Guided coronally advanced flap to treat gingival recession: Digital workflow and case report

BACKGROUND

The inherently technique-sensitive nature of periodontal plastic procedures demands a significant level of skill and expertise. The incorporation of three-dimensional (3D) printing technologies emerges as a potential strategy to optimize and simplify surgical procedures. This case report describes the digital workflow and presents the clinical outcomes achieved using a guided coronally advanced flap for the treatment of a single gingival recession (GR).

METHODS AND RESULTS

A female patient with a gingival recession type 1 (RT1 B-) defect on the mandibular second left premolar underwent successful treatment using a guided coronally advanced flap (g-CAF) and de-epithelized connective tissue graft (CTG). The digital planning included intraoral scanning of the mandible and hard palate using an intraoral scanner, with resulting polygon format (PLY) files exported for virtual model creation. The CAF guide was meticulously designed to orient horizontal and vertical incisions at the papillae base adjacent to the GR defect. For the donor site, a guide was specifically created, positioning the graft area 2 mm apically to the premolars' gingival margins. The delineation of this area involved two horizontal and vertical incisions, meticulously based on the dimensions of the GR. The digitally designed guides were then 3D-printed using a surgical guide-specific resin, contributing to the precise execution of the innovative surgical approach. Complete root coverage was achieved.

CONCLUSION

This case report demonstrates that g-CAF can be a promising approach for the treatment of single GR.

HIGHLIGHTS

Why is this case new information? To the best of the authors' knowledge, this is the first manuscript to report a guided procedure for the treatment of gingival recession. This report provides the digital workflow for the fabrication of a guide to perform the coronally advanced flap for single recession defects. What are the keys to successfully manage this case? It is necessary to adequately scan the recession defect area and palate. Properly not only design the guide using specific software but also print it. The guide has to be stable when in position for the surgical procedure. What are the primary limitations of this technique? This guide was designed to help surgeons during the incisions. However, it does not provide aid to split and release the flap and suture.

Barbell Technique for Three-Dimensional Bone Augmentation

Introduction

Appositional bone augmentation is considered a challenging surgical problem to correct for the deficient alveolar ridge. To overcome this challenge, a novel concept was recently published called "Barbell Technique." This technique has been used more commonly for horizontal bone augmentation. To our knowledge, this is the first report on using the Barbell Technique for vertical bone augmentation. Case Report. This report describes and demonstrates the clinical feasibility of the use of this concept in the reconstruction of a tridimensional alveolar ridge defect in the anterior maxilla. Due to the severity of the defect, both hard and soft tissue deficiencies required augmentation. The first surgery involved a soft tissue grafting procedure while in the second surgical procedure, hard tissue augment was performed using the Barbell device to provide both vertical and horizontal support for the hard tissue graft. The donor material consisted of equal volume of xenograft and autogenous bone used to fill the defect and covered with a collagen barrier membrane. After a healing period of 9 months, the site was reopened. Bone formation clinically verified the correction of alveolar bone contour and volume permitted placement of two titanium implants after the removal of Barbell device.

Conclusion

This case report demonstrates successful vertical and horizontal bone augmentation of a critical size defect in the anterior maxilla, correcting both hard and soft tissue contours, and providing the tissues needed to support dental implants in the anterior maxilla.

A new volume-stable collagen matrix (VCMX) to treat single gingival recession associated with partially restored non-carious cervical lesions: a case series

Collagen matrixes have been developed as possible connective tissue graft substitutes to overcome patient discomfort, undesired palatal healing, and the limited amount of donor tissue. The aim of this case series is to assess a coronally advanced flap (CAF) with a new volume-stable collagen matrix (VCMX) to treat single gingival recession (GR) associated with partially restored non-carious cervical lesions (NCCL). Twelve patients diagnosed with single GR RT1 + NCCL (B+) were included in this study and received a restorative - partial resin composite with apical margin 1 mm beyond the estimated cementoenamel junction (CEJ) - and a surgical approach - CAF+VCMX. Clinical and patient-centered assessments were recorded at baseline and 6 months postoperatively from ten patients. Significant recession reduction (RecRed:2.1mm), clinical attachment level gain (CAL:1.34mm), and combined defect coverage (CDC) of 51.67% were observed at 6 months. The estimate root coverage (RC) was 69.48%, obtained using the estimated CEJ. No difference in keratinized-tissue width (KTW) was observed over time. A gain in gingival thickness (GT) of 0.42 mm was observed after 6 months (p=.002) and an improvement in patient satisfaction due to better esthetics (p<.001). Within the present study's limits, CAF plus VCMX provided significant improvement in treating single GR combined with partially restored NCCL (B+).

