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Biomedical subjects

E Phillips

Publications and source records attributed to E Phillips.

At least 91 records · Page 5Linked to original sources

Expression of functional bradykinin receptors in Xenopus oocytes.

mRNA prepared from various tissues and cultured cells was injected into Xenopus laevis oocytes. Three to five days after injection, the response of the oocytes to the peptide bradykinin was monitored. The oocytes were voltage clamped and the membrane currents generated on application of agonist were recorded. mRNA from NG108-15, rat uterus, and human fibroblast cell line WI38 gave similar responses to bradykinin (1 microM), with an initial inward current (10-20 nA) followed by a prolonged period of membrane current oscillations. The same pattern of response was given by total RNA from rat dorsal root ganglia. No response to bradykinin (10 microM) was recorded from oocytes injected with rat brain mRNA, although these oocytes gave peak inward currents of about 75 nA in response to serotonin (10 microM). mRNA from both NG108-15 cells and rat uterus was fractionated on sucrose gradients. This resulted in an approximately five-fold increase in the size of the response compared to that given by unfractionated mRNA. The largest responses were given by mRNA fractions with a size of approximately 4.5 kb. Data were obtained consistent with the expression of both B1 and B2 receptors by WI38 human fibroblasts and with the expression of only the B2 type of receptor by NG108-15 cells.

Animals↗

The role of cholangiography in laparoscopic cholecystectomy.

Cholangiography is not routinely performed in open surgery, but there are reasons why it should be in laparoscopic cholecystectomy. These include finding common duct stones, identifying the cystic-common duct junction, and noting an inadvertent injury. Thirty-six (7.0%) of 516 laparoscopic cholecystectomies were converted to open surgery; 24 before attempting cholangiography and 12 based on roentgenographic findings. In 73 patients (14.1%), cholangiography showed abnormal findings. Common duct injury was identified in one patient and common duct stones were found in 35. Twenty-one patients were treated laparoscopically and eight underwent open choledocholithotomy. In 22 patients, a short cystic duct was seen that might otherwise have been overlooked, and possible injury was avoided. Cholangiography should be attempted routinely, so that in cases with abnormal findings, open cholecystectomy may be considered.

Catheterization↗

A randomized trial of sodium fluoride as a treatment for postmenopausal osteoporosis.

The anti-fracture efficacy of sodium fluoride (NaF) was evaluated in 84 postmenopausal white women with spinal osteoporosis. The dose of NaF used was 75 mg/day and all patients in this prospective, randomized, double-blind, placebo-controlled clinical trial received calcium supplements (carbonate salt) 1500 mg/day in addition to participating in a structured physical therapy program. For each of the outcome measures (change in stature, change in cortical bone mass in the forearm and development of new vertebral fractures determined by change in vertebral morphometry and by scintigraphy) there was no significant difference between the fluoride or placebo treated groups. Side effects, predominantly gastrointestinal symptoms and the development of the painful lower extremity syndrome, occurred significantly more frequently in the fluoride group (P less than 0.05). Peripheral fractures were not more frequent in the fluoride group. We conclude that, in the dose and manner used in this study, NaF is no more effective than placebo in retarding the progression of spinal osteoporosis. There is no role for NaF in the treatment of osteoporosis outside the confines of clinical research.

Aged↗

Patient peer orientation groups: an innovative approach.

Both clients and staff can benefit from a patient orientation program conducted at a state psychiatric facility by a psychologist and a registered nurse. The program cited by the authors utilized a group format to decrease the stress experienced by clients when transferred from a closed to an open ward, and to increase the social skills of clients residing on an open unit. Informal observation and verbal feedback from clients and staff indicated positive reactions to the program and noticeable behavior changes. Recommendations include replication of this program on a large scale with control group comparisons, formal assessment, and statistical analysis of the results.

Hospitals, Psychiatric↗

Characterization of bradykinin receptors solubilized from rat uterus and NG108-15 cells.

