Spread of injectate around hip articular sensory branches of the femoral nerve in cadavers

BACKGROUND

Anatomical knowledge dictates that regional anaesthesia after total hip arthroplasty requires blockade of the hip articular branches of the femoral and obturator nerves. A direct femoral nerve block increases the risk of fall and impedes mobilisation. We propose a selective nerve block of the hip articular branches of the femoral nerve by an ultrasound-guided injection in the plane between the iliopsoas muscle and the iliofemoral ligament (the iliopsoas plane). The aim of this study was to assess whether dye injected in the iliopsoas plane spreads to all hip articular branches of the femoral nerve.

METHODS

Fifteen cadaver sides were injected with 5 mL dye in the iliopsoas plane guided by ultrasound. Dissection was performed to verify the spread of injectate around the hip articular branches of the femoral nerve.

RESULTS

In 10 dissections (67% [95% confidence interval: 38-88%]), the injectate was contained in the iliopsoas plane staining all hip articular branches of the femoral nerve without spread to motor branches. In four dissections (27% [8-55%]), the injection was unintentionally made within the iliopectineal bursa resulting in secondary spread. In one dissection (7% [0.2-32%]) adhesions partially obstructed the spread of dye.

CONCLUSION

An injection of 5 mL in the iliopsoas plane spreads around all hip articular branches of the femoral nerve in 10 of 15 cadaver sides. If these findings translate to living humans, injection of local anaesthetic into the iliopsoas plane could generate a selective sensory nerve block of the articular branches of the femoral nerve without motor blockade.

Influence of Ultra-Low-Dose and Iterative Reconstructions on the Visualization of Orbital Soft Tissues on Maxillofacial CT

BACKGROUND AND PURPOSE

Dose reduction on CT scans for surgical planning and postoperative evaluation of midface and orbital fractures is an important concern. The purpose of this study was to evaluate the variability of various low-dose and iterative reconstruction techniques on the visualization of orbital soft tissues.

MATERIALS AND METHODS

Contrast-to-noise ratios of the optic nerve and inferior rectus muscle and subjective scores of a human cadaver were calculated from CT with a reference dose protocol (CT dose index volume = 36.69 mGy) and a subsequent series of low-dose protocols (LDPs I-4: CT dose index volume = 4.18, 2.64, 0.99, and 0.53 mGy) with filtered back-projection (FBP) and adaptive statistical iterative reconstruction (ASIR)-50, ASIR-100, and model-based iterative reconstruction. The Dunn Multiple Comparison Test was used to compare each combination of protocols (α = .05).

RESULTS

Compared with the reference dose protocol with FBP, the following statistically significant differences in contrast-to-noise ratios were shown (all, P ≤ .012) for the following: 1) optic nerve: LDP-I with FBP; LDP-II with FBP and ASIR-50; LDP-III with FBP, ASIR-50, and ASIR-100; and LDP-IV with FBP, ASIR-50, and ASIR-100; and 2) inferior rectus muscle: LDP-II with FBP, LDP-III with FBP and ASIR-50, and LDP-IV with FBP, ASIR-50, and ASIR-100. Model-based iterative reconstruction showed the best contrast-to-noise ratio in all images and provided similar subjective scores for LDP-II. ASIR-50 had no remarkable effect, and ASIR-100, a small effect on subjective scores.

CONCLUSIONS

Compared with a reference dose protocol with FBP, model-based iterative reconstruction may show similar diagnostic visibility of orbital soft tissues at a CT dose index volume of 2.64 mGy. Low-dose technology and iterative reconstruction technology may redefine current reference dose levels in maxillofacial CT.

Integration of Peripheral and Glandular Regulation of Triiodothyronine Production by Thyrotropin in Untreated and Thyroxine-Treated Subjects

The objective of the study was to evaluate the roles of central and peripheral T3 regulation. In a prospective study involving 1,796 patients, the equilibria between FT3 and TSH were compared in untreated and L-T4-treated patients with varying functional states, residual thyroid secretory capacities and magnitudes of TSH stimulation. T3 concentrations were stable over wide variations in TSH levels (from 0.2 to 7 mU/l) and endogenous T4 production in untreated patients, but unbalanced in L-T4-treated athyreotic patients where T3 correlated with exogenous T4 supply. T3 stability was related to TSH-stimulated deiodinase activity by clinical observation, as predicted by theoretical modelling. Deiodinase activity in treated patients was reduced due to both diminished responsiveness to TSH and lack of thyroidal capacity. Deiodinase activity was increased in high thyroid volume, compared to lower volumes in euthyroid patients (<5 ml, p<0.001). While deiodinase differed between euthyroid and subclinically hypothyroid patients in high volume, 26.7 nmol/s (23.6, 29.2), n=214 vs. 28.9 nmol/s (26.7, 31.5), n=20, p=0.02, it was equivalent between the 2 functional groups in low volume, 23.3 nmol/s (21.3, 26.1), n=117 vs. 24.6 nmol/s (22.2, 27.5), n=38, p=0.22. These findings suggest that the thyroid gland and peripheral tissues are integrated in the physiological process of T3 homeostasis in humans via a feed-forward TSH motif, which coordinates peripheral and central regulatory mechanisms. Regulatory and capacity deficiencies collectively impair T3 homeostasis in L-T4-treated patients.

Ultralow-dose computed tomography imaging for surgery of midfacial and orbital fractures using ASIR and MBIR

The influence of dose reductions on diagnostic quality using a series of high-resolution ultralow-dose computed tomography (CT) scans for computer-assisted planning and surgery including the most recent iterative reconstruction algorithms was evaluated and compared with the fracture detectability of a standard cranial emergency protocol. A human cadaver head including the mandible was artificially prepared with midfacial and orbital fractures and scanned using a 64-multislice CT scanner. The CT dose index volume (CTDIvol) and effective doses were calculated using application software. Noise was evaluated as the standard deviation in Hounsfield units within an identical region of interest in the posterior fossa. Diagnostic quality was assessed by consensus reading of a craniomaxillofacial surgeon and radiologist. Compared with the emergency protocol at CTDIvol 35.3 mGy and effective dose 3.6 mSv, low-dose protocols down to CTDIvol 1.0 mGy and 0.1 mSv (97% dose reduction) may be sufficient for the diagnosis of dislocated craniofacial fractures. Non-dislocated fractures may be detected at CTDIvol 2.6 mGy and 0.3 mSv (93% dose reduction). Adaptive statistical iterative reconstruction (ASIR) 50 and 100 reduced average noise by 30% and 56%, and model-based iterative reconstruction (MBIR) by 93%. However, the detection rate of fractures could not be improved due to smoothing effects.

Reference range for thyrotropin. Post hoc assessment

Setting the reference range for thyrotropin (TSH) remains a matter of ongoing controversy.

PATIENTS, METHODS

We used an indirect method to determine the TSH reference range post hoc in a large sample. A total of 399 well characterised subjects showing no evidence of thyroid dysfunction were selected for definition of the TSH reference limits according to the method of Katayev et al.. To this end, the cumulative frequency was plotted against the individual logarithmic TSH values. Reference limits were calculated by extrapolating the middle linear part of the regression line to obtain the cut-offs for the 95% confidence interval. We also examined biological variation in a sample of 65 subjects with repeat measurements to establish reference change values (RCVs).

RESULTS

Based on these, the reference interval obtained by the novel technique was in close agreement with the conventionally established limits, but differed significantly from earlier recommendations.

DISCUSSION

Following unverified recommendations could result in a portion of patients with subclinical thyroid dysfunctions being missed, an important consideration in a setting with a high prevalence of thyroid autonomy.

CONCLUSION

Indirect post hoc verification of reference intervals from a large retrospective sample is a modern approach that gives plausible results. The method seems particularly useful to assess the adequacy and performance of reference limits reported or established by others in a particular setting. The present data should encourage re-evaluation of reference systems on a broader scale.

Testosterone levels increase in association with recovery from acute fracture in men

In this longitudinal case-control study, acute fracture was associated with low serum testosterone, which was transient in 43% of men. While assessment of gonadal status is part of the assessment of bone fragility, measurement of testosterone in the early period after fracture may overestimate the prevalence of androgen deficiency.

INTRODUCTION

Measurement of circulating testosterone is recommended in the evaluation of bone fragility in men. Since acute illness can transiently decrease circulating testosterone, we quantified the association of acute fracture and serum testosterone levels.

METHODS

A case-control study was conducted involving 240 men with a radiologically confirmed minimal trauma fracture presenting to a tertiary referral hospital and 89 age-matched men without a history of minimal trauma fracture serving as controls. Follow-up testosterone levels 6 months after baseline were available for 98 cases and 27 controls. Results were expressed as the median and interquartile (IQR) range.

