Parietal neurons represent surface orientation from the gradient of binocular disparity

In order to elucidate the neural mechanisms involved in the perception of the three-dimensional (3D) orientation of a surface, we trained monkeys to discriminate the 3D orientation of a surface from binocular disparity cues using a Go/No-go type delayed-matching-to-sample (DMTS) task and examined the properties of the surface-orientation-selective (SOS) neurons. We recorded 57 SOS neurons from the caudal part of the lateral bank of the intraparietal sulcus (area CIP) of three hemispheres of two Japanese monkeys (Macaca fuscata). We tested 29 of 57 SOS neurons using the square plate of a solid figure stereogram (SFS) and random-dot stereogram (RDS) without perspective cues; almost all of the tested neurons (28/29) showed surface orientation selectivity for the SFS and/or the RDS without perspective cues. Eight of these 28 neurons (28.6%) showed selectivity for both the RDS and SFS, 7 (25.0%) were dominantly selective for the RDS, and 13 (46.4%) were dominantly selective for the SFS. These results suggest that neurons that show surface orientation tuning for the RDS without perspective cues compute surface orientation from the gradient of the binocular disparity given by the random-dot across the surface. On the other hand, neurons that show surface orientation tuning for the SFS without perspective cues may represent surface orientation primarily from the gradient of the binocular disparity along the contours. In conclusion, the SOS neurons in the area CIP are likely to operate higher order processing of disparity signals for surface perception by integrating the input signals from many disparity-sensitive neurons with different disparity tuning.

Voglibose administration before the evening meal improves nocturnal hypoglycemia in insulin-dependent diabetic patients with intensive insulin therapy

Nocturnal hypoglycemia is one of the serious complications of intensive insulin therapy in patients with insulin-dependent diabetes mellitus (IDDM; type 1 DM). We assessed the effect of voglibose (alpha-glucosidase inhibitor) administration before the evening meal on nocturnal hypoglycemia in IDDM patients with intensive insulin therapy. Ten IDDM patients received 0.3 mg voglibose just before the evening meal for 5 days. The diet and insulin regimen were not changed throughout the study. Nocturnal plasma glucose levels (10 PM, 3 AM, and 7 AM) were studied in these patients before and during voglibose administration. Blood glucose levels were measured at 3 AM before and during voglibose treatment. The mean plasma glucose level at 3 AM was 3.4+/-0.4 mmol/L before voglibose treatment and 7.3+/-1.0 mmol/L during treatment. Plasma glucose at 3 AM was elevated in 9 of 10 patients with voglibose. The decrease in plasma glucose from 10 PM to 3 AM was 6.5+/-0.8 mmol/L before voglibose administration but 3.2+/-0.9 mmol/L during treatment (P < .01). The hypoglycemia rate was 52% (17 of 33 nights) before voglibose administration but only 9.1% (3 of 33 nights) during treatment. We conclude that voglibose administration before the evening meal improves nocturnal hypoglycemia in IDDM patients with intensive insulin therapy.

Effects of four mixing methods on setting expansion and compressive strength of six commercial phosphate-bonded silica investments

Six commercial phosphate-bonded silica investments were mixed with four different mixing methods such as hand, two conventional blade-driven vacuum mixers and a new planetary mixing device, and examined for their setting expansion and compressive strength. The two properties often altered, depending upon the mixing method and the investment. The setting expansion of three investments were significantly affected by the mixing method while those of the other three were not. Compressive strength of all six investments varied by changing the mixing method. It is emphasized here that a mixing method and mixing condition must be properly set for each investment to improve the fit of the final metallic castings. This study also suggests that the planetary mixing device is a useful substitute for conventional blade-driven vacuum mixers.

