Polygalacturonase-inhibiting proteins (PGIPs) with different specificities are expressed in Phaseolus vulgaris

The pgip-1 gene of Phaseolus vulgaris, encoding a polygalacturonase-inhibiting protein (PGIP), PGIP-1 (P. Toubart, A. Desiderio, G. Salvi, F. Cervone, L. Daroda, G. De Lorenzo, C. Bergmann, A. G. Darvill, and P. Albersheim, Plant J. 2:367-373, 1992), was expressed under control of the cauliflower mosaic virus 35S promoter in tomato plants via Agrobacterium tumefaciens-mediated transformation. Transgenic tomato plants with different expression levels of PGIP-1 were used in infection experiments with the pathogenic fungi Fusarium oxysporum f. sp. lycopersici, Botrytis cinerea, and Alternaria solani. No evident enhanced resistance, compared with the resistance of untransformed plants, was observed. The pgip-1 gene was also transiently expressed in Nicotiana benthamiana with potato virus X (PVX) as a vector. PGIP-1 purified from transgenic tomatoes and PGIP-1 in crude protein extracts of PVX-infected N. benthamiana plants were tested with several fungal polygalacturonases (PGs). PGIP-1 from both plant sources exhibited a specificity different from that of PGIP purified from P. vulgaris (bulk bean PGIP). Notably, PGIP-1 was unable to interact with a homogeneous PG from Fusarium moniliforme, as determined by surface plasmon resonance analysis, while the bulk bean PGIP interacted with and inhibited this enzyme. Moreover, PGIP-1 expressed in tomato and N. benthamiana had only a limited capacity to inhibit crude PG preparations from F. oxysporum f. sp. lycopersici, B. cinerea, and A. solani. Differential affinity chromatography was used to separate PGIP proteins present in P. vulgaris extracts. A PGIP-A with specificity similar to that of PGIP-1 was separated from a PGIP-B able to interact with both Aspergillus niger and F. moniliforme PGs. Our data show that PGIPs with different specificities are expressed in P. vulgaris and that the high-level expression of one member (pgip-1) of the PGIP gene family in transgenic plants is not sufficient to confer general, enhanced resistance to fungi.     

Stress, social support, and substantiated maltreatment in the second and third years of life

OBJECTIVE: The purpose of this research was to determine whether risk factors for a maltreatment report in the first year of life, especially the interaction of life event stress and social support, persist into the second and third years of life. METHOD: Predominantly low income mothers who had been interviewed shortly after the birth of infants in a longitudinal cohort were re-interviewed around the infants' first birthdays, and reports to North Carolina's Central Registry of Child Abuse and Neglect were tracked for substantiated maltreatment reports. RESULTS: Variables significantly associated with a substantiated maltreatment report in the second or third year of life (p < .01) were first year maltreatment reports and participation in Medicaid. Three interactions between a stressful life event indicator variable and a social support indicator variable were significant predictors of substantiated second or third year reports (p < .05). CONCLUSIONS: Even in the presence of significant risk factors from the first year of life, life event stress can increase the risk of a substantiated maltreatment report in the second or third years of life, but social support may moderate the effect of life events.     

Diffusion and transfer of antibody proteins from a sugar-based hydrogel

Diffusion of antibody protein from hydrogel films and hydrogel encapsulated in a microcapillary was studied. Thin hydrogel films were formed by crosslinking 6-acryloyl-B-O-methylgalactoside with N,N'-methylene-bis-acrylamide and the diffusive transport of monoclonal antimouse IgG-FITC into and out of the hydrate films was measured. Diffusion coefficients in 2 and 4% crosslinked hydrogel films were measured. The measured diffusion constants determined for IgG in both the 2 and 4% hydrogel films were comparable to the free diffusion of IgG in bulk water (Dmean approximately 10(-7) cm2/s). In addition, 2% crosslinked hydrogels were prepared in a capillary tube and the transport of antimouse IgG-FITC into and out of the hydrated hydrogel was measured. Kinetic analysis indicated that the protein transport through the capillary hydrogel was faster than would be expected for a simple diffusion process. Finally, by utilizing the diffusion of antibody from the capillary hydrogel, transfer of antibody to a silica surface was demonstrated. A capillary hydrogel loaded with antimouse IgG-FITC was used to transfer the protein to a silica surface forming a 30-micron spot of antibody, which was imaged using fluorescence microscopy. These results may lead to the development of a nonlithographic method of patterning antibodies on surfaces for use in integrated microimmunosensors.     

Dopamine D3 receptor mutant mice exhibit increased behavioral sensitivity to concurrent stimulation of D1 and D2 receptors

The dopamine D3 receptor is expressed primarily in regions of the brain that are thought to influence motivation and motor functions. To specify in vivo D3 receptor function, we generated mutant mice lacking this receptor. Our analysis indicates that in a novel environment, D3 mutant mice are transiently more active than wild-type mice, an effect not associated with anxiety state. Moreover, D3 mutant mice exhibit enhanced behavioral sensitivity to combined injections of D1 and D2 class receptor agonists, cocaine and amphetamine. However, the combined electrophysiological effects of the same D1 and D2 agonists on single neurons within the nucleus accumbens were not altered by the D3 receptor mutation. We conclude that one function of the D3 receptor is to modulate behaviors by inhibiting the cooperative effects of postsynaptic D1 and other D2 class receptors at systems level.     