In this paper we report the solubilization of bradykinin B2 binding sites from membranes prepared from NG 108-15 tumours and rat uterus with retention of binding activity. Digitonin was found to solubilize the receptors from both tissues, and the addition of CHAPS increased the yield of soluble receptor from rat uterus only. The affinity of a range of bradykinin analogues has been shown to have the same rank order for both the soluble and membrane receptors from both tissues, and in corresponding functional assays. In addition, the binding of bradykinin ligands to the soluble and membrane receptors is similarly modulated by the presence of sodium ions. We conclude that the soluble binding sites correspond to the physiological bradykinin B2 receptor present in these tissues.

Animals↗

The organisation of the mouse chromogranin B (secretogranin I) gene.

A cosmid clone containing the gene for mouse chromogranin B (secretogranin I), a secretory protein found in secretory granules of most endocrine cells and neurons, was isolated and sequenced. The chromogranin B protein was found to be encoded by 5 exons which correspond to the cleaved signal peptide, the short N-terminal sequence preceding the disulfide-bonded loop structure, the disulfide-bonded loop structure itself, the large, variable region comprising approximately 90% of the protein, and the conserved C-terminal sequence. The promoter region of the chromogranin B gene is very GC-rich and contains a CATAA motif, a cAMP-responsive element and an Sp1 binding site.

Amino Acid Sequence↗

Effect of renal replacement therapy on cellular cytokine production in patients with renal disease.

To evaluate the effect of renal replacement therapy on cellular cytokine production in patients with renal disease, we studied interleukin 1 (IL-1) and interleukin-2 (IL-2) production by target cells stimulated with supernatants from cultured peripheral blood mononuclear cells from patients with end-stage renal disease, who were treated with hemodialysis and continuous ambulatory peritoneal dialysis (CAPD) before and after hemodialysis or a peritoneal dialysate exchange, compared to normal subjects used as time controls, and patients with chronic renal insufficiency. Initial cellular IL-2 production was increased in patients with hemodialysis, compared to normal controls. The ratio of pretreatment cellular IL-2 and IL-1 production was increased in all patient groups compared to normal subjects. Both hemodialysis and CAPD treatments resulted in increased cellular IL-1 (51.7%, P less than 0.007, and 42.8%, P less than 0.002, respectively) and IL-2 production (50.5%, P less than 0.015, and 33.3%, P less than 0.0008, respectively). The hemodialysis group had significantly higher cellular IL-2 production compared with normal controls' after treatment. After treatment, the IL-2/IL-1 ratio remained elevated in all groups with renal disease compared with normal subjects. We conclude patients with renal disease have an abnormal functional relationship between IL-1 and IL-2, characterized by increased IL-2 production per level of IL-1, unaffected by type or presence of renal replacement therapy.

Biological Assay↗

Laparoscopic cholecystectomy: instrumentation and technique.

Laparoscopic cholecystectomy is rapidly evolving as a therapeutic modality for the treatment of gallstone disease. The technical details of this procedure and the method by which the gallbladder is dissected and removed are critical to the safe, effective execution of the procedure. Our technique has been developed through extensive practice in porcine models and through experience with more than 250 patients. To perform laparoscopic cholecystectomy we employ a high-resolution video endoscopy system, two high-resolution color monitors, a high-flow CO2 insufflator, a 300 W Xenon light source, electrocautery and/or lasers, and an endoscopic suction-irrigation system. This equipment permits the surgeon to obtain a clear field of view within the abdomen. With these tools, appropriately designed for laparoscopic surgery, including a laparoscope, graspers, dissectors, cholangiography equipment, scissors, and clip appliers, the surgeon can remove the gallbladder without opening the abdomen. The procedure requires the induction of a CO2 pneumoperitoneum, insertion of four trocars, and placement of a grasping retractor to set the operative field. An additional retractor placed on Hartmann's pouch provides countertraction for dissection of the hilum. Careful dissection around the cystic duct and cystic artery with a combination of electrocautery and blunt dissection allows the surgeon to skeletonize the cystic duct and artery. After intraoperative cholangiography confirms the anatomy, the cystic artery and cystic duct are clipped and divided. Electrocautery or laser techniques can be used to perform retrograde dissection of the gallbladder from the liver bed and insure hemostasis. The gallbladder is detached and removed intact through the large trocars. This basic technique can be applied in a wide variety of patients with cholelithiasis. The surgeon proficient in this technique may apply it to a broad range of patients with gallbladder disease.

