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Biomedical subjects

A Shkolnik

Publications and source records attributed to A Shkolnik.

At least 37 records · Page 2Linked to original sources
PubMed1986

Neonatal aortic thrombosis: recent experience.

To evaluate the course, use of diagnostic modalities, management, and outcome of aortic thrombosis associated with umbilical artery catheterization, we reviewed 20 cases of aortic thrombosis diagnosed by ultrasonography (n = 16) or aortography (n = 4) over 4 years. Fourteen of 20 infants had severe perinatal asphyxia, suggesting that asphyxia predisposes to aortic thrombosis. Ultrasonography provided information about the size, location, and configuration of the thrombus and was useful in following thrombus size with therapy. Radionuclide renography-scintigraphy demonstrated abnormal renal function in all 11 patients scanned. Six patients with minor thrombosis (hypertension as the only sign) improved without specific therapy. Nine infants had moderate thrombosis (multiple signs but normal urine output); all survived with a variety of therapies; two were not given anticoagulant or fibrinolytic agents; three improved with heparin alone; and one had surgery without recurrence of the thrombus. Resolution of moderate thrombosis followed streptokinase therapy in two of three infants. All five babies with anuria from major thrombosis died. Hepatic infarction associated with aortic thrombosis was found in three of three autopsies.

Aorta, Abdominal↗
PubMed1985

Disappearance of dextran 70,000 from plasma of hamadryas baboons.

Evans Blue (EB), [131I]human albumin and [14C]dextran 70,000 were injected into three water repleted and water depleted hamadryas baboons, in order to evaluate the permeability of their capillary bed under these conditions. The rate of disappearance of dextran from the plasma is significantly higher than that of the other markers, despite its relatively high molecular weight. Half-life values of EB and albumin in water depleted baboons were significantly higher than values in water repleted animals. Inulin and dextran showed no significant difference before or after dehydration. Chromatography of urine and plasma samples on columns of Sephadex G-75 showed that dextran passed the glomerular capillaries and is excreted into the urine with its same original molecular size. The permeability of capillary beds to dextran 70,000 is negligible. The fact that the kidneys excrete dextran means that dextran 70,000 is not a useful marker for calculating the capillary permeability in hamadryas baboons.

Animals↗
PubMed1985

Sonographic recognition of agenesis of the corpus callosum.

Agenesis of the corpus callosum may be diagnosed successfully in vivo when sonograms demonstrate absence of corpus callosum; absence of pericallosal and cingulate sulci; "sunburst" pattern of sulci along the medial surface of the hemisphere; wide interhemispheric fissure; elevation of the third ventricle; small, laterally positioned frontal horns with concave medial borders; large, laterally positioned and inverted cingulate gyri; and Probst lateral callosal bundles. Comparison of necropsy specimens with sonograms from eight patients with callosal agenesis illustrates the anatomic basis for these diagnostic features.

Abnormalities, Multiple↗
PubMed1985

Gallium scintigraphy in American Burkitt lymphoma: accurate assessment of tumor load and prognosis.

The radiographic evaluation of 18 children with American Burkitt lymphoma was analyzed retrospectively. Pretreatment gallium-67 (67Ga) scintigraphy, done in 12 children, was interpreted as normal in only three children. In the other nine children, 67Ga scans demonstrated more sites of tumor involvement than any other method. Pretreatment abdominal computed tomography and sonography were valuable for evaluating ascites, density and size of the liver and spleen, renal involvement, and the presence of lymphomatous soft-tissue masses. Sonography was less accurate at localizing tumor deposits, but more sensitive to small amounts of ascites. Any of these methods is an effective way of following response to chemotherapy. However, it appears that sequential 67Ga scintigraphy may have significant prognostic value, as those children whose scintigrams reverted to normal within 6 months have survived.

Adolescent↗
PubMed1985

Applications of ultrasound in the neonatal abdomen.

