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PubMed1999

[Growth of breastfed and bottle-fed infants up to 2 years of age: CLACYD (Lactation, Alimentation, Growth and Development) study 1993-1995].

Studies done in various countries show important differences in the growth of breastfed and bottle-fed children. In addition, it has been found that breast-fed children grow more slowly beginning at the age of 2 or 3 months in comparison with the reference pattern of the U.S. National Center for Health Statistics (NCHS) and the World Health Organization (WHO). These results cast doubt on whether maximum growth is the same as optimal growth. The objective of this study was to compare the growth in weight and length, from birth to 24 months, for a group of children who were breast-fed with that of a group who were bottle-fed. The study was also intended to describe the growth of the breastfed group in relation to the NCHS/WHO norms and a WHO "12-month breast-fed pooled data set." For this research, data were analyzed from the "Cordoba: lactation, feeding, growth, and development" study (or CLACYD study, for its Spanish-language acronym). That study looked at a representative cohort, stratified by social class, of children born in 1993 in the city of Cordoba, Argentina. The researchers analyzed anthropometric data on 74 children who were breast-fed during the first year of life and on 108 bottle-fed children. The data had been recorded, using standardized techniques, at birth and at 6, 12, and 24 months of age. Both groups were homogenous with respect to the age and schooling of the parents, social stratum, birth order, maternal height, and child's weight and length at birth. The living conditions (housing construction and availability of water and sewer services) were better among the group that was bottle-fed (P = 0.04). The breast-fed children had a lower weight and a shorter length at 6, 12, and 24 months than did the bottle-fed children. The breast-fed children also showed a slowing in growth with respect to the NCHS/WHO guidelines beginning in the second semester. This indicates that the NCHS/WHO norms are not totally adequate for evaluating the growth of breast-fed children in Cordoba, Argentina. In the high and middle social strata, the values for the breast-fed group resembled those for the WHO "pooled data set," both in weight and length. In the low and very low social strata, weight values were satisfactory, but the figures for length were less than those of the "pooled data set." The gap in length found among the low and very low social strata does not reduce the validity of the WHO "pooled data set" reference, but rather indicates the influence of living conditions on linear growth.

Argentina↗
PubMed1999

The in vitro effect of pegylated recombinant human megakaryocyte growth and development factor (PEGrHuMGDF) on megakaryopoiesis in patients with aplastic anaemia.

Recombinant human megakaryocyte growth and development factor (rHuMGDF), a truncated form of the Mpl ligand, stimulates megakaryopoiesis both in vitro and in vivo. We describe the in vitro effect of pegylated recombinant human MGDF (PEGrHuMGDF) alone and in combination with other haemopoietic growth factors (G-CSF, GM-CSF, IL3, IL6, erythropoietin, SCF) on megakaryopoiesis in bone marrow from 11 normal subjects and 19 patients with aplastic anaemia (AA). We used semi-solid cultures to assess megakaryocyte colony growth (CFU-Mk) and 7 d suspension cultures to assess production of platelet glycoprotein IIIa (CD61) positive cells. CFU-Mk growth from normal marrow increased 3-4-fold and CD61+ve cells in suspension culture increased 8-10-fold with the addition of 10 ng/ml PEGrHuMGDF. In normal subjects growth factor combinations further increased responses in suspension culture, PEGrHuMGDF + SCF, PEGrHuMGDF + IL3 and PEGrHuMGDF + SCF + IL3 + Epo (P<0.05). IL6, GM-CSF, G-CSF or Epo added with PEGrHuMGDF did not consistently give this increase. CFU-M. growth from AA marrow remained very low in the presence of PEGrHuMGDF, with or without the addition of other growth factors. CD61+ve cells in suspension culture were, however, increased in the presence of PEGrHuMGDF alone in 12/19 AA cases. Of the 12 patients responsive to PEGrHuMGDF, nine were tested with additional growth factors and further responses were seen in six. In the AA cases PEGrHuMGDF+SCP and PEGrHuMGDF+SCF+IL3+Epo gave the highest responses. These data suggest that PEGrHuMGDF, alone or in combination with SCF and/or IL3, can enhance megakaryocyte proliferation in some patients with aplastic anaemia and may therefore have a role in the treatment of thrombocytopenia in these cases.

