Brachiocephalic revascularization: a comparison between carotid-subclavian artery bypass and axilloaxillary artery bypass

Sixty-seven patients who underwent carotid-subclavian bypass (CSBP) (28 CSBPs only and eight with carotid endarterectomy) or axilloaxillary artery bypass (n = 31) with polytetrafluoroethylene grafts were followed up for a mean of 69.2 and 71.9 months, respectively. Indications for surgery in the CSBP group included hemispheric transient ischemic attack (TIA)/cerebrovascular accident in five, nonhemispheric TIA in seven, upper extremity ischemia in 15, and combined TIA and arm ischemia in nine patients. In the axilloaxillary artery group, two patients had hemispheric TIA, five had nonhemispheric TIA, 12 had upper extremity ischemia, and 12 had combined TIA and arm ischemia. Graft patency was determined clinically and confirmed by segmental Doppler pressures, duplex ultrasonography, or angiography. The 30-day mortality rate was approximately 3% in both groups. The 30-day complication rate was 3% for the axilloaxillary artery group and 8% for the CSBP group (not statistically significant). Relief of symptoms was achieved in 100% of patients in both groups; however, 20% of the patients in the axilloaxillary artery group had a recurrence of symptoms, in contrast to 5.6% in the CSBP group. The cumulative 10-year primary and secondary patency rates, calculated by life-table analysis, were 66% and 84.6% for the axilloaxillary artery procedures and 93.8% and 93.8% for the CSBP procedures, respectively (statistically significant). Concomitant carotid endarterectomy with CSBP did not influence graft patency. In conclusion, both bypasses have comparable morbidity and mortality rates; however, the CSBP has a statistically significantly better primary patency rate than the axilloaxillary artery bypass. Therefore CSBP should be the procedure of choice and the axilloaxillary artery bypass should be restricted to high-risk patients.

The judicial use of venous duplex imaging and strain gauge plethysmography (single or combined) in the diagnosis of acute and chronic deep vein thrombosis

Sixty-eight patients (79 limbs) with clinically suspected deep vein thrombosis were evaluated by duplex imaging, strain gauge plethysmography and venography. The diagnostic accuracies were projected over a spectrum of disease incidences ranging from 10 to 90 per cent of the population. The sensitivity, specificity, positive and negative predictive values, and over-all accuracy in detecting acute deep vein thrombosis were 90.9, 87.1, 83.3, 93.1, and 88.7 per cent, respectively, for venous duplex imaging, and 81.8, 69.6, 56.3, 88.9 and 73.5 per cent, respectively, for strain gauge plethysmography. The positive predictive value and over-all accuracy of venous duplex imaging were statistically significantly higher than that of strain gauge plethysmography. When both tests were combined and compared with venous duplex imaging alone, none of these parameters were statistically significant. For chronic deep vein thrombosis, the sensitivity, specificity, positive predictive value, negative predictive value and over-all accuracy for venous duplex imaging were 75, 86, 80, 86 and 82 per cent, respectively. Fourteen per cent had inconclusive results obtained at venous duplex imaging. When strain gauge plethysmography was combined with venous duplex imaging, the over-all accuracy was 82 per cent. As the true incidence of the disease increases, the positive accuracy differences between strain gauge plethysmography and venous duplex imaging decrease to a negligible level. We concluded that over-all, venous duplex imaging is superior. However, the strain gauge plethysmography has reasonable accuracy and may be used in places where venous duplex imaging is not available. Combined use of venous duplex imaging and strain gauge plethysmography would be helpful in patients with inconclusive results obtained at venous duplex imaging and, as the true incidence increases, the positive accuracy rate of strain gauge plethysmography becomes close to that of venous duplex imaging.

