Internship: to promote the general welfare.
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Directories as Topic↗
Biomedical subjects
J Johnson
Publications and source records attributed to J Johnson.
Isokinetic strength and endurance and muscle fiber type of elite oarswomen.
Knee extension (KE) and elbow flexion (EF) isokinetic strength (at angular velocities of 0, 1.05, 2.09, 3.14 and 4.19 rad sec-1) and fatigue (strength loss over 50 isokinetic contractions) were examined in ten elite oarswomen and ten untrained subjects. Muscle fiber types of the corresponding muscles were determined for the oarswomen. The oarswomen had a lower slow twitch percentage than previously reported values for oarsmen, which is consistent with the shorter duration of the women's competitive race. A marked similarity was found between untrained subjects and oarswomen in 1) the patterns of the torque velocity curves of the strength measurements and 2) the patterns of the fatigue curves of the isokinetic endurance measurements. Although the patterns were similar, the entire curves for the oarswomen were displaced upward. For each group, however, the patterns of both the KE torque velocity and the isokinetic fatigue curves differed from the patterns of the corresponding curves for EF. These differences are likely due to inherent morphological or physiological characteristics of the two muscle groups.
Fatigue↗
Assessment of pancreatic ductal penetration of antibiotics.
Pancreatic ductal penetration of antibiotics is not uniform. Antibiotic therapy for pancreatic and pancreatic related infections, theoretically, is enhanced by drugs that reach the ductal system. The pancreatic ductal penetrance of Cefamandol (1 gm), Amikacin (7.5 mg/kg), and Chloramphenicol (1 gm) given as a single intravenous dose prior to endoscopic retrograde cholangiopancreatography was studied in ten patients. Serum and pancreatic juice were collected simultaneously, frozen, and later assayed for antibiotic concentration. Each antibiotic achieved its expected therapeutic serum level. In contrast, pancreatic ductal levels of Cefamandol and Amikacin were subtherapeutic, whereas Chloramphenicol levels were therapeutic. Further studies are needed to identify other antibiotics with good pancreatic ductal penetrance.
Amikacin↗
Statistical evidence for the individuality of the human dentition.
A general population sample of bite marks in wax is used to demonstrate mathematically the individuality of the human dentition. The general principles of probability are discussed and applied to the analysis of teeth using a precise method of measurement. The unique nature of the human dentition is confirmed.
Bites and Stings↗
Fetal blood and tissue PO2 during maternal oxygen breathing.
The effect of 100% oxygen breathing on fetal blood and tissue PO2 was examined in chronically catheterised fetal sheep of 12 pregnant ewes. Blood PO2 was monitored with intravascular polarographic electrodes and tissue PO2 with galvanic electrodes implanted in various tissues. In non-acidotic healthy fetuses, oxygen breathing increased fetal PO2 by 30% within 3 min in arterial blood and within 5 min in tissues. Thereafter blood PO2 increased by a maximum of 40% at 9 min and tissue PO2 rose by a maximum of 52% at 12 min. Blood PO2 returned promptly to control values after 15 min of oxygen breathing but washout of oxygen from tissues was slower and tissue PO2 remained significantly higher in the post-oxygen versus the pre-oxygen period. Continuation of oxygen breathing for 30 min did not lead to any further increase in tissue PO2. Oxygen breathing did not prevent a decrease in fetal PO2 associated with spontaneous myoelectrical activity of the uterus. It is concluded that maternal oxygen breathing leads to a significant increase in both blood and tissue PO2 in the healthy fetus. The majority of the increase occurs within the first 3-4 min and no further increase in either blood or tissue PO2 is observed after 12 min.
Animals↗
Synergistic effect of AMP and fructose 2,6-bisphosphate on the protection of fructose 1,6-bisphosphatase against inactivation by trypsin.
The rate of inactivation of chicken liver fructose 1,6-bisphosphatase by trypsin is reduced if the digestive reaction is conducted in the presence of AMP or fructose 2,6-bisphosphate. The effects of these 2 compounds are synergistic. Although fructose 1,6-bisphosphate does not protect the enzyme against tryptic inactivation, it can enhance the effect of AMP. Selective modification of the AMP allosteric site of fructose 1,6-bisphosphatase with pyridoxal-P and NaBH4 renders the enzyme more resistant to tryptic inactivation, but the modified enzyme is no longer responsive to the protective effect of AMP.
