Down syndrome and short-term memory impairment: a storage or retrieval deficit?

The majority of researchers investigating the memory skills of retarded individuals have utilized heterogeneous samples of subjects whose sole criteria for grouping was either IQ or MA. The present experiment was designed to evaluate the short-term memory performance of subjects representing a specific type of retardation. Three groups of subjects (Down syndrome, CA control, and MA control) received a battery of tests designed to assess recall and recognition memory utilizing either auditory or visual input with verbal and nonverbal responses. Results indicated that the Down syndrome group possessed deficits in both storage and retrieval abilities, with storage of visually presented stimuli being particularly impaired.

Hyponatremia and rhabdomyolysis: a possible relationship

A 40-year-old schizophrenic presenting with an acute toxic psychosis was found to be severely hyponatremic with a serum osmolality of 217 mOsm/kg. The patient was combative and required physical restraints. Shortly after admission the patient's serum transaminase level was elevated, and the next day the CPK value was 175,000 IU. In addition, his serum and urinary myoglobin levels were markedly raised. Shortly after rhabdomyolysis was diagnosed, the patient developed reversible acute renal failure presumably secondary to the myoglobinuria. This report examines the possibility that the severe hyponatremia and hypoosmolality caused his skeletal muscles to become potassium depleted, leading to rhabdomyolysis during the stenuous exercise involved in his battling the restraints.

Propranolol-related bronchospasm in patients without history of asthma

Three patients with no history of asthma or allergy developed bronchospasm while taking propranolol for hypertension. The bronchospasm was severe in all three and in one patient resulted in respiratory arrest. Since the bronchospasm was relieved with discontinuation of propranolol and supportive bronchodilator therapy, the bronchospasm was believed to be caused by propranolol. Furthermore, each patient was subsequently treated with other antihypertensive medications which, like propranolol, contain the stabilizer additive tartrazine. Bronchospasm did not recur, making it unlikely that tartrazine hypersensitivity caused this problem. Regardless of a negative history of asthma, therefore, life-threatening bronchospasm must be considered a possible complication of propranolol therapy.

Occupational lead exposure, nephropathy, and renal cancer

A 48-year-old lead worker was found to have a cystic renal carcinoma during an evaluation of his occupational lead poisoning. Clinical studies showed elevated blood lead levels, impaired urinary concentrating ability, and reduced creatinine clearance. Histologic and electron microscopic studies showed this cystic tumor to be similar to renal carcinomas observed in animals with prolonged lead exposure. Lead content of the tumor was elevated (2.49 micrograms/gm) in comparison with adjacent renal tissue and with normal adult levels. In light of previous animal studies, this case adds increased evidence to the concern over the carcinogenic potential of prolonged lead exposure.

T7-induced DNA polymerase. Characterization of associated exonuclease activities and resolution into biologically active subunits

Bacteriophage T7-induced DNA polymerase has been isolated by a procedure suitable for large scale use and which yields near homogeneous enzyme. In addition to previously described DNA polymerase activity and 3' to 5' exonucleolytic activity on single stranded DNA (Grippo, P., and Richardson, C. C. (1971) J. Biol. Chem. 246, 6867-6873), the enzyme also possesses a highly active exonuclease which hydrolyzes duplex substrates with 3' to 5' directionality. The native polymerase has been dissociated using 6 M guanidine HCl and resolved into biologically active subunits: T7 gene 5 protein and Escherichia coli thioredoxin. The phage-specified subunit obtained by this procedure is deficient in DNA polymerase and double strand exonuclease activities, with deficiencies in these activities being apparent at the level of a single turnover. However, it possesses near normal levels of a single strand hydrolytic activity which is identical to that associated with the native polymerase with respect to substrate specificity and suppression of hydrolysis by low levels of deoxyribonucleoside 5'-triphosphates. Thioredoxin forms a molecular complex with the T7 gene 5 protein, and addition of the host protein restores restores DNA polymerase and double strand exonuclease activities to near normal levels.

