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PubMed1995

Evaluation of hormonal testing in the screening for in vitro fertilization (IVF) of women with tubal factor infertility.

PURPOSE: To evaluate the frequency of abnormal prolactin and thyroid stimulating hormone (TSH) test results in ovulatory women with tubal factor infertility who were screened for in vitro fertilization (IVF). METHODS: Charts were identified from 112 ovulatory women with follicle stimulating hormone (FSH) < 20 mIU/ml who were diagnosed with tubal factor infertility and were screened for IVF with thyroid stimulating hormone (TSH) and prolactin levels. Women previously diagnosed with thyroid disease were subsequently excluded and 98 subjects remained. All subjects were determined to be ovulatory by biphasic basal body temperature (BBT) charts, luteal phase progesterone > 4 ng/ml, or endometrial biopsy revealing secretory endometrium. Results of cycle day 3 serum TSH and prolactin concentrations were recorded. The normal range for each test reflects the geometric mean +/- 2 standard deviations (i.e., 95% interval), as obtained from the reference laboratory. Under this construct, hypothesis tests were performed to determine whether or not our study population was consistent with the reference range of normal hormone levels. Under the null hypothesis (normal levels), we expected 5% of the TSH tests to be abnormal (i.e., high or low levels), and 2.5% of the prolactin tests to be abnormal (i.e., high levels). Exact bionomial confidence intervals and P-values were calculated. We also tested for age trend in the proportion of abnormal results. RESULTS: Study subjects had an age range of 25-43. In the study group, 4 (0.041) out of the 98 women screened had abnormal TSH levels. Of these four abnormal TSH results, three were elevated (i.e., TSH > 4.6 microIU/ml) and one was low (i.e., TSH < 0.6 microIU/ml). The frequency of an abnormal TSH value was not significantly different from that expected from the reference laboratory normal values (95% CI 0.011, 0.101). Of the 98 subjects, 7 (0.071) had abnormal prolactin levels, which was significantly different from that expected from the reference laboratory normal values (95% CI 0.029, 0.142; P = 0.023). When stratified by age, there was no observed trend of abnormalities for TSH or prolactin levels with increasing age. CONCLUSIONS: In ovulatory women presenting for IVF with tubal factor infertility, our results show that routine screening with a TSH test does not yield a significantly higher proportion of abnormal results than that expected from the reference laboratory normal values. However, prolactin level screening was found to yield a higher incidence of abnormal tests than expected from the reference laboratory normal values.

Adult↗
PubMed1989

An evaluation of the BIOSELF 110 fertility indicator.

The BIOSELF 110 is a hand-held, non-invasive electronic instrument that measures basal body temperature and cycle length, and automatically identifies the fertile and infertile phases of the menstrual cycle with flashing red light and green light signals, respectively. The device was evaluated in 77 cycles from 33 ovulatory women in Kuala Lumpur, Malaysia. Ultrasound monitoring of maximum follicular diameter (MFD) and urinary LH measurements with Ovustick were used as reference methods to estimate the time of ovulation and the fertile period. Based on the MFD day, the BIOSELF correctly identified the entire fertile period, and at least four fertile days, in 89% and 94% of the cycles studied, respectively. The mean duration of the fertile period as determined by the number of flashing red light days was 11.0 days (SD 2.9). The device correctly identified the onset of the postovulatory infertile phase in 94% of cycles, with a mean duration of about 10 (green light) days. The results were similar using the LH peak day as the reference method. The mean interval from the onset of the fertile period (first flashing red light day) to the MFD day was 6.9 days (SD 2.6), and from the MFD day to the end of the fertile period, 3.1 days (SD 2.2). The BIOSELF 110 showed itself to be a reliable device for identifying the fertile and infertile phases of the menstrual cycle and, thus, should be a useful aid for couples seeking pregnancy. Prospective clinical trials are underway to assess the contraceptive effectiveness of the device.

Adult↗
PubMed2005

Heating infiltration solutions used in tumescent liposuction: minimizing surgical risk.

