Autoimmune thrombocytopenic purpura: maternal and fetal disease.

We have followed up 63 pregnancies in women with autoimmune thrombocytopenic purpura (ATP). Of these, 15 were previously splenectomized. The characteristics of the sample can be summed up as follows: average age 27 years (17-41); platelets at the beginning of pregnancy, mean 129.5 x 10(9)/l (range 16-488); platelets at delivery, mean 133 x 10(9)/l (range 8-477); PA-IgG at delivery, mean 320 ng IgG/10(7) platelets (range 10-1000); SPB-IgG at delivery, mean 262 ng IgG/10(7) platelets (range 10-1000). There were 30 spontaneous deliveries and 33 cesarean sections. Forty-two newborns had a platelet count within the normal range while nine had a platelet count less than or equal to 150 x 10(9)/l, while six had less than or equal to 100 x 10(9)/l and a further six less than or equal to 50 x 10(9)/l. The aim of this study is the evaluation of maternal risk and of possible feto-neonatal thrombocytopenia at birth. In this regard, the following parameters were considered: previous maternal splenectomy; the platelet count at the beginning of pregnancy; the platelet count and the titres of PA-IgG and SPB-IgG at delivery. Preliminary statistical evaluation of these parameters enabled us to identify a risk score. From this it was possible to obtain an optimum management of the final stage of pregnancy regarding the therapeutic approach and the timing of delivery.


Effective measures for the prevention of late abortions and premature births.

After a retrospective study, more than 70% of premature births have been caused by ascending infections. With the use of a specially concerted diagnostic and therapeutic prevention programme, a reduction of 30% in very low birthweight prematures (less than 1500 g) has been achieved in in-hospital care and of about 50% in outpatient care.


The role of fetal blood sampling in prenatal diagnosis.

Fetal blood sampling via cordocentesis is being used with increased frequency. In our clinic, 125 fetal blood samplings (109 patients) have been performed for evaluation of a variety of clinical situations. Our experience confirms the efficacy of the procedure and suggests that it may be an important tool for fetal assessment.


Effect of atrial natriuretic factor (ANF) on water homeostasis of the neonate.

Atrial natriuretic factor (ANF) has been well known as a potent natriuretic peptide. The purpose of this study was to clarify the physiological role of ANF in neonates. We designed two types of study to investigate the role of ANF in neonates. (i) The role of ANF in neonatal fluid homeostasis; (ii) ANF and spontaneous diuresis. As a result, ANF may be released to control the extracellular volume and may have a role in the complex mechanisms that regulate the water homeostasis in neonates.


Perinatal adaptation of the cardiovascular system.

The perinatal changes in the cardiovascular system were studied in fetal rats. The changes in the cardiovascular system occurred earlier than in humans. The ductus arteriosus closes in the rat in one and a half hours.


Fetal amino acids in normal pregnancies and in pregnancies complicated by intrauterine growth retardation.

Plasma amino acid concentrations were measured in normal (AGA) and intrauterine growth retarded (IUGR) percutaneous umbilical blood sampling (PUBS) performed for prenatal diagnosis or at elective cesarean section. IUGR fetuses present significantly lower concentrations of most amino acids, with a significant reduction of the umbilical veno-arterial difference for total alpha-amino nitrogen. These findings are present early in growth retarded fetuses and may be potentially responsible for the growth retardation.


Intrauterine feeding of the growth retarded fetus: can we help?

Intrauterine feeding of the growth retarded fetus appears an attractive therapeutic possibility. However the factors which determine the reversibility of intrauterine growth retardation are poorly understood. While fetal substrate supply is the final common pathway by which many factors restrict fetal growth, improving fetal substrate supply does not always lead to improved fetal growth. Similarly, fetal substrate supply is an important regulator of fetal endocrine status, such as circulating IGF-1 levels, but again, improving fetal substrate supply does not always alter fetal endocrine status or fetal growth. The relationship between substrate supply, endocrine status and growth is regulated in a complex way by placental function. Understanding the role of the placenta in this regulation is essential if in the future we are to help the growth retarded fetus.


Perinatal care in China.

China has a birth rate of 20/1000, maternal mortality of 48.8/100,000, perinatal mortality of 15-20/1000 in cities, and 30-35/1000 in rural areas, infant mortality of 34.68/1000 and a LWB rate of 6%. Among LWBI 50-60% are SGA. As a result the prematurity rate is also quite low, 3-4%, and the rate of VLBWI is only 0.3-0.4%. Therefore, attention should be paid first to bigger birth weight groups. Regionalized perinatal care is important in the cities, but the rural areas suffer more from low staffing levels and poor transportation. In view of the vast areas which are in need of techniques and the uneveness of the situation, sense of appropriate technology is very important. B-ultrasonic scanner versus gravidogram, FHR monitoring versus monitoring of fetal movement, and methods of keeping babies warm are discussed as examples.


Neurological maladaptation in the neonate.

The development of neuronal dendrites dramatically changes in the medullary respiratory centers from prenatal to postnatal periods. The number of spines increases with gestation and decreases rapidly after birth in controls, but persist in sudden infant death syndrome patients. These abnormalities including neurotransmitters may cause a maladaptation in the development of cardiorespiratory control.


The role of insulin in fetal growth.

Disturbances in fetal insulin secretion are associated with abnormalities in fetal growth in a variety of species: excessive insulin secretion can lead to fetal macrosomia while fetal hypoinsulinaemia invariably causes fetal growth retardation. Fetal insulin deficiency caused by pancreatectomy (PX) of the sheep fetus leads to reduced body weight, crown-rump length and limb lengths at delivery near term. The growth rate in utero fell by 40-50% after PX and could be restored to normal values by insulin replacement treatment. These changes in growth were accompanied by reductions of 30-40% in the rates of umbilical uptake, utilization and oxidation of glucose by the sheep fetus. Insulin is therefore a physiological regulator of fetal growth and acts in part by stimulating the cellular uptake of glucose and its preferential use for oxidative metabolism in the fetal tissues.


Training program in Japan for health caretakers from developing countries.

In 1979, the International Center for Medical Research was organized in Kobe University School of Medicine and promoted the scientific cooperation through invitation of foreign scientists from developing countries as the Core University of Medical Science of Japan Society for the Promotion of Science (JSPS). Perinatal medicine is one of the main subjects in this program and we have accepted more than thirty neonatologists from Indonesia, Philippines, Thailand and other developing countries.


Frontiers in perinatal medicine.

A few of the topics of particular interest in perinatal medicine such as surfactants, erythropoietin, cordocentesis and computer assisted decision support are briefly reviewed. Asphyxia and oxygen toxicity are discussed as is the increase in the formation of free radicals which is part of reoxygenation. The infinitely larger problem of the poor in developing countries can best be improved--at least partially--by extending family planning techniques universally, otherwise the population explosion will counteract any other improvements.


HIV in women.

There are three patterns of HIV infection and AIDS. In industrial countries infection is between homosexual and bisexual males and intravenous drug users. Relatively few women are infected but the numbers are increasing. In sub-Saharan Africa the infection is heterosexual. More women are infected. AIDS incidence in other countries is low. Twenty-five percent of babies born to HIV positive women will be infected. Testing of infants at birth is difficult because of placental transmission of antibodies. Anonymous antenatal testing is important to establish prevalence which varies greatly in different areas. HIV infection is unique because of the social stigma, lack of vaccine and lack of effective therapy. There are profound social and psychological implications for the woman, her partner and her family. Therefore, a high level of caring and mature professionalism is required by all involved staff.


Clinical presentation of HIV/AIDS in the high risk neonate in Zambia.

A prospective case series study was conducted Jan 1991-Oct 1991 on 108 neonates admitted to NICU, Lusaka. 90 patients satisfied inclusion criteria, 45 cases and 45 controls. Symptomatic seropositive babies born to seropositive mothers presented with failure to thrive, fever, persistent or recurrent thrush, severe Sepsis and large liver. Tendency to prematurity among cases was high. Diarrhoea, Sepsis and Haemolytic Anaemia appear to be terminal signs. Neonates suffer the most aggressive form of HIV/AIDS, with symptomatic cases dying 3-4/52 of onset of symptoms. Over one quarter of the mothers were symptomatic. Congenital malformations and Lymphadenopathy were not significantly associated. Microcephaly occurred in association with failure to thrive and was not an isolated finding.


Problems of AIDS in India especially in women.

According to the World Health Organisation survey, 3 million women are already infected with HIV all over the World, but in India the problem of AIDS as a whole is not that acute especially in women. At least it is not that alarming. India, having a very high incidence of STD, it will not take much time for the spread of the HIV infection. No case of mother-to-infant transmission of HIV and resultant clinical disease in the neonate and children has as yet been reported in India. Infected babies, however, face a short life--nearly all die before reaching 2 years of age. Breast feeding is not a significant means of transmitting AIDS. The disease can spread only through sexual contact, use of infected syringe or transfusion of infected blood. Therefore, doctors, nurses and other paramedical staff in hospitals who may have to deal with AIDS patients need not fear the virus if they take adequate precautions. There is no known curative treatment for HIV infection causing AIDS, but improving literacy, avoiding sexual promiscuity and using condoms in heterosexual intercourse are positive steps in keeping HIV infection at a considerably low level.


Management of pregnancy of HIV infected woman.

The first case of HIV carrier pregnancy in Japan is reported. Fortunately this resulted in no apparent transmission of HIV to the baby and no manifestation of AIDS symptoms in the mother.


Intrauterine treatment on non-immune hydrops fetalis.

In 51 cases with non-immunologic hydrops fetalis (NIHF), perinatal management was performed based on our protocol. Twenty-two cases were treated by albumin and/or packed red cell (PRC) injection into the fetal abdominal cavity, and 9 cases by transplacental digitalization. Among the cases treated by albumin and/or PRC injection, 6 of 8 cases without pleural effusion recovered in utero, and all 6 cases are alive. However, of 14 cases with pleural effusion, none recovered in utero, and only one case is alive. Of 9 cases treated by transplacental digitalization, 2 cases recovered in utero, and only one case is alive. All fetuses with congenital heart anomaly died. This evidence indicates that albumin and/or PRC injection into the fetal abdominal cavity is an effective procedure for in utero treatment of NIHF without pleural effusion, but suggests that in NIHF resulting from either congenital heart anomaly and/or heart failure, the survival rate may not be increased by transplacental digitalization.


The role of Doppler technology in the evaluation of fetal hypoxia.

