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Biomedical subjects

D Freeman

Publications and source records attributed to D Freeman.

At least 109 records · Page 6Linked to original sources
PubMed1982

Acute poisoning from the ingestion of Nicotiana glauca.

A case is presented of a 76-year-old male who ingested Nicotiana glauca and developed severe nicotine-alkaloid toxicity primarily characterized by neuromuscular blockade and respiratory failure. Recovery occurred with supportive care.

Aged↗
PubMed1981

Nucleus retroambigualis respiratory neurons: responses to intercostal and abdominal muscle afferents.

Studies were performed on anesthetized (Dial), paralyzed, vagotomized, artificially ventilated cats. Phrenic efferent activity, ventral respiratory group neuron activity in the region of the nucleus retroambigualis and, in some instances, thoracic dorsal root compound action potentials were recorded during electrical stimulation of intercostal nerve afferents (INS). Phrenic activity and inspiratory (I) neurons were inhibited by stimulating external, internal and lateral intercostal nerve afferents. Some expiratory (E)-neurons were also inhibited by these afferents. No I or E-neurons were facilitated with INS. Changes in I and E activity were correlated with muscle proprioceptor and cutaneous receptor afferent fibers. It is concluded that the dominant effect of intercostal and abdominal muscle proprioceptive afferent information on medullary respiratory activity in inhibition of inspiratory activity.

Abdominal Muscles↗
PubMed1981

Liposarcoma of the neck. Report of a case.

A case of lipoblastic liposarcoma of the neck is presented. The case is that of a 5-year-old female who underwent a modified neck dissection with a good result. A review of the literature reveals that this is an extremely rare tumor of the neck. It is usually found in the lower extremities, predominantly in adult males. Surgery is the treatment of choice. Lipoblastic liposarcoma is an extremely rare tumor when it occurs in the pediatric neck. Hudson and Saunders in their studies have shown that only 3 patients with this tumor have been reported since 1944. When a 5-year-old female presented with this primary neck mass, questions of diagnosis and treatment were raised. The following case report and discussion will demonstrate the diagnostic methods as well as the course of therapy followed in this type of lesion.

Child, Preschool↗
PubMed1980

Stimulation of chick embryo cartilage sulfate and thymidine uptake: comparison of human serum, purified somatomedins, and other growth factors.

We have compared the stimulation of sulfate and thymidine uptake into 10-day-old embryonic chick cartilage by normal human serum, partially purified somatomedins (Sm) A and B, homogeneous insulin-like growth factors (IGFs) I and II, and several other substances. With the exception of epidermal growth factor, all growth factors ((GFs) were assayed in the absence of other protein. Pelvic rudiments were preincubated in buffer for 6 h and then incubated for 24 h with the GF or serum, with labels added for the final 6 h. Human serum enhanced cartilage uptake of both thymidine and sulfate. There was a dose-dependent stimulation of thymidine uptake by Sm A or B (0.05--2 microgram/ml) and IGF I or II (0.5--20 ng/ml). Unlike serum, neither Sms nor IGFs increased SO4 uptake under these conditions. Bovine GH (10--500 ng/ml), albumin (100-1000 ng/ml), fibroblast GF (1--100 ng/ml), and epidermal GF (1--100 ng/ml) were inactive for both thymidine and sulfate. When a shorter incubation was used (7 h), Sm A enhanced SO4 uptake, and discrimination was increased by preincubation of the rudiments in buffer for 24 h. With this procedure, IGF I (0.5 ng/ml) was nearly equipotent to 5% serum. On a weight basis, IGF I was more active than either Sm A or IGF II. The data suggest that assay conditions are crucial for demonstration of Sm activity. Appropriate conditions may be different for isolated GF than for a complex medium such as serum. The results further suggest that with certain protocols, the responsiveness of chick embryo cartilage is qualitatively similar to that of hypophysectomized rat cartilage.

Animals↗
PubMed1978

Synthesis of 1 alpha-hydroxy[7-3H]cholecalciferol and its metabolism in the chick.

