Evaluation of hemoglobin and hematocrit in pregnant women receiving folate and iron supplements

BACKGROUND AND AIMS: From week 8 there is a reduction in hemoglobin and hematocrit (owing to the increased plasma volume which exceeds the increased erythrocytic content) that continues to fall steadily until week 16-22, flattening out at a level of 10-11 g/100 ml for hemoglobin and 32-34% for hematocrit. Bone marrow produces red blood cells and hemoglobin in proportion to the increase in plasma volume, provided that there is an adequate iron supply (higher in pregnancy compared to the usual dietary intake). For this reason, the authors examined the systematic supplementation of pregnant women with ferrous gluconate and folic acid, another important element for numerous metabolic reactions which is also lacking in pregnancy owing to increased requirements. METHODS: The study showed that pregnant patients receiving folic acid and iron supplements from week 5 to 40 presented hematocrit readings and hemoglobin levels from week 12 that were constantly higher compared to the population not receiving supplements, with statistically significant and highly significant differences respectively. The few collateral effects observed in a limited group of patients allow the authors to define the tolerability of the proposed treatment as "excellent". They emphasise, however, the importance of constant supplementation with folic acid and iron throughout pregnancy to avoid sideropenic anemia, with considerable benefits in terms of the physical conditions of the pregnant woman, the supply of O2 to the villi, fetal wellbeing and the need to resort to possible blood transfusions in the event of major blood losses at birth.     

Safe hemoglobin or hematocrit levels in surgical patients

The terminology and fundamental aspects of the delivery, consumption, and deficits of oxygen are recalled. In chronic and acute, nonseptic states, red blood cell (RBC) transfusion is capable of increasing oxygen consumption (VO2). In acute septic states, the response of VO2 to RBC transfusion is variable and unpredictable, but attempts to increase oxygen delivery (DO2) should be made if the clinical picture raises the suspicion of a potentially lethal oxygen deficit. Therapeutic interventions raising the cardiac index to "supranormal" values in critically ill patients improve their chances of survival; and maintenance of hemoglobin or hematocrit values around 11 g/dl or 33%, respectively, is one part of such interventions. Opinions differ on the general tolerance of anemia, as witnessed by postulated "critical levels" of the hemoglobin concentration between approximately 11 and 4 to 5 g/dl or hematocrit values between 33% and 12% to 15%, respectively. The common denominator underlying these vastly different opinions is the variable behavior of several "non-Hb variables," which influence the venous oxygen tensions apart from the hemoglobin or hematocrit. Abnormalities of these non-Hb variables-typically encountered in the critically ill-increase the dependence of patients on hemoglobin or hematocrit levels that suffice to protect them against an oxygen deficit. For this reason, the "critical" hemoglobin or hematocrit is an individual value, and a generally valid "transfusion trigger" does not exist. Finally, the entity now known as silent myocardial ischemia (SMI) is a decisive factor for the tolerance of anemia. Solid clinical evidence is now available to support the concept that patients over age 40 should not, as an elective procedure, be subjected to levels < 10 g/dl or < 30%, respectively, without prior exclusion of SMI by appropriate investigations.     

Testing methods for exercise intolerance in horses

The many testing methods available and the increasing sophistication of diagnostic equipment have enhanced greatly our capabilities to diagnose causes of exercise intolerance in the equine athlete during the last several years. High-speed treadmill examination has become the focus of this form of evaluation. Not all clinicians perform or have access to high-speed treadmill examinations. Testing methods that require the use of the high-speed treadmill, as well as methods that do not, are discussed.     

Comparative analysis between centrifuged hematocrit and "point-of-care" hemoglobin: impact on erythropoietin dosing

This study was performed to evaluate the efficiency and patient satisfaction with a modified Janeway gastrostomy for patients with head and neck cancer and cancer of the upper GI tract and involved 24 consecutive patients with serious malnutrition caused by advanced cancer of these sites. All underwent surgery during which a tube was constructed from the anterior gastric wall with the aid of GIA-75 automatic stapler. The operation was performed under local anaesthesia, with a senior anaesthesiologist, who sedated the patients, in attendance. The operation was successful in all cases. No postoperative mortality could be attributed to the operation. The complications were minor. The patient's close relatives were able to feed them intermittently with home-made formula made according to the instructions of our dietician. No late complications were recorded. Overall, the patients were satisfied with his technique for managing their feeding problem. The modified Janeway gastrostomy is an easy and safe operative procedure; it is an effective way of managing patients with malnutrition as a result of cancer of the head and neck or of the upper GI tract.     

