A novel simulation module for segmental mandibulectomy and mandible reconstruction using 3D models

INTRODUCTION

Mandibular resection and reconstruction are common but complex procedures in head and neck surgery. Resection with adequate margins is critical to the success of the procedure but technical training is restricted to real case experience. Here we describe our experience in the development and evaluation of a mandibular resection and reconstruction simulation module.

METHODS

3D printed (3DP) models of a mandible with a pathologic lesion were developed from imaging data from a patient with an ameloblastoma. During an educational conference, otolaryngology trainees participated in a simulation in which they reviewed a CT scan of the pathologic mandible and then planned their osteotomies before and after handling a 3DP model demonstrating the lesion. The adequacy of the osteotomy margins was assessed and components of the simulation were rated by participants with pre- and post-training surveys.

RESULTS

52 participants met criteria. After reviewing the CT scan, 34 participants (65.3 %) proposed osteotomies clear of the lesion. This proportion improved to 48 (92.3 %, p = 0.001) after handling the 3D model. Among those with initially adequate margins (n = 33), 45.5 % decreased their margins closer to the ideal, 27.2 % made no revision, 21.2 % widened their margins. 92 % of participants found the simulation beneficial for surgical planning and technical training. After the exercise, the majority of participants had increased confidence in conceptualizing the boundaries of the lesion (69.2 %) and their abilities to ablate (76.5 %).

CONCLUSIONS

The structured mandibulectomy simulation using 3DP models was useful in the development of trainee experience in segmental mandible resection.

LAY SUMMARY

This study presents the first mandibulectomy simulation module for trainees with the use of 3DP models. The use of a 3DP model was also shown to improve the quality of surgical training.

Design, printing optimization, and material testing of a 3D-printed nasal osteotomy task trainer

BACKGROUND

For difficult or rare procedures, simulation offers an opportunity to provide education and training. In developing an adequate model to utilize in simulation, 3D printing has emerged as a useful technology to provide detailed, accessible, and high-fidelity models. Nasal osteotomy is an essential step in many rhinoplasty surgeries, yet it can be challenging to perform and difficult to receive adequate exposure to this nuanced portion of the procedure. As it currently stands, there are limited opportunities to practice nasal osteotomy due to the reliance on cadaveric bones, which are expensive, difficult to obtain, and require appropriate facilities and personnel. While previous designs have been developed, these models leave room for improvement in printing efficiency, cost, and material performance. This manuscript aims to describe the methodology for the design of an updated nasal osteotomy training model derived from anatomic data and optimized for printability, usability, and fidelity. Additionally, an analysis of multiple commercially available 3D printing materials and technologies was conducted to determine which offered superior equivalency to bone.

METHODS

This model was updated from a first-generation model previously described to include a more usable base and form, reduce irrelevant structures, and optimize geometry for 3D printing, while maintaining the nasal bones with added stabilizers essential for function and fidelity. For the material comparison, this updated model was printed in five materials: Ultimaker Polylactic Acid, 3D Printlife ALGA, 3DXTECH SimuBone, FibreTuff, and FormLabs Durable V2. Facial plastic surgeons tested the models in a blinded, randomized fashion and completed surveys assessing tactile feedback, audio feedback, material limitation, and overall value.

RESULTS

A model optimizing printability while maintaining quality in the area of interest was developed. In the material comparison, SimuBone emerged as the top choice amongst the evaluating physicians in an experience-based subjective comparison to human bone during a simulated osteotomy procedure using the updated model.

CONCLUSION

The updated midface model that was user-centered, low-cost, and printable was designed. In material testing, Simubone was rated above other materials to have a more realistic feel.

Using three-dimensional printed models for trainee orbital fracture education

BACKGROUND

Three-dimensional printing is an underutilized technology in ophthalmology training; its use must be explored in complex educational scenarios. This study described a novel approach to trainee education of orbital fracture repair utilizing three-dimensional (3D) printed models as a teaching tool.

