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Bergmann G, Deuretzbacher G, Heller M, Graichen F, Rohlmann A, Strauss J, Duda GN. Hip contact forces and gait patterns from routine activities. J Biomech 2001; 34:859-71. [PMID: 11410170 DOI: 10.1016/s0021-9290(01)00040-9] [Citation(s) in RCA: 1336] [Impact Index Per Article: 55.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In vivo loads acting at the hip joint have so far only been measured in few patients and without detailed documentation of gait data. Such information is required to test and improve wear, strength and fixation stability of hip implants. Measurements of hip contact forces with instrumented implants and synchronous analyses of gait patterns and ground reaction forces were performed in four patients during the most frequent activities of daily living. From the individual data sets an average was calculated. The paper focuses on the loading of the femoral implant component but complete data are additionally stored on an associated compact disc. It contains complete gait and hip contact force data as well as calculated muscle activities during walking and stair climbing and the frequencies of daily activities observed in hip patients. The mechanical loading and function of the hip joint and proximal femur is thereby completely documented. The average patient loaded his hip joint with 238% BW (percent of body weight) when walking at about 4 km/h and with slightly less when standing on one leg. This is below the levels previously reported for two other patients (Bergmann et al., Clinical Biomechanics 26 (1993) 969-990). When climbing upstairs the joint contact force is 251% BW which is less than 260% BW when going downstairs. Inwards torsion of the implant is probably critical for the stem fixation. On average it is 23% larger when going upstairs than during normal level walking. The inter- and intra-individual variations during stair climbing are large and the highest torque values are 83% larger than during normal walking. Because the hip joint loading during all other common activities of most hip patients are comparably small (except during stumbling), implants should mainly be tested with loading conditions that mimic walking and stair climbing.
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Strauss JS, Carpenter WT. The prediction of outcome in schizophrenia. I. Characteristics of outcome. ARCHIVES OF GENERAL PSYCHIATRY 1972; 27:739-46. [PMID: 4637891 DOI: 10.1001/archpsyc.1972.01750300011002] [Citation(s) in RCA: 468] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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53 |
468 |
3
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Strauss JS, Carpenter WT. The prediction of outcome in schizophrenia. II. Relationships between predictor and outcome variables: a report from the WHO international pilot study of schizophrenia. ARCHIVES OF GENERAL PSYCHIATRY 1974; 31:37-42. [PMID: 4835985 DOI: 10.1001/archpsyc.1974.01760130021003] [Citation(s) in RCA: 450] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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51 |
450 |
4
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Harding CM, Brooks GW, Ashikaga T, Strauss JS, Breier A. The Vermont longitudinal study of persons with severe mental illness, II: Long-term outcome of subjects who retrospectively met DSM-III criteria for schizophrenia. Am J Psychiatry 1987; 144:727-35. [PMID: 3591992 DOI: 10.1176/ajp.144.6.727] [Citation(s) in RCA: 351] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The authors present the findings from a long-term follow-up study of 118 patients from Vermont State Hospital who, when rediagnosed retrospectively, met DSM-III criteria for schizophrenia at their index hospitalization in the mid-1950s. The patients were studied with structured, reliable, multivariate instrument batteries by raters who were blind to information in their records. The rediagnostic process is described, and results of the follow-up are presented. Outcome varied widely, but one-half to two-thirds of the sample had achieved considerable improvement or recovered, in contrast to statements in DSM-III that predict a poor outcome for schizophrenic patients.
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Comparative Study |
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Strauss JS, Carpenter WT. Prediction of outcome in schizophrenia. III. Five-year outcome and its predictors. ARCHIVES OF GENERAL PSYCHIATRY 1977; 34:159-63. [PMID: 843175 DOI: 10.1001/archpsyc.1977.01770140049005] [Citation(s) in RCA: 345] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Recent studies of schizophrenia have begun to demonstrate the complex nature of its outcome characteristics and their predictors. However, generalization of findings has been limited by methodological problems such as relatively short-term follow-up the use of retrospective data, or employment of evaluation techniques without demonstrated reliability. This report describes a prospective, five-year follow-up using reliable evaluation techniques to determine whether specific relations between predictors and outcome variables represent behavior patterns persisting over an extended period. Results demonstrate the prognostic importance and specificity of certain predictors over five years. These results support the view that outcome function is comprised of persisting open-linked systems of behavior.
