Scientific and public health rationale for the Dietary Guidelines for Americans

The Dietary Guidelines for Americans, published by DHHS and USDA in 1980, have recently been reviewed by an expert committee that has recommended only minimal changes to scientifically update them. Initial efforts to develop dietary guidelines for prevention of diseases were fraught with controversy, some of which has continued. This controversy exemplifies a larger issue concerning the role that contemporary science, and specifically government, has in assuring and maintaining public health. Two broad questions need to be asked: what is the government's role in facilitating application of contemporary nutrition knowledge to public health, and what standard of scientific surety should be the basis for its application? Government's role in assuring public health and safety indirectly through information is well established. In deciding when the data are sufficient to inform the public, public health scientists must, at some point, make the leap of faith, even though some doubts may remain.

Does bacteremia occur during flexible sigmoidoscopy?

Up to 10% of patients may have bacteremia after rigid sigmoidoscopy. The aim of our study was to determine the frequency of bacteremia accompanying flexible sigmoidoscopy. Blood samples for aerobic and anaerobic cultures were obtained before, during, and after flexible sigmoidoscopy in 100 patients who were examined a mean distance of 49.5 cm, range 15-60 cm, after a bowel preparation of two Fleet enemas. In one patient, a transient bacteremia with Streptococcus intermedius was documented and was attended by no associated clinical manifestations. This organism has been previously isolated from patients with endocarditis, peritonitis, emphysema, and hepatic and appendiceal abscesses. There was no association in our study with bacteremia and such factors as length of bowel examined and duration of procedure, the presence of bowel pathology, performance of endoscopic biopsies, liver disease, and portal hypertension or poor bowel preparation. We conclude that the extremely low incidence of significant bacteremia with flexible sigmoidoscopy may be related to the smaller diameter of the instrument and provides further support for the routine use of flexible rather than rigid sigmoidoscopy.

The effects of hyperglycaemia on changes during reperfusion following focal cerebral ischaemia in the cat

The effects of isosmolar loads of glucose and saline after onset of focal cerebral ischaemia (middle cerebral artery occlusion) were compared in cats. In cats given saline cerebral blood flow (CBF) fell and then rose slightly on the marginal gyrus (infarct penumbra). There was a sustained fall in CBF on the suprasylvian and ectosylvian gyri (infarct core). Reperfusion restored blood flow to preocclusion levels with no overall postischaemic hypoperfusion. Below ischaemic flows of 14 ml/100 g/min brain specific gravity was reduced in a smaller proportion of gyri by contrast with non reperfused cortex, suggesting that in some gyri resolution of cerebral oedema had taken place. GABA uptake was normal in the infarct core, but was reduced within the ischaemic penumbra. In animals given glucose after occlusion, CBF fell on the marginal gyrus during reperfusion. The degree of resolution of cerebral oedema was less than in saline infused cats. GABA uptake showed a pattern of abnormality similar to that seen in saline infused cats, except that uptake values were lower in the infarct core. Pial surface potassium activity remained elevated in the penumbra following reperfusion in glucose infused cats, but returned to normal in saline infused cats. Implications for the management of cerebral ischaemia in man are discussed.

Protection of respiration of a crude mitochondrial preparation in cerebral ischaemia by control of blood glucose

There is evidence that systemic hyperglycaemia influences the evolution of cerebral ischaemia adversely, through enhancement of brain lactic acidosis. A potential protective regimen based on induction of mild hypoglycaemia with insulin was therefore studied. Respiratory control in brain mitochondria prepared from the ischaemic hemisphere of rats subjected to unilateral common carotid artery occlusion for one hour was abolished, but was partially preserved in insulin-treated rats (p = 0.01).

A kinetic model for the action of the enzyme activated irreversible inhibitor 4-amino-5-hexynoic acid in vivo

The extent of inactivation of three aminotransferases by the enzyme activated inhibitor 4-amino-hex-5-ynoate (acetylenic-GABA) increased with increasing dose in an exponential fashion. Theoretical treatment of the data allowed an estimate of the effective concentration of the drug at its site of action to be made and it was apparent that any rises in substrate concentration produced by the inactivation did not protect the enzyme significantly. Altered diet produced distinct changes in the extent of inactivation of aspartate aminotransferase, but not with ornithine aminotransferase. Cysteine sulphinate, a substrate only of aspartate aminotransferase, also affected the inactivation of ornithine aminotransferase, suggesting that secondary metabolic effects were responsible.

