101
|
Myers RE, Myers SE. Use of sedative, analgesic, and anesthetic drugs during labor and delivery: bane or boon? Am J Obstet Gynecol 1979; 133:83-104. [PMID: 367168 DOI: 10.1016/0002-9378(79)90417-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
102
|
Myers RE, Sutherland DJ, Meakin JW, Malkin DG, Kellen JA, Malkin A. Prognostic value of postoperative blood levels of carcinoembryonic antigen (CEA) in breast cancer. Recent Results Cancer Res 1979; 67:26-32. [PMID: 451321 DOI: 10.1007/978-3-642-81320-7_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
103
|
Abstract
Carcinoembryonic antigen (CEA) levels were determined in 742 postoperative patients with breast cancer. Within this group the percentage of elevated (greater than or equal to 4.0 ng/ml) assays increased with UICC clinical stage and was 14.8% (12/81), 23.7% (27/114), 73.1% (190/260) and 20.0% (49/245) for stages I, II, III, IV and X (unstagable due to insufficient data) patients. We have now followed the above 482 stages I, II, III and X patients in whom CEA was performed less than or equal to 3 months after initial surgery at a time when there was no evidence of residual disease, for an average interval of 255 days from date of diagnosis. At present 16.2% (17/105) of patients with elevated CEA values compared to only 4.8% (18/377) of patients with normal values have developed recurrent disease (p less than .0005). There is an association of elevation of CEA postoperatively with different clinical stages of breast cancer. Elevated CEA levels postoperatively are associated with an increased risk of development of recurrent disease in breast cancer patients.
Collapse
|
104
|
Myers RE, Joelsson I, Adamsons K. The effects of isoproterenol on fetal oxygenation. Acta Obstet Gynecol Scand 1978; 57:317-22. [PMID: 29437 DOI: 10.3109/00016347809154024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Infusion of isoproterenol (1 microgram/kg/min, i.v.) into the anesthetized pregnant rhesus monkey near term consistently reduced fetal oxygenation, despite diminishing myometrial activity. The decline in pO2 of fetal arterial blood (mean = 4.3 +/- 2.3 mmHg S.D.) was accompanied by an increase in pCO2 tension (mean = 4.6 +/- 2.7 mmHg) and a decline in pH (mean = 0.04 +/- 0.02 S.D.). There was an increase in heart rate and a widening of pulse pressure in the mother and also in the adequately oxygenated fetus providing evidence that the agent crosses the placenta. The poorly oxygenated fetuses developed bradycardia and hypotension. Administration of isoproterenol directly to the fetus elicited similar changes in the composition of blood, and in blood pressure and heart rate, to those observed after administration of the agent to the mother.
Collapse
|
105
|
Holstein SB, Myers RE. Asphyxia-induced disaggregation of cerebral polyribosomes in rhesus monkey fetuses. J Neuropathol Exp Neurol 1978; 37:85-94. [PMID: 412923 DOI: 10.1097/00005072-197801000-00007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The effects of 3 hours of controlled intrauterine asphyxia (acidotic hypoxia) on the sedimentation patterns of cerebral polyribosomes and on polyribosome supported in vitro protein synthesis were examined in 16 term monkey fetuses. Three outcomes resulted. Four fetuses showed no changes in polyribosome sedimentation profile or in sedimented polyribosome supported in vitro protein synthesis. Four showed changes in sedimentation profiles indicating partial breakdown of polyribosomes and significant decreases in polyribosome supported in vitro protein synthesis. Finally, 8 fetuses showed almost complete disaggregation of cerebral polyribosomes into 80-S monosomal units. This was associated with marked reduction in sedimented ribosomal mediated in vitro portein synthesis. Both the disaggregation of polyribosomes and the associated loss of in virto protein synthesis were related to the severity of the acidosis produced by asphyxia.
