Diagnostic value of dynamic magnetic resonance imaging for salivary gland diseases: a preliminary study

OBJECTIVES

To determine the diagnostic value of dynamic MR imaging for the differentiation between benign tumours, malignant tumours, and inflammatory lesions in the major salivary glands.

METHODS

T1- and T2-weighted spin-echo and dynamic gadolinium-enhanced T1-weighted spin-echo imaging sequences were performed in 27 patients (28 salivary gland lesions). The enhancement curve patterns and tumour margins on dynamic MR imaging were analysed.

RESULTS

All pleomorphic adenomas showed a continuous gradual or rapid increase in the enhancement pattern, whereas other benign tumours had a rapid or gradual enhancement-attenuation pattern. Malignant tumours generally showed a gradual enhancement-attenuation pattern. Inflammatory lesions showed a rapid or gradual enhancement-attenuation pattern. A well-defined margin was observed in all 13 (100%) benign tumours and three of six (50%) malignant tumours.

CONCLUSIONS

Our study suggests that dynamic curve patterns and tumour margin appearance may help to differentiate between benign tumours, malignant tumours and inflammatory lesions.

Scintigraphic evaluation of chronic osteomyelitis of the mandible in SAPHO syndrome

A patient with SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis and osteitis) was evaluated by combined scintigraphy. (99m)Tc HMDP scintigraphy showed accumulation in the sternum and lumbar vertebrae as well as the right mandible, whereas (67)Ga citrate showed an accumulation in the right mandible, but not in the sternum or lumbar vertebrae. These results are consistent with chronic osteomyelitis in the mandible.

Dynamic scintigraphy with thallium-201 chloride (Tl-201) for the diagnosis of tumors of the head and neck

OBJECTIVE

The purpose of this study was to differentiate between malignant tumors and benign tumors of the head and neck by means of thallium-201 chloride scintigraphy.

STUDY DESIGN

Thallium-201 chloride (Tl-201) scintigraphy and Ga-67 citrate (Ga-67) scintigraphy were performed in 10 patients with a benign tumor and in 90 patients with a malignant tumor. The blood flow index and the tumor retention index were obtained by means of Tl-201 scintigraphy. The blood flow index = the count of tumor/the count of control in the early dynamic scan from 30 to 120 seconds after injection, and the tumor retention index = (the count of tumor/the count of control in the delayed dynamic scan 2.5 hours after injection)/(the count of tumor/the count of control in the early dynamic scan from 4 to 5 minutes after injection).

RESULTS

The early and delayed scans with Tl-201 demonstrated a very high correlation with the blood flow index. The tumor retention index had a tendency to increase in malignant tumors, especially in the poorly differentiated tumors and the severely invasive tumors. Likewise, the tumor retention index decreased in benign tumors. These results proved to be statistically significant, and in turn Tl-201 scintigraphy was deemed superior to Ga-67 scintigraphy. Tl-201 scintigraphy was also useful in detecting small-size tumors.

CONCLUSION

The tumor retention index of Tl-201 was useful for the differentiation of malignant tumors of the head and neck from benign tumors of the same areas.

Radiographic evaluation of malignant fibrous histiocytoma affecting maxillary alveolar bone: a report of 2 cases

OBJECTIVE

The purpose of this study was to evaluate the radiographic findings of malignant fibrous histiocytoma (MFH) and to discuss the contribution of these findings to a differentiation of MFH from other malignant tumors of the head and neck.

STUDY DESIGN

Two cases of MFH of the maxillary sinus affecting the alveolar bone were evaluated radiographically and scintigraphically.

RESULTS

We reported the following findings, which have only seldom been described: the presence of fairly well-demarcated bone destruction in the intraoral radiograph; the relatively smooth surface, uniform density, or no necrotic area of the tumor; in computed tomograph images showing the clear separation of the tumor from surrounding soft tissues; bone scintigraphs reflecting the periosteal reaction to tumor invasion; and lymphoscintigraphy of the metastatic lymph nodes.

CONCLUSION

We evaluated the radiographic findings from 2 cases of MFH and describe findings that may aid in the differentiation of MFH. These radiographic features may help dentists differentiate MFH from other malignant tumors in the head and neck, although MFH is a rare disease and there are no radiographic findings that would indicate a specific diagnosis of MFH.

