Experimental peri-implantitis around titanium implants with a chemically modified surface with a monolayer of multi-phosphonate molecules: a preclinical in vivo investigation.

OBJECTIVES: The purpose of this experimental in vivo investigation was to evaluate the influence of modifying the implant surface by adding a monolayer of multi-phosphonate molecules on the development of experimental peri-implantitis. MATERIAL AND METHODS: Eight beagle dogs received 5 tests and 5 control implants each following a split-mouth design 3 months after premolar and molar extraction. On the most mesial implant of each side, a 3-mm buccal dehiscence was artificially created. Experimental peri-implantitis was induced by silk ligatures over a 4-month period; after ligature removal, peri-implantitis was left to progress for another 4 months without plaque control. Clinical, histological, and radiographic outcomes were evaluated. RESULTS: Radiographically, both implant groups showed a similar bone loss (BL) at the end of the induction and progression phases. BL measured on the histological sections of the test and control groups was 3.14 ± 0.42 mm and 3.26 ± 0.28 mm, respectively; the difference was not statistically significant (p > 0.05). The remaining buccal bone to implant contact (bBIC) percentage of the test and control groups was 59.38 ± 18.62 and 47.44 ± 20.46%, respectively; the difference, however, was not statistically significant (p > 0.05). Bone loss observed at dehiscent sites compared to non-dehiscent ones showed no statistically significant difference (p > 0.05). CONCLUSIONS: Addition of a monophosphonate layer to a moderately rough implant surface did not affect development of experimental peri-implantitis. CLINICAL RELEVANCE: Influence of implant surface on peri-implantitis may condition implant selection by the clinician, especially on patients with disease risk factors. In that sense, monophosphate layer implants do not show higher peri-implantitis risk than control implants.

Alveolar crest contour changes after guided bone regeneration using different biomaterials: an experimental in vivo investigation.

OBJECTIVE: To evaluate the changes in alveolar contour after guided bone regeneration (GBR) with two different combinations of biomaterials in dehiscence defects around implants. MATERIAL AND METHODS: Chronic alveolar ridge defects were created bilaterally in the mandible of eight Beagle dogs. Once implants were placed, three treatment groups were randomly allocated to each peri-implant dehiscence defect: (i) test group received a bone substitute composed of hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP) covered by a cross-linked collagen membrane, (ii) positive control group with placement of deproteinized bovine bone mineral (DBBM) plus a porcine natural collagen membrane, and (iii) a negative control with no treatment. Two healing periods (8 and 16 weeks) were evaluated. Dental casts were optically scanned, the obtained files were uploaded into an image analysis software and superimposed to evaluate the linear changes. RESULTS: In both healing periods, the gains in linear contours were higher in the test group and at the intermediate level (3 mm below the gingival margin). While at 8 weeks, no significant differences were found between the groups; at 16 weeks, the test and positive control groups demonstrated significant gains in contour compared with negative control. CONCLUSIONS: GBR using different biomaterials significantly increased the buccal contours of the alveolar crest when used at dehiscence defects around dental implants. CLINICAL RELEVANCE: Particulate highly porous synthetic bone substitute and a cross-linked collagen membrane demonstrated similar outcomes in terms of contour augmentation when compared to bovine xenograft (DBBM) and a collagen membrane.

Actualización en prevención de VRS: Nirsevimab vs vacunación en embarazadas (RSVpreF) / Update on RSV prevention: Nirsevimab vs vaccination in pregnant women (RSVpreF)

El anticuerpo monoclonal Nirsevimab fue el primero que se implantó para la prevención de infección por virus respiratorio sincitial (VRS) de todos los lactantes en sus primeros meses de vida. Recientemente se ha aprobado el uso de una vacuna en la embarazada (RSVpreF) con distinta forma de inmunización pero el mismo objetivo en el lactante. De este modo, surge la necesidad de valorar una nueva estrategia de inmunización. Desarrollo. Nirsevimab demostró en ensayos clínicos buenos datos de eficacia clínica y de seguridad. Tras su inclusión en la temporada epidémica 2023-2024, la cobertura en España ha sido muy alta y los resultados preliminares parecen mantener la tendencia de los ensayos. Queda pendiente una valoración adecuada de su eficiencia. RSVpreF tiene resultados similares pero, de momento, solo en ensayos y, aunque podría tener alguna ventaja inmunológica, se desconoce si se traduciría en eficacia real. Aún así, esta nueva vacuna respaldada por organismos sanitarios y científicos sería una alternativa segura y eficaz. Por otro lado, incluso con la implementación en el calendario vacunal de RSVpreF, Nirsevimab va a continuar siendo clave en la protección de ciertos lactantes. Conclusión. La aprobación de la vacuna en la embarazada RSVpreF añade una segunda herramienta inmunológica frente a la infección por VRS en lactantes. RSVpreF y Nirsevimab pueden desarrollar un papel complementario en la prevención de estas infecciones.(AU)

