G protein coupled receptors -in silico drug discovery and design.

In silico drug discovery is a complex process requiring flexibility and ingenuity in method selection and a careful validation of work protocols. GPCR in silico drug discovery poses additional challenges due to the paucity of crystallographic data. This paper starts by reviewing selected GPCR in silico screening programs reported in the literature, including both structure-based and ligand-based approaches. Particular emphasis is given to library design, binding mode selection, process validation and compound selection for biological testing. Following literature review, we provide insights into in silico methodologies and process workflows used at EPIX to drive over 20 highly successful screening and lead optimization programs performed since 2001. Applications of the various methodologies discussed are demonstrated by examples from recent programs that have not yet been published.

Alfred Russel Wallace's North American tour: transatlantic evolutionism.

Evolutionary theory aroused vigorous debate in the late-19th century, regarding both its scientific status and its sociocultural implications. Alfred Russel Wallace's lecture tour of North America, during 1886-1887, affords a striking insight into his particular interpretation of evolution and reveals the depth of his conviction that science was inseparable from ethical and political realities. Wallace's views on matters scientific and cultural were as controversial and significant in North America as they were in Great Britain and Europe.

Randomized controlled trial of pulse/synchronization cyclophosphamide/apheresis for proliferative lupus nephritis.

OBJECTIVE: To assess the efficacy of pulse/synchronization cyclophosphamide/apheresis in patients with proliferative lupus nephritis. METHODS: Eighteen patients with Class III or IV renal biopsies and chronicity indices <6 were prospectively randomized to receive 6 courses of parenteral cyclophosphamide over 8 months along with prednisone. Nine of these patients also received 3 daily plasmaphereses prior to each of the 6 courses of cyclophosphamide. Assessments compiled at 6 and 24 months included serum creatinine, albumin, anti DNA, 24-hour urine protein, and C3 complement along with SLAM scores. RESULTS: Two out of nine patients in each group evolved end stage renal disease and 3/9 patients in each group went into a renal remission at 24 months. Serum albumin, C3 complement, and SLAM scores improved in both groups, and anti-DNA improved in the pulse/synchronization patients (P < 0.025). No intergroup comparisons were significant. CONCLUSION: The addition of pulse/synchronization apheresis to cyclophosphamide therapy does not improve the course of patients with proliferative lupus nephritis.

Lupus in the 1980s: III. Influence of clinical variables, biopsy, and treatment on the outcome in 150 patients with lupus nephritis seen at a single center.

Of 500 patients with systemic lupus erythematosus observed at our center, 150 fulfilled criteria for lupus nephritis. Of these 150 patients, 91% were female, and 67% were white. The mean age of onset was 26.2 years, and the mean follow-up duration was 11.7 years. Biopsies (n = 142) performed on 107 patients showed the following World Health Organization (WHO) class distribution: class I, n = 1; class II, n = 13; class III, n = 19; class IV, n = 69; class V, n = 17; class VI, n = 8; and class not determinable, n = 15. Ninety-five patients were nephrotic. Therapeutic intervention courses given to all patients (n = 356) included parenteral (IV) cyclophosphamide (n = 58), high-dose oral steroids (n = 126), pulse steroids (n = 49), apheresis (n = 39), azathioprine (n = 43), oral cyclophosphamide (n = 5), nitrogen mustard (n = 27), and chlorambucil (n = 6). In addition to examining the course of disease for various subsets, various predictors for fatality and end-stage renal disease (ESRD) were analyzed. Descriptive data for the short-term response to five therapies are provided for the complete patient sample, proliferative disease, and nephrotic syndrome. Twenty patients died, primarily from cardiovascular complications and sepsis, with 97% and 92% 5- and 10-year survival rates, respectively. Twenty-nine were dialyzed, and 11 were transplanted. Risk of ESRD by WHO class at 5 years was as follows: class III, 0%; IV, 9%; V, 16% (P = .04 for class V v other patterns).(ABSTRACT TRUNCATED AT 250 WORDS)

Emphysematous gastritis in an immunocompromised host.

