Video-assisted neck exploration for primary and secondary hyperparathyroidism: initial experience

BACKGROUND

Minimally invasive surgery (MIS) for primary hyperparathyroidism includes unilateral neck exploration, access via a totally endoscopic approach, and access via a video-assisted procedure. We report herein our initial experience with the video-assisted neck exploration procedure for primary (PHPT) and secondary hyperparathyroidism (SHPT).

METHODS

Between June 1999 and May 2000, 35 patients were selected for PHPT (n = 25) and SHPT (n = 10). In all cases, video-assisted neck exploration was performed under general anesthesia, leading to selective adenoma removal in PHPT or subtotal parathyroid resection in SHPT. Patient selection was based on the preoperative localization studies (ultrasonography and sestamibi scintigraphy).

RESULTS

Five of the 25 patients operated on for PHPT (20%) and three of the 10 patients who underwent surgery for SHPT (30 %) were converted to a conventional surgical technique. The mean operative times in PHPT and SHPT were 48.9 +/- 18.7 min and 136.8 +/- 18.7 min, respectively. The recurrent laryngeal nerve was identified in 45% of the patients. The median size and weight of the resected parathyroid glands were 1.8 cm (range, 0.9-2.5) and 1 g (range, 0.5-7), respectively. The length of skin incision was 24 +/- 1.2 mm. All but one patient are currently cured, with a median follow-up of 6 months (range, 2-13). Postoperative complications included hematoma and transient hoarseness in one patient each (2.85%). The median pain intensity, based on the visual analogue scale (VAS) method, as measured at postoperative day 1 was 0.5 (range, 0-3.6). In the PHPT group, the postoperative hospital stay was

Expression of presumed specific early and late factors associated with liver regeneration in different rat surgical models

Experiments performed on the portal branch ligation (PBL) model indicate that early changes observed after surgery are not related to the regenerative process because they also occur in atrophying lobes. To further confirm the lack of specificity of the early events and to exclude the influence of circulatory factors released by proliferating lobes on their occurrence, we investigated this response after sham operation (SO) and portacaval shunt (PCS), a model characterized by liver atrophy. We also attempted to determine expression of later events associated specifically with regeneration, ie, expression of p53 or c-Ha-ras, or inhibition of proliferation, ie, interleukin-1beta (IL-1beta) and transforming growth factor-beta1 (TGF-beta1) after partial (PH) and temporary partial (TPH) hepatectomy, SO and PCS. Nuclear factor-kappaB (NF-kappaB) and signal transducer and activator of transcription 3 (STAT3) DNA binding were assessed by electrophoretic mobility shift assay (EMSA), interleukin-6 (IL-6) mRNA by reverse transcription-polymerase chain reaction (RT-PCR), c-myc and c-jun mRNAs by Northern blot analysis at 0.5 and 2 hours, p53 and c-Ha-ras mRNAs by Northern blot analysis at 8 and 24 hours, and IL-1beta and TGF-beta1 by RT-PCR at 24 hours. The early response including an increase of NF-kappaB, STAT3, IL-6, and immediate-early genes expression was present after PH, PCS, and SO. In SO, slight differences were observed in comparison with PH: no NF-kappaB p65/p50 DNA binding was observed, only three of six SO rats were positive for IL-6, and immediate-early genes induction showed differences in the intensity of the response. At later times, p53 mRNA increased at 8 hours after PH and TPH, c-Ha-ras mRNA at 24 hours after PH, and IL-1beta mRNA at 24 hours after PCS. Early events are not specifically associated with the reduction of liver mass or with the regenerative process, are not predictive of future cell fate, and are most likely related to surgical stress. p53 and c-Ha-ras induction is closely associated with cell cycle progression whereas IL-1beta, but not TGF-beta1, appears to be one of the negative growth regulators that might play an important role in atrophy.

After portal branch ligation in the rat, cellular proliferation is associated with selective induction of c-Ha-ras, p53, cyclin E, and Cdk2

BACKGROUND

In liver regeneration after portal branch ligation we previously showed that early cellular changes are observed in both the proliferating and atrophying liver lobes. They are therefore not indicative of future proliferative response. In this study we attempted to define precisely, in the same model, the time at which the cellular processes diverge between the lobes by measuring various parameters associated with cellular proliferation. We also investigated the possible role of inhibitors of cell proliferation in the absence of progression towards the S phase in the atrophying lobes.