Introduction: Nirsevimab was the first monoclonal antibody to be implemented in order to prevent respiratory syncytial virus (RSV) infection in all infants in their first months of life. The use of a vaccine in pregnant women (RSVpreF) using a different way of immunization but still sharing the same objective in infants has recently been approved. Thus, there is a necessity to evaluate a new immunization strategy. Development. Nirsevimab showed good clinical efficacy and safety data in medical trials. After its inclusion in the 2023-2024 epidemic season, coverage in Spain has been very high and preliminary results seem to maintain the trend shown in the trials. An adequate assessment of its efficiency is still pending. RSVpreF has similar results but, for now, only in trials and although it could have some immunological advantages, it is unknown if it would result in actual efficacy. Even so, this new vaccine, supported by health and scientific organizations, would provide a safe and effective alternative. Nonetheless, even with the implementation in the RSVpreF vaccine schedule, Nirsevimab will continue to be a key factor in the protection of certain infants. Conclusion. The approval of the RSVpreF vaccine in pregnant women adds a second immunological tool against RSV infections in infants. RSVpreF and Nirsevimab may play a complementary role in the prevention of these infections.(AU)

cis-Diamminedichloroplatinum(II) resistant human tumor cell lines are collaterally sensitive to PtCl4(Rh-123)2: evidence for mitochondrial involvement.

Three human tumor cell lines made resistant to cis-diamminedichloroplatinum(II) (CDDP), SCC-25/CP, MCF-7/CP, and C13, are more sensitive to rhodamine-123 [tetrachloroplatinum(II)] [(PtCl4(Rh-123)2] than are the corresponding parental cell lines. The CDDP-resistant cells have higher intracellular concentrations of PtCl4(Rh-123)2 for the same exposure than do the parent cells. Each of the CDDP-resistant cell lines has an increased level of cytochrome c oxidase activity compared with the parent cell lines, indicating that the resistant cells have greater mitochondrial mass or activity than the parent cells. In fact, there was a linear correlation between the increase in cytochrome c oxidase activity and the increased sensitivity to PtCl4(Rh-123)2 in the CDDP-resistant lines. Exposure of the cells to each of the mitochondrial effectors, chloramphenicol, FCCP, oligomycin, or antimycin prior to and during exposure to CDDP or PtCl4(Rh-123)2 had variable effects on the cytotoxicity of the platinum complexes in the parental lines. However, there was a consistent decrease in the cytotoxicity of PtCl4(Rh-123)2 in the CDDP-resistant cells in the presence of the mitochondrial effectors such that, in some cases, the CDDP-resistant lines were now less responsive to PtCl4(Rh-123)2 than were the parent cell lines. These studies indicate that mitochondrial alterations may be an important component of CDDP resistance in these cell lines and that PtCl4(Rh-123)2 may represent a prototype platinum complex useful in the treatment of CDDP resistant tumors.

Taxonomic implications of the chemical analysis of the D2 group of corynebacteria.

Whole cell acid methanolysates from corynebacteria of the D2 group were found to contain meso-diaminopimelic acid, arabinose and galactose. Among lipids of taxonomic value, saturated and unsaturated straight chain fatty acids (14 to 18 carbon atoms), tuberculostearic acid (10-methyl octadecanoic acid) and mycolic acids were present. The last compounds ranged from 26 to 36 carbon atoms, the predominant types being 28.2, 28.1, 30.3, 30.2, 32.3 and 32.2. By reverse phase thin-layer chromatography the major menaquinone was identified as MK-9(H2)-containing nine isoprene units with two additional hydrogens. Moreover, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides were detected among the phospholipids of these bacteria. Thus, on these bases, the D2 group appears to be closely related to the true corynebacteria.

