Biomedical subjects

I Goldstein

Publications and source records attributed to I Goldstein.

At least 217 records · Page 12Linked to original sources

PubMed1988

Overview of types and results of vascular surgical procedures for impotence.

The pathophysiologic basis for impotence, as related to possible vascular surgical procedures, is briefly discussed. In order to better classify criteria for selection and results of surgery, various relevant terms are defined. In the authors experience, conventional procedures for venous ligation have restored potency in only about 20% of cases. An additional 60% respond when given supplemental papaverine therapy. A new surgical procedure for venous ligation, which allows access to the cavernosal veins, has produced very promising results in a small pilot series. Arterial reconstruction has been effective in about 80% of a highly selected group of patients with arteriogenic impotence.

Erectile Dysfunction↗

PubMed1988

Subnormal cerebellum in fetuses with spina bifida.

The results of a prospective ultrasound study of the posterior fossa structures in 19 fetuses with spina bifida are reported. The transverse cerebellar diameter is below the normal limits and the cisterna magna is obliterated in all cases. Decreased cerebellar size and failure to visualize the cerebellum appear to be specific findings for spina bifida since they are not present in a group of 17 fetuses with isolated hydrocephalus. The results of this study indicate that ultrasound investigation of the posterior fossa may prove useful in the prenatal diagnosis of spina bifida.

Arnold-Chiari Malformation↗

PubMed1988

Sonographic assessment of the distal femoral and proximal tibial ossification centers in the prediction of pulmonic maturity in normal women and women with diabetes.

A noninvasive method for the assessment of fetal pulmonic maturity via the sonographic characterization of fetal distal femoral and proximal tibial epiphyseal ossification centers was evaluated. The study population included 82 patients in the third trimester of pregnancy, 47 of whom had uncomplicated gestations, while 35 had insulin-dependent diabetes. In uncomplicated pregnancies a distal femoral epiphysis measuring greater than or equal to 3 mm in the axial plane or the sonographic identification of a proximal tibial epiphysis of any dimension correlated with pulmonic maturity. The combination of a distal femoral epiphysis greater than or equal to 3 mm and the presence of a proximal tibial epiphysis was highly correlated with a lecithin/sphingomyelin ratio greater than or equal to 2:1 (sensitivity 100%, specificity 63%, negative predictive value 100%, and false-negative rate 0%). The Kappa value (K) for testing the agreement between ultrasound results and amniocentesis results was 0.39 (p less than 0.002). In diabetic pregnancies neither a distal femoral epiphysis greater than or equal to 3 mm nor a proximal tibial epiphysis of any dimension correlated precisely with the presence of phosphatidyl glycerol in the amniotic fluid. However, the combination of a distal femoral epiphysis greater than or equal to 3 mm and a proximal tibial epiphysis greater than or equal to 2 mm improved the prediction of phosphatidyl glycerol (sensitivity 83%, specificity 79%, negative predictive value 96%, false-negative rate 17%). The K value in this instance was 0.36 (p greater than or equal to 0.19). It is concluded that the sonographic assessment of the distal femoral and proximal tibial epiphyses and their dimensions in the axial plane may be useful as markers for pulmonic maturity in uncomplicated pregnancies.

Epiphyses↗

PubMed1988

Ultrasonographic assessment of gestational age with the distal femoral and proximal tibial ossification centers in the third trimester.

