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Biomedical subjects

C Nichols

Publications and source records attributed to C Nichols.

At least 19 recordsLinked to original sources
PubMed1992

Effect of one-legged exercise on the strength, power and endurance of the contralateral leg. A randomized, controlled study using isometric and concentric isokinetic training.

The purpose of this investigation was to study the effect of one-legged exercise on the strength, power and endurance of the contralateral leg. The performance of the knee extensor and flexor muscle of 20 healthy young adults (10 men and 10 women) was first tested by Cybex II+ and 340 dynamometers. Then 10 subjects were chosen at random to train using one leg three times a week for 7 weeks whilst the other 10 served as controls. During the 8th week, the tests were repeated. Both quadriceps and hamstring muscles of the trained subjects showed a cross-transfer effect from the trained limb to the untrained side. This concerned the strength and power, as well as endurance characteristics of these muscles. The average change in peak torque of the quadriceps muscle was +19% (P less than 0.001) in the trained limb, +11% (P less than 0.01) in the untrained limb and 0% in the control limbs. In hamstring muscles the changes were +14% (P less than 0.01), +5% and -1%, respectively. Concerning muscle endurance (work performed during the last 5 contractions in the 25-repetition test) the corresponding changes were +15% (P less than 0.01), +7% (P less than 0.01), and -1% in quadriceps muscle, and +17% (P less than 0.05), +7%, and -3% in hamstring muscles. The average strength benefit in the untrained limb was +36% (hamstring muscles) and +58% (quadriceps muscle) of that achieved in the trained limb. Untrained hamstring muscle showed better benefits in the endurance parameters than in strength or power parameters, while in the quadriceps muscle this effect was reversed. A positive relationship was observed between the changes (greater improvement in the trained limb resulted in greater improvement in the untrained limb) (hamstring muscles: r = 0.83, P less than 0.001, quadriceps muscle: r = 0.53, P less than 0.001). In endurance parameters, this relationship was almost linear while in the strength and power parameters the results were more in favour of a curvilinear relationship with limited benefit.

Adult↗
PubMed1992

Clear cell neoplasm.

We are reporting four cases of clear cell neoplasm. Local infiltration and destruction was observed in one case while in a second case, originating in the sublingual gland, metastasis to the lymph nodes occurred. The behaviour of these neoplasms has prompted the suggestion that these tumours be designated carcinomas rather that noncommittally tumours or neoplasms (Batsakis and Regezzi, 1977). The histopathological characteristics of our four cases conform to those that have been articulated and believed to be the distinctive features of these tumours (Batsakis and Regezzi, 1977). It is hoped that ours and similar reports will be helpful towards clearing the diagnostic and taxonomic confusion regarding these tumours.

Adenocarcinoma↗
PubMed1992

Ca2+ mobilization by the LH receptor expressed in Xenopus oocytes independent of 3',5'-cyclic adenosine monophosphate formation: evidence for parallel activation of two signaling pathways.

The cDNAs encoding the murine LH receptor (LHR) and the human beta 2-adrenoceptor (h beta 2AR) were cloned and RNAs complementary to their sense strands (cRNAs) were injected into defolliculated Xenopus oocytes. This led to expression, respectively, of LH- and isoproterenol-stimulable adenylyl cyclase activities, indicating that functionally active receptor cDNAs had been cloned. In oocytes injected with LHR cRNA, but not in control or h beta 2AR cRNA-injected oocytes, human CG and LH increased a Ca(2+)-activated Cl- current, as measured by the two-microelectrode voltage-clamp method. This effect was not seen with isoproterenol in control or h beta 2AR cRNA-injected oocytes, it was also not observed in response to forskolin or (Bu)2cAMP. The response to human CG could be obtained in the absence of extracellular Ca2+ but was abolished by injection of EGTA, indicating that it was caused by mobilization of Ca2+ from intracellular stores. The response was unaffected by overnight treatment with 1 microgram/ml pertussis toxin. The experiments show that a glycoprotein hormone receptor can be expressed as a functionally active molecule in Xenopus oocytes, and that the LHR has the ability of activating two separate intracellular signaling pathways: one forming the second messenger cAMP, and the other mobilizing Ca2+ from intracellular stores. It is proposed that the latter is secondary to a primary activation of phospholipase C by the LHR, which elevates intracellular Ca2+ via intermediary elevation of inositol phosphates, presumably (1,4,5)inositol trisphosphate.

