The growth hormone response to clonidine in acute and remitted depressed male patients

The growth hormone (GH) response to clonidine was evaluated in 28 acutely depressed male patients, 17 remitted depressed patients, and 26 normal control subjects. The GH response to clonidine was blunted (delta less than 4 ng/ml) in a significantly increased proportion of both acute and remitted patients compared to control subjects. Covarying for age effects, the GH response to clonidine (as area-under-the-curve) was not significantly different between any of the three groups, but was significantly diminished in both the acute and remitted depressed patients who were ever hospitalized for an episode of depression, compared to control subjects. Six patients studied in both the acute and remitted states were blunted in both states. These findings could not be accounted for by other clinical and demographic variables including weight, time off antidepressants, severity of current depressive symptoms, and subtype of depression. These results raise the possibility that the blunted GH response to clonidine may represent a state-independent correlate of some forms of severe depression. Issues regarding the specificity and interpretation of this finding require further clarification.

Detection of bacteriuria and pyuria by URISCREEN a rapid enzymatic screening test

A multicenter study was performed to evaluate the ability of the URISCREEN (Analytab Products, Plainview, N.Y.), a 2-min catalase tube test, to detect bacteriuria and pyuria. This test was compared with the Chemstrip LN (BioDynamics, Division of Boehringer Mannheim Diagnostics, Indianapolis, Ind.), a 2-min enzyme dipstick test; a semiquantitative plate culture method was used as the reference test for bacteriuria, and the Gram stain or a quantitative chamber count method was used as the reference test for pyuria. Each test was evaluated for its ability to detect probable pathogens at greater than or equal to 10(2) CFU/ml and/or greater than or equal to 1 leukocyte per oil immersion field, as determined by the Gram stain method, or greater than 10 leukocytes per microliter, as determined by the quantitative count method. A total of 1,500 urine specimens were included in this evaluation. There were 298 specimens with greater than or equal 10(2) CFU/ml and 451 specimens with pyuria. Of the 298 specimens with probable pathogens isolated at various colony counts, 219 specimens had colony counts of greater than or equal to 10(5) CFU/ml, 51 specimens had between 10(4) and 10(5) CFU/ml, and 28 specimens had between 10(2) and less than 10(4) CFU/ml. Both the URISCREEN and the Chemstrip LN detected 93% (204 of 219) of the specimens with probable pathogens at greater than or equal to 10(5) CFU/ml. For the specimens with probable pathogens at greater than or equal to 10(2) CFU/ml, the sensitivities of the URISCREEN and the Chemstrip LN were 86% (256 of 298) and 81% (241 of 298), respectively. Of the 451 specimens with pyuria, the URISCREEN detected 88% (398 of 451) and Chemstrip LN detected 78% (350 if 451). There were 204 specimens with both greater than or equal to 10(2) CFU/ml and pyuria; the sensitivities of both methods were 95% (193 of 204) for these specimens. Overall, there were 545 specimens with probable pathogens at greater than or equal to 10(2) CFU/ml and/or pyuria. The URISCREEN detected 85% (461 of 545), and the Chemstrip LN detected 73% (398 of 545). A majority (76%) of the false-negative results obtained with either method were for specimens without leukocytes in the urine. There were 955 specimens with no probable pathogens or leukocytes. Of these, 28% (270 of 955) were found positive by the URISCREEN and 13% (122 of 955) were found positive by the Chemstrip LN. A majority of the false-positive results were probably due, in part, to the detection of enzymes present in both bacterial and somatic cells by each of the test systems. Overall, the URISCREEN is rapid, manual, easy-to-perform enzymatic test that yields findings similar to those yielded by the Chemstrip LN for specimens with both greater than or equal to 10(2) CFU/ml and pyuria or for specimens with greater than or equal to 10(5) CFU/ml and with or without pyuria. However, when the data were analyzed for either probable pathogens at less 10(5) CFU/ml or pyuria, the sensitivity of the URISCREEN was higher (P less than 0.05).

