Subject(s)
Feeding Behavior , Fisheries/methods , Fishes/anatomy & histology , Fishes/physiology , Mouth/anatomy & histology , Rotifera/chemistry , Animal Feed/analysis , Animals , Environment , Fishes/growth & development , Larva/anatomy & histology , Larva/growth & development , Larva/physiology , Species SpecificityABSTRACT
We examined the effects of 5-Gy radiation on the expression of hypoxia-inducible factor-1α (HIF-1α) and the radiosensitivity of five human oral squamous cell carcinoma (OSCC) cell lines (SAS, Ca9-22, TT, BSC-OF and IS-FOM). In all of the cell lines, HIF-1α was expressed in mRNA, and radiation had no influence on gene transcription. The number of apoptotic cells increased 72 h after irradiation in cell lines SAS, Ca9-22 and TT cells, indicating low transcriptional levels of HIF-1α, and the levels of non-cleaved caspase-3, an executioner of apoptosis, and non-cleaved poly (adenosine diphosphate-ribose) polymerase (PARP), a marker of DNA damage early in apoptosis, decreased simultaneously. Conversely, radiation failed to induce apoptosis or to decrease expression of non-cleaved caspase-3 and PARP in cell lines BSC-OF and IS-FOM cells that expressed high levels of HIF-1α. BSC-OF and IS-FOM cells exhibited high migratory capacity. When CoCl(2) was present in the medium, HIF-1α expression increased along with the survival of Ca9-22 cells after radiation exposure. These results suggest that OSCC cells expressing high levels of HIF-1α are resistant to radiation. HIF-1α can be used to control the short-term radiosensitivity of cells.
Subject(s)
Carcinoma, Squamous Cell/radiotherapy , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Mouth Neoplasms/radiotherapy , Apoptosis , Cell Line , Cell Line, Tumor , Cell Movement , Cell Survival , Culture Media, Conditioned/pharmacology , Densitometry/methods , Humans , Radiation-Protective Agents , Reverse Transcriptase Polymerase Chain Reaction/methods , Time Factors , Transcription, Genetic , X-RaysABSTRACT
Follicular variant thyroid-type papillary carcinoma (FVTPC) arising from thyroid tissue in mature cystic teratoma of the left ovary is extremely rare, and it is not easy to diagnose preoperatively. However, with reports of an early postoperative death, we must prudently select the strategy for this lesion. A 50-year-old woman had a uterine fibroid with hypermenorrhea and a left ovarian tumor measuring approximately 8 cm diameter. Serum thyroid-stimulating hormone level was within the normal limit. A laparoscopic hysterectomy and left salpingo-oophorectomy were performed. During surgery, there were no signs of invasion or metastasis, and there was no spillage in the abdomen. On histopathological examination of the left ovary, we diagnosed FVTPC arising from thyroid tissue in mature cystic teratoma of the left ovary. FVTPC in ovarian struma is a rare malignant transformation. We must be aware of the possibility of such a rare malignant disease when treating teratoma laparoscopically.
