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Scanning electron microscope studies were performed on the peripheral muscle network (myoepithelium) of the hepatopancreatic ceca of Gammarus pulex (L.) exposed to lindane, copper, or 3, 4-dichloroaniline (3,4-DCA) for a 24-hr period. The structural integrity of the myoepithelium of gammarids from control and test treatments was assessed using semiquantitative techniques. The lowest observed effect concentrations for structural changes were determined as 29.8 microg liter-1 lindane, 55 microg liter-1 copper, and 8.7 mg liter-1 3,4-DCA. The sensitivity of the bioassay and the significance of the morphological changes observed in the hepatopancreatic ceca of G. pulex are discussed.

Typical rates of muscle glycogen resynthesis after short term, high intensity exercise (15.1 to 33.6 mmol/kg/h) are much higher than glycogen resynthesis rates following prolonged exercise (approximately 2 mmol/kg/h), even when optimal amounts of oral carbohydrate are supplied (approximately mmol/kg/h). Several factors differ during post-exercise recovery from short term, high intensity exercise compared with prolonged exercise. The extremely fast rate of muscle glycogen resynthesis following short term, high intensity exercise may originate from these differences. First, peak blood glucose levels range from 6.6 to 8.9 mmol/L during recovery from short term, high intensity exercise. This is markedly higher than the blood glucose values of 2 to 3.4 mmol/L after prolonged exercise. In response to this elevation in plasma glucose levels, insulin levels increase to approximately 60 microU/ml, a 2-fold increase over resting values. Both glucose and insulin regulate glycogen synthase activity, and higher levels of them improve muscle glycogen synthesis. Secondly, high intensity exercise produces high levels of glycolytic intermediates in muscle, as well as high lactate levels ([La]) in muscle and blood. Finally, fast-twitch glycolytic muscle fibres are more heavily used in short term, high intensity exercise. This promotes greater glycogen depletion in the fast-twitch fibres, which have a higher level of glycogen synthase activity than slow-twitch fibres. While the exact contribution of each of these factors is unknown, they may act in combination to stimulate rapid muscle glycogen resynthesis rates. Muscle glycogen resynthesis rates following resistance exercise (1.3 to 11.1 mmol/kg/h) are slower than the rates observed after short term, high intensity exercise. This may be caused by slightly lower muscle and blood [La] after resistance exercise. In addition, a greater eccentric component in the resistance exercise may cause some interference with glycogen resynthesis.

Thermoregulatory studies often investigate thermal responses without considering the influences of clothing. These studies have expanded our understanding of basic human responses to various environmental conditions. However, human thermoregulation is variable and modified by heat transfer interactions between skin surface area, clothing and environment. Much of the original work on the influence of clothing on work performance was the result of ergonomic concerns. Currently, the importance of clothing and the influence of new clothing technology aimed at minimising thermal stress has spawned a new interest. For hot climates, new fabrics have been developed with improved wicking properties to keep the wearer cooler and drier, and to enhance heat transfer from the body while providing greater comfort. In contrast, the challenge of cold environments requires a different approach to clothing, which tries to minimise the free movement of air and water along the skin surface of the body. The materials used should also be able to absorb radiant heat from the environment and be nonconductive. In a cold climate, the wearer needs to balance the need for a clothing barrier for warmth with the potential for accumulating too much heat as the result of metabolic heat production from exercise. To counteract this potential problem, it is suggested that cold-weather clothing be worn in layers that can be removed during exercise and replaced during less active periods. Protective clothing for firefighters, hazardous waste workers and astronauts, and athletic protective gear, have specialised design requirements which may be influenced by considerations, for example, of environmental conditions, garment weight, the need for durability, impact forces.