RESULTS

Compared to controls, cases had lower total testosterone [TT, 7.2 (3.5, 10.8) vs 13.6 (10.9, 17.1) nmol/L, p < 0.001]. The 143 cases treated as inpatients had lower testosterone levels than the 97 cases treated as outpatients [TT 4.7 (2.3, 8.1) vs 10.3 (7.5, 12.7) nmol/L, p < 0.001]. Group differences in calculated free testosterone (cFT) were comparable to the group differences in TT. At follow-up, in 98 cases, median TT increased from 6.5 nmol/L (3.2, 8.5) to 9.6 nmol/L (6.9, 12.0) p < 0.0001, and SHBG remained unchanged. Of cases with low testosterone, 43% with TT <10 nmol/L and/or cFT <230 pmol/L at presentation were reclassified as androgen sufficient at follow-up. TT was unchanged in the controls.

CONCLUSIONS

Low testosterone levels in men presenting with an acute fracture may, at least in part, be due to an acute, fracture-associated, stress response. To avoid over diagnosis, evaluation for testosterone deficiency should be deferred until recovery from the acute event.

Obesity and age as dominant correlates of low testosterone in men irrespective of diabetes status

Although men with type 2 diabetes (T2D) frequently have lowered testosterone levels, it is not well established whether this is ascribable to the diabetic state per se, or because of other factors, such as obesity. Our objective was to determine the prevalence and correlates of low testosterone in middle-aged men with diabetes. We conducted a cross-sectional study in 240 men including 80 men with type 1 diabetes (T1D), 80 men with T2D and 80 men without diabetes. Prevalence of a total testosterone ≤8 nmol/L was low, occurring in none of the men with T1D, 6.2% of men with T2D and 2.5% of men without diabetes. Men with T1D had higher testosterone levels compared with men without diabetes (p < 0.001), even after adjustment for body mass index (BMI) and age (p < 0.02). While men with T2D had lower testosterone compared with controls (p = 0.03), this was no longer significant when BMI and age were taken into account (p = 0.16). In the entire cohort, TT remained inversely associated with BMI independent of age, sex hormone-binding globulin and diabetic status (p = 0.01), whereas calculated free testosterone (cFT) was independently and inversely associated with age (p < 0.001), but not with BMI (p = 0.47). These results suggest that marked reductions in circulating testosterone are uncommon in middle-aged men with diabetes. Increasing BMI and age are dominant drivers of lowered total and cFT, respectively, independent of the presence or absence of diabetes.

Cardiovascular risk and bone loss in men undergoing androgen deprivation therapy for non-metastatic prostate cancer: implementation of standardized management guidelines

Our objective was to evaluate the effectiveness of implementing standardized guidelines to mitigate metabolic and bone side effects of androgen deprivation therapy (ADT) in men with non-metastatic prostate cancer. We conducted a 2-year prospective cohort study at a tertiary referral teaching hospital. Overall, 236 men (mean age 69.8 ± 7.1) commencing ADT for non-metastatic prostate cancer attended a baseline clinic visit between 2007 and 2011, and 153 men were eligible for follow-up after 2 years of continuous ADT. Of these, 113 men had data available for analysis at 2 years. At baseline, 87% of the men were overweight or obese, 61% had hypertension, 56% had hypercholesterolaemia, 27% prior cardiovascular disease, 11% osteoporosis and 40% osteopaenia. After 2 years of ADT, there was an increase in waist circumference (+2.8 ± 6.3 cm, p = 0.002), and, in men without diabetes, in HbA1c (+0.13 ± 0.34%, p = 0.019). Despite this, due to treatment, there were significant reductions in total cholesterol (-0.35 ± 1.00 mmol/L, p < 0.001), and blood pressure (systolic -7.6 ± 19.3 mmHg; diastolic -4.7 ± 11.6 mmHg, p < 0.001). After 2 years, men not receiving anti-resorptive therapy experienced a significant decline in lumbar spine (-0.042 ± 0.134 g/cm(2) , p = 0.012) and total hip bone mineral density (BMD) (-0.026 ± 0.036 g/cm(2) , p < 0.001), whereas bisphosphonate treatment maintained stable BMD. Prevalence of anaemia increased from 13.8 to 32.5%. Older age independently predicted a greater drop in haemoglobin (p = 0.005). We conclude that a structured approach to assess and treat men undergoing ADT effectively improves cardiovascular risk factors and prevents bone decay. Larger studies are needed to determine effects on cardiovascular outcomes, fracture prevention and survival.

Antagonists of the human TSH receptor: in vitro and in vivo studies of their functional and immunological effects

We have developed and characterized a prototype of a TSH receptor antagonist derived from the hCG molecule. This may be used to block human TSH receptor both functionally and immunologically, particularly in the study of Graves' disease. Our hCG derived TSH receptor blocker compares favorably with other substances (e.g. deglycosylated forms of TSH, synthetic peptides of the alpha or beta subunit of TSH) that hare been reported to inhibit bTSH binding or bTSH-stimulated cAMP response (Joshi et al., 1981; Morris et al., 1988). It has a much higher affinity for human TSH receptor than the TSH subunit peptides and it is the only substance an efficacy of which has been proven in vivo so far. Recent progress in the synthesis of recombinant glycoprotein hormones should permit to biosynthetically produce this or a similar TSH receptor antagonist. With respect to Graves' disease, the data suggest that TSH receptor, in addition to its role in maintaining thyroid hyperfunction, plays also a role in propagating the thyroid autoimmune disease itself. Stimulation of TSH receptor by bTSH as well as TSAb enhances the expression of HLA class II antigens on the surface of thyrocytes, and a blockade of TSH receptor results in a substantial inhibition of this immunological key event. This could possibly explain why suppression of TSH by administering levothyroxine was found in a recent study by Hashizume and coworkers (1991) to decrease TSAb titers and to reduce relapse rate in patients with Graves' hyperthyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)

Crude urinary human chorionic gonadotropin contains variant forms of HCG with low sialic acid content that exhibit an increased thyrotropic activity in CHO cells expressing the human TSH receptor

Hyperthyroidism occurs in association with pregnancy or trophoblastic tumours. This is due to the secretion of thyroid stimulators by trophoblastic cells, most likely hCG or a variant form of hCG. In the present studies we sought to identify hCG variants with enhanced thyrotropic activity contained in crude hCG extract from pregnancy urine (hCGc). Such studies seem now feasible, because highly sensitive assays employing CHO cells transfected with the recombinant human TSH receptor recently became available. Initially, we found the activity of hCGc to both inhibit the binding of 125I-bTSH to CHO-TSHr cells and to stimulate the cAMP release by the cells to be increased, compared to highly purified hCG (hCGp), which was tested in comparable immunological concentrations. We then processed hCGc on a DEAE-52 anionexchange column to separate materials of interest, termed hCGv, from hCGp. HCGv was further purified by gel chromatography, and found to be enriched in terms of both, its holo-hCG immunoactivity and its TSH binding inhibiting activity, compared to hCGc where it was derived from. It also proved more potent than hCGp to bind to recombinant hTSH receptor and to stimulate adenylate cyclase activity in CHO-TSHr cells. Enzymatic desialylation was able to increase the potency of both hCGv and hCGp, and rendered the two desialylated hCG forms nearly equipotent. Isoelectric focusing and direct measurement of sialic acid contents revealed hCGv to be less sialylated than hCGp.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced functional activity in thyroid adenomas in vitro

The majority of thyroid adenomas have been shown to be of clonal origin. In a portion of them, somatic or germline point mutations leading to altered TSH receptor or Gs alpha-proteins have been found. The constitutive activation of these proteins consecutively stimulate cAMP-levels. Expression of the TSH receptor mutants in mammalian cells leads to increased cAMP-production compared to cells transfected with the wild type receptor. Presently, the role of these mutations in the development and growth of such tumours is still unclear. In our own investigations we made an attempt to evaluate the functional significance of these observations. In nodular tissue derived from patients with functioning autonomous adenoma we found significantly higher basal and TSH stimulated thyroid hormone releasing activity than in the surrounding paranodular tissue and in thyroid tissue derived from patients with euthyroid goiter. These findings indicate a functional relevance of constitutively activated intracellular signal transducing cascade in thyroid adenomas that may lead to hyperthyroidism in the presence or absence of external thyroid stimulators.

