Effects of plane of nutrition and feed deprivation on insulin responses in dairy cattle during late gestation.

Nonlactating Holstein cows (n=12) in late pregnancy were used to determine effects of plane of nutrition followed by feed deprivation on metabolic responses to insulin. Beginning 48 d before expected parturition, cows were fed to either a high plane (HP) or a low plane (LP) of nutrition (162 and 90% of calculated energy requirements, respectively). Cows were subjected to an intravenous glucose tolerance test [GTT; 0.25 g of dextrose/kg of body weight (BW)] on d 14 of treatment and a hyperinsulinemic-euglycemic clamp (HEC; 1 µg/kg of BW/h) on d 15. Following 24 h of feed removal, cows were subjected to a second GTT on d 17 and a second HEC on d 18 after 48 h of feed removal. During the feeding period, plasma nonesterified fatty acid (NEFA) concentrations were higher for cows fed the LP diet compared with those fed the HP diet (163.6 vs. 73.1 µEq/L), whereas plasma insulin was higher for cows fed the HP diet during the feeding period (11.1 vs. 5.2 µIU/mL). Glucose areas under the curve during both GTT were higher for cows fed the LP diet than for those fed the HP diet (4,213 vs. 3,750 mg/dL × 60 min) and was higher during the GTT in the feed-deprived state (4,878 vs. 3,085 mg/dL × 60 min) than in the GTT during the fed state, suggesting slower clearance of glucose during negative energy balance either pre-or post-feed deprivation. This corresponded with a higher dextrose infusion rate during the fed-state HEC than during the feed-deprived-state HEC (203.3 vs. 90.1 mL/h). Plasma NEFA decreased at a faster rate following GTT during feed deprivation compared with that during the fed state (8.7 vs. 2.9%/min). Suppression of NEFA was highest for cows fed the HP diet during the GTT conducted during feed deprivation, and lowest for cows fed the HP diet during the fed-state GTT (68.6 vs. 50.3% decrease from basal). Plasma insulin responses to GTT were affected by feed deprivation such that cows had a much lower insulin response to GTT by 24 h after feed removal (995 vs. 3,957 µIU/mL × 60 min). During the fed-state HEC, circulating concentrations of NEFA were 21% below basal for cows fed the HP diet and 62% below basal for cows fed the LP diet; during feed deprivation, NEFA were 79 and 59% below basal for the HP and LP diets, respectively (diet × HEC). Cows that are fed below energy requirements or are feed deprived have slower clearance of glucose and greater NEFA responses to glucose challenge. Additionally, feed deprivation had a large effect on insulin secretion. Overall, effects of feed deprivation were larger than effects of plane of nutrition.

Preconceptional diet manipulation and fetus number can influence placenta endocrine function in sheep.

Changes in maternal nutrition during pregnancy can result in profound effects on placental function and fetal development. Although the preconceptional period holds the potential to reprogram embryonic and placental development, little is known regarding the effects of premating nutritional manipulation on placental function and fetal and postnatal offspring growth. To test this, Polypay-Dorset sheep (n = 99) were assigned to 1 of 3 nutritional treatments (n = 33/treatment) receiving 50% (UN: undernutrition), 100% (C: control), or 200% (ON: overnutrition) of maintenance energy requirements for 21 d before mating during April-May (increasing photoperiod). Thereafter, diets were the same across groups. We evaluated maternal reproductive variables and maternal and offspring weight and body mass index through weaning. Maternal plasma was collected through pregnancy until postnatal day 1 to assay pregnancy-associated glycoproteins (PAGs) and progesterone. Fertility rate was similar among treatments, but ON females had a higher reproductive rate (UN: 82%; C: 100%, ON: 145%). When correcting by total birth weight, twin pregnancies had lower PAGs and progesterone versus singleton pregnancies (P < 0.001). At birth, UN lambs were heavier than C lambs regardless of birth type (P < 0.01). Growth velocity, daily gain, and weaning weight were similar, but UN and ON females grew faster and were heavier at weaning versus C females. We demonstrated that a 3-wk preconceptional maternal undernutrition or overnutrition, when correcting by total birth weight, results in lower endocrine capacity in twin pregnancies. Preconceptional maternal undernutrition and overnutrition increased postnatal female lamb growth, suggestive of reprogramming of pathways regulating growth before conception. This highlights how preconceptional nutrition can result in marked sex-specific differences.