Histology of the gastroesophageal junction: an autopsy study

Current diagnostic criteria for reflux disease and Barrett's esophagus are based on the belief that the gastroesophageal junction normally contains 2 cm of cardiac mucosa composed of mucous glands devoid of parietal cells. This autopsy study disproves this belief. Even when the entire circumference of the gastroesophageal junction is examined, pure cardiac mucosa was completely absent in 56% of patients. All patients had oxyntocardiac mucosa, in which glands contained a mixture of mucous and parietal cells. Cardiac and oxyntocardiac mucosae were present only in part of the circumference of the junction in 50% of patients. The measured maximum length of cardiac plus oxyntocardiac mucosa was less than 0.5 cm in 76% of patients. There was a tendency for the presence and extent of cardiac mucosa to increase with age. Cardiac mucosa at the junction is therefore frequently absent, has considerable individual variation, is very small in extent when present, is commonly absent from some part of the circumference of the junction, and increases in prevalence and length with age. These characteristics of cardiac mucosa make it highly unlikely that it is a normal structure. We develop the hypothesis that cardiac mucosa represents an early histologic manifestation of gastroesophageal reflux.

Tubulointerstitial nephritis associated with Legionnaires' disease

A 47-year-old man was admitted to our hospital for community-acquired pneumonia complicated with acute renal failure. Legionella pneumophila serogroup type 1 was grown in BCYE (buffered charcoal yeast extract) agar for sputum culture. Although his respiratory illness responded to intravenous erythromycin therapy, renal failure worsened and necessitated hemodialysis. Renal biopsy showed profound tubulointerstitial nephritis. After initiation of steroid therapy his renal function improved and he was discharged thereafter. These findings suggest that in Legionnaires' disease with acute renal failure, tubulointerstitial nephritis should also be considered and steroid therapy may be an effective modality for the renal complication.

Inhibiting action of carbohydrates on the growth of fluorapatite crystals

Hydroxyapatite (HAp) and fluorapatite (FAp) were synthesized in the presence of carbohydrates (glucose, fructose, galactose and sucrose). X-ray diffraction analysis showed that the crystallinity of two FAp groups that were synthesized in the presence of glucose or sucrose decreased with the increase in carbohydrate content. In SEM photographs we found that the size of their crystals was small and the shape changed. However, FAp groups that were snythesized in the presence of fructose or galactose showed little change in their crystallinity and shape. Four carbohydrates had some influence on size, but not on shape or crystallinity when synthesizing HAp. These results suggest that glucose and/or sucrose has a chemical affinity to FAp and inhibits the growth of FAp crystals.

Effect of cromolyn on adenosine-induced airway microvascular leakage in sensitized rats

Inhalation of adenosine causes bronchoconstriction in asthmatic subjects, but the effect of this purine nucleotide on airway vascular permeability is unknown. In order to determine whether adenosine produces airway microvascular leakage and, if so, to examine the effect of cromolyn (sodium cromoglycate (SCG)) on this extravasation of Evans blue was measured in the airways of ovalbumin-sensitized Brown Norway rats. Inhaled adenosine caused microvascular leakage in sensitized but not in non-sensitized rats, and the response was abolished by capsaicin pretreatment or the tachykinin neurokinin-1 receptor antagonist FK888. Adenosine-induced vascular leakage became apparent in nonsensitized rats when treated with phosphoramidon, and airway neutral endopeptidase activity was lower in sensitized than in non-sensitized animals. The extravasation induced by adenosine in sensitized rats was dose dependently inhibited by SCG aerosols, SCG likewise inhibited microvascular responses to substance P, but had no effect on those to platelet-activating factor. These results suggest that: 1) adenosine induces airway microvascular leakage in sensitized rats through stimulation of neurokinin-1 receptors; 2) this effect is associated with a sensitization-induced decrease in neutral endopeptidase activity; and 3) sodium cromoglycate inhibits adenosine-induced extravasation, presumably via functional antagonism of tachykinins.

