Problems of research and development in health services

One of the main problems to technology utilization is the dynamics of the medical community. The users of the technology are not well acquainted with its potential value, the private entrepreneur (the physician) rarely purchases in quantity, and standards of manufacture have not been set. For these reasons, the medical market is unstable, risky, and expensive to enter. Most large companies get a greater return on engineering talent through mass-produced items. A means must be found to develop an interface between the inventor, the developer, the manufacturer, and the user of medical devices. The medical inventor is usually supported by grants or contracts and as such has little opportunity to develop an idea to the prototype or testing phase. Industry is sometimes unwilling and sometimes unable to invest capital and talent in expensive development and production testing. The logical middleman in the chain is the federal government. Past experience indicates that when a prototype has been developed and successfully tested through government sponsorship, industry then becomes interested in production. As a corollary to development, standardization must be established. The creation of a health caresystem where records on a consumer can be transferred from one point to another with complete understanding requires the standardization of tests, records, and many parts of the system as a whole. Any savings of scale can be accomplished only with mass production and this requires definition of a standard product.     

Immunohistochemical study about the Flt-1/VEGFR1 expression in the gastrointestinal tract of mouse, rat, dog, swine and monkey

Fms-like tyrosine kinase 1 (Flt-1) performs a subordinate effector role in mesenchymal angiogenesis and potentially serves an equally important functional role as a self-contained receptor in epithelial cells. In both endothelial cells and epithelial cells, Flt-1/vascular endothelial growth factor receptor 1 (VEGFR1) downstream signalling is involved in regulating cellular processes such as cytoskeletal changes and cellular survival protection. Cellular renewal of the gastrointestinal mucosa is based on these processes and might involve Flt-1/VEGFR1 pathway activities; the molecular mechanisms regulating these cellular dynamics remain unclear. This study was performed to investigate the presence and distribution of Flt-1/VEGFR1 in epithelial cells of the gastrointestinal tract by immunohistochemistry (IHC). Gastrointestinal tissues were taken from eight anatomical sites from mouse, rat, dog, swine and monkey. Present results revealed a cytosolic Flt-1/VEGFR1 staining pattern in mucosal epithelial cells for all investigated species. Non-epithelial structures also displayed a distinct Flt-1/VEGFR1 positivity and included vascular smooth muscle walls, enteric smooth muscle layers, the enteric nervous system and capillary endothelial cells. Diverse intensities of the Flt-1/VEGFR1 binding reaction within each species were observed in the intestinal mucosa with a strong immunoreaction in enterocytes and with a low protein expression in the ileum in most species. Crypt cells in the large intestine were mostly negative for Flt-1/VEGFR1. A peculiar and mainly intranuclear antibody binding reaction was found in Brunner's gland epithelial cells of mouse and rat whereas Brunner's glands of dog, swine and monkey remained completely negative. These results indicate a potential involvement of Flt-1/VEGFR1 in normal restitution of gastrointestinal structures in the species studied. Additionally, intranuclear Flt-1/VEGFR1 antibody binding in Brunner's glands of rodents may suggest a nuclear translocation of the transmembrane VEGFR1 which has not previously been described.     

Fastigial nucleus activity in the alert monkey during slow eye and head movements

1. Single units were recorded extracellularly from the fastigial nucleus of three macaque monkeys. Two untrained animals were subjected to whole-body yaw rotations in the light and dark and to full-field horizontal optokinetic stimuli provided by a drum with vertical stripes. The third also was subjected to sinusoidal yaw rotations but, in addition, was trained to follow a small spot, which moved in various ways relative to the animal, to reveal possible smooth pursuit and vestibular sensitivities. 2. On the basis of their responses to vestibular and optokinetic stimuli and their responses during smooth pursuit, fastigial neurons could be divided functionally into a rostral and a caudal group. 3. Most rostral neurons exhibited an increased firing for contralateral head rotations and ipsilateral optokinetic stimuli. A few had the opposite combination of directional preferences. The average firing rates increased monotonically both with contralateral head velocity and ipsilateral drum velocity and decreased monotonically for the oppositely directed movements. There was no change in firing rate for either spontaneous saccades or smooth pursuit of a small moving spot. 4. In contrast, neurons in the caudal fastigial nuclei not only have a robust vestibular sensitivity, but respond during smooth pursuit as well. Most discharge during contralateral head velocity and contralateral smooth pursuit so that they exhibit very little modulation during the vestibuloocular reflex (VOR) or when the rotating animal is fixating a target stationary in the world (SIW). The remaining neurons discharge during contralateral head rotations but ipsilateral eye rotations; these units exhibit their greatest modulation during the SIW condition. 5. Because they respond during quite different behavioral situations, it seems likely that rostral fastigial neurons are involved with descending control of the somatic musculature, whereas the caudal neurons are involved in oculomotor control. The sparse anatomic and lesion data that is available is consistent with this idea.     

