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Biomedical subjects

B Halpern

Publications and source records attributed to B Halpern.

At least 19 recordsLinked to original sources
PubMed2000

Spondylolysis.

Spondylolysis is a relatively common incidental radiographic finding that, most frequently, is asymptomatic. Isthmic spondylolysis with a lesion in the pars interarticularis may be a significant cause of pain in a given individual, particularly in adolescent athletes involved in sports with repetitive spinal motions. The pars lesion likely represents a stress fracture of the bone caused by the cumulative effect of repetitive stress imposed by physical activity. The lesion frequently presents as focal LBP and can often be identified on plain radiography. Advanced imaging with SPECT, CT, and MR imaging may be needed to ascertain the acuity of the lesion, assist in identifying a particular pars lesion as potentially symptomatic, and to exclude other spinal pathology that may be present. Conservative treatment is usually successful in controlling symptoms and restoring function; only a small percentage of patients require surgical intervention for pain or progressive spondylolisthesis. Based on current evidence, treatment requires activity restriction (i.e., temporary discontinuation of the aggravating sport or activity) and may require bracing to achieve treatment goals, although healing, pain relief or both may occur without brace application. A full understanding of spinal biomechanics and pathophysiology, the role of diagnostic imaging, and treatment options is needed to care for these patients.

Braces↗
PubMed1988

High school football injuries: evaluation.

An epidemiologic survey of the literature on high school football injuries revealed methodologic problems. These numerator-denominator inconsistencies and other confounding factors are discussed. The authors suggest a more reliable system of reporting these parameters to further reduce the risk of high school football injuries.

Adolescent↗
PubMed1988

High school football injuries: identifying the risk factors.

This epidemiologic survey of the literature on the factors contributing to the high number of high school football injuries consolidates the current information on the characteristics and risk factors associated with these injuries. To reduce the incidence of knee sprains and strains, the most common injuries to this population, the following preventive recommendations are presented: 1) optimum maintenance of playing fields; 2) use of the soccer-style shoe; 3) noncontact and controlled activities in practice sessions; and 4) increased vigilance over technique during injury-prone preseason practices. The authors conclude that more research into factors such as exposure time and activity at injury will further reduce the risk to the high school football player.

Adolescent↗
PubMed1983

Hawkinsinuria--identification of quinolacetic acid and pyroglutamic acid during an acidotic phase.

A second Australian family with the genetic disease Hawkinsinuria has been identified. Affected members excrete hawkinsin and cis- and trans-4-hydroxycyclohexylacetic acid. An infant in this family presented with metabolic acidosis and excreted quinolacetic acid and pyroglutamic acid in the urine together with the tyrosine derived phenolic acids reported in the original index case. It is thought that quinolacetic acid is accumulated as a by-product of the partially defective enzyme, 4-hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27) and that pyroglutamic acid indicated lowered glutathione levels.

Acidosis↗
PubMed1983

Natural history of hydatidiform mole after primary evacuation.

From 1962 to 1978, 738 patients with hydatidiform mole were referred to the John I. Brewer Trophoblastic Disease Center of Northwestern University for follow-up and human chorionic gonadotropin (hCG) testing after evacuation. There was spontaneous regression of trophoblastic disease in 596 (80.8%) of the 738 patients. Of these 596 patients, regression occurred in 11 (1.8%) by day 10 after evacuation, in 124 (20.8%) between days 11 and 30, in 255 (42.8%) between days 31 and 60, and in 206 (34.6%) between days 61 and 170. Treatment with chemotherapeutic agents was required in 142 (19.2%) of the 738 patients; 125 (16.9%) of these had invasive mole (107 nonmetastatic and 18 metastatic) and 17 (2.3%) had choriocarcinoma (13 nonmetastatic and four metastatic). All 596 patients whose hCG titers declined spontaneously to normal levels have remained well and free of disease. All 142 treated patients experienced permanent remission. Thus, all 738 patients are well and free of disease 4 to 18 years after evacuation of the hydatidiform mole. The follow-up regimen described in this report furnishes information on natural history of molar pregnancies after evacuation and provides an excellent means by which all patients can be safely managed following termination of a hydatidiform mole.

Choriocarcinoma↗
PubMed1983

Profiles of urinary volatiles from metabolic disorders characterized by unusual odors.

The profiles of urinary volatiles from patients with phenylketonuria, maple syrup urine disease, isovaleric acidemia, or trimethylaminuria (fish-odor syndrome) were in each case vastly different from the normal urinary volatiles profile. In the maple syrup urine disease case, metabolites that occur distal to the block were found and a mechanism for their formation is suggested. A new major metabolite in isovaleric acidemia was also found. As well as providing a reliable diagnostic tool for diseases characterized by odors, the analysis of urinary volatiles may provide information to help our understanding of still unexplained aspects of the diseases.

Adolescent↗
PubMed1982

Reduced prolactin binding to liver membranes during pheromonal emission in the rat.

Between 14 and 27 days of lactation, female rats excrete a pheromone in their feces that is cholic-acid dependent and that strongly attracts young. Previous research has shown that high circulating levels of prolactin are necessary before the pheromone can be emitted. However, during the time of pheromonal emission prolactin in serum conspicuously declines, while in hepatic cytosol the hormone reaches peak levels. We were interested in the question of how the liver can show peak cytosolic concentrations of prolactin at a time of falling blood levels of prolactin. Accordingly, we examined the prolactin binding capacity of liver membrane fractions during selected periods of lactation. We also studied the livers of virgin and pregnant females for comparison. Three membrane fractions were separated: the cell membrane, the nuclear membrane and a fraction consisting of the cell membrane and large non-nuclear organelles. In all three fractions, there was an increase in available and total prolactin binding in the liver when pregnant females were compared with nulliparous females. However, during the time of pheromonal emission, when prolactin in hepatic cytosol was elevated, there was a significant reduction in the prolactin binding capacity of the liver. How such a reduction increases the cytosolic concentration of the hormone and in turn heightens cholic acid output and pheromonal emission remains unsolved.