Clinical, hemodynamic, and anatomic predictors of long-term outcome of lower extremity venovenous bypasses

Forty-three patients, 24 with crossover femoral saphenous vein bypasses and 19 with saphenopopliteal vein bypasses, were observed for a mean of 5.5 years. All underwent preoperative and sequential postoperative clinical, hemodynamic and foot venous pressure measurement, and anatomic evaluations (duplex and venography). Seventy-one percent of patients undergoing crossover femoral saphenous vein bypasses and 74% of patients undergoing saphenopopliteal vein bypasses had an abnormal preoperative maximum venous outflow, in contrast to 4% and 11% after operation (p = 0.0183). The mean immediate postoperative maximum venous outflow improvement for patients having crossover femoral saphenous vein bypasses and those having saphenopopliteal vein bypasses was 16 and 17 ml, respectively, and the mean late improvement was 19 and 27 ml, respectively. Ninety percent of the patients undergoing crossover femoral vein bypasses and those having saphenopopliteal vein bypasses had abnormal foot venous pressures in contrast to 18% and 22% after operation. The final clinical outcomes (over 1 year) for both patients having the crossover saphenous vein bypasses and those having saphenopopliteal vein bypasses, respectively, were significant improvement (+3 and +2), 63% and 58%; significant worsening (-2), 4% and 5%. Eighty-eight percent of patients undergoing crossover femoral saphenous vein bypasses and 79% of patients undergoing saphenopopliteal vein bypasses with abnormal preoperative maximum venous outflow measurements had significant clinical improvement. In contrast, 86% of patients undergoing crossover femoral saphenous vein bypasses and 80% of patients undergoing saphenopopliteal vein bypasses with normal preoperative maximum venous outflow had no improvement. Seventy-seven percent of patients having saphenopopliteal vein bypasses and a normal venous refill time had significant improvement, in contrast to 17% for patients with an abnormal venous refill time (less than 10 sec). Sixty-seven percent of patients undergoing crossover femoral saphenous vein bypasses and 78% of patients undergoing saphenopopliteal vein bypasses with abnormal foot venous pressure measurements had significant improvement. The cumulative 7-year patency was 75% for patients having crossover femoral saphenous vein bypasses and 56% for those having saphenopopliteal vein bypasses. The operative mortality rate was 0% for both procedures, and the complication rate was 4% and 10%, respectively. The most important preoperative variables that correlated with a good outcome were a low preoperative maximum venous outflow, venous refill time greater than 10 sec, and venous claudication and iliac vein compression. Patients with a normal maximum venous outflow measurement and severe venous reflux should not be candidates for these bypasses.

The risk of ligation of the left renal vein in resection of the abdominal aortic aneurysm

The left renal vein can be ligated during aortic operation to attain better access to the perirenal aorta. This maneuver has been considered safe, with a low incidence of postoperative renal complications. This study was done to evaluate the risk of left renal vein ligation and its influence on renal function in patients with elective resection of abdominal aortic aneurysms. The records of 332 patients undergoing elective repair of abdominal aortic aneurysms during a five year period were reviewed. The clinical and operative data of patients who had left renal vein ligation and those who did not were similar. Left renal vein ligation was not associated with an increased mortality rate but was strongly associated with an increase in serum creatinine level and a clinical diagnosis of postoperative azotemia. Nine of 13 patients who had left renal vein ligation had postoperative azotemia compared with 21 of 319 patients without left renal vein ligation (p less than 0.001). The mean change of preoperative and postoperative creatinine value was an increase of 1.92 milligrams per deciliter in patients with left renal vein ligation in contrast with 0.26 milligram per deciliter in patients without ligation (p less than 0.00075). Thus, ligation of the left renal vein increases the risk of postoperative renal complications and its use should be selective.

