Diurnal variations in the urinary excretion of calcium and phosphate in hyperparathyroidism

The urinary excretion of calcium and phosphate during the day and night was studied in 20 patients with primary hyperparathyroidism and in the same number of controls with normal function of the parathyroids. A significant difference in TRP between day and night was found in the controls but not in the HPT group. In other respects there were no substantial differences between day and night. The higher excretion of calcium observed in the HPT group was largely attributable to the patients with remal calculi. The simplified sampling procedure when only night urine is analysed has no disadvantages-it is more likely to improve the diagnostic reliability as it reduces the influence of meals, for example.     

Accelerating effect of chitosan intake on urinary calcium excretion by rats

The effect of chitosan on calcium (47Ca) metabolism was investigated in rats. The whole-body retention of 47Ca by rats fed on a 5% chitosan diet was significantly decreased when compared with that of rats fed on a cellulose diet, but showed no significant difference from that of rats fed on a fiber-free diet. Although there was no significant difference in the fecal excretion of 47Ca between the chitosan group and the cellulose or fiber-free group, the urinary excretion of 47Ca was significantly increased in the chitosan group when compared with the cellulose group. These results suggest that dietary chitosan would affect the calcium metabolism in animals.     

Secondary amenorrhoea and oral contraceptives

Extirpation of the endolymphatic anlage of the ear vesicle or that part of the ear placode which develops into the endolymphatic anlage in chick embryos, resulted in the absence of the endolymphatic system. In specimens of which the endolymphatic anlage was removed on the fourth day, healing of the wound was completed soon after the fifth day of incubation. Most of these experimental animals developed endolymphatic hydrops at a later stage. However, where healing was delayed after the fifth day, the open wound acted as an escape route for the endolymph (thus preventing further closure) which at that stage (or soon after) reached an appreciable volume.     

Potencies of oral contraceptives

Oral contraceptives are combinations of estrogens and progestogens or, in the case of the mini-pills, progestogens alone. With specific test procedures in laboratory animals or human subjects, it is possible to assign potency evaluations to the components relative to the progestational, estrogenic, or antiestrogenic activities of the progestogen or to the estrogenic potencies of the estrogenic component. It might even be possible to quantify the synergistic effects of the estrogen on the progestational agent. Unfortunately, however, it is impossible now to amalgamate such assay results into single estimates of the potencies of the combinations (either the combination products per se or the combination tablets of sequential products). For example, an over-all estrogenic potency of a combination preparation would involve the integration of contributions form the estrogen itself plus the estrogenic products of metabolism of the progestogen minus the antagonistic effect of the progestational agent, if any. These factors cannot now be quantified independently, much less merged into a single figure of clinical significance. Further, even if it were possible to produce such an estimate, it is unlikely that the evaluation would be meaningful in relation to any putative side effect or adverse reaction, i.e., the alleged thrombogenic effects of oral contraceptives cannot currently be related directly to any measure of potency that will allow prediction of these clinical conditions from laboratory models. Any evaluation of the potential of a given contraceptive to produce a specific side effect will depend upon data generated with specific regard to that adverse reaction and the individual product in question.     

Pharmacology of oral contraceptives

Oral contraceptives include two types of steroids; ethinyl-estradiol as the main estrogenic component which dose vary from 20 to 50 micrograms per tablet (mostly 30 to 35 micrograms) and progestins essentially derivatives of 19 nortestosterone. Derivatives of 19 norprogesterone such as nomegestrol acetate or ST 1435 are not used as oral contraceptives but are being evaluated through parenteral administration, e.g. implants or transdermal systems. The assessment of the pharmacological properties of these progestins indicate a high antigonadotropic and a high antiestrogenic properties for levonorgestrel and for the newer gestagens as well. Therefore very low doses are being used in the current oral contraceptives. However, there is a lower margin of security with the low dose contraceptives than with previous standard combinations and especially when concomitant medications are ingested such as enzyme-inducing agents. Selection of contraceptive methods should be discussed when specific co-medications are necessary.     

