Some properties of rectum and vagina as sites for basal body temperature measurement.

The choice of site for body temperature measurement and consistency in positioning the thermometer are important in achieving reliable and interpretable basal body temperature graphs in women. The distribution of temperatures in vagina (TV) and rectum (TR) were measured in women upon awakening. There were no significant differences between TR and TV at insertion depths of 5, 9, or 13 cm. Estimation of deep body temperature was not improved by inserting a thermojunction beyond 5 cm in vagina or rectum. Rates of change in TV following ingestion of a 300-ml iced drink were significantly greater than rates of change in TR.

PIP: The early morning temperatures of 10 healthy nurses aged 21 to 34 were evaluated to determine temperature distribution in vagina and rectum. Measurements of rectal and vaginal temperature were made continuously for 15 to 25 minutes. Each subject was given approximately 300 ml of an iced orange drink to swallow within 1 minute after the measurements. Statistical analysis (paired Student's T-test) revealed no significant differences between corresponding rectal and vaginal temperatures at each insertion depth (13, 9, and 5 cm) and no overall differences between the 3 insertion depths. There was no improvement in the estimation of body core temperature following insertion of a thermojunction beyond 5 cm from the anus or vulva. After ingestion of an iced drink, the vagina exhibited a higher rate of change than did the rectum.

An estrogen test to determine the times of potential fertility in women.

Defined changes in the concentration of estrone glucuronide in daily samples of early morning urine have been used to locate the limits of the fertile period and the time of maximum conception probability during 118 cycles (106 menstrual, 12 conceptional) in 73 women. The peak day of urinary luteinizing hormone was used as an index of ovulation. Follicular growth was monitored daily by ultrasonography throughout 38 cycles, and the time of maximum follicular diameter was used as an alternative reference point to define the times of potential fertility according to the life spans of the gametes. With optimized algorithms and the best index of ovulation, the estrogen test delineated the limits of the fertile period in 89% of the tests (mean length, 10.8 days; range, 5 to 17 days) and the time of maximum conception probability in 82% of the cycles, with a mean time to the maximum follicular diameter of 0.42 days (range, -4 to +4 days).

Two populations of type I fibres in striated muscle from a case of neutral lipid storage disease.

Percutaneous needle biopsy of the vastus lateralis muscle was performed in a patient with a generalised accumulation of neutral triglyceride. Light microscopy revealed a type I fibre predominance, with neutral lipid droplets in both fibre types but larger and with a greater quantity of lipid per unit area in the type I fibre population. Within type I fibres there were at least two populations based on the lipid droplet size and total accumulated lipid per cell. These observations are discussed, and it is concluded that they support the hypothesis of metabolic differences within the type I fibre population with respect to the use of free fatty acids as a fuel source.

Detailed faecal bile acid profile: a diagnostic test for colorectal cancer?

Detailed profiles of bile acids in faeces were evaluated as a diagnostic test for colorectal cancer in rats. Twenty-seven bile acid peaks were measured using improved methods of extraction and separation followed by the sensitive and specific techniques of capillary column gas liquid chromatography and mass spectrometry. Colorectal cancer was induced in experimental animals (female Sprague-Dawley rats, n = 20) by subcutaneous injection of dimethylhydrazine (DMH) and faecal unconjugated bile acids compared with those in the control group (n = 20). The amount of total faecal unconjugated bile acids was lower in the animals administered DMH (255 mg/day vs 334 mg/day: (P = 0.04), and the excretion of seven individual bile acids was reduced when compared with those in the control group (P less than 0.01). In order to use the faecal bile acid profiles as a diagnostic test, linear discriminant analysis was performed. A discriminant score was derived which was applied to each profile, to determine to which group (control or DMH) each animal belonged retrospectively. All analyses were performed blind, and 90% of the animals were correctly assigned. In man, as in rats, the bile acid profile of faces is equally complex and the bile acid profile may be useful as a diagnostic test.

Serum IGF-I levels and growth failure in juvenile chronic arthritis.

The association between growth failure and serum IGF-I levels has been assessed in 32 children with Juvenile Chronic Arthritis (JCA) aged 5-16 years. A spectrum from normal growth to severe growth failure was included in the study population. Height Standard Deviation Score (SDS) ranged from -5.79 to +1.41 (median -1.22) and Height Velocity from 0.72-8.85 cm/yr (median 3.81 cm/yr). Known risk factors for growth failure (disease activity, steroid treatment, vertebral collapse) were confirmed. Additionally, height SDS was significantly correlated with serum IGF-I levels (rs = 0.49; p = 0.008); height velocity was significantly, although less strongly correlated with IGF-I levels (rs = 0.41; p = 0.027). There was no correlation between IGF-I levels and either of two indices of nutritional status, or between IGF-I levels and current steroid dose. The correlation of serum IGF-I with parameters of growth failure may be due to either insufficient secretion of growth hormone (GH) or defective GH action. In view of the recently increased availability of GH for treatment of short stature, it is important to distinguish between these two mechanisms.