Failing intrauterine support to the fetus can lead to intrauterine growth retardation (IUGR) and hypoxia and it is associated with a high risk of perinatal morbidity and mortality. The main effects of moderate to severe hypoxia on the fetus are different degrees of blood flow redistribution and reduction of oxygen consumption to maintain oxygen delivery to the central organs at the expenses of peripheral organs. The redistribution results in a 'brain sparing' effect. Recently, a Doppler ultrasonic technology (continuous wave, pulsed wave and colour flow imaging) has been developed for the non invasive measurement of flow. Doppler velocimetry detects the flow velocity waveform (FVW) which reflects the cardiac output, the vascular compliance and the resistance to the flow in a defined point of the vessel. Velocity waveform indices or even simpler criteria, such as the presence or absence of diastolic flow or flow reverse during diastole, have been applied to a number of fetal vessels. A significant relationship exists between blood oxygen, systemic lactic acidosis (determined by cordocentesis) and increase PI values in umbilical artery (UA), thoracic aorta (TA) and renal artery (RA). Moreover, in experimental animals during steady state hypoxia, several cardiovascular parameters are affected (heart rate/cardiac output decreases and blood pressure increases) while placental flow don't show a significant variation thus suggesting a raise in placental vascular resistance. Redistribution of the flow may be reliably evaluated by the cerebroplacental ratio (i.e. ratio between PI of MCA and PI of UA, c/p).(ABSTRACT TRUNCATED AT 250 WORDS)


Hydrops fetalis caused by severe alpha-thalassemia.

Alpha-thalassemia is a prevalent condition in South East Asia and spreading because of increasing immigration. Hemodynamic study of Hb Bart's hydrops fetalis, the most severe form of alpha-thalassemia, showed the fetuses were in a hyperdynamic circulatory state and were also more acidotic, hypoxic, and hypercarvic than normal fetuses. The most common molecular defects of Hb Bart's hydrops fetalis was the Southeast Asia type deletion. Prenatal diagnosis of Hb Bart's hydrops fetalis and HbH diseases has been achieved using chorionic villi sampling or fetal blood sampling.


Fetal and neonatal cerebral oxygen monitoring with NIRS: theory and practice.

Near infra-red spectroscopy (NIRS) is a comparatively new method for monitoring the oxygenation in blood and tissue in the brain of the fetus and the neonate. Absorption of light in the wavelength range 700-1000 nm through such tissue is measured, which is then used to calculate changes in the concentration of cerebral oxygenated and de-oxygenated haemoglobin (HbO2 and Hb) and hence cerebral blood volume (CBV). Studies carried out on several groups of newborn babies have shown clear changes in HbO, Hb and CBV with hypoxia and bradycardia. These changes may well have implications in the occurrence of hypoxic/ischaemic brain injury. Intra partum NIR measurements on the fetal brain have demonstrated clear changes in HbO2, Hb and CBVm, coinciding with the onset of contractions.


Intrauterine fetal reanimation in acute intrapartum fetal distress.

Uterine contractions during labour may produce acute intrapartum fetal distress. Intrauterine fetal reanimation is possible by reducing the strength of uterine contractions. Betamimetic therapy appears successful for this.


Longitudinal measurements of fetal heart rate (FHR) monitoring in second trimester.

We investigated the possibility of clinical diagnosis of preterm fetal well-being in the second trimester using the duration of LTVs of less than 4.5 beats/min and characteristic FHR acceleration. Fetuses between 24 and 32 weeks gestation, unlike near-term fetuses are seldom quiet and therefore the prolonged absence of fetal movement may be the best indicator of a sick fetus at these gestational ages. The amplitude and duration of the acceleration of the FHR were also clinically useful diagnostic tools for fetus well-being during the second trimester.


A prospective, randomized trial of early versus late administration of a single dose of surfactant-TA.

Thirty-two neonates weighing 500-1500 g with documented surfactant deficiency and without evidence of severe birth asphyxia, infection, prolonged rupture of membranes greater than or equal to 72 h, or oligohydramnios were randomly assigned to receive a single intratracheal dose of surfactant-TA (100 mg/kg) either within 30 min of birth (n = 16, early group) or at 6 h of age (n = 16, late group). By 6 h of age, all neonates of the late group had moderate/severe RDS, while none of the neonates of the early group had either clinical or radiological respiratory distress syndrome. The incidence of bronchopulmonary dysplasia was significantly lower in survivors of the early group than those of the late group (1/15 versus 7/14, a 43% reduction with a 95% confidence interval of 14-72%, P = 0.025). These beneficial effects of early surfactant treatment remained after controlling for the various confounding factors in the logistic models.


Prenatal prevention of respiratory distress syndrome: new pharmacologic approaches.

A deficit of lung surfactant is known to be involved in the pathophysiology of the respiratory distress syndrome of the neonate (RDS), which is still responsible of about one fourth of total neonatal mortality. It has been well documented that maternal administration of corticosteroids enhances fetal lung maturity, promoting synthesis of surfactants and altering also the structure of the lung parenchyma. Although the beneficial effects of corticosteroids have been substantiated by a number of experimental evidences and clinical studies, about 10% of the treated neonates remains affected by RDS. Corticosteroids affect the composition of lung parenchyma, by increasing elastin content and by decreasing alveolo-capillary permeability to serum proteins. Since thyrotropic releasing hormone (TRH) has been shown to potentiate the effects of corticosteroids a combination of the two drugs may be the treatment of choice for prenatal prevention of RDS.


Patent ductus arteriosus: how important to which babies?

An overview is presented of 21 randomised controlled trials of either surgical closure of the ductus arteriosus or indomethacin therapy in preterm infants. All trials included backup treatment if the ductus arteriosus persisted. Overall, there is no significant effect on mortality or chronic lung disease. In trials treating at a presymptomatic stage, there is a trend to reduce the incidence of chronic lung disease. Early treatment with indomethacin reduces the incidence of periventricular haemorrhage. An ultrasound study of 110 very low birth weight infants showed ductus arteriosus size at 3 days to be related to factors reflecting the infants' condition (ventilation indices, blood product administration), but not to birth weight or gestational age. Infants with a moderate to large ductus arteriosus at 3 days had a significantly lower blood pressure from 12 h of age onwards than those with a closed or small ductuses.


Advances in mechanical ventilation: high frequency ventilation.

High frequency oscillatory ventilation (HFOV) is a technique in which a small tidal volume of airway gas is vibrated by moving a piston at an extremely fast rate (15 Hz). By this technique infants are ventilated in less traumatic ways compared to the conventional mechanical ventilation (CMV). The control study performed in Japan showed the efficacy and safety of HFOV compared to CMV.


The use of high-frequency oscillatory ventilation (HFOV) and extracorporeal membrane oxygenation (ECMO) in the management of the term/near term infant with respiratory failure.

The use of high-frequency oscillatory ventilation (HFOV) was evaluated as a rescue intervention in 122 consecutive infants meeting criteria for extracorporeal membrane oxygenation (ECMO). Fifty-three percent responded to HFOV and never required ECMO, 3/65 died. Infants who ultimately required ECMO had lower aortic and pulmonary peak flow velocities, and lower pulmonary acceleration, circumferential fiber shortening and shortening fraction than those who were successfully managed with HFOV. The use of HFOV with an appropriate strategy decreased the need for ECMO in this patient population.


Rationale for and work of the Perinatal Trials Service.

The Perinatal Trials Service provides a service to busy clinicians who wish to mount large simple-in-design randomized trials. The trials aim to identify moderate, but clinically useful, effects of promising treatments for the most important problems in perinatal care. A combination of a flexible five-person core resource and a cadre of staff employed to work on specific trials allows a programme of trials to be conducted successfully and efficiently. The Perinatal Trials Service has three main areas of work: prevention and treatment of immaturity and its consequent morbidity; identification and management of the compromised fetus or baby; and prevention and treatment of maternal morbidity. Examples of projects from each area are described.


Evaluation of different policies for the management of labour.

Various policies of management of prolonged labour have been proposed to prevent its two main consequences--caesarean section and fetal distress. Two randomised controlled trials were organised; the first to assess the value of amniotomy with oxytocin compared to a more conservative approach. The second trial compared the effect of continuous professional support during labour with the intermittent presence of a member of staff. These were multicentre studies in several countries of Europe. Preliminary results of early amniotomy suggested no difference in the rate of operative delivery. Continuous professional support was associated with a significant reduction in operative deliveries.


Multicentre collaboration in perinatal trials in Canada.

From a request of the Ministry of Health, the Canadian Association of Professors of Obstetrics and Gynecology and the Medical Research Council played a leadership role in convening perinatal investigators of all 16 university departments. The consensus was reached that the best means to improve the health of Canadians was to treat and/or prevent prematurity. In the last 10 years, several multicentre clinical trials were designed and carried out on perinatal interventions. This multicentre Canadian collaboration has recently evolved in the formation of a permanent perinatal clinical trial network of more than 100 members.


Readiness of Japan to participate in international collaborative studies.

A significant improvement has been achieved in perinatal mortality figures during the last decade in Japan with a neonatal mortality rate of 2.6 and a stillbirth rate of 4.1 for 1989. With its unique obstetric and neonatal services, there are advantages and also disadvantages in respect of clinical and basic research. The outlook for Japanese neonatal medicine is shown and the prospects for international collaborative studies in the future are given.


Do breast milk derived hormones play a role in neonatal development?

Many hormones and several growth factors are present in significant concentrations in breast milk. That these substances are of physiologic significance has been suggested by many investigators. This review summarizes the biological roles of thyroid hormones and epidermal growth factor (EGF) derived from breast milk in a variety of developing mammals.


Fortified preterm human milk for very low birth weight infants.

We studied the nutritional effects of two types of human milk fortifiers for very low birth weight infants. These studies suggest that fortified human milk provides nutritional advantages for very low birth weight infants. However, providing calcium and phosphorus with supplementation is necessary for the improvement of bone density.


Randomized clinical trials in perinatology in Latin America.

Latin America needs means to obtain accurate figures about its health conditions in order to apply its resources to priority areas. In addition, health actions must be carefully evaluated to assess their impact, operation and costs. The randomized clinical trial (RCT) is the only design able to show the effectiveness of interventions of moderate effect. Also, it gives appropriate information about the expected effect of the interventions and implies an expediate implementation of interventions in the same places where the project has been performed. In a review of RCTs performed in Latin America on perinatal medicine it can be concluded that some of the focus of research is irrelevant to the region and there is not an orientation towards the cooperative solution of predominant problems in the area. It is imperative for researchers, in Latin America to initiate joint activities in order to assess which are the research priorities of the area, to focus their research on these priorities and to join their efforts in collaborative studies.


Is mother's milk the most suitable food for very low birth weight infants?

