Stress response and adaptation mechanisms in Kluyveromyces marxianus.

Kluyveromyces marxianus is a non-Saccharomyces yeast that has gained importance due to its great potential to be used in the food and biotechnology industries. In general, K. marxianus is a known yeast for its ability to assimilate hexoses and pentoses; even this yeast can grow in disaccharides such as sucrose and lactose and polysaccharides such as agave fructans. Otherwise, K. marxianus is an excellent microorganism to produce metabolites of biotechnological interest, such as enzymes, ethanol, aroma compounds, organic acids, and single-cell proteins. However, several studies highlighted the metabolic trait variations among the K. marxianus strains, suggesting genetic diversity within the species that determines its metabolic functions; this diversity can be attributed to its high adaptation capacity against stressful environments. The outstanding metabolic characteristics of K. marxianus have motivated this yeast to be a study model to evaluate its easy adaptability to several environments. This chapter will discuss overview characteristics and applications of K. marxianus and recent insights into the stress response and adaptation mechanisms used by this non-Saccharomyces yeast.

Application of dielectric spectroscopy to unravel the physiological state of microorganisms: current state, prospects and limits.

Microbial physiology is an essential characteristic to be considered in the research and industrial use of microorganisms. Conventionally, the study of microbial physiology has been limited to carrying out qualitative and quantitative analysis of the role of individual components in global cell behaviour at a specific time and under certain growth conditions. In this framework, groups of observable cell physiological variables that remain over time define the physiological states. Recently, with advances in omics techniques, it has been possible to demonstrate that microbial physiology is a dynamic process and that, even with low variations in environmental culture conditions, physiological changes in the cell are provoked. However, the changes cannot be detected at a macroscopic level, and it is not possible to observe these changes in real time. As an alternative to solve this inconvenience, dielectric spectroscopy has been used as a complementary technique to monitor on-line cell physiology variations to avoid long waiting times during measurements. In this review, we discuss the state-of-the-art application of dielectric spectroscopy to unravel the physiological state of microorganisms, its current state, prospects and limitations during fermentation processes. Key points • Summary of the state of the art of several issues of dielectric spectroscopy. • Discussion of correlation among dielectric properties and cell physiological states. • View of the potential use of dielectric spectroscopy in monitoring bioprocesses.

Dielectric property measurements as a method to determine the physiological state of Kluyveromyces marxianus and Saccharomyces cerevisiae stressed with furan aldehydes.

Cell physiology parameters are essential aspects of biological processes; however, they are difficult to determine on-line. Dielectric spectroscopy allows the on-line estimation of viable cells and can provide important information about cell physiology during culture. In this study, we investigated the dielectric property variations in Kluyveromyces marxianus SLP1 and Saccharomyces cerevisiae ERD yeasts stressed by 5-hydroxymethyl-2-furaldehyde and 2-furaldehyde during aerobic growth. The dielectric properties of cell permittivity, specific membrane capacitance (Cm), and intracellular conductivity (σIn) were considerably affected by furan aldehydes in the same way that the cell population, viability, cell size, substrate consumption, organic acid production, and respiratory parameters were. The yeasts stressed with furan aldehydes exhibited three physiological states (φ): adaptation, replicating, and nonreplicating states. During the adaptation state, there were small and stable signs of permittivity, Cm, and σIn; additionally, no cell growth was observed. During the replicating state, cell growth was restored, and the cell viability increased; in addition, the permittivity and σIn increased rapidly and reached their maximum values, while the Cm decreased. In the nonreplicating state, the permittivity and σIn were stable, and Cm decreased to its minimum value. Our results demonstrated that knowing dielectric properties allowed us to obtain information about the physiological state of the cells under control and stressed conditions. Since the permittivity, Cm, and σIn are directly associated with the physiological state of the yeast, these results should contribute to a better understanding of the stress response of yeasts and open the possibility to on-line monitor and control the physiological state of the cell in the near future.

[Spinal cord stimulation in teenager with complex regional pain syndrome for Lyme’s disease. Case report and review of the literature]. / Estimulación de cordones posteriores en adolescente con síndrome de dolor regional complejo por enfermedad de Lyme. Reporte de un caso.

Lyme disease is an emerging pathology in Mexico, producer of painful muscle skeletal either neurotic pain difficult to control. We present the case of a teenager girl who has complex regional pain type II of pelvic limb secondary to it, where it established a multidisciplinary management that finally was controlled with the placement of a spinal cord stimulator. We consider this as an unusual situation in an adolescent, as well as its evolution by 60 months where the literature only was reported in a few cases.