Despite large environmental variations, the human body maintains a tightly regulated core temperature. Effective thermoregulation must balance the interaction between skin surface, clothing and ambient air. Indices of thermal stress (wet bulb globe temperature, heat stress index, maximum evaporation rate, required evaporative rate and wind chill) provide valuable information concerning the heat exchange between the individual and the environment, and serve as protective guidelines while working in environmental extremes. The role of clothing, as an interactive barrier, greatly affects thermal balance. Clothing is varied according to prevailing environmental conditions, metabolic heat production, gender and age differences, fabric thermal properties, garment design and intended use. Models (static, dynamic and human) have investigated the biophysical transfer of heat between the skin surface area, clothing and ambient air. Additionally, the role of metabolic heat production during exercise can greatly influence tolerance to thermal stress during a variety of environmental conditions.

The purpose of this investigation was to determine the influence of post-exercise carbohydrate (CHO) intake on the rate of muscle glycogen resynthesis after high intensity weight resistance exercise in subjects not currently weight training. In a cross-over design, eight male subjects performed sets (mean = 8.8) of six single leg knee extensions at 70% of one repetition max until 50% of full knee extension was no longer possible. Total force application was equated between trials using a strain gauge interfaced to a computer. The subjects exercised in the fasted state. Post-exercise feedings were administered at 0 and 1 h consisting of either a 23% CHO solution (1.5 g.kg-1) or an equal volume of water (H2O). Total force production, preexercise muscle glycogen content, and degree of depletion (-40.6 and -44.3 mmol.kg-1 wet weight) were not significantly different between H2O and CHO trials. As anticipated during the initial 2-h recovery, the CHO trial had a significantly greater rate of muscle glycogen resynthesis as compared with the H2O trial. The muscle glycogen content was restored to 91% and 75% of preexercise levels when water and CHO were provided after 6 h, respectively.

To determine the effect of a carbonated carbohydrate (CHO) drink on gastric function and exercise performance, eight male cyclists completed four 120-min bouts of cycling. Each bout consisted of a 105-min ride at 70% VO2max followed by a 15-min self-paced performance ride. During each trial, one of four test solutions was ingested: carbonated CHO (C-10%), noncarbonated CHO (NC-10%), carbonated non-CHO (C), and noncarbonated non-CHO (NC). Following the performance ride, the subjects had their stomach contents removed by aspiration. There were no significant differences in gastric emptying (GE) except for Trial C-10%, which averaged 13.3% less than NC. However, there was no difference in the perception of gastrointestinal comfort between this trial and any other. Average power output during the performance ride was not significantly different between carbonated and noncarbonated trials, or between CHO-fed and no-CHO trials; however, the subjects worked at a greater intensity when fed CHO. Finally, acid base status did not change when a carbonated drink was ingested. This indicates that adding carbonation to a sport drink does not significantly alter gastric function, the perception of GI comfort, or exercise performance.

Equine relaxin has been previously determined in a small number of pregnant Thoroughbred mares. To better define the normal pregnancy pattern of relaxin, the current study reports on a much larger number of mares. It also was designed to determine if all equids have the same gestational pattern of relaxin secretion. Plasma samples were collected weekly in 24 Standardbred mares, every 7-10 days in 10 pony mares, and daily in late pregnancy from 16 burros. Standardbreds had higher concentrations of relaxin than that reported for Thoroughbreds during most of gestation and did not exhibit the midpregnancy nadir in relaxin concentrations observed in Thoroughbreds. Relaxin concentrations in Standardbreds showed a small but steady decline from Day 150 until delivery. Pony mares had lower relaxin concentrations throughout pregnancy than other mares and had continuously increasing concentrations during gestation. Burros had relaxin concentrations intermediate to ponies and other mares in late gestation. Burros induced to foal with oxytocin showed a sharp increase in relaxin concentrations. No effect of the sex of the offspring was observed in relaxin profiles in Standardbred mares. Each of three Standardbreds with abnormal termination of pregnancy exhibited abnormally low relaxin concentrations at some point in the gestation prior to termination of the pregnancy. Thus, relaxin may be an indicator of placental functioning and used to assess at-risk pregnancies in mares.

