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1.
Clin Radiol ; 78(9): e668-e675, 2023 09.
Article in English | MEDLINE | ID: mdl-37355355

ABSTRACT

AIM: To evaluate the safety and feasibility of using radiofrequency identification (RFID) tags for the localisation of axillary nodes prior to targeted excision in a National Health Service (NHS) breast unit. MATERIALS AND METHODS: Retrospective data collection was carried out to analyse the first 75 cases of RFID-targeted axillary nodes inserted between 12 June 2019 and 27 October 2022, during which an overall total of 1,296 breast and axillary tags were deployed in 1,120 patients. RESULTS: Of the 75 axillary tags, 70 (93%) had a primary breast cancer and five (7%) had no known breast cancer but had an abnormal node targeted for diagnostic excision. Of the 70 with breast cancer, 20 (29%) underwent neoadjuvant chemotherapy (NAC) including one neoadjuvant endocrine therapy. Localisations were performed an average of 11 days before surgery (median 6, range 1-95; n=75). Patients undergoing NAC had their tags inserted after completing treatment due to the artefact caused by the tags on magnetic resonance imaging (MRI). Tag deployment had a 100% success rate, with 62 tags (83%) lying within the node and 13 tags (17%) lying directly adjacent to the node, either in direct contact (nine of 13), or a maximum of 8 mm from the target (four of 13). All tags and their respective nodes were excised successfully at surgery with no significant complications. There were four cases of tag dislodgement during excision, but overall, this did not compromise retrieval of the tag or the node. CONCLUSIONS: The use of RFID tags for the preoperative localisation of axillary nodes is safe and feasible.


Subject(s)
Breast Neoplasms , Radio Frequency Identification Device , Humans , Female , Lymph Node Excision , Retrospective Studies , Feasibility Studies , State Medicine , Lymph Nodes/diagnostic imaging , Lymph Nodes/surgery , Lymph Nodes/pathology , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/surgery , Breast Neoplasms/drug therapy , Neoadjuvant Therapy , Axilla/pathology , Sentinel Lymph Node Biopsy , Neoplasm Staging
2.
Anal Biochem ; 669: 115113, 2023 05 15.
Article in English | MEDLINE | ID: mdl-36958511

ABSTRACT

The aim of this guideline is to provide a series of evidence-based recommendations that allow those new to using MEGA-PRESS to produce high-quality data for the measurement of GABA levels using edited magnetic resonance spectroscopy with the MEGA-PRESS sequence at 3T. GABA is the main inhibitory neurotransmitter of the central nervous system and has been increasingly studied due to its relevance in many clinical disorders of the central nervous system. MEGA-PRESS is the most widely used method for quantification of GABA at 3T, but is technically challenging and operates at a low signal-to-noise ratio. Therefore, the acquisition of high-quality MRS data relies on avoiding numerous pitfalls and observing important caveats. The guideline was developed by a working party that consisted of experts in MRS and experts in guideline development and implementation, together with key stakeholders. Strictly following a translational framework, we first identified evidence using a systematically conducted scoping literature review, then synthesized and graded the quality of evidence that formed recommendations. These recommendations were then sent to a panel of 21 world leaders in MRS for feedback and approval using a modified-Delphi process across two rounds. The final guideline consists of 23 recommendations across six domains essential for GABA MRS acquisition (Parameters, Practicalities, Data acquisition, Confounders, Quality/reporting, Post-processing). Overall, 78% of recommendations were formed from high-quality evidence, and 91% received agreement from over 80% of the expert panel. These 23 expert-reviewed recommendations and accompanying extended documentation form a readily useable guideline to allow those new to using MEGA-PRESS to design appropriate MEGA-PRESS study protocols and generate high-quality data.


Subject(s)
Brain , gamma-Aminobutyric Acid , Magnetic Resonance Spectroscopy/methods , Signal-To-Noise Ratio , Central Nervous System
3.
Clin Radiol ; 75(12): 942-949, 2020 12.
Article in English | MEDLINE | ID: mdl-32919756

