Preparation and protein conjugation of a divinyl sulphone derivatized bifunctional chelating agent

A new bifunctional chelating agent with a novel linking arm, 2-[p-?N-benzyl-N-(2-vinylsulfoethyl)?- (aminobenzyl)?-1,3-propane-diamine-N,N,N',N'-tetraacetic acid (VS-PDTA) was synthesized and was conjugated to protein for the purpose of attaching radiometals to monoclonal antibodies (MAbs). The effect of various parameters such as ligand concentration, protein concentration, pH, temperature and reaction period on the conjugation have been examined using chromatographic (SE and TLC) analysis after labeling with 111In. The parameters and chemical variables studied have significant effects on the efficiency and rate of protein conjugation.     

Leucoéncephalopathie multifocale progressive

Summary A young woman presented a mixed congenital and familial immunodeficiency syndrome consisting in an absence of IgA and lowered levels of IgG and IgM, with a defect in cellular immunity. She had a mild malabsorption syndrome with slight alterations of the jejunal mucosa. Non-caseating tuberculoid granulomata were found in skin lesions, in lymph nodes and in the spleen. At age 27 the patient died of a neurological disease of 4 months duration. Autopsy revealed a very widespread demyelinating process involving mainly the right cerebellar hemisphere but also most of the pons and left cerebellum, with the typical morphologic characters of PML. In the hemispheres lesions were limited to microscopical microglial nodules with discrete demyelination. A review of 86 published cases of PML revealed 9 other cases in which lesions showed a strong predilection for the subtentorial territories. This sampling allows for the assumption that some 11% of the cases of PML have this particular lesion distribution. Other pertinent features of this case are briefly discussed.

     

Succinylcholine does not worsen bupivacaine-induced cardiotoxicity in pentobarbital-anaesthetized dogs

The intravascular injection of a large dose of bupivacaine induces electrophysiological cardiac impairment, mainly by slowing ventricular conduction velocity, and haemodynamic depression, by a decrease in myocardial contractility. When cardiotoxicity occurs, succinylcholine rapidly stops convulsions. However, the possible interactions between bupivacaine and succinylcholine on cardiac electrophysiology and haemodynamic status have never been investigated. Thus, we used an experimental electrophysiological model involving closed-chest dogs. Three groups (n = 6) of pentobarbital-anaesthetized dogs were given 0.2 mg.kg-1 atropine iv. Dogs in Group 1 were given saline. The others received 4 mg.kg-1 bupivacaine iv over ten seconds. Dogs in Group 2 were then given saline and those in Group 3 were then given 2 mg.kg-1 succinylcholine iv from one to two minutes after the administration of bupivacaine. The following electrophysiological variables were measured: heart rate represented by RR interval (RR), PR, atria-His (AH), and His-ventricle (HV) intervals, QRS duration, and QT interval corrected for heart rate (QTc). The following haemodynamic variables were measured: mean aortic pressure (MAoP), the peak of the first derivative of left ventricular pressure (LV dP/dt max), and LV end diastolic pressure (LVEDP). Comparison between Groups 1 and 2 showed that bupivacaine induced more than 100% HV interval lengthening and QRS widening (P less than 0.01), prolonged QTc interval by more than 25% (P less than 0.01), and decreased LV dP/dt max by more than 50% (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Residual curarization in the neonate after Caesarean section

The transplacental transfer and the neonatal effects of atracurium 0.3 mg.kg-1 (ED95) were compared with those of d-tubocurarine at the usual clinical dose of 0.3 mg.kg-1 (ED90) in 46 patients undergoing elective Caesarean section. The atracurium group (25 patients) was similar to the d-tubocurarine group (21 patients) as far as age, parity and time intervals between precurarization, induction, skin incision, muscle relaxant administration, hysterotomy and birth. The transplacental transfer of atracurium was lower than that of d-tubocurarine, with a feto-maternal ratio of 9 +/- 3% for atracurium and 12 +/- 5% for d-tubocurarine (P less than 0.05). The transplacental transfer of laudanosine was low at 14 +/- 5%, with blood levels of 0.101 +/- 0.032 microM.L-1 in the umbilical vein. Newborns in the two groups were comparable in terms of Apgar scores at one, five and ten minutes, as well as for NACS scores (neurological and adaptive capacity scoring test) at two and 24 hours after birth. However, at 15 min after birth, only 55% of newborns in whom the mothers received atracurium had a normal NACS score (greater than or equal to 35/40) compared with 83% of newborns in whom the mothers received d-tubocurarine (P less than 0.05). Further analysis of the five variables related to active muscle tone revealed that the modal score for active extension of the neck of newborns from the atracurium group was lower than for newborns from the d-tubocurarine group (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of cell surface receptor-altering agents on the binding and biological activity of 12-O-tetradecanoylphorbol-13-acetate in isolated epidermal cells

