Silicosis en trabajadores expuestos aconglomerados de cuarzo / Silicosis in workers exposed to quartz conglomerates

Introducción: la silicosis, enfermedad crónica, causada por la inhalación de polvo de sílice cristalina, sigue siendo un problema de salud laboral vigente. El objetivo de la investigación consistió en estimar el riesgo de silicosis complicada y/o acelerada en trabajadores expuestos a polvo de sílice de conglomerados de cuarzo frente al riesgo de los trabajadores expuestos a roca ornamental. Método: se desarrolló un estudio analítico de casos y controles prevalentes en trabajadores cuya vigilancia de la salud se realizó en el instituto Nacional de Silicosis (España), entre el 1 de enero de 2008 y el 31 de diciembre de 2018 (N = 90). El valor de la significación de todos los contrastes de hipótesis realizados fue α = 0,05. Resultados: se determinó mayor riesgo de silicosis complicada en los trabajadores expuestos a polvo de sílice proveniente del uso de conglomerados de cuarzo mediante el cálculo de Chi cuadrado, con un total de 7 casos (46,67%) de silicosis complicada (p = 0,046). Conclusiones: existe mayor riesgo de silicosis complicada en los trabajadores expuestos a polvo de sílice proveniente del uso de conglomerados de cuarzo frente a los expuestos a polvo de sílice de roca ornamental. No se observó relación entre el riesgo de desarrollar silicosis acelerada y la exposición a conglomerados de cuarzo en la muestra analizada (AU)

Introduction: silicosis, a chronic disease caused by the inhalation of crystalline silica dust, continues to be a current occupational health problem. The objective of the research was to estimate the risk of complicated and/or accelerated silicosis in workers exposed to silica dust from quartz conglomerates compared to the risk of workers exposed to ornamental rock. Method: an analytical study of cases and controls prevalent in workers whose health surveillance was carried out at the National Institute of Silicosis (Spain), between January 1, 2008 and December 31, 2018 was developed (N = 90). The significance value of all the hypotheses tests performed was α = 0.05. Results: a higher risk of complicated silicosis was determined in workers exposed to silica dust from the use of quartz conglomerates by calculating Chi square, with a total of 7 cases (46.67%) of complicated silicosis (p = 0.046). Conclusions: there is a higher risk of complicated silicosis in workers exposed to silica dust from the use of quartz conglomerates compared to those exposed to silica dust from ornamental rock. No relationship was observed between the risk of developing accelerated silicosis and exposure to quartz conglomerates in the analyzed sample (AU)

Percepción del comportamiento alimentario en los hogares de Cali para el primer trimestre de la cuarentena por COVID-19 en 2020 / Perception of feeding behavior in Cali homes during the first trimester of quarantine due to COVID-19 in 2020

Resumen Introducción: En 2020, la Organización Mundial de la Salud (OMS) declaró la emergencia de salud pública por SARS-CoV-21; el 11 de marzo de 2020 se notificó la pandemia global por COVID-19 y el gobierno colombiano decretó para todas las ciudades el aislamiento preventivo obligatorio2. Para el mes de mayo, Cali reportó 1635 casos de COVID confirmados y 85 fallecidos por un virus con un 4,95% de letalidad3. Lo anterior influenció de forma importante las rutinas alimentarias de las familias durante el primer trimestre del periodo de confinamiento. Considerando que esta situación era atípica en el país, era necesario describir la percepción del comportamiento alimentario durante este primer trimestre de aislamiento preventivo obligatorio en la ciudad de Cali, considerando las normas de bioseguridad establecidas para el periodo mencionado. Objetivo: Describir el comportamiento alimentario de 1814 familias en Cali durante el primer trimestre de aislamiento preventivo obligatorio. Metodología: Estudio cuantitativo, descriptivo transversal, con técnica de encuesta. Se aplicó un instrumento virtual compuesto por 28 ítems, que indagó el comportamiento alimentario de las familias. Discusión: Se encontró que el 95,1% de los hogares percibió escasez y aumento de precios en alimentos que componen la canasta alimentaria familiar, y el 67,2% de las familias estuvieron preocupadas por la alimentación. Hubo un aumento en el consumo de alimentos y se modificó el número de tiempos de comida/día. Los hábitos alimentarios, ingesta de refrescos y consumo de alcohol también se modificaron durante confinamiento. Conclusiones: Se puede afirmar que durante el primer trimestre de cuarentena por COVID-19 en Cali se modificó el comportamiento alimentario de las familias encuestadas, una de las razones estuvo relacionada con un cambio en los ingresos económicos, que afectó la cantidad de dinero disponible para alimentos. Durante este periodo se modificaron también los tiempos de comida y la variedad en la ingesta de alimentos. En general, se describieron aspectos que afectaron la seguridad alimentaria de las familias.