Immunoreactive human chorionic gonadotropin beta core fragment in human pituitary

The human pituitary has been shown to produce small amounts of immunoreactive human chorionic gonadotropin (hCG) and its alpha- and beta- subunit (hCG alpha, hCG beta). The aim of the present studies was to further examine the various hCG-related materials in the human pituitary, particularly to search for the existence of pituitary hCG beta core fragment (hCG beta cf)--like material. HCG beta cf has been found in the urine of pregnant women, patients with trophoblastic tumors and also in postmenopausal women. Gel chromatography of pituitary extract on Superdex 200 showed three distinct peaks of hCG-related immunoreactivities, i.e. hCG, hCG beta and hCG beta cf, which were distinguishable from hLH and hLH beta peaks. HCG beta cf was recognized by a specific immunometric assay (crossreactivities with hCG beta 0.016%, hLH beta 0.04%), but unreactive in an hLH + hLH beta assay. It was purified and displayed physical properties similar to those of hCG beta cf derived from pregnancy urine. Apart from immunological differences between the small molecular weight forms or fragments of hCG and LH origin, reversed phase HPLC was able to physically discriminate between hCG beta cf and hLH beta fragment. The latter was much more abundant than the former in the pituitary extract. HCG beta cf showed microheterogeneity related to its sialic acid content. In conclusion, the present data indicate that immunoreactive hCG beta cf is present in human pituitary extracts. The physical and immunological properties of pituitary hCG beta cf are distinguishable from those of the more abundant hLH beta and its fragment, and compare favorably with those of urinary hCG beta cf of trophoblastic origin.

Stimulation of thyroidal and extrathyroidal thyrotropin receptors

TSH receptor plays a pivotal role in the regulation of thyroid function and is intimately involved in the pathogenesis of common thyroid disorders. A lack of specificity and absence of down regulation upon stimulation renders the human TSH receptor susceptible to exogenous overstimulation, which forms the basis of hyperthyroidism in TSHoma, Graves' disease and gestational thyrotoxicosis. Further, TSH receptor activation in the absence of exogenous stimulators due to the expression of endogenously active mutant receptors has recently been described, and may in part account for hyperthyroidism in autonomously functioning thyroid nodules. Signal bifurcating by coupling of TSH receptor to different G proteins may be a likely mechanism to explain the multitude of distinct effects caused by TSH receptor activation including mainly hormone production and growth promotion. Also, TSH receptor appears to mediate immunological stimulation, its activation by TSH R Ab inducing expression of adhesion molecules and HLA class II antigens on thyrocytes. Increasing evidence suggests that TSH receptor is not restricted to thyroid and may be expressed in extrathyroidal tissues with a potential role in the pathogenesis of Graves' orbitopathy.

Impact of Smoking on the Course of Graves' Disease after Withdrawal of Antithyroid Drugs

Cigarette smoking has been reported to alter relapse rate in patients with Graves' disease (GD). However, the predictive effect of smoking in GD patients after withdrawal of antithyroid drug treatment (ATDT) is still controversial. A prospective multicenter trial has previously identified smoking as an independent risk factor for relapse. Based on this study, the present paper gives a more detailed analysis of the impact of smoking on the long-term course of GD after ATDT withdrawal. To this end, 86 smokers and 177 non-smokers were followed during two years after ATDT cessation. At the end of ATDT (visit 1) and four weeks later (visit 2) smokers had significant higher TSH receptor antibody (TRAb) levels than non-smokers (10.0 IU/L+/-1.6; mean+/-SEM vs. 6.4 IU/L+/-0.9; 11.0 IU/L+/-1.8 vs. 6.8 IU/L+/-0.8, p < 0.01, respectively). During follow-up, Kaplan Meier analysis showed a significantly higher relapse rate in smokers than non-smokers. A subset of GD patients with TRAb levels >10 IU/L had the highest risk to develop relapse during follow-up. Among them, smokers more often relapsed than non-smokers irrespective of TRAb levels, p < 0.01. Thus, in smokers with TRAb levels > or =10 IU/L the predictive values of a positive and negative test for relapse was 68% and 73%, respectively (specificity 95%). In conclusion, we identified two effects by which smoking alters the course of GD. First, smoking is implicated to elevate TRAb levels and therefore increase the risk for relapse during follow-up. Second, smoking is an independent risk factor to worsen the clinical course of both, GD patients with low and high immunological risk to experience relapse after a successful outcome of ATDT. Thus, our data suggest that smoking has modifying immunological consequences and an adverse impact on the course of GD after withdrawal of ATDT. Therefore, patients should be encouraged to stop smoking.

Binding, stimulating and blocking TSH receptor antibodies to the thyrotropin receptor as predictors of relapse of Graves' disease after withdrawal of antithyroid treatment

TSH-receptor autoantibodies (TRAbs) are a valuable diagnostic tool for confirming a diagnosis of Graves' disease (GD). While there is evidence that high TRAb levels are associated with relapse of GD, whether a discrimination of TRAb into stimulating (TSAb) and blocking (TBAb) autoantibodies would benefit the clinician in terms of outcome prediction remains unclear. To address this issue, we have determined TRAb, TSAb and TBAb levels in serum samples of ninety-six euthyroid patients with GD taken four weeks after antithyroid drug withdrawal (ATDT). Forty-seven patients (49 %) underwent relapse of GD within two years. Amongst those, forty-one (87 %) had been positive for TRAb and thirty-five (74 %) for TSAb after treatment. All patients except one were negative for TBAb. The correlation between TRAb and TSAb in those treated GD patients was relatively weak (r = 0.268, p < 0.001). Based on a cut-off limit of 1.5 IU/l, the positive and negative predictive values with respect to prediction of relapse were too low for any clinical relevance (TRAb: 49 % and 54 %; TSAb: 51 % and 55 %). However, when a cut-off level above 10 IU/l was used, the positive and negative predictive values increased to 83 % and 62 %. The additional measurement of TSAb or TBAb in those samples after therapy did not add additional information, even at higher decision thresholds. In conclusion, differentiation of TRAb into TSAb and TBAb is of no help in the prediction of relapse of GD in euthyroid patients at the end of ATDT, and only high TRAb levels are associated with relapse.

The human chorionic gonadotropin molecule from patients with trophoblastic diseases has a high thyrotropic activity but is less active in the ovary

To examine the pathogenesis of hyperthyroidism in women with trophoblastic diseases, the biological activity of human chorionic gonadotropin (hCG) molecules in women with normal pregnancy (n = 85) and in women with trophoblastic diseases (vesicular mole, n = 30; and choriocarcinoma, n = 12) was compared. Hyperthyroidism (thyroid stimulating hormone (TSH) < 0.3 mIU/l) was observed more frequently in women with trophoblastic diseases. All the sera were then subjected to Chinese hamster ovary cells transfected with the human TSH receptor (CHO-hTSHr cells) and cAMP production was compared. Sera from the women with choriocarcinoma showed the highest cAMP production. Interestingly, significant correlation between serum hCG level and cAMP production in CHO-hTSHr cells was observed only in women with trophoblastic disease. All the sera were then applied to CHO cells transfected with hCG/luteinizing hormone (LH) receptor (CHO-hCG/LHr cells). In contrast to the findings with the TSH receptor, sera from the women with normal pregnancy showed the highest cAMP production in these cells. Correlation between serum hCG level and cAMP production in CHO-hCG/LHr cells was significant only in normal pregnancy. These results indicate that the hCG molecule from women with trophoblastic diseases displays enhanced thyrotropic activity.

Tumor- and pregnancy-derived isoforms of human chorionic gonadotropin: biological and diagnostic relevance

OBJECTIVES

Human chorionic gonadotropin (hCG) and hCG variants are of high clinical importance for the diagnosis of pregnancy, monitoring of abnormal and ectopic pregnancies, testing for Down's syndrome or monitoring therapy of hCG-secreting malignancies. In serum and urine, hCG appears in microheterogeneous isoforms with respect to protein backbone structure and the extent of glycosylation. The present study reports on the identification, immunological characterization, biological activity of glycosylation isoforms of pregnancy (preg) and tumor-derived (tu) hCG, and the impact of glycosylation on diagnostic immunoassays.

METHODS

Twenty-two urinary preg- and tu-hCG isoforms were separated by preparative isoelectrofocusing (hCG-pI variants) and characterized by Western blot. Number, topography and accessibility pattern of epitopes on their surface was evaluated by two-site radioimmunoassays using 14 different monoclonal antibodies (mabs). Binding of hCG isoforms to four different LH/CG receptors was investigated in radioreceptor assays, and their biological activity determined by measuring cAMP elevation.

RESULTS

All 22 hCG glycosylation variants appeared immunologically intact: each isoform, even when highly acidic, expressed all 14 surface epitopes which were arranged in a topographical manner indistinguishable from crude hCG. hCG isoforms were able to bind to four different receptor variants, with slightly varying affinities, but orientations indistinguishable from each other as shown by identical epitope accessibility patterns. Each of the hCG-pI variants was able to activate the LH/CG-Rs, but with varying reactivities.

CONCLUSIONS

We conclude that in contrast to deglycosylated hCG, all hCG glycosylation isoforms investigated act as receptor agonists. Moreover, there is no overspecificity of mabs to certain hCG isoforms due to carbohydrate variability that exclude others from diagnostic measurement.

