The influence of dapagliflozin on cardiac remodeling, myocardial function and metabolomics in type 1 diabetes mellitus rats

BACKGROUND

Sodium-glucose cotransporter (SGLT)2 inhibitors have displayed beneficial effects on the cardiovascular system in diabetes mellitus (DM) patients. As most clinical trials were performed in Type 2 DM, their effects in Type 1 DM have not been established.

OBJECTIVE

To evaluate the influence of long-term treatment with SGLT2 inhibitor dapagliflozin on cardiac remodeling, myocardial function, energy metabolism, and metabolomics in rats with Type 1 DM.

METHODS

Male Wistar rats were divided into groups: Control (C, n = 15); DM (n = 15); and DM treated with dapagliflozin (DM + DAPA, n = 15) for 30 weeks. DM was induced by streptozotocin. Dapagliflozin 5 mg/kg/day was added to chow.

STATISTICAL ANALYSIS

ANOVA and Tukey or Kruskal-Wallis and Dunn.

RESULTS

DM + DAPA presented lower glycemia and higher body weight than DM. Echocardiogram showed DM with left atrium dilation and left ventricular (LV) hypertrophy, dilation, and systolic and diastolic dysfunction. In LV isolated papillary muscles, DM had reduced developed tension, +dT/dt and -dT/dt in basal condition and after inotropic stimulation. All functional changes were attenuated by dapagliflozin. Hexokinase (HK), phosphofructokinase (PFK) and pyruvate kinase (PK) activity was lower in DM than C, and PFK and PK activity higher in DM + DAPA than DM. Metabolomics revealed 21 and 5 metabolites positively regulated in DM vs. C and DM + DAPA vs. DM, respectively; 6 and 3 metabolites were negatively regulated in DM vs. C and DM + DAPA vs. DM, respectively. Five metabolites that participate in cell membrane ultrastructure were higher in DM than C. Metabolites levels of N-oleoyl glutamic acid, chlorocresol and N-oleoyl-L-serine were lower and phosphatidylethanolamine and ceramide higher in DM + DAPA than DM.

CONCLUSION

Long-term treatment with dapagliflozin attenuates cardiac remodeling, myocardial dysfunction, and contractile reserve impairment in Type 1 diabetic rats. The functional improvement is combined with restored pyruvate kinase and phosphofructokinase activity and attenuated metabolomics changes.

Influence of Isolated Resistance Exercise on Cardiac Remodeling, Myocardial Oxidative Stress, and Metabolism in Infarcted Rats

INTRODUCTION

Exercise is an important therapeutic strategy for preventing and treating myocardial infarction (MI)-induced cardiac remodeling and heart failure. However, the myocardial effects of resistance exercise on infarcted hearts are not completely established. In this study, we investigated the effects of resistance exercise on structural, functional, and molecular cardiac alterations in infarcted rats.

METHODS

Three months after MI induction or simulated surgery, Wistar rats were assigned into three groups: Sham (n = 14); MI (n = 9); and exercised MI (MI-Ex, n = 13). Exercised rats performed, 3 times a week for 12 weeks, four climbs on a ladder with progressive loads. Cardiac structure and left ventricle (LV) function were analyzed by echocardiogram. Myocyte diameters were evaluated in hematoxylin- and eosin-stained histological sections as the smallest distance between borders drawn across the nucleus. Myocardial energy metabolism, lipid hydroperoxide, malondialdehyde, protein carbonylation, and antioxidant enzyme activities were evaluated by spectrophotometry. Gene expressions of NADPH oxidase subunits were evaluated by RT-PCR. Statistical analyses were performed using ANOVA and Tukey or Kruskal-Wallis and Dunn's test.

RESULTS

Mortality did not differ between the MI-Ex and MI groups. MI had dilated left atrium and LV, with LV systolic dysfunction. Exercise increased the maximum load-carrying capacity, with no changes in cardiac structure or LV function. Myocyte diameters were lower in MI than in Sham and MI-Ex. Lactate dehydrogenase and creatine kinase activity were lower in MI than in Sham. Citrate synthase and catalase activity were lower in MI and MI-Ex than in Sham. Lipid hydroperoxide concentration was lower in MI-Ex than in MI. Nox2 and p22phox gene expressions were higher in MI-Ex than in Sham. Gene expression of Nox4 was higher in MI and MI-Ex than in Sham, and p47phox was lower in MI than in Sham.

CONCLUSION

Late resistance exercise was safe in infarcted rats. Resistance exercise improved maximum load-carrying capacity, reduced myocardial oxidative stress, and preserved myocardial metabolism, with no changes in cardiac structure or left ventricle function in infarcted rats.

Effects of resistance exercise in the cardiac remodeling of myocardial infarction rats

Introduction

Exercise is an important therapeutic strategy for heart failure (HF). However, the myocardial effects of resistance exercise during HF are not completely understood. In this study, we investigated the influence of resistance exercise on cardiac remodeling and molecular myocardial changes of rats with myocardial infarction (MI)-induced HF.

Methods

Three months after MI induction or simulated surgery, Wistar rats were divided into three groups: Sham (n=14); MI (n=9); and MI subjected to resistance exercise (MI-R, n=13). Exercised rats trained 3 times a week during 12 weeks performing four climbs in a ladder with progressive loads. Cardiac structure and left ventricular function were assessed by echocardiogram. Myocyte diameters were measured in histological sections. Energy metabolism, lipid hydroperoxide, antioxidant enzymes activity, malondialdehyde, and protein carbonylation were evaluated by spectrophotometry. NADPH oxidase subunits (Nox2, Nox4, p22phox and p47phox) gene expression was assessed by RT-PCR. Statistical analysis: ANOVA and Tukey test or Dunn's test.

Results

Mortality did not differ between MI-R and MI groups. MI-R and MI presented dilated left atrium and left ventricle with systolic and diastolic dysfunction. Exercise improved maximum carrying load with no changes in cardiac structure or left ventricle function. Myocyte diameter was lower in MI than Sham and MI-R. Lactate dehydrogenase and creatine kinase activities were lower in MI than Sham. Activity of citrate synthase and catalase was lower in MI and MI-R than Sham. Lipid hydroperoxide concentration was lower in MI-R than MI. Nox2 and p22phox gene expression was higher in MI-R than Sham. Gene expression of Nox4 was higher in both infarcted groups and gene expression of p47phox was lower in MI than Sham.

Conclusion

Resistance exercise is safe and well tolerated by infarcted rats. Exercise increases maximum carrying load and reduces myocardial oxidative stress with no changes in cardiac structure or left ventricle function of infarcted rats.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): CNPq - National Council for Scientific and Technological Development

Sodium glucose co-transporter 2 inhibition prevents muscle energy metabolism changes in infarcted rats

Introduction

Skeletal muscle energy metabolism is commonly altered in heart failure patients, with a metabolic shift from oxidative to glycolytic muscle fiber. These changes contribute to reduced functional capacity. Sodium glucose co-transporter type 2 (SGLT2) inhibitors improve cardiovascular outcomes in both diabetic and non-diabetic patients, as well as those with and without heart failure. However, the effects of SGLT2 inhibitors on skeletal muscle during heart failure have not been established. The aim of this study was to assess the metabolic effect of empagliflozin (EMPA) on skeletal muscle of rats with myocardial infarction (MI)-induced heart failure.

Methods

One week after MI induction or simulated surgery, male Wistar rats were divided into four groups: Sham (n=10), Sham+Empa (n=12), MI (n=10), and MI+Empa (n=09). EMPA was added to rat chow (5 mg/kg/day). Rats were supplied with ad libitum water and chow for 12 weeks. Infarct size was measured by histological analysis. Metabolic enzyme activity in the soleus muscle was assessed by spectrophotometry. Statistical analysis: ANOVA and Tukey, and Student's t tests.

Results

Only rats with infarction size greater than 35% of total left ventricle area were included in this study. Infarction size did not differ between infarcted groups (MI 41.8±4.2; MI+Empa 40.7±5.7 of total left ventricle area). In the MI soleus muscle, metabolic enzyme activity of glucose-6-phosphate-dehydrogenase, citrate synthase and beta-hydroxy-acyl-dehydrogenase was higher than the Sham group. These changes were not observed in the MI+Empa group. MI+Empa had lower hexokinase, phosfructokinase, and pyruvate kinase activity (glycolytic metabolism enzymes), and lower citrate synthase and glucose-6-phosphate-dehydrogenase activity than MI.

Conclusion

Chronic treatment with SGLT2 inhibitor empagliflozin prevents metabolic abnormalities in skeletal muscle in infarcted rats.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): CAPES, CNPq, FAPESP

Influence of long-term sodium-glucose cotransporter 2 inhibition on cardiac remodeling in rats with type 1 diabetes mellitus

Background

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have beneficial effects on the cardiovascular system in diabetes mellitus (DM) patients. However, as most clinical trials were performed in type 2 DM, the effects of SGLT2 inhibitors in patients with type 1 DM still need further clarification. In this study, we evaluated the effects of long-term treatment with the SGLT2 inhibitor dapagliflozin on cardiac remodeling, myocardial function, and energy metabolism in rats with type 1 DM.

