Femoracetabular impingement treated with surgical hip dislocation: Short-term results

BACKGROUND AND OBJECTIVE

Most of the studies available in the literature related to the treatment of femoroacetabular impingement (FAA) with surgical hip dislocation (CLD) come from Europe and North America. This study describes the short-term results of the LQC technique for treating PFA in a cohort of Colombian patients.

PATIENTS AND METHODS

We retrospectively analysed 42 cases of PFA treated with LQC from 2006 to 2018. The same orthopaedic surgeon performed all surgeries. Clinical outcome was assessed using the Merle d'Aubigné scores, while radiological assessment was performed using the Tönnis score.

RESULTS

Fifteen women and 25 men were included in the study, with a mean age of 36.3 years. Two patients had bilateral symptomatic involvement. Of the 42 cases, there were 13 cam type, 11 pincer type and 18 mixed. Preoperatively, 31 hips were classified as poor and moderate, and 11 as good according to the Merle d'Aubigné scale. The preoperative Tönnis radiological classification showed grade 0 in half of the cases. The mean duration of follow-up was 24 months (12 to 37). The final postoperative Merle d'Aubigné scores classified 7 cases as poor or moderate, and 35 as good to excellent (p<0.05). The postoperative Tönnis score showed no significant variation. As complications, one patient had heterotopic ossification, and three had trochanteric nonunion requiring refixation.

CONCLUSION

Our results suggest that the LQC technique for the treatment of patients with PFA shows satisfactory short-term results with a low complication rate. To our knowledge, this is the first report of results of the surgical procedure for hip dislocation in our region.

Treatment, outcomes and costs of asthma exacerbations in Chilean children: a prospective multicenter observational study

OBJECTIVE

To describe potential regional variations in therapies for severe asthma exacerbations in Chilean children and estimate the associated health expenditures.

METHODS

Observational prospective cohort study in 14 hospitals over a one-year period. Children five years of age or older were eligible for inclusion. Days with oxygen supply and pharmacological treatments received were recorded from the clinical chart. A basic asthma hospitalization basket was defined in order to estimate the average hospitalization cost for a single patient. Six months after discharge, new visits to the Emergency Room (ER), use of systemic corticosteroids and adherence to the controller treatment were evaluated.

RESULTS

396 patients were enrolled. Patients from the public health system and from the north zone received significantly more days of oxygen, systemic corticosteroids and antibiotics. Great heterogeneity in antibiotic use among the participating hospitals was found, from 0 to 92.3% (ICC 0.34, 95% CI 0.16-0.52). The use of aminophylline, magnesium sulfate and ketamine varied from 0 to 36.4% between the different Pediatric Intensive Care Units (ICC 0.353, 95% CI 0.010-0.608). The average cost per inpatient was of $1910 USD. 290 patients (73.2%) completed the follow-up six months after discharge. 76 patients (26.2%) were not receiving any controller treatment and nearly a fourth had new ER visits and use of systemic corticosteroids due to new asthma exacerbations.

CONCLUSIONS

Considerable practice variation in asthma exacerbations treatment was found among the participating hospitals, highlighting the poor outcome of many patients after hospital discharge, with an important health cost.

[Treatment of severe to profound mixed hearing loss with the BAHA Cordelle II]

GOALS

Evaluation of the audiological outcome and subjective satisfaction of BAHA Cordelle II in the treatment of patients with severe to profound bilateral mixed hearing loss.

MATERIAL AND METHOD

Retrospective study of 12 patients suffering a severe to profound bilateral sensorineural hearing loss, using pure tone audiometry (PTA), speech audiometry and subjective evaluation before and after the implantation of a BAHA Cordelle II (Cochlear(®)).

RESULTS

The average gain in conversational frequencies (0.5 to 4kHz) with BAHA in free field was 43, 51, 47 and 44dB, respectively. We observed a GAP over closure in 10 of the 12 patients. Speech audiometry improved from 85% at 83dB of maximum discrimination to 96% at 62dB. The subjective evaluation questionnaires showed great satisfaction with a slight decrease in noisy or windy environments. The great majority of our patients used the BAHA device throughout the entire day.

