Macrovascular and microvascular type 2 diabetes complications are interrelated in a mouse model.

AIM: Evaluate the development of multiple complications, their interactions, and common mechanisms in the same individual with T2D. MATERIAL AND METHODS: 4-week-old male C57BL/6J mice were divided into: control (n = 6) and T2D (n = 6). T2D was induced through a high-carbohydrate-diet and low doses of streptozotocin. T2D was validated by metabolic parameters. Diabetic neuropathy was evaluated by mechanical and thermal sensitivity tests. We performed a histopathological analysis of the heart, kidney, liver, and parotid salivary glands and changes in bone microarchitecture by µCT. We calculated the relative risk (RR), odd ratios (OR) and Pearson correlation coefficients between the different complications and metabolic features. RESULTS: T2D mice have cardiomyopathy, neuropathy, nephropathy, liver steatosis and fibrosis, structural damage in parotid salivary glands, and bone porosity. RR analysis shows that all complications are interrelated by hyperglycaemia, insulin resistance, obesity, and systemic inflammation. CONCLUSIONS: T2D mice develop multiple complications simultaneously, which are related to each other, and this is associated with metabolic alterations. Our findings open up new approaches for the study and new therapeutic approaches of the pathophysiology of T2D and its complications.

CD4+ T-cell activation of bone marrow causes bone fragility and insulin resistance in type 2 diabetes.

Type 2 diabetes mellitus (T2DM) causes an increased risk of bone fractures. However, the pathophysiology of diabetic bone fragility is not completely understood. It has been proposed that an inflammatory microenvironment in bone could be a major mechanism by inducing uncontrolled bone resorption, inadequate bone formation and consequently more porous bones. We propose that activated T-cells in the bone marrow cause a pro-inflammatory microenvironment in bone, and cause bone fragility in T2DM. We induced T2DM in C57BL/6 male mice through a hypercaloric diet rich in carbohydrates and low doses of streptozocin. In T2DM mice we inhibited systemic activation of T-cells with a fusion protein between the extracellular domain of Cytotoxic T-Lymphocyte Antigen 4 and the Fc domain of human immunoglobulin G (CTLA4-Ig). We analysed the effects of T2DM or CTLA4-Ig in lymphocyte cell subsets and antigen-presenting cells in peripheral blood and femoral bone marrow; and their effect on the metabolic phenotype, blood and bone cytokine concentration, femoral bone microarchitecture and biomechanical properties, and the number of osteoblast-like cells in the femoral endosteum. We performed a Pearson multiple correlation analysis between all variables in order to understand the global mechanism. Results demonstrated that CTLA4-Ig decreased the number of activated CD4+ T-cells in the femoral bone marrow and consequently decreased TNF-α and RANK-L concentration in bone, notably improved femoral bone microarchitecture and biomechanical properties, increased the number of osteoblast-like cells, and reduces osteoclastic activity compared to T2DM mice that did not receive the inhibitor. Interestingly, we observed that blood glucose levels and insulin resistance may be related to the increase in activated CD4+ T-cells in the bone marrow. We conclude that bone marrow activated CD4+ T-cells cause poor bone quality and insulin resistance in T2DM.

Upregulation of virulence genes promotes Vibrio cholerae biofilm hyperinfectivity.

Vibrio cholerae remains a major global health threat, disproportionately impacting parts of the world without adequate infrastructure and sanitation resources. In aquatic environments, V. cholerae exists both as planktonic cells and as biofilms, which are held together by an extracellular matrix. V. cholerae biofilms have been shown to be hyperinfective, but the mechanism of hyperinfectivity is unclear. Here we show that biofilm-grown cells, irrespective of the surfaces on which they are formed, are able to markedly outcompete planktonic-grown cells in the infant mouse. Using an imaging technique designed to render intestinal tissue optically transparent and preserve the spatial integrity of infected intestines, we reveal and compare three-dimensional V. cholerae colonization patterns of planktonic-grown and biofilm-grown cells. Quantitative image analyses show that V. cholerae colonizes mainly the medial portion of the small intestine and that both the abundance and localization patterns of biofilm-grown cells differ from that of planktonic-grown cells. In vitro biofilm-grown cells activate expression of the virulence cascade, including the toxin coregulated pilus (TCP), and are able to acquire the cholera toxin-carrying CTXФ phage. Overall, virulence factor gene expression is also higher in vivo when infected with biofilm-grown cells, and modulation of their regulation is sufficient to cause the biofilm hyperinfectivity phenotype. Together, these results indicate that the altered biogeography of biofilm-grown cells and their enhanced production of virulence factors in the intestine underpin the biofilm hyperinfectivity phenotype.

