The effect of natural antibody in guinea-pig serum on mouse lymphoma cells in vitro and in vivo

Normal guinea-pig serum was found to have a cytotoxic effect in vitro upon several newly induced mouse lymphoblastic leukaemias and on normal mouse thymocytes. This reaction was complement dependent, and cross-absorption experiments showed that the reactivity could be abolished by absorption with any susceptible cell type. It was concluded that normal guinea-pig serum contained a natural antibody which reacted in common with normal mouse thymocytes and certain lymphomas. The growth of lymphomas which had proved highly sensitive to guinea-pig serum in vitro was inhibited by guinea-pig serum in vivo. In contrast, lymphomas showing insensitivity to guinea-pig serum in vitro were also insensitive to it in vivo. It is suggested that the inhibition of lymphoma growth in vivo was due to the natural cytotoxic antibody present in guinea-pig serum.     

The effect of local antibody responses on in vivo and in vitro phagocytosis by pulmonary alveolar macrophages

This study used both in vitro and in vivo techniques to determine if local antigen deposition in the lung has a localized effect on immune phagocytosis by pulmonary alveolar macrophages (PAM). Using a fiberoptic bronchoscope, dogs were immunized in the left cardiac and left diaphragmatic lobes with sheep red blood cells (sRBC). The right cardiac and right diaphragmatic lobes of the same animals received saline as controls. Unimmunized dogs served as additional controls. On days 2, 6, 9, 13, and 16 after immunization, the left and right diaphragmatic lobes were lavaged, and the cells and fluids were analyzed in vitro. Opsonizing antibody in lavage fluids was first detectable at 6 days, peaked at 9-13 days, and was significantly higher in the immunized lobe than in the control lobe. Phagocytosis of sRBC caused by cytophilic antibody on PAM also peaked at 9 to 13 days. Significantly more cytophilic antibody activity was detected on day 9 in the immunized lobes, than in the control lobes. In vivo phagocytosis of sRBC was evaluated in the alveoli of immunized and control lobes of immunized dogs and a control lobe of unimmunized dogs. Phagocytosis of sRBC by PAM in the immunized lobes was about four times greater than that of the control lobes and about 40 times greater than that of a control lobe of an unimmunized dog. These results indicate that the local deposition of a particulate antigen in the lung had a localized effect on immune phagocytosis. These data suggest that the accumulation of antibody-secreting cells in the alveolus may play a critical role in pulmonary defense mechanisms.     

Specific antibody synthesis in vitro. IV. The correlation of in vitro and in vivo antibody response to influenza vaccine in rhesus monkeys.

Fourteen female monkeys (Macaca mulatta) received a trivalent influenza vaccine and antibody response was determined by a change in plasma antibody content (ELISA) before and after vaccine. Lymphocyte cultures were also established from these monkeys and the level of antibody response did not correlate with mitogen-induced lymphocyte blastogenesis or natural killer cell function. In vitro anti-influenza antibody synthesis, however, was found to correlate well with the in vivo response. That is, monkeys who were non-responders, as determined by lack of change in plasma antibody content, were also non-responders in vitro. Accordingly, we believe that vaccine response is not necessarily a measure of immune competence but its measurement may, none the less, have clinical utility. The excellent correlation of in vivo and in vitro response provides predictive value for the in vitro test. Furthermore, because the correlation is good, the in vitro test may be useful as a tool in immunopharmacology and toxicology.     

The effect of extracorporeal antibody removal on antibody synthesis and catabolism in immunized rabbits.

Plasma exchange therapy is currently used to remove antibody from the circulation in a number of autoimmune diseases. It has been suggested that the decrease in antibody level may affect synthesis rate by the removal of inhibitory feedback. This would then cause a rapid rise in antibody levels to or beyond those prior to depletion. Based on this supposition immunosuppression is nearly always used concomitantly with plasma exchange to prevent the expected increase in synthesis rates. An assessment of the effect of specific antibody removal by immunoadsorption on synthesis and catabolic rates was undertaken to clarify the nature of the response. Rabbits were immunized to bovine serum albumin (BSA) injected with 125I-anti-BSA IgG and later underwent extracorporeal immunoadsorption with BSA-Sepharose. At least 60% of circulating anti-BSA-IgG was removed. Mathematical analysis of 125I-anti-BSA IgG and anti-BSA-IgG levels demonstrated a reduction in catabolic clearance following immunoadsorption. Conversely synthesis rate was not altered. No significant overshoot of anti-BSA-IgG beyond pre-removal levels occurred. Based on these findings it is postulated that an increase in antibody synthesis does not generally occur following plasma exchange. The rise in antibody levels seen following plasma exchange probably reflect a reduction of catabolism combined with an unchanged rate of synthesis.     

