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Home blood pressure in poorly controlled hypertension: relationship with ambulatory blood pressure and organ damage.

OBJECTIVES: (1) To assess whether home blood pressure measurement is a reliable alternative to ambulatory blood pressure monitoring for the evaluation of treated patients with inadequate blood pressure control at the clinic; and (2) to evaluate the relationship between home blood pressure and several target-organ damage markers. BASIC METHODS: A cross-sectional study was performed in 225 treated hypertensive patients with persistently high blood pressure values at the clinic (systolic blood pressure 140 mmHg and/or diastolic blood pressure 90 mmHg). All study participants underwent clinic blood pressure measurement, 24-h ambulatory blood pressure and home blood pressure monitoring. A subgroup of patients underwent the following procedures: carotid echography (n=74), microalbuminuria determination (n=88) and echocardiography (n=43). We defined out-of-clinic normotension as an average ambulatory or home blood pressure less than 135 mmHg (systolic) and 85 mmHg (diastolic). MAIN RESULTS: The sensitivity, specificity and positive and negative predictive values of the home blood pressure method for predicting out-of-clinic normotension (with the ambulatory method used as reference), expressed as percentages, were 50, 87, 64 and 79%, respectively. Systolic home blood pressure correlated significantly with left ventricular mass (r=0.33, P<0.05) and microalbuminuria (r=0.24, P<0.05). Similar correlation coefficients were found for systolic ambulatory blood pressure (r=0.32, P<0.05 and r=0.24, P<0.05, respectively). Clinic blood pressure did not correlate with either left ventricular mass or microalbuminuria (r=0.19, P=0.09 and r=0.19, P=0.24, respectively). Diastolic home blood pressure, but not ambulatory blood pressure, correlated negatively with mean carotid intima-media thickness (r=-0.27, P<0.05). CONCLUSION: Our results suggest that, in patients with poorly controlled hypertension at the clinic, home blood pressure represents a complementary test rather than an alternative to ambulatory blood pressure, and correlates with several target-organ damage markers.

Aged↗

Ultrasound backscatter at 30 MHz from human blood: influence of rouleau size affected by blood modification and shear rate.

High frequency intravascular ultrasound may show a high intensity backscatter from blood which hampers the discrimination between lumen and arterial wall. In this study, the acoustic behaviour of blood at 30 MHz in relation to rouleau size was analyzed. In a Couette viscometer, high frequency (20-40 MHz) backscatter data from normal and modified blood samples from eight volunteers were obtained at shear rates from 0 to 1000 s-1. The acoustic behaviour of blood was quantified by the integrated backscatter power and the spectral slope of the backscatter coefficient. Backscatter from blood depended on rouleau size. At a shear rate of zero, both whole blood and rouleau-enhanced blood showed a 11-dB-higher integrated backscatter power than rouleau-suppressed blood, which itself was 10 dB higher than that of hemolysed blood, the latter showing a 6-dB-higher backscatter than saline. Platelets did not contribute to the backscatter power. Plasma and saline produced no detectable integrated backscatter power other than noise. The spectral slope of whole and rouleau-enhanced blood was small (1 and 0.5, respectively), whereas rouleau-suppressed blood and hemolysed blood (both with a slope of 3.3) behaved almost like a Rayleigh scattering medium (slope = 4). The backscatter from rouleau-suppressed blood showed no shear rate dependence. At low shear rates ( < 0.8 s-1 for integrated backscatter power and < 0.2 s-1 for the spectral slope), whole blood and rouleau-enhanced blood tended to the results from the static situation (no shear). At high shear rates ( > 80 s-1 for integrated backscatter power and >11 s-1 for spectral slope), these samples tended to the results of rouleau-suppressed blood. Ultrasound backscatter at 30 MHz from human blood is only caused by red blood cells. With increasing aggregate (rouleau) size, the integrated backscatter power increased by 11 dB, and the spectral slope decreased from 3.3 to 1.

Blood↗

[Blood transfusion safety in a limited resources setting: the elaboration of a rational National Blood Policy in Togo].