Emphysematous gastritis is a rare, often lethal condition of gastric mural inflammation and gaseous dissection. Infection with gas-forming organisms is the most frequently cited cause. In all previously reported patients, the clinical presentation was dramatic. We report on an immunocompromised host who had a surprisingly subtle clinical presentation.

Predictive value of clinical, laboratory, pathologic, and treatment variables in steroid/immunosuppressive resistant lupus nephritis.

Twenty-seven patients with lupus nephritis and nephrotic syndrome had persistent disease activity despite an adequate trial of corticosteroids and immunosuppressive drugs; 30% were Asians, compared with 7% of our overall SLE population. Two years later, seven had a very good outcome and seven a poor outcome. Thirty clinical, pathological, laboratory, and treatment variables were analyzed in a good versus poor responder subset comparison in an effort to determine which factors were associated with favorable outcome. Administration of pulse steroids (P = .069) and a low biopsy chronicity index (P = .048) were associated with the good responder subset. Serum creatinine, biopsy class, blood pressure, complement, and anti-DNA values at entry as well as the choice of immunosuppressive drug were not helpful in predicting outcome. All seven good responders were plasmapheresed (P = .026). Patients with refractory lupus nephritis who have a low biopsy chronicity index may benefit from the use of pulse steroids or plasmapheresis, and controlled studies are suggested.

The kininases of Bothrops jararaca plasma.

Evidence is presented to suggest that kininase activity of Bothrops jararaca plasma is due to the presence of at least three distinct enzymes: a carboxypeptidase B type enzyme, similar to that found in human plasma in that its activity is enhanced by Co2+ (1 X 10(-4) M); a carboxypeptidase B type enzyme whose activity is unaffected by Co2+, and an enzyme which cleaves bradykinin to liberate Phe-Arg as the major peptide fragment formed. The latter enzyme is responsible for the major kininase activity of this snake plasma and is identified as a dipeptide hydrolase.

Contribution of urine volume to the elevated urinary prostaglandin E in Bartter's syndrome and central and nephrogenic diabetes insipidus.

1. Urinary PGE is elevated above normal in patients with Bartter's syndrome, central and nephrogenic diabetes insipidus. 2. K+ loading, Mg2+ infusion, and water-loading-all of which increased urine volume-were associated with augmented urinary PGE in Bartter's syndrome, while fluid restriction decreased urinary PGE to normal. 3. Antidiuresis in central diabetes insipidus with DDAVP, and with indomethacin or ibuprofen in nephrogenic diabetes insipidus, is associated with a decrease in urinary PGE. 4. High urine volume may be a contributing factor to the elevated urinary PGE in Bartter's syndrome, central and nephrogenic diabetes insipidus.

The kininases of Bothrops jararaca plasma.

Evidence is presented to suggest that kininase activity of Bothrops jararaca plasma is due to the presence of at least three distinct enzymes: a carboxypeptidase B type enzyme, similar to that found in human plasma in that its activity is enhanced by Co2+ (1 X 10(-4) M); a carboxypeptidase B type enzyme whose activity is unaffected by Co2+, and an enzyme which cleaves bradykinin to liberate Phe-Arg as the major peptide fragment formed. The latter enzyme is responsible for the major kininase activity of this snake plasma and is identified as a dipeptide hydrolase.

The kininases of Bothrops jararaca plasma

Evidence is presented to suggest that kininase activity of Bothrops jararaca plasma is due to the presence of at least three distinct enzymes: a carboxypeptidase B type enzyme, similar to that found in human plasma in that its activity is enhanced by Co2+ (1 X 10(-4) M); a carboxypeptidase B type enzyme whose activity is unaffected by Co2+, and an enzyme which cleaves bradykinin to liberate Phe-Arg as the major peptide fragment formed. The latter enzyme is responsible for the major kininase activity of this snake plasma and is identified as a dipeptide hydrolase.

Components of the renin-angiotensin system in the plasma of Bothrops jararaca.