Impact of smoking on the response to treatment of thyroid associated ophthalmopathy

BACKGROUND

In patients with Graves' disease, smoking considerably increases the incidence and severity of thyroid associated ophthalmopathy (TAO). The authors sought to determine if smoking also influences the course of TAO during treatment, and the efficacy of therapy.

METHODS

41 smokers and 19 non-smokers with moderate untreated TAO were included in this prospective study. All patients were treated with steroids and, 6 weeks after the beginning of drug therapy, with orbital irradiation. Follow up was performed 1.5, 4.5, 7.5, and 12 months after the beginning of the study. Proptosis, clinical activity score (CAS), and motility were evaluated. The extent of smoking was derived from the concentration of the haemoglobin adduct N-2-hydroxyethylvaline (HEV), a parameter of long term smoking.

RESULTS

There was no difference in the clinical manifestations of TAO between smokers and non-smokers at the beginning of treatment. However, CAS decreased (p<0.05) and motility improved (p<0.02) significantly faster and to a greater extent in non-smokers than smokers. Inverse correlations between the CAS decrease and the HEV levels observed 4.5 and 7.5 months after the beginning of treatment and between the improvement of motility and the HEV levels after 1.5, 4.5, and 7.5 months indicated a dose dependence. Mean HEV levels did not vary much during the follow up period and were significantly different in smokers (mean 5.4 (SD 2.7) micro g/l) and non-smokers (mean 1.8 (1.3) micro g/l; p<0.01).

CONCLUSION

Smoking influences the course of TAO during treatment in a dose dependent manner. The response to treatment is delayed and considerably poorer in smokers.

Long-term follow-up of thyroid nodule growth

Benign thyroid nodules are common in iodine deficient countries. Although many recent studies have addressed the molecular basis and short-term outcome of treatment in nodular thyroid disease, data on the long-term follow-up of thyroid nodule growth are widely lacking. The aim of the present study was to evaluate the long-term behaviour of benign thyroid nodules growth. We followed 109 consecutive patients seen at yearly intervals in our Outpatient Clinic for at least 3 years (range 3-12 years, mean 4.9 +/- 2.6 years) presenting with 139 benign nodules in uni- or multinodular goiters. The size of the nodules and thyroid glands was analysed retrospectively. The study included a spectrum of benign thyroid nodules, 86 functioning and 53 non-functioning. 27 patients were treated with levothyroxine, 8 with iodide and 16 with a combination of both. 58 patients were not treated mainly because of thyroid functional autonomy. Patients with overt hyperthyroidism or suspected malignancy by fine-needle aspiration were excluded from the study. The nodules and glands were assessed by ultrasonography at yearly intervals and documented by photoprints. Relevant growth was defined as an increase in nodule volume of at least 30%. For statistical analyses, Cox Proportional Hazard Model and life-table analyses according to Kaplan-Meier were performed. Most thyroid nodules grew slowly but continuously during follow-up. After about 3 years, half of the nodules had increased their volume by at least 30%. Growth of the nodules was significantly faster than of the corresponding thyroid glands (p < 0.0001). Age and sex of the patients and size or function of the nodules at initial presentation were not significantly related to their growth. Suppression of TSH did not affect growth of the nodules irrespective of the source of thyroid hormones, endogenous or by administration of levothyroxine. In conclusion, benign thyroid nodules have a slow intrinsic growth potential, which is apparently higher than that of the non-nodular tissue. In this study, not only nodular but even non-nodular goiter growth continues in the majority of patients. Exogeneous factors, including therapy with levothyroxine and/or iodide, appear to have little effect on the growth behaviour.

Human chorionic gonadotropin exhibits normal biological activity in patients with recurrent pregnancy loss

To test the hypothesis that the structural abnormality of human chorionic gonadotropin (hCG) may induce recurrent pregnancy loss, we examined the biological activity of hCG in pregnant women with a history of repeated miscarriages (n = 44). Pregnant women without a history of miscarriage (n = 85) were included as controls. Serum hCG, estradiol (E2) and progesterone levels were found to be significantly lower in the pregnancy loss group. There was no difference in serum thyroid hormone levels. Sera from both groups of women were then incubated with Chinese hamster ovary (CHO) cells transfected with hCG/luteinizing hormone receptor (CHO-hCG/LHr) or human thyroid stimulating hormone receptor (CHO-hTSHr). Biological response to hCG in women with recurrent pregnancy loss was identical to that of women in the control group in both CHO-hCG/LHr and CHO-hTSHr cells. When sera were subjected to high performance liquid chromatography, no difference in hydrophobicity was observed between control and patients groups. The structure of the hCG molecule and its biological activity in women with a history of recurrent pregnancy loss are apparently not different from those in women with normal pregnancy. Lower serum progesterone and E2 levels in the patient group can be explained by lower serum hCG levels in these women. Intrinsic gonadotropic and thyrotropic activities of the hCG molecule appear to play no major role in recurrent pregnancy loss.

Maturation of thyroidal dendritic cells in Graves' disease

Because thyroidal dendritic cells (t-DC) may be implicated in the pathogenesis of Graves' disease (GD), we compared t-DC in thyroid sections of patients with GD (n = 15) and control patients with toxic (TG; n = 12) or non-toxic goitre (NG; n = 12). Goitres in GD, but not TG or NG, were populated with three discernible t-DC phenotypes. (i) Immature t-DC (major histocompatibility complex (MHC) II+/CD40-/CD80-) were located perifollicularly (95% of the patients with GD, but only 55% of TG and 51% of NG patients); numbers of such t-DC were significantly elevated in GD (P < 0.001). (ii) Partially matured CD80+ t-DC were present in connective tissue (73% of the patients) and focal interstitial clusters (40% of the patients). In 53% of the patients with GD, single as well as clustered interstitial t-DC expressed CD40. (iii) However, phenotypically mature t-DC (MHC II+/CD40+/CD80+/RFD1+) were only present in clusters and colocalized with activated CD4+/MHC class II+ T-helper (Th) cells. Expression of CD54 and CD83 did not significantly differ among the groups. The phenotype of intrathyroidal DC in GD thus supports their role as potential (co)stimulators of thyroid autoimmunity.

Immunological and biological activity of different commercial preparations of human chorionic gonadotropin

In vitro immunological and biological activity of four commercially available preparations of human chorionic gonadotropin (hCG) for clinical use (Predalon(R): hCG-A, Primogonyl(R): hCG-B, Choragon(R): hCG-C and Pregnisin(R): hCG-D) were examined. The methods used include immunoassay, cAMP production in Chinese hamster ovary (CHO) cells and structural analysis of hCG with high performance liquid chromatography (HPLC). There were remarkable differences in immunological activities among preparations. hCG-D had the highest concentration of free hCGbeta. In CHO cells, production of cAMP with hCG-C was significantly higher than that with other preparations. Analyses in HPLC showed similar pattern in hCG-C and a standard preparation of hCG (CR 123). The highest immunological activity in hCG-A could be attributed to the presence of nicked form of hCG in this preparation. Various hCG components in preparation may explain these differences.

Posterior retroperitoneoscopic adrenalectomy: lessons learned within five years

Posterior retroperitoneoscopic adrenalectomy is one of the new endoscopic methods in endocrine surgery. In a prospective clinical study 142 posterior retroperitoneoscopic adrenalectomies (72 right, 70 left) were performed in 130 patients (52 males, 78 females, age 49.1 +/- 14.9 years). Indications were primary adrenal tumors (unilateral, n = 118; bilateral, n = 2), adrenal metastases (n = 2), and bilateral ACTH-dependent hyperplasias (n = 10). Tumor size ranged from 0.5 to 7.0 cm (mean 2.7 +/- 1.4 cm). Partial adrenalectomies were performed in 39 patients. Conversion to open posterior adrenalectomy was necessary in five patients and seven procedures (5%). Intraoperative and postoperative complications were minor and occurred in 5% and 13%, respectively. Mortality was zero. Operating time was 101 +/- 39 minutes (range 35-285 minutes) and depended on tumor type (pheochromocytoma versus others; p < 0.01), tumor size (< 3 vs. > or = 3 cm; p < 0.05), gender (p < 0.05), and extent of resection (partial versus complete, p < 0.05. Twenty-three adrenalectomies (17%) were performed within 1 hour or less. Blood loss was 54 +/- 72 ml. Consumption of analgesics was low (mean 6 mg piritramide postoperatively). Median duration of hospitalization was 3 days. Posterior retroperitoneoscopic adrenalectomy is a safe method that has become a standard procedure in endocrine surgery.