ABSTRACT

AIM: To report the outcome of 150 patients using the Hologic LOCalizer RFID (radiofrequency identification) tag system, including the first reported use of RFID tags in the axilla. MATERIALS AND METHODS: Data were collected prospectively from the first tag insertion (12 June 2019) until 150 consecutive patients had undergone surgery (excision date 9 January 2020). RESULTS: A total of 177 tags were targeted to 177 malignant lesions in 150 women. Tags were inserted an average of 7.8 days before surgery (range 0-71 days). One hundred and twenty-six tags were targeted to a single lesion in one breast only; the remainder of tags were targeted to multiple lesions in one or both breasts, as well as to axillary lymph nodes. In addition, two cases involved the use of two tags to bracket microcalcification. All except three tags were satisfactorily deployed at their initial intended target. The majority of target lesions were masses (n=142, mean size 13.8 mm), with a range of other targets including post-vacuum-assisted biopsy cavities, marker clips post-neoadjuvant chemotherapy, architectural distortions, and clipped metastatic lymph nodes. All tags were successfully retrieved at surgical excision. Re-excision rate was 8.7%. There were no tag-specific surgical complications. CONCLUSIONS: The RFID tag system demonstrates many advantages over guidewires, and is effective at targeting axillary lymph nodes and multiple sites within the same breast.


Subject(s)
Breast Neoplasms/pathology , Lymphatic Metastasis/pathology , Radio Frequency Identification Device , Adult , Aged , Aged, 80 and over , Axilla/pathology , Breast Neoplasms/surgery , Female , Humans , Lymph Node Excision , Middle Aged , Prospective Studies , Stereotaxic Techniques , Ultrasonography, Interventional , United Kingdom
4.
Clin Radiol ; 74(9): 676-681, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31229242

ABSTRACT

AIM: To determine if any malignancies would have been missed in women aged 25-29 years in the absence of needle biopsy of sonographically typical fibroadenomas, and to present a non-biopsy protocol for fibroadenomas in this age group using strict criteria. MATERIALS AND METHODS: Women aged 25-29 years undergoing needle biopsies in three centres over a collective 16-year period were identified. Imaging, clinical information, needle biopsy, and surgical histopathology results were obtained from hospital medical records at each centre. RESULTS: Between January 2001 and December 2016, 885 women aged 25-29 years underwent core biopsy. Of 595 sonographically typical fibroadenomas, 549 were histologically confirmed fibroadenomas, 46 were other benign entities, none were cancers. All cancers were scored as indeterminate or suspicious on ultrasound. With a non-biopsy protocol in clinical practice in Centre A, between 2009 and 2018, 259 sonographically typical fibroadenomas met criteria for non-biopsy, and to date, no cancers have been missed. CONCLUSION: This study provides evidence for safe non-biopsy of typical fibroadenomas in women aged 25-29 years when the clinical and sonographic presentations meet strict criteria. A protocol for non-biopsy to include this age group is suggested on incorporation of these results into existing guidance for managing younger women.


Subject(s)
Biopsy, Needle , Fibroadenoma/diagnostic imaging , Fibroadenoma/pathology , Ultrasonography, Mammary/methods , Adult , Decision Making , Diagnosis, Differential , Female , Humans , Retrospective Studies
5.
Osteoarthritis Cartilage ; 26(10): 1326-1332, 2018 10.
Article in English | MEDLINE | ID: mdl-29981835

ABSTRACT

OBJECTIVE: To report the prevalence of varus thrust and normative values for hip-knee-ankle (HKA) angle deviation across the lifespan, and to explore associations between HKA angle deviation and selected clinical factors. DESIGN: This was a cross-sectional observational study of 572 participants from the 1000 Norms Project, aged 3-101 years and who self-reported as being healthy. Video recordings (2D) of frontal plane gait were reviewed by physiotherapists for presence of knee thrust and quantification of HKA angle deviation (the difference between HKA angle at initial contact and mid-stance). Age and sex-stratified normative HKA angle deviation values were presented as means and 95% confidence intervals (CIs). Correlations were calculated between HKA angle and clinical measures (age, sex, body mass index (BMI), alignment, knee and hip strength, Knee Injury and Osteoarthritis Outcomes Scores (KOOS), foot posture index, temporo-spatial gait, and hypermobility). RESULTS: Overall, 31% of the cohort had varus thrust, most prevalent among adults older than 60 years (42%) and children aged 3-9 (41%). Varus thrust was common in adolescents (25%) and adults aged 20-59 (23%). Mean HKA angle deviation for the entire cohort was 1.2° (95%CI: 1.07, 1.36) towards varus, and 2.1° (95%CI: 1.84, 2.36) among people with clinical varus thrust. Weak associations were identified between HKA angle deviation and BMI, stride width, and KOOS-Sports among adolescents, and in adults weakly associated with height. CONCLUSIONS: Prevalence of varus thrust is common across the lifespan. Normative values established here can be readily used by clinicians and researchers in monitoring this gait deviation.