METHODS

Ophthalmology residents and oculoplastic fellows from multiple training institutions underwent an educational session on orbital fractures, learning through four different models. Participants analyzed orbital fractures through computerized tomography (CT) imaging alone and then utilizing CT imaging with the aid of a 3D printed model. Participants completed a questionnaire assessing their understanding of the fracture pattern and surgical approach. After the training, participants were surveyed on the impact of the educational session. Components of the training were rated by participants on a 5-point Likert scale.

RESULTS

A statistically significant difference (p < .05) was found in participant confidence conceptualizing the anatomic boundaries of the fracture and planning the orbital fracture approach for repair of three out of four models on pre-test post-test analysis. On exit questionnaire, 84.3% of participants thought the models were a useful tool for surgical planning, 94.8% of participants thought the models were a useful tool for conceptualizing the anatomic boundaries of the fracture, 94.8% of participants thought the models were a useful tool for orbital fracture training, and 89.5% of participants thought the exercise was helpful.

CONCLUSION

This study supports the value of 3D printed models of orbital fractures as an effective tool for ophthalmology trainee education to improve understanding and visualization of complex anatomical space and pathology. Given the limited opportunities trainees may have for hands-on orbital fracture practice, 3D printed models provide an accessible way to enhance training.

Tap-Tap: Learning Endonasal and Percutaneous Nasal Osteotomy Techniques on 3D-Printed Midface Models

Nasal osteotomy is one of the most challenging steps of rhinoplasty. Lack of hands-on training and confidence with this procedure adds to the complexity for learners and trainees. As three-dimensional (3D) printing becomes increasingly accessible, simulation on 3D printed models has the potential to address this educational need in a safe, reproducible, and clinically realistic manner. The simulation session described in this communication, which utilized our low-cost, 3D-printed nasal osteotomy ($12.37) task trainer, produced both educational and confidence benefits for trainees. Here we describe the design, organization, curriculum, and pilot data for a 3D-printed nasal osteotomy task trainer for the simulation of endonasal and percutaneous nasal osteotomy.

Standardizing evaluation of patient-specific 3D printed models in surgical planning: development of a cross-disciplinary survey tool for physician and trainee feedback

BACKGROUND

3D printed models are becoming increasingly popular in healthcare as visual and tactile tools to enhance understanding of anatomy and pathology in medical trainee education, provide procedural simulation training, and guide surgical procedures. Patient-specific 3D models are currently being used preoperatively for trainee medical education in planning surgical approaches and intraoperatively to guide decision-making in several specialties. Our study group utilized a modified Delphi process to create a standardized assessment for trainees using patient-specific 3D models as a tool in medical education during pre-surgical planning.

METHODS

A literature review was conducted to identify survey questions administered to clinicians in published surgical planning studies regarding the use of patient-specific 3D models. A core study team reviewed these questions, removed duplicates, categorized them, mapped them to overarching themes, and, where applicable, modified individual questions into a form generalizable across surgical specialties. The core study panel included a physician, physician-scientist, social scientist, engineer/medical student, and 3D printing lab manager. A modified Delphi process was then used to solicit feedback on the clarity and relevance of the individual questions from an expert panel consisting of 12 physicians from specialties including anesthesiology, emergency medicine, radiology, urology, otolaryngology, and obstetrics/gynecology. When the Radiological Society of North America (RSNA)/American College of Radiology (ACR) 3D Printing Registry Data Dictionary was released, additional survey questions were reviewed. A final cross-disciplinary survey of the utility of 3D printed models in surgical planning medical education was developed.

RESULTS

The literature review identified 100 questions previously published in surveys assessing patient-specific 3D models for surgical planning. Following the review, generalization, and mapping of survey questions from these studies, a list of 24 questions was generated for review by the expert study team. Five additional questions were identified in the RSNA/ACR 3D Printing Registry Data Dictionary and included for review. A final questionnaire consisting of 20 questions was developed.

CONCLUSIONS

As 3D printed models become more common in medical education, the need for standardized assessment is increasingly essential. The standardized questionnaire developed in this study reflects the interests of a variety of stakeholders in patient-specific 3D models across disciplines.