T3-release from autonomously functioning thyroid nodules in vitro

Toxic thyroid nodules have been shown to be of clonal origin. In a portion of them, point mutations affecting either the gene of the TSH receptor (TSHr) or the alpha-subunit of stimulating G-protein, consecutively leading to enhanced cAMP levels, which may enhance growth or functional activity of the thyrocyte or both, were recently found. To complement these studies, we evaluated hormone response (i.e. T3 release) in vitro from tissues derived from toxic thyroid nodules as compared directly to the surrounding paranodular tissues as well as tissues derived from euthyroid goiter and from patients with Graves' disease. Experiments were conducted in the presence and absence of bTSH or Graves' immunoglobulines. Tissues obtained during surgery were incubated over 5 h, followed by equilibrium dialysis for 24 h, and determination of free T3 in an aliquot by RIA. Basal T3 release in nodular tissues (n = 10) was significantly higher (median: 7.3 ng/l) compared to paranodular tissues (3.2 ng/l; P < 0.01), tissues derived from euthyroid goiter (1.3 ng/l; n = 12; P < 0.001) and thyroid tissues derived from patients with Graves' disease (2.5 ng/l; n = 6; P < 0.001). Upon stimulation with bTSH (1 IU/l), median T3 concentrations markedly increased to 11.5 ng/l (P < 0.05), 7.3 ng/l (P < 0.05), 4.2 ng/l (P < 0.01) and 3.2 ng/l (P = N.S.), respectively. Stimulation over basal values was 1.6-fold in nodular tissues, 2.3-fold in paranodular tissues, 3.2-fold in euthyroid goiter and 1.3-fold in Graves' disease. In toxic thyroid nodules basal hormone-releasing activities were stimulated by fifteen out of twenty (75%) Graves' sera tested. For comparison, stimulation in other tissues occurred in 45% (paranodular), 80% (euthyroid goiter) and 35% (Graves' disease), respectively. In conclusion, tissue derived from toxic thyroid nodules exhibits enhanced basal hormone release as compared to both, the surrounding paranodular tissues and tissues from euthyroid goiter in vitro, which may reflect constitutional activation of TSHr, alpha-subunit of stimulating G-protein or other so far unknown intermediate by point mutations affecting the respective genes. Hyperactivities in toxic thyroid nodules may be even further enhanced by external stimulators such as TSH or TSH receptor antibodies. The first stimulator may have clinical relevance in patients with toxic thyroid nodules and not yet suppressed TSH; the latter could play a role in the rare Marine Lenhart syndrome.

Second generation assay for thyrotropin receptor antibodies has superior diagnostic sensitivity for Graves' disease

Detection of autoantibodies to the TSH receptor (TSH-R) in Graves' disease has found widespread use in clinical routine and is performed mostly by commercial RRAs measuring TSH binding inhibitory activity. We report in this study on a second generation TSH binding inhibitory assay using the human recombinant TSH-R with two major improvements: 1) superior diagnostic sensitivity for Graves' disease, and 2) for the first time, nonradioactive and radioactive coated tube (CT) technology. Full-length human recombinant TSH-R was expressed in the K562 leukemia cell line and grown in suspension at a high density. A murine monoclonal antibody was selected for binding to the native TSH-R without interfering with autoantibodies or TSH and was coated to polystyrene tubes. After detergent extraction, TSH-R was affinity immobilized on antibody-coated tubes. The binding of TSH to the TSH-R could be demonstrated by the addition of 125I- or acridinium ester-labeled bovine TSH, and this binding could be inhibited by sera from patients with Graves' disease up to 95%. Subsequently, these novel assays, a CT RRA and a CT luminescence receptor assay, were compared to the conventional RRA based on porcine antigen in a blinded clinical multicenter trial. Sera from 328 patients with Graves' disease (86 untreated, 116 treated, and 126 in remission) and 520 controls (comprised of healthy blood donors and patients with autoimmune diseases or goiter) were tested in all 3 assays. Receiver-operating characteristic plot analysis resulted in a specificity of 99.6% with a sensitivity of 98.8% for both CT assays, compared to 99.6% specificity and 80.2% sensitivity for the conventional RRA (P < 0.001). In all 3 groups of patients with Graves' disease, the 2 CT assays were significantly more sensitive for the disease than the conventional assay, without loss of specificity in the control groups. This increase in sensitivity and the nonradioactive or radioactive CT format constitute a significant improvement over the currently available assays.

Course of thyroid nodules

Thyroid nodules are present in up to 30% of the German population. The causative role of iodine deficiency which is still endemic in this country has long been established. Recent progress has shed some light on the pathogenesis of nodular thyroid disease which still remains less well understood than goitrogenesis. Most thyroid nodules appear to be of clonal origin. Functional abnormalities have been related to alterations within the TSH signaling cascade, particularly mutations in the TSH receptor and stimulating G-protein-alpha-subunit. Proliferation which is dissociable from thyroid function has been linked to genetic differences of the thyroid cells themselves and growth factors being partly overexpressed by thyroid nodules. Data regarding the correlation of the molecular characteristics to the clinical behavior and growth potential have not yet been elucidated. On the other hand, there are only a few clinical studies that have addressed the long-term natural history of thyroid nodules. From these studies at least it appears that thyroid nodules tend to grow slowly and their increase in size may even by modern ultrasonography technique become apparent only after several years. Those in vitro and in vivo observations have important implications for the planning of therapeutical trials. Studies have focused so far mainly on short term effects of different therapeutic regimens such as iodine or levothyroxine. However, pathophysiological considerations and clinical observation would encourage studies over more prolonged periods of time.

Pre-evaluation and system optimization of the Elecsys thyroid electrochemiluminescence immunoassays

We present the results of a pre-evaluation of the thyroid function test free thyroxine, free triiodothyronine and third generation TSH using the Elecsys electrochemiluminescence immunoassay system. A collaborative field study between the development center of the manufacturer and a clinical chemistry laboratory addressed the reliability and comparability of the new Elecsys assays to established methods under clinical laboratory conditions using samples from routine in vitro thyroid testing. Preliminary (reference) formulations of the reagents and several electrochemiluminescent pilot models were used for assay measurements, either in the company's research center or in the clinical setting. The new thyroid assays were compared with the respective Enzymun-Test assays, performed on the ES300 automated immunoassay analyzer. A WHO standard was used for standardization of TSH, whereas an equilibrium dialysis method was applied for free triiodothyronine. The free thyroxine assay was standardized against the Enzymun-Test free thyroxine assay, which had previously been calibrated against equilibrium dialysis. The aim of this field study was to support the optimization of the technology used for Elecsys in an early stage of development and thereby prepare the ground for the adaptation of the immunoassays to the final Elecsys 2010 random access analyzer. A subsequent multicenter evaluation demonstrated that the requirements of routine thyroid testing in terms of reliability were fulfilled by the system.

Regulation of intercellular adhesion molecule-1 expression in human thyroid cells in vitro and human thyroid tissue transplanted to the nude mouse in vivo: role of Graves' immunoglobulins and human thyrotropin receptor

To further explore a potential role for the human TSH receptor (hTSHR) in the propagation of thyroid autoimmune disease, we examined immunomodulatory effects in response to its stimulation by Graves' Igs both in human thyroid tissue transplanted to the nude mouse and in primary cultures of human thyrocytes. We injected nude mice bearing transplants derived from normal human thyroid with protein A-Sepharose-purified Graves' IgGs (0.05-1 mg) on 2 days and assessed, in addition to functional stimulation, the expression of intercellular adhesion molecule-1 (ICAM-1) by transplant thyrocytes. In parallel to functional stimulation, as demonstrated by thyroid follicular cell hypertrophy in the transplants and increased T4 production, Graves' IgGs induced a marked dose-dependent expression of ICAM-1 by transplanted thyrocytes, which exceeded that of a continuous interferon-gamma infusion (200 IU/24 h) for 2 days. Normal IgGs were ineffective. Bovine TSH (bTSH) had little effect by itself, but did enhance interferon-gamma-induced ICAM-1 expression. To assess the specificity of their effects, experiments with Graves' IgGs were conducted in the presence and absence of a selective hTSHR antagonist (asialoagalacto-hCG). Asialoagalacto-hCG nearly completely abolished the stimulatory effect of Graves' IgGs on ICAM-1 expression and significantly reduced the combined bTSH/interferon-gamma effect. It failed, however, to affect interferon-gamma action. In vitro studies using human thyroid cells in primary culture confirmed the in vivo observations, treatment with saline resulted in 14% of cells expressing ICAM-1, with pooled normal IgGs (500 mg/L) in 18% and with Graves' IgGs (patient A, 448 mg/L; patient B, 260 mg/L) in 78% and 51%, respectively. Upon exposure to Graves' IgGs (90 mg/L) plus asialo-hCG(350 mg/L), 25% of the cells stained positively for ICAM-1, 29% to bTSH (10 IU/L), 31% to recombinant human TSH (10 IU/L), and 84% to interferon-gamma (10 IU/mL). In conclusion, stimulation of human thyroid cells, either transplanted to the nude mouse in vivo or studied under in vitro conditions, with Igs derived from patients with Graves' disease increased the expression of ICAM-1 on the surface of the cells. The action appears to be specific and mediated by the hTSHR. This particular property of TSHR autoantibodies may be of pathophysiological relevance in Graves' disease, as it may assist in targeting the autoimmune attack and in promoting lymphocyte recruitment to the thyroid gland.

