Effect of Salinity on Embryo and Larval Development of Oyster Crassostrea iredalei

The effects of salinity on the embryonic and larvae stage of Crassostrea iredalei were investigated. Fertilised eggs and one day old D-larvae were subjected to salinities ranging from 0 to 30 ppt at temperature of 30±2°C. At salinity lower than 10 ppt, 100% mortality was observed. For embryo development, the highest survival was observed at salinity 25 ppt with 80.9±2.2% survival with no significant difference compared to 15 and 30 ppt. Shell height and length were both greatest at salinity 30 ppt. Throughout the 11 days culture, the highest larval survival occurred at salinity 15 ppt with no significant difference compared to all other salinities except 10 ppt. Larval shell sizes showed no significant differences between salinities, except for 10 ppt. Optimum culture condition for larvae growth are salinities ranging from 15 to 30 ppt whereby the larval of this species can tolerate wider range of salinity compared to other oyster species and thus, making it a competitive species to be cultured.

Assessment of Temperature Effects on Early Larval Development Survival of Hatchery-reared Tropical Oyster, Crassostrea iredalei

The influence of the cool and warm temperatures on early life development and survival of tropical oyster, Crassostrea iredalei was studied. D-hinged larvae (day 1 larvae) were reared to three different temperatures (20°C, 27°C, and 34°C) for nine days. Oyster larvae reared in temperature 27°C, acted as control (ambient temperature). The highest survival rate occurred when the larvae were reared in 20°C and 27°C. Larvae reared at 34°C exhibited reduced survival but increase in the growth rate. The growth rate in larvae reared in high temperature (34°C) was significantly higher compared to larvae reared in 20°C and 27°C (p<0.05). The results from the present study indicated that tropical oyster larvae, C. iredalei had faster growth rate at the high temperature (34°C). However, the larval survival was decreasing according to days. There is no significant difference in the larval growth and survival in lower temperature (20°C) and control condition (27°C).

Antibacterial silver-containing silica glass prepared by ion implantation

Recently, there is much interest in nanocomposites consisting of metal nanoparticles dispersed in dielectric matrix. Silver is the first candidate used in antibacterial research. In the present study, sliver-containing silica glass is prepared by ion implantation. The bactericidal properties of Ag-implanted samples are investigated using E. coli. The implanted samples are characterized by optical absorption spectroscopy, atomic force microscopy and transmission electron microscopy. The size and position of the silver nanoparticles formed by ion implantation can be optimized by adjusting the implanted process parameters. All the implanted samples show antibacterial properties. But the samples with silver nanoparticle-enriched surfaces possess excellent antibacterial properties in comparison with other implanted samples. This indicates that ion implantation is a potential method for synthesizing antibacterial biomaterials.

Synthesis and Magnetic Properties of Maghemite (gamma-Fe(2)O(3)) Short-Nanotubes

We report a rational synthesis of maghemite (gamma-Fe(2)O(3)) short-nanotubes (SNTs) by a convenient hydrothermal method and subsequent annealing process. The structure, shape, and magnetic properties of the SNTs were investigated. Room-temperature and low-temperature magnetic measurements show that the as-fabricated gamma-Fe(2)O(3) SNTs are ferromagnetic, and its coercivity is nonzero when the temperature above blocking temperature (T(B)). The hysteresis loop was operated to show that the magnetic properties of gamma-Fe(2)O(3) SNTs are strongly influenced by the morphology of the crystal. The unique magnetic behaviors were interpreted by the competition of the demagnetization energy of quasi-one-dimensional nanostructures and the magnetocrystalline anisotropy energy of particles in SNTs.

Peripartum cardiomyopathy--a case report

Peripartum cardiomyopathy in the form of congestive heart disease of unknown etiology appears relatively rarely during the last month of pregnancy or within 5 months after delivery, and it is potentially life-threatening. This case report describes a 34-year-old female, G4P1, at 36 weeks' gestation who was admitted for cesarean section under lumbar epidural anesthesia due to twin pregnancy. She had no past history of cardiovascular diseases. However, rapid onset of dyspnea at ward and acute cardiac failure developed 15 h after cesarean section. Peripartum cardiomyopathy was diagnosed. After a 7-day intensive treatment she was discharged. Since then she was symptom-free and her two babies were doing well during a period of one more years after discharge.