A large Turkish kindred with syndactyly type II (synpolydactyly). 2. Homozygous phenotype?

Syndactyly type II (synpolydactyly (SPD)) is an autosomal dominant condition with typical abnormalities of the distal parts of both upper and lower limbs. We report here a previously undescribed phenotypic feature of people with severe hand and foot deformities who were born to two affected parents. This is the first example of SPD subjects manifesting a very distinctive phenotype, suggesting that they must be homozygous for this condition. The typical characteristic clinical features in these subjects are as follows: (1) short hands with wrinkled fatty skin and short feet; (2) complete soft tissue syndactyly involving all four limbs; (3) polydactyly of the preaxial, mesoaxial, and postaxial digits of the hands; (4) loss of the normal tubular shape of the carpal, metacarpal, and phalangeal bones, so as to give polygonal structures; (5) loss of the typical structure of the cuboid and all three cuneiform bones while the talus calcaneus and navicular bones remain intact; (6) large bony islands instead of metatarsals, most probably because of cuboid-metatarsal and cuneiform-metatarsal fusions; and (7) severe middle phalangeal hypoplasia/aplasia as well as fusion of some phalangeal structures that are associated with the loss of normal phalangeal pattern. We report seven subjects with this phenotype from three different branches of a very large SPD pedigree exhibiting the same phenotype with minimal variation. In mice, the Polysyndactyly (Ps) mutation shows a pattern of synpolydactyly very similar to that of human SPD, suggesting that they may well be homologous mutations. A molecular genetic study is currently under way to determine the chromosomal location of the SPD locus in humans and to identify the corresponding homologous region in mice.     

Gene transfer of costimulatory molecules into a human colorectal cancer cell line: requirement of CD54, CD80 and class II MHC expression for enhanced immunogenicity.

Colorectal cancer is considered a non-immunogenic malignany. One strategy to augment the immunogenicity of such tumours is represented by the expression of costimulatory molecules by gene transfer. Using transfected variants of the human colorectal cancer cell line SW480 we tested various costimulatory molecules (CD80, CD86, CD54) and a class II major histocompatibility complex (MHC) allele (HLA-DR3) alone or in combination on their ability to support primary T-lymphocyte activation in vitro. Expression of CD80 or CD86 similarly as the combination of both was not sufficient to induce proliferation of human allogeneic T cells. Expression of CD54 together with CD80 strongly augmented the costimulatory function of CD80, as observed in the presence of a CD3 monoclonal antibody (mAb), but did not lead directly to a T-cell response against modified tumour cells. Importantly, SW480 cells coexpressing CD54, CD80 and the HLA-DR3 allele effectively promoted T-lymphocyte proliferation. Moreover, the use of such CD54+/CD80+/HLA-DR3+ SW480 variants for repetitive stimulations resulted in the generation of T-cell lines predominantly composed of CD8+ T cells exhibiting class I MHC restricted cytolytic activity towards untransfected SW480 tumour cells. This demonstrates that the generation of immunogenic tumour cell variants, i.e. for the use as cellular vaccines, requires multiple genetic alterations in the case of non-immunogenic human tumours cells, such as colorectal cancer cells.     

Double-blind analysis of the relation between adult periodontitis and systemic host response to suspected periodontal pathogens.