The demand for blood transfusion is high in subSaharan Africa because of the high prevalence of the anemia especially due to malaria and obstetrical damage. Providing a safe and confident system of transfusion requires more and more resources when, in developing countries, these are in fact limited. With a double view to improve the coverage in blood transfusion and ensure the security of blood products, the Ministry of Health of Togo launched in 1999 a series of operations for setting up a rational National Blood Transfusion Policy. The following steps were undertaken. A two-week situation analysis of the blood transfusion sector highlighted the lack of sector regulation, the multiplicity of blood unit production centres (n = 33 for a country of 56,000 km(2)) that could endanger the security of the products especially in limited resources conditions, the inadequacy in quality management in all areas of blood transfusion (insufficiency of human resources, equipment and supply, lack of procedures, etc.) and the lack of an information system on blood transfusion for retrospective survey and planning. The draft of the National Blood Transfusion Policy was then written in a week by two national consultants in accordance with the findings of the situation analysis. It was validated during a three-day multidisciplinary workshop and an ultimate validation was made by an international consultant in order to assess the adequacy of the options considered to the country's specific setting. The options retained for developing the Togolese blood transfusion sector development and which are consigned in the National Blood Transfusion Policy are as follows: development and implementation of blood transfusion regulations; reorganisation of the National Transfusion System by reducing it to 3 blood unit production centres: one in Lomé (the capital town), one in the centre of the country (Sokodé, 480 km from Lomé), and one in the Northern part (Dapaong, 870 km from Lomé); setting up of a system of blood collection, storage and distribution around these centres; promotion of voluntary and anonymous blood donation; promotion of quality assurance in the system and of good blood prescription practice; development and implementation of an appropriate and simple information system for better management; identification of a sustainable and equitable financing system in which the State must play a key role. The implementation of the National Blood Policy; and in particular the achievement of its goals requires: i) permanent State commitment; ii) the building of a rational action plan - with a financing framework for all blood transfusion partners; and iii) regular program evaluation.

Anemia↗

Relation of blood-free to blood-inclusive postmortem lung water measurements in sheep.

Our purpose was to see if the postmortem weight ratio of extravascular lung water to blood-free dry lung (blood-free ratio) was related to similar ratios in blood-inclusive lung and in blood. We developed linear regressions of blood-free ratio on ratios for blood-inclusive lung and blood together and for blood-inclusive lung alone for 73 sheep studied under 11 different protocols and for two subgroups of sheep, one with plasma space expansion and the other without expansion. The relation of ratios of blood-free to blood-inclusive lungs was different between the two subgroups. Although all regressions were highly correlated, the fits of the blood-free ratio on ratios for blood-inclusive lung and blood together were better than for blood-inclusive lung alone. The mean error of prediction of extravascular lung water for all sheep was significantly less for the regression of blood-free ratio on ratios for blood and blood-inclusive lung together (11 g) than for blood-inclusive lung alone (18 g). This study shows that weights of lung homogenate and blood samples before and after simple oven drying can be used to provide accurate inexpensive estimates of postmortem extravascular lung water.

Animals↗

Office blood pressure measurements overestimate blood pressure control in renal transplant patients.

OBJECTIVE: As hypertension is an important risk factor for renal allograft failure, we aimed to assess blood pressure control in renal transplant patients with deteriorating graft function using different methods of blood pressure measurements. METHODS: Forty-nine patients with a graft survival of >1 year, and with more than a two-fold increase in urinary albumin excretion, and/or an increase in serum creatinine level >20% during the previous 12 months, were included. Office blood pressure and home BP were measured, and ambulatory blood pressures were obtained in all patients. RESULTS: The mean office blood pressure (133.2+/-16.3/81.7+/-9.6 mmHg) and 24 h ambulatory blood pressure (133.1+/-12.0/79.8+/-8.3 mmHg) were similar. Home blood pressure in the morning (144.2+/-23.3/87.1+/-12.7 mmHg) and evening (143.2+/-20.6/86.4+/-10.3 mmHg) were significantly higher than ambulatory blood pressure (P<0.001 for both). Only 18% of the patients exhibited a reduction of >or=10% in systolic blood pressure during nighttime while 39% had an overt rise. Adequate blood pressure control was found in 53% of the patients using office blood pressure (<140/90 mmHg), contrasting 29% using home blood pressure (<135/85 mmHg), and 16% using mean 24-h ambulatory blood pressure (<125/80 mmHg). These findings were substantiated by the use of receiver-operating characteristic curve analysis. CONCLUSIONS: Using the 24-h blood pressure as a standard, home blood pressure was superior to office blood pressure in estimating blood pressure control in renal transplant patients. Nocturnal hypertension, however, was observed frequently, adding important clinical information about blood pressure control in this high-risk population.