BACKGROUND: Liposuction, one of the most common operations performed by plastic surgeons, is not free of complications. One of the most common factors is patient hypothermia, a factor little studied but one capable of producing severe arrhythmias and cardiac arrest. A comparative clinical study was conducted to determine what effect using tumescent infiltration solutions at room temperature and at body temperature has on vital signs. METHODS: Two similar groups of 15 healthy female subjects were studied. In the first group (group A), subcutaneous solutions were infiltrated at room temperature (24 degrees C), and in the second group (group B), solutions were infiltrated at body temperature (37 degrees C). Vital signs (i.e., heart rate, respiratory rate, temperature, and blood pressure) were monitored every 15 minutes until the basal vital signs were attained. Variables such as age, body mass index, infiltrated and aspirated liquids, and surgery time were very similar for both groups. RESULTS: Although there were differences in heart rate, respiratory rate, and arterial pressure, they were not statistically significant. Nevertheless, the differences between groups A and B for body temperature (34.9 +/- 1.1 degrees C versus 35.7 +/- 1.3 degrees C, respectively) and for the time necessary to attain basal vital signs (120 +/- 8 minutes versus 69 +/- 4 minutes, respectively) were statistically significant (p < 0.05). CONCLUSIONS: Despite the existence of a significant change in the body temperature in healthy female subjects during manipulation of the temperature of the infiltration solution, this change had no important effect on the intraoperative hemodynamic values. Nevertheless, it could have a more significant effect on patients with greater surgical risk.

Adolescent↗
PubMed1995

Efficacy of progesterone vaginal suppositories in alleviation of nervous symptoms in patients with premenstrual syndrome.

PURPOSE: To further investigate the efficacy of progesterone in the treatment of the symptoms of premenstrual syndrome (PMS). MATERIALS AND METHODS: From an initial cohort of 25 subjects diagnosed with moderate to severe PMS, 17 reproductive age females completed the 7-month, double-blind, placebo controlled trial using 200-mg vaginal progesterone suppositories. Multiple modalities for evaluating symptoms were employed, including the Spielberger self-evaluation rating, the Beck depression inventory, and the Hamilton anxiety scale. In addition, each subject was interviewed by a psychiatrist on a monthly basis; ovulation was determined monthly using a basal body temperature chart; serum hormonal assays included beta endorphin, progesterone, follicle stimulating hormone, luteinizing hormone, estradiol, and prolactin. RESULTS: Hormonal assays confirmed no differences between treatment and control groups. Overall scores on all test vehicles were likewise not significantly different between the two groups; however, in the subcategory of nervous symptoms, a significant improvement was found in symptoms relating to tension, mood swings, irritability, anxiety and lack of control. CONCLUSIONS: Metabolites of progesterone (pregnanolone and allopregnanolone) may play a physiologic role as anxiolytic agents, perhaps modifying mood and anxiety; the current study confirms the utility of twice daily, 200-mg progesterone vaginal suppositories, in the alleviation of some PMS symptoms relating to anxiety and irritability. Further evaluation may be warranted to ascertain which patients in the known heterogeneous PMS population may be most likely to benefit from such treatment.

Adult↗
PubMed1976

The detection of ovulation by intravaginal telemetry.

Following ovulatory control cycles in four celibate, healthy women, 27 to 34 years of age, basal body temperatures (BBT) were obtained in three cycles, utilizing a transistorized transvaginal telemeter. The electronic signals were collected on an automatically activated cassette receiver and later translated into temperature readings. The results were compared with values obtained simultaneously with a standard metabolic oral thermometer. The vaginal temperatures were consistently lower than the oral readings and offered a more sensitive and reproducible method of obtaining BBT. However, this system is very complex, requiring well-informed, highly motivated patients, and should be viewed currently as an investigative tool.

Body Temperature↗
PubMed2007

Prevention of hypothermia in children under combined epidural and general anesthesia: a comparison between upper- and lower-body warming.

BACKGROUND: Children receiving combined epidural and general anesthesia may be at greater risk of hypothermia. Active warming should be undertaken to combat heat loss. With combined epidural and general anesthesia heat loss from the lower body may be greater than from the upper body because of shift of blood towards the vasodilated lower body. We assumed that application of the warming blanket to the lower body might provide better protection against hypothermia. To test this hypothesis, lower-body warming (LBW) was compared with upper-body warming (UBW) in a randomized comparative study. METHODS: Children subjected to open urologic surgery under combined epidural and general anesthesia were randomly allocated to either UBW n = 38 or LBW n = 35 using a forced-air warming blanket. Core and peripheral skin temperatures were monitored. Temperature gradients between forearm and fingertip during LBW and between leg and toe during UBW were calculated. The warmer was set at 32 degrees C, room temperature was around 22 degrees C and fluids were infused at ambient room temperature. RESULTS: The changes in core temperature were comparable and parallel in both groups. Core temperature decreased significantly in each group at 1 h after induction compared with basal values. Temperature gradients at forearm-fingertip and at leg-toe were also comparable in both groups. Recovery was uneventful and no patient shivered in the recovery room. CONCLUSIONS: Lower body warming is as effective as UBW in prevention of hypothermia in children subjected to combined epidural and general anesthesia.

