A simple contrast enhancement by potassium permanganate oxidation for Lowicryl K4M ultrathin sections prepared by high pressure freezing/freeze substitution

A simple contrast enhancement method is presented for Lowicryl K4M ultrathin sections prepared by high pressure freezing/freeze substitution. The sections were treated with an acidified potassium permanganate oxidizing solution followed by uranyl acetate and lead citrate staining. The method, designated KMnO4-UA/Pb staining, provided a much greater contrast in electron microscopy than conventional UA/Pb staining. In detail, the visibility of plasma membrane was especially improved and the nuclear heterochromatin, mitochondria and cytoplasmic ribosomes showed an adequate increase in electron density. In the mucous cells of rat Brunner's glands, the Golgi cisternae were well defined with the KMnO4-UA/Pb staining. Interestingly, the membranes of the intermediate compartments were moderately reactive to the KMnO4-UA/Pb staining, whereas the cis and the trans compartments were only faintly stained. It should be emphasized that the KMnO4 oxidation following colloidal gold labelling did not cause a remarkable reduction of immunogold labelling and the enhanced contrast helped us to examine the gold particles with high accuracy. This contrast enhancement method is highly promising, with the potential to become a useful tool for histochemical investigation, including immunocytochemistry with the Lowicryl K4M ultrathin sections prepared by high pressure freezing/freeze substitution techniques.

Methicillin-resistant coagulase-negative staphylococci isolated from healthy horses in Japan

OBJECTIVE

To determine patterns of methicillin-resistant staphylococci isolated from apparently healthy horses.

SAMPLE POPULATION

44 horses from 8 riding clubs in Japan.

PROCEDURE

Methicill in-resistant staphylococci were isolated from the skin or nares, using a selective medium containing a beta-(symboric) lactam antibiotic, ceftizoxime. Clonality of isolates was determined by use of pulsed-field gel electrophoresis. Detection of mecA, mecl, and mecR1 genes was accomplished by use of polymerase chain reactions.

RESULT

Of the 44 horses, 13 (29.5%) yielded 15 isolates of methicillin-resistant staphylococci. The 15 isolates were identified as 6 species (Staphylococcus epidermidis, S lentus, S saprophyticus, S xylosus, S sciuri, and S haemolyticus). However, methicillin-resistant S aureus was seldom isolated. Each isolate contained the mecA gene and had a high resistance to beta-lactam antibiotics. Some isolates also were resistant to other antibiotics such as erythromycin and kanamycin.

CONCLUSIONS AND CLINICAL RELEVANCE

Methicillin-resistant coagulase-negative staphylococci that were highly resistant to various antibiotics were isolated from apparently healthy horses in Japan. These organisms must be considered a potential threat to horses and veterinarians who care for them.

Tuft cells in the main excretory duct of the rat submandibular gland

The fine structure of tuft cells in the main excretory duct of rat submandibular gland was investigated using the high pressure freezing and freeze substitution (HPF-FS) method and compared with that seen with both conventional chemical fixation (CF) method and en bloc treatment with ruthenium red. Some MEDs also were subjected to histochemistry for lectins. The apical vesicles and tubules of tuft cells observed by TEM after the HPF-FS method were different in shape from those treated by CF. With the first method, these vesicles and tubules, which may represent sections of a tubular system, appeared more slender and filled with a material of moderate density. A prominent glycocalyx covering the microvillar plasma membrane was observed in tuft cells processed both with the HPF-FS method and with ruthenium red. The surface of microvilli and the tubulo-vesicular structures of these cells exhibited the same soybean agglutinin (SBA) reactivity, suggesting a relationship between them.

Characterization of Staphylococcus aureus coagulase type VII isolates from staphylococcal food poisoning outbreaks (1980-1995) in Tokyo, Japan, by pulsed-field gel electrophoresis

Staphylococcus aureus coagulase type VII strains have been the strains most frequently isolated from staphylococcal food poisoning outbreaks in Tokyo, Japan. We applied pulsed-field gel electrophoresis (PFGE) of chromosomal DNA digested with SmaI to characterize 129 coagulase type VII strains. These were isolated from 129 cases occurring in outbreaks in 35 districts during a 16-year period (1980-1995). The 129 outbreak strains were classified into three types, designated A (n = 115), B (n = 10), and C (n = 4). Types A and C were further divided into 33 (A1 to A33) and 4 (C1 to C4) subtypes, respectively. Strains of the same subtypes were isolated from food poisoning cases in the same districts at time intervals of 1 or 2 to 5 years. PFGE typing appears to be a useful method for subdividing strains of S. aureus coagulase type VII. A combination of coagulase typing and PFGE typing would provide more detailed information than the former method alone in epidemiologic investigations of staphylococcal food poisoning.

CALNUC (nucleobindin) is localized in the Golgi apparatus in insect cells

A mouse monoclonal antibody 12B1 was raised against Golgi fractions from Sf21 insect cells and selected as Golgi-specific by immunostaining of the cells. The antigen was purified from the cells by immunoaffinity chromatography with the monoclonal antibody, and its N-terminal and internal amino acid sequences were determined. Based on the partial amino acid sequences, cDNA encoding the antigen protein was cloned and sequenced. The amino acid sequence deduced from the cDNA nucleotide sequence showed a homology to those of CALNUC family proteins, CALNUC (or nucleobindin, a calcium-binding Golgi protein with DNA-binding activity) and protein NEFA (a cell surface protein with DNA-binding, EF-hand, and acidic domains). The insect protein had two EF-hand loops at the same sites as the mammalian CALNUC family proteins, but had no leucine zipper which the mammalian homologues commonly have. An electron microscopic immunoperoxidase study demonstrated that the insect protein was localized in the cis-Golgi cisternae and cis-Golgi networks. Since this localization is identical to that of mammalian CALNUC, the insect protein was considered to be a homologue of CALNUC rather than that of NEFA. Assays involving proteinase K digestion, sodium carbonate extraction and Triton X-114 extraction revealed that the insect CALNUC-like protein was a soluble protein tightly associated with the luminal surface of Golgi membranes as reported for mammalian CALNUC. The insect protein was also shown to have calcium-binding activity as does mammalian CALNUC. These data verify that the insect protein is CALNUC. The existence of CALNUC in insect cells suggests that CALNUC is an essential calcium-binding Golgi protein in a wide range of the animal kingdom. A phylogenetic tree analysis, however, suggested that NEFA was derived from CALNUC long after the segregation of a mammalian ancestor from an insect ancestor.

