The born-again spleen. Return of splenic function after splenectomy for trauma

We assessed splenic activity after splenectomy by interference phase microscopical examination of circulating red cells. Normal eusplenic children had a low number (less than 1 per cent) of red cells with surface indentations or "pits". About 20 per cent of red cells of children who had electively been subjected to splenectomy for hematologic indications were "pitted". Thriteen of 22 children who had had emergency splenectomy because of traumatic injury had a low percentage of "pitted" red cells, suggesting a return of splenic function. In five of these children a 99mTc sulfur colloid scan demonstrated multiple nodules of recurrent splenic tissue. In contrast to the prevailing opinion that splenosis is rare, we have found it to be a frequent occurrence. Return of splenic function may, in part, account for the low frequency with which overwhelming bacterial sepsis and meningitis have been documented after splenectomy for traumatic indications.

T cell growth factor: parameters of production and a quantitative microassay for activity

Several soluble factors have recently been associated with the proliferation and differentiation of thymus-derived lymphocytes. One of these factors present in medium conditioned by T cell mitogen-stimulated lymphocytes has the ability to promote the long-term culture of normal and antigen-specific cytotoxic T cells. We report a method to test for this proliferative stimulus in the form of a sensitive microassay based upon the tritiated-thymidine incorporation of continuous murine tumor-specific cytotoxic T cell lines (CTLL). The microassay requires microliter quantitites of sample fluid and is amenable to quantitative analysis. This highly reproducible, quantitative assay for T cell growth factor (TCGF) has allowed investigation as to the kinetics of TCGF generation and has revealed that T lymphocytes are required for its production. Further investigation has supported the notion that this nonspecies-specific factor is actively removed from tissue culture medium by the proliferation of either T cell mitogen-activated lymphocytes or CTLL.

Effects and receptors of glucocorticoids in rat thymus cells and human peripheral lymphocytes

Glucocorticoids are widely used for therapeutic purposes and have many toxic side effects. It seems likely that their physiological, therapeutic, and toxic effects are exerted through similar receptors and may be inherently inseparable. Lymphoid cells are targets for all these effects. With rat thymus cells in vitro, glucocorticoids immediately bind to cytoplasmic receptors, which are translocated to the nucleus, where they apparently induce messenger RNA for specific proteins that rapidly inhibit glucose transport. Protein and RNA metabolism are inhibited more slowly and eventually the cells die. The rate of formation of nuclear complexes and the timing of the hypothetical RNA-synthetic step are such as to suggest that the hormone-receptor complexes stimulate RNA synthesis in proportion to the rate at which they bind to nuclear sites rather than in proportion to the number of nuclear sites occupied. With normal peripheral human lymphocytes the rates of formation of hormone-receptor complexes are similar to those in rat thymocytes. The rate of onset of inhibition of glucose transport is lower, however, as is the rate of cytolysis. In human peripheral lymphocytes stimulated to undergo blast transformation with concanavalin A there is a dramatic increase in the number of glucocorticoid receptor sites per cell. This increase may be associated with a stage of the normal cell cycle, the mitogen stimulus inducing partial synchronization of the cell population. It has not been found, contrary to widespread belief, that mitogen stimulation renders cells insensitive to glucocorticoids.

The interaction of erythropoietin with fetal liver cells. II. Inhibition of the erythropoietin effect by interferon

To investigate the effect of interferon on the proliferation of normal erythroid precursor cells, various interferon preparations were added to mouse fetal liver cells cultured in a liquid microculture system. The effect of interferon was studied using cellular tritiated thymidine incorporation both in the presence and in the absence of erythropoietin. Interferon was found to suppress cellular tritiated thymidine incorporation. The suppression was directly related to the antiviral activity and was not found when control preparations were used. The mechanism of suppression seemed to involve a direct effect on the cells which was dependent of erythropoietin. These studies suggest that the viral inhibitory effects of interferon may also be accompanied by effects on normal cellular proliferation.