Nicotine gum to help stop smoking

A nicotine gum has been approved as a prescription drug to help smokers stop smoking. This article reviews the rationale, pharmacology, efficacy, adverse effects, and method of use of the gum. Several randomized trials, including double-blind placebo-controlled studies, indicate nicotine gum improves long-term quit rates. The efficacy of the gum seems to be due to its ability to relieve withdrawal symptoms. Successful use of the gum depends on appropriate instructions, expectancies, and adjunct therapies. How effective the gum will be when used in general medical practice, to whom it is best to prescribe the gum, and what proportion of smokers will become dependent on the gum are still unclear.

Vaccination against transplacental cytomegalovirus transmission: vaccine reactivation and efficacy in guinea pigs

The guinea-pig model of cytomegalovirus (CMV) infection was used in continuing studies of experimental CMV vaccines for prevention of congenital CMV infection. Low-passage guinea-pig cytomegalovirus (GPCMV) vaccine, which has been shown to be effective in preventing transplacental CMV transmission, was tested for reactivation during pregnancy. In Hartley strain guinea pigs intraperitoneally given 10(5.5) 50% tissue culture infective doses (TCID50) of low-passage vaccine, 27 (41%) of 66 throat swabs obtained during subsequent pregnancies showed CMV, in contrast to 28 (24%) of 115 throat swabs obtained from nonpregnant control animals. High-passage GPCMV vaccine (approximately 5 X 10(3) TCID50) did not cause acute viremia, detectable generalized infection, or GPCMV reactivation during subsequent pregnancies. Immune pregnant animals and their fetuses were protected against generalized CMV infection when challenged with virulent GPCMV. In contrast, nonimmune pregnant controls developed generalized maternal, placental, and fetal infection. Experimental low-dose, high-passage GPCMV vaccine can protect against transplacental CMV transmission without apparent vaccine reactivation during pregnancy.

Using epidemiology to regulate food additives: saccharin case-control studies

The increasing use of nonnutritive sweeteners and the widely publicized 1969 ban on cyclamate led to additional investigations in rodents of the carcinogenic potential of saccharin. Preliminary results of a long-term feeding study indicated formation of bladder tumors in rodents, and collective experimental evidence has demonstrated that high doses of the synthetic sweetener saccharin can cause bladder cancer in rodents. Based on the results of that and other rodent studies indicating an increased risk of bladder cancer associated with saccharin, the Commissioner of the Food and Drug Administration announced the agency's intention to propose a ban on saccharin. This intention was made known in April 1977 under the Delaney Clause of the Food, Drug, and Cosmetic Act. The clause essentially states that no additive shall be deemed safe if it is found to induce cancer in man or animals, or if it is found, after tests appropriate for the evaluation of the safety of food additives, to induce cancer in man or animals. Also in 1977, a group of epidemiologists began to assess the available epidemiologic information to determine the potential human risk. This report describes the assessment of several human epidemiologic studies available then and the results of more recent epidemiologic studies.

Crystal and molecular structure of a natural vanadyl porphyrin

The crystal and molecular structure of a vanadyl deoxophylloerythroetioporphyrin (dpep) extracted from oil shale has been determined by single crystal X-ray diffraction. The compound crystallizes in space group P21/c of the monoclinic system with four formula units in a cell of dimensions a 12.912(3), b 14.151(4), c 18.404(8) �, β 70.34(2)�. Block matrix least-squares refinement gives a final R index of 0.077 for 2296 reflections. The planar molecules are packed almost parallel, with the chloroform solvent molecules lying between the planes and weakly associated with the vanadyl oxygen. The molecular structure establishes the presence of an isocyclic five-membered ring, which suggests that the molecule is a derivative of chlorophyll.

Distribution of alpha 1-antitrypsin variants in a US white population

A white population from the State of Minnesota of primarily German and Scandinavian heritage was subtyped for alpha 1-antitrypsin variants using isoelectric focusing. The frequencies of the genes PI*M1 (0.724), PI*M2 (0.137) and PI*M3 (0.095) were consistent with those for white populations documented in the literature from Northern Europe. Other genes identified in the study were PI*F, PI*I, PI*P, PI*S and PI*Z.