La enfermedad de Lyme es una enfermedad emergente presente en México, productora de cuadros de dolor musculoesquelético o bien neurótico de difícil control. Se presenta el caso de una adolescente con síndrome de dolor regional complejo secundario a la misma de miembro pélvico donde se instauró un manejo multidisciplinario que finalmente se controló con la colocación de un estimulador de cordones posteriores, situación inusual en un adolescente, así como su evolución por 60 meses, ya que en la literatura sólo se encuentra reportada en pocos casos.

16K prolactin induces NF-kappaB activation in pulmonary fibroblasts.

The amino-terminal 16 kDa fragment of prolactin (16K PRL) promotes the expression of the inducible isoform of nitric oxide synthase (iNOS) accompanied by the production of nitric oxide (NO) by rat pulmonary fibroblasts. The present study was designed to elucidate whether the mechanism by which 16K PRL promotes iNOS expression involves the activation of nuclear factor-kappa B (NF-kappaB), a key transcription factor for iNOS induction. 16K PRL stimulated DNA-binding activity of NF-kappaB in pulmonary fibroblasts as demonstrated by gel shift assays. Likewise, fluorescence immunocytochemistry showed that 16K PRL promotes nuclear translocation of the p65 subunit of NF-kappaB. Finally, treatment with 16K PRL induced the degradation of the NF-kappaB inhibitor kappaB-beta (IkappaB-beta), and such degradation was prevented by blocking IkappaB-beta phosphorylation. Altogether, these results show that 16K PRL activates NF-kappaB nuclear translocation via the phosphorylation and degradation of IkappaB-beta. These findings are consistent with NF-kappaB being part of the signal transduction pathway activated by 16K PRL to induce iNOS expression.

[Peripheral arterial disease in a population of type 2 diabetic patients: its correlation with diabetic microangiopathy and laboratory parameters]. / L'arteriopatia obliterante periferica in una popolazione di diabetici di tipo 2: correlazione con la microangiopatia diabetica e parametri laboratoristici.

BACKGROUND: The aim of this study was to evaluate the incidence of peripheral arterial disease (PAD) in a population of type 2 diabetic patients (NIDDM) and its possible correlation with diabetic nephropathy (DN), diabetic retinopathy (DR) and also with some biochemical parameters of glomerular and tubular renal function. METHODS: The study included a total of 150 NIDDM patients, randomly selected, who have been followed-up at the Metabolic Center of our Division. All patients underwent assessment of the ankle/brachial pressure index (ABI) and Doppler ultrasound of the lower extremities. They were then divided into 2 groups: Group 0 without PAD and Group 1 with PAD. They also underwent a echo color-Doppler study of the renal interlobar arteries in order to evaluate the resistive index (RI), while the retinal vessels were assessed by biomicroscopy and fluorangiography. RESULTS: The incidence of PAD in this study was 30.6%, occurring on average 14 years from the onset of diabetes, and affecting particularly patients with nephropathy. The presence of both albuminuria and retinopathy in the same patient increases by 8.9 times the risk of cardiovascular disease. CONCLUSIONS: The RI, measured at the level of the intrarenal arteries, is of great interest as a marker not only of renal vascular damage in NIDDM patients, but also of a generalized vascular involvement.

Estimulación de cordones posteriores en adolescente con síndrome de dolor regional complejo por enfermedad de Lyme: Reporte de un caso / Spinal cord stimulation in teenager with complex regional pain syndrome for Lyme’s disease: Case report and review of the literature

La enfermedad de Lyme es una enfermedad emergente presente en México, productora de cuadros de dolor musculoesquelético o bien neurótico de difícil control. Se presenta el caso de una adolescente con síndrome de dolor regional complejo secundario a la misma de miembro pélvico donde se instauró un manejo multidisciplinario que finalmente se controló con la colocación de un estimulador de cordones posteriores, situación inusual en un adolescente, así como su evolución por 60 meses, ya que en la literatura sólo se encuentra reportada en pocos casos.

Lyme disease is an emerging pathology in Mexico, producer of painful muscle skeletal either neurotic pain difficult to control. We present the case of a teenager girl who has complex regional pain type II of pelvic limb secondary to it, where it established a multidisciplinary management that finally was controlled with the placement of a spinal cord stimulator. We consider this as an unusual situation in an adolescent, as well as its evolution by 60 months where the literature only was reported in a few cases.