The effect of cimetidine on plasma lipoproteins

The concentration of lipids, lipoproteins and apolipoproteins A-I and -B were measured in the plasma of 12 patients with peptic ulcer disease before and after five weeks of treatment with cimetidine. No statistically significant changes were found, but HDL cholesterol and HDL2 cholesterol tended to increase, and VLDL cholesterol and plasma triglycerides tended to decrease. A review of published studies indicates that the data at present are too uncertain to warrant use of cimetidine as a lipoprotein modulating drug.     

In vivo effect of cimetidine on canine pulmonary responsiveness to aerosol histamine

A series of experiments were designed to discover whether pulmonary histamine H₂ receptors might be of physiologic importance in vivo in the dog. Dose-response curves were performed to aerosol histamine in 11 dogs both before and 1 hr after H₂ receptor blockade with cimetidine (1 mg/kg as a rapid intravenous infusion). Cimetidine had no significant effect on control values of dynamic compliance or resistance of the lung. In the 11 dogs tested H₂ receptor antagonism significantly potentiated (p < 0.05) the animals' pulmonary responsiveness to aerosol histamine. The potentiation of histamine constrictor effects produced by cimetidine were more marked on those dogs initially least responsive to aerosol histamine (p < 0.01). We have found evidence for the presence of inhibitory H₂ receptors in canine airways and for the distribution of these receptors among dogs, explaining in part the previously described differences among dogs in the pulmonary responsiveness to aerosol histamine.     

The effect of diethylcarbamazine on microfilariae ofLitomosoides carinii in vitro and in vivo

Culture-derivedLitomosoides carinii microfilariae (MFF) were used in in vitro and in vivo systems to investigate the effect of diethylcar-bamazine (DEC) on these MFF. In vivo: Male rats,Mastomys natalensis, all of the same age, were injected intrathoracically (12) or intraperitoneally (36) with 10³ or 10⁴ MFF. After 30 min one half of each group of rats was given DEC per os. At 30, 60, and 120 min after DEC administration, two rats from the treated and two from the untreated group were bled and killed. The pleural or peritoneal cavities were rinsed with warm saline (0.15m NaCl) to recover MFF. In both the intrathoracic and intraperitoneal experiments, equal numbers of MFF were recovered from treated and control rats at 30 and 120 min. However, at 60 min 85.5% fewer were recovered from the treated than from the nontreated animals. MFF were not found in the blood. In vitro: MFF were added to tissue culture dish wells (Linbro Div., Flow Labs, Hamden, Conn) prepared as follows: DEC-Serum (serum from normal rats given DEC at 500 mg/kg), DEC+Serum (serum with added DEC), serum only, RPMI 1640 only, and RPMI 1640+DEC. Furthermore, the five treatments were prepared either with or without unstimulated peritoneal exudate (PE) cells. At 30 min in the DEC-Serum wells 45% of the MFF had adherent PE cells; in the remaining wells these cells adhered to 11% or fewer MFF. We interpret the aforementioned phenomena as representing the first step in the trapping and elimination of MFF after DEC treatment ofL. carinii-infectedM. natalensis.     

The effect of antibody on latent pseudorabies virus infection in vitro.

Cytosine arabinoside (Ara C) inhibited the synthesis of pseudorabies virus when Vero cells were infected at a multiplicity of infection of 0.0001-0.05 PFU per cell. On removal of Ara C, infectious virus reappeared after a latent period of 3-5 days. The activation of latent virus was not influenced by elevating the temperature to 40 degrees C at the time of Ara C removal but it was prevented by antiviral antibody. When antiviral IgG was added into the culture fluid of cells either during the incubation with Ara C, or after removal of the inhibitor, the number of infectious centres was reduced to about 10%. The role of antiviral IgG in the maintenance of latency is discussed.     