Does augmented growth impose an increased risk of fetal death?

OBJECTIVE

Our purpose was to examine the risk of fetal death associated with augmented fetal growth.

STUDY DESIGN

All live births recorded in Virginia between January 1, 1991, and December 31, 1993, were examined. Mortality rates were examined for infants born at or beyond 24 weeks' gestational age with weights between the 75th and 90th percentiles, from the 90th to the 95th percentile, and >95th percentile.

RESULTS

Mortality rates were found to rise only slightly with birth weights >90th percentile. A recorded diagnosis of maternal diabetes, however, was associated with a significant risk in the presence of augmented fetal growth. Augmented fetal growth without maternal glucose intolerance showed no increase in mortality.

CONCLUSION

Augmented fetal growth in the absence of maternal glucose intolerance appeared not to be associated with a significant increase in the risk of death among these births. Increased risk was found when augmented fetal growth was associated with maternal diabetes.

Epidural anesthesia for emergency caesarean section in a patient with single ventricle and aortic stenosis

A 24-year-old parturient with single ventricle and moderate aortic stenosis was admitted due to preeclampsia and fetal distress at 31 weeks' gestation. Emergency Caesarean section was performed under lumbar epidural anesthesia and epidural analgesia was given for post-operative pain control. Mother and baby both survived. The anesthetic techniques and managements in other parturients with similar congenital cardiac anomalies are also reviewed and described.

A selective aggressive approach to the neonate exposed to meconium-stained amniotic fluid

OBJECTIVE

We attempted to determine the effect on meconium aspiration syndrome from a selective approach of neonatal endotracheal intubation in meconium-exposed fetuses.

STUDY DESIGN

All pregnancies delivered at the Medical College of Virginia in 1990 were included. Meconium was noted at membrane rupture and qualified as thick, moderate, or thin. Neonates underwent suctioning with a DeLee device at delivery. They were observed without endotracheal intubation if they fulfilled the following criteria: vaginal delivery, gestational age > 37 weeks, birth weight > 2500 gm, and anticipated Apgar score > or = 8 at 1 minute.

RESULTS

Of 4289 deliveries, 659 were exposed to meconium and 48% of infants were intubated. Birth weights, gestational ages at delivery, and umbilical arterial pH were similar between intubated and nonintubated neonates. Neonatal intensive care unit admissions were significantly higher in intubated neonates. All 9 neonates diagnosed with meconium aspiration syndrome were intubated at birth.

CONCLUSIONS

Utilization of this protocol resulted in reduction of neonatal intubation. Meconium aspiration syndrome did not occur in the nonintubated group.

Maternal disease and injury in pregnancy

Progress in the management of medical disorders of pregnancy has occurred in many areas. Only salient features are reviewed. The pathophysiology of maternal hyperglycemia in diabetes and its effects on the fetus are explored. Antiphospholipid antibodies, implicated in adverse pregnancy sequelae, come under closer scrutiny in terms of management and correlation with outcome. Studies defining a need for a strict diet for optimal neonatal outcome are presented regarding maternal phenylketonuria. Coagulopathies including protein C deficiency and deep venous thrombosis are reviewed for their impact on pregnancy. Uncommon disorders including cerebrovascular accidents, ureteric obstruction, and myocardial infarction are discussed in relation to management and outcome in pregnancy.

Obstetric complications in a patient with Bernard-Soulier syndrome

We describe the obstetric complications and management of a patient with Bernard-Soulier syndrome. Severe bleeding at the time of delivery and delayed postpartum hemorrhage were prominent features of her pregnancies. Further complicating this woman's pregnancies was the development of antibodies to platelet glycoprotein IB/IX, leading to neonatal alloimmune thrombocytopenia.