From the ground up: understanding the developing infrastructure and resources of 3D printing facilities in hospital-based settings

Background

3D printing is a popular technology in many industries secondary to its ability to rapidly produce inexpensive, high fidelity models/products, mainly through layer-by-layer fusion of various substrate materials. In healthcare, 3D printing has garnered interest for its applications in surgery, simulation, education, and medical device development, and 3D printing facilities are now being integrated into hospital-based settings. Yet, little is known regarding the leadership, resources, outputs, and role of these new onsite entities.

Methods

The purpose of this research was to survey features of North American hospital-based 3D printing facilities to understand their design and utility in anticipation of future expansion. Hospital-based 3D printing labs were recruited through online special interest groups to participate via survey response. Anonymous, voluntary data were collected from 21 facilities over 9 weeks and reported/analyzed in aggregate.

Results

Of the respondents, > 50% were founded in the past 5 years and 80% in the past decade, indicating recent and rapid growth of such facilities. Labs were most commonly found within large, university-affiliated hospitals/health systems with administration frequently, but not exclusively, through radiology departments, which was shown to enhance collaboration. All groups reported collaborating with other medical specialties/departments and image segmentation as part of the workflow, showing widespread interest in high fidelity, personalized medicine applications. Lab leadership was most often multidisciplinary, with physicians present on nearly all leadership teams. Budgets, personnel, and outputs varied among groups, however, all groups reported engagement in multiple 3D printing applications.

Conclusion

This preliminary study provides a foundation for understanding the unique nature of hospital-based 3D printing labs. While there is much to learn about such in-house facilities, the data obtained reveal important baseline characteristics. Further research is indicated to validate these early findings and create a detailed picture of the developing infrastructure of 3D printing in healthcare settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41205-022-00147-7.

Female Representation at High-profile Urology Conferences, 2014-2019: A Leadership Metric

OBJECTIVE

To measure female leadership through speakership at urology conferences and compare involvement to the overall representation of women in the urologic workforce.

METHODS

A cross-sectional analysis was conducted to identify the gender of conference speakers from 2014 to 2019. Six high-profile urology conferences were selected: AUA; SUFU; SPU; SUO; GURS; WCE. Using programming published by each society, the number of invited female speakers at each conference was recorded. Comparisons were made to the proportion of practicing female urologists based on AUA census data.

RESULTS

A total of 34 conferences were reviewed. From 2014 to 2019, the percentage of female representation increased from 13.7% to 19.3% (P < .05). The proportion of female speakers at all conferences ranged from 0% to 35.6%. The average absolute increase was 1.3% each year. Female representation at urology conferences in 2019 was significantly greater than female representation in the field (19.3% vs 9.9%, P < .05).

CONCLUSION

There is a slight trend of increasing proportion of invited female speakers at academic urology conferences from 2014 to 2019. Although the proportion of women in urology remains low, the trend indicates that the mean proportion of female speakers is higher than the proportion of women in the field. Inclusion of female conference speakers presents an opportunity for increased gender parity within urology leadership.

[Therapeutic impact of streptococcal and enterococcal bacteremia in hematology patients]