Adult↗

Effect of timing and number of baseline blood pressure determinations on postural blood pressure response.

We hypothesized that the blood pressure response to standing may depend on the method of establishing baseline blood pressure. Three hundred elderly subjects previously completed a postural blood pressure protocol with three supine baseline blood pressure readings obtained two minutes apart prior to standing. Comparison of the readings showed a significant drop between the first and the second (P less than .001) but not between the second and third supine systolic blood pressures. The difference between the first supine systolic blood pressure and the one minute standing blood pressure was significantly greater than that between the third supine systolic blood pressure and the one minute standing blood pressure (P less than .001). A second group was prospectively studied to determine whether the change in blood pressure after standing was greater if only a single baseline reading was taken rather than multiple readings, and whether the decline in blood pressure over three readings was related to duration supine or to the number of blood pressures taken. This group also demonstrated a decline in systolic blood pressure with three serial readings. We conclude that supine blood pressure declines significantly between the first and second readings taken two minutes apart and is secondary to the repetition of readings and not the duration supine. However, this change in supine blood pressure does not significantly alter the blood pressure response to standing. Thus, it appears that a single baseline supine blood pressure measurement is adequate for determining the postural blood pressure response, and that pooling of multiple baseline readings may not be appropriate.

Aged↗

Potential substitution of cord blood for infant blood in the neonatal sepsis evaluation.

BACKGROUND: Evaluation of sepsis accounts for one third of all nursery triage admissions. If umbilical cord blood could be accurately substituted for infant blood, it would spare infants the discomfort of an invasive procedure and save both time and resources. While awaiting 48-hour blood culture results, we decide on clinical management based on whether the white blood cell (WBC) immature to total (I:T) granulocyte ratio is >or=0.2. OBJECTIVES: Our goal was to assess the correlation of complete blood count (CBC), I:T ratio and blood culture results between umbilical cord and infant blood. METHODS: We conducted a prospective cohort study comparing CBC/differential and blood culture results of paired samples of umbilical cord and infant blood from term newborns. RESULTS: We sent 113 paired samples of cord and infant venous blood for CBC/differential and blood culture. All 113 umbilical cord and infant blood cultures were negative, yielding a false-positive blood culture rate of zero. For 92% of babies, both the cord and infant blood I:T ratio were <0.2 or both were >or=0.2. Cord and infant WBC, hematocrit and platelet counts were moderately to highly correlated. CONCLUSION: We conclude that cord blood can be safely substituted for infant blood in routine sepsis evaluations of asymptomatic, term infants based on both the low false-positive cord blood culture rate and the significant association between high I:T ratios in cord and infant blood.

Blood Cell Count↗

Comparison of spray-dried blood meal and blood cells in diets for nursery pigs.

We used a total of 680 pigs to compare spray-dried blood meal and blood cells in nursery diets. In Exp. 1, 350 barrows (17 +/- 2 d of age at weaning) were used to compare three levels of spray-dried blood meal or blood cells (2.5, 5.0, and 7.5%) in the diet fed from d 5 to 19 postweaning (6.6 to 9.9 kg). Inclusion of either blood product improved ADG (P < 0.005) and G:F (P < 0.001) compared to pigs fed the control diet without added blood products. However, pigs fed spray-dried blood meal had greater ADG (P < 0.001), ADFI (P < 0.04), and G:F (P < 0.001) from d 0 to 7 compared to those fed blood cells. The greatest differences observed between the two blood products occurred at the 5 and 7.5% inclusion levels. No differences (P > 0.05) in growth performance were detected between the two blood products from d 7 to 14. In Exp. 2, 380 barrows (initial BW of 10.7 kg and 41 +/- 2 d of age) were used to determine lysine bioavailability of spray-dried blood meal and blood cells via the slope ratio procedure. With G:F ratio as the response criterion, blood meal and blood cells had similar lysine bioavailability relative to crystalline lysine. These experiments indicate that both blood products had similar lysine bioavailability, and that pigs fed spray-dried blood meal had greater performance during the initial 7 d (d 5 to 12 after weaning). However, as the pigs became heavier, there were no differences observed in performance of pigs fed either blood meal or blood cells.