Reappraisal of potassium permanganate oxidation applied to Lowicryl K4M embedded tissues processed by high pressure freezing/freeze substitution, with special reference to differential staining of the zymogen granules of rat gastric chief cells

The high pressure freezing/freeze substitution technique is known to yield a deep vitreous freezing of tissues. Combination of this technique with Lowicryl K4M embedding allows us histochemical studies of dynamic cellular processes with improved structural preservation. The disadvantage of Lowicryl K4M embedding is its poor electron density in electron microscopy. To address this problem, we examined the effects of KMnO4 oxidation applied to Lowicryl K4M embedded rat gastric glands processed by high pressure freezing. The KMnO4 oxidation-uranyl acetate-lead citrate sequence succeeded not only in contrast enhancement of cellular components, but also in differential staining of the zymogen granules of rat gastric chief cells. This technique could be applied to semi-thin sections of Lowicryl K4M embedded rat gastric glands. The KMnO4 oxidation-toluidine blue staining provided sufficient contrast with regard to the zymogen granules. Various experiments used in this study verified that the KMnO4 oxidation plays an essential role in the differential staining of the zymogen granules. Combined use of the KMnO4 oxidation with phospholipase A2-immunostaining demonstrated that gold labeling was localized to the zymogen granules without the loss of immunolabeling. Energy dispersive X-ray microanalysis revealed some manganese depositions on the zymogen granules. It is highly anticipated that the KMnO4 oxidation will become a useful tool for histochemical investigations combined with cryofixation/freeze substitution and low temperature embedding techniques.

Prostaglandin I2 analog enhances the expression of urokinase-type plasminogen activator and wound healing in cultured human fibroblast

This study examines the effects of prostaglandin I2 (PGI2) on urokinase-type plasminogen activator (uPA) production and wound healing by human fibroblasts. Employing fibrin autography, it was found that beraprost sodium, a stable PGI2 analog, enhanced the fibrinolytic activity in media conditioned by human fibroblasts, TIG-3-20 cells. Fibrin zymography, ELISA, and Northern blot analysis confirmed that the enhanced activity was caused by an increase in uPA synthesis and secretion and a decrease in type-1 plasminogen activator inhibitor. While cycloheximide and 2',5'-dideoxyadenosine, an adenylate cyclase inhibitor, suppressed the effect of PGI2, dibutyryl cyclic AMP increased the fibrinolytic activity and uPA mRNA. These findings indicate that PGI2 promotes uPA production in TIG-3-20 cells via direct stimulation of the cyclic AMP intracellular pathway. A similar effect was observed in two other fibroblast cell lines, TIG-7-20 and TIG-7-30. Although PGI2 itself did not affect cellular proliferation, it promoted in vitro repopulation of the denuded area in a wounded monolayer. These observations suggest that PGI2 can stimulate wound healing through the enhanced production of uPA.

Cortical projections of the parvocellular laminae C of the dorsal lateral geniculate nucleus in the cat: an anterograde wheat germ agglutinin conjugated to horseradish peroxidase study

The areal and laminar distributions of the projection from the parvocellular part of laminae C of the dorsal lateral geniculate nucleus (Cparv) were studied in visual cortical areas of the cat with the anterograde tracing method by using wheat germ agglutinin conjugated to horseradish peroxidase. A particular objective of this study was to examine the central visual pathways of the W-cell system, the precise organization of which is still unknown. Because the Cparv in the cat is said to receive W-cell information exclusively from the retina and the superior colliculus, the results obtained would provide an anatomical substrate for the W-cell system organization in mammals. The results show that the cortical targets of the Cparv are areas 17, 18, 19, 20a, and 21a and the posteromedial lateral suprasylvian (PMLS) and ventral lateral suprasylvian(VLS) areas. In area 17, the projection fibers terminate in the superficial half of layer I; the lower two-thirds of layer III, extending to the superficial part of layer IV; and the deep part of layer IV, involving layer Va. These terminations form triple bands in area 17. The projection terminals in layer I are continuous, whereas those in layers III, IV, and Va distribute periodically, exhibiting a patchy appearance. In areas 18 and 19, the projection fibers terminate in the superficial half of layer I and in the full portions of layers III and IV, forming double bands. In these areas, the terminals in layer I are continuous, whereas those in layers III and IV distribute periodically, exhibiting a patchy appearance. In area 20a, area 21a, PMLS, and VLS, projection fibers terminate in the superficial part of layer I, in part of layer III, and in the full portion of layer IV, although they are far fewer in number than those seen in areas 17, 18, and 19. The present results demonstrate that the Cparv fibers terminate in a localized fashion in both the striate and the extrastriate cortical areas and that these W-cell projections are quite unique in their areal and laminar organization compared with the X- and Y-cell systems.

Comparison of pulsed-field gel electrophoresis and phage typing for discriminating poultry strains of Staphylococcus aureus

OBJECTIVE

To compare pulsed-field gel electrophoresis (PFGE) patterns of Staphylococcus aureus from chickens in England, Belgium, Bulgaria, Argentina, and Japan, to assess the value of PFGE for discriminating strains, and to compare results obtained by PFGE with those obtained by biotyping and phage typing.

SAMPLE POPULATION

78 S aureus isolates from diseased and healthy chickens.

PROCEDURE

Chromosomal DNA of S aureus was digested with restriction endonuclease Sma I, and fragments were separated by PFGE in 1% agarose gel.

RESULTS

All 78 strains from 5 countries were classified as poultry ecovar according to a previously established biotyping system. Chromosomal DNA was cut by Sma I into 18 to 23 fragments ranging from about 3 to 685 kb. Seventy-eight strains produced 15 types, arbitrarily designated A to O, and 45 subtypes. Some differences were observed in PFGE patterns among countries. However, 10 fragments (333, 190, 110, 63, 55, 42, 34, 19, 10, and 3 kb) were highly conserved and were shared by almost all (> 78%) of the strains examined. The PFGE patterns were compared with those obtained by phage typing. All 29 strains belonging to avian phage-group II produced type A and 19 subtypes. Of the 15 strains belonging to phage-group I, 11 produced 8 types (B to H, O) and 5 subtypes that were different from those of type A.