Enhancement of antibiotics antimicrobial activity due to the silver nanoparticles impact on the cell membrane.

The ability of microorganisms to generate resistance outcompetes with the generation of new and efficient antibiotics; therefore, it is critical to develop novel antibiotic agents and treatments to control bacterial infections. An alternative to this worldwide problem is the use of nanomaterials with antimicrobial properties. Silver nanoparticles (AgNPs) have been extensively studied due to their antimicrobial effect in different organisms. In this work, the synergistic antimicrobial effect of AgNPs and conventional antibiotics was assessed in Gram-positive and Gram-negative bacteria. AgNPs minimal inhibitory concentration was 10-12 µg mL-1 in all bacterial strains tested, regardless of their different susceptibility against antibiotics. Interestingly, a synergistic antimicrobial effect was observed when combining AgNPs and kanamycin according to the fractional inhibitory concentration index, FICI: <0.5), an additive effect by combining AgNPs and chloramphenicol (FICI: 0.5 to 1), whereas no effect was found with AgNPs and ß-lactam antibiotics combinations. Flow cytometry and TEM analysis showed that sublethal concentrations of AgNPs (6-7 µg mL-1) altered the bacterial membrane potential and caused ultrastructural damage, increasing the cell membrane permeability. No chemical interactions between AgNPs and antibiotics were detected. We propose an experimental supported mechanism of action by which combinatorial effect of antimicrobials drives synergy depending on their specific target, facilitated by membrane alterations generated by AgNPs. Our results provide a deeper understanding about the synergistic mechanism of AgNPs and antibiotics, aiming to combat antimicrobial infections efficiently, especially those by multi-drug resistant microorganisms, in order to mitigate the current crisis due to antibiotic resistance.

Defining the optimal sequence for the systemic treatment of metastatic breast cancer.

Metastatic breast cancer is a heterogeneous disease that presents in varying forms, and a growing number of therapeutic options makes it difficult to determine the best choice in each particular situation. When selecting a systemic treatment, it is important to consider the medication administered in the previous stages, such as acquired resistance, type of progression, time to relapse, tumor aggressiveness, age, comorbidities, pre- and post-menopausal status, and patient preferences. Moreover, tumor genomic signatures can identify different subtypes, which can be used to create patient profiles and design specific therapies. However, there is no consensus regarding the best treatment sequence for each subgroup of patients. During the SABCC Congress of 2014, specialized breast cancer oncologists from referral hospitals in Europe met to define patient profiles and to determine specific treatment sequences for each one. Conclusions were then debated in a final meeting in which a relative degree of consensus for each treatment sequence was established. Four patient profiles were defined according to established breast cancer phenotypes: pre-menopausal patients with luminal subtype, post-menopausal patients with luminal subtype, patients with triple-negative subtype, and patients with HER2-positive subtype. A treatment sequence was then defined, consisting of hormonal therapy with tamoxifen, aromatase inhibitors, fulvestrant, and mTOR inhibitors for pre- and post-menopausal patien ts; a chemotherapy sequence for the first, second, and further lines for luminal and triple-negative patients; and an optimal sequence for treatment with new antiHER2 therapies. Finally, a document detailing all treatment sequences, that had the agreement of all the oncologists, was drawn up as a guideline and advocacy tool for professionals treating patients with this disease.

Intraperitoneal Immunization with Cry1Ac Protoxin from Bacillus thuringiensis Provokes Upregulation of Fc-Gamma-II/and Fc-Gamma-III Receptors Associated with IgG in the Intestinal Epithelium of Mice.