Neural representation of three-dimensional features of manipulation objects with stereopsis

In the first part of this article, we review our neurophysiological studies of the hand-manipulation-related neurons in the anterior part of the lateral bank of the intraparietal sulcus (area AIP). We describe the properties of visually responsive neurons in area AIP. Object-type visual-dominant neurons responded to the sight of objects and showed selectivity not only for simple geometrical shapes, but also for complex objects such as a knob-in-groove and a plate-in-groove. Some of the object-type visual-dominant neurons showed selectivity for the orientation of the longitudinal axis or the plane (surface) of a plate or a ring. In the second part of this article, we review our study of binocular visual neurons in the caudal part of the lateral bank of the intraparietal sulcus (c-IPS area), in particular, of axis-orientation-selective (AOS) neurons and surface-orientation-selective (SOS) neurons. AOS neurons preferred long and thin stimuli, were sensitive to binocular disparity, and tuned to the axis orientation in three-dimensional (3D) space. SOS neurons preferred broad and flat stimuli and were tuned to the surface orientation in depth. Some SOS neurons responded to a square in a random dot stereogram (RDS) with orientation tuning, suggesting that they encode surface orientation from a disparity gradient. Others responded to solid figure stereograms with orientation disparity and/or width disparity. It was concluded that the c-IPS area is a higher center for stereopsis, which integrates various binocular disparity signals received from the V3 complex and other prestriate areas to represent the neural code for 3D features. It may send projections to the AIP area and contribute to visual adjustment of the shape of the handgrip and/or hand orientation for manipulation and grasping. Neurons of the AIP area may also receive monocular cues of depth from the ventral visual pathway to discriminate the 3D shape of the object of manipulation.

Control of hippocampal morphogenesis and neuronal differentiation by the LIM homeobox gene Lhx5

The mammalian hippocampus contains the neural circuitry that is crucial for cognitive functions such as learning and memory. The development of such circuitry is dependent on the generation and correct placement of the appropriate number and types of neurons. Mice lacking function of the LIM homeobox gene Lhx5 showed a defect in hippocampus development. Hippocampal neural precursor cells were specified and proliferated, but many of them failed to either exit the cell cycle or to differentiate and migrate properly. Lhx5 is therefore essential for the regulation of precursor cell proliferation and the control of neuronal differentiation and migration during hippocampal development.

Sickness absence due to mental disorders in Japanese workforce

This study was conducted to elucidate sickness absence due to mental disorders in Japanese companies. Data on sickness absence taken for seven consecutive days or more at eight companies (total number of employees: 44,816) was used for the analysis. Diagnosis of mental disorders was based on medical certificates prepared by physicians. The frequency of absence due to all diseases and mental disorders was 3.0% and 0.3%, respectively. The proportion of frequency absence due to mental disorders compared to that for all diseases was 9.4%. Figures for absence prevalence were almost the same as those for frequency absence. The average length of absence due to mental disorders and non-mental disorders was 119.5 days and 47.3 days, respectively. Rate of absence days due to mental disorders compared to that for all diseases was 21.0%. Percent of sickness absenteeism was 0.4%. In one company, the proportion of frequency absence and rate of absence days due to mental disorders compared to those for all diseases had an increasing tendency over the last six years.

Studies on optical properties of two commercial visible-light-cured composite resins by diffuse reflectance measurements

Two commercial visible-light (VL)-cured composite resins were examined for their optical properties by diffuse reflectance measurements in VL spectrum and Kubelka-Munk's theory. Cured Silux Plus displayed diffuse reflectance similar to that of cured Z100, although uncured Silux Plus showed diffuse reflectance less than that of uncured Z100. By Kubelka-Munk's analyses, two optical constants of the composites at eight wavelengths such as absorption and scattering coefficients were calculated using the difference in diffuse reflectance of the composites backed between white and black standards. Upon curing, the two optical constants of the composites significantly altered especially in the shorter wavelengths. By lowering the wavelength, two optical constants of the composites tended to increase, giving rise to less light reflection and transmission. The theoretical optical transmittance of the composites was expressed in terms of hyperbolic functions of thickness of the composites at eight wavelengths in VL, dependent upon the two optical constants. The actual optical transmittance of 1 mm composites were fairly comparative with the theoretical values at 1 mm. The depth of cure of the two composites matched well with the thickness of the uncured composites which yielded the minimum theoretical optical transmittance in the wavelength region of 400-500 nm.