Cost implications of alternative treatments for AIDS patients with cryptococcal meningitis. Comparison of fluconazole and amphotericin B-based therapies

The extra demands placed upon health care resources by management of AIDS patients have increased the focus on cost implications of therapeutic alternatives. Cryptococcal meningitis is a common life-threatening infection in AIDS patients, usually treated with amphotericin B, often in combination with flucytosine. Administered intravenously, this therapy is associated with frequent and often severe side effects. Fluconazole is a new alternative which can be given orally once daily and has fewer such side effects. The purpose of this study was to examine the cost implications of these different therapies for both primary and maintenance treatment of cryptococcal meningitis. Comparison of these two therapies in recent clinical trials has indicated that fluconazole is at least as effective as amphotericin B, and therefore cost-minimisation analysis is an appropriate method to study the economic consequences of the alternative treatments. Patient management and resource-use information for both treatments was obtained using a modified Delphi technique with a panel of European physicians experienced in the treatment of this disease, and three models were developed to reflect the variability of practice evident among the panel members. U.K. health care costs were used to value these resources. The results indicated that, despite the higher cost of the drug itself, the costs associated with fluconazole were likely to be markedly less than those for amphotericin B for primary treatment, and similar or slightly cheaper for maintenance treatment. Over 1 year of treatment, the saving from the use of fluconazole would be in the range of 4000-14,000 pounds.

Identification and partial characterisation of a serum enzyme which hydrolyses epidermal inhibitory pentapeptide

We have identified an enzyme present in mammalian, avian, and reptilian serum which cleaves epidermal inhibitory pentapeptide (pGlu-Glu-Asp-Ser-GlyOH) to form a relatively stable tripeptide (pGlu-Glu-Asp). The enzyme has an inhibitor profile unlike any readily identifiable serum enzyme, and is stable at 4 degrees C for up to 3 months. As most experiments using the pentapeptide are carried out in the presence of serum this finding may have important implications on future research into the biological function of the pentapeptide.

Elective resection of 332 abdominal aortic aneurysms in a southern West Virginia community during a recent five-year period

This study analyzed 33 variables that might potentially affect outcome in a series of 332 consecutive elective abdominal aortic aneurysm repairs in a southern West Virginia community. One of the interesting features of this series was that the repairs were done by 22 surgeons with varying degrees of experience. The mortality and complication rates were compared for various potential risk factors by both univariant methods (chi 2, Fisher's exact, and Student t tests) and multivariant methods of analysis. Our early mortality (2.1%) and postoperative complication rates were consistent with those of other series. With multiple linear regression models, five factors were selected as significant independent risk factors associated with an increasing number of postoperative complications: the number of blood transfusions (p less than 0.0001), left renal vein ligation (p less than 0.0001), the presence of greater than 50% renal artery stenosis (p = 0.0012), the lesser experience of the surgeon (p = 0.0203), and the history of prior cardiac catheterization (p = 0.0245). The only factor statistically correlated with mortality rate was an increased number of postoperative complications (p less than 0.0001). Neither postoperative complications nor mortality rate was found to be significant and independently influenced by other demographic, clinical, or operative factors. It is tempting to speculate that surgeons with less experience might be well served to refer patients with significant renal artery stenosis and coronary artery disease. Our mortality and complication rates were not increased by performing preoperative angiography and therefore prudent surgeons may find this helpful in selecting patients for safer repair.

Axillary subclavian vein thrombosis. Changing patterns of etiology, diagnostic, and therapeutic modalities

Fifty-two patients with axillary-subclavian vein thrombosis were treated in the last 10 years and were available for follow-up for at least 1 year. Eighteen of these were treated in the first 5 years, Group A, and 34 in the last 5 years, Group B. The causes in both Group A and Group B included respectively: effort or spontaneous 28 per cent and 29 per cent, catheter insertion related 17 per cent and 47 per cent, and malignancy or systemic disease 55 per cent and 24 per cent. None of the patients in Group A had noninvasive vascular testing (NIT). However, 27 patients in Group B had IPG/duplex imaging (NIT). All 18 cases in Group A and 27 cases in Group B were treated conventionally (anticoagulants). Seventy-three per cent of these had residual pain on exertion (venous claudication) and/or swelling. Fourteen of these cases had posttreatment NIT/venography. Four of these showed total resolution of the thrombus and all were symptom free. Ten had no resolution, and nine were symptomatic. Seven cases in Group B were treated with thrombolytic therapy. Five of these had total resolution of thrombus and were symptom free (71%). Two had no resolution with residual symptoms (29%) (statistically significant). In conclusion (1) More patients with axillary-subclavian vein thrombosis seen recently are catheter insertion related; 2) Diagnosis should be initiated with duplex imaging; and (3) Thrombolytic therapy significantly decreased residual symptoms and yielded better resolution than anticoagulants.