Methods

Male Wistar rats were divided into three groups: control (C, n=15); DM (n=15); and DM treated with dapagliflozin (DM+DAPA, n=15) for 30 weeks. DM was induced by streptozotocin; DAPA was added to the rat chow (5 mg/kg/day). Cardiac performance was evaluated by echocardiogram and myocardial function in isolated left ventricular (LV) papillary muscle preparations. Myocardial energy metabolism enzyme activities were evaluated by spectrophotometry. Statistical analyzes: ANOVA and Tukey or Kruskal-Wallis and Dunn.

Results

DM+DAPA had lower glycemia than DM [C 112 (108–116); DM 531 (522–535)*; DM+DAPA 267 (179–339) mg/dL; p<0.05 vs C and DM+DAPA]. Echocardiogram showed that DM and DM+DAPA had left atrium and left ventricle dilatation with systolic and diastolic dysfunction; in DM+DAPA, the changes were attenuated in relation to DM. Developed tension and +dT/dt were higher in DM+DAPA than DM in basal condition. After inotropic stimulation with post-pause contraction, extracellular calcium concentration elevation, and isoproterenol addition to the nutrient solution, +dT/dt and –dT/dt were higher in DM+DAPA than DM. Hexokinase, phosphofructokinase, and pyruvate kinase activity was lower in DM than the C. Phosphofructokinase and pyruvate kinase activity was higher in DM+DAPA than DM.

Conclusion

Long-term dapagliflozin treatment attenuates cardiac remodeling and myocardial dysfunction and preserves hexokinase, phosphofructokinase and pyruvate kinase activity in rats with type 1 diabetes mellitus.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): CNPq - National Council for Scientific and Technological Developmentdoctor

Influence of resistance exercise on cardiac remodeling and soleus muscle of infarcted rats

Introduction

Resistance exercise (RE) provides several benefits for healthy individuals. However, its effects during heart failure are unclear. The aim of this study was to evaluate the effects of RE on functional capacity, cardiac remodeling, and soleus muscle molecular and biochemical features in rats with myocardial infarction (MI).

Methods

Three months after MI or simulated surgery (Sham), Wistar rats were divided into three groups: Sham (n=14), MI (n=13), and MI subjected to RE (RE-MI, n=14). Exercised rats trained 3 times a week performing four climbs with progressive loads on a ladder over 12 weeks. Functional capacity was assessed by maximum carrying capacity test in the ladder and exercise tolerance test in treadmill. Echocardiogram was performed at the end of the study. Energy metabolism and antioxidant enzyme activities were assessed by spectrophotometry in the soleus muscle. Oxidative stress markers were analyzed in soleus muscle (lipid hydroperoxide) or serum (malondialdehyde and protein carbonylation). Protein expression of insulin type-1 growth factor-like pathway, protein kinase B, and rapamycin target complex was analyzed by Western-blot. Statistical analysis: ANOVA and Bonferroni or Dunn, Student's t and Goodman tests; p<0.05.

Results

Mortality was higher in MI than Sham. Infarction size did not differ between groups. Resistance exercise increased maximum load carrying capacity, without changing functional capacity or cardiac remodeling. Catalase activity was lower in MI than Sham and glutathione peroxidase activity was lower in MI than Sham and RE-MI. Protein carbonylation was higher in RE-MI than MI. Energy metabolism did not differ between groups, except for lower phosphofructokinase activity in RE-MI than MI. Expression of p70s6K, p-FoxO3a, and p-FoxO3a-to-FoxO3a ratio was lower, and p-p70s6K-to-p70s6K ratio was higher in MI than Sham.

Conclusion

The practice of resistance exercise is safe, attenuates mortality, and improves maximum load carrying capacity regardless of changes in cardiac remodeling in infarcted rats. In soleus muscle, resistance exercise preserves phosphofructokinase and antioxidant enzyme activity and expression of the proteins involved in muscle trophism.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): CNPq UNESP

Relationship Between Stink Bug Populations in Winter Shelters and Atmospheric Variables in Soybean Growing Areas in Southern Brazil

Stink bugs (Pentatomidae) are among the main entomological problems in the international farming. Their ability in using alternative plants (refuges) during the off-season is one of the reasons that led them to the status of key pests in several crops. Like other insect species, stink bugs are subject to atmospheric variations. Therefore, the objective of this experiment was to evaluate the abundance, the co-occurrence, and its variations according to the weather in the off-season. The work was conducted between 2014 and 2018, in the municipality of Cruz Alta, state of Rio Grande do Sul (RS), Brazil. Every year, refuges formed by Poaceae and located around the cropped area were evaluated in the second fortnight of June, corresponding to the beginning of the winter solstice. Atmospheric variables corresponding to the evaluation period were used to explain the variation in the populations. In short, our results demonstrated interannual variations in the population abundance of stink bugs in the evaluated refuges. We also found variations in the co-occurrence between species. Finally, we demonstrate the trend in the increase in these refuges in years with cold and dry off-seasons.

Secondary origin, hybridization and sexual reproduction in a diploid-tetraploid contact zone of the facultatively apomictic orchid Zygopetalum mackayi

The production of triploids and apomictic reproduction are important processes for polyploid establishment and cytotype coexistence, but we know little about the interaction between triploids and facultatively apomictic plants. To bridge this gap, we studied the pollen-dependent, facultatively apomictic orchid Zygopetalum mackayi from high-elevation outcrops of southeast Brazil. We described the nature of the contact between Z. mackayi cytotypes and patterns of genetic diversity and structure based on eight microsatellite markers and 155 individuals of pure tetraploid, pure diploid and mixed cytotype populations. Our results revealed high values of genetic and genotypic diversity within all populations of Z. mackayi. Each cytotype emerged as a genetic distinct cluster, combining individuals from different populations. Triploids clustered in an intermediate position between diploids and tetraploids. Most genetic variance is associated with individuals within populations and genetic differentiation is high among populations. Mixed cytotype populations of Z. mackayi originate from secondary contact. Triploids are hybrids between diploids and tetraploids and likely act as a bridge. Our results point to the predominance of sexual reproduction in all populations but do not corroborate previous basic chromosome number for this species. Polyploidy rather than facultative apomixis may explain the larger geographic distribution of tetraploids of Z. mackayi.

Changes in cardiac biomarkers in goats naturally affected by pregnancy toxemia

Pregnancy toxemia (PT) is considered one of the most common metabolic diseases with high impact on the production of small ruminants. The objective of this study was investigate possible myocardial damage in goats affected with PT by the determination of serum myocardial biomarkers CK-MB and cTnI. A total of 44 goats affected with PT, and 10 apparently healthy goats (control group or CG) were used in the study. In goats with PT, the serum concentrations of cTnI (0.43 ng/mL) were significantly higher than that in CG goats (0.06 ng/mL). Although CK-MB showed no significant difference, it was approximately three times higher in animals with PT. The serum concentrations of insulin were significantly lower in PT goats (5.03 ppmol/L) compared to CG goats (10.66 pmol/L). The serum concentrations of cortisol in PT goats (155.41 nmol/L) were significantly higher than that in CG goats (36.58 nmol/L). Results of this study indicate that a clinically significant myocardial damage might occur in goats affected with PT leading to significant elevations in values of cTnI and CK-MB. Therefore, these parameters could be used as a potential prognostic indicator in goats affected with this important disease.

P2499Effects of aerobic and resistance exercise on skeletal muscle of infarcted rats

Background

Skeletal muscle changes contribute to reduced physical performance after myocardial infarction (MI). Exercise has been recommended to stable patients. However, the effects of resistance exercise after MI are not clear. We compared the effects of aerobic and resistance exercise initiated during compensated cardiac remodeling in infarcted rat gastrocnemius muscle.

Methods

Three months after MI induction, Wistar rats were divided into four groups: Sham (n=20); sedentary MI (MI-S, n=9); aerobic exercised MI (MI-A, n=9); and resistance exercised MI (MI-R, n=13). Exercised rats trained three times a week for 12 weeks on a treadmill or ladder. Energy metabolism, oxidative stress markers, and antioxidant enzyme activities were assessed by spectrophotometry. Satellite cells activation markers (MyoD, NCAM, and myosin heavy chain neonatal isoform) were assessed by immunofluorescence or Western blot (Pax-7). Statistical analysis: ANOVA or Mann Whitney.