Nonuniform vertical and horizontal setting expansion of a phosphate-bonded investment

PURPOSE

This study developed a new device for measuring the internal setting expansion of phosphate-bonded investment and assessed the effect that different pattern materials may have on the internal setting expansion.

MATERIAL AND METHODS

The measuring device consisted of 2 horizontal plungers, a vertical needle, 2 digital dial gauges, and a protection tube with a disk. Outward displacement of the 2 horizontal plungers by investment setting expansion was transmitted to a digital dial gauge through the vertical needle. Upward displacement of a protection tube was measured by another digital dial gauge. Three pattern materials, including soft and hard inlay waxes and an autopolymerizing resin, were used. Data were analyzed with ANOVA and Scheffe's F test for all post hoc pairwise comparisons (95% confidence level).

RESULTS

For all pattern materials, vertical setting expansion (range of means, 2.26% to 2.73%) was significantly higher than the horizontal setting expansion (range of means, 0.09% to 1.50%) (P <.05). In addition, for the hard inlay wax pattern, the horizontal setting expansion for the cervical aspect (means, 1.39%) was significantly higher than that of the occlusal aspect (means, 0.54%) (P <.05).

CONCLUSION

In this study, the new measuring device was a convenient and reliable method for quantitative assessment of internal setting expansion. Regardless of the type of pattern material, a phosphate-bonded investment caused nonuniform setting expansion, especially in a horizontal direction, which lead to the distortion of the pattern.

Prevalence and clinical features of hepatitis delta virus infection in the Miyako Islands, Okinawa, Japan

The aims of this study were twofold: (1) to determine the prevalence and clinical features of hepatitis delta virus (HDV) infection among subjects positive for hepatitis B surface antigen (HBsAg) living in the Miyako Islands, Okinawa Prefecture, Japan, and (2) to clarify the relationship between HDV-RNA level and severity of HDV-related liver disease. One hundred and ninety-nine HBsAg-positive subjects (123 asymptomatic carriers [ASCs], 3 patients with acute hepatitis [AH], 50 patients with chronic hepatitis [CH], 15 patients with liver cirrhosis [LC], and 8 patients with hepatocellular carcinoma [HCC], were tested for antibody to HDV (anti-HDV) by radioimmunoassay. Anti-HDV-positive individuals were examined to determine semi-quantified HDV-RNA level by polymerase chain reaction (PCR). The overall prevalence of anti-HDV among the 199 subjects was 21.1%. The positivity rate tended to increase with age or the severity of the underlying liver disease: anti-HDV-positive rates were 10.6% (13/123) in ASCs, 32.0% (16/50) in patients with CH, 40.0% (6/15) in patients with LC, and 87.5% (7/8) in patients with HCC. None of the patients with AH were positive for anti-HDV. There was no correlation between semi-quantified serum HDV-RNA levels and the severity of chronic liver disease in patients positive for anti-HDV. The present study showed the local spread of HDV infection in the Miyako Islands, Okinawa, Japan. Although the anti-HDV positivity rate tended to increase with the severity of the underlying liver disease, the severity of HDV-related liver disease did not correlate with the semi-quantified serum HDV-RNA level.

A case of diabetic muscle infarction in Japan

Diabetic muscle infarction (DMI) is a rare complication of diabetes mellitus. We report the first recorded case in Japan. A 45-year-old Japanese woman presented with severe pain in the left antero-medial thigh. She had a 14-year history of Type 2 diabetes mellitus (DM). She had first noticed pain in her left thigh after a walk 2 weeks prior to presentation. The pain worsened progressively. She noticed a firm mass in her left thigh. T2-weighted magnetic resonance imaging (MRI) demonstrated a high-intensity signal in the muscle bulk of the anterior component of the left thigh. A needle biopsy of the mass showed necrosis. She was treated with bedrest and an antiplatelet agent. The mass disappeared 8 weeks after admission. DMI is a rare complication of poorly controlled diabetes mellitus. Twenty-seven cases with DMI have been reported in the English literature but we believe this is the first Japanese case with DMI.