Lower serum osteocalcin in ethanol-fed rats

Serum osteocalcin was remarkably and significantly (-34 and -41% in two separate experiments; p less than 0.001) lower in rats fed an 8% (w/v) ethanol liquid diet (ELD) for 1 week than in rats fed an isocaloric control liquid diet (CLD). In a longer experiment that spanned 4 weeks, the ELD rats were given 6% ethanol on day 4, increased stepwise to 8% by day 9, and then maintained at 8% until day 28, when the experiment was terminated. Again, serum osteocalcin was much lower (-32%, p less than 0.001) in the ELD-fed rats than in CLD-fed rats. Even in rats fed only a 6% ELD for 12 days, serum osteocalcin was lower (-33%, p less than 0.001) than in controls. Also, the femora were weaker, more compliant, and more ductile in ELD-than in CLD-fed rats, findings that confirmed our earlier, related work. The fall in serum osteocalcin in ELD-fed rats is associated with a fall in femur ash weight and bone strength. There were significant correlations between serum osteocalcin and bone strength (r = 0.80; p less than 0.001) and between serum osteocalcin and bone stiffness (r = 0.83; p less than 0.001). Serum ionized calcium, like osteocalcin, was consistently lower in rats given ethanol for 1 or 4 weeks than in controls. From these experiments we conclude that excessive ethanol consumption inhibits osteoblastic activity as indicated by the reduced serum osteocalcin. The inhibition is also associated with other deleterious effects of ethanol on bone, including ash weight, bone strength, and bone stiffness.(ABSTRACT TRUNCATED AT 250 WORDS)

An integrated, hospital information system based obstetrical medical record and database

Described in this paper is the implementation and integration of an obstetrical medical record and database into an existing hospital information system. A unique feature of this system was the integration of existing data captured by the established hospital information systems with the newly implemented obstetrical database to form a complete patient data profile. This complete database integrated data from hospital functions such as demographic data obtained at patient registration, outpatient visits and tests, inpatient admission historical data, tests and procedures, newborn data and miscellaneous data required for birth registration. An important second feature was the utilization of physicians and nurses to enter the obstetrical data. This permitted immediate access to patient data from any hospital information system terminal, immediate retrieval for generating reports, and subsequently, ad hoc queries, statistical analysis and the electronic transfer of birth registration data to the State Vital Statistics Registry.

Prevalence of human papillomavirus infections in term pregnancy

The prevalence of human papillomavirus (HPV) infections in the lower genital tracts of pregnant and nonpregnant women was studied. Cervical and vaginal exfoliated cells were obtained during a routine pelvic examination in 45 pregnant women in early labor, and in 44 nonpregnant women. A detailed questionnaire with emphasis on sexual history and sexually transmitted diseases was administered. The two groups of women were comparable with respect to mean age, prior pregnancy experiences, and number of lifetime sexual partners. Compared with pregnant women, the nonpregnant women had a more frequent history of sexually transmitted diseases (61% versus 39%; p = 0.06), and of genital warts (16% versus 0%; p = 0.01). Utilizing Southern transfer and hybridization with 32P-labeled viral DNA probes for HPV types 6, 11, 16, 18, and 31, DNAs extracted from cervicovaginal exfoliated cells were assessed for HPV genomic sequences. HPV genomic sequences were identified in 25% of nonpregnant women compared with 13.5% of term pregnant women. This difference was not statistically significant (p = 0.26). Six HPV isolates identified in pregnant women were distributed as follows: type 6/11, 1; type 16, 1, type 31, 1; and unknown type, 3. Eleven isolates were identified in nonpregnant women and were distributed as follows: type 6/11, 2; type 16, 6; type 18, 2; and type 31, 1. HPV type 6/11, the type responsible for laryngeal papillomatosis of juvenile onset, was identified in 2% of the pregnant population and accounted for only one of six isolates. HPV DNA-positive pregnant and nonpregnant women were predominantly asymptomatic and had normal Papanicolaou smears and normal clinical examinations.

Vulvar leiomyosarcoma in pregnancy

To our knowledge, this is the first case of vulvar leiomyosarcoma occurring during pregnancy to be reported. The neoplasm was resected immediately after a term vaginal delivery. A wide local excision of the vulva with bilateral superficial inguinal node sampling was performed 6 weeks post partum. Four previous cases of vulvar sarcoma occurring in pregnancy are reviewed. The need to perform biopsy of vulvar lesions during pregnancy is emphasized.

