Influence of salmonid aquaculture activities on a rock-cliff epifaunal community in Jervis Inlet, British Columbia.

Benthic video surveys were carried out at two marine finfish aquaculture and associated reference sites in Jervis Inlet (JI), British Columbia. Substrate composition, epifaunal diversity, mat-forming taxa (primary indicators: opportunistic polychaete complexes (OPCs) and sulfide-oxidizing bacteria) and waste pellets were quantitatively assessed. Hard-bottom substrates were dominated by rock wall, skeletal sponge matrix, graded bedrock, rock-veneer, and cobble. Aquaculture waste outputs (modelled depositional carbon fluxes and observations of waste feed/faecal pellets) were correlated with benthic organic enrichment indicators (OPC and sulfide-oxidizing bacteria). Sulfide-oxidizing bacteria varied in abundance up to a modelled depositional carbon flux of ~2gCm-2day-1 where it sustained 50% areal coverage. Glass sponges revealed an inverse relationship with aquaculture waste outputs and sulfide-oxidizing bacteria. Plumose anemones and shrimp showed a low frequency of occurrence at reference sites; however, they were abundant within the near-field zone of the aquaculture sites associated with a higher modelled carbon flux. Future research should focus on the response of various taxa to depositional gradients and their potential role as secondary indicators of aquaculture activities associated with rock-cliff communities.

Measuring softness of inner female urethra. Part I. Simple new device.

A new device is described to measure clinically the softness of the female urethra. It is a rod-shaped urethral sound with a longitudinal groove along its surface. The sound is constructed in sizes 12 to 24 French. Each has one groove which is 2 mm wide and either 2, 2.5, or 3 mm deep. The groove is 11 cm long. When inserted into the filled female bladder per urethram, the groove will span the urethra from the bladder to the outside. If the urethral inner lining is soft and deformable, it will fill itself into the groove and prevent leakage of urine from the bladder along the groove to the outside. If the urethra is relatively rigid, urine will leak from the bladder. This instrument permits testing of women to determine urethral properties in preventing leakage when studied with a range of probe sizes.

Evaluation of inner urethral softness. Part II. Clinical study using new grooved probe device.

This study, in incontinent women, evaluates the effectiveness of a new device to measure properties of urethral softness. The device is a straight sound with a longitudinal groove cut along its surface. It is inserted through the urethra and into the bladder. A soft, deformable urethra is expected to fill itself into the groove and prevent the loss of urine from the bladder along the groove to the outside. Using this instrument it is learned that (1) postmenopausal women are less able to seal the urethra than younger ones; (2) as the urethra is stretched it is less able to form a seal; and (3) the anterior urethra is the weakest link in sustaining continence when tested by methods used in this program.

Role of inner urethral softness in urinary continence.

Given adequate external squeeze upon suitable urethral geometry, continence depends on the mechanical properties of the outflow tract wall. Evidence indicates that these mechanical properties include an ability to deform and behave in a fluid-like manner.

Megestrol acetate in treatment of benign prostatic hypertrophy.

In this study we found no significant effect on benign prostatic hypertrophy due to megestrol using standard clinical criteria. However, there is evidence using urinary drop spectrometer data which makes one suspect that megestrol does have a positive effect. If there is an effect, it is apparently so small as to be undetectable using the clinical protocol of this investigation. Since the urodynamic evidence does indicate a possibility of a positive effect, it appears reasonable to investigate further using a different protocol - perhaps a higher dosage and/or a more controlled test population.

Development and evaluation of a mass spectrometer-based continuous emission monitor for volatile organic compound emissions from combustion devices.

A mass spectrometer-based continuous emission monitor (MS-CEM) for organic compound emissions from combustion devices was developed and evaluated at the Louisiana State University (LSU) pilot-scale rotary kiln incinerator (RKI). The MS-CEM consists of a stack probe, heat-traced sampling line, vacuum pump, particulate filter, Nafion@ dryer and mass spectrometer. The mass spectrometer includes a computer that controls and optimizes the operation of the unit. The MS-CEM is capable of continuously analyzing up to 40 different volatile organic compounds on a real-time basis. The MS-CEM is capable of analyzing, computing and recording the analytical results for each and up to 40 different organic compounds in less than 0.3 s. Four different volatile organic compounds were mixed together and injected into the baghouse inlet while simultaneously analyzing each organic component exiting the RKI stack gas. The results obtained from MS-CEM were compared with the material balance values. The system response time (including the MS-CEM) varies from 1.1 to 1.5 min.

Measurement of the elasticity of the male urethral meatus by urinary drop spectrometry.

The urinary stream breaks up into drops shortly after leaving the external meatus. For normal males the frequency of the drops is related in a characteristic way to the flow rate. From this relation the elastic properties of an elastic constriction near the external meatus are calculated, using a theory of flow through distensible tubes. The elastic constriction behaves as if rigid at low flow rates, but distends elastically at flow rates above a critical value. This theoretical result is verified by observations of the stream emerging from a mechanical model, constructed with similar elastic properties. Functional meatal stenosis is associated with a lack of distensibility at the higher flow rates, which is reflected clinically in a changed relation between drop frequency and flow rate. Measurement of the relation, by the urinary drop spectrometer, offers a quick, non-invasive way of diagnosing this type of urethral obstruction.

Effect of atovaquone and atovaquone drug combinations on prophylaxis of Pneumocystis carinii pneumonia in SCID mice.

