Origin of IgA-secreting plasma cells in the mammary gland.

Lymphoblasts from the mesenteric lymph nodes (MN) of mice home to the mammary glands of syngeneic recipients late in pregnancy and during lactation, and within hours of transfer most can be shown to contain IgA. Homing does not occur in virgins, in early pregnancy, or after weaning. Homing MN lymphoblasts are sensitive to antiserum to IgA plus complement, but not to other class-specific antisera. Thus, lymphoblasts in MN with the potential to home to the mammary gland are already committed to IgA synthesis and bear surface IgA before reaching their destination. These results explain observations, made by others, of specific IgA antibodies and IgA plasma cells in milk and colostrum after oral immunization. Under natural conditions it is likely that IgA precursor cells, after stimulation in the gut-associated lymphoid tissue by intestinal antigens, migrate to the mammary gland where they secrete antibodies which constitute an important defense mechanism of the newborn. In the absence of lactation, these cells probably form part of the normal traffic to the lamina propria of the small intestine.

Long-term results of monthly inhaled pentamidine as primary prophylaxis of Pneumocystis carinii pneumonia in HIV-infected patients.

PURPOSE: To evaluate the long-term efficacy and safety of inhaled pentamidine as primary prophylaxis against Pneumocystis carinii pneumonia (PCP) in patients infected with human immunodeficiency virus (HIV). PATIENTS: Two hundred thirty-two HIV-infected patients with a CD4 cell count below 20% of the total lymphocyte count were given aerosolized pentamidine once every 4 weeks for more than 3 months. Pentamidine aerosols were administered at the hospital under medical supervision. Prevention of bronchospasm was carried out using inhaled salbutamol. RESULTS: Mean duration of prophylaxis was 15.9 months. Eleven patients (4.7%; [95% confidence interval 2% to 7.4%]) developed PCP. Probability to remain free of PCP is 95.6% at 12 months, 94% at 18 months, and 88% at 24 months. Mean delay between the onset of the prophylaxis and the occurrence of PCP for the 11 patients was 12.9 months (range: 4 to 26 months). No major side effect was observed, and minor side effects (cough, acute dyspnea) were infrequent. CONCLUSION: The efficacy and tolerance of aerosolized pentamidine as shown in our study support its use as primary prophylaxis against P. carinii in HIV-infected patients.

Impaired differentiation of Ig A-B cell precursors in the Peyer's patches of protein depleted rats.

The aim of this study has been set on Ig A plasma cell precursors that are found in the Peyer's patches. In a previous work it has been shown that protein deficiency at weaning led to the presence in the Peyer's patch of very immature B cells, mostly cu+ su- cells. In this report we demonstrate the c mu+ s mu- cells comprise a (c mu OX7)+ s mu- cell population that is predominant in the protein-deprived rats (41.5 versus 16.8 in 39 day-old control rats). Protein refeeding reinitiates the differentiation as follows: (a) the (c mu OX7)+ s mu- cell population was able to differentiate to (cs mu+ as in the normal Peyer's patch (53.6 versus 44.9 in 39 day-old control rats); (b) the switching of sIg M-bearing cells to sIg A-bearing cells occurs in a restricted pattern; only 27.9 versus 47.6 in the 60 day-old control rats; (c) concomitantly, protein-refed rats showed a low absolute number of W3/13+ and W3/25+ T cells. Therefore, this experimental model of immunodeficiency provides further evidence that specialized T helper cells or their soluble factors are needed for Ig A-B cell differentiation "in vivo."

Impairment of B and T cell maturation in gut associated lymphoid tissues due to malnutrition during lactation.