In vitro generation of tumor-specific cytotoxic lymphocytes. Secondary allogeneic mixed tumor lymphocyte culture of normal murine spleen cells

In vivo or in vitro immunity to murine leukemia virus (MuLV)-induced leukemia cells which do not effectively produce virus, has been difficult to demonstrate. Because immunizations with allogeneic murine leukemia cells have been used to confer syngeneic tumor immunity to virus- producing cells, we attempted to generate lymphocytes, cytotoxic to syngeneic nonproducer leukemia cells, by stimulating normal murine spleen cells with allogeneic nonproducer leukemia cells in mixed tumor lymphocyte culture (MTLC) reactions in vitro. Secondary allogeneic MTLC of normal C57BL/6 or DBA/2 spleen cells effectively produced syngeneic tumor-specific cytotoxic lymphocytes. Target cells lysed in lymphocyte- mediated cytolysis (LMC) assays, included both Friend and Rauscher virus- induced syngeneic murine leukemia cells and chemically-induced hematopoietic tumor cells. Syngeneic tumor cells were lysed regardless of whether they produced infectious MuLV or expressed viral antigens gp-71, p-30, or p-12 at the cell surface. Syngeneic normal cells (thymus, lymph node, or Concanavalin A-stimulated spleen cells) used as targets in LMC assays were uneffected by lymphocytes harvested from secondary allogeneic MTLC. Several other in vitro culture treatments including secondary syngeneic MTLC and repetitive mixed lymphocyte culture stimulations were incapable of generating tumor-specific cytotoxic lymphocytes. Based upon these results, we propose that secondary MTLC stimulation of normal spleen cells with allogeneic nonproducer leukemia cells selects for the proliferation of two subpopulations of antigen-specific cytotoxic lymphocytes. The population capable of effecting syngeneic tumor cell lysis is directed against tumor-associated cell surface antigens which may be distinct from viral structural proteins or glycoproteins. The growth of these tumor-specific cytotoxic lymphocytes may be enhanced by a soluble allogeneic effect factor produced by the proliferation of the second subpopulation of lymphocytes generated in repetitive allogeneic MTLC, namely those lymphocytes with specificities directed against differing histocompatibility antigens.

Anti-keyhole limpet hemocyanin antibody in normal unsensitized individuals

Antibody to keyhole limpet hemocyanin (KLH) has been detected in normal unimmunized subjects by means of a sensitive micropassive hemagglutination technique. Prior sensitization was not detected by either skin testing or lymphocyte transformation. After immunization with KLH there was no correlation between the level of this antibody and subsequently acquired skin test reactivity and lymphocyte transformation.

Sympathetic regulation of cephalic blood flow

Blood flow to bilateral tissues (cranial and extracranial) was studied by means of the particle distribution method in two groups of anesthetized dogs (five using 25-mu radioactive microspheres, six using 15-mu microspheres) and five anesthetized stumptail Macaques monkeys (8-mj spheres) during unilateral sympathetic stimulation. The stimulatory parameters were adjusted to produce maximum pupillary dilatation. In the five dogs hemispheric and regional cerebral blood flow decreased but not significantly. Flow to the extracranial tissues decreased 82%. Hemispheric brain blood flow averaged 0.70 ml/min/gm for Paco2 of 40 mm Hg. In the six dogs sympathetic stimulation did not significantly decrease cerebral blood flow but decreased flow to extracranial tissues (72.3%). At an average Paco2 of 33.2 mm Hg, hemispheric blood flow to the unstimulated side averaged 0.51 ml/min/gm. In the five monkeys findings were essentially the same as those observed in the dogs. The hemispheric blood flow averaged 0.36 ml/min/gm on the nonstimulated side for an average Paco2 of 36.6 mm Hg. Under the conditions studied, electrical stimulation of the cervical sympathetic nerves does not appear to modify regional or total brain blood flow in dogs and Macaques monkeys. The vascular response in oral and other extracranial tissues is very dramatic, however.

The distribution of labeled albumin across the rabbit thoracic aorta in vivo

125I-albumin was injected intravenously into normal conscious rabbits. The rabbits were killed after 10 minutes to 24 hours, and the descending thoracic aorta was excises immediately, opened longitudinally, rinsed, and frozen. Samples of frozen aorta were sectioned paralled to the intimal surface and washed with trichloroacetic acid (TCA) prior to counting. TCA-soluble tissue radioactivity slowly increased with time, suggesting that 125I was cleaved gradually from the labeled albumin within the aortic wall. At up to 4 hours, transmural concentration profiles of TCA-precipitable radioactivity had steep gradients near the intimal surface, moderate gradients near the medial-advential border, and were relatively falt in the middle of the media. After 24 hours, the steep intimal gradient had disappeared. Concentrations were otherwise comparable to those at 4 hours. The rate of accumulation of TCA-precipitable radioactivity was rapid initially (measurable concentrations were found throughout the media after only 10 minutes) and decreased with time. The results are consistent with entry of 125I-albumin into the media from both the luminal and adventitial sides. Approximate calculations indicate that the albumin mass transfer resistance associated with the intimal endothelium is about 1 order of magnitude greater than that associated with the media.