CONCLUSIONS

Genomic DNA fingerprinting by PFGE is an effective technique for discriminating poultry S aureus strains and appears to be a useful method for subtyping strains of avian phage groups or the poultry-specific ecovar.

Genetic analysis of equine methicillin-resistant Staphylococcus aureus by pulsed-field gel electrophoresis

Pulsed-field gel electrophoresis (PFGE) was used to determine genetic relationships among 15 methicillin-resistant Staphylococcus aureus (MRSA) isolates from mares with metritis and from a stallion with dermatitis in Hokkaido. All the 15 isolates showed phage pattern 6/47/54/75, coagulase type IV, and enterotoxin type A. The restriction endonuclease SmaI cut their genomic DNAs into 15 or 16 fragments ranging in size from 8 to 630 kb. Fourteen of the 15 isolates showed the same PFGE pattern, whereas the remaining one appeared to be closely related. The 9 human MRSA isolates showing the same phenotypic characteristics as the horse isolates gave different PFGE patterns from those of the horse isolates.

Isolation of methicillin-resistant coagulase-negative staphylococci from chickens

Methicillin-resistant coagulase-negative staphylococci were isolated from the nares and skin of 1- to 8-week-old healthy chickens in three flocks from a farm. Isolation of methicillin-resistant coagulase-negative staphylococci was positive for 72 (25.7%) of the 280 chickens tested, with the frequency varying from 2.2 to 100% according to flock. A total of 45 appropriate isolates were selected and subjected to identification. Of the 45 methicillin-resistant coagulase-negative staphylococcal isolates selected, 37 were identified as Staphylococcus sciuri, 5 were identified as Staphylococcus epidermidis, and 3 were identified as Staphylococcus saprophyticus. The distribution of the species was different among the flocks. Comparative analysis of the SmaI-digested chromosomal DNA by pulsed-field gel electrophoresis revealed that the isolates could have originated from a single clone of each of S. sciuri and S. saprophyticus and three clones of S. epidermidis. By two methods based on the PCR technique, the mecA gene was detected in all five representative isolates of each methicillin-resistant coagulase-negative staphylococcal clone. The nucleotide sequence of a PCR fragment obtained from an isolate of S. sciuri was completely identical to the corresponding region of mecA genes reported in human methicillin-resistant Staphylococcus aureus isolates and Staphylococcus epidermidis isolates. The representative methicillin-resistant coagulase-negative staphylococcal isolates were resistant to many beta-lactam antibiotics, and some isolates were also resistant to macrolide and aminoglycoside antibiotics. This is the first evidence of the existence of methicillin-resistant coagulase-negative staphylococci from animals possessing the mecA gene.

Crossed projection neurons are generated prior to uncrossed projection neurons in the lateral superior olive of the rat

The present study examined in the lateral superior olive (LSO) of the rat whether LSO neurons projecting to the ipsilateral inferior colliculus (IC) might be generated later than those projecting to the contralateral IC. Rat fetuses were exposed in utero to 5-bromodeoxyuridine (BrdU), a thymidine analogue, to label neurons proliferating at different embryonic stages from day E11 through to E20. Upon reaching adulthood, the rats were given unilateral injections of fluoro-gold (FG), a retrograde fluorescent tracer, into the IC. Subsequently, the tissue sections of the brains obtained from the rats were immunostained for BrdU to simultaneously detect neurons that were BrdU-positive and/or FG-positive. BrdU-positive LSO neurons were found in the rats which had been exposed to BrdU during E12-E16. In E12 and E13 BrdU-exposure cases, the vast majority of doubled-labeled (BrdU-positive and FG-positive) neurons were seen on the contralateral side to the FG injection. In E14, E15 and E16 BrdU-exposure cases, in contrast, all double-labeled neurons were found on the ipsilateral side to the FG injection. The distribution of these double-labeled neurons within the nucleus was diffuse in all the BrdU-exposure cases. Thus, the results indicate that LSO neurons are generated during E12-E16, that the crossed projection neurons are generated 1-4 days earlier than the uncrossed projection neurons, and that no topographical relationships exist between the early- and the late-generated populations of the LSO neurons.

Desulfation of tyrosine-O-sulfated peptides by some eukaryotic sulfatases

Three mammalian and eight non-mammalian arylsulfatases were investigated for their activities toward tyrosine-O-sulfate (TyrS) in peptides. None of the mammalian arylsulfatases exhibited detectable activities toward TyrS-containing peptides. Of the non-mammalian arylsulfatases tested, Types VII, VIII, and H-1, 2, and 5 displayed strong activity on endo-TyrS residues. The prokaryotic sulfatase, Type VI, was active only on free TyrS and N-terminal TyrS of Leu-enkephalin. All the sulfatases were active on p-nitrophenyl sulfate and p-nitrocatechol sulfate.

Electron microscopic study of synaptogenesis and myelination of the olfactory centers in developing rats

Development of the central olfactory system was studied in the rat with an electron microscope at three main structures: the olfactory bulb, the lateral olfactory tract, and the primary olfactory cortex (the piriform cortex). As a parameter of development, the synaptic density was examined quantitatively in the bulbar glomerulus and layer Ia (termination of bulbofugal fibers) of the piriform cortex. which are the key stations of the olfactory pathway. The synaptic densities in the glomerulus and those in layer Ia were 5.7% and 4.6% on embryonic day 19, 15.8% and 12.5% on postnatal day (P) 0, and 57.3% and 37.2% on P10, as compared with the adult (100%). As another parameter of development, the density of myelinated axons in the lateral olfactory tract was examined quantitatively. The densities of myelinated axons in the tract were 0% on P5, 15.1% on P10, and 73.5% on P21 of the adult density. Maturation in the tract was still progressing, even at P21, in terms of bundle formation and the thickness of myelin sheaths. The results show that synaptogenesis in the bulbar glomerulus is followed by synaptogenesis in layer Ia of the piriform cortex, and that myelination in the lateral olfactory tract occurs over a prolonged period, even in the stages after P21.

