Psychobiological mechanisms of resilience: relevance to prevention and treatment of stress-related psychopathology.

Resilience refers to the ability to successfully adapt to stressors, maintaining psychological well-being in the face of adversity. Recent years have seen a great deal of research into the neurobiological and psychological factors and mechanisms that characterize resilient individuals. This article draws from that research to outline some of the most important contributors to resilience. The authors hope that by contributing to a growing understanding of the genetic, developmental, neurobiological, and psychological underpinnings of resilience, researchers and clinicians in the field will move closer toward the goal of identifying and treating individuals at risk for developing posttraumatic psychopathology.

Pathologic analysis of advanced adult soft tissue sarcomas, bone sarcomas, and mesotheliomas. The Eastern Cooperative Oncology Group (ECOG) experience.

A total of 488 tumors entered in the Eastern Cooperative Oncology Group (ECOG) Study EST 3377 were evaluated histologically by a panel of pathologists from member institutions for quality control purposes. The overall agreement rate between the eligible submitting diagnosis and the pathology review panel's diagnosis was 74% (312/424). In 10% (44/424), the case was excluded because it was deemed to be nonsarcoma. In the other 16%, the disagreement concerned the type of sarcoma. The histologic type with the lowest agreement rate was rhabdomyosarcoma (17%), followed by sarcoma not otherwise specified (NOS) (27%), angiosarcoma (33%), and fibrosarcoma (48%). These figures reflect the significant degree of difficulty in the diagnosis of these tumor types. The treatment response rate of soft tissue sarcomas in the randomized study of Adriamycin (Adria Laboratories, Columbus, OH) regimens was slightly higher for those with lower grade sarcomas, i.e., 25% (four of 16) response rate for Grade 1 lesions; 22% (17/77) for Grade 2, and 21% (35/170) for Grade 3. When adjusted for type of sarcoma, there was no noticeable difference between Grade 1-2 versus 3 in response rate. A statistically significant difference in the percentage of complete responders was noted between Group A tumors (synovial sarcoma, hemangiopericytoma, sarcoma NOS, and Ewing's; 12.2%) versus Group B tumors (all other types--mostly spindle cell sarcomas; 3.5%) (P = 0.02).

Cytotoxicity of cholesterol oxidase to cells of hypercholesterolemic guinea pigs.

1. A high cholesterol diet caused guinea pig erythrocytes to become sensitive to lysis by cholesterol oxidase (CO), a protein not hemolytic to normal cells. 2. Lysis was associated with conversion of membrane cholesterol to its oxidation product (delta-4-cholesten-3-one). 3. Intravenous injection of CO to hypercholesterolemic guinea pigs produced a reduction in serum cholesterol, but was not lethal as it was in rabbits. 4. Homogenized spleen, liver and kidney from the hyperlipidemic animals were sensitive to in vitro cholesterol oxidation while tissues from non-lipemic animals were resistant to modification.

The American Rheumatism Association 1987 revised criteria for the classification of rheumatoid arthritis.

The revised criteria for the classification of rheumatoid arthritis (RA) were formulated from a computerized analysis of 262 contemporary, consecutively studied patients with RA and 262 control subjects with rheumatic diseases other than RA (non-RA). The new criteria are as follows: 1) morning stiffness in and around joints lasting at least 1 hour before maximal improvement; 2) soft tissue swelling (arthritis) of 3 or more joint areas observed by a physician; 3) swelling (arthritis) of the proximal interphalangeal, metacarpophalangeal, or wrist joints; 4) symmetric swelling (arthritis); 5) rheumatoid nodules; 6) the presence of rheumatoid factor; and 7) radiographic erosions and/or periarticular osteopenia in hand and/or wrist joints. Criteria 1 through 4 must have been present for at least 6 weeks. Rheumatoid arthritis is defined by the presence of 4 or more criteria, and no further qualifications (classic, definite, or probable) or list of exclusions are required. In addition, a "classification tree" schema is presented which performs equally as well as the traditional (4 of 7) format. The new criteria demonstrated 91-94% sensitivity and 89% specificity for RA when compared with non-RA rheumatic disease control subjects.

The nature and designation of osteoarthritis determined by its histopathology.

Specimens of synovial tissue and articular cartilage removed at operations of patients with primary degenerative joint disease were scrutinized for defined histopathological parameters. The findings in the synovial membrane were subsequently compared as to frequency and intensity with identical parameters ascertained in specimens removed from patients with definite rheumatoid arthritis. These examinations disclosed the presence of synovial inflammatory features, although at lesser incidence and intensity than in rheumatoid arthritis; therefore the designation of arthritis is indicated. On the basis of the concurrently examined tissue specimens of the articular cartilage, and in consensus with the generally acknowledged start of the degenerative joint disease by disintegrating changes in the articular cartilage, the prefix of chondrosis is appropriate.

Toxicity of enzymically-oxidized low-density lipoprotein.