[Severe hypertriglyceridemia induced by tamoxifen]

A 71-year-old woman was admitted to our hospital because of severe hypertriglyceridemia. The patient had a 26-year history of non-insulin-dependent diabetes mellitus and hyperlipidemia (T-chol 300 mg/dl, TG 300 mg/dl). She was treated with sulfonylurea and clofibrate. Seven years before admission, she had undergone a radical mastectomy for cancer of the left breast. After the operation, she had received tamoxifen and fluorouracil. One month before admission, she had marked hypertriglyceridemia (triglyceride 2,106 mg/dl). After discontinuation of tamoxifen and fluorouracil, her serum triglyceride level decreased to 372 mg/dl; when tamoxifen was given again, it increased to 581 mg/dl, and her hepatic triglyceride lipase activity decreased from 0.228 to 0.164 mumol FFA/ml/min. Apolipoprotein E phenotype was wild type E3/3. The concentration of sex-hormone-binding globulin increased from 110 to 130 nmol/l. These changes associated with tamoxifen treatment were similar to those seen after administration of estrogen. Tamoxifen, an anti-estrogen, has been used as adjuvant therapy in cases of estrogen-receptor-positive breast cancer. Tamoxifen has some weak estrogenic activity. The tamoxifen-induced hypertriglyceridemia seen in this case was an effect of its estrogenic action.

Differential expression of non-muscle myosin heavy chain genes during Xenopus embryogenesis

Class II non-muscle myosins are implicated in diverse biological processes such as cytokinesis, cellularization, cell shape changes and gastrulation. Two distinct non-muscle myosin heavy chain genes have been reported in all vertebrates: non-muscle myosin heavy chain-A (NMHC-A) and -B (NMHC-B). We report here the isolation of the Xenopus homolog of NMHC-A and present a comparative analysis of the developmental and spatial expression patterns of NMHC-A and the previously isolated NMHC-B to address the role of NMHCs in Xenopus development. A 7.5 kb NMHC-A mRNA is present, maternally in unfertilized eggs and throughout embryogenesis, as well as in all adult tissues examined. An additional 8.3 kb zygotic transcript for NMHC-A is also detected, but only during embryonic stages. Whole mount in situ hybridization with tailbud stage embryos shows that NMHC-A mRNA is predominantly expressed in the epidermis, whereas NMHC-B mRNA is expressed in the somites, brain, eyes and branchial arches. Interestingly, the expression of NMHC-B in developing somites is gradually restricted to the center of each somite as differentiation proceeds. DAPI nuclear staining demonstrated that NMHC-B mRNA is colocalized with the nuclei or perinuclear area. In animal cap experiments, treatment with activin A or ectopic expression of Xbra and an activated form of Xlim1 markedly up-regulates NMHC-B as well as muscle actin mRNAs and slightly down-regulates NMHC-A mRNA, consistent with NMHC-B expression in the somitic muscle and NMHC-A expression in the epidermis.

Improvement of bond strength in metal-ceramic systems using a gold intermediate layer

The mechanism of bonding between metal and ceramic in systems using the functionally graded method with pure gold and gold mixture as a primer was examined. Four types of samples, porcelain, porcelain-gold, porcelain-metal and porcelain-gold-metal were prepared. The gold intermediate layer was fired at 1000 degrees C. For porcelain and metal, low-fusing opaque, body porcelain and palladium alloy were used. The intermediate layer was composed of three layers; pure gold, gold-palladium and gold-porcelain layer. During the bending test of each sample, the porcelain peeled away from the porcelain-metal system, while porcelain with the gold intermediate layer remained on the metal surface even after maximal loading. The bond strength of the porcelain-gold-metal system was much higher than that of the porcelain-metal system, and the toughness of the former was much greater than that of the latter. Laser microscopy and scanning electron microscopy (SEM) showed a smooth interface between the intermediate layer and the metal which suggested proper chemical bonding, and no gap was observed. At the interface between the porcelain and the gold intermediate alloy, a good mechanical anchor lock was observed. Electron probe microanalysis (EPMA) showed a clear distribution of each element (e.g. Si, Au and Pd) in the porcelain, gold intermediate layer and metal frame.