Adolescent↗
PubMed2000

[Follow-up study related to raising low-birth-weight infants relationship among physical growth, mental development and child-rearing anxiety].

OBJECTIVE: In order to clarify relationship among physical growth, mental development of low-birth-weight (LBW) infants and child-rearing anxiety of mothers, a follow-up study was accomplished for LBW cases from birth to three years of age in a regional group. METHODS: A self-administered questionnaire survey was conducted for mothers whose premature infants were born from April 1992 through March 1993 and whose existence was confirmed from April 1995 through March 1996 in Fukui prefecture. A control group was selected from mature infants whose gestation was 37 weeks or more, who were born in the same year and in the same region. The questionnaire was focused on fetal and child growth, as well as child-rearing anxiety. RESULTS: Of the subjects, while including only 6% very LBW infants, the percentage of full-term LBW infants was 55.3% and that of pre-term LBW infants was 44.7%. In the former group, the mean birth weight (MBW) was 2,319 g, the percentage of females was 63.3%, firstborn children was 59.2%, and light-for-dates (LFD) infants due to intrauterine growth retardation 76.9%. In the latter group, the MBW was 1,983 g, the percentage of females was 52.9%, that of firstborn children was 44.5%, and LFD infants was 14.3%. The growth of the LBW infants through the age of three fell into the same category of growth as the upper portion (1,250-1,499 g) of the very LBW infants rather than that of the mature infants. While the growth of appropriate-for-dates (AFD) infants at full-term were normal, that of LFD infants and pre-term infants was insufficient, and the percentage of those demonstrating catch-up of mature infants was less than 80%. The group of pre-term infants was retarded in the gross motor skills, but not language understanding and pronunciation of two-word sentences. The child-rearing anxiety in mothers who delivered pre-term infants was extremely severe after child birth. As the child grew older, however, the feeling of uneasiness was reduced. Mothers who were delivered of full-term LBW infants did not exhibit any fluctuation in child-rearing anxiety during the first three years. CONCLUSION: Fetal size affects growth progress of children. The prognosis of LBW infants is not satisfactory and mothers who deliver full-term LBW infants continue to worry about their child's growth.

Anxiety↗
PubMed1983

Growth and development of full-term nonasphyxiated small-for-gestational-age newborns: follow-up through adolescence.

Previous studies of growth and development in small-for-gestational-age (SGA) infants have been plagued by several methodologic defects, including a lack of control for socioeconomic status and parental height and an inability to distinguish among the effects of prematurity, neonatal asphyxia, and intrauterine growth retardation. An attempt has been made to overcome these defects in a study of 33 full-term, nonasphyxiated small-for-gestational-age neonates born between 1960 and 1966 and 33 matched control infants of normal birth weight. The infants were followed up and compared for physical growth and sexual, neurologic, and cognitive development at ages 13 to 19 years. Significant deficits in height, weight, and head circumference were found among the SGA cohort, even after statistical adjustment for differences in socioeconomic status and parental height. Sexual development and bone age were not delayed in the SGA group, however, indicating that the deficits in growth are permanent. On neurologic and cognitive testing, the SGA group had trends toward lower scores but scores were well within the normal range. It is concluded that full-term nonasphyxiated SGA infants have an impaired potential for physical growth, but a good prognosis for neurologic and cognitive development. Previous findings of more severe cognitive deficits are attributed to a failure to distinguish the effects of isolated intrauterine growth retardation from effects due to asphyxia.

Adolescent↗
PubMed2001

Feeding preterm infants after hospital discharge: growth and development at 18 months of age.