By means of high voltage electrophoresis experiments it could be demonstrated that the dipeptide hydrolase present in the plasma of Bothrops jararaca is similar to the angiotensin I converting enzyme of human plasma. Therefore, angiotensin I can be considered as a probable natural substrate for this potent snake peptidase in contrast to bradykinin, which is excluded in that case, since this snake plasma was previously found to be deficient in intrinsic kinin releasing system. On the other hand, the presence of angiotensinase activity in this snake plasma could also be demonstrated. Through the pharmacological comparison of angiotensin II with the pressor peptide released from the Bothrops jararaca plasma by chymotrypsin, an indirect indication of the presence of angiotensinogen in the plasma of this reptile was obtained.

Urinary cyclic AMP analyzed as a function of the serum calcium and parathyroid hormone in the idfferential diagnosis of hypercalcemia.

Urinary cyclic AMP (UcAMP) appropriate for the serum calcium concentration was determined in normal subjects during the base-line state and during alteration in their serum calcium concentrations by saline and calcium infusions. This was compared to the UcAMP in 76 patients with hypercalcemia and 5 patients with hypocalcemia. In 54 of 56 patients with primary hyperparathyroidism, the UcAMP was inappropriately high for their serum calcium concentration, the 2 exceptions having renal failure. In four patients with vitamin D intoxication, sarcoidosis, milkalkali syndrome, and thiazide-induced hypercalcemia and in five patients with hypocalcemia due to hypoparathyroidism, the UcAMP was appropriately low for their serum calcium concentration. In 16 patients with nonparathyroid neoplasms, 10 had UcAMP levels that were inappropriately high suggesting ectopic parathyroid hormone (PTH)-mediated hypercalcemia and 6 had UcAMP levels that were appropriately low suggesting that their hypercalcemia was due to osteolytic factors other than PTH. Correlations between UcAMP, serum calcium concentration, and carboxyl-terminal immunoreactive PTH suggest that random UcAMP is a sensitive accurate reflection of circulating biologically active PTH. If there is adequate renal function (serum creatinine concentration less than 2.0 mg/dl), a random UcAMP expressed as mumol/g creatinine and analyzed as a function of the serum calcium concentration completely separates patients with PTH and non-PTH-mediated hypercalcemia.

Renal transplantation in a Community Hospital.

Eighty renal transplantations were performed at an urban community hospital over a ten-year period. Forty-two transplants were from living related donors and 38 from cadaver donors. The one-year rejection rate for cadaveric transplants was 35% and for transplants between parents and children, 31%, whereas only one of 21 (5%) transplants between siblings was rejected during the first year. These results compare favorably with those reported by others and appear to justify performance of kidney transplantation in the community hospital setting where large numbers of transplant surgeons and nephrologists are involved, and where the number of transplants never has exceeded 15 per year.

Role of prostaglandins in the pathogenesis of Bartter's syndrome.

Increased renal prostaglandins activated by beta-catecholamines could produce renal tubular sodium wasting and angiotensin pressor resistance observed in Bartter's syndrome. We therefore measured plasma renin activity (PRA), aldosterone and prostaglandin A (PGA) by radioimmunoassay, and body composition by isotope dilution prior to and following beta-adrenergic blockade with propranolol (200 mg/day for 4 days) and prostaglandin synthesis inhibition by indomethacin (200 mg/day for 4 days) in a patient with Bartter's syndrome on a 250 meq sodium diet. After the administration of propranolol, body weight increased 3 kg, daily urine sodium decreased within 24 hours from 230 to 64 meq, and urine potassium from 102 to 45 meq, but PRA and the aldosterone level remained elevated. With the administration of indomethacin, body weight increased 5 kg, daily urinary sodium decreased within 24 hours to 11meq and urine potassium to 16 meq, PRA (normal less than 3 ng/100 ml/hour) decreased from 55 to 4.3 ng/ml/hour, plasma aldosterone (normal less than 8 ng/100 ml) from 74.1 to 3.6 ng/100 ml, and whole blood PGA (normal 546 +/- 307 pg/ml) decreased from 1,390 and 945 to 86 pg/ml. After the administration of propranolol or indomethacin, exchangeable sodium, total body water, extracellular volume and plasma volume all increased from less than to greater than predicted, and pressor resistance to angiotensin was normalized. These results suggest that Bartter's syndrome results from beta adrenergic and prostaglandin-mediated proximal tubular rejection of sodium leading to increased distal sodium-potassium exchange.