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Biomedical subjects

C Barrios

Publications and source records attributed to C Barrios.

At least 55 records · Page 3Linked to original sources
PubMed1993

Healing complications after internal fixation of trochanteric hip fractures: the prognostic value of osteoporosis.

In a 3-year prospective randomized trial, the prognostic value of osteoporosis in terms of predicting healing complications due to implant failures or loss of fracture reduction has been studied in 113 patients with inter-trochanteric hip fractures treated with either a sliding screwplate or Ender nailing. According to the Barnet and Nordin's osteoporosis index, 66 patients were considered to have moderate or severe osteoporosis. There were no differences between patients with or without osteoporosis as regards the number of fractures with collapse in varus > 10 degrees, redislocation > 10 mm, or compression exceeding 10 mm. Six months after surgery, 48 patients failed in healing or healed with complications. These cases disclosed increased osteoporosis in comparison with those showing noncomplicated healing. Patients with osteoporosis who had unstable fractures treated by Ender nailing were found to have the worst prognosis for healing complications (p = 0.006). Of the 33 fractures with implant failures, 25 (76%) occurred in patients with osteoporosis (p = 0.04). In patients with osteoporosis, the frequency of mechanical failures was significantly higher in fractures with the device positioned incorrectly. Independently of the device used, patients with unstable trochanteric hip fractures and osteoporotic bone were the group with the highest risk for failures of the implant.

Aged↗
PubMed1993

Walking ability after internal fixation of trochanteric hip fractures with Ender nails or sliding screw plate. A comparative study of gait.

The influence of several clinical and radiographic parameters on the functional outcome of 92 patients with trochanteric hip fractures treated at random with either Ender nails or a sliding screw plate (SSP) was prospectively investigated. Apart from other clinical variables such as pain, the use of walking aids, and walking distance, the walking ability of patients was assessed by gait analysis performed on an electronic walkway. The parameters investigated were the maximal vertical force (MVF) and single-limb support phase (SLS). Independent of the type of fixation, no differences were observed between stable and unstable fractures in any of the parameters analyzed six months after surgery. In fractures treated with Ender nails, the use of walking aids and MVF were influenced by a satisfactory fracture reduction. Walking distance was the sole factor correlated with the status of fracture healing. In fractures treated with SSP, the pain was the only clinical variable significantly influenced by the outcome of fracture healing. In trochanteric fractures treated with Ender nails, the quality of fracture reduction was the most valuable predictor of patients' recovery of walking ability.

Aged↗
PubMed1992

Mycobacterial heat-shock proteins as carrier molecules. II: The use of the 70-kDa mycobacterial heat-shock protein as carrier for conjugated vaccines can circumvent the need for adjuvants and Bacillus Calmette Guérin priming.

In a recent work, we have shown that mycobacterial heat-shock proteins (hsp) of 65-kDa (GroEL-type) and 70-kDa (DnaK-type) acted as carrier molecules in mice, previously primed with Mycobacterium tuberculosis var. bovis (bacillus Calmette-Guérin, BCG), for the induction of high and long-lasting titers of IgG against the repetitive malaria synthetic peptide (NANP)40. Anti-peptide antibodies were induced when the malaria peptide, conjugated to the mycobacterial hsp, was given in the absence of any adjuvants (Lussow et al., Eur. J. Immunol. 1991. 87:2960). In this report, we show that mice immunized with peptides or oligosaccharides conjugated to the 70-kDa hsp produced high titers of IgG antibodies in the absence of any previous priming with BCG. The anti-peptide antibody response persisted for at least 1 year. This adjuvant-free carrier effect of the 70-kDa hsp was T cell dependent, since no anti-peptide nor anti-70-kDa IgG antibodies were induced in athymic nu/nu mice. Previous immunization of mice with the 65-kDa or 70-kDa hsp did not have any negative effect on the induction of anti-peptide IgG antibodies after immunization with hsp-peptide conjugates in the absence of adjuvants. Furthermore, preimmunization with the 65-kDa hsp could substitute for BCG in providing an effective priming for the induction of anti-(NANP) antibodies. Finally, both the 65-kDa and 70-kDa hsp acted as carrier molecules for the induction of IgG antibodies to group C meningococcal oligosaccharides, in the absence of adjuvants. These findings strongly suggest that the use of hsp as carriers in conjugated constructs for the induction of anti-peptide and anti-oligosaccharide antibodies could be of value in the design of new vaccines for eventual use in humans.

