Plasma docosahexaenoic acid levels in various genetic forms of retinitis pigmentosa

In 188 patients from separate families with various forms of retinitis pigmentosa (RP) and 91 normal subjects, plasma fatty acids were measured as a percentage of total plasma fatty acids, and their concentrations were determined using capillary-column gas-liquid chromatography. After controlling for the effects of age and gender, those with RP had significantly lower (P less than 0.01) mean plasma percentages and concentrations of the omega-3 fatty acids: 18:3 omega 3 (alpha-linolenic acid), 22:3 omega 3 (13,16,19 docosatriaenoic acid), and 22:6 omega 3 (docosahexaenoic acid, DHA) compared with the group of normal subjects. The mean percentages were reduced 15%, 14%, and 10%, respectively, below the mean percentages in normal subjects. Analysis by genetic type revealed that the X-linked and isolate forms of RP had significantly lower (P less than 0.01) mean percentage values for DHA (18% and 17%, respectively). Dominant and recessive forms of RP had DHA levels close to normal. Mean absolute plasma DHA concentrations in X-linked RP were not significantly different from the concentrations in the control subjects, although these levels were significantly lower in patients with isolate RP. These data identify the possibility that some forms of RP may have alterations in plasma omega-3 fatty acid metabolism resulting in decreased plasma DHA content. These observations await additional confirmation using an analysis of the fatty acid content of specific erythrocyte phospholipid classes.

CT evaluation of malformed external and middle ear and its surgical correlation

This study evaluated the diagnostic value of high resolution CT (HRCT) for atresia of the external auditory meatus (EAM) and isolated middle ear malformation. CT scan of the temporal bone was done in 33 patients with such disorders and 5 patients with otosclerosis etc. were studied in the same way for comparison. Coronal HRCT clearly showed conditions of the atresia plate and malformation of the malleus, incus, abnormal course of facial canal and changes in the vestibular window. The axial HRCT is useful to demonstrate the articulations in between the malleus, incus, stapes and the cochlear window. All the HRCT findings were confirmed during operation. Axial and coronal HRCT for external and middle ear deformation is highly valuable for decision making and surgical planning.

Molecular pathogenesis of HIV-associated lymphomas

The data presented here indicate that the pathogenesis of AIDS-NHL is variably associated with multiple genetic alterations including monoclonal EBV infection, oncogene activation (c-myc, N-, Ki-ras) and tumor suppressor gene (p53) inactivation. Up to three (3 cases) or four (1 case) different lesions have been observed in the same tumor. The distribution of these lesions among the various histotypes is heterogeneous, although some preferential associations have been found either between lesion and histotype or between lesions. The most notable case involves p53 mutations/loss that is exclusively associated with the SNCC lymphoma subtype. Since alterations of the c-myc gene occur at very high frequency in this same histotype it is possible that both lesions may be required for the pathogenesis of the BL phenotype. The consistent negativity of p53 lesions in other NHLs associated or non associated with HIV infection (18) reinforces this hypothesis. Finally, we note that the frequency of p53 mutations is significantly higher in AIDS-BL than in non HIV-related BL (18), although the significancy of this difference remains to be assessed. This study confirms the relatively low frequency of EBV infection in systemic AIDS-NHL in general, but reinforces the notion that EBV may be required for the pathogenesis of AIDS-LC-IBP, as recently suggested by the high frequency of EBV positivity in primary CNS AIDS-NHL which are mostly represented by LC-IBP (2). Conversely, the low frequency of EBV sequences in the AIDS-SNCC lymphomas appears similar to that observed in sBL. Only in a small minority of cases were ras oncogene mutations found, mostly associated with the BL type.(ABSTRACT TRUNCATED AT 250 WORDS)

[24-hour esophageal pH monitoring. An analysis of 21 cases]

Esophageal pH monitoring was carried out with self-made portable pH recorder in 21 subjects for 24 hours under normal conditions. The results were as follows: the number of physiological gastroesophageal reflux (GER, pH < 4) was less than 23 times; the percentage of GER duration calculated by dividing the cumulative time of pH less than 4 by the total monitoring time was less than 1.4; the percentage was about 2 in upright position and less than 0.2 in lying position; the duration of the longest reflux episode was less than 5 minutes; the physiological gastroesophageal reflux occurred more often in upright position; while the pathological GER took place both in upright and lying position. Our study also indicated that the degree of esophagitis had no relation with the type of GER.

