Observations on ultrastructure of the anterior adhesive areas and other anterior glands in the monogenean, Monocotyle spiremae (Monocotylidae), from the gills of Himantura fai (Dasyatididae)

Observations with the light microscope and the scanning and transmission electron microscopes have shown that the anterior end of Monocotyle spiremae has 8 slit-like apertures on the ventrolateral margins at each side of the mouth. Gland cells located next to the pharynx produce rod-shaped secretory bodies that are conveyed in ducts that open on to the surfaces of rounded lobes inside "reservoirs" behind each ventral, slit-like aperture. Rod-shaped secretory bodies are extruded into the "reservoirs" and appear to combine and form a homogeneous secretion which may bond the ventrolateral regions of the head of the parasite to a substrate. At no stage, however, were intact rods observed outside the duct endings. Gland cells that produce an ovoid secretory body also supply the head of M. spiremae, but ducts from these open dorsal and anterior to the mouth in a region where the parasite is not known to attach. There appears to be little or no chance for the ventral rods and the dorsal ovoid secretion to mix. This is the first record of a monogenean parasite with a single type of secretion supplying the ventral surfaces of the anterior end. The rods in M. spiremae differ in some respects from the rod-shaped bodies recorded previously among gyrodactylid, dactylogyrid, capsalid and acanthocotylid monogeneans.     

Technically accurate intracavitary insertions improve pelvic control and survival among patients with locally advanced carcinoma of the uterine cervix

The purpose of this study was to document whether the technical qualities of a brachytherapy application impacts on the outcome of patients with locally advanced cervix cancer treated by definitive irradiation. A previous report from the patterns of care study demonstrated the importance of brachytherapy in the treatment of locally advanced cervix cancer. Locally advanced disease was defined as FIGO stages Ib (if tumor diameter was < or = 4 cm), IIb (if disease was bilateral or involved the lateral aspect of either parametrium), and III. Localization films from 128 patients with locally advanced squamous cell carcinoma of the cervix were reviewed by a radiation physicist and a radiation oncologist with expertise in gynecologic radiotherapy. All patients received external beam irradiation followed by one brachytherapy application (median point A dose = 8040 cGy; range, 4083-10,020 cGy). Brachytherapy parameters assessed were (a) the distance between the right colpostat source and the distal tandem source, (b) the distance between the left colpostat source and the distal tandem source, and (c) the symmetry of colpostat placement. Implants were scored as "ideal" (n = 8) when all three parameters were deemed satisfactory, "unacceptable" (n = 17) when none of the parameters was deemed satisfactory, and "adequate" (n = 41) in all other cases. Significantly improved 5-year local control was seen when comparing ideal and adequate placements to unacceptable placements (68% vs 34%, P = 0.02). A strong trend toward improved 5-year survival was also noted among the group with ideal and adequate implants as opposed to unacceptable implants (60% vs 40%). Multivariate analysis showed that the technical adequacy of the brachytherapy implant was the most important prognostic discriminant of local control. In conclusion, these analyses demonstrate the direct influence of competent technical implant performance on tumor control and even survival. While only a small fraction of implants for cervical cancer are performed poorly in the United States, there is a need for continued emphasis of the principles for proper implant technique.     

Pyloric gland adenoma of the main pancreatic duct

A case of a pyloric gland type adenoma of the main pancreatic duct in a 69-year-old woman is reported. The tumor led to occlusion and cystic dilatation of the main duct in the pancreatic tail. The surgical resection specimen disclosed a polypoid, bilobed mass attached to the wall of the main pancreatic duct by a thin fibrous stalk. Light-microscopic examination revealed a well-demarcated nodule composed of closely packed tubular glands lined by columnar, mucin-secreting cells with abundant clear cytoplasm and basally oriented nuclei. Focal, mild cytologic atypia was seen. Pyloric metaplasia and focal papillary hyperplasia was present in the adjacent ductal epithelium. Periodic acid-Schiff reactions, with and without diastase predigestion, showed reactivity in the tubular glands, whereas alcian blue (pH 2.5) was negative. Immunohistochemical stains for chromogranin, serotonin, somatostatin, and gastrin failed to detect the respective antigens. Genetic analysis using polymerase chain reaction with mutant enrichment and allele specific oligonucleotide hybridization detected a single mutation at codon 12 of K-ras, which changed the wild-type glycine to arginine. This mutation is commonly found in invasive pancreatic ductal carcinomas. Although tumors with microscopic and immunohistochemical features consistent with pyloric gland adenoma have been described in the gallbladder, to our knowledge, this is the first reported case within the pancreatic ductal system. The finding of a K-ras, codon 12 mutation and the presence of focal dysplasia may denote neoplastic potential in association with this lesion.     

MIRD pamphlet No. 17: the dosimetry of nonuniform activity distributions--radionuclide S values at the voxel level. Medical Internal Radiation Dose Committee

The availability of quantitative three-dimensional in vivo data on radionuclide distributions within the body makes it possible to calculate the corresponding nonuniform distribution of radiation absorbed dose in body organs and tissues. This pamphlet emphasizes the utility of the MIRD schema for such calculations through the use of radionuclide S values defined at the voxel level. The use of both dose point-kernels and Monte Carlo simulation methods is also discussed. PET and SPECT imaging can provide quantitative activity data in voxels of several millimeters on edge. For smaller voxel sizes, accurate data cannot be obtained using present imaging technology. For submillimeter dimensions, autoradiographic methods may be used when tissues are obtained through biopsy or autopsy. Sample S value tabulations for five radionuclides within cubical voxels of 3 mm and 6 mm on edge are given in the appendices to this pamphlet. These S values may be used to construct three-dimensional dose profiles for nonuniform distributions of radioactivity encountered in therapeutic and diagnostic nuclear medicine. Data are also tabulated for 131I in 0.1-mm voxels for use in autoradiography. Two examples illustrating the use of voxel S values are given, followed by a discussion of the use of three-dimensional dose distributions in understanding and predicting biologic response.     

The effect of fluoride on Streptococcus sanguis 7863 IgA1 protease production and activity

Fluoride was found to affect the production of the bacterial IgA1 protease but to have no effect on IgA1 protease activity. The concentrations of fluoride that do affect Streptococcus sanguis growth and IgA1 protease production are higher than those normally seen in vivo under normal circumstances. The concentrations of fluoride in dental plaque following use of a fluoride rinse or dentifrice would be sufficient to reduce Strep. sanguis IgA1 protease production.