Effects of protein depletion and repletion on cell-mediated immunity in experimental animals.

Protein-calorie malnutrition leads to depression of host cell-mediated immunity. Nutritional repletion initially results in rapid weight gain followed by a more gradual return of immunocompetence. Administration of a synthetic amino acid diet to normal animals did not preserve body weight or cell-mediated immunity any better than did a high carbohydrate, protein-free diet. Administration of a synthetic amino acid diet to malnourished animals maintained body weight, but did not restore immunocompetence. Proper nutritional repletion should provide both adequate protein and nonprotein calories if a return of immunocompetence is to be anticipated.     

Impaired cell-mediated immunity in experimental abdominal sepsis and the effect of interleukin 2.

A murine model of experimental sepsis, ie, cecal ligation and puncture, was used to determine the potential effects of infection on in vitro cell-mediated immunity. Following cecal ligation and puncture, in vitro responses of mouse splenocytes to mitogens (phytohemagglutinin and concanavalin A), the effects of in vitro interleukin 2 on these responses, and the impact of in vivo interleukin 2 on survival were studied. Compared with controls (sham cecal ligation and puncture), phytohemagglutinin responses 1 day after cecal ligation and puncture were enhanced (43% +/- 17%, n = 9), phytohemagglutinin and concanavalin A responses at day 4 were suppressed (45.5% +/- 4.4% and 57.5% +/- 5.6%), and, by day 7, phytohemagglutinin and concanavalin A responses were approaching values in mice treated by sham cecal ligation and puncture. Suppressed phytohemagglutinin responses at day 4 after cecal ligation and puncture were restored to normal with in vitro interleukin 2 (61,052 +/- 3407 cpm for cecal ligation and puncture and 64,643 +/- 4727 cpm for sham cecal ligation and puncture). Mortalities following cecal ligation and puncture were identical at day 1 after cecal ligation and puncture (6/20) for both interleukin 2- and vehicle-treated groups; thereafter, interleukin 2-treated groups fared better. At day 1 after cecal ligation and puncture, the mean spleen cell phytohemagglutinin response was enhanced (43.8% +/- 17%, n = 9) compared with sham cecal ligation and puncture (= 10). By day 4, the responses to both concanavalin A and phytohemagglutinin were suppressed (45.5% +/- 4.4% and 57.5% +/- 5.6%, respectively). Responses at day 7 approached those of controls given sham cecal ligation and puncture. Sepsis causing a temporary impairment of cell-mediated immunity may be a factor in the frequent coexistence of altered cell-mediated immunity and sepsis, and interleukin 2 may have a role in limiting the adverse effects of sepsis.     

Insulin and insulinlike growth factors in embryonic development. Effects of a biologically inert insulin (guinea pig) on rat embryonic growth and development in vitro.

Congenital anomalies occur up to four times more frequently in diabetic pregnancy than in the nondiabetic population. Although past work has shown that maternal hyperglycemia and hyperketonemia may increase embryonic abnormalities, recent experimental evidence suggests that low insulin levels may also contribute to diabetic embryopathy. This study investigated the effects of guinea pig serum (whose insulin is inactive in rat systems) on rat embryonic growth and development in culture. Supplementation of guinea pig serum with pork insulin at low (1 ng/ml) and high (5 ng/ml) physiological concentrations and insulinlike growth factors (IGF) I and II were also studied. Culture of rat embryos from the early headfold stage in guinea pig serum resulted in poor embryonic growth and development with a 92% rate of anomalies. Supplementation of guinea pig serum with zinc-binding pork insulin significantly improved rat embryonic growth and development (46% anomaly rate) especially between the first 5 and 21 h of the period of organogenesis. This evidence supports our most recent findings that low insulin levels, as encountered in untreated diabetic pregnancy, may contribute to the increased risk of congenital abnormality. Insulin at low physiological concentrations improved growth, whereas higher physiological concentrations were required to increase growth and development. IGF-I or IGF-II supplementation improved rat embryonic growth and development but failed to match that of the controls, indicating that other growth factors including insulin may also be required.     

Effects of cisapride on the motility of the digestive tract in dogs and guinea pigs

Effects of cisapride on the motility of the digestive tract in vivo in dogs and the guinea-pig intestine in vitro were studied. Cisapride (0.05-2.0 mg/kg, i.v.) produced an increase in amplitude of spontaneous contractions and basal tone in the stomach, duodenum, jejunum and proximal and distal colon in dogs. In some animals, however, it induced an inhibition with decrease in amplitude and tone. It also induced an increase in amplitude of contractions in the gallbladder and the sphincter of Oddi in dogs. The tone of the gallbladder was elevated by the same dose of cisapride, but the tone of the sphincter of Oddi was decreased. The drug produced a reverse response in some animals. These excitatory responses to cisapride were abolished by atropine (0.2 mg/kg, i.v.). Motility of the guinea-pig isolated ileum and colon was enhanced with an increase in their amplitude of contractions and basal tone at low concentrations of cisapride (10(-9)-10(-6)M) but it was inhibited at higher concentrations (10(-5)-10(-4)M). Atropine abolished the excitatory response of the ileum to cisapride in all cases. It abolished the excitation of the colon in some preparations but reduced only in some degree in the other. The inhibitory effect of cisapride on isolated preparations was unaffected by tetrodotoxin. From these results, it is concluded that cisapride enhances motility of the gastrointestinal tract and biliary tract by acting on myenteric cholinergic neurons and inhibits it by acting on the smooth muscle itself.     