AIMS

Expression of p53, c-Ha-ras, cyclin E, cyclin dependent kinase (Cdk2), transforming growth factor (TGF)-beta, and interleukin (IL)-1alpha and IL-1beta were assessed in relation to their potential role in proliferating and atrophying cellular phenomenons.

METHODS

Immunohistochemistry, northern blotting, western blotting, and reverse transcription-polymerase chain reaction were performed, mainly at time points corresponding to mid-G1/S phase progression (8-24 hours after surgery).

RESULTS

The common and thus most likely non-specific response was still evident 5-8 hours after surgery and included an increase in IL-1 mRNA as well as p53 and cyclin E proteins. From 12 hours onwards, p53, c-Ha-ras, cyclin E, and Cdk2 were selectively induced in proliferating lobes whereas IL-1beta was predominantly activated in atrophying lobes. No changes in TGF-beta or IL-1alpha expression were observed at the same time points in any of the liver lobes.

CONCLUSIONS

The initial response to portal branch ligation and thus probably to partial hepatectomy seems to be non-specific for at least eight hours. Thereafter, p53, c-Ha-ras, cyclin E, and Cdk2 seem to drive cellular proliferation while IL-1beta is associated with cellular atrophy. In contrast, TGF-beta and IL-1alpha do not seem to play a role in determining the commitment of cells towards atrophy or proliferation.

Erectile dysfunction and lower androgenicity in type 1 diabetic patients

OBJECTIVE

To analyse the clinical characteristics and relevant hormonal profile in type 1 diabetic patients with and without ED.

MATERIAL AND METHODS

Fifty one type 1 diabetic patients were studied. ED was assessed by direct interview. Chronic diabetic complications, smoking and alcohol status as well as current use of medications were recorded. Hormonal profile consisted of plasma LH, FSH, prolactin, androstenedione (Delta(4)), dehydroepiandrosterone (DHEA), DHEA-sulfate (DHEA-S), free testosterone (FT), estradiol (E(2)), sex hormone binding globulin (SHBG), dihydrotestosterone (DHT), cortisol, TSH and free thyroxine (FT(4)).

RESULTS

ED was present in 24 patients (47%) (group 1), who were older (P<0.001), had a longer diabetes duration (P<0.001) and a higher systolic blood pressure (P=0.017) when compared to the subjects who did not complain (group 2). ED was positively correlated to all diabetes-related complications (P<0.02). Antidepressive drug(s) were more frequent in group 1 (P=0.007), as well as prokinetics (P=0.043) and ACE-inhibitors (P=0.010). HbA(1)c was comparable. Patients with ED had lower levels of Delta(4) (P=0.003), DHEA (P<0.001), DHEA-S (P=0.002), FT (P=0.08) while SHBG (P=0.010) and LH (P=0.022) were higher compared to group 2. Multiple logistic regression analysis showed an independent association of ED with Delta(4) (P=0.016), DHEA-S (P=0.037), SHBG (P=0.001) and insulin dose (P=0.025). There was no significant difference for all other measured hormones.

CONCLUSION

ED is impressively prevalent in type 1 diabetes and is associated with age, diabetes duration, chronic complications and decreased androgens.

Slow-release lanreotide in the treatment of acromegaly: a study in 66 patients

OBJECTIVE

Slow-release (SR) lanreotide is a long-acting somatostatin analog that has been developed in order to overcome the inconvenience of multiple daily subcutaneous injections of octreotide, required for metabolic control in acromegaly. Lanreotide SR has been found to be well tolerated and effective in reducing GH and IGF-I levels but clinical data are still limited compared with those with subcutaneous octreotide treatment.

DESIGN

Sixty-six unselected patients with active acromegaly were therefore evaluated in a multi-center, prospective, open label study. Lanreotide SR was given at a dose of 30mg intramuscular every 7-14 days.

METHODS

At baseline and after 2, 4, 8, 12, 24, 36 and 48 weeks patients underwent a clinical examination with assessment of acromegaly related symptoms, and blood was sampled for serum GH, IGF-I, prolactin, glycosylated hemoglobin, fasting glucose, hematology, kidney function and liver function tests. Biliary ultrasonography and pituitary magnetic resonance imaging were performed at baseline and after one year.