Cholecystectomy↗

The primary structure of human secretogranin II, a widespread tyrosine-sulfated secretory granule protein that exhibits low pH- and calcium-induced aggregation.

Secretogranin II (previously also called chromogranin C) is a tyrosine-sulfated secretory protein found in secretory granules in a wide variety of endocrine cells and neurons. Here, we have determined the primary structure of human secretogranin II from a full length cDNA clone and have investigated its properties, predicted from the sequence, by studying the behavior of purified secretogranin II under conditions characteristic of the milieu of secretory granules. Analysis of a 2.35-kilobase cDNA clone isolated from a human pituitary library and identified as secretogranin II by various criteria showed that human presecretogranin II is a 617-residue polypeptide containing an NH2-terminal located signal peptide. Secretogranin II lacks the disulfide-bonded loop structure near the NH2 terminus which is conserved in chromogranin A and chromogranin B (secretogranin I), two other widespread constituents of neuroendocrine secretory granules, but like the latter two proteins contains (i) an -E-N/S-L-X-A/D-X-D/E-X-E-L- motif and (ii) multiple potential dibasic cleavage sites for the generation of smaller, perhaps biologically active peptides. Another structural feature that secretogranin II shares with chromogranin A and chromogranin B (secretogranin I) is the abundance of acidic residues all along the polypeptide chain whose negative charge must somehow be neutralized to allow condensation and packaging of the protein into secretory granules. Experiments with purified secretogranin II showed that in the presence of 10 mM calcium at pH 5.2, conditions characteristic of the milieu of neuroendocrine secretory granules, this protein formed aggregates. Immunoglobulin G, a secretory protein that in vivo is not packaged into secretory granules, did not form aggregates under these in vitro conditions and was excluded from the secretogranin II aggregates. Very little aggregation of secretogranin II was observed in the absence of calcium at pH 5.2 or in the presence of calcium at neutral pH. In vivo, ammonium chloride, which is known to neutralize the pH of acidic intracellular compartments, inhibited the packaging of newly synthesized secretogranin II into secretory granules. Our results suggest that the low pH- and calcium-induced aggregation of secretogranin II may be important for the organization of the secretory granule matrix and raise the possibility that aggregation of secretogranin II may be involved in its sorting to secretory granules.

Amino Acid Sequence↗

Upper thoracic disk herniation secondary to vertebral metastases.

Thoracic disk herniations are exceedingly rare, particularly those in the upper thoracic region. The etiology of these protrusions is generally considered to be either traumatic or degenerative in nature. A case of upper thoracic disk herniation secondary to destructive changes caused by breast cancer metastatic to the vertebral body is presented.

Aged↗

A radioimmunoassay for bradykinin based on monoclonal antibodies.

We describe two monoclonal antibodies with recognise the peptides bradykinin and kallidin. These antibodies were used in a study to assess the feasibility of using monoclonal antibodies in place of conventional sera for radioimmunoassay. Antibody SBK1 recognises bradykinin with a Kd of 0.67 +/- 0.17 nM. It fails to recognise bradykinin from which any carboxyl terminal amino acid has been removed. Antibody SBK2 recognises bradykinin with a Kd of 58.11 +/- 7.55 nM; it recognises 1-8 and 1-7 bradykinin about 30% as effectively as the full-length sequence, and shorter carboxyl terminal truncated sequences with a progressively declining efficiency. In this model system, bradykinin concentrations of 0.2 nM could be reliably measured, and carboxyl truncated versions of the peptide could be distinguished from the parent molecule. The feasibility of using monoclonal antibodies to assay bradykinin and other small peptides is discussed in the light of these results.

