Spontaneous teratoma in a Sprague-Dawley rat

An 6-week-old male Sprague-Dawley rat which had undergone no experimental treatment died from enlargement of the abdomen. At necropsy, a spherical mass measuring about 3 X 4cm in diameter was connected to the retroperitoneal region cross to the middorsal line of the body. The tumor was composed of skin, ganglion, striated and smooth muscle, cartilage, bone, pancreas, glands, lymph node, and fibrous and adipose tissue, and diagnosed as teratoma.

[Macroamylasemia, report of two cases]

Serum amylase isozyme was determined in 2 cases with normal urinary amylase but persistantly high serum amylase. Both cases showed dominant S-type amylase associated with tailing findings that was characteristic of macroamylasemia. Moreover, using the immunofixation method, the serum amylase was found to be bound with IgG (K) in case 1 and with IgA (L) in case 2.

Spontaneous swine glomerulonephritis in littermates from a leukemic sow

Spontaneous glomerulonephritis was found in seven six-month-old littermates from a leukemic sow. Light microscopy of the glomerular lesions showed proliferation of the mesangial cells and increase of the mesangial matrix with deposition of homogeneous materials. All glomeruli were affected, but the severity of the lesions varied among pigs. The glomerular capillary walls had local and segmental changes such as thickening and/or irregularity. Electron microscopy revealed dense deposits in the mesangial, paramesangial, subendothelial, subepithelial, and intramembranous areas. The mesangial and paramesangial deposits were most characteristic and prominent. In five of seven pigs, the clusters of extracellular spherical microparticles with a diameter ranging from 25 to 60 nm were observed in the subepithelial, intramembranous, subendothelial, and mesangial areas. No conspicuous lesions were noted in other organs.

[Role of angiography in the diagnosis of pancreatic cancer]

Endoscopic Retrograde Choledocho-Pancreatography, Ultrasonography and Computer Tomography can show dilated pancreatic duct in the patients with small resectable pancreatic carcinoma. However they can not predict the size of the tumor. Angiography is a complementary examination, being able to demonstrate the size of the tumor and predict its resectability.

[Problems of early diagnosis of pancreatic cancer and evaluation of various morphological studies]

Clinical symptoms and abnormality of laboratory examinations in 62 patients with proven pancreatic carcinoma were studied. The following indications for detailed examination of the pancreas have been evolved: (1) vague abdominal symptoms, (2) jaundice, (3) abnormalities of laporatory examinations including serum LAP, ALP, amylase and cholinesterase level, and abnormal GTT. In the jaundiced patient the initial examination is US followed by PTCD to relieve the jaundice, and then angiography to assess resectability of the tumor. In the non-jaundiced patient US is used as a screening procedure. Should this be abnormal a lesion may be confirmed by CT. If not ERCP is indicated when there is some distinct reason to suspect pancreatic disease. If ERCP reveals abnormality then angiography is performed to determine whether the lesion is benign or malignant, and if malignant it is resectable or not. In the period of 1968 and 1981, 112 proven pancreatic carcinomas were studied. Overall resectability was 26%. Thirty tumors were less than 3 cm and the smallest lesion measured 1.2 cm.

Fine pathology of mouse spinal cord infected with the Tyzzer organism

After intraspinal inoculation in mice, Tyzzer organisms were shown to grow within neurons resulting in degeneration and destruction of the host cells. Intraneuronally parasitising organisms were located within the cytoplasmic matrices or nuclear chromatin granules, and host cell organelles were disarranged or decreased in number seemingly by movement of bacterial peritrichous flagella. Axonal as well as myelin degeneration occurred in the white matter, and demyelination seemed to be in consequence of the axon damage due to intraxonal growth of organisms. Some organisms were present within cytoplasmic matrices of oligodendroglia cells and also within phagosomes of macrophages without active intracellular growth.

A method of using the incident beam tilt as a eucentric goniometer in transmission electron microscopy

The principal difficulties in constructing and operating a eucentric specimen tilting goniometer in a transmission electron microscope are discussed, together with the goniometric function of the incident beam tilt. The latter function is found easy to operate in a eucentric manner. The imaging beam then will have a non-axial path, which will increase particularly the field chromatic aberration. Earlier, however, a technique for the compensation of the chromatic aberration during displaced aperture dark field image formation has been developed. In combination with this technique, it proved possible to use the ordinary incident beam tilt as a eucentric goniometer. Image sequences were obtained, with accurately varied diffraction conditions. The tilt angles and the direction of the tilt axis can be very accurately determined from the displacements of the diffraction pattern.

On dark field techniques in transmission electron microscopy

Different dark field techniques in transmission electron microscopy are investigated. In particular, a displaced aperture technique is developed, which produces high quality off-axis dark field images. The essential feature of the method is that the chromatic aberration of the objective and intermediate lenses is compensated for with the aid of a one-stage beam deflector in the object plane of the intermediate lens. In addition, the image distortion and the effect of the curvature of the image field are minimized by reducing the coefficient of sperical aberration of the intermediate lens. Diffracted beams, forming angles alpha up to 2.5 degrees with the optical axis, can be used for dark field imaging. Resolutions better than 30 A for alpha = 2 degrees, and 17 A for alpha = 1 degree, are obtained.