RESULTS

Treatment resulted in a significant improvement in the symptom score from 2.69+/-0.27 to 1.06+/-0.17 (P<0.0001). Serum IGF-I levels fell from 699+/-38microg/l at baseline to 399+/-26microg/l (P<0.0001, n=60) after one month, after which levels remained stable: 480+/-37microg/l after 6 months (n=54) and 363+/-32microg/l after one year (n=46). GH levels dropped from 13.8+/-3.2microg/l to 4.3+/-0.7microg/l after one month (P<0.0001, n=60) and remained stable thereafter: 3.9+/-0.4microg/l (n=54) after 6 months and 3.5+/-1.1microg/l after one year (n=46). Twenty-nine out of 66 patients (44%) attained a normal age-corrected IGF-I level and 30 patients (45%) attained a GH level below 2.5microg/l. Pituitary adenoma shrinkage of at least 25% was found in 5 of 14 patients (36%) after one year. Side effects were mainly transient gastrointestinal symptoms and pain at the injection site, resulting in drug discontinuation in only 6 patients (9%). Two patients developed new gall stones. No difference was found between subcutaneous octreotide and lanreotide SR in efficacy and almost all patients preferred the easier dose administration of lanreotide SR.

CONCLUSIONS

Long-term treatment of acromegaly with SR-lanreotide is effective in controlling GH and IGF-I levels and symptoms and is well tolerated in the majority of patients. Compared with subcutaneous octreotide, lanreotide SR considerably improves patient's acceptance of therapy while having the same overall efficacy.

Potentiation of growth hormone-induced liver suppressors of cytokine signaling messenger ribonucleic acid by cytokines

Endotoxin and proinflammatory cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNFalpha) induce a state of GH resistance. A new family of suppressors of cytokine signaling (SOCS), induced by cytokines activating the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway, has been recently identified as a negative feedback loop of intracellular signaling. Overexpression of some SOCS (SOCS-3, CIS, and SOCS-2) has been reported to inhibit the JAK-STAT pathway stimulated by GH. To assess the possible role of these three SOCS proteins in the GH resistance induced by endotoxin and cytokines, we investigated the regulation of their gene expression by endotoxin and GH in rat liver and by proinflammatory cytokines and GH in primary culture hepatocytes. Both GH and lipopolysaccharide induced the three SOCS messenger RNAs (mRNAs) in vivo. In vitro, GH also increased the liver mRNAs encoding SOCS-2, SOCS-3, and CIS. Although IL-1/beta and TNFalpha alone induced only weakly the expression of SOCS-3 and CIS, these cytokines strongly potentiated the induction of these two SOCS by GH. In contrast, IL-6 alone markedly induced SOCS-3 mRNA, but did not potentiate the GH action on SOCS-3 and CIS mRNAs. The GH induction of SOCS-2 was not potentiated by any of these cytokines. Considering the ability of these SOCS to inhibit the JAK-STAT pathway induced by GH, these results suggest that the overexpression of SOCS-3 and CIS mRNAs induced by IL-1beta and TNFalpha or by endotoxin in vivo may play a role in the GH resistance induced by sepsis.

[Prolactinoma in man: clinical and histological characteristics]

Prolactinoma usually occurs a small intrasellar tumor in women or as a large tumor in men. To determine whether the predominance of macroprolactinomas in men is due to a delay in diagnosis as has been suggested, or whether there is a sex-related difference in growth rate we conducted a retrospective study in 45 men and 51 women with prolactinomas. Preoperative prolactin level (PRL) was 2,789 573 ng/ml and mean tumor size was 26 2 mm. Prolactin levels and tumor size were significantly higher in women (292 74 ng/ml and 10 1 mm; p<0.01). There was no correlation with age at diagnosis or duration of symptoms. Giant tumors were only observed in men (n=8). Frequency of resistance to bromocriptine (30% vs 5%, p<0.01) and invasive tumors (52% vs 27%, p<0.001) were significantly higher in men than in women. Likewise, proliferation rate was higher for the prolactinomas in men (Ki-67: 2.6 1.1% positive nuclei vs 0.4 0.2%; p=0.08; PCNA: 5.0 2.3% vs 3.7 1.1%). In conclusion, prolactinomas in men are more aggressive than in women. They grow rapidly, often invade the cavernous sinus and are resistant to bromocriptine; proliferation rates can be increased.