Previously we found that malnutrition during lactation in rats produces an impairment in the immune response to cholera toxin. In this report we found that malnutrition during lactation provokes in 28-day-old rats an increase of Thy1+ c mu+ cells in gut associated lymphoid tissues concomitantly with a decrease of sIgA+ B cells. No differences were found in the percentages of the IgM+ B cell populations. Furthermore, no differences were found in the Peyer's patch (PP) and mesenteric lymph node (MLN) T cell subsets in weaning rats when compared to controls. However, after 1 week of refeeding a higher percentage of the Thy1+ c mu- subset together with a lower percentage of CD5+, CD4+, and CD8+ T cells, were found in malnourished rats when compared to controls. The above results may indicate that B-cell maturation is delayed in malnourished rats at two stages of differentiation: (a) in the passage of pre-B cells (Thy1+ c mu+) to immature B cells (s mu+), and (b) in the switch from s mu+ B cells to s alpha+ B cells. The decrease of CD5+, CD4+, and CD8+ T cells together with an increase of the Thy1+ c mu- subset in gut-associated lymphoid tissues (GALT) may indicate that T-cell maturation is also delayed. Results obtained at weaning may be due to an engraftment by maternal milk-derived lymphocytes in the pups.

Developmental study of immunocompetent cells in the bronchus-associated lymphoid tissue (BALT) from Wistar rats.

The aim of the present report was to study in growing Wistar rats the development of immunocompetent cells in the bronchus-associated lymphoid tissue (BALT). We found at day 4 postpartum, a high number of TCRgamma/delta+ T cells and very few CD8alpha+, CD8beta+, CD5+, TCRalpha/beta+ T cells in BALT. The latter cells and CD4+ T cells increase with age. Even though T cells expressing TCRgamma/delta outnumber those expressing TCRalpha/beta early in development, until 45 days of age, alpha/beta+ predominate over gamma/delta+ T cells only in adult rats (60 days of age). Moreover, a predominance of suppressor/cytotoxic T cells over T-helper cells was found in 60 days old rats. Surprisingly, more CD8alpha+ than CD8beta+ T cells in BALT are observed. The number of IgA+ B and CD4+ T cells found in the BALT increases with age. The early appearance - 4 days of age - of all T-cell phenotypes in BALT especially of gamma/delta+ T cells may imply a benefit to respond to inhaled antigen soon after birth.

Cytogenetic studies in bone marrow cells from Wistar rats in protein malnutrition.

The effect of severe protein deficiency at weaning has been studied in bone marrow, which is a primary lymphoid organ. Our experimental model of secondary immunodeficiency in Wistar rats has shown: (1) a decreased number of viable bone marrow cells (P <.0001); (2) diminished percentage of mitosis (P <.01); and (3) severe alteration in the percentage of chromosome pairs 3, 11, and 12 bearing nucleolar organizer regions (NORs) (P <.05). This last finding indicates a poor ribosomal gene activity. These alterations were reverted after the oral administration of a 20% casein diet during 5 to 9 days. However, there were no karyotype variations between the experimental groups. We conclude from these results that severe protein deficiency at weaning alters several aspects of bone marrow cell proliferation and ribosomal gene activity as determined by the number of silver stained nucleolus organizer regions.

Leg ulcers and hydroxyurea: forty-one cases.

BACKGROUND: Hydroxyurea is an antitumor agent used to treat chronic myeloproliferative disorders. Leg ulcerations have been reported in patients undergoing long-term hydroxyurea therapy for myeloproliferative diseases. To better define this dermatological adverse effect of hydroxyurea therapy and to try to understand the pathophysiological process of this disease, we collected medical information for such patients in a multicenter retrospective study. OBSERVATIONS: Forty-one patients (mean age, 67 years) developed leg ulcerations while undergoing hydroxyurea therapy (mean therapy duration, 5 years). The sex ratio was 1, and there was no underlying vascular disease. Hematologic abnormalities were identified. Complete recovery from the ulcerations occurred quickly after withdrawal of treatment in 33 (80%) of the cases. CONCLUSIONS: This longest-reported series of patients confirms the role of hydroxyurea therapy in the onset of leg ulcerations. Healing or improvement requires cessation of treatment. Cutaneous atrophy and impaired wound healing may explain the relationship between hydroxyurea and leg ulcers. In addition, the megaloblastic erythrocytes resulting from the presence of hydroxyurea may circulate poorly through the capillary network. A prospective study in hematologic centers would be valuable.

T and B lymphocyte populations in uterus draining lymph nodes at estrus and diestrus in Wistar rats.