Adenosine Monophosphate↗
Induction of tissue transglutaminase in mouse peritoneal macrophages.
Tissue transglutaminase accumulates rapidly and to very high levels (1-2% of cellular protein) in mouse peritoneal macrophages cultured in mouse serum. The induction is due to accelerated synthesis of the enzyme (150-fold increase) that occurs within 90 min of exposure of the cells to a heat-labile constituent of serum or plasma. The induction is reversible and is not reproduced by known activators of macrophage function such as lipopolysaccharide, muramyl dipeptide, and tuftsin. In animals, elevated levels of tissue transglutaminase are also found in inflammatory macrophages elicited by thioglycolate broth.
Acyltransferases↗
Evaluation of a protocol for post-mortem examination of stillbirths.
A variety of procedures have been recommended for post-mortem examination of stillbirths to determine the cause of the loss of the pregnancy and to provide an estimate of the risk of recurrence. We studied the relative usefulness of several such techniques, including gross and microscopical autopsy, photography, radiography, bacterial cultures, and chromosome studies. In 44 (35 per cent) of 124 cases of stillbirth or early neonatal death, structural physical abnormalities were evident at autopsy. In 35 of the 44 cases the abnormalities were due to chromosomal, single-gene, or polygenic disorders. The single most useful examination was the gross autopsy. Analysis of the various procedures suggests that when resources are limited, gross autopsy, photography, radiography, and bacterial cultures should be performed in all cases of stillbirth and early neonatal death, but that karyotyping and histopathology may be used selectively. This approach should minimize the use of expensive, low-yield procedures without compromising the ability to provide information for purposes of genetic counseling.
Autopsy↗
Nuclear progesterone uptake by endometrial tissue in cases of subfertility.
To investigate the ability of steroid hormones to interact with endometrium, particularly in cases of unexplained subfertility, intact cells were incubated with tritiated progesterone and oestradiol and their uptake into the nuclei was measured. Samples were taken at dilatation and curettage from 23 fertile women, 14 women with unexplained primary subfertility, and 9 patients whose primary subfertility could be explained. Serum oestradiol and progesterone levels were not significantly different between the three groups, nor were values of 3H-oestradiol uptake. However, low (below 5 pmol/mg DNA) values for nuclear 3H-progesterone uptake were present in most samples from women with unexplained subfertility but in only about half of the women in the other two groups. This biochemical defect may be the cause of some cases of unexplained subfertility.
Cell Nucleus↗
Identification of motoneurons innervating the tensor tympani and tensor veli palatini muscles in the cat.
The somatotopic arrangement of the motoneurons associated with the two non-masticatory muscles innervated by the trigeminal motor nerve, tensor tympani (TT) and tensor veli palatini (TVP), was determined in the cat using retrograde transport of horseradish peroxidase. The motoneurons of the TT are distinct and separate, ventral and ventral-lateral to the rostral two-thirds of the trigeminal motor nucleus. The cells are smaller than those of the motor nucleus and constitute a parvocellular division. Based on functional and morphological criteria, TT motoneurons may be considered as an accessory trigeminal nucleus. The somatotopic arrangement of TVP motoneurons has been described for the first time. These motoneurons are located in the rostral two-thirds of the ventromedial division of the cat trigeminal motor nucleus. The location of motoneurons associated with TT and TVP does not fit the parcellation of the cat trigeminal motor nucleus as described by previous investigators. The motoneurons of these muscles can now be assigned to areas either within (TVP) or adjacent to (TT) the rostral two-thirds of the motor nucleus.
Animals↗
Can antibody responses in cattle vaccinated with a multivalent leptospiral bacterin interfere with serologic diagnosis of disease?
