Cryo-transmission electron tomography of native casein micelles from bovine milk.

Caseins are the principal protein components in milk and an important ingredient in the food industry. In liquid milk, caseins are found as micelles of casein proteins and colloidal calcium nanoclusters. Casein micelles were isolated from raw skim milk by size exclusion chromatography and suspended in milk protein-free serum produced by ultrafiltration (molecular weight cut-off of 3 kDa) of raw skim milk. The micelles were imaged by cryo-electron microscopy and subjected to tomographic reconstruction methods to visualize the 3-dimensional and internal organization of native casein micelles. This provided new insights into the internal architecture of the casein micelle that had not been apparent from prior cryo-transmission electron microscopy studies. This analysis demonstrated the presence of water-filled cavities (∼20 to 30 nm in diameter), channels (diameter greater than ∼5 nm), and several hundred high-density nanoclusters (6 to 12 nm in diameter) within the interior of the micelles. No spherical protein submicellar structures were observed.

The effect of ethanol and heat on the functional hydrophobicity of casein micelles.

Milk proteins are very important ingredients to the food industry. As new uses and applications for these proteins are developed, it becomes more important to understand their physicochemical properties when they are subjected to different treatments. It has been reported that casein micelles dissociate when heated in the presence of ethanol. The changes to the hydrophobicity of milk proteins during that process were evaluated by using the fluorescent hydrophobic probe 1-anilinonaphthalene-8-sulfonic acid (ANS). Raw skim milk, pasteurized skim milk, and whey protein isolate samples with ethanol concentrations of 0 to 60% (vol/vol) were heated from 20 to 60 degrees C. The fluorescence of the samples with and without the addition of ANS was measured at an excitation wavelength of 390 nm and an emission wavelength of 400 to 500 nm. The results showed a decrease in the extrinsic fluorescence of the samples as the ethanol concentration and temperature increased, indicating competitive inhibition of the ANS-hydrophobic site interaction by ethanol. This inhibition was further enhanced by the addition of heat. This resulted in a reduction in the functional hydrophobicity of the milk proteins as ethanol rendered the hydrophobic sites unavailable for interaction.

Anticoagulación en COVID-19 / Anticoagulation in COVID-19

La vida del mundo cambió como la conocíamos, desde diciembre de 2019, por una nueva pandemia viral, el "Coronavirus 2". Virus de alta contagiosidad y gravedad por el Síndrome Respiratorio Agudo Severo (SARS CoV-2) provocando alta morbimortalidad, desbordado las Unidades de Cuidados Intensivos del mundo, para atender a estos pacientes cuyo cuadro es primariamente respiratorio. Actualmente, además se enfrenta a una segunda amenaza, el aumento sustancial en comparación a otros pacientes hospitalizados (no COVID-19) de las complicaciones tromboembólicas.Esta publicación pretende realizar una revisión de la información actualizada disponible respecto a la epidemiología, fisiopatología y manejo de la enfermedad tromboembólica en pacientes con COVID-19 hospitalizados.

The life of the world changed as we knew it, since december 2019, due to a new viral pandemic, the "Coronavirus 2". Virus of high contagiousness and severity due to Severe Acute Respiratory Syndrome (SARS CoV-2) causing high morbidity and mortality, overwhelmed the Intensive Care Units of the world, to care for these patients whose primarily respiratory symptoms. Currently, it also faces a second threat, the substantial increase compared to other hospitalized patients (not COVID-19) of thromboembolic complications.This publication aims to review the updated information available regarding the epidemiology, pathophysiology, and management of thromboembolic disease in hospitalized COVID-19 patients.

A t(1;22)(p13;q13) in four children with acute megakaryoblastic leukemia (M7), two with Down syndrome.

We report four children with acute megakaryoblastic leukemia (AML-M7) and t(1;22)(p13;q13), two of them with Down syndrome; their ages were 7 months, and 6, 7, and 10 years. These findings differ from those reported in children with M7 and t(1;22) at the age of presentation (exclusively under 1-year-old) and in the two cases associated with Down syndrome (t[1;22],+21c) that may be due to the high heterogeneity of the chromosomal changes in children with AML. We cannot disregard ethnic difference distribution of chromosomal changes and age of presentation in Mexican children with AML.

Cytogenetic findings in 303 Mexican patients with de novo acute myeloblastic leukemia.