Comparison of three methods of ulnar fixation in horses

BACKGROUND: This study was done to determine whether the difference in duration of action of the long-acting angiotensin-converting enzyme (ACE) inhibitor spirapril compared with the short-acting ACE inhibitor captopril affects clinical efficacy in patients with congestive heart failure. METHODS AND RESULTS: The effects on exercise capacity, neurohumoral status, and quality of life were studied in 20 patients with mild to moderate congestive heart failure in a double-blind, randomized, comparative study in parallel groups with a duration of 12 weeks. All assessments during the study were performed in the morning, before intake of the study medication, to avoid the expected peak effect of the ACE inhibitors used. Mean peak oxygen consumption (peak Vo2) was 17.4 mL/min/kg (range, 14.2-19.9 mL/min/kg) and mean left ventricular ejection fraction was 28% (range, 13-40%). Exercise duration in the captopril group showed a significant increase after 12 weeks (P < .05) of treatment compared with the spirapril group. Peak oxygen consumption tended only to increase in the captopril-treated patients compared with the spirapril-treated patients. Serum ACE activity was significantly different between the two treatment groups during treatment (P < .0001) and showed only a significant decrease in the spirapril group. There was no difference in improvement of quality of life between the two treatment groups. CONCLUSIONS: This study showed that the effects of the ACE inhibitors spirapril and captopril on exercise capacity are not related to the degree of inhibition of serum ACE activity.     

Analytical methods for measuring urea in pharmaceutical formulations

Two new methods are described for the routine determination of urea that utilize HPTLC-densitometry and colorimetry. The methods involve derivatization of urea with p-dimethylaminobenzaldehyde to a yellow-coloured compound. Validation of the methods was accomplished with respect to linearity, accuracy, reproducibility and limit of detection/quantification. Both methods were compared with an enzymatic method previously described in the literature and were found to be in close agreement. The proposed methods have the advantages of being simple, rapid and involve a single step sample preparation. Under experimental conditions HPTLC was the most sensitive method.     

Assessment of methods for measuring social support.

Reviewed 23 instruments for assessing social support; evaluated their reliability, validity, and specificity; and simulated correlations between 4 instruments and 4 criterion measures. 13 instruments had acceptable validity data for this study, and major conceptual differences in the definition and measurement of social support were found. Results indicate that discriminant validity between the measures may be low and that similarities and differences must be assessed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some modern methods of measuring the hall effect

Summary A method is described for measuring the Hall effect applying alternating current and an alternating magnetic field. A block diagram of the set-up is presented an estimate is given of its sensitivity and the effect of possible interferences is analyzed.     

Preavoidance hypercapnia and decreased hematocrit in micropigs

Previous studies found that regular confinement of dogs in an experimental environment preceding onset of an avoidance task was associated with increases in blood pressure and decreases in heart rate and respiration rate that were not prevented by adrenergic antagonists. The present study investigated a) whether divergent changes in blood pressure and heart rate also occur in micropigs preceding onset of an avoidance task, and b) the nature of changes in blood gases, plasma pH, plasma bicarbonate, hematocrit, and plasma electrolytes observed under these conditions. Blood pressure increased and heart rate decreased during 2-h preavoidance periods, whereas both blood pressure and heart rate were elevated during 20-min avoidance periods. During preavoidance periods, pO2, plasma pH, and plasma potassium pCO2 were decreased below home kennel levels during early preavoidance, whereas pCO2 and plasma bicarbonate were persistently increased and hematocrit was persistently decreased for the duration of the preavoidance periods. Each of these changes was reversed during the avoidance sessions. These findings suggest that behaviorally induced hypercapnia might participate in blood pressure regulation via increased renal sodium/hydrogen exchange and renal sodium retention.     