Amino Acid Sequence↗
PubMed1992

Experimental kyphoscoliosis induced in rats by selective brain stem damage.

The relationship between damage to particular brain stem nuclei related to postural control and equilibrium and the occurrence of spinal deformity has been investigated. The model used was the Wistar albino rat and the brain stem structures damaged were the gracillis nucleus, the superior colliculus and the lateral vestibular nucleus. Out of 60 brain stem damaged animals, 44 had accurate lesions from which 11 (25%) showed kyphoscoliotic deformities. Rats with spinal deformity showed an imbalance of the paraspinal muscles when assessed by EMG; this was expressed by an increase of muscular activity on the convex side. This study indicates that postural dysfunction caused by brain stem damage may induce kyphoscoliosis in experimental animals and could be one of the underlying mechanisms in the production of human idiopathic scoliosis.

Animals↗
PubMed1992

A prospective randomized study of the use of sliding hip screws and Ender nails for trochanteric fractures of the femur.

The functional outcome of trochanteric hip fractures was investigated prospectively in a group of 92 patients treated at random with either Ender nails or a sliding hip screw. Apart from clinical variables, the walking ability of the patients was assessed by gait analysis performed on an electronic walkway. No perioperative complications were noted. The patients in the Ender group had significantly less blood loss and a shorter operation time than the patients treated with the sliding hip screw, indicating that the former method is more gentle as a primary intervention. However, over time there were more reoperations in the Ender group and the functional outcome, including gait analysis after 6 months, showed more favourable results for fractures treated with the sliding hip screw. We therefore recommend the sliding hip screw for an optimal functional result.

Aged↗
PubMed1992

Oral administration of clonidine in patients with alcoholic cirrhosis. Hemodynamic and liver function effects.

The effects of long-term oral clonidine treatment on hepatic and systemic hemodynamics and on quantitative liver function tests were investigated in 15 patients with alcoholic cirrhosis. Clonidine was administered at a mean dose of 0.33 +/- 0.1 mg/day (mean +/- SD) for a mean period of 64 +/- 10 days. Oral clonidine induced a significant reduction in the hepatic venous pressure gradient from 18.8 +/- 3.0 mm Hg to 15.9 +/- 3.4 mm Hg (P less than 0.001), which was the result of an increase in the free hepatic venous pressure from 5.1 +/- 4.2 mm Hg to 8.7 +/- 3.8 mm Hg (P less than 0.05). In 10 of the 15 patients (67%), the reduction in the hepatic venous pressure gradient was greater than 10% of baseline values. Hepatic blood flow did not change significantly after clonidine treatment. Additionally, treatment with clonidine decreased mean arterial pressure by 15.5% +/- 6% (P less than 0.001), heart rate by 17.7% +/- 7% (P less than 0.001), and cardiac output by 14.6% +/- 7% (P less than 0.001). However, systemic vascular resistance did not change significantly. There were no adverse effects on liver function, as shown by the nonsignificant changes in galactose-elimination capacity (149 +/- 59 vs. 170 +/- 58 mg/min), hepatic clearance of indocyanine green (0.19 +/- 0.10 vs. 0.17 +/- 0.07 L/min), and hepatic intrinsic clearance of indocyanine green (0.23 +/- 0.14 vs. 0.21 +/- 0.1 L/min) before and after clonidine treatment, respectively. In none of the patients was the drug withdrawn because of side effects, although 12 subjects complained of dry mouths. This study suggests that in patients with alcoholic cirrhosis, long-term oral clonidine administration achieves a reduction in the hepatic venous pressure gradient without adverse effects on hepatic blood flow and liver function.