Long-term evaluation (up to 7 years) of the use of a collagen matrix to treat gingival recession associated with noncarious cervical lesion: Report of two cases

INTRODUCTION

Gingival recession (GR) is a relevant clinical condition due to its high prevalence worldwide, which leads to aesthetic demands and dentin hypersensitivity. Collagen matrices have been associated with different designs of coronally advanced flaps (CAFs) to treat GR defects. However, the literature lacks long-term follow-up of this treatment option. The aim of this study is to present the long-term follow-up (up to 7 years) of two GR defects (associated or not with noncarious cervical lesion) treated with a CAF and a collagen matrix (CM).

CASE PRESENTATION

Case 1 underwent a CAF associated with a CM to treat a single GR defect. After 7 years, Case 1 presented with 3 mm of recession reduction, which corresponds with the 85.7% of root coverage. Case 2 presented two GR defects associated with noncarious cervical lesions (NCCLs). The NCCLs were partially restored with resin composite and then underwent a modified CAF for multiple defects and a CM. After 5 years of follow-up, Case 2 presented with 1.5 and 2.5 mm of recession reduction, which corresponds with the average 83.3% defect coverage.

CONCLUSION

These two cases may show that CMs can provide long-term stable outcomes in the treatment of GR defects. Why is this case new information? One of the cases is the first one to describe a 7 years of follow-up after CAF+CM to treat gingival recession defects. What are the keys to successful management of this case? Correct material handling. Adequate restorative protocol and surgical technique. What are the primary limitations to success in this case? Diagnose Patient compliance.

Multiple gingival recessions associated with non-carious cervical lesions treated by partial restoration and modified coronally advanced flap with either connective tissue graft or xenogeneic acellular dermal matrix: A randomized clinical trial

BACKGROUND

This study aimed to compare a connective tissue graft (CTG) to a (porcine) xenogeneic acellular dermal matrix (XDM), both associated with modified coronally advanced flap (MCAF) and partial resin composite restoration to treat multiple combined defects (CDs).

METHODS

Seventy-eight defects in 38 patients presenting multiple combined defects, that is, gingival recession associated with non-carious cervical lesions, were treated by partial resin composite restoration (apical margin up to 1 mm of the estimated cement-enamel junction) and MCAF along with CTG or XDM. After 6 months, the groups were compared with regard to clinical, patient-centered, and esthetic outcomes.

RESULTS

CD coverage was 72.9% for CTG versus 50.7% for XDM (P < 0.001). Recession reduction was 2.3 mm for CTG versus 1.5 mm for XDM (P < 0.001). CTG resulted in a greater increase in keratinized tissue width (CTG: 0.96 mm vs. XDM: 0.3 mm, P = 0.04) and gingival thickness (CTG: 0.9 mm vs. XDM: 0.3 mm, P < 0.001). Both treatments successfully reduced dentin hypersensitivity and increased esthetics satisfaction, with no statistically significant intergroup differences. Moreover, XDM patients experienced a shorter surgery duration (CTG: 57.2 min vs. XDM: 37.4 min, P < 0.001) and less time to no pain (visual analog scale  =  0; CTG: 6.5 days vs. XDM: 3.5 days, P = 0.04).

CONCLUSION

CTG resulted in significantly greater root coverage and increased keratinized tissue width compared to XDM for treating multiple partially restored CDs. However, increased root coverage at the CTG sites was accounted for by increased probing depth compared to the XDM sites.