Results

Physical aerobic capacity was greater in MI-A and strength gain higher in MI-R. Cardiac structures and left ventricular function evaluated by echocardiogram did not differ between infarcted groups. Histological analysis showed that MI size and gastrocnemius cross sectional area did not differ between infarcted groups. Oxygen reactive species production was higher in MI-S than Sham and lipid hydroperoxide concentration was lower in MI-A than the other groups. Catalase activity was higher and glutathione peroxidase lower in infarcted groups than Sham. Superoxide dismutase activity was higher in Sham and MI-R than MI-S. Skeletal muscle metabolism enzyme activity did not differ between groups, except for increase pyruvate kinase in MI-S against the other groups, and β-hydroxyacyl CoA dehydrogenase in MI-S against Sham. Satellite cell activation and protein expression of MAPK and NF-kB did not differ between groups.

Conclusion

Aerobic and resistance exercise respectively improves physical capacity and muscle strength without changing echocardiographic parameters of infarcted rats. Myocardial infarction increases oxygen reactive species production and changes antioxidant enzyme activity and glucose and fatty acid metabolism. Aerobic exercise is superior to resistance exercise against oxidative stress reducing muscle lipid hydroperoxide concentration and attenuating change in glutathione peroxidase activity.

Acknowledgement/Funding

Financial support: Fapesp, CNPq, Capes, and UNESP

Coccinellidae Parasitoids in Brazil: Neglected Species in a Mega-Diverse Country

Current knowledge on coccinellids is primarily focused on their role as natural enemies of soft-bodied insects. However, there is a great diversity of coccinellid parasitoid species that are less studied. Here, we describe new records of coccinellid parasitoids with emphasis on new host-parasitoid interactions in 11 sample sites in Brazil. We collected 122 coccinellid individuals parasitized by six species of parasitoids in the Cerrado and in the Atlantic Rainforest biomes. New records of coccinellid parasitoids and host associations, expansion of habitat ranges and interactions are discussed focusing on the lack of basic information on these interactions in Brazil.

Naringenin degradation by the endophytic diazotroph Herbaspirillum seropedicae SmR1

Several bacteria are able to degrade flavonoids either to use them as carbon sources or as a detoxification mechanism. Degradation pathways have been proposed for several bacteria, but the genes responsible are not known. We identified in the genome of the endophyte Herbaspirillum seropedicae SmR1 an operon potentially associated with the degradation of aromatic compounds. We show that this operon is involved in naringenin degradation and that its expression is induced by naringenin and chrysin, two closely related flavonoids. Mutation of fdeA, the first gene of the operon, and fdeR, its transcriptional activator, abolished the ability of H. seropedicae to degrade naringenin.

Jarisch-Herxheimer reaction among syphilis patients in Rio de Janeiro, Brazil

The Jarisch-Herxheimer reaction (JHR) is a syndrome observed after antimicrobial treatment of some infectious diseases. The syndrome has clinical characteristics of an inflammatory reaction to antibiotic treatment. A prospective study of patients with a clinical and laboratory diagnosis of syphilis was conducted at a sexually transmitted diseases clinic in Rio de Janeiro, Brazil. Patients were treated with benzathine penicillin and observed for the JHR. A total of 115 patients were included in this study. Fifty-one patients (44%) had secondary syphilis; 37 (32%), primary; 26 (23%), latent; and one (1%), tertiary syphilis. Ten patients (9%) developed the JHR. All JHRs occurred in patients with secondary and latent syphilis. No patients experienced an allergic reaction to penicillin. The JHR occurred less frequently than in previous studies. It is important that health-care professionals recognize the clinical characteristics of the JHR so that it is not misinterpreted as an allergic reaction to penicillin.

The opportunistic fungal pathogen Scedosporium prolificans: carbohydrate epitopes of its glycoproteins

Isolated from the mycelium of Scedosporium prolificans were complex glycoproteins (RMP-Sp), with three structurally related components (HPSEC). RMP-Sp contained 35% protein and 62% carbohydrate with Rha, Ara, Man, Gal, Glc, and GlcNH(2) in a 18:1:24:8:6:5 molar ratio. Methylation analysis showed mainly nonreducing end- of Galp (13%), nonreducing end- (9%), 2-O- (13%), and 3-O-subst. Rhap (7%), nonreducing end- (11%), 2-O- (10%), 3-O- (14%), and 2,6-di-O-subst. Manp units (13%). Mild reductive beta-elimination of RMP-Sp gave alpha-l-Rhap-(1-->2)-alpha-l-Rhap-(1-->3)-alpha-l-Rhap-(1-->3)-alpha-d-Manp-(1-->2)-d-Man-ol, with Man-ol substituted at O-6 with beta-d-Galp units, a related pentasaccharide lacking beta-d-Galp units, and beta-d-Galp-(1-->6)-[alpha-d-Manp-(1-->2)]-d-Man-ol in a 16:3:1w/w ratio. Traces of Man-ol and Rha-ol were detected. ESI-MS showed HexHex-ol and Hex(3-6)Hex-ol components. Three rhamnosyl units were peeled off successively from the penta- and hexasaccharide by ESI-MS-MS. The carbohydrate epitopes of RMP-Sp differ from those of the glycoprotein of Pseudallescheria boydii, a related opportunistic pathogen.

Sleep patterns and sleep-related complaints of Brazilian interstate bus drivers

Sleep-related complaints have become a highlight for physicians as well as public health administrators. Studies of sleep patterns and sleep-related complaints of shift workers have been useful in minimizing reduction in the quality of life due to the warping of the sleep-wake cycle. The objective of the present study was to assess patterns of sleep, sleep-related complaints as well as physical activity and scoring rates for depression and anxiety in interstate bus drivers. Data were obtained with a sleep questionnaire, with the Beck inventory for depression, and the State-Trait Anxiety Inventory (STAI). A total of 400 interstate bus drivers from the northern, southern, central-western and south-eastern regions of Brazil were interviewed. Sixty percent of the subjects interviewed presented at least one sleep-related complaint, 16% admitted to have dozed at the wheel while on duty, and 41% stated that they exercised on a regular basis. Other sleep disturbance complaints reported were: sleep latency 29'17"; physical fatigue, 59.8%; mental fatigue, 45.4%; sleepiness, 25.8%; irritability, 20.6%; insomnia, 37.5%, respiratory disturbances, 19. 25% and snoring, 20.75%. Scores for anxiety and depression were not in the pathological range. The present data reinforce the view that bus drivers are generally discontent with shift work and its effects on sleep. Consequently, it is very important to establish an appropriate work schedule for drivers, besides implementing photo-therapy and physical activities in order to minimize sleepiness when driving.

Human immunodeficiency virus type 1 Vpr interacts with HHR23A, a cellular protein implicated in nucleotide excision DNA repair

The human immunodeficiency virus type 1 (HIV-1) vpr gene is an evolutionarily conserved gene among the primate lentiviruses HIV-1, HIV-2, and simian immunodeficiency viruses. One of the unique functions attributed to the vpr gene product is the arrest of cells in the G2 phase of the cell cycle. Here we demonstrate that Vpr interacts physically with HHR23A, one member of an evolutionarily conserved gene family involved in nucleotide excision repair. Interaction of Vpr with HHR23A was initially identified through a yeast two-hybrid screen and was confirmed by the demonstration of direct binding between bacterially expressed recombinant and transiently expressed or chemically synthesized protein products. Visualization of HHR23A and Vpr by indirect immunofluorescence and confocal microscopy indicates that the two proteins colocalize at or about the nuclear membrane. We also map the Vpr-binding domain in HHR23A to a C-terminal 45-amino-acid region of the protein previously shown to have homology to members of the ubiquitination pathway. Overexpression of HHR23A and a truncated derivative which includes the Vpr-binding domain results in a partial alleviation of the G2 arrest induced by Vpr, suggesting that the interaction between Vpr and HHR23A is critical for cell cycle arrest induced by Vpr. These results provide further support for the hypothesis that Vpr interferes with the normal function of a protein or proteins involved in the DNA repair process and, thus, in the transmission of signals that allow cells to transit from the G2 to the M phase of the cell cycle.

Interleukin 3 or interleukin 1 abrogates the reconstituting ability of hematopoietic stem cells

Because of their known myelopoietic activities, both interleukin (IL)-3 and IL-1 are often used in combination with other cytokines for in vitro (ex vivo) expansion of stem cells. We have investigated the effects of IL-3 and IL-1 on in vitro expansion of murine hematopoietic stem cells with long-term engraftment capabilities, using a highly purified progenitor population. Lineage-negative, Ly-6A/E+, c-kit+ bone marrow cells from male mice were cultured in suspension in the presence of stem cell factor, IL-6, IL-11, and erythropoietin with or without IL-3 or IL-1. Kinetic studies revealed an exponential increase in total nucleated cells and about 10-fold enhancement of nucleated cells by IL-3 during the initial 10 days. Addition of IL-3 hastened the development but significantly suppressed the peak production of colony-forming cells. Addition of IL-1 also significantly suppressed the numbers of colony-forming cells. The reconstituting ability of the cultured cells was tested by transplanting the expanded male cells into lethally irradiated female mice. The cells expanded from enriched cells in the absence of IL-3 and IL-1 revealed engraftment at 2, 4, 5, and 6 months, whereas addition of IL-3 or IL-1 to the cultures significantly reduced the reconstituting ability. The results suggest that these cytokines may have a modulatory role on the self-renewal of stem cells and further indicate that the use of IL-3 and IL-1 for in vitro expansion of human stem cells needs to be cautiously evaluated.

