[Enlargement of heart muscle cell mitochondria following venesection].
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Animals↗
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Relationship between cochlear blood flow and perilymphatic oxygen tension.
To clarify the characteristics of the blood circulation in the cochlea, we correlated cochlear blood flow and perilymphatic oxygen tension at various blood pressures. Cochlear blood flow was measured in guinea pigs by laser Doppler flowmetry, and perilymphatic oxygen tension by polarography. Blood pressure changes were induced by angiotensin II injection, trimetaphan camsylate injection and blood withdrawal. Cochlear blood flow generally paralleled systemic blood pressure, indicating a close correlation. In contrast, perilymphatic oxygen tension was slower to increase and decrease. However, when systemic blood pressure was lowered more gradually, perilymphatic oxygen tension did not show the same lag. These findings indicate that perilymphatic oxygen tension parallels systemic blood pressure when changes induced are slower and in a physiological range.
Angiotensin II↗
Autoregulation of cochlear blood flow. A comparison of cerebral blood flow with muscular blood flow.
The cochlear blood flow of healthy adult guinea pigs was measured with a laser Doppler flowmeter and flow dynamics were analyzed on the basis of autoregulation. Angiotensin II infusion was used to raise blood pressure, while phlebotomy was done to lower blood pressure. The characteristics of autoregulation of cerebral blood flow and muscular blood flow were also investigated. Cochlear blood flow was considered to have some autoregulation but was less than brain blood flow, which showed significant regulation. Muscular blood flow seemed to have no similar regulatory mechanism.
Angiotensin II↗
Post-renal transplant erythrocytosis in a child.
We report the case of a 7-year-old boy who developed severe erythrocytosis 4 months after successful kidney transplantation, with a well-functioning graft. When the haematocrit rose above 60%, phlebotomy had to be performed once to twice a week in order to keep the haematocrit below 50%. A 3-month course of theophylline therapy did not influence the erythrocytosis significantly. There were 5 further patients with erythrocytosis out of 186 children who had undergone kidney transplantation at our centre.
Bloodletting↗
Central venous pressure and plasma arginine vasopressin in man during water immersion combined with changes in blood volume.
To investigate the influence of central venous pressure (CVP) changes on plasma arginine vasopressin (pAVP), 8 normal male subjects were studied twice before, during and after immersion to the neck in water at 35.1 degrees +/- 0.1 degrees C (mean +/- SE) for 6 h. After 2 h of immersion, blood volume was either expanded (WIEXP) by intravenous infusion of 2.0 1 of isotonic saline during 2 h or reduced by loss of 0.5 1 of blood during 30 min (WIHEM). The two studies were randomised between subjects. WIEXP increased CVP, systolic arterial pressure (SAP), diuresis, natriuresis, kaliuresis and osmolar clearance compared to WIHEM while haematocrit, haemoglobin concentration and urine osmolality decreased. Heart rate, mean arterial (MAP) and diastolic arterial pressure, plasma osmolality, plasma sodium, plasma potassium and free water clearance did not differ significantly in the two studies. pAVP was significantly higher after 6 h in WIHEM than after 6 h in WIEXP (2.0 +/- 0.2 vs. 1.6 +/- 0.2 pg X ml-1, mean +/- SE; P less than 0.05). pAVP values were corrected for changes in plasma volume due to infusion in order properly to reflect AVP secretion. In conclusion, there was a weak, but significant, negative correlation between CVP and pAVP during the two studies, while during recovery from WIHEM and WIEXP decrements in SAP and MAP correlated significantly and strongly with increases in pAVP. It is therefore concluded that it is the arterial baroreceptors rather than the cardiopulmonary mechanoreceptors which are of importance in AVP regulation in man.
Adult↗
Sex difference in maximal oxygen uptake. Effect of equating haemoglobin concentration.