A commercially available leptospiral bacterin containing 5 serovars (canicola, grippotyphosa, hardjo, icterohemorrhagiae, pomona) was used per label directions to vaccinate 45 steers and bulls. In animals in which the prevaccination sera were negative for microscopic agglutinating antibody, the increase and decrease of titers were similar among all serovars. A serologic response was stimulated by a single dose and enhanced by the 2nd dose. Most titers peaked at 2 weeks and then fell rapidly by 15 weeks after the 2nd dose. Thirty-four animals with prevaccinal titers to serovar hardjo responded with high microscopic agglutinating titers for a sustained period. Of these cattle, 31 still had titers between 200 and 400 by 29 weeks after the 2nd dose. These results were interpreted as representing an anamnestic response initiated by the bacterin to a sensitization that had followed natural exposure.
Agglutination Tests↗
Increased serum procollagen III aminoterminal peptide in myelofibrosis.
Myelofibrosis has been shown to involve an increase in type III collagen in the marrow. The aminoterminal procollagen III (PC III) peptide fragment is released during the production of PC III by fibroblasts and its serum level is therefore a marker for type III collagen synthesis. Using a recently developed sensitive radioimmunoassay, serum levels of PC III peptide were measured in 30 patients with myeloproliferative disease and 23 normal volunteers. Levels were found to be elevated above normal values in patients with polycythemia vera, even more elevated in patients with polycythemia and evidence of secondary myelofibrosis with myeloid metaplasia, and most strikingly elevated in patients with agnogenic myeloid metaplasia and severe marrow fibrosis. There was a significant association between serum levels of PC III peptide and the extent of reticulin fibrosis in bone marrow biopsies. Serum PC III level appears to be a quantitative marker for myelofibrosis.
Adult↗
Tumour epithelial cellularity and quantitative oestrogen receptor values in primary breast cancer.
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Breast Neoplasms↗
Hypertensive crisis induced by eating in a patient with pheochromocytoma.
Catecholamines have an important effect on the gastrointestinal tract. Patients with pheochromocytomas frequently have gastrointestinal complaints. We report a 13-year-old girl with a 250-g intra-abdominal pheochromocytoma who presented with symptoms of excessive catecholamines release and hypertensive crisis that was provoked by eating. The patient's pheochromocytoma was so large that it was palpable and compressing the greater curvature of the stomach.
Adolescent↗
Use of quinine for self-induced abortion.
We present four recent cases in which quinine was used for self-induced abortion. Abortion was achieved in only one of these cases. Literature review suggests that quinine is an ineffective abortifacient, even when taken in toxic doses. Adverse effects of quinine include cinchonism, potentially fatal renal failure, and possible teratogenesis. Quinine is available over-the-counter, but it has few legitimate medical indications. Health care personnel treating women with undesired pregnancies should be alert to the signs and symptoms of quinine toxicity.
Abortifacient Agents↗
Trophoblast sampling by blind transcervical aspiration.
Blind transcervical aspiration for trophoblast was carried out on 137 patients undergoing elective termination of early pregnancies. Trophoblast was obtained from 45 patients (33%) usually at the first attempt. Collection was not necessarily more successful between 8 and 11 weeks of gestation. In only 13 patients (9%) was trophoblast collected without contamination by maternal tissue, or blood. Perforation of the amniotic sac in one patient (1%), bleeding either observed, or detected histologically (34%) and introduction of infection (4%) constitutes a real threat to fetal survival. Maternal serum alpha-fetoprotein estimation appears useful and may forewarn likelihood of fetal damage. Although transcervical aspiration should encounter ready acceptability as an out-patient procedure, modifications in the technique are essential before clinical application for detection of gene, or chromosome anomalies can be considered.
Biopsy, Needle↗
Effects of amitriptyline, desipramine and zimeldine, alone and in combination with ethanol, on information processing and memory in healthy volunteers.
Interactions of three antidepressants--amitriptyline, desipramine and zimeldine--with a single 0.8 g/kg body weight dose of alcohol were studied in healthy male volunteers. The dependent variables were performance measurements in the Continuous Performance Task and a cognitive memory task. Alcohol and desipramine showed different and specific deleterious effects on cognitive and memory functions, whereas amitriptyline produced a more generalized impairment. Zimeldine slightly improved performance in the Continuous Performance Task and antagonized effects of alcohol in both tasks.
Adult↗
Evaluation of a new filter for leucocyte depletion of blood.
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Blood↗