The paradoxial movement of the mediastinum. A diagnostic sign of foreign-body aspiration during childhood

The paradoxical movement of the mediastinum, in relation to the respiratory cycle, is a valuable fluoroscopie sign in the evaluation of partial obstruction of air-flow through the trachea or larynx. Its recognition in the presence of the normal chest radiograms together with the clinical history of aspiration, is of importance in the diagnosis of a foreign body located above the tracheal bifurcation. The pathophysiology and the radiographic manifestations of this phenomenon are described. Various etiologies are discussed in which this sign is also seen. The experience with 18 pediatric patients is presented and 3 cases are outlined in details.

Life-threatening metabolic alkalosis in a comatose patient

A 63-year-old man with obstructive pulmonary disease developed severe metablic alkalosis and coma while receiving steroid therapy and nasogastric suction. Treatment, which included the acute induction of hypercarbia and the simultaneous administration of acetazolamide and saline, restored acid-base balance within 24 hours. This combined approach eliminated the need to infuse hydrochloric acid.

An extrarenal role for parathyroid hormone in the disposal of acute acid loads in rats and dogs

Acid infusion studies were performed in nephrectomized rats and dogs with either intact parathyroid glands (intact) or after thyroparathyroidectomy (thyroparathyroidectomized [TPTX]) to determine the role of parathyroid hormone (PTH) in extrarenal disposal and buffering of acutely administered acid. 29 intact rats given 5 mM/kg HCl and 6 intact dogs given 7 mM/kg HCl developed severe metabolic acidosis but all survived. However, each of 12 TPTX rats and 4 TPTX dogs given the same acid loads died. Intact rats and dogs buffered 39 and 50% of administered acid extracellularly, respectively, whereas extracellular buffering of administered acid was 97 and 78% in TPTX rats and dogs, respectively. 17 TPTX rats and 6 TPTX dogs given synthetic PTH 2 h before acid infusion survived. The blood bicarbonate and extracellular buffering in these animals, measured 2 h after acid infusion, was similar to intact animals. Changes in liver, heart, and skeletal muscle pH determined from [(14)C]5,5-dimethyl-2,4 oxazolidinedione distribution seemed insufficient to account for the increased cell buffering of PTH-replaced animals. Indeed, muscle pH in TPTX dogs given PTH and acid was only 0.06 pH units lower than in control dogs given no acid, suggesting that another tissue, presumably bone, was the target for PTH-mediated increased cell buffering. This conclusion was supported by the observation that PTH did not alter the pH of intact rat diaphragms in vitro. These results indicate that PTH is necessary for the optimal buffering of large, acute acid loads presumably by increasing bone buffering.

Effect of early plasmapheresis and immunosuppressive therapy on natural history of anti-glomerular basement membrane glomerulonephritis: report of a 22-month follow-up

A patient with anti-glomerular basement membrane (GBM)-mediated necrotizing and proliferative glomerulonephritis with crescents was treated with plasmapheresis, cyclophosphamide, and steroids. Treatment resulted in decreased circulating anti-GBM antibody and prompt improvement of renal function that remained stable for 15 months after all treatment was discontinued. Renal biopsies were performed initially, at seven and 17 months. Immunofluorescent examination showed that anti-GBM antibody continued to be present on GBMs although light and electron microscopic findings demonstrated a transformation to a form of sclerosing glomerulonephritis. To our knowledge, this patient's course is the first demonstration that early treatment with plasmapheresis and immunosuppressions may transform the histologic findings in anti-GBM-induced rapidly progressive glomerulonephritis, thereby altering the natural history of this disease.

Intervening polyadenylate sequences in RNA transcripts of vesicular stomatitis virus

Purified and partially resolved vesicular stomatitis virus (VSV) messenger RNA has been annealed to the VSV genomic RNA and visualized in the electron microscope under conditions in which duplex regions have a wider image width than single-stranded RNA. The locations of the intercistronic boundaries between the messages have been mapped on the VSV genome. The contour of the double-stranded regions is occasionally interrupted by looped-out single-stranded RNA. The loops are comprised of post transcriptionally synthesized polyadenylate. Most of these structures are found at the intercistronic boundaries and covalently bridge adjacent message sequences. In this paper, we discuss the possible significance of these loops.