We have shown that preterm infants fed a preterm formula grow better than those fed a standard term infant formula after hospital discharge. The purpose of this follow-up study was to determine whether improved early growth was associated with later growth and development. Preterm infants (< or =1750 g birth weight, < or =34 wk gestation) were randomized to be fed either a preterm infant formula (discharge to 6 mo corrected age), or a term formula (discharge to 6 mo), or the preterm (discharge to term) and the term formula (term to 6 mo). Anthropometry was performed at 12 wk and 6, 12, and 18 mo. Mental and psychomotor development were assessed using the Bayley Scales of Infant Development II at 18 mo. Differences in growth observed at 12 wk were maintained at 18 mo. At 18 mo, boys fed the preterm formula were 1.0 kg heavier, 2 cm longer, and had a 1.0 cm greater occipitofrontal circumference than boys fed the term formula. Boys fed the preterm formula were also 600 g heavier and 2 cm longer than girls fed the preterm formula. However, no differences were noted in MDI or PDI between boys fed the preterm formula and boys fed the term formula or between the boys fed preterm formula and girls fed the preterm formula. Overall, boys had significantly lower MDI than girls (mean difference, 6.0; p < 0.01), primarily reflecting lower scores in boys fed the term formula. Thus, early diet has long-term effects on growth but not development at 18 mo of age. Sex remains an important confounding variable when assessing growth and developmental outcome in these high-risk infants.

Child Development↗
PubMed1981

Two components from eye tissue that differentially stimulate the growth and development of ciliary ganglion neurons in cell culture.

Survival and development of chick ciliary ganglion neurons in vivo appear to depend on information from the embryonic eye structure that contains the postsynaptic targets of the neurons. We have tested embryonic eye extracts on ciliary ganglion neurons in dissociated cell culture for stimulation of growth and development. Control conditions were chosen that permitted the long term maintenance of the neurons in the absence of tissue extracts of conditioned medium. The conditions included coating the culture substratum with fibroblast material and increasing the K+ concentration in the culture medium to 25 mM. Neurons survived for at least 3 weeks in control conditions. Two major components were resolved in eye extracts that stimulated growth and development of the neurons above the basal levels obtained with control conditions. One component, with an apparent molecular weight of about 2 X 10(4) by gel filtration analysis, stimulated neuronal growth without increasing the levels of choline acetyltransferase activity per neuron. The second component, with an apparent molecular weight of about 5 X 10(4), increased development of choline acetyltransferase levels per neuron but had no effect on neuronal growth. Both components were effective in normal K+ as well as 25 mM K+. These components may represent mechanisms by which the postsynaptic target tissue acts in vivo to direct the growth and development of ciliary ganglion neurons.

Animals↗
PubMed2000

Incidence of focal white matter lesions in a population of hemophiliac children and their normal siblings. Hemophilia Growth and Development Study.

OBJECTIVE: This analysis was undertaken to evaluate the etiology and sequelae of 2- to 5-mm focal white matter hyperintensities on T2-weighted MR images of some participants enrolled in the Hemophilia Growth and Development Study (HGDS). MATERIALS AND METHODS: The HGDS is a multicenter study of the growth and development, neurological, neuropsychological, and immune functioning of a cohort of children and adolescents, 62% of whom were infected with HIV through the use of clotting factor concentrates, and their non-hemophiliac, non-HIV infected male siblings. The current investigation was conducted with all three groups of HGDS participants: HIV-positive hemophiliacs (n = 207), HIV-negative hemophiliacs (n = 126), and their siblings (n = 47). Magnetic resonance imaging was performed at each center, with a variety of 0.3 to 1.5 T instruments. Standard examinations included 5-mm-thick T1-weighted sagittal and axial images, intermediate, and T2-weighted axial images. A study of abnormalities of the coagulation system known to be associated with thrombotic events was conducted among a subgroup of participants (n = 51) from eight centers. RESULTS: Lesions were not associated with hemophilia-related factors, immune function, hematologic, or neurologic factors. There were no associations between the presence of white matter lesions and defects of coagulation in any of the assays completed. CONCLUSION: The 2- to 5-mm focal white matter hyperintensities on T2-weighted MR images of the brain were incidental findings in our study population.

Adolescent↗
PubMed1978

General observations on the growth and development of the young pouch opossum, Didelphis virginiana.

A 3-year study of general growth and development revealed a uniform increase in body length of young pouch opossums during the first 10 weeks of life. Throughout this period, growth was linear and constant for all animals regardless of sex, litter size, or whether animals were obtained from first, second or third litters. Body weights were somewhat more variable, but there were no significant sex differences. Various aspects of external gross morphology are presented and discussed as they relate to growth of the young opossum.

