Dental root resorption and repair: histology and histometry during physiological drift of rat molars

OBJECTIVE: The process of dental root resorption and subsequent cementum regeneration has not been sufficiently elucidated. This study aimed to examine the process of the root resorption and cementum regeneration during physiological tooth drift using a rat model, and to evaluate this experimental model. METHODS: Distal roots in mandibular first molars and the surrounding periodontal tissues were investigated with light and electron microscopy. The light microscopic approach included histochemical and histometric analyses utilizing the tartrate-resistant acid phosphatase (TRAP) reaction. RESULTS: Root resorption was observed in the distal side of the roots and was most active in 5- to 6-week-old rats, and gradually decreased hereafter. An increase in the number of TRAP-positive mononuclear cells, which seemed to be odontoclast precursor cells, preceded the increase in the number of odontoclasts. Root resorption was transient, and was followed by the new formation of acellular extrinsic fiber cementum accompanied with only a slight inflammation, and therefore classified as external surface resorption. Preparation for new cementum started adjacent to the resorption areas when root resorption was most active. CONCLUSIONS: The root resorption during drift in rats is transient and followed by acellular extrinsic fiber cementum regeneration. Cellular kinetics suggested that odontoclast precursor cells are supplied as mononuclear cells from vascular spaces.     

Relationship between cranial base structure and maxillofacial components in children aged 3-5 years

The aim of this study was to clarify the inter-relationships between cranial base angle, the morphological variations of maxillofacial components, and growth of the anterior cranial base length. One hundred and twenty-two Japanese children aged 3-5 years with normal occlusion in the primary dentition were included in this investigation. To analyse the relationship between cranial base structure and maxillofacial components, the subjects were divided into three groups according to facial type (prognathic, orthognathic, or retrognathic) assessed by the magnitude of their NSAr angle (as cranial base angle). These categorized cephalometric profiles suggested that the antero-posterior location of the maxillofacial components corresponded to the NSAr angle. Factor analysis of cephalometric variables showed that the variation of maxillofacial components from the S-N line was strongly related to the cranial base angle. This normal range of morphological variation was distinguished from that of growth by the factor loadings. From these results, theoretical models of cephalometric profiles with normal occlusion were computed by linear regression analysis. Using the models, a standard profile related to an arbitrary cranial base angle was obtained for children with normal occlusion, aged 3-5 years.     

Immunohistochemical localization of carbonic anhydrase I and II in submandibular salivary glands of the mouse, rat, hamster and guinea pig

Tissues were fixed in Bouin and Carnoy solutions, and the peroxidase, anti-peroxidase (PAP) method was used. Serous acinar cells of the guinea pig were positive for carbonic anhydrase (CA), but acinar cells of rodents were negative. Granular convoluted tubule (GCT) cells of the mouse, rat and hamster had varying degrees of staining for CA isoenzyme I and II. Striated and excretory ducts from all four species were usually positive for CA. Scattered cells containing a high concentration of CA I and CA II were present in striated ducts and GCT of the hamster, GCT of the rat and striated and excretory ducts of the guinea pig.     

Morphological features of elderly patients with obstructive sleep apnoea syndrome: a prospective controlled,comparative cohort study

Clin. Otolaryngol. 2011, 36 , 139–146 Objectives: To investigate the pharyngeal morphologic features and its pathogenic role on obstructive sleep apnoea syndrome in the elderly population. Design: Prospective controlled, comparative cohort study. Setting: Territory referral centre. Participants: We enroled 320 consecutive patients with complaints of snoring who visited Nagoya University Hospital from January 2004 to December 2007. We also collected 26 control subjects aged over 60 years from community‐dwelling people. Main outcome measures: We underwent a morphological evaluation, measurement of nasal resistance, assessment of daytime sleepiness and nocturnal polysomnography. Results and conclusions: Two hundred and ninety‐two patients were analysed. The constitution ratio of men, the body mass index and Epworth sleepiness scale were decreased with ageing. Tonsil size was reduced progressively with ageing. Retroglossal space was wider, and soft palate was lower in ≥60 year group than in <40 year group. Retroglossal space was wide in elderly patients with sleep apnoea compared with control subjects. Tonsil size was not correlated to apnoea/hypopnoea index in ≥60 year group unlike the other generations. Modified Mallampati Score and tongue size were significantly but mildly correlated only in ≥60 year group. Width of fauces was correlated in all the groups. Multiple regression analysis showed that body mass index, age, gender, tonsil size and width of fauces were independent factors for apnoea/hypopnoea index. Conclusions: Morphologically, the tonsil could play a minor role but the width of fauces could play relatively a major role. Additionally, wide retroglossal space, low positional soft palate and large tongue size may be characteristics for elderly patients of obstructive sleep apnoea syndrome.     