CONCLUSIONS

The BAHA Cordelle II (Cochlear(®)) is a good option in the treatment of severe to profound bilateral mixed hearing loss. Its best advantages are a low risk of labyrinthization, high result predictability, easy and step-by-step surgery, no need for general anaesthesia, and the GAP over closure in all frequencies. Active middle ear devices represent another alternative, but specific indications have not been defined yet because of low universal experience. When the intelligibility of the patient is poor, cochlear implantation should be considered.

[Surgical treatment of carotid paragangliomas]

The present article reviews the current panorama of the surgical treatment of carotid paragangliomas. The article begins by discussing surgical indications and preoperative aspects (Shamblins classification, the value of genetic study, informed consent, the utility of embolization, etc). Intraoperative aspects (surgical team) and features of the surgical technique (the patients position, incision and exposition, vessel control and identification of nerves, subadventitial or periadventitial tumoral excision, the need for arterial resection and reconstruction, etc.) are discussed in depth. Postoperative aspects, morbidity (neurological and vascular) and mortality, as well as how to follow-up these patients, are discussed at the end of the first part of the article. The second part analyzes special situations concerning carotid paraganglioma (unresectable, malignant, residual [persistent] or recurrent, bilateral and multiple tumors, associated diseases, tumors in children, etc.). The final part of the article, in the form of an appendix, shows the characteristics and results of our series (30 carotid paragangliomas in 26 patients between 1994 and 2008).

[Diagnosis and follow-up of head and neck paragangliomas. Contributions of nuclear medicine]

Head and neck paragangliomas are neuroendocrine tumors that express somatostatin type 2 receptors and can consequently be visualized through nuclear imaging techniques, using radionuclide-labelled somatostatin analogs, specifically 111In-pentetreotide. 111In-pentetreotide scintigraphy is a safe and non-invasive technique that can be used to explore the entire body; thus, multifocal paragangliomas as well as malignant paragangliomas with local and distant metastasis can be detected. Because this technique is functional, it is highly useful to confirm recurrence or residual tumors, as well as to follow-up patients undergoing surgery. Paragangliomas can be familial and consequently this technique can be used for screening of familial cases. Recently, other nuclear imaging techniques, based on positron emission tomography (PET) technology, have been developed for the diagnosis of these tumors. Appropriately radiolabeled somatostatin analogs could potentially be used for the treatment of paragangliomas.

[Diagnosis and evaluation of head and neck paragangliomas. Clinical and biological manifestations]

Head and neck paragangliomas are slow-growing tumors and the initial symptoms are sometimes non-specific, often hampering and delaying diagnosis. These tumors may be asymptomatic, even when they have reached a considerable size. Symptomatology is highly varied in terms of anatomical location, stage (degree of invasion, local involvement and the presence of metastasis) and catecholamine secretion (pheochromocytoma), which not only produces a series of systemic manifestations but also serves as a guide to the search for specific genetic diseases, of which these tumors may be a component. Thus, in addition to identifying their anatomical location, excess catecholamine production must be assessed and genetic diagnosis must be completed before surgery is performed.

[Aorto-oesophageal fistula in patient with Montgomery salivary bypass tube]

Aorto-oesophageal fistula is a well-reported pathology with several known causes. The co-existence of this pathology associated with the use of a Montgomery salivary bypass tube (MSBT) is exceptional and only one case is described in the literature. We present here a case report about an 81-year-old patient with an MSBT who died because of a massive upper gastrointestinal bleeding caused by an aorto-oesophageal fistula at the site of the MSBT. The literature on this pathology will also be reviewed.

[Clinical picture of 8th pair schwannoma. Is it expressive enough?]

OBJECTIVE

To describe the stage-related clinical features of 8th cranial nerve schwannoma.

MATERIAL AND METHOD

Descriptive study of 71 patients whose diagnosis and/or treatment have been carried out at our centre between 1997-2003. Gender, age, and symptoms were considered, with special attention to gender. Determination of tumoral stage following Tos and Thomsen image criteria.

RESULTS

The mean age was 64.6 (range, 20-87) with a marked incidence between 52 and 70 years (62 % of the whole), slightly higher in females and in the left ear. The main symptoms were those derived from involvement of the 7th and 8th cranial nerves, with other cranial nerves and cerebello-pontine structures being involved in larger tumours, although a high variability was noted in clinical patterns of same-stage cases and in the first symptom. Our study also found a high variability in hearing conservation and a marked frequency of vestibular or facial (motor and sensory) symptoms. There were also very infrequent forms of presentation that are highlighted.

