In vitro growth of murine T cells. IV. Use of T-cell growth factor to clone lymphoid cells

Murine bone marrow cells can suppress the in vitro primary antibody response of normal spleen cells without apparent cytotoxicity. The bone marrow cells suppress the response to both T-dependent (SRBC) and T-independent (DNP-Ficoll) antigens. When bone marrow cells are fractionated on a sucrose density gradient, the suppressive activity is found in the residue rather than the lymphocyte fraction. The suppressive activity is either unaffected or enhanced by treatment with anti-T- and anti-B-cell serums. Pretreatment of mice with phenylhydrazine which reduces the number of pre-B cells did not reduce the suppressive activity of their bone marrow cells. Suppressive activity is abolished by irradiation of the marrow cells in vitro with 1000 R prior to assay. The activity is present in the marrow of thymus deficient (nude) mice, infant mice, and mice which have been made polycythemic by transfusion. Furthermore, the suppressor cell can phagocytize iron carbonyl particles, is slightly adherent to plastic and Sephadex G-10, and can bind to EA monolayers. We conclude that the suppressor cell is not a mature lymphocyte or granulocyte nor a member of the erythrocytic series, but is likely to be an immature cell possibly of the myeloid series. We speculate on the physiologic role of this cell.     

Rabbit kidney function in vitro: the effect of colloids, energy substrate, a vasodilator, perfusion pressure, and bovine serum albumin

An in vitro perfusion system at 37 degrees C for the assessment of rabbit kidney function is described. The purpose of this assay system is to evaluate the effects of cryobiological manipulation on kidney function. The effect of the colloids dextran (MW = 70,000, 80,000, and 180,000) in the perfusate at 110 mm Hg were compared to a reduced perfusion pressure, colloid-free perfusate. Better function was obtained at lower perfusion pressure with the colloid-free perfusate. Less damage was noted histologically on light and electron microscopy. Investigation of energy substrates on rabbit kidney function demonstrated that butyrate, or lactate, in addition to glucose resulted in increased sodium and glucose reabsorption over glucose alone. Substrate-free perfused kidneys exhibited depressed Na transport. Lactate, and to some extent butyrate, decreased net glucose utilization. An alpha-adrenergic blocking agent, isoxsuprine, in the initial flush solution did not appear to be beneficial. An increase of perfusion pressure from 50 to 75 mm Hg resulted in an increase in GFR. Tubular function was enhanced by inclusion of small amounts of BSA in the perfusate.     

A mechanism and an evaluation of surface specific iodination by the chloramine-T procedure.

Both internal and external proteins in vesicular stomatitis virus were labeled when intact virions were iodinated with 50 μm iodide; however, only the surface proteins were labeled when the same procedure was carried out at low iodide concentrations (below 0.5 μm). This result together with similar observations reported earlier with another enveloped virus, Rous-associated virus-61 (RAV-61), suggest that viral envelopes provide a barrier to iodination by chloramine-T at low, but not at high, iodide concentrations. By monitoring the permeability of the RAV-61 envelope to successive iodinations and to iodination in the presence of chaotropic thiocyanate ions, it was shown that the permeability of the viral envelope was not altered at the higher concentrations of iodide. Further results support the hypothesis that iodination mediated by chloramine-T inolves two different iodinating species: (a) a membrane impermeable one, possibly “iodamine-T,” which predominates at low iodide concentrations, and (b) a membrane permeable species, possibly molecular iodine, which predominates at high concentrations of iodide. These results reinforce the proposal that the chloramine-T procedure is a useful method for specifically labeling surface proteins of lipid-enveloped structures.     

The differential effects of PGE on the immune response in normal and immunosuppressed mice

The effect of 16,16-dimethyl-PGE₂-methyl ester (di-M-PGE₂) on humoral and cellular immunoresponsiveness has been compared in normal mice and in mice immunosuppressed by splenectomy and thymectomy plus antithymocyte serum (ATS). Splenectomy resulted in immunosuppression manifested by augmentation of B-16 melanoma growth; this stimulatory effect was reversed by di-M-PGE₂. In animals immunosuppressed by thymectomy plus ATS, di-M-PGE₂ augmented the humoral and cellular immune responses; this was manifested by slowing of the growth of B-16 melanoma and by stimulating the number of plaque-forming cells, hemagglutinin titers, and delayed-hypersensitivity reactions to sheep erythrocytes. In contrast, in normal (nonthymectomized) mice, di-M-PGE₂ was mildly immunosuppressive. Finally, adriamycin-immunosuppressed normal mice and this suppression were reversed by the addition of di-M-PGE₂ to the treatment regimen.     