In this report we show the chromosomal changes seen in a group of 303 Mexican patients with de novo Acute Myeloblastic Leukemia (AML). Two hundred forty-two patients were diagnosed and treated at two hospitals affiliated with the Instituto Mexicano del Seguro Social (IMSS). These are the Centro Medico Nacional Siglo XXI and Centro Medico La Raza Hospitals; the remaining 61 patients were diagnosed and treated at the Hospital General de Mexico (HGM). Clonal abnormalities were detected in 75.6% of the patients; this result agrees with what has been reported in other large series of AML studies. The incidence of changes per hospital was similar in patients from the IMSS hospitals (72-75%), while an increase was seen in patients from the HGM (85.2%). The chromosomal changes seen in this study in order of frequency were: t(15;17)[18.8%], t(9;22)[9.2%], miscellaneous chromosomal changes (mainly rearrangements of chromosomes 1,2,3,12y17)[8.2%], abnormalities of 16q22 [7.3%], t(8;21)[6.3%], -7/del(7q)[5.6%], t(6;9)[5.3%], and abnormalities of 11q23 [4.6%]. We reported an increase in the incidence of certain types of chromosomal changes seen in cases of AML, in comparison with reports from other countries. These differences could be due to methodological variations, although ethnic, socioeconomic and nutritional differences must not be disregarded. We support this finding when comparing distribution of changes in the population of patients seen in the IMSS hospitals with those from the HGM; the main difference lies in the socioeconomic level.

Calmodulin binding proteins in the membrane vesicles released during the acrosome reaction and in the perinuclear material in isolated acrosome reacted sperm heads.

Calmodulin has been suggested as the Ca(2+)-mediator in diverse cellular functions via its interaction with a number of proteins in a calcium-dependent manner. Its participation in the acrosome reaction has been suggested based on its localization in the acrosome region, on the effects produced by calmodulin antagonists, and by the changes in calmodulin compartmentation observed to occur throughout guinea pig acrosome reaction. To define the role of calmodulin in the membrane fusion events that occur during the acrosome reaction, the identification of calmodulin-binding proteins, by the overlay technique with biotinylated or unmodified calmodulin, was made in the following sperm fractions: in the membrane vesicles released during the acrosome reaction, in the remaining perinuclear material of acrosome reacted sperm heads and in a total membrane fraction from intact spermatozoa. The membrane vesicles released after the acrosome reaction showed four major calmodulin-binding proteins, M(r)s 66, 95, 97 and 110 kDa. The perinuclear material showed a 31-34, 43 and 97 kDa calmodulin-binding polypeptides. The membrane fraction from intact sperm showed eleven calmodulin-binding proteins, M(r)s between 14-110 kDa. Most of the binding proteins detected by this method corresponded to the class of calcium-independent calmodulin-binding proteins but proteins which only interacted with calmodulin in a calcium-inhibited mode were also observed. No calcium-dependent calmodulin-binding proteins were detected in any of the fractions studied. A possible role of these binding proteins in calmodulin compartmentation is discussed. The potential role of these binding proteins in membrane fusion and in membrane receptor localization in the postacrosomal region remain to be defined.

[The applicability and diagnostic effectiveness of transjugular liver biopsy]. / Aplicabilidad y rentabilidad diagnóstica de la biopsia hepática transyugular.

BACKGROUND: The aim of this study was to evaluate the applicability, the diagnostic profitability and the incidence of complications associated with tranjugular liver biopsy associated with the measurement of the hepatic venous pressure gradient (HVPG). PATIENTS AND METHODS: The clinical histories of 829 consecutive patients in whom transjugular liver biopsy was performed from 1982 to 1993 were reviewed. The diagnostic value of the sample obtained was evaluated in all the patients and the HVPG determined. Moreover, the size of the greatest fragment obtained during biopsy was also determined. RESULTS: Material for histologic study was obtained in 95% of the cases. In 70% the biopsy was diagnostic, in 11% it provided data contributing to diagnosis and in 19% it was not useful. Potentially severe complications were presented in 0.8% of cases being fatal in one (0.1%). The obtention of a fragment of small size was significantly associated with the presence of disease with marked fibrosis and high HVPG. A HVPG > 10 mmHg in patients with a suspicion of liver disease had a sensibility of 92% and a specificity of 63% for the diagnosis of hepatic cirrhosis. In 83% of patients with a GPVH > 10 mmHg in whom the biopsy was not useful, the diagnosis of hepatic cirrhosis was performed by other methods. CONCLUSIONS: Transjugular biopsy in a safe, effective diagnostic method in patients with severe coagulation disorders. The appearance of the material obtained and the HVPG provide useful information for diagnosis although the biopsy is not diagnostic.

[Interferon in the eradication of the Philadelphia chromosome in chronic myeloid leukemia]. / El interferón en la erradicación del cromosoma Filadelfia de la leucemia mieloide crónica.

