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Biomedical subjects

B S Smith

Publications and source records attributed to B S Smith.

At least 55 records · Page 3Linked to original sources
PubMed1986

Hormonal measurements in patients with theca lutein cysts and gestational trophoblastic disease.

Concentrations of human chorionic gonadotropin (HCG), human placental lactogen (HPL), prolactin (PRL), follicle-stimulating hormone (FSH), estradiol (E2) and progesterone (P) were measured in serum and fluid from ovarian theca lutein cysts (TC) in patients with gestational trophoblastic disease (GTD). Either intact hydatidiform mole (HM) or persistent GTD was present. The values were compared to serum hormone concentrations in ten GTD patients whose ovaries were not enlarged. In the presence of intact HM and TC, significant elevations in the mean serum concentration of HCG, PRL, P and E2 were observed when compared to levels in GTD patients with normal-sized ovaries (P less than .01). Serum FSH and HPL were not elevated in either control or TC patients. The mean concentration of P in cyst fluid from patients with intact HM was higher than that in patients with persistent GTD (P less than .05). From both groups of GTD patients with TC, the mean concentrations of P in cyst fluid were higher than those in the sera. These findings suggest that besides the markedly elevated HCG levels generally seen in TC patients, other hormones, such as P, PRL and E2 are elevated and may be involved in the formation and/or maintenance of TC.

Chorionic Gonadotropin↗
PubMed1985

The connections between the basolateral and central amygdaloid nuclei.

With the use of the rapid Golgi method, axons that originate in the basolateral amygdaloid nucleus have been traced directly into the central amygdaloid nucleus in young mouse brains. The axons, which arise from pyramidal cells, have two patterns of collaterals within the central nucleus. In one type, the axon goes through the central nucleus toward the stria terminalis and emits only one or two collaterals. In the second type, the axon enters the central nucleus and gives off a number of thin collaterals, which have many boutons en passant along their course.

Amygdala↗
PubMed1985

An anatomical study of a duplication 6p based on two sibs.

Dup (6p) patients have a peculiar facial appearance (frontal bossing, hypotelorism, hypoplastic midface), low birthweight, cardiovascular defects, small kidneys, and psychomotor retardation. We thought that a detailed anatomical dissection would more precisely define the syndrome, which has been developed from clinical evaluations and autopsy reports. Our patient, a female adolescent, died at 17 11/12 years and is the oldest patient with this syndrome to be described. The brain and skull showed the greatest number of abnormalities. The brain was smaller than normal and abnormally shaped. Many of the skull abnormalities, including shortened basisphenoid/basiocciput, reduced size of cranial fossae, and steep orbital roofs, may be attributed to the brain's shape. There were no olfactory bulbs, and only one rudimentary olfactory tract was present. Other findings were the following: a high interventricular septal defect and right ventricular hypertrophy, absence of uterus and vagina, hypoplastic ovaries, a common mesentery, two left extensor indicis bellies, bilateral absence of palmaris brevis and of peroneus tertius. Our results are compared with anomalies found in other aneuploidy syndromes. Variations in some organ systems may be similar to those whose presence Shapiro [1983] has attributed to amplified developmental instability. Relationships between the brain shape and size and skull abnormalities are also discussed. From 16 reported cases, a detailed autopsy report of the affected brother, and our anatomical findings, we suggest that this syndrome may also be characterized by arhinencephaly, common mesentery, absent uterus in the female, and growth retardation in those surviving the neonatal period.

Abnormalities, Multiple↗
PubMed1985

Effects in sheep of high dietary levels of vitamin D3 as measured by circulating concentrations of some vitamin D metabolites and skeletal examination.

Housed non-pregnant ewes were given diets supplemented with five, 10, 20, 40 and 80 times the Agricultural Research Council's recommended requirement for vitamin D for 16 weeks. The effects on vitamin D status were assessed by measuring 25-hydroxylated vitamin D metabolites (25-OHD) in plasma at intervals. After 16 weeks, animals on the lowest and two highest vitamin D intakes were killed for histological examination of selected soft tissues and bones. Circulating concentrations of 25-OHD increased with intake and time during the experiment. However the increases were not proportional to intake and only when intakes exceeded 20 times the recommended requirement were concentrations greater than those seen in summer in grazing sheep. There was some evidence for the production of an additional vitamin D metabolite in animals on high vitamin D intakes. No abnormalities were detected in any of the tissues examined histologically.