Human milk feeding (HMF) as compared with formula feeding (FF) has the advantage of more effective utilization of proteins, fat, minerals and trace elements. HMF provides passive immunologic protection and active immunostimulation. It prevents the VLBWI from antigenic and toxic loads. The disadvantage of HMF is the high volume required tomeet the energy and protein needs of the VLBWI and the growing potential risk of AIDS, hepatitis and cytomegaly infections which makes human milk banking increasingly difficult. The current concept of VLBWI formula feeding (FF) is based on high protein, energy and mineral concentrations to compensate for the lower biological value, for lower bioavailability and for side effects related to the antigenicity of food proteins. FF as compared with HMF results is increased mineral and water retention, in high renal load and in a completely different body composition. The risk of necrotizing enteritis is significantly higher. All this has to be considered a challenge to further adapt LBWI formulas to the amino acid composition of human milk protein to induce bifidogenic effects and to provide sufficient amounts of essential fatty acids and carbohydrates which serve as building stones for normal brain development.


Reproductive health: a global overview.

A global overview of reproductive health outlines major challenges for action. Worldwide, 60 million to 80 million couples suffer from infertility. At the same time, there is a striking unmet need for contraception in developing countries. Unsafe abortion practices result in between 115,000 and 204,000 deaths each year. Female genital mutilation in one form or another continues to exist in around 40 countries. A second generation of organisms has now made sexually transmitted diseases the most common group of notifiable diseases in most countries. For the year 2000, it is projected that there will be a cumulative total of about 40 million HIV infections in men, women and children. About half a million women die each year because of complications related to pregnancy and childbirth. A total of about 15 million infants and children die annually, mostly from preventable childhood diseases. At least 17% of all babies in developing countries are born with a low birth weight.


Trace elements and mineral requirements for very low birth weight infants in rickets of prematurity.

To establish mineral and trace element requirements for very low birth it is important to prevent bone mineral disorder. Those infants fed mother's milk only are thought to be at higher risk of this disorder. Both calcium and phosphorus supplementation were thought to be needed to prevent it. Copper and zinc are important as cofactors of major enzymes involved in the synthesis of collagen. These trace elements especially zinc may not be enough for very low birth weight infants fed mother's milk. At present however the relationship between these trace elements and minerals, and bone metabolic disease in preterm infants is not completely clear.


Antenatally detected ovarian cysts--a therapeutic dilemma.

Twenty-four instances of ovarian cysts detected antenatally are reported. Most cysts were functional in origin, histologically benign simple cysts. Pregnancy was clinically uncomplicated in all, followed by a spontaneous vaginal delivery in 20 cases between the 33rd and 41st week, four neonates were delivered by a cesarean section for obstetrical reasons. Nine cysts more than 5 cm in diameter at birth were treated surgically. The operative indications were as follows; 5 neonates had clinical symptoms caused by abdominal distention or vomiting. The remaining four showed a sign of hemorrhage following torsion. Thirteen cysts less than 5 cm in diameter, and two cysts more than 5 cm in diameter began to regress spontaneously within 6 months after birth and finally 10 of them disappeared between 2 weeks and 2 years.


Esophageal atresia (T-E fistula): an index for neonatal surgery.

During the period 1978-1990 (12.5 years), 929 neonatal general surgical emergencies were treated at the Seoul National University Children's Hospital. There were 308 anorectal malformations, 128 atresia/stenosis of the gut, 125 neonatal Hirschsprung's disease, 75 gastroschisis and 67 esophageal atresias. The highest operative mortality rate of 26.9% was experienced in esophageal atresia with or without tracheo-esophageal atresia. Problems in respiratory care and surgical technical failure were the main causes of failure. Esophageal atresia can be used as an index for the status of neonatal surgical care since analysis of mortality of other operations indicates a similar but less exaggerated pattern.


Prenatal diagnosis of congenital diaphragmatic hernia and perinatal care: assessment of lung hypoplasia.

To assess the severity of lung hypoplasia, we have attempted to measure the lung thorax transverse area ratio (L/T) by using ultrasonic echography and to select immediate surgery after delivery by caesarean section. The evaluation of L/T for an index of lung hypoplasia was made by arterial blood gas data and clinical courses. Of 14 fetuses diagnosed, 13 had left sided CDH and one right sided case, from 11 to 38 weeks of pregnancy, 10 cases survived. The L/T in 14 fetuses with CDH was from 0.08 to 0.36 (mean 0.2 +/- 0.073) and was significantly lower than that of the controls. L/T was correlated best with data of arterial pH, PCO2, preductal A-aDO2 before operation and the duration of mechanical ventilation in survivors. Although L/T was also significantly low in the cases with severe grade, diaphragmatic patch closure and ECMO therapy, no significant differences were noted in L/T between survivors and non-survivors. These results indicated that L/T may predict the severity of lung hypoplasia in CDH and that the combination of perinatal management bases on prenatal diagnosis of CDH and ECMO support may improve the outcome of fatal CDH with severe lung hypoplasia.


Composition of premature breast-milk during lactation: constant digestible protein content (as in full term milk).

There is much discussion about the protein requirements of (very) preterm infants. The protein content of breast milk plays an important role in this discussion. For this reason, we took a close look at the protein content and its composition in premature breast milk. Complete 24 h expressions-were examined using the Kjedahl method, GPC, SDS-PAGGE and nephelometric detection of sIgA. Colostrum of premature breast milk contains a large amount of undigestible proteins, up to 70% of true protein, which decreases to 20-40% in transitory and mature preterm milk. The NPN fraction of mature preterm breast milk was, dependent on the degree of prematurity 20-25%; increasing during lactation from about 18% to 22-26%. This means that, depending on the lactation period only 30-60% of the total protein content of breast milk is available for body protein synthesis. In absolute amounts, digestible protein is reasonably stable during lactation.


Transvaginal ultrasound in the first trimester of pregnancy.

Recent improvements in transvaginal ultrasound permit the extremely detailed observation of the morphology of the early conceptus in utero. It is possible to use the term "sonoembryology" for the delineation and observation of features such as brain vesicles and the neural tube as early as at the beginning of the 7th week of gestation. In this paper, sonoembryology from 4 to 11 weeks of gestation is briefly described.


Antenatal diagnosis of fetal abnormality by ultrasonic real time scanner.

Recent progress in antenatal diagnosis has made it possible to detect most fetal malformations which can be treated and cured by neonatal surgery. In this study an analysis of antenatal diagnosis by ultrasonography in the author's clinic is reported.


Transvaginal color Doppler assessment of uteroplacental circulation in normal and abnormal early pregnancy.

Transvaginal color Doppler offers the potential to study uteroplacental circulation in early normal pregnancies and pregnancies associated with intrautine fibroids. A total of 62 patients (30 early pregnancies complicated by myoma and 32 normal pregnancies representing the control group) whose gestational age ranged from the 6th to the 14th week were examined. The equipment used was an Aloka color Doppler SSD-680 with 5.0 MHz curve-linear transvaginal transducer. The main uterine, radial and spiral arteries were identified in all patients. Peak systolic velocity and resistance index were measured and automatically calculated. Statistical analysis used was Student t-test. This study documents a physiological decrease in impedance in the uteroplacental circulation in pregnancy associated with fibroids, while the blood velocity of the radial arteries showed a significant increase between the 10th and 14th week of gestation.


A study on the development of sleep-wakefulness cycle in the human fetus.

We observed fetal behavior by using three ultrasonic real-time scanners simultaneously in 30 normal pregnant women between 20 and 40 weeks of gestation and analyzed developmental changes in behavioral pattern focussing the attention on the characteristics of REM and non-REM sleep and wakeful state. The frequency of REM significantly increased with gestational age, and its occurrences formed a group in late pregnancy. REM and non-REM periods, which were defined as the phase with uninterrupted appearance of rapid eye movements and the phase without them over 3 min, respectively, became clearly distinguishable between 28 and 31 weeks of gestation. The correlation between the occurrence of rapid eye movements and breathing movements was high after 27 weeks. These results demonstrate the course of the development of sleep-wakefulness cycle in the human fetus.


Ethical considerations in safe motherhood (SM) programs in developing countries.

There are still many maternal deaths in the world each year and over 98% are in developing countries. A program of safe motherhood is needed to make certain that every woman has the right of basic maternity care.


The effect of glucose on Doppler flow velocity waveforms and heart rate pattern in the human fetus.

Twenty-four healthy pregnant women were studied between 36 and 40 weeks gestation to determine the effect of glucose on the Doppler flow velocity waveform in the cerebral and umbilical arteries of the human fetus near term. The Resistance Index (RI), as an index of vascular resistance, was calculated for the anterior cerebral, internal carotid and umbilical arteries during a fasting control period, 45 min and again at 120 min after a 50-g maternal oral glucose drink or an equivalent amount of water. Fetal heart rate (FHR) pattern as determined by FHR variability was monitored as a measure of behavioural state. The RI of both cerebral vessels was significantly lower after the glucose drink, while that of the umbilical artery was little changed subsequent to either of the drinks. However the FHR mean min range, as an index of long term FHR variability was significantly increased when measured 30 to 60 min after the glucose drink and controlling for this change removed the effect of glucose on the RI of the cerebral vessels. We conclude that glucose does have an indirect effect on the cerebral Doppler waveform indices of the human fetus which is mediated through induced changes in behavioural state.


Approaching the millennium: perinatal problems and software solutions.

Strategic planning for rational development of perinatal computing capabilities for the year 2000 should be driven by anticipated trends in (1) the health care business, (2) computer technology and (3) medicine, as well as (4) the needs of perinatal practitioners. In the USA, health care is the fastest growing segment of the economy. This will produce increasing attention from hardware and software developers, and vendors, and will lead to a proliferation of computing platforms, operating systems and specific medical application software. Desktop computers, already capable of 20 million instructions per second (MIPS) with massive storage capacities, will continue to evolve and fall in price. Increasingly, perinatologists will develop software packages to facilitate patient care in their own environments. All of these trends will lead to severe fragmentation in medical computing. Simultaneously, however, the need for integrated institutional computer-based data access for quality assurance and fiscal and operations management will increase. Perinatal care will be more regionalized, complex and rigorous with new clinical trial- and effectiveness research-based interventions, as well as molecular diagnosis and therapy. To practice appropriately, clinicians will need to be familiar with computer capabilities. Having been exposed to computer-aided instruction (CAI) at the undergraduate and postgraduate levels, they will except on-line access to detailed and accurate patient information with linkage to laboratory, radiology and other medical databases, as well as to reference databases, such as Medlines and the Oxford Database of Perinatal Trials. Artificial intelligence (AI) software may support perinatal decision making; computerized professional and facility billing will be available.


The temporal relationship between the onset of rapid eye movement period and the first micturition thereafter in the human fetus with advance in gestation.

