A pseudopeptide incorporating the tetrahydrophthalazine nucleus,a constrained Aza analog of phenylalanine

Replacement of the α-carbon with a nitrogen in α-amino acids gives rise to azaamino acids. Most examples of azaamino acids that have been incorporated into peptides are linear analogs, in which conformational effects are restricted to the immediate vicinity of the urea bond. In contrast to the linear azaamino acids, the heterocyclic analogs might be expected to exhibit stronger conformational preferences, but examples of this class of azaamino acids are very limited. We synthesized tetrahydrophthalazine (THPhth) as a constrained phenylalanine analog and elaborated it into the model pseudotripeptide N-{([N-alanyl]-1,2,3,4-tetrahydro-2-phthalazinyl)carbonyl)}-L-alanine (1). As shown by NMR studies, tetrahydrophthalazine 1A has a secondary structure in which ψTHPhth is fixed at 16–18° and there are two equal populations of cis and trans amide bonds from the N-terminal alanine. © Munksgaard 1996.     

Acoustic Stimuhtion-induced Fetal Response Compared to Traditional Nonstress Testing

Eighty-eight nonstress tests (NSTs) were obtained on gravid women between 27 and 44 weeks' gestation to compare the results of a three-second acoustic stimulus with a traditional NST. Length of testing time was significantly decreased with the use of acoustic stimulation. Consequently, nursing time and equipment use were also considerably lessened per test. Previous studies indicated that the predictive value of the acoustic stimulation test is comparable or better than the traditional NST.     

The Pathogenesis of Idiopathic Hypercalciuria: Evidence for Parathyroid Hyperfunction

We studied the effect of calcium deprivation and loading in17 healthy subjects and 76 patients with renal calculi. Fivehad primary hyperparathyroidism with an elevated plasma ionisedcalcium and detectable plasma parathyroid hormone. Forty-ninehad idiopathic hypercalciuria, defined by a urine calcium greaterthan 7 mmol/day on a free diet. Twenty-two were normo-calciuric.Fasting plasma calcium, corrected for albumin, was higher inthe patients with idiopathic hypercalciuria (2.40±0.10mmol/1) than in controls (2.28 ±0.05 mmol/1, p < 0.005).Plasma calcium was intermediate in the normocalciuric stoneformers (2.35 ±0.08 mmol/1) and elevated in the patientswith primary hyperparathyroidism (2.62 ± 0.07 mmol/1).Nephrogenous cyclic adenosine monophosphate (cAMP) and parathyroidhormone levels were highest in the primary hyperparathyroidgroup and did not differ significantly within the other groups.Nephrogenous cAMP correlated positively with plasma calciumin the patients with primary hyperparathyroidism and negativelyin controls; there was no correlation in the idio-pathic hypercalciuriagroup. Following an oral calcium load, plasma calcium rose andnephro-genous cAMP fell similarly in all groups. Fasting urinarycalcium and its increase after load were greatest in the idiopathichypercalciuria and primary hyperparathyroid groups, with inter-mediateresults in the normocalciuric patients. Neither the initialmetabolic patterns nor the response to thiazide fitted withthe previously described patterns of absorptive and renal hypercalciuria.Increased parathyroid gland activity is the most probable causeof idiopathic hypercalciuria.     

Waldenstrom's Macroglobulinemia: Correlation Between Expanded Plasma Volume and Increased Serum Viscosity

In 17 patients with Waldenström’s Macroglobulinemia, total chromiumspace, red cell mass, plasma volume and relative serum viscosities were determined; aldosterone excretion was determined in 12. Ten of the 15 patients whomanifested elevated serum viscosity at some time during the course of studypresented signs and symptoms of hyperviscosity syndrome. All patients had increased total blood volume. Fifteen had moderate decreases in red cell massbut all had elevations of plasma volume far in excess of that required to compensate for the lowered cell mass. The degree of the increase in plasma volumecorrelated (r = 0.74) with the degree of abnormality in relative serum viscosity. Aldosterone excretion in such patients was normal to low. It is concluded that the plasma volume increase is correlated with serum viscosity andis mediated by sodium retention mechanisms not involving modification ofaldosterone secretion.

     

Plaque inhibition by guanidino propyl piperazine (CKO 569A)

The plaque inhibiting effect of the antibacterial substance, guanidino propyl piperazine (CKO 569A) has been analyzed in a clinical study of 10 adults. Plaque formation was enhanced by three daily rinses with 15% sucrose. Normal hygiene was performed. The effects of a twice daily mouthwash of 30 s duration with 0.2, 0.1 and 0.05% CKO 569A, 0.05% chlorhexidine and a placebo on plaque formation were compared through a registration of plaque scores. Each solution was tested over a period of 5 days. As a result of this study it could be concluded that in humans CKO 569A is an effective inhibitor of plaque, and that lingual plaque scores appear to be a good indicator of plaque inhibiting activity.     

The Effect of Early Feeding on the Development of Obesity

Early influences associated with adult obesity include overfeeding leading to fat cell hyperplasia, inactivity, and faulty mechanisms of control of food intake. The first year of life is critical for the intiation of these influences; thus we need to reevaluate some of the approaches to infant feeding. Excessive weight gains in infants must be taken seriously. This article reviews related literature and makes recommendations for preventing early obesity.     

Pulp structure in bilateral and opposing pairs of teeth

abstract — The general structure, degree of vacuolization of the odontoblast layer, and the stage of root development were evaluated in demineralized, hematoxylin-eosin stained sections of 21 monkey incisors and 35 human premolars. Emphasis was placed on a comparison between bilateral and opposing pairs. It was found that opposing pairs did not differ more than bilateral pairs. These observations imply that bilateral and opposing pairs are equally satisfactory as control teeth in experimental studies. It is suggested that the unaffected pulp tissue in the experimental tooth may be the most reliable control tissue except in situations where the major part of the pulp tissue is affected by the experimental procedure.