Biomedical subjects
Publications and source records attributed to M J Ross.
Subjects differing in body consciousness were compared on face memory. Compared to subjects low in body awareness, subjects with a highly developed body image showed enhanced retention of faces judged for similarity to self-appearance. Although the imaginal component of the self-concept may not be effective in general, subjects who are schematic on that dimension can effectively encode experiences in this way.
An excellent functional result was obtained after microsuture of a trochlear nerve which was inadvertently divided during the course of a craniotomy. Successful intracranial suture of this nerve has not previously been reported. Ophthalmoscopic detection of excyclotorsion of the eye on the side of the trochlear nerve palsy is discussed, along with its value in the differential diagnosis of acquired vertical diplopia.
The simultaneous presentation of unilateral proptosis and subcutaneous nodules on the upper chest, back, and thigh was observed in a 46-year-old woman with a previous history of ovarian carcinoma. Excisional biopsy of a subcutaneous nodule revealed metastatic adenocarcinoma similar to the primary ovarian tumor histopathology. This case is singular in its concomitant orbital and subcutaneous cancer metastases and provides rare support for ovarian carcinoma spreading to the orbit.
Target and distractor likability were examined in two studies of face memory. Subjects studied faces that had been rated by others as likable or unlikable . The test required subjects to identify the previously studied face in an array of four faces, where the distractor faces were either likable or unlikable . Overall, unlikable targets were more readily recognized than likable targets. In Experiment 2, distractor likability appeared to have little effect on correct recognition when response bias was ruled out. However, in Experiment 2, arrays involving all new faces showed that likable faces were more apt to be falsely identified as targets. In general, these results seem more in accord with an interpretation based on distinctiveness instead of affective responses.
Normal adult male hamsters have low levels (10-20 micrograms) of female protein (FP) in serum which increase approximately fivefold during an acute phase response. In contrast, normal females have 50- to 100-fold higher serum levels and the acute phase reaction consists of a transient decrease in FP (approximately 50%), followed by a return to normal levels even under adverse conditions such as cortisone treatment (which by itself has a depressing effect on FP levels in normal females). The acute phase response was not inherently associated with gender, as the pattern of response could be changed to that of the opposite sex by appropriate hormonal manipulation. That is, castrated or diethylstilbestrol-treated males with high FP levels showed a female-type response whereas testosterone-treated females with low FP levels showed a male-type response. Studies on catabolism of 125I-FP showed a similar rapid half-life (T1/2, 9-16 h) in normal males and females and indicated that the sex difference in serum concentration was due to greater synthesis of FP in females. The divergent acute phase reaction of serum FP was related directly to changes in the FP synthetic rate (increased in males, decreased in females). As an indicator of serious pathology, a decrease of FP to very low levels in females was associated frequently with impending death.
Pseudorheumatoid nodules are subcutaneous necrobiotic granulomas that are histopathologically similar or identical to those seen with rheumatoid arthritis, granuloma annulare, necrobiosis lipoidica diabeticorum, and systemic lupus erythematosus. Although these nodules are most common in children, they are also seen in adults and are usually located on the extremities and scalp. Eyelid and eyebrow involvement is seen infrequently. We histopathologically verified episcleral and orbital pseudorheumatoid nodules in an adult with eyelid and eyebrow nodules. Pseudorheumatoid nodules must be included in the differential diagnosis of subconjunctival mass lesions that may concomitantly involve the orbit, episclera, and periocular region.