The objective of this study was to investigate whether micturition occurs, temporally related to the onset of the rapid eye movement (REM) period, in the human fetus. The study was made on 139 fetuses at 33-36 weeks and 153 at 37-41 weeks gestation. The discrepancies between the expected (F(exp)) and observed (F(obs)) frequencies of time lag between the onset of the REM period and the first micturition thereafter were assessed using the goodness-of-fit test. At 33-36 weeks gestation, there was no statistical difference between F(obs) and F(exp) (P greater than 0.05). At 37 weeks onwards, however, significant differences were noted between F(obs) and F(exp) (P less than 0.005). Seventy-two percent of all micturitions occurred within eight minutes after the onset of the REM period. This indicates that there is a temporal relationship between the onset of the REM period and the first micturition thereafter, at term, during 37-41 weeks of gestation.


Surfactant in the perinatal period.

Surfactant is now available for general clinical use in infants with RDS. While surfactant is effective, it does not prevent lung disease in many preterm infants because of other aspects of lung immaturity. In experimental models, corticosteroids alter the fetal lung by improving compliances, increasing lung volumes, decreasing pulmonary edema, and altering surfactant-compliance dose response curves. These effects are independent of changes in surfactant pools but augment the responses of the lungs to surfactant treatment. Optimal outcomes for the preterm require the combined use of fetal maturation strategies and postnatal surfactant.


A 50-year overview of perinatal medicine.

Infant mortality in 1990 was approximately one-tenth that of 1950 in most of the industrialized countries of the world. The forces of change included the social-political climate, advent of neonatal intensive care, better insight into nutritional requirements of preterm infants and application of basic science to the study of events around the time of birth, and illnesses of the neonate. Attention has been paid to the advantages of human milk for the newborn infant, the importance of maternal bonding and involvement of both parents in care of the infant. Prenatal diagnosis, with option of abortion, has reduced the prevalence of some serious disorders of the fetus.


Two different low birth weight formulae compared.

The performance of two different, commercially available, low birth weight formulae feeds was compared in preterm infants. The aim of the study was to determine the effect of compositional differences on tolerance, stool frequency and consistency, fat balance and weight gain. Inborn infants with birth weight less than 1500 g were randomised at birth to receive Prematil or Osterprem. Thirty infants received more than 900 ml/kg per week of designated formula alone during a total of 70 weeks of study. Three day fat balance was performed on 23 infants. Osterprem contains 40% more fat than Prematil. The composition of this fat is different in that Osterprem contains no medium chain triglycerides (MCT) compared to 30% in Prematil. Clinical evaluation demonstrated that Osterprem is associated with a significantly higher mean energy intake compared to Prematil (3442 and 3127 kJ/kg per week) but mean weight gain is not significantly different (123 and 112 g/kg per week). Mean stool frequency is higher on Osterprem (20.5 and 14.5 stool/week) and the consistency of stools firmer. This is attributable to a higher mean fat output (2.3 and 0.9 g/kg per day) secondary to the higher fat content of the feed and lower mean absorption (71.6 and 83.5%). Both feeds are well tolerated. The study also confirms that absorption of unsaturated fatty acids is inversely proportional to chain length.


Fetal Doppler velocimetry in the internal carotid and umbilical artery during Braxton Hicks' contractions.

Using Doppler ultrasound, previous studies revealed a considerable increase in vascular resistance in the uteroplacental circulation during Braxton Hicks' contractions. Consequently, uteroplacental blood flow is reduced and this affects placental oxygen transfer to the fetus, causing a fall in fetal arterial PO2. In view of the important role of arterial PO2 in the regulation of cerebral blood flow in the fetus, we hypothesised that Braxton Hicks' contractions cause a decrease in cerebral vascular resistance. A study was undertaken in 16 healthy near term pregnancies, using pulsed-wave Doppler ultrasound to evaluate the influence of Braxton Hicks' contractions on cerebral vascular resistance of the fetus. Flow velocity waveforms (FVWs) were recorded of the fetal internal carotid and umbilical artery and the Pulsatility Index (PI) was calculated. During Braxton Hicks' contractions the PI in the recorded vessels did not change. Fetal heart rate showed also no changes during Braxton Hicks' contractions. These findings indicate that resistance to blood flow downstream of these arteries, is not significantly altered, suggesting that Braxton Hicks' contractions have little or no effect on fetal haemodynamics and on fetal oxygenation in the healthy near term fetus.


Ethical problems in neonatal intensive care unit--medical decision making on the neonate with poor prognosis.

In current NICU (neonatal intensive care units), it is inevitable that ethical decisions on neonates with a poor prognosis will have to be made. At Tokyo Women's Medical College, we have been applying our own policy of medical decision making, which is somewhat different to those of most western countries. Most families are not asked to make final decisions, and the ethical committee is not actively involved. Staff in the NICU make the decision after plenary discussions. The position after decision making is not to discontinue the life supporting system but to observe, with no additional treatments and with routine care (class C). From October 1984 to September 1989, 58 out of 1589 neonates admitted to the NICU at Tokyo Women's Medical College died and 32 (55%) of them were classified as class C. The main causes of medical decision making were; non-viable (4/4, 100%), lethal malformations (13/20, 65%) and birth asphyxia (15/19, 79%).


Fetal biochemistry in growth retardation.

A substantial proportion of fetuses with severe early onset growth retardation are chromosomally abnormal and in these cases detailed ultrasound scanning will often demonstrate the presence of fetal anatomical defects. Chromosomally normal SGA fetuses with no biochemical abnormalities are likely to be normal small fetuses and seem to develop normally. SGA fetuses with evidence of impaired placental perfusion such as altered fetal cardiovascular dynamics and disturbances in biochemical, haematological, metabolic and endocrine status are at increased of neurodevelopmental delay. Although incomplete, the data collected so far suggest the biochemical changes may be caused by reduced placental transfer of nutrients (e.g. oxygen, glucose and essential amino-acids) and subsequent reduced fetal metabolism leading to high levels of substrates (e.g. triglycerides and non-essential amino-acids) and low levels of tissue products (e.g. thyroid hormone, insulin, platelets and white cells).


Cerebral blood flow fluctuation in low-risk preterm newborns.

Cerebral blood flow (CBF) fluctuation was studied by analyzing Doppler internal carotid blood velocity recordings of 13 healthy preterm newborns obtained in the course of their first 5 days of life. As measures of fluctuation we used the interquartile range (IQR) and the coefficient of variation (CV) of the ensemble of heart beats of a 20-s recording. In this way we determined fluctuation of the following velocity curve parameters (VCPs): end diastolic velocity; mean velocity; peak systolic velocity and pulsatility index (PI). The pooled data 5-95% intervals for fluctuation thus measured, were: 93-281% for CV; 0.6-3.7 cm/s for the IQR of the velocities; and 4-19% for the PI-IQR. Multiple regression analysis of IQR revealed significant relationships with: the VCP level; with restlessness; and with patency of the ductus arteriosus. Our findings imply that: (1) CBF has various qualities with different stability, mean velocity being the most stable; (2) for all the VCPs investigated, fluctuation is physiological in the early days after preterm birth; (3) most likely, there exists no age trend; (4) restlessness rather than wakefulness, enhances fluctuation; (5) patent ductus arteriosus destabilizes CBF; and (6) for a proper insight into fluctuation, the level of the VCP in question must be taken into account. We suggest that, the enhancing effect that patent ductus arteriosus has on fluctuation pays a contribution to the pathogenesis of brain damage. Finally, we conclude that the IQR represents fluctuation better than does the more commonly used CV.


Behavioral and neurochemical sequelae in young rats of antenal hypoxia.

To test the hypothesis that perinatal hypoxia may have postnatal consequences via à vis learning memory, and neurochemical sequelae, we exposed pregnant Sprague-Dawley rats to 10.5% O2 for 4 h per day (0800-1200 h) or continuously from gestional day E15 to E20. On E20 we quantified ornithine decarboxylase activity and polyamine concentrations in fetal brain. We also conducted behavioral tests from postnatal day P3 to P110. Relatively mild antenatal hypoxia resulted in altered learning, memory, and delayed maturation of early developmental sensorimotor function. These behavioral changes disappeared at various postnatal ages, depending on the function. Perinatal hypoxia also altered the pharmacological response to dopaminergic drugs. In addition, antenatal hypoxia feminized a male nonreproductive sexual behavior, that of saccharin preference. Acute hypoxia also resulted in an increase in the enzyme ornithine decarboxylase and polyamines, which may affect brain development.


Maternal smoking and tooth formation in the foetus. I. Tooth crown size in the deciduous dentition.

Altogether 2159 pregnancies among black and white Americans in the Collaborative Perinatal Study and dental casts from the children at the age of 5-12 years were studied to find out the effect of maternal smoking on deciduous tooth crown growth. Minor crown size reduction (2-3%) in some dimensions was found in children whose mothers had smoked during pregnancy. The possible change in dimensions seems to be influenced by sex, race and smoking habit. The critical time periods of the gestational development (16th to 19th) weeks would possibly appear from these data to be targeted by the detrimental effect of maternal smoking. It is concluded that deciduous tooth sizes seem to be greatly unaffected when compared to reduction in birthweight.


Metabolic aspects of fetal and neonatal growth.

This review covers the transplacental transport of amino acids to the fetus and the role of placental metabolism and fetal metabolism in the utilization of amino acids. Particular attention is paid to the non-essential amino acids and to their rates of production within the fetus or placenta. The supply of amino acids is compared with their requirements for accretion in protein and for their use as metabolic fuels. Recent studies of protein synthesis in relation to gestational age are also reviewed.


Development of the brainstem auditory pathway in low birthweight and perinatally asphyxiated children with neurological sequelae.

Low birthweight (LBW) and perinatal asphyxia are known to be high-risk factors for a number of neurodevelopmental deficits. In this study, we analyzed brainstem auditory evoked response (BAER) in 18 LBW and 36 perinatally asphyxiated children with non-progressive neurological sequelae after the age of 6 months to inspect and compare the long-term influence of LBW and perinatal asphyxia on the brainstem auditory pathway. The typical changes in the BAER of children born with LBW were slightly shorter III-V interpeak interval and smaller III-V/I-III interval ratio than normal controls. On the contrary, the abnormalities in the BAER of 36 children surviving perinatal asphyxia were characterized by a reduction of the amplitude of wave V with normal intervals. This discrepancy in the BAER between the children born with LBW and those with perinatal asphyxia implies that the two high-risk factors exert different long-term influences on the development of the brainstem auditory pathway. It is hypothesized that these characteristic changes may be indicative of a major influence of LBW on the generators contributing to wave III and that of asphyxia on the generators contributing to wave V. An increase in response threshold with abnormal latency-intensity function was found in 11% of the LBW children and 19% of the asphyxiated children, suggesting that sensorineural hearing impairment occurred more frequently in children surviving perinatal asphyxia than in those born with LBW. Follow-up study demonstrates that the abnormalities in the brainstem auditory pathway of LBW and asphyxiated children after the age of 6 months is likely to be persistent.