Intraoperative peripheral Nd:YAG laser-assisted thermal balloon angioplasty: short-term and intermediate-term follow-up

Laser-assisted thermal balloon angioplasty was performed in 48 arteries (iliac, superficial femoral, and popliteal). Indications for surgery were limb salvage (25%), rest pain (38%), and claudication (38%). Patients were categorized into three groups: lesions less than 5 cm, greater than 5 to 10 cm, or greater than 10 cm in length. Demographic characteristics, risk factors, and outcome measures were compared by use of Fisher's exact test and Student's t test. The time for vascular patency failure was compared by use of a standard Kaplan-Meier survival analysis for the three groups. Initial failure to recanalize was noted in 14% in lesions less than 5 cm, 40% in lesions greater than 5 to 10 cm, and 73% in lesions greater than 10 cm. The overall success rate was 38%, with a mean follow up of 1 year. The less than 5 cm lesion group had a significantly higher rate of overall success (59%, p = 0.005) than the other two groups combined. The greater than 10 cm lesion group did significantly worse (9%) than the other two groups combined (p = 0.028). Patients in the less than 5 cm group had significantly longer patency than the other two groups (p less than 0.01). Iliac lesions had a higher overall success rate (73%) than superficial femoral and popliteal artery lesions (35%) (p = 0.038). In conclusion, the widespread application of laser-assisted thermal balloon angioplasty cannot be justified without further long-term clinical and laboratory investigation. Conversely, the potential of this technique should not be dismissed out of hand. Proper patient selection, length and nature of the lesion to be treated, and the appropriate forms, doses, and method of delivery of laser energy, remain to be defined.

Fluconazole for life-threatening fungal infections in patients who cannot be treated with conventional antifungal agents

Fluconazole therapy was evaluated prospectively in patients with serious fungal infections who failed to respond to or could not tolerate conventional antifungal therapy. Patients were enrolled if they had a life-threatening fungal infection and conventional therapy had failed to eradicate the infection, had caused serious toxic reactions, or was contraindicated. Patients were treated with 200 mg/day, a dosage that could be increased to 400 mg/d if the initial response was not satisfactory. AIDS was the underlying risk factor in 65% of 232 patients evaluated in the study and in 85% of 151 patients with cryptococcal infection. Fifty-eight patients had active cryptococcal infection; 74% had a satisfactory clinical response, and 75% of 44 patients became culture-negative. Patients with inactive infection had a relapse rate of 4.5/1,000 patient-weeks. Twenty-three of 30 patients with coccidioidal infection and 10 of 14 patients with candidiasis or another mycosis were clinically improved. Five patients (2%) discontinued fluconazole therapy because of adverse effects possibly attributable to therapy. Fluconazole may be effective in the treatment of serious fungal infections in patients who cannot continue conventional antifungal therapy.