Effect of exercise on energy intake and eating patterns in lean and obese humans.

Twelve obese and four lean subjects increased their energy expenditure by 100 kcal/day by cycling on a bicycle ergometer. The order of testing was alternated so that half of the subjects did exercise on the first three days and the remainder on the last three days. Ad lib energy intake was measured over six days using an automated food dispensing machine. The obese subjects ate 1196 +/- 517 kcal/day and the lean subjects ate 1162 +/- 301 kcal/day and showed no overall significant difference in energy intake or eating patterns. However, these obese subjects ate 18 kcal/day less and the lean subjects ate 155 kcal/day more during the exercise period. The difference in response confirms the hypothesis that lean subjects tend to regulate energy intake more accurately than obese subjects. Exercise increased the frequency of eating and drinking and decreased hunger and appetite for all subjects. There was a significantly greater decrease in hunger and appetite with exercise for the obese subjects. However, as there was no accompanying decrease in energy intake and some subjects had difficulty in completing the exercise, the value of small increases in voluntary exercise in the treatment of obesity is questioned.

Basal body temperature, ovulation and the risk of conception, with special reference to the lifetimes of sperm and egg.

The risks of conception, due to sexual intercourse at various times before and after the periovulatory rise in the woman's basal body temperature, are evaluated. In general, the risk is small nine or more days before, and two or more days after, the first day of elevated temperature. The model for the conception probabilities assumes exponential survival distributions for sperm and egg and a specific probability that an egg is viable. Median survival times for sperm and egg are estimated at 1.0 days and 0.5 days, respectively. The Pearl indices for intercourse on the third and fourth day of elevated temperatures are 4.7 and 1.2 pregnancies per 100 woman-years, respectively.

The hidden effect of time.

It is customary to regard datasets as homogeneous with respect to the order of collection of the measurements. Examples are given in which this assumption is breached. Hidden time trends have implications for the design of studies, their analysis and interpretation. It is suggested that, if the order of observations is known, a plot by time should be performed, perhaps using a cusum.

An objective method for detecting the shift in basal body temperature in women.

The upward shift in basal body temperature (BBT) observed in women of child-bearing age is often used as an indicator that ovulation has occurred and that a period of infertility has begun. In natural family planning programmes it is important to detect the BBT shift reliably and with a minimum of user uncertainty, against a background of physiologically induced temperature variations. The cumulative sum (CUSUM) test is adapted to the problem of detecting BBT shift and applied to 137 BBT charts obtained from 21 women using natural family planning. Results show successful detection of the shift in all cases. Shifts occurred at gynaecologically appropriate times in the menstrual cycle.

PIP: Waking, or basal, body temperature (BBT) is a variable which in fertile women normally follows a cyclical pattern. The pattern of BBT is biphasic, shifting near the middle of the menstrual cycle from a low to a high phase, due to an association with progesterone levels in the blood. The shift in temperature coincides with ovulation and is followed after a few days by a period of infertility. The magnitude in this shift is known to vary. The cumulative sum (CUSUM) method of detecting the BBT shift is explained and illustrated graphically. The CUSUM Parameters were determined from a set of 137 BBT charts of 21 healthy women using natural family planning. Results of the application of CUSUM to these 21 charts show successful detection of the temperature shift in every case. Shifts occurred at ovulation time during the menstrual cycle.

The effect of freezing and pasteurizing bovine milk on its ability to protect neonatal guinea-pigs against colonization of the small intestine by Escherichia coli.

The ability of frequent feeding of bovine milk diets to prevent the colonization of the small intestines of newborn guinea-pigs with orally inoculated Escherichia coli was tested. At 3--4 days small intestinal samples from suckled controls were frequently sterile or were colonized with only very low numbers of Esch. coli. No bovine milk diet exhibited a significant "protective" effect but the diets could, however, be ranged in order of effectiveness in decreasing colonization by Esch. coli. Raw, fresh bovine milk was best, followed by milk pasteurized at 56 degrees or 63 degrees, then boiled milk; frozen milk was the worst. Because of this last finding, neither the bacteriostatic lactoferrin-dependent activity nor the lactoperoxidase could be correlated with the ability to decrease the colonization of the small intestines by Esch. coli.

Carboxyhaemoglobin and pulmonary epithelial permeability in man.