Fifty-nine healthy senior center participants were interviewed to determine how, when, and why the durable power of attorney for health care is being used. The 21 users of the durable power of attorney for health care executed a form for the expected reasons; however, a majority had not given a copy of the form to their physician and few had discussed details of their preferences with the proxy. Of the 38 nonusers, the most frequent reasons for not executing a durable power of attorney for health care were: lack of awareness of the form, procrastination, and difficulty choosing a proxy. The new Patient Self-Determination Act requiring hospitals to inform patients of advance directives will help to overcome some of the obstacles in use of the durable power of attorney for health care; however, community education must still be encouraged.

The lethal toxicities of the four pollutants 3,4-dichloroaniline (DCA), atrazine, copper, and lindane were determined for the 2nd larval instar of the insect Chironomus riparius Meigen and the juvenile stage (2nd or 3rd moult) of the crustacean Gammarus pulex (L.). Median lethal concentrations (LC50s) were determined over a 240 h test period. The order of toxicity of the test chemicals is different for each species. For C. riparius, lindane was the most toxic, followed by copper, DCA, and atrazine. During the first 96 h of exposure, the order for G. pulex was copper, lindane, then DCA and atrazine with similar LC50 values. However, at 240 h lindane replaced copper as the most toxic chemical to G. pulex. The relative sensitivity of the two species was dependent on both the toxicant and the exposure period. The lethal concentrations determined for the four chemicals are compared to the results of other toxicity studies and discussed with respect to current standard test methods.

This study investigated the effects of preliminary exercise (warm-up) on glycogen degradation and energy metabolism during intense cycle ergometer exercise. After determination of VO2max, six male subjects were randomly assigned to perform warm-up (WU) and no warm-up (NWU) trials incorporating a 2 min standardized sprint ride (SR) at 120% of the power output attained at VO2max (POmax). Muscle biopsies and temperature (Tm) recordings were obtained from the vastus lateralis muscle. Tm was elevated above the resting level prior to the SR during the WU trial (37.7 +/- 0.1 vs 35.4 +/- 0.4 degrees C; P less than 0.05) and remained higher than the NWU trial after the SR (38.6 +/- 0.2 vs 37.1 +/- 0.4 degrees C; P less than 0.05). Similar trends existed for rectal temperature (Tr). The increases in Tm and Tr during the SR were both greater in the NWU trial (P less than 0.05). Muscle glycogen degradation was similar for the WU and NWU trials (30.8 +/- 3.7 vs 25.6 +/- 3.7 mmol.kg-1, respectively). When blood and muscle lactate concentrations after the SR were expressed relative to values before the SR, the WU trial resulted in a lower accumulation of blood lactate (6.5 +/- 0.9 vs 10.7 +/- 0.8 mEq.l-1; P less than 0.01) and muscle lactate (20.1 +/- 0.1 vs 23.4 +/- 2.2 mEq.kg-1 wet wt.; P less than 0.05). Furthermore, oxygen consumption during the 1st min of the SR was higher in the WU trial (2.3 +/- 0.2 vs 1.9 +/- 0.2 l.min-1; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Low-intensity exercise (less than or equal to 50% VO2max) has been demonstrated to produce heat acclimation (HA) in trained subjects. The purpose of this study was to determine whether shorter-duration, moderate-intensity exercise would also result in HA. Nine trained runners performed two 9-d exercise heat-stress protocols. Each protocol consisted of a 90-min heat tolerance test on days 1 (HTT1) and 9 (HTT2). On days 2-8 the subjects exercised at 50% VO2max for 60 min.d-1 (T50) or at 75% VO2max for 30-35 min.d-1 (T75). Final HTT2 heart rate and rectal temperature (Tr) were significantly (P less than 0.001) reduced, as compared to HTT1, with no differences between T50 and T75. Both protocols resulted in significant (P less than 0.05) reductions in HTT2 pre-exercise Tr and total exercising caloric expenditure, both of which are known to contribute to HA. No changes in resting plasma volume, osmolality, protein, post-HTT aldosterone, and exercising sweat rate were observed. These results demonstrate that equal levels of HA were obtained with T50 and T75, which suggests that moderate-intensity, short-duration exercise in the heat can produce HA in trained subjects.