Collapse
|
106
|
Adamsons K, Myers RE. Late decelerations and brain tolerance of the fetal monkey to intrapartum asphyxia. Am J Obstet Gynecol 1977; 128:893-900. [PMID: 407796 DOI: 10.1016/0002-9378(77)90059-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Eight monkey fetuses near term were subjected to regulated asphyxia during labor by mechanically constricting the maternal abdominal aorta and diminishing blood flow to the uterus. A magnitude of asphyxia was produced and maintained for an initial three hours that was close to but not sufficient to elicit late decelerations. The asphyxia was then augmented during a fourth hour to cause late decelerations of magnitudes of 5 to 15 per cent of the initial heart rate. After termination of the fourth hour of asphyxia, the fetuses were delivered by hysterotomy and provided intensive care. During the three to nine months of survival after birth, all animals were neurologically intact; on necropsy the brains were free of pathologic changes both grossly and microscopically. These results support the thesis that fetal heart rate monitoring during labor exhibits a sensitivity sufficient to diagnose asphyxia of the fetus of clinical significance before it reaches a magnitude that may cause permanent neurological injury. The results are particularly pertinent to those clinical circumstances where the decreases in intervillous space blood flow brought about by uterine contractions are accentuated due to low maternal blood pressure.
Collapse
|
107
|
Huddleston JF, Perlis HW, Macy J, Myers RE, Flowers CE. The prediction of fetal oxygenation by an on-line computer analysis of fetal monitor output. Am J Obstet Gynecol 1977; 128:599-605. [PMID: 879220 DOI: 10.1016/0002-9378(77)90205-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The deceleration delay index (DDI) is a statistical parameter computed by an on-line system which analyzes fetal monitor output for the temporal relationship between each uterine contraction and any associated deceleration of the fetal heart rate. A similar parameter describing this relationship is known to be quantitatively predictive of fetal oxygenation in the rhesus monkey, a species for which the level of fetal oxygenation is also known to be directly and progressively related to aberrations in the vital signs, to brain damage, and to fetal death. Thus, the DDI should be of significant, practical value in predicting fetal hypoxia at a time early enough to avert severe neonatal depression and/or hypoxic brain damage. A blind clinical trial of 106 parturients is presented which supports this concept by showing the DDI to be highly correlated with another oxygenation-associated parameter, the one-minute Apgar score.
Collapse
|
108
|
Myers RE, Yamaguchi S. Nervous system effects of cardiac arrest in monkeys. Preservation of vision. ARCHIVES OF NEUROLOGY 1977; 34:65-74. [PMID: 402127 DOI: 10.1001/archneur.1977.00500140019003] [Citation(s) in RCA: 369] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Thirteen juvenile monkeys were taught two visual discrimination tasks. After 12 to 24 hours of food deprivation, ten underwent 14-minute episodes of cardiac arrest. Three served as controls. Five of the ten arrested animals survived and were tested in the discrimination box. All continued to perform color and pattern discrimination tasks with one to eight days' delay. All appeared neurologically intact, while brain pathologic examination after 11 to 64 days' survival showed either intact brains or injury restricted to nuclear structures in the brain stem, cerebellar Purkinje cells, and hippocampus. Five animals died 4 to 36 hours after they were resuscitated. Two required prolonged cardiac massage and, despite return of adequate cardiovascular function, died early. A third animal dislodged its arterial catheter and exsanguinated. The remaining two animals, who received infusions of glucose just prior to arrest, developed widespread fasciculations and myoclonic seizures. They became decerebrate and opisthotonic and were killed after 10 and 36 hours. Their brains showed mild edema and widespread necrosis of cortex and basal ganglia. Thus, food-deprived monkeys tolerate 14 minutes of circulatory arrest well and show minimal neurologic and pathologic changes, while administration of glucose just before arrest markedly augments the severity of brain injury and alters its distribution.
