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Biomedical subjects

R L Naeye

Publications and source records attributed to R L Naeye.

At least 109 records · Page 6Linked to original sources
PubMed1977

Effects of cigarette smoking on intramyocardial arteries and arterioles in man.

Proliferative lesions, which include collagen, elastic fibers and abnormally oriented muscle fibers, were found to develop in intramyocardial arteries more rapidly with age in cigarette smokers than in nonsmokers. The study attempted to determine whether these lesions reduce perfusion pressures in the subendocardial zone of the left ventricle. The amount of muscle in arterioles appears to reflect perfusing pressures, so measurements were made of decreases in muscle in arterioles between the subepicardial and subendocardial zones of the left ventricle to detect decreases in arteriolar perfusing pressures between the two areas. The decreases in arteriolar muscle between the two zones were then compared with the extents of the intramyocardial arterial lesions. Those individuals who had the most extensive arterial proliferative lesions had the greatest decreases in arteriolar muscle from the subepicardial to the subendocardial zones. In persons less than 60 years old the mean decreases in arteriolar muscle between the two zones were 1% for nonsmokers and 17% for smokers. For those more than 60 years old the values were 21 and 41%.

Adult↗
PubMed1977

Epidemiological features of perinatal death due to obstructed labour in Addis Ababa.

Obstructed labour was the second most common cause of perinatal death in Addis Ababa, Ethiopia, being responsible for 9.1 perinatal deaths/1000 births. Most obstructed labours were due to cephalopelvic disporportion. There was a ninefold increase in the perinatal death rate when the patients were anaemic but most perinatal deaths were due to delays in seeking available obstetrical care. Formal education of the patients had little influence on the death rates but the informal education that comes with prolonged urban residence had a markedly favourable effect. Use of prenatal medical services and adequate income also had a favourable influence.

Anemia↗
PubMed1977

Placental abnormalities in victims of the sudden infant death syndrome.

Placentas from 79 victims of the sudden infant death syndrome (SIDS) were compared with placentas from 30,640 controls who survived in a search for evidences of infections or other disorders that might have damaged the SIDS victims before birth. Placentas from the SIDS victims had an increased frequency of acute funisitis, acute chorioamnionitis, lymphocytic infiltration of the decidua and macrophages in the fetal membranes. The acute funisitis and chorioamnionitis were associated with preterm deliveries and were probably related to amniotic fluid bacterial infections which are a common cause of premature delivery.

Bacterial Infections↗
PubMed1977

Causes of perinatal mortality in an African city.

Little has been published about the causes of most of the deaths responsible for the high perinatal mortality rates characteristic of preindustrial, urban societies. The present study searched for answers in one such society by identifying the causes of death in a large-scale analysis of perinatal mortality in Addis Ababa, Ethiopia. A 72% autopsy rate was achieved when 1019 postmortem examinations were performed for 1424 consecutive perinatal deaths. The overall perinatal mortality rate was 65.3 per thousand live births. The ratio of stillbirths to neonatal deaths was 2.7:1, indicating that maternal factors were dominant in causing the deaths. One-third of the deaths were due to amniotic fluid infections, 15% to obstructed labour, 8% to abruptio placentae, and the rest to more than 20 other specific disorders.

Ethiopia↗
PubMed1977

The sudden infant death syndrome: a review of recent advances.

When deaths during the first year of life are sudden, unexpected, and unexplained by any clinical or routine postmortem finding, they are placed in the category of sudden infant death syndrome (SIDS). The syndrome may have many causes, but there are probably only a few final pathways to death. Much recent evidence supports sleep apnea as the most common of these final pathways. Several SIDS victims have had reccurent episodes of sleep apnea prior to death. Such episodes are associated with chronic underventilation of the lungs in other disorders, and more than half of SIDS victims have postmortem markers of antecedent chronic underventilation and hypoxemia. The hypoventilation-apnea hypothesis is also attractive because it fits most of the unique epidemiologic features of SIDS.

ABO Blood-Group System↗
PubMed1977

Placental infarction leading to fetal or neonatal death. A prospective study.

The pathogenesis of perinatal death due to placental infarction was analyzed in a large prospective study that included more than 1000 medical, demographic, hereditary, and postmortem variables. The disorder was the fifth most frequent cause of death in the study with a perinatal mortality of 2.26/1000 births. Its frequency was directly correlated with the gravidas' blood pressures, an effect augmented by albuminuria and work during pregnancy. Fatal infarcts were increased 20-fold with glomerulonephritis, fivefold with abruptio placentae, and twofold when the gravidas' hemoglobins were over 12 g/100 ml. Maternal weight gains were suboptimal and the involved neonates had a pattern of growth retardation characteristic of undernutrition. The disorder was more frequent when the gravida had made few prenatal visits for medical care and had had prior unsuccessful pregnancies.

Abruptio Placentae↗
PubMed1976

Carotid body in the sudden infant death syndrome.

Sixty-three percent of victims of the sudden infant death syndrome had a subnormal volume and 23 percent an enlarged volume of glomic cells in their carotid bodies. Evidences of antecedent chronic alveolar hypoxia and hypoxemia were found in both groups but were more severe in the victims with enlarged glomic tissue.

Age Factors↗
PubMed1976

Mycoplasma T strains and perinatal death.

In 23 out of 290 perinatal deaths in Addis Ababa, mycoplasma T strains were the only organisms responsible for congenital pneumonia and death. All but 2 of the infants were stillborn, 16 dying during the last six weeks of gestation. Infections apparently occurred through intact fetal membranes.

Animals↗
PubMed1976

Sudden infant death syndrome. A prospective study.