T helper type 2 cell differentiation occurs in the presence of interleukin 12 receptor beta2 chain expression and signaling.

The differentiation of CD4(+) T cells into T helper type 1 (Th1) cells is driven by interleukin (IL)-12 through the IL-12 receptor beta2 (IL-12Rbeta2) chain, whereas differentiation into Th2 cells is driven by IL-4, which downregulates IL-12Rbeta2 chain. We reexamined such differentiation using IL-12Rbeta2 chain transgenic mice. We found that CD4(+) T cells from such mice were able to differentiate into Th2 cells when primed with IL-4 or IL-4 plus IL-12. In the latter case, the presence of IL-4 suppressed interferon (IFN)-gamma production 10-100-fold compared with cells cultured in IL-12 alone. Finally, in studies of the ability of IL-12 to convert Th2 cells bearing a competent IL-12R to the Th1 cells, we showed that: (a) T cells bearing the IL-12Rbeta2 chain transgene and primed under Th2 conditions could not be converted to Th1 cells by repeated restimulation under Th1 conditions; and (b) established Th2 clones transfected with the IL-12Rbeta2 chain construct continued to produce IL-4 when cultured with IL-12. These studies show that IL-4-driven Th2 differentiation can occur in the presence of persistent IL-12 signaling and that IL-4 inhibits IFN-gamma production under these circumstances. They also show that established Th2 cells cannot be converted to Th1 cells via IL-12 signaling.

Shearing during late pregnancy increases size at birth but does not alter placental endocrine responses in sheep.

Shearing during the latter half of pregnancy is a common practice to improve flock health and productivity. Previous studies have demonstrated that shearing pregnant ewes at mid or late pregnancy is associated with an increase in lamb birth weight. In the present study, we used singleton Polypay × Dorset pregnant sheep, to investigate the potential roles of placental function and changes in maternal metabolism in underlying this increased birth weight response. Two groups were randomly established and blocked at enrollment by animal BW, body condition score and subcutaneous adipose tissue depth. The groups were shorn (SH; n = 18) or not (C; n = 20) at gestational day (GD) 107 ± 1 (mean ± SEM). Weekly maternal plasma samples were collected between shearing and birth, but only six samples were assayed for progesterone, pregnancy-associated glycoproteins (PAG1), glucose and non-esterified fatty acids (NEFAs). At birth, sex, birth weight, and newborn body mass index (BMI) were recorded. Maternal BW during mid- to late-pregnancy was similar between groups. Shearing resulted in increased lamb birth weight and BMI (P < 0.05) regardless of fetal sex but did not affect the maternal concentration of PAG1 or progesterone from GDs 100 to 142. After shearing (GD100) and up to lambing, shorn females had higher circulating glucose concentrations (P < 0.05), but not NEFA, compared to the control group. Maternal circulating PAG1, progesterone, glucose or NEFA concentration across pregnancy did not differ according to lamb sex. Across pregnancy, birth weight was positively associated with PAG1 (P < 0.001), but not with progesterone concentrations. In conclusion, weight and BMI at birth were higher in both sexes upon shearing in singleton pregnancies. Despite PAG1 being associated with birth weight, late-pregnancy shearing did not alter the placental endocrine response. Whether other placental factors are altered upon shearing and may influence the increase in birth weight and BMI remain to be investigated.

Effects of trace mineral amount and source on aspects of oxidative metabolism and responses to intramammary lipopolysaccharide challenge in midlactation dairy cows.