Temporomandibular disorders: relationship between joint pain and effusion and nitric oxide concentration in the joint fluid

OBJECTIVES

To evaluate the relationship between joint effusion, contrast enhancement of effusion, nitric oxide concentration in TMJ fluid and TM joint pain.

METHODS

Nonenhanced T1- and T2-weighted and gadolinium-enhanced T1-weighted spin-echo sequences were performed in 77 patients with TMD. The nitric oxide concentration in TMJ fluid was analysed spectrophotometrically by the Griess reaction.

RESULTS

Some or marked effusion was seen in five (9%) of the 56 asymptomatic joints and in 55 (56%) of the 98 symptomatic joints. The prevalence of contrast enhancement of joint effusion was significantly higher in the joint pain group than in the joint sound or asymptomatic joint groups (chi2 test, P<0.001). On postcontrast T1-weighted images, there was no evidence of synovial proliferation in patients with TMD. Anterior disk displacement without reduction was detected in 93% of the TMJs with marked effusion. The degree of joint pain correlated with raised nitric oxide concentration (Spearman's rank correlation, P<0.05).

CONCLUSIONS

Painful joints are more likely to demonstrate contrast enhancement of joint effusion. Nitric oxide concentration in TMJ fluid is closely associated with inflammatory changes and painful TM joints.

A rare case of intraosseous polymorphous low-grade adenocarcinoma (PLGA) of the maxilla

A rare case of intraosseous, polymorphous low-grade adenocarcinoma (PLGA) of the maxilla is presented. The lesion appeared to be cystic radiographically and the only finding which suggested malignancy was an irregular cortical border.

Temporomandibular Disorders: MR Assessment of Inflammatory Changes in the Posterior Disk Attachment During the Menstrual Cycle

PURPOSE

Our goal was to correlate the menstrual cycle with joint pain, MR evidence of the disk, and posterior disk attachment in patients with temporomandibular disorders.

METHOD

Forty-two women underwent MRI involving conventional T1-and T2-weighted gadolinium-enhanced fat-suppressed SE imaging sequences.

RESULTS

There was a strong statistical difference in the degree of joint pain between proliferated phase and secretory phase groups (p < 0.005). Joint pain had a tendency to increase at the secretory phase. Significantly less contrast enhancement of the posterior disk attachment was observed in the proliferated phase than in the secretory phase (p < 0.001) or menstrual phase (p < 0.01). In addition, anterior disk displacement without reduction of the temporomandibular joint was closely associated with joint pain.

CONCLUSION

Our results suggest that positional changes of the disk and the menstrual cycle may play a role in the degree of joint pain and inflammatory pathology of the posterior disk attachment.

Complement system is involved in anaphylactoid reaction induced by lipopolysaccharides in muramyldipeptide-treated mice

We previously reported that an intravenous injection of specified bacterial lipopolysaccharides (LPS) induced anaphylactoid shock in muramyldipeptide (MDP)-primed mice of various strains, including LPS-resistant C3H/HeJ, accompanied with occasional mortality of mice within 1 h. Prior to shock, rapid accumulation of blood platelets into the lungs and liver followed by degradation of the platelets and tissue destruction were observed. In this report we present the following evidence suggesting that complement activation by LPS is responsible for the anaphylactoid reaction. In C5-deficient DBA/2 mice, the platelet degradation and anaphylactoid reactions did not occur following injection of Prevotella intermedia LPS, although transient platelet accumulation into the lungs and liver was observed. Anti-complement agents K-76 COOH (C5 inhibitor) and cobra venom factor (C5 consumer) protected MDP-primed C3H/HeJ mice from mortality in the anaphylactoid reaction induced by P. intermedia and Salmonella typhimurium LPS, respectively. K-76 COOH also inhibited platelet degradation, but not accumulation, induced by P. intermedia LPS in C3H/HeN mice. LPS specimens carrying mannose-homopolymer (MHP) prepared from wild-type Klebsiella 03 and Escherichia coli 08 and 09 and recombinant E. coli 08 and 09 strains, which have been reported to markedly activate the human complement system probably through the lectin pathway, induced anaphylactoid reactions in MDP-primed C3H/HeJ mice. In contrast, LPS from R-mutant of Klebsiella 03 and the parental strain of the recombinant E. coli strains, which lacked MHP, did not induce anaphylactoid reaction. Based on these findings together with those of our previous studies, we postulated the following mechanism for the anaphylactoid reaction: strong complement activation by specified LPS preparations induced degradation of platelets which have accumulated in the lungs and liver, resulting in acute inflammation accompanied with severe tissue destruction, especially in the lungs, which in turn leads to anaphylactoid reaction. However, the mechanism of platelet accumulation induced by LPS is not yet clear.