Influence of supplementation on the dental caries incidence and growth of rats fed two model diets

In order to improve the quality of caries-promoting diets MIT 200 and NIH 2000, both diets were supplemented with fat. In addition, the NIH 2000 diet was supplemented with minerals and vitamins. Supplementation with essential nutrients improves the quality of the diets and enhances growth when compared to control animals. Adding minerals and vitamins to diet NIH 2000 abolishes loss of pigmentation of incisors, improves hemoglobin and hematocrit and reduces caries scores in the buccal surfaces by 50% when compared to the non-supplemented diet. It is possible that the cariogenic properties of diet NIH 2000 may be a function in part of a nutrient deficiency.

Growth, development and dental caries in rats fed two experimental diets

In order to determine the nutritional adequacy of diets MIT 200 and NIH 2000 on the growth and development of experimental animals, these two diets were fed to two groups of animals during three periods of development: 1) pregnancy; 2) lactation, and 3) post-weaning. These diets were compared with a diet that satisfied the requirements of the National Research Council for growth and maintenance. It was found that for the two experimental diets, growth was compromised due to a caloric deficit in both diets. In addition, NIH 2000 was deficient in other nutrients such as iron. Analysis of other parameters such as hemoglobin, hematocrit, salivary protein, saliva flow and weight of vital organs upon autopsy revealed a picture of iron deficiency in the NIH 2000 group. Caries formation can be precipitated by a mechanism influenced by a nutrient deficit.

Influence of dietary iron on the dental caries incidence and growth of rats fed an experimental diet

In view of the fact that supplementation with essential nutrients improves the quality of diet NIH 2000 and enhances growth, this study was carried out to determine the effects of supplementation with a specific nutrient. Diet 2000 was supplemented with 35 ppm of FeSO4 and fed ad libitum for 40 days. Iron supplementation reverses the caries process and reduces its incidence especially in the buccal surfaces which are bathed readily by saliva. In addition, hemoglobin and hematocrit, growth and pigmentation of the incisor teeth improve significantly with supplementation. The results of this experiment suggest that the effect of diet in the caries process involves not only the sucrose component of the diet but also an essential nutrient such as iron.

Fetal sex determined by ultrasound

In an ultrasonographic laboratory we scanned 545 consecutive obstetric patients for obstetric indications based on the consultative needs of the physicians involved in their care. We attempted to determine the sex on all fetuses. The gestational age ranged from 15 weeks to term. Fetal sex was established in 196 (36%). After the 25th week of gestation, we predicted the sex in greater than 50%. There were no errors in the entire series. The basis of sex determination was the demonstration of male and female genitalia.

A point prevalence of otitis media in a Nigerian village

One hundred seventy children and 103 adults from a rural Nigerian village were examined for the presence of middle and external ear pathology. Ear, nose and throat examination included: (1) pneumatic otoscopic exam, (2) tympanometry and (3) contralateral acoustic reflex. A diagnostic algorithm was applied to these 3 findings for each subject and each ear. Our data showed a point prevalence of otitis media in children (less than or equal to 15 years) to be 21.2% compared to 4% in adults (greater than 15 years). Of the 36 children with otitis media, only 3 had perforation and otorrhea; a diagnosis of otitis media with effusion behind an intact tympanic membrane was made in the other 33 children. The prevalence of otitis media varied significantly with age and evidence of upper respiratory tract infection. There was no significant difference between sexes. External ear pathology was found as an independent variable in 24% of the 170 children; three-fourths of these children had concurrent middle ear pathology. The results are discussed in relation to the current understanding of the differences that exist in the epidemiology and pathogenesis of otitis media in different racial groups.