Trace minerals have important roles in immune function and oxidative metabolism; however, little is known about the relationships between supplementation level and source with outcomes in dairy cattle. Multiparous Holstein cows (n=48) beginning at 60 to 140 days in milk were utilized to determine the effects of trace mineral amount and source on aspects of oxidative metabolism and responses to intramammary lipopolysaccharide (LPS) challenge. Cows were fed a basal diet meeting National Research Council (NRC) requirements except for no added zinc (Zn), copper (Cu) or manganese (Mn). After a 4-week preliminary period, cows were assigned to one of four topdress treatments in a randomized complete block design with a 2×2 factorial arrangement of treatments: (1) NRC inorganic (NRC levels using inorganic (sulfate-based) trace mineral supplements only); (2) NRC organic (NRC levels using organic trace mineral supplements (metals chelated to 2-hydroxy-4-(methythio)-butanoic acid); (3) commercial inorganic (approximately 2×NRC levels using inorganic trace mineral supplements only; and (4) commercial organic (commercial levels using organic trace mineral supplements only). Cows were fed the respective mineral treatments for 6 weeks. Treatment effects were level, source and their interaction. Activities of super oxide dismutase and glutathione peroxidase in erythrocyte lysate and concentrations of thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity (TAC) in plasma were measured as indices of oxidative metabolism. Effects of treatment on those indices were not significant when evaluated across the entire experimental period. Plasma immunoglobulin G level was higher in cows supplemented with organic trace minerals over the entire treatment period; responses assessed as differences of before and after Escherichia coli J5 bacterin vaccination at the end of week 2 of treatment period were not significant. Cows were administered an intramammary LPS challenge during week 5; during week 6 cows fed commercial levels of Zn, Cu and Mn tended to have higher plasma TAC and cows fed organic sources had decreased plasma TBARS. After the LPS challenge, the extent and pattern of response of plasma cortisol concentrations and clinical indices (rectal temperature and heart rate) were not affected by trace mineral level and source. Productive performance including dry matter intake and milk yield and composition were not affected by treatment. Overall, results suggest that the varying level and source of dietary trace minerals do not have significant short-term effects on oxidative metabolism indices and clinical responses to intramammary LPS challenge in midlactation cows.

Effect of nutrition on the GH responsiveness of liver and adipose tissue in dairy cows.

Dairy cows enter a period of energy insufficiency after parturition. In liver, this energy deficit leads to reduced expression of the liver-specific GH receptor transcript (GHR1A) and decreased GHR abundance. As a consequence, hepatic processes stimulated by GH, such as IGF-I production, are reduced. In contrast, adipose tissue has been assumed to remain fully GH responsive in early lactation. To determine whether energy insufficiency causes contrasting changes in the GH responsiveness of liver and adipose tissue, six lactating dairy cows were treated for 4 days with saline or bovine GH when adequately fed (AF, 120% of total energy requirement) or underfed (UF, 30% of maintenance energy requirement). AF cows mounted robust GH responses in liver (plasma IGF-I and IGF-I mRNA) and adipose tissue (epinephrine-stimulated release of non-esterified fatty acids in plasma, IGF-I mRNA, and p85 regulatory subunit of phosphatidylinositol 3-kinase mRNA). Reductions of these responses were seen in the liver and adipose tissue of UF cows and were associated with decreased GHR abundance. Reduced GHR abundance occurred without corresponding reductions of GHR1A transcripts in liver or total GHR transcripts in adipose tissue. In contrast, undernutrition did not alter the abundance of proteins involved in the early post-receptor signaling steps. Thus, a feed restriction reproducing the energy deficit of early lactation depresses GH actions not only in liver but also in adipose tissue. It remains unknown whether a similar reduction of GH action occurs in the adipose tissue of early lactating dairy cows.

Localisation of glucose transport in the ruminant placenta: implications for sequential use of transporter isoforms.

The facilitative glucose transporters 1 and 3 are the major routes for glucose transport across placental membranes. Using light and electron microscope immunocytochemistry on acrylic sections this study shows a similar pattern of expression from mid to late pregnancy in all four ruminants examined [cow, deer, ewe and goat]. GT1 and GT3 are localised on different membrane layers of the synepitheliochorial placental barrier and glucose must utilise both isoforms sequentially to pass from the maternal to fetal circulations. It is suggested that this arrangement is designed to support the high glucose utilisation by the multilayered placenta in the ruminant.

Successful autografting following myeloablative conditioning therapy with blood stem cells mobilized by chemotherapy plus rhG-CSF.

