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Biomedical subjects

K Goitein

Publications and source records attributed to K Goitein.

At least 19 recordsLinked to original sources
PubMed1995

Effect of hypoxemia and ethacrynic acid on ABR and distortion product emission thresholds.

Various studies have shown that induction of hypoxemia in animals such that arterial blood oxygen tensions reach 20-30 mm Hg is accompanied by reversible threshold elevations of the auditory nerve-brain-stem evoked response (ABR). In this state, the endocochlear potential (EP) is depressed, causing a smaller potential difference across the hair cells and/or reduced activity of the cochlear amplifier of the outer hair cells. In order to test these possibilities, ABR threshold (an expression of the overall sensitivity of the cochlea) and changes in threshold of the cubic (2f1-f2) distortion product emissions (DPE) (an expression of activity of the cochlear amplifier) were measured in the same cats while the EP was depressed by hypoxemia or by ethacrynic acid. During the episodes of hypoxemia, DPE thresholds were elevated by 10 dB while ABR thresholds were elevated by 22.8 dB. Therefore, it seems that a normal EP is necessary both for normal cochlear transduction (inner hair cells) and for normal cochlear amplification (outer hair cells). The human fetus in utero is relatively hypoxic and there is evidence that its auditory threshold is also similarly elevated. Therefore the threshold elevation in the fetus in utero, estimated to be about 20 dB, is a consequence of both reduced transduction current through the inner hair cells (about 10 dB) and an additional 10 dB reduction in the activity of the cochlear amplifier of the outer hair cells.

Animals↗
PubMed1994

Improvement in sensorineural auditory threshold of the guinea-pig fetus following delivery.

The human fetus in utero is hypoxic relative to the neonate due to differences between placental and pulmonary oxygenation. Comparable degrees of hypoxia induced in young and adult animals caused an elevation in hearing threshold of a sensorineural nature. It was hypothesised therefore that the human fetus may also have such an elevation of threshold. This was tested in this study by recording ABR thresholds to bone conducted stimuli in fetal guinea-pigs that were near full term and again in the same animals, after delivery and consequent pulmonary oxygenation. In every animal studied (n = 9), the neonatal threshold was better than that in the fetus. In those fetuses in which a response could be recorded (n = 5), the neonatal threshold was on average 20 dB better than in the fetus. These findings are probably due to a depression of the endocochlear potential induced by the relatively hypoxic state of the fetus. The hypoxic state would lead to a reduced transduction current in the hair cells in response to a stimulus and an elevated hearing threshold. At birth, with the shift to pulmonary oxygenation, the neonate becomes normoxic, the endocochlear potential rapidly reaches near maximal levels and threshold is improved.

Animals↗
PubMed1991

Gastrointestinal protein loss in children recovering from burns.

Qualitative gastrointestinal protein loss was evaluated in 10 children with second- and/or third-degree burns covering 10% or more of their body surface area (BSA) by using fecal alpha-1-antitrypsin (FA-1-AT) as a marker. Patients were subdivided according to the extent of the burned area: group I (5 patients) had burns covering less than 20% of BSA; group II (5 patients) had burns covering more than 20% of BSA (mean, 37.2% = 24.9%). Results were compared with those of 12 healthy normal controls. Mean maximal FA-1-AT excretion in group II patients (2.71 +/- 1.35 mg/g) was significantly greater than that found in group I children (0.43 +/- 0.26 mg/g; P = .006) and in the controls (0.62 +/- 0.25 mg/g; P = .004). The mean maximal FA-1-AT excretion positively correlated to the percent of BSA covered with burns (r = 0.83). Although the mean septic score (SS) of group I patients (7 +/- 2.9) was significantly greater than that calculated for group II children (3 +/- 2.45; P = .047), only 2 patients in group II had positive microbiological cultures. Patients in both groups had received more than the recommended enteral caloric and protein allowance during the 96 hours prior to the maximal FA-1-AT measurements. Within this range, no correlation was found between the amount of FA-1-AT and the number of calories per kilogram protein consumed. By using the method of FA-1-AT quantification, this study provides the first report on postburn intestinal protein loss in children.

