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.

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 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.

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.

The adjustment of basal body temperature measurements to allow for time of waking.

During one menstrual cycle, each of eleven volunteer student nurses at Northwick Park Hospital recorded their vaginal temperature on waking and noted the clock time. Waking times varied between 0530 hours and 1100 hours. Regression analysis revealed significant linear relation between temperature and time of waking, with a slope of 0.086 degrees C/hour (SE, 0.009 degrees C/hr) in the postmenstrual (hypothermal) phase. A rounded adjustment factor of 0.1 degrees C/hour is shown to improve the interpretability of basal body temperature (BBT) charts in a group of seven women regularly using natural family planning methods. The adjustment factor is simple to apply and only involves counting one square on a BBT chart for each hour that the waking time differs from normal.

Thermal features of the female axilla.

Axillary (Tax), vaginal (Tv), and sublingual (Tsl) temperatures were measured in 12 women between 0600 and 0730 h prior to their arising from bed. Isothermal maps made of closed axilla 30 min after thermojunctions had been inserted showed a distribution of several temperatures, the lowest Tv-Tax isotherm occupying approximately 40% of the anteroposterior distance. Tax at this point was 0.1 to 0.5 degrees C less than Tv and -0.03 to 0.26 degrees C less than Tsl. The time course of Tax rise varied considerably among subjects, with the slowest still rising 30 min after insertion, whereas the fastest was almost steady after 3 min. The width of the 0.5 degrees C isotherm along the fold averaged 5.8 cm and occupied about 60% of the axillary width. A significant negative correlation was noted between width of the 0.5 degrees C isotherm and Tv-Tax. Effects on the time course of 1) preexposure to air of the axilla for 5 min and 2) different initial thermometer temperatures (10 and 30 degrees C) were studied in 6 women. Analysis of variance showed a significantly higher value of Tax (10 min)-Tax (3 min), i.e., a slower time course with the cooler thermometer. The effects of exposure of the axilla were much more pronounced.

The reproducibility of double-isotope deconvolution measurements of intestinal calcium absorption.

1. Radiocalcium absorption was measured in duplicate in 10 subjects by the double-isotope method, with calcium as the oral carrier (2.5 mmol). Analysis of variance gave 95% confidence limits for a single measurement of fractional absorption and maximum absorption rate in a given individual of +/- 16.5% of administered dose and +/- 18.2% of dose/h respectively. 2. The size of these within individual variations suggests that alterations in the rate of calcium absorption may contribute to the week-to-week stabilization of some other controlled variable, such as plasma concentration of calcium. 3. In six of the subjects, calcium absorption was also measured with calcium loads at concentrations of 0.5, 5.0 and 20 mmol. Significant falls in fractional absorption, maximum absorption rate and mean transfer rate occurred as the load increased, together with a rise in mean transit time. Although between-individual differences at a given load were considerable, given a single-test result with a known carrier load, it is possible to predict quite accurately the results which would be obtained if a different carrier load were to be given.

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.

Case note descriptions of the placenta: are they worthwhile?

In 429 placentae, measurements were made of weight, diameter, shape, eccentricity of the cord and weight and length of the cord, and the results were compared with Apgar score of the infant at birth and its standardized birth weight. There was no evidence that cord eccentricity, placental shape or "thickness", or the dimensions of the cord had any significant relation to the growth of the fetus or its condition at birth. The value of routine recording of crude measurements and qualitative assessments of the placenta in case notes is questioned.

Steady state glucose kinetics and their relation to plasma glucose concentration in the premature and full term neonatal piglet.

Steady state glucose kinetics were measured in 19 premature and 16 full-term piglets. Bodyweight, plasma glucose concentration, total body glucose turnover rate, and glucose pool size were not significantly different between the two groups. This suggests that the premature piglet is capable of maintaining glucose homeostasis during the first 24 h of life. Although there appeared to be a correlation between glucose turnover and plasma glucose concentration, analysis of covariance showed that it was spurious, suggesting that glucose utilization proceeds independently of the glucose concentration in plasma. Glucose turnover rate in the premature piglet is closely comparable with that reported in the premature human infant. These findings encourage the use of the neonatal piglet as an animal model for the study of the problems of the neonatal human.

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 merits of special antenatal care for twin pregnancies.

A combined series of 101 twin pregnancies for whom routine hospital rest during the last trimester was replaced by intensified antenatal care in a special twins clinic was studied. Perinatal mortality and morbidity was similar to that found in a comparison group of 137 twin pregnancies under the care of consultants and not referred to the twins clinic. Routine cervical assessments and uterine activity measurements were unhelpful in predicting premature delivery. Urinary oestrogens and ultrasonic measurements of fetal biparietal diameter were of little or no value in predicting weight for gestational age but the ultrasonic measurement of abdominal circumference provided limited information on fetal growth. The contribution of a placebo effect to the results of patients receiving more personalised care cannot be discounted.

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.