Ten men and 11 women were studied to determine the effect of experimentally equating haemoglobin concentration ([Hb]) on the sex difference in maximal oxygen uptake (VO2max). VO2max was measured on a cycle ergometer using a continuous, load-incremented protocol. The men were studied under two conditions: 1) with normal [Hb] (153 g X L-1) and 2) two days following withdrawal of blood, which reduced their mean [Hb] to exactly equal the mean of the women (134 g X L-1). Prior to blood withdrawal, VO2max expressed in L X min-1 and relative to body weight and ride time on the cycle ergometer test were greater (p less than .01) in men by 1.11 L X min-1 (47%), 4.8 ml X kg-1 min-1 (11.5%) and 5.9 min (67%), respectively, whereas VO2max expressed relative to fat-free weight (FFW) was not significantly different. Equalizing [Hb] reduced (p less than .01) the mean VO2max of the men by 0.26 L X min-1 (7.5%), 3.2 ml X kg-1 min-1 (6.9%) or 4.1 ml X kg FFW-1 min-1 (7.7%), and ride time by 0.7 min (4.8%). Equalizing [Hb] reduced the sex difference for VO2max less than predicted from proportional changes in the oxygen content of the arterial blood and arteriovenous oxygen content difference during maximal exercise. It was concluded that the sex difference in [Hb] accounts for a significant, but relatively small portion of the sex difference in VO2max (L X min-1). Other factors such as the dimensions of the oxygen transport system and musculature are of greater importance.
Adult↗
[Studies on the etiology and treatment of fat embolism].
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Acidosis, Respiratory↗
A non-transferrin-bound serum iron in idiopathic hemochromatosis.
The nature of iron in the serum of patients with idiopathic hemochromatosis has been studied utilizing an isotope labeling method and results have been compared with those from normal individuals and patients with other forms of liver disease. Between 2 and 4% of a tracer dose of 59Fe added to normal serum was retained by DEAE Sephadex and has been designated non-transferrin-bound. Alcoholic liver disease, chronic active hepatitis, and iron deficiency have no effect on this fraction. In idiopathic hemochromatosis 34.6 +/- 3.9% of the added iron was not bound to transferrin at diagnosis, representing approximately 700 microgram Fe/liter serum. Treatment lowers this fraction before serum iron concentration falls to normal. The majority of the non-transferrin-bound iron is of low molecular weight and is not bound to albumin. The presence of this fraction may contribute significantly to the development of tissue siderosis.
Binding Sites↗
Present status of 32P-therapy in management of polycythemia vera.
The aim of this study is to assess the present status of 32P-therapy in the management of polycythemia vera. The nature of the disease and its associated clinical problems was considered with respect to the characteristics of the different therapeutic approaches. We concluded that 32P is preferably administered to older patients, especially if long term remissions are achieved, if drugs are taken unreliably, or if patients are difficult to supervise. At present chemotherapy is preferably administered to younger patients, to those who respond inadequately to 32P, or who demonstrate early relapsing hyperproliferation of granulocytopoiesis, or who require 32P-administration at intervals shorter than one year.
Alkylating Agents↗
Whole body (59)Fe-elimination rates and corresponding blood losses in patients with factitious anemia induced by self-blood letting.
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Adult↗
The use of leeches for treatment of venous congestion of the nipple following breast surgery.
The medicinal leech, Hirudo medicinalis, played a central role in the evolution of medieval and folk medicine. Today, for the first time in history, the leech actually has a real and valuable purpose in medicine as a useful adjunct for the plastic surgeon: It provides relief of venous congestion. For over 2000 years, leeches were needlessly applied for a multitude of maladies as an adjunct to blood-letting. Their use in Europe peaked between 1830 and 1850, however, shortages led to a subsequent decline in leech application. Today there is a real clinical use for leeches which had led to a resurgence in their use in plastic surgery. Plastic surgeons use leeches in microsurgery to salvage congested flaps, whose viability is uncertain due to venous congestion. We present our experience with two patients where leeches were used to treat isolated venous engorgement of the nipple following breast surgery. Leech therapy is painless, well tolerated, and does not result in significant scarring. Prompt initiation of treatment is mandatory and produces dramatic resolution of venous congestion.
Adult↗
Treatment of polycythemia vera by isovolemic large-volume erythrocytapheresis.