Abstract Introduction: In 2020, the World Health Organization (WHO) declared a public health emergency due to SARS-CoV-21. On March 11, 2020, the global pandemic due to COVID-19 was declared, with which the Colombian government decreed mandatory preventive isolation in the country2. In May, Cali reported 1,635 confirmed COVID cases and 85 deaths from a virus with a 4.95 % case fatality rate3. This situation affected families eating routines during this period. Considering that this situation was atypical in the country, it was necessary to describe the perception of feeding behavior during this first trimester of mandatory preventive isolation in the city of Cali, considering the biosafety standards established by the national government. Objetive: To describe the feeding behavior of 1,814 families in Cali during the first trimester of mandatory preventive isolation. Methodology: Cross-sectional, descriptive and quantitative study. A virtual instrument composed of 28 items was applied, which investigated the feeding behavior of the families. Convenience sampling. Results: The results show that the economic income of families, as well as the distribution of expenses within the home, were affected in the evaluated period. In addition, it was found that 95.1 % of households perceived shortages and price increases in foods that make up the family food basket; 67.2% of families were concerned about food. There was an increase in food consumption and the number of perhaps consider, meals per day was modified. Eating habits, soft drink intake and alcohol consumption also changed during confinement in the evaluated time. Conclusions: It can be affirmed families modified their feeding behaviors during the first quarter of quarantine due to COVID-19. Because the economic income of families was affected, the money available for food purchases was affected as well. During this time, perhaps consider: meal frequencies and, in general, the variety in food intake was also modified. Finally, the results suggest perhaps consider: a negative effect in the food security of families.

The electronic nose as a rule-out test for tuberculosis in an indigenous population.

INTRODUCTION: To end the tuberculosis (TB) epidemic, efficient diagnostic tools are needed. In a previous calibration study, a portable 'point of care' electronic nose device (AeonoseTM ) proved to be a promising tool in a hospital setting. We evaluated this technology to detect TB in an indigenous population in Paraguay. METHODS: A total of 131 participants were enrolled. eNose results were compared with anamnesis, physical examinations, chest radiography and mycobacterial cultures in individuals with signs and symptoms compatible with TB. The eNose analysis was performed in two stages: first, the training with a combination of a previous study population plus 47 participants from the new cohort (total n = 153), and second, the 'blind prediction' of 84 participants. RESULTS: 21% of all participants (n = 131) showed symptoms and/or chest radiography abnormalities suspicious of TB. No sputum samples resulted culture positive for Mycobacterium tuberculosis complex. Only one patient had a positive smell print analysis. In the training model, the specificity was 92% (95% confidence interval (CI): 85%-96%) and the negative predictive value (NPV) was 95%. In the blind prediction model, the specificity and the NPV were 99% (95% CI: 93%-99%) and 100%, respectively. Although the sensitivity and positive predictive value of the eNose could not be assessed in this cohort due to the small sample size, no active TB cases were found during a one year of follow-up period. CONCLUSION: The eNose showed promising specificity and negative predictive value and might therefore be developed as a rule-out test for TB in vulnerable populations.

Chikungunya virus antagonizes cGAS-STING mediated type-I interferon responses by degrading cGAS.

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus known to cause epidemics resulting in predominantly symptomatic infections, which in rare cases cause long term debilitating arthritis and arthralgia. Significant progress has been made in understanding the roles of canonical RNA sensing pathways in the host recognition of CHIKV; however, less is known regarding antagonism of CHIKV by cytosolic DNA sensing pathways like that of cyclic GMP-AMP synthase (cGAS) and Stimulator of Interferon Genes (STING). With the use of cGAS or STING null cells we demonstrate that the pathway restricts CHIKV replication in fibroblasts and immune cells. We show that DNA accumulates in the cytoplasm of infected cells and that CHIKV blocks DNA dependent IFN-ß transcription. This antagonism of DNA sensing is via an early autophagy-mediated degradation of cGAS and expression of the CHIKV capsid protein is sufficient to induce cGAS degradation. Furthermore, we identify an interaction of CHIKV nsP1 with STING and map the interaction to 23 residues in the cytosolic loop of the adaptor protein. This interaction stabilizes the viral protein and increases the level of palmitoylated nsP1 in cells. Together, this work supports previous publications highlighting the relevance of the cGAS-STING pathway in the early detection of (+)ssRNA viruses and provides direct evidence that CHIKV interacts with and antagonizes cGAS-STING signaling.

