Effect of milk-borne epidermal growth factor on the hepatic microcirculation and Kupffer cell function in suckling rats

A Rehabilitation Information System was created in July 1993 in order to register war victims in need of physical rehabilitation all over Croatia. The system is currently operating and presented data covers the period from July 1991 to July 1995. Approximately 15,000 questionnaires had been completed and returned from medical institutions on in total 8589 disabled war victims in need of rehabilitation. People with severe disabilities comprised about 20% of all in need of rehabilitation. Those reported injured were 3.5 times more than those in need of physical rehabilitation. Most common types of injuries were fractures with a permanent disabling condition (3109 persons), peripheral nerve injuries (1213 persons) and amputations (956 persons). Traumatic brain injuries were registered for 594 and spinal cord injuries for 262 persons. Causes of injuries were explosive devices (such as mines, mortar shell shrapnel, etc.) in 37% of cases, bullets in 22%, accidents in 7%, other (such as fire, blast injuries, etc.) and unknown causes in 34%.     

The cuffed oropharyngeal airway as an aid to fibreoptic intubation

OBJECTIVE: To determine if a structured encounter form for well-child care improves documentation of well-child care. DESIGN: Retrospective medical record review of a before-and-after trial. SETTING: Family practice residency clinic serving a primarily low-socioeconomic urban population. PATIENTS: Children younger than 6 years receiving well-child care visits. INTERVENTION: Detailed checklists were developed and implemented in 1994 for each of 12 well-child examinations for the assessment of children aged 2 weeks to 5 years based on recommendations from the American Academy of Pediatrics and the US Preventive Services Task Force. MAIN OUTCOME MEASURES: Documentation of multiple aspects of well-child care, including developmental assessment, safety and nutrition counseling, and laboratory tests for 6-month periods in 1993 and 1994, before and after implementation of the structured encounter form. RESULTS: A total of 842 well-child visits were reviewed. Documentation improved significantly with the use of the encounter form for 19 of the 23 aspects of well-child care that were studied. Screening test rates were less than optimal despite the encounter form. CONCLUSIONS: The structured encounter form was very effective in improving documentation of almost all aspects of well-child care. However, effective communication is needed among physicians, nurses, and parents to ensure optimal screening test rates.     

Characterization of interactions between the anti-apoptotic protein BAG-1 and Hsc70 molecular chaperones

The anti-cell death protein BAG-1 binds to 70-kDa heat shock proteins (Hsp70/Hsc70) and modulates their chaperone activity. Among other facilitory roles, BAG-1 may serve as a nucleotide exchange factor for Hsp70/Hsc70 family proteins and thus represents the first example of a eukaryotic homologue of the bacterial co-chaperone GrpE. In this study, the interactions between BAG-1 and Hsc70 are characterized and compared with the analogous GrpE-DnaK bacterial system. In contrast to GrpE, which binds DnaK as a dimer, BAG-1 binds to Hsc70 as a monomer with a 1:1 stoichiometry. Dynamic light scattering, sedimentation equilibrium, and circular dichroism measurements provided evidence that BAG-1 exists as an elongated, highly helical monomer in solution. Isothermal titration microcalorimetry was used to determine the complex stoichiometry and an equilibrium dissociation constant, KD, of 100 nM. Kinetic analysis using surface plasmon resonance yielded a KD consistent with the calorimetrically determined value. Molecular modeling permitted a comparison of structural features between the functionally homologous BAG-1 and GrpE proteins. These data were used to propose a mechanism for BAG-1 in the regulation of Hsp70/Hsc70 chaperone activity.     

Remission of human breast cancer xenografts on therapy with humanized monoclonal antibody to HER-2 receptor and DNA-reactive drugs