Administration, Oral↗
PubMed1992

Lymphocyte response to polymethylmethacrylate in loose total hip prostheses.

We investigated the lymphocyte-mediated immune response to polymethylmethacrylate bone cement in 26 patients who had revision surgery for aseptic loosening of cemented total hip arthroplasties, at a mean time of seven years after the first replacement. We studied eight patients with cemented total hip arthroplasties which were not loose as controls. Patch tests to polymethylmethacrylate bone cement were positive in 13 patients with loosening, and these patients had higher lymphoblast transformation values against polymethylmethacrylate bone cement patients with a negative skin reaction (p < 0.01) or those in the control group (p < 0.001). Specific monoclonal antibodies were used to assess the percentage of certain cells of the immune system according to their cluster of differentiation (CD). There was a higher number of total T and B lymphocytes (CD2 and CD22) and interleukin-2 receptor-positive lymphocytes (activated cells, CD25) in patients with loose prostheses. More CD25 lymphocytes were found in patients with positive patch tests. The activation of the lymphocyte-mediated immune response was not related to the presence or absence of aggressive granulomatous lesions at the cement-bone interface.

Adolescent↗
PubMed1992

Amplification of the c-myc proto-oncogene in human chondrosarcoma.

The genomic organization of four oncogenes, i.e., c-myc, c-myb, c-Ha-ras, and c-fms, was investigated in fresh surgical specimens from 10 patients with cartilaginous tumors. Among nine chondrosarcomas, six were primary lesions and three local recurrences. The remaining case was a chondroblastoma. Amplification of the c-myc proto-oncogene was the sole abnormality detected in this series, occurring in two chondrosarcomas (four- and eight-fold). No other genetic alteration such as oncogene rearrangement was found. Nor was there any amplification of the other oncogenes studied. Both c-myc-amplified tumors were primary lesions and histologically classified as grade II; according to flow DNA cytometry, one was diploid and the other aneuploid. In our limited series, there was no overall relationship between c-myc amplification, on the one hand, and histologic subtype, malignancy grade, surgical stage, or ploidy level, on the other. Our study shows that amplification of the c-myc oncogene, presumed to be involved in the development of malignancy, is encountered in occasional human chondrosarcomas, however, without any relationship to other well-known features of this tumor entity. The clinical significance of this gene amplification remains to be established.

Adult↗
PubMed1992

Clinical features and walking ability in the early postoperative period after treatment of trochanteric hip fractures. Results with special reference to fracture type and surgical treatment.

The purpose of this study was to analyze the functional outcome during the early postoperative period (six weeks) in patients with trochanteric fractures. A consecutive series of 149 patients were randomized to treatment with either the DHS or Ender operative technique. 120 patients were available at review six weeks after surgery. Groups were comparable with respect to age (mean 77 years), sex ratio (73% women), type of fracture (59% and 55% unstable), experience level of the surgeon, prefracture health condition and ambulatory status. During follow-up eight patients died and there were 19 complications of neurologic and cardiovascular types equally spread among the two groups. All four infections were found in the DHS group. Orthopaedic hospital stay averaged 19 days and more patients in the Ender group could return to their previous home at time of discharge. At the six week visit 14% in the Ender group compared to 33% in the DHS group had not recovered functional walking distance (less than 15 m). All patients in the Ender group managed to walk, but 11% of the patients in the DHS group could not walk. Walking ability was most impaired for unstable fractures. It is concluded that the Ender technique will involve less operative trauma (shorter operations with less blood loss) and in the early postoperative period it can provide better conditions for walking and less need for further hospitalization than the DHS technique.

Aged↗
PubMed1991

Mycobacterial heat-shock proteins as carrier molecules.