Metabolic acidosis after hyperalimentation with casein hydrolysate. Occurrence in a starved patient

A 29-year-old woman with short bowel syndrome and prolonged starvation developed hyperchloremic metabolic acidosis after initiation of hyoeralimentation with a casein hydrolysate solution. The acidosis was not due to bicarbonate loss but was associated with diminished ability of the kidney to increase urinary acid excretion, particularly titratable acidity. Supplemental parenteral bicarbonate administration was necessary for two weeks until urinary acid excretion rose to normal.

Control of cholesterol embolization by discontinuation of anticoagulant therapy

A 64-year-old man developed multisystem disease including renal failure while receiving anticoagulants. Renal biopsy showed cholesterol embolization. Discontinuation of anticoagulants resulted in prompt cessation of symptoms and dramatic improvement in renal function.

Correction of hyperkalemia by bicarbonate despite constant blood pH

Patients having hyperkalemia often are given bicarbonate to raise blood pH and shift extracellular potassium into cells. Blood pH in many hyperkalemic patients, however, is compensated. To determine whether bicarbonate, independent of its pH action, affects plasma potassium, 14 hyperkalemic patients were treated with bicarbonate in 5% dextrose. In five patients (changed pH group), blood pH rose at least 0.08, while in nine (constant pH group), it changed less than 0.04. In the first group, pH rose 0.12, bicarbonate rose 5.9 mEq/liter, and plasma potassium fell 1.6 mEq/liter, and plasma potassium fell 1.4 mEq/liter. The correlation between changes in plasma potassium and bicarbonate was identical in the two groups and independent of urinary potassium excretion. Four additional patients, who were treated with 5% dextrose alone, did not significantly lower their plasma potassium, although subsequent treatment with bicarbonate in 5% dextrose lowered their plasma potassium. Thus, bicarbonate lowers plasma potassium, independent of its effect on blood pH, and despite a risk of volume overload, should be used to treat hyperkalemia in compensated acid-base disorders, even in the presence of renal failure, provided the plasma bicarbonate concentration is decreased.

Potassium and intracellular pH

Recent work has clarified some of the complex interrelationships between cell pH and potassium. These studies have been limited by the techniques available for accurately measuring cell pH. At present it is obvious that intracellular pH is a major regulator of the cellular potassium concentration, but the precise relationship between these two is still uncertain. It has become increasingly clear, however, that no simple relationship exists between the intracellular to extracellular hydrogen ion and potassium ion ratios. Many experiments do demonstrate that the extracellular metabolic alkalosis of potassium depletion is accompanied by a decrease in skeletal muscle pH in rat, rabbit, and probably dog. The response of cardiac and renal tubular cell pH to potassium depletion is less clear, although most evidence indicates that there is also a reduction in the pH of these tissues. This effect on cell pH appears to be independent of chloride. By contrast, hyperkalemia seems to raise muscle cell pH at the same time it induces an extracellular metabolic acidosis. The metabolic and physiologic consequences of potassium-induced alterations in cell pH have yet to be fully elucidated.

[Cerebrospinal fluid protein electrophoresis in non-inflammatory central nervous system diseases]

Cerebrospinal fluids (CSF) (N = 365) from patients with non-inflammatory diseases of the central nervous system were analyzed for protein distribution by agar gel microelectrophoresis. After subdivision into diagnostically well defined groups, these patients were compared with 79 normal controls. Most of the diseases investigated were found to follow the "plasma-type" pattern. In some of them the deviations from normal were so extensive that a CSF-protein pattern similar to the "acute-phase reaction" in the serum occurred. Moreover, the following characteristics were found: a considerable increase in total protein and the gamma-globulin fractions in neurinomas; a reproducible increase in the alpha1-globulins in metastases of the central nervous system; and a statistically significant difference of CSF protein findings between male and female patients with protrusion of lumbar intervertebral discs.