OBJECTIVE: To evaluate if human recombinant interferon alpha (IFN) combined with chemotherapy is able to suppress the Philadelphia chromosome clone in patients with chronic myeloid leukemia (CML). MATERIAL AND METHODS: The cytogenetic evolution in 53 patients with CML in chronic phase de novo was studied. They received one of three treatment schemes: a) induction of remission with daunorubicin, vincristine, cytosine arabinose and prednisone (DOAP) and maintenance with IFN (n = 12); b) induction with busulfan (BUS) or hydroxyurea (HYDX) and maintenance with IFN (n = 26); c) induction with DOAP and maintenance with BUS (n = 15). RESULTS: The remission was seen two to six months after the start of treatment: 10 had complete remission, six a partial one, 14 a minor remission and 23 none. The 16 with complete or partial response received treatment with IFN. None of the 15 cases maintained with BUS had complete or partial response. The proportion of cases with complete response (3/12) was slightly lower in patients treated with intensive chemotherapy (BUS/HIDX/IFN) than in those receiving conventional treatment (7/26). CONCLUSIONS: Our results showed that: a) IFN in combination with chemotherapy induced partial or complete response in 30% of our cases; and b) intensive chemotherapy combined with IFN was not superior in terms of a cytogenetic response to treatment with monodrugs (BUS/HIDX) and IFN.

[Cytogenetic study of 22 adults and 3 children with acute lymphoblastic leukemia]. / Estudio citogenético en 22 adultos y tres niños con leucemia linfoblástica aguda.

Between 1987 and 1990 cytogenetic studies of bone marrow and lymphocytes from peripheral blood from 25 patients with de novo ALL were performed. All cases had chromosomal aberrations; however in 23 patients a normal cell line was also present. The most important structural aberrations found were: t(17;19)(q11;p13), t(2;9;22)(q34;q34;11), t(1;7)(p13;q33), t(6;11)(q26;p16), t(3;4)(q24-25;q26), t(1;12)(q23;q34), t(2;18)(q15;p12), t(2;4)(q23;q35) and t(4;11)(q21;q23). These chromosome abnormalities correlate with the response to treatment and survival and improve the identification of high-risk patients. Our study shows the presence of some chromosomal abnormalities different to those reported in the literature; however the breakpoints involved seem to be the same which suggests that these critical regions may be directly involved in the pathogenesis of these disorders.

[Laparoscopic management of gastroesophageal reflux disease. Experience with 100 cases]. / Manejo laparoscópico de la enfermedad por reflujo gastroesofágico. Experiencia en 100 casos.

OBJECTIVE: To evaluate the results of laparoscopic Nissen-Rossetti funduplication and to compare them with the results obtained in open surgery. DESIGN: Prospective, observational, longitudinal, pre and post-procedure. CENTERS: Beneficencia Española, Hospital Angeles, and Hospital Francisco Galindo Chávez, ISSSTE, in Torreón, Coahuila, Mexico. PATIENTS AND METHOD: From December 1992 to February 1999, 100 patients with surgical indications due to gastroesophageal reflux disease (GERD) prospectively underwent a laparoscopic Nissen-Rossetti procedure. A clinical and endoscopic follow up from 3 months to 9 years was performed in 87 cases. RESULTS: Symptomatic control was achieved in 98% (85/87) of the cases and remission of overall endoscopic esophagitis in 79% (69/87); excluding Barrett cases, esophagitis remission was observed in 93% (67/72) of the subjects. The following recurrences took place: two with G-II and two with G-III esophagitis, one requiring pyloroplasty due gastric stasis, and other patient with G-IV esophagitis, who has needed to continue with postoperative dilations. Of 16 cases with Barrett's esophagus, two-showed remission and one did not return control. Perioperative complications included gastric perforations (3), acute pulmonary edema during the immediate postoperative period (1), deep vein thrombosis (1), and late esophageal perforation (1). All were resolved satisfactorily. Surgical mortality was 0 in the 100 cases undergoing the procedure. Eighty-six percent of cases had a 24-h hospital stay. Early morbidity: dysphagia in 60 patients, early satiety in 91 cases, abdominal distention in 25 cases, all this symptomatology disappears during the subsequent 3 months. Persistent morbidity: flatulence in 60% of patients, difficulty for vomiting in 10% of cases. CONCLUSION: The laparoscopic procedure is as effective as the open method with the advantage of being minimally invasive.

Maternal protein restriction in pregnancy and/or lactation affects seminiferous tubule organization in male rat offspring.