Evaluation of inhospital cardiopulmonary resuscitation

Of 77 patients who received cardiopulmonary resuscitation (CPR) for an inhospital cardiac arrest from Jan. 1987 to Mar. 1988. 48(68%) survived the initial resuscitation, but only 11(16%) survived to leave hospital. A follow-up survey to Oct. 1988, of these 11 patients showed that one died within 11 months of discharge, but that others were all alive and living independently. The major cause of cardiopulmonary arrest was airway obstruction. Survival rates were lower if resuscitation efforts lasted more than 30 minutes or if the event occurred between midnight and 8:00 AM. Thirty of the 48 patients who were successfully resuscitated initially were transferred to the intensive care unit for prolonged cardiac life support. Of the patients who had underlying disease or severe neurologic impairment due to hypoxic encephalopathy, 19(63%) were dead within a few days or even hours after CPR. Therefore, we recommend (1) programs for routine CPR assessment (2) extension of CPR training for key personnel, especially ward staff working night shifts (3) assessment by CPR providers as to whether or not to continue or to give DNR (do-not-resuscitate) orders.

Influence of ethanol on stiffness, toughness, and ductility of femurs of rats

Recently, we reported that the ingestion of alcohol in rats reduced the mechanical strength of femurs. Our results showed that, as the dose exceeded 0.012 g of ethanol per gram of body weight, a significant (p less than 0.001) loss of "strength" occurred that was independent of sex according to the relationship, Strength (N) = 140.4 - 6003 dose (g/g). In the present effort, the same flexure tests were reevaluated to include the parameters of stiffness, toughness, and ductility. These latest results confirm that the femurs of rats fed an ethanol liquid diet for 4 weeks are not only weaker but also more compliant and less energy absorbing. Although the femurs of rats fed ethanol are more ductile, the bones are more prone to fracture in fatigue and impact circumstances as well as under simple loading situations. The rat may be an appropriate model to study the mechanisms that lead to the higher incidence of fractures in the alcoholic human.

Ethanol-induced changes in morphology and strength of femurs of rats

Chronic ingestion of ethanol resulted in ultrastructural and mechanical changes in rat femurs. Scanning electron microscopy of the distal end of the femur revealed that the trabeculae of bones from ethanol-fed rats were thinner, more columnar, and more extensive than those from control rats. Three-point bending tests of the rat femurs showed that the maximum force or so-called "strength" required to break the bone was less in ethanol- than in control-fed animals. A significant inverse correlation was observed between the strength required to break the femur and the dose of ethanol calculated on a body weight basis. For the first time our study presents quantitative proof that a relationship exists between bone strength and the consumption of ethanol in rats. The study revealed that ethanol consumption resulted in a weaker femur compared to controls. We suggest that a common mechanism may be responsible for the decreased bone strength of ethanol-fed rats and the increased incidence of fractures in human alcoholics.

Modulation of serum parathyroid hormone and ionized calcium concentrations during reproduction in rats fed a low calcium diet

Moderate dietary restriction of calcium (0.1% Ca) was used to accentuate the changes in serum immunoreactive parathyroid hormone (iPTH) that had been reported earlier in lactating rats fed 0.4% Ca diet. In addition, the effects of this low-Ca diet on serum total and ionized Ca and iPTH during pregnancy, extended lactation, and weaning were examined. The positive correlation between serum total and ionized Ca was highly significant (r = 0.88, p less than 0.001, n = 120). Serum iPTH was significantly higher (36%) in pregnant rats on the day of parturition compared to nonmated controls, and there was a concomitant decrease in both total and ionized serum Ca. Within 1 day after parturition, however, serum Ca had risen to the control level. Serum iPTH remained significantly elevated during the first 2 weeks of lactation, and increased further during the third week of lactation to a level more than twice that of nonlactating controls. Serum Ca fell gradually during the second week of lactation. The high serum iPTH levels were maintained for another 2 weeks when lactation was extended with foster litters. Within 6 hr of removal of the suckling pups on day 16 of lactation, maternal serum ionized and total Ca had risen and serum iPTH had fallen; all three parameters were at levels similar to those of nonmated controls by 24-48 hr after weaning. The data suggest that serum ionized Ca is a major factor contributing to the hyperparathyroid state during lactation in rats fed a low-Ca diet.