1. 1 alpha-Hydroxy[7-3H]cholecalciferol (specific radioactivity of 2-Ci/mmol) was synthesized, and its metabolism in chicks studied. 2. 1 alpha-Hydroxy[7-3H]cholecalciferol was metabolized very rapidly in the chick to 1 alpha,25-dihydroxy[7-3H]cholecalciferol and to a metabolite less polar than 1 alpha-hydroxycholecalciferol. Intestine exhibited highest accumulation of 1 alpha-25-dihydroxy[7-3H]cholecalciferol, and liver exhibited highest accumulation of the non-polar metabolite. 3. Tissue uptake of 1 alpha-hydroxy[7-3H]cholecalciferol and its metabolites in chicks that were dosed continuously for 16 days with 1 alpha-hydroxy[7-3H]cholecalciferol did not exceed by very much that observed in tissues obtained from chicks that were dosed with a single injection of 1 alpha-hydroxy[7-3H]cholecalciferol 24 h before killing, except for liver and kidney. 4. Lowest accumulation of metabolites was noted in muscle and bone, and for the latter, highest uptake of 1 alpha,25-dihydroxy[7-3H]cholecalciferol was noted in the epiphysial periosteum and the metaphysis. 5. Formation of 1 alpha,24,25-trihydroxy[7-3H]cholecalciferol was not observed in the chicks that were dosed continuously with 1 alpha-hydroxy[7-3H]cholecalciferol, despite the fact that plasma calcium and phosphorus were normal and despite the presence of renal 24-hydroxylase activity. 6. The vitamin D status of the chicks did not appear to affect the metabolic profile of the administered 1 alpha-hydroxy[7-3H]cholecalciferol.

Animals↗
PubMed1977

Binding and biologic activity of glucagon in liver cell membranes of chronically hyperglucagonemic rats.

Glucagon binding by liver cell membranes was examined in rats with chronically elevated plasma levels of immunoreactive glucagon (IRG) resulting from insulin deficiency, starvation, or twice daily glucagon injections. The concentration of specific glucagon binding sites was significantly reduced in the three chronically hyperglucagonemic (IRG greater than 125 pg/ml) groups as compared with nondiabetic controls and insulin-treated diabetic control rats with only mild hyperglucagonemia. A reduction in glucagon binding sites did not occur with hyperglucagonemia of 12 h or less. Despite the reduced binding of glucagon in the three chronically hyperglucagonemic groups, the ability of glucagon to stimulate cAMP production was not reduced. It is concluded that while decreased glucagon binding occures in the forms of chronic hyperglucagonemia studied, it is not associated with a reduction in the ability of glucagon to stimulate cAMP production.

Adenylyl Cyclases↗
PubMed1975

Hematology and blood chemistry in saturation diving: I. Antiplatelet drugs, aspirin, and VK744.

Blood chemistry and cellular parameters were studied before, during, and after saturation (2.4 ATA) dives in the HYDRO-LAB habitat on two separate occasions. In both, platelet count fell greater than 20% 12-24 hours after surfacing and moderate (5%) reductions in hemoglobin, red-cell count, and packed-cell volume were observed. Plasma cholesterol and triglyceride levels were depressed postdive as were most plasma enzymes (GOT, GPT, CPK, LDH, ALP). The latter changes were very slight. In the first study, the incidental ingestion of aspirin by some divers did not prevent the loss of platelets even though the platelet-release reaction in response to ADP was inhibited. In the second study the platelet-suppressive drug VK744 was administered, on a double-blind randomized basis, to six divers, six others taking a placebo capsule. Dosage of VK744 was 300 mg TID for 2 days before, 5 days during, 3 days after saturation dive. The drug inhibited the postdive loss of circulatory platelets and in fact the treated group showed a rebound in platelet count above control values, 48-72 hours postdive. Megathrombocyte counts indicated the production of new platelets in both groups at this point. The treated group also showed a marked and significant reduction in plasma cholesterol and triglycerides, suggesting an antilipidemic effect of the drug. Theses results confirm previous observations and indicate that postdecompression loss of platelets may be related to sequestering of reactive platelets, possibly by microbubbles, and that the phenomenon can be inhibited by some antiplatelet drugs.

Adult↗
PubMed1975

Hematology and blood chemistry in saturation diving: II. Open-sea vs. hyperbaric chamber.

Hematograms, platelet function, and blood-enzyme chemistry were compared in two similar saturation-excursion dives, one conducted in a hyperbaric chamber and the other in the open sea. The chamber dive was more stressful in that it was preceded by a series of bounce decompression dives (one of which produced a 100% incidence of cutaneous pruritus in four subjects) and in that the excursions from saturation depth (60 fsw or 2.818 ATA) were longer and deeper (producing one case of O2 convulsions, one of confirmed decompression sickness, and several of Doppler-detected vascular bubbles). The chamber dive was associated with a marked and significant reduction in circulating platelet count; significant increases in plasma enzyme activities in the victim of O2 toxicity (LDH, CPK) and in one subject with Doppler bubbles and questionable bends symptoms (LDH, GOT, GPT) but not in another; and mild but significant anemia. In the open-water dive, one subject, who developed symptoms of gastroenteritis, showed moderate elevation of LDH, GOT, and GPT activity. No significant change in platelet counts occurred. Both dives were associated with elevated white-cell counts, apparently as a result of numerous minor infections, and reduced sensitivity of platelets of ADP-induced aggregation.

Alanine Transaminase↗
PubMed1971

Doctors' fees.

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Australia↗