A prospective sonographic evaluation of the distal femoral and proximal tibial epiphyseal ossification centers in 228 normal pregnant women was carried out from 28 to 40 weeks' gestation. The mean gestational age at which the distal femoral epiphysis and proximal tibial epiphysis were imaged was 34 and 38 weeks, respectively. The distal femoral epiphysis was not identifiable before 28 weeks but was observed in 72% of fetuses at 33 weeks and in 94% of fetuses at 34 weeks' gestation. The presence of a distal femoral epiphysis measuring 1 or 2 mm was associated with a gestational age of greater than 33 weeks in 87.0% of fetuses, whereas a distal femoral epiphysis measuring greater than or equal to 3 mm was associated with a gestational age greater than 37 weeks in 85% of fetuses. The proximal tibial epiphysis, which was absent before 34 weeks' gestation, was observed in 56% of fetuses at 36 weeks, in 80% of fetuses at 37 weeks, and in 100% of fetuses at 39 weeks of gestation. The presence of a proximal tibial epiphysis of 1 or 2 mm was associated with a gestational age of greater than 36 weeks in 88% of fetuses, whereas a proximal tibial epiphysis greater than or equal to 3 mm was associated with a gestational age of greater than 38 weeks in 94% of fetuses. The sonographic evaluation of distal femoral epiphysis/proximal tibial epiphysis can be used as independent markers for estimation of gestational age during the third trimester, a period in which standard fetal biometric estimates of gestational age are least accurate.

Epiphyses↗

PubMed1988

Griffonia simplicifolia I: fluorescent tracer for microcirculatory vessels in nonperfused thin muscles and sectioned muscle.

Previous studies on mice have revealed that the Griffonia simplicifolia I (GSI) lectin selectively binds to capillaries in a number of microvascular beds. These observations suggest that the lectin might be a suitable microvascular marker for physiological studies of skeletal muscle, particularly when fluorescent visualization of vessels is desired independently of their perfusion status. Since species and strain heterogeneity has been demonstrated for certain lectins associated with the microcirculatory vessels, lectin binding was studied in a number of muscles taken from the major species of mammals used for experimental purposes. Staining of cryostat sections confirmed the utility of GSI as a marker for capillaries from muscle of mice, rats, hamsters, rabbits, dogs, and monkeys. Differential staining of arterioles and veins was revealed by double labeling with GSI and antisera to Factor VIII-related antigen. Double labeling for GSI binding and alkaline phosphatase activity revealed that the GSI method detects many more capillaries and terminal arterioles than does the alkaline phosphatase method. GSI binding to unfixed whole mounts of thin skeletal muscles (hamster cheek pouch, mouse diaphragm, and rat cremaster) was studied to determine whether the GSI lectin would be a suitable marker for intravital studies. An extensive microvascular bed, including terminal arterioles, venules, and capillaries, was revealed which could be visualized in the complete absence of perfusion with fluorescent markers. These observations suggest that the GSI lectin may be extremely useful as a probe for the microcirculation of skeletal muscle in many types of physiological experiments.

Animals↗

PubMed1988

Fetal body and breathing movements as predictors of intraamniotic infection in preterm premature rupture of membranes.

A prospective study of fetal behavior in cases complicated with preterm premature rupture of membranes was conducted in 41 patients. The length of time and the number of fetal breathing and gross body movements were correlated with the amniotic fluid culture results. An episode of fetal activity (body movements and breathing movements) of greater than or equal to 30 seconds during 30 minutes of observation was associated with the absence of intraamniotic infection in 100% of the cases. On the other hand, the absence of fetal breathing movements and gross body movements of less than a 50 second duration during 30 minutes of observation was associated with positive amniotic fluid cultures in all cases. If an episode of fetal breathing movements was present but lasted less than 30 seconds and/or the total time of gross body movements was greater than 50 seconds, 64% of patients had an intraamniotic infection.

Amniocentesis↗

PubMed1988

Sonographic appearance of the fetal heel ossification centers and foot length measurements provide independent markers for gestational age estimation.

The sonographic measurement of fetal foot length and the assessment of fetal heel ossification centers were conducted as an additional method for the estimation of gestational age. Such an approach is particularly desirable in cases where measurements of other biometric parameters are precluded, for example, in diseases such as anencephaly, hydrocephalus, and short limb dysplasia. A significant correlation was found between fetal foot length and gestational age (r = 0.9, p less than 0.0001) and between fetal foot length and femur length (r = 0.9, p less than 0.0001). Ossification centers of the calcaneus and talus were all present by the twenty-second week of gestation. However, their measurements discriminated between gestational ages of 18 to 22 weeks. The utilization of fetal foot length and heel ossification centers will serve as a useful adjunct in the estimation of gestational age and possibly in the diagnosis of diseases affecting the fetal foot.