HER-2 oncogene encodes a transmembrane growth factor receptor that is overexpressed in 25-30% of patients with primary breast and ovarian cancer. A murine monoclonal antibody, 4D5, to the extracellular domain of HER-2 receptor elicits cytostatic growth inhibition of tumor cells overexpressing HER-2 protein, but clinical use of this antibody is limited by genesis of human anti-mouse antibodies. To avoid this problem, a recombinant humanized 4D5 monoclonal antibody (rhuMAb HER-2) was developed and tested using a human tumor xenograft model. Human breast and ovarian cancer cells which overexpress HER-2 were inhibited in vivo by the rhuMAb HER-2 antibody. Tumor growth relative to control was reduced at all doses of antibody tested, and the magnitude of growth inhibition was directly related to dose of rhuMAb HER-2. Tumor growth resumed on termination of antibody therapy, indicating a cytostatic effect. To elicit a cytotoxic response, human breast tumor xenografts were treated with a combination of antibody and antitumor drugs, cisplatin or doxorubicin. The combination of antibody with either cisplatin or doxorubicin resulted in significantly greater growth inhibition, with the cisplatin combination demonstrating a greater response. In addition, therapy with cisplatin and antireceptor antibody elicited complete tumor remissions after 2-3 cycles of therapy. The schedule of administration of anti-receptor antibody and cisplatin was critical for occurrence of antibody-induced potentiation in cisplatin cytotoxicity. Enhanced killing of tumor cells was found only if antibody and drug were given in close temporal proximity. Since interference with DNA repair pathways may contribute to this receptor-enhanced chemosensitivity, repair of cisplatin-damaged reporter DNA (pCMV-beta) was determined in human breast cells. As in studies of antibody-enhanced cisplatin cytotoxicity in vivo, treatment with rhuMAb HER-2 blocked the repair of cisplatin-damaged DNA only if the antibody was administered in close temporal proximity to transfection of the drug-exposed reporter DNA. An alternative measure of DNA repair, unscheduled DNA synthesis, was also assessed. Treatment with either cisplatin or doxorubicin led to an increase in unscheduled DNA synthesis that was reduced by combined therapy with antireceptor antibody specific to HER-2-overexpressing breast cancer cells. Using a direct measure of DNA repair, therapy of HER-2-overexpressing cells with rhuMAb HER-2 also blocked the removal of cisplatin-induced DNA adducts. Expression of p21/WAF1, an important mediator of DNA repair, was disrupted in breast cancer cells with HER-2 overexpression, but not in control cells, after treatment with HER-2 antibody, thus suggesting cross-communication between the HER-2 signaling and DNA repair pathways. These data demonstrate an in vivo antiproliferative effect of rhuMAb HER-2 on tumors that overexpress HER-2 receptor and a therapeutic advantage in the administration of the antireceptor antibody in combination with chemotherapeutic agents.     

Suspected Brazilian purpuric fever in a toddler with overwhelming Epstein-Barr virus infection

We describe a toddler from Connecticut who developed purulent conjunctivitis, fever, and a morbilliform rash. Blood cultures were positive for Haemophilus influenzae biogroup aegyptius; further investigation was performed to assess the possibility that the illness was consistent with Brazilian purpuric fever, which, to our knowledge, has not been reported in the United States. This isolate shared morphological and some biochemical characteristics with previously studied H. influenzae biogroup aegyptius strains but differed according to slide agglutination testing, plasmid characterization, and ribotyping. Blood and tissue samples obtained during his hospitalization were also positive for Epstein-Barr virus. The child died 8 days after hospitalization. Fifty other cases of invasive H. influenzae infection were identified by active surveillance studies. Of the 49 viable surveillance isolates, 10 were biotype III (two of which had the same ribotype as the strain from our case.     

Quantitative assessment of enzyme specificity in vivo: P2 recognition by Kex2 protease defined in a genetic system

The specificity of the yeast proprotein-processing Kex2 protease was examined in vivo by using a sensitive, quantitative assay. A truncated prepro-alpha-factor gene encoding an alpha-factor precursor with a single alpha-factor repeat was constructed with restriction sites for cassette mutagenesis flanking the single Kex2 cleavage site (-SLDKR downward arrowEAEA-). All of the 19 substitutions for the Lys (P2) residue in the cleavage site were made. The wild-type and mutant precursors were expressed in a yeast strain lacking the chromosomal genes encoding Kex2 and prepro-alpha-factor. Cleavage of the 20 sites by Kex2, expressed at the wild-type level, was assessed by using a quantitative-mating assay with an effective range greater than six orders of magnitude. All substitutions for Lys at P2 decreased mating, from 2-fold for Arg to >10(6)-fold for Trp. Eviction of the Kex2-encoding plasmid indicated that cleavage of mutant sites by other cellular proteases was not a complicating factor. Mating efficiencies of strains expressing the mutant precursors correlated well with the specificity (kcat/KM) of purified Kex2 for comparable model peptide substrates, validating the in vivo approach as a quantitative method. The results support the conclusion that KM, which is heavily influenced by the nature of the P2 residue, is a major determinant of cleavage efficiency in vivo. P2 preference followed the rank order: Lys > Arg > Thr > Pro > Glu > Ile > Ser > Ala > Asn > Val > Cys > AsP > Gln > Gly > His > Met > Leu > Tyr > Phe > Trp.     

Minimizing pain for liposuction anesthesia

The publication of the complete genome sequence of Helicobacter pylori and the computer analysis of the genes it contains represents an enormous advance in H. pylori research. Besides providing an overview of H. pylori biology, the genome sequence will aid future research and radically alter the research process. In particular, it will enable a 'top down' approach whereby genes are investigated because of their similarity to genes of known function in other organisms. Other advances in biotechnology will allow all H. pylori genes to be studied simultaneously, proteins to be identified quickly, and potential drug targets to be evaluated efficiently. Progress in H. pylori research should now be rapid, and with the research interest and resources focused on it, H. pylori could become the paradigm for post-genomic research.     