Adolescent↗
PubMed1997

Resection of a large, high-flow arteriovenous malformation during hypotension and hypothermia induced by a percutaneous cardiopulmonary support system. Case report.

The key to successful surgical resection of cerebral arteriovenous malformations (AVMs) is control of bleeding and cerebral swelling. Induced hypotension is one of the most valuable means of achieving this control. The authors introduced induced hypotension with mild hypothermia by using a percutaneous cardiopulmonary support system (PCPS) to resect a large, high-flow AVM. The efficacy and technical points of this method are discussed. The PCPS, whose entire intraluminal surface was coated with heparin, was established through a transfemoral route. During resection of the AVM, a mean arterial blood pressure of 60 mm Hg and a mean body temperature of 30 degrees C were easily maintained by regulating the flow rate of the PCPS and by blood cooling. The activated coagulation time was maintained at approximately 250 seconds with a minimum systemic administration of heparin. The authors report the case of a 30-year-old woman who presented with intraventricular hemorrhage and was diagnosed as having a large, high-flow AVM located in the left sylvian fissure. The AVM was fed by the left middle, posterior, and anterior cerebral arteries and drained by the many cortical ascending veins and the basal vein. The patient underwent surgery after hypotension and hypothermia had been induced via the PCPS method. Induced hypotension decreased the tension of the nidus and made its dissection easier. The AVM was totally resected and no hemostatic difficulties were encountered. On the basis of the authors' experience, they suggest that hypotension and hypothermia induced by using the PCPS is a powerful tool for the successful resection of large, high-flow AVMs.

Adult↗
PubMed1995

Autonomic and thermal sensory symptoms and dysfunction after stroke.

BACKGROUND AND PURPOSE: Symptoms interpreted as unilateral disturbances of autonomic function, such as coldness, dryness, sweating, and trophic changes, are well known but incompletely understood clinical problems after stroke. The present study provides data related to the incidence and mechanisms behind such symptoms. METHODS: Temperature perception thresholds, skin temperatures, evaporation rates, and skin blood flow responses were measured bilaterally in 37 stroke patients aged 58 +/- 13 years (mean +/- SD) and in a control group of 15 patients aged 64 +/- 15 years with a single transient ischemic attack. RESULTS: Of the 37 stroke patients, 43% reported a sensation of coldness in the contralesional side of the body. Basal skin blood flow and temperature were relatively lower in the contralesional side. There was an excess of evaporation in the contralesional side after brain stem lesions and in the ipsilesional side after hemispheric lesions. Vasomotor reflex asymmetries occurred in 34% of the patients and were due to weak vasodilator or vasoconstrictor reflexes in the ipsilesional side. These abnormalities correlated significantly to sensations of unilateral coldness, hypalgesia, and thermohypesthesia in the contralesional side and anatomically to lesions in spinothalamo-cortical pathways. CONCLUSIONS: Focal central nervous system lesions due to stroke may result in symptoms and measurable evidence of unilateral disturbance of skin sympathetic function. Vasomotor asymmetries are probably due to lesions of vasomotor pathways descending uncrossed. Subjective coldness may be due to disturbed central processing.

Aged↗
PubMed2002

Temporary amelioration of bilirubin conjugation defect in Gunn rats by transplanting conditionally immortalized hepatocytes.