Subject(s)
Carcinoma, Papillary/surgery , Laparoscopy , Ovarian Neoplasms/surgery , Ovariectomy/methods , Salpingectomy/methods , Struma Ovarii/surgery , Carcinoma, Papillary/diagnosis , Female , Humans , Middle Aged , Ovarian Neoplasms/diagnosis , Struma Ovarii/diagnosisSubject(s)
Nasal Polyps , Administration, Intranasal , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Anti-Inflammatory Agents/therapeutic use , Child , Child, Preschool , Eosinophils/physiology , Female , History, 17th Century , History, Ancient , Humans , Incidence , Ion Transport/physiology , Male , Mast Cells/pathology , Middle Aged , Nasal Polyps/drug therapy , Nasal Polyps/epidemiology , Nasal Polyps/history , Nasal Polyps/pathology , Nasal Polyps/surgery , Otolaryngology/history , Prevalence , Quality of Life , Sex Distribution , Surgical Instruments/historyABSTRACT
Elastic system fibers are load-bearing proteins found in periodontal tissue. There are three types--oxytalan, elaunin, and elastic fibers--which differ in their relative microfibril and elastin contents. Oxytalan fibers are known to be distributed in the periodontal ligaments and gingiva, whereas elaunin and elastic fibers are present only in the gingiva. We examined gene expression and accumulation of tropoelastin in the cell-matrix layers of human gingival fibroblasts (HGF) and periodontal ligament fibroblasts (HPLF) in vitro. HGF and HPLF were cultured in MEM containing 10% newborn calf serum for 8 wks. Northern blotting and RT-PCR analyses showed that only HGF expressed mRNA encoding tropoelastin. Western blotting analysis demonstrated 77-kDa protropoelastin and 68-kDa tropoelastin only in the cell-matrix layer of HGF cultured for 8 wks. These results suggest that the different tropoelastin expression patterns reflect the difference between HGF and HPLF phenotypes.
Subject(s)
Fibroblasts/metabolism , Periodontal Ligament/metabolism , Tropoelastin/analysis , Adolescent , Adult , Blotting, Northern , Blotting, Western , Cell Membrane/metabolism , Cells, Cultured , Elastin/analysis , Elastin/genetics , Electrophoresis, Polyacrylamide Gel , Extracellular Matrix/metabolism , Gene Expression Regulation , Gingiva/cytology , Gingiva/metabolism , Humans , Periodontal Ligament/cytology , Phenotype , Protein Precursors/analysis , Protein Precursors/genetics , RNA, Messenger/analysis , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Tropoelastin/geneticsABSTRACT
The purpose of this study was to examine the morphological changes in alveolar bone osteocytes on the pressure side during experimental tooth movement, using quantitative evaluation on hematoxylin and eosin-stained sections, the TUNEL method, confocal laser scanning microscopy (CLSM), and transmission electron microscopy. In 8-week-old Wistar rats, the left first molar was forced to move mesially with an average load of 10 g by a nickel-titanium superelastic wire. After 6 hours, nuclear condensation and fragmentation appeared in osteocytes adjacent to the hyalinized periodontal ligament (PDL). These cells showed TUNEL-positive reaction. The number of osteocytes with apoptosis progressively increased up to 1 day. At 1 and 2 days, cytoplasmic and nuclear destruction and distribution within the lacunae occurred and increased up to 4 days. The proportion of necrotic osteocytes and near empty lacunae peaked at 2 and 4 days, respectively. At 7 days, necrotic osteocyte and empty lacunae numbers returned to the level of control bone, probably due to resorption of the alveolar bone containing apoptotic and necrotic osteocytes. Ultrastructually, the osteocytes showed apoptotic morphology at 6 and 12 hours and 1 day; at 2 and 4 days, several osteocytes exhibited characteristics of necrosis and destructive images of the surrounding bone matrix, which resulted in enlargement of the lacunae. The present results demonstrate that osteocytes in alveolar bone adjacent to the hyalinized PDL underwent cell death via apoptosis and "secondary necrosis" during orthodontic tooth movement, which may be associated with the subsequent bone resorption.
Subject(s)
Alveolar Process/cytology , Apoptosis , Osteocytes/cytology , Tooth Movement Techniques , Animals , Male , Molar , Rats , Rats, WistarABSTRACT
Fast scan techniques, which are used to reduce scanning times, have raised scanning noise levels in magnetic resonance imaging (MRI) systems, resulting in greater patient discomfort and stress. It is well known that this noise is caused by vibration of the gradient coil due to the Lorentz forces generated by the current in the gradient coil, which is placed in a static magnetic field. We have confirmed that MRI noise can be substantially reduced by sealing the gradient coil in a vacuum chamber to block airborne vibration propagation, by supporting the gradient coil independently to block solid vibration propagation and by decreasing the eddy currents induced in RF coils, the RF shield and the static-field-magnet cryostat. Based on these findings, we have developed a silent MRI system in which scanning noise is markedly reduced under a wide range of scanning conditions.