Lymphoscintigraphy for interpretation of changes of cervical lymph node function in patients with oral malignant tumors: comparison of Tc-99m-Re and Tc-99m-HSA-D

OBJECTIVE

The purpose of this study is to compare the usefulness of technetium-99m-rhenium colloid (Tc-99m-Re) and technetium-99m-human serum albumin diethylene-triamine-pentaacetic acid (Tc-99m-HSA-D) as lymphoscintigraphic agents and to discuss the significance of lymphoscintigraphy in comparison with computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US).

STUDY DESIGN

Dynamic and static lymphoscintigraphies were performed with Tc-99m-Re and Tc-99m-HSA-D. The usefulness of the 2 agents was evaluated statistically in comparison with pathologic findings and palpation. The significance of lymphoscintigraphy is discussed in comparison with CT, MRI, and US (by the literature of CT, MRI, and US).

RESULTS

Lymphoscintigraphy was superior to palpation, and Tc-99m-Re was superior to Tc-99m-HSA-D in accuracy, specificity, and the incidence of true-positive and false-positive. Statistical significance was shown between the static lymphoscintigraphy with Tc-99m-Re and palpation. The reliability of lymphoscintigraphy seemed to be slightly inferior to CT and MRI in specificity and accuracy. However, lymphoscintigraphy had some advantages that CT and MRI lacked; for example, it showed very high sensitivity (100%) and no false-negative (0%). It also showed changes of lymph node function, showed all levels of neck nodes at one time, and showed a possibility of detecting small lymph node metastases.

CONCLUSION

Lymphoscintigraphy was more useful than palpation in detecting lymph node metastases, and Tc-99m-Re was superior to Tc-99m-HSA-D as an agent. Lymphoscintigraphy is significant when it is performed as a preliminary examination before CT or MRI.

Morphological and positional assessments of TMJ components and lateral pterygoid muscle in relation to symptoms and occlusion of patients with temporomandibular disorders

Disc displacement is accepted as one of major findings in temporomandibular disorders (TMD). However, the associations of disc positions with morphological and positional changes of temporomandibular joint (TMJ) components and lateral pterygoid (LP), TMD clinical symptoms, and occlusion have rarely been discussed quantitatively. In this study, the morphological and positional changes of TMJ components and LP were assessed by means of magnetic resonance imaging (MRI) and tomography of the TMJ in 41 TMD and nine control (CN) subjects. Disc positions in TMD subjects were divided into normal position (NP) and anterior displacement with and without reduction (ADR+ and ADR-, respectively). From MRI scans and tomograms, the morphological and positional changes of TMJ components and LP were measured and compared among CN, NP, ADR+ and ADR- groups. Correlations between these measurements and the scored clinical symptoms and occlusal factors were analysed in TMD subjects. The results indicated that: (1) TMJ osseous structures and LP showed no significant difference among CN and the three TMD groups, except for a posterior seat of condyle and shorter/steeper condylar movement during jaw opening; (2) disc length and inclination were significantly shorter and steeper, respectively, in ADR+ and ADR-; (3) disc positions were not specified by clinical symptoms and occlusal factors, except for the dominant TMJ sounds in ADR+; (4) an uncoordinated movement of the condyle/disc complex was found in ADR+ and/or ADR-; (5) TMJ osseous structures and the disc were weakly associated with clinical symptoms and occlusal factors. However, the LP showed negative associations with palpable pain for both the TMJ and jaw muscles and the static occlusal factors. These findings suggest that TMJ internal derangements are more related to the positional changes or spatial relationships of TMJ components but less to the individual morphologies of TMJ osseous structures, disc and LP, as well as specific clinical symptoms and occlusal factors, which might be in disagreement with a large body of previous statements.