Subject(s)
Bone Malalignment/etiology , Knee Joint/physiopathology , Longevity , Osteoarthritis, Knee/complications , Adolescent , Adult , Aged , Aged, 80 and over , Biomechanical Phenomena , Bone Malalignment/epidemiology , Bone Malalignment/physiopathology , Child , Child, Preschool , Cross-Sectional Studies , Female , Gait/physiology , Humans , Incidence , Knee Joint/diagnostic imaging , Male , Middle Aged , New South Wales/epidemiology , Osteoarthritis, Knee/diagnosis , Osteoarthritis, Knee/physiopathology , Radiography , Reference Values , Retrospective Studies , Video Recording , Young Adult
6.
Clin Radiol ; 73(4): 396-409, 2018 04.
Article in English | MEDLINE | ID: mdl-29439780

ABSTRACT

The presence and extent of axillary nodal metastases at the time of breast cancer diagnosis is a critical factor in disease prognosis and plays a central role in deciding the best treatment for patients. Accurate assessment of the axilla is therefore an essential component in staging breast cancer. Over the years, axillary staging has evolved from surgical axillary lymph node dissection (ALND), with its numerous associated long-term complications, to the much less-radical surgical sentinel lymph node excision biopsy (SLNB), the current reference standard. In parallel, radiological staging of the axilla has become increasingly more useful as our knowledge and techniques have improved. Preoperative axillary ultrasound is used widely to stage patients with breast cancer, providing an evaluation of node morphology and allowing targeted biopsy of abnormal nodes. This is important in helping stratify which patients should proceed directly to ALND and which should undergo SLNB first. Grey-scale ultrasound on its own is not perfect and can over- and underestimate axillary disease. Newer ultrasound techniques such as elastography may help to improve diagnostic confidence when visually assessing axillary nodes; for example, in more accurately assessing the extent of axillary disease burden or in differentiating benign reactive nodes from malignant nodes in equivocal cases. The use of intradermal "microbubbles" has shown great promise in being able to locate and biopsy the sentinel lymph node under ultrasound guidance, and raises the possibility that in the future such techniques may obviate the need for surgical SLNB in select patient populations.


Subject(s)
Breast Neoplasms/pathology , Lymph Nodes/diagnostic imaging , Lymph Nodes/pathology , Lymphatic Metastasis/diagnostic imaging , Lymphatic Metastasis/pathology , Axilla , Female , Humans , Neoplasm Staging , Ultrasonography/methods
7.
Transl Psychiatry ; 6(6): e832, 2016 06 07.
Article in English | MEDLINE | ID: mdl-27271858

ABSTRACT

Electroconvulsive therapy (ECT) is a highly effective and rapidly acting treatment for severe depression. To understand the biological bases of therapeutic response, we examined variations in cortical thickness from magnetic resonance imaging (MRI) data in 29 patients scanned at three time points during an ECT treatment index series and in 29 controls at two time points. Changes in thickness across time and with symptom improvement were evaluated at high spatial resolution across the cortex and within discrete cortical regions of interest. Patients showed increased thickness over the course of ECT in the bilateral anterior cingulate cortex (ACC), inferior and superior temporal, parahippocampal, entorhinal and fusiform cortex and in distributed prefrontal areas. No changes across time occurred in controls. In temporal and fusiform regions showing significant ECT effects, thickness differed between patients and controls at baseline and change in thickness related to therapeutic response in patients. In the ACC, these relationships occurred in treatment responders only, and thickness measured soon after treatment initiation predicted the overall ECT response. ECT leads to widespread neuroplasticity in neocortical, limbic and paralimbic regions and changes relate to the extent of antidepressant response. Variations in ACC thickness, which discriminate treatment responders and predict response early in the course of ECT, may represent a biomarker of overall clinical outcome. Because post-mortem studies show focal reductions in glial density and neuronal size in patients with severe depression, ECT-related increases in thickness may be attributable to neuroplastic processes affecting the size and/or density of neurons and glia and their connections.