Beta-human choriogonadotropin therapy and HIV-related Kaposi's sarcoma

Recently, two clinical trials demonstrated an antitumour effect of systemic high-dose beta-hCG therapy and of different regimens of local beta-hCG injections in AIDS-related Kaposi's sarcoma. We report the efficacy and safety of subcutaneous beta-hCG treatment (low-dose (2500-25000 IU/day) or high dose (25000-100000 IU/day)) in eight patients with advanced HIV disease in whom systemic chemotherapy and radiation were contraindicated or had failed. During therapy, serum hCG-concentrations as well as LH and FSH were measured. In the low-dose regimen one partial response was achieved. In the high-dose regimen, one patient maintained his response without further improvement. Three patients had stable disease and four patients disease progression. Serious side effects related to beta-hCG therapy were not observed. In conclusion, systemic beta-hCG-therapy for Kaposi's sarcoma is safe but associated with regression only in a minority of patients with advanced HIV-disease.

Cholesterol 7 alpha-hydroxylase activity in hypothyroidism and hyperthyroidism in humans

Alterations of serum cholesterol levels are well recognized findings in hypothyroidism and hyperthyroidism. It remains unclear, whether thyroid hormones may affect serum concentrations of cholesterol through changes in the activity of cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme in the catabolic conversion of cholesterol to bile acids. We determined serum concentrations of the bile acid precursor 7 alpha-hydroxy-4-cholesten-3-one, which reflects cholesterol 7 alpha-hydroxylase activity in the liver, in 19 patients with hypothyroidism and in 10 patients with hyperthyroidism before and after treatment, respectively. In patients with hypothyroidism, serum concentrations of cholesterol and LDL-cholesterol decreased by 33% (p < 0.0005) and 39% (p < 0.0005), respectively, after replacement therapy with thyroid hormones. In contrast, serum concentrations of 7 alpha-hydroxy-4-cholesten-3-one (21.7 +/- 15.8 ng/ml vs 24.5 +/- 18.1 ng/ml before treatment, n.s.) as well as serum HDL-cholesterol were unchanged during substitution therapy. In patients with hyperthyroidism, serum concentrations of cholesterol and LDL-cholesterol increased by 27% (p < 0.01) and 39% (p < 0.01) after antithyroid treatment, respectively. Again, serum concentrations of 7 alpha-hydroxy-4-cholesten-3-one did not change significantly during treatment (15.8 +/- 12.6 ng/ml vs 14.7 +/- 8.1 ng/ml before treatment, n.s.). These findings indicate that in humans, thyroid hormones influence serum lipid concentrations by other mechanisms than by affecting the activity of cholesterol 7 alpha-hydroxylase.

Immunochemical mapping of gonadotropins

As a glycoprotein hormone, human chorionic gonadotropic (hCG) is not a single molecular entity but this term rather comprises an array of molecular variants such as hCG, hCG beta, hCGn, hCG beta n, hCG beta cf, -CTPhCG, hCG beta CTP, deglyhCG, asialohCG, hCGav and the closely related molecules hLH, hLH beta and hLH beta ef. The advent of monoclonal antibodies (MCA), the availability of ultrasensitive detection systems and the recent determination of the crystal structure of hCG, made it possible to design special purpose diagnostic and clinical research immunoassays for hCG-like molecules. For more than a decade we and others have tried to refine epitope maps for hCG and related molecules by means of a large panel of MCA, naturally occurring metabolic variants of hCG (hCGn, hCG beta, hCG alpha, hCG beta cf, hCG beta CTP), homologous hormones and subunits of various species (e.g. hLH, hLH beta, hFSH, hTSH, oLH, rLH beta), chemically modified molecules (deglyhCG, asialohCG, tryptic and chymotryptic hCG beta and hCG alpha fragments) and synthetic peptides (octapeptides and longer). It appeared that all epitopes on molecular hCG-variants recognized by our MCA are determined by the protein backbone. Except for the two major epitopes on hCG beta CTP and parts of two antigenic domains on hCG alpha, epitopes on hCG-derived molecules are determined by the tertiary and quarternary structure. Operationally useful descriptive epitope maps were designed including information on assay suitability of antigenic determinants. On this basis we established ultrasensitive time-resolved fluoroimmuno-assays for hCG, hCG and hCGn, hCG beta and hCG beta n and hCG beta cf, hCG alpha and additional assays recognizing different spectra of hCG-variants. Such assay have been applied by us and others to the detection of pregnancy, early pregnancy loss, choriocarcinoma, testicular cancer, other cancers and prenatal diagnosis. However, as the molecular structure of many epitopes utilized in immunoassays of different laboratories was not resolved, comparability of results was not satisfactory. Consequently, attempts were made to compare schematic epitope maps from different research institutions. The situation has been much improved by solving the three-dimensional (3D) structure of hCG. It has been shown that hCG is a member of the structural superfamily of cystine knot growth factors like NGF, PDGF-B and TGF-beta. Each of its subunits is stabilized in its topology by three disulfide bonds forming a cystine knot. Moreover, it turned out that the disulfide bridges in their majority have previously been wrongly assigned. Computer molecular modeling of crystallographic coordinates of hCG and subsequent selective combined--PCR-based and immunological--mutational analyses of hCG beta expressed via the transmembrane region of a MHC molecule made it possible to more precisely localize epitopes on hCG-derived molecules. Although the entire surface of hCG has to be regarded as potentially immunogenic there seems to be hot spots where epitopes are clustered in antigenic domains. These are located on the first and third loops protuding from the cystine knots of both subunits and are possibly centered around the knot itself. Ultimate answers on epitope localizations will be given by the crystal structure determination of hCG complexed with different Fabs.

Expression of the human chorionic gonadotropin-beta gene cluster in human pituitaries and alternate use of exon 1

Previous studies have indicated that in addition to other glycoprotein hormones, the pituitary gland produces small amounts of hCG beta, the classical pregnancy and tumor marker. At the gene transcription level, definitive proof for hCG beta messenger ribonucleic acid transcription was still lacking, largely due to the 90% homology to hLH beta at the DNA sequence level, which renders specific hCG detection in the presence of a vast excess of LH difficult. We investigated both the presence of hCG beta messenger ribonucleic acid and the protein itself in normal human female postmenopausal (n = 4) and male pituitaries (n = 2). Reverse transcription-PCR and subsequent restriction enzyme analysis revealed that the hCG beta 3, 5, 7, and 8 genes coding for genuine hCG beta were transcribed in all pituitaries. Additionally, three alternatively spliced gene products derived from hCG beta genes 1 and 2 were detected and verified by single strand sequencing of the complementary DNAs. The most abundant fragment (244 bp) showed a point mutation (T-->A) in the splice donor site for the first intron, resulting in an alternate use of exon 1 and a frame shift in the open reading frame that might give rise to a hypothetical protein, 132 amino acids in length. With regard to protein synthesis, we confirmed the pituitary as the site of production for hCG beta by reverse phase high performance liquid chromatography and subsequent immunoradiometric assays, including a monoclonal antibody directed against the unique C-terminal extension of hCG beta.

Posterior retroperitoneoscopy as a new minimally invasive approach for adrenalectomy: results of 30 adrenalectomies in 27 patients

Posterior retroperitoneoscopic adrenalectomy is a new minimally invasive method. It represents an alternative to conventional open procedures and laparoscopic techniques. Between July 1994 and November 1995 a total of 30 retroperitoneoscopic adrenalectomies were performed on 27 patients. In 24 patients, unilateral tumors were seen (size 1-7 cm): seven Cushing adenomas, five Conn adenomas, seven pheochromocytomas, four hormonally inactive tumors, one cyst. Three patients suffered from Cushing syndrome with bilateral adrenal gland hyperplasias (two inoperable pituitary gland tumors, one bronchial carcinoid with ACTH secretion). The operations were carried out in prone position. After balloon dilatation of the retroperitoneum and creation of a pneumoperitoneum the preparation of the adrenal gland was performed via three trocar sites positioned below the 12th rib. Twenty-five adrenalectomies were completed endoscopically, and five times (among four patients) conversion to the conventional posterior technique was necessary. The average operating time of complete endoscopic adrenalectomies was 124 minutes (45-225 minutes); blood loss was 10 to 120 ml. With minimal need for postoperative analgesia (average dosage 7.9 mg of piritramide), mobilization and adequate food uptake were possible on the day of operation. The posterior retroperitoneoscopic adrenalectomy is a relatively fast, safe method, with the advantages of the posterior open approach and minimally invasive surgery. It therefore represents an important addition to adrenal gland surgery.

