The Effects of Some Chlorinated Hydrocarbons on Certain Soil Bacteria

S ummary . Some common soil bacteria have been shown to tolerate the presence of chlorinated hydrocarbon fumigants. Several of these bacteria indicated an ability to utilize the chemicals as carbon or energy sources. The breakdown of these fumigants may yield compounds either beneficial or detrimental to plants grown in treated soil. Such information is critical to plant disease control since these chemicals are used for the control of plant pathogens, primarily nematodes. It is suggested that the side effects of soil treatment by which plants are stimulated in their growth is a direct consequence of enhanced beneficial microbial activity.     

Electronic recording of mosquito activity

Spontaneous locomotor activity of mosquitoes (Aedes aegypti) was tested over twenty-four hour periods using an electronic recording device which gave a permanent time graph of activity. Single mosquitoes were placed on a wire grid with alternate strands connected to the positive and negative poles of an electric circuit. Each time the mosquito moved, the electric current changed and the event was recorded by a pen-writer. The number of peaks per time interval gave the index of activity. Variables which may affect activity include age, physiological state, sex and strain. A distinct activity cycle was evident in both virgin and mated females but not in males; peak activity came in the early evening and activity was lowest in the early afternoon.

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Zusammenfassung Die spontane lokomotorische Aktivität von Mücken (Aedes aegypti) wurde über 24stündige Perioden mit Hilfe einer elektronischen Registriereinrichtung untersucht, die eine ununterbrochene Zeitschreibung der Aktivität ergab. Einzelne Mücken wurden auf einen Gürtel feiner Drähte gesetzt, deren Stränge abwechselnd zu den positiven und negativen Polen eines elektrischen Stromkreises führten. Jedesmal wenn sich die Mücke bewegte, änderte sich der elektrische Stromfluß; dieses Ereignis wurde von einer Schreibfeder aufgezeichnet. Die Anzahl der Ausschläge pro Zeiteinheit ergab den Aktivitätsindex. Variable, welche die Aktivität beeinflussen, umfassen Alter, physiologischen Zustand, Geschlecht und Abstammung. Bei jungfräulichen wie bei begatteten Weibchen war ein bestimmter Aktivitätszyklus erkennbar, jedoch nicht bei Männchen; der Aktivitätsgipfel lag in den frühen Abendstunden und die Aktivität war am zeitigen Nachmittag am geringsten.

     

Transepithelial prostacyclin gradient in isolated canine trachea

Cyclooxygenase products of arachidonic acid, potential modulators of airway smooth muscle, have recently been described in bronchoalveolar lavage from canine lungs. To evaluate the possibility that airway epithelium represents a barrier to movement of prostacyclin (PGI2), an important bronchodilator synthesized by isolated airway, we measured the concentrations of 6-oxoprostaglandin F1 alpha (6-oxo-PGF1 alpha), the stable degradation product of PGI2, on the mucosal and serosal sides of isolated canine tracheal segments (CTS) mounted in Ussing chambers. 6-oxo-PGF1 alpha was measured by radioimmunoassay after purification by high-performance liquid chromatography. The concentration of 6-oxo-PGF1 alpha was significantly higher on the serosal than the mucosal side of CTS (1,262 +/- 252 vs. 390 +/- 168 pg.min-1.g-1, n = 8, P less than 0.05). A significant correlation was present between 6-oxo-PGF1 alpha measured on both sides of each CTS (r = 0.778, n = 26, P less than 0.01). 6-oxo-PGF1 alpha production from CTS stripped of mucosa was significantly greater than from isolated mucosa. Radiochromatograms obtained after incubation with [3H]arachidonic acid and calcium ionophore A23187 confirmed PGI2 as the predominant cyclooxygenase product of the submucosa, whereas the mucosa produced only small amounts of PGI2 in proportion to other cyclooxygenase products. PGI2 (10(-8) to 10(-6) M) applied to the mucosal surface of closed tracheal segments precontracted with histamine resulted in no significant relaxation, whereas serosal application showed a concentration-dependent effect. Radiolabeled 6-oxo-PGF1 alpha did not cross the isolated epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)     

Outcome of elective prostatectomy.