One hundred twenty-five sudden infant death syndrome (SIDS) victims followed up since birth from a large prospective study were compared with matched controls. Some of the future SIDS victims showed evidences of neonatal brain dysfunction including abnormalities in respiration, feeding, temperature regulation, and specific neurologic tests. These abnormalities could not be ralated to events in labor or delivery. A greater proportion of the future victims were mildly underweight for gestational age. The gestations that produced the SIDS victims were characterized by a greater frequency of mothers who smoked cigarettes and had anemia. The demographic profile of SIDS families proved to be indentical to the profile for families with excessive perinatal mortality. Many of the SIDS victims showed a retardation in postnatal growth prior to death.

Anemia↗
PubMed1976

Sudden infant death syndrome temperament before death.

A retrospective study was made of the behavioral patterns of 46 infants whose deaths were attributed to the sudden infant death syndrome. Controls were the victims' siblings. Data concerning the infants' behavioral pattern were collected retrospectively from the parents, utilizing a modification of the Carey temperament questionnaire. The parents' recollection of the victims indicated that they: (1) had less intense reactions to environmental stimuli, (2) were less active physically, (3) were more breathless and exhausted during feeding, and (4) had more abnormal cries. The behavioral characteristics had a positive correlation with various postmortem evidences of antecedent chronic hypoventilation and hypoxemia. It would be a serious error for any parent to be told that their infant was at risk based on the behavioral pattern reported retrospectively by parents of victims of SIDS, because the pattern is also a common one in other infants.

Child Behavior↗
PubMed1976

Brain-stem and adrenal abnormalities in the sudden-infant-death syndrome.

Fourteen of 28 sudden-infant-death syndrome (SIDS) victims had an abnormal proliferation of astroglial fibers in their brain stems and an enlarged mass of chromaffin cells in their adrenal medullas. Both of these abnormalities were associated with greater than normal muscle in the small pulmonary arteries, abnormal brown fat retention, and retained extramedullary erythropoiesis. These latter three findings are probably evidences of chronic alveolar hypoventilation and hypoxemia. The brain stem and adrenal abnormalities are probably also secondary to chronic hypoxemia.

Adrenal Medulla↗
PubMed1976

Cardiac and other abnormalities in the sudden infant death syndrome.

Many victims of the sudden infant death syndrome (SIDS) have abnormally heavy cardiac right ventricles. The degree of this abnormality is directly proportional to: a) the mass of muscle about small pulmonary arteries, b) the amount of brown fat retention about adrenal glands, and c) the presence of hepatic erythropoiesis. The pulmonary arterial abnormality is probably the result of chronic alveolar hypoventilation, while brown fat retention and hepatic erythropoiesis are likely consequences of chronic hypoxemia. These abnormalities are found in both SIDS victims who die with and those who die without mild respiratory tract infections. However, there are some differences between the two SIDS groups. Infected victims die at an older age and have smaller thymus glands and larger spleens; there is a greater proportion of males in the infected victims than in the noninfected victims.

Adipose Tissue, Brown↗
PubMed1976

Unsuspected pulmonary vascular abnormalities associated with diaphragmatic hernia.

The pulmonary vasculature of 12 newborn infants who died with unilateral diaphragmatic hernias was studied. Four developed severe ventilatory insufficiency after birth and promptly died. Their lungs were both hypoplastic and airless dur to compression by displaced abdominal viscera and mediastinal shift. Corrective surgery permitted lung expansion and adequate ventilation for one to two hours in five infants. Subsequently, ventilatory insufficiency supervened and they died. Postoperative blood gases revealed a right-to-left ductus arteriosus shunt in one infant. Ten of the infants with hernias had a significantly greater mass of muscle in pulmonary arteries than did matched controls. This may partially explain the fetal-type circulatory infants.

Ductus Arteriosus, Patent↗
PubMed1976

Consequences of intramyocardial arterial lesions in aortic valvular stenosis.

Proliferative lesions, which included collagen deposition, developed with age in intramyocardial arteries of 27 patients with aortic stenosis and matched controls. Those with the most extensive intramyocardial artery lesions developed massive subendocardial infarcts during surgery. Using histologic quantitation, the percent of intramyocardial arteries with lesions in a patient was correlated with decreases in the amount of muscle in arterioles between the subepicardial and subendocardial zones of the left ventricle. The mean decrease in arteriolar muscle was 43% in patients with aortic stenosis and 19% in controls. Blood pressures correlate with the amount of muscle in arterioles, so subendocardial perfusing pressures were presumably low in those with aortic stenosis. Patients with the greatest decrease in arteriolar muscle across the myocardium had the most impaired left ventricular function, i.e., highest end diastolic pressures, lowest ejection fractions, and lowest mean fiber shortening rates.

Adult↗
PubMed1975

Fetal lung and kidney maturation in abnormal pregnancies.

A variety of gestational factors have been reported to increase or decrease the incidence of hyaline membrane disease in newborn infants. The purpose of the current study was to determine if some of these factors influence the rate at which fetal lung structures mature. Histologic measures of lung maturation were retarded in some infants with Rh erythroblastosis and in some whose mothers had diabetes mellitus. By contrast, such maturation was accelerated in offspring of some toxemic gestations and in those whose membranes had ruptured before the onset of labor. Congenital bacterial pneumonia with intact membranes did not accelerate maturation. None of the factors that altered lung maturity influenced renal maturation.

Abruptio Placentae↗
PubMed1974

Hypoxemia and the sudden infant death syndrome.

Infants with known chronic hypoxemia before death retained a large proportion of the brown fat cells that are normally replaced by white fat cells after birth. Many of these hypoxemic infants also had an abnormal retention of extramedullary hematopoiesis. These same abnormalities were found in many victims of the sudden infant death syndrome.

Adipose Tissue↗