Non-ketotic hyperglycinemia: a life-threatening disorder in the neonate.

Non-ketotic hyperglycinemia (NKH) is a well-recognized metabolic cause of life-threatening illness in the neonate. The fundamental defect is in the glycine cleavage enzyme (GCE), which consists of four protein components. Our study revealed that the majority of NKH patients had a specific defect in P-protein (glycine decarboxylase). The primary lesion of NKH in gene level was investigated, using cDNA encoding human glycine decarboxylase. A three-base deletion; resulting in deletion of Phe756 was found in a Japanese patient with NKH. In the majority of NKH patients in Finland, where there is a high incidence of NKH, it was found to be due to a common mutation--a point mutation resulting in amino acid alternation from Ser564 to Ile564. Prenatal diagnosis is possible by determining the activity of GCE and also by DNA analysis. Recent findings suggest that the high concentrations of glycine in the brain may contribute to the pathophysiology of NKH by overactivating NMDA receptors via an action at the associated glycine modulatory site. These provide a possibility that early treatment with NMDA receptor antagonist may prevent brain damage in NKH.


Ultrasonic dating of pregnancies: effect on incidence of SGA diagnoses. A randomised controlled trial.

In order to study the incidence of antenatal identification and postnatal diagnosis of small for gestational age (SGA) infants, 4997 women with optimal menstrual history were randomised. One group had the gestational age estimated from last menstrual period (LMP), the other from ultrasonographically measured biparietal diameter (BPD) in the second trimester. Both the incidence of antenatally suspected and postnatally diagnosed SGA infants were reduced by approximately 30% in the BPD-dated group. It is concluded that this was due to the shift in gestational age estimation.


Chronic arsenic poisoning masquerading as Landry-Guillain-Barré syndrome.

Acute arsenic intoxication may present as Landry-Guillain-Barré syndrome because of similarities in clinical symptoms involving the gastrointestinal tract, weakness, and sensory symptoms. Electrodiagnostic findings may be similar with demyelinating changes predominating early in both diseases. A case is presented of repeated arsenic poisoning over two years misdiagnosed as Landry-Guillain-Barré syndrome. Proximal F-loop latency (M-wave latency at wrist + F-wave latency at wrist - 2 M-wave latency at axilla) helped to establish the correct diagnosis. Serial electrodiagnostic studies were done documenting the evolution of chronic repeated arsenic poisoning from a picture showing demyelination to one with severe axonal loss.


Ephaptic influence of the electrical activity of muscle on the neighboring nerve.

Experiments were performed on isolated nerve-muscle and leg preparations of frog in order to investigate the excitatory influence of the electrical activity of muscle on the contiguous nerve under various conditions. The results show that the active muscles are able to induce multiple transmission of excitation from muscle to nerve and to modify the excitation travelling in the nerve being in contact with the muscle. It is concluded that under some special circumstances the ephaptic influence of the electrical activity of muscle on the nerve in its neighborhood can play an occasional role in the processes related with the nerve and muscle excitation.


Electrically elicited short and long-latency responses of intrinsic hand muscles in hereditary ataxias. Effects of isometric and ballistic isotonic voluntary contractions.

Short- and long-latency responses (HR and LLR) from thenar muscles were studied in patients with Friedreich's ataxia and pure cerebellar ataxia with later onset by applying electrical stimuli on the median nerve at the wrist. HR and LLR were examined during two different voluntary activities of the opponens pollicis muscle: isometric ("hold") and isotonic ballistic ("move") conditions. A preliminary conventional study of motor and sensory conduction of the median nerve was also carried out. Patients with Friedreich's ataxia had reduced or absent HR and LLR. Furthermore, those who preserved both responses had prolonged HR-LLR interpeak latency. All patients with Friedreich's ataxia also showed peripheral nerve conduction abnormalities, mainly in sensory fibers. These data can be accounted for by the widespread degeneration of many neural structures in this disorder. No abnormalities in HR were observed in pure cerebellar ataxia with later onset, whereas LLR was grossly enlarged in most patients, notably during "move" condition. Since cerebellar structures (especially the cerebellar cortex) are the only ones involved in this disorder, the cerebellum may play a role in modulating LLR. In particular, this effect could be more evident in isotonic ballistic movements.


Myokymic discharges: prompt cessation following nerve root decompression during spine surgery.

In surgical cases during which spine nerve roots are at risk, we have found it useful to monitor EMG from the muscles supplied by those roots. Mechanical irritation of a root results in muscle activity, whose amplified signals can be broadcast over a loudspeaker, providing immediate feedback to the surgeon that the root is being irritated. We report here on a patient undergoing spinal canal decompression and fusion following a burst fracture of the L5 vertebral body sustained five days previously. EMG was continuously monitored from the tibialis anterior (TA) and medial gastrocnemius (MG) muscle groups bilaterally. During the period leading up to decompression, myokymic discharges from the left TA muscle were observed, whereas the other 3 muscles monitored did not show such activity. These semi-rhythmic and repetitive discharges from the left TA ceased immediately following surgical removal of a bone fragment compressing the left L5 nerve root. This indicates that the site of axonal irritation was the nerve root, and that myokymic discharges secondary to acute axonal compression can cease immediately upon nerve root decompression.


Increased F-wave duration in patients with spasticity.

F-wave responses of the posterior tibial nerve have been studied in 22 patients with spasticity and in 18 normal control subjects with surface EMG. Mean amplitude and mean duration of the F-waves were significantly (p less than 0.001) longer in patients with spasticity than in healthy controls. These findings could be the result of an enhanced spinal excitability in spasticity. Based on the present results F-wave recording may be used as a simple and practical technique for detection and documentation of spasticity.


Clinical application of spinal root neurograms for detection of conduction block in radiculopathy.

In order to assess effects on conductivity of the spinal nerve roots which were compressed due to lumbar disc herniation (LDH) and spinal canal stenosis (SCS) at the lumbosacral vertebrae, spinal nerve root potentials (SRP) were recorded epidurally at multiple levels upon stimulation of the tibial and peronea nerves. Subjects were five normal volunteers and fifteen clinical cases (10 LDH and 5 SCS). Simultaneous recording of evoked EMGs was used to identify afferent and efferent components of SRPs. The shortest latency SRP consisted of orthodromic group I afferent and antidromic alpha-efferent potentials. The potential on liminal M-wave stimulation was regarded as representing exclusively group I volley and that on maximal M-wave stimulation as predominantly alpha-efferents. A centrifugally conducting nerve potential for H-reflex could be also recorded. Conduction blockage in the lumbar spinal roots of the clinical cases could be recognized as increased positivity and desynchronization. Quantitative assessment of these signs was devised in comparison to the control data. The present method revealed at least one of these signs in all clinical cases, and was found useful to determine the levels at which surgical decompression is indicated, supplementing radiological examination.


Computer-aided EMG-analysis in patients with neurogenic lesions.

A new system for computer aided EMG-analysis was tested in 3 groups of patients with neurogenic lesions (ALS, ulnar nerve lesions, diabetic polyneuropathy). The system entails automatic segmentation and parametrization of the single MUAP as well as the automatic classification of the MUAP into motor units. Emphasis was placed on its practicability in an everyday clinical setting. All patient groups differed significantly from normal groups in most of the computed parameters of the motor units. Moreover, on the basis of the computer-aided analysis of the MUAP up to 90% of individual patients in the ALS and ulnar nerve lesion groups and up to 40% in the diabetic polyneuropathy group, who did not have any pathological spontaneous activity or paris, could be classified as pathological. It is concluded, that computer-aided EMG-analysis has become a practical tool for routine use in the clinical laboratory simplifying early diagnosis of subtle EMG-changes, and aiding the less experienced examiner.


Exteroceptive suppression of the trapezius muscle produced by mental nerve stimulation in normal subjects.

The purpose of the present study was to evaluate the similarities and differences in exteroceptive suppression produced by mental nerve stimulation between the masseter and trapezius muscles. Six normal subjects were studied using various intensities of stimulation. Although the duration and degree of exteroceptive suppression were increased with stimulus intensity in the masseter muscle, they did not correlate with stimulus intensity in the trapezius muscle. The latency and duration in the trapezius muscle were almost the same as those in the masseter muscle. The degrees in the masseter muscle were significantly larger than those in the trapezius muscle. Exteroceptive suppression of the trapezius muscle might have a similar mechanism as that of the masseter muscle, but it may be mediated by the separate interneurons. The projection from the trigeminal afferent to the trapezius motoneuron might be smaller than that to the masseter motoneuron.


Proliferative retinopathy: value of the oscillatory potentials.

Oscillatory potentials (OPs) and retinal fluorescein angiography (RFA) were performed in 45 patients with diabetes mellitus. OPs were normal in 28 patients, altered (increased latencies and or inter-peak times) but with normal shape in 9, changes in morphology in 8: none of these patients had normal RFA, 2 had no proliferative retinopathy, 6 proliferative retinopathy (PR). In the authors' opinion OP changes in morphology are nearly always caused by a serious diabetic retinopathy, often by a PR. The authors emphasize the usefulness of OPs for studying the neurophysiologic properties of the retina of diabetic patients, particularly in PR.


Effects of angiotensin converting enzyme inhibition, sodium depletion, calcium, isoproterenol, and angiotensin II on renin secretion by individual renocortical cells.

Angiotensin-converting enzyme inhibition with enalapril increases the number of glomeruli with juxtaglomerular cells and the number of cells in the afferent arteriole that express the renin gene and contain renin. However, renin release from these newly recruited renin-containing cells has not been demonstrated. Sodium depletion also has been shown to increase renal renin messenger RNA levels. The aim of these studies was to determine whether increases in renin secretion are a result of altered numbers of cells synthesizing/releasing renin or a change in the amount of renin release per cell, or both. Adult Wistar-Kyoto rats were treated with enalapril or sodium depleted and single cell renin secretion of enzymatically dispersed renal cortical cells was examined by reverse hemolytic plaque assay. Enalapril treatment increased the number of renin secreting cells by approximately 10-fold (P < 0.05). The newly recruited renin-secreting cells were not responsive to changes in extracellular calcium concentration or the presence of isoproterenol. At physiological (2.5 mM) extracellular calcium concentration, the amount of renin secreted per cell was approximately 2-fold greater (P < 0.05) when cells from enalapril-treated rats were compared to controls and sodium depletion increased both the number of renin-secreting cells and the amount of renin secreted by approximately 35% (P < 0.05). Angiotensin II (AII) inhibited the number of cells secreting renin in cortical cells prepared from enalapril-treated and control rats. In conclusion, angiotensin converting enzyme inhibition increased renin secretion predominantly by recruitment of additional renin-secreting cells and, to a lesser extent, by augmentation of the amount of renin released per cell. In contrast, sodium depletion increased renin secretion equally by both mechanisms. Newly recruited renin-secreting cells were not regulated by the extracellular calcium concentration or beta-adrenergic stimulation. Angiotensin II inhibited renin secretion directly by decreasing the number of individual cells releasing renin through a process which was independent of the extracellular calcium concentration.