Subject(s)
Electromagnetic Fields , Magnetic Resonance Imaging/instrumentation , Magnetic Resonance Imaging/methods , Noise , Physical Phenomena , Physics , Signal Processing, Computer-Assisted , SoundABSTRACT
OBJECTIVE: Late phase response (LPR) is difficult to investigate in patients with perennial nasal allergy because of their continuous presentation with nasal symptoms. Contribution of histamine to the LPR is also controversial. In this study, we investigated whether exogenous histamine can induce LPR in asthmatic patients with perennial nasal allergy to house dust. METHODS: A total of 40 asthmatic children were divided into clinical, subclinical and non-rhinitis groups based on their daily nasal symptoms. Changes in nasal patency and in inflammatory cells in nasal secretion were quantitatively measured for 6 h by acoustic rhinometry and light microscopy respectively before and after nasal challenge with allergen or histamine. RESULTS: The allergen challenge produced a significant biphasic decrease in nasal patency in the subclinical group and a marginal decrease in the clinical group, with increases in eosinophils 6 h after the challenge. By contrast, histamine challenge induced significant responses in the clinical group and only a slight response in the subclinical group. Eosinophils also accumulated in nasal secretion of the clinical group to significant levels 6 h after histamine challenge. Eosinophil accumulation following histamine challenge was earlier than that after exposure to allergen. CONCLUSION: We conclude that LPR can be demonstrated in asthmatic children with perennial nasal allergy. Exposure to exogenous histamine also induced LPR, mediated mainly by eosinophil-related mediators.
Subject(s)
Asthma/diagnosis , Nasal Provocation Tests , Rhinitis, Allergic, Perennial/diagnosis , Adolescent , Allergens , Child , Female , Histamine , Humans , Male , Reproducibility of Results , Rhinometry, Acoustic , Sensitivity and SpecificityABSTRACT
To examine the differential properties of mucous glycoproteins, we produced hypertrophic and metaplastic changes in goblet cells of rat nasal epithelium by intranasal instillation of ovalbumin (OVA) in OVA-sensitized rats, and by intranasal lipopolysaccharide (LPS) instillation. The epithelial mucosubstance was quantitatively examined by alcian blue-periodic acid-Schiff (AB-PAS) and lectin histochemistry. The newly produced mucin after OVA challenge or LPS instillation contained a high amount of sulfomucin and a low amount of neutral glycoprotein: LPS-induced mucin contained more sulfomucin (70.1% of total) and less neutral glycoprotein (8.6%) than OVA-induced mucin (sulfomucin, 33.6%; neutral glycoprotein, 41.8%; p < 0.01). Four of the lectins stained some of the mucosubstance, indicating the presence of galactose-N-acetylgalactosamine, alpha2,3- and alpha2,6-linked sialic acid-galactose, and fucose residues. After LPS instillation, the reactivity was higher for galactose-N-acetylgalactosamine (64.8% of total) and alpha2,3-linked sialic acid-galactose (75.8%) than after saline instillation (3.5 and 19.1%, respectively) or OVA challenge (5.8 and 32.3%; p < 0.05). OVA challenge did not induce the alteration of terminal sugar residues. A 2-fold increase in mucin mRNA (rat Muc5ac) expression was induced after LPS instillation or OVA challenge, compared with animals treated with saline instillation (p < 0.05). These results indicate that mucin mRNA expression (for peptide backbone) increases similarly after LPS instillation or OVA challenge; however, carbohydrate compositions of newly produced mucin are different between the two groups.