Maxillary Sinus Elevation Using the Bone Ring Technique with Immediate Implantation: A Case Report

Compared to other areas of the oral cavity, an edentulous posterior maxilla poses a unique challenge for implant placement. The most important aspect to consider is the maxillary sinus. This paper describes a case in which the bone ring technique was used to raise the floor of the maxillary sinus, followed by immediate implantation. A 37-year-old woman presented with a ridge defect in the left maxilla and the absence of teeth 26 and 27 (FDI tooth-numbering system) on the same side. The treatment plan involved the extraction of tooth 25, periodontal regeneration on the distal face of tooth 24, and concomitant raising of the maxillary sinus (using the bone ring technique) with simultaneous implantation. The bone ring technique promotes bone augmentation, raises the maxillary sinus, and reduces the surgical time, surgical costs, and length of the rehabilitation period. In the case presented herein, bone tissue stability around the implants, ridge maintenance, and gingival margin stability were found at the 1-year follow-up after rehabilitation.

Bone Ring Technique for the Treatment of Vertical and Horizontal Bone Defects with Immediate Implants: A Report of Two Cases

In dental implant surgery, bone grafts are used for the reconstruction and reestablishment of alveolar bone volume and to improve bone architecture for better positioning of an implant. The present report describes the use of the bone ring technique for vertical and horizontal bone augmentation with simultaneous implant placement. This is a simple technique for acquiring donor bone in a ring shape and performing 3D reconstruction of bone defects, with an increase in the alveolar crest, using autogenous bone in a surgical procedure together with implant placement. Block bone grafts taken from the mentum can be used for predictable bone augmentation of up to 6 mm in the horizontal and vertical dimensions. The thickness of the bone ring collected from the mentum is very important. It cannot be too thin due to the risk of fracture, nor can it be too thick, as its contour could become deformed when placed in the receptor site. For stabilization and synthesis, a horizontal mattress suture is performed at the receptor site without promoting tension, and simple sutures are used for the complete co-optation of the flap and consequent stabilization of the clot. In the present type of bone defect, single-stage implant placement may be useful to shorten the overall treatment period.

Obtaining intraoral subepithelial connective tissue graft: Dermabrasion Technique- Case report

Objectives: The present study aims to describe the dermabrasion technique to obtain connective tissue rich in collagen, with satisfactory thickness and anatomy, removing the epithelial layer with diamond drill in high speed handpiece and under refrigeration. Materials and Methods: A 50-year-old patient was selected for immediate dental implant (element 25) and soft tissue augmentation in the periodontal and peri-implant region. An epithelial connective tissue graft was performed in the area comprising elements 23, 24, 25 and mesial of 26. For the preparation of the donor area of the graft, the dermabrasion technique was used through a spherical diamond drill bit (medium or thick granulation) in high speed and under refrigeration, being able to remove the epithelium without losing part of the subepithelial layer. Results: The healing process is by second intention and presented a normal evolution with formation of adequate tissues. Conclusions: The Dermabrasion technique allows to obtain adequate grafts, removing the epithelial layer in a simple way and guarantee the desired thickness.

Prosthetic Rehabilitation in Older Adult with Free Gingival Graft: Case Report

Aim: The aim of the present study was to perform the clinical evaluation of the thickness of the soft tissue around dental implants using a free gingival graft obtained from the palate. Background: Rehabilitation in elderly patients improves physiological functions and quality of life, and when this rehabilitation involves a surgical stage, it becomes a challenge, even for more experienced surgeons. Methods: a 64-year-old, white, female patient with a complaint of difficulty chewing and discomfort stemming from her dental status. Rehabilitation was proposed involving a multidisciplinary approach to reestablish esthetics, function and wellbeing. For such, 4.1 Bone Level Tapered® implants were installed. During the presurgical preparation, a free gingival graft was planned to increase the gingival area using the Miller technique. After establishing the suitability of the oral environment, impressions were made in alginate for the fabrication of an acrylic surgical stent to protect the donor site on the hard palate and minimize the morbidity of the surgical intervention. Conclusion: In the case reported, the increase in the gingival tissue using a free gingival graft provided satisfactory peri-implant health in an older patient  throughout annual follow-up for 15 years.

Treatment of gingival recession in two surgical stages: Free gingival graft and connective tissue grafting

This report describes a clinical case of severe Miller Class II gingival recession treated by two stages of surgery that combined a free gingival graft and connective tissue grafting. First, a free gingival graft (FGG) was performed to obtain an adequate keratinized tissue level. Three months later, a connective tissue graft (CTG) was performed to obtain root coverage. The results indicated that the FGG allows for a gain in the keratinized tissue level and the CTG allows for root coverage with decreased recession level after 16 months. Therefore, for this type of specific gingival recession, the combination of FGG and CTG can be used.