BACKGROUND: Conditionally immortalized hepatocytes (CIH) have been used in hepatocyte transplantation as an alternative to primary hepatocytes to cope with the shortage of donor organs. However, CIH are known to undergo apoptosis at body temperature and survive in vivo for a short period. In the present study, we investigated whether CIH function or not and how long their function is maintained in vivo. METHODS: Various CIH cell lines that were established with temperature-sensitive Simian virus 40 large T antigen were transplanted into the spleen of Gunn rats, which are defective in bilirubin uridine diphosphate glucuronoside transferase (BUGT). Then, we measured biological changes over 3 months. RESULTS: Serum bilirubin of the syngeneic CIH recipients decreased by 30%, which was maintained for 8 weeks. Thereafter, it began to rise to basal levels. The recipients of allogeneic CIH showed a minor reduction of bilirubin, although this was not statistically significant. However, there was no significant change in the bilirubin level in recipients of BUGT-defective congeneic CIH throughout the study period. Bilirubin monoglucuronides in the bile were not detected in the recipients of BUGT-defective CIH. However, they appeared in recipients of non-defective CIH and made up approximately 41% of total bile pigments. CONCLUSIONS: Conditionally immortalized hepatocytes expressed hepatocyte function in vivo as well as in vitro, but the function lasted for a couple of months. According to our previous study, the limited functional duration may be related to the inevitable occurrence of apoptosis of these cells at body temperature. These data suggest that CIH can be used in hepatocyte transplantation only for temporary hepatic support.

Animals↗
PubMed2002

Cycle characteristics after discontinuation of oral contraceptives.

Nearly 60% of the women between 20 and 40 years of age who do not want to conceive choose oral contraceptives (OCs) for contraception in Germany. In an ongoing prospective study on the use of natural family planning in Germany, 175 women have been observed for 3,048 cycles immediately after having discontinued OCs (post-pill group). They were compared to a control group of 284 women observed for 6,251 cycles, who had never taken OCs. Both groups were comparable in age and sociodemographic characteristics. After discontinuing OCs, 57.9% of all first cycles were ovulatory with sufficient luteal phases. However, for the total post-pill group the cycle length was significantly prolonged up to the ninth cycle. A significantly higher number of luteal phases were insufficient in the post-pill group. Major cycle disturbances (cycle length > 35 days or luteal phase of < 10 days of elevated basal body temperature or anovulatory cycles) were significantly more frequent in the post-pill group up to the seventh cycle. Cycle disturbances after discontinuing OCs were reversible but the time of regeneration took up to 9 months (significant) or even longer (not significant). These results will help to counsel couples who wish to conceive after discontinuing OCs or who want to continue contraception with alternative methods.

Adult↗
PubMed1992

Reliability of urinary LH testing for planning of endometrial biopsies.

A rapid urinary luteinizing hormone (LH) test was used to plan a late luteal phase endometrial biopsy from 20 women undergoing an infertility evaluation. Histologic dating was correlated with the day of urinary LH surge detection, the day of the basal body temperature (BBT) nadir, and the onset of the next menstrual period (NMP). From 17 interpretable specimens, histologic dating correlated well with the day of the biopsy as determined following a positive LH test detection (P = 0.079). No correlation was found following the BBT shift (P = 0.65), and it was significantly correlated with the NMP (P = 0.016). Moreover, the urinary LH test showed to be the best method to predict the onset of the NMP. These findings confirm urinary LH testing as a valuable adjunct in the investigation of luteal phase disorders.

Adult↗
PubMed2005

L-Arginine inhibiting pulmonary vascular remodelling is associated with promotion of apoptosis in pulmonary arterioles smooth muscle cells in broilers.

OBJECTIVE: Pulmonary vascular remodelling is one of the important pathological bases of broiler pulmonary hypertension syndrome (PHS). Nitric oxide (NO) has been found to inhibit proliferation and to induce apoptosis in pulmonary artery smooth muscle cells (SMC) in mammals with pulmonary hypertension. The present study was conducted to evaluate the effects of NO precursor l-arginine on pulmonary vascular remodelling in broilers with pulmonary hypertension induced by cold exposure and to examine whether NO-induced apoptosis in pulmonary arteriole SMC is involved in the regulatory mechanisms. METHODS: Two hundred and forty mixed-sex commercial broilers were equally assigned to three groups and reared in normal brooding temperatures before day 14. Starting on day 14 continuing until the end of the experiment, the control group was brooded in normal temperatures whereas the other two groups were subjected to low ambient temperatures with or without l-arginine added to the basal diets. Cumulative PHS mortality and body weight were recorded in each group. Right/total ventricle ratio (RV/TV), plasma NO concentration and pulmonary vascular morphological changes were analyzed. TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay was used to detect apoptosis in pulmonary arteriole SMC. RESULT: l-Arginine, in group A, had no effect on body weights under cold temperature condition. Birds kept in group B had increased PHS mortality, RV/TV ratio, vessel wall area/vessel total area ratios (WA/TA) and mean media thickness in pulmonary arterioles (mMTPA) (P<0.05). Percentages of apoptotic SMC in pulmonary arterioles in group B were not altered by cold exposure (P>0.05). Supplemental dietary l-arginine in group A elevated plasma NO level (P<0.05), reduced PHS mortality (P<0.05), attenuated pulmonary vascular remodelling and increased the percentages of apoptotic SMC (P<0.05) when compared with the group B. CONCLUSION: Supplemental l-arginine partially inhibited pulmonary vascular remodelling that occurred secondary to increased pulmonary pressure; NO-induced apoptosis in arteriole SMC might contribute to its regulatory effect on pulmonary vascular structural changes.