The purpose of this study was to examine differences in muscle glycogen storage during three successive days of running or cycling. In a crossover design, seven male subjects performed two 3-d trials of either running (trial R) or cycling (trial C) for 60 min at 75% VO2max. Biopsy samples were obtained before and after each day's exercise from the gastrocnemius (trial R) or vastus lateralis (trial C) muscle. Diets in the 2 d preceding and during each trial contained 5 g carbohydrate.kg-1.d-1 and 14,475 +/- 402 kJ.d-1. Mean pre-exercise glycogen content (mmol.kg-1 wet wt.) was significantly reduced in both trials on day 3 (103.4 +/- 6.0) when compared to day 1 and day 2 (119.9 +/- 6.8 and 116.4 +/- 5.7, respectively). Day 1 glycogen reduction was significantly greater in trial C (P less than 0.03), and glycogen restorage was greater (P less than 0.02) only in trial C between the 1st and 2nd d. On day 3, spectrophotometric analysis of PAS strains showed that pre-exercise glycogen content in either muscle group was significantly (P less than 0.01) less in Type I as compared to Type II fibers. This difference in fiber glycogen storage did not appear to be attributable to muscle damage as negligible leukocyte infiltration and low blood CK levels were obtained. No difference between modes were observed for CK values throughout the trials. These data suggest that the depressed glycogen storage before the 3rd d of exercise was due to the moderate carbohydrate intake.

Child victims of sexual abuse are being identified in increasing numbers. An appropriate and therapeutic intervention requires a trained multidisciplinary staff. This article describes the San Francisco Child and Adolescent Sexual Abuse Resource Center (CASARC), a 24-hour crisis intervention program for sexually abused children based in a pediatric setting. The training needs of medical professionals as well as community agencies serving children are discussed. Areas for new research are also presented.

Cadmium-binding protein (Cd-BP) was detected in the liver and kidney of stoneloach, Noemacheilus barbatulus, roach, Rutilus rutilus and rainbow trout, Salmo gairdneri which had been dosed i.p. with 1 mg cadmium (Cd)/kg body weight 168 h previously. The cadmium content (microgram Cd/g wet weight tissue) was much lower in the liver and kidney of trout than in stoneloach and roach, but there was no clear relationship between the amount of Cd-BP detected and the reported sensitivity of each species to cadmium.

The geometry exhibiting the least marginal discrepancy in this investigation was the shoulder of the slightly oversize casting (Fig. 4). This was significantly better (p = .05) than the oversize bevel, the control shoulder, or the control bevel.

We evaluated 758 sick children younger than 3 years of age for Group A beta-hemolytic streptococcal (GABHS) upper respiratory infection (URI) to determine the usual clinical presentation of the disease in this age group, indications for culture and the optimal site(s) from which to isolate the organism. GABHS infection was documented in 35 subjects (4.6%). The classic presentation (as proposed in the 1940s) of GABHS URI in children younger than 3 years of age was not confirmed by this study. In 32 of the GABHS cases there were pharyngitis, common cold symptoms or both, and these were associated with acute otitis media 10 times and with otitis media with effusion 3 times. Clinical impetigo was associated with GABHS URI (4 of 32 cases). GABHS URI would not have been documented in 6 of 32 cases if cultures of the anterior nares had not been performed. Children between 18 and 36 months of age were more likely to have GABHS disease than were younger children. Hoarseness and vomiting occurred less frequently in children younger than 36 months with GABHS infection than in those of that age who had non-beta-hemolytic streptococcal illnesses. A history of two or more siblings at home or a family member with a recent streptococcal infection and the presence of irritability, a reddened throat or palate or uvular edema were each associated with GABHS URI. We concluded that sick children between 18 and 36 months of age with a reddened throat should have cultures taken of the throat and anterior nares for GABHS.(ABSTRACT TRUNCATED AT 250 WORDS)

The records of two hundred consecutive patients undergoing cholecystectomy for gallstones in the university department of surgery, Christchurch Hospital, were reviewed to evaluate the benefit and standard of operative cholangiography. The main benefit lay in the avoiding of unnecessary common bile duct exploration. Of the cholangiograms later reviewed by an independent radiologist, only 70 percent were considered satisfactory.

