Biomedical subjects
Publications and source records attributed to C Castagnetti.
The authors describe a suturing technique for end-to-end anastomosis in small vessels, which involves the use of continuous suturing without resorting to rotation of the approximator. The method is described in detail.
When characterization of the specificity of an antiserum for radioimmunoassay (RIA) is performed by the conventional method, the conditions under which interference occurs are not respected because of the lack of specific antigen. We have studied the behavior of antisera reproducing the real environment existing in unknown samples, in which antigen, interferent and tracer complete simultaneously. A testosterone (T) antiserum and a 5 alpha-dihydrotestosterone (D) anti serum were characterized by setting up two distinct hapten recovery tests in the presence of both the hapten and the crossreactant added to steroid-free serum in various concentrations in order to reproduce multiple concentration ratios. These samples, together with the standard curves samples (prepared by 'spiking' steroid-free serum with known concentrations of T or D) were extracted and subjected to T-RIA and D-RIA without purification. The results have shown that the interferent-induced incremental ratio is a linear function of the ratio of the levels of cross-reactant and hapten via a proportionality factor inversely correlated to the antiserum specificity. By means of this function, the overestimated T and D levels found in samples after 'extraction only' have been corrected and the resulting values have shown acceptable correlation with the corresponding levels determined after column chromatography.
The experimental parameters of a Double Antibody Solid Phase (DASP) radioimmunoassay (RIA) for the determination of serum luteinizing (LH) and follicle-stimulating (FSH) hormones, are described. The lowest detection limits can be fixed at about 20 pg LH and about 10 pg FSH. Evidence of parrallelism among the dose-response curves and the dilution curves of different sera is provided for FSH-RIA and for about 92% of the tested sera for LH-RIA. The antisera dilution curves are reported (final titres: (/160 - 10(3) for anti-LH and 1/40 - 10(3) for anti-FSH). The traditional cross-reaction study in buffer indicates that 5.38 and 46.8) muU TSH/ml mimic 1 ng LH/ml and 1 ng FSH/ml respectively. The regression-line equations of antigen recovery (f = found, e = expected) are: lH f = 0.94 LH e + 0.91 and FSH f = 1.05 FSH e + 0.17; the same equations when TSH is added become: LH f = 1.30 LH e + 1.46 and FSH f = 1.40 FSH e -- 0.37. It is concluded that LH-RIA is interfered by TSH over 8-10 muM TSH/ml and in function of TSH concentration; FSH-RIA is not interfered by TSH up to 4-5 ng FSH/ml; for higher FSH levels, TSH interferes according to a linear law (angular coefficient 1.40) and not in function of its concentration. LH and FSH levels throughout normal menstrual cycle in follicular phase, centre peak and luteal phase are: 3.14 +/- 1.16, 16.71 +/- 12.99, 2.31 +/- 1.04 ng LH/ml (mean +/- 2SD) and 3.57 +/- 0.95, 5.72 +/- 2.90, 2.57 +/- 0.80 ng FSH/ml (mean +/- 2SD) respectively. Finally, the within-assay coefficient of variation is 7.65% for LH-RIA and 3.16% for FSH-RIA.
The reconstruction of complex cutaneous tendinous dorsal hand injuries represents a problem that is not easy to solve. The transferral in a single surgical stage, with a single flap, of skin, tendons, and nerves, all completely vascularized, is probably the ideal solution. Between 1988 and 1999 the one-stage reconstruction method was used in 13 patients. A cutaneous tendinous dorsalis pedis free flap was used in 7 cases, and a cutaneous tendinous radial forearm island flap with an inverted flow was used in 6. The dorsalis pedis flap allows for the inclusion of 4 tendons that are completely vascularized (extensor digitorum communis), while the radial flap allows us to completely insert a single tendon (palmaris brevis) and two vascularized tendinous strips taken from the flexor carpi radialis and from the brachioradialis. All of the flaps transferred survived perfectly with good functional recovery. One-stage reconstruction that is "completely vascularized" allows us to reduce the amount of time spent in hospital, the number of operations, and above all it provides cosmetic and functional results that are close to normal. The dorsalis pedis flap is indicated in cases of cutaneous tendinous dorsal hand injuries that require the simultaneous reconstruction of three or four extensor tendons. On the other hand, the radial flap may be used in situations where it is necessary to reconstruct only 1 or 2 tendons.
The radioimmunoassay (RIA) blank (Blk) value (as calssically determined) does not represent the real aspecific portion of the radioactivity because of the lack of both antigen and antiserum and the consequent total availability of free tracer, and is, therefore, unlike the standard and unknown tubes. Gastrin-RIA with bound-free separation by charcoal adsorption was chosen as example for providing evidence that the subtraction of such an empirical constant (Blk) from the dependent variable (the response) of a function (response versus dose) is analytically incorrect. Antigen-recovery and parallelism (serum dilution) tests were carried out, and the results obtained by the so-called "Blk subtraction procedure" (BS values) were compared with the corresponding values without Blk subtraction (BNS values). In the recovery test, the BS values were higher than the BNS values, but the former were higher than the expected values, whereas the latter showed a quantitative recovery. The same result was also found in the serum dilution test: the BNS values gave dilution curves more parallel to the BNS standard curve than did the BS values to the BS standard curve. It is concluded that the Blk subtraction procedure must be avoided in processing RIA results.
The authors report 16 cases of partial arthrodeses of the wrist for the treatment of Kienboeck's disease, pseudarthrosis of the scaphoid, rotatory subluxation of the scaphoid, rheumatoid arthritis, etc. Based on the good results obtained (76.6%) the authors believe that partial arthrodeses constitute the type of treatment indicated for the treatment of pathologies that involve only some of the carpal bones, and they also emphasize that this type of surgery represents a valid alternative to total arthrodesis of the wrist.