Animals↗
PubMed1996

Dysregulation of growth and development in HIV-infected children.

Growth dysregulation is quite common in HIV-infected children and growth failure is one of the most sensitive indicators of disease progression. Beginning at birth, HIV-infected infants often have smaller size and lower birthweight than noninfected children born to HIV-infected women. The causes of growth dysregulation are varied, and can be due to alterations in gastrointestinal function, chronic or repetitive infections, and alterations in metabolic and endocrine function. The metabolic and endocrine effects may be the consequence of the primary infection or secondary to the use of any of the medications required to treat HIV infection and its complications. Correlational studies have identified an inverse relationship between viral burden and linear growth and body mass index, i.e., the use of antiviral medications that reduce viral burden is associated with improvements in anthropometric indices of growth. Alterations in cytokine profiles, possibly related to reported abnormalities in thyroid indices, fat metabolism, and the somatomedin axis, may be indicative of dysregulation on a cellular level. Pubertal delay, especially among boys, is common, and may contribute to the overall growth failure associated with HIV infection. If the basis for growth failure resides in metabolic and regulatory abnormalities, then interventions beyond increasing caloric intake will be necessary to increase linear growth rate and reverse growth failure in HIV-infected children.

Antiviral Agents↗
PubMed1984

Development and growth of extensor carpi radialis longus muscle in normal and dystrophic chickens.

The development and growth of the skeletal muscles in normal and dystrophic chickens were studied to obtain a clue to the mechanism of dystrophic pathogenesis. A relatively small and isolated muscle--the extensor carpi radialis longus (ECRL) muscle--was utilized to analyze quantitatively the histologic and physiologic parameters. Both normal and dystrophic chickens attained qualitatively the same parameters, but there were some quantitative differences. The first disorder to appear in the dystrophic muscle was a substantial retardation of muscle cell proliferation in the early postnatal development, and the fiber loss was fully compensated by hypertrophy of the remaining cells. The succeeding abnormalities in the dystrophic muscle, e.g., reduction of efficiency in the tension output per unit area, were interpreted as compensating reactions. Therefore, it is likely that the dystrophic lesions in avian muscular dystrophy are caused by retardation of muscle cell proliferation in the early postnatal period. Possible mechanisms for the retardation are discussed in terms of the nerve--muscle trophic interactions which could be greatly intensified in the early postnatal period.

Animals↗
PubMed2000

The effect of muscle transplantation after unilateral partial facial paralysis on craniofacial growth and development: relationship between muscle and nerve histomorphometric findings.

Muscle transplantation has become an indispensable tool to restore the smile in patients with long-standing or congenital facial paralysis. However, little is known of the effect of this surgical intervention on craniofacial growth and development or of the adaptation of the transplant to its recipient site under circumstances of growth. The present study investigates these phenomena in the rabbit model. Twelve-day-old New Zealand White rabbits were randomly assigned to three experimental groups. The control group was used to study normal craniofacial growth and development (n = 15). In the nerve ablation group, unilateral paralysis of the buccal branches of the facial nerve was surgically induced (n = 15). In the transplant group, the surgically induced unilateral paralysis of the buccal branches was immediately followed by a neuromuscular graft (n = 12). All animals were operated on at the age of 12 days, and follow-up evaluations were performed at the ages of 2 months and 6 months. Computerized dorsoventral roentgencephalometric and computed tomography investigations were performed at both ages. Nerve and muscle histomorphometric measurements were performed at the age of 6 months to relate the quality of nerve and muscle regeneration to the growth parameters. The roentgencephalometric measurements revealed that analogous disturbed parameters were present in the nerve ablation and the transplant groups. However, in the transplant group, an additional significant effect of time between 2 and 6 months was seen for some parameters. This resulted in significant differences between the nerve ablation and transplant groups at 6 months for these parameters. Computed tomography measurements showed no significant differences in maxillary or mandibular volume in the transplant group compared with the control or nerve ablation groups. However, a significantly diminished increase in bone volume existed in the transplant group for the time period between 2 and 6 months in comparison with the control and nerve ablation groups. Muscle histomorphometric findings revealed a significant change in muscle fiber composition in the graft compared with the normal latissimus dorsi muscle; this was due to a major decrease in type IIB fibers, with an increase in type I and type IIA fibers. Compared with the normal zygomaticoauricular muscle, the amount of type I fibers was significantly increased. No fiber atrophy was found. Macroscopically, the transplanted muscle failed to increase its length during growth. Nerve histomorphometric findings demonstrated a normal amount of nerve fibers; however, they had significantly decreased diameters and reduced myelin areas. The nerve histomorphometric parameters were related to the muscle histomorphometric findings, which in turn were related to craniofacial growth disturbances. These findings suggested that the main growth differences between the transplant group and the control group may have been due to altered nerve function influencing muscle function. Scar tissue formation and the development of more intense muscle activity later are suggested as the causes of the additional effect of time between 2 and 6 months for the several parameters in the transplant group. Reasons for the failure of complete conversion of the graft to a fast muscle and the failure of the transplant to elongate during growth are discussed.