One hundred mares carrying twin conceptuses between gestation days (GD) 12 and 30 were assigned to 4 groups. Group-1 mares (n = 20) were given a placebo (sterile saline solution, IV, and sesame oil, IM). Group-2 mares (n = 32) were given a single dose of progesterone (625 mg, IM) in sesame oil. Group-3 mares (n = 28) were given multiple progesterone treatments (625 mg, IM) at 6-day intervals until GD 42. Group-4 mares (n = 20) were given a single treatment of flunixin meglumine (500 mg, IV) and progesterone (625 mg, IM). Each group was further assigned to equal subgroups A and B according to the age of the embryos. In subgroup A, with embryos at GD 12 to 16, embryonic vesicle rupture was performed after the selected conceptus was moved to the tip of a uterine horn. In subgroup B, with embryos at GD 17 to 30, embryonic vesicle rupture was performed on the selected conceptus in situ. An additional 6 mares carrying single conceptuses (GD 12, 14, 16, 20, 25, and 30) were used as subjects for sham embryonic vesicle rupture. Both rupture techniques usually caused the release of prostaglandin (PG) F2 alpha for up to 90 minutes. Amounts of PGF2 alpha were directly correlated with the pressure required to effect embryonic vesicle rupture. Sham embryonic vesicle rupture attempts caused small PGF2 alpha releases after each manipulation, which rapidly returned to basal values. All 6 mares were still pregnant at GD 42. Flunixin meglumine inhibited PGF2 alpha release after embryonic vesicle rupture, regardless of the technique.(ABSTRACT TRUNCATED AT 250 WORDS)

The uptake of cadmium by sticklebacks and its distribution between the body tissues was compared following two methods of exposure, i.e., natural exposure to the heavy metal in water and direct intraperitoneal injection. In both cases, the greatest concentration of cadmium was detected in the liver. In naturally exposed fish high concentrations were also found in the gut and gills while in injected fish high levels were demonstrated in the gall bladder and kidney.

Acute toxicity tests using a static-with-replacement testing procedure were carried out with the four larval instars of the freshwater detritivore Chironomus riparius (Meigen). Median lethal concentrations (10, 24, 48 and 96 h LC50's) indicated great differences in sensitivity to cadmium between instars. Larvae became more tolerant with increasing age, the most resistant stage (fourth instar) having a 24 h LC50 of 2,400 mg Cd l -1 , approximately 950 times greater than the corresponding value of 2.1 mg Cd l -1 recorded for the most sensitive (first instar) stage. These observations are discussed in relation to the establishment of water quality standards.

Eight hearing-impaired subjects were tested with a binaural master hearing aid. This aid has "on-the-head" miniature transducers and has an adjustable frequency response. Five frequency responses were used, two of them were defined by their response in a 2-cm3 coupler: 1) uniform coupler gain (UCG), and 2) 6 dB per rise (6 dB). The other responses were defined in terms of functional gain (difference between unaided and aided thresholds): 3) uniform functional gain (UFG); 4 uniform hearing level (UHL); and 5) a simulation of a commercial hearing aid (AS). A significant difference between coupler and functional gain was seen. Discrimination was tested with a special closed-set word list which includes fifty monosyllabic words with a high percentage of voiceless phonemes. Discrimination scores were consistently better with the UHL response. The lowest scores were obtained with the AS response. The average difference in scores between these two responses was 18.4%. Further testing replicated these results and also compared the effects of a different type of word list phonetically balanced (PB); with these lists, the above-mentioned difference in scores was smaller in quiet (5.9%) but larger in noise (20.9%).