Effect of number of suckling pups and dietary calcium on bone mineral content and mechanical properties of femurs of lactating rats

The bone loss that occurs during lactation in rats was aggravated by increasing the number of suckling pups and was further accentuated by feeding the rats a calcium (Ca)-deficient diet. The bone loss was evenly distributed along the whole length of the femur in severe cases. In less severe cases, the metaphyses were affected more than the midshaft. Mechanical properties of femurs, i.e., bone 'strength', 'stiffness', 'toughness' and 'ductility', were all affected in lactating rats suckling seven to eleven pups and fed the 0.1% Ca diet. The positive correlation between bone 'strength' and ash weight is consistent with the concept that when there is loss of bone, bone becomes more susceptible to fracture. The fall in serum ionized Ca and the rise in serum iPTH were closely related to the intensity of lactation and were profoundly affected by litter size and Ca concentration of the diet. We conclude that the change in Ca homeostasis in lactating rats is due to the large loss of Ca required for milk production and that the loss of Ca is associated with hyperfunction of the parathyroid gland. Furthermore, a Ca-deficient diet severely reduced bone mineral content and affected the mechanical properties of femurs of lactating rats adversely, especially those suckling large litters of pups.

Interrelationships of bone ash and whole bone properties in the lactating and parous rat

Several investigators have studied the mechanical properties of long bones of rats and have found that bone strength may be associated with bone mineral content. In this study we examined further the interrelationships of whole bone properties and bone ash weight of the rat femur. Using a 3-point bending test, the bones were evaluated during lactation and after one to three pregnancy + lactation periods--experiments in which bone ash was significantly reduced. A relationship was established between the time of lactation and the ash weight, stiffness, strength, and toughness but not the ductility. Using all of the experimental data, a highly significant relationship was observed between ash weight and stiffness. A similar significant correlation was revealed between bone ash and strength or toughness, although drawing individual lines for each experiment rather than a common line for all the experiments appeared more appropriate. Given the inherent inaccuracies in the material property measurements of bone, the results suggest that routine measurements of whole bone properties provide an important and sensitive way to evaluate bone quality and that these properties correlate significantly with the bone ash weight.

Increase in serum parathyroid hormone concentration in the lactating rat: effects of dietary calcium and lactational intensity

The change in circulating levels of immunoreactive parathyroid hormone (iPTH), measured with an N-terminal specific radioimmunoassay, was examined during lactation in rats. In lactating rats consuming a diet containing 0.4% Ca (basic diet), serum iPTH was a) increased by an average of 53% between days 10 and 18 compared to the level of age-matched nonlactating rats (24.7 +/- 2.1 pg/ml vs 16.1 +/- 0.8 pg/ml, mean +/- SE, p less than 0.01) and b) significantly higher in dams suckling large litters (10-15 pups) than in dams suckling small litters (3 pups) over the period 3-13 days of lactation. Lactating rats consuming a low calcium diet (0.04% Ca), had serum iPTH levels on days 16-18 of lactation approximately twice those of nonlactating rats fed the same diet and 73% higher than those of lactating rats fed the basic diet. Serum Ca concentrations were 22% and 10% lower in dams consuming the 0.04 and 0.4% Ca diets, respectively, than in the nonlactating controls fed the same diets. Regression analysis showed a significant (p less than 0.001) negative correlation between iPTH and total serum calcium. Compared with nonmated controls, net mineral loss from femurs of dams consuming the 0.4% Ca diet was a) insignificant at day 6, b) 27% at day 15, and c) 34% at day 21 of lactation. Our data demonstrate that lactation in the rat is characterized by hyperparathyroidism that appears to be related to lactational intensity and that is accentuated when dietary calcium intake is restricted.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of lactation and pregnancy + lactation on mechanical properties and mineral content of the rat femur

The quality of bone was assessed from femurs of rats both during lactation and after pregnancy + lactation. Mechanical properties of stiffness, strength, toughness, and ductility were measured, along with standard measurements of dry weight, ash weight, and total bone mineral. No changes occurred during the first week of lactation. During the second and third weeks of lactation all bone parameters except ductility decreased significantly. These data are consistent with bone losing mineral in order to supplement the dietary calcium intake necessary for milk production. In other experiments, femurs were collected from nulliparous rats and from rats that had previously undergone 1-3 pregnancy + lactations. The largest changes in bone mineral and mechanical properties occurred after a single pregnancy + lactation period, although significant further decreases in stiffness and strength occurred after the second pregnancy + lactation. No additional losses occurred following the third pregnancy + lactation. Even 5 months after only one pregnancy + lactation period, the bone quality was still impaired as all bone properties were lower than in nulliparous controls. Because the changes, especially stiffness and strength, were relatively larger than the changes in dry and ash weights of bone, measurements of these mechanical properties provide a more sensitive method to evaluate the quality of bone.