Chromosomal aberrations in soft tissue tumors. Relevance to diagnosis, classification, and molecular mechanisms

In recent years, significant progress has been made in identifying characteristic chromosomal rearrangements associated with several solid tumor types, notably sarcomas, a relatively rare subset of human cancer. Most sarcomas analyzed have been found to be characterized by recurrent chromosome translocations that are specific to histological types. We have reviewed published reports of chromosomal aberrations in benign and malignant soft tissue tumors and found an incidence of specific translocations in these neoplasms that ranged from 20% to 93% within histological tumor types. Identification of recurrent chromosomal abnormalities in benign tumors has resulted in a reappraisal of the general concept that benign tumors have a normal (diploid) chromosome constitution. The variety of recurrent changes present in the different tumor types attests to the cytogenetic diversity inherent in these tumors. The chromosomal rearrangements in each of the tumor types were unique and did not correspond to cancer-associated aberrations known from other solid or hematopoietic malignancies. Cytogenetics thus provides an essential adjunct to diagnostic surgical pathology in the case of malignant soft tissue tumors, which often present substantial diagnostic challenges. In addition, it represents another approach to determine the histogenetic origin of some tumors and identifies sites of gene deregulation for molecular analysis. Indeed, recent molecular analyses of several sarcoma-associated translocations have identified novel genes and novel mechanisms of their dysregulation.     

Glucose metabolism in photoreceptor outer segments. Its role in phototransduction and in NADPH-requiring reactions

Glucose metabolism in the photoreceptor rod outer segment produces both ATP (GTP) and NADPH to support phototransduction and NADPH-requiring processes in this organelle. Glycolysis in isolated bovine rod outer segments produces 44.0 +/- 6.4 nmol of ATP/min/mg of protein or 5.7 mM ATP/min. This rate of ATP production is more than sufficient to maintain the basal rate of cGMP synthesis (0.86 mM cGMP/min) in the dark requiring 1.7 mM ATP/min. Following photoexcitation, the 4.5-fold increase in the turnover of cGMP requires an ATP synthesis rate of up to 7.7 mM ATP/min (Ames, A., Walseth, T. F., Heyman, R. A., Barad, M., Graeff, R. M., and Goldberg, N. D. (1986) J. Biol. Chem. 261, 13034-13042). Under these conditions the rate of ATP production by glycolysis as measured in isolated rod outer segments is not sufficient for the regeneration of cGMP. Additional energy is most likely provided by the phosphocreatine shuttle which transports high energy phosphate groups in the form of creatine phosphate from the rod inner segment to the rod outer segment for conversion to ATP. The hexose monophosphate pathway in bovine rod outer segments can produce up to 39.8 +/- 2.2 nmol of NADPH/min/mg of protein. This rate of NADPH production is sufficient to support both the reduction of retinal to retinol (1.2 +/- 0.2 nmol of NADPH/min/mg of protein) following the photobleaching of rhodopsin and glutathione reduction (1.1 +/- 0.1 nmol of NADPH/min/mg of protein) for the protection of rod outer segments from oxidative damage. These studies provide insight into the contribution of anaerobic glycolysis and the hexose monophosphate pathway in providing energy and nucleotides for phototransduction and other outer segment processes.     

Human dermatophyte-responsive T-cell lines recognize cross-reactive antigens associated with mannose-rich glycoproteins

Resistance to dermatophyte infections has been shown to be mediated in part by T lymphocytes. The dermatophyte antigens recognized by human T lymphocytes and their degree of cross-reactivity were analyzed. Dermatophyte-responsive T-cell lines were generated by in vitro sensitization to crude fungal extracts obtained from Trichophyton rubrum, Trichophyton tonsurans, Microsporum canis and Epidermophyton floccosum. Proliferation was measured by incorporation of 3H-thymidine. The human T-cell lines responded to fungal extracts derived from these various dermatophyte species, demonstrating the recognition of cross-reactive antigens by human T cells. However, the T cells were dermatophyte-specific as they did not respond to herpes antigen, nor did herpes-specific T cells derived from the same donors respond to dermatophyte antigens. The mannose-rich glycoprotein fraction (mannan) isolated from T. rubrum was able to induce proliferation of T-cell lines generated by stimulation with various fungal extracts. Furthermore, a T-cell line generated by stimulation with mannan derived from T. rubrum proliferated in response to extracts from various fungal species, indicating that a major cross-reactive dermatophyte T-cell antigen was present in the mannose-rich glycoprotein fraction.