Anatomical plasticity in the medial superior olive following ablation of the inferior colliculus in neonatal and adult rats

We evaluated the consequences of unilateral ablation of the inferior colliculus (IC) upon the ascending projection from the medial superior olive (MSO) to the IC. Ablation of the IC was performed in rats aged between postnatal day 1 (P1) and maturity. All the rats were given injections of Fluoro-Gold (FG) into the ipsilateral IC at birth (P0) (before the ipsilateral IC was ablated in any case) so that growth of early-developing axons to the ipsilateral IC could be examined for any labeled neurons in the ipsilateral MSO. Upon reaching adulthood, the rats received injections of Fluoro-Ruby (FR) into the contralateral (intact) IC so that aberrant crossed projections to the intact IC could be examined for any labeled neurons in the ipsilateral MSO. These rats were killed 2 days after FR injections. The number of surviving cells in the ipsilateral MSO were counted in Nissl-stained sections for quantitative analysis of retrograde degeneration. The results show that: (1) the total number of neurons was reduced to 64-34% in the ipsilateral MSO as a result of IC ablation; (2) cell reduction by retrograde degeneration followed a U-shaped curve with a maximal effect in rats operated at P7 (reduced to 34%); (3) adult ablation of the IC led to retrograde degeneration that was less severe than that in late neonatal (P7) ablation; (4) an aberrant projection from the MSO to the contralateral IC occurred in rats operated at P1 and P3 but not in rats operated at P7 or maturity. Thus, our findings suggest that growth of late-developing axons is a major factor in the plasticity of this system of projection.

Postnatal development of the projection from the medial superior olive to the inferior colliculus in the rat

Normal projection development from the medial superior olive (MSO) to the inferior colliculus (IC) was examined by injecting Fluoro-Gold (FG), a retrograde tracer, into the IC unilaterally at postnatal days 0 (P0), P3, P7 and maturity. The rats were killed 1 day after FG injection. At all ages, labeled neurons in the MSO appeared on the ipsilateral side only, as in adult controls. The total number of MSO neurons counted in Nissl-stained sections was constant throughout the postnatal periods. The labeled frequency index of MSO neurons was increased stepwise (from 35% to 90%) with increasing postnatal stages (from P0 to adulthood), suggesting differential growth of early- and late-developing axons.

Differentiation of the olfactory epithelium during development

Maturation of the olfactory epithelium was studied in the rat. As a developmental index of the olfactory epithelium, quantitation was based on the thickness and the number of cell layers of the epithelium. Mean epithelial thicknesses were 84 microns on embryonic day (E) 19, 94 microns on postnatal day (P) 0, 98 microns on P10 and 57 microns in adult. Average numbers of cell layers were 7 (E19), 8 (P0), 10 (P10) and 7 (adult). Thus the olfactory epithelium progressively increased in thickness between P0-P10, and later decreased in thickness as well as in number of cell layers toward adult. To clarify the number of mature receptor cells sending their axons to the olfactory bulb, the percentages of receptor cell labeling (number of labeled cells/total number of receptor cells) were estimated with an aid of retrograde fluorescent tracer injected into the olfactory bulb. As a result, their percentages were 34% (P1-P3), 50% (P8-P10) and 78% (adult). The ablation experiment of the bulb on P1 pups and adult rats revealed that the percentages of receptor cell degeneration were 31% in neonates (P1) and 76% in adults, confirming the results obtained from the retrograde tracing. Thus the present study shows the substantial increase of mature receptor cells during development and may provide a morphological basis in understanding of the functional maturity of olfaction.

A new type of staphylococcal exfoliative toxin from a Staphylococcus aureus strain isolated from a horse with phlegmon

A new type of staphylococcal exfoliative toxin (sET) was isolated from the culture filtrate of a Staphylococcus aureus strain isolated from a horse with skin infection including phlegmon. The new sET was purified by precipitation with 80% saturated ammonium sulfate, column chromatography on DEAE-cellulofine A-500, gel filtration on a Sephadex G-75 column, and polyacrylamide gel electrophoresis (7.5% polyacrylamide). The new sET elicited general exfoliation of the epidermis with the so-called Nikolsky sign when inoculated into both 3-day-old mice and 1-day-old chicks, whereas sETA and sETB from human strains of S. aureus caused exfoliation in a 3-day-old mouse alone and shET from a porcine strain of Staphylococcus hyicus caused exfoliation in 1-day-old chicks alone. Intraepidermal splitting was observed at the granular layer of the epidermis of mice inoculated with the new sET as well as those inoculated with sETA. Exfoliation at the germinative layer of the epidermis was also observed in the chicks inoculated with the new sET as well as those inoculated with shET. The new sET was serologically different from sETA, sETB, and shET and showed the same molecular weight on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It was thermolabile and lost its toxicity after being heated at 60 degrees C for 15 min. We propose that the new sET be designated as sETC.

Purification and immunohistochemistry of Griffonia simplicifolia agglutinin-II-binding mucus glycoprotein in rat stomach

Gastric mucus is thought to protect the gastric wall from mechanical trauma, desiccation, pathogenic microorganisms, acid and proteases. We purified Griffonia simplicifolia agglutinin-II (GSA-II)-binding mucus glycoprotein (GMG) from rat gastric mucosa by solubilization in a guanidine-containing buffer, gel permeation chromatography, Ricinus communis agglutinin-I (RCA-I)-affinity chromatography and GSA-II-affinity chromatography. Rat GMG showed high molecular weight on a Sephacryl S-1000 column, and a single band in 0.5% agarose-2% polyacrylamide composite gels and blots. A protein of approximately 60 kDa was contained in the GMG preparation. GMG was deglycosylated with trifluoromethanesulphonic acid treatment. An antibody was raised against deglycosylated GMG (deGMG). The antibody recognized deGMG, GMG, periodic acid-treated deGMG and O-glycanase-digested deGMG, but did not react to trypsin-digested deGMG. These results suggest that the antibody recognizes proteinase-sensitive region or peptide backbone of GMG. In immunohistochemistry, the mucous gel layer of the stomach luminal surface was stained with antibody. The antibody recognized not only gastric mucous neck cells and pyloric gland cells, but also gastric surface mucous cells, mucous cells in the duodenal gland, and goblet cells in the small intestine and colon. These results indicate that GMG is a component of rat gastric mucus, and that the antibody recognizes mucous-secreting cells in rat stomach and intestine.