Subject(s)
Goblet Cells/physiology , Hypersensitivity/physiopathology , Inflammation/physiopathology , Lipopolysaccharides/administration & dosage , Mucins/physiology , Animals , Data Interpretation, Statistical , Epithelium/metabolism , Epithelium/pathology , Epithelium/physiology , Goblet Cells/metabolism , Goblet Cells/pathology , Histocytochemistry , Hypersensitivity/pathology , Inflammation/pathology , Lectins , Male , Mucins/genetics , Mucins/metabolism , Mucus/metabolism , Mucus/physiology , Ovalbumin/administration & dosage , RNA, Messenger/analysis , Rats , Rats, Inbred F344 , Reverse Transcriptase Polymerase Chain Reaction , Sodium Chloride/administration & dosageABSTRACT
To evaluate the effects of sterol regulatory element-binding proteins (SREBPs) on the expression of the individual enzymes in the cholesterol synthetic pathway, we examined expression of these genes in the livers from wild-type and transgenic mice overexpressing nuclear SREBP-1a or -2. As estimated by a Northern blot analysis, overexpression of nuclear SREBP-1a or -2 caused marked increases in mRNA levels of the whole battery of cholesterogenic genes. This SREBP activation covers not only rate-limiting enzymes such as HMG CoA synthase and reductase that have been well established as SREBP targets, but also all the enzyme genes in the cholesterol synthetic pathway tested here. The activated genes include mevalonate kinase, mevalonate pyrophosphate decarboxylase, isopentenyl phosphate isomerase, geranylgeranyl pyrophosphate synthase, farnesyl pyrophosphate synthase, squalene synthase, squalene epoxidase, lanosterol synthase, lanosterol demethylase, and 7-dehydro-cholesterol reductase. These results demonstrate that SREBPs activate every step of cholesterol synthetic pathway, contributing to an efficient cholesterol synthesis.
Subject(s)
CCAAT-Enhancer-Binding Proteins/metabolism , Cholesterol/biosynthesis , DNA-Binding Proteins/metabolism , Transcription Factors/metabolism , Animals , Base Sequence , CCAAT-Enhancer-Binding Proteins/genetics , DNA Primers , DNA-Binding Proteins/genetics , Diphosphates/metabolism , Gene Expression Regulation, Enzymologic , Mice , Mice, Transgenic , Sterol Regulatory Element Binding Protein 1 , Sterol Regulatory Element Binding Protein 2 , Transcription Factors/geneticsABSTRACT
We have developed an automated multiplex system for simultaneously screening hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus type 1 (HIV-1) in blood donations. The assay, designated AMPLINAT MPX HBV/HCV/HIV-1 Test (AMPLINAT MPX), consists of virus extraction and target sequence-specific probe capture on specimen preparation workstation GT-X (Roche Diagnostics K.K., Tokyo, Japan) and amplification and detection by TaqMan PCR on the ABI PRISM 7700 Analyzer (Perkin-Elmer Applied Biosystems, Foster City, Calif.). An internal control (IC) is incorporated in the assay to monitor the extraction, target amplification, and detection processes. The assay yields qualitative results without discrimination of the three targets. Detection limits (95% confidence interval) are 22 to 60 copies/ml for HBV, 61 to 112 IU/ml for HCV, and 33 to 66 copies/ml for HIV-1, using a specimen input volume of 0.2 ml. The AMPLINAT MPX assay detects a broad range of genotypes or subtypes for all three viruses and has a specificity of 99.6% for all three viruses with seronegative specimens. In an evaluation of seroconversion panels, the AMPLINAT MPX assay detects HBV infection an average of 24 days before the detection of HBsAg by enzyme immunoassay. HCV RNA was detected an average of 31 days before HCV antibody. HIV-1 RNA was detected an average of 14 days before HIV-1 antibody and an average of 9 days before p24 antigen. The Japanese Red Cross has been evaluating the AMPLINAT MPX system since October 1999. The clinical performance indicates that the AMPLINAT MPX system is robust, sensitive, and reproducible, with a high percentage of valid assay runs (96.8%), a low false-positive rate (0.34%), and a low IC failure rate (0.24%).