Predicted annual costs for inpatients with diabetes and foot ulcers in a developing country-a simulation of the current situation in Brazil

AIMS

The objective of this cost-of-illness analysis was to quantify the annual costs associated with hospital admission for people with diabetes and foot ulcers in Brazil.

METHODS

A hypothetical cohort was simulated using a decision tree model. Prevalence and incidence rates and clinical outcomes were estimated from published studies and applied to the general Brazilian population over 30 years. Costs were quoted in Brazilian real (BRL) and converted to US dollars ($US) at the 2008 currency exchange rate ($US1 = BRL 1.64). In the sensitivity analysis, we reduced and increased rates to assess the robustness of the cost estimates.

RESULTS

In this hypothetical cohort there are 6.48 million (95% confidence interval 4.47-7.12) Brazilians citizens with Type 2 diabetes. Each year, approximately 323,000 (89,500-484,500) of these people develop foot ulcers and almost 97,200 (17,900-169,600) require hospital admission as a result. Each year, almost 46,300 (8500-80,900) limb amputations and 12,400 (2300-21,700) deaths occur as a result of diabetic foot disease in Brazil. The annual cost associated with these hospital admissions is estimated to be almost $US264m ($US51m-461m). The estimated cost for patients with amputation is nearly $US128m ($US24.5m-222.3m).

CONCLUSIONS

Our model shows that the social and economic impact of diabetic foot disease in Brazil is high. Government decision makers should reflect on the current situation and provide organized foot care throughout the whole country.

Increased immunoglobulin secretion by B lymphocytes from Trypanosoma cruzi infected mice after B lymphocytes-natural killer cell interaction

In the present study, we investigated whether natural killer (NK) cells modulate immunoglobulin (Ig) secretion by B cells from Trypanosoma cruzi-infected mice. B cells from infected mice increased IgM and IgG2a secretion in the presence of a NK cell line, and this response was cell contact-dependent. Stimulation of splenic B cells with polyinosinic-polycytidylic acid, a NK cell activator, also increased Ig secretion by B cells from infected mice. B cells from infected mice expressed higher levels of the B7.2 molecule. Our results suggest that NK cells may be involved in the control of the abnormal B cell activation observed during T. cruzi infection.

Increased susceptibility of Fas ligand-deficient gld mice to Trypanosoma cruzi infection due to a Th2-biased host immune response

Infection of BALB/c mice with Trypanosoma cruzi resulted in up-regulated expression of Fas and Fas ligand (FasL) mRNA by splenic CD4+ T cells, activation-induced CD4+ T cell death (AICD), and in Fas: FasL-mediated cytotoxicity. When CD4+ T cells from infected mice were co-cultured with T. cruzi-infected macrophages, onset of AICD exacerbated parasite replication. CD4+ T cells from T. cruzi-infected FasL-deficient BALB gld/gld mice had no detectable AICD in vitro and their activation with anti-TCR did not exacerbate T. cruzi replication in macrophages. However, infection of BALB gld/gld mice with T. cruzi resulted in higher and more prolonged parasitemia, compared to wild-type mice. Secretion of Th2 cytokines IL-10 and IL-4 by CD4+ T cells from infected gld mice was markedly increased, compared to controls. In addition, in vivo injection of anti-IL-4 mAb, but not of an isotype control mAb, reduced parasitemia in both gld and wild-type mice. These results indicate that, besides controlling CD4+ T cell AICD and parasite replication in vitro, an intact Fas: FasL pathway also controls the host cytokine response to T. cruzi infection in vivo, being required to prevent an exacerbated Th2-type immune response to the parasite.