Adenylyl Cyclases↗
PubMed1991

Knowledge and beliefs about cancer in a socioeconomically disadvantaged population.

Americans living in poverty experience a higher incidence of and greater mortality from cancer than the nonpoor. At least 50% of the difference in mortality is believed to be due to delay in diagnosis, although risk-promoting lifestyles and behaviors also contribute to decreased survival. A potential exacerbating factor among the poor is inadequate information and knowledge about cancer and its treatment. Interviews were conducted with 128 cancer patients from a socioeconomically disadvantaged population to assess knowledge of cancer and its treatment and to evaluate care-seeking behaviors. Results indicated that although patients relied primarily on their physicians for information about their disease and treatment, a number of misconceptions regarding cancer existed in this population. Notably, nearly 50% of the patients surveyed either denied or did not know that smoking was related to the development of cancer. Additionally, patients frequently reported inappropriate care-seeking behaviors when asked to respond to a series of common disease-related signs or symptoms. These findings suggest that misinformation and misconceptions regarding cancer and its treatment among patients in this sample may contribute to inappropriate care-seeking behaviors.

Consumer Behavior↗
PubMed1990

Treatment of refractory lymphoma with high dose cytarabine, cyclophosphamide and either TBI or VP-16 followed by autologous bone marrow transplantation.

This study was designed to test the efficacy and toxicity of combining high-dose cytarabine (3 g/m2 every 12 h x 8 doses day -7 to day -4, total dose 24 g/m2), methyl prednisolone (0.5 mg/kg every 4 h day -7 to day -1), and cyclophosphamide (CY) (60 mg/kg day -3 and day -2) with either total body irradiation (TBI) (900 cGy in a single fraction on day -1) or VP-16 (600 mg/m2/days -7, -5, and -3) in patients not eligible for TBI secondary to prior radiotherapy. We treated 14 patients (eight male, six female) with either non-Hodgkin's lymphoma (n = 5) or Hodgkin's disease (n = 9). All patients had failed prior conventional chemotherapy (median two regimens range 1-5). Five patients were treated with TBI and nine with VP-16. There were eight complete remissions, two partial remissions, four were inevaluable for response due to early death. Overall survival is 21% (3/14) and relapse-free survival is 7% (1/14) with the sole disease-free survivor now 40 months from transplant. Very significantly, among patients receiving TBI, there were no survivors (median survival 24 days, range 17-330 days) and 4/5 had pulmonary complications. Median DLCO in these four patients was 61% (range 50-67) prior to transplant and none had an infectious etiology established by bronchoalveolar lavage. Median time to an absolute granulocyte count of 500 x 10(6)/l was 16 days (range 10-37 days) and to a platelet count of 20 x 10(9)/l was 12 days (range 7-22 days). In conclusion, the addition of high-dose cytarabine (24 g/m2) to CY and single-dose TBI or VP-16, while being very active, produced excessive pulmonary toxicity in this group of patients with lymphoma.

Adolescent↗
PubMed1989

Combined Kirschner-Ehmer device and dorsal spinal plate fixation technique for caudal lumbar vertebral fractures in dogs.

A new surgical technique was developed for the fixation of caudal lumbar vertebral fractures in dogs. The technique provides optimal stabilization, can be used in combination with dorsal decompression, and does not require an intact spinous process on the fractured vertebra or attachment of the fixation devices to the fractured vertebra. The fixation consists of a Kirschner-Ehmer device and dorsal spinal plates. After fracture healing, only mild sedation of the dog is needed to allow removal of the external hardware used in the fixation. The technique, its indications, and its use in 5 cases are described.

Animals↗
PubMed1988

Combined Kirschner-Ehmer apparatus and dorsal spinal plate fixation of caudal lumbar fractures in dogs: biomechanical properties.