Experimental characterization of a biosensor based on a tapered optical fiber for kisspeptin detection.

This paper presents the development of a biosensor based on optical fiber, using a polyclonal antibody kisspeptin receptor as a biological recognition element that is connected to puberty onset and may also help to suppress metastasis in melanoma breast cancer. The fiber surface was chemically prepared to immobilize the antibody. The structural homogeneity of the biosensor, at each stage of the self-assembly, was characterized by Fourier transform infrared spectroscopy and by measurements of the transmission at the output of the biosensor. The morphological homogeneity analysis was performed by optical microscopy and scanning electron microscopy. The biosensor developed was checked to detect kisspeptin in brain tissues by spectral transmission using a superluminescent diode. The data were analyzed using principal component analysis. The interaction of the kisspeptin with its counterpart by means of the evolution of the transmission spectrum as a function of time was observed.

Giant mesenteric cyst from the small bowel mesentery in a young adult patient.

Mesenteric cysts are rare tumors, they can emerge from any part of the mesentery of the bowel from the duodenum to the rectum. Their symptomatology can mimic almost any abdominal disease making diagnosis troublesome. In some circumstances, these cysts can grow to considerable sizes making resection almost impossible since its size can compromise different structures. Surgery is the treatment of choice as complete resection is the only curative treatment. We present a case of a female patient, she suffered from recurrent episodes of abdominal pain mistaken as gastritis. After a profound evaluation, a giant mass in her abdomen was identified and successfully treated. Giant primary mesenteric cyst was the final diagnosis.

Caracterización y comparación de la actividad antibacteriana intrínseca del suero de búfalo y del suero de bovino

La actividad antibacteriana de los sueros de bovino y de búfalo fue evaluada in vitro de manera indirecta con dos reacciones de inmunohemólisis: (i) un ensayo de hemólisis-hemoaglutinación sobre eritrocitos no sensibilizados de conejo y (ii) un ensayo de cinética de eritrocitos no sensibilizados de conejo frente a concentraciones crecientes de suero. La actividad bactericida de los sueros fue evaluada in vitro cuantificando la reducción de desarrollo de un inóculo de Escherichia coli en medio de cultivo enriquecido con suero de ambas especies. En el ensayo de hemólisis-hemoaglutinación, la hemólisis máxima se observó hasta la dilución 1:16 del suero de ambas especies. El mayor porcentaje de hemólisis se obtuvo con el suero de búfalo (84,7 ± 9,71%) respecto del suero bovino (71,0 ± 5,05%). Sin embargo no se hallaron diferencias en las diluciones de suero necesarias para obtener el 50% de la hemólisis total, siendo estas de 10,2 ± 2,48 para el suero de bovinos y de 11,8 ± 2,18 para el suero de búfalo. El suero de búfalo redujo el desarrollo bacteriano en un 69,8% respecto del 47,2% obtenido por el suero de bovino. No obstante estos resultados, se necesitarán estudios adicionales para corroborar estos hallazgos in vivo.

The antibacterial activity of serum of bovine and buffaloes was evaluated in vitro indirectly by two immunohemolysis assays: (i) an unsensitized rabbit blood cells hemolysis-hemagglutination assay and (ii) and a hemolytic-kinetic of unsensitized rabbit blood cells in function of increasing serum concentrations. The serum bactericidal activity was evaluated in vitro by quantifying the reduction of the development of an Escherichia coli inoculum in a culture medium enriched with serum of both species. In the hemolysis-hemagglutination assay, the máximum haemolysis was observed until a 1:16 serum dilution for both species. The highest percentage of hemolysis was obtained with buffalo serum (84.7 ± 9.71%) with respect to bovine serum (71.0 ± 5.05%). However, no differences were found in the serum dilutions necessary to obtain 50% of the total hemolysis, being these 10.2 ± 2.48 for the serum of cattle and 11.8 ± 2.18 for the serum of buffalo. Buffalo serum reduced bacterial growth by 69.8% compared to 47.2% obtained by bovine serum. Despite these results, additional studies will be needed to corroborate these findings in vivo.