In this paper, data are presented on the characterization of uterus draining lymph nodes (UDLN) B and T lymphocytes of virgin rats at estrus (E) and diestrus (D). We established that the T/B lymphocyte relationship in the UDLN is less than one at estrus and more than one at diestrus. This is due to a decrease in the percentage and in the total number of mature T cell population in association with a decrease in the percentage of the OX8 subset in the UDLN at estrus. This situation may be related to an increase in estrogens known to produce thymic involution. These changes were not observed when we studied peripheral (popliteal) lymph nodes. The changes observed in the UDLN T cell population at estrus could be under hormonal control and we think that this condition may be important to prepare the immune system for an eventual pregnancy.

Compartmentalisation between gut and lung mucosae in a model of secondary immunodeficiency: effect of thymomodulin.

UNLABELLED: Compartmentalisation of mucosal immune response seems to be the result mainly of the preferential migration of activated cells back to their inductive sites. The aim of this report was to demonstrate, in a model of secondary immunodeficiency in Wistar rats (severely protein deprived at weaning and refed with casein 20%; group R21), that the oral administration of Thymomodulin (group:R21TmB) has different effects on gut and BALT (Bronchus-associated lymphoid tissue). Tissue sections (5 mu) were studied by immunohistochemistry 1). The oral administration of Thymomodulin restores only in gut Lamina propria (LP) the IgA B and CD4 T cell populations to control levels. The CD8a and CD25 subpopulations do not vary in gut as they return to control levels when refed with 20% casein diet. All the populations mentioned above remained decreased even after receiving Thymomodulin by the oral route. However, the same behaviour was observed for the TCR delta T cells that were decreased and return to normal levels in both mucosae by the effect of the immunomodulator; 2) when studying the iIEL (intestinal intraepithelial lymphocytes) CD8 alpha, CD25 and TCR gamma delta T cells, that were increased in R21, return to control levels in R21TmB. In BALT intraepithelium CD8 alpha and CD25 T cells remained decreased, while only TCR gamma delta T cells (increased in R21) return to control values. CONCLUSIONS: 1) there exists a compartmentalisation between both mucosae, as T CD4+ and IgA B+ cells are restored by TmB only in gut; 2) only those iIEL involved in inflammation (CD8 alpha+/CD25+ and TCR gamma delta+/CD25+) are normalised by means of the Thymomodulin 3) however, in BALT,only TCR gamma delta+ T cells are restored 4) the oral administration of the present immunomodulator may be useful as a therapeutic agent, although the preferential survival in the tissue of initial stimulation is the major factor in the preferential distribution of activated cells.

Requirement of prestimulated THP-1 monocytic cells for endothelial cell activation. Involvement of TNF alpha.

Blood monocytes spontaneously activate endothelial cells in culture, leading to adhesion of monocytic cells onto the endothelial surface and overproduction of endothelial proteins such as von Willebrand factor (vWf) and plasminogen activator inhibitor type 1 (PAI-1). To overcome the difficulty in obtaining quiescent monocytes, we studied the ability of promonocytic THP-1 cells to activate endothelial cells. Lipopolysaccharide (LPS)-prestimulated and untreated THP-1 cells were cocultured with resting human umbilical vein endothelial cells (HUVEC) for 3 and 24 h in the presence of colimycin to neutralize LPS traces. Addition of untreated THP-1 cells had little effect on HUVEC adhesiveness. Addition of prestimulated THP-1 cells was followed by a noticeable adhesion after 3 h which reversed to basal values within 24 h. Under these conditions HUVEC adhesion molecules, E-selectin, VCAM-1 and ICAM-1, were increased at 3 h with only ICAM-1 remaining overexpressed at 24 h. Diffusible endothelial proteins such as soluble E-selectin, PAI-1 and vWf to a minimal extent, increased in supernatants from HUVEC cocultured for 24 h with prestimulated THP-1 cells. In those cocultures, TNF alpha concentrations peaked at 3 h whereas IL-1 beta levels progressively rose until 24 h. Addition of an anti-TNF alpha antibody decreased by 40% E-selectin and ICAM-1 induction and suppressed PAI-1 overproduction with a weak effect on vWf. An anti-IL-1 beta antibody had negligible effects on HUVEC adhesion molecules, PAI-1 or vWf production. These results provide evidence that promonocytic THP-1 cells require prestimulation in order to activate HUVEC and that TNF alpha contributes to this phenomenon.