Cytochemical bioassay of circulating concentrations of rat parathyroid hormone: application to a study of age and sex

We have found that the cytochemical bioassay (CBA) method, originally developed to measure circulating levels of biologically active parathyroid hormone (bioPTH) in humans, also can measure endogenous concentrations of PTH in rats. Therefore, we have applied this assay method to examine the relationships between age and sex and the circulating levels of bioPTH, calcium, and phosphorus in Fischer rats. The concentration of bioPTH increased in both males and females from 5 to 15 months of age (p less than .001) with no significant sex-related difference. Mean bioPTH values ranged from 2.3 to 3.6 pg (human PTH equivalents)/ml; these values were much lower (1 to 2 orders-of-magnitude) than those reported by others who used radioimmunoassays for PTH that do not discriminate between biologically active and inert PTH fragments. The CBA values for bioPTH were also 1/4-1/5 those obtained in rat serum by newer, more sensitive methods, the N-terminal specific PTH radioimmunoassay and the bioassay based on stimulation of chick renal adenylate cyclase. Regression analysis did not reveal any significant correlation between serum calcium and age. However, serum inorganic phosphorus decreased significantly (p less than .001) from 5 to 15 months of age in both male and female rats and was much lower in females than in males (p less than .001). The fall in serum phosphorus was negatively correlated with the rise in bioPTH (p less than .001). This study, the first to our knowledge to use a CBA to detect physiological changes in the circulating levels of bioPTH in rats, demonstrates the usefulness of the assay in experiments in this species.

Secretion of calcitonin gene-related peptide from baby rat thyroid glands in vitro

Thyroid glands from 8-day-old rat pups were incubated in serum-free medium for 6 hr. Both calcitonin (CT) and calcitonin gene-related peptide (CGRP) released into medium were measured by radioimmunoassay. In 6 separate experiments CGRP was easily detected in medium in ng/ml concentrations. In 4 of the 6 experiments, where CT release was stimulated by high medium [Ca], the concentration of CGRP in medium showed a positive, significant correlation with the medium CT concentration (r = 0.41-0.69, p less than .05- less than .01). The results are in concert with reports describing the presence of CGRP in the C-cell, and they further show that CGRP, as well as CT, can be secreted by C-cell.

Serum calcitonin, calcium and thyroxine in young and old Zucker fatty rats (fa/fa)

We determined the serum levels of calcitonin (CT), calcium (Ca), and thyroxine (Ti) in lean (?/+) and fatty (fa/fa) male Zucker rats 10 weeks and 10-12 months of age. The most dramatic finding was a high level of serum CT (3.24 +/- 1.18 ng/ml) in young fatties whereas sera from young leans were all below the limit of assay detection (less than 0.120 ng/ml, p less than 0.01). Young fat rats also had elevated levels of both Ca (11.2 +/- 0.2 vs. 9.7 +/- 0.2 mg/dl, p less than 0.001) and Ti (6.7 +/- 0.48 vs. 4.72 +/- 0.28 micrograms/dl, p less than 0.01). In older animals the mean serum level of CT increased further in the fatties and became readily measurable in leans (5.67 +/- 1.94 vs. 1.49 +/- 0.55, p less than 0.01). Thyroid C-cells, identified immunohistochemically, were abundant in both leans and fatties at this age but were substantially more numerous in the fat rats (p less than 0.001). Calcium levels increased somewhat in the older leans, but still remained higher in the fat rats (p less than 0.05). Thyroxine values were essentially the same for old animals of both genotypes (5.07 +/- 0.61 vs. 5.54 +/- 0.88). Age effects were not significant for any measure in the fat animals, but in the leans there were significant age-related increases in CT (p less than 0.02) and serum Ca (p less than 0.05).

