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Biomedical subjects

S Harris

Publications and source records attributed to S Harris.

At least 307 records · Page 17Linked to original sources
PubMed1985

Localization studies in patients with persistent or recurrent hyperparathyroidism.

Preoperative localization studies are essential for patients who have undergone previous parathyroid operations. This is because the remaining parathyroid glands are more difficult to identify at operation because of increased scarring with loss of normal tissue planes and because the remaining abnormal parathyroid tissue is more likely to be situated in an ectopic position. This investigation concerns the accuracy of preoperative localization studies in 36 consecutive patients. All patients had symptoms and clinical and laboratory data diagnostic of primary (31 patients) or secondary (five patients) hyperparathyroidism. Ultrasonography was performed in all 36 patients; 18 (50%) were positive, 14 (39%) were negative, and four (11%) were false positive examinations. Eight of the negative study results occurred in patients with abnormal parathyroid glands situated in the mediastinum. Computerized tomography (CT) was performed in 25 patients. There was an equal number of positive (11; 44%) and negative (11; 44%) studies with three (12%) false positive test results. CT was helpful in identifying substernal lesions and other abnormal parathyroid glands situated in ectopic positions. Thallium chloride 201-technetium 99m pertechnetate scans were used in 22 patients. There was an equal number of positive (eight; 36%) and negative (eight; 36%) studies. Six patients (27%) had false positive scans. One or more of these noninvasive tests was positive in 27 of the 36 patients (75%). Highly selective venous catheterization for the measurement of immunoreactive parathyroid hormone concentrations localized the elusive parathyroid tumor in 12 of the 16 patients (75%) overall and in six of the nine patients (66%) whose tumors were not identified by other studies. One patient had both a false positive ultrasound and thallium chloride 201-technetium 99m pertechnetate scan. Preoperative localization studies were therefore very helpful for locating hyperfunctioning parathyroid glands in patients with recurrent or persistent hyperparathyroidism, and 75% of the tumors were identified by noninvasive studies. Seventy-five percent of the tumors not identified by noninvasive studies were localized by selective venous catheterization. Most tumors not identified by noninvasive studies were mediastinal or ectopic in position.

Adult↗
PubMed1984

The primate psi beta 1 gene. An ancient beta-globin pseudogene.

The human beta-globin gene cluster contains five functional genes plus a single pseudogene termed psi beta 1. Hybridization and comparative sequence analysis show that this pseudogene is not the product of a recent gene duplication, but is ancient and has been maintained in all major primate groups ranging from prosimians to anthropoids, at the same position as in man, between gamma- and delta-globin genes. In the lemur, a prosimian, the central exons of the psi beta 1 and delta-globin genes have undergone an unequal exchange, which has resulted in a contraction of the beta-globin gene cluster and the formation of a Lepore-type psi beta 1-delta globin pseudogene. Comparisons of defects shared by prosimian, New World monkey and human psi beta 1 sequences suggest that the ancestral primate gene was probably a pseudogene with an abnormal initiation codon but few if any additional defects, and that most contemporary pseudogene defects were accumulated relatively recently by slow neutral drift. We suggest that psi beta 1 arose early in primate evolution by silencing of a pre-existing discrete functional gene, and show that psi beta 1-related sequences are also present in other mammalian orders. In view of the antiquity of psi beta 1-related sequences, we propose that this gene be renamed the eta-globin gene.

Animals↗
PubMed1984

Phenotypic and genotypic characterization of monoclonal anti-digoxin antibodies.

Eleven hybridoma cell lines secreting monoclonal anti-digoxin antibody have been produced. They are primarily gamma heavy chain and kappa light chain molecules. Affinity constants for digoxin range from 2 X 10(6) to 3.5 X 10(8) liters/mole. Fine specificity analysis using a series of digoxin congeners demonstrates that an unsaturated lactone ring attached to the aglycone at the C-17 position is necessary for hapten recognition. The impact of other changes in digoxin's structure on antibody binding were also studied. DNA hybridization analysis demonstrates that there are at least three different variable region gene arrangements used to produce the heavy chains of the different hybridoma antibodies. Correlations between antigen binding characteristics and antibody V-gene arrangements are demonstrable.

Animals↗
PubMed1984

Ultrastructure of pacinian corpuscle primary afferent terminals in the cat spinal cord.