Animals↗
PubMed1985

Effect of parenteral vitamin D3 on plasma 25-hydroxyvitamin D3 concentration in sheep.

Vitamin D3 ranging in total amount from 10(5) iu (2.5 mg) to 9 X 10(5) iu (22.5 mg) was given intramuscularly either as a single injection or in three aliquots at three-weekly intervals to housed nonpregnant ewes on a vitamin D deficient diet. The effects on plasma concentrations of 25-hydroxyvitamin D3 (25-OHD3), the major metabolite of vitamin D, were monitored. The increase in plasma 25-OHD3 showed a large variation between animals and was related to, but not proportional to, the dose. None of the treatments produced 25-OHD3 concentrations greater than those in grazing sheep in summer. Repeated dosing provided for more efficient use of the injected vitamin D3.

Animals↗
PubMed1985

The diagnostic accuracy of spinal nerve injection studies. Their role in the evaluation of recurrent sciatica.

The spinal nerve injection study (SNIS) is a diagnostic test for the evaluation of sciatica. SNIS consists of selective infiltration of nerve root with local Xylocaine anesthesia. The most common indication is in the postlaminectomy patient with persistent or recurrent sciatica and peridural scarring causing myelograms or CT scans to be difficult to interpret. Of 105 patients with SNIS, 55 subsequently had surgical exploration of the suspected lesion. In patients with a diagnostic or highly suggestive SNIS, an accurate diagnosis was made in 43 (93%); myelograms in the same group had an accuracy of 24%. At follow-up evaluations ranging from 12 to 60 months (average, 20 months), 40 (73%) of the patients were improved by further surgical treatment.

Adult↗
PubMed1984

Relative contributions of diet and sunshine to the overall vitamin D status of the grazing ewe.

Circulating concentrations of 25-hydroxyvitamin D2 (25OHD2) and 25-hydroxyvitamin D3 (25OHD3) provide, respectively, a measure of the contributions of the diet and sunshine to the overall vitamin D status. These indices were measured in grazing sheep over a 16 month period which included their first pregnancy. Seasonal fluctuations in 25OHD3 concentrations were very marked, demonstrating both the dominance of photobiosynthesis as a source of vitamin D in the summer and also the lack of an effective storage mechanism. The concentration of 25OHD2 was subject to much smaller fluctuations, but when young grass was being consumed it was significantly lower than when mature grass or hay was fed. Supplementation in winter maintained circulating concentrations at a satisfactory level and may be a wise precaution in practice.

25-Hydroxyvitamin D 2↗
PubMed1983

Intraosseous lipoma.

Intraosseous lipoma is the rarest benign primary tumor of bone. The incidence is less than one per 1,000 bone tumors. Because of its rarity and non-specific clinicopathologic findings, large biopsy specimens are needed for an accurate diagnosis. Once diagnosis has been established, a conservative treatment protocol is mandatory. The prognosis is generally excellent, and recurrences have not been reported.

Aged↗
PubMed1981

Seasonal variation in serum 25-hydroxyvitamin D concentrations in sheep.

Seasonal changes in serum 25-hydroxyvitamin D were followed in pregnant and non-pregnant sheep kept indoors or at pasture. In housed sheep circulating levels depended on starting value, dietary intake and requirements. thus, in wethers given hay values declined steadily; in non-pregnant ewes on the standard diet values were constant; and in pregnant ewes given hay and nuts values were minimal at lambing. In sheep at pasture seasonal changes were aggravated by those changes due to pregnancy so that the lowest values were always observed at or near parturition.

Animals↗
PubMed1981

Reproductive anomalies in stenoglossan snails related to pollution from marinas.