Collapse
|
109
|
Myers RE, Stånge L, Joelsson I, Huzell B, Wussow C. Effects upon the fetus of oxygen administration to the mother. A study in monkey. Acta Obstet Gynecol Scand 1977; 56:195-203. [PMID: 17994 DOI: 10.3109/00016347709162120] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Catheters were placed into assorted arteries and veins of 8 anaesthetized pregnant monkeys and their fetuses. Oxygen-sensitive electrodes were also inserted subcutaneously into 3 of the 8 fetuses. Periodic samples of maternal and fetal blood were analyzed for PO2, PCO2 and pH. Oxygen administration to the mothers reliably increased the PO2 of blood taken from the fetal carotid artery and less constantly augmented the PO2 of blood withdrawn from the femoral artery and vein. During 5-6 hours of study the oxygen tension of fetal blood samples of all animals progressively declined. However, the most marked declines in PO2 values at all fetal sites were regularly observed at those times as--or after--the mothers emerged from anaesthesia. At these times also the magnitudes of the increases in fetal blood PO2 brought about by administering oxygen to the mothers diminished markedly and in parallel at all sample sites. The closely similar magnitudes of these various reductions at all fetal sample sties indicate that the basic mechanisms leading to decreased oxygen delivery lie outside the fetuses and are most likely due to decreased maternal blood flow to the uterus because of increased maternal sympathetic stimulation. These reductions in oxygen delivery to the fetus are all regularly reversed by reanasthetizing the mothers. The studies carried out with oxygen-sensitive electrodes demonstrate that administering oxygen to the mothers regularly increases oxygen tension of fetal tissues but after a 50 sec delay.
Collapse
|
110
|
Myers RE. Production of fetal asphyxia by maternal psychological stress. THE PAVLOVIAN JOURNAL OF BIOLOGICAL SCIENCE 1977; 12:51-62. [PMID: 404618 DOI: 10.1007/bf03001799] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Several lines of evidence indicate that maternal psychological stress leads to adverse pregnancy outcome in rhesus monkey. Chronic anxiety causes an increased stillbirth rate, fetal growth retardation, and altered placental morphology. On another time scale, lightening of maternal anesthesia during surgery produces an impaired fetal oxygenation while re-institution of anesthesia ameliorates the fetal asphyxia. The present study, for the first time, demonstrates a relationship between specific episodes of meternal psychological stress and exacerbation of fetal asphyxia in utero. Eight term pregnant rhesus monkeys were anesthetized with sodium pentobarbital. Catheters were placed both into the maternal and the fetal femoral arteries for the continuous recording of blood pressure and heart rate and for the intermittent campling of maternal and fetal blood. An open-ended catheter recorded intrauterine pressures. Following a complete repair, the anesthesia of the mothers was allowed to lighten. As the mothers awakened, the fetuses invariably showed the developemnt of fetal asphyxia. A fetal acidosis developed and the fetal oxygenation and repair of acidosis. Studies while the mothers were fully awake showed the repeated and regular development of episodes of heightened fetal asphyxia produced by episodes of stressful stimulation of the mothers. Episodes of maternal psychological stress led to changes in both fetal vital signs and blood chemical findings. These alterations in fetal state regularly followed the onset of the episodes of psychological stress by 50 seconds. These changes also usually remitted 50 seconds following the termination of the periods of stress. These results demonstrated a direct and unequivocal relationship between meternal psychological stress and fetal asphyxia. It is assumed the maternal stress produces impairments in the circulation to the uterus through an increased sympathetic nervous system activity and a shunting of the maternal blood-flow from the abdominal viscera to other organs as occurs in the fight-orflight reaction.
Collapse
|
111
|
Myers RE, Brann AW. Abruptio placentae in rhesus monkey causing brain damage to the fetus. Am J Obstet Gynecol 1976; 126:1048-9. [PMID: 826158 DOI: 10.1016/0002-9378(76)90704-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
112
|
|
113
|
Myers RE, Ebner FF. Localization of function in corpus callosum: tactual information transmission in Macaca mulatta. Brain Res 1976; 103:455-62. [PMID: 1252937 DOI: 10.1016/0006-8993(76)90444-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Different portions of the corpus callosum were transected in 28 juvenile rhesus monkeys. These animals were then taught a tactual roughness discrimination task while using their right hands and tested for transfer of training while using their left. Animals with some part of the posterior body region of the corpus callosum preserved exhibited intermediate or high levels of transfer of training. Animals with other portions of the commissures preserved, including the splenium, the anterior body, the genu, and/or the anterior commissure but with the posterior body region transected generally failed to show such transfer. It is concluded that tactual information is transmitted between the hemispheres through the posterior body region of the corpus callosum.