Neural coding of 3D features of objects for hand action in the parietal cortex of the monkey

In our previous studies of hand manipulation task-related neurons, we found many neurons of the parietal association cortex which responded to the sight of three-dimensional (3D) objects. Most of the task-related neurons in the AIP area (the lateral bank of the anterior intraparietal sulcus) were visually responsive and half of them responded to objects for manipulation. Most of these neurons were selective for the 3D features of the objects. More recently, we have found binocular visual neurons in the lateral bank of the caudal intraparietal sulcus (c-IPS area) that preferentially respond to a luminous bar or place at a particular orientation in space. We studied the responses of axis-orientation selective (AOS) neurons and surface-orientation selective (SOS) neurons in this area with stimuli presented on a 3D computer graphics display. The AOS neurons showed a stronger response to elongated stimuli and showed tuning to the orientation of the longitudinal axis. Many of them preferred a tilted stimulus in depth and appeared to be sensitive to orientation disparity and/or width disparity. The SOS neurons showed a stronger response to a flat than to an elongated stimulus and showed tuning to the 3D orientation of the surface. Their responses increased with the width or length of the stimulus. A considerable number of SOS neurons responded to a square in a random dot stereogram and were tuned to orientation in depth, suggesting their sensitivity to the gradient of disparity. We also found several SOS neurons that responded to a square with tilted or slanted contours, suggesting their sensitivity to orientation disparity and/or width disparity. Area c-IPS is likely to send visual signals of the 3D features of an object to area AIP for the visual guidance of hand actions.

[Insulin receptor abnormality and its clinical aspect]

About 50 cases of insulin receptor abnormality were reported after in 1985 when human insulin receptor cDNA was cloned. The abnormalities were found in syndrome of type A insulin resistance, Leprechaunism, and syndrome of Rabson-Mendenhall. We have reported 3 families with insulin receptor gene abnormality, Type C (Chiba), Type A (Yamanashi) and Type C (Hokkaidou-2). Type C (Chiba) and Type A (Yamanashi) have a deletion of from 17 to 22 exon and 14 exon of insulin receptor gene, respectively. Type C(Hokkaidou-2) shows a substitution of valine for glycine at codon 1008 in the tyrosine kinase domain. They all showed the typical symptoms of type A insulin resistance, and the insulin resistance was dominantly inherited in the family of Type C(Chiba) and Type C(Hokkaidou-2), and not in the family of Type A(Yamanashi).

Expression and characterization of deletion recombinants of two cGMP-inhibited cyclic nucleotide phosphodiesterases (PDE-3)

cDNAs encoding two PDE-3 or cyclic GMP-inhibited (cGI) cyclic nucleotide phosphodiesterase (PDE) isoforms, RPDE-3B (RcGIP1) and HPDE-3A (HcGIP2), were cloned from rat (R) adipose tissue and human (H) heart cDNA libraries. Deletion and N- and C-terminal truncation mutants were expressed in Escherichia coli in order to define their catalytic core. Active mutants of both RPDE-3B and HPDE-3A included the domain conserved among all PDEs plus additional upstream and downstream sequences. An RPDE-3B mutant consisting of the conserved domain alone and one from which the RPDE-3B 44-amino acid insertion was deleted exhibited little or no activity. All active recombinants exhibited a high affinity (< 1 microM) for cyclic AMP (cAMP) and cyclic GMP (cGMP), were inhibited by cAMP, cGMP, and cilostamide, but not by rolipram, and were photolabeled with [32P]-cGMP. The IC50 values for cGMP inhibition of cAMP hydrolysis were lower for HPDE-3A than for RPDE-3B recombinants. The deduced amino acid sequences of HPDE-3A and RPDE-3B catalytic domains are very similar except for the 44-amino acid insertion not found in other PDEs. It is possible that this insertion may not only distinguish PDE-3 catalytic domains from other PDEs and identify catalytic domains of PDE-3 subfamilies or conserved members of the PDE-3 gene family, but may also be involved in the regulation of sensitivity of PDE-3s to cGMP.