[Evaluation of corticosteroid replacement therapy and its effect on bones in Addison's disease]

Assessment of patients on steroid replacement therapy is important to avoid the consequences of overtreatment such as osteoporosis. The aim of this prospective study is to evaluate the severity and the etiology of osteopenia in 24 patients (15 women, 9 men) with Addison's disease receiving 30 mg hydrocortisone. Mean age of patients was 55 15 years. Osteoporosis, diagnosed by the measurement of bone mineral density (BMD) at the level of lumbar spine and right hip, was found in 58% of patients, i.e. in 10 women and 4 men. The latter had normal testosterone levels while seven women had an early menopause, the etiology of their Addison's disease being autoimmune. Three were on hormonotherapy. Correlations were found between BMD in the femoral neck and hip and the dose of hydrocortisone (mg/m(2)/day; mg/kg/day), the duration of treatment and 24 hr-cortisoluria/g creatinine. Multivariate analysis shows that 24-hr cortisoluria/g creatinine is a good predictor of BMD values. Thus, osteoporosis is frequent in Addison's disease and cortisoluria could be a useful tool to predict this complication.

In vitro effects of oestradiol on galanin gene expression in rat anterior pituitary cells

While the pituitary galanin gene is highly responsive to oestrogen stimulation in vivo, in vitro effects of oestrogens on pituitary galanin gene expression have been less studied. We therefore examined the short-term effects of 17beta-oestradiol on galanin synthesis by dispersed rat anterior pituitary cell cultures and investigated the mechanisms by which oestrogens may modulate galanin gene expression. 17beta-oestradiol increased galanin mRNA expression in a dose-dependent manner, with a maximal increase observed at a concentration of 10-7 M. The 17beta-oestradiol (10-7 M)-induced increase in galanin mRNA expression varied from 3- to 20-fold (average 12-fold) depending upon the experiments and was also time-dependent, reaching significance after 6 h. A 1-h exposure of anterior pituitary cells to 17beta-oestradiol was sufficient to induce markedly galanin mRNA expression after 24 h (by 16-fold) and 48 h (by 25-fold). Tamoxifen administered simultaneously with or following 17beta-oestradiol treatment completely abolished the oestrogen-induced increase of galanin mRNA levels. Cycloheximide (10 microg/ml), a protein synthesis inhibitor, also blocked 17beta-oestradiol-induced galanin gene expression. Using transcription blockade by actinomycin D, we observed similar decreases of pituitary galanin mRNA concentrations, in the presence and absence of 17beta-oestradiol, implying no oestrogen effect on mRNA stability. We conclude that oestrogens stimulate rat pituitary galanin gene expression, mainly through a transcriptional mechanism, and that this effect requires persistent binding of the hormone to its nuclear receptor and newly synthesized protein intermediates.

Peritoneal carcinomatosis following laparoscopic resection of an adrenocortical tumor causing primary hyperaldosteronism

A clinical syndrome combining hypertension and hypokalemic alkalosis led to the diagnosis of primary hyperaldosteronism, caused by a right-sided, 2 cm large, apparently benign aldosterone-producing adenoma. The adrenal tumor was completely resected by laparoscopic adrenalectomy. Six months after surgery, the patient exhibited a severe relapse of hyperaldosteronism. Extensive peritoneal metastases of a mixed aldosterone- and cortisol-secreting adrenocortical carcinoma were found at abdominal laparotomy. In the light of this case report, we discuss the possibility that laparoscopic resection of adrenocortical tumors might contribute to their subsequent peritoneal dissemination.

Involvement of STAT5 (signal transducer and activator of transcription 5) and HNF-4 (hepatocyte nuclear factor 4) in the transcriptional control of the hnf6 gene by growth hormone

HNF-6 is a tissue-restricted transcription factor that participates in the regulation of several genes in liver. We reported earlier that in adult rats, HNF-6 mRNA concentration in liver drops to almost undetectable levels after hypophysectomy and returns to normal after 1 week of GH treatment. We now show that this results from a rapid effect of GH, and we characterize its molecular mechanism. In hypophysectomized rats, HNF-6 mRNAs increased within 1 h after a single injection of GH. The same GH-dependent induction was reproduced on isolated hepatocytes. To determine whether GH regulates hnf6 expression at the gene level, we studied its promoter. DNA binding experiments showed that 1) the transcription factors STAT5 (signal transducer and activator of transcription 5) and HNF-4 (hepatocyte nuclear factor 4) bind to sites located around -110 and -650, respectively; and 2) STAT5 binding is induced and HNF-4 binding affinity is increased in liver within 1 h after GH injection to hypophysectomized rats. Using transfection experiments and site-directed mutagenesis, we found that STAT5 and HNF-4 stimulated transcription of an hnf6 gene promoter-reporter construct. Furthermore, GH stimulated transcription of this construct in cells that express GH receptors. Consistent with our earlier finding that HNF-6 stimulates the hnf4 and hnf3beta gene promoters, GH treatment of hypophysectomized rats increased the liver concentration of HNF-4 and HNF-3beta mRNAs. Together, these data demonstrate that GH stimulates transcription of the hnf6 gene by a mechanism involving STAT5 and HNF-4. They show that HNF-6 participates not only as an effector, but also as a target, to the regulatory network of liver transcription factors, and that several members of this network are GH regulated.