Clinical evaluation of lymphoscintigraphy with a new technetium compound for metastatic cervical lymphadenopathy

OBJECTIVES

To evaluate the potential usefulness of lymphoscintigraphy for the detection of metastatic cervical lymphadenopathy.

METHODS

Dynamic and static lymphoscintigraphy with 99Tcm-HSA-D was performed in 23 patients with malignant oropharyngeal tumors. The internal jugular nodes were excised and examined pathologically. The results of the lymphoscintigraphy were compared with the pathological examination and clinical palpation for accuracy.

RESULTS

All cases showed abnormal findings on lymphoscintigraphy. The accuracy on dynamic scintigraphy was 69% for asymmetric drainage, 69% for delayed drainage and 100% for inverse drainage. The overall accuracy for each side was 71%. With static scintigraphy, the accuracy was 69% for asymmetry, 86% for fitting defect, 67% for mottled-patchy appearance, 70% in swelling and 100% for collateral pathway. The overall accuracy for each side was 74%. The agreement between lymphoscintigraphy and palpation was 44%.

CONCLUSIONS

Lymphoscintigraphy with 99Tcm-HSA-D was superior to palpation. The method is useful as a supplementary modality for the evaluation of metastatic cervical lymphadenopathy because of its relatively high accuracy and a low false-negative rate.

Severity of synovium and bone marrow abnormalities of the temporomandibular joint in early rheumatoid arthritis: role of gadolinium-enhanced fat-suppressed T1-weighted spin echo MRI

PURPOSE

Our goal was to evaluate the efficacy of dynamic contrast-enhanced fat-suppressed MRI of the temporomandibular joint (TMJ) in detecting early joint involvement in patients with rheumatoid arthritis (RA).

METHOD

Conventional T1- and T2-weighted, gadolinium-enhanced T1-weighted, and dynamic gadolinium-enhanced fat-suppressed SE imaging sequences were performed in 22 patients with RA.

RESULTS

The dynamic gadolinium-enhanced fat-suppressed T1-weighted SE sequence was more sensitive than the other techniques in detecting early changes in inflamed synovium of periarticular tissue and in detecting condylar bone marrow involvement. In patients with RA, 17 joints with joint pain showed synovial proliferation in 10 (59%) cases and joint effusion in 4 (24%). Of 14 joints with joint sound, 4 (29%) showed synovial proliferation and 7 (50%) showed joint effusion. A lower positional change of the disk was observed in joints with RA than in those with TMJ disorders (82 patients).

CONCLUSION

Gadolinium-enhanced fat-suppressed MRI was extremely effective in diagnosing early changes of the inflamed TMJ.

Gadolinium-enhanced MR imaging of temporomandibular disorders: improved lesion detection of the posterior disk attachment on T1-weighted images obtained with fat suppression

OBJECTIVE

The purpose of this study was to assess the potential for improved lesion detection in the posterior disk attachment and its surrounding tissue in temporomandibular disorders when gadolinium-enhanced MR imaging performed with fat suppression is used.

MATERIALS AND METHODS

Forty-five patients underwent MR imaging with conventional T1- and T2-weighted, gadolinium-enhanced T1-weighted, and gadolinium-enhanced fat-suppressed spin-echo imaging sequences. Qualitative and quantitative assessments of the contrast enhancement of each type of imaging were also performed.

RESULTS

The contrast-enhanced fat-suppressed T1-weighted imaging sequence had several advantages over the other imaging techniques in detecting abnormalities of the posterior disk attachment and in detecting bone marrow lesions in the mandibular condyle. The most significant advantage was better enhancement of lesion conspicuity. The diagnostic accuracy of contrast-enhanced fat-suppressed imaging was 77% versus 70% for conventional contrast-enhanced imaging. The kappa value for interobserver agreement was .95 for contrast-enhanced fat-suppressed imaging and .72 for conventional contrast-enhanced imaging.