Combination oral contraceptives and cardiovascular disease

The abundance of rapid eye movement (REM) sleep in the neonatal mammal and its subsequent decline in the course of development, as well as the dramatic and widespread enhancement of CNS activity during REM sleep, led us to propose that this state plays a functional role in the normative physiological and structural maturation of the brain [54]. When, after 1 week of monocular deprivation (MD), a second week of MD was coupled with behavioral deprivation of REM sleep, the structural alteration in the visual system provoked by MD alone (interlaminar relay cell-size disparity in the lateral geniculate nucleus (LGN) was amplified. With the addition of REM deprivation during MD, the LGN cells connected to the surgically patched eye, which are smaller than normal after MD, became even smaller, whereas the LGN cells receiving input from the seeing eye, which display compensatory hypertrophy after MD, grew even larger. We believe that the interlaminar disparity effect widened because during REM deprivation, the already vision-compromised LGN cells associated with the patched eye also lose the ascending brainstem activation reaching them during the REM state. Loss of the two main sources of 'afference' by these LGN cells permits their seeing-eye LGN counterparts to gain even greater advantage in the competition for synaptic connections in cortex, which is reflected in the relative soma sizes of the LGN relay cells. It is likely that the relatively abundant REM state in early maturation provides symmetric stimulation to all LGN relay cells, irrespective of eye of innervation. The symmetric activation propagated from brainstem to LGN acts to 'buffer' abnormal, asymmetric visual input and, thereby diminishes the extreme, asymmetric structural alteration that results from MD in the absence of REM sleep. We conclude that REM sleep-generated CNS discharge in development has the effect of 'protecting' the CNS against excessive plasticity changes. This is consistent with the possibility that REM sleep plays a role in the genetically programmed processes that direct normative brain development.     

Anti-nidation activity of oral contraceptives

The antinidatory activity of the oral contraception is generally unknown: the contraceptive pill mainly prevents the gametes from meeting. However, pregnancies under pill indicate conception of embryos. Besides, missed pills protocols sometimes record ovulatory escape. We suggest the computation of an Embryo Destruction Index (EDI), in order to measure the antinidatory effect of two categories of oral contraceptives: combined estroprogestatives and microprogestatives.     

Tumors of the liver and oral contraceptives

In this editorial, the authors review the body of literature dealing with primary tumors of the liver (hepatomas) that occur in women using oral contraceptives; since 1972 reports of 23 such cases have been published. The affected women ranging in age from 22 to 52 years, and most reported that they had used the "combined pill." The women had been using the pill for a mean duration of 5 years; there was no direct association between the duration of pill use and the appearance of the hepatoma. Diagnosis of the tumor was made either by liver scan or by intra-abdominal arteriography. Since it was possible to palpate the tumor in 10 patients, the authors emphasize the importance of continuous medical supervision of women who are using oral contraceptives. Treatment may be conservative or surgical; in this series, 20 of the patients underwent surgery despite the risks of considerable operative morbidity. The mechanism leading to the appearance of hepatomas in these women is not clear, although it is certain that it is related to the liver's role in the metabolism of hormones. The authors note that only 23 cases of hepatoma have been reported among the more than 20 million women using the pill; the frequency of the tumor in the general population of women of reproductive age must be examined before concluding that there is a direct association between the appearance of the tumor and use of the pill.     

Urinary calcium excretion. (Normal values for urinary calcium/creatinine ratio in Hungary). Multicenter study

Metabolic bone disorders have attracted increasing attention in Hungary due to their significant impact on public health care. Measuring urinary calcium excretion is the first step in the biochemical assessment of bone metabolism. Fasting urinary calcium corrected by creatinine excretion is widely used all over the world. The aim of the present study was to establish standard methods and normal values for the calcium/creatinine ratio in Hungary. Twenty-four centers specializing in metabolic bone diseases participated in the study. Urine standards were sent out to these centers for calcium and creatine determinations. Based on the collected data, methods were corrected in order to achieve similar results for the standards. In the second phase of the study, the normal values for calcium/creatinine ratio were determined in SI units based on the data from 1846 healthy subjects (age 20-80 yrs) including 944 females and 902 males. The normal value for females was 0.438 +/- 0.391 (means +/- SD), and 0.395 +/- 0.352 for males, respectively (p < 0.03). The ratio increased with age in both sexes. The highest values were observed between 60-64 years in women and 70-74 years in men, respectively. After this peak, the calcium/creatinine ratio decreased. The values before and after 45 years of age were significantly different both in women (0.37 +/- 0.36, vs. 0.52 +/- 0.41, p < 0.001; and men (0.32 +/- 0.23, vs. 0.47 +/- 0.45, p < 0.001). The use of this distinction is recommended in the everyday practice.     