The site of recA cleavage of the phage lambda and P22 repressors has been determined. Each repressor is cut once by the recA enzyme, lambda repressor between residues 111 and 112, and P22 repressor between residues 94 and 95. recA cleavage occurs at identical alanyl-glycyl sequences in both repressors, and in both repressors, the cleavage separates the repressor's NH2-terminal DNA-binding domain from its COOH-terminal oligomerization domain. A papain-generated proteolytic fragment of lambda repressor consisting of repressor residues 93-236 is also efficiently cleaved by recA protein. Moreover, the recA cleavage of radioactive lambda repressor can be inhibited by certain COOH-terminal proteolytic fragments of lambda repressor which do not contain the alanyl-glycyl cleavage sequence. These facts suggest that recA cleavage of lambda repressor requires an intact COOH-terminal domain but not an intact NH2-terminal domain.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The dimensions of bacteriophage T7 and T7 capsids have been investigated by small-angle x-ray scattering. Phage T7 behaves like a sphere of uniform density with an outer radius of 301 +/- 2 A (excluding the phage tail) and a calculated volume for protein plus nucleic acid of 1.14 +/- 0.05 x 10(-16) ml. The outer radius determined for T7 phage in solution is approximately 30% greater than the radius measured from electron micrographs, which indicates that considerable shrinkage occurs during preparation for electron microscopy. Capsids that have a phagelike envelope and do not contain DNA were obtained from lysates of T7-infected Escherichia coli (capsid II) and by separating the capsid component of T7 phage from the phage DNA by means of temperature shock (capsid IV). In both cases the peak protein density is at a radius of 275 A; the outer radius is 286 +/- 4 A, approximately 5% smaller than the envelope of T7 phage. The thickness of the envelope of capsid II is 22 +/- 4 A, consistent with the thickness of protein estimated to be 23 +/- 5 A in whole T7 phage, as seen on electron micrographs in which the internal DNA is positively stained. The volume in T7 phage available to package DNA is estimated to be 9.2 +/- 0.4 x 10(-17) ml. The packaged DNA adopts a regular packing with 23.6 A interplanar spacing between, DNA strands. The angular width of the 23.6 A reflection shows that the mean DNA-DNA spacing throughout the phage head is 27.5 +/- less than 2.2 A. A T7 precursor capsid (capsid I) expands when pelleted for x-ray scattering in the ultracentrifuge to essentially the same outer dimensions as for capsids II and IV. This expansion of capsid I can be prevented by fixing with glutaraldehyde; fixed capsid I has peak density at a radius of 247 A, 10% less than capsid II or IV.
A human alpha interferon, designated HuIFN-alpha A, produced in E. coli by direct expression of cloned cDNA [Goeddel et al., Nature 287, 411--416 (1980)] has been purified from bacterial extracts and characterized. The protein has a molecular weight (19,400 by SDS/PAGE) and amino acid composition consistent with the DNA sequence. The pI was determined to be 6.1. The molecule has a specific activity of 1.5 x 10(8) NIH reference units/mg of protein. The sequence of the first 35 amino acids is identical to that expected from the nucleotide sequence. About 50% of the molecules begin with the expected cysteine, and 50% begin with the initiator methionine which E. coli apparently did not remove efficiently. Analysis of a trypsin digest of the native molecule showed that all four of the molecule's cysteines are involved in disulfide bonds: Cys1 is bonded to Cys98, and Cys29 is bonded to Cys 138.
DNA coding for human growth hormone was constructed by using chemically synthesised DNA in conjunction with enzymatically prepared cDNA. This 'hybrid' gene was expressed in Escherichia coli under the control of the lac promoter. A polypeptide was produced having the size and immunological properties characteristic of mature human growth hormone.
Immunity to phage superinfection is a useful selective marker in molecular cloning experiments. Plasmids which have unique sites for several different restriction endonucleases and which specify immunity to bacteriophage are described.
We report a case of mesothelioma of the atrioventricular node with congenital complete heart block and sudden death in a 15-year-old girl. This benign tumor probably represents a hamartoma derived from mesothelium with a constant anatomic location and uniform association with heart block. The clinical course of such patients, however, has been variable. The tumor has been associated with sudden, unexpected death in infancy or adolescence, but has more often been discovered as an incidental finding at autopsy in a middle-aged or elderly patient.
Explore the source record for details and available documents.
An unusual and impressive hyperbilirubinemia was induced in Chinese hamsters by administration of diethylstilbestrol (DES). This icterus was dose-dependent and affected females more severely than males. However, a similar mortality was detected in both sexes. Another hamster, the Armenian hamster, was even more susceptible to the icteric and lethal effects of DES. The hamster model of DES-induced icterus showed many clinical dissimilarities when compared to the human estrogen-induced jaundice, simple cholestatic jaundice. Furthermore, hepatic pathology was distinctly different as canalicular cholestatic was absent although other degenerative and regenerative hepatocellular changes were present. Livers of Armenian hamsters were more severely affected than were livers from Chinese hamsters and contained Mallory bodies even within 1 week after DES treatment. A modest, nonlethal jaundice also was detected in European hamsters after DES injection, whereas Syrian hamsters were not affected even after larger doses. This unique sensitivity to DES, and the spectrum of sensitivity within these related hamsters (Armenian greater than Chinese greater than European vs. resistant Syrian) provide an interesting model for study of DES effect on hepatic function.
Studies using conventional and patch-clamp microelectrode techniques demonstrate that in a number of cell types angiotensin II (AII) causes reversible changes in transmembrane ionic currents, and that these effects can be mimicked by various membrane-associated and cytosolic messengers. AII modulates the current amplitude of ion channels, as well as their activation threshold and their open/closed time probability. Stimulatory and inhibitory effects on ion channel activity are a fundamental feature of the development of AII actions on target organs.
Explore the source record for details and available documents.