In this article, the uses of real-time sonography relative to evaluation of the neonatal abdomen are presented. Included are some of the more recent applications that, to a great extent, have evolved because of the ease with which portable real-time examination of the fragile or compromised infant can be accomplished.

Adrenal Gland Diseases↗
PubMed1984

Homeostatic responses to water deprivation or hemorrhage in lactating and non-lactating Bedouin goats.

Three lactating and three non-lactating black Bedouin goats were subjected to four days of water deprivation or to hemorrhage. Four days of water deprivation caused body wt losses of 32 and 23% and plasma volume losses of 30 and 34% in lactating and non-lactating goats respectively. Plasma osmolality increased 17 and 15% in lactating and non-lactating goats. Plasma arginine vasopressin concentration rose from about 5 pg/ml to a mean of 36 pg/ml. Plasma renin activity increased from about 0.7 ng/ml/hr to a mean of 3.45 ng/ml/hr in lactating and to 3.15 ng/ml/hr in non-lactating goats. At 4.5 hr post-rehydration plasma osmolality and plasma vasopressin concentration were back to normal in non-lactating, but still elevated in lactating goats. Plasma renin activity increased after rehydration. Rapid blood volume loss of 21-28% increased plasma vasopressin concentration to 16-35 pg/ml in non-lactating and to 70 or greater than 500 pg/ml in lactating goats. It is concluded that black Bedouin goats are well adapted to endure severe dehydration and rapid rehydration, but that they (especially lactating animals) react strongly to rapid volume depletion.

Animals↗
PubMed1984

Milk composition and yield of the black Bedouin goat during dehydration and rehydration.

Milk composition and yield were measured in the black Bedouin goat during 4 d of dehydration followed by 2 d of rehydration. During this time the goats were exposed to strong solar radiation with no access to shade; all of these conditions occur commonly in the desert. Milk yield, initially similar to that found in the desert, was maintained during the first 2 d of dehydration, fell to 35% of the initial value over the third and fourth days and recovered fully during 2 d of rehydration. As yield fell, milk osmolality, and milk fat and protein concentrations rose. During rehydration all 3 fell once more, but whereas osmolality finished below initial values the concentrations of fat and protein remained higher than before dehydration. The milk remained isosmolar with plasma throughout. Total yields of milk solids and milk water during the whole experimental period were 70 and 67% of normal respectively and normal growth of the young was not disturbed.

Animals↗
PubMed1984

Conservation of blood plasma fluids in hamadryas baboons after thermal dehydration.

After 2 days of water deprivation in a warm climate, Papio hamadryas baboons lost 10% of their body mass, 12.5% of their total body water (3H2O) space, but only 4% of their plasma volume [Evans blue (EB) space]. Hematocrit and hemoglobin concentration as well as blood viscosity and blood pressure were not affected by thermal dehydration. Plasma colloid osmotic pressure (COP) in the dehydrated animals was, however, 8 Torr higher than in fully hydrated baboons. Total mass and concentration of plasma albumin, and protein concentration increased after dehydration. Both half times (T 1/2) of EB and T 1/2 of 131I-serum albumin were twice as high as in the dehydrated animal than in the fully hydrated ones. Incorporation rate of L-[3H]leucine in the plasma proteins was similarly higher in the dehydrated animals. The capacity of the P. hamadryas baboon to maintain its plasma volume at the expense of losses from other body fluid compartments is related to an increase in the blood COP that is brought about by a more efficient retention of albumin and an increase in its rate of synthesis.

Animals↗
PubMed1984

John Caffey Award. Sonography of the caudal spine and back: congenital anomalies in children.