Nutrition disorders and immunologic parameters: study of the thymus in growing rats.

OBJECTIVES: We studied the effect of a low-quality dietary protein on cellular proliferation and maturation in the thymus of growing rats over time. METHODS: After weaning Wistar rats were fed a diet containing 6.5 g/100 g of corn flour for 6, 10, 18, and 45 d (M groups). For comparison, other rats were fed a diet containing 6.5 g/100 g of casein (Cas groups), and well-nourished age-matched control rats were fed a commercial laboratory diet (C groups). Food intake, body weight, thymus weight, total number of thymocytes, and the percentages of CD43(+) and Thy1(+) thymocyte phenotypic antigen determinants were measured. RESULTS: M versus Cas and C groups showed significant differences (P < 0.01) in body and thymus weights after 6 d of feeding, and the total number of thymocytes and the percentages of CD43(+) and Thy1(+) were significantly lower after 10 d of feeding. The results indicated that consuming a cereal diet for short or long periods causes thymus atrophy in growing rats, with significant reductions in the total number of T-cells concomitant with increases in the number of immature thymocytes. CONCLUSIONS: The data showed that, in addition to low-protein concentration, low-quality dietary protein is a limiting factor in certain steps of cellular intrathymic pathways, probably related to the requirement of specific amino acids for optimal immune response.

Effect of low-quality dietary protein on the thymus of growing rats.

The status of the thymus of growing rats fed for 45 days after weaning on a low-quality dietary protein (7.5% maize) was compared with that in an age-matched control group receiving a diet containing casein at the same concentration. At the end of the feeding period, body weight (bw) was determined and the thymus was removed; its weight and cell number and the mature T-cell population--characterized by the monoclonal antibody W3/13 using the indirect immunofluorescence technique--were determined. Thymus weight expressed as mg/bw0.75 (3.9 +/- 0.75 vs 7.7 +/- 2.0), cell number (4.4 +/- 2.2 vs 26.3 +/- 7.6), and the absolute number of W3/13+ T cells (1.59 +/- 0.75 vs 17.8 +/- 5.4) were significantly lower (p less than 0.0005) in the experimental group than in the control group. The results suggest severe atrophy of the thymus of weaning animals chronically fed a low-quality protein.

Hypothesis on the time course of antigen dependent changes in lymphoid organs proved by experimental data of depleted growing rats' mesenteric lymph nodes.

The results described in this paper partially agree with the hypothesis that mesenteric lymph nodes (MLN) of depleted growing rats recover their antigen specific determinants after the oral administration of 20% casein for 5-9 days following the time course of antigen dependent changes observed in virgin lymph nodes. With respect to the 39 days old control group, depleted MLN showed a highly diminished number of mature T cells (W3/13+) as well as surface and intracellular alpha heavy chain (alpha s and alpha cit). The oral administration of a 20% casein diet during 5 days tends to restore the appearance of these determinants; however, normal values were not attained even if refeeding was continued for 9 days. The discrepancy between the proposed hypothesis and the observed results might be ascribed to: a) defective migration of T cells from thymus; b) the diminished number of TH cells involved in terminal differentiation; c) inability of B cells to respond to T cell-derived factors.

Development of the IgA system in the mammary gland.

1) Lymphoblasts in gut-associated lymphoid tissue, committed to the production of IgA, can home to the mammary glands of syngeneic mice and differentiate there into IgA-containing plasmablasts. The phenomenon is limited to near term and lactating recipients. 2) The ability of lymphocytes originating in gut-associated lymphoid tissue and sensitized to intestinal antigens to migrate to the mammary gland can account for the specificity of milk IgA toward intestinal microorganisms and the consequent passive protection offered to suckling infants. 3) The secretory immune system of the mammary gland is apparently under hormonal control since mammotropic hormones given to virgin females can induce morphological and functional characteristics seen naturally only during pregnancy and lactation. Examples are increased numbers of IgA plasma cells and the ability to trap their circulating precursors taken from mesenteric lymph nodes.