Subject(s)
Electroconvulsive Therapy , Image Interpretation, Computer-Assisted , Limbic System/diagnostic imaging , Magnetic Resonance Imaging , Neocortex/diagnostic imaging , Neuronal Plasticity/physiology , Adult , Dominance, Cerebral/physiology , Entorhinal Cortex/diagnostic imaging , Entorhinal Cortex/pathology , Female , Gyrus Cinguli/diagnostic imaging , Gyrus Cinguli/pathology , Humans , Limbic System/pathology , Male , Middle Aged , Neocortex/pathology , Parahippocampal Gyrus/diagnostic imaging , Parahippocampal Gyrus/pathology , Reference Values , Temporal Lobe/diagnostic imaging , Temporal Lobe/pathology , Treatment Outcome
8.
Transl Psychiatry ; 4: e380, 2014 Apr 08.
Article in English | MEDLINE | ID: mdl-24713861

ABSTRACT

Whether plasticity of white matter (WM) microstructure relates to therapeutic response in major depressive disorder (MDD) remains uncertain. We examined diffusion tensor imaging (DTI) correlates of WM structural connectivity in patients receiving electroconvulsive therapy (ECT), a rapidly acting treatment for severe MDD. Tract-Based Spatial Statistics (TBSS) applied to DTI data (61 directions, 2.5 mm(3) voxel size) targeted voxel-level changes in fractional anisotropy (FA), and radial (RD), axial (AD) and mean diffusivity (MD) in major WM pathways in MDD patients (n=20, mean age: 41.15 years, 10.32 s.d.) scanned before ECT, after their second ECT and at transition to maintenance therapy. Comparisons made at baseline with demographically similar controls (n=28, mean age: 39.42 years, 12.20 s.d.) established effects of diagnosis. Controls were imaged twice to estimate scanning-related variance. Patients showed significant increases of FA in dorsal fronto-limbic circuits encompassing the anterior cingulum, forceps minor and left superior longitudinal fasciculus between baseline and transition to maintenance therapy (P<0.05, corrected). Decreases in RD and MD were observed in overlapping regions and the anterior thalamic radiation (P<0.05, corrected). Changes in DTI metrics associated with therapeutic response in tracts showing significant ECT effects differed between patients and controls. All measures remained stable across time in controls. Altered WM microstructure in pathways connecting frontal and limbic areas occur in MDD, are modulated by ECT and relate to therapeutic response. Increased FA together with decreased MD and RD, which trend towards normative values with treatment, suggest increased fiber integrity in dorsal fronto-limbic pathways involved in mood regulation.


Subject(s)
Depressive Disorder, Major/therapy , Electroconvulsive Therapy , Frontal Lobe/pathology , Limbic System/pathology , Neural Pathways/pathology , Neuronal Plasticity/physiology , White Matter/pathology , Adult , Depressive Disorder, Major/pathology , Depressive Disorder, Major/physiopathology , Diffusion Tensor Imaging , Female , Frontal Lobe/physiopathology , Humans , Limbic System/physiopathology , Male , Middle Aged , Neural Pathways/physiopathology , Treatment Outcome , White Matter/physiopathology
9.
Hip Int ; 12(2): 135-138, 2002.
Article in English | MEDLINE | ID: mdl-28124356

ABSTRACT

In retrograde cementing, blood often rises proximally on the surface of injected cement. This blood contamination weakens the cement-bone interface. The major source of bleeding into the proximal femoral medullary canal is the severed nutrient artery. The aims of this study were to define the clinically relevant anatomy of the nutrient artery supplying the proximal femur and establish the optimum depth of cement insertion to minimise blood contamination. Sixty cadaveric femora were radiographed with a wire placed in the nutrient foramen to assess the distance from the tip of the greater trochanter to its entry into the proximal femoral medullary canal. The nutrient artery entered the medullary canal at an average of 13.9 cm from the tip of the greater trochanter and never more proximal than 10.3cm. In 30 patients undergoing primary total hip replacement, cement was inserted retrogradely at 7.5cm, 10 cm or 15 cm from the tip of the greater trochanter and blood contamination recorded. There was blood in significantly fewer cases when cement was inserted at 10cm. Cement insertion 10cm distal to the tip of the greater trochanter appears to occlude the bleeding nutrient artery and should give a stronger proximal cement-bone interface. (Hip International 2002; 2: 135-8).