Comparison of the efficacy of three different treatments with imipenem versus the classical clindamycin plus tobramycin in experimental peritonitis.

This study compares the efficacy of three different treatment modalities of imipenem/cilastatin and the conventional clindamycin plus tobramycin in an experimental model of intra-abdominal sepsis. 145 Wistar rats were used. 40 served as control and 105 as study groups. A capsule with 0.5 ml of inoculum was surgically implanted in the peritoneal cavity. The inoculum was prepared from human feces of healthy volunteers, with a composition of E. coli 10(6), E. faecalis 10(6), B. fragilis, Clostridium sp 10(5) to 10(6) and anaerobic streptococci 10(5) to 10(6). Eighty animals were treated with imipenem/cilastatin and divided in 3 subgroups: "short pretreatment"--29 animals treated 1 hour prior to surgery and 3 days after; "short"--26 animals starting treatment 2 hours post-surgery and continuing it for 3 days; and "long"--25 animals treated for 10 days, starting 2 hours post-surgery. 25 animals received clindamycin plus tobramycin for 10 days. Mortality and the presence of visceral and peritoneal abscesses were the endpoints of the study. The control group had 100% mortality. There were no statistically significant differences among the treated groups although lower mortality was obtained with "short pretreatment" and "long" treatment with imipenem. The presence of abscesses were statistically significant between the imipenem and the combination group. In the imipenem groups, the "short pretreatment" and the long treatment had fewer abscesses than the short one. We conclude that imipenem may be a good alternative monotherapy to conventional therapy with clindamycin plus tobramycin. The "short pretreatment" seemed as good as the long one and better than the short treatment.

In vitro activity of fosfomycin trometamol against pathogens from urinary tract infections: a Spanish multicenter study.

The in-vitro susceptibilities of a total of 1371 urinary tract pathogens to fosfomycin trometamol were determined. According to the NCCLS breakpoints, Enterobacteriaceae and gram-positive microorganisms were, in general, very sensitive to this antimicrobial. More than 90.0% of the Escherichia coli and Citrobacter spp. and more than 70.0% of the Klebsiella pneumoniae, K. oxytoca, Enterobacter spp., Proteus mirabilis, Staphylococcus aureus, coagulase-negative staphylococci and Enterococcus spp. strains tested were susceptible to fosfomycin trometamol. However, Pseudomonas aeruginosa and Acinetobacter spp. strains were more resistant. In general, recent clinical isolates from urinary tract infections (UTIs) in both community and hospital were also very sensitive (> 80.0%) to fosfomycin, its activity being higher than that of the rest of the antimicrobials commonly used for therapy of uncomplicated UTIs. More than 75.0% of the most frequently isolated pathogens from UTIs, except for P. aeruginosa (31.8%) and Acinetobacter spp. (11.1%), were susceptible to fosfomycin trometamol. The results obtained in this study, together with the infrequency of side effects and its pharmacokinetic properties, indicate that fosfomycin trometamol may be a useful alternative for single-dose therapy of uncomplicated UTIs.

Treatment of experimental endocarditis caused by penicillin-resistant Streptococcus sanguis with different doses of teicoplanin.

Streptococcus viridans continues to be the most frequent causal agent of infective endocarditis. Treatment has become more complicated due to the increase in resistance to penicillin and cephalosporins. In order to study the possible efficacy of teicoplanin at low and high doses, this antibiotic was investigated in rabbits as a monotherapy and in association with gentamicin. The effects were compared with a control group and a group given classical penicillin-gentamicin treatment. Infective endocarditis was induced in 120 rabbits with a clinical isolate of Streptococcus sanguis. Treatment was started 48 h after infection, and lasted 5 days. Animals were divided into 6 groups of 20 rabbits each: G1, untreated controls; G2, penicillin+gentamicin; G3 low-dose teicoplanin; G4, low-dose teicoplanin+gentamicin; G5, high-dose teicoplanin; and G6, high-dose teicoplanin+gentamicin. Response to therapy was evaluated with mortality curves, negativization of blood cultures, concentration of S. sanguis in aortic vegetations and rate of sterilization of vegetations. Vegetation weight was significantly lower in treated groups than in controls; lower weights were found in G4, the only treatment that sterilized 65% of vegetations. Death occurred only in the control group (10% mortality). Negativization of blood cultures was greatest and most rapid in G4, followed by G6. Concentrations of S. sanguis in aortic vegetations were significantly lower in all treated groups compared with controls, with the lowest being in groups G4 and G6. Combined treatment with teicoplanin+gentamicin may be highly efficacious in patients with endocarditis caused by penicillin-resistant Streptococcus sanguis. High-dose teicoplanin+gentamicin does not seem to be more efficacious than low-dose teicoplanin+gentamicin.