Proapoptotic activity of a Trypanosoma cruzi ceramide-containing glycolipid turned on in host macrophages by IFN-gamma

The effects of glycoinositolphospholipid (GIPL), from the pathogenic protozoan Trypanosoma cruzi, and its isolated glycan and lipid (dihydroceramide) components, were investigated in J774 cells and primary macrophages. Isolated GIPL ceramide, but not intact GIPL or its glycan, induced intense fluid phase endocytosis when added exogenously. In the presence of the cytokine IFN-gamma, GIPL ceramide induced marked apoptosis in J774 cells and macrophages, independent of nitric oxide secretion. When cells were preincubated with the GIPL-derived glycan chain, addition of intact GIPL induced macrophage apoptosis in the presence of IFN-gamma. Synthetic C2-dihydroceramide also induced apoptosis in the presence of IFN-gamma. Induction of apoptosis in T. cruzi-infected macrophages by GIPL ceramide plus IFN-gamma led to increased parasite release compared with IFN-gamma treatment alone. Viable parasites released comprised both infective trypomastigote and spheromastigote forms. These results identify a novel pathway by which T. cruzi glycosylphosphatidylinositol family molecules affect host macrophages, with implications for the infectious process.

Activation-induced T cell death exacerbates Trypanosoma cruzi replication in macrophages cocultured with CD4+ T lymphocytes from infected hosts

Activation-induced cell death (AICD) of CD4+ T lymphocytes was described in infection with Trypanosoma cruzi, but a role for AICD in modulating parasite spread in host cells has not been investigated. In this study, replication of T. cruzi in vitro in murine macrophage (Mphi) monolayers was investigated. Long term (5 to 13 day) replication of infective (trypomastigote) T. cruzi forms was blocked by supernatants from activated (anti-TCR) CD4+ T cells of infected mice or by rIFN-gamma. However, when CD4+ T cells from infected mice were cocultured with Mphi and activated by anti-TCR, marked exacerbation of trypomastigote growth in Mphi ensued. The deleterious effect required contact between T cells and infected Mphi. Both anti-Fas and TCR activation killed a proportion of CD4+ T cells. Ly-6 activation did not induce AICD and did not exacerbate parasite growth. However, Fas-mediated killing of T cells before Ly-6 activation led to exacerbated parasite growth. Although a minor population, Fas-susceptible cells were the major source of IFN-gamma production by activated T cells. Addition of a neutralizing anti-Fas ligand antibody blocked 50 to 60% of CD4+ T cell AICD and reduced trypomastigote growth in T/Mphi cocultures stimulated by anti-TCR. The results demonstrate that in CD4+ T cells from infected mice, the onset of AICD selectively ablates IFN-gamma production and up-regulates parasite replication in Mphi in vitro. These findings suggest a deleterious role for AICD in T. cruzi infection.

Delivery by Trypanosoma cruzi of proteins into the MHC class I antigen processing and presentation pathway

Class I MHC-restricted T cell responses have been shown to be critical for the development of immune resistance to Trypanosoma cruzi in mice. However, to date, no antigenic targets of this anti-parasite response have been characterized. We have analyzed the characteristics of potential T. cruzi CTL target molecules by expression of the model CTL target molecule chicken OVA in different cellular compartments of T. cruzi. OVA (amino acids 139-385) was expressed as a secretory, cytoplasmic, transmembrane, or glycosylphosphatidylinositol-anchored protein in T. cruzi transfectants. Host cells infected with T. cruzi transfectants that secreted or released OVA, but not those producing cytoplasmic or transmembrane forms of OVA, could process and present OVA peptide via the class I MHC pathway, as indicated by the stimulation of OVA-specific CD8+ T cell hybridomas and the cytolysis of host cells infected with OVA-secreting parasites by OVA-specific CTLs. In addition, infection of mice with OVA-secreting parasites elicited the production of OVA-specific CTLs. These studies demonstrate the ability to target proteins to specific cellular compartments in T. cruzi using either trypanosomal or mammalian signal sequences. Furthermore, these results suggest that proteins secreted or released by T. cruzi in infected cells are a major source of peptides for MHC class I presentation and for the generation of parasite-specific CTL.