10.
Aust J Physiother ; 47(2): 146-8, 2001.
Article in English | MEDLINE | ID: mdl-11552870
11.
Article in English | MEDLINE | ID: mdl-10359021

ABSTRACT

Arachidonic acid (AA) plays a signaling role in the induction of several genes. We previously demonstrated that AA induces c-jun gene expression in the stromal cell line +/+.1 LDA 11 by a signaling pathway involving activation of the c-jun amino-terminal kinase (JNK). This study investigated the role of calcium in AA signaling of c-jun activation in +/+.1 LDA 11 cells. AA (10-50 microM) caused a rapid dose-dependent rise in cytosolic calcium. AA-induced calcium mobilization involved both influx of extracellular calcium and the release of intracellular calcium. The importance of calcium was investigated by variation of the extracellular calcium concentration, chelation of intracellular calcium and by calcium ionophore-induced influx of extracellular calcium. AA-induced c-jun gene expression and increased luciferase activity of a construct containing the high affinity AP-1 binding site was decreased in cells preincubated with the intracellular calcium chelator 1,2-bis(o-aminophenoxy)-eThane-N,N,N',N',-tetraacetic acid tetra(aceToxymethyl-esTer) (BAPTA-AM, 10 microM) prior to stimulation with AA. Similarly, chelation of intracellular calcium decreased AA-induced JNK activation. On the contrary, changes in the extracellular calcium concentration had no effect. Also, ionophore A23187 failed to induce c-jun and JNK activation either alone than in combination with AA. These results suggested that calcium was required for AA-dependent activation of c-jun, but that calcium alone was insufficient to induce activation of c-jun. Thus, release of calcium from intracellular stores is implicated in the signaling pathway of AA-induced c-jun activation in stromal cells.


Subject(s)
Arachidonic Acid/pharmacology , Calcium/metabolism , Proto-Oncogene Proteins c-jun/biosynthesis , Binding Sites , Biological Transport , Calcimycin/pharmacology , Cytosol/metabolism , Dose-Response Relationship, Drug , Egtazic Acid/analogs & derivatives , Egtazic Acid/pharmacology , Endoplasmic Reticulum , Gene Expression Regulation , Promoter Regions, Genetic , Proto-Oncogene Proteins c-jun/genetics , Signal Transduction , Transcription Factor AP-1/metabolism
12.
Hum Immunol ; 34(4): 242-52, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1464552

ABSTRACT

We describe here a number of Caucasoid MHC haplotypes that extend from HLA-B to DR and that have been conserved en bloc. These haplotypes and recombinants between any two of them account for 73% of unselected haplotypes in our Caucasoid population. The existence of ancestral haplotypes implies conservation of large chromosomal segments. Irrespective of the mechanisms involved in preservation of ancestral haplotypes, it is clear that these haplotypes carry several MHC genes, other than HLA, which may be relevant to antigen presentation, autoimmune responses, and transplantation rejection. In light of the existence of ancestral haplotypes, it is critical to evaluate MHC associations with disease and transplantation outcome in terms of associations with ancestral haplotypes rather than individual alleles.


Subject(s)
Haplotypes , Major Histocompatibility Complex , Alleles , Genetic Markers , Humans , Polymorphism, Genetic , Recombination, Genetic , White People/genetics
13.
J Immunogenet ; 17(6): 379-86, 1990 Dec.
Article in English | MEDLINE | ID: mdl-2096182

ABSTRACT

Insulin-dependent diabetes mellitus (IDDM) is associated with several DR3- or DR4-containing ancestral haplotypes (AHs). Using pulsed field gel electrophoresis (PFGE), long range maps of 35 haplotypes have been derived and classified. Two diabetogenic DR3-containing AHs (8.1 and 18.2) possess deletions in the central non-HLA region; these have not been found on non-diabetogenic AHs tested to date. In addition, 8.1 and 18.2 also carry other deletions not found on other AHs. Three DR4 containing AH lack a Not I site, which may imply excision of an unidentified gene. These and other data suggest that deletions may be relevant to the pathogenesis of autoimmune disease, possibly through causing quantitative differences in autoimmune responses involved in IDDM. The MHC contains several regions of potential interest in relation to susceptibility to IDDM; these may explain the association with only certain DR3- and DR4-carrying AH and DR3,4 heterozygosity in terms of cis and trans interactions. On the other hand, the class II region may be particularly important in protection.