In humans, intestinal epithelial FcRn is expressed throughout life and mediates the bidirectional transport of IgG, but in mice, it is markedly expressed in neonatal intestine. In adults, its expression is only faintly upregulated after intestinal IgG induction such as that elicited by i.p. immunization with Cry1Ac protoxin (pCry1Ac) Bacillus thuringiensis. This led us to suggest that additional Fcγ receptors (Fcγ-R) may be participating in epithelial IgG uptake. So, first we determined whether CD16/32 [an epitope shared by Fcγ-RII (CD32) and Fcγ-RIII (CD16)] was expressed in the intestinal epithelia of mice. Using confocal microscopy and flow cytometry, we detected co-localization of IgG and CD16/32 in epithelial cells, whose frequency was increased by immunization with pCry1Ac. Western blot and cross-immunoprecipitation results with anti-CD16/32 and IgG antibodies in epithelial cell extracts suggested that epithelial cells bear both Fcγ-RII and Fcγ-RIII and contained IgG associated with Fcγ-RII/RIII. Using anti-CD32 and anti-CD16 antibodies, we confirmed by Western blot, confocal microscopy and flow cytometry that both Fcγ-RII and Fcγ-RIII were expressed and suggested that upregulation occurred upon immunization in intestinal epithelia. Finally, we examined the in vitro effect of anti-CD16/32, anti-CD16 and anti-CD32 antibodies on IgG uptake and transport by intestinal epithelial cells and found that it was partially reduced. Although further studies are still required, our results suggest that Fcγ-RII and Fcγ-RIII might participate in the uptake and/or transport of IgG through the intestinal epithelia of adult mice.

Coadministration of protoxin Cry1Ac from Bacillus thuringiensis with metacestode extract confers protective immunity to murine cysticercosis.

The Bacillus thuringiensis Cry1Ac protoxin (pCry1Ac) is a promising mucosal immunogen and adjuvant that induces protective immunity against Naegleria fowleri and malaria infection models. We determined whether pCry1Ac acted as a protective adjuvant against infection with Taenia crassiceps. BALB/C mice were thrice i.p. immunized with (i) pCry1Ac, (ii) metacestode extract, (iii) extract + pCry1Ac or (iv) vehicle, challenged with metacestodes on day 26 and then sacrificed 35 days later. Cysticerci in the peritoneal cavity were counted, while the serum antibody response and cytokines were analysed after immunization and during infection. Only immunization with pCry1Ac plus extract conferred a significant protection (up to 47%). This group presented fluctuating antibody peaks during infection and the highest IgG1 and IgM titres. Immunization with extract alone elicited high IgG1 and the highest IgG2a responses after 25 days of infection, while nonimmunized mice presented a poor, mixed-Th1/Th2 response during infection. Sharp peaks of TNFα and IFN-γ occurred immediately after the first immunization with extract, especially in the presence of pCry1Ac, but not after the challenge, while in the control and pCry1Ac-alone groups, cytokines were only detected after the challenge. The data support the protective-adjuvant effect of co-administration of pCry1Ac in cysticercosis.

Transient mGlu5R inhibition enhances the survival of granule cell precursors in the neonatal cerebellum.

The generation of the most abundant neurons of the cerebellum, the granule cells, relies on a balance between clonal expansion and apoptosis during the first 10 days after birth in the external germinal layer (EGL). The amino acid glutamate controls such critical phases of cell development in other systems through specific receptors such as metabotropic glutamate receptor 5 (mGlu(5)R). However, the function of mGlu(5)Rs on the proliferation and survival of granule cell precursors (GCPs) remains elusive. We found mGlu(5)R mRNA transcripts in EGL using RT-PCR and observed mGlu(5)R-mediated Ca(2+) responses in GCPs in acute slices as early as postnatal day (P) 2-3. Using in vivo injections of the selective non-competitive mGlu(5)R antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) in P7-P9 mice, we found a 20% increase in the number of proliferative GCPs labeled at P7 with the S-phase marker bromodeoxyuridine (BrdU), but no increase in cell proliferation examined 2h following a BrdU injection. Furthermore, similar treatments led to a significant 70% decrease in the number of apoptotic GCPs in the EGL as determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. In contrast, in vivo treatment with the mGlu(5)R agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG) resulted in a ∼60% increase in the number of TUNEL-labeled GCPs compared to control. These findings identify a unique role for glutamate acting at mGlu(5)Rs as a functional switch regulating GCP survival in the EGL, thus controlling the total number of cerebellar granule cells produced.

Transcriptional regulation of the assT-dsbL-dsbI gene cluster in Salmonella enterica serovar Typhi IMSS-1 depends on LeuO, H-NS, and specific growth conditions.