Evidence of a toxic effect of ethanol on bone in rats

Tibiae from rats treated chronically for 12 days with enough ethanol to induce physical dependence were found to have an increased incidence of fracture during dissection and cleaning (7 of 12 or 58%) compared to control animals (1 of 12 or 8%). The site of the fractures, the proximal end of the tibia, showed an increased opacity to X-rays, and the dried bones were distinctly darker in appearance than similarly prepared control bones. The effects noted in our study suggest that the rat model could be useful for the study of the mechanisms by which alcohol affects bone growth, remodeling, and strength. These studies might shed new light on the pathogenesis of increased bone fragility in alcoholics.

Age-associated C-cell hyperplasia in the human thyroid

C cells in 26 normal human thyroids from forensic autopsies were identified by immunoperoxidase staining for calcitonin. C-cell concentrations and total C-cell numbers were determined with the use of morphometric techniques. There was great variation in C-cell density within a given gland and among individuals, although C cells tended to concentrate about one third of the way down the vertical axis of the lateral lobes. Densities of 1-2000 cells/cu mm were found in the third and later decades. In addition there was a statistically significant (P less than 0.01) positive Spearman correlation between total C-cell numbers and age in males. C-cell hyperplasia appears to be an age-related phenomenon that may have physiologic significance and must be taken into consideration in evaluation of thyroid glands for the diagnosis of premalignant lesions of C cells.

C-cell nodules in adult human thyroid. A common autopsy finding

This study was designed to examine the morphologic features and distribution of calcitonin-producing cells (C-cells) in normal adults and in a general autopsy population. Random or serial sections from thyroid glands in forensic and general autopsies were examined by an immunoperoxidase stain for calcitonin to identify C-cells. Six glands out of 30 cases contained large C-cell nodules (85-343 C-cell nuclei per nodule). Five of the nodules were in patients over 50 years of age. C-cell nodules in thyroid sections may represent age-related hyperplasia or a normal variation of ontogeny. This study underscores the importance of serially sectioning the thyroid to evaluate nodular C-cell hyperplasia in preneoplastic or nonneoplastic functional disorders.

Calcitonin-like immunoreactivity in rat and human pituitary glands: histochemical, in vitro, and in vivo studies

This study was designed to determine whether pituitary glands contain an immunoreactive material which reacts with antisera to calcitonin (CT) and, if so, whether secretion of the material could be demonstrated. Testing 15 antisera to rat and human CT and using an immunoperoxidase method, we found 2 antisera to human CT which stained rat pituitaries and several which stained human pituitaries. Essentially all cells in the rat intermediate lobe and scattered cells in the rat and human anterior lobes showed staining, and staining was not entirely abolished by prior adsorption of antisera with rat or human CT. The 2 antisera which stained rat pituitaries showed cross-reactivity with several synthetic human CT fragments (1-18, 11-23 and 22-32) but not with ACTH-(1-39), ACTH-(1-24), beta-endorphin, alpha- or beta MSH, or bovine lipotropin. Crude extracts of pituitaries from 2 strains of young rats showed CT-like immunoreactivity which could be measured easily by RIA (0.2-0.3 ng/gland). In vivo, an antiserum which stained pituitaries and 1 which did not were compared using young rats made hypercalcemic (15-20 mg/dl) with iv Ca. In rats with thyroids, both antisera showed an increase in serum CT of more than 15-fold whether the pituitary was present or absent. In thyroidectomized rats, serum CT remained undetectable (less than 50 to 100 pg/ml) during hypercalcemia even if the pituitary was present. In vitro, rat pituitaries in a serum-free medium did not release measurable amounts of immunoreactive CT-like material even when medium contained high Ca (2.5 mM), high K (25 mM), or TRH (10(-6) M). Therefore, the findings agree with other reports of a CT-like material in the pituitary, but no secretion of the material could be demonstrated. We hypothesize that the material is not authentic CT but is, rather a related peptide sequence probably contained in the 31 K precursor protein of ACTH-beta-lipotropin.

