Search PubMed⌕ Search

Biomedical subjects

D Kelley

Publications and source records attributed to D Kelley.

47 records · Page 3Linked to original sources

Androgen-induced myogenesis and chondrogenesis in the larynx of Xenopus laevis.

We investigated a possible role for testosterone-induced cell proliferation in the development of sexual dimorphism in the larynx of South African clawed frogs, Xenopus laevis. Androgen-induced cell proliferation was studied using [3H]thymidine autoradiography. Nuclei of cartilage, perichondrium, and muscle were labeled in the larynx of sexually immature frogs of both sexes but not in adults. Cell proliferation did not occur with estradiol treatment nor was it seen in nonlaryngeal muscle or cartilage. Electron microscopic/autoradiographic studies of laryngeal muscle indicate that testosterone stimulates satellite cell division which later results in formation of myonuclei. We conclude that testosterone induces both chondrogenesis and myogenesis in juvenile larynx and that this process may contribute to the pronounced sexual dimorphism of the adult vocal organ.

Animals↗

Measurement of antibody-dependent binding, proteolysis, and turnover of C1s on liposomal antigens localizes the fluidity-dependent step in C1 activation.

The antibody-dependent binding and activation of the first component of human complement (C1) by liposomes containing nitroxide spin-label lipid haptens have been simultaneously measured. The liposomes were either fluid (dimyristoylphosphatidylcholine) or solid (dipalmitoylphosphatidylcholine) at the temperature of the experiments (32 degrees C). In 10 minutes fluid liposomes activate 40% of the C1 whereas solid liposomes only activate 10% of the C1. The fraction of C1 bound at the end of the activation incubation is approx. 2% for fluid liposomes and approx. 4% for solid liposomes. This binding is consistent with the relative amounts of antibody which bind to these two types of liposomes. These results demonstrate turnover of C1 or C1r2s2 on the liposome surface. It is concluded that the differential activation of C1 is due to a difference in the rate of activation of C1 after it is bound to the liposome surface. Lower limits for the activation rate constant for C1 bound to fluid and solid liposomes are estimated to be 8 X 10(-2) s-1 and 1 X 10(-2) s-1, respectively.

Animals↗

Mortality and cancer frequency among military nuclear test (Smoky) participants, 1957 through 1979.

Follow-up of health status has been completed through 1979 for 3,072 (95.5%) of 3,217 nuclear test participants on military maneuvers during the 1957 nuclear test "Smoky." In these participants, 112 cases of cancer were diagnosed, compared with 117.5 cases expected. During the same follow-up period (1957 through 1979), 64 persons died of cancer, compared with an expected 64.3. Statistically significantly increased frequency of occurrence and mortality was found only for leukemia. The amount of cumulative gamma radiation exposure for 1957 ranged from 0 to 10,397 mrem as measured by individual personnel film badges. Although uncertainty remains about the exact amount of radiation exposure, the lack of a significant increase after 22 years in either the incidence of or the mortality from any other cancer and the apparent lack of a dose effect by unit lead to the consideration that the leukemia findings may be attributable either to chance, to factors other than radiation, or to some combination of risk factors possibly including radiation.

Follow-Up Studies↗

Acyl-CoA synthase and acyltransferase activity in developing skeletal muscle membranes.

Enzymes participating in the activation and esterification of fatty acids for complex lipid biosynthesis were characterized in neonatal and adult rabbit skeletal muscle membranes. The activity of acyl-CoA synthase was 1.4-1.6-fold greater in neonatal vs. adult sarcoplasmic reticulum for the fatty acid substrates linoleic (2.6 vs. 1.61 nmol 18:2-CoA/min per mg), stearic (0.94 vs. 0.66 nmol 18:0-CoA/min per mg) and palmitic (2.43 vs. 1.51 nmol 16:0-CoA/min per mg) acids. Enzyme activity was identical between neonate and adult for coenzyme A, ATP and linoleic acid concentration dependence. Glycerol-3-phosphate acyltransferase activity was 6-fold greater in neonatal than adult sarcoplasmic reticulum for both linoleoyl-CoA (1.4 vs. 0.22 nmol 18:2/min per mg) and stearoyl-CoA (1.1 vs. 0.13 nmol 18:0/min per mg) donor substrates, whereas lysophosphatidylcholine acyltransferase activity was similar. Enriched fractions of sarcolemmal membranes possessed the highest activity for lysophosphatidylcholine acyltransferase activity, being 2-4-fold greater than sarcoplasmic reticulum. In contrast to sarcoplasmic reticulum, lysophosphatidylcholine acyltransferase activity was 2-3-fold greater in neonatal compared to adult sarcolemma for lineoleic (18.9 vs. 8.5 nmol 18:2/min per mg) and the stearic (2.8 vs. 0.68 nmol 18:0/min per mg) acid incorporation. The greater capacity of neonatal membranes for acylation by the de novo pathway is in accord with the requirements for neonatal muscle to effect high rates of triacylglycerol and phospholipid synthesis essential for oxidative metabolism and membrane synthesis during postnatal development and growth.

