[Spontaneous expulsive choroidal hemorrhage. Case report]. / Hemorragia coroidea expulsiva espontánea. Caso clínico.

CLINICAL CASE: A case is presented of an 85-year-old woman living in a geriatric residence, who was admitted to the emergency department of our hospital with a spontaneous expulsive choroidal hemorrhage in her left eye. There was no a history of ophthalmic disease, and the patient only reported having intracapsular cataract surgery in both eyes 25 years ago, and that she also became blind in her left eye in the past few years. DISCUSSION: Non-surgical spontaneous expulsive choroidal hemorrhage is a very rare and disastrous clinical event. The predisposing factors involved are: advancing age, vascular illness (especially atherosclerosis), glaucoma, and severe corneal damage.

A simple mathematical model that describes the growth of the area and the number of total and viable cells in yeast colonies.

UNLABELLED: We propose a model, based on the Gompertz equation, to describe the growth of yeasts colonies on agar medium. This model presents several advantages: (i) one equation describes the colony growth, which previously needed two separate ones (linear increase of radius and of the squared radius); (ii) a similar equation can be applied to total and viable cells, colony area or colony radius, because the number of total cells in mature colonies is proportional to their area; and (iii) its parameters estimate the cell yield, the cell concentration that triggers growth limitation and the effect of this limitation on the specific growth rate. To elaborate the model, area, total and viable cells of 600 colonies of Saccharomyces cerevisiae, Debaryomyces fabryi, Zygosaccharomyces rouxii and Rhodotorula glutinis have been measured. With low inocula, viable cells showed an initial short exponential phase when colonies were not visible. This phase was shortened with higher inocula. In visible or mature colonies, cell growth displayed Gompertz-type kinetics. It was concluded that the cells growth in colonies is similar to liquid cultures only during the first hours, the rest of the time they grow, with near-zero specific growth rates, at least for 3 weeks. SIGNIFICANCE AND IMPACT OF THE STUDY: Mathematical models used to predict microbial growth are based on liquid cultures data. Models describing growth on solid surfaces, highlighting the differences with liquids cultures, are scarce. In this work, we have demonstrated that a single Gompertz equation describes accurately the increase of the yeast colonies, up to the point where they reach their maximum size. The model can be used to quantify the differences in growth kinetics between solid and liquid media. Moreover, as all its parameters have biological meaning, it could be used to build secondary models predicting yeast growth on solid surfaces under several environmental conditions.

[Phenotypic changes in the mononuclear cells of patients with primary immunodeficiencies]. / Alteraciones fenotípicas en células mononucleares de pacientes con inmunodeficiencias primarias.

The study of differentiation antigens of circulating mononuclear cells in 70 patients with primary immunodeficiency (PID) using monoclonal antibodies allowed us to define phenotypic profiles that are characteristic of the different described syndromes. In common variable immunodeficiency we found percentages of lymphocytes within normal ranges, and an altered CD4/CD8 ratio. In sex-linked agammaglobulinemia, absence of B lymphocytes with normal distribution of regulatory populations (CD4/CD8) were found. These results allow us to distinguish two clinically and infectologically similar conditions. In selective IgA deficiency, distribution of lymphocytic populations was normal. In immunodeficiency with hyper IgM, considered up to date as an abnormal maturation of B lymphocytes, we observed a deficiency in cellular immune response, and a phenotypic profile characterized by: decreased number of CD3 cells, inverted CD4/CD8 ratio, and increased CD38 population; this profile being similar to the one that we found in predominantly cellular immunodeficiency. In predominantly cell-mediated immunodeficiency and in those immunodeficiencies associated to other defects (such as: hyper IgE syndrome, Di George syndrome), the most important finding was a significative increase in CD38 population. Although it's not possible to consider on this basis that there is a defect at the thymic level of T-cells maturation, the high levels of circulating CD38 cells were a clear indication of altered cellular immune response in our series of patients. Patients with predominantly cell-mediated immunodeficiency showed the lowest levels of CD4 cells and the corresponding inversion of CD4/CD8 ratio. In Di George syndrome we found a markedly diminished CD8 population that differentiates this entity from the rest of the studied syndromes. In chronic mucocutaneous candidosis distribution of lymphocytic populations was normal, but a significative increase in the percentages of CD11b+ cells was observed. In patients with antibodies deficiency that received substitutive treatment with gammaglobulin we found no variations in lymphocytic populations distribution. In the group of patients with altered cellular immunity treated with thymic hormones, observed phenotypic changes (increase in T-cells population, trend to normalization in CD4/CD8 ratio, and decrease in CD38 population) were transient, and lasted only during the treatment period. We considered that describing these phenotypic profiles is a useful diagnosis tool when evaluating patients with PID, since these profiles are characteristic and very stable.