High-dose conditioning therapy followed by autografting with blood stem cells rather than bone marrow has become an increasingly used transplantation modality for patients with chemosensitive malignancies. We treated 10 patients with malignant lymphoma in sensitive relapse with recombinant human granulocyte colony-stimulating factor (rhG-CSF) following salvage therapy. rhG-CSF was given subcutaneously (5 micrograms/kg/day) starting 24 hours after chemotherapy and stem cell collection was performed by repeated leukaphereses during leukocyte recovery. The yield of myeloid progenitors varied between 0.79 and 38.36 x 10(4) CFU-GM/kg body weight (median 4.1 x 10(4). A strong correlation was found between the number of granulocyte-macrophage colony-forming cells (CFU-GM) plus blast-forming erythroid cells (BFU-E) and CD34-positive (CD34+) cells (R = 0.80; p < 0.001). The majority of CD34+ cells (> 95%) strongly coexpressed human lymphocyte antigen-DR (HLA-DR) and CD38, whereas CD33 varied between 20% and 94%. Costaining of CD34+ cells for CD19 above the control level could not be detected, suggesting that early B lymphoid progenitors are not expanded or released into the circulation by rhG-CSF. Following total body irradiation (TBI)/cyclophosphamide or the CBV regimen (cyclophosphamide, BCNU, VP-16), all patients achieved complete engraftment with a median of 14 days for 1.0 x 10(9)/L white blood cells (WBC), 15 days for 0.5 x 10(9)/L polymorphonuclear cells (PMN) and 22 days for 20 x 10(9)/L platelets. The quantity of CFU-GM/kg transplanted was predictive for neutrophil and platelet recovery. The strongest correlation, however, was found between the number of CD34+ cells/kg autografted and platelet recovery (R = -0.86; p < 0.001). The patients transplanted with more than 5 x 10(6)/kg CD34+ cells reached an unsubstituted platelet count > 20 x 10(9)/L within 8 to 12 days. Our data demonstrate that rapid and complete engraftment can be achieved following myeloablative conditioning therapy with rhG-CSF-exposed blood stem cells without the need for additional bone marrow support or growth factor administration posttransplantation.

Insensitivity of well-conditioned mature sheep to central administration of a leptin receptor antagonist.

Ruminants remain productive during the energy insufficiency of late pregnancy or early lactation by evoking metabolic adaptations sparing available energy and nutrients (e.g. higher metabolic efficiency and induction of insulin resistance). A deficit in central leptin signaling triggers these adaptations in rodents but whether it does in ruminants remains unclear. To address this issue, five mature ewes were implanted with intracerebroventricular (ICV) cannula in the third ventricle. They were used in two experiments with an ovine leptin antagonist (OLA) when well-conditioned (average body condition score of 3.7 on a 5 point scale). The first experiment tested the ability of OLA to antagonize leptin under in vivo conditions. Ewes received continuous ICV infusion of artificial cerebrospinal fluid (aCSF), ovine leptin (4 µg/h) or the combination of ovine leptin (4 µg/h) and its mutant version OLA (40 µg/h) for 48 h. Dry matter intake (DMI) was measured every day and blood samples were collected on the last day of infusion. ICV infusion of leptin reduced DMI by 24% (P < 0.05), and this effect was completely abolished by OLA co-infusion. A second experiment tested whether a reduction in endogenous leptin signaling in the brain triggers metabolic adaptations. This involved continuous ICV infusions of aCSF or OLA alone (40 µg/h) for 4 consecutive days. The infusion of OLA did not alter voluntary DMI over the treatment period or on any individual day. OLA did not affect plasma variables indicative of insulin action (glucose, non-esterified fatty acids, insulin and the disposition of plasma glucose during an insulin tolerance test) or plasma cortisol, but tended to reduce plasma triiodothyronine and thyroxine (P < 0.07). Overall, these data show that a reduction of central leptin signaling has little impact on insulin action in well-conditioned mature sheep. They also raise the possibility that reduced central leptin signaling plays a role in controlling thyroid hormone production.

Idarubicin/cytosine arabinoside and mitoxantrone/etoposide for the treatment of de novo acute myelogenous leukemia.

