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Biomedical subjects

J Miller

Publications and source records attributed to J Miller.

At least 757 records · Page 42Linked to original sources
PubMed1989

Unrecognized injuries of the lateral ligaments associated with lateral malleolar fractures of the ankle.

Of four patients who were treated between May 1985 and November 1987 and who had both a lateral malleolar fracture and a tear of the lateral ligaments of the ipsilateral ankle, three could be followed. The fractured malleolus was treated with rigid internal fixation, but the injury to the lateral ligaments was not diagnosed until the ankle was stressed to test for stability after the internal fixation. We believe that if disruption of the lateral ligaments is noted at operation, repair is indicated. This involves only a slight prolongation of time under anesthesia and markedly increases the chances for a stable ankle. It is important to check intraoperatively for a possible tear of the lateral ligaments in a patient who has a fracture of the ankle, especially when the injury was caused by high-energy trauma.

Adult↗
PubMed1989

Interaction of antibodies with human glomerular epithelial cells.

We tested the hypothesis that the pathogenesis of human idiopathic membranous glomerulonephritis is similar to that of Heymann glomerulonephritis, a model of membranous glomerulonephritis induced in rats by immunization with renal brush border preparations; the characteristic subepithelial deposits result from interaction of antibodies with a brush border antigen (gp330) expressed on the plasma membrane of glomerular visceral epithelial cells (GEC), followed by redistribution and shedding of gp330 immune complexes. The experiments were performed in cultured glomerular visceral epithelial cells, in living monkeys and rats, and in isolated perfused human, monkey, and rat kidneys. Antigens from plasma membranes of human renal brush border vesicles (HBBV) and GEC vesicles (HGECV) and their corresponding polyclonal and monoclonal antibodies reactive with human and monkey GEC were prepared. First, polyclonal antibodies to HGECV bound diffusely to cultured GEC; monoclonal antibody 8G5, recognizing a 60-kDa protein, mainly bound to the coated pits and apical invaginations; both polyclonal HGECV and 8G5 monoclonal antibodies induced antigen redistribution (capping) at 37 degrees C. Second, monkeys were actively or passively immunized, and isolated human and monkey kidneys were perfused with the antibodies. Active immunization with HBBV induced tubular immune deposits, whereas active immunization with HGECV did not provoke renal lesions. After passive immunization HBBV and HGECV antibodies bound diffusely to glomerular cells, and subepithelial deposits were observed during the autologous phase; in contrast, 8G5 induced early (day 3) granular deposits. Third, fine granular deposits developed in glomeruli of human and monkey kidneys perfused for 4 hours at 37 degrees C with 8G5; these deposits were more difficult to detect by electron microscopy than those occurring in kidneys of Lewis rats perfused with sheep antiHBBV. The results show that some antibodies redistribute antigens at the surface of human and monkey GEC in vitro, in vivo, and ex vivo and induce formation of granular deposits in human glomerular capillary walls. Failure to induce more severe lesions in human and monkey kidneys may be ascribed to lack of GEC antigens comparable to rat gp330, insufficient cross linking by monoclonal antibody, lack or insufficient concentration of epitope-specific antibodies, insufficient time of kidney perfusion, or a combination of these factors.

Animals↗
PubMed1989

The fragmentation of 670A MeV neon-20 as a function of depth in water. I. Experiment.

We present the final analysis of an experiment to study the interaction of a beam of 670A MeV neon ions incident on a water column set to different thicknesses. The atomic number Z (and, in some cases, the isotopic mass A) of primary beam particles and of the products of nuclear interactions emerging from the water column close to the central axis of the beam was obtained for nuclei between Be (Z = 4) and Ne (Z = 10) using a time-of-flight telescope to measure the velocity and a set of silicon detectors to measure the energy loss of each particle. The fluence of particles of a given charge was obtained and normalized to the incident beam intensity. Corrections were made for accidental coincidences between multiple particles triggering the TOF telescope and for interactions in the detector. The background due to beam particles interacting in beam line elements upstream of the detector was calculated. Sources of experimental artifacts and background in particle identification experiments designed to characterize heavy ion beams for radiobiological research are summarized, and some of the difficulties inherent in this work are discussed. Complete tables of absolutely normalized fluence spectra as a function of LET are included for reference purposes.