Animals↗
PubMed2004

Cryosurgery for skin cancer: 30-year experience and cure rates.

BACKGROUND: Cryosurgery is capable of destroying nonmelanotic skin cancers, and numerous reports from around the world attest to its efficacy. However, there are few long-term data of large series of patients that were treated in this manner. OBJECTIVE: To report and evaluate the author's experience of using deep cryosurgery in the management of basal and squamous cell carcinomas on all areas of the body over a 30-year period. METHODS: Records of cryosurgical treatment in 4406 new and recurrent basal and squamous cell carcinomas in 2932 patients were reviewed. All cases were treated by the same physician. Liquid nitrogen was the cryogen. The open spray technique was mostly employed, and a double freeze-thaw cycle was carried out. Treatment was monitored clinically as well as by measurement of the tissue temperature in some cases;-50 degrees to-60 degrees C was reached in the tissue during the past 2 decades. RESULTS: The overall 30-year cure rate was 98.6% and was remarkably similar in all locations. A recent 5-year cure rate of 522 cases was 99.0%. There were five recurrences. CONCLUSIONS: Cryosurgery is a safe and effective treatment for selected nonmelanotic skin cancers and yields a high cure rate.

Adult↗
PubMed1981

A Bayesian change-point problem with an application to the prediction and detection of ovulation in women.

Under the assumptions of independent normally distributed and sequentially observed responses, a Bayesian rule for detecting a change from a constant mean response is derived. It is known that both basal body temperature (BBT) and preovulatory estrogen values undergo such a change in mean value at some random time during the menstrual cycle. The Bayesian rule is applied to estrogen to predict ovulation and to BBT to detect ovulation. Data from an aggregate of women are used to obtain prior information about the change-points and the parameters that define the changes in estrogen and BBT. A method is proposed by which the accumulation of information for a specific women can be incorporated into the aggregate prior information.

Bayes Theorem↗
PubMed2005

Influence of moonlight on the birth of male and female babies.

Effects of full moon and no moon on the birth of male and female offsprings were studied in Indian Couples of the age group 20 to 40 years. It was observed that 42 wives who were conceived within 24 hours of ovulation at full moon gave birth of 40 male and 2 female babies. On the other hand 40 women conceived on the day of ovulation 3 days prior to full moon gave birth of 13 male and 27 female babies. But only 5 women conceived on no moon, all of them gave birth of female babies. It was also observed that vaginal pH of the ovulated women during full moon was alkaline (pH 8.7 +/- 0.4) while pH was weak acidic in women ovulated 3 days prior to full moon and no moon (pH 6.4 +/- 0.5; 6.2 +/- 0.5). The basal body temperature (BBT) was increased 0.7 degrees F to 1.3 degrees F during the ovulation period when compared with women during the absence of ovulation. But there is an increase in temperature 0.5 degrees F more in women ovulated in full moon than no moon. Together, these results indicate that alkaline vaginal fluid medium and more rise of BBT during full moon favour conception of male [corrected] babies. This method gives the couple more chance of having male child if conception occurs in the day of ovulation in full moon and having female child if conception occurs in no moon.

Adult↗
PubMed1993

Effect of dihydroergotamine on leg blood flow during combined epidural and general anaesthesia and postoperative deep vein thrombosis after cholecystectomy.