Collapse
|
114
|
Gamache FW, Myers RE, Monell E. Changes in local cerebral blood flow following profound systemic hypotension. J Neurosurg 1976; 44:215-25. [PMID: 812963 DOI: 10.3171/jns.1976.44.2.0215] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The authors studied local cerebral blood flow in monkeys rendered hypotensive by infusion of a ganglionic blocking agent. Application of the 14C-antipyrine method demonstrated that the blood flow: 1) normally varies reproducibly from one structure to another within the brain; 2) appears at its lowest level in all structures during the early minutes of a rapid-onset hypotension; 3) maintains the same general rank order of blood flow rate during hypotension as was present during normotension; and 4) returns to supranormal levels immediately following the rapid restoration of blood pressure. The values for local cerebral blood flow remain close-to-normal in some animals and diminish significantly in others during late recovery from hypotension. The close-to-normal values accompany uncomplicated recoveries while the diminished values appear in those animals which became neurologically depressed. Areas of the brain considered predisposed to hypotensive injury did not exhibit depressions in blood flow rate during hypotension more markedly than did other brain areas. The present results are interpreted as strong evidence against the "border zone" hypothesis.
Collapse
|
115
|
Kirshner HS, Blank WF, Myers RE. Changes in cortical subarachnoid fluid potassium concentrations during hypoxia. ARCHIVES OF NEUROLOGY 1976; 33:84-90. [PMID: 814882 DOI: 10.1001/archneur.1976.00500020012003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Seventeen rhesus monkeys underwent 20-minute episodes of hypoxia (mean Po2, 18 to 28 mm Hg). In 14 animals that maintained mean blood pressures greater than 60 mm Hg, increases in potassium concentration averaging greater than 1 mEq/liter were observed in the cortical subarachnoid fluid. These changes were reversible with oxygen administration and were usually not associated with morphologic evidence of brain injury. Cisterna magna fluid, sampled in five animals, showed smaller increases in potassium concentration (mean, 0.3 +/- 0.4 mEq/liter). The arteriovenous difference in potassium concentration was consistently positive, suggesting movement of potassium from blood to brain during hypoxia. The amount of potassium accumulation in the cortical subarachnoid fluid was closely related to the severity of the hypoxia. Threshold Po2 levels, below which potassium changes occurred, were estimated at 29 mm Hg for the arterial blood and 20 mm Hg for the jugular venous blood. Massive potassium accumulations in the cortical subarachnoid fluid (greater than 10 mEq/liter) developed in three animals that sustained severe arterial hypotension during hypoxia.
Collapse
|
116
|
Dambska M, Dydyk L, Szretter T, Wozniewicz J, Myers RE. Topography of lesions in newborn and infant brains following cardiac arrest and resuscitation. Damage to brain and hemispheres. BIOLOGY OF THE NEONATE 1976; 29:194-206. [PMID: 953100 DOI: 10.1159/000240864] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The brain lesions produced by temporary arrest of circulation in a newborn and an 11-month-old infant are described. In the newborn, two periods of arrest occurred, one on the fifth day after birth and the second a few day before death on the sixth week. The older infant suffered a single episode of cardiac arrest at the age of 11 months and survived 8 days. In both cases, postmortem examination revealed lesions in spinal cord, in brain stem, and in cerebral hemispheres. This distribution of damage is compared with the patterns of injury produced experimentally by episodes of partial (hypoxia) and total (anoxia) asphyxia in subhuman primates. The coexistence of hemispheral and brain stem nuclear patterns of pathology indicates that both hypoxia and anoxia had occurred in the present cases.
Collapse
|
117
|
Ginsberg MD, Myers RE. Fetal brain injury after maternal carbon monoxide intoxication. Clinical and neuropathologic aspects. Neurology 1976; 26:15-23. [PMID: 813158 DOI: 10.1212/wnl.26.1.15] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
In a model of brain damage in the rhesus monkey fetus, carbon monoxide inhalation by the mother was used to produce graded fetal hypoxia. Four fetuses with aterial oxygen contents of 2.1 to 2.4 ml per 100 ml during the most severe insult hour appeared neurologically normal, and their brains contained no lesions. A single animal with an intermediate degree of hypoxia was moderately abnormal; its brain showed extensive necrosis of the basal ganglia. Four fetuses with arterial oxygen contents of 1.6 to 1.8 ml per 100 ml during the most severe insult hour showed profound clinical deficits, and on postmortem examination the brains were markedly swollen and showed an extensive hemorrhagic necrosis. The fetal brain exhibits a high threshold to the effects of sustained hypoxia, but once a critical level of deoxygenation is exceeded, extensive brain damage with early death results.