CONCLUSION

Contrast-enhanced fat-suppressed T1-weighted spin-echo MR imaging is a valuable technique for visualizing the extent and degree of lesions in the posterior disk attachment and bone marrow lesions in the mandibular condyle.

MRI of the temporomandibular joint disk and posterior disk attachment before and after nonsurgical treatment

PURPOSE

Our goal was to investigate the role of serial dynamic contrast-enhanced SPGR MRI in the nonsurgical follow-up of patients with temporomandibular joint (TMJ) pain.

METHOD

Ten patients (10 joints) with internal derangement of the TMJ were imaged with T1-weighted SE and serial postgadolinium SPGR MR pulse sequences.

RESULTS

On T1-weighted images prior to treatment, the disk position was normal in one joint and anteriorly displaced without reduction in nine joints. After treatment, the disk remained normally positioned in one joint, was anteriorly displaced without reduction in eight joints, and was anteriorly displaced with reduction in one joint. The dynamic study after treatment showed a decrease in contrast enhancement of the posterior disk attachment in 7 of 10 joints. These seven patients had resolution or reduction in joint pain.

CONCLUSION

These results suggest an association between a decrease in contrast enhancement of the posterior disk attachment and resolution or reduction in joint pain. This association was much stronger than the association between the clinical findings and the anatomy of the disk.

Double dens in dente with a central cusp and multituberculism in bilateral maxillary supernumerary central incisors: report of a case

A case of bilateral molarized teeth in the maxillary central incisor region is reported. The bilateral central incisor teeth were extracted in a 13-year-old boy and examined radiographically and histologically. Both malformed teeth were diagnosed as double dens in dente with a central cusp and multituberculism in maxillary supernumerary central incisors.

Interpretation of scintigraphy of papillary cystadenoma lymphomatosum (Warthin's tumor) on the basis of histopathologic findings

OBJECTIVES

The accumulation of 99mTc-pertechnetate in Warthin's tumor was estimated scintigraphically and histopathologically to determine the role of the epithelial component in scintigraphy.

STUDY DESIGN

Six cases underwent histopathologic examination and scintigraphic evaluation with 99mTc-pertechnetate. Histopathologically the tumors were classified into types according to the epithelial component and cystic space and compared with scintigraphic results evaluated by dynamic radioactive index and wash-out image.

RESULTS

Histopathologic and scintigraphic observations showed an adequate correlation. Cases with a large epithelial component and poor cystic space showed a large radioactive index of dynamic scintigraphy and hot accumulation of wash-out image.

CONCLUSION

The scintigraphic results were chiefly due to the epithelial component, but the influence of the cystic space could not be disregarded.

Vertebral growth disturbance in rapidly growing rats during 14 days of spaceflight

The effect of 14 days of spaceflight on the vertebrae of rapidly growing rats was studied. The hardness of the vertebrae was measured with a Knoop microhardness tester, and bone mineral density was measured from X-ray photographs. Histomorphometric examination was performed with a microcomputer-aided system. No significant difference (P > 0.05) was observed between flight rats and ground controls with regard to mechanical hardness or bone mineral density. However, histological examination revealed irregular thickening of the endosteal surface of cortical bone in the flight rats, whereas it was uniform in the ground controls. The relative area of lamellar bone showed a significant reduction (P < 0.001) in the flight rats. These findings suggest that the structural disturbances were due to retardation of endosteal modeling and remodeling. We conclude that delay of vertebral maturation can occur in rapidly growing rats after even short-term exposure to microgravity.

Dynamic MR imaging of the temporomandibular joint in patients with arthrosis: relationship between contrast enhancement of the posterior disk attachment and joint pain

OBJECTIVE

The purpose of this study was to determine the relationship between joint pain, disk position, and the degree of contrast enhancement of the posterior disk attachment in patients with temporomandibular joint arthrosis using dynamic contrast-enhanced MR imaging.