CONCLUSIONS

There is no typical clinical pattern and no typical first symptom in 8th cranial nerve schwannomas. Any audiovestibular or facial symptom, even the slightest, may be the first expression of 8th cranial nerve schwannoma. There is no stage-specific symptom except for those with involvement of the cerebello-pontine or cerebral structures.

Ultrastructure of airway smooth muscle

There is an abundance of ultrastructural data in the literature on vascular, visceral, and other smooth muscles; such data on airway smooth muscle, however, are conspicuously missing. Here we present a series of electron micrographs depicting contractile and cytoskeletal elements as well as organelles in porcine trachealis. Myosin thick filaments are present in the relaxed muscle; thick filament density increases substantially when the muscle is activated. Actin thin filaments are present in large excess over the thick filaments; the thin/thick filament ratio is about 31/1 in the relaxed state; this ratio is reduced to about 22/1 when the muscle is activated. The sarcoplasmic reticulum is often found associated with caveolae and mitochondria. Cells within a bundle are well connected by intermediate and gap junctions. The results demonstrate that quantitative morphological analysis of ultrastructure of airway smooth muscle fixed under different functional states is possible and will be essential in elucidating the structural basis of adaptation and contraction of the muscle.

Plasmid DNA-recombinant Opc protein complexes for nasal DNA immunization

The nasal mucosa may provide a simple, non-invasive route to deliver DNA encoding genes that stimulate a specific immune response. Based on this, a new approach using pCMVbeta-gal plasmid DNA complexed to the Opc meningococcal outer membrane protein was assayed for. Optimal conditions of interaction were established between recombinant Opc protein and pCMVbeta-gal plasmid DNA. Complexes were fully characterized by electrophoresis analysis, DNAse resistance assay and transmission electron microscopy. DNA-protein complexes were also evaluated in in vitro transfection experiments. After the characterisation of complexes, Balb/c mice were intranasal (i.n.) and intramuscularly (i.m.) immunized. The humoral immune response against beta-galactosidase was measured by ELISA. The proliferative response in the spleen lymph nodes was also measured. Complexes administered by i.n. route induced both systemic and mucosal antibody responses. This behavior was not observed with the naked DNA. Finally, a lymphoproliferative response specific to beta-galactosidase induced by DNA-protein complexes was also detected.

Multivalent DNA-based immunization against hepatitis B virus with plasmids encoding surface and core antigens

The immune response against hepatitis B surface and core antigens was evaluated by either coinoculation or independent intramuscular administration of pAEC compact DNA immunization vectors carrying their genes. The pAEC vectors bear just the essential elements for mammalian expression and bacterial amplification. Balb/c mice were immunized with 100 microg of each construct, either alone or in combination. In spite of lacking known immunostimulatory sequences (e.g., AACGTT), significant cellular (proliferative) and humoral immune responses were raised against both antigens. Coadministration of both plasmids maintained the immune response against the two antigens, without interference between them. Modulation of the antigen expression and further immune response, by using the Kozak's translation initiation sequence, was also analyzed. No differences due to its presence or absence were observed.

A family of compact plasmid vectors for DNA immunization in humans

DNA immunization technology is based on the availability of adequate vectors for cloning and expression of heterologous immunoactive proteins in mammalian cells. We have developed a family of DNA plasmid vectors suitable to manipulate antigen expression and location. Their in vitro and in vivo functionality and application are also reported. The developed immune response, the aspects considered for vector design, and the possible independent manipulation of both blocks for the generation of bicistronic constructs, make of the pAEC family of plasmid vectors a source for DNA vaccine candidate's development for further evaluation in human clinical trials, and for potential use in the gene therapy approach.

Efficiency of erythropoietin's signal peptide for HIV(MN)-1 gp 120 expression

The HIV-1 gp120 gene with natural signal sequence expressed in eukaryotic expression systems showed extremely low levels of synthesis and secretion. Several expression systems have been used to improve the secretion levels of gp 120. In mammalian cells, the efficient expression of gp120 fused to t-PA signal peptide has been previously reported. Here, the effects of t-PA and EPO signal peptides were compared as secretion sequences for expression of gp120 in COS-7 cells. The EPO's signal peptide is used for the first time as leader sequence for secretion of foreign proteins. Our results indicated that higher amounts of secreted gp 120 were obtained when vectors containing EPO signal peptide were used.

