in fetuses and elderly adults. Lipofuscins were located in the periphery of muscle fibers, dominantly in the levator, and became numerous and larger with age. Our observations suggest that 1) the tensor produces a rapid opening of the eustachian tube while the levator creates tension and dilates the pharyngeal orifice of the tube for a relatively long period, and 2) these muscle functions deteriorate with advancing age.

Type II collagen-induced autoimmune endolymphatic hydrops in guinea pig

Endolymphatic hydrops was induced in guinea pigs by immunizing them with native bovine type II collagen. Histopathologic changes consisted of moderate extension of the Reissner's membrane, spiral ganglion degeneration, atrophied organ of Corti, and mild atrophy of the surface epithelium in the endolymphatic duct. These findings suggest that an immune response directed against type II collagen--a type of collagen found in the membranous labyrinth, subepithelial layer of the endolymphatic duct, spiral ligament, and enchondral layer of the otic capsule--may induce endolymphatic hydrops.

Serum transfer of collagen-induced arthritis. II. Identification and localization of autoantibody to type II collagen in donor and recipient rats

Collagen-induced arthritis can be transferred from immunized arthritic rats to unimmunized recipients by intravenous injection of an immunoglobulin concentrate of sera. This study identifies antibodies in the transfer concentrate which localize to the articular surface of cartilage in joints of recipients. Immunoglobulin can also be demonstrated in the same location in arthritic joints from rats after immunization. Antibody capable of transferring arthritis is present in donor rats over a period of at least 3 weeks and can be absorbed using homologous type II collagen. In addition, anti-type II collagen antibodies can be eluted from arthritic joints of rats with early disease.

Temporal bone findings in trisomy 13 with cyclopia

Temporal bone findings in a fetus with trisomy 13 syndrome and cyclopia may be histopathologically characterized by the dysplasia of bony and membranous labyrinth and of the nervous system. In the left ear, there was a shortened cochlea housing a malformed Corti's organ appearing as a ribbonlike structure, an unexpected canal running obliquely through the scala tympani, a peculiar shape of the utricular macula and posterior canal crista, and a delayed ossifying process in the otic capsule. The poor development of the structures in the seventh and eighth nerves and their ganglions was observed in both ears. The type of anomaly can be classified as Mondini or Mondini-Alexander. The several anomalies might involve the organs that begin to develop during the period from five to eight gestational weeks.

Type II collagen-induced autoimmune sensorineural hearing loss and vestibular dysfunction in rats

Autoimmune sensorineural hearing loss was induced in rats by immunizing them with native bovine type II collagen. Type I and denatured type II collagen, administered by an identical immunization procedure, would not induce disease. Evidence of sensorineural hearing loss was obtained by measuring the brainstem evoked potential and by observing histopathologic changes consisting of cochlear nerve degeneration and perineural vasculitis in affected animals. Immunized animals had high levels of antibodies to native type II collagen.

Type II collagen-induced autoimmune otospongiosis. A preliminary report

Otospongiosis-like lesions were induced in rats by immunizing them with native type II collagen. Immunized rats had antibody responses specific for native type II collagen and developed otospongiosis-like lesions. The spongiotic lesion was characterized by numerous osteocytes and osteoblasts in the vascular spaces and by dark staining probably due to the chemical alteration of ground substances. Bone resorption and new bone formation were clearly visible. Immunofluorescence studies demonstrated deposition of immunoglobulin and complement on the bone matrix and wall within the area of spongiosis. An antibody-mediated etiopathogenesis was suspected.