SUBJECTS AND METHODS

T1- and T2-weighted spin-echo and spoiled gradient-recalled acquisition in the steady state MR imaging was performed in 36 healthy volunteers and 105 patients who were asymptomatic or who had joint pain, muscular pain, or both. On T1-weighted images, the position of the disk was classified as normal and anteriorly displaced. Next, on sagittal spoiled gradient-recalled acquisition in the steady state MR images, signal intensity from teh posterior disk attachment was measured. Time-intensity curves of the signal-intensity ratio versus the time after contrast administration were obtained in each case. Diagnostic accuracy of enhancement among the clinical symptoms was assessed using receiver operating characteristic curves. Imaging findings of contrast enhancement were correlated with pain and disk position.

RESULTS

In quantitative measurement, a rapid enhancement pattern was seen most frequently in patients with joint-pain, whereas relatively gradual enhancement was seen in the healthy subjects and in patients who were asymptomatic or who had muscular pain. The mean peak-signal-intensity ratio of the group with joint pain was significantly higher than that of the other groups (p < .001). In the group with joint pain, anterior disk displacement without reduction was strongly associated with the mean signal-intensity ratio (p < .01). With regard to receiver operating characteristic analysis, the group with joint pain showed significantly greater accuracy than did the other groups (p < .001).

CONCLUSION

Our results suggest that prominent contrast enhancement of the posterior disk attachment on spoiled gradient-recalled acquisition in the steady state MR images may help differentiate intraarticular from extraarticular causes of pain in and around the temporomandibular joint. In the group with joint pain, anterior disk displacement without reduction was closely associated with prominent enhancement.

Molecular cloning and expression of human caldecrin

Earlier we reported the primary structure of serum calcium-decreasing factor (caldecrin) from rat pancreas, a protein which is considered to be a member of the elastase family. In this report, we describe the isolation of the two homologous cDNA clones encoding caldecrin from human pancreas, the structures of which are identical except for one base and the corresponding amino acid residue. These human caldecrin isoforms are composed of a signal peptide of 16 amino acids, a propeptide of 13 amino acids, and a mature form of 239 amino acids. Both recombinant caldecrins showed the same chymotrypsin-type protease activity and hypocalcemic activity. The hypocalcemic activity of both remained intact even after treatment with PMSF to abolish their protease activity. These results suggest that human caldecrin possesses hypocalcemic activity that has no connection with its protease activity.

Molecular cloning and expression of serum calcium-decreasing factor (caldecrin)

We previously reported on the purification of a serum calcium-decreasing factor, referred to as caldecrin, from porcine pancreas, that is thought to be a serine protease (Tomomura, A., Fukushige, T., Noda, T., Noikura, T., and Saheki, T. (1992) FEBS Lett. 301, 277-281). In the present study, we purified caldecrin from rat pancreas and determined its primary structure by cDNA cloning. The predicted caldecrin protein is presumed to be synthesized as a preproenzyme of 268 amino acids with a signal peptide of 16 amino acids and an activation peptide of 13 amino acids, and is, with the exception of a central region, almost identical to the reported rat pancreatic elastase IV sequence. The caldecrin gene is selectively expressed in the pancreas, as judged by Northern blot analysis. After expression in BMT-10 cells, immunoreactive caldecrin was found in the culture supernatant, and it inhibited the parathyroid hormone-stimulated 45Ca release from cultured fetal long bones. Catalytic site mutants were synthesized in a baculovirus system, and recombinant mutants also decreased the serum calcium level of mice. These data implicate caldecrin, a protease closely related to elastase IV, in the regulation of blood calcium levels.

Caldecrin proform requires trypsin activation for the acquisition of serum calcium-decreasing activity

Proform serum calcium-decreasing factor (procaldecrin) was purified from porcine pancreas acetone powder. Procaldecrin showed chymotrypsin activity after trypsin treatment in a time- and dose-dependent manner. Procaldecrin did not possess serum calcium-decreasing activity but acquired serum calcium-decreasing activity as well as protease activity after trypsin treatment. However, PMSF treatment after activation of procaldecrin by trypsin did not affect the serum calcium-decreasing activity, even though protease activity was nullified by treatment with PMSF. These findings suggest that the serum calcium-decreasing activity acquired by procaldecrin requires conformational change caused by trypsin treatment.