From January 1999 to May 2000 (17 months), 21 strains of streptococci and four strains of enterococci have been isolated from 74 blood cultures in 25 infectious episodes in hematologic patients. They concerned 21 patients, of 21 to 77 years old. These patients suffered from acute leukaemia (14 cases), chronic lymphoid leukaemia (two cases), non-Hodgkin's lymphoma (two cases) or myeloma (three cases). Seventeen patients displayed a single streptococcal or enterococcal episode, two had two episodes in the course of a single stay in the hospital, two others in the course of two different stays. During 16 episodes (64%), the bacteremia occurred within 15 days after the onset of neutropenia consecutive to antimitotic chemotherapy, and in nine episodes (36%) it has occurred after a period exceeding 15 days. In six cases the patients had already received antibiotics with a large antibacterial activity (beta-lactam, fluoroquinolone and/or glycopeptide +/- aminoside) and in four cases a single antibiotic (synergistine or cotrimoxazole). Most streptococci (20/21) were oral streptococci (ten Streptococcus mitis, five S. oralis, two S. sanguis, three S. pneumoniae). A single strain of beta-hemolytic streptococci has been identified as S. dysgalactiae subsp. equisimilis. The enterococci were one strain of Enterococcus faecalis and three E. faecium. Ten streptococci were susceptible to 0.25 mg/L of penicillin G, ten were less susceptible (0.5 < or = MIC < 32 mg/L), and a strain was resistant (MIC = 32 mg/L). Eighteen strains were susceptible to amoxicillin and cefotaxime. For three strains, the MICs of amoxicillin and cefotaxime (8-16 mg/L and 8-32 mg/L, respectively) were higher. Levels of resistance of the enterococci to the beta-lactam (penicillin, amoxicillin, and piperacillin) were variable. All species were susceptible to glycopeptides. Three patients were transferred in intensive care unit for respiratory distress or shock syndrome. Their evolution has remained severe under antibiotherapy comprising beta-lactam or vancomycin associated with an aminoside. This results demonstrate the interest of species identification to adapt the antibiotic treatment and confirms the frequency of oral streptococci in severe bacteremia in neutropenic patients.

Pulsed field gel electrophoresis typing of coagulase-negative staphylococci with decreased susceptibility to teicoplanin isolated from an intensive care unit

Increased isolation of coagulase-negative staphylococci (CoNS) with decreased susceptibility to teicoplanin prompted this epidemiological survey in the authors intensive care unit. Of 224 medical and surgical patients with hepatobiliary disease, in hospital between December 1998 and July 1999, 14 (6.3%) had at least one isolate of CoNS with decreased susceptibility to teicoplanin. A total of 27 isolates with decreased susceptibility to teicoplanin were recovered from these 14 patients. Pulsed field electrophoresis (PFGE) with Sma I endonuclease demonstrated that CoNS isolates obtained from different patients were unrelated. In addition, different isolates obtain from the same patient were also unrelated, with the exception of two patients. Eighteen out of 27 isolates (66.7%) with decreased susceptibility to teicoplanin were recovered after an earlier treatment with teicoplanin or vancomycin (median 13.1 g, range 2.4-32.7 g per patient). Only four CoNS strains with decreased susceptibility to teicoplanin induced serious infection, all of which responded well to vancomycin therapy. Emergence of CoNS strains with decreased susceptibility to teicoplanin remained limited in hospitalized patients, and was not related to a clonal spread of a particular resistant strain.

In vitro activity of midecamycin diacetate, a 16-membered macrolide, against Streptococcus pyogenes isolated in France, 1995-1999

OBJECTIVE

To compare the in vitro activity of midecamycin diacetate to that of five other macrolides (erythromycin, clarithromycin, roxithromycin, azithromycin, and josamycin) and of clindamycin against 146 clinical isolates of Streptococcus pyogenes, with regard to three different phenotypes of erythromycin resistance.

METHODS

Susceptibility pattern and resistance phenotype were determined by disk diffusion method and double disk test. Minimal inhibitory concentrations of antibiotics were obtained by the agar dilution method and evaluated according to the recommendations of the 'Comité de l'Antibiogramme de la Société Française de Microbiologie' (CA-SFM). The major determinants of erythromycin resistance in S. pyogenes (ermB, ermTR and mefA genes) were investigated by specific amplification protocols.

RESULTS

Most of the isolates of S. pyogenes collected during 1995-99 were susceptible to midecamycin (93.8%), erythromycin (90.4%), clarithromycin (93.2%), roxithromycin (91.8%), azithromycin (88.4%), josamycin (94.5%), and clindamycin (94.5%). According to the CA-SFM criteria, 132 of the 146 isolates studied were susceptible to erythromycin (MICs < or = 1 mg/L), four were intermediate (MICs 2-4 mg/L), and 10 were resistant (MICs > 4 mg/L). Only nine isolates were midecamycin resistant (MICs > 4 mg/L), and the others were susceptible. The increased activity of midecamycin (MIC90 < or = 0.06 mg/L), as compared to erythromycin (MIC90 = 0.5 mg/L) and to other 14- or 15-membered macrolides, was related to the absence of the ermB determinant in seven isolates which displayed an efflux phenotype (five isolates) or an inducible resistance phenotype due to an ermTR determinant (two isolates).