Evaluation of acetaldehyde-modified hemoglobin and other markers of chronic heavy alcohol use: effects of gender and hemoglobin concentration

The present study examined whether measurement of hemoglobin-acetaldehyde (HbA1-AcH) using an improved methodology may be useful as a biological marker of alcohol abuse. Red blood cell hemolysates of 182 patients consecutively admitted to the drug and alcohol treatment unit of our institution were analyzed for HbA1-AcH concentration using cation exchange HPLC. Mean HbA1-AcH of those who claimed to drink > or = 6 drinks/day [mean = 0.055 (% total hemoglobin), SD = 0.051] was significantly higher than the mean of those who drank < 6 drinks/day (mean = 0.026, SD = 0.0174). The greatest sum of sensitivity (67%) and specificity (77%) came with a cut-score of 0.030 area% of total hemoglobin. A cut-score of 0.080 produced a 100% specificity, but lowered the sensitivity to 20%. The Pearson product moment correlation (r) between HbA1-AcH and reported drinks per day was r = 0.30 (p < 0.001). There was no significant difference in the association of HbA1-AcH and reported drinking between males and females, and the small difference observed was shown to be entirely associated with differences in hemoglobin levels between the sexes. Cocaine use did not significantly alter the correlation between reported drinking and HbA1-AcH levels. Hemoglobin levels were shown to have a significant correlation with HbA1-AcH independent of drinking. HbA1-AcH was shown to have a better sensitivity and specificity than gamma-glutamyltransferase, ALT, AST, or mean corpuscular volume in this population. The results suggest that HbA1-AcH may be a useful marker to help detect alcohol abuse, especially in populations where other markers have been shown to fail.     

Comparison of hemoglobin A1C results by two different methods on patients with structural hemoglobin variants

OBJECTIVES: The objective was to compare hemoglobin A1C (HbA1C) results obtained by two methods based on different analytical principles for individuals with a structural hemoglobin variant. DESIGN AND METHODS: Hemoglobin A1C results were obtained using the Bio-Rad Variant (based on cation exchange chromatography) and the Bayer DCA 2000 (based on an immunological reaction) on individuals with a structural hemoglobin variant. The identity of the hemoglobin variant was confirmed by high pressure liquid chromatography (HPLC) and electrophoresis. RESULTS: Hemoglobin A1C results obtained by the two methods on individuals with S, C, D, and E trait were in close agreement. CONCLUSION: The Bio-Rad Variant and Bayer DCA 2000 produce equivalent hemoglobin A1C results on patients with S, C, and E trait. With appropriate correction, correlation of hemoglobin A1C results from the Bio-Rad Variant for individuals with D trait was good (r = 0.927). Glycohemoglobin results obtained by the two methods for some unusual structural hemoglobin variants were in close agreement.     

Evaluation of itraconazole-dimethyl sulfoxide ointment for treatment of keratomycosis in nine horses

The effect of a 24-h maternal deprivation at day 3 was studied on the hypothalamus-pituitary-adrenal axis of 18-day-old Brown Norway pups, whose stress-hyporesponsive period is similar to other rat strains. Deprivation resulted at day 18 in reduced basal ACTH levels. The rate of onset and the duration of stress-induced ACTH release were enhanced. CRH mRNA, brain corticosteroid mRNA levels and corticosterone receptor levels were not affected by deprivation, but adrenal weight was increased. It is concluded that maternal deprivation has persistently diminished adrenocortical function in containment of the ACTH response to stress.     

Evaluation of in vitro precipitation methods

As CD44 is believed to be a homing receptor involved in lymphoid trafficking and inflammatory responses, it is expected to be closely linked to transplant rejection. In this study, the expression of CD44 during liver transplant rejection was compared with the expression of lymphocyte-function associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1), which play an essential role in cell interactions and the initiation of immune responses. Male Brown Norway (BN) and Lewis (LEW) rats were used as donors and recipients, respectively. Orthotopic liver transplantation (OLTX) was done using the cuff technique of Kamada and Calne. Animals were killed on days 3, 5, and 7 after OLTX, and a piece of tissue from each of the liver grafts was obtained. Immunohistochemical staining was used to investigate the expression of CD44, ICAM-1, and LFA-1. CD44 was strongly expressed in portal areas of the rejected liver, and LFA-1 and ICAM-1 were expressed mainly on sinusoids and hepatocytes. These findings indicate that CD44 is closely involved in lymphocyte infiltration, which is dominant in portal areas, and that lymphocyte infiltration during the rejection process may involve a homing mechanism.     