Liver damage from low-dose oral contraceptives

OBJECTIVE: To study whether the decrease in the content of oestrogen and gestagen in modern low-dose oral contraceptives (OC) has yielded a lower incidence of adverse liver reactions, and to describe the biochemical pattern of the adverse liver reactions from low-dose OC. DESIGN: We surveyed all liver reactions from OC reported to SADRAC (Swedish Adverse Drug Reactions Advisory Committee) from 1966 to 1989. MAIN OUTCOME MEASURE: Incidence of reported adverse liver reactions (number of reported adverse reactions/OC sales in defined daily dose [DDD]). RESULTS: There was a sharp decline in the number of reports during the studied period, suggesting changes in reporting habits. However, there was also a significantly lower incidence of reports for medium-compared to high-oestrogen dose OC, and a further decrease, albeit non-significant, in incidence with low-oestrogen dose OC. Furthermore, in three comparisons of pairs of OC that differed only in the gestagen dose, there was a strong trend towards a higher reporting rate with higher gestagen dose. Cholestatic and hepatocellular liver enzyme patterns were equally frequent in patients with adverse reactions from low-dose oestrogen OC. There was no report of liver tumours related to use of low-oestrogen dose OC. CONCLUSION: There seems to be a decrease in the incidence of adverse liver reactions related to lower contents of both oestrogen and gestagens in OC of the combined-preparation type.     

Effect of an oral calcium load on urinary markers of collagen breakdown

Aim of this study was to investigate whether osteoclast activity changes as a consequence of even mild physiological perturbation of plasma calcium as such induced by an oral calcium load. Osteoclast activity was determined indirectly by measuring, in spot urines at two and four hours after oral calcium load, the urinary excretion of hydroxylysylpyridinoline (Pyr), deoxylysylpyridinoline (D-Pyr), hydroxyproline (Hyp) and galactosyl-hydroxylysine (GHyl). The occurrence of the metabolic perturbation of plasma calcium homeostasis was assessed by measuring three indexes: i.e. calcemic response, PTH reduction and calciuric response at times following oral calcium loading. A significant fall of urinary D-Pyr and Pyr followed the perturbation of calcium homeostasis induced by the oral calcium load in two groups of healthy young adult and postmenopausal women. The highest mean percent reduction was observed for D-Pyr and was quantitatively similar in the two groups. Since urinary D-Pyr is the most specific bone resorption marker, it may be inferred that the perturbation of plasma calcium homeostasis induced by an oral calcium load is able to acutely inhibit osteoclast activity. This supports the view that osteoclasts are involved in the short-term error correction of plasma calcium.     

Dietary protein intake and urinary excretion of calcium: a cross-sectional study in a healthy Japanese population

Efforts in dental research and training have received the contribution of individuals who had no formal training in dentistry, yet they understood the dental field and the educational needs of those who would be engaged in dental research, teaching, and service in industry and academia. Dr. Robert S. Harris (1904-1983) was such a man. What follows is a personal remembrance of his character, his research accomplishments, and his successful educational endeavors in the dental field.     

Amenorrhea following the use of oral contraceptives

Clinical aspects and the incidence of the various underlying etiologic factors were studied in 86 patients with post-oral contraceptive amenorrhea. Patients were divided into two groups according to the presence or absence of detectable galactorrhea. Group I was composed of 55 amenorrheic patients without detectable galactorrhea and group II included 31 patients with amenorrhea associated with galactorrhea. Both groups were comparable for age, gravidity, duration of intake of oral contraceptives, and duration of amenorrhea. The incidence of previous oligomenorrhea and late menarche was high in both groups. The most striking difference between the two groups was in the incidence of pituitary prolactin-secreting tumor--32% among patients with galactorrhea and less than 2% among patients without galactorrhea. Identification of galactorrhea and accurate diagnosis of its causes are mandatory for successful management of postpill amenorrhea.