Burns↗
PubMed1987

Surgical treatment of infants with esophageal atresia and VATER association.

Our surgical experience in 10 infants with esophageal atresia and the VATER association of multiple congenital anomalies is reviewed. Early recognition and evaluation of the various lesions enabled the planning of a staged surgical approach with a satisfactory outcome. Seven of the patients survived. There were no immediate postoperative deaths. Development and growth curves of the surviving patients are satisfactory. Despite multiple operative procedures infants with VATER association may lead a reasonably normal life.

Abnormalities, Multiple↗
PubMed1986

The depression of the auditory nerve-brain-stem evoked response in hypoxaemia--mechanism and site of effect.

During severe hypoxaemia in the cat the ABR was depressed in 2 different patterns: if mean arterial blood pressure (MAP) was maintained then all other evoked potentials (EPs--somatosensory and visual) remained. If MAP was not maintained, all of these EPs were depressed. This study sought to document these different patterns of ABR depression and to ascertain their mechanisms. When MAP fell, the ABR loss began with the later waves and progressed to the earlier waves. These are signs of a central brain lesion. The hypoxaemia, detrimental to normal function of the cardiovascular system, leads to depression of MAP, to a fall in cerebral perfusion pressure and blood flow, to cerebral ischaemia and ABR loss. On the other hand, when MAP was maintained, severe hypoxaemia was accompanied by a depression of all of the ABR waves at the same time. The cochlear microphonic potential was also simultaneously depressed. These are signs of a peripheral, cochlear effect similar to the demonstrated depression of the positive endocochlear resting potential of the scala media and of the cochlear microphonic potential during hypoxaemia. This leads to interference with the cochlear transduction mechanism so that all of the auditory evoked potentials, including the ABR, are simultaneously depressed. These results lead to the suggestion that the ABR abnormalities seen in patients who suffered a hypoxic (anoxic) insult or an ischaemic episode (prolonged interpeak latencies, loss of later waves and finally all waves absent or only the first wave remaining) is always due to ischaemia even when the initial insult was hypoxic.

Animals↗
PubMed1986

Arhinia.

Explore the source record for details and available documents.

Humans↗
PubMed1985

Multiple hornet stings with features of Reye's syndrome.

Hornet's venom is known to possess a variety of toxic effects. A 19-mo-old girl who developed a Reye-like syndrome following multiple stings by the Oriental hornet (Vespa orientalis) is described. She presented with encephalopathy associated with hepatomegaly, elevated transaminase levels, low prothrombin time, and hyperammonemia. Liver biopsy demonstrated microvesicular fatty infiltration and diffuse mitochondrial changes. Additional features were acute renal tubular necrosis and massive hemolysis.

Antibodies↗
PubMed1985

Simultaneous superior and inferior vena cava pressure recordings in giant omphalocele repair--a possible guideline for prevention of postoperative circulatory complications.

Eleven children underwent second stage repair of giant omphaloceles containing the liver. Simultaneous SVC and IVC pressure before, during and after closure of the abdominal wall was recorded. In all patients with circulatory complications the SVC pressure decreased following surgery. The postoperative pressure ratios in IVC and SVC (Formula: see text) was found to be four times greater in the group with complications. It is suggested that this ratio might serve as an important index in the prediction of abdominal wall closure feasibility in giant omphaloceles.

Central Venous Pressure↗
PubMed1985

Scorpion sting in children. A review of 51 cases.

