Hematological malignancies with a deletion of 11q23: cytogenetic and clinical aspects. European 11q23 Workshop participants

OBJECTIVE: Using receiver-operating characteristic (ROC) curves, we tried to determine the diagnostic threshold of amniotic fluid index (AFI) that will identify abnormal fetal size (birth weights under 2500 g or at least 4000 g) at 37 weeks or beyond. METHODS: We analyzed prospectively over 2 years all parturients with intact membranes and known AFI in early labor. Patients with the following conditions were excluded: pregestational or gestational diabetes, known anomalies, and preterm labor. Two ROC curves were constructed, and the areas (+/- standard error of the mean [SE]) under the curves were calculated. P < .05 was considered significant. RESULTS: Of the 1038 subjects meeting study criteria, 3.6% and 11.5% gave birth to infants who were small for gestational age (SGA) or macrosomic, respectively. Overall, 28.7% had oligohydramnios (AFI at most 5.0 cm) and 3.6% had hydramnios (AFI at least 24.0 cm). Small for gestational age was more common in patients with AFI at most 5.0 cm (6.4%) than in those with adequate fluid (AFI 5.1-23.9; 2.5%), or hydramnios (2.7%; P = .012). Macrosomic newborns were less likely to be born to women with oligohydramnios (7.7%) than to those with adequate amniotic fluid (13.1%) or hydramnios (13.5%). Areas under ROC curves are not significantly different from the area under the nondiagnostic line, indicating that AFI (0-34 cm) cannot differentiate between newborns under 2500 g and at or over 2500 g or under 4000 and at or more 4000 g. CONCLUSION: Intraparterium AFI appears to be a poor screening test to identify risk for delivery of SGA or macrosomic fetus.     

Effects of oral rabeprazole on oesophageal and gastric pH in patients with gastro-oesophageal reflux disease

BACKGROUND: This study examined the dose-response effects of the new proton-pump inhibitor rabeprazole on oesophageal and gastric pH in patients with gastro-oesophageal reflux disease. METHODS: This study had a single-centre, double-blind, randomized, two-way crossover design. Twenty patients were treated for two 7-day periods separated by a 7-10-day washout period. Patients were randomly assigned to receive either 20 mg of rabeprazole once daily during the first treatment period and 40 mg once daily during the second treatment period, or 40 mg during the first treatment period and 20 mg during the second treatment period. The primary efficacy variable was oesophageal acid exposure determined by 24-hour ambulatory pH monitoring. Acid-reflux time was defined as the percentage of time over 24 h that oesophageal pH was < 4. A dosage was considered effective if reflux time was reduced to < 6%, a number which has been our internal laboratory reference. RESULTS: Both rabeprazole 20 mg and 40 mg, given once daily, normalized reflux time, with decreases of 79% and 92% in acid exposure by day 7. Both dosages also decreased the mean total number of reflux episodes and the number of episodes lasting > 5 min, with no significant differences between dosages for any reflux parameter. Mean gastric pH increased with 20 mg from 1.86 at baseline to 3.71 on day 1 and 4.17 on day 7. Rabeprazole 40 mg once daily increased gastric pH from 2.01 to 4.37 on day 1, and to 4.65 on day 7. Safety analyses revealed no significant acute side-effects for either dosage. CONCLUSIONS: Pathological oesophageal acid exposure was normalized with both 20 mg and 40 mg dosages of rabeprazole, and the effects of these two doses did not differ. Rabeprazole was well-tolerated in this short-term study.     

Effect of caffeine on metabolism, exercise endurance, and catecholamine responses after withdrawal