Ions↗
PubMed1989

The natural history of flexion contracture in total knee arthroplasty. A prospective study.

A prospective study was carried out to document the natural history of flexion contractures of the knee after total knee arthroplasty (TKA). Thirty-five knees in 33 patients with TKA were followed for a mean duration of 55 weeks. In no case did the surgical procedure include excessive bony resection in order to correct a flexion contracture. Standard goniometric measurements were used to determine the knee flexion contractures preoperatively and postoperatively while the patient was anesthetized and at each successive follow-up visit. All preoperative and postoperative flexion contractures were less than 30 degrees. The mean fixed flexion deformity of the entire group preoperatively was 12.9 degrees; immediately postoperatively, 14.8 degrees; and at final follow-up, 2.9 degrees. No difference was found in the amount of flexion contracture present at final follow-up evaluation with respect to age or gender. The impression that fixed flexion contractures must be corrected at the time of arthroplasty has led to the intraoperative removal of excess bone from the distal femur and/or proximal tibia. The present findings indicate that knee flexion contractures can significantly improve after TKA. There appears to be little, if any indication for excessive removal of bone in an attempt to achieve intraoperative correction.

Adult↗
PubMed1988

The order and orientation of mouse lambda-genes explain lambda-rearrangement patterns.

Mouse lambda-genes are rearranged in specific V lambda-JC lambda associations: V lambda 1 has only been found to rearrange with JC lambda 3 or JC lambda 1, whereas V lambda 2 mainly rearranges with JC lambda 2 and very rarely with JC lambda 1,3. In order to determine the physical basis for these associations we have cloned the respective lambda-genes and large portions of their flanking regions by chromosomal walking in a total of 141 kb of phage and cosmid clones. With the use of unique probes obtained from such clones, the order and orientation of the mouse lambda-gene segments were determined by analyzing patterns of DNA deletion associated with lambda-gene rearrangements in various cell lines. All V and C gene segments were found to be in the same transcriptional orientation, and V2 and V1 were found not to be next to each other, thus supporting the gene order V2-C2-C4-V1-C3-C1.

Animals↗
PubMed1988

Atrial natriuretic peptide clearance receptor. Complete sequence and functional expression of cDNA clones.

The major class of atrial natriuretic peptide (ANP) receptors was isolated from cultured vascular smooth muscle cells, and a partial amino acid sequence was obtained. This allowed the isolation of cDNA clones from which the entire amino acid sequence was established. The smooth muscle cell ANP receptor appears to be synthesized as a 537-amino acid precursor with an N-terminal membrane translocation signal. The mature form consists of 496 amino acids with a single potential transmembrane domain predicting a 37-amino acid cytoplasmic domain and a large, acidic, extracellular domain low in cysteine and probably containing attached carbohydrate. The receptor is therefore similar in structure to the growth factor receptors but notably lacks repetitive cysteine-rich domains and has a relatively small intracellular domain. Expression of the cloned receptor in Xenopus oocytes elicited high affinity, membrane-associated binding sites for ANP and for truncated and internally deleted analogs of ANP. These results reflect the ligand binding specificity found for the major class of ANP receptors on smooth muscle cells and thus provide additional evidence that two distinct ANP receptors exist since ANP receptor-coupled guanylate cyclase activity exhibits a very different ANP analog specificity.

Amino Acid Sequence↗
PubMed1988

A new A4 amyloid mRNA contains a domain homologous to serine proteinase inhibitors.

The amyloid proteins isolated from neuritic plaques and the cerebrovasculature of Alzheimer's disease are self-aggregating moieties termed A4 protein and beta-protein, respectively. A putative A4 amyloid precursor (herein termed A4(695] has been characterized by analysis of a human brain complementary DNA. We report here the sequence of a closely related amyloid cDNA, A4(751), distinguished from A4(695) by the presence of a 168 base-pair (bp) sequence which adds 57 amino acids to, and removes one residue from, the predicted A4(695) protein. The peptide predicted from this insert is very similar to the Kunitz family of serine proteinase inhibitors. The two A4-specific messenger RNAs are differentially expressed: in a limited survey, A4(751) mRNA appears to be ubiquitous, whereas A4(695) mRNA has a restricted pattern of expression which includes cells from neuronal tissue. These data may have significant implications for understanding amyloid deposition in Alzheimer's disease.