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Peck GL, Olsen TG, Yoder FW, Strauss JS, Downing DT, Pandya M, Butkus D, Arnaud-Battandier J. Prolonged remissions of cystic and conglobate acne with 13-cis-retinoic acid. N Engl J Med 1979; 300:329-33. [PMID: 153472 DOI: 10.1056/nejm197902153000701] [Citation(s) in RCA: 335] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Fourteen patients with treatment-resistant cystic and conglobate acne were treated for four months with oral 13-cis-retinoic acid, a synthetic isomer of naturally occurring all-trans-retinoic acid. The average dose was 2.0 mg per kilogram per day. Thirteen patients experienced complete clearing of their disease; the other had 75 per cent improvement, as determined by the number of acne nodules and cysts present before and after therapy. Prolonged remissions, currently lasting as long as 20 months after discontinuation of therapy, have been observed in all 14 patients. Clinical toxicity was limited to the skin and mucous membranes in most patients and was dose dependent and rapidly reversible upon discontinuation of therapy. The mechanism of action of 13-cis-retinoic acid in the therapy of acne probably involves a direct inhibitory effect of the drug on the sebaceous gland.
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335 |
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Davidson L, Strauss JS. Sense of self in recovery from severe mental illness. THE BRITISH JOURNAL OF MEDICAL PSYCHOLOGY 1992; 65:131-45. [PMID: 1633118 DOI: 10.1111/j.2044-8341.1992.tb01693.x] [Citation(s) in RCA: 318] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This report based on research interviews conducted with persons struggling to recover from prolonged psychiatric disorders suggests that the rediscovery and reconstruction of an enduring sense of the self as an active and responsible agent provides an important aspect of improvement. This process of developing a functional sense of self in the midst of persisting psychotic symptoms and dysfunction is described, and its implications for understanding severe mental illness and processes of change are discussed. It is suggested that viewing the development of a dynamic sense of self as central to the improvement process provides a coherent thread which ties together diverse research findings concerning factors influencing course and outcome of illness. It is also suggested that for treatment and rehabilitation to elicit and foster a more functional sense of self, models of improvement will need to allow for, and encourage, a more active and collaborative role for the person with the disorder.
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Case Reports |
33 |
318 |
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Wertz PW, Miethke MC, Long SA, Strauss JS, Downing DT. The composition of the ceramides from human stratum corneum and from comedones. J Invest Dermatol 1985; 84:410-2. [PMID: 3158712 DOI: 10.1111/1523-1747.ep12265510] [Citation(s) in RCA: 292] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Human epidermal surface lipids were collected by an ethanol wash and the ceramides were quantified by thin-layer chromatography-photodensitometry. Six ceramide fractions were isolated and the structural components of each were analyzed in detail. The most unusual of the epidermal ceramides contained a sphingosine base with amide-linked 30- and 32-carbon omega-hydroxyacids and an ester-linked nonhydroxyacid, 41% of which was linoleic acid. The proportion of linoleic acid in the analogous ceramide from comedones was 6%. This supports the hypothesis that a localized insufficiency of linoleic acid in the follicular epithelium is an etiologic factor in comedogenesis.
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Comparative Study |
40 |
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Strauss JS, Carpenter WT, Bartko JJ. The diagnosis and understanding of schizophrenia. Part III. Speculations on the processes that underlie schizophrenic symptoms and signs. Schizophr Bull 2001:61-9. [PMID: 4469362 DOI: 10.1093/schbul/1.11.61] [Citation(s) in RCA: 287] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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24 |
287 |
10
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Carpenter WT, Strauss JS, Bartko JJ. Flexible system for the diagnosis of schizophrenia: report from the WHO International Pilot Study of Schizophrenia. Science 1973; 182:1275-8. [PMID: 4752222 DOI: 10.1126/science.182.4118.1275] [Citation(s) in RCA: 265] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Behavioral data on a large patient group were collected by investigators from nine countries in the International Pilot Study of Schizophrenia, sponsored by the World Health Organization. The data on half the group were analyzed to derive a system of 12 signs and symptoms for the identification of schizophrenia, as this disorder is diagnosed in many centers throughout the world. The findings were replicated with the other half of the patient group. The criteria constitute an operational method for identifying patients who would be commonly considered schizophrenic in many centers.