Calcaneus↗

PubMed1988

Psychophysiological reactivity to mental arithmetic stress in black and white normotensive men.

Racial differences in physiological responses to a behavioral stressor were examined. Thirty-four Black and 42 White male normotensives 34 to 55 years old (mean age = 43.01 years) performed a mental arithmetic task while blood pressure, heart rate, and skin conductance were recorded. Compared to Whites, Blacks had significantly higher baseline diastolic blood pressure (77.93 mm Hg vs. 73.11 mm Hg) and lower skin conductance levels (11.08 microS vs. 12.25 microS). These effects persisted during performance of the mental arithmetic task. However, when baseline differences were covaried, there were no significant physiological effects associated with the task. Analysis of changes in response levels from baseline revealed a nonsignificant trend for Whites to show greater increases in systolic blood pressure than Blacks. There were no significant race or family history effects. Further, task performance did not influence the outcome. Failure to demonstrate greater cardiovascular reactivity in Blacks and all men with a positive family history of hypertension is discussed with regard to possible "survivor effects" and methodologic limitations.

Adult↗

PubMed1988

Cholinergic neurotransmission in human corpus cavernosum. I. Responses of isolated tissue.

To investigate the role of cholinergic neurotransmission in erection, human penile corpus cavernosum tissue was studied. Electrical stimulation of strips of corpus cavernosum suspended in an organ chamber induced contractions and relaxations that were blocked by tetrodotoxin. The contractions also were blocked by bretylium and prazosin. Norepinephrine and phenylephrine contracted the isolated strips and this response was prevented by prazosin. Electrical stimulation-induced relaxations were enhanced by bretylium and physostigmine and partially blocked by atropine. The effect of atropine, but not that of physostigmine, was prevented by bretylium. Corporal strips contracted with norepinephrine relaxed to acetylcholine; this effect was blocked by atropine and enhanced by physostigmine. Strips lacking endothelium contracted normally with norepinephrine, but the relaxation caused by acetylcholine was virtually abolished. Thus endothelium lining the lacunar spaces within human corpus cavernosum is required for the relaxation caused by exogenous acetylcholine. There may be three neurotransmitter effector systems that control corpus cavernosum smooth muscle tone: adrenergic (excitatory), cholinergic (inhibitory), and nonadrenergic noncholinergic (inhibitory). Cholinergic nerves do not dilate or constrict directly the smooth muscle but may modulate other neuroeffector systems and/or the endothelium.

Acetylcholine↗

PubMed1988

Cholinergic neurotransmission in human corpus cavernosum. II. Acetylcholine synthesis.

Physiological and histochemical evidence indicates that cholinergic nerves may participate in mediating penile erection. Acetylcholine synthesis and release was studied in isolated human corporal tissue. Human corpus cavernosum incubated with [3H )choline accumulated [3H]choline and synthesized [3H]acetylcholine in a concentration-dependent manner. [3H]Acetylcholine accumulation by the tissue was inhibited by hemicholinium-3, a specific antagonist of the high-affinity choline transport in cholinergic nerves. Transmural electrical field stimulation caused release of [3H]acetylcholine which was significantly diminished by inhibiting neurotransmission with calcium-free physiological salt solution or tetrodotoxin. These observations provide biochemical and physiological evidence for the existence of cholinergic innervation in human corpus cavernosum.

Acetylcholine↗

PubMed1988

Simultaneous recording of fetal breathing movements and body movements in twin pregnancy.

Fetal breathing and body movements were simultaneously evaluated in twin pregnancies in order to determine to what extent these activities occur in a synchroneous pattern in both twin fetuses and if fetal position, presentation or sex have an influence on their behavior. Thirty healthy pairs of twins at 34-37 weeks of gestation were studied. Twenty-six percent of fetal body movements and 49% of breathing movements occurred simultaneously in both fetuses. The overall total simultaneous fetal activity rate was 53.3%. The length of breathing movements and total activity (summation of breathing and body movements) of the fetuses positioned on the right side of the uterus were significantly longer than in fetuses positioned on the left side of the uterus (p = 0.002) and (p less than 0.0001) respectively. This was also true for subgroups where only fetuses in the same presentation or of the same sex were compared. It is concluded that the fetus positioned on the right side of the uterus is more active and that fetal sex or presentation had no significant effect on intrauterine fetal activity in twin pregnancies.