Collapse
|
118
|
Kirshner HS, Blank WF, Myers RE. Brain extracellular potassium activity during hypoxia in the cat. Neurology 1975; 25:1001-5. [PMID: 1237815 DOI: 10.1212/wnl.25.11.1001] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Brain extracellular potassium activity, recorded by a potassium-selective microelectrode technique, was studied in 27 anesthetized, paralyzed cats during hypoxia. Potassium activity remained essentially constant until the arterial pO2 decreased to 20 to 23 mm Hg. If the blood pressure was allowed to decrease during hypoxia, even to the 70 to 100 mm Hg range, the associated increases in potassium activity were accentuated, often to levels greater than 20 mEq per liter. The electrocorticogram regularly became isoelectric by the time the potassium activity reached 6 to 10 mEq per liter. Elevations of the blood pressure with epinephrine injections reversed both the increases in potassium activity and the electrocorticogram flattening. Extracellular potassium homeostasis during hypoxia appears to depend on the maintenance of a normal arterial perfusion pressure.
Collapse
|
119
|
Mueller-Heubach E, Adamsons K, Myers RE. Production of disseminated intravascular coagulation in monkeys by injection of cell-free extracts of placenta. THE MOUNT SINAI JOURNAL OF MEDICINE, NEW YORK 1975; 42:415-23. [PMID: 1081191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
120
|
Comas-Urrutia A, Adamsons K, Myers RE. Response of the primate fetus to intra-amniotic saline injection. Am J Obstet Gynecol 1975; 122:549-54. [PMID: 238395 DOI: 10.1016/0002-9378(75)90047-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The amniotic fluid was replaced with 20 per cent sodium chloride solution during the second half of gestation in 12 pregnant rhesus monkeys. This produced a congealing of the fetal blood in the small umbilical vessels which overlie in the placental chorionic plate. Death of severe asphyxia followed within 20 to 50 minutes in the younger fetuses due to a prompt cessation of umbilical blood flow. During this time, the rise in serum sodium of the fetus was moderate and could not be implicated as the cause of fetal death. In older fetuses, the asphyxia produced by the saline injection was transient and less severe, occasionally permitting survival. The caliber of the affected fetal umbilical blood vessels and their blood flow rates are presented as the principal determinants of the rapidity of development and the severity of the asphyxia produced by saline instillation.
Collapse
|
121
|
Abstract
Twenty-one late-juvenile rhesus monkeys were rendered profoundly hypotensive for 0-, 15-, or 30-minute periods by means of infusion of trimethaphan camsylate. Blood pressure was then restored to prehypotensive levels with phenylephrine infusions. Respiratory gas tensions and pH of arterial blood were maintained within their normal limits throughout experimental and recovery periods. Animals either recovered and showed no sequelae or diet 12 to 48 hours later of cardiorespiratory difficulties, often accompanied by brain swelling. Brain injury and death occurred in 64% of cases when arterial blood pressure was maintained at 25 mm Hg for up to 30 minutes. Multifocal myoclonus, depressed electroencephalographic activity, rises in cisternal cerebrospinal (CSF) pressure, respiratory depression, and characteristic changes in serum and cisternal CSF glucose followed episodes of controlled hypotension. Hypoxia and acidosis occurring during insult or recovery periods rather than hypotension itself probably account for neuropathological sequelae described by others.