In this study the effects of acute caffeine ingestion on exercise performance, hormonal (epinephrine, norepinephrine, insulin), and metabolic (free fatty acids, glycerol, glucose, lactate, expired gases) parameters during short-term withdrawal from dietary caffeine were investigated. Recreational athletes who were habitual caffeine users (n = 6) (maximum oxygen uptake 54.5 +/- 3.3 ml x kg-1 x min-1 and daily caffeine intake 761.3 +/- 11.8 mg/day) were tested under conditions of no withdrawal and 2-day and 4-day withdrawal from dietary caffeine. There were seven trials in total with a minimum of 10 days between trials. On the day of the exercise trial, subjects ingested either dextrose placebo or 6 mg/kg caffeine in capsule form 1 h before cycle ergometry to exhaustion at 80-85% of maximum oxygen uptake. Test substances were assigned in a random, double-blind manner. A final placebo control trial completed the experiment. There was no significant difference in any measured parameters among days of withdrawal after ingestion of placebo. At exhaustion in the 2- and 4-day withdrawal trials, there were significant increases in plasma norepinephrine in response to caffeine ingestion. Caffeine-induced increases in serum free fatty acids occurred after 4 days and only at rest. Subjects responded to caffeine with increases in plasma epinephrine (P < 0.05) at exhaustion and prolonged exercise time in all caffeine trials compared with placebo, regardless of withdrawal from caffeine. It is concluded that increased endurance is unrelated to hormonal or metabolic changes and that it is not related to prior caffeine habituation in recreational athletes.     

Body temperature daily rhythms in the striped mouse Rhabdomys pumilio: the effects of alpha and beta blockade

Body temperature (Tb) daily rhythms and the effects of alpha and beta blockade were studied in the South African diurnal striped mouse Rhabdomys pumilio. Eleven mice (8 males and 3 females) with a body mass of 42.7+/-7.8 g (mean +/- SD) were tested. Mice were acclimated to a 13 h:11 h light-dark photoperiod at an ambient temperature of 25 degrees C. To assess the daily rhythm of pineal melatonin secretion, urinary 6-sulfatoxymelatonin (6-SMT) was determined. Mice displayed a robust Tb daily rhythm with an acrophase in the dark period, which is unexpected for a diurnal species. The nocturnal increase in Tb was accompanied by a significant rise in urinary 6-SMT. The beta blocker propranolol (4.5 mg/kg), injected 1 h before lights-off, resulted in a higher Tb value, whereas the alpha blocker prazosin (1 mg/kg) blocked the increase of Tb during the dark period. Prazosin also significantly attenuated the nocturnal increase of urinary 6-SMT. These results are in agreement with those obtained from the golden spiny mouse Acomys russatus and support the idea that small diurnal mammals retain the Tb rhythm of a nocturnal rodent. They also suggest that pineal melatonin secretion in these rodents is regulated by alpha rather than by beta receptors.     

Water supplementation enhances the effect of high-fiber diet on stool frequency and laxative consumption in adult patients with functional constipation

BACKGROUND/AIMS: The purpose of this study was to determine the effects of a high-fiber diet and fluid supplementation in patients with functional chronic constipation. METHODOLOGY: One hundred and seventeen patients with chronic functional constipation (aged 18-50 years) were randomly divided into two treatment groups. For two months both groups consumed a standard diet providing approximately 25 g fiber per day. Group 1 (58 patients) was allowed ad libitum fluid intake, while Group 2 was instructed to drink 2 liters of mineral water per day. Compliance was monitored throughout the study and results were assessed in terms of bowel-movement frequency and laxative use. RESULTS: Fiber intake was similar in the two groups, while total daily fluid intake in Group 2 (mean 2.1 liters) was significantly greater than that of Group 1 (1.1 liters)(p < 0.001). In both groups, there were statistically significant increases in stool frequency and decreases in laxative use during the two-month trial, but both changes were greater in Group 2 (stool frequency: p < 0.001 vs. Group 1; laxative use: p < 0.001 vs Group 1). CONCLUSIONS: A daily fiber intake of 25 g can increase stool frequency in patients with chronic functional constipation, and this effect can be significantly enhanced by increasing fluid intake to 1.5-2.0 liters/day.     