Isohydric regulation of plasma potassium by bicarbonate in the rat

pH and bicarbonate affect many metabolic reactions but each may change independently. To study bicarbonate's effect onplasma potassium, blood bicarbonate in normal, hypokalemic or hyperkalemic rats was either maintained constant, lowered by hydrochloric acid or raised by sodium bicarbonate administraion. Blood pH was maintained constant by changing PCO2. In normokalemia lowering bicarbonate increased plasma potassium 2.0mEq above values obtained in the other groups. To eliminate urinary potassium losses, experiments were also performed in rats with bilateral ureteral ligation. Again, plasma potassium concentration rose significantly more in the lowered bicarbonate group. Similarly, in hypokalemia, plasma potassium rose 1.2 and 0.4mEq in the lowered and unchanged groups, but fell 0.2mEq/liter in the elevated group. Differences could not be ascribed to renal potassium losses as potassium excretion was essentially zero in each group. In hyperkalemia, plasma potassium concentration remained elevated for 150 min in the lowered bicarbonate group but fell 1.3 and 2.0mEq in the unchanged and elevated groups, respectively. Urinary potassium losses in the three groups were statistically identical. In all experiments blood pH was maintained unchanged during the experiment. The data show that bicarbonate, independent of blood pH, alters transcellular potassium distribution suggesting the usefulness of bicarbonate therapy in hyperkalemia even at a compensated blood pH.

Effect of volume expansion on renal citrate and ammonia metabolism in KCl-deficient rats

When rats with desoxycorticosterone acetate (DOCA)-induced potassium chloride deficiency are given sodium chloride there is simultaneously a partial correction of metabolic alkalosis and a marked reduction in urinary citrate excretion and renal citrate content. To examine DOCA's role in this phenomenon and to determine how sodium chloride alters renal metabolism, rats were made KC1 deficient using furosemide and a KC1-deficient diet. Renal citrate and ammonia metabolism were then studied after chronic oral sodium chloride administration or acute volume expansion with isotonic mannitol. Although both maneuvers partially corrected metabolic alkalosis, sodium chloride raised serum chloride concentration while mannitol significantly decreased it. Urinary citrate excretion decreased to 10% of control in rats given NaCl and to 50% of control in rats infused with mannitol. The filtered load of citrate was constant or increased indicating increased tubular citrate reabsorption. Renal cortical citrate content also decreased approximately 50%. Renal cortical slices from KCl-deficient rats incubated in low or normal chloride media produced equal amounts of 14CO2 from (1, 5-14C) citrate. In addition, urinary ammonia excretion increased by over 300% in both groups. This occurred in the mannitol group despite increased urinary pH and flow rate indicating a rise in renal ammonia production. It seems that neither DOCA nor an increase in serum chloride concentration explains the experimental results. Rather, it appears that volume expansion is responsible for increased renal tubular citrate reabsorption and renal ammonia production. As these renal metabolic responses ordinarily occur in response to acidosis, the data are consistent with the hypothesis that volume expansion reduces renal cell pH in 3KCl-deficient rats.

The effect of normothermic anoxic arrest and ventricular fibrillation on the coronary blood flow distribution of the pig

Normothermic anoxic arrest of 15 and 30 minutes, repeated for up to a total of 90 minutes of anoxia was employed in 24 pigs. The purpose was to determine the effect of varying the duration of anoxia on coronary blood flow, coronary vascular resistance, and the distribution of coronary flow to the free wall of the ventricle. Five minutes of reperfusion at pressures of 50 and 100 mm. Hg with the ventricle fibrillating, was employed between each anoxic interval. Results were compared to control studies performed during ventricular fibrillation without anoxic arrest in 12 pigs. Prolonging the anoxic interval to 30 minutes served to create a maldistribution of coronary flow away from the left ventricular endocardium and to reduce the reactive hypermic response to anoxia. Increasing the perfusion pressure to 100mm. Hg accentuated these changes. Both light and electron microscopy of sections demonstrated edema and early myocardial necrosis in the subendocardial layer of the left ventricle subjected to repeated 30 minute intervals of anoxia at a high perfusion pressure. We postulate that repeated anoxic insults with inadequate repayment of oxygen debt results in subendocardial edema, a decrease in perfusion, increasing necrosis, and further edema. A myocardial infarction must result if this vicious cycle cannot be interrupted.