The fertility of autumn calving suckler beef cows is increased by the addition of prostaglandin to progesterone and eCG estrus synchronization treatment.

The objective of this study was to determine the efficacy of PGF2 alpha treatment on pregnancy and calving rates in autumn-calving suckler beef cows synchronized with progesterone and eCG. The population studied consisted of 124 Charolais and 130 Limousin cows in 13 and 12 beef herds, respectively. In each herd, pairs of cows were formed according to parity, body condition score and calving difficulty. Group 1 received a progesterone releasing intravaginal device (PRID) for 12 d with a capsule containing 10 mg estradiol benzoate at implant insertion and 500 IU eCG at PRID removal (Day 0). Group 2 received the same treatment plus 25 mg i.m. dinoprost at Day -2. Each cow was artificially inseminated 56 h after PRID removal (Day 3). Plasma progesterone concentrations were measured to determine cyclicity prior to treatment in samples take on Days -22 and -12, to confirm the occurrence of ovulation (Day 13) and to determine the early pregnancy rate (Day 26). Serum pregnancy-specific protein B (PSPB) concentrations were determined to assess pregnancy rate at Day 39. The effects of variation factors on pregnancy and calving rates after treatment were studied using logistic mixed models and a Cox model, respectively. There were no significant differences between groups or breeds for the rate of cyclicity before treatment nor for ovulation rate (means, 74.1 and 95.7%, respectively). Cyclicity was, however, influenced by individual factors such as body condition score (OR = 3.36, P = 0.001), parity (OR = 5.4, P = 0.001) and herd factors such as stocking rate (OR = 5.62, P = 0.001). The use of a prostaglandin injection increased pregnancy rate at Day 26 (71.7 vs 56.7%, P = 0.01) and at 39 d (67.7 vs 54.3%, P = 0.02) and the calving rate at induced estrus (64.5 vs 48.5%, P = 0.01). We observed 9 twin calvings (5.6%) which occurred in cyclic cows only before treatment. Cows in Group 2 had a 1.5 greater chance of calving before 300 d following the first AI than cows in Group 1 (P = 0.03). In conclusion, the addition of PGF2 alpha injection, 48 h before PRID removal, increased reproductive efficiency in autumn-calving Charolais and Limousin suckler beef cows compared to a classical estrus synchronization treatment using a PRID + eCG.

Oral tolerance to dextrin mediated by specific suppressor T-cells induced in the intestinal intraepithelium and their systemic migration.

Antigens presented to the immune system through the oral route induce antigen specific secretory IgA and systemic unresponsiveness, termed oral tolerance (OT). We studied the induction of OT towards a diet antigen: dextrin (DEX) in rats that underwent protein deprivation and were further re-fed. Peyer's patches (PP), mesenteric lymph nodes (MLN) and spleen (Sp) cells from protein re-fed (R) rats mediated hyporesponsiveness after transfer into naïve recipient rats. Low numbers of MLN T cells transferred hyporesponsiveness while higher numbers transferred an enhancement of the delayed type hypersensitivity (DTH) reaction. MLN T cells were further separated based on their ability to bind Vicia villosa (VV). MLN VV- T cells, mainly CD8+, mediated hyporesponsiveness and MLN VV+ T cells (CD45RC+ CD4- CD8- cells) abrogated the hyporesponsiveness. Moreover, Sp DEX adherent T cells were mainly CD8+. Intestinal intraepithelial lymphocytes (iIELs) mainly CD8alpha+ gamma(delta)-TCR+ cells also inhibited the DTH response to DEX after transfer. The positive DTH response to another carbohydrate (levan) indicates the specificity of the suppression to dextrin. Therefore, our data indicate that after oral administration of DEX, two different populations of T cells were generated: one found only in the MLN that mediated DTH responses and the other one capable of migrating from the intestinal intraepithelium through PP and MLN to the Sp, mediating systemic tolerance.

Essential oils and low-intensity electromagnetic pulses in the treatment of androgen-dependent alopecia.