Successful unrelated umbilical cord blood cell transplantation without conditioning for a neonate with severe combined immunodeficiency

Taga T, Itoh E, Noda Y, Kato H, Maruo Y, Takano T, Ohta S, Takeuchi Y, Kumaki S. Successful unrelated umbilical cord blood cell transplantation without conditioning for a neonate with severe combined immunodeficiency.
Pediatr Transplantation 2011: 15: E152–E155. © 2010 John Wiley & Sons A/S. Abstract: A neonate was diagnosed as having SCID from his umbilical cord blood cells immediately after birth because his older brother had died of SCID eight months earlier. One locus‐mismatched unrelated umbilical cord blood cell transplantation without conditioning was performed at the age of 30 days. The CD3‐positive cells were detected on day 14 post‐transplantation. There were no peri‐transplantation complications. Four yr after transplantation, the boy is in excellent condition and T and NK cell engraftments are complete. His peripheral B cells with a common gamma chain were not detected by flow cytometry, and he still needs IgG replacement; however, his IgM and IgA levels have gradually increased, and the dosage of IVIG per body weight has gradually decreased. We speculate that the very few B cells that proliferate from transplanted cord blood cells produce gamma globulin. Unrelated cord blood cell transplantation, even though mismatched, without conditioning would be a treatment option for neonates with severe combined immunodeficiency.     

Activation of human and rabbit prokallikrein by serine and metalloproteases

Human and rabbit kidney and urine contain an inactive form of kallikrein. Studies on the mRNA sequence suggested that the active form of the enzyme and the propeptide are linked by a peptide bond between a basic and hydrophobic amino acid. We studied the activation of prokallikrein by serine proteases and a neutral metalloproteinase, thermolysin, because serine proteases cleave the peptide chain after a basic amino acid and thermolysin before a hydrophobic amino acid. The activity of kallikrein was measured by RIA and with a fluorogenic peptide substrate. Trypsin was used as a standard reference activator. We found that human plasmin and plasminogen, activated by urokinase, activate prokallikrein. Pronase coupled to Sepharose also enhanced the activity of the renal kallikrein zymogen. On a molar basis, thermolysin was a more effective activator of prokallikrein than trypsin. The activation by thermolysin was blocked by the inhibitor phosphoramidon, but not by DFP or SBTI. These experiments indicate that, in addition to serine proteases, neutral metalloproteases of tissues may activate prokallikrein.     

Fli1 deficiency contributes to the suppression of endothelial CXCL5 expression in systemic sclerosis

CXCL5 is a member of CXC chemokines with neutrophilic chemoattractant and pro-angiogenic properties, which has been implicated in the pathological angiogenesis of rheumatoid arthritis and inflammatory bowel diseases. Since aberrant angiogenesis is also involved in the developmental process of systemic sclerosis (SSc), we herein measured serum CXCL5 levels in 63 SSc and 18 healthy subjects and investigated their clinical significance and the mechanism explaining altered expression of CXCL5 in SSc. Serum CXCL5 levels were significantly lower in SSc patients than in healthy subjects. In diffuse cutaneous SSc (dcSSc), serum CXCL5 levels were uniformly decreased in early stage (<1 year) and positively correlated with disease duration in patients with disease duration of <6 years. In non-early stage dcSSc (≥1 year), decreased serum CXCL5 levels were linked to the development of digital ulcers. Consistently, the expression levels of CXCL5 proteins were decreased in dermal blood vessels of early stage dcSSc. Importantly, Fli1 bound to the CXCL5 promoter and its gene silencing significantly suppressed the CXCL5 mRNA expression in human dermal microvascular endothelial cells. Furthermore, endothelial cell-specific Fli1 knockout mice, an animal model of SSc vasculopathy, exhibited decreased CXCL5 expression in dermal blood vessels. Collectively, these results indicate that CXCL5 is a member of angiogenesis-related genes, whose expression is suppressed at least partially due to Fli1 deficiency in SSc endothelial cells. Since Fli1 deficiency is deeply related to aberrant angiogenesis in SSc, it is plausible that serum CXCL5 levels inversely reflect the severity of SSc vasculopathy.