Natural killer cells in children with malignant solid tumors. Effect of recombinant interferon-alpha and interleukin-2 on natural killer cell function against tumor cell lines

Natural killer (NK) cells and NK cell activity were determined in three groups (newly diagnosed [n = 21], on therapy [n = 21], and off therapy [n = 18]) of children with various types of malignant solid tumors and in a control group (n = 26) by means of Leu-7 and Leu-11b monoclonal antibodies and a 4-hour 51Cr-release assay, respectively. The erythroleukemia cell line K562 was used as a target cell. The newly diagnosed group included eight patients with localized disease (Stage I-II), ten with bulky but nonmetastatic disease (Stage III), and three with metastases (Stage IV). The mean percent of NK cell activity in the newly diagnosed group was significantly higher than that of the control group. Children with Stage III tumors at diagnosis had higher mean NK cell function than those with Stage I-II and Stage IV. On therapy patients had significantly fewer NK cells and lower NK cell cytotoxicity than those in the other groups studied. We also studied the following: (1) the in vitro effect of recombinant interferon-alpha (rIFN-alpha) and recombinant interleukin-2 (rIL-2) on NK cell function of peripheral blood lymphocytes (PBL) from children with solid malignancies; and (2) the susceptibility of neuroblastoma-derived (CHP-126 and SKNSH) and rhabdomyosarcoma-derived (A-204) cell lines to NK cell lysis. Both rIFN-alpha and rIL-2 enhanced NK cell activity of PBL from children with malignancies and healthy children against K562 and solid tumor cell lines. The enhancing effect or rIL-2 was greater than that of rIFN-alpha. CHP-126 and SKNSH cell lines were susceptible to NK cell lysis mediated by the PBL of children with neuroblastoma and the control group. The A-204 cell line was less sensitive than K562 to NK cell cytotoxicity. Our results suggest a potential therapeutic role for both cytokines in the treatment of malignant solid tumors of childhood.     

The effect of harmaline on intestinal sodium transport and on sodium-dependentd-glucose transport in brush-border membrane vesicles from rabbit jejunum

Harmaline inhibition of sodium uptake and of sodium-dependentd-glucose transport was investigated using brush-border membrane vesicles from frozen rabbit jejunum. Under sodium-gradient conditions, initiald-glucose uptake (20 s) was inhibited by harmaline at concentrations above 0.5 mM, but at lower harmaline concentrationsd-glucose uptake was stimulated by 10–15%. When a similar potassium gradient was used, harmaline had no effect. At concentrations upt to 2 mM, harmaline did not alter the equilibrium uptake ofd-glucose ord-mannitol. After pre-equlibration with sodium (25 mM),d-glucose uptake was inhibited at harmaline concentrations ranging from 0.1 to 2 mM. Sodium (10 mM) uptake was also inhibited by harmaline. Increasing the sodium concentration reduced the inhibitory effect of harmaline on tracer sodium uptake as well as on sodium-dependentd-glucose uptake. Similar to phlorizin, harmaline (1 mM) was able to prevent glucose-induced sodium influx across the brush-border membrane.Sodium uptake into brush-border membrane vesicles seems to be inhibited at lower harmaline concentrations than sodium-dependentd-glucose uptake. At high (2 mM) inhibitor concentrations, however, sodium-dependent glucose uptake is more strongly inhibited than sodium uptake. These results suggest that harmaline inhibits both sodium and sodium-dependent transport across intestinal brush-border membranes by interacting with specific sodium-binding sites.     

A severe form of amyloidotic polyneuropathy in a Costa Rican family with a rare transthyretin mutation (Glu54Lys)

Four affected siblings in a Costa Rican family presented an aggressive polyneuropathy with widespread involvement of many visceral organs and onset during the third decade of life with rapid loss of muscle mass in the lower limbs and severe dysautonomy. The medical histories include vitreous opacity, cardiac enlargement, dermal and gastrointestinal infiltration, and autonomic dysfunction including circulatory compromise and gastrointestinal disturbances. Histological studies using Congo red stain and immunohistochemical assays with antibodies against the transthyretin (TTR) protein showed widespread deposition of amyloid in extracellular areas, including dermis and gastrointestinal lamina propia, endo- and perineural spaces, and vascular walls. A mutation search in the transthyretin (ttr) gene was performed seeking the cause of this severe form of familial amyloidotic polyneuropathy (FAP). We applied single-stranded conformational polymorphism (SSCP)-analyses followed by sequencing of the four exons of the ttr gene, revealing a point mutation in exon 3, a G to A transition that causes a Glu54Lys codon change. Western blots of plasma proteins incubated with anti-transthyretin antibodies after gel electrophoresis provided separation of wild-type and mutant TTR protein in affected family members.     