Production of mouse placental lactogen-I and placental lactogen-II by the same giant cell.

In previous studies, mouse placental lactogen I (mPL-I) and mPL-II were localized to trophoblast giant cells in the placenta at midpregnancy. The present study was undertaken to determine whether mPL-I and mPL-II are produced by two distinct populations of giant cells or by the same cells. A heterogeneous population of cells that included trophoblast giant cells was obtained by enzymatic dispersion and Percoll gradient centrifugation of placentas from days 7 and 9 of pregnancy. Cells from day 7 of pregnancy were cultured in serum-free medium for 5 days, and cells that contained mPL-I, mPL-II, or both mPL-I and mPL-II were identified by double-staining immunocytochemistry. The percentage of PL cells that contained both mPL-I and mPL-II increased from about 30% on the first day of culture to about 90% on the third, and then declined to zero by day 5. Between 50% and 60% of the PL cells contained only mPL-I on the first 2 days of culture, and then the percentage of PL cells containing only mPL-I declined. The percentage of cells that contained only mPL-II was low for 3 days (<10%) and then increased to about 80% of the PL-containing cells by day 5. Cells from day 9 of pregnancy were analyzed for the release of mPL-I and/or mPL-II by sequential reverse hemolytic plaque assay. Cells that released only one of the PLs, as well as those that released both PLs, were identified. A shift was present in the type of PL released by the cells when they were followed for two consecutive days of culture. On day 1, most of the plaque-forming cells released only mPL-I, but by day 2, the fraction of plaque-forming cells that released only mPL-I declined whereas the fraction that released only mPL-II increased. Cells that released only mPL-I on the first day of culture and both mPL-I and mPL-II or only mPL-II on the second day of culture were observed. These data suggest that under these culture conditions, PL cells follow a pathway in which they initially produce only mPL-I, then both mPL-I and mPL-II, and finally only mPL-II. In vivo, there is a shift at midpregnancy in the type of PL that is produced by the mouse placenta, and these data suggest that this shift results, at least partly, from a change in gene expression in one population of giant cells.


Effect of restricted feeding, fasting, and diabetes on the relationship between thyroid hormone receptor occupancy, growth hormone induction, and inhibition of thyrotropin release in thyroidectomized rats.

The present study was undertaken to test the effect of food restriction, fasting, and diabetes on the relationship between thyroid hormone receptor occupancy and two biological end points, GH production and the inhibition of TSH secretion, in thyroidectomized rats. The estimated maximal binding capacity (MBC) in diabetic (D) and fasting (F) rats and in animals limited to 25% (FR25) of the food consumption of normal (C) rats was decreased to 57%, 73%, and 76%, respectively, of C values (P < 0.01-0.001), whereas normal values were found in thyroidectomized (Tx) rats and in animals limited to 50% (FR50) of the food intake of C animals. The nuclear T3 content and T3 receptor occupancy were reduced, respectively, to 25% and 29% in Tx, 77% and 81% in FR50, 52% and 69% in FR25, 49% and 66% in F, and 36% and 64% in D rats of the corresponding C values (P < 0.05-0.001). Pituitaries from Tx, FR50, FR25, F, and D rats contained less GH than C pituitaries (0.14%, 81%, 69%, 88%, and 51%, respectively, of C pituitaries; P < 0.05-0.001). Plasma TSH was lower in FR50, FR25, F, and D rats than in C animals (78%, 57%, 52%, and 48%, respectively (P < 0.01-0.001)), and markedly increased in Tx animals. Administration of a single dose of 2, 5, or 10 micrograms T3/100 g BW to Tx C, Tx FR50, TX FR25, Tx F, and Tx D rats resulted in a similar and progressive increase in nuclear T3 in all groups, except for lower values in Tx D animals. However, receptor occupancy did not differ among the different groups at each T3 dose. This treatment resulted in a progressive increase in pituitary GH in all groups; however, in Tx FR50, Tx FR25, Tx F, and Tx D pituitaries, the GH responses to 10 micrograms T3 were only 77%, 59%, 44%, and 27%, respectively, of that in Tx C rats. (P < 0.05-0.001). Moreover, significant differences in the GH response to 10 micrograms T3 were observed among Tx FR50, Tx FR25, Tx F, and Tx D animals (P < 0.01-0.001). In addition plasma TSH levels in untreated Tx FR50, Tx FR25, Tx F, and Tx D rats were only 88%, 82%, 79%, and 72%, respectively, of that in Tx C animals (P < 0.05-0.01).(ABSTRACT TRUNCATED AT 400 WORDS)


Tissue selective modulation of redox and phosphate potentials by beta,beta'-methyl-substituted hexadecanedioic acid.

beta,beta'-Methyl-substituted hexadecanedioic acid (MEDICA 16) shares some of the calorigenic-hypolipidemic characteristics of thyroid hormones. In light of this similarity, MEDICA 16 was further evaluated here as a modulator of rat liver redox and phosphate potentials as well as an effector of cardiac high energy intermediates level in comparison to thyroid hormone. 1) Similarly to thyroid hormone, MEDICA 16 treatment resulted in 3.5-fold decrease in cytosolic redox potential. With both treatment modes, the induced decrease in cytosolic redox potential resulted in a concomitant increase in the liver capacity of handling an ethanol or xylitol load. 2) The apparent liver cytosolic phosphate potential calculated from the glycerol-3-phosphate 3-phosphoglyceric acid ratio evaluated under conditions of rapid equilibrium within the glycerol-3 phosphate/3-phosphoglyceric acid metabolic section was found to remain unaffected by either MEDICA 16 or T3 treatment. However, the apparent cellular phosphate potential was substantially decreased by both treatment modes, thus reflecting a decrease in the apparent liver mitochondrial phosphate potential. 3) Similarly to thyroid hormone, the effect of MEDICA 16 on liver redox and phosphate potentials could be accounted for by induction of mitochondrial glycerol-3-phosphate dehydrogenase. 4) In contrast to liver, heart high energy intermediates were affected by thyroid hormone but not by MEDICA 16 treatment. 5) The effect of T3 and MEDICA 16 with respect to liver redox and phosphate potentials may partially account for the calorigenic-hypolipidemic effect of both. MEDICA 16 may however serve as a selective liver thyromimetic agent lacking the cardiac affect induced by thyroid hormone.


Expression of insulin-like growth factor-II (IGF-II) and IGF-II/mannose-6-phosphate receptor in the rat hippocampus: an in situ hybridization and immunocytochemical study.

After 3 or 4 weeks of age, insulin-like growth factor-II (IGF-II) gene expression in normal rats has been detected only in mesenchymal tissue associated with the central nervous system. In contrast, the IGF-II/mannose-6-phosphate receptor has been reported to be widely distributed in adult rat brain. This study was performed in order to clarify the cellular localization of IGF-II and IGF-II/mannose-6-phosphate receptor in rat brain by comparing an immunocytochemical map with the distribution of mRNAs by in situ hybridization. The highest levels of IGF-II mRNA were detected in the choroid plexus and meningeal membranes. In contrast, IGF-II receptor transcripts were mainly present in neuron-rich areas such as the hippocampus, with a lower signal present in the choroid plexus and meninges. Specific IGF-II receptor immunoreactivity was present in neurons throughout the forebrain, with the highest intensity in the pyramidal cell and polymorphic layers of the hippocampus and the granule cell layer of the dentate gyrus. This distribution was similar to that obtained with the in situ hybridization technique. No glial staining was detected. Although the role of IGF-II in the adult rat brain, acting through its specific receptor, is not clear; in vitro and in vivo data suggest a possible neurotropic and/or neuromodulatory action.


Interleukin-1 is both morphogenic and cytotoxic to cultured rat ovarian cells: obligatory role for heterologous, contact-independent cell-cell interaction.

An increasing body of information now suggests that intraovarian interleukin-1 (IL-1) may play an intermediary role in the ovulatory process. Given that follicular rupture inevitably requires marked tissue remodeling and possibly cell death, we set out to examine the morphogenic potential of IL-1 under in vitro circumstances. Treatment of freshly plated whole ovarian dispersates from immature rats with any one of several batches of IL-1 (10 ng/ml) for up to 96 h produced marked time-dependent morphological alterations, including cellular retraction, rounding, clumping, aggregation, blebbing, swelling, and, ultimately, irreversible detachment. Evidence of (asynchronous) cell death consisted of reduced total cell number, diminished cellular protein content, enhanced cellular release of lactic dehydrogenase, failure to exclude trypan blue, and attenuated reduction of the tetrazolium dye 3-[4,5-dimethylthiazol-2-y]2,5-diphenyltetrazolium bromide to spectrophotometrically detectable formazan. Comparable results were obtained when using established day 4 cultures, arguing against a possible critical action of IL-1 at the time of plating. Dose-response curves revealed IL-1 beta (EC50, 0.2-0.4 ng/ml) to be substantially more potent than IL-1 alpha (EC50, 2.7-2.8 ng/ml). Importantly, the concurrent provision of an IL-1 beta-directed polyclonal antibody yielded complete immunoneutralization of the IL-1 beta effect, arguing against the possible involvement of a non-IL-1 contaminant. An unrelated polyclonal antiserum raised against insulin-like growth factor-I was without effect. IL-1 action proved relatively specific, in that tumor necrosis factor-alpha (10 ng/ml), a putative cytotoxic principle, as well as IL-1-inducible ILs (IL-2 and -6; 100 U/ml) were without effect. Although minimally effective at the level of the isolated granulosa or theca-interstitial cell, IL-1 proved highly potent in heterologous (but not homologous), contact-dependent and independent cocultures of these somatic cell types, strongly suggesting obligatory cell-cell cooperation. These observations further indicate that IL-1 action is indirect and may require the induction of an intermediary soluble principle to serve as the final effector. Taken together, these findings indicate that relatively low concentrations of IL-1 (beta >> alpha), possible of somatic ovarian cell or resident ovarian macrophage origin, are capable of exerting specific dose- and time-dependent (immunoneutralizable) morphogenic as well as cytotoxic effects at the level of ovarian cells.(ABSTRACT TRUNCATED AT 400 WORDS)


Transforming growth factor-alpha is a potential mediator of estrogen action in the mouse uterus.