A protein-specific monoclonal antibody to rat liver beta 1-->4 galactosyltransferase and its application to immunohistochemistry

We have produced a new protein-specific monoclonal antibody (MAb) to rat liver beta 1-->4 galactosyltransferase. This MAb, GTL2, was selected as the most reactive IgG to a periodate-treated antigen. Antigen and protein specificities of GTL2 were verified by immunoblotting of a non-glycosylated recombinant protein of human galactosyltransferase and enzymatically deglycosylated rat galactosyltransferase. Using GTL2, an immunohistochemical study was done in rat liver, epididymis, and salivary glands. Intense staining was observed in Golgi areas of epididymal duct epithelial cells, and submandibular and sublingual acinar cells. Hepatocytes showed weaker staining. Immunoelectron microscopic observation revealed that the staining was exclusively localized in trans-Golgi membranes of these cells.

Human colorectal carcinoma-specific glycoconjugates detected by pokeweed mitogen lectin

Pokeweed mitogen (PWM) lectin, known to bind branched poly-N-acetyllactosamines, has a highly selective affinity for human colorectal carcinomas. We performed light microscopic (LM) histochemistry with PWM lectin on paraffin sections of human colorectal tissues. In histological sections, normal mucosae and adenomas with mild dysplasia exhibited negative reaction (0/10, 0/13, respectively) with or without neuraminidase pre-digestion, whereas adenomas with moderate dysplasia showed a small increase in PWM lectin reactivity after neuraminidase digestion (4/23). In contrast, we observed a high incidence of positive reactivity in colorectal carcinoma without neuraminidase pre-digestion (38/44). After digestion with neuraminidase, there was increased reactivity of colorectal carcinomas in situ (7/12) and invasive carcinomas (13/32). These results imply that human colorectal carcinomas consistently contain substantial amounts of PWM-reactive branched poly-N-acetyllactosamine glycoconjugates structures. We also compared the staining patterns of PWM lectin and monoclonal antibodies (MAb) directed to Lewis X (LeX) or Lewis Y (LeY) antigen. PWM lectin reactivity was largely confined to the apical membranes of carcinoma tissues. MAb-LeX or MAb-LeY immunoreactivity was seen on the apical membranes and in the cytoplasm of both adenomas and carcinomas. Therefore, histochemical studies with this lectin should be useful for identification of carcinoma tissues and analysis of glycoconjugates associated with colorectal carcinoma.

Differential projections to the superior collicular layers from the perihypoglossal nuclei in the cat

The primary objective of the present study is to demonstrate the presence of a projection to the superficial layers of the superior colliculus (SC) from the perihypoglossal nuclei, specifically from the nucleus intercalatus (INT) in the cat. Iontophoretic application of WGA-HRP into the perihypoglossal complex produced orthogradely labeled terminals in the SC contralaterally forming two bands: one is in the superficial gray layer, and the other in the intermediate gray layer. The superficial band was evenly distributed in the upper portion of the superficial gray layers (layers II1-2) and the deeper band existed in the intermediate gray layer (layer IV) being arranged in a discontinuous manner. Injections of the tracer into the superficial layers of the SC yielded retrogradely labeled cells only in the rostral part of the contralateral INT; by contrast, the injection confined to the deep layers produced labeling of cells exclusively in the nucleus prepositus hypoglossi (PH). Thus, the INT and the PH each project separately to the functionally different superficial and intermediate layers of the SC, respectively. On the basis of the present anatomical findings, it is suggested that the perihypoglossal nuclei as a whole contribute not only to the oculomotor but also to the visuosensory regulatory function in the SC.

Bromodeoxyuridine-immunohistochemistry on cellular differentiation and migration in the fundic gland of Xenopus laevis during development

Cellular differentiation and migration in the fundic glands of adult and larval Xenopus laevis have been examined using bromodeoxyuridine-immunohistochemistry. In the adult fundic gland, cumulative labeling with bromodeoxyuridine revealed a proliferative cell zone between the surface mucous cells and mucous neck cells, in what is referred to as the neck portion of the gland. The labeling-index of mucous neck cells had rapidly increased by week-5. The labeling-index of oxynticopeptic cells showed a more delayed increase until week-7, coincident with the decrease in the labeling of mucous neck cells. In the immature fundic glands of larvae, the labeled proliferating cells were randomly distributed throughout the developing gastric mucosa. During metamorphosis, the labeling-index of immature epithelial cells was highest at stage 63. Following administration of bromodeoxyuridine at this stage, there was no significant loss of labeled epithelial cells during the metamorphosing period. Furthermore, there was no significant difference in the labeling-indices among the epithelial cells, such as surface mucous cells/generative cells, mucous neck cells, and oxynticopeptic cells, 7 days after administration. Cellular differentiation and migration pathways of epithelial cells in the fundic gland of adult X. laevis and its larvae are discussed.

Characterization of beta 1----4 galactosyltransferase purified from rat liver microsomes

beta 1----4 Galactosyltransferase was purified from rat liver microsomes. Catalytic properties of the enzyme resembled those of previously purified soluble and membrane-bound beta 1----4 galactosyltransferases. The enzyme purified in the present study showed a major band around a molecular weight of 53,000 on SDS-PAGE. The NH2-terminal sequence of the enzyme was determined up to the 20th residue. The sequence was identical to the amino acid sequence from Ala-13 to Lys-32 deduced from mouse beta 1----4 galactosyltransferase cDNA. These results suggest that most of the mature enzyme in rat liver microsomes is produced by removal of the NH2-terminal 12 amino acids from a precursor polypeptide.

Immunohistochemical localization of dipeptidyl aminopeptidase IV in thyroid papillary carcinoma

The localization of dipeptidyl aminopeptidase IV expressed aberrantly in thyroid carcinoma was studied by immunoelectron microscopy using a monoclonal antibody to the enzyme with special reference to enzyme-histochemical staining of the enzyme. Five thyroid papillary carcinomas were investigated including two lymph-node metastases. All cases showed the dense immunoreaction product on the apical membrane and only traces of the product on lateral membranes, endoplasmic reticulum and nuclear membranes. In one case only, the dense product was observed on basal tubular structures. Analysis, using immunogold labelling on pre-embedded cryosections, revealed that dipeptidyl aminopeptidase IV was localized on the luminal surface of cancer cells. Two different distribution patterns of dipeptidyl aminopeptidase IV activity staining, diffuse and apical patterns, reported previously were thought to be due to different amounts of dipeptidyl aminopeptidase IV in the cytoplasm of cancer cells. This enzyme-histochemical staining method is useful for pathological diagnosis of thyroid tumours and can be applied to clinical materials. The enzyme localization is revealed by the staining pattern.