Animals↗

Identification of women at risk for developing postmenopausal osteoporosis with vertebral fractures: role of history and single photon absorptiometry.

Putative risk factors for the development of postmenopausal osteoporosis (PMO) with vertebral fractures were examined in a retrospective study of 663 postmenopausal white females aged 45-75 years (266 women with non-traumatic vertebral compression fractures (VF+), 134 non-fractured women from a general medicine clinic (controls) and 263 non-fractured women who were evaluated when they presented specifically for osteoporosis screening (VF-]. The VF+ women differed from control women in several respects. The VF+ group reported a higher prevalence of a positive family history of osteoporosis, and a higher prevalence of a history of medical or surgical conditions known to be independently associated with metabolic bone disease, had fewer children, were smaller (weight, height) and were slightly older. The two groups, VF+ and controls, did not differ with respect to cigarette smoking, alcohol consumption, exercise habits, menstrual or menopausal history, dietary intake of milk and cheese or in amount taking calcium supplements during pregnancy. The VF+ group also differed in certain respects from the VF- group. The VF+ group were smaller (weight, height) and were older. The VF+ group had lower cortical bone mass (measured by single photon absorptiometry of the non-dominant forearm) than either the control or VF- groups. The latter two groups did not differ from each other with respect to this measurement. These markers demonstrated limited sensitivity and specificity as estimated from a confirmatory data set, particularly for the historical and anthropometric variables. We conclude that an assessment of the risk of developing PMO with vertebral fractures cannot be based on the putative risk factors as measured in our study, but must be based on measurement of bone mass.

Absorptiometry, Photon↗

Metastatic lesions of the upper cervical spine.

Metastatic lesions of C1 and C2 most frequently present with severe pain and only rarely with neurologic involvement. The lesions are poorly visualized on plain roentgenogram and most often require bone scan and/or computed axial tomography (CAT) scan for definitive diagnosis. Delay in diagnosis in frequent in these patients (8 of 16). Radiation therapy and external mobilization yield satisfactory results for minor fractures or diffuse involvement without instability. Surgery is rarely indicated for decompression. However, in patients with C1 lateral mass involvement or severe C2 body destruction with instability, posterior stabilization gives excellent relief of pain. Onset after diagnosis of the primary tumor ranges from months to years. Survival is reasonable (mean, 9 months) after diagnosis of upper cervical spine involvement. Understanding these characteristics and the occurrence of metastatic disease in the upper cervical spine allows earlier diagnosis with appropriate radiographic studies and prompt palliation of symptoms.

Adult↗

Construction of a physiologically active photoaffinity probe based on the structure of bradykinin: labelling of angiotensin converting enzyme but not candidate bradykinin receptors on NG108-15 cells.

The peptides bradykinin and kallidin are released in response to noxious stimuli and mediate various physiological effects, including a direct stimulation of nociceptive afferent neurones. The nature of the receptor molecules through which these ligands act is presently unknown. We synthesised an iodinatable photoaffinity probe, N epsilon-4-azidosalicylylkallidin, and used it in an attempt to identify candidate bradykinin receptors on the NG108-15 neuroblastoma X glioma hybrid cell line. The ligand bound in subdued light to a particulate fraction of NG108-15 tumours and could be displaced by bradykinin with an IC50 of 0.33 nM. In a physiological assay, it behaved as an agonist equipotent with bradykinin. Gel analysis of the labelled products after photolysis of the iodinated ligand in the presence of NG108-15 cells or tumour membranes revealed bradykinin-blockable labelling of a glycoprotein with an Mr of 166,000. The probe was also able to label purified commercial angiotensin converting enzyme. The band labelled in NG108-15 cells was immunoprecipitable with a polyclonal antiserum to angiotensin converting enzyme, an enzyme shown to be present in low amounts in these preparations by direct binding using the iodinatable specific ligand MK351A.

Affinity Labels↗