The effect of cigarette smoke exposure on pulmonary epithelial permeability was studied in 45 smokers and 22 non-smokers. An index of cigarette smoke exposure was obtained from the carboxyhaemoglobin concentration (HbCO%). Pulmonary epithelial permeability was proportional to the half-time clearance rate of technetium-99m-labelled diethylene triamine pentacetate (99mTc DTPA) from lung to blood (T1/2LB). The relationship between T1/2LB and HbCO% was hyperbolic in form and the data could be fitted to the quadratic formula (formula; see text) where the parameters a0, a1, and a2 represent respectively the asymptotic T1/2LB value at large carboxyhaemoglobin values and the slope and shape of the curve. The values of these parameters were a0 4.4 (2.6), a1 = 77.8 (15.5), and a2 -25.5 (9.7) (SE). This is the first demonstration of a dose-response relationship between carboxyhaemoglobin and an increased permeability of the lungs in man and provides a technique for identifying the roles of carbon monoxide and other cigarette smoke constituents in causing increased pulmonary epithelial permeability.

The effect of covert changes in energy density of preloads on subsequent ad libitum energy intake in lean and obese human subjects.

1. Covert changes in energy intake were made by giving preloads of disguised energy density three times daily to 14 obese and 6 lean subjects. 2. The preloads contained 2.51 MJ (600 kcal)/d on days 2 and 3 and either 3.77 MJ (900 kcal)/d or 1.26 MJ (300 kcal/d) on days 4 and 5 and 1.26 MJ (300 kcal)/d or 3.77 MJ (900 kcal)/d on days 6 and 7. The order of testing was alternated for each subject. 3. Subsequent energy intake at each meal (lunch, dinner and breakfast) was measured with an automated food-dispensing machine. 4. Overall the obese subjects ate significantly less from the machine, 3.28 +/- 1.89 MJ (785 +/- 452 kcal)/d, than the lean subjects, 6.03 +/- 1.26 MJ (1442 +/- 300 kcal)/d. 5. Both groups of subjects adjusted their energy intake in the right direction to counterbalance the effect of the preloads but the lean subjects changed their intake by an average of 0.74 MJ (176 kcal)/d compared with the obese subjects who changed their intake by an average of 0.29 MJ (70 kcal)/d. 6. Although the lean subjects were better at adjusting their energy intake than the obese subjects, regulation was still imprecise relative to the 2.51 MJ (600 kcal)/d difference in energy intake that was imposed. 7. There were no significant differences in hunger or appetite between subjects or test situations.

An automatic electronic device (Rite Time) to detect the onset of the infertile period by basal body temperature measurements.

Two trials of an electronic thermometer (Rite Time), designed to record and interpret basal body temperature (BBT) patterns in normal ovulating women, are described. A total of 140 menstrual cycles from 34 women, who used the thermal or symptothermal methods of natural family planning, were studied. Rite Time gave a signal for the start of the infertile period in 117 cycles, of which 114 (97%) appeared to have occurred at appropriate times. Further studies using hormonal and ultrasound reference points for ovulation were carried out in 21 cycles. Rite Time generally produced BBT patterns of quality acceptable for interpretation of the periovulatory BBT shift. About one-half of the volunteers said that they would be willing to replace their conventional charting methods with Rite Time.

Specific conductance using forced airflow oscillation in mechanically ventilated human subjects.

A method is described to measure specific airway conductance in mechanically ventilated patients. Airflow resistance (R) was measured continuously using the forced airflow oscillation method and plotted against volume during slow deflation of the lungs. The previously reported hyperbolic configuration of the resistance-volume curve was confirmed, but a nonlinear conductance-volume relationship was found that could be explained by a constant resistance (A) in series with the volume-dependent resistance of the lower airways. A computer-aided analysis of the resistance-volume curve determined the parameters of the hyperbola that best fitted the data and from this the volume-dependent conductance, Glaw = 1/(R - A), was calculated. This method consistently provided a very good fit to the data and resulted in a linear lower airway conductance-volume relationship in anesthetized and in awake subjects. The slope of this linear relationship (Glaw) was therefore independent of volume, and specific lower airway conductance was used as an index of bronchomotor tone. In awake subjects given bronchoconstrictor and bronchodilator aerosols, good correlation was shown between changes in specific conductance measured by this technique and by the standard plethysmographic method.

Pathological features of intra-uterine growth retardation in the piglet: differential effects on organ weights.

The body and organ weights of twenty-four intra-uterine growth retarded neonatal piglets were compared with those of seventeen normal littermate controls. There was a highly significant relation between organ weight and body weight for the following organs which all showed a reduction as body weight decreased: liver, kidneys, heart, lungs, spleen and pancreas. In contrast, brain, pituitary, adrenal and thyroid weights did not change significantly with body weight implying preferential protection from the pathological effects of intra-uterine growth retardation. Our results also show that the pattern of natural growth retardation in the piglet is similar to that reported in man, and to that of the experimental growth retardation produced in a number of animal species.

The temporal relationship between vaginal fluid volumes obtained with the Rovumeter vaginal aspirator and the fertile phase of the cycle.