Urgencias en ginecología oncológica / Emergencies in oncological gynaecology

En este trabajo se describen los signos de sospechade neoplasia por los que la paciente acude al Serviciode Urgencias, centrándonos en el sangrado genital,la masa pélvica y el prurito vulvar. Los pacientestambién pueden acudir por procesos resultantes decomplicaciones de la enfermedad, como en el caso dela obstrucción ureteral, la carcinomatosis, la ascitis,procesos tromboembólicos, hemorragias, estreñimiento,náuseas y vómitos, obstrucción intestinal y dolor.Por último, se describen complicaciones secundarias altratamiento como el linfocele abdominal e inguinal y laenteritis y proctitis postradioterápica(AU)

This article describes the signs for suspecting neoplasiathat lead the patient to come to the Accident andEmergency Service, concentrating on genital bleeding,pelvic mass and vulvar pruritus. Patients can also comedue to processes resulting from complications of thedisease, such as urethral obstruction, carcinomatosis,ascites, thromboembolic processes, haemorrhages,constipation, nausea and vomiting, intestinal obstructionand pain. Finally, we describe complications thatare secondary to the treatment, such as abdominal andinguinal lymphocele and post-radiotherapy enteritisand proctitis(AU)

[Emergencies in oncological gynaecology]. / Urgencias en ginecología oncológica.

This article describes the signs for suspecting neoplasia that lead the patient to come to the Accident and Emergency Service, concentrating on genital bleeding, pelvic mass and vulvar pruritus. Patients can also come due to processes resulting from complications of the disease, such as urethral obstruction, carcinomatosis, ascites, thromboembolic processes, haemorrhages, constipation, nausea and vomiting, intestinal obstruction and pain. Finally, we describe complications that are secondary to the treatment, such as abdominal and inguinal lymphocele and post-radiotherapy enteritis and proctitis.

[Psychological impact of the diagnosis of Alzheimer's disease]. / Impacto psicológico del diagnóstico de la enfermedad de Alzheimer.

INTRODUCTION: The communication of the diagnosis of Alzheimer's disease (AD) may represent important emotional distress for the patient and his/her caregiver. This present work aimed to investigate if the disclosure of the diagnosis generates any emotional or psychological impact on the patient or his/her caregiver. PATIENTS AND METHODS: Thirty-three consecutive AD patients (NINCDS/ADRDA criteria) and their main caregivers were evaluated before and after the diagnosis disclosure. Patients were evaluated with the Neuropsychiatric Inventory Questionnaire (NPI-Q) and the Geriatric Depression Scale (GDS) and caregivers were evaluated with Beck's Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), the stress subscale from the NPI-Q and Zarit's burden interview. RESULTS: A total of 26 patients wanted to receive the diagnosis. AD diagnosis disclosure did not produce any significant clinical or emotional changes in the patient. On the contrary, the caregivers were significantly affected by AD diagnosis disclosure. This was reflected on the BDI scores, that increased from 6.9+/-6.5 to 9.7+/-7.5 (p=0.003). CONCLUSIONS: AD diagnosis may be safely disclosed to the patient. However, the caregivers should be carefully followed-up since depressive symptoms are common after diagnosis disclosure.

Impacto psicológico del diagnóstico de la enfermedad de Alzheimer / Psychological impact of the diagnosis of Alzheimer’s disease

Introducción. La comunicación del diagnóstico de la enfermedad de Alzheimer (EA) puede representar un importante impacto emocional para el paciente y su cuidador. El objetivo de este estudio es investigar si la transmisión de dicho diagnóstico genera algún impacto emocional o psicológicoen el paciente o el cuidador.Pacientes y métodos. Treinta y tres pacientes consecutivos con EA (criterios NINCDS/ADRDA) y sus cuidadoresprincipales fueron evaluados prospectivamente antes y despuésde recibir el diagnóstico. Los pacientes fueron evaluados con el Neuropsychiatric Inventory Questionnaire (NPI-Q) y la Geriatric Depression Scale (GDS) y los cuidadores fueron evaluados a través del Beck’s Depression Inventory(BDI), el State-Trait Anxiety Inventory (STAI), la subescala deestrés del cuidador del NPI y la entrevista sobre la carga delcuidador Zarit. Resultados. Veintiséis pacientes quisieron recibir eldiagnóstico. La comunicación del diagnóstico de EA no produjocambios clínicos ni emocionales significativos en los pacientes. Por el contrario, los cuidadores al conocer eldiagnostico de EA de su familiar presentaron sintomatologíadepresiva leve, que se reflejó en los cambios de la escala BDI, que de 6,9±6,5 aumentó a 9,7±7,5 (p=0,003).Conclusiones. La comunicación del diagnóstico de EA resulta segura para los pacientes. Sin embargo, los cuidadores deberían ser también valorados, dado que la sintomatologíadepresiva es común después de la comunicación deldiagnóstico (AU)