To better understand the role of peptide growth factors in sex steroid hormone-mediated growth of the female reproductive tract, the effect of estrogen on the expression of transforming growth factor-alpha (TGF alpha) in mouse uterus was investigated. Our results show that estrogen induces the expression of TGF alpha mRNA in the mouse uterus in a dose- and time-dependent manner. The up-regulation of TGF alpha transcripts occurs predominantly in uterine epithelial cells. RIA and Western blot analysis demonstrate that immunoreactive TGF alpha protein is secreted at high levels into mouse uterine luminal fluid after estrogen treatment. The induction of uterine TGF alpha mRNA is specific to estrogen; nonestrogenic steroids did not induce expression. Antibody specific to TGF alpha significantly reduces estrogen-mediated uterine growth, which supports the concept that TGF alpha is a mitogen for the reproductive tract. Analysis of TGF alpha/EGF receptors by binding, affinity labeling, and phosphorylation studies indicates that functional receptors are present in the mouse uterus after estrogen exposure. Thus, our data support a physiological role for TGF alpha and its receptor pathway in the female mouse reproductive tract.


Photoperiodic modulation of luteinizing hormone secretion in orchidectomized Syrian hamsters and the influence of excitatory amino acids.

The effect of N-methyl-D,L-aspartate (NMA) on LH secretion was investigated in Syrian hamsters of the LSH/Ss Lak strain, maintained under either long days (14 h of light, 10 h of darkness) or short days (6 h of light, 18 h of darkness). After 6 weeks of photoperiodic treatment, the animals were orchidectomized. Ten days later, 10-min blood samples were remotely collected from each animal, using surgically implanted intraatrial catheters, and individual pulsatile LH release profiles were subsequently determined by RIA. At the end of the 4-h sampling period, NMA was administered iv (30 mg/kg BW), and the LH response was determined in the next three plasma samples. Hamsters maintained under long days had very high mean plasma LH levels (453 +/- 46 ng/ml) and displayed episodic release patterns characterized by high amplitude pulses. In marked contrast, hamsters that were maintained under short days had significantly (P less than 0.001) lower mean plasma LH levels (90 +/- 12 ng/ml) and showed a significantly (P less than 0.001) lower mean pulse amplitude. The interpulse interval was similar in both of the groups, with LH peaks occurring, on the average, once every 65 min. When challenged with NMA, the long-day hamsters showed only a 37% increase in mean plasma LH levels, which was not statistically significant. In contrast, the short-day hamsters showed a highly significant (P less than 0.01) increase of 294%. Interestingly, the mean plasma LH levels after NMA administration were the same in the two photoperiodic groups despite a marked difference in the plasma levels that preceded the administration. These findings demonstrate that short days can inhibit the neuroendocrine activity of the hamster's reproductive axis independently of gonadal influences. They also suggest that the LHRH neurons have an intrinsic capacity to secrete very high levels of the neuropeptide, regardless of the photoperiod. Taken together, the results support the hypothesis that the breeding season in the hamster is regulated by a gonad-independent mechanism involving a photoperiodic modulation of neuroexcitatory inputs to the LHRH neurons.


Apoptosis in atretic ovarian follicles is associated with selective decreases in messenger ribonucleic acid transcripts for gonadotropin receptors and cytochrome P450 aromatase.

Although atresia of ovarian follicles is of critical importance during preovulatory follicle selection as well as during normal and premature menopause, the mechanisms underlying atresia remain poorly understood. To study molecular events associated with atresia, we evaluated changes in mRNA levels for cytochrome P450 aromatase, FSH receptor, LH receptor, and a structural protein, beta-actin, during atresia in small (3-mm diameter) and large (6-mm diameter) porcine follicles. In addition, internucleosomal fragmentation of DNA characteristic of apoptosis ("programmed cell death") was assessed in individual healthy and atretic follicles using a sensitive autoradiographic method. Follicles were classified as morphologically healthy or atretic based on the absence or presence of follicular haemorrhagia and the degree of follicular clarity. Morphological signs of atresia in individual follicles were correlated with the occurrence of internucleosomal DNA fragmentation in granulosa cells as well as in thecal cells during advanced stages of atresia. The presence of apoptosis in atretic follicles was also associated with significant decreases in follicular fluid estrogen concentrations compared to those in healthy follicles of the same size. The decline in estrogen synthesis in degenerating follicles was further correlated with decreased levels of a predominant 2.6-kilobase aromatase mRNA. Moreover, substantial declines in both FSH receptor and LH receptor mRNAs were found in atretic follicles, consistent with previous reports of their decreased responsiveness to gonadotropins. The observed decreases in mRNAs for aromatase and gonadotropin receptors could not be attributed to a generalized degradation of cellular RNA during atresia, as evidenced by the presence of intact 18S and 28S ribosomal RNA as well as constitutive expression of beta-actin mRNA in atretic follicles. These data indicate that apoptotic cell death is initiated in both granulosa and thecal cells of porcine follicles during atresia. Associated with internucleosomal DNA fragmentation, decreased transcription of specific ovarian genes or destabilization of their transcripts leads to selective decreases in aromatase and gonadotropin receptor mRNAs. The atresia of ovarian follicles provides an interesting model to further study the molecular events associated with DNA fragmentation and selective mRNA down-regulation during apoptosis.


Pretreatment with 1,25-dihydroxycholecalciferol enhances thyrotropin-releasing hormone- and inositol 1,4,5-trisphosphate-induced release of sequestered Ca2+ in permeabilized GH4C1 pituitary cells.

In GH4C1 cells 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] has been shown to enhance the TRH- and bombesin-induced increase in intracellular Ca2+ ([Ca2+]i). The aim of the present study was to investigate whether this increase in [Ca2+]i could be due to enhanced release of sequestered Ca2+ in cells pretreated with 1,25-(OH)2D3. In digitonin-permeabilized cells, the addition of 10 microM inositol 1,4,5-trisphosphate (IP3) rapidly increased free Ca2+ ([Ca2+]) to 50 +/- 10 nM (mean +/- SE) in cells pretreated with 1 nM 1,25-(OH)2D3 for 24 h, compared with 25 +/- 5 in control cells (P < 0.05). Furthermore, stimulating permeabilized cells with TRH increased [Ca2+]. The increase in control cells was 20 +/- 2, compared with 55 +/- 11 in cells pretreated with 1,25-(OH)2D3 (P < 0.05). Repeated additions of IP3 resulted in an attenuation of the response of [Ca2+] in both control cells and cells pretreated with 1,25-(OH)2D3. However, only the first addition of IP3 resulted in an enhanced increase in [Ca2+] in cells pretreated with 1,25-(OH)2D3 compared with control cells. If the cells were stimulated first with TRH and then with IP3, no difference in the [Ca2+] response was observed between control cells and cells pretreated with 1,25-(OH)2D3. Furthermore, if cells were stimulated with IP3 and then with TRH, no difference in the [Ca2+] response was observed between control cells and cells pretreated with 1,25-(OH)2D3. Stimulating the permeabilized cells with thapsigargin resulted in an increase in [Ca2+]. However, no difference in the response was observed between control cells and cells pretreated with 1,25-(OH)2D3. Addition of GTP or the nonhydrolyzable GTP analog guanosine 5'-O-(3-thiotriphosphate) had no effect on [Ca2+]. The results suggest that 1,25-(OH)2D3 has a modulatory effect on an IP3-sensitive intracellular Ca2+ pool in GH4C1 cells.


Induction of type III deiodinase activity in astroglial cells by thyroid hormones.

The type III deiodinase (D-III) activity in astroglial cells is induced by multiple pathways activated by cAMP, 12-O-tetradecanoylphorbol-13-acetate (TPA), and fibroblast growth factors (FGFs). This study examines the effects of thyroid hormones on D-III activity in astroglial cells with or without induction by these factors. Addition of 10 nM T3 to the culture medium caused a slow increase in D-III activity, which reached a plateau after 48 h. This increase was concentration dependent (maximal response at 10 nM). Doses as low as 0.3 nM caused significant increases in D-III activity. The effect of T3 was reversible. A dose of 10 nM L-T3, D-T3, T4, 3,5,3'-triiodothyroacetic, or 3'-isopropyl-3,5-diiodothyronine produced 5- to 15-fold increases in D-III activity after 48 h. In contrast, 10 nM L-thyronine, 3-monoiodothyronine, 3,3'-diiodothyronine, 3,5-diiodothyronine, and rT3 were without effect. A dose of 10 nM T3 or T4 amplified the D-III activity stimulated by 0.1 microM TPA, 20 ng/ml acidic FGF, or 1 mM 8-bromo-cAMP 3- to 8-fold. Otherwise, T3 rapidly inhibited D-II activity. This inhibition was concentration dependent, with a half-maximal effect around 10 nM. In conclusion, thyroid hormones induce D-III activity and potentiate the D-III activity induced by cAMP, TPA, and FGFs in astroglial cells. These reversible effects together with inhibition of D-II activity may contribute to protect the brain against hyperthyroidism.


A study of metabolism of deaminated and sulfoconjugated iodothyronines by rat placental iodothyronine 5-monodeiodinase.

The interaction of the rat placental type III iodothyronine 5-monodeiodinase (5-MD) with acetic acid (AA), propionic acid (PA), and sulfoconjugate (SA) derivatives of thyroid hormones has been investigated in comparison with hepatic iodothyronine type I MD. PA and AA derivatives of both T3 and T4 were potent inhibitors of 5-monodeiodination of [125I]T3 by rat placental microsomes. 3,5,3'-Triiodothyroacetic acid (T3AA) and 3,5,3'-triiodothyropropionic acid (T3PA) were comparable to T3 in their ability to inhibit 5-monodeiodination of [125I]T3, whereas T4AA and T4PA were more potent than T4. 3,5,3'-triiodothyrosulfonic acid (T3SA), T4SA, and rT3SA caused little or no inhibition of placental 5-MD activity. Among various analogs of T3 or T4, the order of relative potency of inhibition of hepatic 5'-MD was PA > AA > SA > parent iodothyronine. The metabolism of T3 and its derivatives by rat placental microsomes was studied by determining the rates of disappearance of the various substrates and the production of the metabolites generated by inner ring monodeiodination of the substrate. T3AA and T3PA were metabolized at a rate comparable to that of T3. Under the same conditions, essentially 100% of T3SA remained intact. Kinetic studies of placental inner ring monodeiodination of T3, T3AA, and T3PA demonstrated comparable values for Km (1.3, 1.8, and 2.3 nM, respectively) and maximum velocity (44, 57, and 74 fmol/micrograms.h, respectively). All derivatives of T3 studied were deiodinated by hepatic type I MD more avidly than the parent iodothyronine. Our data suggest that 1) deamination does not appreciably influence, while sulfoconjugation markedly inhibits type III 5-monodeiodination of T3; and 2) deamination may be even more conducive to degradation of thyroid hormone than sulfoconjugation.