Between 1982 and 1985, 1015 mares were evaluated using the following parameters: age, mare status (maiden, barren, lactating), Caslick index, Caslick operation, ovarian cycle, ovarian and follicular size, treatments (hCG and intrauterine infusions), number of ovulations after mating (184 mares), number of conceptuses present, dimensions of embryonic vesicles, and pregnancy status 45 days after mating. Mares were examined ultrasonographically between Days 12 and 25 to detect the presence of embryonic vesicles and measure the dimensions of each vesicle. The data were analysed by a stepwise logistic regression method. Mare and follicular status were significant (P less than 0.005) predictors of pregnancy outcome. Results from 2949 mare cycles (268 maiden; 1047 lactating; 618 barren) for twin conceptus rates were 15.3%, 8.8% and 14.0% respectively. Based on follicle status, twin-conceptus rates with a single palpable follicle greater than 25 mm in diameter were 11% in maiden, 11% in barren and 5.3% in lactating mares. In 23.7% of cycles (22.4%, 28.8% and 20.7%) 2 palpable follicles greater than 25 mm were recorded, resulting in twin conception rates of 30%, 23.3% and 22% in maiden, barren and lactating mares, respectively. Twin conceptus rate for all mares with a single follicle greater than 25 mm was 7.6% and with 2 follicles greater than 25 mm 23.6%. Mares with 2 large follicles (greater than 40 mm) at mating had a 38.2% (29/76) twin conception rate. Mares with known synchronous double ovulations had a 40% (22/55) twin conception rate. An analysis of co-variance was used to calculate the daily embryonic growth rate between Days 10 and 16 of gestation for 11 Standardbred mares.(ABSTRACT TRUNCATED AT 250 WORDS)

The complementary role of aquatic toxicity tests in relation to other forms of pollution assessment is discussed. These tests may be predictive and designed to estimate hazard, or used for monitoring waters to assess compliance with standards. The effects of pollutants are significantly modified by certain water quality characteristics and by a variety of biological factors. The latter, particularly those causing physiological stress, are discussed.

Serum antibody concentrations against influenza A-equi-1 virus and A-equi-2 virus were measured in a group of 18 foals from birth to 4 months of age. More than 50% of the foals were seronegative to A-equi-1 virus infection by 4 weeks of age, with titers of less than or equal to 1:16. For A-equi-2 virus, more than 50% of the foals were seronegative by 2 weeks of age, with titers of less than or equal to 1:8. Passively derived antibodies against influenza A-equi-1 virus and A-equi-2 virus in foals obtained from recently vaccinated mares and from mares not vaccinated within 6 months before foaling were low in titer. The duration of passively derived antibodies was also short-lived.

The effects on the three-spined stickleback, (Gasterosteus aculeatus L.), of various combinations of stresses due to parasitism by Schistocephalus solidus, dietary restriction, and exposure to cadmium (0.032 mg 1-1) were investigated. Sticklebacks exposed to a combination of all three stressors died first with a median period of survival significantly shorter than that for fish subjected to fewer stressors. Compared with fish on a restricted diet alone, parasitism plus dietary restriction also reduced survival; however, the combination of cadmium exposure and restricted diet did not. A possible explanation for this finding is proposed.

A surgical technique for removal of one conceptus from mares with twin concepti more than 35 days of gestational age was evaluated. One conceptus was removed surgically from each of 15 mares carrying twin concepti that were 41 to 65 days of gestational age. As determined by ultrasonography, eight mares had bicornuate and seven mares had unicornuate twin concepti. For maintenance of pregnancy if surgical trauma should cause prostaglandin release and luteolysis, progesterone was administered prophylactically. Flunixin meglumine was administered perioperatively to minimize prostaglandin release. Five mares with bicornuate twin concepti delivered a single viable foal; in one mare the fetus was alive 4 days after surgery when the mare was euthanatized because of a fractured femur. None of the remaining feti in the seven mares with unicornuate twin concepti survived. The poor survival rate of unicornuate twin concepti was attributed to disruption of the remaining chorioallantois during surgery. Thirteen mares have been rebred successfully.