Animal Feed↗

Assessment of blood substitutes: I. Efficacy studies in anesthetized and conscious rats with loss of 1/3, 1/2 and 2/3 blood volume.

Acute and long-term recovery (14 days) studies were conducted in conscious rats bled 1/3, 1/2, and 2/3 blood volume, and in anesthetized rats bled 1/3 volume. Study I: bled 1/3 blood volume. Study Ia: Anesthetized rats bled 1/3 blood volume were in shock and most died within 1 hour; the group which received infusion of 3x volume Ringer's lactate regained blood pressure with 100% long-term recovery. Study Ib: In conscious rats bled 1/3 blood volume, blood pressure did not fall to shock levels, and the long-term recovery in both the control group and the group which received 3x volume Ringer's lactate was 100%. Study II: Bled 1/2 blood volume. In conscious rats bled 1/2 volume, the blood pressure of the control group was slightly above 70 mmHg. Infusion of 3x volume Ringer's lactate or 7 gm% human albumin in Ringer's lactate increased blood pressure to above 90 mmHg in the acute study. Long-term recovery and survival rate was 80% in both the controls and the Ringer's lactate group, and 100% in the albumin group. Study III: bled 2/3 blood volume. In conscious animals, loss of 2/3 blood volume resulted in fall of blood pressure to shock levels and death of the animal within 1 hour. Infusion of 3x volume Ringer's lactate did not increase blood pressure to above shock level. Stroma-free hemoglobin and polyhemoglobin increased blood pressure, and whole blood returned blood pressure to normal. In long-term recovery, poly-hemoglobin, but not SFHb, was as effective as whole blood with 100% long term recovery. Animal models in Study I and II are suitable only for studies of volume replacement. Animal models in Study III, especially using long-term recovery studies, are more suitable for studying both volume and red blood cells replacements.

Anesthesia, General↗

Intrapulmonary administration of natural honey solution, hyperosmolar dextrose or hypoosmolar distill water to normal individuals and to patients with type-2 diabetes mellitus or hypertension: their effects on blood glucose level, plasma insulin and C-peptide, blood pressure and peaked expiratory flow rate.

Safety and effect intrapulmonary administration (by inhalation) of 60 % honey solution, 10% dextrose or distill water on blood sugar, plasma insulin and C-peptide, blood pressure, heart rate, and peaked expiratory flow rate (PEFR) in normal or diabetic subjects were studied. - Twenty-four healthy subjects, 16 patients with type 11 diabetes mellitus and six patients with hypertension were entered for study. They were underwent complete physical examination and laboratory investigations. Twelve healthy subjects were subjected for distill water inhalation for 10 min, and after one week they received inhalation of honey solution (60% wt/v) for 10 min. Another 12 healthy subjects received inhalation of 10% dextrose for 10 min. Blood glucose level, plasma insulin and C-peptide, blood pressure, heart rate and PEFR were estimated before inhalation and during 2-3 hrs after inhalation, at 30 min intervals. Random blood glucose level was estimated in eight patients with poorly controlled diabetes mellitus, and repeated 30 min after honey inhalation. One week later, fasting blood glucose level was estimated in each patient and blood glucose level was re-estimated during three hrs after honey inhalation, at 30 min intervals. Glucose tolerance test was performed in another eight patients with type-2 diabetes mellitus, and after one week the procedure was repeated with inhalation of honey, which was started immediately after ingestion of glucose. Six hypertensive patients received honey inhalation for 10 min; supine blood pressure and heart rate were measured before and after inhalation. - Results showed that in normal subjects distill water caused mild elevation of blood glucose level, mild lowering of plasma insulin, and significant reduction of plasma C-peptide. 10% dextrose inhalation caused mild reduction of plasma insulin and C-peptide and unremarkable changes in blood glucose level. No significant changes were obtained in blood pressure, heart rate or PEFR after distill water or 10% dextrose inhalation. Honey inhalation caused lowering of blood glucose level and elevation of plasma insulin and C-peptide, mild reduction of blood pressure and up to 11 and 16 percent increase in PEFR. Honey inhalation significantly reduced random blood glucose level from 199 +/- 40.9 mg/dl to 156 +/- 52.3 mg/dl after 30 min (p = 0.0303). Fasting blood glucose level was reduced after honey inhalation during three hr post-inhalation, which was significant at hr three (p<0.05). Intensity of hyperglycemia was significantly lowered in glucose tolerance test when patients received honey inhalation. Systolic and diastolic blood pressure was reduced by honey inhalation in hypertensive patients; significant changes were obtained at 60 and 120 min after inhalation. No adverse effects were observed with inhalation of distill water, 10% dextrose and 60% honey solution except for nasal watery discharge experienced by all subjects and mild cough that was experienced by seven subjects after honey inhalation. - The results demonstrated that honey inhalation was safe and effective in reducing blood glucose level, in normal and diabetic subjects, it could improve glucose tolerance test, elevate plasma insulin and C-peptide and PEFR, and reduce elevated blood pressure in hypertensive patients.