Scorpion sting in children is a hazardous and potentially lethal condition. Fifty-one infants and children were admitted to the Pediatric Departments at the Hadassah-Hebrew University Hospitals in Jerusalem, during a 5-year period, following scorpion sting. Fifteen (29.4%) had severe systemic signs of envenomation and two (3.9%) died. Analysis of our data showed that patients with severe toxicity were brought to the hospital after a significantly longer time lapse than were the patients with mild-to-moderate symptoms. The current management of children with scorpion envenomation consists of administration of specific antivenom and close surveillance in an intensive care unit, where vital signs and continuous cardiac monitoring enable early initiation of therapy for life-threatening complications, such as cardiac and respiratory failure, convulsions, or hypertension.

Antivenins↗
PubMed1984

Pericardial tamponade complicating central venous catheterization in a newborn infant.

Complications of central venous catheterizations are divided into immediate or early complications such as haematoma, pneumothorax and haemothorax, and late complications such as infection and venous thrombosis. One of the rare but life-threatening complications of central venous catheterization is pericardial tamponade. We review the literature and add an additional case, the first reported in a newborn infant.

Cardiac Tamponade↗
PubMed1983

Auditory nerve-brain stem evoked potentials in cats during manipulation of the cerebral perfusion pressure.

In order to study the effects of various degrees of cerebral ischemia on the auditory nerve-brain stem evoked potentials (BAEP), the cerebral perfusion pressure (CPP), defined as the difference between mean arterial blood pressure (MAP) and intracranial pressure (ICP), was systemically manipulated in anesthetized, paralyzed and ventilated cats. The CPP was varied by decreasing MAP, either by hemorrhage or by the infusion of a vasodilating drug, and elevating ICP by infusion of mock CSF into the cisterna magna, or by MAP depression and ICP elevation simultaneously. Even though the lower limit of adequate CPP is considered to be 40 mm Hg, the EEG became isoelectric at an average CPP of 24 mm Hg and the BAEP became isoelectric at an average CPP of 7 mm Hg. These extremely low CPP values of 7-24 mm Hg are far below the range of autoregulation of cerebral blood flow (CBF) so that the brain stem auditory pathway is still capable of generating its electrical response (BAEP) at very low CBF. This is paradoxical since these same regions of the brain have been shown to have the highest levels or regional metabolism as shown by their very high local cerebral blood flow and local glucose utilization.

Animals↗
PubMed1982

Combined treatment of severe hyponatremia due to inappropriate antidiuretic hormone secretion.

A 6-year-old girl developed generalized seizures followed by coma, five days after surgical removal of a craniopharyngioma. Low serum sodium levels and low serum osmolality with inappropriately high urinary sodium output confirmed the diagnosis of inappropriate antidiuretic hormone (ADH) secretion. Treatment with 3% hypertonic saline solution and repeated doses of furosemide (1 mg/kg) improved her clinical condition; serum sodium levels, however, rose slowly and urinary excretion remained high. Deoxycorticosterone acetate (DOCA), 4 mg/sq m/day, was added to the above regimen. A striking clinical improvement was noted. Serum sodium levels returned to normal with a concomitant sharp decline in urinary sodium output. The clinical course of this patient demonstrates the efficacy of the addition of deoxycorticosterone acetate to hypertonic saline and furosemide in the treatment of severe, life-threatening hyponatremia due to the syndrome of inappropriate antidiuretic hormone secretion.

Child↗
PubMed1975

Penetration of parenterally administered gentamicin into the cerebrospinal fluid in experimental meningitis.

The penetration of parenterally administered gentamicin into the CSF was examined in dogs. The experiments were carried out in three stages: (1) in healthy dogs, (2) in dogs with meningitis, and (3) during recovery from the acute inflammation. Gentamicin was found to penetrate poorly into the CSF, reaching mean peak levels of 0.7 mug/ml in healthy dogs. During the height of the meningeal inflammation the mean peak gentamicin level in the CSF was 0.9 mug/ml. The ratio of mean maximum CSF to mean maximum serum levels of gentamicin was 5.8% in healthy dogs, and 11.3% in dogs with meningitis. Thus, inflammation increases the penetration of parenterally administered gentamicin into the CSF, but therapeutically adequate levels for gram-negative bacillary meningitis are not achieved.

Animals↗