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265 |
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Carpenter WT, Strauss JS, Muleh S. Are there pathognomonic symptoms in schizophrenia? An empiric investigation of Schneider's first-rank symptoms. ARCHIVES OF GENERAL PSYCHIATRY 1973; 28:847-52. [PMID: 4707991 DOI: 10.1001/archpsyc.1973.01750360069010] [Citation(s) in RCA: 249] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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52 |
249 |
12
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Strauss JS. Hallucinations and delusions as points on continua function. Rating scale evidence. ARCHIVES OF GENERAL PSYCHIATRY 1969; 21:581-6. [PMID: 5823480 DOI: 10.1001/archpsyc.1969.01740230069010] [Citation(s) in RCA: 241] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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56 |
241 |
13
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Harding CM, Brooks GW, Ashikaga T, Strauss JS, Breier A. The Vermont longitudinal study of persons with severe mental illness, I: Methodology, study sample, and overall status 32 years later. Am J Psychiatry 1987; 144:718-26. [PMID: 3591991 DOI: 10.1176/ajp.144.6.718] [Citation(s) in RCA: 224] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The authors report the latest findings from a 32-year longitudinal study of 269 back-ward patients from Vermont State Hospital. This intact cohort participated in a comprehensive rehabilitation program and was released to the community in a planned deinstitutionalization effort during the mid-1950s. At their 10-year follow-up mark, 70% of these patients remained out of the hospital but many were socially isolated and many were recidivists. Twenty to 25 years after their index release, 262 of these subjects were blindly assessed with structured and reliable protocols. One-half to two-thirds of them had achieved considerable improvement or recovery, which corroborates recent findings from Europe and elsewhere.
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38 |
224 |
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Greene RS, Downing DT, Pochi PE, Strauss JS. Anatomical variation in the amount and composition of human skin surface lipid. J Invest Dermatol 1970; 54:240-7. [PMID: 5436951 DOI: 10.1111/1523-1747.ep12280318] [Citation(s) in RCA: 201] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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55 |
201 |
15
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Abstract
The sebaceous glands of man show age-related differences in their activity as determined by quantitative and qualitative examination of sebum. Sebaceous secretion is low in children and begins to increase in mid- to late childhood under the influence of androgens. This rise continues until the late teens, after which no further significant change takes place until late in life. In elderly men, sebum levels remain essentially unchanged from those of younger adults until the age of 80. In women, sebaceous secretion decreases gradually after menopause and shows no significant change after the 7th decade. The most likely explanation for the decrease in sebaceous gland secretion with age in both men and women is a concomitant decrease in the endogenous production of androgens. Although surface lipid levels fall with age, paradoxically the sebaceous glands become larger, rather than smaller, as a result of decreased cellular turnover. Nonetheless, as the higher surface lipid levels after administration of fluoxymesterone (a synthetic testosterone derivative) indicate, the glands have the capacity to respond to androgens.