Differential proliferation in morphogenesis of lateral body folds

Morphometric analysis and thymidine autoradiography were used to test the hypothesis that differential growth in the form of proliferative asymmetry is a major contributor to formation of lateral body folds in somatopleure. Chick embryos provided an opportunity to study both spatial and temporal differentials within an individual stage of development. Ectoderm and mesoderm were studied as separate tissues. Thymidine labeling index ranged from 34% to 49% in ectoderm and 43% to 66% in mesoderm and was assumed to reflect rate of proliferation in populations with a 100% proliferation index. Density of cells ranged from ten to 13 cells/1,000 micrometers2 in ectoderm and ten to 15 cells/1,000 micrometers2 in mesoderm, with a mean density of 12 cells/1,000 micrometers2. Cellular proliferation was important in folding, because ectoderm showed highest frequencies of labeling and highest cell density in folding levels. Correlation of proliferative differentials with morphogenesis suggests that proliferation is the form of growth contributing to formation of lateral body folds in 20-somite chick embryos.

Differences of adrenal stress control mechanisms in subjects with glaucoma and normal subjects. Effect of vasopressin and pyrogen

Various types of glaucomatous and normal subjects were tested for the adequacy of the stress response of their hypothalamic-pituitary-adrenal axis to pyrogen and vasopressin. With pyrogen, a significant response of elevation of plasma cortisol levels was positively correlated with ocular pressure and changes of the optic disc. Those subjects with increased ocular pressure and optic disc cupping and pallor had greater rises of plasma cortisol levels. With vasopressin, a decreased response of plasma cortisol levels was negatively correlated with the degree of elevated ocular pressure. Those subjects with increased ocular pressure and lower tonographic outflow facilities had smaller rises of plasma cortisol levels. Both tests indicated a disturbance of the hypothalamic-pituitary-adrenal axis in subjects with glaucoma.

Radioimmunoassay of creatine kinase B-isoenzymes in serum of patients with azotemia, obstructive uropathy, or carcinoma of the prostate or bladder

We measured the concentrations of creatine kinase B-isoenzymes by radioimmunoassay in 271 serum specimens from patients with azotemia, benign prostatic hyperplasia, adenocarcinoma of the prostate, and transitional cell carcinoma of the bladder. There was no correlation between the concentrations of B-isoenzymes and creatinine in the sera of azotemic patients. Above-normal concentrations of B-isoenzymes were found in sera from three patients with acute renal failure, but in only two of 28 specimens from patients with chronic renal failure. Above-normal concentrations of B-isoenzymes also were found in sera from three of 18 patients with untreated carcinoma of the prostate, 10 of 25 patients with treated carcinoma, 20 of 135 patients with benign prostatic hyperplasia, and 10 of 33 patients and with transitional cell carcinoma of the bladder. An above-normal concentration of B-isoenzymes in serum has a low predictive value for adenocarcinoma of the prostate, was not a sensitive indicator of the presence of carcinoma, and was noted paradoxically in six patients with treated carcinoma who had normal acid phosphatase activities in serum. We conclude that routine measurement of B-isoenzymes is not useful to establish the diagnosis of adenocarcinoma of the prostate.

Radioimmunoassay of creatine kinase B-isoenzymes in serum of patients with azotemia, obstructive uropathy, or carcinoma of the prostate or bladder

We measured the concentrations of creatine kinase B-isoenzymes by radioimmunoassay in 271 serum specimens from patients with azotemia, benign prostatic hyperplasia, adenocarcinoma of the prostate, and transitional cell carcinoma of the bladder. There was no correlation between the concentrations of B-isoenzymes and creatinine in the sera of azotemic patients. Above-normal concentrations of B-isoenzymes were found in sera from three patients with acute renal failure, but in only two of 28 specimens from patients with chronic renal failure. Above-normal concentrations of B-isoenzymes also were found in sera from three of 18 patients with untreated carcinoma of the prostate, 10 of 25 patients with treated carcinoma, 20 of 135 patients with benign prostatic hyperplasia, and 10 of 33 patients and with transitional cell carcinoma of the bladder. An above-normal concentration of B-isoenzymes in serum has a low predictive value for adenocarcinoma of the prostate, was not a sensitive indicator of the presence of carcinoma, and was noted paradoxically in six patients with treated carcinoma who had normal acid phosphatase activities in serum. We conclude that routine measurement of B-isoenzymes is not useful to establish the diagnosis of adenocarcinoma of the prostate.

Choroidovitreal neovascular ingrowth after photocoagulation for proliferative diabetic retinopathy

In eight patients with proliferative diabetic retinopathy treated with focal photocoagulation for preretinal new vessels, recurrent preretinal new-vessel systems supplied from the choroid developed. Subsequent treatment in most cases failed to produce permanent obliteration of the new-vessels networks.