Collapse
|
122
|
Gamache FW, dold GM, Myers RE. Changes in cortical impedance and EEG activity induced by profound hypotension. THE AMERICAN JOURNAL OF PHYSIOLOGY 1975; 228:1914-20. [PMID: 1155622 DOI: 10.1152/ajplegacy.1975.228.6.1914] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Fourteen late juvenile monkeys were subjected to a single 30-min episodes of markedhypotension using an infusion of trimethaphan. Afterward, blood pressure was rapidly restored to and maintained at preinsult levels with an intravenous drip of phenylephrine (.02 mg/ml). The respiratory gas tensions and pH of the arterial blood weremaintained within normal limits at all times. During the 30-min episodes, the cortical electrical impedence increased by a mean of 27% while the EEG frequencies and amplitudes decreased by 47 and 30%, respectively. The impedance and EEG activity generally altered at the same time but inversely to one another, although, on restoration of blood pressure, the impedance recovered within minutes while the EEG activity returned to normal only after 1 h. The impedance values and EEG activity of those animals that eventually died began to diverge significantly from the values of theanimals that were to survive at about 2.5 h after restoration of blood pressure.
Collapse
|
123
|
Abstract
Fifteen pregnant rhesus monkeys near term were anesthetized with pentobarbital. Catheters were placed into the right femoral arteries of the mother and fetus, the fetuses being retained in utero. After repair of all incisions, the mothers were placed on their sides and allowed to recover from anesthesia. As they awakened, their fetuses regularly developed blood chemical and, frequently, vital signs changes indicative of deepening asphyxia. In eight cases, anesthesia was reinstated with intravenous pentobarbital, 30 mg. per kilogram. This caused an immediate and significant improvement in oxygenation of the fetus in all instances. The remaining animals were transferred to restraining chairs where the blood chemical and cardiovascular statuses of the mothers and fetuses were followed over the next 3 to 72 hours. During this time, the mothers, fully awake, were subjected to both "contrived" and "incidental" episodes of psychological stress stimulation. In the majority of instances, these periods of stress to the mothers caused episodes of bradycardia and hypotension in their fetuses. These induced vital signs changes of the fetuses appeared regularly about 50 seconds after the beginning of the periods of stress stimulation of the mother. Similarly, the vital signs changes frequently began returning toward more normal values with 1 to 2 minutes after the alleviation of maternal stress. Blood samples drawn in single cases before, during, and after recovery from bradycardia identified an associated increase in asphyxia of the fetuses. These episodic aggravations of the already existent fetal asphyxia of the fetuses. These episodic aggravations of the already existent fetal asphyxia brought about by stress stimulation of the mother are interpreted as resulting from activation of the maternal sympathetic nervous system causing vasoconstriction throughout the abdominal viscera and an accompanying retardation in intervillous space perfusion.
Collapse
|
124
|
Brann AW, Myers RE. Central nervous system findings in the newborn monkey following severe in utero partial asphyxia. Neurology 1975; 25:327-38. [PMID: 235749 DOI: 10.1212/wnl.25.4.327] [Citation(s) in RCA: 141] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Seizures, brain swelling, and cortical necrosis have been observed in the newborn rhesus monkey following a 2 to 4-hour period of intrauterine partial asphyxia produced by halothane-induced maternal hypotension. These clinical and neuropathologic findings are similar to those seen in human newborn infants who have experienced an episode of intrauterine asphyxia from such a cause as premature placental separation. The present study strongly indicates that fetal partial asphyxia, from any cause, in the absence of fetal circulatory collapse or fetal head compression, may be the primary event that sets in motion a vicious cycle of brain swelling and impaired cerebral blood flow, leading finally to cerebral necrosis.
Collapse
|
125
|
Abstract
Term monkey fetus 1620 sustained 50 min of rapidly developing severe asphyxia which began immediately after its in utero version. The arterial blood pO2 decreased from a normal value of 34 to 11-12 mm Hg while the blood pH fell from 7.35 to 6.70. During this asphyxia, hemoglobin-oxygen saturations below 5% were recorded. The complete collapse of the umbilical circulation several minutes prior to the reoxygenation of the fetus added an episode of total asphyxia. With reoxygenation following delivery, fetal cardiovascular performance improved rapidly though over an hour was required for recovery from the severe acidosis. The animal prospered but was found moribund on the 13th postnatal day due to dehydration. Brain examination after euthanasia revealed severe paracentral cortical and basal ganglia damage. Damage also appeared symmetrically in nuclei in the lower brain stem and in thalamus. These three zones of injury are attributed to the partial, the partial combined with the total, and the total asphyxia, respectively. The present case makes clear that compression of the umbilical cord may cause damage of a variety of types depending on the severity and duration of the asphyxia induced. It also demonstrates the possibility of recovery from a systemic acidosis where the pH values have fallen to levels below 6.70 for up to an hour.