Delivery by Trypanosoma cruzi of proteins into the MHC class I antigen processing and presentation pathway

Class I MHC-restricted T cell responses have been shown to be critical for the development of immune resistance to Trypanosoma cruzi in mice. However, to date, no antigenic targets of this anti-parasite response have been characterized. We have analyzed the characteristics of potential T. cruzi CTL target molecules by expression of the model CTL target molecule chicken OVA in different cellular compartments of T. cruzi. OVA (amino acids 139-385) was expressed as a secretory, cytoplasmic, transmembrane, or glycosylphosphatidylinositol-anchored protein in T. cruzi transfectants. Host cells infected with T. cruzi transfectants that secreted or released OVA, but not those producing cytoplasmic or transmembrane forms of OVA, could process and present OVA peptide via the class I MHC pathway, as indicated by the stimulation of OVA-specific CD8+ T cell hybridomas and the cytolysis of host cells infected with OVA-secreting parasites by OVA-specific CTLs. In addition, infection of mice with OVA-secreting parasites elicited the production of OVA-specific CTLs. These studies demonstrate the ability to target proteins to specific cellular compartments in T. cruzi using either trypanosomal or mammalian signal sequences. Furthermore, these results suggest that proteins secreted or released by T. cruzi in infected cells are a major source of peptides for MHC class I presentation and for the generation of parasite-specific CTL.

Prevention of suicide phenomenon in aeromonads

Clinical isolates of Aeromonas (13 Aeromonas caviae), 8 Aeromonas hydrophila, 3 Aeromonas spp., and 2 Aeromonas media recovered from diarrheal feces of children were submitted to the suicide phenomenon test and investigated at intervals of 24 h for up to 120 h. The same isolates were also stimulated by repeated passages in broth for ten days before the test. After the bacterial stimulus, a decreases in the number of aeromonads with suicidal capacity was observed. The suicide phenomenon was expressed after 72 h of incubation in only some isolates. The results show that the suicide phenomenon can be prevented by stimulation of bacterial metabolism.

Occurrence of Plesiomonas shigelloides in water environments of Rio de Janeiro city

Fresh and salt water samples analyzed in Rio de Janeiro city showed the presence of Plesiomonas shigelloides. Forty-six strains were isolated from both environments. A high incidence of P. shigelloides was achieved in polluted fresh and salt waters as well as in samples from non-polluted streams. P. shigelloides isolates had biochemical characteristics similar to those already described in the literature. None of the isolates analyzed produced enterotoxin in the suckling mouse assay. Hemolytic activity against sheep and human type A erythrocytes was detected in the strains tested. The results of the antibiotic susceptibility tests indicated that all the isolates were susceptible to the cephalosporins, penicillins combined with a beta-lactamase inhibitor, aminoglycosides, imipenem, norfloxacin, tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole. All the isolates were resistant to the penicillins.

Aeromonas species exhibit aggregative adherence to HEp-2 cells

Clinical and environmental isolates of Aeromonas species (five A. hydrophila isolates, three A. caviae isolates, and two A. sobria isolates) were tested for their adherence to HEp-2 cells. Clinical isolates of A. hydrophila and A. sobria exhibited aggregative adherence similar to that presented by enteroadherent-aggregative Escherichia coli. Bacterial aggregates adhered to cells with a typical "stacked-brick" appearance. In contrast, A. caviae strains showed a diffuse adherence pattern.

Quantification of Trypanosoma cruzi in the heart, lymph nodes and liver of experimentally inffected mice, using limiting dilution analysis

Limiting dilution analysis was used to quantify Trypanosoma cruzi in the lymph nodes, liver and heart of Swiss and C57Bl/10 mice. The results showed that, in Swiss and Bl/10 mice infected with T. cruzi Y strain, the number of parasites/mg of tissue increased during the course of the infection in both types of mice, although a greater number of parasites were observed in heart tissue from Swiss mice than from Bl/10. With regard to liver tissue, it was observed that the parasite load in the initial phase of infection was higher than in heart. In experiments using T. cruzi Colombian strain, the parasite load in the heart of Swiss and Bl/10 mice increased relatively slowly, although high levels of parasitization were nonetheless observable by the end of the infection. As for the liver and lymph nodes, the concentration of parasites was lower over the entire course of infection than in heart. Both strains thus maintained their characteristic tissue tropisms. The limiting dilution assay (LDA) proved to be an appropriate method for more precise quantification of T. cruzi, comparing favorably with other direct microscopic methods that only give approximate scores.