Misrepresentation of research citations among medical school faculty applicants

PURPOSE

A descriptive study of bibliographic misrepresentations by applicants to medical school faculty positions.

METHOD

The authors reviewed 250 1995 faculty applicant bibliographies from eight medical institutions, representing six medical specialities. Using computerized library database searches or direct retrieval, they evaluated the legitimacy of each journal, abstract, and book citation. The authors classified and tabulated the following discrepancies as misrepresentations: (1) citing a nonexistent article in an existent source, (2) claiming authorship on an article that did not list the applicant as an author, and (3) altering authorship order to enhance the applicant's position.

RESULTS

The authors found 56 misrepresented citations among 2,149 verified articles (2.6%). These misrepresentations were distributed among 39 applicants (15.6%; 95% CI, 11.5% to 20.9%); 11 of whom (4.4%) had multiple discrepancies. Sixty-eight percent of all misrepresentations were due to discrepancies in authorship order, while journal citations constituted the most frequent source of misrepresentation (77%).

CONCLUSIONS

Misrepresentation of bibliographic citations does exist among medical school faculty applicants. One possible solution to this problem would be to require applicants to document their bibliographic citations.

Microdialysis sampling for determination of plasma protein binding of drugs

The use of microdialysis sampling to study the binding of drugs to plasma proteins was evaluated. Microdialysis sampling is accomplished by placing a short length of dialysis fiber in the sample and perfusing the fiber with a vehicle. Small molecules in the sample, such as drugs, diffuse into the fiber and are transported to collection vials for analysis. Larger molecules, such as proteins and protein-bound drugs are excluded by the dialysis membrane. Microdialysis was found to give values for in vitro protein binding in plasma equivalent to those determined by ultrafiltration. Microdialysis offers advantages in terms of maintaining equilibria and experimental versatility. Microdialysis sampling also provides potential use for in vivo determinations of protein binding.

Sinusitis. Its association with asthma

Sinusitis may present as an indolent infection, without the classic symptoms and signs commonly expected, and will probably be missed in children who have only cough and persistent rhinorrhea unless this diagnosis is kept in mind. Plain radiography is the most commonly used diagnostic procedure for sinusitis, but computed tomography may be more sensitive. The contribution of sinusitis to the induction and exacerbation of asthma is still unresolved. The existence of a nasobronchial reflex is not clearly supported by available data, although it is a likely explanation for the observed relationship between the two processes. However, sinusitis appears to be an important underlying trigger for some cases of asthma and, therefore, should be suspected any time that acute or chronic asthma is difficult to control.

Immunoglobulin composition of three commercially available intravenous immunoglobulin preparations

To evaluate whether significant differences in immunoglobulin composition exist among the three commercially available intravenous immunoglobulin (IVIG) preparations, we compared three of these products in terms of their quantitative immunoglobulin concentration, IgG subclass concentration, and the presence of IgG aggregates. Three different lots were tested for each of the IVIG formulations, and the IgG subclass assays were performed by three different laboratories. Differences were found among the three formulations in subclass concentration and aggregate content. Sandoglobulin (Sandoz Pharmaceuticals, East Hanover, N.J.) contained a significantly higher amount of IgG2 (p less than 0.002) compared to the other formulations. All the formulations tested were found to be deficient in IgG4 relative to the World Health Organization standards, with Gammagard (Hyland Therapeutics, Glendale, Calif.) demonstrating only negligible amounts. Immunoglobulin aggregate content was different among manufacturers with Gamimmune N (Cutter Biological, Berkeley, Calif.) containing the highest amount of monomer IgG (99.8%). Significant differences were found in the subclass results obtained by the ICN ImmunoBiologicals assay (Lisle, Ill.), compared to the two reference laboratories. This difference among the subclass assays raises the question as to the use of these assays in the evaluation of patients with suspected subclass deficiencies. The differences in subclass concentration and aggregate content in IVIG preparations were great, and future clinical trials with these formulations would be indicated to determine the clinical significance of these findings.