Animals↗
PubMed1996

Megakaryocyte growth and development factor stimulates enhanced platelet recovery in mice after bone marrow transplantation.

Megakaryocyte growth and development factor (MGDF) is a recently characterized ligand for the cell surface receptor mpl. We have evaluated the effects of polyethylene glycollated recombinant human MGDF (PEG-rHuMGDF) on recovery of hematopoietic cells in mice following bone marrow transplantation (BMT) to support lethal irradiation. Mice treated with PEG-rHuMGDF (50 micrograms/kg/d) had accelerated recovery of platelet numbers compared with BMT mice treated with carrier or recombinant human granulocyte colony-stimulating factor (rHuG-CSF, 72 or 200 micrograms/kg/d). In contrast, PEG-rHuMGDF had no effect on white blood cell (WBC) or red blood cell (RBC) recovery. As previously reported, animals treated with rHuG-CSF had an enhanced recovery of WBC but not platelet or RBC levels. Interestingly, BMT receipient mice treated with the combination of PEG-rHuMGDF and rHuG-CSF showed simultaneous enhanced recovery of both leukocytes and platelets. PEGylated rHuMGDF was found to be considerably more potent than non-PEGylated rHuMGDF in this setting. PEG-rHuMGDF is an effective growth factor for enhancing platelet recovery in mice following BMT either alone or in combination with rHuG-CSF. It will be of interest to evaluate in a clinical setting the ratios of PEG-rHuMGDF and rHuG-CSF for simultaneous administration of these factors and accelerated recovery of both leukocytes and platelets.

Animals↗
PubMed1999

Growth and development in Arabidopsis thaliana through an entire life cycle under simulated microgravity conditions on a clinostat.

The effects of simulated microgravity conditions produced by a horizontal clinostat on the entire life cycle of Arabidopsis thaliana ecotype Columbia and Landsberg erecta were studied. Horizontal clinorotation affected little germination of seeds, growth and development of rosette leaves and roots during early vegetative growth stage, and the onset of the bolting of inflorescence axis and flower formation in reproductive growth stage, although it suppressed elongation of inflorescence axes. The clinorotation substantially reduced the numbers of siliques and seeds in Landsberg erecta, and completely inhibited seed production in Columbia. Seeds produced in Landsberg erecta on the clinostat were capable of germinating and developing rosette leaves normally on the ground. On the other hand, growth of pin formed mutant (pin/pin) of Arabidopsis ecotype Enkheim, which has a unique structure of inflorescence axis with no flower and extremely low levels of auxin polar transport activity, was inhibited and the seedlings frequently died during vegetative stage on the clinostat. Seed formation and inflorescence growth of the seedlings with normal shape (pin/+ or +/+) were also suppressed on the clinostat. These results suggest that the growth and development of Arabidopsis, especially in reproductive growth stage, is suppressed under simulated microgravity conditions on a clinostat. To complete the life cycle probably seems to be quite difficult, although it is possible in some ecotypes.