Sex difference in serum calcitonin level in rats as related to feeding, fasting, and age

Serum calcitonin (CT) was measured in male and female Fischer fasted and fed rats from 1-24 months of age. Previous findings by ourselves and others that serum CT rises with advancing age and is higher in females than in males were confirmed and extended. The effects of feeding were examined with the use of three different protocols, overnight fasting then feeding for 1 h, feeding ad libitum, and feeding rats for 2 h after they had been on a fixed feeding schedule for 4 weeks. At 1 month of age serum CT was too low to measure in either sex, fed or fasted. From 2-24 months of age, feeding increased serum immunoreactive CT much more in females than in males. The increase in serum CT was accompanied by a slight decrease in serum calcium. We concluded that the release of CT in rats after eating is sex related.

Hypercalcitoninemia associated with return of serum calcium concentration toward normal in chronically parathyroidectomized rats

In chronically parathyroidectomized male Fischer and Holtzman rats, we found a progressive rise in the levels of serum immunoreactive calcitonin (CT) despite hypocalcemia. The rise was preceded by an increase in the thyroidal CT concentration (determined by RIA) and hyperplasia of C cells (determined by the immunoperoxidase bridge technique). In association with the rise in serum CT, we also observed a return of serum Ca toward normal levels, which the evidence suggests was not due to compensatory regeneration of parathyroid remnants after incomplete parathyroidectomy. It also is unlikely that ectopic parathyroid tissue was responsible for the return of serum Ca toward normal. Since the increase in serum CT after parathyroidectomy coincided with the return of serum Ca toward normal, we postulate that a gradual rise in serum Ca in chronically parathyroidectomized rats might stimulate the "CT-saturated" thyroid glands to release CT, thus leading to a progressive increase in serum CT. Alternatively, it is possible that the increase in serum CT after parathyroidectomy may be due in part simply to nonspecific leakage of CT from the "CT-saturated" thyroid glands.

Identification of C-cells in normal and goitrous rat thyroid tissues using antiserum to rat thyrocalcitonin and the immunoperoxidase bridge technique

Application of the immunoperoxidase bridge technique to the light microscopic localization of C-cells in rat thyroid tissue is described. Guinea pig antisera to rat thyrocalcitonin (TCT) were produced by the injection of highly purified rat TCT (100-300 MRC U/mg) emulsified in complete Freund's adjuvant. A 1:1000 dilution of the antiserum used in this study gave a strong positive reaction with rat C-cells, and 1 ml of undiluted antiserum provided sufficient material for staining approximately 5000 slides. The substitution of nonimmune guinea pig serum for the anti-rat TCT serum or the prior absorption of anti-rat TCT serum with increasing amounts of highly purified rat TCT both eliminated the staining of thyroid C-cells. Likewise, no staining was observed in tissue sections from rat parathyroid, ovary, pituitary gland, and skeletal muscle. Antiserum to synthetic human TCT also could be used to identify rat thyroid C-cells. The method revealed abundant C-cells in goiters from rats fed a low-iodine diet for more than 1 year. This finding was supported by electron microscopic evaluation of goitrous tissue and by the detection, by radioimmunoassay, of TCT in thyroid tissue and in peripheral blood from goitrous rats.

Effects of ethanol on chicks in vivo and on chick embryo tibiae in organ culture

Hypocalcemia previously reported in rats and dogs following oral administration of ethanol may have been caused by a movement of calcium from blood to bone. This present study was undertaken to determine whether ethanol also causes hypocalcemia in chicks and to investigate the direct effects of ethanol on mineral accretion, glucose metabolism and growth of embryonic chick tibiae in an organ culture system. A high dose of ethanol (6 g/kg body wt) produced hypocalcemia, hypermagnesemia and an elevated hematocrit in chicks. Results in vitro were as follows: 1) 5 to 30 mul ethanol/ml medium produced dose-related increases in bone mineral from 58-440%; 2) lactate production was inhibited at all ethanol levels; 3) increased mineral accretion did not occur in ethanol-treated tibiae when iodoacetate was in the medium, but did occur in mechanically disrupted bones exposed to ethanol; and 4) the ethanol response in bone was directly related to the medium phosphate concentration. The results lead to the following conclusions: 1) ethanol has a direct stimulatory effect on bone mineral accretion and an inhibitory effect on bone glucose metabolism in vitro; 2) viable bone cells and an adequate phosphate supply are necessary for the ethanol response, but tissue integrity is not; and 3) the hypocalcemic effect of ethanol in vivo may at least partially result from ethanol-stimulated bone mineral deposition.