The glabrous skin of the hindlimb of the cat contains 3 types of low-threshold mechanoreceptors: Pacinian corpuscles (PC), and slowly and rapidly adapting receptors. In the present study, 12 primary afferent fibers transmitting impulses from PC were injected intra-axonally with horseradish peroxidase (HRP) in the spinal cord to examine the morphology of their terminals in the dorsal horn. At the light microscopic level, terminal arborizations were observed in laminae II-VI of the dorsal horn, extending up to 7 mm rostrocaudally in and near the seventh lumbar segment. Bouton-like swellings, predominantly (67%) of the en passant type, were distributed in two discrete clusters, one concentrated rostrally in Rexed's laminae III-IV, and the other concentrated caudally in lamina V. At the electron microscopic level, a combination of morphometric and serial reconstructive analyses with 3 fibers revealed the following. Boutons labelled with HRP invariably contained clear round vesicles, approximately 40 nm in diameter. Labelled bouton sections had longest dimensions of 1.84 +/- 0.63 micron. Their shapes varied from rounded to elongated forms with occasional scalloped appearances. A majority (73%) of the contacts associated with HRP-filled boutons were made with dendritic spines and shafts. Thick postsynaptic densities were usually associated with these synapses, although thinner densities were also observed. 24% of the contacts made by labelled boutons were synapse-like contacts with unlabelled vesicle-containing structures. The vesicles in the unlabelled structures were usually pleomorphic, but sometimes round. These contacts were identified as 'synapse-like' because labelling obscured possible landmarks necessary for definitive identification of synapses. However, in most of these contacts, there was an accumulation of vesicles near the cleft on the unlabelled side, suggesting that the labelled boutons were postsynaptic. Only 3% of the contacts made by labelled boutons were axosomatic. The lengths of contacts with dendritic spines (0.49 +/- 0.23 micron) or with dendrites proper (0.45 +/- 0.20 micron) were significantly longer than those with vesicle-containing unlabelled structures (0.31 +/- 0.18 micron). The portions of cross-sectional bouton contours devoted to synaptic or synapse-like contacts accounted for 9-13% of the perimeters. The larger the bouton, the longer the summed lengths of contacts. Serial reconstruction of selected labelled boutons revealed both simple and quite complex synaptic organizations, including glomeruli with labelled boutons as the central component.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1984

Plasma zinc and copper levels of infants fed different milk formulas.

The plasma zinc and copper levels of 32 full-term healthy infants, aged 3-4 months, using different infant formulas, were measured. The plasma zinc levels of infants using soy formula (45.1 +/- 19.1 micrograms/dl) and iron-fortified cow's milk formula (61.6 +/- 12.9 micrograms/dl) were significantly lower than those of the infants using cow's milk formula not fortified with iron (77.5 +/- 13.4 micrograms/dl). The plasma copper levels of the infants using the different formulas were not significantly different from each other. Fortification of infant formulas with high levels of iron may reduce the zinc absorption from such formulas.

Animals↗
PubMed1984

Hearing threshold measurement in Menière's disease.

The hearing thresholds of 21 subjects with a typical history of Menière's disease on one side were determined four times by Békésy audiometry at fixed frequencies (250, 500, 1 000 and 2 000 Hz). The reliability of the hearing thresholds was calculated and no differences could be found between the Menière ear and the unaffected ear. A considerable increase in standard deviation of hearing thresholds could be noted if the middle ear pressure varied more than +/- 50 mm H2O between the tests. The results showed that with Békésy audiometry a 7-dB increase or decrease in hearing thresholds reflects a significant change in hearing in Menière's disease.

Adult↗
PubMed1984

Congenital cytomegalovirus infection and disease in Sweden and the relative importance of primary and secondary maternal infections. Preliminary findings from a prospective study.

In a prospective Swedish study started in 1977 and still in progress 10 328 newborn infants in an urban district were investigated for cytomegalovirus (CMV) excretion in the urine by the virus isolation test. Congenital infection was found in 50 cases (0.5%). Of 47 infected infants with known clinical status at birth 9 (19%) had hepatomegaly, splenomegaly, jaundice and/or petechiae. The symptoms were moderate or mild. Of the infants followed up, 2 (25%) of 8 neonatally symptomatic ones and 3 (9%) of 35 asymptomatic ones developed neurologic sequelae. Altogether 5 (12%) of 43 had permanent neurologic symptoms corresponding to 0.06% in the general population. The children ranged in age from 6 months to 4 yr at the last examination. 21 mothers of the 47 infants with known status at birth had a confirmed or presumed primary infection, 15 a confirmed or presumed secondary infection and 11 an undetermined type of infection. Of the 5 infants with neurologic sequelae, 1 with a grave psychomotor retardation and deafness was born to a mother with a primary infection in the 1st trimester; 1 infant with a moderate retardation and 3 deaf infants were all exposed to confirmed or presumed secondary maternal infections. Prospective serological studies of maternal sera in early pregnancy would have suspected only the gravely retarded infant to be at risk.