Isolated epidermal cells were incubated with a variety of compoundsknown to interfere with or alter the ultrastructure of cellsurface receptors, and the ability of 12-O-tetradecanoyl-phorbol-13-acetate(TPA) to bind to these cells and induce epidermal ornithinedecarboxylase (ODC) activity was investigated. The - and ß-adrenergicantagonists, phentolamine and propranolol, and the cholinergicantagonist, atropine, which competed effectively for the bindingreceptors of [³H]dihydro--ergocryptine, [³H]dihydroalprenolol,and [¹⁴C]acetylcholine, did not inhibit the induction of ODCactivity by TPA or the specific binding of [³H]TPA to the cells.Neuraminidase treatments caused a time- and dose- related releaseof sialic acid from the cells and enhanced the stimulatory effectof cholera toxin on basal and TPA-induced ODC activities asmuch as the monosialoganglioside GM₁. Neuraminidase and theother membrane-altering agents, fucosidase, galactosidase, galactoseoxidase, phospholipases A2 and C, and NaIO₄, were used aloneand/or in various combinations in our studies. All treatmentstested inhibited the specific binding of several ¹²⁵I-labeledhormones and epidermal growth factor to the cells. In contrast,none of these treatments was able, in the same cell system,to affect either the binding or the biological activity of TPA.Therefore, these results suggest that the primary interactionof TPA at the plasma membrane level as well as its biologicaleffect in the intact cell do not proceed through adrenergicor cholinergic receptors and do not require the integrity ofthe cell surface glycoconjugates and phospholipids. In addition,the inhibitory effect of retinoic acid on TPA-induced ODC activityremained unaffected by some of the above treatments, suggestingthat retinoic add is unlikely to interfere with TPA interactionsat the plasma membrane level.     

The effects of antiinflammatory steroids on the response of the guinea-pig isolated ileum to acetylcholine,histamine, nicotine, 5-hydroxytryptamine and electrical stimulation

Summary High concentrations of antiinflammatory steroids (2.5–40 g/ml) reversibly inhibited the electrically induced contractions of the guinea-pig isolated ileum. At 40 g/ml they also reversibly inhibited contractions clicited by acetylcholine, histamine, nicotine and 5-hydroxytryptamine. PGE₁ (2.5 ng/ml), PGE₂ (2.5 ng/ml) and PGF₂ (25 ng/ml) antagonized these effects.The inhibition of contractions elicited by direct agonists were less pronounced than those elicited by indirect or partly indirect agonists. The inhibitory effect of steroids may be related to non-specific actions on biological membranes. An overall sensitization of the smooth muscle by PG's may explain their antagonism to inhibition by steroids.     

Clinical experience with intraurethral alprostadil (MUSE) in the treatment of men with erectile dysfunction. A retrospective study. Medicated urethral system for erection

OBJECTIVE: The Food and Drug Administration (USA) approved the transurethral administration of prostaglandin (alprostadil in January 1997), which had an efficacy of approximately 50% in clinical trials. We studied its effectiveness in clinical practice. METHODS: Patient and partner education was followed by an initial office trial of a medicated urethral system for erection (MUSE) after other medical risk factors were corrected during a 2- to 4-month period. The initial titration dose of alprostadil was usually 125 or 250 microg. Further titration, if needed, was instituted by the patient at home. Success was determined as the satisfactory completion of sexual intercourse in more than 66% of attempts, with a minimum of two being required. RESULTS: Two hundred and seventy patients entered the trials, and follow-up information was available in 229 (85%). The overall success rate was 56%. The dose required was 500 microg in 49.2% and 1,000 microg in 42.2%. Of the 44% in whom treatment failed, 61.4% did so because of lack of efficacy and 38.6% because of side effects (genital pain or urethral bleeding). Minor urogenital symptoms, which did not interfere with treatment, occurred in an additional 40% of patients. CONCLUSIONS: The efficacy of transurethral administration of alprostadil (56%) is higher than the initial published clinical trial data and higher than recent reported clinical experiences, although higher doses were required in our study. Men over 50 years of age, having an organic cause for erectile dysfunction, had better responses. Patient and partner education is important for successful treatment, and the in-office initial titration is an integral part of this success. Prior correction of medical risk factors may enhance the success rate.     

Early predicted time to normalization of tumor markers predicts outcome in poor-prognosis nonseminomatous germ cell tumors.

PURPOSE: The prognostic relevance of the rate of decline of serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) during the first 3 weeks of chemotherapy for nonseminomatous germ cell tumors (NSGCT) was studied in the context of the International Germ Cell Cancer Collaborative Group (IGCCCG) classification. PATIENTS AND METHODS: Data from 653 patients prospectively recruited in clinical trials were studied. Tumor markers were obtained before chemotherapy and 3 weeks later. Decline rates were calculated using a logarithmic formula and expressed as a predicted time to normalization (TTN). A favorable TTN was defined when both AFP and HCG had a favorable decline rate, including cases with normal values. RESULTS: The median follow-up was 50 months (range, 2 to 151 months). Tumor decline rate expressed as a predicted TTN was associated with both progression-free survival (PFS; P <.0001) and overall survival (OS; P <.0001). The 4-year PFS rates were 64% and 38% in patients from the poor-prognosis group who had a favorable and an unfavorable TTN, respectively. The 4-year OS rates were 83% and 58%, respectively. This effect was independent from the initial tumor marker values, the primary tumor site, and the presence of nonpulmonary visceral metastases: tumor marker decline rate remained a strong predictor for both PFS (hazard ratio = 2.5; P =.01) and OS (hazard ratio = 4.6; P =.002) in patients from the IGCCCG poor-prognosis group in multivariate analysis. CONCLUSION: Early predicted time to tumor marker normalization is an independent prognostic factor in patients with poor-prognosis NSGCT and may be a useful tool in the therapeutic management of these patients.