Assessment of conservation of number: an attempt to enhance ecological validity and diagnostic sensitivity

Two procedures were used to assess conservation of number in 56 kindergarten boys and girls. In the Standard condition children responded to the usual verbal questions about number. In the Modified condition the ability to conserve number was inferred from the child's judgments concerning which operations did or did not produce a promised increment in his collection of candies. In comparison to the Standard tests, the latter procedure was intended to be simpler verbally, more motivationally engaging, and more similar to the real-life situations in which children make judgments about quantity. Children performed significantly better in the Modified condition than in the Standard condition, a finding which suggests that the usual tests may not fully capture the child's understanding of number. Performance was also significantly better on tests of identity conservation than on tests of equivalence conservation. This identity-equivalence difference, however, was limited to the Standard condition; the two concepts were of equal difficulty when assessed by means of the Modified procedure.

Pars plana vitrectomy. Treatment for tractional macula detachment secondary to proliferative diabetic retinopathy

Pars plana vitrectomies were performed on 43 eyes with traction macular detachment secondary to proliferative diabetic retinopathy. Anatomic success, as judged by reattachment of the macula, occurred 28 (65%) eyes. Improved visual acuity occurred in 11 (26%) eyes. Severe complications occurring after vitrectomy included moderate to severe rubeosis iridis diabetica (28%), neovascular glaucoma (16%), vitreous hemorrhage (49%), and phthisis bulbi (14%). Eyes that received scatter photocagulation therapy at some time prior to macular detachment had a substantially lower incidence of successful postoperative reattachment of the macula than eyes never treated with photocoagulation.

Scleral buckling procedure for retinal detachments secondary to proliferative diabetic retinopathy

Ninety-two patients (99 eyes) underwent scleral buckling procedures for retinal detachment associated with proliferative diabetic retinopathy. Fifty-three procedures were for rhegmatogenous retinal detachment and 46 for tractional retinal detachment. The average follow-up period was 38 months. Anatomic success was assessed in terms of closure of retinal breaks (59/69, 86%), macular reattachment (42/90, 46%), and reduction in extent of retinal detachment postoperatively as compared to preoperatively (62/99, 63%). The visual acuity was better postoperatively in 33/99 (34%) of the eyes; 58/99 (58%) of the eyes maintained finger counting visual acuity. Improvement in visual acuity was more frequent in eyes with rhegmatogenous detachment (23/53, 43%) than in those with traction detachment (10/46, 22%). Although improvement is generally limited, some patients are markedly benefitted by scleral buckling procedures.

Column chromatography and immunoassay compared for measuring the isoenzymes of aspartate aminotransferase in serum

We compare a column-chromatographic method and a homogeneous immunoassay method for separately measuring the mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase. Analytical recovery for the two methods averaged 102% (SD, 2%) and 103% (SD, 4%), respectively, for 11 pools prepared by adding the purified isoenzymes to serum and 102% (SD 8.9%) and 89% (SD, 8.1%) for 26 unaltered specimens of human serum. In comparing the results of the immunoassay method (y) to the chromatographic method (x), our measurements agreed closely for the mitochondrial (y = 0.947 X + 7, r = 0.9991, standard error of estimate = 2.9 U/L) and cytoplasmic (y = 0.92x-6, r = 0.9995, standard error of estimate = 2.1 U/L) isoenzymes in pools prepared from the purified isoenzymes. Similar measurements of the 26 human serum specimens yielded the following results for least-squares evaluation; cytoplasmic isoenzyme y = 1.03x-11, r = 0.994, and standard error of estimate = 6.0 U/L; mitochondrial isoenzyme y = 0.75x+0, r = 0.927, and standard error of estimate = 3.9 U/L.