Since January 1989, 56 patients (31 females and 25 males) with de novo acute myelogenous leukemia have been included in the study. Their median age was 43 years (range, 15 to 60 years) with a distribution according to French-American-British morphologic subtypes as follows: six M1, 14 M2, four M3, 19 M4, nine M5, two M6, and two M7. The induction regimen (IDAC) consisted of idarubicin (12 mg/m2/d intravenously [IV] days 1 to 3) in combination with cytarabine (100 mg/m2/d continuous IV days 1 to 7). Patients achieving complete remission (CR) or partial remission received another cycle of IDAC followed by NOVE (mitoxantrone 10 mg/m2/d IV days 1 to 5 and etoposide 100 mg/m2/d IV days 1 to 5). Fifty-four patients are evaluable for response: after two cycles of IDAC, 42 patients had attained CR (78%), while 76% of these had already reached CR after the first cycle. Of the initial 11 nonresponders to IDAC, four obtained CR after NOVE. Thus, 46 of 54 patients (85%) achieved CR after sequential treatment with IDAC and NOVE. In the last 17 patients who entered CR or partial remission after the first cycle of IDAC, recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF; 3 micrograms/kg/d) was administered for 6 days starting 3 days prior to the second cycle of IDAC. For consolidation with NOVE, rhGM-CSF was given according to the same dosage schedule. After 72 hours of rhGM-CSF treatment, the white blood cell count showed a median 3.9-fold increase, without appearance of myeloblasts in the peripheral blood. During sequential chemotherapy, no significant complications (in particular, no major cardiac toxicity) were observed. Postremission, patients were either given bone marrow transplants, received late consolidation with high-dose cytarabine/mitoxantrone, or were followed up without any further treatment. Of the 46 patients evaluable for disease-free survival, 21 patients (45%) remain in CR with a 34% probability of disease-free survival at 37 months. The response-adapted treatment with IDAC/NOVE is effective and very well tolerated. To define the therapeutic impact of rhGM-CSF, a randomized trial will be required.

Effect of recombinant human interleukin 2 (rIL-2) on normal peripheral blood B cells and B lymphoblastoid cell lines.

The role of interleukin 2 (IL-2) for growth and differentiation of normal and malignant B cells still remains controversial. We assessed normal peripheral blood B cells and cell lines derived from patients with B non-Hodgkin's lymphomas (NHLs) with respect to their responsiveness to recombinant human IL-2 (rIL-2). The NHL cell lines used in our experiments expressed the Tac antigen (CD25)--a compound of the IL-2 receptor (IL-2R)--in a percentage ranging from 28 to 57%. As measured in a [3H]thymidine uptake assay, the normal peripheral blood B cells demonstrated a dose-dependent proliferative response to rIL-2, whereas the NHL cells did not show any responsiveness to rIL-2. In a clonogenic culture assay we evaluated the colony formation of the NHL cells and found a decrease of 28 to 41% on average in the presence of rIL-2 (10-50 U/ml). This moderate inhibitory effect on the clonal growth of the NHL cells was not due to a differentiation inducing effect of rIL-2, as studied by measuring the Ig production under increasing doses of rIL-2 (1 to 100 U/ml). Thus, malignant NHL B cells may express the CD25 compound of the IL-2 receptor on their surface, demonstrating a different functional responsiveness to rIL-2 compared to normal peripheral blood B cells.

Development of a specific radioimmunoassay to measure physiological changes of circulating leptin in cattle and sheep.

Studies of leptin in large domestic ruminants have been limited to measurements of gene expression because methods to measure circulating levels are not available. To develop a bovine leptin radioimmunoassay, we produced recombinant bovine leptin and used it to immunize rabbits, and to prepare bovine leptin tracer and standards. A single antiserum with sufficient affinity and titer was identified. Using this antiserum, logit-transformed binding of (125)I-labeled bovine leptin was linearly related (R(2)= 0.99) to the log of added bovine or ovine leptin between 0.1 to 2.0 ng. Serial dilution of bovine and ovine plasma, chicken serum and bovine milk gave displacement curves that were parallel to those of bovine or ovine leptin. Recoveries of external addition of bovine leptin in ewe and cow plasma ranged between 94 and 104%. Plasma leptin concentration measured by this assay was directly related to the plane of! nutrition in growing calves and lambs. At 11-14 weeks of age, ewe lambs had a higher circulating leptin concentration than ram lambs. Finally, plasma leptin concentration was linearly related to the fat content of the empty carcass in growing cattle and to body condition score in lactating dairy cows. We conclude that circulating leptin in sheep and cattle is increased by fatness and plane of nutrition, consistent with results in humans and rodents. This assay provides an important tool to investigate mechanisms that regulate plasma leptin in cattle and sheep.