[Rabies control in Brazil from 1980 to 1990]

The epidemiological situation of rabies in Brazil at the period of 1980 to 1990, when the National Program for Rabies Prevention was implemented on a national scale, and which yielded positive results, is presented. The main controlling actions carried out in order to achieve these results are also described. Rabies in Brasil registered a considerable decrease in human and canine cases (78% and 90%, respectively), half way through the series of analyses undertaken for this study. Towards the end of the decade, the disease began to recrudesce, several cases occurring in some parts of the country, mainly in the northeastern region, where 70% of the total number of infections for 1990 was recorded. Moreover, human rabies transmitted by bats experienced a considerable increase, accounting for 15.1% of the total. The Program, which is implemented by State and Municipal authorities. Covers the 350,000 people who are attacked by animals, and vaccinates approximately 9,000,000 animals every annually year. Epidemiological control is considered to be of basic importance, so that indicators for the definition of the areas of risk have been developed.

Expression patterns of immediate early transcription factors in human non-small cell lung cancer. The Lung Cancer Study Group

In 1995, there will be 172,000 new cases of lung cancer diagnosed and 153,000 deaths from this disease in the United States. While the pathogenesis of the disease process is poorly understood, a growing body of evidence suggests that abnormalities in cellular regulatory genes may play an important role in the induction, maintenance and/or progression of some tumor types. These genes include both growth promoting oncogenes as well as growth inhibitory or suppressor genes. Included among these genetic sequences are several cellular transcription factors. A group of these factors including c-jun, c-fos and EGR1 are members of a class of genes known as immediate early genes whose expression are inducible by a variety of stimuli including mitogenic and differentiation inducing growth factors, indicating a potential important role for these genes in normal growth processes. Since these genes are involved in early regulation of cellular growth properties and at least two (c-jun and c-fos) can act as oncogenes, we wished to determine whether their expression levels were altered in human non-small cell lung cancers (NSCLC) compared to normal lung tissue. To address this, Northern blot analyses were performed using c-fos, c-jun and EGR1 probes on RNA extracted from 101 NSCLC tumor specimens and adjacent uninvolved lung tissue. Analysis of this cohort revealed that 72% of the normal tissues demonstrate significantly greater expression of these transcription factors as compared to adjacent malignant tissue. Moreover, this expression pattern appeared to be coordinate for all three genes in the majority of cases. This differential expression pattern was confirmed at the protein level using an immunohistochemical approach with antibodies directed against the c-jun, c-fos and EGR1 gene products. Southern blot analyses demonstrated no gross alterations of these sequences at the DNA level, indicating that the observed differential expression pattern was not due to gross structural changes in the genes. These data suggest that down-regulation of these genes may be involved in the pathogenesis of lung cancer.

Antisomatostatin-induced growth acceleration in chinook salmon (Oncorhynchus tshawytscha)

Since somatostatin (SRIF) inhibits the release of growth hormone (GH), its immunoneutralization may provide an alternative to GH therapy as a means of enhancing somatic growth in fish. The present study examined the feasibility of accelerating growth in juvenile chinook salmon by means of antiSRIF administration. Yearling salmon of Nicola River stock (BC, Canada) were injected intraperitoneally every 5 days, for a total of 40 days, with either SRIF (1 μg g-1 body wt.), antiSRIF (SOMA-10, 1 μg g(-1)), recombinant bovine GH (rbGH, 2.5 μg g(-1)), recombinant porcine GH (rpGH, 2.5 μg g(-1)) or saline (controls). No significant differences were observed in length, weight or final condition factor (k) between the SRIF-treated and control fish over the experimental period. However, the fish treated with the antiSRIF were significantly (p ≤ 0.05) longer and heavier than the control salmon after 25 and 30 days respectively. Furthermore, antiSRIF treatment caused a lowering in k when compared to the control salmon. Fish injected with rbGH or rpGH were significantly longer and heavier than all other groups (p ≤ 0.05), after only 5 days. GH treated groups also returned higher k when compared against all other treatments (p ≤ 0.05). No differences were observed in growth between the two rGH treatments over the experimental period.

Growth enhancement following dietary delivery of recombinant porcine somatotropin to diploid and triploid coho salmon (Oncorhynchus kisutch)

Diploid (2n) and triploid (3n) coho salmon were fed upon control (diet 1), recombinant porcine somatotropin (rpST)-supplemented (diet 2; 20 μg rpST/g body wt/day) or rpST/antacid/detergent-containing feed (diet 3; 20, 100 & 20 μg/g body wt/day respectively) for 16 wk. Fish were weighed and measured bimonthly and their relative performances assessed. By wk 4, 2n and 3n groups fed upon diet 2 were significantly heavier and longer than control 2n fish. At the termination of the trial, diet 3 fed animals were greater in weight than all other treatment groups. Diet 3 salmon also returned better feed conversion efficiencies than either diet 1 or 2 groups. RpST therapy induced a 28.7% and 60.2% increase in group wt for 3n diet 2/3 coho versus (-vs-) controls. Likewise, 2n rpST-treated fish increased wt -vs-2n control coho by 17% and 50% respectively over the same period. No differences were recorded between groups for body moisture, but diet 2, 3n and both diet 3 groups exhibited decreased condition factors when compared to control fish (p ≤ 0.05).

Effects of recombinant canine granulocyte colony-stimulating factor on white blood cell production in clinically normal and neutropenic dogs

Recombinant canine granulocyte colony-stimulating factor (rcG-CSF) was administered to clinically normal dogs, cyclic-hematopoietic dogs, and dogs undergoing autologous bone marrow transplantation, to determine whether rcG-CSF could be used to stimulate WBC production and function in normal and neutropenic dogs. To the normal dogs, rcG-CSF was administered by SC injection at rates of 1 microgram/kg of body weight, q 12 h; 2 micrograms/kg, q 12 h; or 5 micrograms/kg, q 12 h. A significant dose-dependent increase in the WBC count resulted from the stimulation of bone marrow progenitor cells. The increased WBC count was characterized by mature neutrophilia and monocytosis. Neutrophil myeloperoxidase and phagocytic activity were normal in rcG-CSF-treated normal dogs, demonstrating the production of normal functional neutrophils in response to rcG-CSF treatment. Recombinant canine G-CSF prevented neutropenia and associated clinical signs but did not completely eliminate the cycling of neutrophils in cyclic-hematopoietic dogs when it was administered at rates of 1 microgram/kg, q 12 h, and 2.5 micrograms/kg, q 12 h. The time to bone marrow reconstitution was not decreased in dogs treated with rcG-CSF at a rate of 2.5 micrograms/kg, q 12 h, for 13 days following autologous bone marrow transplantation. On the basis of our findings, we suggest that treatment with rcG-CSF is an effective way to stimulate myelopoiesis in dogs, but that the dose of rcG-CSF required to stimulate WBC production will vary depending on the cause of neutropenia. Recombinant canine G-CSF should be useful in stimulating production and maintaining function of WBC for treatment of clinical diseases seen commonly in veterinary practice.

Postirradiation treatment with granulocyte colony-stimulating factor and preirradiation WR-2721 administration synergize to enhance hemopoietic reconstitution and increase survival

These studies tested whether WR-2721 could be used to protect hemopoietic stem cells, which after irradiation could be stimulated by granulocyte colony-stimulating factor (G-CSF) to proliferate and reconstitute the hemopoietic system. Female C3H/HeN mice were administered WR-2721 (4 mg/mouse, i.p.) 30 min before 60Co irradiation and G-CSF (2.5 micrograms/mouse/day, s.c.) from days 1-16 after irradiation. In survival studies, saline, G-CSF, WR-2721, and WR-2721 + G-CSF treatments resulted in LD50/30 values of 7.85 Gy, 8.30 Gy, 11.30 Gy, and 12.85 Gy, respectively. At these LD50/30 values, the dose reduction factor (DRF) of 1.64 obtained in combination-treated mice was more than additive between the DRF's of G-CSF-treated mice (1.06) and WR-2721-treated mice (1.44). Bone marrow and splenic multipotent hemopoietic stem cell (CFU-s) and granulocyte-macrophage progenitor cell (GM-CFC) recoveries were also accelerated most in mice treated with WR-2721 + G-CSF. In addition, mice treated with WR-2721 + G-CSF exhibited the most accelerated peripheral blood white cell, platelet, and red cell recoveries. These studies (a) demonstrate that therapeutically administered G-CSF accelerates hemopoietic reconstitution from WR-2721-protected stem and progenitor cells, increasing the survival-enhancing effects of WR-2721 and (b) suggest that classic radioprotectants and recombinant hemopoietic growth factors can be used in combination to reduce risks associated with myelosuppression induced by radiation or radiomimetic drugs.