Maternal protein restriction (MPR) during pregnancy impaired the reproduction of male offspring. We investigated, during the first wave of spermatogenesis, whether MPR exerts deleterious effects on germ cell proliferation and differentiation, as well as androgen receptor (AR) protein expression, which was used as a marker for Sertoli cell (SC) maturation. At the beginning of pregnancy (day 0), dams were fed a control diet (C: 20% casein) or a restricted isocaloric diet (R: 10% casein). After birth, four groups were established: CC, RR, CR and RC (first letter diet during pregnancy and second during lactation). Male offspring were studied at postnatal days 14, 21 and 36. At birth, pup body weight was unchanged. Body weight and testis weight were reduced in RR and CR groups at all ages evaluated. MPR delayed the germinal epithelium development at all ages evaluated. On performing Western blot and immunohistochemistry, AR expression was found to be lower in the three restricted groups. The results suggest that MPR during pregnancy and/or lactation delays SC maturation and germ cell differentiation, and affects intratubular organization. These changes might be responsible for the lower fertility rate at older ages.

Microangiopatía trombótica en paciente con diagnóstico de lupus eritematoso sistémico: revisión de la literatura en relación a un caso clínico / Thrombotic microangiopathy in patients diagnosed with systemic lupus erythematosus: literature review with regards to a clinical case

El Síndrome Púrpura Trombótico Trombocitopénico/Síndrome Hemolítico Urémico (PTT/SHU) es la principal causa de Microangiopatía Trombótica (MAT) en pacientes con Lupus Eritematoso Sistémico (LES). Entre sus manifestaciones destacan la presencia de anemia hemolítica autoinmune, con trombocitopenia y falla renal en grados variables. No existe correlación entre los niveles de actividad de ADAMTS 13 y MAT. Presentamos un caso clínico de MAT asociado a LES. Se debe tener una alta sospecha diagnóstica por la sobreposición de las manifestaciones clínicas de PTT/SHU y LES. El tratamiento con plasmaféresis ha disminuido la mortalidad de 90 por ciento a 15 por ciento. En casos refractarios se ha reportado el uso de Rituximab, aunque aún falta evidencia que lo avale.

The thrombotic Thrombocytopenic Purpura Syndrome / Hemolytic Uremic Syndrome (TTP/HUS) is the main cause behind Thrombotic Microangiopathy (TMA) in patients with Systemic Lupus Erythematosus (SLE). Among the ways in which it manifests itself is the presence of autoimmune hemolytic anemia (AIHA), with thrombocytopenia and kidney failure in various degrees. There is no co-relation between the levels of activity of ADAMTS13 and TMA. We present a clinical case of TMA associated to SLE. A high suspicion is paramount for diagnose due to the overlapping of clinical manifestations of TTP/HUS and SLE. Treatment with plasmapheresis has decreased mortality from 90 percent to 15 percent. Use of Rituximab in refractory cases has been reported, albeit a lack of supporting evidence.

Amiloidosis: revisión a propósito de un caso clínico / Amyloidosis: review of clinical case purpose

La amiloidosis constituye un grupo de enfermedades caracterizadas por el depósito extracelular de material proteico autólogo, fibrilar e insoluble. Existe una variedad que se asocia a enfermedades inflamatorias crónicas mal controladas que presentan manifestaciones orientadoras al diagnóstico, lo que es importante de conocer, ya que hace variar el pronóstico de la enfermedad de base. A continuación se presenta un caso clínico de amiloidosis secundaria a artropatía psoriásica, discutiendo su diagnóstico y posibilidades terapéuticas tanto para la enfermedad de base como para su asociación y complicación por amiloidosis.

Amyloidosis is a group of diseases characterized by the extracellular deposition of protein material autologous fibrillar insoluble. There is a variety that is associated with poorly controlled chronic inflammatory diseases that have manifestations in the diagnosis. Below we present a clinical case of secondary amyloidosis in psoriatic arthropathy and discuss its diagnosis and further management.

Calmodulin content, Ca2+-dependent calmodulin binding proteins, and testis growth: identification of Ca2+-dependent calmodulin binding proteins in primary spermatocytes.