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Comparative Study |
46 |
196 |
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Strauss J, Mach RL, Zeilinger S, Hartler G, Stöffler G, Wolschek M, Kubicek CP. Cre1, the carbon catabolite repressor protein from Trichoderma reesei. FEBS Lett 1995; 376:103-7. [PMID: 8521952 DOI: 10.1016/0014-5793(95)01255-5] [Citation(s) in RCA: 189] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In order to investigate the mechanism of carbon catabolite repression in the industrially important fungus Trichoderma reesei, degenerated PCR-primers were designed to amplify a 0.7-bp fragment of the cre1 gene, which was used to clone the entire gene. It encodes a 402-amino acid protein with a calculated M(r) of 43.6 kDa. Its aa-sequence shows 55.6% and 54.7% overall similarity to the corresponding genes of Aspergillus nidulans and A. niger, respectively. Similarity was restricted to the aa-region containing the C2H2 zinc finger and several aa-regions rich in proline and basic amino acids, which may be involved in the interaction with other proteins. Another aa-region rich in the SPXX-motif that has been considered analogous to a region of yeast RGR1p, was instead identified as a domain occurring in several eucaryotic transcription factors. The presence of the cre1 translation product was demonstrated with polyclonal antibodies against Cre1, which identified a protein of 43 (+/- 2) kDa in cell-free extracts from T. reesei. A Cre1 protein fragment from the two zinc fingers to the region similar to the aa-sequence of eucaryotic transcription factors, was expressed in Escherichia coli as a fusion protein with glutathione S-transferase. EMSA and in vitro footprinting revealed binding of the fusion protein to the sequence 5'-GCGGAG-3', which matches well with the A. nidulans consensus sequence for CreA binding (5'-SYGGRG-3'). Cell-free extracts of T. reesei formed different complexes with DNA-fragments carrying this binding sites, and the presence of Cre1 and additional proteins in these complexes was demonstrated. We conclude that T. reesei Cre1 is the functional homologue of Aspergillus CreA and that it binds to its target sequence probably as a protein complex.
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189 |
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Strauss J, Abitbol C, Zilleruelo G, Scott G, Paredes A, Malaga S, Montané B, Mitchell C, Parks W, Pardo V. Renal disease in children with the acquired immunodeficiency syndrome. N Engl J Med 1989; 321:625-30. [PMID: 2770791 DOI: 10.1056/nejm198909073211001] [Citation(s) in RCA: 181] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Of 155 children with the acquired immunodeficiency syndrome (AIDS) whom we evaluated during a 6 1/2-year period, 12 were found to have proteinuria. Histologic studies of tissue from these 12 patients revealed a wide spectrum of renal disease: focal glomerulosclerosis in 5, mesangial hyperplasia in 5, segmental necrotizing glomerulonephritis in 1, and minimal change disease in 1. In addition, 6 had tubulointerstitial infiltrates, and 10 had glomerular dense deposits. All 10 renal specimens studied by electron microscopy contained endothelial tubuloreticular inclusions. The mean age (+/- SD) of the five patients with focal glomerulosclerosis when this condition was identified was 27 +/- 19 months. All five had severe renal failure within a year and died of other causes during the following year. The mean age of the five patients with mesangial hyperplasia was 38 +/- 31 months. Although none of them went on to have renal failure, four died within 8 +/- 7 months. Ten of the 12 patients with proteinuria died during the study period. Of the two surviving, one had mesangial hyperplasia and the other had minimal change disease. We conclude that children who acquire human immunodeficiency virus (HIV) infection during the perinatal period may have renal disease, most often focal glomerulosclerosis, as is the case in adults, or mesangial hyperplasia. Although 5 of the 12 children we studied had renal failure during the study period, none died of it. Further studies are needed to determine the correlations between clinical and pathological features and the pathophysiology of AIDS nephropathy in children.