Prophylaxis in transurethral surgery: oral lomefloxacin versus intravenous cefuroxime.

A randomized study compared the efficacy of a single dose of lomefloxacin given orally vs. cefuroxime given intravenously for prophylaxis against urinary tract infection in patients who were undergoing transurethral surgery. Patient groups were demographically similar; 25 received 400 mg lomefloxacin orally 2-6 h before surgery and 26 received 1.5 g cefuroxime intravenously 30-90 min before surgery. Urine cultures were obtained prior to surgery, 24 h after surgery and 3-5 days after surgery or before hospital discharge. Treatment was considered successful if bacterial culture showed < 10(5) CFU/ml. Clinical results expressed as success/failure rates showed success in 18 patients in the lomefloxacin group (72%) and 15 patients in the cefuroxime group (57.7%). Results demonstrated that lomefloxacin is superior to cefuroxime when used as prophylaxis against urinary tract infection following transurethral surgery. In addition, lomefloxacin may be preferable because of its convenient single-dose oral administration.

[Pulmonary nocardiosis. A case report (author's transl)]. / Nocardiosis pulmonar: descripción de un caso.

Within the genus Nocardia three species are at present considered to have human pathologic interest: N. asteroides, N. brasiliensis, and N. caviae. These species are usually the etiologic agents of at least two clinical pictures: nocardiosis and actinomycetoma. A case of pulmonar nocardiosis in a 62-year-old male is reported. The patient had asthmatic episodes and on several occasions received treatment with corticoids. The clinical picture basically consisted of an impairment of the general condition with respiratory symptomatology and fever of 38 to 39 degrees C. An opaque pleuropulmonary image was observed on the chest X-ray film, and the diagnosis of tuberculosis was initially established. The correct diagnosis was confirmed through the bacteriological examination of the transtracheal aspirate with the isolation of N. asteroides. Treatment with streptomycin, sulfamethoxazole and trimethoprim achieved the clinical and roentgenologic cure of the patient. After 2 months of treatment the clinical manifestations had disappeared and after 5 months the chest X-ray was normal. Some epidemiologic data are reviewed.

[Sensivity of Mycobacterium kansaii and Mycobacterium marinum to different antituberculous drugs (author's transl)]. / Sensibilidad de Mycobacterium kansasii y Mycobacterium marinum a diferentes fármacos antituberculosos.

Mycobacteriosis includes clinical manifestations caused by especies of the genus Mycobacterium other than M. tuberculosis and M. bovis. Therapy for these conditions has not been clearly sistematized as it has for tuberculosis, particularly because of the natural resistance that the etiologic agents present to a large number of antituberculous drugs. The sensitivity of M. kansasii and M. marinum to eleven tuberculostatic agents was studied in order to determine which one were best suited for treatment of cases caused by these species. The drugs showing the strongest action against M. kansasii were rifampin, cycloserine, streptomycin, and prothionamide. M. marinum was even more sensitive except to isoniazid, which is ineffective. As a general rule, especially if the sensitivity of the isolated strain is unknown drugs with little or no action on M. kansasii and M. marinum should not be used. Particularly the use of isoniazid and PAS should be avoided.

[Cerebral abscess in a general hospital. Analysis of 66 consecutive cases]. / Los abscesos cerebrales en un hospital general. Análisis de 66 casos consecutivos.