Over 3090 snails of the dioecious intertidal species Nassarius obsoletus Say were collected from a total of 71 localities. Their reproductive anatomy was examined for a superimposition of male characteristics on to the normal female anatomy, an abnormality called 'imposex'. Imposex was rated numerically in terms of the fraction of the population affected and the intensity of expression in bearer snails. An initial survey of 22 localities in Fairfield and Westport, Connecticut, led to the hypothesis that imposex was related to a substance arising from marinas. This was tested at nine pairs of marina and control localities in Long Island Sound, as well as six pairs along a transect ranging from Rhode Island to Georgia. Imposex scores were significantly higher at the marina locality in every pair. Further confirmation was found in a detailed survey of the estuarine harbor at Southport, Connecticut, which showed that adjacent populations could differ in the amount of imposex to the extent that both the snails and the waters they lived in remained separated by natural or man-made barriers. Imposex has been found in populations of N. obsoletus ranging from Damariscotta, Maine, to Savannah, Georgia, and it has been reported from San Francisco Bay, California. Similar anatomical abnormalities have been reported in at least 27 other species of taenioglossan and stenoglossan snails, extending the range to the Atlantic and Mediterranean coast of Europe and the British Isles. Concern is raised regarding the possible existence of another global pollutant with novel effects on marina biota.

Animals↗
PubMed1981

Male characteristics on female mud snails caused by antifouling bottom paints.

This study continues an investigation of an anatomical abnormality, named 'imposex', which consists of a superimposition of male characteristics on to a functionally normal female reproductive anatomy of the dioecious snail Nassarius obsoletus Say. Imposex is prevalent in natural populations living near yacht basins and rarely found distant from them. In the current study caged snails were transferred between a yacht basin and a distant 'clean' locality where the natural population of snails was normal. Imposex was induced in some normal snails kept at the marina and suppressed, but not lost in abnormal snails kept at the clean locality. A similar positive result was obtained in the laboratory by exposing normal snails to organotin-containing antifouling paints and abnormal snails to clean sea water. Results were negative in parallel tests of various marina-associated materials which did not contain organotin. The laboratory studies have thus identified a causative factor for the anatomical abnormalities common near yacht basins in the natural environment. They also provide a rare, if not unique, example of a chemical agent which causes the appearance of superfluous anatomical features in an animal.

Animals↗
PubMed1981

Tributyltin compounds induce male characteristics on female mud snails Nassarius obsoletus = Ilyanassa obsoleta.

Superimposition of male characteristics on to normal females of this dioecious snail is prevalent near marinas in estuaries. In the laboratory it can be caused by exposure to parts per billion concentrations of three organotin biocides: tributyltin oxide, tributyltin resinate and tributyltin chloride. Occurrence of such abnormalities in natural populations is thus an indicator of organotin pollution which might present an environmental hazard.

Abnormalities, Drug-Induced↗
PubMed1980

The response of serum 25-hydroxyvitamin D concentrations to vitamin D intake and insolation in sheep.

1. Vitamin D-depleted, housed sheep were given diets providing fixed intakes of cholecalciferol ranging from 0.0 to 0.8 microgram/kg body-wt per d for 220 d. Thereafter they were shorn, deprived of dietary cholecalciferol and turned out from 30 June to 30 November. The concentration of 25-hydroxyvitamin D (25-OHD) in serum was determined at frequent intervals. 2. The serum concentrations of 25-OHD took approximately 10 weeks to stabilize after which they reflected dietary intake over 0.1--0.4 microgram/kg body-wt per d. For intakes of 0.4 and 0.8 microgram/kg body-wt per d the mean maximum concentrations were similar, but the rates of increase differed. The latter was proportional to the logarithm of intake over the range studied. 3. Changes in serum 25-OHD due to insolation were similar in all sheep regardless of their starting values, and consequently in some animals reached levels considerably greater than from the dietary source. 4. Although the response of serum 25-OHD to the higher dietary intakes appeared to be limited there was no evidence of any such control over the response ot endogenously-synthesized vitamin.

Animal Nutritional Physiological Phenomena↗
PubMed1977

The transfer of circulating 131I IgG1 and 125I IgG2 to the nasal secretions of sheep.

Ovine IgG1 and IgG2 labelled with 131I and 125I respectively were injected intravenously into four sheep. Serum and nasal secretion samples were collected and fractionated by gel filtration on columns of Sephadex G100. Results showed that in serum more than 95 per cent of the radioactivity was associated with intact IgG molecules whereas in nasal secretion samples the percentage varied from five to 47. It was found that the concentrations of IgG1 and IgG2 in the nasal secretions were similar and were approximately 2 per cent of the serum concentrations. This finding indicates a lack of selective transfer of either IgG1 or IgG2 from blood to nasal secretions in sheep.

Animals↗