Indication and results of insulin therapy for gestational diabetes mellitus

The aim of this study was to determine whether amniotic fluid insulin concentration (AFI) is a better parameter than mean maternal blood glucose values (MBG) for deciding about insulin therapy in patients with gestational diabetes. MBG's were calculated on the base of 9 blood glucose levels during a 24 hour period after one week of diet therapy. In a prospective trial between 1987 and 1989 in Karlsburg, 123 gestational diabetic patients were randomized into two groups. Treatment was either based on the concentration of AFI or MBG levels. In a second series in Berlin, 103 patients were offered amniocentesis. 81 patients agreed and 22 refused. Treatment was then analogous to that in Karlsburg. In both groups of the randomized population, strict metabolic control was achieved. There was no difference regarding pregnancy complications. Earlier labor induction and higher cesarean section rates were seen in the non-invasive group (p < 0.05). The incidence of diabetic fetopathy and neonatal hypoglycemia was significantly lower in the invasive group (p < 0.01), even though the metabolic control parameters did not differ between the two groups. The results in Berlin correspond to these findings. In conclusion, AFI enables the recognition of any hyperinsulinism reaction to the maternal metabolic situation. We recommend the additional measurement of the AFI concentration between 28 and 36 weeks as the direct fetal parameter for deciding about insulin treatment.     

Effects of finasteride on hematuria associated with benign prostatic hyperplasia: long-term follow-up

OBJECTIVE: To construct an ultrasonography-based gestation-specific amniotic fluid index (AFI) curve in a Chinese population. METHODS: Routine obstetric ultrasonography examinations were performed in 5496 normal pregnancies (more than 95% first births) in five obstetric ultrasound laboratories in Central-South China from January 1, 1992, to December 31, 1993. A gestation-specific AFI curve was constructed and compared with previous studies. RESULTS: The gestational ages of the patients included in this study ranged from 16 to 40 weeks. The gestation-specific AFI showed patterns similar to those observed previously, with the median being 72 mm at 16 weeks, increasing to 119 mm at 26 weeks, and then gradually declining to a median of 91 mm at 40 weeks. However, the absolute value of AFI in this Chinese population was consistently and substantially lower than values reported in previous studies in populations with mixed parities. CONCLUSION: Different standards of AFI are needed for different populations.     

Glucose polymer ingestion--effect on fluid balance and glycemic state during a 4-d march

The effect of glucose-polymer solution on physical performance has been extensively studied under controlled laboratory conditions. The present study was conducted to investigate the influence of such beverages on fluid balance and on glycemic state during a moderate, prolonged field exercise. Forty-eight endurance trained, male subjects participated in the study. The maneuver consisted of a 4-d march; 29, 39, 36, 30 km.d-1, at a speed of 5-6 km.h-1. The subjects covered a total distance of 134 km at an estimated exercise intensity of approximately 40% VO2max, under hot climate conditions (ambient temperature, 32-41 degrees C; relative humidity, 60-14%). Subjects were randomly assigned to one of two groups: glucose polymer-electrolyte beverage (GP; N = 24) and tap water (TW; N = 24). Each group was then divided into two subgroups consuming fluid ad libitum (TWa, GPa) or instructed to consume 900 ml.h-1 (TWb, GPb). The mean daily fluid consumption of all subgroups was similar (5252 +/- 229 and 4640 +/- 67 ml in TWa and TWb; 5257 +/- 317 and 5253 +/- 216 ml in GPa and GPb, respectively). Weight loss, reflecting the degree of dehydration, was 1.2 +/- 0.1% and 1.9 +/- 0.3% of initial body weight in TW and GP, respectively. On day 1, plasma volume changed by +0.4% and -1.8% in the TW and GP groups, respectively. On the days 2-4 changes in both groups were similar.(ABSTRACT TRUNCATED AT 250 WORDS)     

Two-day quadruple therapy for cure of Helicobacter pylori infection: a comparative, randomized trial