Column chromatography and immunoassay compared for measuring the isoenzymes of aspartate aminotransferase in serum

We compare a column-chromatographic method and a homogeneous immunoassay method for separately measuring the mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase. Analytical recovery for the two methods averaged 102% (SD, 2%) and 103% (SD, 4%), respectively, for 11 pools prepared by adding the purified isoenzymes to serum and 102% (SD 8.9%) and 89% (SD, 8.1%) for 26 unaltered specimens of human serum. In comparing the results of the immunoassay method (y) to the chromatographic method (x), our measurements agreed closely for the mitochondrial (y = 0.947 X + 7, r = 0.9991, standard error of estimate = 2.9 U/L) and cytoplasmic (y = 0.92x-6, r = 0.9995, standard error of estimate = 2.1 U/L) isoenzymes in pools prepared from the purified isoenzymes. Similar measurements of the 26 human serum specimens yielded the following results for least-squares evaluation; cytoplasmic isoenzyme y = 1.03x-11, r = 0.994, and standard error of estimate = 6.0 U/L; mitochondrial isoenzyme y = 0.75x+0, r = 0.927, and standard error of estimate = 3.9 U/L.

The effect of calcitonin in vitro on tooth germs in protein-energy malnourished rats

The effect of calcitonin on the development of incisor and molar tooth germs was studied in normal and nutritionally deprived newborn rats. Calcitonin affected the calcium uptake of nutritionally deprived molar tooth germs in the early postnatal period; this interaction was not seen in the later postnatal period, however.

Retinal branch vessel occlusion in acute intermittent porphyria

Three patients with acute intermittent porphyria were noted to have retinal branch vessel occlusion. Branch "vein" occlusion, segmental optic atrophy, and soft exudate were the most common ocular manifestation. Two patients had labile elevated hypertension. When patients present with retinal branch vessel occlusion and a constellation of bizarre symptoms that might include hypertension, abdominal pain, acute psychotic behavior and/or cutaneous photosensitivity, the diagnosis of acute intermittent porphyria should be considered.

The effect of protein-energy malnutrition on the development of bones in newborn rats

Collagen synthesis, 45Ca uptake, and the half-life of 45Ca in mandibles and long bones of rat pups suckled on dams fed 25 or 6% protein diets were determined. Collagen synthesis in both mandibles and long bones was impaired in the malnourished group at an early age. Protein-energy malnutrition appears to affect different developmental processes in these two bones. The principal interference with collagen synthesis in the mandible occurs when bone proline is converted into hydroxyproline. In contrast, proline uptake from the blood for deposit in bone matrix is the step of collagen synthesis mainly affected in long bone. In addition, the critical growth period of mandible was different from that of long bone. The calcium complex fraction (calcium bound to protein plus that in inorganic salts) was the main compartment affected in the malnourished group. However, the efficiency of calcification per milligram of matrix in the calcium complex fraction of the mandible and long bone was approximately the same in the control and malnourished groups, thus suggesting that accumulation of calcium occurs in parallel with the formation of bone matrix regardless of the nutritional conditions. The half-life of 45Ca in the various calcium fractions of both types of bone was 72 hours in both the control and malnourished groups except the calcium complex portion of the long bone of the control group, which was about 100 hours.

Physical and biochemical changes of the mandible and long bone in protein-energy malnourished newborn rats

The activities of alkaline and acid phosphatases, the linear dimensions and volumes of mandibles and long bones, and the level of calcitonin in serum of rat pups suckled on dams fed 25 or 6% protein diets were determined. In both mandibles and long bones, alkaline phosphatase activity corresponded to the calcification pattern, and acid phosphatase activity paralleled organic matrix formation. The calcitonin level in blood serum of the malnourished pups differed from that of controls only on day 5. The linear dimensions and volume were consistently more affected in long bones than in mandibles. These results may be explained in terms of the critical growth periods of these bones. In the mandible, the critical growth period appears to occur prenatally, whereas in the long bone it occurs postnatally, when the nutritional stress of this experiment was applied. Long bones were thus generally more affected than mandibles.

In vitro collagen synthesis of tooth germs from newborn rats with protein-energy malnutrition

Mineralization and matrix formation are closely related processes in the growth and development of both incisor and molar tooth germs. Addition of ascorbic acid does not affect in vitro collagen synthesis of tooth germs from protein-energy malnourished rats.