Human chorionic gonadotropin-beta in the differentiation of malignancy-related and nonmalignant ascites

The clinical value of the tumor marker human chorionic gonadotropin-beta (hCG-beta) in ascitic fluid for the differentiation of malignancy-related and non-malignant ascites was evaluated. Ascitic fluid protein, cholesterol and cytological examination were determined for comparison. Thirty-six patients with malignancy-related ascites (27 peritoneal carcinomatosis, 9 miscellaneous malignant causes without peritoneal carcinomatosis) and 69 patients with nonmalignant ascites (55 with liver cirrhosis, 14 with miscellaneous nonmalignant causes) were investigated. hCG-beta concentrations were elevated in malignant samples and with a cut-off value of 10 mIU/ml hCG-beta yielded a sensitivity of 61%, specificity of 94% and efficiency of 83%. Ascitic fluid protein (cut-off value 3.0 g/100 ml) and cholesterol (cut-off value 45 mg/100 ml) concentrations showed a sensitivity of 64%/83%, specificity of 77%/81% and efficiency of 72%/82%. The combination of hCG-beta and cytological examination yielded 89.5% differential diagnostic efficiency, superior to the combinations of protein and cytology or protein and hCG-beta. hCG-beta tended to be superior to protein/cholesterol determination regarding sensitivity (44% vs. 11%/33%) and specificity (79% vs. 50%/57%) in the subgroups of patients with miscellaneous causes of ascites. In conclusion, hCG-beta is frequently elevated in malignancy-related ascites and seems to be as useful a parameter as total protein for the differentiation of malignancy-related from nonmalignant ascites.

Measurement of human chorionic gonadotropin-related immunoreactivity in serum, ascites and tumour cysts of patients with gynaecologic malignancies

Human chorionic gonadotropin (hCG)-like molecules have been reported to be elevated in a substantial fraction of serum samples from patients with various gynaecologic tumours and have been discussed as possible markers in these malignancies. Employing highly sensitive and specific immunoradiometric assays, we determined total hCG-related immunoreactivity (hCG/hCG beta), as well as free alpha-subunit (alpha-SU), common to all glycoprotein hormones, in serum (n = 106) and malignant effusions (n = 26) of women with gynaecologic malignancies. For comparison, we also measured hCG/hCG beta in nonmalignant ascitic fluids (n = 21). HCG/hCG beta serum levels were elevated (> 5 IU L-1) in 39 of 106 patients (37%) with gynaecologic malignancies, whereas free alpha-SU was above normal range only in seven (6.6%). Frequencies of hCG/hCG beta elevations were similar in women with endometrial, (n = 39), cervical (n = 40) and ovarian (n = 27) cancer, being 30%, 35% and 41%, respectively. In malignant ascites (n = 15) and tumour cyst fluids (n = 11) of patients with ovarian cancer, hCG/hCG beta concentrations were significantly higher than in the corresponding serum samples and benign ascitic samples. Free alpha-SU, on the other hand, was increased in only one of 26 malignant effusions. In conclusion, hCG/hCG beta is frequently elevated in serum of patients with endometrial, cervical and ovarian cancer and may serve as a tumour marker in these malignancies, particularly in patients where other markers are negative. In this respect, analysis of ascitic or tumour cyst fluids may be of higher diagnostic value as serum measurements.

Spontaneous regression of hepatocellular carcinoma

Spontaneous regression of cancer is a rare phenomenon seldom described in patients with hepatocellular carcinoma. A case of spontaneous regression of hepatocellular carcinoma is reported and compared with the reports published in the English literature. A 52-yr-old man presented with biopsy-proven hepatocellular carcinoma, which was considered to be unresectable at initial laparotomy. The tumor subsequently regressed without specific treatment, as assessed radiologically and by normalization of a previously elevated alpha-fetoprotein level. At repeat laparotomy 14 months after initial diagnosis, intraoperative ultrasound failed to disclose a hepatic mass, and multiple biopsies showed no evidence of malignancy. To date, only nine case reports of apparently spontaneous regression of hepatocellular carcinoma have been published in the English literature. Clinical characteristics discriminating these patients from less fortunate patients with hepatocellular carcinoma could not be identified. The mechanisms underlying this intriguing phenomenon remain unknown.

Variation in the thyrotropic activity of human chorionic gonadotropin in Chinese hamster ovary cells arises from differential expression of the human thyrotropin receptor and microheterogeneity of the hormone

The role of hCG as a stimulator of the human thyroid has been a subject of controversy, because discrepant results have been obtained in different in vitro assays. In an attempt to explain the variation observed in the thyroid response to hCG, we investigated the ability of hCG and that of its isoforms and glycosylation variants to inhibit [125I]bovine (b) TSH binding and stimulate adenylate cyclase in two clones, JP09 and JP26, of Chinese hamster ovary cells stably transfected with the human TSH receptor (hTSHr). The two clones differed with respect to the number of hTSHr expressed per cell (34,000 in JP09 and 2,000 in JP26 cells). Both responded extremely well to bTSH; the cAMP response to 0.001 IU/L bTSH was distinguishable from basal values. Interestingly, JP09 cells were readily stimulated by hCG (20-100 mg/L; 0.52-2.6 x 10(-6) mol/L) to release cAMP, whereas JP26 cells showed little if any response. Also, cAMP stimulation produced by asialo-hCG was 12-fold in JP09 cells and only 4-fold in JP26 cells compared to 45- and 67-fold stimulations by bTSH, respectively. Stimulation by asialo-hCG was approximately 30% that of bTSH in JP09 cells, but less than 6% in JP26 cells. When assessing the thyrotropic activity of the microheterogeneous isoforms of hCG, more alkaline pI forms were found to be more active than those of a more acidic pI regardless of whether they were derived from normal or molar pregnancy urine. Further studies with hCG, asialo-hCG, asialoagalacto-hCG, and deglycosylated hCG revealed that removal of sialic acid caused a marked increase in both its affinity for hTSHr and its cAMP-releasing potency, whereas removal of further carbohydrate, although it slightly enhanced receptor binding, was detrimental to adenylate cyclase activation. In conclusion, differences in hTSHr expression may cause a variation in the cAMP response to hCG or its glycosylation variants, as does the microheterogeneity of the hormone itself. These mechanisms may be responsible at least in part for the divergent responses of different cell types to hCG and render interpretation of the physiological meaning of the data obtained in recombinant receptor systems difficult.

Immunological recognition and clinical significance of nicked human chorionic gonadotropin in testicular cancer

We studied the physical properties, immunological recognition, and clinical significance of nicked human chorionic gonadotropin (hCGn) in testicular cancer. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions, the beta-subunit of hCGn (hCG beta n) dissociated into two peptides, and, by reversed-phase chromatography, hCG beta n was found to be less hydrophobic than hCG beta. Immunologically, hCGn lacked two epitopes specific for holo-hCG (c1, c2), whereas at least five hCG beta epitopes (beta 1-beta 5) were preserved, and, as a result, recognition of hCGn by different hCG assays varied widely. In 309 sera and 88 urine samples from patients with seminomatous or nonseminomatous testicular cancer, hCG-only, hCG+hCGn, and hCG+hCGn+hCG beta+hCG beta n+hCG beta core-fragment assays gave parallel results. hCGn was more abundant in urine than in serum samples. In conclusion, hCGn lacks two conformationally dependent epitopes of hCG, causing a change in hydrophobicity and explaining its failure to react in certain holo-hCG assays. Recognition of hCGn, however, does not seem to be crucial in the routine use of serum hCG as a tumor marker in patients with testicular cancer.

Immunological recognition and clinical significance of nicked human chorionic gonadotropin in testicular cancer

We studied the physical properties, immunological recognition, and clinical significance of nicked human chorionic gonadotropin (hCGn) in testicular cancer. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions, the beta-subunit of hCGn (hCG beta n) dissociated into two peptides, and, by reversed-phase chromatography, hCG beta n was found to be less hydrophobic than hCG beta. Immunologically, hCGn lacked two epitopes specific for holo-hCG (c1, c2), whereas at least five hCG beta epitopes (beta 1-beta 5) were preserved, and, as a result, recognition of hCGn by different hCG assays varied widely. In 309 sera and 88 urine samples from patients with seminomatous or nonseminomatous testicular cancer, hCG-only, hCG+hCGn, and hCG+hCGn+hCG beta+hCG beta n+hCG beta core-fragment assays gave parallel results. hCGn was more abundant in urine than in serum samples. In conclusion, hCGn lacks two conformationally dependent epitopes of hCG, causing a change in hydrophobicity and explaining its failure to react in certain holo-hCG assays. Recognition of hCGn, however, does not seem to be crucial in the routine use of serum hCG as a tumor marker in patients with testicular cancer.