Ssytemic effects of intravenous polyriboinosinic-polyribocytidylic acid in man

To investigate the systemic, clinical and laboratory effects of iv polyriboinosinic-polyribocytidylic acid (poly I-poly C), 32 doses of poly I-poly C were administered to 22 patients. Doses between 1 and 10 mg/kg induced the formation of serum interferon (IF) and fever. Whereas a direct relationship was seen between the poly I-poly C dose and fever, serum IF levels were not significantly changed by increasing the dose of poly I-poly C over a log range from 1 to 10 mg/kg. Transient abnormalities were noted in liver function tests in 4 of 13 patients who received greater than 6.0 mg/kg. Other laboratory changes were confined to an increase in the absolute granulocyte count that paralleled fever development and abnormalities in coagulation parameters of 1 patient. In vitro lymphocyte DNA synthesis in response to mitogens was transiently impaired at times corresponding to serum IF appearance. These studies have established dose levels of poly I-poly C that can be safely administered to man with minimal toxicity and result in IF induction.

Medical opinion on abortion in Jamaica: a national Delphi survey of physician, nurses, and midwives

A national sample of 120 Jamaican physicians, public health nurses, and licensed midwives participated in a two-stage Delphi survey to identify medical opinion on proposed liberlization of Jamaica's abortion law, and to predict the likely impact of such legislative action on existing health and family planning services. More than 80 percent of the respondents favored legalization of abortion, and most supported changes in the health service delivery system to accommodate the expected demand. They believed that clandestine abortion, involving pharmacists and physicians, is already widely practiced.

Distribution of cardiac output in dogs during intravenous infusion of betahistine

Cardiac output (CO), arterial blood pressure (ABP), heart rate (HR), blood gases and blood flow (BF) to the brain, heart, kidney and skeletal muscles and other cephalic tissues in five dogs were studied before and at 30 minutes of betahistine infusion (0.12 to 0.2 mg per minute per kilogram). The particle distribution method using radioactive labeled 141Ce (15 mu) and 85Sr (15 mu) microspheres was utilized to quantitate and assess BF and CO. In the five dogs, the increase in CO averaged 20.8%, ABP remained constant, and HR increased in all but one exception where it decreased slightly concomitant with a decrease in Paco2. Brain BF increased (+ 29.6%) in the dogs whose Paco2 reamined constant. The BF increased to the heart (25.4%) and skeletal muslce (80%), while BF to the kidney and other tissues did not change. The change in HR appears to account for the change in CO. The dilating effect of betahistine on blood vessels, in the skeletal muscle, brain and heart could reduce peripheral resistance and decreace ABP. Thus, the increase in HR may be mediated through baroreceptor mechanisms rather than by a direct effect of betahistine. In addition, a decrease in Paco2, is more effective for decreasing cerebral BF than betahistine is for increasing blood flow.

Chloroethyl-cyclohexyl-nitrosourea (CCNU) in the treatment of malignant brain tumors

✓ Oral 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), a lipid-soluble non-ionized chemotherapeutic agent, was used in the treatment of 26 patients with malignant brain tumor, primarily glioblastoma. Most patients had first received conventional surgery, and about one half had received x-ray therapy. Over 1½ years, 113 courses of CCNU (130–150 mg/m2) were given and analyzed for clinical results and agent toxicity. A new central nervous system (CNS) disease staging system was used to measure patient impairment and therapeutic response. Thirty-seven per cent of all symptomatic patients had significant remission of clinical disease, lasting a median of 5 months. Data are presented implying that the treatment of asymptomatic patients may also be of considerable value. The most significant toxicity was delayed reversible thrombocytopenia, which was less severe than that seen with nitrosourea BCNU. Despite the cumulative toxicity observed with all three bone-marrow elements, serious complications were rare. Our initial experience indicates that CCNU is an effective agent for the treatment of malignant brain tumor and that the CNS disease staging system is useful in obtaining quantitative results.