PURPOSE: Small intestinal transplantation remains a significant clinical problem. Allogeneic fetal intestinal (AFI) transplantation shows promise, particularly regarding procurement; however, no studiesto date have evaluated the potential success of true allogeneic loci implantation. The authors hypothesized that isolated segments of AFI could be heterotopically transplanted but would require immunosuppression to survive. METHODS: Donor tissue was obtained from late-gestation Brown Norway rat fetuses with a histo-locus RTN and Fischer fetuses with a histo-locus RT1L. The recipients were adolescent male Fischer rats with a histo-locus RT1L. A 1.2-cm segment of fetal small bowel was implanted in the omentum of the recipient rat and allowed to mature for 5 weeks. Animals were then separated into five groups. Group A served as controls with syngeneic fetal intestinal (SFI) transplant. Group B received AFI with no immunosuppression; group C, AFI transplant with five days of FK506; group D, AFI with 10 days of FK506; and Group E, AFI with daily FK506 for the entire 5-week maturation period. Animals were killed on day 35. RESULTS: All animals gained weight over the maturation period. Groups B, C, and D had no viable transplant segments at day 35. Groups A and E both had well-developed viable segments confirmed by gross and histological evaluation. CONCLUSIONS: FK506 allows for normal intestinal development for use in allogeneic fetal bowel transplantation. With this observation, the use of fetal intestine transplanted into the portal circulation emerges as a potentially viable alternative to present intestinal transplant models.     

Long-term non-invasive measurement of intraocular pressure in the rat eye

To study the optic neuropathy associated with glaucoma, a system for accurate, reliable, and non-invasive monitoring of intraocular pressure (IOP) is required. Of particular interest is the effect of sampling frequency on IOP. To address this issue, ten adult male brown Norway rats (group 1) were acclimatized to a 12-h/12-h light/dark cycle. On 20 days over a 30-day period, rats were anesthetized with short-acting isoflurane (Forane) inhalant anesthesia and IOP for each eye was determined by averaging 15 valid individual readings obtained with a TonoPen 2 tonometer. The last 12 measurement sessions were performed on a daily basis. To determine the minimum tolerable interval between IOP measurement sessions, a second group of 10 animals (group 2) was acclimatized in the same manner as group 1, and IOP was measured every 4 days over a period of 80 days. Next, IOP was measured every 4 days over a period of 28 days, and finally, every 2 days over a period of 19 days. For all group 1 measurements, there was no statistically significant difference between the right and left eye IOP, 14.75 +/- 1.08 (SEM) and 14.90 +/- 1.09 mm Hg, respectively. However, daily measurements produced a steady decrease in IOP and gradual weight loss. For group 2, overall mean right and left eye IOPs were 15.24 +/- 1.28 (SEM) and 15.12 +/- 1.26, respectively and were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hemodynamic effects of a calcium channel promoter, BAY y 5959, are preserved after chronic administration in ischemic heart failure in conscious dogs

BAY y 5959 is a dihydropyridine derivative that binds to L-type calcium channels in a voltage-dependent manner and promotes calcium entry into the cell during the plateau of the action potential by influencing mean open time. Because myofilament responsiveness to calcium is preserved in congestive heart failure (CHF), the inotropic responsiveness to this compound should be preserved in CHF, and tolerance should not develop despite long-term treatment. To test these hypotheses, CHF was induced in 14 chronically instrumented dogs by daily (30 +/- 5 days) intracoronary microsphere injections. The effects of BAY y 5959 (2-h i.v. infusions of 3 microg/kg/min and 10 microg/kg/min) were determined before heart failure, after heart failure was established and then 2 h after the end of a 5-day continuous BAY y 5959 intra-atrial infusion. Before CHF, the positive inotropic effect of BAY y 5959 at a dose of 10 microg/kg/min [left ventricular dP/dt (LVdP/dt) increased from 2955 +/- 132 mmHg to 4897 +/- 426 mmHg, P < .05] was associated with bradycardia (HR decreased from 92 +/- 4 to 78 +/- 6 b/min, P <.05), slight increases in mean arterial pressure (it increased from 100 +/- 2 mmHg to 113 +/- 5 mmHg, P <.05) and did not alter left ventricular end-diastolic pressure. In CHF, BAY y 5959 continued to induce dose-dependent increases in left ventricular systolic pressure, LVdP/dt and mean arterial pressure, as well as causing bradycardia and a significant decrease in left ventricular end-diastolic pressure. After a 5-day infusion of BAY y 5959, base-line LVdP/dt and left ventricular end-diastolic pressure improved. The responses of LVdP/dt and mean arterial pressure to BAY y 5959 were similar to those of the control state. The sustained responses in CHF and after long-term infusion suggest that BAY y 5959 may be an effective and potent inotropic agent for treatment of CHF that does not lead to tolerance to its positive inotropic effects.     