Articulated-arm, B-mode 3.5-5.0 MHz sonograms from 27 children with congenital anomalies of the caudal spine were analyzed retrospectively and correlated directly with patient appearance, preoperative myelograms, intraoperative photographs, and pathologic specimens to determine how effectively sonography could display the major pathologic features known to be present. Anterior spina bifida, posterior spina bifida, and (partial) sacral agenesis were displayed as focal absence of normal spinal echoes and distortions of the paraspinal/gluteal muscles. Subcutaneous anechoic spaces continuous with the spinal canal through a spina bifida identified the presence, site, and configuration of each meningocele present. Highly echoic masses were easily discerned at the sites of 14 of 16 lipomas and at the solid fibroadipose portions of both sacrococcygeal teratomas. Echoes from the surface of the spinal cord and occasionally from the central canal identified abnormally low cord position in 16 of 17 cases and identified herniation of the cord (or filum) into a concurrent meningocele in seven of 10 cases. Sonographic display of an anechoic meningocele bordered by a lobular, highly echoic, subcutaneous lipoma that inserted onto a low-lying or herniated spinal cord reliably identified lipomyelomeningocele. Despite limitations discussed in the text, initial experience suggests that sonography will be a useful method for screening patients for possible tethered spinal cord, (lipo)(myelo)meningocele, sacrococcygeal teratoma, and other anomalies of the caudal spinal axis.

Child↗
PubMed1983

Temperature regulation and water metabolism in the elephant shrew Elephantulus edwardi.

1. The Cape elephant shrew Elephantulus edwardi maintained a stable body temperature (37.6 C) over a wide range of ambient temperatures. 2. Normal eutherian mechanisms of temperature regulation were employed in the maintenance of homeothermy. 3. Water turnover rate and metabolic rate were lower than predicted for a similar-sized eutherian. 4. Maximal urine concentration was fairly high (3118 +/- 267 mOsm/kg) with urine osmolality largely dependent on the urea concentration. 5. Relative medullary thickness of the kidney (6.61 +/- 0.84) indicated a higher maximum urine concentration than found in the laboratory and reflected an arid habitat. 6. E. edwardi can be classed among the "advanced" homeotherms in view of the physiological adaptations employed for survival.

Animals↗
PubMed1983

Work in progress. Intraoperative neurosurgical ultrasound: localization of brain tumors in infants and children.

Intraoperative real-time ultrasonic sector scanning was performed through the unincised dura mater or the intact brain surface of eight patients (aged six months to 13 years), each of whom had a previously documented mass lesion (four supratentorial, three infratentorial, one intraventricular). In each case, there was a clear definition of the location, configuration, and tissue consistency of the mass. With the exception of a choroid plexus papilloma, all lesions demonstrated both solid and fluid components. The location of a subcortical parietal lobe mass (ependymoma) was apparent only by prior sonography. All neoplastic tissue of one cerebellar astrocytoma that was identified at gross examination was removed, but additional intraoperative scanning following removal of the neoplasm suggested the presence of residual abnormal tissue. This was confirmed during further exploration, and additional gross tumor tissue was excised.

Adolescent↗
PubMed1982

Intracardiac Wilms' tumor: diagnosis and management.

Complete excision of Wilms' tumor may require resection of adjacent organs and removal of intracaval tumor propagation. Extension of tumor to the right atrium can be determined preoperatively guiding a direct and safe approach to intracardiac tumor at the time of nephrectomy. Preoperative ultrasonography of two children with Wilms' tumor demonstrated caval and right atrial tumor. Laparotomy for nephrectomy and abdominal caval exposure was combined with cardiopulmonary bypass and atriotomy. In both patients, tumor contiguous with the renal pelvis extended from the iliac bifurcation into the right atrium with a large atrial mass. In one patient nephrectomy was performed first, and she was then placed on cardiopulmonary bypass. Caval tumor was easily removed through the atriotomy and open renal vein. In the second patient, bypass was instituted first because of cardiac instability. The large right atrial mass extended through an atrial septal defect into the left atrium. The cardiac tumor and a large amount of caval tumor were removed. Bypass was discontinued after repair of the ASD. Tumor remained in the IVC below the renal veins necessitating a separate venotomy. Combined abdominal and cardiac exploration allows safe and complete excision of all gross tumor. Ultrasonography is a sensitive and noninvasive method of diagnosing retrohepatic and atrial tumor extension and can be obtained easily even on very sick patients.