Systemic iodine absorption during endoscopic application of radiographic contrast agents for endoscopic retrograde cholangiopancreaticography

Hyperthyroidism induced by contrast agents in a major problem in patients with pre-existing thyroid disease, particularly in patients with functional thyroid autonomy. The present study was undertaken to evaluate whether contrast media applied during endoscopic retrograde cholangiopancreaticography (ERCP) may result in a significant increase of serum iodine levels and thus may be associated with the risk of iodine-induced hyperthyroidism. The courses of serum concentrations of total iodine and free iodide, as well as of urinary iodine excretion, were measured in 15 patients before and up to 21 days after ERCP. During ERCP, the non-ionic contrast medium iopamidol was instilled in amounts resulting in a total iodine load of 57.4 +/- 22.8 mmol (7.3 +/- 2.9 g). In all patients, ERCP resulted in a highly significant increase in serum levels of total iodine from 0.8 +/- 0.5 to 85.2 +/- 116.9 mumol/l 4 h after application of the contrast agent. In parallel, serum iodide levels were raised from 0.06 +/- 0.04 to 5.42 +/- 6.09 mumol/l and urinary iodine excretion from 71.1 +/- 35.7 mumol/mol creatinine to 621,620.9 +/- 636,492.2 mumol/mol creatinine. Peak concentrations of serum iodine are well related to the total amount of iodine applied (p < 0.05). During follow-up, iodine levels returned to pre-exposure levels within 2-3 weeks. Levels of thyrotropin, free thyroxine, and free triiodothyronine remained unchanged during the follow-up period. In conclusion, endoscopic application of iodinated contrast agents during ERCP leads to significant increases of serum levels of total iodine and free iodide and of urinary iodine excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction of human chorionic gonadotropin (hCG) and asialo-hCG with recombinant human thyrotropin receptor

hCG is a putative thyroid stimulator. The present studies were undertaken to examine its interaction and that of its desialylated variant asialo-hCG with recombinant human TSH (hTSH) receptor (hTSHr). To this end, we transfected a human thyroid carcinoma cell line (HTC) lacking endogenous TSHr with the full-length cDNA of the hTSHr. Unlike the wild type, the transfected cells, termed HTC-TSHr cells, were able to bind bovine TSH (bTSH) with high affinity and increase cAMP production in response to bTSH stimulation. Of the hCG forms, intact hCG displayed a weak activity to inhibit [125I] bTSH binding to HTC-TSHr cells, with 100 mg/L (2.6 x 10(-6) mol/L) producing maximally a 20% inhibition, whereas asialo-hCG achieved half-maximum binding inhibition at a concentration of 8 mg/L (2.3 x 10(-7) mol/L). The inhibitory constant (Ki) of asialo-hCG for recombinant hTSHr was calculated from saturation experiments in the presence of variable doses of bTSH and a fixed concentration of asialo-hCG to be approximately 8 x 10(-8) mol/L. The interaction of asialo-hCG with TSHr was further assessed by studies of the direct binding of the radioactively labeled hormone to both HTC and HTC-TSHr cells. [125I]Asialo-hCG binding to HTC-TSHr cells was 4.7%, compared to 1.5% in the wild-type cells lacking TSHr and was displaceable by bTSH (0.1-100 IU/L), indicating specific binding of the tracer to TSHr. Functionally, hCG (up to 100 mg/L; 2.6 x 10(-6) mol/L) proved unable to evoke any significant cAMP response over basal values in HTC-TSHr cells, as did asialo-hCG. Asialo-hCG, but not hCG, inhibited bTSH-stimulated adenylate cyclase activity in the cells in a dose-dependent manner. In conclusion, the present data show that intact hCG binds only weakly to HTC-TSHr cells and produces no significant cAMP stimulation, which is at variance with data obtained in FRTL-5 and Chinese hamster ovary-TSHr cells, but in good accord with previous findings in human thyroid membranes. Asialo-hCG, on the other hand, strongly binds to recombinant TSHr and inhibits the cAMP response to bTSH in HTC-TSHr cells, indicating that the desialylated hCG variant directly interacts with the receptor and truly is an antagonist of the hTSHr.

Alpha-subunit and human chorionic gonadotropin-beta immunoreactivity in patients with malignant endocrine gastroenteropancreatic tumours

In the serum of patients with malignant endocrine gastroenteropancreatic (GEP) tumours, both alpha-subunit (alpha-SU), common to all glycoprotein hormones, as well as free beta-subunit of human chorionic gonadotropin (hCG-beta) have been reported to be elevated in a substantial fraction. Both have been discussed as markers of malignancy in these neoplasms. In the present study we evaluated the diagnostic significance of alpha-SU and hCG-beta as serum markers in patients with malignant endocrine gastroenteropancreatic tumours. The study group consisted of 52 patients with endocrine GEP-malignancies (24 nonfunctioning, 23 carcinoid syndromes, four gastrinoma, one glucagonoma), located in the small intestine (n = 29), pancreas (n = 17), colon or rectum (n = 3), retroperitoneum (n = 2) and stomach (n = 1). alpha-SU and hCG-beta immunoreactivity was also assessed in the serum of patients with benign GEP-tumors (five insulinoma, and three gastrinoma). Concentrations of alpha-SU and hCG-beta were determined using two highly sensitive and specific immunoradiometric assays employing two monoclonal antibodies each. In 19 of 52 patients (37%), either alpha-SU (n = 9), hCG-beta (n = 7) or both subunits (n = 3) were elevated. In the subgroup of 24 patients with nonfunctioning GEP-tumours, increased concentrations of either alpha-SU (n = 6) or hCG-beta(n = 3) or both subunits (n = 1) were found in 10 of 24 patients (42%). In four of 23 patients with carcinoid syndrome (17%), either alpha-SU (n = 2), hCG-beta(n = 1) or both subunits (n = 1) were above the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular heterogeneity of human chorionic gonadotropin in serum and urine from patients with trophoblastic tumors

Many studies on the structure and function of human chorionic gonadotropin (hCG) have relied on purified hCG preparations obtained from pregnancy urine. In the present studies, in order to demonstrate possible differences between the hCG species present in serum and those released into urine, we examined serum and urinary samples derived from patients with trophoblastic tumors and of pregnancy origin by sodium dodecyl sulfate electrophoresis, isoelectric focusing, and two-dimensional electrophoresis including immunostaining with a specific hCG antibody and densitometry of the protein bands. This type of analysis was presently feasible only in patients presenting with extremely high serum levels of hCG and was therefore limited to seven patients with testicular cancers, one woman with a hydatidiform mole, and one pregnancy sample. We found marked differences in the isoelectric focusing pattern between urinary and serum hCG samples, with the urinary hCG consisting of more alkaline pI variants than that present in the serum of the same patients. Tumor hCG differed from pregnancy hCG in that it contained more acidic variants, and this was true for urinary and serum-derived materials. In some tumor and pregnancy samples an hCG immunoreactive material of lower molecular weight than hCG itself was found. In conclusion, the present studies, extending previous findings on the microheterogeneity of hCG, indicate that serum and urinary-derived hCG may differ in the composition of the isoform spectrum, as does tumor and pregnancy hCG. Further, in some patients hCG immunoreactive molecules exist that differ markedly from hCG in size and charge. These observations suggest that, whenever possible, serum-derived hCG materials should be used to define the molecular structure of hCG and assess its biological activities.

Increased binding capacity of receptors for the epidermal growth factor in benign thyroid nodules and thyroid malignancies

To determine the role of epidermal growth factor (EGF) receptors in thyroid tumorigenesis, EGF binding was compared in membranes from malignant and from benign thyroid tumors. Surgical specimens were obtained from 28 patients with thyroid carcinomas (3 papillary, 13 follicular, 6 undifferentiated, and 6 medullary carcinomas) and from 30 patients with benign thyroid tumors (15 scintigraphically functional and 15 nonfunctional nodules). In 30 cases normal tissue adjacent to the tumor was also obtained. EGF binding was seen to be increased not only in thyroid carcinomas but also in benign thyroid tumors, particularly in functional thyroid adenomas. The highest EGF binding was found in undifferentiated carcinomas. A direct comparison of the EGF binding characteristics in tumor and adjacent normal thyroid tissue revealed that the increased binding of EGF is due mainly to an increase in the number of binding sites rather than an alteration in receptor affinities. EGF binding capacities were 18.4 +/- 16.7 fmol/mg protein in thyroid carcinomas and 10.5 +/- 5.2 fmol/mg in the corresponding normal tissue (P < 0.05, Kd 0.84 +/- 0.26 nM, n = 11). In autonomously functioning thyroid adenomas binding capacities were 14.2 +/- 8.2 fmol/mg in the nodules and 8.9 +/- 4.8 fmol/mg in normal tissue (P < 0.01, Kd 0.73 +/- 0.62 nM, n = 15). In conclusion, EGF receptor levels are increased not only in malignant thyroid tumors but also in well-differentiated benign thyroid nodules.(ABSTRACT TRUNCATED AT 250 WORDS)