The in-vitro activity of temafloxacin, against gram-positive bacteria

Temafloxacin, a new fluoroquinolone with enhanced activity against Gram-positive bacteria, was compared with other antibiotics. A review of the literature on the in-vitro activity of temafloxacin was also done. The susceptibility of Gram-positive cocci isolated from blood cultures was determined using a broth microdilution method. Temafloxacin MIC90s for Staphylococcus aureus (oxacillin-sensitive and -resistant) and Streptococcus pneumoniae were less than 0.12, less than 0.12 and 0.76 mg/L respectively. Temafloxacin was more active than either ciprofloxacin or ofloxacin against these organisms. A review of the literature supported these findings. Temafloxacin was the most active of the quinolones tested against a small number of S. pneumoniae with decreased sensitivity to penicillin. Temafloxacin activity was not appreciably affected by changes in pH or the presence of serum, but activity was slightly reduced in urine at pH 6.5-7.2, and at high magnesium ion concentrations. With the exception of S. pneumoniae at high concentration, no significant inoculum effect was observed.

Growth hormone responses to intravenous clonidine challenge correlate with behavioral irritability in psychiatric patients and healthy volunteers

To explore the relationship between central noradrenergic receptor responsivity and indices of impulsive aggression, growth hormone responses to infusions with the alpha 2-adrenergic receptor agonist clonidine (GH[CLON]) and responses on the Buss-Durkee Hostility Inventory (BDHI) were examined in healthy male volunteers and male patients with major affective or personality disorder. GH[CLON] values were found to correlate significantly with the BDHI "Irritability" subscale in all subjects, but especially in healthy volunteer and personality disorder patients. GH[CLON] values did not correlate with the BDHI "Assault" subscale. These results suggest a role for central alpha 2-adrenergic receptor responsivity in the personality trait characterized by behavioral irritability, but not overt assaultiveness, in humans.

Effect of nitrogen fertilizer on beef production and forage quality of Russian wildrye

A grazing study was conducted for 12 yr on a Brown loam in a semi-arid climate at Swift Current, Saskatchewan to determine the effect of nitrogen (N) fertilizer on beef production, forage quality, and economic returns of Russian wildrye (Psathyrostachys juncea (Fisch) Nevski) (RWR). Treatments were: annual broadcast of N fertilizer such that available soil N (0–60 cm depth) plus applied N totalled 55 kg ha−1; an application in which available plus applied N totalled 110 kg ha−1; a one-time application of 390 kg N ha−1 (April 1977); and a control treatment with no fertilizer. Treatments were compared by regression analysis using soil available plus fertilizer N and age of stand as the independent variables. Pastures were grazed each year with yearling steers from early May until 5 cm grass height remained or when steers did not gain weight in a 2-wk period (resulting in an average grazing period of 120 d). Total grazing days averaged 166, 179, 165 and 132 days ha−1, respectively, for the four treatments. For the 55 N treatment, in which 32 kg N ha−1 was applied annually, an average of 1 kg of beef gain was obtained for each kilogram of N applied. Daily gain of steers averaged 0.84 kg d−1 for all years and treatments. Stocking rate (grazing days/ha) was positively correlated to spring soil moisture plus grazing season precipitation (r = 0.67) and negatively related to pan evaporation (r = 0.87). Fertilizer treatments marginally increased forage N and OMD early in the season. Forage N, phosphorus, and organic matter digestibility (OMD) declined in a linear relationship with time from 1 May. The rate of decline was not affected by the treatments. On the basis of liveweight gain, all fertilizer treatments were profitable. Profitability varied with the ratio of the cost of fertilizer N to steer price; annual fertilizer applications were more profitable than the one-time application. Key words: Psathyrostachys juncea, yearling steer performance, forage digestibility, forage quality

The incidence of secondary hemorrhage after traumatic hyphema

A retrospective study was undertaken to determine the incidence of secondary hemorrhage after traumatic hyphema in a medium-sized Canadian city. This was found to be 10%, which is similar to the incidence reported in other Canadian and northern European cities but much lower than that reported in some large American cities. The different racial mix of the sample populations is the most likely reason for these differences.