Collapse
|
126
|
Rivera A, Martinez-de Jesus J, Myers RE. Changes in tissue glycogen of recovering asphyxiated newborn monkeys. BIOLOGY OF THE NEONATE 1975; 27:279-88. [PMID: 810187 DOI: 10.1159/000240784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Newborn rhesus monkeys were used to investigate the relation between the duration of total asphyxia and the magnitude of the postasphyctic cerebral glycogen hyper-deposition response. The latter has been observed to occur following episodes of total asphyxia lasting 12.5 min and to be maximal at 12 h into the recovery period. The changes in glycogen contents of other vital organs were also studied. A minimum duration of 9 min of total asphyxia was required for the first elicitation of the cerebral glycogen hyperdeposition response. The magnitude of the response once elicited did not vary whatever the duration of the asphyxia beyond 9 and up to 30 min. During the actual episodes of total asphyxia, the glycogen content of the brain diminished more rapidly and completely than did that of kidney or heart. The hepatic, pulmonary and muscle glycogen contents did not change significantly either during asphyxia or during the recovery period.
Collapse
|
127
|
Kopf GS, Mirvis DM, Myers RE. Central nervous system tolerance to cardiac arrest during profound hypothermia. J Surg Res 1975; 18:29-34. [PMID: 235042 DOI: 10.1016/0022-4804(75)90138-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
128
|
Marich KW, Treytl WJ, Hawley JG, Peppers NA, Myers RE, Glick D. Improved Q-switched ruby laser microprobe for emission spectroscopic element analysis. JOURNAL OF PHYSICS E: SCIENTIFIC INSTRUMENTS 1974; 7:830-4. [PMID: 4423270 DOI: 10.1088/0022-3735/7/10/015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
129
|
Myers RE, Symchych P, Strauss L, Comas A, Figueroa-Longo J, Kerenyi T, Adamsons K. Morphologic changes of uterine wall following intra-amniotic injection of hypertonic saline in the rhesus monkey. Am J Obstet Gynecol 1974; 119:877-88. [PMID: 4210246 DOI: 10.1016/0002-9378(74)90002-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
130
|
Ginsberg MD, Myers RE, McDonagh BF. Experimental carbon monoxide encephalopathy in the primate. II. Clinical aspects, neuropathology, and physiologic correlation. ARCHIVES OF NEUROLOGY 1974; 30:209-16. [PMID: 4204853 DOI: 10.1001/archneur.1974.00490330017003] [Citation(s) in RCA: 87] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
131
|
Ginsberg MD, Myers RE. Experimental carbon monoxide encephalopathy in the primate I. Physiologic and metabolic aspects. ARCHIVES OF NEUROLOGY 1974; 30:202-8. [PMID: 4204852 DOI: 10.1001/archneur.1974.00490330010002] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
132
|
Roux JF, Myers RE. In vitro metabolism of palmitic acid and glucose in the developing tissue of the rhesus monkey. Am J Obstet Gynecol 1974; 118:385-92. [PMID: 4203898 DOI: 10.1016/s0002-9378(16)33798-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
133
|
Ginsberg MD, Myers RE. Fetal brain damage following maternal carbon monoxide intoxication: an experimental study. Acta Obstet Gynecol Scand 1974; 53:309-17. [PMID: 4440458 DOI: 10.3109/00016347409157744] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
134
|
Myers RE, Swett C, Miller M. Loss of social group affinity following prefrontal lesions in free-ranging macaques. Brain Res 1973; 64:257-69. [PMID: 4205547 DOI: 10.1016/0006-8993(73)90182-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
135
|
Myers RE. Two classes of dysergic brain abnormality and their conditions of occurrence. ARCHIVES OF NEUROLOGY 1973; 29:394-9. [PMID: 4202406 DOI: 10.1001/archneur.1973.00490300056007] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
136
|
Yamaguchi S, Myers RE. Prefrontal lobe functions and the neocortical commissures in monkeys. Exp Brain Res 1973; 18:119-30. [PMID: 4203198 DOI: 10.1007/bf00234717] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