Excess red blood cells (RBC) in patients with polycythemia vera (PV) are usually removed by repeated phlebotomy. In order to improve the efficacy of this treatment, we used isovolemic large-volume erythrocytapheresis (EA) by a cell separator. A retrospective analysis of our experience with 69 PV patients (206 EA procedures) is reported. EA induced a rapid, well-tolerated, and long-lasting reduction of Hct, Hb, and RBC counts, as well as an immediate disappearance or reduction of clinical symptoms of PV, while tissue oxygen tension - as measured in 8 patients - increased. Hct was reduced by EA from 56.8% +/- 5.6% to 41.9% +/- 6.6%, Hb from 17.5 +/- 2.3 to 12.7 +/- 2.4 g%, RBC counts from 7.4 +/- 0.9 to 5.4 +/- 0.9 x 10(6)/mm3. The mean volume of the apherisate was 1410 +/- 418 ml, (mean Hct 79.7% +/- 9.3%), and the actual RBC volume removed 1113 +/- 367 ml. The isovolemic procedure was well tolerated and the acceptance by patients seemed to be better than with repeated phlebotomy. In 21 patients whose Hct values (Hct before and after EA 58% +/- 5.7% and 41.5% +/- 4.9%) were regularly followed after EA the mean period with Hct less than 50% after a single EA procedure was 6.1 +/- 4.1 months (median, 6); in 14 out of these 21 patients a Hct of less than 43% after EA was reached and their mean period with Hct less than 50% after EA was 7.6 +/- 4.0 months (median, 7.5). For three patients this period was 11, 13, and 15 months, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Blood Component Removal↗
Radial artery catheterization by surgical exposure in infants.
56 radial arteries were cannulated by cutdown technique in 54 critically ill infants (age (mean +/- SD) 12.2 +/- 25.9 days, weight 2710 +/- 910 g) for continuous pressure monitoring and repeated blood sampling. 30 patients survived their illness, 24 died. The mean catheterization time in the survivors was 8.1 +/- 4.1 in the non-survivors 6.9 +/- 5.6 days. Most cannulae were removed electively. 27 of the surviving infants were followed up after 10.5 +/- 5.1 months. 25 (86%) vessels were patent, 4 (14%) occluded. No trophic changes of hands or fingers were noted. We concluded that radial artery cannulation by cutdown in infants is a quick and safe technique and is suitable in patients with severe peripheral vasoconstriction.
Arm↗
Influence of blood sampling from venipunctures and catheter systems on serial determinations of prothrombin activation fragment 1 + 2 and thrombin-antithrombin III complex.
To evaluate the influence of different blood sampling techniques on test results of thrombin-antithrombin III complex (TAT) and prothrombin fragment 1 + 2 (F1 + 2) serial determinations were performed. In six groups of nonrandomized patients (ten patients each) the concentrations of the coagulation markers of blood samples from central catheters (internal jugular, caval, Shaldon, pulmonary artery) and peripheral cannulas (17G and 18G) were compared with those of blood samples obtained simultaneously from direct venipunctures of the contralateral arm. Medians and 25th-75th percentiles of TAT and F1 + 2 concentrations of plasmas obtained from central catheters were not different from those taken from venipunctures. When delta mean values (catheter - venipuncture) were calculated negative results were obtained, indicating lower concentrations measured from blood sampled through central catheters with the exception of blood that taken from Shaldon catheters. Only for TAT concentrations significantly were lower values measured in blood samples taken from internal jugular catheters when compared with blood samples obtained from direct venipunctures. Significantly higher TAT concentrations were determined in blood samples obtained from Shaldon catheters. For both coagulation markers correlations were found between concentrations in blood samples from central catheters and venipunctures. In blood samples taken from peripheral venous cannulas only F1 + 2 concentrations correlated with the concentrations found in samples from direct venipuncture. In contrast to F1 + 2, TAT concentrations measured from blood samples via peripheral cannulas were determined significantly higher than those taken from direct venipunctures.(ABSTRACT TRUNCATED AT 250 WORDS)
Antithrombin III↗
Incidence and clinical risk factors for bleeding and thrombotic complications in myeloproliferative disorders. A retrospective analysis of 260 patients.