Acyl Coenzyme A↗

The joining of V and J gene segments creates antibody diversity.

The variable regions of mouse kappa (kappa) chains are coded for by multiple variable (V) gene segments and multiple joining (J) gene segments. The V kappa gene segments code for residues 1 to 95; the J kappa gene segments code for residues 96 to 108 (refs 1-3). This gene organisation is similar to that encoding the V lambda regions. Diversity in V kappa regions arises from several sources: (1) there are multiple germ-line V kappa gene segments and J kappa gene segments; (2) combinatorial joining of V kappa gene segments with different germline J kappa gene segments; and possibly, (3) somatic point mutation, as postulated for V lambda gene segments. Also, from a comparison of the number of germ-line J kappa gene segments and amino acid sequences, it has been suggested that J kappa region sequences may be determined by the way V kappa and J kappa gene segments are joined. This report supports this model by directly associating various J kappa sequences with given J kappa gene segments.

Animals↗

Methadone maintenance: an assessment of potential fluctuations in behavior between doses.

Thirty methadone maintenance outpatients were measured 1 and 25 hours after ingestion of methadone on auditory threshold, distance perception, simple and differential reaction time, time perception, attention span, and short-term memory. The results revealed a small but statistically significant difference between the two tests for distance perception. In addition, treatment interacted with preparatory interval on differential reaction time and with sex on attention span.

Adolescent↗

Functional outcomes of patients with multiple limb trauma.

A retrospective chart review was performed to assess the effects of acute care hospital-based rehabilitation in patients with multiple limb trauma on functional status and length of stay and to determine whether the distribution of limbs involved has any effect on these variables. Admission and discharge motor Function Independence Measure scores and length of stay were compared for all patients and the injury subgroups. Significant functional gains were made between admission motor Functional Independence Measure (45.4+/-11.9) and discharge motor Functional Independence Measure (74.1+/-11.6; P < 0.05) for the group as a whole and across subgroups, with no significant differences between the subgroups. For all patients, the rehabilitation length of stay was 27.7+/-23.0, with again no difference noted between the subgroups. Individuals with functional deficits attributable to multiple limb trauma benefit significantly from comprehensive intensive acute inpatient rehabilitation. The distribution of limbs involved has little effect on functional outcome or length of stay.

Activities of Daily Living↗

Burns in alcohol and drug users result in longer treatment times with more complications.

Brezel, Kassenbrock, and Stein (J Burn Care Rehabil 1988;9:169-71), surveyed a group of 180 patients who were substance abusers or who were neurologically or mentally impaired and found that their inpatient care was more costly, more complicated, and more lengthy. In our institution we undertook a similar study to determine whether our findings would be similar. During a 12-month period, the charts of all patients over the age of 18 who were admitted for treatment of acute burns were reviewed. One hundred and thirty-one charts were available for study. Review of the charts revealed that 19 (14.5%) met our criterion of being impaired by drugs or alcohol, and the remaining 112 patients served as control subjects. The total body surface area burn averaged 25.8% in the impaired group and 21.3% in the control group. The amount of third-degree burns averaged 11% in the impaired group and 11% in the control group. Although the amount of third-degree burns was virtually identical in the two groups, the control group required an average of 1.2 procedures per patient, whereas the impaired group required 2.1 procedures per patient. A list of possible complications or adverse reactions that could occur was used to compare the two groups. The control group averaged 1.83 complications per patient, and the impaired group averaged 3.16 complications per patient. The average length of stay in the hospital for the control group was 19 days, and the average length of stay for the impaired group was 34.1 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