This double-blind randomized study vs placebo in healthy male and female volunteers demonstrates the positive biologic effect on hair loss and hair regrowth of a pulsed electromagnetic field in combination with essential oils administered according to a regular treatment schedule of 26 weeks. Mean hair count comparisons within the groups significantly favor the treatment group, which exhibited a decrease in hair loss in 83% of the volunteers and a more than 20% hair count increase over baseline in 53% of patients. The process exhibited no side effects or untoward reactions. The histologic examination correlated with the clinical study. A parallel immunohistochemical examination showed an increase in the proliferation index, and when the expression of Ki67 (a cell proliferation marker) is increased, the mitoses are barely visible in the histologic examination. The rationale of this phenomenon is considered to be due to an electrophysiologic effect on the quiescent hair follicle.

[Familial amyloidosis]. / Amyloses familiales.

Familial amyloidosis is characterized by its great clinical and genetic heterogeneity. The most frequent form is amyloidotic neuropathy which may be due to deposits of several amyloid proteins, such as transthyretin, apolipoprotein A1 and gelsolin. Other varieties include predominant lesions of another organ, such as kidney, heart, eye or skin. In most of these lesions, a punctual mutation affects the amyloid protein itself. In other varieties, the amyloid protein is not affected by mutation and, rarely, unknown. The advances achieved in our understanding of transthyretin deposition should improve our knowledge of amyloidosis in general.

[The lymphoid system and protein deficiency. Differentiation in the thymus and Peyer's patches]. / Sistema linfoide y deficiencia proteica. Diferenciación en timo y placas de Peyer.

A: Thymuses from protein deprived rats present: 1) a significant decrease in the absolute number of thymic cells bearing the CD5 phenotype (OX19+), as well as Thy 1.1 (OX7+). The predominant cell population was the one containing TdT (terminal deoxynucleotidyl transferase) as a sole marker: 2) in severely protein deprived rats followed by refeeding during 9 and 21 days, the existence of a small population of cells containing TdT as a sole marker. The TdT+W3/13+ cell population was restored but the CD4+ subpopulation (W3/25+) exists in lower numbers than in the age-matched controls. B: Severe protein deficiency at weaning, led to the presence in the Peyer's patches of very immature B-cells mostly c mu+OX7s mu-. Protein refeeding reinitiated the differentiation process as follows: 1) c mu+OX7+s mu- c mu-OX7-s mu+ as in the normal Peyer's patches; 2) however, switching of sIgM to sIgA-bearing cells was altered; 3) a low absolute number of W3/13+ and W3/25+ T-cells (CD4+) was found. C: Oral tolerance to dextrin evolved due to antigen specific CD8+ T-cells (found in Peyer's patches, mesenteric lymph nodes and spleen) and could be transferred to normal recipients.

Effect of RN-301 immunomodulator on bronchus-associated lymphoid tissue (BALT) in protein depleted rats at weaning.

It has been previously demonstrated in Wistar rats that severe protein deprivation at weaning, even after refeeding with a 20% casein diet for 21 days, provokes alterations in IgA+ B cell and T cell populations from gut and GALT (gut associated lymphoid tissue) that are reverted by immunomodulator IM-104. In the present report, we investigate the influence of RN-301 (quite similar to IM-104) given by the oral or subcutaneous route during the protein deprivation period, in the seeding of BALT with IgA+ B and CD5+ T cells. The immunomodulator RN-301 contains LPS from E. coli and membrane and ribosomal fractions of P. acne. Tissue sections of the lower respiratory tract were studied by immunohistochemistry. The immunomodulator RN-301 administered by the oral route favours the significant increase in the seeding of the BALT lamina propria with IgA+ B and CD5+ T cells (p < 0.001). However, the RN-301 given by the subcutaneous route does not favour the repopulation of the BALT lamina propria. The ribosomal fractions from P. acne associated with LPS from E. coli contained in the immunomodulator RN-301 administered by the oral route may rescue the small resting lymphocytes in the gut-associated lymphoid tissue (GALT). This event favours their proliferation and migration to the BALT.