A fast T1 algorithm

Multispectral tissue classification using magnetic resonance T1, T2, and rho images may be useful in diagnosing and locating certain pathology. Techniques for generating the T1 images necessary for this classification scheme often require longer data collection and post processing times than are practical. As a consequence, further development of this classification scheme may be limited. This paper addresses an improvement in the post processing time required to generate T1 images. A nonlinear least-squares algorithm is described for rapidly generating spin-lattice relaxation time images from variable repetition time magnetic resonance images. The algorithm generates a 256 x 256 pixel T1 image from nine variable repetition time images in approximately 60 sec on a VAX-6510 computer.

White cells protect donor blood against bacterial contamination

The possible beneficial role of white cells (WBCs) in donor blood has been investigated with respect to their capacity to remove bacteria. Preparations of buffy coat and whole blood, containing as well as reduced of WBCs, were inoculated with Staphylococcus epidermidis, S. aureus, Escherichia coli, Pseudomonas aeruginosa, and Propionibacterium species. Upon storage at room temperature, the presence of WBCs resulted in a reduction of the bacterial content. Units inoculated with S. epidermidis and E. coli were completely cleared of bacteria within 5 to 24 hours. On the other hand, S. aureus, after an initial reduction in number, started to multiply. In WBC-reduced units, the initial bacterial content remained unchanged for 5 hours, but the bacteria then exhibited vigorous growth within 48 hours in buffy coat and slower growth in whole blood. Propionibacterium sp. did not grow with or without WBCs. P. aeruginosa did not grow in buffy coat but showed a growth pattern similar to that of S. aureus in whole blood. The presence of WBCs in the donor blood during the first hours after collection thus seems to rid the blood of at least some species of bacteria. These results indicate that it would be favorable not to perform WBC reduction during blood collection and that several hours of contact can be needed to obtain sterility.

[Gastric elimination research on patients with gastric disease]

Liquid elimination function of the stomach was studied in 41 patients and 9 normal subjects by using SPECT technique. The result suggested that six kinds of the liquid elimination curve of stomach can be classified. Patients with chronic gastritis and peptic ulcer mostly were kinds of slow elimination (1) and (2). Normal subjects mostly were kind of (6). The pathophysiologic significance of six kinds liquid elimination pattern needs further research.

Factors affecting adhesion of Fibrobacter succinogenes subsp. succinogenes S85 and adherence-defective mutants to cellulose

Fibrobacter succinogenes subsp. succinogenes S85, formerly Bacteroides succinogenes, adheres to crystalline cellulose present in the culture medium. When the cells are suspended in buffer, adhesion is enhanced by increasing the ionic strength. Heat, glutaraldehyde, trypsin, and pronase treatments markedly reduce the extent of adhesion. Treatment with dextrinase, modification of amino and carboxyl groups with Formalin or other chemical agents, and inclusion of either albumin (1%) or Tween 80 (0.5%) do not decrease the degree of adhesion. Adherence-defective mutants isolated by their inability to bind to cellulose exhibited different growth characteristics. Class 1 mutants grew on glucose, cellobiose, amorphous cellulose, and crystalline cellulose. Class 3 mutants grew on glucose and cellobiose but not on amorphous or crystalline cellulose. No substantial changes were detected in the endoglucanase, cellobiosidase, and cellobiase activities of the wild type and the mutants. These data suggest that adhesion to crystalline cellulose is specific and that it involves surface proteins.

Optical sine transformation

The phase mask distribution of optical sine transformation (OST) has been calculated according to the optical general transformation theory. To avoid the diffraction loss of the phase mask, the optical waveguide method is used. Computation shows that the optical sine transformation is possible with only one phase mask, i.e., one-half of a cylindrical lens in the 1-D case and one-quarter of a spherical lens in the 2-D case. Experimental results agree with the theoretical prediction. Image compression by OST is also given.

Direct connections between hypothalamus and lumbar spinal cord in rabbits

Horseradish peroxidase (HRP) was injected into the L6 spinal cord in seven rabbits and the labeling in the hypothalamus traced. The distribution of the retrogradely labeled cells was studied and the anterogradely labeled fibers and terminal branches were unequivocally identified. Hypothalamo-spinal projection cells were found predominantly on the ipsilateral side, mainly distributed in the posterior, dorsal, and lateral hypothalamic areas, and the paraventricular nucleus. Some were found in the perifornical nucleus and a few could be seen in the tuber area, supramammillary nucleus and the region dorsal to the supraoptic nucleus. Spino-hypothalamic projections were found to terminate mainly on the contralateral side via two routes: (i) The dorsal longitudinal fasciculus, distributed to the posterior hypothalamic area. Some might end in the supramammillary nucleus; (ii) Fibers running latero-medially ventral to the mammillothalamic tract to terminate in the dorsal parts of the medial and lateral hypothalamus. Some are dispersed into the ventral areas.