The assT gene encodes an arylsulfate sulfotransferase, an enzyme that catalyzes sulfuryl transfer from phenolic sulfate to a phenolic acceptor. In Salmonella enterica serovar Typhi IMSS-1, the assT gene is located upstream of the dsbL and dsbI genes, which are involved in a disulfide bond formation required for its activation. The assT-dsbL-dsbI gene cluster forms an operon transcribed by a LeuO-dependent promoter, in rich medium A (MA). Interestingly, in the absence of cloned leuO and in a ΔleuO background, two transcription start sites were detected for assT and two for dsbL-dsbI in minimal medium. The H-NS nucleoid protein repressed the expression of the assT-dsbL-dsbI LeuO-dependent operon, as well as of the assT transcriptional units. Thus, the expression of the assT-dsbL-dsbI gene cluster depends on the global regulatory proteins LeuO and H-NS, as well as on specific growth conditions.

Sodium caseinate induces mouse granulopoiesis.

OBJECTIVE AND DESIGN: Sodium caseinate (CasNa) induces differentiation and M-CSF production in mouse band granulocytes in vitro; however, it is not yet known if this molecule can also induce the proliferation and activation of the granulocyte lineage in vivo. In this work we evaluated the induction in vivo of granulopoiesis and the activation of granulocytes in mice treated with CasNa. MATERIAL OR SUBJECTS: BALB/c male mice 8-12 weeks old were used. TREATMENT: The animals were inoculated intraperitoneally with 1 ml of CasNa (10% in PBS p/v) four times (every 48 h). METHODS: Granulocyte proliferation was evaluated by flow cytometry; activation was evaluated by phagocytic indices. The cytokine was measured using an ELISA assay. RESULTS: We show that CasNa increased bone marrow granulopoiesis percentage (38.35 ± 10.88 vs. 64.94 ± 34.14 BrdU+/Gr-1+ cells) and the granulocytes generated presented increased phagocytic indices (0.3 ± 0.1 vs. 0.6 ± 0.11, p < 0.05). We also show that G-CSF (974 ± 411 vs. 3189 ± 350 pg/ml, p < 0.05) and GM-CSF increased in serum, but only G-CSF in bone marrow plasma. CONCLUSIONS: CasNa induces granulopoiesis with functional granulocytes, suggesting that this molecule could be an innate immune system activator.

Expression of toll-like receptors 2, 4 and 9 is increased in gingival tissue from patients with type 2 diabetes and chronic periodontitis.

BACKGROUND AND OBJECTIVE: Broad evidence indicates that diabetes both increases the risk and hastens the progression of periodontal disease. Likewise, chronic inflammation or infections seem to provoke insulin resistance and thereby contribute to the development of diabetes and its complications. Innate immune responses, which appear to be altered in individuals with diabetes, are usually mediated by the recognition of pathogens through toll-like receptors (TLRs). The constitutive expression of some TLRs has been reported in healthy human gingival tissue. Interestingly, the expression of TLRs 2 and 4 is increased with the severity of periodontal disease. Considering that the inflammatory reaction is exacerbated in individuals with diabetes and periodontitis, we suspected that the expression of some TLRs might be increased in gingival tissue in these patients. MATERIAL AND METHODS: In this study, we analyzed, by immunofluorescence, the expression of TLRs 2, 3, 4 and 9 in gingival tissues from healthy individuals and from periodontal patients with or without type 2 diabetes. RESULTS: We found that the expression levels of TLRs 2, 3, 4 and 9 were higher in all periodontal patients than in healthy individuals. The expression of some TLRs was increased in subjects with periodontitis and diabetes relative to subjects with periodontitis but without diabetes; this increase in expression was found particularly in TLR2 and TLR9 in the connective tissue and in TLR4 at the epithelial region. CONCLUSION: These data suggest that the expression of these TLRs 2, 3, 4 and 9 in gingival tissue is higher in individuals with diabetes because its inflammatory reaction is exacerbated. Additionally, the expression of these TLRS is positively regulated with the severity of periodontal disease.

The CRISPR/Cas immune system is an operon regulated by LeuO, H-NS, and leucine-responsive regulatory protein in Salmonella enterica serovar Typhi.