In vivo effects of interferon-alpha and interferon-gamma on lipolysis and ketogenesis.

The host response to infection and cancer produces disturbances in fatty acid (FA) oxidation and ketogenesis. Interferons (IFNs) stimulate lipolysis in cultured adipocytes. Since FA mobilization is a major stimulus for ketogenesis, we studied the effect of IFN alpha and IFN gamma on lipolysis and ketogenesis in intact mice. Both IFNs acutely stimulated lipolysis; however, their effects on ketogenesis differed. INF gamma increased serum and hepatic ketone body levels in parallel to its effect on serum FFA, whereas IFN alpha exerted a biphasic effect on ketogenesis. At low doses, IFN alpha increased serum and hepatic ketone body levels, whereas at higher doses, this ketogenic effect was abolished. To determine the mechanism of the biphasic response, we studied the effect of IFN alpha on hepatic malonyl-coenzyme-A (malonyl-CoA), the first committed intermediate in FA synthesis and an inhibitor of FA oxidation and ketogenesis. At low doses, IFN alpha had no effect on malonyl-CoA; however, higher doses of IFN alpha significantly increased malonyl-CoA levels, which could counterbalance its mobilization of FFA. In contrast, INF gamma had little effect on malonyl-CoA, and hence, the FA oxidation was not opposed. By using phenylisopropyladenosine to block IFN-induced lipolysis, we found that in the absence of increased FA flux, INF gamma did not exert a ketogenic effect. However, when IFN alpha-induced lipolysis was blocked, the higher doses of IFN alpha that raise malonyl-CoA levels were antiketogenic. These data suggest that both IFNs exert a ketogenic effect by stimulating lipolysis, but at higher doses the ketogenic effect of IFN alpha is counteracted by its effect on hepatic FA synthesis.


Central C-type natriuretic peptide but not atrial natriuretic factor lowers blood pressure and adrenocortical secretion in normal conscious sheep.

C-type natriuretic peptide (CNP) and its specific receptor (ANPRB) are richly distributed throughout the brain, especially the anterior pituitary and hypothalamus but not in tissue of nonneural origin. These findings suggest that the actions of CNP, unlike atrial natriuretic factor (ANF), are largely confined to the brain where CNP may participate in the central regulation of hemodynamics and salt and water balance. Therefore, we have studied the hemodynamic, renal, and hormonal effects of continuous intracerebroventricular infusions of CNP (5 micrograms/h for 4 h) in a vehicle-controlled study and compared the responses to those of ANF in normal conscious sheep. Hemodynamic and hormonal responses to ANF were not different from control infusions. There was a trend for urinary sodium and potassium excretion to increase throughout the control infusion but not on the ANF day. Water intake during control infusion (358 +/- 160 ml/4 h) was almost 3-fold that ingested during ANF (127 +/- 89 ml/4 h, NS). In contrast, CNP induced a prompt fall in mean arterial pressure (mean decrement 5 mm Hg), arterial pressure remaining below time control values for the remainder of the infusion (P = 0.006). Rises in both heart rate and PRA observed on the control day tended to be attenuated by CNP. Urine electrolyte response to CNP was similar to that observed with ANF. Compared with control infusions, the responses of both plasma aldosterone (P = 0.006) and cortisol (P = 0.043) were significantly different. Following CNP-induced hypotension, plasma cortisol and aldosterone increased abruptly at 30 min after which values fell to control or lower levels until the infusion was terminated. These studies show that intracerebroventricular CNP lowers arterial pressure without increasing heart rate and also suppresses the adrenocortical response, whereas ANF given under the same conditions has no significant effects. These data support the hypothesis that CNP plays an important role in the central regulation of blood pressure and hormones.


Impairment of glycosyl-phosphatidylinositol-dependent insulin signaling system in isolated rat hepatocytes by streptozotocin-induced diabetes.

The addition to different types of cells of an inositol-phosphate glycan, generated by the phospholipase C-catalyzed hydrolysis of a insulin-sensitive glycosyl-phosphatidylinositol (glycosyl-PI), mimics some of the biological effects of this hormone. Recently, a specific, time-, dose-, and energy-dependent transport system for this inositol-phosphate glycan has been identified in isolated rat hepatocytes. Here, we show that streptozotocin-induced diabetes mellitus reduced (by about 60%) the basal content of the insulin-sensitive glycosyl-PI in isolated rat hepatocytes. Moreover, streptozotocin-induced diabetes blocked the hydrolysis of the glycosyl-PI in response to insulin, diminished inositol phosphate-glycan uptake by the hepatocytes, and abolished the stimulatory effect of this compound on glycogen synthesis. All these metabolic changes caused by streptozotocin administration were reversed by treatment of the animals with insulin. Our results support the hypothesis that insulin resistance in streptozotocin-induced diabetic rats is related to the impairment of glycosyl-PI metabolism.


Characterization of the structure and glycosylation properties of intracellular and cell surface rat hepatic prolactin receptors.

In this study we examined the structure of the PRL receptor of rat liver. We used immunoblotting with monoclonal antibodies to binding and nonbinding site epitopes of the PRL receptor to assess receptor subtypes in different hepatic subcellular fractions. Analysis of frozen-thawed cell fractions revealed 40- and 42-kilodalton (kDa) species. Digestion with neuraminidase indicated that both species were terminally sialylated. Freshly isolated membranes exhibited a single 42-kDa species in all subcellular fractions, whereas freeze-thawing generated the 40-kDa species. The carbohydrate linkages present in the PRL receptor were examined using enzymes to deglycosylate iodinated purified receptors. These studies indicated that oligosaccharides comprise about 7 kDa of receptor mass and that they are exclusively N-linked, consisting of tri- and/or tetra-antennary complex glycans. Monoclonal antibodies to the receptor recognized the deglycosylated receptor. Maximally deglycosylated receptors retained about 85% of their binding capacity. After in vivo tunicamycin treatment of rats, total PRL receptors (as determined by immunoblot analysis and binding activity) disappeared with a half-time of about 25 min. In this circumstance, no aglycosylated receptor species were recognized by monoclonal antibodies. Since deglycosylation of mature receptors did not markedly reduce binding capacity, we infer that mature receptors do not accumulate during the blockade of glycosylation by tunicamycin. Thus, glycosylation appears to be required for the acquisition of a mature receptor status, but is not necessary for the maintenance of that status.


Thyroxine sulfate is a major thyroid hormone metabolite and a potential intermediate in the monodeiodination pathways in fetal sheep.

T3 and rT3 production rates in the fetus account for roughly only a third of the total T4 production rate; thus, the fate of the majority of T4 produced in the fetus is unknown (the "T4 disposal gap"). We developed sensitive and specific T4 sulfate (T4S) and T3 sulfate (T3S) RIAs to investigate the roles of these compounds in fetal T4 metabolism. T3, T4, T3S, and T4S were determined in a variety of tissue fluid and/or serum samples obtained from fetal, newborn (n = 6), and adult (n = 6) sheep. Four groups of fetal animals, with gestational ages of 94 days (n = 5), 110-111 days (n = 6), 130-131 days (n = 6), and 145 days (n = 6; term = 150 days), were studied. In addition, type I 5'-monodeiodinase (5'-MDI) activity was quantified in liver and kidney tissues. 5'-MDI activities were lower in 94- to 131-day-old fetuses than in fetuses near term or in newborn animals. Mean serum T3 concentrations increased progressively from 94 days (19 ng/dl) to term (371 ng/dl), while mean T3S and T4S serum concentrations were highest at 130 days gestation (237 and 989 ng/dl), decreasing to term. Serum T3S and T4S concentrations decreased further in newborns and adult sheep. T4S and T3S levels in allantoic fluid were significantly higher than those in urine and amniotic fluid in all fetal age groups studied. T4S levels in bile were high from 94-130 days gestation (873-1006 ng/dl), decreasing by 50% at term (529 ng/dl). T4S concentrations in meconium were 46- to 83-fold higher than those in bile from 94 days gestation to term. In contrast, bile T3S levels increased progressively from 94-145 days gestation (191-605 ng/dl), while meconium T3S levels decreased during the same period (33-14 micrograms/100 g). These data demonstrate that 1) sulfated iodothyronines, particularly T4S, are major thyroid hormone metabolites in the fetus; 2) both T4S and T3S are excreted into bile and urine and concentrated in meconium and allantoic fluid; and 3) the high levels of T4S and T3S in serum and other fluids may reflect lower tissue type I 5'-MDI activities. We speculate that T4S and T3S may be further metabolized to other sulfated metabolites and may account in part for the T4 disposal gap in fetal sheep.


Mechanisms of desensitization to parathyroid hormone in human osteoblast-like SaOS-2 cells.

Signal transduction by the PTH receptor is now known to involve generation of multiple second messengers. Desensitization of the adenylate cyclase response to PTH is a common feature of bone- and kidney-derived target cells; however, no single mechanism appears to explain desensitization in the different cell types studied. To examine the role of protein kinase-A (PKA) in homologous desensitization to PTH, we employed human SaOS-2 osteoblast-like cells and a mutant subclone (Ca 4A), which expresses an inducible cAMP-resistant form of PKA. Pretreatment of SaOS-2 cells with PTH for 4 h reduced by 60-80% the cAMP response to subsequent rechallenge with the hormone. This homologous desensitization was significantly, but not completely, inhibited in Ca 4A cells. Desensitization was not mimicked by pretreatment of the cells with forskolin. PTH binding to its receptor was reduced 50% in both SaOS-2 and Ca 4A cells after 4-h incubation with PTH (homologous down-regulation), whereas forskolin did not cause receptor down-regulation. Pretreatment with the ionophore ionomycin for 4-24 h did not mimic desensitization to PTH. Both desensitization to PTH and receptor down-regulation were induced, however, by pretreatment with a phorbol ester (12-O-tetradecanoyl phorbol-13-acetate), and these effects were blocked completely by staurosporine. PTH-induced desensitization was not blocked by staurosporine, and receptor down-regulation was enhanced by the drug. Pertussis toxin did not prevent desensitization induced by either PTH or 12-O-tetradecanoyl phorbol-13-acetate. We conclude that homologous desensitization to PTH in SaOS-2 cells involves both cAMP-dependent and -independent mechanisms. Homologous PTH receptor down-regulation apparently is mediated by mechanisms independent of PKA activation. Neither pathway of homologous desensitization to PTH involves the action of pertussis toxin-sensitive G-proteins.