Twenty-one pregnant mares with single or twin conceptuses between 41 and 65 days of gestational age were allotted to 5 treatment groups. A ventral median celiotomy was performed in all mares. In group-1 mares (3 mares, single conceptus), the uterus and fetus were palpated for 5 minutes. In group-2 mares (3 mares, single conceptus, flunixin meglumine), 250 ml of sterile placental fluid was injected into the nongravid uterine horn. In group-3 mares (4 mares, unicornuate twin conceptuses), group-4 mares (3 mares, unicornuate twin conceptuses, flunixin meglumine), and group-5 mares (8 mares, bicornuate twin conceptuses, flunixin meglumine), 1 conceptus was removed from the uterus via hysterotomy. All mares received progesterone prophylactically until day 100 of gestation or until the fetus died. The 3 mares in group 1 delivered clinically normal, live foals. The mean prostaglandin F2 alpha metabolite (PGFM) plasma concentration peaked at 180 +/- 5.2 pg/ml during uterine manipulation and fetal palpation, then declined to baseline by 1 hour. Free placental fluid (group 2) undermined the chorioallantois ventrally and resulted in fetal death within 3 hours after surgery. The mean PGFM plasma concentration peaked at 39 +/- 4 pg/ml following injection of placental fluid. None of the remaining fetuses in the 7 mares with unicornuate twin conceptuses (groups 3 and 4) survived. Five mares with unicornuate twin conceptuses (group 5) delivered single viable foals. In another mare in group 5, the fetus was alive 4 days after surgery, when the mare was euthanatized for a fractured femur.(ABSTRACT TRUNCATED AT 250 WORDS)

Thirty mares with normal estrous cycles were allotted equally to 5 groups and infused with 250 ml of saline (NaCl) solution in utero on the seventh day after ovulation to test the effects of temperature, osmolarity, or pH of the saline solution on prostaglandin F2 alpha (PGF2 alpha) release and luteolysis. Intrauterine infusion of phosphate-buffered saline solution failed to alter the duration of the luteal phase, compared with the control group. Similarly, increasing the temperature of phosphate-buffered saline solution to 42 C or increasing (600 mosm) or decreasing osmolarity (less than 10 mosm) did not change the duration of the luteal phase. Decreasing the pH of saline solution to 3 caused significant (P less than 0.0001) releases of PGF2 alpha from the uterus within the first hour after infusion, and the luteal phase was shortened to 8.8 +/- 1.0 days (mean +/- SEM; control, 15 +/- 1.2 days). The results of this study showed that pH is the main factor in eliciting PGF2 alpha release by intrauterine infusion of a saline solution, whereas increased temperature and osmolarity have no effect on the release of PGF2 alpha. The intrauterine infusion of sterile water or physiologic saline (NaCl) solution has been used to induce estrus in mares for the past 50 years. Many investigators have reported that intrauterine infusion of physiologic saline solution or water at body temperature (37 C) or warmer up to 45 C) causes most "anestrous" mares to return to estrus in 1 to 8 days.(ABSTRACT TRUNCATED AT 250 WORDS)

This article indicates that the gingival opening of a two-surface cast restoration after cementation is minimized by the use of a preparation with proximal grooves.

The toxicity of cadmium to rainbow trout fry resulting from brief or continuous exposure is compared. Results of tests involving brief cadmium exposure followed by restoration to clean water indicate that postexposure mortalities may result from contact for as little as 32 min to 1.0 mg Cd liter-1 or 10 min to 10 mg Cd liter-1. These results highlight the inadequacy of standard toxicity tests in predicting the consequences of an episodic pollution incident such as that resulting perhaps from an accidental spillage. For example, the median lethal time (LT50) following continuous exposure to 1.0 mg Cd liter-1 is 1900 min whereas exposure for only 32 min will ultimately result in 50% mortality. The term median postexposure lethal time (peLT50) is proposed as a means of assessing and comparing the results of brief exposure to a pollutant and it is suggested that brief or episodic exposure tests should be incorporated into the hazard evaluation process.