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Biomedical subjects

C Nolan

Publications and source records attributed to C Nolan.

72 records · Page 4Linked to original sources
PubMed1976

A comparison of mice in rebound-thrombocytosis with platelet-hypertransfused mice for the assay of thrombopoietin.

Rebound-thrombocytosis and platelet hypertransfusions were compared as methods of preparing assay animals for the measurement of thrombopoietin (TSF). In immunothrombocythaemic mice, the amount of 35S incorporation into the platelet mass after injections of a standard dose of TSF was related to the length of time after rabbit anti-mouse platelet serum (RAMPS) injection. After 2 platelet transfusions, however, there was no decrease in 35S incorporation values of mice with time after injections of control or TSF-containing substances. When platelet counts were made 3 days after the last platelet transfusion, the counts decreased with the number of transfusions. Mice in rebound-thrombocytosis were responsive to TSF as evidenced by higher platelet counts (P less than 0.05) and increased 35S incorporation into platelets (P less than 0.005), whereas mice made thrombocytotic by platelet transfusions were not. Assuming that increased platelet counts induced by the different techniques affect assay mice only by inhibiting blood cell production by haematopoietic cells, these data are consistent with the hypothesis that sensitivity to TSF depends upon the proliferative state of the megakaryocytic precursor population.

Animals↗
PubMed1976

Computer-based consultation in "care" of the critically ill patient.

Despite far-reaching progress in all areas of surgery, methods of medical data analysis and communication have not kept pace with the increased rate of data acquisition. The needs to organize and communicate these data and to provide a medium for continuing education are great in critical-care areas where the amount and the diversity of data collected are enormous, and the number of surgical team members involved in patient care has grown proportionately. The computer-based Clinical Assessment, Research, and Education System (CARE) is a time-shared computer system now available on a national basis designed to provide a management and education aid for the treatment of critically ill surgical patients. An initial clinical assessment and operative note are entered by the surgeon from which an estimation of the initial fluid, blood, and electrolyte deficits are calculated. Daily doctor's progress notes, shift nurses' summaries of vital signs, clinical information, intake and output data, and drug administration, biochemical, cardiovascular, blood gas, and respiratory information are entered for each shift. From these, a metabolic balance is calculated; fluid, electrolyte, and caloric requirements are determined; cardiorespiratory parameters are computed; and various therapuetic suggestions and cautions are given to alert the physician to problems that may be arising. The surgeon-user is assisted in making the best critical-care decisions through computer-directed, interactive prompting which focuses on the most important clinical conditions and correlations and metabolic considerations and relates the important problem to the relevant literature.

Acute Disease↗
PubMed1975

Thrombopoietin production by human embryonic kidney cells in culture.

Human embryonic kidney cells were maintained in culture in a medium containing lactalbumin hydrolysate for 5 to 6 weeks and the supernatant fluid tested for thrombopoietin content. Thrombopoietin was determined by a bioassay procedure which utilized mice that were in rebound thrombocytosis. The results indicate that the medium from kidney cells in culture contained a factor that stimulates thrombopoiesis in assay mice as measured by per cent 35-S incorporation into platelets. A dose-response relationship was demonstrated between the volume of thrombopoietically active production medium injected and the level of isotope that subsequently appeared in the circulating platelets. Thrombopoietin was not found in control production media. Moreover, thrombopoietin-rich production medium did not contain erythropoietin, erythroginin, or white blood cell-stimulating factors. The results of this study indicate that kidney cells in culture produce a specific thrombopoietic stimulating factor. It seems probable from these in virto data that a site of production of thrombopoietin in vivo is the kidney.

Animals↗
PubMed1972

The primary structure of cytochrome c from the rust fungus Ustilago sphaerogena.

1. The complete amino acid sequence of cytochrome c from the basidiomycete Ustilago sphaerogena was determined from the amino acid compositions and sequences of either tryptic or chymotryptic peptides, and in homology with at least thirty other established sequences of cytochrome c. 2. The primary structure of the molecule bears all of the characteristics of a mammalian-type cytochrome c, showing the typical clustered distribution of hydrophobic and basic residues with a single polypeptide chain of 107 residues. 3. Like all other fungal cytochromes c, it possesses a free N-terminus, and one less residue at the C-terminus than vertebrate cytochromes c. The region of residues 70-80 is strictly conserved, as is histidine at position 18. Position 26 is occupied by an asparagine residue, in contrast to histidine which occurs at this location in most of the known sequences of mammalian-type cytochromes c. 4. In contrast to some other fungal and plant cytochromes c of known primary structures, the Ustilago cytochrome c molecule does not contain trimethyl-lysine. 5. The sequence of Ustilago cytochrome c differs from the sequences of human, horse, chicken, tuna, wheat, and baker's yeast proteins at loci 47, 43, 44, 44 and 38 respectively.