Factors contributing to the resistance of chickens to infection with Japanese Fasciola sp

Attempts were made to clarify the factors contributing to the resistance of chickens to infection with Japanese Fasciola sp. Infection was not successfully established in chickens by oral inoculation of metacercariae, nor by inoculation of excysted juvenile flukes into the body cavity or to the liver surface. Many metacercarial cysts were detected within two days in the feces of orally inoculated chickens. In the in vitro excystation test with chicken bile at 42 degrees C, metacercariae emerged successfully. These results indicate that the major resistant factors may not act during the migration from the mouth to the liver. Histopathological examination of the liver of experimental chickens could not prove the effect of a resistant factor. Excysted flukes were cultivated at 37-42 degrees C in RPMI1640 supplemented with calf serum, with the result that the survival rate of flukes fell with higher temperatures. When chicken serum was used instead of calf serum, flukes survived for a long period of time at 37 degrees C, while all died within four days at 42 degrees C. The higher body temperature of chickens than that of other mammalian hosts is considered to be the major factor contributing to the resistance of chickens to infection with Fasciola sp.

Penetration in vitro of newly excysted juvenile flukes of Japanese Fasciola sp. through ligated intestines of rabbits, mice, rats and chickens

Ligated intestines of rabbits, mice, rats and chickens were used to examine the penetration of newly excysted juvenile flukes of Japanese Fasciola sp. in vitro. In rabbit intestines, the penetration rate was relatively high in the rectum and duodenum. Penetration rates in the jejunum, ileum, cecum and colon were comparable to those in the rectum and duodenum, although it was lower in the appendix. In the case of mouse, juvenile flukes penetrated the duodenum, jejunum, cecum, and rectum at considerably high rates. In rat intestine, penetration by flukes was less in the duodenum and rectum, although flukes were detected in the jejunum. In chicken intestine, flukes barely penetrated the duodenum, jejunum and rectum. Consequently, newly excysted flukes of Fasciola sp. seem to penetrate any region of the intestine in rabbits and mice. In rats, the middle small intestine may be the site suitable for flukes to penetrate. In chickens, the difficulty in penetration of the intestinal wall may be one of the reasons why chickens are scarcely infected with Fasciola sp.

Factors contributing to phoneme recognition ability of users of the 22-channel cochlear implant system

A study was carried out to determine which factors contributed to the vowel and consonant recognition ability of recipients of the 22-channel cochlear implant system. On the basis of the statistical analysis, no isolated factor showed a strong correlation with vowel recognition score. On the other hand, negative correlations were found between patients' consonant recognition scores and postoperative psychophysical percepts such as threshold levels and maximum comfortable loudness levels. However, multiple regression analysis also showed that the combination of lower threshold levels, a larger number of usable electrodes, and wider dynamic ranges contributed to higher consonant recognition scores.

Sialomucin in middle ear cholesteatoma perimatrix

Mucosubstance histochemistry of human middle ear cholesteatoma revealed that sialomucins are abundant and sulfomucins present in small amounts in the glandlike structures of the cholesteatoma perimatrix. Based on the study, various glycoproteins were injected into the dermis of the external ear canal and infiltrated into the tympanic membranes of guinea pigs. Tympanic membranes were obtained 7 days later and light- and electron-microscopically studied. Injection of a sialomucin from bovine submaxillary gland resulted in marked proliferation of epidermis and degeneration of the lamina propria. Asialomucin prepared from sialomucin by hydrolysis produced mild thickening of the epidermis but the lamina propria was not degenerated. Fetuin and bovine serum albumin did not cause proliferation of the epidermis. Cholesterol granuloma formed in some of the specimens injected with sialomucin. The presence of sialomucin in cholesteatoma perimatrix and these experimental studies using tympanic membranes of guinea pigs suggests that sialomucins participate in the proliferation of epidermis and degeneration of subepidermal connective tissue in human middle ear cholesteatoma.

Glycoconjugate histochemistry of Xenopus laevis fundic gland with special reference to mucous neck cells during development

Mucous neck cells (MNCs) of the fundic gland are phylogenetically thought to have first appeared in amphibians. We studied the origin and differentiation of MNCs in fundic glands of Xenopus laevis. By means of lectin histochemical methods using Griffonia simplicifolia agglutinin-II (GSA-II), MNCs were detected specifically in fundic glands of adult X. laevis. Mucous granules of MNCs were labeled by GSA-II-colloidal gold (CG) staining. Other cells such as surface mucous cells (SMCs), oxynticopeptic cells (OPCs), and endocrine cells did not react to GSA-II. Ulex europaeus agglutinin-I specifically stained OPCs, but not MNCs and SMCs. During the morphogenetic period of the stomach in metamorphosing larvae, GSA-II reactive cells randomly appeared in various portions of the underdeveloped fundic glands and then rapidly localized in the neck portion. At this time, newly appearing mucous granules of MNC type were labeled by GSA-II-CG. Two types of cells intermediate to MNCs and SMCs and intermediate to MNCs and OPCs were observed in the larval gastric region. Cells intermediate to MNCs and OPCs were also found in adults. In these cells, mucous granules of MNC type were labeled by GSA-II-CG, but mucous granules of SMC type and zymogen-like granules did not react to GSA-II. These observations suggest that GSA-II is a useful marker in studying the differentiation of MNCs and their precursors regardless of species differentiation.

