Increased Ion Temperature and Neutron Yield Observed in Magnetized Indirectly Driven D_{2}-Filled Capsule Implosions on the National Ignition Facility

The application of an external 26 Tesla axial magnetic field to a D_{2} gas-filled capsule indirectly driven on the National Ignition Facility is observed to increase the ion temperature by 40% and the neutron yield by a factor of 3.2 in a hot spot with areal density and temperature approaching what is required for fusion ignition [1]. The improvements are determined from energy spectral measurements of the 2.45 MeV neutrons from the D(d,n)^{3}He reaction, and the compressed central core B field is estimated to be ∼4.9  kT using the 14.1 MeV secondary neutrons from the D(T,n)^{4}He reactions. The experiments use a 30 kV pulsed-power system to deliver a ∼3  μs current pulse to a solenoidal coil wrapped around a novel high-electrical-resistivity AuTa_{4} hohlraum. Radiation magnetohydrodynamic simulations are consistent with the experiment.

Inhibition of methemoglobin and metmyoglobin reduction by cobalt

Because cobalt compounds tend to form stable complexes, there has been continued interest in the use of the salts and chelates of cobalt in cyanide poisoning, and continued uncertainty about the precise nature of their protective effects. We have found that cobalt ions inhibit the enzymatic reduction of both methemoglobin and metmyoglobin. Virtually total inhibition of methemoglobin and metmyoglobin reductase activity occurred with the addition of 2.5 mM cobalt acetate to the assay system. Both enzymes were inhibited by lower levels of cobalt in a dose-dependent manner. The similarity in susceptibility of cobalt inhibition is further evidence that the enzymes which reduce methemoglobin and metmyoglobin are functionally comparable. The inhibition of methemoglobin reductase activity may be, in part, responsible for the therapeutic effectiveness of cobalt salts and chelates in cyanide poisoning.

Influence of dietary iron deficiency on hemoglobin, myoglobin, their respective reductases, and skeletal muscle mitochondrial respiration

Male weanling rats were fed a control diet (46 ppm iron) or an iron-deficient diet (11 ppm iron) for 7 wk to determine the influence of iron deficiency on heme proteins and skeletal muscle mitochondrial respiration. At the end of 7 wk, the hemoglobin in the blood of the iron deficient rats was 35% less and skeletal muscle myoglobin was 20 to 37% less than in the control animals. The concentration of myoglobin in the heart was not appreciably diminished by iron deficiency. Cytochrome c concentration was 20% less in the heart and 35% less in the mixed-fiber gastrocnemius in the iron-deficient animals. Iron deficiency did not influence the activity of metmyoglobin reductase in either heart or skeletal muscle. There was about 30% more methemoglobin reductase activity in the red blood cells of the iron-deficient animals, which resulted in methemoglobin levels that were so low as to be virtually unmeasurable. In the iron-deficient rats, skeletal muscle mitochondrial respiration with either pyruvate-malate or palmitylcarnitine as substrate was 17 to 20% less than in the control animals. This study demonstrates that dietary iron deficiency of sufficient severity to reduce blood Hb and skeletal muscle myoglobin or cytochrome c also results in an impaired skeletal muscle oxidative capacity. The study also illustrates the preferential utilization of iron, not only between tissues, but within tissues, and tissue specific adaptive responses to iron deficiency.

The influence of exercise and diet on myoglobin and metmyoglobin reductase in the rat

This study was designed to evaluate the influence of exercise and diet on selected aspects of heme protein metabolism in the rat. Two levels of treadmill exercise and three levels of dietary restriction were imposed on growing male rats over a 12-week experimental period. Neither training nor diet had any effect on erythrocyte NADH-MetHB reductase. The group undergoing the highest level of treadmill exercise had a significantly lower HB concentration. The activity of NADH-MetMB reductase was increased in the group undergoing the highest level of training and decreased in the groups whose diet was restricted by 25% and 35%. These changes were seen only in the soleus muscle. Other muscles, including the heart, psoas, and quadriceps were unaffected by either exercise of diet. Both levels of exercise were effective in increasing muscle MB concentration, but only in the quadriceps and soleus muscles. These data illustrate the adaptive nature of muscle MB and NADH-MetMB reductase. They also illustrate the different adaptive patterns of these two components of muscle.