Medroxyprogesterone acetate enhances in vivo and in vitro antibody production

In the present study we examine the effects of medroxyprogesterone acetate (MPA) on the specific antibody secretion to T-dependent antigens. Our results show that the in vivo administration of MPA to mice, 7 or 90 days before immunization with sheep red blood cells (SRBC), significantly enhanced both, primary and secondary antibody responses, without affecting delayed-type hypersensitivity (DTH). These effects could be counteracted by the anti-progestin onapristone or ZK 98299 (ZK) suggesting that MPA interacted with progesterone (PRG) receptors to increase B-cell response. To better understand the mechanisms involved in MPA activity we carried out cultures of splenocytes, bone marrow cells or lymph node cells from immunized mice in the presence of MPA, and evaluated the amount of antibody release to supernatants. We found that low doses of MPA (10(-9) M and 10(-10) M) significantly enhanced the in vitro production of specific immunoglobulin G (IgG) antibodies, an effect that appears to involve the interaction of the progestin with PRG receptors, as judged by the inhibition of MPA effects with ZK (10(-8) M) or RU486 (10(-9) M). These receptors were detected by flow cytometry analysis in a proportion of T lymphocytes. Because MPA did not increase the number of immunoglobulin-secreting cells, our findings suggest that MPA enhanced the capacity of individual cells to produce specific immunoglobulin.     

去甲肾上腺素对大鼠体外抗体生成的影响

目的 观察不同浓度甲肾上腺素（ＮＡ，１０＾－１～１０＾－６ｍｏｌ／Ｌ）对大鼠体外抗体生成的影响，并初步探讨其作用机制。方法 在体外用百红细胞（ＳＲＢＣ）刺激大鼠肠系结Ｂ细胞转化成形成细胞（ＡＦＣ），然后检测其抗体生成量。结果 （１）１０＾－１０、１０＾－６、１０＾－８和１０＾－７ｍｏｌ／Ｌ ＮＡ都能显著高于外抗体生成，其中１０＾－６ｍｏｌ／Ｌ ＮＡ的作用最强。（２）γ受体激动剂异丙肾上腺素亦能明显     

Induction of immunoglobulin and antibody synthesis in vitro by lipopolysaccharides

Lipopolysaccharides (LPS) from E. coli bacteria were found to be mitogenic for bone marrowderived (B) lymphocytes, but had no effect on thymusderived (T) lymphocytes. When added to normal spleen cells in culture, LPS selectively stimulated the secretion of 19 S proteins, whereas there was no demonstrable increase of 7 S protein synthesis. Spleen cell cultures treated with various doses of LPS exhibited atypical dose response curve with regard to induction of DNA synthesis, 10 μg/ml being optimal, higher and lower concentrations giving lower responses. When direct antibody producing cells to horse and sheep red cells were studied in normal spleen cell cultures exposed to different concentrations of LPS in vitro, it was found that their number increased in parallel with stimulation of DNA synthesis. In contrast, the number of antibody producing cells to LPS itself did not parallel activation of DNA synthesis. Spleen cells from LPS tolerant animals responded with increased numbers of antibody producing cells to heterologous red cells after treatment with LPS in vitro to the same extent as normal spleen cells. Thus, a B cell mitogen, such as LPS, could activate division in B cells, resulting in an increased number of cells producing antibodies to non-cross-reacting antigens, mimicing the effect of specific antigen.     

The effect of cimetidine on parathyroid function and histopathology in primary hyperparathyroidism

Recent evidence suggests that cimetidine given pre-operatively in primary hyperparathyroidism (1 degree HPT) might cause structural changes in parathyroid glands, while its suppressive effects on the disease are disputable. To determine these possible changes we studied 38 patients with 1 degree HPT who underwent parathyroidectomy. In 14 of these (group I) cimetidine was given pre-operatively (1000 mg orally daily for 4 weeks). The remaining 24 patients (group II) did not take any drug. Parathyroid function was estimated by nephrogenous cAMP (NcAMP) and serum immunoreactive parathyroid hormone (iPTH) measurements. Histological examination of the parathyroids was made by conventional techniques. In group I at the end of cimetidine treatment, the only change observed was a small but significant (p less than 0.05) decrease of plasma calcium (-0.77 mg/dl). Histologically, the glands of group I--compared with those of group II--showed the following findings: increased gland mass: mean increase 1050 mg (adenomas) and 700 mg (hyperplasias); central oedema in all the cases of group I only; increased (about 50 per cent) cellular size and intranuclear 'inclusions' in 10 out of 14 cases of group I only. It is concluded that treatment with cimetidine in 1 degree HPT is followed by histopathologic alterations leading to increased size of the diseased parathyroids.