CONCLUSION

Midecamycin diacetate is active against most S. pyogenes strains isolated in France and may represent an attractive alternative to the treatment of streptococcal infections due to resistant isolates with efflux of erythromycin.

[Apropos of a case of Streptococcus pneumoniae salpingitis, epidemiology of female genital pneumococcal infections]

BACKGROUND

Pneumoccocci were sometimes isolated from female genital tract specimens, usually without any clinical signification. However few cases of female pneumococcal genital infections were previously reported.

CASE REPORT

We describe an additional report of salpingitis, occurring in a 35-years old female early after installation of an intra-uterine device.

DISCUSSION

Data collected by the National Reference Center for Pneumococci show that 0.9% of the strains documented in the past five years (1992 to 1996) were isolated from the female genitals tract. Most of these infections are caused by S. pneumoniae belonging to the serotypes 1 or 3. About 20% of the strains displayed a reduced sensitivity to penicillin. Although genital infections caused by S. pneumoniae and the neonatal colonisation with the maternal strain are rare, their potential occurrence should not be neglected. Thus, in order to limit the risks of such infections, an antibiotic treatment should immediately started following the detection of a pneumococcal genital carriage.

Bacterial dissemination and metabolic changes in rats induced by endotoxemia following intestinal E. coli overgrowth are reduced by ornithine alpha-ketoglutarate administration

The efficacy of ornithine alpha-ketoglutarate (OKG) in preventing bacterial translocation and dissemination, metabolic disorders and changes in mucosal enzyme activities was assessed in a model of bacterial translocation in rats. Antibiotic decontamination was performed 4 d before intragastric inoculation with an Escherichia coli strain (10(10) bacteria/kg body). Two days later, the rats were given either a lipopolysaccharide (LPS) 0127:B8 or a saline injection and were deprived of food for 24 h. Enteral nutrition, [Osmolite, 880 kJ/(kg. d)] supplemented with either OKG (LPS + OKG) or glycine (Saline + Gly or LPS + Gly), was then given for 2 d. Urinary total nitrogen losses and 3-methylhistidine excretion were determined daily. On killing at d 3, bacterial translocation to the mesenteric lymph nodes (MLN) and dissemination to the spleen and liver were evaluated, jejunal mucosa enzyme activities were assayed and tissue free amino acids in muscles were measured. Endotoxin induced translocation from the gut lumen to the MLN in all groups, whereas dissemination occurred only in LPS-treated rats. OKG significantly reduced dissemination of the bacteria in the spleen. 3-Methylhistidine excretion was greater in the LPS + Gly group (+25%, P: < 0.05) than in either the LPS + OKG or Saline + Gly group. The group fed the OKG-enriched diet had higher muscular glutamine, ornithine and arginine concentrations than did the Gly-supplemented groups (P: < 0.05). Intestinal sucrase and aminopeptidase activities were higher in the LPS + OKG group than in the LPS + Gly group (-30%, P: < 0.05). OKG supplementation limits bacterial dissemination and metabolic changes after injury in rats and thus may be useful in the prevention of gut-derived sepsis in critically ill patients.