Myeloid cell kinetics in mice treated with recombinant interleukin-3, granulocyte colony-stimulating factor (CSF), or granulocyte-macrophage CSF in vivo

Myeloid cell kinetics in mice treated with pure hematopoietic growth factors have been investigated using tritiated thymidine labeling and autoradiography. Mice were injected subcutaneously with 125 micrograms/kg granulocyte colony-stimulating factor (G-CSF) (in some cases 5 micrograms/kg), or 10 micrograms/kg of granulocyte-macrophage CSF (GM-CSF), or interleukin-3 (IL-3) every 12 hours for 84 hours. 3HTdR labeling was performed in vivo after 3 days of treatment. G-CSF increased the peripheral neutrophil count 14-fold and increased the proportion and proliferation rate of neutrophilic cells in the marrow, suppressing erythropoiesis at the same time. Newly produced mature cells were released into the circulation within 24 hours of labeling, compared with a normal appearance time of about 96 hours. By contrast, GM-CSF and IL-3 had little effect on either marrow cell kinetics or on the rate of release of mature cells, although GM-CSF did stimulate a 50% increase in peripheral neutrophils. Monocyte production was also increased about eightfold by G-CSF and 1.5-fold by GM-CSF, but their peak release was only slightly accelerated. While the peripheral half-lives of the neutrophilic granulocytes were normal, those of the monocytes were dramatically reduced, perhaps due to sequestration in the tissues for functional purposes. The stimulated monocyte production in the case of G-CSF required an additional five cell cycles, a level that might have repercussions on the progenitor compartments.

Impaired response of myelodysplastic marrow progenitors to stimulation with recombinant haemopoietic growth factors

The regulation of haemopoiesis in myelodysplastic syndromes (MDS) was evaluated by measuring and comparing the in vitro response of marrow progenitors from 18 MDS patients to stimulation with recombinant haemopoietic growth factors (HGFs), granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte CSF (G-CSF) and interleukin-3 (IL-3). A similar pattern of colony growth was detected with all three HGFs in most MDS patients, exhibiting subnormal growth of GM-CFU and markedly poor to absent growth of BFU-E and CFU-GEMM. A common severe impairment in the growth of all colony types with all three HGFs was observed in five patients, four of whom presented with pancytopenia. The stimulation of MDS marrow progenitors with a five-fold higher than control saturating dose of HGFs induced a significant increase in the frequency of one, two, or all three colony types in cultures of 14 patients, whereas colony numbers in control (n = 8) marrow cell cultures were not significantly changed. All four of the non-responders were pancytopenic and three exhibited markedly impaired colony growth. Supersaturating GM-CSF, G-CSF and IL-3 increased GM-CFU numbers in six, three, and three patients, respectively. The values for BFU-E were three, six, and seven and for CFU-GEMM two, one, and five. The enhancement of MDS marrow colony numbers by supersaturating HGFs which exert their effects directly or via the action of marrow accessory cells, suggests that the progenitor cell growth abnormalities in these disorders may involve a defect in the capacity of accessory and/or progenitor cells to respond to stimulation with specific haemopoietic growth regulators.

Administration of interleukin-6 stimulates multilineage hematopoiesis and accelerates recovery from radiation-induced hematopoietic depression

Hematopoietic depression and subsequent susceptibility to potentially lethal opportunistic infections are well-documented phenomena following radiotherapy. Methods to therapeutically mitigate radiation-induced myelosuppression could offer great clinical value. In vivo studies in our laboratory have demonstrated that interleukin-6 (IL-6) stimulates pluripotent hematopoietic stem cell (CFU-s), granulocyte-macrophage progenitor cell (GM-CFC), and erythroid progenitor cell (CFU-e) proliferation in normal mice. Based on these results, the ability of IL-6 to stimulate hematopoietic regeneration following radiation-induced hematopoietic injury was also evaluated. C3H/HeN female mice were exposed to 6.5 Gy 60Co radiation and subcutaneously administered either saline or IL-6 (1,000 micrograms/kg) on days 1 through 3 or 1 through 6 postexposure. On days 7, 10, 14, 17, and 22, femoral and splenic CFU-s, GM-CFC, and CFU-e contents and peripheral blood white cell, red cell, and platelet counts were determined. Compared with saline treatment, both 3-day and 6-day IL-6 treatments accelerated hematopoietic recovery; 6-day treatment produced the greater effects. For example, compared with normal control values (N), femoral and splenic CFU-s numbers in IL-6-treated mice 17 days postirradiation were 27% N and 136% N versus 2% N and 10% N in saline-treated mice. At the same time, bone marrow and splenic GM-CFC values were 58% N and 473% N versus 6% N and 196% N in saline-treated mice; bone marrow and splenic CFU-e numbers were 91% N and 250% N versus 31% N and 130% N in saline-treated mice; and peripheral blood white cell, red cell, and platelet values were 210% N, 60% N, and 24% N versus 18% N, 39% N, and 7% N in saline-treated mice. These studies demonstrate that therapeutically administered IL-6 can effectively accelerate multilineage hematopoietic recovery following radiation-induced hematopoietic injury.

Chronic neutropenia. A new canine model induced by human granulocyte colony-stimulating factor

Normal dogs were treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF) at 10 micrograms/kg/day for 30 d, which caused an initial neutrophilia, followed by a prolonged period of chronic neutropenia. A control dog treated with recombinant canine G-CSF (rcG-CSF) showed persistent neutrophilia over 3 mo. Serum from dogs during neutropenia contained an antibody to rhG-CSF, which neutralized the stimulatory effects of both rhG-CSF and rcG-CSF on dog marrow neutrophilic progenitor cell growth and on NFS-60 cell proliferation. 4 mo after discontinuation of rhG-CSF, the dogs' neutrophil counts returned to the normal range. Rechallenge with the rhG-CSF re-induced severe neutropenia in 1 wk. Neutropenia was transferred by plasma infusion from a neutropenic dog to a previously normal dog. These data suggest that human rhG-CSF immunizes normal dogs and thereby induces neutralization of endogenous canine G-CSF and neutropenia. This model system should allow more precise definition of the in vivo role of G-CSF.

Effects of recombinant granulocyte colony-stimulating factor treatment on hematopoietic cycles and cellular defects associated with canine cyclic hematopoiesis

Canine cyclic hematopoiesis (CH) is an autosomal recessive disease of gray collie dogs that is characterized by 14-day cycles of neutropenia, monocytosis, thrombocytosis, and reticulocytosis. Platelets from CH dogs have decreased dense-granule serotonin pools and decreased aggregation responses to collagen, platelet-activating factor (PAF), and thrombin. Recombinant granulocyte colony-stimulating factor (rG-CSF) was administered (5 micrograms/kg, b.i.d.) to four CH and six normal dogs to determine if G-CSF therapy corrected qualitative platelet defects in CH dogs. Neutrophil counts increase to greater than 25,000 cells/microliters within 24 h after starting treatment in all dogs. Treatment with G-CSF blocked neutropenic episodes in the CH dogs. Platelet aggregation, and serotonin content and secretion were significantly (p less than 0.05) decreased in the CH dogs both before and during recombinant human (rh) G-CSF treatment compared to normal dogs. Neutrophil myeloperoxidase, a primary granule enzyme, was significantly (p less than 0.05) decreased in CH dogs and was not corrected by rhG-CSF treatment. Administration of rG-CSF to CH dogs eliminated cell cycles but apparently did not correct cellular defects in CH dogs. Identification of primary biochemical defects in cells from CH dogs may be crucial to investigating the biochemical basis for cyclic hematopoiesis.

Survival enhancement and hemopoietic regeneration following radiation exposure: therapeutic approach using glucan and granulocyte colony-stimulating factor

C3H/HeN female mice were exposed to wholebody cobalt-60 radiation and administered soluble glucan (5 mg i.v. at 1 h following exposure), recombinant human granulocyte colony-stimulating factor (G-CSF; 2.5 micrograms/day s.c., days 3-12 following exposure), or both agents. Treatments were evaluated for their ability to enhance hemopoietic regeneration, and to increase survival after radiation-induced myelosuppression. Both glucan and G-CSF enhanced hemopoietic regeneration alone; however, greater effects were observed in mice receiving both agents. For example, on day 17 following a sublethal 6.5-Gy radiation exposure, mice treated with saline, G-CSF, glucan, or both agents, respectively, exhibited 36%, 65%, 50%, and 78% of normal bone marrow cellularity, and 84%, 175%, 152%, and 212% of normal splenic cellularity. At this same time, granulocyte-macrophage colony-forming cell (GM-CFC) values in saline, G-CSF, glucan, or combination-treated mice, respectively, were 9%, 46%, 26%, and 57% of normal bone marrow values, and 57%, 937%, 364%, and 1477% of normal splenic values. Endogenous spleen colony formation was also increased in all treatment groups, with combination-treated mice exhibiting the greatest effects. Likewise, although both glucan and G-CSF alone enhanced survival following an 8-Gy radiation exposure, greatest survival was observed in mice treated with both agents. These studies suggest that glucan, a macrophage activator, can synergize with G-CSF to further accelerate hemopoietic regeneration and increase survival following radiation-induced myelosuppression.