Heterogeneous fluoridated apatites synthesized with a three-step fluoride supply system

Two types of heterogeneous fluoridated apatite, H-F-H and F-H-F, were synthesized by supplying fluoride during the middle half (H-F-H) or initial and final quarters (F-H-F) of the experimental period. Although X-ray diffraction patterns and SEM photographs of both H-F-H and F-H-F-type apatites were not significantly different, high-resolution transmission electron microscopy showed quite different features; H-F-H-type apatite crystals were elongated hexagons, while those of F-H-F-type apatite were rather wider hexagons with electron damage in three-quarters of the inner core. These results supported the previous speculations on the two different types of heterogeneous fluoridated hydroxyapatites synthesized with fluoride concentrations stoichiometrically equivalent to that of fluorapatite: hydroxyapatite covered with fluorapatite and fluorapatite covered with hydroxyapatite. F-H-F-type apatite was less soluble than that of H-F-H-type apatite.

MUC-1 mucin expression in invasive areas of intraductal papillary mucinous tumors of the pancreas

The expression of MUC-1 mucin (membrane-associated mucin) and MUC-2 mucin (secretory mucin) were immunohistochemically examined in 46 invasive ductal carcinomas (IDC) and 16 intraductal papillary mucinous tumors (IPMT) of the pancreas. Intraductal papillary mucinous tumors usually reveal expansive growth. However, of the 16 IPMT examined in the present study, three showed an invasive growth pattern, which was similar to 'mucinous carcinoma', around the non-invasive growth areas. Of 46 IDC, MUC-1 mucin detected by monoclonal antibodies, DF3 and MY.1E12, was expressed in 44 cases (96%) and in 45 cases (98%), respectively, whereas MUC-2 mucin detected by polyclonal antibody, anti-MRP, was not expressed in any of the cases (0%). In contrast, in the non-invasive growth areas of the 16 IPMT, MUC-1 mucin detected by DF3 and MY.1E12 was expressed in four cases (25%) and in six cases (38%), respectively, whereas MUC-2 mucin detected by anti-MRP was expressed in 13 cases (81%). The invasive growth areas of the three IPMT showed positive expression of MUC-1 mucins detected by DF3 and MY.1E12, although the non-invasive growth areas showed negative expression of MUC-1 mucins, except for their focal positive expression in one of the three cases. These findings indicate that the invasive growth areas of IPMT acquire a characteristic of MUC-1 mucin expression that is usually seen in IDC.

Differences in solubility of two types of heterogeneous fluoridated hydroxyapatites

Two types of heterogeneous fluoridated apatites, H-F and F-H, were synthesized by supplying fluoride over the whole range of the degree of fluoridation (X = 0-1.0) during the initial or final half of the experimental period. Although X-ray diffraction patterns and scanning electron microscopy (SEM) photographs of both H-F and F-H type apatites were not significantly different, high-resolution transmission electron microscopy (HR-TEM) showed quite different features; H-F type apatites were elongated hexagons with electron beam damage in the core, while F-H type apatites were rather wider hexagons and approached the typical hexagon of fluorapatite. These results supported the previous speculations on the two different types of heterogeneous fluoridated hydroxyapatites synthesized with fluoride concentration stoichiometrically equivalent to that of fluorapatite: hydroxyapatite covered with fluorapatite and fluorapatite covered with hydroxyapatite. The apparent solubility of H-F type apatites decreased with increases in degree of fluoridation, while that of F-H type apatites decreased markedly and then remained almost constant.