Ticrynafen and hydrochlorothiazide. A double-blind study of antihypertensive properties with an open crossover

Twenty-eight patients completed a double-blind study of the antihypertensive effects of ticrynafen compared with those of hydrochlorothiazide. The results of blood pressure reduction were comparable in the two groups. After six months, 12 patients were crossed over to ticrynafen therapy from hydrochlorothiazide. They maintained their blood pressure reduction. The most striking difference between the two groups was in the uric acid response. The uric acid level in the patients receiving hydrochlorothiazide therapy rose from a baseline of 5.9 to 7.5 mg/dL (normal range, 3.0 to 8.0 mg/dL). The uric acid level of those patients receiving ticrynafen therapy decreased from a baseline of 6.4 mg/dL to a low of 3.3 mg/dL. In view of ticrynafen's appreciable antihypertensive and uric-acid-lowering effects, it appears to be a useful new antihypertensive drug.

The effect of protein-energy malnutrition on the growth of tooth germs in newborn rats

The effect of protein-energy malnutrition on the growth of molar and incisor tooth germs was studied. Significant differences were found between control and malnourished groups in the weights and calcium contents of both tooth germs. The data point to the importance of the effect of nutrient deficiency on the critical growth period of an oral structure.

The effect of hypervitaminosis A on rat palatal development

Retinoic acid or retinyl acetate was administered to pregnant rats in doses sufficient to induce a 90% incidence of cleft palate. In another study, a delay in the reorientation of the palatal shelves was observed to be longer with the more potent teratogen, retinoic acid. On day 16 of gestation, 24 hours after final dosage with vitamin A, the synthesis of DNA and protein was studied in fetal carcass, mandible, and palate, and that of sulfated mucopolysaccharides (S-MPS) and glycoproteins (GP) in fetal head, mandible, and palate. Increases in DNA synthesis in fetal palate and in GP synthesis in fetal palate were found; thus, the mechanism of action of vitamin A in inducing cleft palates in rats may be caused by interference with the normal biochemical synthetic pattern of the palatal shelves.

Column-chromatographic separation of isoenzymes of aspartate aminotransferase

We describe a column-chromatographic method for separating the mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase in human serum. Bed height of the ion exchanger, pH, and salt concentrations in the eluting buffers are shown to be variables affecting the separation of the isoenzymes. Under the optimized conditions selected for this study, a 30% increase in volume was observed in one fraction, associated with changing the salt concentration of the eluting buffer and attributed to a contraction of the DEAE-Sephadex A-50. Elution profiles (enzyme activity vs. fraction number) were examined with highly purified mitochondrial and cytoplasmic isoenzymes of human origin in bovine serum albumin and human serum. Recovery of the enzyme in the eluted fractions averaged 102% (SD, 2.0%) for specimens prepared from the purified isoenzymes and 104% (SD, 10.7%) for 38 human serum specimens. The separation technique showed linearity to catalytic concentrations in excess of 200 U/liter (reaction temperature 30 degrees C) for each isoenzyme. Additional information is presented regarding among-day precision and the effect of specimen dilution.

Column-chromatographic separation of isoenzymes of aspartate aminotransferase

We describe a column-chromatographic method for separating the mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase in human serum. Bed height of the ion exchanger, pH, and salt concentrations in the eluting buffers are shown to be variables affecting the separation of the isoenzymes. Under the optimized conditions selected for this study, a 30% increase in volume was observed in one fraction, associated with changing the salt concentration of the eluting buffer and attributed to a contraction of the DEAE-Sephadex A-50. Elution profiles (enzyme activity vs. fraction number) were examined with highly purified mitochondrial and cytoplasmic isoenzymes of human origin in bovine serum albumin and human serum. Recovery of the enzyme in the eluted fractions averaged 102% (SD, 2.0%) for specimens prepared from the purified isoenzymes and 104% (SD, 10.7%) for 38 human serum specimens. The separation technique showed linearity to catalytic concentrations in excess of 200 U/liter (reaction temperature 30 degrees C) for each isoenzyme. Additional information is presented regarding among-day precision and the effect of specimen dilution.

Systemic reaction to subconjunctival phenylephrine

After a subconjunctival injection of phenylephrine, cocaine and atropine, a patient's blood pressure rose to 220/180 mmHg. This rise was followed by hypotension, pulmonary edema, and subendocardial ischemia, all of which resolved spontaneously within 12 hours. This report reemphasizes the hazardous effects on blood pressure of phenylephrine applied to the eye.