Hemogram changes in lactating dairy cows given human recombinant granulocyte colony stimulating factor (r-MethuG-CSF)

As a prelude to mammary gland challenge experiments, this investigation was implemented to assess the hematologic changes in lactating dairy cattle induced by two dosage regimes of human recombinant colony stimulating factor (Hr-GCSF). This study documents the capability of the human recombinant colony stimulating factor to produce hematologic changes in both a time and dose dependent manner when administered to the adult lactating bovine. A screening dose of 1 microgram/kg of Hr-GCSF administered to three study subjects produced a three- to four-fold increase in peripheral blood mature neutrophil counts (P less than 0.043) by day 12 of the trial. The priming dose treatment group of four lactating cows (3 micrograms/kg of Hr-GCSF) exhibited a three- to five-fold increase in peripheral blood mature neutrophil counts (P less than 0.05) and two- to three-fold increases in white blood cell counts by day 5 of the trial. Hematologic examinations of the control group (n = 4; no Hr-GCSF administration) did not detect significant changes in their neutrophil counts over baseline values. The milk somatic cell counts did not statistically shift over baseline values in any of the control or Hr-GCSF treatment groups. When attempting to alter the course of infectious disease processes, potential applications of colony stimulating factors provide interesting speculations about new therapeutic modalities.

A comparison of treatment of canine cyclic hematopoiesis with recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF interleukin-3, and canine G-CSF

Cyclic hematopoiesis in gray collie dogs is a stem cell disease in which abnormal regulation of cell production in the bone marrow causes cyclic fluctuations of blood cell counts. In vitro studies demonstrated that recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and granulocyte colony stimulating factor (G-CSF) all stimulated increases in colony formation by canine bone marrow progenitor cells. Based on these results, gray collie dogs were then treated with recombinant human (rh) GM-CSF, IL-3, or G-CSF subcutaneously to test the hypothesis that pharmacologic doses of one of these hematopoietic growth factors could alter cyclic production of cells. When recombinant canine G-CSF became available, it was tested over a range of doses. In vivo rhIL-3 had no effect on the recurrent neutropenia but was associated with eosinophilia, rhGM-CSF caused neutrophilia and eosinophilia but cycling of hematopoiesis persisted. However, rhG-CSF caused neutrophilia, prevented the recurrent neutropenia and, in the two animals not developing antibodies to rhG-CSF, obliterated periodic fluctuation of monocyte, eosinophil, reticulocyte, and platelet counts. Recombinant canine G-CSF increased the nadir neutrophil counts and amplitude of fluctuations at low doses (1 micrograms/kg/d) and eliminated all cycling of cell counts at high doses (5 and 10 micrograms/kg/d). These data suggest significant differences in the actions of these growth factors and imply a critical role for G-CSF in the homeostatic regulation of hematopoiesis.

Recombinant human granulocyte colony-stimulating factor accelerates hematopoietic recovery after DLA-identical littermate marrow transplants in dogs

We studied whether treatment of dogs with recombinant human granulocyte colony-stimulating factor (rhG-CSF), after 920 cGy total body irradiation (TBI) and transplantation of 3.3 +/- 1.0 x 10(8) bone marrow cells per kilogram from a DLA-identical littermate, accelerated hematopoietic recovery and influenced the incidence of subsequent marrow graft failure or graft-versus-host disease (GVHD). Ten animals were treated with 100 micrograms rhG-CSF/kg/d from days 1 through 10 after TBI. Results were compared with those of historical control of 14 dogs not administered rhG-CSF. Neither group of dogs received GVHD prophylaxis. The median time to recovery of 1,000 neutrophils/mm3 was 8 days for dogs administered rhG-CSF compared with 14 days in controls (logrank test: P less than .03). The median time to reach 100 monocytes/mm3 was 17 days in G-CSF-treated dogs compared with 49 days in controls (P less than .002). The median time to attain 500 lymphocytes/mm3 was 15 days versus 31 days, respectively (P less than .01). The median time to reach 20,000 platelets/mm3 was 26 versus 20 days (P = .68). Graft failure occurred in 1 of 10 G-CSF-treated dogs versus 2 of 14 controls (two-tailed Fisher's exact test: P = 1.00). GVHD was seen in 4 of 9 rhG-CSF-treated dogs compared with 1 of 12 controls (P = .12). Two G-CSF-treated dogs died of GVHD versus none of the controls (P = .17). No unusual toxicities were seen in dogs receiving rhG-CSF. In summary, rhG-CSF significantly accelerated recovery of neutrophils, monocytes, and lymphocytes after DLA-identical littermate marrow transplantation without altering platelet recovery. Graft failure was not seen more often than in controls, but there was a trend toward an increased incidence of GVHD.

Therapeutic use of recombinant human G-CSF (rhG-CSF) in a canine model of sublethal and lethal whole-body irradiation

The short biologic half-life of the peripheral neutrophil (PMN) requires an active granulopoietic response to replenish functional PMNs and to maintain a competent host defence in irradiated animals. Recombinant human G-CSF (rhG-CSF) was studied for its ability to modulate haemopoiesis in normal dogs as well as to decrease therapeutically the severity and duration of neutropenia in sublethally and lethally irradiated dogs. For the normal dog, subcutaneous administration of rhG-CSF induced neutrophilia within hours after the first injection; total PMNs continued to increase (with plateau phases) to mean peak values of 1000 per cent of baseline at the end of the treatment period (12-14 days). Bone-marrow-derived granulocyte-macrophage colony-forming cells (GM-CFC) increased significantly during treatment. For a sublethal 200 cGy dose, treatment with rhG-CSF for 14 consecutive days decreased the severity and shortened the duration of neutropenia and thrombocytopenia. The radiation-induced lethality of 60 per cent after a dose of 350 cGy was associated with marrow-derived GM-CFC survival of 1 per cent. Treatment with rhG-CSF markedly reduced the lethality associated with exposure to 350 cGy of radiation to zero. White blood cell (WBC) and platelet recovery kinetics were correlated with degree of marrow damage. The rhG-CSF reduced the severity and duration of neutropenia. Control animals required antibiotic therapy (WBC less than 1000 mm3) for a total of 16 days versus 3 days for rhG-CSF-treated dogs. The duration of thrombocytopenia was reduced, although the severity of depletion was unchanged with treatment. These data indicate that in the lethally irradiated dog, effective cytokine therapy with rhG-CSF will increase survival through the induction of earlier recovery of neutrophils and platelets.

Therapeutic administration of recombinant human granulocyte colony-stimulating factor accelerates hemopoietic regeneration and enhances survival in a murine model of radiation-induced myelosuppression

The primary cause of death after radiation exposure is infection resulting from myelosuppression. Because granulocytes play a critical role in host defense against infection and because granulocyte proliferation and differentiation are enhanced by granulocyte colony-stimulating factor (G-CSF), this agent was evaluated for the ability to accelerate hemopoietic regeneration and to enhance survival in irradiated mice. C3H/HeN mice were irradiated and G-CSF (2.5 micrograms/day, s.c.) or saline was administered on days 3-12, 1-12 or 0-12 post-irradiation. Bone marrow, splenic and peripheral blood cellularity, and bone marrow and splenic granulocyte-macrophage progenitor cell recoveries were evaluated in mice exposed to 6.5 Gy. Mice exposed to 8 Gy were evaluated for multipotent hemopoietic stem cell recovery (using endogenous spleen colony-forming units) and enhanced survival. Results demonstrated that therapeutic G-CSF 1) accelerates hemopoietic regeneration after radiation-induced myelosuppression, 2) enhances survival after potentially lethal irradiation and 3) is most effective when initiated 1 h following exposure.

Recombinant human granulocyte colony-stimulating factor hastens granulocyte recovery after high-dose chemotherapy and autologous bone marrow transplantation in Hodgkin's disease

To determine whether recombinant human granulocyte colony-stimulating factor (rhG-CSF) can accelerate granulocyte recovery after high-dose combination chemotherapy with autologous bone marrow transplantation (ABMT) in patients with Hodgkin's disease, we performed a nonrandomized phase II study using historical controls as a comparison. Eighteen relapsed/refractory Hodgkin's disease patients who received cyclophosphamide at 1.5 g/m2/day (days -6 to -3), carmustine (BCNU) at 300 mg/m2 (day -6), and etoposide (VP-16) at 125 mg/m2 every 12 hours (days -6 to -4), followed by ABMT (day 0) were treated with rhG-CSF at 60 micrograms/kg/day for a maximum of 28 days beginning on day 1. rhG-CSF dosage was gradually diminished and stopped once an adequate granulocyte count was maintained. rhG-CSF significantly accelerated absolute granulocyte count (AGC) compared with historical controls recovery to the 100/microL level (median, 9 days v 13 days; P = .103 x 10(-4), 500/microL level (median, 13 days v 22 days; P = 0.189 x 10(-2), and 1000/microL level (median, 16 days v 30 days levels; P = .125 x 10(-5). Platelet recovery to 50,000/microL was not significantly altered (P = .370). rhG-CSF was well tolerated, bone pain and myalgia being the only side effects noted. rhG-CSF hastens granulocyte recovery after high-dose chemotherapy with ABMT in patients with relapsed/refractory Hodgkin's disease without significant toxicity.