BACKGROUND: Analysis of the epidemiologic characteristics of cerebral abscesses and comparison with 2 therapeutic schedules. METHODS: The clinical history of 66 patients with cerebral abscesses admitted over 14 years in the Neurosurgical Ward of the Virgen de la Arrixaca Hospital in Murcia were reviewed. Two therapeutic groups were designed of 33 and 31 patients respectively treated with classical or modern schedules and clinical efficacy was evaluated. RESULTS: Infections in the ORL area, craneoencephalic trauma, and brain surgery were the predisposing factors in 63% of the cases. The most frequent symptoms were migraine, fever, and alteration of consciousness in 75, 68 and 68% respectively. The most frequent locations were the temporal (36%), parietal (26%) and frontal lobes (23%). Microbiological studies were positive in 75% of the patients with the most frequent microorganisms being group A Streptococcus, Proteus mirabilis, Staphylococcus aureus and anaerobes. Mortality was 14%. Twenty-two percent of the patients had neurological sequelae. The rate of mortality was significantly associated to age greater than 40 years, fatal underlying disease, coma, initial clinical criteria and inadequate antibiotic treatment. The combination of cephotaxime-metronidazole was significantly associated to greater cure in comparison with the classical antibiotic combination although no significant differences were found in either the rate of mortality or relapse. CONCLUSIONS: The combination of cephotaxime-metronidazole may constitute an interesting advance in the treatment of these processes. The epidemiological data obtained confirm those of larger series.

[Efficacy evaluation of cloxacillin and cloxacillin-gentamicin in an experimental model of methicillin-sensitive Staphylococcus aureus]. / Valoración de la eficacia de la cloxacilina y cloxacilina-gentamicina en un modelo experimental de Staphylococcus aureus meticilín-sensible.

23 rabbits with Staphylococcus aureus methicillin-sensitive, SAMS, experimentally induced endocarditis (EIE) were studied to compare the efficacy of cloxacillin vs the association cloxacillin-gentamicin. Twelve animals made the control group and 11 the treated ones, 5 with cloxacillin-gentamicin and 6 with cloxacillin. The animals were treated 3 days, then, mortality, blood cultures at 48 and 72 hours and the title of the unit-forming colonies per gram of vegetation (UFC/g) were evaluated. The control group had a mortality of 100% in the first 72 hours, its blood cultures were positive at 48 and 72 hours and the UFC/g was 10,48 o 0.20. There was statistical significance between the control group and both treatment, in mortality, blood culture's positivity and the UFC/g of vegetation. This results confirm the similar efficacy of cloxacillin either alone or in combination in the treatment of SAMSIE and the effectiveness of the experimental model to evaluate antimicrobial treatments.

[Bacteriologic findings in ear exudates from ambulatory care patients]. / Hallazgos bacteriológicos en exudados óticos de pacientes ambulatorios.

The results obtained in a microbiological survey carried out with 102 samples of otic effusions taken from 95 outdoor patients in a ORL surgery are shown. Sixty-eight of these patients had supurative otitis media symptoms and 25 had diffuse otitis externa. Results of microbiological cultures are commented according to different statistics variables (age, sex, supuration time and type of tympanic perforation) and compared with the results obtained by other authors.

[Serodiagnosis in pulmonary tuberculosis. Clinical evaluation]. / Serodiagnóstico en la tuberculosis pulmonar. Valoración clínica.

The IgA, IgG, IgM and IgG subsets antibodies levels were determined in 200 patients with pulmonary tuberculosis and compared to three control groups: 80 healthy individuals (50 with negative PPD skin test, 30 with positive PPD skin test), 30 leprosy patients and 20 patients with different pulmonary diseases. The technique used was an enzyme linked assay. As antigens, purified tuberculin and Ag60 from M. bovis were used. There were not statistically significant differences between antibody levels among all control groups studied, but when we compare the level in control groups with that observed in tuberculous patients, they showed higher levels of IgA, IgG, IgM, IgG2 (p less than 0.01) and IgG4 (p less than 0.05). A definite diagnosis of tuberculosis of the lung should only be established if the patient showed to be positive to IgG plus IgA or IgM and in special cases to IgG1, reaching then a diagnostic efficacy of 90% in a patient population with a 68% of positive smears for acid-fast bacilli.

A rational proposal for plasmid nomenclature.