[Phase III trial of 99mTc-rhenium colloid for lymphoscintigraphy]

A multicenter study was carried out on 191 patients (196 examinations) with lymphatic system disorders to evaluate the efficacy and safety of 99mTc-rhenium Colloid, a tracer for lymphoscintigraphy (TCK-17). Local pain and swelling occurred at the site of injection in 79.6% and 5.1% of patients, respectively, and 2 patients experienced mild fever. The accuracy was calculated on the basis of the results obtained by other diagnostic methods. Lymphoscintigraphy using TCK-17 was sensitive diagnostic procedures, but low specificity. The efficacy was classified into five grades: "Excellent", "Good", "Moderate", "Equivocal", and "Poor". 67.3% of all examination were evaluated as "Excellent" or "Good". This study revealed TCK-17 was a useful radiopharmaceutical for lymphoscintigraphy because of its safety and effectiveness.

Serum calcium-decreasing factor (caldecrin) from porcine pancreas has proteolytic activity which has no clear connection with the calcium decrease

We purified a serum calcium-decreasing factor, which showed chymotrypsin-like protease activity, from porcine pancreas to homogeneity. The factor administered to mice intravenously at a dose of 20 micrograms/kg b.w. decreased serum calcium by 15%. Treatment of the factor with the serine protease inhibitor, PMSF, caused a leftward shift in the dose-response curve, showing strengthened activity. It also caused a decrease in serum calcium and hydroxyproline levels in rats. At a dose of 10 ng/ml, the factor inhibited 45Ca release from cultured fetal long bone stimulated by parathyroid hormone (PTH) and PTH-related protein, but not by interleukin-1 alpha, prostaglandin E1 and 1,25-dihydroxy vitamin D3. No other well-known pancreatic proteases had these effects. In view of the results of experiments using protease inhibitor and pancreatic proteases, and in view of the specificity of this factor in vitro, we propose that the factor exerts its serum calcium-decreasing activity most probably not through proteolytic degradation of PTH, but through an inhibition of PTH action on bones by a yet undefined mechanism.

[Assessment of alveolar bone changes with gamma-ray absorptiometry--on the analysis of detectability of a measuring system]

It is important to determine the changes in alveolar bone during periodontal treatments. At present, radiography is widely used to determine the changes. But small changes in alveolar bone cannot be detected on X-ray films. To detect these small changes, a direct observation system using gamma-ray from 133Ba was considered. Using a multi-channel analyzer, gamma-ray absorption through the bone was detected in this method. This method was compared with densitometric measurement on the films using sliced animal bone. The newly developed method detected the bone changes more accurately. To evaluate the influence of soft tissue, Mix-D was used in both measurements. 133Ba absorptiometry showed that soft tissue did not influence the measurement more than the densitometric method.

Autosomal recessive rough hypoplastic amelogenesis imperfecta. A case report with clinical, light microscopic, radiographic, and electron microscopic observations

A case is presented of a 12-year-old Japanese girl with nearly complete lack of enamel in the deciduous and the permanent dentitions, coupled with a gross abnormality in the pattern of eruption. There was no family history of a similar condition. Deciduous molars were extracted, and hyperplastic gingival tissue was resected. On the basis of clinical, radiographic, and microscopic findings, a diagnosis of autosomal recessive rough hypoplastic amelogenesis imperfecta was made. The configuration of the abnormal enamel was examined with scanning and transmission electron microscopy as well as with light microscopy. Prismatic structure was virtually absent, and the scant enamel showed globular protrusions superficially. Two different surface structures were identified as covering parts of the enamel. At the ultrastructural level, calcified bodies located in the gingival tissue appeared to be composed, in part, of a dense enamel-like substance and, in part, of a tissue with features of afibrillar cementum.

Evaluation of submandibular gland function by sialo-scintigraphy following sialolithectomy

Submandibular gland function following transoral sialolithectomy was examined by 99mTc-pertechnetate sialo-scintigraphy in 10 cases. An intraindividual comparison between the function of the treated gland and that of the contralateral normal gland was made using a time-activity curve. Although glandular recovery was not affected by the duration of symptoms or the existence of the symptom at mealtimes, it was inversely proportional to the size of the calculus. Furthermore, the prognosis was more favorable in patients when the anatomically normal orifice of the submandibular duct was preserved.