The prophylactic efficacies of atovaquone (ATQ) alone and in combination with azithromycin, clarithromycin, rifabutin, proguanil, PS-15, trimethoprim, co-trimoxazole, or dapsone were investigated in a SCID mouse model of Pneumocystis carinii pneumonia (PCP). ATQ alone was shown to have a significant dose-related effect, and at 200 mg/kg of body weight per day administered orally, the efficacy of ATQ was comparable to that of Septrin (co-trimoxazole). Of the drugs investigated orally in combination with ATQ, only dapsone (25 mg/kg/day) and to a lesser extent PS-15 (5 mg/kg/day) had any noteworthy antipneumocystis activity (at the doses examined) when administered alone. ATQ drug combinations affected the prophylactic efficacy of a subcurative dosage of ATQ (50 mg/kg/day given orally) in the following ways: dapsone (25 mg/kg/day) or co-trimoxazole (25 mg of sulfamethoxazole plus 5 mg of trimethoprim per kg/day) had no significant effect on ATQ, azithromycin (200 mg/kg/day) or clarithromycin (200 mg/kg/day) had a slight additive effect with ATQ, trimethoprim (100 mg/kg/day) or PS-15 (5 mg/kg/day) had an additive effect with ATQ, and proguanil (25 mg/kg/day) or rifabutin (200 mg/kg/day) had a marked synergistic effect on ATQ. The last result was particularly noteworthy as neither proguanil nor rifabutin was effective against PCP when administered alone. None of the drugs examined antagonized the prophylactic activity of ATQ in experimental PCP in SCID mice. The results suggest that clinical trials of ATQ with synergistic drug combinations may now be justified, particularly if such drug combinations improve ATQ's efficacy and broaden its spectrum of activity.

Artificial infections of Pneumocystis carinii in the SCID mouse and their use in the in vivo evaluation of antipneumocystis drugs.

A model for the in vivo evaluation of antipneumocystis drugs has been developed in SCID mice infected intratracheally with cryopreserved mouse-derived Pneumocystis carinii. The development of a highly reproducible fatal P. carinii pneumonia occurred within 10 weeks (mean survival time +/- SEM = 72.2 +/- 1.2 days). Continuous administration of dexamethasone (2 mg/liter in the drinking water) exacerbated the rate of onset of severe P. carinii pneumonia (mean survival time +/- SEM = 63 +/- 1.3 days) in SCID mice. The number of cysts per g of lung homogenate (homogenate counts) were maximal with an inoculum of 20,000 cysts at 6 weeks post infection. Homogenate counts correlated with infection scores (graded assessments of immunofluorescent cysts on lung impression smears) suggesting that infection scoring accurately and rapidly reflects the severity of P. carinii pneumonia in SCID mice. These studies led to the development of a drug screening protocol in which Pneumocystis-free female SCID mice (20-25 g) were started on dexamethasone 7 days prior to IT inoculation with a single dose of 20,000 cysts. Drugs were evaluated either for: a) prophylaxis (continuously from day 1 post infection) or b) treatment (from day 21 post infection) until day 42 post infection, when all mice were killed and infection scores determined. Co-trimoxazole (at 250 mg sulfamethoxazole + 50 mg trimethoprim/kg/day) given in the drinking water was found to be highly effective in both the prophylaxis and treatment of mouse P. carinii pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)

A new aspect of voiding dynamics: the relationship between flow rate and the frequency of drops in the external urinary stream.

The method of drop spectrometry gives the possibility of registering the instantaneous trend drop frequency and the instantaneous trend flow rate. By plotting the flow rate against the frequency, patterns are obtained which depend on the flow and the elasticity of the external meatus.

Physical information in the external urinary stream of the normal and obstructed adult male.

The qualitative status of physical information contained in the stream of the male lower urinary tract is traced from the bladder to the broken-up external stream. The progression of modifications of this information is discussed and it is argued that information remains in the drops. Electro-optical measurements of the drops leads to pulses which can be analysed for various types of information content. These confirms that there is potential clinical value in some aspects of the information.

The physical basis of some urodynamic measurements.

This report concerns certain principles of physics that are relevant to the clinical practice of Urology as well as the research urodynamicist. Supplemental material is available in previous publications for the physiologist, cardiovascular, dynamicist, anesthesiologist and the like. The material is fairly recent only in its application to the lower urinary tract. Pressure-volume relationships were applied to be cardiovascular system more than 20 years age. Indeed, for those interested in urodynamic methods, there is a vast fund of useful pertinent information in the literature on vascular dynamics. The problems of steady and unsteady flow in flexible structures are common to both specialties. It would be unfortunate if urodynamicists were required to learn of the phenomena and their implications by the drudgery of repeated measurements rather than taking guidance from previous work. This report is intended to serve as an introduction to the approach and, hopefully, will stimulate those who are interested in urodynamic methods to seek out this information and to interpret their measurements in the light of fundamental physical phenomena that have been described and analyzed.

The variability of normal male voiding patterns measured by drop spectrometry.

Voidings from 7 healthy men were recorded by means of the urinary drop spectrometer. The voiding patterns were characterised by the trend drop frequency and the distribution of drop time intervals. The variability of these voiding patterns was studied by statistical techniques. The data were grouped for each person. Variances were considerable both within and between groups. Although individual differences in the mean values existed, the groups could not be separated from each other.