The effects of dihydroergotamine (DHE) on the circulation of the leg during combined epidural and general anaesthesia were studied to determine if DHE would enhance leg blood flow and prevent postoperative deep vein thrombosis in a double-blind trial of 40 elderly female patients subjected to cholecystectomy. Central and big toe temperature, arterial blood pressure, heart rate, calf volume and arterial inflow of the leg by electrical impedance plethysmography and the venous outflow by Doppler method were measured. DHE 0.5 mg subcutaneously reduced the volume of the leg, i.e. increased the electrical impedance, probably due to venous vasoconstriction. Simultaneously the need for etilefrine hydrochloride was reduced. No significant changes in the pulsatile inflow of the leg or the outflow were detected. Deep vein thrombosis (DVT) was detected by fibrinogen uptake test in five patients (three in DHEH and two in the control group) and verified by ascending phlebography in four patients. Intraoperative characteristics in patients with postoperative DVT were tachycardia (P < 0.001), enhanced need for etilefrine (P < 0.01) and a more rapid increase in big toe temperature (P < 0.05) after induction of epidural analgesia, compared with patients without DVT. Femoral vein flow velocity remained at the preinduction level, whereas pulsatile arterial inflow slightly increased. Together with a low basal impendance of the leg, the changes were indicative of a more intense vasodilatation, probably leading to stagnant flow and development of postoperative deep vein thrombosis.

Aged↗
PubMed1984

Volumetric vaginal aspirator may aid in natural family planning.

All natural family planning (NFP) methods are based on the determitnation of a woman's fertile period so that a couple may abstain from sexual relations or use a mechanical means of birth control during that time. Researchers are seeking more accurate methods of predicting the onset of ovulation in order to increase the effectiveness of NFP. A new device developed by Dr. Gebhard F.B. Schumacher, a fertility specialist at the University of Chicago who serves on FHI's Technical Advisory Committee, and Dr. Stepen J. Usala, a former medical student at the University's Pritzker School of Medicine, holds the promise of providing a new, cheap, and relatively simple way of predicting ovulation. Called a volumetric vaginal aspirator, the instrument allows women to measure their own vaginal fluid on a daily basis. In early studies of 7 women carefully studied over 18 menstrual cycles, a striking 3 fold to 30-fold increase in the volume of vaginal fluid occurred a few days before ovulation. Results from 12 more women for a total of 26 cycles confirmed the earlier studies. Blood samples were taken in order to measure the levels of estrogen, known to increase prior to ovulation, and luteinizing hormone, which peaks sharply on the day of ovulation, in the women studied. These confirmed that ovulation typically had occurred after the fluid volume increase. In addition, participants recorded their basal body temperature (BBT) upon awakening. Although the BBT does not predict ovulation, it frequently increases by 1/2-1 degree Fahrenheit after ovulation thus serving as an indicator of the end of the fertile period. The prototype of the vaginal aspirator is a disposable plastic syring marked at .05 milliliter intervals so that fluid levels can be easily measured. After the manufacturing process for the aspirator is perfected so that the instrument can be mass produced, Dr. Schumacher hopes that largescale clinical trials will be initiated in the US and abroad. The larger studies and an endocrine study are needed in order for effective rules to be developed for applying the method in either birth control or fertility enhancement. The vaginal aspirator could be useful not only for preventing unplanned pregnancy but also for aiding couples experiencing infertility to pinpoint the time that conception is most likely to occur. As an aid in birth control, the aspirator should have a success rate similar to or better than that of a diaphragm, Dr. Schumacher believes. Although the women testing the vaginal aspirator were ablet to use it without assistance, Dr. Schumacer emphasizes that some patient education will be necessary if it becomes commercially available. Fertility awareness teachers could incorporate it into their courses. Research on the volumetric vaginal aspirator has been supported by FHI and by Mothers' Aid Research Fund of Chicago Lying-In Hospital.

Clinical Laboratory Techniques↗
PubMed2006

Energetics of osmoregulation: I. Oxygen consumption by Fundulus heteroclitus.

We have developed a flow-through method for measuring oxygen consumption in fish which allows continuous monitoring over periods of days with good accuracy. Our goal was to determine the changes in basal metabolic rate in estuarine fish as a function of salinity. We show that in Fundulus heteroclitus, the oxygen consumption drops by 50% during the first 12 hr in the respirometer, as the fish cease exploratory movements. We have determined the influence of temperature and body size on resting respiratory rate, but failed to find any circadian or tidal rhythm in aerobic respiration. With these variables controlled, we determined that changing from 10 to 30 ppt water had no demonstrable effect on oxygen uptake. Since there must be a large change in osmotic flux due to this change in salinity, it appears that the fish might be diverting energy from other uses rather than increasing aerobic energy production to meet the increased osmoregulatory work load.

Animals↗