Bleeding and thrombosis are frequent complications in myeloproliferative disorders (MPD) and are associated with severe organ damage and a high mortality. Elevated platelet count, elevated hematocrit, and patient age are regarded as risk factors for bleeding and thromboembolic events in MPD, although the significance of these parameters was not confirmed by clinical studies. We retrospectively analyzed vascular complications in 260 patients with MPD and tried to identify parameters predictive for bleeding and thrombembolic events. Our cohort consisted of 115 patients with chronic myeloid leukemia (CML), 84 patients with polycythemia vera (PV), 26 with essential thrombocythemia (ET), 25 with osteomyelofibrosis (OMF), and 10 patients with unclassifiable MPD. During a median follow-up period of 31 months, 126 patients with chronic MPD suffered bleeding or thrombotic events. Bleeding was observed in 57% of patients with OMF, 23% with PV, 20% with chronic phase CML, and 16% with ET. Thrombotic events were most common in patients with PV (36% of patients), followed by ET, OMF, and chronic phase CML (20%, 17%, and 6% of patients, respectively). Recurrent thrombotic episodes frequently occurred in patients with PV and ET, whereas patients with OMF often had more than one bleeding event. Thirty patients died of thrombohemorrhagic complications during follow-up. Multivariate analysis, including all patients with chronic MPD, revealed that elevated red blood cell count, higher hemoglobin level, and increased percentage of segmented neutrophils at the time of diagnosis were associated with thrombosis, whereas patients with bleeding complications were characterized by low red cell count, lower hemoglobin, and a lower percentage of segmented neutrophils. However, when analyzed by MPD subgroup, none of these parameters retained a predictive value for bleeding or thrombotic events. Moreover, elevated platelet count and patient age were not risk factors for bleeding complications. Thrombotic events were less frequent in patients below the age of 40, and were increased in patients aged 70 and above. However, this was primarily due to the high percentage of elderly patients in subgroups mainly affected by thrombosis (PV and ET). In most MPD subgroups, the rate of bleeding and thrombosis was highest just before and during the first months after diagnosis, and declined thereafter. Thrombohemorrhagic complications were less frequent after phlebotomy in PV and after therapy with alkylating agents in CML. The institution of cytoreductive therapy soon after the diagnosis was made may explain the reduced incidence of complications later in the disease. We conclude that morbidity and mortality from thrombohemorrhagic complications are high in myeloproliferative disorders.(ABSTRACT TRUNCATED AT 400 WORDS)
Bloodletting↗
Treatment of resistant hypertension by phlebotomy.
In 15 essential hypertensives resistant against a standard triple combination of antihypertensive drugs phlebotomy was performed. Mean arterial pressure was lowered from 140.1 +/- 12.2 mm Hg to 123.8 +/- 14.9 mm Hg after 14 days. No serious side effects were observed. The duration of the hypotensive effect of phlebotomy was about 4 weeks. Phlebotomy can be used in addition to drug treatment in resistant essential hypertension.
Adult↗
A prospective comparison between treatment with phlebotomy alone and with interferon-alpha in patients with polycythemia vera.
Interferon alpha (alpha-IFN) is increasingly used for the treatment of patients affected by polycythemia vera (PV). As prior studies are difficult to interpret in view of the lack of appropriate controls, we undertook a randomized comparison of lymphoblastoid alpha-IFN (alpha n-1 IFN) treatment against venesection treatment alone. In a crossover trial, we treated 22 PV patients alternatively for 5 months each with 3 MU/day sc of alpha n-1 IFN and phlebotomy alone. During IFN treatment, red blood cell count and hematocrit level were well controlled in both trial groups, reducing or eliminating the need for phlebotomy in all patients; furthermore, platelet number and white blood cell count declined during alpha-IFN therapy. In addition, the number of symptomatic patients was greatly reduced, and in six patients a reduction in splenic size was observed. Finally, the only patient with chromosomal abnormalities showed a complete cytogenetic conversion after 5 months of alpha-IFN therapy. Thus, for the first time, our results provide the unequivocal demonstration that alpha-IFN is superior to phlebotomy in controlling the pathologic expansion of erythroid elements and all the clinical aspects of this disease.
Adult↗
Increased plasma creatine kinase activity in rabbits: effect of systematically repeated blood sampling.
Various physical, chemical and biological factors are involved in an increased plasma creatine kinase activity. Repeated blood sampling induced in all rabbits studied a reaction of similar pattern but of different intensity, expressed by a maximum of plasma CPK activity. The physiological origins of this variation of CPK activity seems to be, as seen in control animals, the consequence of emotional stress due to handling and possibly an additional stress due to the venepunctures.
Animals↗