Actin filament organization of the Dunning R3327 rat prostatic adenocarcinoma system: correlation with metastatic potential

Recently, Volk, Geiger, and Raz (Cancer Res., 44: 811-824, 1984) addressed the question of whether variations in actin organization in clones of the murine K-1735 melanoma tumor correlated with their metastatic capability. Using immunofluorescence techniques, they found that clones which had a more ordered actin network were less metastatic, whereas clones having a diffuse actin staining pattern were more metastatic. Similarly, we have found that in the Dunning rat R3327 prostatic adenocarcinoma tumor system, the non-metastatic (less than 0.1%) H-prostatic tumor cell line has a prominent network of actin filament bundles, whereas the highly metastatic (greater than 90%) MatLyLu cell line has a diffuse actin staining pattern. In the low-metastatic (less than 10%) AT1 cell line an intermediate actin organization between H and MatLyLu was observed. Analysis of cell extracts from H- and MatLyLu-cells revealed differences in the level of activity of cellular proteins which affect actin filament assembly and structure in a manner similar to that of the cytochalasins, fungal metabolites which bind with high affinity to the fast-growing end of actin filaments. Extracts of MatLyLu were significantly more effective than those of H-cells in decreasing the extent of actin filament network formation and in inhibiting the rate of filament assembly by blocking monomer addition onto the fast-growing end. Measurements of spin-lattice nuclear magnetic resonance water proton relaxation times (T1) were made in surgically removed tumor tissue from four sublines (H, AT1, MatLyLu, and MatLu) of the Dunning R3327 tumor system. The highly metastatic cell lines had significantly longer water proton T1 relaxation times than did the lines with low metastatic potential. These differences in T1 may reflect the observed alterations in organization of actin filaments within these various sublines of the Dunning R3327 prostatic adenocarcinoma tumor system.

Reactions of methyl-substituted Hex-5-enyl and Pent-4-enyl radicals

Relative and absolute kinetic data have been determined for ring closure of methyl-substituted hex-5-enyl radicals: 2-methyl- (10a), 3-methyl-(4a), 4-methyl-(5a), 2,2-dimethyl-(10c), 3,3-dimethyl-(4c) and 4,4-dimethyl-hex-5-enyl (5c) radicals, generated by interaction of tributylstannane with the corresponding bromides (1a)-(3a) and (1c)-(3c). Each radical undergoes regiospecific or highly regioselective 1,5-cyclization more rapidly than does the unsubstituted radical (4d). The rate enhancements, which arise mainly from lowering of the activation energy, can be rationalized in terms of the gem-dimethyl effect. 1,5-Ring closures of monosubstituted species are stereoselective: 2-methyl- and 4-methyl-hex-5-enyl radicals (10a) and (5a) give mainly trans products, whereas 3-methylhex-4- enyl radical gives mainly the cis. This behaviour reflects the effect of the substituent on the stabilities of cyclic transition complexes in chair-like conformations. Ring closure of 2,2-dimethylpent-4-enyl radical or of 3,3-dimethylpent-4-enyl radical (19) could not be detected.