137
|
Franzen EA, Myers RE. Age effects of social behavior deficits following prefrontal lesions in monkeys. Brain Res 1973; 54:277-86. [PMID: 4196749 DOI: 10.1016/0006-8993(73)90049-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
138
|
|
139
|
Franzen EA, Myers RE. Neural control of social behavior: prefrontal and anterior temporal cortex. Neuropsychologia 1973; 11:141-57. [PMID: 4197348 DOI: 10.1016/0028-3932(73)90002-x] [Citation(s) in RCA: 122] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
140
|
Myers RE, Mueller-Heubach E, Adamsons K. Predictability of the state of fetal oxygenation from a quantitative analysis of the components of late deceleration. Am J Obstet Gynecol 1973; 115:1083-94. [PMID: 4632417 DOI: 10.1016/0002-9378(73)90557-7] [Citation(s) in RCA: 98] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
141
|
|
142
|
Selzer ME, Myers RE, Holstein SB. Unilateral asphyxial brain damage produced by venous perfusion of one carotid artery. Neurology 1973; 23:150-8. [PMID: 4631497 DOI: 10.1212/wnl.23.2.150] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
|
143
|
Myers RE. Threshold values of oxygen deficiency leading to cardiovascular and brain pathological changes in term monkey fetuses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1973; 37:1047-53. [PMID: 4203245 DOI: 10.1007/978-1-4684-5089-7_47] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
144
|
Myers RE, Panigel M. Experimental placental detachment in the rhesus monkey: changes in villous ultrastructure. J Med Primatol 1973; 2:170-89. [PMID: 4203710 DOI: 10.1159/000460320] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
145
|
Myers RE, Valerio MG, Martin DP, Nelson KB. Perinatal brain damage: porencephaly in a cynomolgous monkey. BIOLOGY OF THE NEONATE 1973; 22:253-73. [PMID: 4201063 DOI: 10.1159/000240558] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
An infant monkey exhibited the clinical evidences of severe brain injury following birth. It was blind, partially deaf and showed severe motor disabilities. Postmortem brain examination at 1½ years of age revealed bilateral porencephalic defects centered well within the supply territories of the middle cerebral arteries. Other foci of injury suggestive of asphyctic brain damage appeared in the remaining, better preserved tissues. It is proposed that such porencephalic defects result from zones of cerebral necrosis and liquifaction of intermediate size produced by <i>in utero </i>fetal asphyxia. The body and organ growth retardation associated with the severe perinatal brain injury is also briefly described.
Collapse
|
146
|
Myers RE. The pathology of the rhesus monkey placenta. ACTA ENDOCRINOLOGICA. SUPPLEMENTUM 1972; 166:221-57. [PMID: 4627295 DOI: 10.1530/acta.0.071s221] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
147
|
Selzer ME, Myers RE, Holstein SB. Maturational changes in brain water and electrolytes in rhesus monkey with some implications for electrogenesis. Brain Res 1972; 45:193-204. [PMID: 4627595 DOI: 10.1016/0006-8993(72)90226-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
148
|
Myers RE. The gross pathology of the rhesus monkey placenta. THE JOURNAL OF REPRODUCTIVE MEDICINE 1972; 9:171-98. [PMID: 4627809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
149
|
Ginsberg MD, Myers RE. The topography of impaired microvascular perfusion in the primate brain following total circulatory arrest. Neurology 1972; 22:998-1011. [PMID: 4628244 DOI: 10.1212/wnl.22.9.998] [Citation(s) in RCA: 95] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
|
150
|
Miller JR, Myers RE. Neuropathology of systemic circulatory arrest in adult monkeys. Neurology 1972; 22:888-904. [PMID: 4628387 DOI: 10.1212/wnl.22.8.888] [Citation(s) in RCA: 92] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
|