Prospective clinicopathophysiologic follow-up study of asymptomatic neck bruit

Three hundred asymptomatic carotid bruits (ACB) were followed prospectively, clinically, and by duplex ultrasound with Gee/ocular plethysmography (OPG) for a period ranging from one to 72 months (mean, 32 months). All patients underwent baseline duplex/OPG, which was repeated every six months until the endpoint, transient ischemic attack (TIA) or cerebrovascular accident (CVA). One hundred seven had arteriograms. Five classes were identified: class I (normal): 96/300 (32%), 79 of these were followed and one had TIA (1/79, 1.3%); class II (less than 50% stenosis): 118/300 (39%), 105 of these were followed, three had TIA, and one had CVA (4/105, 3.8%); class III (50-60% stenosis): 25/300 (8%), 21 were followed, one had TIA (1/21, 4.7%); class IV (more than 60% stenosis with negative OPG): 39/300 (13%), 34 were followed, three had TIA, and one had CVA (4/34, 11.7%); and class V (more than 60% stenosis with positive OPG): 22/300 (7%), 18 were followed, three had TIA, and one had CVA (4/18, 22.2%). Data was analyzed using chi-square with Yates correction. In conclusion, in ACB 32 per cent had no carotid stenosis and 39 per cent had minimal disease with minimal risk of TIA or stroke. Patients with the most severe stenoses (classes IV and V) had a statistically significantly higher likelihood of TIA or CVA occurring during the follow-up period. This last group (class V) would be ideal for prophylactic carotid endarterectomy.

Clinical parameters for predicting response to lumbar sympathectomy in patients with severe lower limb ischemia

A prospective study of 85 lumbar sympathectomies for inoperable peripheral vascular disease was conducted to analyze the correlation between lumbar sympathectomy, ankle/arm index (AAI), popliteal-brachial index (PBI), and the clinical presentation; and to study if predicted clinical criteria, single or combined, could be defined for selection of patients who might benefit from lumbar sympathectomy. Good results were obtained if at six months after surgery pain at rest was absent, ischemic ulcers had healed, and there were no major amputations. Seventy-seven percent of all limbs with a preoperative AAI greater than or equal to 0.3 had a good outcome in contrast to 94% failure for index less than 0.3 (p = .000000477). Sixty-nine percent of all limbs with PBI greater than or equal to 0.7 had a good outcome vs. 52% if index less than 0.7 (p = 0.199). Patients with rest pain, simple leg ulcers, and toe gangrene had a good outcome if the AAI greater than or equal to 0.3 and if the postoperative AAI increased by greater than or equal to 0.1. The PBI and diabetic status had no prognostic value.

Partial sequence of the rat heavy neurofilament polypeptide (NF-H). Identification of putative phosphorylation sites

A 3 kb cDNA clone has previously been isolated in this laboratory corresponding to the rat heavy neurofilament polypeptide (NF-H). This clone, equivalent to approximately 70% of the total mRNA of the protein has been sequenced and shown to contain the carboxy-terminal region of the message. This contains 51 of the Lys-Ser-Pro repeat triplets which are reported to be the site of neurofilament phosphorylation. The sequence obtained was subsequently compared to those of mouse and human NF-H, showing a homology of approximately 85%. There is, however, one region which is variable between the species, this being the highly phosphorylated region of the protein containing the Lys-Ser-Pro triplet repeat.

Nitrocellulose-bound antigen repeatedly used for the affinity purification of specific polyclonal antibodies for screening DNA expression libraries

We present a simple, efficient and rapid method for affinity-purifying antibodies from a relatively crude antiserum in quantities large enough to screen a DNA expression library. The method presents a very convenient way to remove crossreacting or contaminating antibody specificities. The affinity matrix, antigen non-covalently bound to nitrocellulose, is prepared by the electrophoretic separation of antigen by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, followed by the transfer of antigen to nitrocellulose. The matrix can be used repeatedly. A brief wash with 6 M guanidine hydrochloride is included between steps to remove residual antibodies which bind with high affinity to nitrocellulose-bound antigen. Various buffer solutions were assessed as antibody/antigen-dissociating agents. Glycine/HCl buffer, pH 2.5, appeared to be the most efficient in our hands, although a number of other less efficient dissociating reagents, including 4.5 M magnesium chloride, pH 7.5, 6 M urea, pH 7, and 0.05 M diethylamine, pH 11.5, also could be used; these may be the elution conditions of choice for other antibody/antigen combinations. The use of affinity-purified antibody solutions instead of the corresponding antisera gave increased signal-to-noise ratios with the detection systems that are commonly used to identify positive signals in screening expression libraries. Protein A- and goat anti-rabbit-alkaline phosphatase conjugates gave the most sensitive signals.