Amino Acid Sequence↗
PubMedDate not supplied

Forearm arterial vascular responsiveness in insulin-dependent diabetic subjects.

The vascular reactivity of forearm arterioles was measured in 16 control subjects (C) and 30 insulin-dependent diabetic (IDDM) subjects, 16 of whom were shown to have microvascular and/or neuropathic complications (DC) including 8 with autonomic neuropathy (DCa) and 14 were shown to be free of complications (DNC). Forearm blood flow was measured by strain gauge plethysmography basally, following a cold pressor stress and following a period of arterial occlusion (reactive hyperaemia). The tests were repeated 24 h later following aspirin treatment. Both C and DNC showed a significant reduction in blood flow in the cold pressor test (C 0.64 +/- 0.12, DNC 0.89 +/- 0.22 ml/100 ml forearm tissue/min reduction in flow P < 0.005), while DC showed no significant response. Reactive hyperaemia was significantly greater in C than in DNC or DC (8.37 +/- 1.14, 5.51 +/- 1.27 and 4.95 +/- 0.75 ml/100 ml tissue/min, respectively, P < 0.02). In the DC group, DCa had significantly less response than those without autonomic neuropathy. Aspirin treatment restored the response of DNC but not DC to normal, suggesting that the abnormality in the former group may have been due to overproduction of a vasoconstrictive cyclooxygenase product (such as thromboxane A2). It is concluded that the abnormalities of vasomotor responses in diabetic subjects are complex and are apparently dependent on autonomic neuropathy, humoral and perhaps structural changes.

Adult↗
PubMedDate not supplied

Effects of a high-starch diet with low or high fiber content on postabsorptive glucose utilization and glucose production in normal subjects.

The effects of fiber, added to a high-starch diet, on glucose and insulin metabolism were studied in seven healthy men in a controlled environment. Diets rich in starch (carbohydrate provided 62% energy) contained either 16 g or 100 g of fiber from several sources of food and were given for 10-day periods. Two parameters of glucose control were measured: glucose metabolism during insulin-glucose infusions (seven subjects) and glucose production measured by infusing tritiated glucose tracer (five subjects). Three sets of studies were carried out in the sequence: low-fiber, high-fiber, low-fiber. The respective mean values (+/- SE) for glucose utilization were 6.70 +/- 1.4, 7.01 +/- 1.02, and 6.77 +/- 1.34 mg/kg X min. Analysis of variance failed to show a significant effect of dietary change. Values for basal glucose production were 2.0 +/- 0.1, 1.9 +/- 0.2, and 2.4 +/- 0.3 mg/kg X min with the low-fiber, high-fiber, and low-fiber diets, respectively, which were not significantly different. The one significant response to the high-fiber diet was a lowering in plasma cholesterol, the mean values for the seven subjects during the three periods being 154 +/- 12, 138 +/- 10, and 156 +/- 13 mg/dl (P less than 0.05).

Adult↗
PubMedDate not supplied

Low intensity laser therapy for chronic venous leg ulcers.

Ulceration of the lower extremities is one of the most important medicosocial problems (Skobelkin et al 1990). In this article, two case studies show that it is the length of time that laser therapy is used that can have a significant impact on ulcer size.

Aged↗
PubMedDate not supplied

Substance abuse and child welfare: clear linkages and promising responses.

Parental substance abuse is a significant factor in many of the families served in the child welfare system. This article examines: (1) the prevalence of substance abuse among families involved with the child welfare system; (2) the impact of substance abuse on child welfare practice; (3) how both the Adoption and Safe Families Act of 1997 and welfare reform legislation intensify the need to address parental substance abuse effectively; and (4) promising strategies for addressing these families' needs.

Adult↗
PubMedDate not supplied

The impact of antithrombotic therapy on neurosurgical emergency referral load.

The authors sought to determine the impact of antithrombotic therapy on emergency referrals at one neurosurgical centre. All emergency telephone referrals over a 90 day period were carefully documented with particular attention paid to current antithrombotic medications and their indication. Details regarding age, gender, diagnosis, radiological findings and treatment were also recorded. 713 emergency referrals were documented in the data collection period. 174 (24.4%) patients presented with intracranial or spinal haemorrhage and 75 (43.1%) of these were on antithrombotic therapy, ranging in age from 46-94 years (mean 71.1 years) with 29 (31.8%) on warfarin, 43 (47.2%) on aspirin and 15 (16.4%) on clopidogrel alone or in combination with another antithrombotic agent. 17 (22.6%) had no documented indication for antithrombotic therapy (all of these were on aspirin therapy) and 9 (31%) of those on warfarin had an INR in excess of 3.5 on presentation. Almost one quarter of those on antithrombotic therapy who presented with a haemorrhagic complication had no obvious indication for such therapy. One third of those on warfarin were over anticoagulated.

Aged↗