Electrophysiological effects of catheter ablation of inferior vena cava-tricuspid annulus isthmus in common atrial flutter

BACKGROUND: The electrophysiological mechanisms for successful catheter ablation of atrial flutter (AFI) targeting the inferior vena cava-tricuspid annulus (IVC-TA) isthmus have not been determined. METHODS AND RESULTS: Twenty patients with common AFI were studied. All had inducible common AFI, and 8 of them had both common and reverse AFI. Right atrial (RA) activation sequences were investigated during pacing from sites proximal (low lateral RA) and distal (proximal coronary sinus) to the IVC-TA isthmus both during entrainment of common or reverse AFI and during pacing in sinus rhythm. This was repeated after ablation. During pacing in sinus rhythm from the low lateral RA, the septum was activated by caudocranial and craniocaudal wave fronts. Similarly, during pacing from the proximal coronary sinus, the lateral RA was activated by two wave fronts. Catheter ablation of the IVC-TA isthmus induced dramatic changes in mapping due to the loss of caudocranial wave front in all but 1 patient. The septum and the lateral RA were activated by a single craniocaudal front as during entrainment of reverse or common AFI, respectively. After a follow-up of 8 +/- 2 months, common or reverse AFI occurred in 4 patients. Two had no or only unidirectional changes in the isthmus conduction induced by ablation. The other 2 had a late recovery of conduction. CONCLUSIONS: The present study provides evidence that the mechanism of successful AFI ablation targeting the IVC-TA isthmus is local bidirectional conduction block. This change can be used as a new and complementary electrophysiological end point for the procedure. AFI recurrences are associated with failure to achieve a permanent block.     

Malignomas after transplantation of thoracic organs]

The ultraclean air environment in a plastic isolator has been used in cerebrospinal fluid shunt interventions in an attempt to reduce the incidence of infections. The blower that maintains a continuous flow of filtered air in the operative field may create body temperature changes. In this study we assessed the temperature before, during and at the end of the operation in preterm and term infants in whom ventriculoperitoneal shunts were being placed. There were 12 preterm and 9 term infants. The duration of the operative intervention ranged from 25 to 50 min. In the preterm infants the mean initial temperature was 36.2+/-0.2 degrees C, and the final temperature was 35.7+/-0.2 degrees C. This difference was not significant. The initial temperature in the term infants was 36.26+/-0.2 degrees C, and the final temperature was 35.9+/-0.3 degrees C, also not significantly different. The surgical isolation bubble system does not alter the temperature of preterm and term infants significantly during ventriculoperitoneal shunt procedures performed within the operative times seen in this study.     

Influence of localized auxiliary heating on hand comfort during cold exposure

There is a need for a hand-heating system that will keep the hands warm during cold exposure without hampering finger dexterity. The purpose of this study was to examine the effects of torso heating on the vasodilative responses and comfort levels of cooled extremities during a 3-h exposure to -15 degreesC air. Subjects were insulated, but their upper extremities were left exposed to the cold ambient air. The effect of heating the torso [torso-heating test (THT)] on hand comfort was compared with a control condition in which no torso heating was applied, but Arctic mitts were worn [control test (CT)]. The results indicate that mean finger temperature, mean finger blood flow, mean toe temperature, mean body skin temperature, body thermal comfort, mean finger thermal comfort, and rate of body heat storage were all significantly (P < 0.05) higher on average (n = 6) during THT. Mean body heat flow was significantly (P < 0.05) lower during THT. There were no significant differences (P >/= 0.05) in rectal temperature between CT and THT. Mean unheated body skin temperature and mean unheated body heat flow (both of which did not include the torso area in the calculation of mean body skin temperature and mean body heat flow) were also calculated. There were no significant differences (P >/= 0.05) in mean unheated body skin temperature and mean unheated body heat flow between CT and THT. It is concluded that the application of heat to the torso can maintain finger and toe comfort for an extended period of time during cold exposure.     