Isolation of cDNAs coding for epitopes shared by microtubule-associated proteins and neurofibrillary tangle in Alzheimer's disease

5 cross-hybridizing cDNA clones of sizes 2.2 (3 cDNAs), 1.3 and 0.8 kb corresponding to tau microtubule-associated protein have been isolated from a rat brain lambda gt11 expression library. Antibodies affinity-purified using the fusion protein encoded by the cDNAs were observed to label tau polypeptides on Western blots and Alzheimer's neurofibrillary tangles.

Isolation of a cDNA for the rat heavy neurofilament polypeptide (NF-H)

We have isolated from a rat brain lambda gt11 expression library two overlapping cDNA clones of sizes 2.5 and 3.0 kb corresponding to the heavy neurofilament polypeptide (NF-H). The 2.5 kb insert apparently represents virtually the whole of the C-terminal tail, the 3.0 kb insert also encodes the conserved epitope for the monoclonal antibody, anti-IFA. The identity of the cDNAs was established by comparison of the predicted amino acid sequence with the known partial amino acid sequence of porcine NF-H. A repeat peptide sequence that may be a multiphosphorylation site was identified in the C-terminal non-helical tail.

Physicochemical characteristics of human sex hormone binding globulin: evidence for two identical subunits

We have developed a rapid protocol for the purification of human sex hormone binding globulin (SHBG) which allows the protein to be purified from pregnancy serum within 48 h. This minimizes any possible degradation of the protein by serum proteases, and has enabled us to re-examine some important and controversial aspects of its structural composition. Our physicochemical data are consistent with the hypothesis that SHBG is a dimeric glycoprotein composed of 2 protomers that exhibit size heterogeneity (approximately 50 and approximately 52 K daltons). The dimeric SHBG molecule appears to contain only approximately 8% carbohydrate, and sequence information indicates that an N-linked oligosaccharide chain may be attached to residue 7 (asparagine) from the NH2-terminal amino acid (leucine). When compared with earlier reports, differences in the relative amounts of heavy (approximately 52 K) and light (approximately 50 K) protomers, and the microheterogeneity of NH2-terminal amino acids, have led us to conclude that they may be caused by proteolytic degradation in vivo as well as during the storage of blood samples prior to protein purification. However, the NH2-terminal amino acid sequence data indicate that the primary structures of the heavy protomers, which evidently interact to form the majority of SHBG dimer in serum, are similar and may even be identical. Evidence to support this is provided by the observation that a monoclonal antibody, which recognises a configurational epitope, interacts with two epitopes per native dimeric form of human SHBG.

A liquid-phase immunoradiometric assay (IRMA) for human sex hormone binding globulin (SHBG)

An immunoradiometric assay (IRMA) for sex hormone binding globulin (SHBG) has been developed in which an 125I-labeled monoclonal antibody [( 125I]S1B5) and a rabbit anti-SHBG antiserum (RAb) are incubated in "liquid-phase" with standards or samples, and RAb-bound complexes are separated using donkey anti-rabbit IgG antibody-coated cellulose. This immunoassay technique is characterized by several advantages; the [125I]S1B5 imparts additional specificity and obviates the requirement for pure SHBG; the use of excess reagents reduces incubation times and also improves assay performance and sensitivity, and incubation in "liquid-phase" conserves and increases the efficiency of the RAb. The assay measures only non-denatured SHBG and is not influenced by the presence of steroid at the binding site. Assay specificity was demonstrated by parallelism between dilutions of pure SHBG and different serum samples. The quantitative recovery of SHBG added to serum, and the agreement between specific activities of SHBG in pure standards and sera, confirm the accuracy of the method. The within and between assay coefficients of variation were less than 7% and less than 11%, respectively, between 12 and 450 nmol/l. The assay sensitivity may be manipulated by altering the concentration of RAb and/or by preincubation with either [125I]S1B5 or RAb, and 0.2 fmol SHBG may be measured on a standard curve. The SHBG assay has been used to measure SHBG concentrations in sera, amniotic fluid, cerebral spinal fluid, seminal plasma and saliva.