Female↗

PubMed1988

Diabetic penile neuropathy.

In vitro studies strongly suggest the presence of autonomic neuropathy in impotent patients with diabetes mellitus. Morphologic studies reveal structural damage to the penile autonomic nerves. Biochemical, histochemical, and immunohistochemical evidence suggests a general depletion of the adrenergic, cholinergic, and NANC neurotransmitter systems that control penile erection. These in vitro studies on human tissue are, however, not performed with appropriate control tissue from potent patients with diabetes mellitus. For this reason, it is important to study diabetic penile neuropathy by developing animal models. The investigative work by Crowe and Fani in streptozocin-induced diabetes mellitus is encouraging, but more research efforts should be directed toward this objective. Clinical testing is needed to assess the functionality of the autonomic corporal nerves objectively. At present, the patient's erectile response to an intracavernosal injection of vasoactive agents is being studied. If there is an isolated autonomic neuropathy, as commonly exists in young patients with spinal cord injury, the erectile response to the intracavernosal injection is immediate and complete. This intracavernosal injection test for autonomic neuropathy records hemodynamic and not neurophysiologic responses. In patients with an accompanying hemodynamic impairment, such as cavernosal artery insufficiency or corporal veno-occlusive dysfunction, as commonly exists in patients with diabetes mellitus, the hemodynamic erectile response to the intracavernosal injection is impaired, and the presence or absence of autonomic neuropathy is subsequently masked.

Animals↗

PubMed1988

Sonographic evaluation of the normal developmental anatomy of fetal cerebral ventricles: I. The frontal horn.

A prospective ultrasound study was conducted in 179 normal pregnant women with gestational ages ranging from 15-40 weeks. Several biometric measurements were obtained throughout pregnancy, including the cerebrofrontal horn distance of the lateral ventricle, the frontal hemispheric width, and the calculated ratio of cerebrofrontal horn distance/hemispheric width. Curvilinear relationships were found between cerebrofrontal horn distance and gestational age (R2 = 0.597; P less than .0001) and between cerebrofrontal horn distance and the biparietal diameter (R2 = 0.618; P less than .0001). In addition, a curvilinear relationship existed between cerebrofrontal horn distance/hemispheric width ratio and gestational age (R2 = 0.492; P less than .0001) and biparietal diameter (R2 = 0.930; P less than .0001). These data represent a comprehensive characterization of normal growth of the fetal frontal horns. They provide a method by which variations from the norm can be assessed and early prenatal diagnosis of developmental anomalies of the fetal ventricular system can be made.

Cerebral Ventricles↗

PubMed1988

Local control of penile erection. Nerves, smooth muscle, and endothelium.

This article reviews the state of knowledge on the neurologic and non-neurologic mechanisms that control the tone of the corpus cavernosum trabecular smooth muscle and the smooth muscles of penile arteries and veins. It includes discussion of the role of the adrenergic, the cholinergic, and the nonadrenergic noncholinergic neuroeffector systems as well as the potential role of the vascular endothelium and prostaglandins in the control of penile erection.

Animals↗

PubMed1988

Sonographic assessment of the fetal frontal lobe: a potential tool for prenatal diagnosis of microcephaly.