Animals↗
PubMed1982

Gestational trophoblastic disease. The effect of duration of disease and hCG titer on response to therapy.

The height of the pretreatment hCG titer and the time interval from termination of the antecedent pregnancy to institution of treatment were determined in 352 patients with gestational trophoblastic disease in order to judge their effect, both individually and together, on response to therapy. When all patients in need of treatment for gestational trophoblastic disease, both metastatic and nonmetastatic, were considered as one group, examination of time alone, of hCG titer alone and of time and titer together each permitted the identification of patients at high risk with equal reliability (p less than 0.0005 for each). When patients with only metastatic gestational trophoblastic disease were evaluated, time and titer taken separately and together each identified those patients at high risk, but not in an equal manner (time alone, p = 0.02; titer alone, p less than 0.05; time and titer together, p less than 0.0005). Time and hCG titer, alone or in combination, did not have a statistically significant effect on outcome when patients with metastatic choriocarcinoma were considered separately. Other factors, such as metastatic site and antecedent pregnancy, seem to be more important in determining prognosis than duration of disease and hCG titer in this group of patients.

Choriocarcinoma↗
PubMed1982

Gestational trophoblastic disease: treatment results at the Brewer Trophoblastic Disease Center.

Three hundred fifty-nine patients with gestational trophoblastic disease (choriocarcinoma and invasive mole) received complete treatment at the Brewer Trophoblastic Disease Center of Northwestern University Medical School from 1962 through 1978. Data were gathered as of December 31, 1978, to permit a minimum follow-up of 2 years. An overall remission rate of 92% was achieved: 100% (185/185) for nonmetastatic disease and 83% (144/174) for metastatic disease. All 200 patients with invasive mole and 129 of 159 patients (81%) with choriocarcinoma were cured. Chemotherapy was the main form of treatment, with adjuvant surgery and radiation therapy being used in selected patients. Five factors were determined to significantly influence response to treatment in patients with metastatic disease: 1) clinicopathologic diagnosis of choriocarcinoma versus invasive mole (71 versus 100%, P much less than .0005); 2) pretreatment human chorionic gonadotropin titer greater than 100,000 IU/liter and time greater than 4 months from pregnancy event to treatment (62 versus 93%, P much less than .0005); 3) metastases to sites other than lung and/or vagina (37 versus 92%, P much less than .0005); 4) antecedent term gestation compared with hydatidiform mole, abortion, and ectopic pregnancy (56 versus 79%, P less than .02); and 5) prior unsuccessful chemotherapy compared with no previous treatment (48 versus 83%, P much less than .0005). The value of secondary chemotherapy and adjuvant irradiation was evaluated. Relapse from remission was also studied.

Antineoplastic Agents↗
PubMed1981

Mass spectographic analysis of stimulated release of endogenous amino acids from rat hippocampal slices.

Amino acids released from in vitro rat hippocampal slices following stimulation of the Schaffer's collateral pathway, were collected by micro-perfusion and analysed by chemical ionization mass spectrometry, with isotope ratiodetermination as the quantitative technique, through the use of stable, isotopically labeled internal standards. Stimulation at 10 pulses/sec resulted in a doubling of the release of aspartic acid over the resting level and about a 60% increase in glutamate release, which is in essential agreement with studies utilizing K+ depolarization-evoked release from slices.

Amino Acids↗
PubMed1981

Improved procedure for the anion-exchange isolation of urinary organic acids.

DEAE-Sephadex equilibrated in 0.5 M triethylammonium acetate is suitable for the quantitative isolation of lactonisable organic acids. Mono-, di- and tricarboxylic acids can be eluted sequentially from DEAE-Sephadex by the use of 0.5 M triethylamine, 0.5 M triethylamine--0.1 M acetic acid, and 1.5 M pyridinium acetate.

Carboxylic Acids↗
PubMed1981

New metabolites in isovaleric acidemia.

Two metabolites, 4-hydroxyisovaleric acid and mesaconic acid, have been identified and quantified in the urine of a patient with isovaleric acidemia. These compounds do not appear to have been reported previously as being components of human metabolism. In addition, large quantities of 3-methylbutyrolactone, the lactone of 4-hydroxyisovaleric acid, were observed in the volatile profile obtained by headspace chromatography. The demonstration of 4-hydroxyisovaleric acid supports the contention that urinary methylsuccinic acid seen in patients with isovaleric acidemia has arisen by omega-oxidation of isovaleric acid. The identification of mesaconic acid may indicate that the methylsuccinic acid formed in these patients is subject to further metabolism.

4-Butyrolactone↗
PubMed1981

Two new sulphur-containing amino acids in man.

Two unusual sulphur-containing amino acids have been isolated from urine of a baby who died with major physical malformations and failure of growth and development. Sensitive mass spectrometric methods were used to identify the nanomole quantities of the compounds available as S-(2-carboxypropyl)-cysteine and S-(2-carboxypropyl)-cysteamine. Incubation of fibroblasts in either [14C]Valine or [35S]cysteine resulted in radioactive labelling of the compounds, suggesting their origin from conjugation of methacrylic acid with cysteine and subsequent decarboxylation of the cysteine conjugate. Specific assay of methacrylyl-CoA hydratase is needed for final proof that this is a new inborn error of that enzyme, but these findings and parental consanguinity make this very likely. It seems possible that methacrylic acid or one of its derivatives may have caused the malformations present in the baby.

Abnormalities, Multiple↗