Human papillomavirus type 16 and 18 L1 protein peptide binding to VERO and HeLa cells inhibits their VLPs binding

Human papillomaviruses (HPVs) are the cause of epithelial lesions, HPV type 16 and type 18 being associated with the development of anogenital cancer. The L1 Major Capsid Protein (L1) represents about 90% of total HPV protein and is involved in virus-host cell interaction, but little is known about this binding process. L1 sequences from HPV types 16 and 18 were synthesized in 56 20-mer peptides, covering the entire protein, HPLC-purified, (125)I-radiolabeled and tested in VERO and HeLa cell-binding assays to identify those peptides with high specific binding activity. Peptides 18283 (residues 54-77) and 18294 (274-308) from HPV16 L1, as well as 18312 (59-78) and 18322 (259-278) from HPV18 L1, presented high specific target cell binding activity. Peptide 18283 and 18294 affinity constants were 300 and 600 nM, respectively. Enzyme cell treatment before binding assay indicated that VERO and HeLa cell peptide receptor is a surface-exposed protein. There was a 60% reduction in peptide 18283 binding to heparin lyase-treated cells. Cross-linking assays showed that these proteins molecular weights were around 69 and 54 kDa. Peptides 18283 and 18294 specifically inhibited HPV-16 VLP binding to HeLa cells. According to the L1- and VLP-reported structure, both peptides are close on the VLP-surface, belonging to the outer surface broad pockets suggested as being potential receptor sites. Furthermore, it has been reported that a conserved motif from peptide 18294 is the target for neutralizing antibodies. These results suggest that such binding sequences are used by the virus as cell-binding regions.     

Cannabinoids: potential anticancer agents

Cannabinoids - the active components of Cannabis sativa and their derivatives - exert palliative effects in cancer patients by preventing nausea, vomiting and pain and by stimulating appetite. In addition, these compounds have been shown to inhibit the growth of tumour cells in culture and animal models by modulating key cell-signalling pathways. Cannabinoids are usually well tolerated, and do not produce the generalized toxic effects of conventional chemotherapies. So, could cannabinoids be used to develop new anticancer therapies?     

Abdomen release in prone position does not improve oxygenation in an experimental model of acute lung injury

OBJECTIVE: To analyze the effect of abdomen release in the prone position on oxygenation in an experimental model of acute lung injury. DESIGN: Experimental randomized controlled study. SETTING: Experimental laboratory of a tertiary university hospital. PARTICIPANTS: Mixed-breed adolescent pigs weighing between 25-31 kg. INTERVENTIONS: Thirty minutes after pulmonary edema was produced with oleic acid, the animals were turned prone and randomized into two groups: group I or control (n = 9), lying directly on the operating table; and group II (n = 11) with abdomen release, with positioning rolls under the upper part of the chest wall and the pelvis to allow free movement of the abdomen. MEASUREMENTS AND RESULTS: The gas exchange, respiratory mechanics, hemodynamics, intra-abdominal pressure (IAP) and the extravascular lung water (EVLW), determined by double indicator dilution method (DI), were recorded at baseline (time 0) and at 30, 60, 90, 120 and 150 min. The PaO2/FIO2 increased in both groups at 30 min after the pigs were placed in the prone position (time 60) and then decreased progressively until the end of the experimental period, with no statistical differences between the groups at any time (73.1 +/- 14.5 vs 79.5 +/- 14.9 at 150 min). Abdomen release was not associated with changes in the respiratory mechanics, EVLW or intra-abdominal pressure. CONCLUSIONS: Abdomen release in prone position does not improve oxygenation in an experimental model of acute lung injury.     

Simplified technique for incisional hernia repair with mesh prosthesis

This paper describes a simplified technique for the repair of incisional hernias. The previous scar is resected, and the peritoneal sac is carefully dissected until it is completely exposed. The sac is opened to liberate structures adherent to the sac or to the area immediately surrounding the defect. The peritoneum is closed and invaginated to form a sac bed underlying the entire extent of the defect, and the mesh is laid on this sac bed. The mesh is then fixed with "U" stitches, reinforcing these by inserting a second line from the edge of the defect to the mesh. Suture material used is polypropylene 1/0 or 2/0. This procedure has been carried out on 15 patients, and after 1 year of follow-up, there has been no recurrence of the hernia. Operating time was reduced, and the surgical technique was found to be easier. Placing a mesh prosthesis inside the hernia sac and fixing it to the abdominal wall with two lines of suturing simplifies the repair procedure, reduces operating time, and is effective in the repair of all incisional hernias. A study is required to compare this outcome with the different mesh repair techniques.     

Diagnostic reasoning in neurology. An analysis of the more frequent errors

Diagnostic reasoning is a cognitive proccess that has various performance and results. There are several kinds of clinical reasoning, such as model or pattern recognizing, causal or physiopathologic reasoning, deterministic, exhaustive, and hypotetic-deductive ones. Each form of reasoning may be relevant in certain clinical context, and all of the forms are also complementary. The logical consequence of diagnostic reasoning, like every cognitive proccess, is a clinical error. It is necessary that the neurologist knows the principles of diagnostic reasoning and the more frequent errors and biases. These can be summarized as: errors associated with the proccess of taking history and clinical examination, mnesic and semantic components of clinical reasoning, failure of hipotetic- deductive reasoning, and inadequate use of probability theory in Medicine.     

Prevalence of headache in Puerto Rico

BACKGROUND: Headache is one of the most frequently reported disorders in the general adult population. Despite the fact that this disorder is common, no official estimate of the prevalence of headache exists in Puerto Rico. PURPOSE: To examine the prevalence of headache and migraine, specifically, in Puerto Rico. METHODS: A telephone survey of 1610 individuals was conducted. The telephone calls were distributed using the 1990 census adjusted to the population of Puerto Rico in 1998, and according to gender, geographical area, and age. RESULTS: The prevalence of headache in Puerto Rico was 35.9% and migraine, in particular, 13.0%. When prevalence was fractionated by age, gender, and geographical areas, the prevalence of headache was similar for all ages, with females exhibiting a 2:1 preponderance over males. In the younger population (between 20 and 50 years of age), the female-male ratio for migraine was 3:1, and the prevalence for migraine was lower in the Metropolitan area. CONCLUSION: This study, the first of its type in Puerto Rico, demonstrates that headache (and migraine specifically) is a common disorder in this country.     

Study of 1,000 patients with disequilibrium

We present a series of one thousand patients tested with electronystagmography (ENG) for evaluation of complaints of unstability. Personal data and electronystagmographic results are analysed.