Decompression comparison of N2 and O2 in rats

We have previously reported that O2 in the breathing gas mixture contributed significantly to the risk of decompression sickness (DCS) in rats after rapid (less than 10 s) decompression to the surface from depth. The rate of O2 uptake was extremely fast (less than 1 min estimated for equilibrium after a pressure change) compared to much slower rates for He and N2. To further define the role that O2 plays in diving, the present investigation examined decompression outcome in unanesthetized male albino rats after 60-min N2-O2 dives (1-3 atm abs O2, depth 6.26 or 7.26 atm abs). Slower decompression profiles were used to determine the elimination rates of N2 and O2 as pressure was reduced and included "stops" of up to 20 min. The probability of DCS was modeled using the maximum likelihood technique. O2 again contributed significantly to the risk of DCS, although O2 was eliminated very rapidly during decompression; the washout of N2 was considerably longer. These findings support the view that O2 can add significantly to decompression risk. However, this phenomenon may not normally be encountered during human diving operations where relatively slower decompression and lower PO2's are used.     

Detection of HIV-1 proviral sequences in lymphocytes using a qualitative polymerase chain reaction assay

The performance and clinical relevance of a qualitative PCR-based assay for the detection of HIV-1 DNA sequences in peripheral blood mononuclear cells (PBMCs) was evaluated by two different laboratories. Four hundred and one samples were obtained from 397 individuals from different risk populations. All blood donors tested had negative results; positive signals were obtained from all infected patients. HIV-1 DNA was detected in 3 of 17 infants born to seropositive mothers; Western blot indeterminate blood donors and exposed healthcare workers had negative results. Our results demonstrate that this PCR assay provides both sensitive and specific results and is suitable for testing large numbers of samples and for rapid identification of HIV-1 infection.     

Pseudodiastrophic dysplasia type Burgio in a newborn

Pseudodiastrophic dysplasia is a distinct disorder that differs from diastrophic dysplasia on the basis of elbow and proximal interphalangeal joint dislocations, platyspondyly, and scoliosis. We report on a new patient with this rare skeletal dysplasia and two previously undescribed major malformations: omphalocele and complex heart defect. Am. J. Med. Genet. 71:222–225, 1997. © 1997 Wiley-Liss, Inc.     

Human papillomavirus with co-existing vulvar vestibulitis syndrome and vestibular papillomatosis.

OBJECTIVE: The role of HPV infection in cases of vulvar papillomatosis and vulvar vestibulitis syndrome is still unclear and data from the literature is controversial. In this study we intended to investigate the prevalence of viral infection, with a multidisciplinary approach, in cases with a co-existence of the two patterns. METHOD: Sixteen consecutive cases with diagnosis of vulvar vestibulitis syndrome and co-existence of vestibular papillomatosis were enrolled in the study and investigated by the means of vulvar cytology, vulvoscopy, histology, ViraPap and Polymerase Chain Reaction. RESULT: Cytology, vulvoscopy and histology did not demonstrate suitable accuracy for the diagnosis. Viral DNA identification revealed two (12.50%) positive cases using PCR and one (6.25%) positive case with ViraPap. CONCLUSION: The results of the present investigation indicate that even in cases of co-existing vulvar papillomatosis and severe vulvar vestibulitis syndrome, the prevalence of HPV infection is too low to be considered causal.     

Combinatorial antibody libraries from cancer patients yield ligand-mimetic Arg-Gly-Asp-containing immunoglobulins that inhibit breast cancer metastasis

Combinatorial antibody libraries have the potential to display the entire immunological record of an individual, allowing one to detect and recover any antibody ever made, irrespective of whether it is currently being produced. We have termed this the "fossil record" of an individual's antibody response. To determine whether cancer patients have ever made antibodies with disease-fighting potential, we screened combinatorial antibody libraries from cancer patients for immunoglobulins that can identify metastatic tumor cells. This strategy yielded human antibodies specific for the activated conformation of the adhesion receptor integrin alphavbeta3 that is associated with a metastatic phenotype. In a remarkable example of convergent evolution, two of these antibodies were shown to contain the Arg-Gly-Asp integrin recognition motif of the natural ligand within the third complementarity-determining region of the heavy chain. These antibodies interfered with lung colonization by human breast cancer cells in a mouse model and inhibited existing metastatic disease. Our data imply that, at least at some time, these antibodies were part of a patient's surveillance system against metastatic cells, targeting the activated conformer of integrin alphavbeta3 and disrupting its functions. The ligand-mimetic nature of these antibodies, combined with specificity for a single receptor, is unique in the integrin-ligand repertoire. The convergent evolution of critical sequences in antibodies and other ligands that bind to the same target means that the immune response has sufficient power to find a best chemical solution for the optimization of binding energy, even though antibodies evolve in real time, as compared with billions of years for the natural ligand.     

Investigation of the migration path for new rod photoreceptors in the adult cichlid fish retina

In the retina of adult teleost, precursor cells divide in the outer nuclear layer and give rise to new rod photoreceptors. These new rods migrate from the outer limiting membrane to the inner edge of the outer nuclear layer (ONL) before differentiating. In order to understand which cues these cells use during migration and insertion at the appropriate location we combined cell-specific stains in the retina of the cichlid fish Haplochromis burtoni, viewed with confocal laserscan microscopy: Dividing cells were labeled with bromodeoxyuridine (BrdU), Müller glial cells, cone photoreceptors, and horizontal cells were detected by specific antibodies. During the migration phase (24 to 48 h after BrdU uptake) up to 46% of BrdU-labeled cells were spindle shaped and radially oriented. Most of them were in direct proximity to Müller cell processes. Four days after BrdU-uptake, most labeled cells (91%) were found in the inner portion of the ONL and displayed a spherical shape. This marks the end of the movement of the new rods. At this stage, the labeled cells showed no preference to lie near glial fibers but were often found close to the pedicles of double cones. The leading edge of migrating cells reached into the outer plexiform layer (OPL) but not further than processes of horizontal cells. This is beyond the location of mature rods. We hypothesize that the cells are repelled in the OPL and insert back in the ONL to differentiate as rods.     

Endovascular treatment of aneurysms in the elderly

The constant increase in the median age over 80 requires more and more care from vascular surgeons to obtain better results in the treatment of aortic degenerative diseases. In the last years a remarkable improvement in the procedures of endovascular surgery of abdominal aortic aneurysms has been reached. Actually different prostheses are available for the treatment of aortic aneurysms. The early results of these procedures are similar to the traditional surgical techniques, but at the moment long term results are not yet available. The Authors underline the importance of a long term follow up to allow a correct evaluation of physiopathological modifications in the aortic circulation.