Metmyoglobin reductase. Identification and purification of a reduced nicotinamide adenine dinucleotide-dependent enzyme from bovine heart which reduces metmyoglobin

Beef heart muscle has been found to contain an enzyme which will rapidly and directly reduce metmyoglobin in vitro. Reduction rates are far greater than any previously reported for nonspecific or nonenzymatic systems. The enzyme is NADH-dependent and requires the presence of ferrocyanide ion for in vitro assay. The artificial electron carriers, dichlorophenolindophenol and methylene blue, are not required. Nonenzymatic reduction of metmyoglobin, which has previously been reported, was not encountered under the assay conditions described herein. Demonstration of enzymatic activity is dependent on a suitable myoglobin substrate, NADH, and ferrocyanide. An equimolar amount of cytochrome b5 was more effective than ferrocyanide in the enzymatic reduction of metmyoglobin. The methods for preparation of beef heart myoglobin and for purification of the enzyme are presented. The enzyme has been purified over 2000-fold. The enzyme has a pH optimum about 6.5 and a Km of 5.0 x 10(-5) M, and is unaffected by the absence of O2. Sodium dodecyl sulfate-gel electrophoresis revealed a molecular weight around 30,000. Purified enzyme does not react with lipoamide. The reaction is markedly influenced by the composition of the buffering milieu. Enzyme activity is inhibited by p-chloromercuriphenyl sulfonic acid, quinacrine dihydrochloride, and N-ethyl-maleimide. Activity was slightly stimulated by FMN. The characteristics of the enzymatic activity and the assay system are similar to those reported by Hegesh et al. (J. Lab. Clin. Med. 72, 339-344, 1968) for erythrocyte methemoglobin reductase.

Work-induced muscle hypertrophy in vitamin D-deficient rats

To determine if vitamin D deficiency would retard the ability of muscle to hypertrophy in response to mechanical stress, we severed the gastrocnemius tendon on one leg of rats in each of three groups, the treatment of which differed only in the amount of vitamin D in the diet. After 1 week the increased size of the soleus and plantaris in the leg in which the gastrocnemius was severed relative to that of the sham operated leg, was determined for each rat. Despite differences in body weight and serum calcium among the groups, we found no difference in the percent of muscle hypertrophy. We conclude that muscle hypertrophy can occur in response to local mechanical forces despite a deficient hormonal environment that otherwise retards growth.

Isolated galactorrhea with normal serum prolactin levels: clinical implications

Detailed endocrine-metabolic studies were performed on five women who were otherwise well but who had had inappropriate breast secretions for variable periods of time (three months to 16 years). Our results suggest that the presence of a lactose-containing breast secretion, which strictly defines galactorrhea, does not necessarily indicate a recognizable abnormality if normal hypothalamic-pituitary function is present. In these regularly menstruating women with isolated galactorrhea, we suggest a minimum initial evaluation, but careful long-term follow-up studies to identify those cases which may progress to the other recognized, more serious amenorrhea-galactorrhea syndromes.

Improvement in jejunal enzyme adaptation in obese adult-onset diabetic patients following a 30-day fast

The adaptive responses of gastrointestinal enzymes, glucose tolerance, and plasma insulin to diet, folic acid, and insulin of five obese adult-onset diabetic patients were studied before and after a 30-day fast. Their data were compared to the adaptive responses of gastrointestinal enzymes to diet, folic acid, and insulin of 15 normal male volunteer subjects, ages 18 to 24. Each group during each testing period received a carbohydrate diet (50% calories as carbohydrate consisting of 1/2 glucose and 1/2 fructose) and a noncarbohydrate diet (70% of calories as corn oil and 30% as sodium caseinate) each without and with folic acid (5 mg three times per day). The effect of insulin was studied only on the carbohydrate diet plus folic acid. Our data demonstrate that obese adult-onset diabetic patients have an impaired adaptive response of jejunal carbohydrate-metabolizing enzyme activities (hexokinase, pyruvate kinase, fructose-1-6-diphosphate aldolase, fructosediphosphatase) to dietary carbohydrate, oral folic acid, and insulin when compared to normal subjects and nondiabetic obese patients. Following a 30-day fast, the obese diabetic patients showed an improvement in glucose tolerance, hyperinsulinemia, and the adaptive response of the jejunal carbohydrate-metabolizing enzyme activities to dietary carbohydrate, folic acid, and insulin. The greatest improvement in the adaptive response of the jejunal enzyme activities occurred on the carbohydrate diet.