Administration, Inhalation↗

Blood type AB in the feline AB blood group system.

OBJECTIVE: To assess the genetics, frequency, and biochemistry of the AB blood type in cats. ANIMALS: Domestic shorthair and purebred cats in a breeding colony and privately owned catteries and blood samples from a large feline blood typing laboratory. PROCEDURES: Samples from cats with blood type AB were selected from the feline blood typing laboratory at the university. Breeding experiments and family studies were used for the genetic analysis of cats with blood type AB. Simple slide hemagglutination assays were used to type cats. Hemagglutination assays, flow cytometry, and ganglioside analysis by high-performance thin layer chromatography were applied to characterize the AB antigens. RESULTS: Type AB was rare (13/9,239 cats; 0.14% frequency) in cats of the United States and Canada. Type AB occurred only in breeds in which type B was also detected. Cats with type-AB blood express biochemical features of type-A and type-B antigens. Genetic analyses of families with blood type-AB cats are consistent with the hypothesis of 3 alleles: A, B, and AB. The AB allele is recessive to the A allele, but dominant over the B allele. There may be an additional genetic mechanism responsible for the inheritance of blood type AB in cats. CONCLUSION: Blood type AE is an extremely rare and separately inherited type in the feline AB blood group system. CLINICAL RELEVANCE: Kittens with type-AB blood born to queens with type-B blood are at similar risk for neonatal isoerythrolysis as kittens with type-A blood because anti-A alloantiserum from blood type-B queens recognizes AB red blood cells. Furthermore, cats with type-AB blood are best transfused with type-AB or type-A blood.

ABO Blood-Group System↗

The effects of perioperative blood salvage and autologous blood donation on transfusion requirements in scoliosis surgery.

Fifty consecutive cases of surgical instrumentation and fusion for adolescent idiopathic scoliosis were prospectively studied to test the hypothesis that the use of predonated autologous blood combined with judicious perioperative blood salvage could decrease the amount of homologous blood needed. All cases had posterior instrumentation and fusion. Nineteen patients had their rib prominence resected with an average of 4.8 ribs per patient. Our protocol called for perioperative blood salvage with the cell saver and reinfusion of postoperative drained blood if more than 300 ml were drained in 4 hours. Two units of predonated autologous blood was made available. Hypotensive anesthesia and meticulous hemostasis kept the blood loss to a minimum. The average total blood loss was 1,055 ml. Blood loss per segment was 91 ml with an average of 11 segments fused per patient. Patients with rib resection had a blood loss of 1,105 ml, while those without had a blood loss of 955 ml. The cell saver blood returned per case was 391 ml with the hematocrit of the product averaging 46%. Twelve patients were reinfused an average of 300 ml of the postoperative drained blood. The predonated autologous blood was used as part of the intraoperative fluid management. In no patient was homologous blood needed. The average starting hematocrit was 35.6%, with the hematocrit at discharge (seventh day) being 32.4%. There were no complications or blood transfusion reactions. Our results suggest that judicious perioperative blood management may decrease the need for homologous blood transfusion in selected posterior idiopathic scoliosis surgery.

Adolescent↗

The blood-donation experience: perceived physical, psychological and social impact of blood donation on the donor.