Serological survey for canine cutaneous and visceral leishmaniasis in areas at risk for transmission in Rio de Janeiro where prophylactic measures had been adopted

A serological survey for canine visceral (VL) and American cutaneous leishmaniasis (ACL) has been carried out during 1984-1989, to assess the effects of the prophylactic measures adopted in areas where there was a risk of transmission of the diseases in Rio de Janeiro. A previous serological survey (1982/83) had detected serum positive dogs as well as the human disease in these same areas. A total of 22,828 dogs have been examined in this last survey, 7,807 of which came from Campo Grande (VL and ACL area), 4,110 from Jacarepaguá (ACL area), 4,146 from Realengo, 3,879 from Bangu and 2,886 from Senador Camará, (three VL areas). The analysis of these results showed a notable reduction in the number of serum positive dogs, compared to those of the first survey of 1982/83 as follows: (a) in Campo Grande (VL and ACL) the infection rate of the first survey was 12.7%, against 0.62% of the second; (b) in Jacarepaguá (ACL) it decreased from 8.6% to 1.8% (c) in Bangu, Realengo and Senador Camará (VL) the rate decreased from 4.3% to 0.38%. The results indicate that this decrease was due to the prophylactic measures adopted in those areas.

[Ecological aspects of American tegumentary leishmaniasis: 8. Evaluation of the enzootic activity of Leishmania (Viannia) braziliensis, in forest and peridomiciliary environments of the Ribeira Valley region, São Paulo State, Brazil]

The evidence of mucocutaneous leishmaniasis transmission in the non-forest environment in the Ribeira Valley region, São Paulo, Brazil, has made this epidemiologic four years' study possible, viewing the enzootic activity of L. (V.) braziliensis. Furthermore, the natural infection in small mammals and the domestic dog population has been completed in collecting of phlebotomine sandflies in the forest and peridomiciliar environments. Positive test-results have only been found in resident dogs (Canis familiaris) with a rate of 5.6 and 2.4% for serological and parasitological test respectively. Among silvatic and synanthropic rodents collected, Oryzomys (Olygoryzomys) and Rattus rattus are pre-eminent having both been collected in equal proportions, in peridomiciliar environment. The sandfly Lutzomyia intermedia has contributed only with 166 feminine specimens due to insecticide (DDT) application on and in the human and domestic habitations. From the general epidemiologic standpoint the fragile L. (V.) braziliensis cycle in the unforested areas as well as the canine and small mammals roles as a domiciliar infection source are discussed, and their potencial in the dispersion of this parasite in the researched area is analysed too.

Trypanosoma cruzi: quantification in tissues of experimentally infected mice by limiting dilution analysis

A limiting dilution assay (LDA) was developed for the quantification of Trypanosoma cruzi in the heart and blood of infected mice. Three groups of swiss mice were injected ip with "CL", "Colombiana," and "Y" strains. At 1-day intervals after infection, blood and the heart were removed. Serial blood dilutions in LIT medium were performed and distributed in four groups of 24 microplate wells. The growth of parasite was visually checked in an inverted microscope. It was found that curves of parasitemia obtained by parasite counting in a hemocytometer or estimated by LDA were similar. A similar method was used to quantify parasites in the heart of mice. The heart was cut, washed, dried, and its weight was determined. The heart pieces were disrupted by passage through a mesh stainless-steel screen into LIT. Serial dilutions of the heart homogenate were made in LIT and added to at least 24 replicate microplate wells. Parasites were detectable earlier in the heart of mouse infected with Y strain when compared to CL and Colombiana strains. Parasites were detected in the heart of mice of all strains by 6 days after infection. This LDA for quantification of T. cruzi permits a more precise evaluation of the number of living parasites in infected tissues.

Indirect immunofluorescence test in New World leishmaniasis: serological and clinical relationship

The indirect immunofluorescence test (IF) for anti-Leishmania antibodies (IgG and IgM) was performed with sera from the following groups of individuals: 214 cutaneous leishmaniasis patients, 28 healthy subjects with positive Montenegro's skin test (MST), 29 healthy subjects with negative MST and 16 visceral leishmaniasis patients. The first four groups came from a suburban area of Rio de Janeiro (Jacarepaguá) where cutaneous leishmaniasis caused by Leishmania braziliensis braziliensis is endemic. It was observed that IF-IgM titers were significantly higher amongst the cutaneous leishmaniasis patients with less than four months of disease as compared to those with longer periods and that IF-IgG titers were significantly higher in patients with multiple lesions as compared to those with single lesions. The visceral leishmaniasis patients had IF-IgG titers significantly higher than those from cutaneous leishmaniasis patients. A group of 28 individuals selected amongst the 214 cutaneous leishmaniasis patients had their IF-titers (IgG and IgM) compared to those of the two control groups of healthy subjects from the endemic area, respectively with positive and negative MST. Significantly higher titers of IF-IgG and IF-IgM were found in the group with active disease. The same group of patients showed IF-IgG titers significantly lower at the end of the antimonial therapy than those observed during this treatment.