Decreased concentration of plasma leptin in periparturient dairy cows is caused by negative energy balance.

Dairy cows suffer from an intense energy deficit at parturition due to the onset of copious milk synthesis and depressed appetite. Despite this deficit, maternal metabolism is almost completely devoted to the support of mammary metabolism. Evidence from rodents suggests that, during periods of nutritional insufficiency, a reduction in plasma leptin serves to co-ordinate energy metabolism. As an initial step to determine if leptin plays this role in periparturient dairy cows, changes in the plasma concentration of leptin were measured during the period from 35 days before to 56 days after parturition. The plasma concentration of leptin was reduced by approximately 50% after parturition and remained depressed during lactation despite a gradual improvement in energy balance; corresponding changes occurred in the abundance of leptin mRNA in white adipose tissue. To determine whether negative energy balance caused this reduction in circulating leptin, cows were either milked or not milked after parturition. Absence of milk removal eliminated the energy deficit of early lactation, and doubled the plasma concentration of leptin. The plasma concentration of leptin was positively correlated with plasma concentrations of insulin and glucose, and negatively correlated with plasma concentrations of growth hormone and non-esterified fatty acids. In conclusion, the energy deficit of periparturient cows causes a sustained reduction in plasma leptin. This reduction could benefit early lactating dairy cows by promoting a faster increase in feed intake and by diverting energy from non-vital functions such as reproduction.

Growth and metabolism of the ovine placenta during mid-gestation.

The timing and metabolic basis for the rapid increase then cessation of placental growth in sheep and the accompanying changes in tissue cellularity were defined in the present study. Placental growth proceeded rapidly from day 40 of gestation to an apex at day 75-80 with no change is tissue dry matter content observed thereafter to day 100. These macroscopic growth patterns are similar to those observed previously, but present results define an earlier apex in placental mass. Absolute growth rate of the placenta reached a maximum near day 55, as derived from the Gompertz equation, concomitant with a period of maximum hyperplastic growth between days 50 and 60. A rapid increase in DNA synthesis and tissue mass per nuclei number from day 40-50 was followed by proliferative growth to day 70. Net cellular proliferation apparently ceased by day 80 as indicated by the apex in DNA content and the beginning of a static, low rate of DNA synthesis that continued to day 100. Patterns of change in the fractional rates of protein synthesis (Ks) and accretion (Kg) were similar suggesting that changes in Ks explain much of the change in Kg. This study, through its identification of key phases in the cellular growth of the ovine placenta, has laid the foundation for future research on mechanisms of placental growth regulation.

Autologous blood progenitor cell transplantation in relapsed Hodgkin's disease--the role of haematopoietic growth factors.

Thirty-seven patients with Hodgkin's disease in sensitive relapse were autografted using blood-derived haematopoietic progenitor cells. At the time of transplantation 22 patients were in complete remission and 15 patients in partial remission. Twenty-six patients were male and 11 female, with a median age of 31 years (range 21-52). The pre-transplant conditioning therapy consisted of cyclophosphamide, BCNU and etoposide (CBV). Five patients died of transplant-related complications and 11 patients relapsed after a median time of four months following autografting. For the remaining 21 patients the probability of event-free survival (EFS) was 45% at 68 months. Blood progenitor cell collection can be integrated into salvage therapy by administering haematopoietic growth factors (HGFs) to enhance the chemotherapy-induced progenitor cell rebound during leucocyte recovery. In a subgroup of 14 patients, seven received recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) (250 micrograms/m2/day) by continuous intravenous infusion following dexamethasone, BCNU, etoposide and melphalan (Dexa-BEAM) as salvage therapy, while seven patients were treated without haematopoietic growth factor (HGF) post-chemotherapy. The yield of total nucleated cells (TNC) and granulocyte-macrophage colonies (CFU-GM) collected per leukapheresis was 2.2- and 2.4-fold higher respectively in the rhGM-CSF-treated patients. Following high-dose conditioning therapy, the seven patients autografted with rhGM-CSF-mobilised stem cells showed a faster leucocyte recovery compared with the control group. Neutrophil recovery (> 1.0 x 10(9)/L) and platelet recovery (> 20 x 10(9)/L) were also accelerated in the rhGM-CSF-treated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) subsequent to chemotherapy improves collection of blood stem cells for autografting in patients not eligible for bone marrow harvest.