Prokaryotes have developed multiple strategies to survive phage attack and invasive DNA. Recently, a novel genetic program denominated the CRISPR/Cas system was demonstrated to have a role in these biological processes providing genetic immunity. This defense mechanism is widespread in the Archaea and Bacteria, suggesting an ancient origin. In the last few years, progress has been made regarding the functionality of the CRISPR/Cas system; however, many basic aspects of the system remain unknown. For instance, there are few studies about the conditions and regulators involved in its transcriptional control. In this work, we analyzed the transcriptional organization of the CRISPR/Cas system as well as the positive and negative regulators involved in its genetic expression in Salmonella enterica serovar Typhi. The results obtained show that in S. Typhi the CRISPR/Cas system is a LeuO-dependent operon silenced by the global regulator LRP, in addition to the previously known nucleoid-associated protein H-NS; both LRP and H-NS bind upstream and downstream of the transcriptional start site of casA. In this study, relevant nucleotides of the casA regulatory region that mediate its LeuO transcriptional activation were identified. Interestingly, specific growth conditions (N-minimal medium) were found for the LeuO-independent expression of the CRISPR/Cas system in S. Typhi. Thus, our work provides evidence that there are multiple modulators involved in the genetic expression of this immune system in S. Typhi IMSS-1.

Novel Crystalline SiO(2) Nanoparticles via Annelids Bioprocessing of Agro-Industrial Wastes.

The synthesis of nanoparticles silica oxide from rice husk, sugar cane bagasse and coffee husk, by employing vermicompost with annelids (Eisenia foetida) is reported. The product (humus) is calcinated and extracted to recover the crystalline nanoparticles. X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and dynamic light scattering (DLS) show that the biotransformation allows creating specific crystalline phases, since equivalent particles synthesized without biotransformation are bigger and with different crystalline structure.

The LysR-type transcriptional regulator LeuO controls expression of several genes in Salmonella enterica serovar Typhi.

LeuO is a LysR-type transcriptional regulator that has been implicated in the bacterial stringent response and in the virulence of Salmonella. A genomic analysis with Salmonella enterica serovar Typhi revealed that LeuO is a positive regulator of OmpS1, OmpS2, AssT, and STY3070. In contrast, LeuO down-regulated the expression of OmpX, Tpx, and STY1978. Transcriptional fusions supported the positive and negative LeuO regulation. Expression of ompS1, assT, and STY3070 was induced in an hns mutant, consistent with the notion that H-NS represses these genes; transcriptional activity was lower for tpx and STY1978 in an hns background, suggesting that this global regulatory protein has a positive effect. In contrast, ompS2 and ompX expression appeared to be H-NS independent. LeuO specifically bound to the 5' intergenic regions of ompS2, assT, STY3070, ompX, and tpx, while it was not observed to bind to the promoter region of STY1978, suggesting that LeuO regulates in direct and indirect ways. In this work, a novel set of genes belonging to the LeuO regulon are described; interestingly, these genes are involved in a variety of biological processes, suggesting that LeuO is a global regulator in Salmonella.

Arsenic-induced skin lesions among Atacameño people in Northern Chile despite good nutrition and centuries of exposure.

It has been suggested that the indigenous Atacameño people in Northern Chile might be protected from the health effects of arsenic in drinking water because of many centuries of exposure. Here we report on the first intensive investigation of arsenic-induced skin lesions in this population. We selected 11 families (44 participants) from the village of Chiu Chiu, which is supplied with water containing between 750 and 800 microg/L inorganic arsenic. For comparison, 8 families (31 participants) were also selected from a village where the water contains approximately 10 microg/L inorganic arsenic. After being transported to the nearest city for blind assessment, participants were examined by four physicians with experience in studying arsenic-induced lesions. Four of the six men from the exposed village, who had been drinking the contaminated water for more than 20 years, were diagnosed with skin lesions due to arsenic, but none of the women had definite lesions. A 13-year-old girl had definite skin pigmentation changes due to arsenic, and a 19-year-old boy had both pigmentation changes and keratoses on the palms of his hands and the soles of his feet. Family interviews identified a wide range of fruits and vegetables consumed daily by the affected participants, as well as the weekly intake of red meat and chicken. However, the prevalence of skin lesions among men and children in the small population studied was similar to that reported with corresponding arsenic drinking water concentrations in both Taiwan and West Bengal, India--populations in which extensive malnutrition has been thought to increase susceptibility.

