Preclinical characterization of an anti-tat ribozyme for therapeutic application

A hammerhead ribozyme retroviral construct, denoted RRz2, targeting the coding region of the human immunodeficiency virus type 1 (HIV-1) tat gene, has shown itself to be effective in a range of test systems. Inhibition of the replication of HIV-1 IIIB and primary drug-resistant strains in pooled transduced CEMT4 cells was consistently found to be more than 80% compared with the control-vector transduced cells, whereas a mutant RRz2 gave approximately 45% inhibition. A multiple HIV-1 passage assay showed the absence of emergence of mutations within the specific viral RNA ribozyme target sequences. This lack of generation of ribozyme "escape mutants" occurred despite the almost complete disappearance of a HIV-1 quasi-species in the testing virus. When RRz2 was tested in peripheral blood lymphocytes (PBLs) from HIV-1-infected patients, paired analysis showed that cell viability in the ribozyme-transduced HIV-1-infected PBLs was significantly higher than that in the vector-transduced cells. This difference in viability (vector versus RRz2) was not observed in PBLs from non-HIV-1-infected donors. Taken together, these results indicate that the transfer of an anti-HIV-1 ribozyme gene into human T lymphocytes could have major impact on viral replication and T cell viability in the HIV-1-infected individual.     

Biomechanics of torsion in the human mandible

Staff competence in the application of behavioral techniques is critical to improve quality of life for persons with a developmental disability. Development of efficient staff training programs is therefore of great importance. This paper describes some of the procedures most frequently used in staff training research. Research in this area is reviewed in relation to client outcomes as a function of staff training, maintenance of staff skills, and transfer of staff skills across settings, clients, and programs. Current concerns and further improvements in behavioural techniques, acquisitional strategies, and assessment are discussed.     

Corticosteroid responsive tenosynovitis is a common pathway for limited joint mobility in the diabetic hand

OBJECTIVE: To test the hypothesis that diabetic tenosynovitis participates in the contractures of the syndrome of limited joint mobility (SLJM). METHODS: Adults with diabetes mellitus were referred for the evaluation of diabetic hand conditions. Patients with SLJM or diabetic trigger finger were studied after Dupuytren's contracture, hand neuropathy, carpal tunnel syndrome, and arthritis were excluded. A time series design was employed in which patients were observed for 3 mo to obtain a baseline, then the planar flexor tendon sheaths were injected with 10 mg of methylprednisolone acetate or 10 mg triamcinolone acetonide and were reassessed at 1, 3, and 12 mo. RESULTS: Response rates, defined by complete resolution of digital contractures and triggering after corticosteroid injection, were 94% (31/33), 76% 28/33), and 61% (17/29) at 1, 3, and 12 mo, respectively, which were all significantly different from preinjection (p < 0.001). Individual response rates for SLJM and trigger finger were similar. No appreciable differences between methylprednisolone acetate and triamcinolone acetonide were observed, although there was a trend for earlier recurrence with methylprednisolone. CONCLUSION: Corticosteroid injection is a safe and effective therapy that should be considered in patients with SLJM or diabetic trigger finger. The excellent response to injection indicates that diabetic tenosynovitis is a common pathway in diabetic hand conditions.     

Iliac vessel injury: operative physiology related to outcome

BACKGROUND: Fifty-three patients treated at a level I trauma center with iliac vessel injury were studied to determine if body temperature and acid-base status in the operating room predicts outcome. METHODS: Records were reviewed for demographics, mechanism of injury, body temperature, acid-base status, operative management, and outcome. Statistical methods included Student's t test, odds ratio determination, and chi-square analysis to determine statistical significance. RESULTS: Fifty-three patients (47 male, 6 female) sustained 92 iliac vascular injuries (36 arterial, 56 venous). Mortality was 34%, with 72% of deaths due to shock within 24 hours. Physiologic parameters differed significantly between survivors and nonsurvivors. Odds ratio identified six conditions; the number present predicted outcome. CONCLUSIONS: (1) There are significant differences between initial and final operating room temperature and acid-base status in survivors versus nonsurvivors with iliac vessel injury. Conditions for odds ratio can be calculated and correlated with outcome. (2) A patient with two or more conditions should be considered for an abbreviated laparotomy to allow for reversal of "physiologic failure."     

