Biomedical subjects
M Kaplan
Publications and source records attributed to M Kaplan.
A woman's view of DSM-III.
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Fetal breathing movements. An update for the pediatrician.
Although the presence of fetal breathing movements (FBMs) has been suspected for almost a century, the major advances in the field were made during the last decade. Experimental animal techniques of detection include instrumentation of fetuses with electronic recording equipment. Human studies use more indirect, although no less accurate, A-mode or real-time B-scan ultrasonography in the recording of FBMs. The fetus does not make breathing movements continuously; however, there are periods of FBMs interspersed with periods of apnea. Inherent to FBMs is a diurnal variation. Hypoxia and hypoglycemia diminish FBMs, while hypercarbia and hyperglycemia have the opposite effect. Caffeine, barbiturates, and general anesthetics modify FBMs by their influence on the CNS. Preliminary studies have shown the presence of FBMs to indicate a state of fetal well-being. Possibly, in the future, testing for FBMs may become a useful clinical tool in the identification of the fetus at risk.
CNS infections caused by Eikenella corrodens.
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Portasystemic shunts in primary biliary cirrhosis: survival is the same as in patients with Laennec's cirrhosis and postnecrotic cirrhosis.
There is little information regarding survival of patients with primary biliary cirrhosis (PBC) who undergo portasystemic shunt operations. The few published reports suggest that survival may be better in this group than in patients with other types of cirrhosis who undergo this procedure. Therefore, we reviewed our experience with 17 patients with PBC who underwent portasystemic shunts and compared their survival with 100 patients with Laennec's and postnecrotic cirrhosis, using the life-table method. We find that survival rates are the same in patients with PBC, Laennec's cirrhosis, and postnecrotic cirrhosis following portasystemic anastomosis.
Sodium homeostasis in dogs with chronic renal insufficiency.
Volume homeostasis in the fasting rate and 24-hr sodium balance are maintained in chronic renal insufficiency as a result of adaptations in the residual nephrons. This study evaluates the limitations to these adaptations and the dynamics of sodium excretion (UNaV) after an acute challenge with 100 mEq of sodium chloride in normal dogs (GFR 50 ml/min) and in dogs with one remnant kidney and moderate chronic renal insufficiency (GFR 15 ml/min). When food was administered with the sodium challenge, no or minimal changes in serum protein and hematocrit values occurred, and the natriuretic responses were small and equivalent in normal and remnant dogs. On the other hand, when the sodium challenge was given without food, the natriuretic response was large in normal dogs and markedly blunted in remnant. Within 5 hr of the sodium challenge, the various groups of normal dogs excreted 40 to 63% of the sodium load, but the remnant animals eliminated only 12 to 22% (P less than 0.001). The blunted natriuresis in remnant dogs was associated with a prolonged hemodilution of circulating proteins, indicating a longer lasting expansion of the intravascular volume. The blunted response was independent of sodium diet, of the administration route (p.o. vs. i.v.) or strength (isotonic vs. hypertonic) of the sodium load, and appears to result from an inability of the remnant kidney to rapidly excrete a sodium load. Thus, administration of sodium to dogs with chronic renal insufficiency leads to prolonged sodium retention, prolonged extracellular fluid (ECF) volume expansion, and requires a prolonged excretory cycle to restore 24-hr balance.
A comparison of androgens for anemia in patients on hemodialysis.
To compare the erythropoietic effects of nandrolone decanoate, testosterone enanthate, oxymetholone, and fluoxymesterone, we performed a randomized clinical trial in patients with anemia who were receiving maintenance hemodialysis (the women were not given testosterone enanthate). After a control period of at least two months, patients received one of the drugs for six months and then returned to control status; a second and third drug were administered in a similar fashion. Seventy-seven patients completed the first drug period, 56 the second, and 35 the third. The response to nandrolone and testosterone enanthate, the two drugs given by injection, was clearly superior to the response to oxymetholone or fluoxymesterone, given by mouth, in terms of the percentage of patients responding and the mean rise in hematocrit. Approximately half the patients had an increase of at least 5 percentage points in hematocrit after an injectable androgen was given; more than half the women responded. Patients who required transfusions regularly and those who had bilateral nephrectomies did not respond.
Day care experiment proves cost-effective.
Funded by Blue Cross Plan, day hospital care provided benefits for hospital staff and patients and proved to be 23% less expensive than inpatient care.
Actin polymerization accompanies Thy-1-capping on mouse thymocytes.
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Lymphatic complications in renal allografts--a new look.
The pathophysiology of lymphatic complications was evaluated in 10 patients as to the possible source of lymphatic fluid. Both the recipient's peripheral lymphatics and the allograft's lymphatics were found to contribute to lymphatic complications. The prevention of lymphoceles and lymphatic fistulas may be accomplished by careful ligation of both the recipient's and the allograft's lymphatics.