Subject(s)
DNA, Viral/blood , HIV-1/isolation & purification , Hepacivirus/isolation & purification , Hepatitis B virus/isolation & purification , Polymerase Chain Reaction/methods , RNA, Viral/blood , Blood Donors , HIV Infections/diagnosis , HIV Infections/virology , HIV-1/classification , HIV-1/genetics , Hepacivirus/classification , Hepacivirus/genetics , Hepatitis B/diagnosis , Hepatitis B/virology , Hepatitis B virus/classification , Hepatitis B virus/genetics , Hepatitis C/diagnosis , Hepatitis C/virology , Humans , Mass Screening , Reagent Kits, Diagnostic , Sensitivity and Specificity , Taq Polymerase/metabolismABSTRACT
Sewage and treated water can be a heat source in urban area due to large heat capacity, thus recovery and reuse of its energy is one of the most desirable plans for the sewerage system. In this paper, characteristics of heat energy in wastewater, reuse plans, and some experiences in Japan are presented. Full-scale reuse projects for heating and cooling in the Tokyo Metropolitan Districts and project for melting snow in Sapporo City are discussed. The key factors found in experience of Tokyo were setting the heat pumps near the demand points and the technical developments of equipment to prevent system from clogging, corrosion, and decrease in the heat transfer efficiency. It was also found through the project for melting snow in Sapporo that the key factor in public acceptance was the multi-purpose use of the sewerage system both for melting snow in winter and retaining rain water in summer.
Subject(s)
Conservation of Energy Resources/methods , Energy Transfer , Hot Temperature , Waste Management/methods , Air Conditioning/economics , Air Conditioning/instrumentation , Conservation of Energy Resources/economics , Heating/economics , Heating/instrumentation , Japan , Snow , Waste Management/economics , Waste Management/instrumentationABSTRACT
We describe the configuration and size of the artificial fascial dome created in 57 cadavers. This dome protrudes into the thoracic cavity from the esophageal hiatus. This dome was a potential space realized by finger dissection (i.e., a specific but common surgical procedure during surgery of the upper part of the stomach). The vagus nerves penetrated the top of the dome and ran down along the esophagus. The height of the ventral wall of the dome ranged from 10-60 mm, while the dorsal wall was 10-40 mm longer than the ventral one since the dorsal wall attached to the lower, dorsal limb of the esophageal hiatus. Accordingly, the dorsal wall separated the "thoracic" aorta from the "abdominal" esophagus. We considered that the upper leaf of the phreno-esophageal membrane forms the fascial dome, although the lower leaf of the membrane was not identified in this study. According to the results, we proposed a schematic representation of the phreno-esophageal membrane.
Subject(s)
Esophagus/surgery , Phrenic Nerve/surgery , Aged , Diaphragm/anatomy & histology , Esophagus/anatomy & histology , Esophagus/innervation , Female , Humans , Male , Middle Aged , Phrenic Nerve/anatomy & histology , Surgical Flaps , Suture Techniques , Vagus NerveABSTRACT
To examine the effects of running exercise on the mandible and tibia of ovariectomized (OVX) rats, 26-week-old sham-operated (Sham) and OVX rats 1 week post-ovariectomy were subjected to non-exercise (Sham-Cont and OVX-Cont) and exercise (Sham-Exc and OVX-Exc) for 8 weeks. OVX induced a significant decrease in alkaline phosphatase (ALP) and an increase in tartrate-resistant acid phosphatase (TRAP) activity and a reduction of 17beta-estradiol in the serum. In OVX-Cont rats, histology and bone mineral density (BMD) showed bone loss in the proximal tibia, and histology, soft X-ray photographs and bone marrow area (BMA) revealed enlargement of the bone marrow cavity in the neck of the condylar process. In OVX-Exc rats, exercise significantly increased ALP activity, decreased TRAP activity and markedly elevated serum progesterone levels. Histology and BMD in the tibia and histology, X-ray photographs and BMA in the mandible were comparable to those in Sham rats. In Sham-Exc rats, unexpected decreases were observed in serum enzymes and hormones, but the histology and BMD in the tibia and histology, X-ray photographs and BMA in the mandible were very similar to those in Sham-Cont rats, suggesting a decrease of bone turnover with no change of bone mass in the tibia and mandible. We conclude that exercise has a beneficial effect not only on bone loss in the tibia, but also on differential changes in the neck of the condylar process, perhaps by increasing serum levels of progesterone in OVX rats.