BACKGROUND AND OBJECTIVES: This study aimed to investigate the impact and effects of blood donation on blood donors as perceived and reported by donors themselves. MATERIALS AND METHODS: A self-administered questionnaire was distributed to 600 consecutive whole-blood donors (who had a history of at least one previous donation) consisting of an open-ended question asking whether the blood donation had any impact on the donor. The answers to this question were considered as descriptions of effects perceived by the donors to be evoked by whole-blood donation. RESULTS: In all, 528 subjects completed the questionnaire (88%; 319 males and 209 females) and answered the question about the effects of blood donation. Altogether, 54% (287 out of 528) of the blood donors reported one or several effects. Exclusively positive effects were described by 29% (151) of blood donors, while exclusively negative effects and mixed effects (i.e. concomitant positive and negative effects in the same subject) were described by 19% (103) and 6% (33), respectively, while no effect was reported by 46% (241) of the donors. A majority of the effects commenced within 1 h of blood donation. The positive effects lasted significantly longer (often for weeks, P < 0.0001) than negative effects (min/h/days). Among positive effects a feeling of satisfaction, of being more alert, and feeling generally better than before the blood donation predominated for both female and male donors. Among negative effects, vertigo/dizziness was reported more frequently by female donors (P < 0.0001). Logistic regression analysis revealed that the negative effects were less likely to occur with increasing age (P < 0.001) and that they were more likely to occur in female donors (P < 0.001) in comparison to male donors, irrespective of age. CONCLUSIONS: The majority of effects elicited by blood donation on blood donors were positive (i.e. feelings of satisfaction, greater alertness, increased wellbeing, etc.). The positive effects did not differ from the negative regarding time of onset, yet their duration was reported to be significantly longer. There was no association between frequency of occurrence of positive effects and the number of blood donations, indicating that there is no 'addictive' relationship between donors and blood donations. The findings in this study of high frequency of occurrence of positive long-lasting effects elicited in blood donors by blood donation may be of great importance for the recruitment of new blood donors as it may make blood donation less frightening and perhaps even attractive.

Adult↗

Detection of upper gastrointestinal blood with fecal occult blood tests.

OBJECTIVE: Although fecal occult blood (FOB) tests have most often been used to detect occult bleeding from the lower gastrointestinal (GI) tract, their utility in detecting occult blood loss from the upper GI tract is less well understood. The aims of this study were to determine whether small amounts of blood from the upper GI tract can be detected by currently available FOB tests and, if so, to correlate FOB tests with semiquantitative GI blood. METHODS: Groups of 10 healthy volunteers without a history of GI disease drank 5, 10, or 20 ml of their own blood mixed with tomato juice for 5 or 3 consecutive days. Standard dietary and medication restrictions were observed. Consecutive stools were tested for 2 days before, as well as 4 days after, blood ingestion. Each stool was simultaneously tested for FOB with HemoQuant (HQ), Hemoccult II (HO II), Hemoccult II SENSA (SENSA), HemeSelect (HS), and FlexSure OBT (FS). RESULTS: The mean age and hemoglobin concentration of the study population were 29.3+/-0.5 yr and 14.3+/-0.3 g/dl, respectively. No subject noted GI symptoms during blood ingestion. Fecal blood levels (measured by HQ) were elevated within 2 days after initiation of blood ingestion and remained elevated until 2-3 days after cessation of blood ingestion. Mean fecal blood levels peaked at 2.1, 7.9, 8.0, and 13.5 (mg hemoglobin/g stool) in groups ingesting 5 ml/5 days, 10 ml/3 days, 10 ml/5 days, and 20 ml/3 days, respectively. The proportion of positive tests during and immediately after the period of blood ingestion was greatest in the 20 ml/3 day group; 16% of HO II samples were positive as were 64% of SENSA and 67% of HQ samples. SENSA was more sensitive than HO II in all blood ingestion groups. At least one positive SENSA test was present in 50% of subjects ingesting 10 ml of blood (each 3 and 5 day groups) and in all subjects ingesting 20 ml/day. Immunochemical tests did not detect upper GI blood in any blood ingestion group. CONCLUSION: Inasmuch as many upper GI tract lesions have been reported to bleed small quantities of blood such as that studied here, and this amount of blood is readily detected with widely used guaiac-based FOB tests including Hemoccult II SENSA, the data emphasize that caution is warranted before attributing positive guaiac tests only to sites in the lower GI tract. The data raise the possibility that a combination of a highly sensitive guaiac-based FOB test plus an immunochemical could help differentiate occult upper from lower GI bleeding.

Adult↗

In situ radiation sensitivity of recombinant human granulocyte colony-stimulating factor-recruited murine circulating blood and bone marrow progenitors (colony-forming unit [CFU]-granulocyte-macrophage and CFU-megakaryocyte): evidence for possible biologic differences between mobilized blood and bone marrow.