Intravenous injection of cholesterol oxidase into hyperlipidemic rabbits in which aortic atheromatous lesions have been induced by dietary means is lethal within hours, whereas injection of the same enzyme into normal rabbits has no visible adverse effect. The lethal effect of the enzyme is explicable by the finding that injection of cholesterol-oxidase treated low-density lipoprotein kills normal rabbits, in contrast to untreated low-density lipoprotein which does not. Enzymically oxidized low-density lipoprotein was also found to be cytotoxic for two human cell lines and for cultured bovine aortic endothelial cells. We suggest that in vivo enzymic conversion of low-density lipoprotein cholesterol to low-density lipoprotein cholestenone may possibly play a role in the initiation of atheromatous lesions in humans.

A mathematical method for analysing plasmid stability in micro-organisms.

A mathematical model describing the instability of plasmids in micro-organisms has been developed. The model is based on the assumption that the overall causes of plasmid instability are described by the segregational instability of the plasmid, R (i.e. the rate at which plasmid-free cells are generated from plasmid-bearing cells), and the growth rate difference, d mu (i.e. the difference in growth rate between plasmid-free and plasmid-bearing cells). A method for determining the values of R and d mu (accompanied by 95% confidence limits) for any plasmid-bearing micro-organism is described. This method is based on the observation that, depending on the plasmid, various exponential patterns of plasmid instability are observed. The stability of Escherichia coli 1B373(pMG169), where d mu much greater than R, and E. coli RV308(pHSG415), where R much greater than d mu, are analysed in order to demonstrate the method.

Investigation of the effect of growth environment on the stability of low-copy-number plasmids in Escherichia coli.

The stability of a low-copy-number plasmid, pHSG415, in Escherichia coli, was investigated in batch and continuous culture. The plasmid was unstable in batch culture, but was significantly stabilized by growth in continuous culture with phosphate, nitrogen or potassium limitation. However, the plasmid was very unstable when grown in continuous culture with sulphate limitation. These results contrast with those obtained with multicopy plasmids such as pBR322, which is particularly unstable in carbon- or phosphate-limited continuous culture. The effect of growth rate on the stability of E. coli(pHSG415) grown in continuous culture with glucose limitation was also investigated. The plasmid was significantly more stable in cells grown at higher growth rates. The segregational instability (R) of the plasmid and the difference in growth rate between plasmid-free and plasmid-bearing cells (dmu) were calculated for each condition using the method of Cooper et al. (accompanying paper: Journal of General Microbiology 133, 1871-1880). It was found that the primary cause of the loss of pHSG415 from the cell population was the segregational instability of the plasmid.

Gamma-linolenic acid inhibits the development of the ethanol-induced fatty liver.

In the context of recent work showing numerous interactions between ethanol, essential fatty acids (EFA) and prostanoids, we have evaluated the effects of gamma-linolenic acid methyl ester (GLA 99%; 18:3, n-6), on hepatic pathology induced by ethanol in rats. Groups of animals were pair-fed an alcohol-containing liquid diet or an iso-caloric maltose-dextrin diet. Animals fed ethanol for ten days had markedly increased hepatic triglycerides and histological evidence of fatty liver. These effects were partially attenuated by administration of GLA during the period of ethanol administration.

The synovial changes in rheumatoid arthritis under corticosteroid treatment.

Light microscopic examination of histological sections of synovial membrane from patients with rheumatoid arthritis revealed that prolonged administration of corticosteroids had an inhibiting effect on the participation of lymphocytes and histiocytes in inflammatory infiltrates, as well as on the hypertrophy of synoviocytes, the proliferation of fibroblasts, the accumulation of fibrocytes, the deposition of fibrous tissue, and the formation of villi. Short-term (i.e., 12- to 24-h) steroid administration inhibited proliferation of fibroblasts only.

Diagnostic specificity of synovial lesions.

Sections of synovium from 393 operations on diseased joints were re-examined without knowledge of the clinical findings. Specimens were scored for each of 37 histopathologic features. Independently, patients were assigned to one of 10 diagnostic groups after review of all available clinical data. Computer analysis revealed statistically significant differences in the incidence of one or more histologic parameters between the members of all except three of the possible disease pairs. The possibility of exploiting these differences to increase diagnostic precision was examined.

A statistical approach to the histopathologic diagnosis of synovitis.

Synovial tissue from 393 operations on diseased joints were scored for each of 37 histopathologic variables; the patients fell into 10 clinically defined diagnostic categories. The five most populous of these diagnostic groups provided a data set for calculating diagnoses based on histopathologic findings. For each pair of clinical diagnostic categories we derived a linear discriminant function dependent solely on the histopathologic assessments. The functions gave a numerical score for segregating each case into one of the diagnostic categories. The histopathology based diagnoses agreed with the clinical diagnoses in 54 to 78 per cent of the cases. Illustrations of the application of this technique are presented.