Subject(s)
Mandible/physiology , Motor Activity/physiology , Tibia/physiology , Alkaline Phosphatase/blood , Animals , Bone Density , Cervical Vertebrae/diagnostic imaging , Cervical Vertebrae/physiology , Estradiol/blood , Female , Mandible/diagnostic imaging , Mandibular Condyle/diagnostic imaging , Mandibular Condyle/physiology , Ovariectomy , Radiography , Rats , Rats, Wistar , Running , Tibia/diagnostic imagingABSTRACT
OBJECTIVES: Sinusitis is characterized by quantitative and qualitative changes in mucus biosynthesis that contribute to sinus disease. In general, patients with acute sinusitis complain of purulent rhinorrhea, whereas those with chronic sinusitis complain of mucoid or mucopurulent rhinorrhea Locally produced mucin largely contributes to the high viscoelasticity of mucus in sinusitis. In this study, the authors attempt to quantify the concentrations of mucin and lectin in the maxillary sinus fluids from these patients. STUDY DESIGN: To assess the concentrations of mucin and lectin in aspirates of 11 acutely and 11 chronically inflamed maxillary sinuses, the concentration of mucin was measured by enzyme-linked immunosorbent assay (ELISA) and that of lectin by sandwiched enzyme-linked lectin assay (ELLA). RESULTS: The concentrations of mucin and lectin that were measured using monoclonal antibodies (HCS 4, HCS 14, and HCS 18) and Ulex europaeus agglutinin-1 (UEA-1) in chronic sinusitis were higher than those in acute sinusitis. The concentration of total protein in chronic sinusitis was lower than that in acute sinusitis. Each mucin and lectin versus total protein ratio in chronic sinusitis was higher than that in acute sinusitis. CONCLUSIONS: These data suggest that hypersecretion in chronic sinusitis may result from locally increased mucin production. Comprehension of this mechanism may be a strategy to prevent the viscous cycle of paranasal sinus fluids in chronic sinusitis.
Subject(s)
Bacterial Infections/diagnosis , Lectins/metabolism , Maxillary Sinusitis/diagnosis , Mucins/metabolism , Acute Disease , Adolescent , Adult , Aged , Chronic Disease , Female , Humans , Male , Middle AgedABSTRACT
BACKGROUND: Airway epithelial cells produce cytokines and participate in the regulation of mucosal immunity. Although nasal epithelial cells express histamine receptors, it is not exactly known how nasal epithelial cells respond to histamine. OBJECTIVE: The objective of this study was to examine whether histamine can alter the expression of the 4 genes encoding H1 receptor, IL-8, TNF-alpha, and ZO-1 tight-junction protein in cultured nasal epithelial cells. METHODS: We added histamine or vehicle to cultured human nasal epithelial cells and extracted RNA from them 4 hours later. After DNase treatment, mRNAs of beta-actin, H1 receptor, IL-8, TNF-alpha, and ZO-1 tight-junction protein were amplified by using RT-PCR. RESULTS: Histamine significantly upregulated IL-8 mRNA expression and significantly downregulated ZO-1 mRNA expression. The latter effect was blocked by pretreatment with mepyramine, an H1 receptor antagonist. CONCLUSION: The reduction of ZO-1 mRNA by histamine may cause increased permeability of the mucosa during allergic reactions in the nose.