The strength and rigidity of a new surgical technique for the stabilization of caudal lumbar fractures in dogs, using a Kirschner-Ehmer apparatus and a dorsal spinal plate (KE/DSP), were compared with 2 other methods of internal spinal fixation and with intact (control) spines, using a spinal test system that subjected the spines to 4-point bending. The fixation devices were applied to isolated canine lumbosacral spines (L1 to S3) from cadavers. A complete spinal separation was made in the spine implant specimens at L5-L6 by sharp dissection of all ligamentous structures connecting the two vertebrae. Bending moment vs L5-L6 angular deformation curves, and rigidity and load sustained at 10 degrees angular deformation (failure) were recorded for each fixation method and for the control spines. Values were compared by statistical analysis. The combined KE/DSP fixation and a combined vertebral body plate/dorsal spinal plate (VBP/DSP) fixation were stronger and more rigid than were the control spines and those fixed with a modified segmental-fixation method (P less than 0.05). There were no statistical differences in strength and rigidity between the 2 combined-fixation techniques. Although the VBP/DSP technique is not applicable to clinical caudal lumbar (L5-L6) fractures, it was compared in this study to the KE/DSP technique because a similar VBP/DSP technique was reported strongest in a similar study of L3-L4 simulated fractures, compared with 3 other spinal-fixation techniques that have been used in repair of caudal lumbar fractures. The technique has been used successfully in 6 dogs with caudal lumbar fractures.

Animals↗
PubMed1979

The National Football Head and Neck Injury Registry. Report and conclusions 1978.

The National Football Head and Neck Injury Registry has documented 1,129 injuries since 1971 that involved hospitalization for more than 72 hours, surgical intervention, fracture-dislocation, permanent paralysis, or death. Of this group of injuries, 550 were fracture-dislocations of the cervical spine, of which 176 were associated with permanent quadriplegia. It appears that during the last two decades, there has been a decrease in the incidence of direct fatalities, head injuries associated with intracranial hemorrhage, and injuries associated with death. Conversely, cervical spine injuries with fracture-dislocation and with permanent quadriplegia have increased. We believe that these observations are the result of the development of a protective helmet-face mask system that has effectively protected the head, and by so doing has allowed it to be used as a battering ram in tackling and blocking techniques, thus placing the cervical spine at risk of injury.

Athletic Injuries↗
PubMed1978

Diabetes mellitus and periodontal disease.

A sample of 54 patients with diabetes mellitus were subjects to detailed assessment of periodontal disease levels using standard indices. In order to determine whether the severity of periodontal disease was related to the severity of diabets mellitus, a series of parameters of the diabetes mellitus population was simultaneously studied. There were no significant relationships between the levels of periodontal disease and the duration of diabetes, the type of treatment and the frequency of systemic complications. Periodontal disease in the diabetic appeared to the affected by the same etiologic factors [plaque, calculus, neglect] as would be expected in nondiabetic patients. Further studies with larger population samples would be appropriate.

Adult↗
PubMed1977

Biosynthesis of prodigiosin by non-proliferating wild-type Serratia marcescens and mutants deficient in catabolism of alanine, histidine, and proline.

Mutants of Serratia marcescens Nima, designated as Aut, Hut, or Put, did not utilize L-alanine, L-histidine, or L-proline, respectively, as a sole carbon source but did utilize other amino acids or glycerol as carbon sources. The bacteria were permeable to alanine, histidine, and proline but lacked the enzymes responsible for degradation of these amino acids. The Aut mutant contained no L-alanine dehydrogenase activity, whereas the Hut and Put mutants contained only 7 and 4% of the histidase and proline oxidase activities, respectively, found in the wild-type strain. Rates of oxygen uptake and protein synthesis were significantly lower when the mutants were incubated in the presence of amino acids they could not degrade. Studies of L-[14C]alanine, L-[14C]histidine, and L-[14C]proline incorporation into prodigiosin synthesized by these mutants and the wild-type strain revealed that proline was incorporated intact, whereas all of alanine except the carboxyl group was incorporated into the pigment molecule. Histidine did not enter prodigiosin directly. These data suggested that the presence of unique biosynthetic pathways, independent of primary metabolism, leads to formation of prodigiosin from specific amino acids.

Alanine↗