Alzheimer Disease↗
PubMed1988

Effects of dietary peanut oil on serum lipoprotein patterns of rats.

Oils prepared from two varieties of peanuts and from a hybrid corn having linoleic acid concentrations substantially different from the respective commercial oils were compared with commercial oils for their effects on serum lipids of weanling female rats. In the first experiment, serum lipid patterns appeared to reflect linoleic acid content of the dietary oil. However, with a longer feeding period in the second experiment, serum lipid patterns were determined by the plant source of the dietary oil rather than its linoleic acid content; all peanut oils differed from both corn oils in their physiological effects. Diets containing triglyceride, hydrocarbon and sterol fractions obtained by liquid chromatography of peanut and corn oils were fed to female rats. The data provide no evidence that the hydrocarbon or sterol fractions of peanut oil are responsible for its unusual atherogenicity when fed as the sole fat source or that similar fractions from corn oil are protective against the effects of peanut oil.

Animals↗
PubMed1988

Associate and non-associative tolerance to morphine: support for a dual-process habituation model.

Some unique predictions of a dual-process habituation model of morphine analgesic tolerance were examined concerning the interactions of drug-signal conditions and dose/frequency parameters. The model assumes that tolerance is the result of a combination of associative and non-associative habituation mechanisms which are differentially affected by dose and drug-signal conditions. In accordance with predictions of the model, low doses and long interdrug intervals (IDI's) resulted in faster tolerance acquisition, greater tolerance retention, and higher levels of associative tolerance, than high doses and short IDI's. Alternative accounts of tolerance based on Pavlovian conditioning mechanisms cannot explain this pattern of results. The question of generality of these findings to other drugs and other response measures is discussed.

Analgesia↗
PubMed1988

Cloning of the fusion gene of rinderpest virus: comparative sequence analysis with other morbilliviruses.

We have cloned the cDNA of the fusion (F) gene of the virulent (Kabete O) strain of rinderpest virus and provided a comparative analysis of its sequence with that of the F genes of measles and distemper viruses. The gene has an open reading frame of 2241 nucleotides with two potential initiation codons in-frame. Use of the first ATG would produce a polypeptide 747 amino acids long with a calculated molecular weight of 81,068. However, we suggest that the second ATG is used to generate the Fo protein, which is 546 amino acids long with a calculated molecular weight of 58,754. During maturation, the cleavage of F0 gives rise to the functional F1 and F2 polypeptides. The F1 polypeptide is 438 amino acids long and has a calculated molecular weight of 46,791, with a single (potential) glycosylation site in its cytoplasmic domain. The F2 polypeptide, probably 89 amino acids long after the signal sequence is cleaved, is estimated to be 9,800 Da and has three potential glycosylation sites. There is a divergence of 18.7% in amino acid sequences between rinderpest and measles virus F0 polypeptides; between distemper and rinderpest viruses the divergence is 31.8%. No significant homology in nucleotide sequences of rinderpest DNA to measles or distemper DNA was found in the 5' and 3' untranslated regions.

Base Sequence↗
PubMed1988

Comparison of transurethral resection to radical therapies for stage B bladder tumors.

We evaluated the survival rate and time to recurrence for 114 patients in whom an initial histological diagnosis of stage B1 or B2 bladder tumor was made between 1974 and 1983. The 5-year survival rates for stages B1 and B2 disease, respectively, were 63 and 38 per cent in 43 patients treated by transurethral resection alone, 48 and 54 per cent in 40 treated by preoperative radiation and radical cystectomy, 33 and 25 per cent in 15 treated by radical cystectomy alone, and 53 and 11 per cent in 16 treated by definitive radiation therapy alone. Similar results were found among the groups with regard to time to development of metastases. The distribution of stage, grade and number of tumors was not significantly different among the treatment groups. Patients in the transurethral resection group were older, and had smaller tumors and more medical problems. Comparing transurethral resection of muscle invasive bladder tumors to standard radical surgery with or without radiotherapy yielded comparable long-term survival and time to distant recurrence.

Actuarial Analysis↗