Pancreatic mucinous cystic neoplasm of the main pancreatic duct

Mucinous cystic neoplasm and intraductal papillary mucinous neoplasm are 2 types of cystic pancreatic mucinous tumors, each with its own distinct clinicopathologic features and pathogenetic mechanisms. We report here an unusual pancreatic mucinous neoplasm with features of both a mucinous cystic neoplasm and an intraductal papillary mucinous neoplasm in a 40-year-old woman who underwent total pancreatectomy. The endoscopic retrograde cholangiopancreatogram and gross examination demonstrated a mucin-producing intraductal neoplasm involving the length of the main pancreatic duct, typical of main duct intraductal papillary mucinous neoplasm, but histology of the main duct showed involvement by a biphasic tumor composed of columnar epithelium overlying ovarian-type stroma, characteristic of a mucinous cystic neoplasm. Immunohistochemistry confirmed that the stromal cells expressed estrogen and progesterone receptors, inhibin, and calretinin. Pancreatic mucinous cystic neoplasm involving the entire main pancreatic duct has not, to our knowledge, been previously reported.     

Effects of duct ligation on choline acetyltransferase activity in salivary glands of rats.

Duct ligation was found to cause a decrease in the weights of submaxillary and parotid glands examined 3 weeks postoperatively. Choline acetyltransferase activity in ligated glands was compared with that in unligated contralateral glands. The enzyme activity was also measured in the glands from both sides of unoperated control animals. Interference in the assay of choline acetyltransferase by other acetylated compounds was avoided by introducing suitable control incubations. Ligated submaxillary glands showed a small decrease in the activity of choline acetyltransferase both when compared with contralateral glands and with glands of control rats. In parotid glands the enzyme activity was found to be lower only when ligated and contralateral glands were compared. Structural changes in the nerves and reduced traffic of impulses in them may have to be considered as explanations for the reduction in enzyme activity in duct-ligated glands.     

The development of the glands of the common bile duct

The number of glands at a constant level within the wall of the common bile duct was measured in the foetus, infant, child and adult. The number of glandular acini increases from foetal life to reach a maximum within the 1st year of life. Thereafter it remains remarkably constant. This is in contrast to the lumen and wall of the common bile duct which only reaches adult proportions in adult life. Conversely, the density of acini within the wall of the common bile duct is at a peak in early foetal life and decreases progressively throughout infancy and childhood.     

Studies of Brunner's glands in the opossum. I. Adult morphology

The duodenal glands of the adult opossum form a lobed, glandular collar in the submucosa immediately distal to the pyloric sphincter. They empty into funnel-shaped mucosal depressions. The depressions, which form two or three irregular rows that run parallel to the pyloroduodenal junction, are lined by either pyloric or intestinal epithelium. An individual gland of Brunner has an extensive intralobular duct system which terminates in a single excretory duct just prior to entry into a depression. Histochemical studies indicate that the duodenal glands elaborate a neutral glycoprotein whereas the duct system appears to produce both neutral and acidic elements. Light and electron microscopic studies have shown the duodenal glands to consist of large, pyramidal cells which lie on a distinct basal lamina. Discrete, mottled or pale secretory granules are found in close association both with the apices of the cells and with the Golgi complexes. The ergastoplasm, cisternae of which are dilated and contain amorphous material, is associated with polysomes and, in the supranuclear region, often becomes markedly dilated, forming what appear to be large vacuoles containing fibrillar material. Blebbing of the ergastoplasm results in the formation of several small vesicles, many of which lie in close association with the Golgi network. Direct membrane continuity has been noted between the two elements.     

Terminal duct carcinoma of minor salivary glands. A nonpapillary subtype of polymorphous low-grade adenocarcinoma

The clinicopathologic features of five terminal duct carcinomas arising in minor salivary glands are presented. These nonpapillary, low-grade adenocarcinomas are part of the spectrum of polymorphous low-grade adenocarcinoma. The patients ranged in age from 47 to 77 years. Symptoms were nonspecific and related to a mass that usually was present for several years. Histologically, the tumors had a ductal pattern with areas of solid and cribriform architecture. Cytologically, they were composed of uniform, cuboid cells with round to oval nuclei and fine chromatin. One patient developed a recurrence after 13 years, but none of the tumors has metastasized. One lesion in this series was studied ultrastructurally and demonstrated both glandular and pseudoglandular structures analogous to those of adenoid cystic carcinoma. Nonetheless, terminal duct carcinoma is cytologically distinctive from adenoid cystic carcinoma and appears to have a more favorable prognosis.     

The Staining Pattern of Collagen Fibrils: I. an Analysis of Electron Micrographs

Electron micrographs of calf-skin collagen in the reconstituted native-type fibril and the segmented long spacing (SLS) forms are matched with one another and with the distribution of charged residues in the known α1 chain sequence.

It is shown that:

a) the pattern of bands in SLS corresponds closely with the charge distribution in the sequence

b) most of the bands in the fibril pattern can be matched in position (but not in intensity) to bands in the SLS pattern, confirming a substantial measure of matching of charged regions with charged regions (and therefore of hydrophobic regions with hydrophobic regions) on assembly of molecules into fibrils

c) when the al chain sequences are regularly staggered by 233 residues (to simulate the postulated packing in a fibril) the greatest concentrations of charged residues occur in regions which correspond closely with the bands in positively stained fibrils

d) the positions of the abrupt contrast steps(the overlaplgap junctions) in the image of a negatively contrasted fibril lie slightly inside the positions predicted by the sequence, indicating a more condensed conformation for the extra-helical telopeptides. This could be a consequence of the methods used for the preparation and examination of the specimen. The ratio of molecular length to fibril period is therefore uncertain in the range 4.40 to 4.53.     

Hypersensitivity reactions to acetylsalicylic acid. I. Detection of antibodies in human sera using acetylsalicylic acid attached to proteins through the carboxyl group

Aspirin–protein conjugates (aspirin coupled to rabbit anti-human `O' antibody and to anti-bacteriophage-Fab') were prepared by a method which links aspirin through its carboxyl group. The protein conjugates were used to raise specific aspirin antibodies in guinea-pigs. Such antibodies helped to characterize the other preparations which were subsequently used to test suspected hypersensitive sera for aspirin antibodies. Although an antibody of aspirin specificity was detected it could not be related to the clinical hypersensitivity state.     

Toluene diisocyanate respiratory reactions. I. Reassessment of the problem

A series of workers with exposure to and respiratory symptoms from toluene diisocyanate (TDI) was compared with a group of exposed, asymptomatic workers and with normal controls using immunologic and clinical evaluations. Improved understanding of TDI-induced respiratory disease may best be achieved by categorizing the symptomatic workers into at least 3 and possibly 4 groups: immunologic TDI asthma; pre-existing chronic respiratory disease exacerbated or unaffected by TDI; asthma coincidental with TDI exposure, and possibly TDI respiratory disease secondary to toxic or inflammatory mechanisms.