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36 |
181 |
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Pochi PE, Strauss JS. Endocrinologic control of the development and activity of the human sebaceous gland. J Invest Dermatol 1974; 62:191-201. [PMID: 4361985 DOI: 10.1111/1523-1747.ep12676783] [Citation(s) in RCA: 174] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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51 |
174 |
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Chen DT, Jiang X, Akula N, Shugart YY, Wendland JR, Steele CJM, Kassem L, Park JH, Chatterjee N, Jamain S, Cheng A, Leboyer M, Muglia P, Schulze TG, Cichon S, Nöthen MM, Rietschel M, McMahon FJ, Farmer A, McGuffin P, Craig I, Lewis C, Hosang G, Cohen-Woods S, Vincent JB, Kennedy JL, Strauss J. Genome-wide association study meta-analysis of European and Asian-ancestry samples identifies three novel loci associated with bipolar disorder. Mol Psychiatry 2013; 18:195-205. [PMID: 22182935 DOI: 10.1038/mp.2011.157] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Meta-analyses of bipolar disorder (BD) genome-wide association studies (GWAS) have identified several genome-wide significant signals in European-ancestry samples, but so far account for little of the inherited risk. We performed a meta-analysis of ∼750,000 high-quality genetic markers on a combined sample of ∼14,000 subjects of European and Asian-ancestry (phase I). The most significant findings were further tested in an extended sample of ∼17,700 cases and controls (phase II). The results suggest novel association findings near the genes TRANK1 (LBA1), LMAN2L and PTGFR. In phase I, the most significant single nucleotide polymorphism (SNP), rs9834970 near TRANK1, was significant at the P=2.4 × 10(-11) level, with no heterogeneity. Supportive evidence for prior association findings near ANK3 and a locus on chromosome 3p21.1 was also observed. The phase II results were similar, although the heterogeneity test became significant for several SNPs. On the basis of these results and other established risk loci, we used the method developed by Park et al. to estimate the number, and the effect size distribution, of BD risk loci that could still be found by GWAS methods. We estimate that >63,000 case-control samples would be needed to identify the ∼105 BD risk loci discoverable by GWAS, and that these will together explain <6% of the inherited risk. These results support previous GWAS findings and identify three new candidate genes for BD. Further studies are needed to replicate these findings and may potentially lead to identification of functional variants. Sample size will remain a limiting factor in the discovery of common alleles associated with BD.
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157 |
20
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Hawk AB, Carpenter WT, Strauss JS. Diagnostic criteria and five-year outcome in schizophrenia. A report from the International Pilot Study of schizophrenia. ARCHIVES OF GENERAL PSYCHIATRY 1975; 32:343-7. [PMID: 1115575 DOI: 10.1001/archpsyc.1975.01760210077005] [Citation(s) in RCA: 155] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Systematic psychiatric assessment was undertaken on 131 patients (the American cohort of the International Pilot Study of Schizophrenia). Nine areas of outcome functioning were assessed five years later at follow-up evaluation on 63% of these patients. An analysis of 66 clinical and demographic variables established that the patients sucessfully followed-up were representatives of the entire cohort. Diagnostic data from initial evaluations and follow-up outcome assessment were used to examine the relationship between diagnostic criteria and outcome in schizophrenia. Applying the criteria for schizophrenic diagnosis defined by Langfeldt, by Schneider, and Carpenter et al failed to define a poor outcome group. No difference in outcome was found when traditional schizophrenic subtypes were contrasted. Overall outcome in 61 patients with conditions diagnosed as schizophrenic was heterogeneous. However, despite overlap, the mean outcome in the schizophrenic cohort was poorer than in the 19 nonschizophrenic patients.
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Comparative Study |
50 |
155 |
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Carpenter WT, Strauss JS. The prediction of outcome in schizophrenia. IV: Eleven-year follow-up of the Washington IPSS cohort. J Nerv Ment Dis 1991; 179:517-25. [PMID: 1919553 DOI: 10.1097/00005053-199109000-00001] [Citation(s) in RCA: 153] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Two- and five-year follow-up observations of the International Pilot Study of Schizophrenia's Washington cohort provided data bearing on several controversial issues regarding the course of schizophrenia. Forty schizophrenic patients have now been observed 11 years after their index admission. Social, occupational, hospital utilization, and symptom areas of functioning continue to be only modestly correlated with one another and do not become increasingly uniform over time. Initial prognostic variables continue to be more predictive of long-term outcome than are cross-sectional symptom manifestations. Restricted affect at the initial evaluation had been a predictor of 5-year outcome, but it was not a significant predictor of outcome at 11 years. While serious long-term consequences of illness are observed, the follow-up data suggest that the illness tends to reach a plateau of psychopathology early in the course, with as many patients tending to improve in the long-term as those who tend to show further deterioration.