Renal handling of potassium in dogs with chronic renal insufficiency.
The dynamics of potassium excretion were examined in normal dogs and dogs with chronic renal insufficiency of at least 4 weeks' duration (remnant model). All animals, in balance on diets providing 15, 50, or 100 mEq of potassium and 100 mEq of sodium, were challenged with 50 mEq of potassium chloride. Immediately thereafter, hourly clearances were obtained for 5 hours. Irrespective of dietary potassium, mean fasting serum potassium and urinary potassium excretion (UKV) were similar in normal and remnant dogs with mean GFR's of 57 +/- 3 and 16 +/- 3 ml/min, respectively. After orogastric administration of 50 mEq potassium, serum potassium rose significantly more in remnant (2.2 to 2.5 mEq/liter) than in normal (0.9 to 1.2 mEq/liter) groups (P less than 0.001). Conversely, UKV increased significantly less, 70 to 96 vs. 151 to 194 micro Eq/min, respectively (P less than 0.001). In 5 hours, normal animals excreted 61 to 67% of the load, but remnant dogs only 30 to 37% (P less than 0.001). In all groups, UKV correlated directly with serum potassium concentration. But this relationship was markedly attenuated in the remnant groups (P less than 0.001) and independent of dietary potassium. In contrast, the same slope describes the relationship between UKV/GRF and serum potassium for all, normal and remnant, animals. The blunted kaliuresis occurred despite the more severe hyperkalemia in remnant than in normal dogs; it was not associated with significant changes in acid-base, diuresis, natriuresis, serum glucose, insulin, and glucagon concentrations and occurred despite prolonged hyperaldosteronism. The results demonstrate a severe limitation of the remnant kidney's ability to rapidly excrete a potassium load. Changes in serum potassium, or a consequence thereof, are important for the urinary excretion of potassium following its acute administration.
Frequency of transient hypothyroxinaemia in low birthweight infants. Potential pitfall for neonatal screening programmes.
Thyroid function was studied in 54 low birthweight infants during a 3-week period. Each infant was placed in one of three groups. Group 1 (n = 21), infants who were well and appropriately grown fro gestational age; group 2 (n = 23), infants who were appropriately grown but who had hyaline membrane disease; group 3 (n = 10), infants who were small-for-gestational-age. In group 1, 5 (24%) infants had at least one serum thyroxine value less than 3.0 micrograms/100 ml (39 nmol/l). There were 8 (35%) infants in group 2 who had similarly low serum thyroxine values as did 5 (50%) of the 10 infants in group 3. Serum thyrotropin levels and serum binding of the thyroid hormones, as measured by a T3-charcoal uptake test, were normal in all infants. In all instances but 2, serum thyroxine values were at least 4.0 micrograms/100 ml (51 nmol/l) by the end of the 3-week period. There is thus a high incidence of transient 'hypothyroxinaemia' in low birthweight infants, particularly if such infants have hyaline membrane disease or are small-for-gestational-age. These findings must be considered when interpreting results of screening programmes for congenital hypothyroidism and they lend further support to the use of a combination of serum thyroxine and thyrotropin determinations for optimum screening of such infants.
New rehabilitation program decreases hospital costs.
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Isotype-specific human B lymphocytes that produce immunoglobulin E in vitro when stimulated by pokeweed mitogen.
Normal human peripheral blood lymphocytes can be stimulated by PWM and T cells to produce IgE in vitro. Between 4% and 10% of circulating B lymphocytes were found to bear noncytophilic membrane IgE. In contrast, limiting diluton analysis of active B cell precursor frequency revealed that only about 1 in 50,000 B cells was responsible for the synthesis of IgE in vitro. Variation inthe precursor frequency was primarily responsible for differences in the amount of IgE produced in vitro by different individuals while the amount of IgE produced per precursor cell was relatively constant. B lymphocytes with surface IgM, IgG, or IgE were depleted. Depletion of IgE-bearing cells decreased IgE production 70% to 83% while IgM-bearing-cell removal lowered IgE synthesis by 59% to 72%. Dual removal of IgM- and IgE-bearing cells did not give an additive effect. IgE- and IgM-positive B cells showed enhanced IgE synthesis of 327% and 182%, respectively. The consequences of crosslinking different surface isotypes on subsequent IgE production were also assessed. Anti-epsilon treatment inhibited IgE production up to 68% while anti-mu treatment decreased it by up to 38%. Thus only a very limited subset of B lymphocytes is responsible for PWM and T cell-dependent IgE synthesis in vitro and those cells probably bear both surface IgE and IgM.
Subclinical herpes simplex genitalis infections in the perinatal period.
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Acute cardiopulmonary decompensation and complement activation during hemodialysis.
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Motivational success in pediatric dentistry: a case in point.
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"Magnification phenomenon" in chronic renal disease.
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