Hematologic effects of recombinant human granulocyte colony-stimulating factor in patients with malignancy

The effect of recombinant human granulocyte colony-stimulating factor (G-CSF) on hematologic parameters was evaluated in a phase I clinical study in 18 patients with advanced malignancy. G-CSF was administered once daily as a 30-minute infusion for 14 days; three patients each were treated at increasing dose levels of 1, 3, 10, 30, and 60 micrograms kg-1 day-1. A transient decrease in neutrophil and monocyte counts was observed immediately after the G-CSF infusion, followed by a dose-dependent increase of up to 15-fold. G-CSF-induced neutrophils exhibited an increased O2- radical production, and serum levels of enzymes related to granulocyte turnover, including lysozyme and elastase, were markedly elevated during therapy. A dose-dependent depression of platelet counts occurred in the second third of the treatment course, followed by a spontaneous recovery despite continuing therapy. G-CSF was well-tolerated; minor to moderate bone pain was the most common side effect. The primary course of the malignant diseases studied was not significantly altered. G-CSF appears to be an appropriate means to selectively increase the number of functionally competent polymorphonuclear phagocytes.

Effect of recombinant human granulocyte colony-stimulating factor on hematopoiesis of normal dogs and on hematopoietic recovery after otherwise lethal total body irradiation

This study was designed to test whether recombinant human G-CSF (rh G-CSF) affects hematopoiesis in normal dogs and, if so, to test the effects of G-CSF in dogs given otherwise lethal total body irradiation (TBI). Rh G-CSF given subcutaneously at 10 or 100 micrograms/kg/d for 14 days to two normal dogs increased peripheral blood neutrophils eight to tenfold and monocytes four to sixfold above controls. Lymphocyte counts remained unchanged at the lower dose and increased threefold at the higher dose of rh G-CSF. No significant changes were observed in eosinophil, platelet, reticulocyte, or hematocrit levels. After 2 weeks of treatment with rh G-CSF, bone marrow displayed myeloid hyperplasia and left-shifted granulocytopoiesis. After discontinuation of rh G-CSF, peripheral leukocyte counts returned to control levels within three days. Five dogs administered 400 cGy TBI at 10 cGy/min from two opposing 60Co sources and no marrow infusion or growth factor, all developed profound pancytopenia and died between 17 and 23 days after TBI with infections secondary to marrow aplasia. Four of five dogs treated within two hours after 400 cGy TBI with 100 micrograms rh G-CSF/kg/d subcutaneously twice a day for 21 days showed complete and sustained endogenous hematopoietic recovery. In contrast, five dogs irradiated with 400 cGy TBI and treated with 100 micrograms rh G-CSF/kg/d starting on day 7 after TBI, all died between days 17 and 20 after TBI with infections secondary to marrow aplasia. Rh G-CSF, if administered shortly after irradiation, can reverse the otherwise lethal myelosuppressive effect of radiation exposure.

Treatment of myelodysplastic syndromes with recombinant human granulocyte colony-stimulating factor. A phase I-II trial

STUDY OBJECTIVE

To determine the hematopoietic effects and toxicity of recombinant human granulocyte colony-stimulating factor (G-CSF) in patients with myelodysplastic syndromes.

DESIGN

The G-CSF was administered by daily subcutaneous injection to outpatients in a phase I-II trial. Dose was escalated every 2 weeks between 0.1 to 3.0 micrograms/kg body weight.d over an 8-week treatment period.

SETTING

Outpatient clinical research center at a university hospital.

PATIENTS

Twelve consecutive patients with myelodysplastic syndromes: two refractory anemia, seven refractory anemia with excess of blasts, three refractory anemia with excess of blasts in transformation.

MEASUREMENTS AND MAIN RESULTS

In 10 of 12 patients, elevations in blood leukocyte counts (2- to 10-fold) and absolute neutrophil counts (5- to 40-fold) were seen over the 8-week treatment period. Five of seven severely neutropenic patients (absolute neutrophil count, less than 0.5 x 10(9)/L) had a rise in count to 1.2 to 16.3 x 10(9)/L. Increased reticulocyte counts occurred in 5 patients, and were associated with decreased transfusion requirements in 2 of 9 erythrocyte transfusion-dependent patients. Treatment with G-CSF enhanced marrow myeloid cell maturation in 9 of 11 evaluable patients. Neutrophil chemotaxis and phagocytosis in vitro were improved or unchanged after treatment in 6 of 8 patients tested. In 11 of 12 patients, there were no substantial changes in platelet, lymphocyte, eosinophil, or monocyte counts. Three responding patients initially had abnormal cytogenetics that persisted after G-CSF therapy, suggesting induced differentiation of the abnormal clone. The therapy was associated with minimal toxicity. None of the patients' conditions converted to acute leukemia during treatment or in short-term follow-up.

CONCLUSIONS

Treatment with G-CSF administered by subcutaneous injection is well tolerated and effective for improving the neutropenia, and less commonly the transfusion-dependent anemia, over 6 to 8 weeks in patients with myelodysplastic syndromes.

Treatment of cyclic neutropenia with granulocyte colony-stimulating factor

Six patients with cyclic neutropenia were treated with recombinant human granulocyte colony-stimulating factor (G-CSF) for 3 to 15 months. All had a history of recurrent aphthous stomatitis, pharyngitis, lymphadenopathy, fever, and numerous infections during periods of neutropenia. Serial blood-cell counts, findings on bone marrow examination, and signs and symptoms were evaluated before and during the daily administration of G-CSF (3 to 10 micrograms per kilogram of body weight per day), either intravenously or subcutaneously. The kinetics of labeled autologous blood neutrophils and the migration of neutrophils to skin chambers were also measured. Recombinant human G-CSF increased the mean (+/- SEM) neutrophil counts from 717 +/- 171 per microliter to 9814 +/- 2198 per microliter (P = 0.009). In five of the six patients, the cycling of blood-cell counts continued, but the length of the period decreased from 21 to 14 days. The number of days of severe neutropenia was reduced (P = 0.002). Neutrophil turnover increased almost four-fold (P = 0.005), whereas neutrophil migration to a skin chamber was normal. G-CSF therapy reduced the frequency of oropharyngeal inflammation, fever, and infections in these patients. During the first 40 months of treatment, no typical mouth ulcers or bacterial infections occurred; recurrent gingivitis improved. We conclude that G-CSF is effective for the treatment of cyclic neutropenia in humans.

Stimulation of human hematopoietic progenitor cell proliferation and differentiation by recombinant human interleukin 3. Comparison and interactions with recombinant human granulocyte-macrophage and granulocyte colony-stimulating factors

Recombinant human interleukin 3 (IL3) produced in Escherichia coli was purified and its activities examined in cultures of highly enriched human bone marrow progenitor cells. Human IL3 stimulated multipotential (CFU-GEMM) and erythroid (BFU-E) progenitor cells, generating 95% more BFU-E than recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF). No further enhancement of BFU-E or CFU-GEMM occurred when IL3 and GM-CSF were used in combination. Human IL3 was more effective than GM-CSF in stimulating granulocyte-macrophage colony-forming cells (CFU-GM) in short-term suspension cultures, but did not induce an increase of CFU-GM, BFU-E, or CFU-GEMM above input levels. IL3 was more active on day-14 (d14) than on d7 CFU-GM, similar to GM-CSF, but generated fewer and smaller CFU-GM-derived clones than either GM-CSF or granulocyte CSF (CI-CSF). The simultaneous addition of plateau levels of IL3 and GM-CSF resulted in an infra-additive augmentation of d7 and d14 CFU-GM-derived clones, whereas IL3 and G-CSF enhanced the number and cellularity predominantly of d14 CFU-GM. In liquid cultures, IL3 induced a greater than 100-fold increase in the number of basophil-mast-like cells and eosinophils and allowed maintenance of these cultures for up to 7 weeks. Human GM-CSF was an almost equally potent, stimulus of eosinophil development but had only a marginal effect on basophilic precursors, whereas G-CSF lacked both activities. Therefore, human IL3 is a multilineage hemopoietic growth factor whose activities appear to encompass and extend beyond those of GM-CSF.