Alzheimer’s disease Introduction. The communication of the diagnosisof Alzheimer’s disease (AD) may represent important emotional distress for the patient and his/her caregiver.This present work aimed to investigate if the disclosure of the diagnosis generates any emotional or psychological impact on the patient or his/her caregiver. Patients and methods. Thirty-three consecutive ADpatients (NINCDS/ADRDA criteria) and their main caregivers were evaluated before and after the diagnosis disclosure.Patients were evaluated with the Neuropsychiatric Inventory Questionnaire (NPI-Q) and the GeriatricDepression Scale (GDS) and caregivers were evaluated with Beck’s Depression Inventory (BDI), State-Trait AnxietyInventory (STAI), the stress subscale from the NPI-Q and Zarit’s burden interview. Results. A total of 26 patients wanted to receive the diagnosis. AD diagnosis disclosure did not produce anysignificant clinical or emotional changes in the patient. On the contrary, the caregivers were significantly affectedby AD diagnosis disclosure. This was reflected on the BDI scores, that increased from 6.9±6.5 to 9.7±7.5 (p=0.003). Conclusions. AD diagnosis may be safely disclosedto the patient. However, the caregivers should be carefully followed-up since depressive symptoms are commonafter diagnosis disclosure (AU)

Trastornos de la conducta alimentaria en mujeres embarazadas controladas en atención primaria / Eating disorders in pregnant women controlled in primary care

Antecedentes: En relación al impacto de los trastornos de la conducta alimentaria (TCA) sobre el embarazo, la mayoría de la evidencia advierte sobre consecuencias negativas prenatales y postnatales para la madre y el feto. Objetivo: Determinar la presencia de comportamientos alimentarios anormales en gestantes controladas en atención primaria, y analizar descriptiva y comparativamente las pacientes con estas actitudes en relación con variables maternas, del embarazo, rasgos psicológicos y conductuales. Método: 141 pacientes embarazadas fueron encuestadas con el test de actitudes alimentarias (EAT-40) y el inventario de trastornos alimentarios (EDI), a los cuales se añadieron preguntas relativas al embarazo e historia de TCA. Resultados: 23,4 por ciento de las encuestadas obtuvieron puntajes en rango patológico de EAT-40, donde la historia previa de TCA emerge como un factor de riesgo importante para el desarrollo de un desorden alimentario en estas pacientes. Otras diferencias se observaron en los puntajes del EAT-40, el EDI y todas sus subescalas. Conclusión: La cifra alcanzada para conductas anormales de alimentación supera ampliamente a la planteada para TCA clínicos, los que además reflejan tendencia a la cronicidad aun en el embarazo. Se requieren estudios adicionales que orienten a los profesionales de salud en la prevención, detección y tratamiento de los TCA en el embarazo.

Background: According to the impact of eating disorders on pregnant women, most evidence shows negative pre and post natal consequences for the mother and the fetus. Objective: To determine the presence of abnormal eating behaviors in pregnant women controlled in primary care, and to describe and compare eating disordered patients in relation to the pregnancy, maternal, psychological and behavioral characteristics. Method: The Eating Attitudes Test (EAT-40), the Eating Disorders Inventory (EDI) and a questionnaire about demographic and pregnancy data and previous history of eating disorders were administered to 141 pregnant women. Results: 23.4 percent of the polled women scored within the pathological range of EAT-40, in whom the prior history of eating disorders emerged as the most important factor of risk to develop an eating disorder in these patients. Furthermore, considerable differences were seen in the average of EAT-40 scores and in the EDI and its all subscales. Conclusion: The percentage of pregnant women who displayed abnormal eating behaviors exceeds the rate described in literature for clinical eating disorders. Besides, it reflect tendency to be a chronic disease even in pregnancy. Additional studies are required to help health personnel to prevent, detect and treat women with eating disorders in pregnancy.

[Severe intoxication with verapamil]. / Intoxicación grave con verapamilo.

Calcium channel blockers are currently widely used to treat many cardiological alterations; however, overdose and poisoning have been associated with morbidity and mortality mainly in those patients with suicidal attempts. We report a case and review the pathophysiology of overdose, treatment, and prognosis.

Murine cytomegalovirus CC chemokine homolog MCK-2 (m131-129) is a determinant of dissemination that increases inflammation at initial sites of infection.