Acute effects of oral and intravenous ethanol on rat hepatic enzyme activities

1. Oral administration of ethanol (3 ml) of 95% in 12 ml total volume over a two day period) significantly decrease plasma glucose and insulin levels and the activities of two key gluconeogenic enzymes, pyruvate carboxylase (pyruvate: CO2 ligase (ADP), EC 6.4.1.1) and fructose diphosphatase, (D-Fru-1,6-P2 1-phosphohydrolase, EC 3.1.3.11), and one glycolytic enzyme, fructose-1,6-P2 aldolase (Fru-1,6-P2 D-glyceraldehyde-3-P lyase, EC 4.1.2.13). In each instance, the administration of 2400 mug daily of oral folate in conjuction with the ethanol prevented these alterations in carbohydrate metabolism. 2. Intravenous injection of ethanol produced a rapid decrease (within 10--15 min) in the activities of hepatic phosphofructokinase, (ATP:D-fructose-6-phosphate 6-phosphotransferase, EC 2.7.1.11), pyruvate kinase, (ATP:pyruvate phosphotransferase, EC 2.7.1.40), fructose diphosphatase and fructose-1,6-P2 aldolase. 3. Intravenous ethanol significantly increased hepatic cyclic AMP concentration approximately 60% within 10 min, while oral ethanol did not alter hepatic cyclic AMP concentrations. 4. These data confirm the known antagonism ethanol and folate and suggest that oral folate might offer a protective effect against hypoglycemia in rats receiving ethanol.

Comparison of the adaptive changes in disaccharidase, glycolytic enzyme and fructosediphosphatase activities after intravenous and oral glucose in normal men

Seven subjects were fed a 3,000 kcal defined formula diet daily for 19 days. Except for one 5-day period, 50% of the total caloric intake was provided as either oral or intravenous glucose. The study was divided into four periods as follows: period I lasted 5 days and provided 50% of calories as glucose; period II lasted 5 days and provided no carbohydrate (70% fat and 30% protein); period III lasted 4 days and provided 50% of calories as intravenous glucose and 50% of calories as oral fat plus protein; period IV lasted 5 days and provided 50% of calories as oral glucose. Intestinal biopsy specimens were taken on days 3 and 5 of each period, except period III when biopsies were done only on day 4. No change in intestinal morphology occurred during the study. The carbohydrate-free diet caused the alpha-glucosidase (maltase and sucrase) activities to decrease significantly from that seen with the glucose diet. Sucrase decreased from 14.4 +/- 1.0 to 7.1 +/- 0.9 mumoles/min per g tissue and maltase decreased from 56.1 +/- 3.4 to 30.0 +/- 2.1 mumoles/min per g tissue. Glycolytic enzyme activities decreased during the carbohydrate-free period (pyruvate kinase decreased from 236 +/- 12 to 78 +/- 8, fructose 1-phosphate aldolase decreased from 147 +/- 6 to 53 +/- 4, fructose-1,6-diphosphate aldolase decreased from 151 +/- 8 to 55 +/- 3, and hexokinase decreased from 21 +/- 3 to 7 +/- 1 nmoles/min per mg protein, respectively). Intravenous glucose caused no change in disaccharidase activities. The enzyme activities during periods I and IV were identical and significantly higher than during period II with the exception of fructose-1,6-diphosphatase which increased during period II as compared with periods I and IV. These findings provide an explanation for the transient period of decreased tolerance to dietary sugars when patients are weaned from total parenteral feedings to enteral feedings.

Clinical implications of lactose-positive breast secretions in nonpuerperal females

Inappropriate milk-like secretion from the breasts is not infrequently encountered in patients. Usually these secretions have been identified as milk on the basis of their characteristic appearance, and only rarely has their identity as milk been proven by appropriate analysis. Since milk is chemically defined as a lactose-containing mammary secretion, the presence of lactose in a breast secretion identifies it as milk irrespective of its appearance or the presence of other constituents. Lactose can be readily identified by thin-layer chromatographic methods, which despite their inherent speed and sensitivity have not been widely utilized. A method using commercially prepared cellulose layers and a sandwich developing apparatus is presented in detail. This method utilizes current advances in chromatographic techniques and permits rapid and accurate identification of lactose in breast secretions. Such secretions from 10 nonpuerperal women were screened for the presence of lactose. The milk-like secretions from 8 contained varying amounts of lactose, which was not detectable in the secretions from the other 2. There was no correlation between the appearance of the secretion and the presence of lactose.