Subject(s)
Diabetes Mellitus, Type 1/genetics , Haplotypes , Major Histocompatibility Complex , Chromosome Deletion , Diabetes Mellitus, Type 1/immunology , HLA Antigens/genetics , HLA-DR3 Antigen/genetics , HLA-DR4 Antigen/genetics , Humans , Immunogenetics
15.
J Autoimmun ; 3 Suppl 1: 63-8, 1990 Apr.
Article in English | MEDLINE | ID: mdl-2187461

ABSTRACT

Juvenile insulin-dependent diabetes mellitus develops in susceptible children exposed to unknown environmental factors. If the genes responsible for susceptibility could be identified, it should be possible to understand the method of injury to beta cells as well as identify the infectious or other agents involved. For a decade it has been known that one or more of the susceptibility genes must be within the major histocompatibility complex (MHC). Unfortunately, there are at least 20 different genes in the complex and it has not been possible to determine which are actually responsible. Therefore, we undertook to apply a new concept and new technology to the problem. Over several years we have shown that the diabetogenic gene(s) are contained within conserved ancestral haplotypes which can then be used as markers of the DNA which must contain the gene(s), whether present in a patient or an asymptomatic carrier such as a parent. This approach avoids the confusion which has resulted from using DR3 or DR4 which are only sometimes associated with the relevant genes. The new technology involves pulsed field gel electrophoresis which allows examination of large fragments of DNA containing all of the MHC, and makes it possible to identify deletions and duplications which were otherwise undetectable. In the first instance we compared two ancestral haplotypes [1,8,3 (8.1) and 18,F1,3 (18.2)] known to contain the relevant genes, and contrasted the DNA with that of another ancestral haplotype [3,7,2(7.1)] which is known to lack these genes. We have shown that there are three major deletions common to the two carrier haplotypes but absent in the protective haplotypes.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Diabetes Mellitus, Type 1/genetics , Major Histocompatibility Complex/genetics , Diabetes Mellitus, Type 1/immunology , Genetic Predisposition to Disease , Haplotypes/genetics , Humans
16.
Hum Immunol ; 26(2): 91-7, 1989 Oct.
Article in English | MEDLINE | ID: mdl-2573586

ABSTRACT

We describe here an Nco I restriction fragment length polymorphism of tumor necrosis factor carried by the 8.1 (HLA-A1,B8,BfS,C4AQ0,C4B1,DR3) and the 44.1 (HLA-B44,BfS,C4A3,C4BQ0,DR4) ancestral haplotypes associated with complications of rheumatoid arthritis. By examining multiple examples of these and other ancestral haplotypes it was seen that 8.1 and 44.1 ancestral haplotypes yield fragments of approximately 5.5 kb while many other ancestral haplotypes carry fragments of approximately 10.5 kb. The polymorphism is associated with the ancestral haplotype rather than the HLA-B or -DR allele defined by conventional serology.


Subject(s)
Genetic Diseases, Inborn/genetics , Haplotypes , Polymorphism, Restriction Fragment Length , Tumor Necrosis Factor-alpha/genetics , Cell Line, Transformed , Electrophoresis, Polyacrylamide Gel , Genetic Diseases, Inborn/immunology , HLA Antigens/immunology , Histocompatibility Testing , Humans
17.
Arch Oral Biol ; 28(11): 1047-54, 1983.
Article in English | MEDLINE | ID: mdl-6318708

ABSTRACT

Human cementum was demineralized and exhaustively extracted with EDTA and then digested with collagenase. The insoluble residue after digestion was extracted successively with 8M urea and with 8M urea containing 0.1M mercaptoethanol. The non-collagenous fraction accounted for a larger proportion of the total organic matrix than previously found in bone and dentine, largely due to the presence of more collagenase-insoluble material. Fractionation of the EDTA-soluble material resulted in less-acidic fractions, showing similarities to the corresponding fractions of bone and dentine, and anionic fractions with lower levels of acidic amino acids than those from other hard tissues. Fractions obtained from the soluble collagenase-released material after ion-exchange chromatography and gel filtration, although more heterogeneous than those of bone and dentine, showed many similarities, thus confirming the close homology within this fraction from the various hard tissues. The insoluble residue after collagenase digestion appeared to be of the acid-structural protein type found also in bone, dentine and a wide range of connective tissues.


Subject(s)
Amino Acids/analysis , Dental Cementum/analysis , Chromatography, DEAE-Cellulose , Chromatography, Gel , Dental Cementum/metabolism , Electrophoresis, Cellulose Acetate , Humans , Microbial Collagenase/pharmacology , Solubility
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