Arabidopsis↗
PubMed1995

[Effects on the growth and development of mandible with different treatment following condylar neck fracture in rat]

The condylar necks of young rats are fractured on this experiment.Fractures are treated with nonfixation and fixation,The growth and development of mandible can be interrupted in two groups,with a relatively small in condylar head,a relatively thick in condylar neck.A coronoid and a mandible length are relatively short.But the growth and development of mandible almost are completed,bilateral mandibles are almost symmetry except for ramus.The difference are not found in between two groups.The results of this study implied that young condylar neck fracture may be treated by conservation.

Journal Article↗
PubMed2002

Marked improvement of thrombocytopenia in a murine model of idiopathic thrombocytopenic purpura by pegylated recombinant human megakaryocyte growth and development factor.

OBJECTIVE: We examined the stimulatory effect of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) on platelet production in male (NZW x BXSB) F(l) (W/B F(1)) mice, a murine model of idiopathic thrombocytopenic purpura. MATERIALS AND METHODS: A cohort of 19- to 25-week-old, severely thrombocytopenic male W/B F(1) mice were given PEG-rHuMGDF at different dosing schedules. Before and at various times after therapy, platelet counts, reticulated platelets, platelet lifespan, and levels of platelet-associated immunoglobulin G were measured. Analysis of megakaryocytic cells was performed. RESULTS: Treatment of male W/B F(1) mice with PEG-rHuMGDF (30 microg/kg/day) three times per week for several weeks resulted in sustained thrombocytosis, accompanied by increased megakaryocytopoiesis in both the bone marrow and spleen. The degree of the platelet response to PEG-rHuMGDF varied between individual mice, likely reflecting the heterogeneity of the disease. Production of new platelets in response to PEG-rHuMGDF was manifested by an increase in reticulated platelets. Levels of platelet-associated immunoglobulin G decreased inversely during periods of thrombocytosis. PEG-rHuMGDF therapy also improved thrombocytopenia in male W/B F(1) mice refractory to splenectomy. Platelet lifespan was not affected by PEG-rHuMGDF. Male W/B F(1) mice treated with pegylated murine MGDF, a homologue of PEG-rHuMGDF, had persistent thrombocytosis for at least 7 months, suggesting that antiplatelet antibody production was not enhanced. CONCLUSIONS: PEG-rHuMGDF therapy potently stimulated platelet production, effectively ameliorating thrombocytopenia in a murine model of idiopathic thrombocytopenic purpura.

Animals↗
PubMed1998

Effects of Recombinant Human Megakaryocyte Growth and Development Factor (rHuMGDF) on Platelet Production, Platelet Aggregation, and Thrombosis.

Recombinant human megakaryocyte growth and development factor (rHuMGDF) is a c-mpl ligand that promotes the differentiation of CD34+ precursor cells into megakaryocyte, and then platelets. In experimental animals, injection of this and other c-mpl ligands leads to profound increases in the circulating platelet count in a matter of days. However, c-mpl ligands have also been shown to sensitize platelets to aggregating agents in vitro, raising the possibility that c-mpI ligands may have prothrombotic effects in vivo. Therefore, characterizing rHuMGDF in an in vivo model of thrombosis is a necessary and critical step in defining the in vivo pharmacology of this novel and important hernatopoietic factor, a pegylated form of which is currently in clinical trials. To determine the biologically effective doses in the rabbit, daily subcutaneous injections of rHuMGDF at 0.1, 1.0, or 10 µg/kg were administered ever 7 days. Daily injection of 10 µ/kg produced an approximate fourfold increase in platelet count and 1.0 µ/kg doubled platelet count over the injection period, both of which were statistically significant. The serum concentrations of rHuMGDF were determined 10 minutes following a single intravenous injection with 0.1, 1.0, and 10 µ/kg, and were 0.05 +/- 0.02, 0.98 +/- 0.07, and 21.32 +/- 21.35 ng/ml. To determine whether rHuMGDF can sensitize platelets in vivo, platelet aggregometry was performed on platelets isolated from animals immediately before and 10 minutes after they had been injected intravenously with rHuMGDF (0.1, 1.0, and 10 µ/kg). Intravenous injection of 10 µ/kg produced measurable changes in platelet aggregometry ex vivo, as evidenced by an increased sensitivity of platelets to adenosine diphosphate (ADP). To assess. the in vivo prothrombotic potential of rHuMGDF, a rabbit carotid artery model of cyclic flow reduction (CFR) was used to measure the effect of intravenous rHuMGDF administration on the rate of thrombus formation as assessed by CFR slope and frequency. Intravenous administration of rHuMGDF had no effect on CFR slope or frequency when administered in doses ranging from 0.1 to 10 µ/kg. Control experiments demonstrated that CFR slope and frequency can be enhanced by intravenous infusion of epinephrine and can be abolished by the combined administration of aspirin and ketanserin, indicating that potentially prothrombotic and antithrombotic agents can be identified in this model. We conclude that biologically active doses of rHuMGDF used in this study (1.0 and 10 µ/kg) produce measurable serum levels, induce a thrombopoietic effect, and sensitize platelets in vivo, as determined by ex vivo aggregometry, at 10 µ/kg. Despite the sensitization of platelets to aggregation induced by ADP, it is clear that rHuMGDF does not alter the pattern of CFRs observed in the rabbit carotid artery, whereas agents known to sensitize platelets (epinepherine) and to inhibit platelets (aspirin and ketanserin) readily affected the CFR pattern. These findings indicate that intravenous rHuMIGDF administration, while capable of sensitizing pIatelets, does not enhance platelet-dependent thrombosis in vivo.