Streptococcus infantarius sp. nov., Streptococcus infantarius subsp. infantarius subsp. nov. and Streptococcus infantarius subsp. coli subsp. nov., isolated from humans and food

Eighteen strains isolated from human specimens or from food products were characterized as atypical variants of mannitol-negative Streptococcus bovis. They were tested for extended biochemical criteria, ribotyping and DNA-DNA hybridization in order to define their taxonomic status. These strains were demonstrated to constitute a DNA relatedness group that includes strains of DNA group 4 of Farrow et al. (1984). Comparative analysis of 16S rRNA sequences demonstrated that these strains represent a new species which belongs to the Streptococcus bovis/Streptococcus equinus complex and which has been provisionally named S. infantarius by Bouvet et al. (1997). Biotyping and ribotyping allowed differentiation of these strains from the aesculin-positive strains of S. bovis belonging to the previously described biotypes I, II.1 and II.2. The results of the ribotyping and hybridization assays demonstrated the presence of two different DNA subgroups within the 18 strains. On the basis of these data, the names S. infantarius subsp. infantarius (aesculin-negative for five strains out of seven, including the type strain HDP 90056T = NCDO 599T) and S. infantarius subsp. coli (aesculin-positive, reference strain HDP 90248 = NCDO 2620) are proposed as the names for these two subspecies within the S. infantarius species.

Epidemiological investigation of Ochrobactrum anthropi strains isolated from a haematology unit

Ochrobactrum anthropi is an oxidase-producing gram-negative bacillus preferring aqueous environments. It is an opportunist of low pathogenicity with a wide and unpredictable antibiotic resistance. We observed bacteraemia caused by this organism in two immunocompromized patients hospitalized in the same haematology unit and catheter-associated sepsis was recognized within two days. Another isolate was obtained from the stools of a third patient of the same unit. Environmental investigations recovered an isolate from a tap-water sample of the unit. Pulsed-field gel electrophoresis analysis of these four isolates and two others isolates previously found in the same ward, showed identical restriction patterns for the two blood isolates and confirmed that the two bacteraemia were epidemiologically related.

Seroprevalence of retroviral infections among pregnant women in Martinique (French West Indies)

A seroepidemiologic study of human T cell lymphotrophic virus type-1 (HTLV-1) and human immunodeficiency virus (HIV) infections was carried out in Martinique among 467 pregnant women receiving prenatal care at the Martinique Department for the Protection of Motherhood and Childhood. A seroprevalence rate of 1.93% was found for HTLV-1 infection. No HIV serum marker was observed. Given the epidemiology of these viral diseases, it is suggested that serologic status should be determined for all pregnant women on this island. A further, large-scale, prospective survey of HIV seroprevalence in Martinique should be performed to confirm the results of the present study.

Bacterial dissemination, rather than translocation, mediates hypermetabolic response in endotoxemic rats

OBJECTIVE

To study the pathogenesis of the host response during bacterial translocation, a rat model was designed for prolonged follow-up after injury.

DESIGN

A prospective, controlled animal study.

SETTING

Animal laboratory.

SUBJECTS

Young male Wistar rats.

INTERVENTIONS

Antibiotic decontamination of rats was performed 4 days before intragastric inoculation with a selected Escherichia coli strain (10(10) bacteria/kg of body weight). Two days later, the rats received a lipopolysaccharide injection or not (control group) and were observed for 3 days. They were then killed. A reference group (pair-fed healthy animals) was studied in parallel.

MEASUREMENTS AND MAIN RESULTS

During observations, urinary total nitrogen loss and 3-methylhistidine excretion were determined daily. When the rats were killed, mesenteric lymph nodes (MLNs), spleen, and liver were aseptically removed and cultured. Colonies identified as translocated E. coli were counted in each organ. Intracellular amino acid free pools were measured in extensor digitorum longus and anterior tibialis. Endotoxin induces bacterial translocation of bacteria from gut lumen to MLNs (100% vs. 59% in the lipopolysaccharide-untreated control group; p < .05) and dissemination to spleen and liver (65% and 45% of positive cultures after endotoxemia, respectively, vs. 6% and 12% in the control groups). No translocation occurred in the reference group. Evidence for the hypermetabolic response was seen in lipopolysaccharide-treated and infected rats, but protein catabolism was more closely related to the occurrence of bacterial dissemination to spleen and liver than to translocation alone (e.g., the cumulative 3-methylhistidine excretion during the observation period was 4.07+/-0.18 micromol in uninfected rats, 4.48+/-0.29 in rats with positive MLN cultures alone and 6.17+/-0.30 in MLN, spleen, or liver infected rats; 1 vs. 2, NS; 3 vs. 1, and 3 vs. 2, p < .05).