Fourteen patients with relapsed Hodgkin's disease responded to a salvage therapy with Dexa-BEAM (dexamethasone, BCNU, etoposide, Ara-C and melphalan). In seven patients a continuous i.v. infusion with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) was started subsequent to Dexa-BEAM (+rhGM-CSF) while the other seven patients received no hemopoietic growth factor (-rhGM-CSF). It was our objective to study the impact of rhGM-CSF on the collection of blood-derived hemopoietic stem cells in patients with extensive prior chemo- and radiotherapy not eligible for marrow harvest. Compared to baseline, we observed a significant increase of colony-forming units granulocyte-macrophage (CFU-GM) in the peripheral blood of patients receiving rhGM-CSF (p less than 0.05). On average, the yield of total nucleated cells and CFU-GM collected per single leukapheresis was 2.2 and 2.4-fold higher in the rhGM-CSF-treated patients respectively (p less than 0.05). With rhGM-CSF the interval from the start of chemotherapy to the end of blood stem cell collection could be reduced by 6 days (p less than 0.05). Following the CBV pretransplant regimen (cyclophosphamide, BCNU, etoposide), the reinfusion of rhGM-CSF-exposed stem cells resulted in a shorter time of leukocyte recovery (p less than 0.05). The number of CFU-GM/kg body weight transplanted was found to be predictive for the time of neutrophil recovery (p less than 0.05). In patients with bone marrow hypoplasia or fibrosis, rhGM-CSF as part of an effective salvage therapy improves the collection of blood stem cells that are capable of restoring hemopoiesis after high-dose pretransplant therapy.

Autografting with peripheral blood stem cells mobilized by sequential interleukin-3/granulocyte-macrophage colony-stimulating factor following high-dose chemotherapy in non-Hodgkin's lymphoma.

This report summarizes our results of sequential treatment with IL-3 and GM-CSF following high-dose chemotherapy with respect to the yield and composition of peripheral blood stem cells (PBSC). Eight patients with high-grade non-Hodgkin's lymphoma were included in the study. Starting 24 h after high-dose cytosine arabinoside (Ara C)/mitoxantrone, IL-3 was given for 6 days, followed by GM-CSF. The increase of circulating hematopoietic progenitor cells during leukocyte recovery varied substantially from patient to patient. Up to a 22-fold interindividual difference was observed for the peak levels of CD34+ cells. A special focus of our study was the antigenic profile of the CD34+ PBSC. On analysis of the antigenic profile of the CD34+ cells, the proportion of CD34+/HLA-DR- and CD34+/CD38- cells representing non-committed hematopoietic stem cells was consistently < 5%. The vast majority of CD34+ cells was found to coexpress CD33 (86.3 +/- 2.1%, mean +/- SEM), reflecting myeloid lineage commitment. CD71 antigen was present on 47.4 +/- 3.0% CD34+ cells with two populations (CD71dim/bright), while the percentage of early B lymphoid (CD34+/CD19+) progenitor cells was extremely low (0.38 +/- 0.13%). We therefore conclude that the cytokines currently available such as G-CSF, GM-CSF or IL-3 facilitate an ontogenetic phenomenon supporting the redistribution of hematopoietic progenitor cells after cytotoxic treatment. Six patients were autografted with the IL-3/GM-CSF-exposed blood stem cells following high-dose conditioning therapy. It is worth noting that no additional BM or hematopoietic growth factors were given post-transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Bombesin and its analogues inhibit interleukin-2-induced proliferation of CTLL-2 cells.