Journal Article↗
PubMed1998

Mobilization of primitive haemopoietic progenitor cells and stem cells with long-term repopulating ability into peripheral blood in mice by pegylated recombinant human megakaryocyte growth and development factor.

We investigated in detail the effect of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) on peripheral blood progenitor cell (PBPC) mobilization in male BDF1 mice. Treatment with PEG-rHuMGDF for 5 d stimulated a striking expansion of the circulating levels of multiple types of colony-forming units in culture (CFU-c), including CFU-granulocyte-macrophage, CFU-megakaryocyte, burst-forming units-erythroid, and multipotent CFU-c, and primitive day-12 CFU-spleen. All of these progenitors were mobilized into the peripheral blood (PB) with similar kinetics; their numbers peaked after the cessation of treatment and then declined earlier than platelet numbers peaked. The maximal increase in any of the four CFU-c in the PB was attained with at least 300 microg/kg/d of PEG-rHuMGDF, whereas peripheral platelet counts plateaued at 30 microg/kg/d. Adoptive transfer with PB from PEG-rHuMGDF-treated donor mice resulted in greater survival of lethally irradiated recipients. The majority of the recipients that survived at 187 d after transplantation with PEG-rHuMGDF-mobilized PB showed significant donor engraftment at the progenitor cell level. The combined administration of appropriate doses of PEG-rHuMGDF and recombinant human granulocyte colony-stimulating factor induced a synergistic increase in the circulating levels of the four CFU-c compared to either factor alone. These results indicate that PEG-rHuMGDF as a single agent can mobilize a full spectrum of PBPCs in mice.

Animals↗
PubMed1996

The excessive production of indole-3-acetic acid and its significance in studies of the biosynthesis of this regulator of plant growth and development.

Because of the importance of indole-3-acetic acid (IAA) in the growth and development of plants, extensive studies of the biosynthesis of IAA have been performed during the four decades since the discovery of IAA as a plant hormone. The pathway for the biosynthesis of IAA in plants remains, however, to be unelucidated, even though studies within the past decade have revealed unexpected aspects of such biosynthesis. By contrast, two pathways to IAA have been characterized in bacteria at the molecular level: the indole-3-acetamide (IAM) pathway (L-tryptophan-->IAM-->IAA); the indole-3-pyruvic acid pathway (L-tryptophan-->indole-3-pyruvic acid-->indole-3-acetaldehyde-->IAA) (Fig. 1). In both pathways, the details of the biosynthesis of IAA were clarified using IAA-overproducing bacteria. After a description of recent advances of the studies of the biosynthesis of IAA in plants, this review focuses on the excessive production of IAA in several organisms and its significance in the studies of the biosynthesis of IAA.

Forecasting↗