By using a sensitive enzyme-linked immunosorbent assay, 200 randomly selected sera from Red Cross blood donors were screened for immunoglobulin G (IgG), IgA, and IgM levels against Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Bacteroides intermedius. A subgroup of 79 blood donors was clinically examined for type and extent of periodontal destruction, and serological and clinical data were subjected in all possible dual combinations to correlation analyses. The results revealed that the majority of the blood donors suffered from moderate to severe adult periodontitis, often coupled with severe gingival inflammation. No cases of localized juvenile periodontitis or rapidly progressive periodontitis were observed. The extent of periodontal destruction proved to be significantly correlated only to the IgG response levels against B. gingivalis. Corresponding correlation tests assessing the relationships of loss of attachment, bone loss, pocket depth, and papillary bleeding index with the IgG responses to A. actinomycetemcomitans were of marginal significance, while the IgG responses to B. intermedius revealed no relationship to the periodontal health status. The specific IgM responses proved to be unrelated to the clinical parameters, but interestingly, they were found to be highly correlated with each other. Specific IgA levels were frequently too low for enzyme-linked immunosorbent assay testing and, therefore, had to be exempted from statistical analyses. Assessments of the serotype specificity of strongly elevated IgG responses to A. actinomycetemcomitans disclosed no evidence for an association of a particular serotype-specific IgG response with the occurrence of adult periodontal destruction. In contrast to results of earlier studies, a number of sera were found to contain strongly elevated IgG levels against two or even all three serotypes. Although derived by an alternative approach, the reported results largely corroborate earlier observations linking only the occurrence of elevated anti-B. gingivalis IgG responses to the presence of marked periodontal lesions in adults.     

Recombinant Human Tumour Necrosis Factor β (Lymphotoxin) Lacks Chemotactic Activity for Human Peripheral Blood Neutrophils, Monocytes, and T Cells

Human recombinant tumour necrosis factor beta (rhuTNF beta)/lymphotoxin was tested for human neutrophil granulocyte (PMN), monocytes (MO), and T-cell chemotactic activity by means of a modified Boyden chamber system. Over a wide range of concentrations (10(-7)-10(-14)M)rhuTNF beta showed no chemotactic activity for PMN, MO, or T cells. In contrast, strong chemotactic migration was elicited in PMN and MO with the tripeptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) and in T cells when complement split product C5a and leukotriene B4 (LTB4) were used as chemotaxins. The results of this study indicate that rhuTNF beta/lymphotoxin is not a chemotaxin for human PMN, MO, or T lymphocytes in vitro.     

Defective Aspergillus killing by neutrophil leucocytes in a case of systemic aspergillosis.

A persistent defect of Aspergillus killing was observed in the neutrophils of a 6-year-old patient with a systemic A. fumigatus infection which was highly refractory to anti-mycotic therapy. Aspergillus phagocytosis in vitro was normal, but nearly 80% of the ingested organisms (versus 30% in the controls) survived intracellularly during the 2-hr assay period. The patient's neutrophils showed a subnormal frequency of nitroblue tetrazolium reduction and a subnormal hexose monophosphate shunt activation in response to phagocytosis. The metabolic responsiveness, however, was clearly superior to that of chronic granulomatous disease neutrophils tested for comparison. The immune status of the patient and the following properties of his neutrophils were found to be normal: random and chemotactic motility, killing of S. aureus and C. albicans, and the contents of several granula enzymes. Our findings suggest the existence of neutrophil factors or functions which are required for killing Aspergillus, but not S. aureus and C. albicans.     

Pulmonary granuloma caused by Pseudomonas andersonii sp nov

Pulmonary granuloma is a common lesion for which gram-negative bacteria are rarely implicated as a cause. Hence, most physicians are unaware of this etiology. We isolated a gram-negative bacterium from a surgically resected pulmonary granuloma in a 42-year-old, nonimmunocompromised woman. Within the necrotizing granuloma, numerous organisms also were demonstrated by Gram stain, suggesting a cause-disease relationship. Characterization of the bacterium by sequence analysis of the 16S ribosomal gene, cellular fatty acid profiling, and microbiologic studies revealed a novel bacterium with a close relationship to Pseudomonas. We propose a new species for the bacterium, Pseudomonas andersonii. These results suggest that the differential diagnosis of a lung granuloma also should include this gram-negative bacterium as a potential causative agent, in addition to the more common infections caused by acid-fast bacilli and fungi. This bacterium was shown to be susceptible to most antibiotics that are active against gram-negative bacteria.