We have previously shown that the priming of mice with live Mycobacterium tuberculosis var. bovis (Bacillus Calmette-Guérin, BCG) and immunization with the repetitive malaria synthetic peptide (NANP)40 conjugated to purified protein derivative (PPD), led to the induction of high and long-lasting titers of anti-peptide IgG antibodies, overcoming the requirement of adjuvants and the genetic restriction of the antibody response to the peptide (Lussow et al., Proc. Natl. Acad. Sci. USA 1990. 87:2960). This initial work led us to the following observations. BCG had to be live for priming to lead to the induction of anti-peptide antibodies. Surprisingly, priming with other living microorganisms which chronically infect the macrophage (e.g. Salmonella typhimurium and Leishmania major) also induced anti-peptide antibodies in mice immunized with PPD-(NANP)40 conjugate. It was, thus, hypothesized that molecules expressed during active infection and also known to be highly conserved between species, namely the heat-shock proteins (hsp), could mediate the T cell sensitization required for the production of anti-peptide antibodies. In fact, when the PPD protion of the conjugate was replaced by a highly purified recombinant protein corresponding to the 65-kDa (GroEL-type) hsp of M. bovis, this resulted in the production of anti-(NANP) IgG antibodies in BCG-primed mice, irrespective of the major histocompatibility complex-controlled responsiveness to the (NANP) sequence itself. Further, similar induction of anti-peptide antibody response was also obtained with a recombinant 70-kDa (DnaK-type) hsp of M. tuberculosis, but not with a small molecular mass (18 kDa) of M. leprae. Finally, an adjuvant-free carrier effect for anti-peptide IgG antibody production in BCG-primed mice, was also exerted by the GroEL hsp of Escherichia coli. This finding that hsp can act as carrier molecules without requiring conventional adjuvants is of potential importance in the development of vaccine strategies.

Adjuvants, Immunologic↗
PubMed1991

Posttraumatic ulnar neuropathy versus non-traumatic cubital tunnel syndrome: clinical features and response to surgery.

The outcome of 53 patients operated on either for posttraumatic ulnar neuropathy (PUN) or non-traumatic cubital tunnel syndrome (CTS) was reviewed after 3 years follow-up. Results were analyzed and compared considering the surgical technique used (neurolysis versus anterior transposition or combined) and a variety of clinical features that could influence outcome after nerve release. In the whole series, excellent outcome was obtained in 39 patients (73%). No major differences were found with the different surgical procedures. Slightly better results, but no statistically significant, were found in cases with CTS. As to clinical parameters, patients with CTS had a higher mean age, a shorter duration of symptoms and most were men. The presence of symptoms for more than one year before operation significantly diminished the chance of satisfactory recovery in cases with CTS, but not in those with PUN. For both CTS- and PUN-cases with symptoms for more than one year, neurolysis plus anterior transposition was the more useful technique. Our study shows that CTS and PUN differ to a certain extent in their clinical profile, electrophysiological findings and response to different surgical approaches and hence can be considered as two different clinical entities.

Adolescent↗
PubMed1991

Leg lengthening by distraction through the callus of an arthrodesis.

Limb lengthening by means of distraction through the callus of a knee arthrodesis was performed in a 14-year-old boy with congenital hypoplasia of one lower limb. Knee arthrodesis was indicated because of destruction of the distal femoral epiphysis caused by a previous bone lengthening procedure.

Adolescent↗
PubMed1990

Human fibroblasts show expression of the leukotriene-A4-hydrolase gene, which is increased after simian-virus-40 transformation.

Human fibroblasts in cell culture converted the epoxide intermediate leukotriene A4 into the potent chemotaxin leukotriene B4. The identity of leukotriene B4 was ascertained by its mobility in reverse-phase high performance liquid chromatography, ultraviolet spectroscopy and gas chromatography/mass spectrometry. The presence of the enzyme responsible for the conversion (i.e. leukotriene A4 hydrolase), as well as the corresponding mRNA, were demonstrated by Western and Northern blot analyses. Leukotriene-A4-hydrolase enzyme activity, protein and mRNA were all enhanced (approximately threefold) in human fibroblasts that had been transformed by simian virus 40.

Cell Line↗