Cyclosporin A in patients receiving renal allografts from cadaver donors. 1978

A psychrotrophic yeast, Rhodotorula glutinis KUJ 2731, isolated from soil, effectively produced an extracellular endo-beta-glucanase (EC 3.2.1.4). The enzyme was monomeric, and the molecular mass was about 40,000 Da. The N-terminal amino acid sequence was H-Ser-Leu-Pro- Lys-Leu-Gly-Gly-Val-Asp-Leu-Ala-Gly-Leu-Asp-Ile-Gly-Lys-Asp-Lys-Asn-. alpha-Helix content was calculated to be about 32.6%. The isoelectric point was 8.57. The activation energy was 20.9 kJ/mol, which was much smaller than that of mesophilic enzymes. The enzyme was active at temperatures from 0 to 70 degrees C, with a highest initial velocity at 50 degrees C similar to other psychrotrophic enzymes. The enzyme was inhibited by Hg2+. The enzyme catalyzed hydrolysis of carboxymethyl cellulose with an apparent K(m) of 1.1% and Vmax of 556 mumol/min/mg. Products from the enzymatic hydrolysis of carboxymethyl cellulose by the enzyme were glucose, cellobiose, and cellotriose. The enzyme also catalyzed the transglycosylation of p-nitrophenyl-beta-cellotrioside to cellotetraose.     

The "first generation" of endovascular stent-grafts for patients with aneurysms of the descending thoracic aorta

OBJECTIVE: Our goal was to determine whether endovascular stent-grafting is feasible and effective for patients with aneurysms of the descending thoracic aorta. METHODS: Starting in July 1992, we conducted a prospective, uncontrolled clinical trial in 103 patients (mean age 69 years [range 34-89 years]) who underwent endovascular treatment of aneurysms of the descending thoracic aorta using a custom-fabricated, self-expanding stent-graft device. Follow-up was 100% complete and averaged 22 months. Sixty-two patients (60%) were judged not to be reasonable candidates for a conventional "open" surgical procedure. RESULTS: Complete thrombosis of the aneurysm was ultimately achieved in 86 (83%) patients. The early mortality rate was 9% +/- 3% (+/- 70% CL). Multivariable analysis revealed that myocardial infarction or stroke was linked with a higher likelihood of early death (P = .001). Early serious complications included paraplegia in 3% +/- 2% and stroke in 7% +/- 3%. Actuarial survival estimates at 1 year and 2 years were 81% +/- 4% and 73% +/- 5% (+/- 1 SE), respectively; being judged not to be a surgical candidate portended a higher probability of death (P = .003). According to the intent-to-treat principle, "treatment failure" (including all late sudden unexplained deaths) occurred in 38 patients; 53% +/- 10% of patients were free from treatment failure at 3.7 years. Stent-graft related complications occurred commonly and were linked with several anatomic, technical, and patient-related risk factors. CONCLUSIONS: This 5-year clinical trial involving use of a "first generation" device indicates that endovascular stent-grafting of descending thoracic aortic aneurysms is feasible with acceptable medium-term results. More refined, commercially developed devices available today offer less traumatic and more precise stent-graft deployment; these major technical advantages, coupled with important lessons we have learned over time and better patient selection, should be associated with more salutary clinical results in the future.     

Trials and tribulations of vascular surgical benchmarking

The purpose of this study was to review the efficacy of a protracted venous infusion of 5-fluorouracil (PVI 5-FU)-based chemotherapy in advanced small bowel adenocarcinoma. Data on all patients with small bowel malignancy who were seen at a single institution over a 5-year period were retrieved from the gastrointestinal unit and hospital databases, and these cases were reviewed. Eight patients with advanced small bowel adenocarcinoma received PVI 5FU-based chemotherapy. The overall response rate in assessable patients was 37.5% (3/8). The median overall survival was 13 months (range 1-28), and progression-free survival was 7.8 months (range 0-15). Overall, the treatment was well tolerated and symptomatic benefit was seen. In conclusion, PVI 5-FU has activity in this disease. This should be assessed either as a single agent or as part of a combination regimen such as epirubicin/cisplatin/PVI FU (ECF) in a multicentre randomized study.     

Malignant fibrous histiocytoma in a child''s hand

Mycobacterium szulgai is a rare cause of human infections, and when present it is mostly known to cause lung infection. We report the first case of isolated Mycobacterium szulgai osteomyelitis in a 68-year-old woman on chronic immunosuppressive therapy. Review of the literature revealed a total of three other cases of M. szulgai osteomyelitis. In all these cases there was evidence of hematogenous or contiguous spread, including one with extensive dissemination. Pulmonary M. szulgai infections tend to occur in patients with chronic lung disease and/or concomitant lung infections, whereas osteomyelitis tends to occur in patients who have severe immunosuppression secondary to disease or drugs.