Feasibility of a rapid method to evaluate platelet survival time

The purpose of this study was to evaluate the feasibility of a shorter method of performing platelet kinetic studies with respect to the conventional 8-9-day approach. METHODS: We studied 41 patients (28 women, 13 men; mean age 52 yr) with primary idiopathic thombocytopenic purpura (ITP) (n = 20), secondary ITP (n = 9), HCV associated thrombocytopenia (n = 9), splenectomy (n = 1) and hairy-cell leukemia (n = 1). The patients were in a steady-state of platelet turnover. Initial platelet counts ranged from 19 to 302 x 10(9)/liter (mean value = 83). Platelet survival times (PST) were measured from the blood radioactivity disappearance curve of 111In-oxine-labeled autologus platelets following the recommendations of the International Committee for Standardization in Haematology: blood samples were taken at 30 min and 2 and 4 hr and thereafter daily for 7 days. PST was calculated by the weighted mean method and ranged from 18 to 219 hr (mean value = 98). PST was also calculated using only the data collected at 2, 48 and 96 hr. If the radioactivity in the blood at 96 hr exceeded 10% of the 2-hr value, the additional point at 168 hr was used. RESULTS: By using this reduced dataset, we obtained a correlation of r = 0.97 with the PST obtained from the whole dataset. In 24 patients, the difference was between +/- 10 hr and exceeded 1 day in only 4. CONCLUSION: About 94% of the data may be recovered with only three or four blood samples and the duration may be shortened to 4 days in a significant proportion of patients (48% of ITP patients). This approach offers the advantages of increased patient throughput, compliance and reduced examination costs.     

Fever and antipyresis in the lizard Dipsosaurus dorsalis

Lizards (Dipsosaurus dorsalis) were placed in a desertlike environment in which the ambient temperature (Ta) at night (1800-0600 h) was 12 degrees C and the day (0600-1800 h) Ta was between 30 and 55 degrees C depending on the location within the chamber. When dead Aeromonas hydrophila (4 X 10(9) organisms) was injected into nine lizards, an elevation in body temperature (Tb) of 2.7 degrees C was observed during the same day. On the day after bacterial injection the lizards' body temperatures averaged 41.6 degrees C, an increase of 4.2 degrees C over their control day Tb. Further investigations on the febrile response of D. dorsalis were conducted at the University of Wisconsin's Biotron, where there exists a simulated desert environment with the light intensity, temperature, and humidity closely parelleling a typical spring day in the southwestern desert of the United States (the natural habitat of Dipsosaurus). In this environment injection of dead bacteria into seven lizards led to an average febrile response of similar magnitude (Tb = 40.5 degrees C) but with a longer latency than that found at the University of Michigan. Injection of 13 lizards with live A. hydrophila (5 X 10(9) organism subcut.) in the simulated desert at Michigan led to a daytime fever averaging 2.3 degrees C (mean Tb = 40.6 degrees C) over a 5-day period. During the 6th and 7th day the lizards' body temperature returned to the normal or afebrile level. Injections of sodium salicylate along with dead A. hydrophila resulted in a dose-dependent attenuation of the febrile response. These results demonstrate that the reptilian febrile response is strikingly similar to avian and mammalian fever and suggest a common origin and perhaps function for the febrile mechanism.     

The effects of lipopolysaccharide (LPS) on the fever response in rats at different ambient temperatures

There is a complex interplay between the immune system, nervous system, and sleep. When an organism is challenged with lipopolysacchride (LPS), the immune system is stimulated, producing a fever response that is independent of ambient temperature, and an increase in slow-wave sleep (SWS). The study investigated sleep patterns of immune-challenged rats during the light phase cycle to determine the effects of various ambient temperatures. It was hypothesised that fever response would occur independently of ambient temperatures. Also, the febrile response would be monophasic, and there would be an increase in slow-wave sleep (SWS) and a decrease in rapid-eye-movement (REM) sleep. Thirty Wistar rats were randomly placed in 3 different ambient temperature groups, 22 degrees C, 15 degrees C, and 30 degrees C. Within each of these conditions, the same subjects served as control and experimental groups. Four animals were placed in 4 subsections of 2 standard boxes that were placed in the ambient-temperature box. The electrodes were connected to the analog to digital computer board, where all the data was processed and stored on a hard drive. The animals were injected I.P. with saline and recorded for a period of 6 h to establish a baseline. On Day 2, the same animals were injected I.P. with LPS and recorded for 6 h to determine the febrile effects of LPS on the immune system; the same procedure was repeated in the other ambient temperatures. The results have shown that animals experienced a monophasic fever response in low and normal temperatures, but not in the high temperatures. Although there was no increase in SWS, there was a significant decrease in REM sleep in 3 groups.     