Increasing evidence especially stemming from peripheral blood progenitor transplantation studies points to a possible biologic difference between mobilized blood and bone marrow progenitor cells. The objective of this study was to compare the in situ radiation sensitivity of recombinant human granulocyte colony-stimulating factor (rhG-CSF)-recruited circulating granulopoietic (blood colony-forming unit-granulocyte-macrophage [CFU-GM(blood)]) and megakaryocytopoietic (blood CFU-megakaryocyte [CFU-Meg(blood)]) progenitors, with the nonmobilized fraction remaining in the bone marrow (CFU-GM(femur) and CFU-Meg(femur)). Splenectomized male B6D2F1 mice received 50 micrograms/kg/d rhG-CSF daily for 8 days to induce high levels of circulating progenitors, followed by either total body X-irradiation (TBI) or X-irradiation of the chest (CI) with 62.5, 125, 250, or 500 cGy. Progenitor cells were assayed 24 hours after irradiation. Circulating CFU-GM and CFU-Meg in the blood were decreased in a dose-dependent fashion by both TBI and CI, with TBI causing greater damage than CI. Average D0 values for TBI were 53 cGy for CFU-GM(blood) and 40 cGy for CFU-Meg(blood) D0 values for CI were 90 cGy for CFU-GM(blood) and 140 cGy for CFU-Meg(blood). As seen for blood progenitor cells, TBI caused a dose-dependent decrease of both CFU-GM(femur) (D0, 136 cGy) and CFU-Meg(femur) (D0, 148 cGy). However, radiation-induced bone marrow progenitor cell kill was significantly lower when compared with blood progenitors. Despite the fact that circulating blood elements only received a fraction of the total dose administered as Cl, the extent of blood progenitor kill caused by Cl was higher than the effects of identical TBI doses on bone marrow CFU. The results of this study showed that rhG-CSF-recruited CFU-Meg(blood) and CFU-GM(blood) were considerably more radiosensitive than femoral progenitors, thereby providing novel evidence for a biologic difference between rhG-CSF-recruited peripheral blood progenitors and the nonrecruited bone marrow CFU.

Animals↗

How good are standardized blood pressure recordings for diagnosing hypertension? A comparison between office and ambulatory blood pressure.

Ambulatory blood pressure monitoring was compared with office blood pressure in 48 normotensive, 81 borderline hypertensives and 35 untreated hypertensives. The studied groups were chosen from a geographically defined population of middle-aged men in southern Sweden. The mean 24-h ambulatory blood pressure values for the normotensives, borderline hypertensives and untreated hypertensives were 120/76, 127/82 and 140/92 mmHg, respectively. The diurnal mean ambulatory blood pressure in the three groups was 126/80, 134/86 and 146/96 mmHg, respectively. The percentage of 24-h diastolic blood pressure peaks greater than or equal to 95 mmHg in the groups were 7%, 22% and 53%, respectively. The corresponding values greater than or equal to 90 mmHg were 16%, 38% and 69%, respectively. In the untreated hypertensive group, there was a more pronounced (P less than 0.05) systolic blood pressure increase during the morning hours (0600-1000 h) than in the normotensive and borderline hypertensive groups. Fourteen per cent of the hypertensives showed normal blood pressure values during 24-h blood pressure monitoring. Fifteen per cent of the borderline hypertensives were normotensive during ambulatory blood pressure monitoring despite repeated office diastolic blood pressure greater than or equal to 90 mmHg. The opposite (increased blood pressure during ambulatory blood pressure monitoring and at screening but normal office blood pressure) was seen in 14% of the borderline hypertensives. Normotensives were characterized by lower mean blood pressure values, fewer blood pressure peaks and a lower systolic blood pressure increase during the morning hours than hypertensives in this study of middle-aged men. The established way of diagnosing hypertension, borderline hypertension and normotension correlated well with the results of ambulatory blood pressure monitoring.

Blood Pressure↗

Pressor effect of recombinant human erythropoietin: results of ambulatory blood pressure monitoring and home blood pressure measurements.