The influence of prostacyclin on coronary occlusion induced arrhythmia in cats

The present study examined the effect of prostacyclin (PGI2) on ventricular arrhythmias following coronary artery occlusion in the cat. The left anterior descending coronary artery (LAD) was occluded abruptly in 50 cats anesthetized with alpha-chloralose. The ECG (Lead II) along with arterial blood pressure were monitored before and for at least one hour after occlusion. Either vehicle or PGI2 was infused at a rate of 0.15 ml . min-1 into the left atrium 15 min before and 1 hour after LAD occlusion. PGI2 was infused at 4 doses: 2.7,27,270 and 2700 pmole . kg-1 . min-1. Infusion of PGI2 before occlusion produced a dose dependent decrease in mean arterial blood pressure with no significant change in heart rate. Abrupt occlusion of the LAD produced ventricular arrhythmia in all cats ranging from ventricular premature beats to ventricular fibrillation (VF). In cats infused with PGI2 the incidence of VF ranged from 30-40% at the low and middle doses to a maximum of 60% at the highest dose (2700 pmole . kg-1 . min-10. The incidence of VF in the latter group was two times greater than that observed in the control group (30%). In addition, the mean number of ventricular ectopic beats was greater at the 27 and 2700 pmole . kg-1 . min-1 doses of PGI2 than in the control group. An increase in ventricular ectopic beats was not observed at the 2.7 or 270 pmole . kg-1 . min-1 doses of PGI2. These data indicate the PGI2 can exert an arrhythmogenic effect following coronary artery occlusion and that this effect occurs in a biphasic manner i.e., the increase in arrhythmia observed at 27 did not occur at 270 but occurred again at the 10 fold higher dose (2700 pmole . kg-1 . min-1). At the lowest dose of PGI2 infarct size was approximately 14% less than in the control group while, at the highest dose, infarct size was 20% greater than control and approximatey 40% greater than the lowest dose of PGI2.

Comparison of the effects of prostaglandins E1 and A1 on coronary occlusion induced arrhythmia

The present study compares the effects of PGE1 and PGA1 on ventricular arrhythmias following coronary artery occlusion. The left anterior descending coronary artery (LAD) was occluded abruptly in 55 cats anesthetized with alpha-chloralose. Lead II of the ECG along with arterial blood pressure were monitored for one hour after occlusion. Either vehicle or prostaglandin was infused into the left atrium (LA) or femoral vein (IV) 15 min prior to and for 1 hour after LAD occlusion at a rate of 0.15 ml/min. Prostaglandin was infused at either a high dose (1.0 microgram/kg/min) or a low dose (0.1 microgram/kg/min). Infusion of either PGE1 or PGA1 produced a marked fall in blood pressure and heart rate which returned toward control before occlusion. Abrupt occlusion of the LAD produced ventricular arrhythmia in all cats ranging from ventricular premature beats to ventricular fibrillation (VF). The control animals had a 38% incidence of VF. VF occurred in 75% of the animals in which PGE1 was administered into the LA at either the high or low dose while the occurrence in those administered PGA1 was 67% and 50%, respectively. Intravenous administration of the high dose of PGE1 or PGA1 resulted in VF in 13% and 67% of the animals after LAD occlusion, respectively. These data indicate that the IV administration of PGE1 may protect the heart from VF while the infusion of PGE1 or PGA1 into the LA may enhance VF after LAD occlusion.

INHERITANCE OF A VARIEGATED FOLIAGE CHARACTER IN RUSSIAN WILD RYEGRASS, ELYMUS JUNCEUS FISCH

Segregation in population derived by crossing heterozygous progeny of Sc.260181, a variegated plant of Russian wild ryegrass, and Sc.25311, a normal plant, showed a 12 normal green:3 variegated:1 albino ratio indicating inheritance according to the dominant epistasis pattern for two factors.

THE INTERRELATIONSHIP OF GENETIC AND MATERNAL CONTROL IN A SELECTED POPULATION OF LOLIUM PERENNE

The interrelationship of the maternal and genetic control for seed weight, rate of tiller production, length of fifth leaf, and total adult plant production in a 5 × 5 diallel cross of Lolium perenne L. were studied by estimation of the phenotypic, environmental, genetic, and maternal correlations. Genetic and maternal components of increased seed size lead to a reduction in tillering, leaf size and final production indicating that large seeds are not generally advantageous to growth and development. Environmental factors which promoted tillering also increased leaf length. Maternal control showed a similar pattern. However, genetic control indicated that the faster the tillering, the shorter the leaves, thus emphasizing the possible danger of considering only a single factor in selecting for increased yield. Phenotypic correlations indicate that total production was determined largely by tiller production with environmental factors influencing leaf length and tiller production. Neither genetic nor maternal control of tiller number or leaf size at the seedling stage greatly influenced final production, indicating that selection for either of these characters separately would not likely influence yield. The controls for maternal and additive genetic effects were found to be different. Maternal effects were strong and extended well beyond the influence of seed size effects.