Identification of murine p120 isoforms and heterogeneous expression of p120cas isoforms in human tumor cell lines

Heat stress is a common problem for cattle. General consequences of heat stress include increased body temperatures and reduced feed intakes. As a measure of heat stress, core body temperatures of unshaded feedlot steers (crossbred Bos taurus) were monitored from mid-June to early November in Nebraska using transmitters implanted in the peritoneum of 10 steers (initially 10 mo of age). Steers were fed at 0630 and 1430 using a finishing diet of 1.52 NEg Mcal/kg with 13% protein and 4% roughage per day and housed in two open lots with stocking densities of 15.2 or 19.3 m2/steer. Core body temperatures, ambient temperature, relative humidity, and wind speed were measured at 3-min intervals and mathematically filtered to produce 120 readings/ d. For 94 usable daily records, body temperature means (39.04 +/- .12 degrees C), maxima (39.89 +/- .21 degrees C at 1836 +/- .73 h), minima (38.33 +/- .29 degrees C at 0823 +/- .38 h), and patterns were similar among steers. As daily maximum ambient temperatures increased, minimum body temperatures decreased slightly (.04 degree C per 5 degrees C; P < .01). After daily maximum ambient temperatures reached a threshold of 25.6 degrees C, daily maximum body temperatures increased linearly with maximum ambient temperatures (.42 degree C per 5 degrees C; P < .01). Sharp peaks in body temperature were often seen in the late evening (approximately 2200) after ambient temperature had decreased to well below maximum values. These evening peaks occurred on an average of 25% of the days, had amplitudes ranging from .7 to 3.5 degrees C relative to mean daily temperatures and lasted for 1.5 h. From a practical standpoint, we suggest that producers monitor meteorological forecast of peak ambient temperatures and make special efforts, such as spraying animals, when exceptionally hot weather is predicted.     

The relation between freely chosen meals and body habitus

By bomb calorimetry, we conducted a 7-day study of the energy contents of the freely chosen meals of 11 male subjects under their ordinary living conditions. Their body weights ranged from 60 to 99 kg and Quetelet indices ranged from 211 to 271 X 10(-5). Despite the wide range of body weight, there was no relation between daily energy intake and body weight, height, or Quetelet index. However the thickset subjects took diets and meals with higher energy density than the lean subjects (p less than 0.05 one-tailed for diets, p less than 0.025 one-tailed for meals). On average, the energy of lunch and dinner contributed 26 and 44% of daily energy, respectively. There was a significant negative relation between the energy of lunch and that of dinner (p less than 0.01), but no significant association between weight of lunch and that of dinner (p greater than 0.1).     

Circadian rhythms of rat internal temperatures and thermal ambiance (author's transl)]

Chronic recording of cerebellar and subcutaneous temperatures were carried out in rats maintained at different ambient temperatures in a 12 h light-dark cycle (light from 7 to 19 h). Cerebellar and subcutaneous temperatures followed a rhythm with a period of 24 h with acrophase at 1 h and an amplitude of 0.75 degrees C. The amplitude and acrophase were not altered by modification of the ambient temperature (20-25-30-34 or 35 degrees C), but each elevation of ambient temperature produced a rise in the mean internal temperature of the rat. This rise, hardly perceptible at ambient temperatures of 25 and 30 degrees C, reaches 0.5 degrees C between 20 and 25 degrees C and 1 degrees C between 30 and 34 degrees C. This elevation of temperature was maintained for the duration of the 10 days of observation. These results pose at least three questions: the degree of liaison between the rhythms of activity (waking) and temperature; the lability of the mean internal temperature, which alter with ambient temperature while the amplitude of the circadian rhythm is unaltered and the absence of reduction of mean interanl temperature several days exposure to a raised ambient temperature, even when activity and metabolism are reduced by the second day of exposure.