Fibrinolytic activity in the inner ear of human beings and guinea pigs.

Fibrinolytic activity in the inner ear of human beings and guinea pigs was assayed qualitatively and quantitatively. It was found that fibrinolytic activity of the stria vascularis was caused by a conversion of plasminogen to plasmin by tissue plasminogen activator and was moderate in degree compared with that of other organs in both species. In human beings, endolymph showed higher plasminogen activator activity than that of CSF. Plasminogen activator activity was not detected in either endolymph or perilymph of guinea pigs. Thrombin infusion diminished plasminogen activator activity in the stria vascularis of guinea pigs.     

Effects of ketamine and halothane on normal and asthmatic smooth muscle of the airway in guinea pigs

in vitro preparations of trachea isolated from normal and asthmatic guinea pigs were used to measure their maximum contractile response to histamine challenge and to determine spontaneous relaxation of smooth muscle of the airway. The effect of ketamine and halothane on these reactions was investigated. The optimal ketamine concentration was found to be 10 μg/ml. This dose attenuated the maximum contraction and produced greater relaxation (p < 0.01) of isolated trachea. However, ketamine failed to prevent an anaphylactic (Schultz-Dale) response when antigen (one per cent albumin) was added in an experimental chamber containing pre-sensitized guinea pig trachea. In contrast, halothane abolished any response to histamine challenge and prevented development of the Schultz-Dale response of smooth muscle from the airway of asthmatic guinea pigs.     

Viral-specific humoral immunity to herpes simplex-induced antigens in patients with squamous carcinoma of the head and neck.

Serum antibodies to herpes simplex virus-induced antigens (HSVIA) were quantitated in 122 patients with head and neck squamous carcinoma, 93 patients tumor-free after treatment for these malignant lesions, 27 patients with nonsquamous malignant lesions, 30 heavy smokers, and 36 nonsmokers. Serum IgA anti-HSVIA antibodies were detected in a greater percentage of sera of patients with squamous carcinoma (61 per cent), patients previously treated for these malignant lesions (56 per cent), and heavy smokers (57 per cent) than in patients with nonsquamous malignant lesions (11 per cent) or nonsmokers (8 per cent). Furthermore, titers of these antibodies were higher in patients with squamous carcinoma than in smokers. In patients tumor-free more than three years after treatment, the percentage of positive sera was significantly lower than that in untreated patients and in patients three years or less after treatment. This study demonstrates for the first time a high frequency of antibodies to HSV-induced antigens confined to subjects at high risk of developing head and neck squamous carcinoma and in patients with these malignancies as well as a correlation between the levels of these antibodies and clinical course after treatment.     

Prostaglandins and cell-mediated immunity. The role of prostaglandin E1 in the induction of host-versus-graft and graft-versus-host reactions in mice

Based on studies in lymphocyte cultures it has been suggested that endogenous prostaglandins (PG), especially those of the E series (PGE), suppress cell-mediated immune reactions during their induction phase. We have tested this theory in experimental animals using local host-versus-graft (HVG) and graft-versus-host (GVH) reactions in mice. These reactions were suppressed in a dose-dependent manner by treatment of the animals with PGE1. If, however, endogenous PGE was neutralized through treatment of the animals with immune sera directed against PGE (APSE1) then inhibition of the development of HVG and GVH reactions was seen. This inhibition could be abrogated in "add back" experiments by treatment of the animals with PGE1. We suggest that the action of PGE1 during the induction phase of CMI responses is governed by a bell-shaped dose-response curve with a response-enhancing effect at low PGE1 and a suppressive effect at high PGE1 concentrations. APSE1 has proved to be very effective in inhibiting responses, and thus treatment with anti-PG antibodies may not only represent a valuable tool for the study of the role of PG in immunoregulation, but may become useful in therapeutic interventions with the immune system--e.g., after bone marrow transplantation.     

Regional heterogeneity in intracellular distribution of superoxide and hydrogen peroxide within the sperm and its relation to sperm development.

This study was performed to understand the regional distribution of superoxide anion radicals and hydrogen peroxide within the spermatozoa of mice during both normal and altered situations of epididymal maturation. The intracellular O2*- levels were probed employing dichlorodihydrofluorescein diacetate (DDF) as a reporter. The testicular spermatozoa from normal animals showed strong regional heterogeneity in the DDF fluorescence patterns over the various domains. Vasectomy resulted in strong inhibition in the O2* levels of spermatozoa at all stages of maturation. Interestingly, the fluorescein diacetate staining pattern was strong in the head of spermatozoa from the testis, caput, corpus, and cauda region. Further. there was a progressive reduction in the fluorescence in the head region in the spermatozoa toward the cauda region. The midpiece and tail showed moderate fluorescence, which also diminished as the spermatozoa matured. The spermatozoa from the vas deferens exhibited a weak fluorescence over the head domain, with the other domain staining extremely weak. Here again, vasectomy introduced considerable loss in the fluorescence intensity. The implications of programmed production of reactive oxygen species in specific domains of the spermatozoa during various stages of development are discussed.