Characteristics of Staphylococcus aureus isolated from lesions of horses

Seventy-six Staphylococcus aureus strains isolated from various lesions of horses were characterized. All of the 76 strains were identified as biotypes B (38.2%) and C (61.8%). Of 55 strains tested, 42 (76.4%) were differentiated into 7 coagulase types. Coagulase types V and VII were predominant in the metritis strains. Coagulase type II was found most frequently in the strains from phlegmon, dermatitis, sinusitis, empyema sinus, and nasal catarrh. Forty-two (55.3%) of the 76 strains were differentiated into 24 phage patterns. Twenty (58.8%) of 34 typable strains from metritis were lysed by the human group I phage 52, and group II phages 3A, 3C, 55 and 71. Forty-five (59.2%) of the 76 strains were resistant to 1 or more of 6 antibiotics. Strains resistant to penicillin G, irrespective of source, were most frequent (95.6%). Forty (93.0%) of 43 strains resistant to penicillin G alone or in combination with other antibiotics produced beta-lactamase. Only 8 (10.5%) of the 76 strains produced enterotoxins A (n = 2), B (n = 1) or C (n = 5), and they all were isolated from metritis. Only 1 strain isolated from phlegmon and 2 from metritis produced exfoliative toxin (ET) and toxic shock syndrome toxin-1 (TSST-1), respectively. The latter 2 strains also produced enterotoxin C. The results of the present study showed the first evidence of the presence of both ET- and TSST-1-producing S. aureus isolated from horses.

[A case of postpartum fever caused by Mycoplasma hominis infection]

A 26-year-old housewife was admitted to our hospital with a history of high fever after previous cesarean delivery. She had premature rupture of the membrane on the 41st week of pregnancy and the amniotic fluid was found to be cloudy on the fourth day after rupture. Therefore, cesarean delivery was performed. On the first day of operation, her body temperature increased up to 38 degrees C in spite of the treatment with Latamoxef (LMOX), 3 g/day. A sample of intrauterine material yielded M. hominis in pure culture. After administration of Minocycline (MINO) with antimycoplasmal activity, the clinical symptoms improved by the 11th day of operation. Sera obtained after the infection showed antibodies to M. hominis in ELISA study. These results suggested that the cause of this postpartum fever was M. hominis infection.

Subcellular localization of N-acetylglucosaminide beta 1----4 galactosyltransferase revealed by immunoelectron microscopy

We prepared a monoclonal antibody (MAb) against N-acetylglucosaminide beta 1----4 galactosyltransferase purified from F9 embryonal carcinoma cells. The MAb recognized the protein portion of the enzyme, since it inhibited galactosyltransferase activity, reacted with the enzyme both from F9 cells and from bovine milk, and did not exhibit anti-carbohydrate activity. Using this MAb, we studied the subcellular localization of the enzyme by immunoelectron microscopy. Intense staining was observed in trans-Golgi stacks within testicular interstitial cells and mucous neck cells, confirming the specificity of the immunological reaction. Cell surface galactosyltransferase was detected in the following regions: cultured cells such as F9 embryonal carcinoma cells, testicular interstitial cells, seminiferous tubule epithelial cells, Sertoli cells, the head of the epididymal sperm, epididymal epithelial cells, and apical surfaces of epithelial cells in the fundic gland and of intestinal goblet cells. The use of Triton X-100 intensified the cell surface immunoreactivity, and in certain cases the mode of distribution of the cell surface enzyme was different from that described in previous reports. In addition, nuclear envelopes of cultured cells were distinctly stained. The possible significance of the latter finding is discussed in relation to recent advances in nuclear localization of glycoproteins.

[Radiographic evaluation of 12% Au-Ag-Pd alloy cast lower denture plates constructed by dental student as a laboratory exercise]

We evaluated 12% Au-Ag-Pd alloy cast lower denture plates prepared by dental students in laboratory exercises for casting defects. First, we determined the most suitable exposure conditions for nondestructive radiographic test of 12% Au-Ag-Pd alloy. Subsequently, 130 plates were nondestructively evaluated by radiography under the most suitable exposure conditions. In radiographic testing using X-Omat RP films (Eastman Kodak Co.) and X-Omatic Fine Screen (Eastman Kodak Co.), the most suitable exposure conditions involved a target-to-film distance of 1.9 m, tube voltage of 148 Kvp, tube current of 10 mA, and exposure time of 1.5 sec. Preliminary radiographic examination of artificial casting defects revealed semispherical defects in the diameter of 0.25 mm in 1.6 mm-thick 12% Au-Ag-Pd alloy plates and detects of 0.26 mm in 2.4 mm thick plates. In the 130 cast plates, 56 casting defects were detected. These defects were found at the left webbing part in 40 (30.8%), right webbing part in 36 (27.7%), lingual bar in 7 (5.4%), I-bar in 4 (3.0%), and at other regions of the metal frames in 3 (2.3%) cases. These results indicate that nondestructive radiographic testing is as effective in detection of casting defects in 12% Au-Ag-Pd alloy cast plates as it is in Co-Cr and Ni-Cr alloy plates. This method was also found to be effective in evaluation of the practice metal frames constructed by dental students.

Isolation of Staphylococcus species from the tonsils of healthy cattle and phage patterns of isolates

Staphylococci were found in the tonsils of 121 (75.2%) of 161 cattle. There were 15 different species, 10 belonging to novobiocin-sensitive species. The most predominant species was S. simulans (79.3% of the 121 carriers), followed by S. aureus (20.7%), S. chromogenes (10.7%) and S. epidermidis (8.3%). The other 11 species were present in 0.8 to 5.8%. Twenty-six unidentifiable isolates were isolated from 26 (21.5%) carriers. Sixty-two (51.2%) of the 121 carriers yielded two to five Staphylococcus species together while only one species could be found in each of the other 59 (48.8%). Combinations of S. simulans and other species were most frequently encountered in 50 (41.3%) of the 121 carriers. Twenty-four (96.0%) out of 25 S. aureus isolates, 3 (42.9%) of 7 S. hyicus isolates and 45 (25.4%) of 177 coagulase-negative staphylococci (13 species and unidentifiable isolates) isolates were phage typable. Most of S. aureus isolates were lysed by bovine phages 119 (n = 16) or 116 (n = 5). Thirty-three (25.4%) of 45 coagulase-negative staphylococci typable isolates with Pulverer's phage set showed the phage pattern ph5/ph9/ph10/ph12/ph13/U4/U14/U16/++ +U20/U46. The tonsils of cattle thus appear to be a suitable environment for Staphylococcus species, particularly novobiocin-sensitive species.