Specifically interleukin-2 (IL-2)-dependent CTLL-2 cells were incubated in short term culture in the presence of IL-2 together with bombesin and two analogues, [Lys3]bombesin and [Tyr4]bombesin in different concentrations. Cell proliferation, determined by [3H]thymidine incorporation was significantly inhibited by 35.6 +/- 5%, 39.0 +/- 5.6% and 57.0 +/- 11% (mean +/- S.E.M. of 3 independent experiments). A typically U-shaped dose-response relationship was observed, showing a maximum effect between 10(-12) and 10(-10) M. Our data support the hypothesis that this effect is mediated by a specific receptor for bombesin and closely related peptides on CTLL-2 cells. As IL-2 plays a critical role in the clonal expansion of activated lymphocytes, antagonism of the effect of IL-2 is of high biological significance.

Maternal leptin is elevated during pregnancy in sheep.

Maternal plasma leptin is elevated during pregnancy in several species, but it is unclear to what extent this elevation reflects changes in adiposity or energy balance. Therefore, Karakul ewes (n = 8) were fed to minimize changes in maternal energy status over the pregnancy-lactation cycle. They were studied 20-40 d before breeding and during mid pregnancy (d 50-60 post coitus [PC]), late pregnancy (d 125-135 PC) and early lactation (d 15-22 post partum). Consistent with the maintenance of near energy equilibrium in nongravid maternal tissues, maternal body weight was increased only during late pregnancy when the weight of the conceptus became significant and plasma concentrations of insulin, NEFA and glucose did not vary with physiological state. In contrast, maternal plasma leptin concentration rose from 5.3 to 9.5 ng/mL between prebreeding and mid pregnancy and then declined progressively through late pregnancy and early lactation. Leptin gene expression increased 2.3 fold in maternal white adipose tissue (WAT) from prebreeding to mid pregnancy and declined to prebreeding levels during early lactation. To determine whether tissue response to insulin was involved in this effect, insulin tolerance tests were performed. The maternal plasma glucose response declined from prebreeding to early lactation, but was not correlated with either plasma leptin concentration or WAT leptin mRNA abundance. In conclusion, pregnancy causes an increase in the synthesis of leptin in sheep. This stimulation does not require increases in adiposity or energy balance and is unrelated to the ability of insulin to promote glucose utilization.

Protein requirements of sheep in late pregnancy: partitioning of nitrogen between gravid uterus and maternal tissues.

The objective of this study was to quantify effects of maternal protein nutrition on N accretion or loss in conceptus and maternal tissues of ewes during late pregnancy. Ewes, pregnant with twins, were fed low (LP, 79 g CP/kg DM), medium (MP, 116 g CP/kg DM), or high (HP, 157 g CP/kg DM) protein diets, each with an estimated ME concentration of 2.7 Mcal/kg DM, between d 111 and 140 of pregnancy; all ewes had been fed the same diet (2.7 Mcal ME, 120 g CP/kg DM) for the previous 30 d (d 80 to 110). Dry matter intakes were varied (LP = 1.0, MP = 1.2, and HP = 1.4 kg/d) according to predicted energy costs of protein deposition for each diet. Nitrogen accretion was estimated by comparative slaughter (d 140 minus d 110) and by collection of excreta between d 120 and 130. Fresh weights of maternal and gravid uterine tissues were measured at slaughter, before proximate analysis of these components. Whole-body N retention was directly and linearly related to N intake, but efficiency of deposition of apparently absorbed N decreased linearly with increasing N intake (LP, .79; MP, .70; HP, .62). Nitrogen accretion in the gravid uterus, maternal viscera, and mammary gland was significantly less in LP than in MP or HP ewes. Nitrogen balance in maternal carcass tissues was linearly related to N intake, ranging from a negative value in LP ewes to a positive value in HP ewes (LP, -63 g; MP -39 g; HP, 55 g). These data provide the basis for estimating N requirements for protein accretion in the conceptus and in maternal tissues during late pregnancy. They also highlight the capacity of maternal carcass tissues to mobilize or deposit amino acids in response to variations in dietary protein supply.