Child, Preschool↗
PubMed1982

Abdominal manifestations of pediatric leukemias: sonographic assessment.

The abdominal sonograms of 64 leukemic children were reviewed and correlated with clinical, hematological, and, when available, autopsy findings. Sonographic abnormalities including enlargement of the liver, spleen, pancreas, and kidneys, with or without alteration of parenchymal echo architecture, hydronephrosis, lymphadenopathy, and ascites were encountered in 70% of the patients. Ultrasound proved useful in detecting occult visceral leukemia and relapse, monitoring tumor response to chemotherapy, and assessing the complications of chemotherapy. Ultrasound is recommended for the routine evaluation and follow-up of the pediatric leukemic patient.

Abdominal Neoplasms↗
PubMed1982

Intra-operative real-time ultrasonic guidance of intracranial shunt tube placement in infants.

Real-time-intra-operative ultrasonography via the anterior fontanelle, previously employed in hydrocephalic infants to guide placement of the proximal end of a ventriculoperitoneal shunt, was used to establish a cystoperitoneal shunt in 2 infants with an enlarging midline brain cyst and to simultaneously confirm the presence of an intraventricular abscess and establish drainage in a third infant.

Brain Abscess↗
PubMed1982

Mini-thoracotomy and chest tube insertion for children with empyema.

In contrast to the two prior decades, empyema in children has become a rare disease during the past 10 years. Thirty-two children with empyema from all causes were treated at The Children's Memorial Hospital in Chicago in the 11 years between 1970 and 1982. Twenty cases followed postinfectious pneumonia, most commonly due to Staphylococcus aureus. The remaining patients had either an esophageal leak or a pleural infection following an intrathoracic operation. Fourteen of our patients were managed with a "mini-thoracotomy," which allowed accurate drainage of purulent material, débridement of fibrinous exudate, and rapid expansion of the lung with prompt relief from fever and toxicity. In our hands, this procedure provided results which were superior to those obtained with simple closed chest tube drainage. In addition, during this period of time, ultrasound examination of the chest has provided a rapid, accurate technique for the early detection and localization of fluid accumulations within the pleural cavity. Pre-drainage thoracentesis can be accurately guided by ultrasonic imaging.

Child↗
PubMed1981

Desaturation of exhaled air in camels.

We have found that camels can reduce the water loss due to evaporation from the respiratory tract in two ways: (1) by decreasing the temperature of the exhaled air and (2) by removal of water vapour from this air, resulting in the exhalation of air at less than 100% relative humidity (r.h.). Camels were kept under desert conditions and deprived of drinking water. In the daytime the exhaled air was at or near body core temperature, while in the cooler night exhaled air wat at or near ambient air temperature. In the daytime the exhaled air was fully saturated, but at night its humidity might fall to approximately 75% r.h. The combination of cooling and desaturation can provide a saving of water of 60% relative to exhalation of saturated air at body temperature. The mechanism responsible for cooling of the exhaled air is a simple heat exchange between the respiratory air and the surfaces of the nasal passageways. On inhalation these surfaces are cooled by the air passing over them, and on exhalation heat from the exhaled air is given off to these cooler surfaces. The mechanism responsible for desaturation of the air appears to depend on the hygroscopic properties of the nasal surfaces when the camel is dehydrated. The surfaces give off water vapour during inhalation and take up water from the respiratory air during exhalation. We have used a simple mechanical model to demonstrate the effectiveness of this mechanism.

Air↗
PubMed1981

Eight-minute excretory urographic film: once is enough.

A film reading exercise was developed to test the advisability and accuracy of using one "postinfusion" roentgenogram instead of a series of films for a complete antegrade urographic evaluation. The experience of the radiologist making the interpretations was also considered. In most cases a singly eight-minute postinfusion delayed film showed enough detail to rule out pathology when none existed and adequately revealed either specific abnormal findings or suggested an abnormality existed when such was indeed present. No false negative call was made by and of the radiologists, but experience did aid in detailing the pathology.

Adolescent↗