Improvement of leukocyte functions in young prematurely aging mice after a 5-week ingestion of a diet supplemented with biscuits enriched in antioxidants

In our previous studies, diet supplementation with therapeutic thiolic antioxidants improved the function of peritoneal leukocytes from mice, especially in adult prematurely aging mice (PAM). In the present work, we have studied the effects of ingestion during 5 weeks of a diet supplemented with 20% (wt/wt) of biscuits enriched with antioxidants (vitamin C, vitamin E, beta-carotene, zinc, and selenium) on several immune functions of peritoneal leukocytes from young PAM. The results show that, in macrophages, chemotaxis and phagocytosis as well as the intracellular free radical levels, which are depressed in PAM in comparison with the control nonprematurely aging mice (NPAM), increase after supplementation, especially in the PAM. An increase also occurs in lymphocyte chemotaxis, proliferative response to the mitogen concanavalin A, and interleukin-2 release, as well as in natural killer cell activity. However, the release of tumor necrosis factor-alpha, which increases with aging, decreases after 5 weeks of supplementation. As a well preserved function of the immune system is an excellent marker of health and longevity, the improvement of leukocyte functions after ingestion of the present diet suggests that this antioxidant supplementation may be useful for the preservation of health and functional longevity in aging populations.     

Nystatin studies of the skin of larval Rana catesbeiana

Transport and electrical characteristics of the isolated skin of larval Rana catesbeiana were analyzed using ion substitution and nystatin. When the inner (IBS) and outer (OBS) bathing solutions contained Na Ringer solution the electrical potential (TEP), short-circuit current (SCC), and resistance (R2) were 23.5 +/- 7.0 mV, 2.8 +/- 0.7 microA . cm-2, and 8.00 +/- 0.74 k omega. cm2, respectively (n = 4). When K was substituted for Na in the OBS these values were not changed significantly. When nystatin (120 U.cm-3), a drug that increases the permeability of membranes to small cations, was added to the OBS (Na Ringer) there was a striking increase in the TEP to 52.8 +/- 3.1 mV, SCC to 14.8 +/- 2.0 microA . cm-2, and drop in R2 to 3.75 +/- 0.52 k omega . cm2. The response to nystatin was similar with Na or K Ringer solution in the OBS (Na Ringer in the IBS). With Na Ringer in the OBS and IBS, the increase in SCC induced by low doses of nystatin equaled net Na flux measured isotopically. Plots of transepithelial conductance against SCC after nystatin were linear and provided estimates of shunt resistance (R*sh = 14.6 +/- 1.3 k omega . cm2) and electromotive driving force for ions (E*A = 76 +/- 3 mV). Similar curves were obtained with K Ringer in the OBS. In the presence of nystatin, characteristics of the basolateral membrane were evaluated. It displayed selective permeability to K relative to Na or Tris.     

Resecciones pulmonares anatómicas por vía robótica: análisis de la curva de aprendizaje

IntroductionRobotic surgery has become a safe and effective approach for the treatment of pulmonary surgical pathology. However, the adoption of new surgical techniques requires the evaluation of the learning curve. The objective of this study is to analyze the learning curve of robotic anatomical lung resections.MethodsRetrospective analysis of all robotic anatomical lung resections performed by the same surgeon between June 2018 and March 2020. The learning curve was evaluated using CUSUM charts to estimate trend changes in surgical time, surgical failure and the occurrence of post-operative cardiorespiratory complications throughout the sequence of cases.ResultsThe study included a total of 73 cases. The median duration of all complications was 120 min (interquartile range: 90-150 min), the prevalence of surgical failure was 23.29%, while 4/73 patients had any postoperative cardiorespiratory complication. Based on the CUSUM analysis, the learning curve was divided into 3 different phases: phase i (from the first to the 14th intervention), phase ii (between the 15th and 30th intervention) and phase iii (from the 31st intervention).ConclusionsThe learning curve for robotic anatomical lung resections can be divided into 3 phases. The technical competence that guarantees satisfactory perioperative outcomes was achived in phase iii from the 31st intervention.     

Upper Extremity Overuse Injuries and Obesity After Spinal Cord Injury

Persons with spinal cord injury (SCI) are at high risk for developing neurogenic obesity due to muscle paralysis and obligatory sarcopenia, sympathetic blunting, anabolic deficiency, and blunted satiety. Persons with SCI are also at high risk for shoulder, elbow, wrist, and hand injuries, including neuromusculoskeletal pathologies and nociceptive pain, as human upper extremities are poorly designed to facilitate chronic weight-bearing activities, including manual wheelchair propulsion, transfers, self-care, and day-to-day activities. This article reviews current literature on the relationship between obesity and increased body weight with upper extremity overuse injuries, detailing pathology at the shoulders, elbows, and wrists that elicit pain and functional decline and stressing the importance of weight management to preserve function.     

Hepatitis C immunology

This review summarizes what is currently known about the cellular and humoral immune responses to hepatitis C virus. The results of viral protein immunogenicity studies reported so far are analyzed, and points of controversy about the immunology and immunopathology of hepatitis C are discussed. A body of evidence supports the existence in hepatitis C virus-infected subjects of strong humoral and cellular immune responses. HCV Core, NS3 and NS4 proteins are the most immunogenic antigens for B cells and HLA class II-restricted CD4+ T cells. For its part, liver-infiltrating CD8+ CTL recognize epitopes within the Core, E1, E2/NS1 and NS2 proteins in a HLA class I restricted manner. CTL responses to HCV Core, NS3, NS4 and NS5 have been detected in peripheral blood of patients chronically infected with HCV. Although these B and T cell responses may contribute to clear the virus, in most cases they are unable to resolve chronic HCV infections. No protective B or T cell epitope has been found yet. It is becoming clearer that the immune response plays a fundamental role in the pathogenesis of liver disease in hepatitis C patients.