Gallium-67-citrate scanning for the localization and staging of lymphomas

One-hundred-eight 67Ga-citrate scans were evaluated in Hodgkin's and non-Hodgkin's lymphomas for staging, diagnosis of recurrence, and for determing the results of treatment. Accuracy as confirmed by comparing the scans with pathologic material or roentgenologic and clinical findings was found to be 83%. Known lymph node involvement was diagnosed correctly in 87% but accuracy was only 48% for extranodal areas. Bone lesions were diagnosed correctly in 83% compared with only 48% of lesions of the lungs and liver. Scans were 75% accurate in 28 patients scanned for initial staging. False negatives were present in 12%; recurrent tumor in an area of prior radiation therapy appeared to be the most common cause. There were 5% false positives. Gallium scanning is a useful adjunct to other methods of detecting lymphoma.

Effect of osmolarity on intracellular pH of rat diaphragm muscle.?22

To investigate the effect of altered extracellular osmolarity on cell pH, intact rat diaphragms were incubated in a Krebs-Ringer bicarbonate solution. Cell pH was measured simultaneously by weak-acid (pH DMO) or weak-base (ph nicotine) distribution. When osmolarity was raised by mannitol addition, cell water decreased 5-10% (P smaller than .01) while both pH DMO and pH nicotine increased (P smaller than .01) under acid, normal, and alkaline external pH conditions. Hyperosmolarity of identical degree caused by urea resulted in no changes in either cell water or cell pH. Identical amounts of mannitol added to the bath in the absence of external osmolar changes resulted in no changes in either cell water or cell pH. When extracellular osmolarity was lowered by decreasing sodium chloride concentration, cell water increased 10-12% (P smaller than .01). Despite this large change in cell water, no changes in pH DMO or pH nicotine occurred. These data indicate that osmolar induced alterations in cell water only partially explain cell pH changes found in abnormal osmolar states. Alterations in passive and active hydrogen ion transport must also play significant roles.

Nondependence of cell pH on sodium transport in rat diaphragm muscle

Both sodium and hydrogen ions are in lower concentration in muscle cell water than would be predicted from thermodynamic considerations alone, indicating active transport of these two ions out of muscle cells, To determine whether their transport is coupled, intact rat diaphragms were incubated at an external pH of 7.40, and sodium efflux was altered by exposure to ouabain. Despite a sixfold increase in intracellular sodium concentration, cell pH measured simultaneously by the distribution of both a weak acid (pH DMO) and a weak base (pH nicotine) was unaffected. Similarly, when sodium influx was decreased by incubating intact diaphragms in low sodium isoosmolar buffer, pH DMO and pH nicotine were unaltered. In addition, a pH-sensitive reaction, the evolution of 14CO2 from 1, 4-14C citrate by rat hemidiaphragm, was not changed by exposure to ouabain or low sodium media. These experiments demonstrate that in diaphragm muscle sodium and hydrogen ion transport appear not to be coupled, since alterations in sodium transport are unaccompanied by a change in cell pH. Although changes in membrane potential may explain part of the results, the data are most consistent with the hypothesis that active hydrogen ion transport in skeletal muscle in directly coupled to metabolic energy-producing reactions.