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34 |
153 |
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Long SA, Wertz PW, Strauss JS, Downing DT. Human stratum corneum polar lipids and desquamation. Arch Dermatol Res 1985; 277:284-7. [PMID: 4004327 DOI: 10.1007/bf00509081] [Citation(s) in RCA: 151] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The ceramides and steryl-sulfate components from desquamated and cohesive human stratum corneum were examined using a combination of chemical and chromatographic means. Six structurally distinct series of ceramides were identified, and the relative amounts of these species, as measured by quantitative thin-layer chromatography, did not differ in cohesive and desquamated stratum corneum. In contrast, the level of cholesteryl sulfate was significantly reduced in the desquamated material. The results are in accord with the hypothesis that cholesteryl sulfate serves in cell-to-cell cohesion within the stratum corneum, and its hydrolysis may be necessary to permit shedding of cells from the surface.
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40 |
151 |
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Abstract
Acne is characterized by hyperkeratosis of the follicular epithelium, leading to horny impactions that may lie dormant as open or closed comedones or may cause inflammation of the follicle. Although persons with acne have consistently been observed to have elevated levels of sebum secretion, no mechanism relating sebum secretion rates to comedogenesis is known. Acne patients have also been shown to have low levels of linoleic acid in their skin surface lipids. To explain this observation, the hypothesis is advanced that the linoleate concentration in human sebum depends on the quantity of linoleic acid present in each sebaceous cell at the commencement of its differentiation and on the extent to which this initial charge is diluted by subsequent endogenous lipid synthesis in each sebaceous cell. A corollary hypothesis holds that low concentrations of linoleate in sebum impose a state of essential fatty acid deficiency on the cells of the follicular epithelium and induce the characteristic response of hyperkeratosis. Both hypotheses could hold, without there being a systemic deficiency of linoleic acid, simply as the result of elevated lipogenesis in individual sebaceous cells.
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39 |
149 |
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Ramasastry P, Downing DT, Pochi PE, Strauss JS. Chemical composition of human skin surface lipids from birth to puberty. J Invest Dermatol 1970; 54:139-44. [PMID: 5414607 DOI: 10.1111/1523-1747.ep12257164] [Citation(s) in RCA: 144] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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55 |
144 |
25
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Mach RL, Strauss J, Zeilinger S, Schindler M, Kubicek CP. Carbon catabolite repression of xylanase I (xyn1) gene expression in Trichoderma reesei. Mol Microbiol 1996; 21:1273-81. [PMID: 8898395 DOI: 10.1046/j.1365-2958.1996.00094.x] [Citation(s) in RCA: 142] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The filamentous fungus Trichoderma reesei forms two specific, xylan-inducible xylanases encoded by xyn1 and xyn2 to degrade the beta-1,4-D-xylan backbone of hemicelluloses. This enzyme system is formed in the presence of xylan, but not glucose. The molecular basis of the absence of xylanase I formation on glucose was the purpose of this study. Northern blotting of the xyn1 transcript as well as the use of the Escherichia coli hygromycin B phosphotransferase-encoding gene (hph) as a reporter consistently showed that the basal expression of xyn1 was affected by glucose, whereas its induction by xylan remained uninfluenced. The repression of basal xyn1 transcription is mediated by the carbon catabolite repressor protein Cre1, which in vivo binds to two of four consensus sites (5'-SYG-GRG-3') in the xyn1 promoter, which occurred in the form of an inverted repeat. T. reesei strains, bearing a xyn1::hph reporter construct, in which four nucleotides from the middle of the inverted repeat had been removed, expressed hph on glucose at a level comparable to that observed during growth on a carbon catabolite derepressing carbon source. Northern analysis of xyn1 expression in a T. reesei mutant strain (RUT C-30), which contains a truncated, non-functional cre1 gene, also confirmed basal transcription of xyn1. In this strain, xyn1 transcription was still inducible by xylose or xylan to an even higher degree than in the wild-type strain, suggesting that induction overcomes glucose repression at the level of xyn1 expression. Based on these data, we postulate that basal transcription of xyn1 is repressed by glucose and mediated by an inverted repeat of the consensus motif for Cre1-mediated carbon catabolite repression.
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142 |