Reproducibility of three different methods of measuring baroreflex sensitivity in normal subjects

1. Baroreflex sensitivity is a useful tool for investigating cardiovascular reflexes in a number of clinical settings. Several different methods of measuring baroreflex sensitivity are available. In order to determine a clinically useful non-invasive method of measuring baroreflex sensitivity we compared two methods (spectral analysis and the Valsalva manoeuvre) with regard to reproducibility, agreement with a standard invasive method (phenylephrine infusion) and failure rate.2.Twenty-six healthy subjects aged 22 to 63 years attended on three separate occasions for measurement of baroreflex sensitivity using the different methods. The effect of a recent head-up tilt on baroreflex sensitivity was measured.3. Reproducibility was best for the low-frequency component of the spectral method [coefficient of variation 25.0% (range 3.5-42.4%)] and worst for the Valsalva method [coefficient of variation 29.3% (range 13.8-93.1%)]. Both non-invasive methods overestimated values compared with the phenylephrine method [bias of low-frequency component of the spectral method, 1.17 (0.38-3.6); bias of the Valsalva method, 1.13 (0.19-6.7)]. The high-frequency component of the spectral method did not agree with the phenylephrine method.4. The spectral analysis method had the fewest failures (seven subjects with a failure on at least one occasion), and the phenylephrine method the most (16 subjects with a failure on at least one occasion). A short head-up tilt did not affect the subsequent non-invasive measurement of baroreflex sensitivity.5. It was concluded that the low-frequency component of the spectral method was the most clinically useful non-invasive measurement of baroreflex sensitivity.     

New ultrasonic methods for measuring deformation and fracture related material states

The ability of ultrasonic measurements to detect and characterize discrete flaws in solids is well known. This paper discusses a series of new techniques which characterize distributed properties and their changes during mechanical deformation and fracture. Stress, texture, and porosity play important roles in the evolution of damage. Each influences the ultrasonic velocity, but difficulties in interpretation occur when more than one is unknown. However, the angular variation of the velocity can be used to differentiate those quantities. Examples are given of the use of velocity information to monitor these microstructural features during creep and large scale plastic deformation studies. It is then shown how ultrasonic scattering provides important information about the closure state near the tip of a fatigue crack and, thus, on the effective stress intensity factor and crack growth rate. A limitation in applying ultrasonics during mechanical testing is the size of the volume interrogated. Possible uses of high resolution acoustic microscopes to implement the above ideas on a smaller scale are indicated.     

How to evaluate measuring methods in the case of non-defined external validity

In the clinical routine of chronic diseases, a new measurement has to be compared to an established criterion to see whether there is agreement on assessing disease progress. Because of the nonexistence of established criteria for rheumatoid arthritis the evaluation of grading systems for radiological assessment needs an alternative approach. Using the measurement error as a measure for repeatability and rater agreement in comparison to the progress of the grading score might be a solution to this dilemma.     

Two methods of measuring muscle tone applied in patients with decerebrate rigidity

Two methods were used to measure muscle tone in patients with decerebrate rigidity. In the first method forces of square waveform were applied and the calculated compliance of the joint was used as an index of rigidity. Oscillatory transients were seen at the same frequency as the physiological tremor. The range of normal variation in compliance was large and the values measured in the patients flucuated markedly which limited the value of this index. In the second method, where forces of sinusoidal waveform were employed, the resonant frequency of the joint was measured and used as an index of rigidity. This index proved reliable and reproducible.     

Increase of hematocrit in experimental renal hypertension and its reversal

The electroencephalograms of 82 infants (between 27 and 37 weeks of conceptional age) recorded during the neonatal period were analyzed and compared with the ultimate clinical evolution. Three groups of infants were identified according to their neurological state at 3 years of age or older: group A: normal (34 infants), group B: minor neurological sequellae (13 infants) and group C: major neurological sequellae (17 infants). A fourth group (group D: 18 infants) died during the neonatal period. The E.E.Gs were classified as: normal, questionably abnormal, moderately abnormal or grossly abnormal. The analysis revealed that E.E.Gs classified as grossly abnormal, were found only in groups B, C and D. Serial E.E.Gs were of more value in distinguishing these groups. Only infants in groups C and D (with I exceptional case in group B) had E.E.Gs which remained abnormal for several weeks or which deteriorated during the neonatal period. This study shows the prognostic value of the E.E.G. recorded during the neonatal period, particularly serial recordings obtained during and after a period of clinical deterioration. A detailed statistical analysis of the E.E.Gs is in progress.