Pneumatosis cystoides coli

Pneumatosis cystoides coli in most cases is a disease of unknown etiology. In a few patients, it is secondary to an infarction or ulcerative colitis. Associated pulmonary emphysema is not uncommon. The gas pockets, which may be of varying size, can be identified along the contour of the bowel. The left side of the colon is more frequently involved than the right. The lesion is usually segmental. The rectum is almost always spared. Symptoms are negligible and operation is not required.     

Dynamics of transcription activity of cerebellar Purkinje cell chromatin after systemic circulatory arrest

Institute of General Resuscitation, Academy of Medical Sciences of the USSR. N. I. Pirogov Second Moscow Medical Institute N. K. Kol'tsov Institute of Developmental Biology, Academy of Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR. V. A. Negovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 111, No. 3, pp. 232–235, March, 1991.     

Diagnostic casts--an additional dimension

The indications and usefulness of diagnostic casts are well documented in the literature. A method is presented that enables increased access to the lingual aspect of the casts by sectioning them in a midsagittal plane. The sectioned portions are held together in maximum intercuspation by acrylic keys. The interdigitated casts can thus be examined from all aspects, thereby deriving maximum benefit from them.     

DNA vaccine delivery by densely-packed and short microprojection arrays to skin protects against vaginal HSV-2 challenge

There is an unmet medical need for a prophylactic vaccine against herpes simplex virus (HSV). DNA vaccines and cutaneous vaccination have been tried for many applications, but few reports combine this vaccine composition and administration route. We compared DNA administration using the Nanopatch™, a solid microprojection device coated with vaccine comprised of thousands of short (110 μm) densly-packed projections (70 μm spacing), to standard intramuscular DNA vaccination in a mouse model of vaginal HSV-2 infection. A dose-response relationship was established for immunogenicity and survival in both vaccination routes. Appropriate doses administered by Nanopatch™ were highly immunogenic and enabled mouse survival. Vaginal HSV-2 DNA copy number day 1 post challenge correlated with survival, indicating that vaccine-elicited acquired immune responses can act quickly and locally. Solid, short, densely-packed arrays of microprojections applied to the skin are thus a promising route of administration for DNA vaccines.     

Growth retardation and destruction of experimental squamous cell carcinoma by interstitial radioactive wires releasing diffusing alpha-emitting atoms

In the present study, we examined the antitumoral effects caused by the release of alpha emitting radioisotopes into solid squamous cell carcinoma (SCC) tumors. Using a novel method termed DART (Diffusing Alpha-emitters Radiation Therapy), we assessed the efficacy of short-lived daughters of (224)Ra releasing alpha particles, dispersing in the malignant tissue, to cause tumor growth retardation and destruction. It was carried out using specially designed wires loaded with (224)Ra activities in the range of 7-42 kBq in a set of experiments performed on BALB/c and nude mice bearing metastatic SCC tumors derived from either mouse SQ2 or human CAL27 cell lines. The insertion of a DART wire to the center of 6-7 mm primary tumors, retarded tumor growth, reduced lung metastatic load, prolonged life expectancy and in some cases caused tumor eradication. These effects were enhanced either when treating smaller tumors or treating identical tumors with 2 DART wires. Similar experiments on human-derived SCC tumors in nude mice were consistent with the outcomes of the murine model. Histological assessments revealed the tissue damage pattern, and indicated a role for the tumor vasculature in the dispersion of the atoms and the propagation of the damage. Our findings indicate that Diffusing Alpha-emitting Radiation Therapy is effective in a model system using SCC primary tumors. The in situ destruction of primary solid tumors by DART is evidently a necessary step toward curing cancer and might be augmented by chemotherapy and other modalities such as immunotherapy or antigrowth factors agents.     

Histological changes in the cervical lymph nodes after radiotherapy.

Radiotherapy to the neck is frequently employed in the treatment of malignancies, sometimes alone and sometimes before or after surgery or with or without chemotherapy. We checked the histopathological changes in the neck after radiotherapy, dividing the changes into two groups. One with short-term changes between six months to one year, and the second group with long-term changes after more than six years. We compared these two groups with a control group without radiotherapy. The changes in the long-term group were more pronounced than in the short-term group, with more stromal fibrosis, vascular changes, and specially lymph nodes smaller than one centimeter. Thus, bigger lymph nodes (more then one centimeter) are more radiosensitive and become smaller after six years.     

A theory of the Benham Top based on center-surround interactions in the parvocellular pathway.

A model color-opponent neuron was used to investigate the subjective colors evoked by the Benham Top (BT). Color-opponent inputs from cone-selective parvocellular (P) pathway neurons with center-surround receptive fields were subtracted with a short relative delay, yielding a small transient input in response to a white spot. This transient input was amplified by BT-like stimuli, modeled as a thin dark bar followed by full-field illumination. The narrow bar produced maximal activation of the P-pathway surrounds but only partial activation of the P-pathway centers. Due to saturation, subsequent removal of the bar had little effect on the P-pathway surrounds, whereas the transient input from the P-pathway centers was amplified via disinhibition. Responses to BT-like stimuli became weaker as surround sensitivity recovered, producing an effect analogous to the progression of perceived BT colors. Our results suggest that the BT-illusion arises because cone-selective neurons convey information about both color and luminance contrast, allowing the two signals become confounded.