Recent trends in family planning demonstrate an increasing interest in natural methods of birth regulation. In their present form, however, these methods are highly subjective and individualistic. A further trend in fertility programmes has been a very rapid development of technological methods to detect fertility in the female cycle, some of which could possibly benefit natural family planning users. One such technique--that of changing volumes of cervico-vaginal fluid (CVF), which is a mixture of cervical mucus and vaginal transudate--has been tested in a pilot study to ascertain its reliability to demarcate the fertile phase of the cycle. Results show that in all cycles tested, it is possible using the Rovumeter aspirator to detect the beginning of the fertile phase by rapidly increasing volumes of CVF; this volume reaches a peak approximately 1 day before ovulation detected by ultrasound and demonstrates an abrupt fall after ovulation and the onset of the infertile phase. From the results of this pilot study, we believe that, by the use of suitable algorithms and larger studies, it should be possible to develop a CVF volume method which could be offered as an objective alternative method for users of natural family planning and programmes.

PIP: Natural family planning methods rely on clinical indicators to determine the onset of ovulation and the fertile period. Cervico-vaginal fluid volumes are known to change in different cycle phases. In 1985 a graduated vaginal aspirator, the Rovumeter, was developed, which enabled women to collect their own cervico-vaginal fluid. To test the feasibility of daily measurement of cervico-vaginal fluid volume as a method of natural family planning, 6 fertile women recorded for 13 cycles their daily cervico-vaginal fluid volumes. They also recorded, for comparison, urinary luteinizing hormone levels measured with a dipstick, cervical mucus changes, basal body temperatures, and changes in the uterine cervix. Follicular diameter measurements were tracked ultrasonically. Volumetric changes in the cervico-vaginal fluid corresponding to the fertile and infertile phases were detected in all 13 cycles, and they displayed a more precise relationship with the start of the fertile period than either mucus or cervix changes. The signal for the start of the fertile period is the 1st day of appreciable rise of the cervico-vaginal fluid, and the day of fall is the 1st of 2 consecutive days on which the cervico-vaginal fluid is equal or less than the threshold. The method is inexpensive and accurate and should offer a new objective approach to natural family planning.

Detection of the fertile phase from changes in cervico-vaginal fluid volume.

Characteristic changes in cervico-vaginal fluid (CVF) volume which occur during the menstrual cycle might be used to detect the fertile phase. Twenty-five normal women were asked to withdraw CVF and measure its volume at home using a small, disposable, graduated vaginal aspirator. In 16 cycles day 0 (ovulation) was defined as the day of maximum follicular diameter according to serial ultrasound examination. A rise in CVF volume occurred between day -9 and -2 and a peak between day -4 and 0. In these sixteen, and in a further 72 cycles, day 0 (time of maximum fertility) was taken as the day of peak cervical mucus secretion. CVF volume rose, on the average, on day -6.2 (range -17 to -2) and peaked on day -0.8 (range -5 to +2). In two cycles, no rise and peak were identified. Changes in CVF volume were easy to recognise and could be useful to couples wishing to achieve pregnancy.

The tissue-blood partition coefficient of iodoantipyrine in pig brain and its change with age.

The tissue-blood partition coefficient of 125I-labelled iodoantipyrine was measured in pig brain. The mean coefficient for 11 neonatal piglets (aged 0.5 to 4 days) was 0.718 mL/g (SD 0.083). Measurements in a further 11 animals up to 144 days old (at which time pigs are sexually mature), showed that the partition coefficient increased significantly with age, possibly as a result of the accumulation of brain lipid during growth. The change in partition coefficient with age was curvilinear, rising to unity as the animals reached maturity. There were significant differences between the partition coefficients in grey and in white matter, but these were so small relative to the differences between pigs that they could be neglected for all practical purposes. Since the accuracy of measurement of cerebral blood flow (CBF) by the Kety-Schmidt technique depends directly on the partition coefficient of the tracer, it is important to confirm that apparent changes of CBF do not simply reflect alterations in the partition coefficient rather than real changes in blood flow.

Glucose homeostasis in the newborn: effects of an intravenous glucose infusion in normal and intra-uterine growth-retarded neonatal piglets.

Disturbances of glucose homeostasis are a common clinical problem in low birth weight human infants. Previous studies have demonstrated that the intra-uterine growth-retarded piglet is a suitable animal model for the study of such problems. The effects of an intravenous glucose infusion on glucose homeostasis have been studied in normal and intrauterine growth-retarded neonatal piglets using a non-steady state tracer technique. Despite suppression of hepatic glucose output, hyperglycaemia (plasma glucose greater than 10.0 mmol/l) developed in the majority of animals. The hyperglycaemia resulted from a failure to increase glucose utilisation adequately in response to the glucose infusion. Growth-retarded animals had an impaired ability to increase their rate of glucose utilisation, although, in common with the normally grown animals, they demonstrated a graded response to different infusion rates of glucose.