CONCLUSIONS

Gut barrier failure is associated with a deep excessive catabolic response in the host. The mechanism by which the metabolic state affects the resistance to infection apparently involves amino acid metabolism.

Is the L-arginine-nitric oxide pathway involved in endotoxemia-induced muscular hypercatabolism in rats?

We investigated the role of the nitric oxide (NO) synthase (NOS) pathway in muscular metabolism during endotoxemia in four groups of male Wistar rats. Two groups were injected with the lipopolysaccharide (LPS) of Escherichia coli (3 mg/kg), with one group treated using N(G)-nitro-L-arginine methylester ([L-NAME] 85 mg/kg/d) and the other not. The two control groups included one treated with L-NAME and the other not. After 24 hours of fasting, the rats were fed by controlled enteral nutrition and killed on day 3. The results showed that (1) NOS inhibition was detrimental during endotoxemia, increasing lethality from 20% to 80.5%, and (2) NOS inhibition did not modify the hypercatabolic state consecutive to endotoxemia, particularly at the muscular level (nitrogen balance, total-body and muscular weight loss, and muscular protein and glutamine concentrations). However, myofibrillar catabolism was delayed in the LPS-NAME group. In conclusion, NO production is of major importance for survival after an endotoxemic challenge, but contributes weakly to the metabolic response of muscle to injury.

[Dengue in Martinique in 1995-1996]

The incidence of dengue increased sharply in Martinique from the end of 1995 into 1996. Virological tests performed jointly on 36 serum samples by the Pasteur Institute in French Guyana and the Center for Disease Control in Puerto Rico led to identification of serogroups 1, 2, and 4 for six dengue virus. Between January 1995 and December 1996, the Departmental Hygiene Laboratory of Martinique carried out screening tests to detect specific IgM by the immunocapture method (MAC ELISA) in patients with suspected dengue. Results were positive in 701 of the 2,143 patients tested (32.7%). Symptoms were studied in 421 of these positive cases. The most frequent presentation was a flu-like syndrome with hyperalgia. Nausea, vomiting, joint pain, and retroocular pain were frequent. At least one clinical sign of coagulation disturbance was noted in 83 patients (19.7%). Dengue hemorrhagic syndrome was diagnosed according to the criteria of the World Health Organization in six patients including one who developed circulatory collapse and died. This fatality was the first to be reported in Martinique. The incidence of typical dengue as well as of the hemorrhagic form is probably underestimated in Martinique because specific serological tests are not routinely requested and application of WHO criteria for diagnosis of hemorrhagic forms is often impractical.

[Presumptive tests and molecular hybridization for the identification of untypable strains of Streptococcus pneumoniae]

Five different methods for identification of pneumococci (optochine susceptibility, bile solubility, Slidex Pneumo-kit, Phadebact Pneumococcus test, AccuProbe DNA test) were evaluated with a total of 280 Streptococcus pneumoniae non typable strains. 189 strains were identified as pneumococci according to the AccuProbe test results. Among these, 180 strains (95.2%) were optochine sensitive (d > or = 12 mm). Bile solubility was seen in 125 (66.1%) of the pneumococci. Immunological identifications were respectively positive for 67 and 56 among 140 strains. By comparison with the DNA/RNA reassociation method, the poor sensitivities and specificities of the presumptive identification tests are actually demonstrated for pneumococcal non typable strains. Thus, the AccuProbe DNA test is seen as the only adequate method for identification of such strains.