Effects of insulin, tolbutamide, and glucagon on activities of jejunal carbohydrate-metabolizing enzymes in humans

The activities of jejunal carbohydrate-metabolizing enzymes show adaptive drugs, and sex hormones. To learn whether insulin, tolbutamide, and glucagon had effects on these enzymes, we performed serial peroral jejunal biopsies in normal young men and in obese patients, before and after treatment with these agents. Jejunal mucosa was assayed for glycolytic enzyme activities, pyruvate kinase (PK), hexokinase (HK), and fructose-1,6-diphosphate aldolase (FDPA), and the nonglycolytic enzyme activity, fructose diphosphatase (FDPase). Insulin significantly increased the activity of jejunal PK (+48% change from control) and HK (+6%), decreased the activity of FDPase (-36%),and had no effect on FDPA. Glucagon had opposite effects; the activity of PK was decreased (-33%) and FDPase was increased (+50%). Tolbutamide significantly increased the activities of PK (+47%), HK (+14%), and FDPA (+7%), and decreased the activities of FDPase (-36%). The results of tolbutamide on glycolytic enzyme activities were independent of endogenous insulin. The data support the concept that jejunal carbohydrate-metabolizing enzymes in man respond to hormones and drugs similar to responses observed in rat liver. This is important because it now gives us a means of studying the actions of these hormones directly in human tissue.

Aplastic anemia following viral hepatitis: report of two fatal cases and literature review

Within recent years the combination of aplastic anemia following viral hepatitis has been reported with increasing frequency suggesting the existence of a causal relationship between the two conditions. Two case histories of aplastic anemia following hepatitis are presented in detail, and the information on 193 such patients reported in the literature through 1972 is summarized. A number of parameters were evaluated and extensive cross correlation carried out in order to define criteria which might have diagnostic, prognostic or therapeutic value. Males were more likely to develop bone marrow failure following hepatitis (p congruent to 0.05), but females were less likely to survive the marrow depression (p smaller than 0.025). No other statistically identifiable criteria were detected. The hematologic changes commonly encountered in hepatitis are reviewed. These and other observations support the concept that subclinical hepatitis may be responsible for a significant percentage of so-called idiopathic aplastic anemia, for which, at present, no etiology can be determined in nearly half the cases. Possible pathogenetic mechanisms are discussed as they might relate to chromosomal abnormalities which were found in one of our patients. It is suggested that occasional fortuitious human infection with animal viruses known to be both hepato- and myelotoxic could relate the hepatitis and aplasia.

Are abnormalities in insulin secretion responsible for reactive hypoglycemia?

Seventy patients with reactive hypoglycemia strictly defined by criteria which interpret the low blood glucose value in relationship to clinical and physiologic parameters, were studied to determine if abnormalities in insulin secretion could be demonstrated. These patients were separated into four groups: alimentary (N = 5), diabetic (N = 16), hormonal (N = 5), and idiopathic (N = 44). The findings in these patients were compared to normal control subjects and to weight- and disease-matched patient controls. All of the patients with hormonal and most patients with idiopathic reactive hypoglycemia (thirty-two of forty-four) demonstrated delayed insulin secretion regardless of the control group used for comparison. Diabetic reactive hypoglycemic patients exhibited delayed insulin secretion when compared to normal controls but not when compared to weight-matched diabetic controls. Excessive insulin secretion was consistently found only in the patients with the alimentary variety of reactive hypoglycemia. Using weight- and diseasematched control groups, no abnormalities in insulin secretion could be found to account for the hypoglycemia in the diabetic reactive hypoglycemic patients and some idiopathic reactive hypoglycemic (nine of forty-four) patients. These results help to explain the inconsistent findings of previous investigators and suggest that reactive hypoglycemia is a syndrome having multiple etiologies.