Primary intrasellar mixed germ-cell tumor with precocious puberty and diabetes insipidus

A case-control study using data from the Baltimore-Washington Infant Study (BWIS) examined possible paternal risk factors in the etiology of isolated membranous ventricular septal defects (VSD). There were 641 total VSD case infants and 3,549 randomly selected control infants ascertained between 1981 and 1989. Isolated membranous VSDs were identified in 499 cases. Socio-demographic factors (such as parental age and race), social habits, and medical conditions were analyzed by multiple logistic regression in order to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI). Paternal age was not found to be a risk factor per se, but small positive associations were found for some social habits and maternal factors. Significant associations were found for paternal marijuana use (OR 1.36, 95% CI 1.05-1.76), African-American race of the infant (OR 1.34, 95% CI 1.09-1.65), and for cocaine use among older fathers (OR 3.92, 95% CI 1.30-11.86). These associations support a multifactorial etiologic hypothesis for isolated membranous VSDs and point to some interesting parental behavioral and medical considerations which may contribute to risk for this common birth defect.     

Replacement of an intracorporeal left ventricular assist device

An intracorporeal left ventricular assist device was placed as a bridge to cardiac transplantation in a 51-year-old man after an acute myocardial infarction. After 126 days of support, the left ventricular assist device malfunctioned. The pump, which had a tear in its pneumatic drive line, was successfully replaced.     

Minimally invasive axillary-coronary artery bypass

Axillary artery-to-coronary artery bypass using reversed saphenous vein provides a simple method of applying the minimally invasive coronary bypass grafting procedure when the internal thoracic artery is not an adequate conduit. Although this may allow extended use of the minimally invasive coronary bypass procedure, the long-term patency of this technique is unknown.     

The carboxy-terminal two-thirds of the cowpea chlorotic mottle bromovirus capsid protein is incapable of virion formation yet supports systemic movement

Previous investigations into recombination in cowpea chlorotic mottle bromovirus (CCMV) resulted in the recovery of an unusual recombinant virus, 3-57, which caused a symptomless infection of cowpeas but formed no detectable virions. Sequence analysis of cDNA clones derived from 3-57 determined that mutations near the 5' terminus of the capsid protein gene introduced an early translational termination codon. Further mutations introduced a new in-frame start codon that allowed translation of the 3' two-thirds of the capsid protein gene. Based on the mutations observed in 3-57, wild-type CCMV clones were modified to determine if the carboxyl two-thirds of the capsid protein functions independently of the complete protein in long-distance movement. Analysis of these mutants determined that while virion formation is not required for systemic infection, the carboxy-terminal two-thirds of the capsid protein is both required and sufficient for systemic movement of viral RNA. This indicates that the CCMV capsid protein is multifunctional, with a distinct long-distance movement function in addition to its role in virion formation.     

TNF-alpha down-regulates type 1 cytokines and prolongs survival of syngeneic islet grafts in nonobese diabetic mice

Administration of TNF-alpha to autoimmune diabetes-prone nonobese diabetic mice and biobreeding rats inhibits diabetes development; however, the mechanism(s) of diabetes prevention by TNF-alpha has not been established. We used the model of syngeneic islet transplantation into diabetic nonobese diabetic mice to study the effects of TNF-alpha administration on the types of mononuclear cells and cytokines expressed in the islet grafts and on autoimmune diabetes recurrence. Twice daily i.p. injections of TNF-alpha (20 microg/day) from day 1 to day 30 after islet transplantation significantly prolonged islet graft survival; thus, 70% (16 of 23) of mice treated with TNF-alpha were normoglycemic at 30 days after islet transplantation compared with none (0 of 14) of vehicle-treated control mice. Islet grafts and spleens from TNF-alpha-treated mice at 10 days after islet transplantation contained significantly fewer CD4+ and CD8+ T cells, and significantly decreased mRNA levels of type 1 cytokines (IFN-gamma, IL-2, and TNF-beta) than islet grafts and spleens from control mice. Regarding type 2 cytokines, IL-4 mRNA levels were not changed significantly in islet grafts or spleens of TNF-alpha-treated mice, whereas IL-10 mRNA levels were decreased significantly in islet grafts of TNF-alpha-treated mice and not significantly changed in spleens. TGF-beta mRNA levels in islet grafts and spleens were similar in TNF-alpha-treated and control mice. These results suggest that TNF-alpha partially protects beta cells in syngeneic islet grafts from recurrent autoimmune destruction by reducing CD4+ and CD8+ T cells and down-regulating type 1 cytokines, both systemically and locally in the islet graft.