Child, Preschool↗
PubMed1983

An electron microscopic study of primary afferent terminals from slowly adapting type I receptors in the cat.

Primary afferent fibers transmitting impulses from slowly adapting (SA) Type I receptors in the glabrous skin of the hind paw of the cat were injected intraaxonally in the spinal cord with horseradish peroxidase (HRP). At the light microscopic level, terminal arborizations were observed in the medial dorsal horn extending up to 6 mm rostrocaudally in and near the seventh lumbar segment. Boutonlike swellings labelled with HRP were distributed in clusters in Rexed's laminae III-VI. There was a tendency for the most dorsal clusters from an individual fiber to be located rostrally and for the most ventral clusters to be located caudally. At the electron microscopic level, a combination of morphometric analysis and serial reconstruction revealed the following: (1) All the boutons labelled with HRP contained predominantly clear, round synaptic vesicles, 40-50 nm in diameter. (2) Labelled boutons (n = 75) had cross-sectional longest dimensions of 1.72 +/- 0.53 micron (Mean +/- S.D.), perimeters of 4.95 +/- 1.52 micron, and areas of 1.18 +/- 0.59 micron 2. Their shapes in section varied from rounded to elongated forms. (3) The sizes of labelled boutons decreased significantly and linearly with depth from lamina IV to VI. The shapes of the bouton cross sections also became rounder with depth in the dorsal horn. (4) About 72% of synaptic contacts associated with HRP-filled boutons were with dendritic spines and shafts; most of these synapses were of the asymmetric type. (5) The remainder (28%) of the appositions were synapselike contacts between labelled boutons and unlabelled structures containing flattened or pleomorphic vesicles, and occasional dense-cored vesicles. (6) We observed no unequivocal axosomatic contacts made by labelled boutons. (7) The lengths of synaptic appositions with dendritic spines (0.46 +/- 0.20 micron) or with dendritic shafts (0.51 +/- 0.18 micron) were significantly greater than the synapselike contacts with vesicle-containing unlabelled structures (0.29 +/- 0.09 micron). (8) Complex neuropilar organization was occasionally seen with labelled boutons as central elements, although simpler organizations were much more common. In summary, HRP-labelled fibers ended predominantly in boutons containing clear, round vesicles forming axospinous and axodendritic synapses.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1983

Primary explant culture: an in vitro model of the human prostate.

Human prostate tissue gave rise to essentially pure cultures of basal cells in vitro. Careful analysis by phase-contrast microscopy and photography suggested that these cells attempt to differentiate into secretory acinar cells. This was confirmed by immunocytochemical analysis for prekeratin which is present only in basal cells in situ and for prostatic acid phosphatase, prostate-specific antigen, and prostate fluid antigen, which are present only in secretory acinar cells in situ.

Acid Phosphatase↗
PubMed1983

Women physicians during residency years: workload, work satisfaction and self concept.

Fifteen women pediatric residents, 15 non-medical women academicians similar in age and marital status and 15 women pediatricians at least 10 years past residency were surveyed. Subjects were asked to estimate the amount of time they devote to their professional work, domestic work and the degree to which they feel overworked. Subjects were also questioned regarding their perceptions of the advantages and disadvantages of their life-style and their self-concept as a women and as a professional. The results of this study show that residents, who work significantly more hours per week, have a significantly lower level of work satisfaction than do women in the other two groups. It also suggests the fact that the stress of the residency years affects not only the residents' work satisfaction but their entire self-concept as well. The paper offers possible suggestions the medical profession can take in order to help physicians better cope with their professional stress.

Adaptation, Psychological↗
PubMed1983

Congenital cytomegalovirus infection: on the relation between type and time of maternal infection and infant's symptoms.

Maternal sera from 45 live-born infants with congenital cytomegalovirus (CMV) infection and 4 cases of legal abortion were analysed for CMV IgG and IgM. The investigation included cases from routine work and prospective studies of unselected infants. The purpose was to elucidate the relation between the maternal type and time of infection and the signs and symptoms of the offspring at birth and follow-up. Serological patterns compatible with primary maternal infection during trimesters I and II, but also with secondary infection (in at least 1 case), were associated with infant sequelae or death. Asymptomatic infant infection was found after primary infection in trimesters II and III and after secondary infection. Virus could not be isolated from some of the fetuses legally aborted due to primary maternal infection in trimester I. Attempts to demonstrate CMV IgM activity as a marker of active infection in sera from early pregnancy (period of legal abortion) were successful in only half of the 10 cases with infant sequelae or death. Symptoms at birth were prognostically serious, but the further course was sometimes uneventful even in infants with neonatal signs of cerebral infection. A few children without initial symptoms developed sequelae (impairment of hearing).

Abortion, Legal↗