The murine cytomegalovirus CC chemokine homolog MCK-2 (m131-129) is an important determinant of dissemination during primary infection. Reduced peak levels of viremia at day 5 were followed by reduced levels of virus in salivary glands starting at day 7 when mck insertion (RM461) and point (RM4511) mutants were compared to mck-expressing viruses. A dramatic MCK-2-enhanced inflammation occurred at the inoculation site over the first few days of infection, preceding viremia. The data further reinforce the role of MCK-2 as a proinflammatory signal that recruits leukocytes to increase the efficiency of viral dissemination in the host.

Reactions of amino alcohols in superacid: the direct observation of dicationic intermediates and their application in synthesis.

[reaction: see text]. The chemistry of amino alcohols has been studied in superacidic media, and these compounds have been found to ionize cleanly to the dication intermediates. Several dicationic species have been directly observed by low-temperature 13C NMR, including those from epinephrine (adrenaline) and synephrine. Amino alcohols react (70-99% yields) with C6H6 in triflic acid (CF3SO3H) by electrophilic aromatic substitution.

Linfangioma quístico retroperitoneal tratado durante la gestación / Retroperitoneal cystic lymphangioma treated during gestation

No disponible

[Monitoring of cytomegalovirus infection in patients with kidney transplantation: the first experience in Cuba]. / Monitoreo de la infección por citomegalovirus en pacientes con trasplante renal: primera experiencia en Cuba.

Kidney transplantation is at present the most efficient therapeutic tool to treat end-stage chronic kidney failure. Graft rejection and infections are the most important barriers to the success of transplantation, whereas cytomegalovirus (CMV) has been the most reported causal agent of morbidity in this type of patients. The evolution of a group of 12 patients who underwent kidney transplantation at the Nephrology Institute was studied during 16 weeks aimed at monitoring the infection caused by CMV. 58.4% of these patients were positive and 28% showed clinical evidences of the disease. Most of the infected patients were observed between the 4th and the 12th week after transplantation. CMV infection was confirmed in 70% of the individuals undergoing a high immunosuppression. 50% of the total of patients developed graft rejection episodes some time during the evolution and 83.3% were diagnosed CMV infection.

[Effect of trace metals on cell morphology, enzyme activation, and production of citric acid in a strain of Aspergillus wentii]. / Efecto de metales traza sobre la morfología celular, actividad enzimática y producción de ácido cítrico en una cepa de Aspergillus wentii.

Data concerning the effect of very low concentrations of metals on citric acid production by microorganisms, as well as on the activity of enzymes presumptively involved in the process, are confuse. The bulk of information was obtained mainly studying selected strains of Aspergillus niger. Information concerning other citric acid producer filamentous fungi, such as A. wentii, is scanty. In the present article we report the effect of different cations on the growth pattern of A. wentii P1 as well as on the related citric acid production and the activity of several enzymes. It was found that without any addition to the culture medium the fungus developed a pelleted form of growth, pellets being about 1.5 mm in diameter. The citric acid yield was about 90%. The addition of Cu2+ impaired the sugar uptake, as well as the production of citric acid and biomass. The uptake of sugar increased in the presence of Zn2+, and there was a marked increase of the biomass production, which could account for the low citric acid production. The addition of Fe2+ impaired the citric acid production and, as sulfate, the sugar uptake. The presence of Fe3+ markedly impaired the citric acid production and increased the sugar uptake. There is no agreement about the enzymes involved in the accumulation of citric acid by microorganisms. In spite of this, aconitase (Ac), isocitrate lyase (IL), isocitrate dehydrogenase NAD(+)-dependent (ICDH- NAD+) and isocitrate dehydrogenase NADP(+)-dependent (ICDH-NADP+) are often postulated as key enzymes. In our case, these enzymes were active during the standard fermentation, although with variations, particularly concerning Ac and IL. The behavior of enzymes might be different when tested in vivo or in vitro, mainly from the quantitative point of view. Nevertheless, the activity determined in vitro might give some indication concerning the effect on fermentation of substances present in the medium. It was found that all the enzymes tested increased their activity in the presence of Fe2+ and Fe3+. The addition of Cu2+ improved the activity of Ac, IL and ICDH-NADP+, while that of ICDH-NAD+ was impaired. The presence of Zn2+ decreased the activity of the enzymes excepting that of ICDH-NADP+ which increased. It must be pointed out that according to these results there are differences concerning the behavior of ICDH-NAD+ and ICDH-NADP+ in the presence of Cu2+ or Zn2+.