We investigated whether treatment of anemic hemodialysis patients with a low dose of recombinant human erythropoietin (erythropoietin) for a short period would increase their blood pressure. Ambulatory blood pressure monitoring and home blood pressure measurements were used to detect minute increase in blood pressure. Thirty-two patients with a hematocrit of 25% or less received erythropoietin at the dose of 4500 IU/week, by the intravenous route for 8 weeks. Erythropoietin increased the hematocrit from 20.9 +/- 2.1 to 26.2 +/- 2.1%. Erythropoietin elevated mean ambulatory blood pressure by 5 mmHg or more in two-thirds of patients (n = 20; pressor group), while it elevated home mean blood pressure by 5 mmHg or more in one-third of patients (n = 11). An increase in clinic mean blood pressure by more than 5 mmHg was observed only in one-fourth of patients (n = 7). Circadian variation of blood pressure (nocturnal fall and diurnal rise) had been attenuated in the patients of the pressor group before erythropoietin treatment and erythropoietin decreased the nocturnal fall of blood pressure further more. Erythropoietin elevated nocturnal blood pressure more than diurnal blood pressure. Therefore, the increase in blood pressure induced by erythropoietin was detected more reliably by ambulatory blood pressure monitoring. There was no relation between the change in hemoglobin concentration and the increase in ambulatory blood pressure induced by erythropoietin. Erythropoietin tended to decrease cardiac output and plasma volume while it increased total peripheral resistance. It also decreased plasma norepinephrine and vasopressin levels but did not affect other humoral factors. Although the pressor effect of erythropoietin treatment for 8 weeks at the dose of 4500 IU/week was not evident on clinic blood pressure measurements, any increase in blood pressure determined by ambulatory blood pressure should be treated carefully to reduce the risk of a cardiovascular complication in patients receiving hemodialysis.

Aldosterone↗

Polarized arrest with warm or cold adenosine/lidocaine blood cardioplegia is equivalent to hypothermic potassium blood cardioplegia.

BACKGROUND: Hypothermic depolarizing hyperkalemic (K + 20 mEq/L) blood cardioplegia is the "gold standard" in cardiac surgery. K + has been associated with deleterious consequences, eg, intracellular calcium overload. This study tested the hypothesis that elective arrest in a polarized state with adenosine (400 micromol/L via adenosine triphosphate-sensitive potassium channel opening) and the Na + channel blocker lidocaine (750 micromol/L) as the arresting agents in blood cardioplegia provides cardioprotection comparable to standard hypothermic K + -blood cardioplegia. METHODS: Anesthetized dogs were placed on cardiopulmonary bypass and assigned to 1 of 3 groups receiving antegrade cardioplegia delivered every 20 minutes for 1 hour of arrest: cold (10 degrees C) K + -blood cardioplegia (n = 6), cold (10 degrees C) adenosine/lidocaine blood cardioplegia (n = 6), or warm (37 degrees C) adenosine/lidocaine blood cardioplegia (n = 6). After an hour of arrest, cardiopulmonary bypass was discontinued, and reperfusion was continued for 120 minutes. RESULTS: Time to arrest was longer with cold and warm adenosine/lidocaine blood cardioplegia (175 +/- 19 seconds and 143 +/- 19 seconds, respectively) compared with K + -blood cardioplegia (27 +/- 2 seconds; P < .001). Postcardioplegia left ventricular systolic function (slope of the end-systolic pressure/dimension relationship) was comparable among the 3 groups (K + -blood cardioplegia, 15.2 +/- 2.1 mm Hg/mm; cold adenosine/lidocaine blood cardioplegia, 15.9 +/- 3.4 mm Hg/mm; warm adenosine/lidocaine blood cardioplegia, 14.1 +/- 2.8 mm Hg/mm; P = .90). Plasma creatine kinase activity in cold and warm adenosine/lidocaine blood cardioplegia was similar to that in K + -blood cardioplegia at 120 minutes of reperfusion (cold adenosine/lidocaine blood cardioplegia, 11.5 +/- 2.1 IU/g protein; warm adenosine/lidocaine blood cardioplegia, 10.1 +/- 0.9 IU/g protein; K + -blood cardioplegia, 7.6 +/- 0.8 IU/g protein; P = .17). Postcardioplegia coronary artery endothelial function was preserved in all groups. CONCLUSIONS: Intermittent polarized arrest with warm or cold adenosine/lidocaine blood cardioplegia provided the same degree of myocardial protection as intermittent hypothermic K + -blood cardioplegia in normal hearts.

Adenosine↗