We propose a more rational system for nomenclature of wild plasmids of bacteria. With this proposal for nomenclature of bacterial plasmids, it is established in an unambiguous way: 1) if a plasmid is wild or derivative, and 2) in which species and bacterial strain it was found (in the case of wild plasmids).

[Relation between isolation of bacteriophages from Clostridium difficile and cytotoxicity of the strains]. / Relación entre el aislamiento de bacteriófagos en Clostridium difficile y citotoxicidad de las cepas.

We studied the possible relationship between the presence of bacteriophages and cytotoxicity of Clostridium difficile strains from multiple origin. A total of 143 strains were studied, 38.46% showed lysogenic activity to at least one of control strains and 85.3% produces cytopathic effects on McCoy cells, that were neutralized by C. sordellii antitoxin. All bacteriophages seen on electron microscopy showed similar shape and size (hexagonal head shape and flexible tail ended in a basal plate). According to our results, a significant relationship between those two factors seems not to exist.

[Treatment with vancomycin of experimental endocarditis caused by Streptococcus sanguis II resistant to penicillin]. / Tratamiento de endocarditis experimental por Streptococcus sanguis II resistente a penicilina con vancomicina.

BACKGROUND: Streptococcus viridans continues to be the most frequent causal agent of infective endocarditis. Treatment has become more complicated due to the increase in resistance to penicillin and cephalosporins. In order to study the possible efficacy of vancomycin, this antibiotic was investigated in rabbits as a monotherapy and in association with gentamicin. The effects were compared with a control group and a group given classical penicillin-gentamicin treatment. MATERIAL AND METHODS: Minimum inhibitory concentration, minimum bactericidal concentration, lethality curves and synergism were determined against Streptococcus sanguis II. Infective endocarditis was induced in 80 rabbits, which were infected via catheter. Treatment was started 48 hours after infection, and lasted 5 days. The animals were divided into 4 groups of 20 rabbits each: 1, untreated controls; 2, penicillin-gentamicin; 3, vancomycin; 4, vancomycin-gentamicin. Response to therapy was evaluated with mortality curves, negativization of blood cultures, concentration of Streptococcus sanguis II in aortic vegetations, rate of sterilization of vegetations, body weight and serum bactericidal capacity. RESULTS: Vegetations weight was significantly lower in treated groups than in controls; lower weights were found in groups 2 and 4. The lowest vegetation weight was recorded in group 4, the only treatment that sterilized 75% of vegetations. Death occurred only in the control group (10%). Negativization of blood cultures was greatest and most rapid in group 4. Serum bactericidal capacity was greater after the two combined treatments, and highest in group 4. CONCLUSIONS: Combined treatment with vancomycin-gentamicin may be highly efficacious in patients with endocarditis caused by penicillin-resistant Streptococcus viridans.

Comparative study of the virulence of two Leishmania donovani isolates of different origin.

The virulence of two isolates of Leishmania donovani (LMU-6 isolated from a human case in Ethiopia and LMU-16 isolated from an asymptomatic dog in the south-east of Spain) in BALB/c and C57Bl/6 mice and in hamsters was observed over a period of 14 weeks. Regular measurements of the liver parasite burdens and observations of external signs of infection were made, and the humoral and delayed type hypersensitivity responses were tested. No major differences were observed in the infection patterns produced by the two isolates in mice, except for a slightly stronger humoral and lower delayed type hypersensitivity response detected in C57Bl/6 mice infected with LMU-16. However, LMU-16 showed a higher virulence in hamsters than did LMU-6.

[Comparative study of 2 rapid techniques (DNA hybridization and chromatography) for the identification of Mycobacterium tuberculosis complex isolated from clinical specimens]. / Estudio comparativo de dos técnicas rápidas (hibridación de ADN y cromatografía) para la identificación de Mycobacterium tuberculosis complex aislados de muestras clínicas.

We have compared the capacity of two combined chromatographic methods (gas chromatography and thin-layer chromatography) and a nucleic acid hybridization probe (Gen-Probe) to identify members of the Mycobacterium tuberculosis complex. The results of a single test show 6% of false-negatives with Gen-Probe and 8.5% doubtfuls with chromatography. After repeated, the specificity of both methods was improved to 100%. The advantages and disadvantages of the two methods in relation to its capacity to provide a rapid identification of Mycobacterium tuberculosis are discussed.