OBJECTIVES--To determine the symptomatic and urodynamic outcome of elective prostatectomy and to establish whether the outcome is influenced or can be predicted by preoperative urodynamic measurements. DESIGN--Prospective non-randomised study with follow up at a mean of 11 months after operation. Most men were assessed jointly by a urologist and a general practitioner. SETTING--Department of urology in a teaching hospital serving a large district population. PATIENTS--253 Men listed for elective prostatectomy because of symptoms and low urinary flow rates (less than 15 ml/s) and excluding those already on a waiting list or with acute urinary retention, clinically apparent prostatic cancer, and neurological or cerebrovascular disease; 217 (86%) were followed up. INTERVENTION--Elective prostatectomy. MAIN OUTCOME MEASURE--Classification on the basis of relief of symptoms assessed by patients and urologist and general practitioner and of symptom scores obtained by questionnaire. RESULTS--Of the 217 men followed up, 171 (79%) had a satisfactory subjective review and 155 (72%) had a satisfactory review and also low symptom scores. An unsatisfactory outcome was associated with preoperative symptoms of urge incontinence, small prostatic size and resected weight, low voiding pressures, and low urethral resistance. Preoperative maximum urinary flow rates did not predict outcome. Men with poor outcome could be classified into two groups: those with irritative symptoms who were more likely before operation to have had urge incontinence and detrusor instability and men with symptoms of poor urinary flow who were more likely before operation to have had a small prostate, low voiding pressures, and low urethral resistance. In patients in the second group flow rates or voiding pressures improved little after operation. Men with stable detrusors and either low urethral resistance or low voiding pressures were less likely to do well after prostatectomy, but despite these associations preoperative urodynamic measurements were unable to predict outcome accurately. CONCLUSIONS--Prostatectomy was satisfactory in relieving symptoms and improving urodynamic measurements in most men, but even in those with classic symptoms and low urinary flow rates a substantial minority experienced little improvement afterwards and urodynamic measurements did not accurately predict outcome in individual patients.     

The use of peptide analogs with improved stability and MHC binding capacity to inhibit antigen presentation in vitro and in vivo

The identification of a core region for OVA 323-339, which is critical in determining binding to IAd, has enabled us to generate a series of analog peptides in which this core region was extended at both the N and C termini with different amino acid residues. When assessed for binding capacity, several peptides were shown to have increased affinity for IAd compared with the parent sequence, and in addition, some peptides had acquired binding specificities for class II MHC haplotypes not present for OVA 323-339. These peptides were next examined for their ability to inhibit T cell responses in vitro and in vivo. The correlation between binding and the ability to inhibit T cell activation in vitro was good. However, when assessed in vivo, it was clear that high Ia binding was not sufficient in itself to define the inhibitory capacity of a given peptide. That this discrepancy was due to differences in degradation of the core-extended peptides was suggested by 1) results from an inhibition of Ag presentation assay, in which the pulse period with Ag and inhibitor was extended to 20 h; and 2) direct analysis of peptide stability by using reverse phase HPLC. Finally, by protecting the peptide from degradation with N- and C-terminal substitutions of D-amino acids, the inhibitory capacity of an unstable core-extended peptide in vitro could be greatly enhanced. These data indicate that the core extension approach may be one method by which antagonists for MHC class II molecules may be generated.     

Linkage of PGK1 to X-linked severe combined immunodeficiency (IMD4) allows predictive testing in families with no surviving male

Summary We present a linkage map of DNA probes around the X-linked severe combined immunodeficiency (IMD4) locus at Xq11-13. DXS159 and PGK1 show no cross-overs with the disease locus (Lod 3.01 at = 0.00). The order of loci is DXS1-DXS106-(DXS159-PGK1-IMD4)-DXS72-DXYS1. Members of families whose carrier status has been established by X-inactivation patterns were included in the analysis. As the probe (pSPT/PGK), which is used for investigation of X-inactivation patterns, has been shown to be linked to the disease itself, it is possible to assign phase in mothers of sporadic cases who have been shown to be carriers, even when they have no surviving male offspring.