Splenectomy for hematologic depression in lymphocytic lymphoma and leukemia

Fifty patients with lymphocytic lymphoma and chronic lymphocytic leukemia underwent splenectomy for various combinations of anemia, thrombocytopenia, and leukopenia. All of these patients had advanced lymphoproliferative disease, and most had infiltration of bone marrow by neoplastic cells. Good response in all hematologic parameters was obtained in 27 of 48 evaluable patients. An additional 13 patients responded in one or two parameters; there were only 8 complete failures. The over-all surgical mortality was 8%. The median duration of response was 4 months, and the mean, 7 months. Increased tolerance to further antitumor therapy and a decreased transfusion requirement were seen among responding patients. Those patients with anemia who had evidence of shortened erythrocyte survival and splenic sequestration of 51Cr-labelled erythrocytes uniformly responded with rises in hemoglobin. However, half of the patients with negative splenic sequestration also showed improvement of anemia. Preoperative diagnostic studies failed to predict favorable responses of patients with thrombocytopenia or leukopenia. The classical criteria for the diagnosis of hypersplenism are not applicable in many cases of neoplastic lymphoproliferative disease; splenectomy could have been considered "contraindicated" in most of the patients in this series. We conclude that splenectomy is worth undertaking in patients with lymphoproliferative disease complicated by hematologic depression regardless of marrow findings or the results of other diagnostic studies.

Cathodic oxygen consumption and electrically induced osteogenesis

Small amounts of electric current stimulate bone formation in the region of a cathode. The purpose of this experiment is to compare changes in oxygen and hydroxyl ion concentration that occur at the cathode at current levels known to be capable of inducing osteogenesis (10-20 muamps) with those changes that occur at current levels known to be toxic to bone (100 muamps). An oxygen consumption chamber containing an oxygen electrode is fitted with two stainless steel electrodes which are connected to a constant current source. At the cathode, with a current of 100 muamps, oxygen is consumed at nearly stoichiometric rates. At higher current (100 muamps) levels, cathodic oxygen consumption gives way to hydrogen evolution. Cathodic hydroxyl ion production is directly proportional to current. It is concluded from these in vitro experiments that at 10-20 muamps the oxygen tension in the vicinity of the cathode is lowered and the pH is moderately increased. At 100 muamps the oxygen tension is not lowered, but the pH is increased dramatically. If these same changes occur in the vicinity of a cathode in vivo, then lowering the local tissue oxygen tension and raising the local pH may be mechanisms operative in electrically induced bone formation.

The simultaneous determination of muscle cell pH using a weak acid and weak base

Should significant pH heterogeneity exist within cells then the simultaneous calculation of intracellular pH from the distribution of a weak acid will give a value closest to the highest pH in the system, whereas calculation from the distribution of a weak base will give a value closer to the lowest pH. These two values should then differ significantly. Intact rat diaphragms were exposed in vitro to varying bicarbonate concentrations (pure metabolic) and CO(2) tensions (pure respiratory), and steady-state cell pH was measured simultaneously either by distribution of the weak acid 5,5-dimethyloxazolidine-2,4-dione-(14)C (pH DMO) or by distribution of the weak base nicotine-(14)C (pH nicotine). The latter compound was found suitable to measure cell pH since it was neither metabolized nor bound by rat diaphragms. At an external pH of 7.40, pH DMO was 7.17 while pH nicotine was 6.69-a pH difference of 0.48 pH units (P < 0.001). In either respiratory or metabolic alkalosis both DMO and pH nicotine rose so that differences between them remained essentially constant. Metabolic acidosis induced a decrease in both values though they fell more slowly than did extracellular pH. In contradistinction, in respiratory acidosis, decreasing extracellular pH from 7.40 to 6.80 resulted in 0.35 pH unit drop in pH DMO while pH nicotine remained constant. In every experiment, under all external conditions, pH DMO exceeded pH nicotine. These results indicate that there is significant pH heterogeneity within diaphragm muscle, but the degree of heterogeneity may vary under different external conditions. The metabolic implications of these findings are discussed. In addition, the data show that true overall cell pH is between 6.69 and 7.17-a full pH higher than would be expected from thermodynamic considerations alone. This implies the presence of active processes to maintain cell pH.