In vitro adherence of microorganisms to denture base resin with different surface texture

We examined the effects of various denture base resin surface textures on the adherence of microorganisms. S. sanguis and B. gingivalis adhered in greater amounts to the denture base resin than the other microorganisms tested. As to bacterial adherence according to polishing state, S. oralis, B. gingivalis C-101, and B. intermedius C-001 more adhered to the No. 400 paper-polished surface than to the buff-polished and smoothening-treated surfaces. S. sanguis less adhered to the smoothening-treated surface. S. mitis and C. albicans, on the other hand, more adhered to the smoothening-treated surface. For the other microorganisms tested, no relationship was observed between surface texture and bacterial adherence. The fall-off test revealed no remarkable differences in the fall-off of S. sanguis and B. gingivalis C-101 by the types of surface treatment. However, the fall-off of C. albicans was poorest from the No. 400 paper-polished surface. These results indicate that smoothening the denture base surface is important for denture plaque control.

[Clinico-statistical observation of various prosthetic restorations at the Prosthetic Department, Asahi University Hospital. 4. Circumstances concerning prosthetic method for missing teeth for the duration from April 1986 to March 1987]

The statistics for prosthetic restorations used for missing teeth at the Prosthetic Department of Asahi University Hospital from April 1986 to March 1987 were compared with those obtained for an earlier period (April 1983 to March 1984). Fixed bridges and removable partial dentures constituted the majority of the prosthetic restorations for posterior teeth. Fixed bridges were twice more frequently used for anterior teeth during this period than during the previous period. For a single missing tooth, fixed bridges amounted to 90% and removable partial dentures to 10%, as they did in the previous period. For two or more missing teeth, the use of fixed bridges was some what increased compared to the previous period. As in the previous report, the use of so-called one-tooth denture was most frequent for missing lower first molar. For bridges, the average number of missing teeth and that of abutment teeth were 1.3 and 2.4 respectively. Bridges for one missing tooth with two abutment teeth were most frequently used. For removable partial dentures, the average number of missing teeth and that of abutment teeth were 6.1 and 2.8 respectively. Removable partial dentures for two missing teeth with two abutment teeth were most frequently used. Full cast crowns were most frequently used for bridge retainers, followed by facing crowns. Facing crowns were used more than twice as frequently during this period as they were during the previous period.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinico-statistical observation of various prosthetic restorations at the Prosthetic Department, Asahi University Hospital. 3. Frequency of various prosthetic restorations inserted for the duration from April 1986 to March 1987]

The statistics for prosthetic restorations used at the Prosthetic Department of Asahi University Hospital from April 1986 to March 1987 were compared with those obtained in earlier period (April 1983 to March 1984). A total of 2,360 prosthetic restorations were used. This was a 12.5% decrease compared to the previous period. No significant sex-related difference was found in the number of restorations used. The number of prosthetic restorations was decreased in patients in their forties who had the most restorations in the previous period. During the period investigated in this study, the number of prosthetic restorations was highest in the patients in their fifties and lowest in those in their eighties. By sex, prosthetic restorations were used most frequently in males in their fifties and in females in their thirties. The prosthetic restorations used during this period had almost the same proportions as in the previous period. Most frequently used were full cast crowns followed by facing crowns, as were during the previous period. The former amounted to 36.1% and the latter to 22.1%. Full dentures were the least used restorations and amounted to 5.2% of all the prostheses. The use of facing crowns had considerably decreased in patients in their forties, although this age group had the highest frequency of use during the previous period. Full cast crowns were most frequently used in patients in their thirties, removable partial dentures in those in their fifties and total dentures in those in their seventies.

[Clinical study on the correlation between occlusion raising and free-way space]

This paper presents three cases in which CSC telescope dentures were inserted following occlusion raising. Post-operative course remained uneventful in all three cases. Follow-up observations suggested that the use of CSC telescope denture, is helpful in prosthetic treatment which includes occlusion raising. In Case 1, occlusion was raised to a level above the free-way space. However, a new free-way space appeared after occlusion raising and it existed for a long time. A free-way space, which conformed to a space calculated from the free-way space before occlusion raising and the amount of occlusion raising, appeared in Case 2. In Case 3, however, the free-way space after occlusion raising was narrower compared to a space calculated from free-way space before occlusion raising and amount of occlusion raising.

[Studies on oral sensation in patients with implant denture. 4. Ability of hardness discrimination]

The ability of hardness discrimination in 11 implant denture wearers was compared with those in 10 bridge wearers and 11 normal dentate subjects. The hardness discrimination was tested using silicone rubber blocks having rubber hardness that ranged at intervals of 10 degrees from 30 degrees to 70 degrees. Using a rubber block with rubber hardness of 50 degrees as a standard, the ability of discriminating rubber blocks of different hardness was examined. All the three groups examined had excellent ability of discriminating the rubber blocks of rubber hardness of 30 degrees and 70 degrees from the standard block. The ability to discriminate the rubber block of rubber hardness of 40 degrees from the standard block was only slightly lower than but almost the same as the ability of discriminating the hardness of 30 degrees and 70 degrees in all the three groups. However, the ability of discriminating the rubber block of rubber hardness of 60 degrees from the standard block was significantly lower in the implant denture wearers, compared to the normal dentate subjects and bridge wearers.

Leachability of denture-base acrylic resins in artificial saliva

We studied the influence of salivary acidity on leachability of denture-base acrylic resins with etiological interest in denture stomatitis because denture surfaces are frequently exposed to acidic conditions in the oral cavities. Auto-, heat-, and microwave-polymerized resins were immersed in artificial saliva with pH ranging from 4.0 to 6.8 at 37 degrees C, and leachables were pursued quantitatively with time. Methyl methacrylate, methacrylic acid, and benzoic acid leached from all resins. Their concentrations in the saliva were markedly high for auto-polymerized resins, while leachability of heat- and microwave-polymerized resins was so low that quantitative analysis of leachables was impossible. Lower pH showed higher concentrations of methyl methacrylate, although no apparent association was confirmed between salivary acidity and its own leachability. The concentrations of methacrylic acid increased remarkably with an increase in pH, which was probably due to hydrolysis of methyl methacrylate. These results suggest that chemotoxic actions of auto-polymerized resins are potentially ascribable to methyl methacrylate under more acidic conditions and to methacrylic acid under less acidic conditions.