A prospective ultrasound evaluation of 150 normal pregnant women was conducted between 15 and 40 weeks' gestation. A variety of biometric measurements were obtained that included measurements of the frontal lobe distance (the anterior edge of the frontal horns of the lateral ventricles to the frontal bone) and the thalamic frontal lobe distance (measured from the posterior edge of the thalami to the frontal bone). Analysis of these data revealed a high degree of correlation between the gestational age and the frontal lobe distance (R2 = 0.89, p less than 0.0001), and between the gestational age and thalamic frontal lobe distance (R2 = 0.93, p less than 0.0001). Similarly, a high degree of correlation was also found between the biparietal diameter and the frontal lobe distance (R2 = 0.95; p less than 0.0001), between the biparietal diameter and the thalamic frontal lobe distance (R2 = 0.90, p less than 0.0001), and between the frontal lobe distance and the thalamic frontal lobe distance (R2 = 0.92, p less than 0.0001). The relationships between femur length and frontal lobe distance (R2 = 0.89, p less than 0.0001) and between the femur length and the thalamic frontal lobe distance (R2 = 0.945, p less than 0.0001) were also evaluated. Nomograms for the relationships between gestational age and frontal lobe distance and thalamic frontal lobe distance were generated and included the mean +/- SD and the percentile distributions. Growth of the frontal lobe was best described by a first-degree linear equation. The results of this study demonstrate the pattern of growth of the frontal lobe and the high rate of correlation between growth of the frontal lobe and the gestational age and the biparietal diameter. These findings offer a potential method by which the decreasing size of the frontal lobe, as shown in three cases described herein, can be evaluated prenatally and thus serve as a useful tool in the prenatal diagnosis of microcephaly.

Female↗

PubMed1987

Cerebellar measurements with ultrasonography in the evaluation of fetal growth and development.

A prospective study of ultrasonography was conducted in 371 normal pregnant women, with gestational ages ranging from 13 weeks to 40 weeks. Several biometric measurements were obtained including the transverse cerebellar diameter, the biparietal diameter, the occipitofrontal diameter, and the calculated head circumference. Curvilinear relationships were found between the transverse diameter of the cerebellum (measured in millimeters), and the gestational age (R2 = 0.948; P = 0.001), the biparietal diameter (R2 = 0.956; P = 0.0001), and the head circumference (R2 = 0.969; P = 0.0001). A nomogram of cerebellar measurements estimating gestational age and predicting the biparietal diameter and head circumference was generated. Throughout pregnancy the establishment of normative cerebellar measurements allows for the estimation of gestational age that is independent of the shape of the fetal head and offers potential for evaluation of abnormal fetal growth and anomalous development of the central nervous system.

Anthropometry↗

PubMed1987

Fetal cerebellar growth unaffected by intrauterine growth retardation: a new parameter for prenatal diagnosis.

Nineteen pregnant women with a clinical suspicion of intrauterine growth retardation and with gestational age confirmed by early ultrasound examination were referred to our departments for sonographic evaluations. Multiple biometric parameters were obtained, including the transverse cerebellar diameter by use of the electronic calipers of the machine. A prenatal diagnosis of intrauterine growth retardation was made in all cases based on: (1) the transverse cerebellar diameter being consistently correlated with gestational age as predicted by the last menstrual period, whereas most of the other measurements were consistently discrepant with the transverse cerebellar diameter by more than 2.5 weeks (i.e., more than 2 SD above the mean), and (2) the estimated fetal weight of all fetuses being equal to or less than the tenth percentile for gestational age. Neonatal examination confirmed all fetuses to be growth retarded with birth weights at or below the tenth percentile for gestational age. These findings indicate that growth of the transverse cerebellar diameter is unaffected by intrauterine growth retardation; thus this sonographic measurement may serve as an independent and reliable correlate of gestational age against which potential deviations of growth may be compared.

Cerebellum↗

PubMed1987

Characterization of penile erectile states using external computer-based monitoring.

The states of penile erection have not been quantified to establish their relationship to intracorporal fluid pressure and to soft tissue constraint. Computer-based circumferential rigidity sensing during erectile cycles now permits circumferential size and rigidity characterization. Measurements during dynamic infusion cavernometry and cavernosography relate intracorporal pressure and axial rigidity to circumference and circumferential rigidity characterization. Tumescence/rigidity coupling and tissue elastic contributions are identified from the combined data.

Compliance↗