Subject(s)
Epithelial Cells/metabolism , Epithelial Cells/physiology , Histamine/pharmacology , Nasal Mucosa/cytology , Cells, Cultured , Gene Expression/drug effects , Histamine H2 Antagonists/pharmacology , Humans , Pyrilamine/pharmacology , RNA, Messenger/biosynthesis , Ranitidine/pharmacology , Receptors, Histamine H1/genetics , Tumor Necrosis Factor-alpha/geneticsABSTRACT
OBJECTIVE: The purpose of this study is to find out the effects of hearing impairment on the QOL of nursing home residents. METHODS: We constructed the self-assessment questionnaire designed for evaluating the QOL for the elderly in nursing homes. The questionnaire is constructed of physical, social, communicational and psychological states. It was administered to 60 subjects >65 years of age (mean age: 79 years) living in nursing homes, with hearing threshold levels in the better ear ranging from normal to severe and their response were analyzed. RESULTS: Chronbach's alpha-values of the questionnaire obtained ranged from 0.66 to 0.91 and was 0.84 overall. The reliability and validity of the questionnaire as well as its brevity, simplicity, ease of administration and interpretation, all satisfied its use in assessing the QOL of the elderly in nursing homes. It tended to decrease the points of communication scale, sociability scale and psychological scale (PGC Morale Scale) accordingly to elevate the threshold. As for subscales of communication, hearing disability was correlated statistically to the sociability and psychological. CONCLUSION: Our questionnaire is regarded as a useful tool for evaluating the QOL of the elderly. Hearing loss affects the communication, sociability and psychological aspect of the QOL for the elderly in the nursing homes.
Subject(s)
Hearing Disorders/psychology , Nursing Homes , Quality of Life , Aged , Aged, 80 and over , Audiometry, Pure-Tone , Depression/etiology , Female , Hearing Disorders/diagnosis , Humans , Male , Reproducibility of Results , Self-Assessment , Speech Discrimination Tests , Surveys and QuestionnairesABSTRACT
Membrane type 1-matrix metalloproteinase (MT1-MMP) is capable of mediating proteolysis of extracellular matrix. The enzyme has been demonstrated in osteoclasts, in vitro. However, the precise localization in vivo, and therefore the function of the enzyme in osteoclasts, is still unclear. In this study, we immunohistochemically examined the localization of MT1-MMP in rat osteoclasts to clarify the role of MT1-MMP in osteoclastic bone resorption and bone turnover. The localization of MT1-MMP was visualized by the pre-embedding method using anti-MT1-MMP antibody and horseradish peroxidase (HRP) or gold-conjugated antibody. Immunoreactivity of anti-MT1-MMP was found in osteoclasts at the osteoclast-bone interface, but it was not uniform. Ultrastructurally, the immunoreactivity visualized by HRP was found in sealing zone. The plasma membrane at this site showed an irregular border and some invaginations. Immunoreactivity was also found on the surface of certain small vesicles in the cytoplasm. Enhanced silver granules were mainly associated with the sealing membrane. In this study, we demonstrated, for the first time, the localization of MT1-MMP in the sealing zone of osteoclast in vivo. Its distribution suggests that the enzyme modifies the bone surface to facilitate the migration and attachment of osteoclasts as well as scavenging the resorption lacunae.
Subject(s)
Metalloendopeptidases/analysis , Osteoclasts/chemistry , Animals , Immunoenzyme Techniques , Male , Matrix Metalloproteinases, Membrane-Associated , Rats , Rats, WistarABSTRACT
We studied the case of a 48-year-old woman who had resection of a pineal body tumor in terms of postoperative audiological function. Postoperative magnetic resonance imaging disclosed partial inferior colliculi destruction and medial geniculate body degeneration. A pure tone audiogram revealed only moderate sensorineural hearing loss, but her speech perception was totally impaired. The binaural sound localization function was also impaired. The auditory brain stem response (ABR) showed waves I, III, and V to have normal latencies. The amplitude of wave III was larger than that of wave V. These results support the view that the waves of the ABR are elicited from multiple sources in the auditory brain stem nuclei and tracts. This case suggests a substantial role for the inferior colliculus and medial geniculate body in the processing of speech perception and sound localization.