Disulfide and secondary structures of recombinant human granulocyte colony stimulating factor

Molecular characteristics and secondary structures of recombinant methionyl human granulocyte colony stimulating factor produced by genetically engineered Escherichia coli are described. Limited radiolabeling of the protein with tritiated iodoacetate and determination of the labeled residue revealed that this recombinant protein contains only one free cysteine at position 17 which is not essential for activity. The free cysteine is inaccessible to modification unless the molecule is unfolded under denaturing conditions. The molecule forms two disulfide bridges which were assigned as Cys(36)-Cys(42) and Cys(64)-Cys(74) based on the results of isolation and characterization of disulfide-containing peptides obtained from a subtilisin digest of the intact protein. CD analyses and secondary structure prediction suggest that the molecule is abundant in alpha-helical structures.

Correction of canine cyclic hematopoiesis with recombinant human granulocyte colony-stimulating factor

Canine cyclic hematopoiesis (CH) is an autosomal recessive disease of gray collie dogs that is characterized by neutropenic episodes at 14-day intervals. The biochemical basis for CH is not known but may involve a regulatory defect of the response to or production of a hematopoietic growth factor. Administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) to two CH and one normal dog caused a marked leukocytosis (greater than 50,000 WBCs) in all three dogs. The leukocytosis was due largely to a greater than tenfold increase in neutrophils. Less pronounced but significant elevations in monocytes occurred during G-CSF treatment. The elevated WBC count was maintained for more than 20 days in all three dogs, and two predicted neutropenic episodes were prevented in both CH dogs during rhG-CSF treatment. A decline in the WBC count occurred simultaneously in all three dogs during the last five treatment days and was presumably associated with the development of neutralizing antibodies to the heterologous rhG-CSF protein. Bone marrow evaluation indicated that the swings in the myeloid/erythroid progenitor cells that are characteristic of CH were eliminated by rhG-CSF treatment in both CH dogs. These results suggest that the regulatory defect in canine CH can be temporarily alleviated by treatment with rhG-CSF and point to the potential treatment of human cyclic neutropenia with this agent.

Synergistic effect of dolichyl phosphate and human recombinant granulocyte colony-stimulating factor on recovery from neutropenia in mice treated with anti-cancer drugs

Severe hematopoietic injury in mice was induced by using either 5-fluorouracil, adriamycin, mitomycin C, or vinblastine. Daily subcutaneous administration of purified human recombinant granulocyte colony-stimulating factor (rG-CSF; 0.3-10.0 micrograms/day) markedly accelerated recovery from the drug-induced granulocytopenia in a dose-dependent manner, as reported previously. On the other hand, daily intraperitoneal administration of dolichyl phosphate (Dol-P) also enhanced granulopoiesis to accelerate recovery from granulocytopenia, although the effect of Dol-P was relatively moderate as compared with that of rG-CSF. A synergistic recovery of granulopoiesis was observed when Dol-P was administered together with rG-CSF to the mice treated with anti-cancer drugs. Joint use of Dol-P (1 mg/day) and rG-CSF (0.3 micrograms/day) was as effective as a higher dose of rG-CSF (3 micrograms/day). Joint use of Dol-P (1 mg/day) and rG-CSF (3 micrograms/day) was sometimes more effective.

Clinical studies with granulocyte colony stimulating factor (G-CSF) in patients receiving cytotoxic chemotherapy

Bacterially synthesised human granulocyte colony-stimulating factor (G-CSF) was administered to patients with advanced cancer. The immediate effect of G-CSF was a fall in the level of circulating neutrophils followed by a rise after 4 hours that was sustained during G-CSF administration. The rise in neutrophil level was less in patients who had been treated previously with chemotherapy and/or radiotherapy. G-CSF was also administered to patients following melphalan and this resulted in a reduction in the duration of the neutropenia that invariably follows melphalan. G-CSF was well tolerated and did not have to be stopped in any patient.

Recombinant human granulocyte-colony stimulating factor: in vivo effects on myelopoiesis in primates

G-CSF belongs to a family of hematopoietic growth factors, also known as colony stimulating factors. It supports the growth and differentiation of predominantly committed neutrophil precursors and activates the function of peripheral blood neutrophils in vitro. In vivo studies in primates (Cynomolgus monkeys) demonstrated that G-CSF is a potent myeloid growth and differentiation factor causing a dose-dependent increase predominantly in the peripheral blood neutrophils. To assess the effects of G-CSF in chemotherapy induced cytopenias, we administered G-CSF to monkeys that had been treated with cyclophosphamide (60 mg/kg/dx2), or repeated cycles of busulfan (4, 6 or 10 mg/kg/dx3). In both, cyclophosphamide and busulfan induced myelosuppression, G-CSF in doses between 10 and 30 micrograms/kg/d was able to significantly shorten the time of neutropenia. In addition, monkeys were treated with G-CSF (50 or 100 micrograms/kg/d) for one month post autologous bone marrow transplantation following total body irradiation. The time of neutropenia (less than 1,000 neutrophils/mm3) was shorter in the G-CSF treated monkeys (10 days in the 100 micrograms/kg/d treated monkey) compared to two controls (21 days). The post transplant absolute neutrophil count of approximately 30,000/mm3 could be maintained for the entire period of G-CSF exposure.

Phase I/II study of recombinant human granulocyte colony-stimulating factor in patients receiving intensive chemotherapy for small cell lung cancer

Twelve patients with advanced small cell carcinoma of the bronchus were treated by continuous infusion of recombinant human granulocyte colony-stimulating factor (rh G-CSF) at the following dose levels: 1 microgram, 5 micrograms, 10 micrograms, 20 micrograms and 40 micrograms/kg/day for 5 days. No toxicities resulted from the treatment and in all 12 patients the number of peripheral neutrophils increased rapidly to a maximum of 100 x 10(9)/l in one patient at 10 micrograms/kg/day. The neutrophils were shown to be functionally normal in tests of their mobility and bactericidal activity. During the Phase II part of the patients were treated using a combination of i.v. Adriamycin, Ifosfamide and Etoposide. The chemotherapy was repeated every 3 weeks. rh G-CSF was given to each patient for 14 days on alternate cycles of chemotherapy and reduced the period of absolute neutropenia considerably (median of 80%), with a return to normal, or above normal, neutrophil counts within 2 weeks after day 1 of chemotherapy. Ten severe infective episodes were observed during the 20 cycles of chemotherapy which did not include rh G-CSF, while only one infective episode occurred in 20 courses when treated with rh G-CSF. These results demonstrate the utility of rh G-CSF in restoring functional neutrophils to patients undergoing intensive chemotherapy.

In vitro and in vivo analysis of the effects of recombinant human granulocyte colony-stimulating factor in patients

Twelve patients with small cell lung cancer were treated with recombinant human granulocyte colony-stimulating factor, rhG-CSF, given by continuous infusion at doses ranging from 1 to 40 micrograms kg-1 day-1. Patients received the rhG-CSF before the start of intensive chemotherapy and after alternate cycles of chemotherapy. Several in vitro assays were performed using peripheral blood neutrophils and marrow progenitor cells collected from patients prior to and after infusion of the growth factor. Peripheral blood neutrophils were tested for mobility and phagocytic activity. In addition, in vitro clonogenic assays of marrow haemopoietic progenitor cells and analysis of bone marrow trephines and aspirates were carried out. We found that rhG-CSF in vivo has at least two main effects: (a) an early fall in peripheral neutrophils, within the first hour, followed by a rapid influx of mature neutrophils into the circulatory pool; (b) stimulation of proliferation and differentiation of neutrophil precursors in the bone marrow. Neutrophils released into the circulation were normal in tests of their mobility and phagocytic activity.

Granulocyte colony-stimulating factor enhances interleukin 3-dependent proliferation of multipotential hemopoietic progenitors

In cultures of spleen cells from normal mice, recombinant human granulocyte colony-stimulating factor (G-CSF) supported the formation of multipotential blast cell colonies. Serial replating of the blast cell colonies in the presence of G-CSF, however, failed to demonstrate any direct effect of G-CSF on murine multipotential progenitors. We therefore examined the effects of G-CSF in combination with murine interleukin 3 on proliferation of murine blast cell colony-forming cells. The time course of total colony formation and multilineage colony formation by spleen cells harvested from mice 4 days after injection of 5-fluorouracil at 150 mg/kg was significantly shortened in cultures containing both factors in contrast with cultures supported by either factor alone. Serial observations of individual multipotential blast cell colonies (mapping) revealed that blast cell colonies emerged at random time intervals in the presence of interleukin 3 or G-CSF. The appearance of blast cell colonies, however, was significantly hastened in cultures containing both factors relative to cultures grown with either factor. In cultures of day-2 post-5-fluorouracil bone marrow cells, G-CSF in concentrations as low as 1 unit/ml revealed synergism with interleukin 3 in supporting the proliferation of multipotential progenitors. This synergistic activity may explain the previous in vivo studies suggesting the effects of G-CSF on apparent multipotential stem cells.