Ultrasound biomicroscopic analysis of iris cysts.

PURPOSE: To describe the ultrasound biomicroscopic (UBM) features and complications associated with iris cysts. DESIGN: A retrospective case series. METHODS: Thirteen patients with iris cysts were identified in a 10 year period study at a ophthalmologic reference Center in Mexico City. The variables included demographic data, ocular and medical history, clinical course, and complications. All patients were examined by UBM, and type, number, location, and acoustic characteristics of cysts were evaluated. Descriptive statistics were performed. RESULTS: Thirteen patients were included (8 men and 5 women). The mean age was 44.5 ± 15.5 years (range 6-70 years). The origin most prevalent was neuroepithelial (92.3%), and 7.7% had stromal cysts. Regarding to location 76.9% were found in the periphery, and 69.2% between meridians II and VI. All cysts showed a moderate to high reflectivity in the wall. Complications were present in 38.5% of cases (15.4% partial angle closure, 15.4% secondary angle closure glaucoma and 7.7% dyscoria). CONCLUSIONS: Most cysts are derived from iris pigmented epithelium, with a benign course and a minor rate of complications. The UBM is an indispensable tool that allows us to plan more specific and conservative treatments, with less damage to ocular structures and, therefore, better visual prognosis.

Frequency of antibodies to Toxoplasma gondii in stray dogs of Oaxaca, México.

We studied the frequency of antibodies against Toxoplasma gondii in stray dogs in the city of Oaxaca, Mexico through the evaluation of 154 sera by indirect ELISA. A frequency of 61.7% was found; it was higher in males (45 of 65, 69.2%) than in females (49 of 89, 55.0%), although this difference was not statistically significant. An increase in frequency was observed with age, the lowest being among animals younger than 1 yr (4 of 20, 20.0%) and the highest in dogs older than 7 yr (21 of 25, 84.0%). This is the first study in dogs of this region of Mexico and revealed high T. gondii transmission and evidence of early exposure in animals that are in close contact with contaminated water or raw meat, or both. Further studies are needed in order to understand the role of T. gondii infection in public health.

Compliance to the prescribed overall treatment time (OTT) of curative radiotherapy in normal clinical practice and impact on treatment duration of counteracting short interruptions by treating patients on Saturdays.

BACKGROUND AND PURPOSE: To evaluate the compliance of the prescribed OTT in a normal clinical practice and to establish the incidence, duration and causes of unplanned interruptions of radiation therapy. To quantify the impact of an institutional policy to maintain the OTT counteracting some short interruptions by treating patients on Saturday morning. MATERIAL AND METHODS: The treatment charts of all new patients treated with curative intent in a period of one year were reviewed retrospectively. All treatments started on Monday or Tuesday and split-course was not used. The difference between the actual realized and the planned OTT was calculated as a measure of compliance. Recalculations of OTT were made to quantify the impact of compensating short gaps by treating patients on Saturday. The cause of interruption was also recorded and classified. RESULTS: The charts of 478 consecutive patients treated with curative intent were reviewed. The overall incidence of unplanned interruptions was 76.6%. Public holidays and machine maintenance caused most of interruptions, and machine breakdown caused 13%. 17.9% of the interruptions were greater than 5 days and 5.6% greater than 10 days. Only 23.4% of patients finished their radiotherapy in the planned OTT (12.6% if no compensation on Saturday). 48.9% of head and neck cancer patients finished their treatment in the planned OTT (19.5% if no compensation on Saturday). The time in excess ranged up to 44 days, and the average time in excess was 3.3 days for the entire group (4.2 days if no compensation on Saturday). For head and neck cancer patients, the time in excess was 1.9 days (3.9 days if no compensation on Saturday). CONCLUSIONS: This study has documented that the incidence and duration of unplanned interruptions of standard treatment schedules is a major problem in normal clinical practice. Most interruptions are short and due mainly to public holidays and machine maintenance and for these reasons they can be planned. In spite of the extra costs, counteracting some short interruptions by treating patients on Saturday is a good way to maintain the OTT without loss of local control.

[Current immunologic and molecular data on the epidemiology of histoplasmosis in Morelos, Mexico]. / Actualidades inmunológicas y moleculares sobre la epidemiología de la histoplasmosis en Morelos, México.

The aim of the present paper was to analyze current data distribution of systemic mycosis, i.e. histoplasmosis, in the state of Morelos, Mexico. Data were collected based on immunoepidemiologic studies and preliminary molecular-epidemiologic results. The occupational activities of the rural population exposed to risk of infection, findings on genetic polymorphisms, and spread of the causative agent in nature were considered. These will be processed to propose criteria for establishing the prevalence of this mycosis in Morelos and to elaborate an epidemiologic map of the state.

The syndrome of presumed ocular histoplasmosis in Mexico: a preliminary study.

A study to screen for the syndrome of presumed ocular histoplasmosis (SPOH) among native populations from three Mexican states was performed. Two of these states, Guerrero and Querétaro, were selected as histoplasmosis is endemic there, whereas Tlaxcala was considered a control, due to the absence of reported cases. A total of 253 individuals were submitted to ocular fundus examination to obtain evidence of SPOH. A high percentage of positive reactors to histoplasmin skin test (ST) was observed in Guerrero (83%) and Querétaro (53%), whereas in Tlaxcala positive ST were almost absent (2.04%). Only five individuals had retinal lesions, although these lesions were not characteristic of the syndrome. Stimulation of these individual's cells showed different patterns in the histoplasmin-induced lymphocyte transformation response, and two out of five individuals with retinal lesions presented a stimulated response, as well as three controls without lesions. Histocompatibility antigens (HLA) were determined in a sample of each population and no particular allele, including HLA-B7, was found to be related to SPOH as reported in the USA; however, HLA-B22 was found in three individuals who developed pulmonary histoplasmosis. Results do not provide clinical evidence or data on specific HLA risk factors, for the presence of SPOH in the population studied.

Retrospective serological study of histoplasmosis in Mexico.

Mycotic immunodiagnosis was performed in 325 patients with clinical evidence of systemic mycoses, over a 5-year period, from different hospitals of Mexico City. Results showed 168 individuals that presented one positive serological test to Histoplasma capsulatum antigens. From these, only 27 patients were serologically positive to two or more tests, such as tube precipitin, immunodiffusion, complement fixation, and ELISA, and developed signs and symptoms of a histoplasmosis clinically classified as primary pulmonary. Four of them presented an underlying disease including one positive HIV patient. Twenty-two came from endemic histoplasmosis zones of the country and most of them acquired the disease in caves or uninhabited houses. The diagnosis of histoplasmosis should be based on reliable laboratory data which could raise more significant information of its incidence in Mexico.