In contrast with the transient pre-replicative increase in calmodulin (CaM) level observed in proliferative activated cells, postnatal development of rat testis was paralleled by 3 specific rises in CaM. The first one occurred between 5 and 10 days, coincident with the appearance and proliferation start of spermatogonia and Sertoli cells. Meiosis accomplishment and spermatid differentiation were paralleled by 2 additional rises, at 24 and 32 days, respectively. The plateau phase of testis growth was coincident with the appearance of maturating spermatids and spermatozoa in the germinal epithelium, and with a decrease in CaM content. Testicular DNA:g wet tissue ratio reached the highest level in 15-day-old rats and gradually decreased up to 35 days, when a constant level was reached. A similar level of Ca2+-CaMBPs was observed in 5- and 20-day-old rat testis. Although all subcellular fractions showed the ability to bind CaM in a Ca2+-dependent manner, CaM was mainly recovered in the nuclear and soluble fractions of adult and immature rat testis. Several Ca2+-CaMBPs with an apparent M(r) of 82, 75, 64, 19, and 14 kD were purified by affinity chromatography from pachytene primary spermatocyte nuclear matrix. Ca2+-CaMBPs showing an M(r) of 120, 78, 72, and 66 kD were also purified from the supernatant obtained after DNA and RNA hydrolysis of meiotic nuclei. Major cytosolic Ca2+-CaMBPs of primary spermatocytes showed an M(r) of 120, 84, 44, and 39 kD. The functions that these Ca2+-CaMBPs might have during the first meiotic prophase is discussed.

Changes in calmodulin compartmentalization throughout capacitation and acrosome reaction in guinea pig spermatozoa.

Calmodulin has been postulated as a mediator in the calcium-dependent processes that culminate in the acrosome reaction. Changes in calmodulin compartmentalization as a consequence of the increased permeability to extracellular calcium during capacitation and acrosome reaction have been suggested. In the present study the temporal localization of calmodulin in guinea pig spermatozoa was studied during in vitro capacitation and acrosome reaction by indirect immunofluorescence. Capacitation was achieved by incubation in Tyrode medium supplemented with pyruvate, lactate, and glucose in the presence and in the absence of calcium. Acrosome reaction was elicited in three different conditions: 1) by transfer to minimal culture medium containing pyruvate and lactate (MCM-PL) after in vitro capacitation 2) by 0.003% Triton-X 100 treatment, and 3) by A 23187 addition to sperm samples incubated in MCM-PL. During capacitation, calmodulin was observed both in the acrosome and in the flagellum; this localization seemed to be independent of the presence of extracellular calcium and of exogenous substrates. Throughout the acrosome reaction, different stages of calmodulin compartmentalization were observed. It became clustered around the equatorial region just before or a little after the acrosome reaction had occurred. Later, it was observed around the postacrosomal region in the acrosome-reacted sperm. The changes in calmodulin distribution were found to be dependent on the stage in the acrosome reaction.

[Predictive value of ventricular extrasystole in the exertion test and its relation to the magnitude of coronary damage]. / Valor predictivo de la extrasistolia ventricular en la prueba de esfuerzo y su relación con la magnitud del daño coronario.

The predictive value of ventricular arrhythmias, associated with treadmill exercise testing was evaluated in 115 patients undergoing coronary angiography and left ventriculography within three months of the exercise test. 39 patients with ventricular arrhythmias (at least one premature ventricular complex, paired complex or ventricular tachycardia) had a higher or multivessels disease than the patients without ventricular arrhythmias (P less than 0.05). This study demonstrated that ventricular arrhythmias detected at exercise testing are related to the extent of coronary artery disease, and the presence of the left ventricular disfunction.

Effects of quercetin on rat testis aerobic glycolysis.

Lactate production by testicular fragments and isolated germinal cells at various stages of spermatogenesis was studied in aerobic and anerobic conditions. Several ATPase inhibitors were used to determine the role of ATPase activities in the control of aerobic lactate production. Aerobic glycolysis reached a high level in spermatogonia plus Sertoli cell and in primary spermatocyte populations. The activity was twice that found in early spermatids. Neither Na+-K+ ATPase nor mitochondrial F1 ATPase seemed to participate directly in the control of aerobic glycolysis. The uncoupling of oxidative phosphorylation revealed the potential role of F1 ATPase in providing ADP and P(i) for the glycolytic pathway. Lactate production was inhibited by quercetin in all the experimental conditions tested. Quercetin (100 microM) halted lactate production by the Sertoli cell plus spermatogonia population and by isolated primary spermatocytes. In spermatids, quercetin inhibited aerobic glycolysis only by 40%, even at higher concentrations. Only during the first meiotic prophase did quercetin inhibit the activity of a cytosolic Ca(2+)-Mg2+ ATPase. This ATPase was also inhibited by erythro-9-[3-3(hydroxynonyl)]adenine (EHNA), suggesting that a cytoplasmic dynein could be involved in the control of glycolysis in Sertoli cells, spermatogonia, and early primary spermatocytes.