Beta-lactamase-positive strains of Haemophilus influenzae: susceptibility to and inactivation of beta-lactam antibiotics

Susceptibility and time-kill studies were done with low and high inocula of both beta-lactamase-positive and -negative strains of Haemophilus influenzae with cefamandole, ampicillin, cefoperazone, mezlocillin, moxalactam, and ceftriaxone. Bioassay was done to test for antibiotic inactivation by beta-lactamase-positive strains. All six antibiotics were highly active against the low inoculum (10(4) to 10(5) colony-forming units/ml) of beta-lactamase-negative strains; ceftriaxone, moxalactam, and cefoperazone were equally active against the same inoculum concentration of beta-lactamase-positive strains. In contrast, cefamandole, mezlocillin, and ampicillin were less active against the low inoculum of beta-lactamase-positive H influenzae. A marked inoculum effect occurred with the high inoculum (10(7) to 10(8) CFU/ml) with all six antibiotics, regardless of beta-lactamase production. In time-kill studies, marked differences in bacterial killing resulted after low and high inocula. Ampicillin, cefamandole, cefoperazone, and mezlocillin were rapidly inactivated by the high inoculum of beta-lactamase-positive H influenzae.

Copper chelates of antirheumatic and anti-inflammatory agents: their superoxide dismutase-like activity and stability

An in vitro assay is described which simultaneously tests for the superoxide dismutase-like activity of low-molecular-weight copper chelates and their stability in the presence of excess EDTA. The EDTA is introduced to simulate the competitive endogenous ligands a copper-chelating drug will encounter in plasma and other body fluids. Under the conditions of the assay, antirheumatic drugs of the D-penicillamine type are clearly distinguished both from nonsteroidal anti-inflammatories and from some drugs which chelate copper but lack antirheumatic activity.

A solid-phase radioimmunoassay for human corticosteroid binding globulin

A radioimmunoassay (RIA) for human corticosteroid binding globulin (CBG) has been developed using 125I-labelled CBG and a monospecific solid-phase CBG-antiserum (CBG-Ab-cellulose). In an RIA of serum CBG concentrations, pure CBG standards (1-100 ng protein) or samples (1:200) were incubated (16 h at 20 degrees C) with 125I-labelled CBG and CBG-Ab-cellulose. After addition of 2 ml 0.9% NaCl, the tubes were centrifuged, supernatants were aspirated and the 125I-labelled CBG bound to the CBG-Ab-cellulose pellet was counted. The specificity of the RIA was confirmed by parallel displacement curves for serial dilutions of male, female and pregnancy sera, as well as pure CBG standards. The mean +/- S.D. recovery (99 +/- 8%) of pure CBG (1.6-25.0 ng) added to a diluted serum sample verified the accuracy of the method, and a good correlation (r = 0.97; n = 43) existed between serum CBG cortisol binding capacity (nmol/l) measurements and CBG concentrations (mg protein/l) measured by RIA. Intra- and interassay precisions (C.V.) at low to high serum CBG concentrations were less than 5% and less than 9% respectively. The mean +/- S.D. serum CBG concentrations (mg protein/l) measured by the RIA were: 21.8 +/- 4.6 in boys (n = 12), 20.0 +/- 4.2 in girls (n = 9), 20.7 +/- 2.7 in men (n = 6), 20.5 +/- 2.9 in women (n = 6) and 47.1 +/- 10.5 in pregnant women (n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)