Mesenchyme cells degrade epithelial basal lamina glycosaminoglycan

We investigated whether turnover of basal lamina glycosaminoglycan (GAG), an active process during epithelial morphogenesis, involves the mesenchyme. Fixed, prelabeled, isolated mouse embryo submandibular epithelia were prepared retaining radioactive surface components, as determined by autoradiographic and enzymatic studies, and a basal lamina, as assessed by electron microscopy. Recombination of mouse embryo submandibular mesenchyme with these epithelia stimulates the release of epithelial radioactivity when the labeled precursor is glucosamine or glucose but not when it is amino acid. The release is linear with time during 150 min incubation. Augmented release of epithelial label requires living mesenchyme which must be close proximity with the epithelia. Although heterologous mesenchymes, including lung, trachea, and jaw, stimulate the release of submandibular epithelial label, epithelial tissues do not. The label released by intact submandibular mesenchyme from prelabeled epithelia is in GAG and in two unique fractions: heterogeneous materials of tetrasaccharide or smaller size and N-acetylglucosamine. Enzymatic treatment of the heterogeneous materials revealed the presence of glycosaminoglycan-derived oligosaccharides. These unique products were not obtained by incubating prelabeled epithelia with a mesenchymal cell extract, suggesting that intact mesenchymal cells are required. N-Acetylglucosamine was also released when mesenchyme was recombined with living prelabeled epithelia which contained labeled basal laminar GAG. Our results establish that submandibular epithelial basal lamina GAGs are degraded by submandibular mesenchyme. We propose that one mechanism of epithelial-mesenchymal interaction is the degradation of epithelial basal laminar GAG by mesenchyme.     

Surgery versus radiotherapy: Long term outcomes of T1 glottic cancer

AimThe aim of this study was to compare the outcomes, patterns of failure and laryngeal preservation rates in patients with T1N0 glottic cancer treated with surgery or radiotherapy.Materials/methodsRetrospective study of T1N0 glottic cancer patients treated in our institution between January 2007 and December 2017. Histologically proven squamous cell carcinoma patients, treated with upfront cordectomy/partial laryngectomy (S group) or radiotherapy (RT group) were included. Elective treatment of the neck was not permitted. Local failure (LF), disease-free survival (DFS), ultimate disease-free survival (UDFS), laryngectomy-free survival (LFS), disease-specific mortality (DSM) and overall survival (OS) were evaluated.ResultsTwo hundred and one patients were eligible (172 S group, 29 RT group), with a median follow-up of 38.8 months. Overall, 33 (16%) patients had a recurrence, 30 (17%) in the S group and 3 (10%) in the RT group. Local failure was the predominant site of failure (28 S, 2 RT). Overall, of all those that were salvaged, 17 (8%) underwent total laryngectomy (15 S, 2 RT). There was no significant difference in the 5-year cumulative incidence of LF (20.8% S, 8.1% RT, p = 0.138), 5-y LFS (85.0% vs. 91.7%, p = 0.809), 5-y DFS (67.5% vs. 82.1%, p = 0.343), 5-y UDFS (82.5% vs. 90.3%, p = 0.647) and 5-y OS (84.5% vs. 90.3%, p = 0.892). Multivariate analysis showed no correlation between initial treatment and the analyzed outcomes.ConclusionPrimary surgery or radiotherapy were similar first line options, since they do not differ in all outcomes. Patients’ and physician's preferences must be considered when choosing first treatment.     

Total neoadjuvant treatment in locally advanced rectal cancer

Locally advanced rectal cancer requires a multidisciplinary management, traditionally based on neo-adjuvant (chemo) radiotherapy, conservative surgery with total mesorectal excision and adjuvant chemotherapy. Despite effective in term of local control, this strategy is linked to a high risk of distant metastasis (up to 30%). In this context, recent published randomized phase III clinical trials have tested the potential benefits with a different sequencing and/or intensification of the standard components of the trimodal therapy.Here, we briefly assess the efficacy and discuss the clinical relevance of total neoadjuvant treatment with a focus on indications and results in the short-course radiotherapy followed by chemotherapy use for this setting of patients. Long term results and additional prospective studies are necessary to more accurately estimate the clinical benefit and further establish the role of total neoadjuvant therapy in locally advanced rectal cancer disease.     

A Model of Chronic Nutrient Infusion in the Rat

Chronic exposure to excessive levels of nutrients is postulated to affect the function of several organs and tissues and to contribute to the development of the many complications associated with obesity and the metabolic syndrome, including type 2 diabetes. To study the mechanisms by which excessive levels of glucose and fatty acids affect the pancreatic beta-cell and the secretion of insulin, we have established a chronic nutrient infusion model in the rat. The procedure consists of catheterizing the right jugular vein and left carotid artery under general anesthesia; allowing a 7-day recuperation period; connecting the catheters to the pumps using a swivel and counterweight system that enables the animal to move freely in the cage; and infusing glucose and/or Intralipid (a soybean oil emulsion which generates a mixture of approximately 80% unsaturated/20% saturated fatty acids when infused with heparin) for 72 hr. This model offers several advantages, including the possibility to finely modulate the target levels of circulating glucose and fatty acids; the option to co-infuse pharmacological compounds; and the relatively short time frame as opposed to dietary models. It can be used to examine the mechanisms of nutrient-induced dysfunction in a variety of organs and to test the effectiveness of drugs in this context.