Canine American cutaneous leishmaniasis: a clinical and immunological study in dogs naturally infected with Leishmania braziliensis braziliensis in an endemic area of Rio de Janeiro, Brazil

Clinical and immunological findings from 35 dogs infected with Leishmania braziliensis braziliensis are described. The majority of the dogs had ulcerated single lesions on the ears. Sera from all infected dogs showed detectable Leishmania-induced antibodies using an indirect fluorescent antibody test. Antimonial therapy resulted in prompt healing of the lesions in 80.9% of the animals followed by a significant reduction in the anti-Leishmania antibody titers. However, treatment follow-up showed recurrences at the site of the primary lesion in 42.8% of the cases. These data were correlated with a persistence of the parasite in clinically healed lesions as well as with a negative intradermal test (leishmanin-delayed type hypersensitivity) observed in all animals but one.

A survey for American cutaneous and visceral leishmaniasis among 1,342 dogs from areas in Rio de Janeiro (Brazil) where the human diseases occur

There are areas in the periphery of Rio de Janeiro city where human cases of Visceral and/or Cutaneous Leishmaniasis occur. The parasites have been identified as Leishmania donovani and Leishmania braziliensis braziliensis respectively. A survey for Leishmaniasis was done among 1,342 dogs from those areas using an indirect immunofluorescent test. From the dogs, 616 came from areas where only human cases of Visceral Leishmaniasis occurred, 373 from an area where all human cases were of Cutaneous Leishmaniasis and 353 from a third area (Campo Grande) where both visceral and cutaneous human cases were detected. The prevalence of parasite antibody titers among dogs from areas of Cutaneous Leishmaniasis was significantly higher than that of Visceral Leishmaniasis (8.6% vs. 4.3%, p less than 0.02). The highest prevalence was observed among dogs from the area where both diseases are present (12.7%).

Detection of Yersinia enterocolitica heat-stable enterotoxin by suckling mouse bioassay

A comparison of heat-stable enterotoxins from Escherichia coli and Yersinia enterocolitica by the suckling mouse bioassay showed that whereas E. coli heat-stable enterotoxin evoked a maximum ratio of gut weight to remaining body weight after a 4-h incubation period, the maximum ratio for Y. enterocolitica was achieved at 2 h, decreasing thereafter to values regarded as negative (less than 0.083). This action of Y. enterocolitica heat-stable enterotoxin may give false-negative results for the standard suckling mouse bioassay.

Bacteriophage specificity in the identification of Yersinia pestis as compared with other enterobacteria

Bacteriophage typing of Yersinia pestis and the specificity of the phage among Enterobacteriaceae were investigated. The bacteriophage used for rapid identification of Y. pestis reacted with representative strains of all recognized species of Shigella as well as with Salmonella cholerae-suis. Reactive Shigella serotypes were Sh. dysenteriae 1 and 9, Sh. flexneri 2a, Sh. boydii 1 and 6, and Sh. sonnei. Patterns consisting of isolated plaques (two cases) or absence of plaques were observed when the routine test dilution (RTD) of the phage was used. Results were independent of the incubation temperature (20, 28 or 37 degrees C). Representative strains of Escherichia, Proteus, Providencia and Klebsiella were resistant to the bacteriophage even at 1000 X the RTD established for Y. pestis.

Anti-brucella agglutinins in bats and "Callithrix" monkeys

Anti-Brucella agglutinins were found in 5 of 53 (9.4%) vampire bats Desmodus rotundus, captured in the State of Bahia, Brasil. Two specimens of Diphylla ecaudata were negative. Fifty specimens of the small monkey, Callithrix penicillata, were also negative.