[Prevalence of intestinal parasitism in the public laboratories of Martinique: development from 1988 to 1995]

This survey drew up the epidemiological situation of intestinal parasitism in Martinique in 1994-1995. 13,978 stool specimens collected in 1994-1995 were tested by parasitologic examination. Stool specimens were from patients hospitalised in the 3 principal hospitals of Martinique or coming to the Laboratoire départemental d'hygiène. The parasitism rate was 8.73%. This study showed a significant reduction of intestinal parasitism between results of 1988 and results of 1994-1995. The oro-faecal parasitism was not very important that reflected the good economic and sanitation level of Martinique. On the other hand, regarding the important prevalence of parasitism with Strongyloïdes stercoralis and hookworm, it would be good to improve detection, sanitary education and know better local contamination factors to decrease the prevalence of this parasitism.

[Control of intestinal schistosomiasis in Martinique island]

The presence of schistosomiasis mansoni is known in Martinique since the beginning of the XXth century. A general survey of the distribution of the disease was carried out in 1977 and showed a mean prevalence of 12% (coprology and serology taken together) in the whole of the island. Following this survey, an integrated control programme associating sanitary education, detection and treatment of patients and improved sanitation, was developed. In addition, a biological control programme against the intermediate snail host, Biomphalaria glabrata using the competitor snail, Melanoides tuberculata, was developed in the transmission sites. The decline of snail populations and of its parasite, as well as a strong reduction of the prevalence in humans were recorded between 1977 and 1996. At the present time, only few cases corresponding to older infections are detected. This epidemiological situation is quite different from that in Guadeloupe island where, in spite of an excellent control programme which was achieved on the Basse-Terre district, an important focus is still functioning on Grande-Terre district with the black rat as host reservoir. Such foci do not exist on Martinique island.

Ornithine alpha-ketoglutarate metabolism after enteral administration in burn patients: bolus compared with continuous infusion

Ornithine alpha-ketoglutarate (OKG) has been successfully used as an enteral supplement in the treatment of catabolic states, including burn injury. However, specific questions remain unanswered concerning burn patients, including OKG metabolism and metabolite production, appropriate mode of administration, and dose. We thus performed a kinetic study and followed plasma ornithine and OKG metabolite concentrations on day 7 postburn in 42 (35 men, 7 women) consecutive burn patients aged 33 +/- 2 y with a mean (+/-SEM) total burn surface area (TBSA) of 31 +/- 1%. Patients were randomly assigned to receive OKG as a single bolus (10 g; n = 13) or in the form of a continuous gastric infusion (10, 20, or 30 g/d over 21 h; n = 13) or an isonitrogenous control (n = 16). Plasma pharmacokinetics of ornithine followed a one-compartment model with first-order input (r = 0.993, P < 0.005). OKG was extensively metabolized in these patients (absorption constant = 0.028 min-1, elimination half-life = 89 min), with the production of glutamine, arginine, and proline; proline was quantitatively the main metabolite [in OKG bolus, area under the curve (AUC)0-7h: proline, 41.4 +/- 5.6 mmol.min/L; glutamine, 20.4 +/- 5.7 mmol.min/L; and arginine, 7.3 +/- 1.9 mmol.min/L]. Proline production was dose-dependent and quantitatively similar between modes of OKG administration. Glutamine and arginine production were not dose-dependent and were higher in the bolus group than in the infusion group. Overall, the bolus mode of OKG administration appeared to be associated with higher metabolite production compared with continuous infusion in burn patients, especially for glutamine and arginine.

In-vitro killing activity of combinations of beta-lactam agents with aminoglycosides against penicillin-resistant pneumococci

Streptococcus pneumoniae has developed resistance to almost every antibacterial agent used in clinical practice, including the most active beta-lactams. This has led to the proposed use of drug combinations. The aim of this study was to determine the efficacy of combinations of beta-lactam agents (cefotaxime or imipenem) with aminoglycosides (gentamicin, netilmicin or amikacin) against pneumococci showing high-level resistance to penicillin and streptomycin and/or kanamycin. All tested combinations were bactericidal and synergic despite the weak concentrations of antibiotics used. Our results suggest that combinations of beta-lactam agents with aminoglycosides may be useful for treating infections by penicillin-resistant pneumococci located outside the central nervous system.