[Levels of lead, cadmium, zinc and arsenic in the water in the province of Salamanca. Multidepartmental coordinated project of investigation supported by the Junta of Castilla Leon in 1884]. / Estudio de los niveles de plomo, cadmio, zinc y arsénico, en aguas de la provincia de Salamanca. Proyecto de Investigación Coordinado Multidepartamental subvencionado por la Junta de Castilla León n.o 1884.

BACKGROUND: To establish the degree of contamination by lead, cadmium, zinc and arsenic in the water in Salamanca province and its relationship with the provenance of the samples and their collection point. METHODS: Transverse, observational, descriptive epidemiological study. Province of Salamanca. RESULTS: Water from water pipes, fountains, springs, wells, rivers, streams and lakes in the province of Salamanca were studied, analyzing the lead, cadmium, zinc and arsenic contents of 180 samples using Atomic Absorption Spectroscopy. Results indicated that 56% of samples analyzed showed toxic levels of cadmium, and 28% of samples gave toxic levels of lead, but showed tolerable levels of zinc and arsenic. No major differences were observed in the degree of contamination by the four elements between the four provincial district areas. Levels of contamination by the four elements were compared for water from the water supply, and samples from wells, fountains, springs and surface water, showing similar contents of the elements studied. CONCLUSIONS: Findings suggest that the water in the province of Salamanca shows "naturally" high cadmium and lead content, probably due to the geological characteristics of the terrain.

Selection and partial characterization of a Pseudomonas aeruginosa mono-rhamnolipid deficient mutant.

Pseudomonas aeruginosa produces rhamnolipids which are tenso-active compounds with potential industrial and environmental applications. There are two main types of rhamnolipids produced in liquid cultures, rhamnosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate (mono-rhamnolipid) and rhamnosyl-rhamnosyl-beta-hydroxydecanoyl-beta-hydroxyd ecanoate (di-rhamnolipid). In this work we report the selective isolation of a rhamnolipid deficient mutant (IBT8), which does not accumulate mono-rhamnolipid while still producing di-rhamnolipid. IBT8 was selected after random mutagenesis with Tn501; yet, its mono-rhamnolipid deficiency was found associated neither with its Tn501 insertion nor with a possible alteration in the rhlABRI genes for rhamnosyl-transferase 1 synthesis. Different possibilities to explain IBT8 phenotype are discussed.

[The effect of lime cooking of corn on phytic acid, calcium, total and ionizable iron content]. / Efecto de la nixtamalización del maíz sobre el contenido de ácido fítico, calcio y hierro total y disponible.

The present study was carried out with the objective to learn about the effect of the nixtamalization process of corn on the content of phytic acid and availability of iron in the lime-cooked corn. For the study, lots of corn with 0, 0.4, 0.8 and 1.20% of lime on the basis of corn weight, in water in the ratio of 3 to 1, and cooking times at each level of lime of 55, 65 and 75 minutes, were processed. Half of the treatments were not soaked after cooking, while the other half were soaked in the cooking solution for a 12-hour period. Statistical analysis of the data and correlations calculated showed that the phytic acid content decreased significantly during the nixtamalization process, affected by the cooking time and the level of lime used, reaching levels of reduction of around 35%. Both the ionizable iron and calcium level increased up to 52-77% and 400-478% respectively. The amount of calcium present in the cooked corn as the result of the lime cooking process, is significantly higher in comparison with the phytic acid content, which may be easily saturated and thus, unavailable to bind iron. An inverse relationship was found between phytic acid and bioavailable iron and its absorption percentage. On the other hand, soaking time did not significantly affected the phytic acid and available iron, although it contributed to a slightly higher Ca accumulation. The amount of ionizable iron was higher at higher levels of lime, which suggested that the nixtamalization process would favor the biological utilization of iron in lime-cooked corn and provide calcium to the diet.

Serotyping of Candida albicans isolated from clinical specimens.

A specific antiserum to Candida albicans serotype A was prepared absorbing a total antiserum with Candida albicans serotype B cells. This specific antiserum was used for serotyping C. albicans strains obtained from patients in different hospitals of Havana City, Cuba. Two hundred strains (95.2%) were serotype A, the remaining 10 (4.8%) were serotype B. Results were also correlated with strains isolated from the specimen origin, sex and race of the patient. The usefulness of this specific antiserum to determine C. albicans serotypes and its therapeutic value are pointed out.