Monoclonal antibodies to growth hormone (GH) prolong liver GH binding and GH-induced IGF-I/IGFBP-3 synthesis

This time-course study further explored the mechanisms whereby monoclonal antibodies (MAbs) may enhance growth hormone (GH) effects. Hypophysectomized rats were killed 0, 1, 3, 6, 12, 24, and 48 h after a single injection of bovine (b) GH alone or complexed with an anti-bGH MAb. Serum insulin-like growth factor I (IGF-I) concentrations were increased more and for a longer period after MAb-GH complexes (peak at 24 h: 295 +/- 24 ng/ml) than after bGH alone (peak at 12 h: 219 +/- 37 ng/ml; P < 0.01), whereas liver IGF-I mRNA was similar at 12 h in both groups but remained higher at 24 h (by 65%, P < 0.001) and 48 h (by 64%, P < 0.001) in the presence of the MAb. Induction of serum insulin-like growth factor-binding protein (IGFBP)-3 and liver IGFBP-3 mRNA by bGH also was markedly amplified by the MAb (3.6- and 2-fold at 24 h, respectively; P < 0.01). GH receptors (GHR) remained occupied for a longer period after MAb-GH injection (36 +/- 16 and 35 +/- 8% at 6 and 12 h, respectively) compared with bGH alone (0 +/- 28 and -15 +/- 11%), whereas total liver GH-binding sites and GHR mRNA levels were not affected by the MAb. We conclude that MAbs against GH amplify and prolong the serum IGF-I response to GH, which may result from both a prolongation of liver IGF-I synthesis and an enhanced induction of IGFBP-3. These two effects may in turn be the consequences of sustained GH binding to its liver receptors in the presence of MAb.

Cabergoline in the treatment of hyperprolactinemia: a study in 455 patients

Cabergoline is a new long-acting dopamine agonist that is very effective and well tolerated in patients with pathological hyperprolactinemia. The aim of this study was to examine, in a very large number of hyperprolactinemic patients, the ability to normalize PRL levels with cabergoline, to determine the effective dose and tolerance, and to assess the effect on clinical symptoms, tumor shrinkage, and visual field abnormalities. We also evaluated the effects of cabergoline in a large subgroup of patients with bromocriptine intolerance or -resistance. We retrospectively reviewed the files of 455 patients (102 males and 353 females) with pathological hyperprolactinemia treated with cabergoline in 9 Belgian centers. Among these patients, 41% had a microadenoma; 42%, a macroadenoma; 16%, idiopathic hyperprolactinemia; and 1%, an empty sella. The median pretreatment serum PRL level was 124 microg/L (range, 16-26,250 microg/L). A subgroup of 292 patients had previously been treated with bromocriptine, of which 140 showed bromocriptine intolerance and 58 showed bromocriptine resistance. Treatment with cabergoline normalized serum PRL levels in 86% of all patients: in 92% of 244 patients with idiopathic hyperprolactinemia or a microprolactinoma and in 77% of 181 macroadenomas. Pretreatment visual field abnormalities normalized in 70% of patients, and tumor shrinkage was seen in 67% of cases. Side effects were noted in 13% of patients, but only 3.9% discontinued therapy because of side effects. The median dose of cabergoline at the start of therapy was 1.0 mg/week but could be reduced to 0.5 mg/week once control was achieved. Patients with a macroprolactinoma needed a higher median cabergoline dose, compared with those with idiopathic hyperprolactinemia or a microprolactinoma: 1.0 mg/week vs. 0.5 mg/week, although a large overlap existed between these groups. Twenty-seven women treated with cabergoline became pregnant, and 25 delivered a healthy child. One patient had an intended abortion and another a miscarriage. In the patients with bromocriptine intolerance, normalization of PRL was reached in 84% of cases, whereas in the bromocriptine-resistant patients, PRL could be normalized in 70%. We confirmed, in a large-scale retrospective study, the high efficacy and tolerability of cabergoline in the treatment of pathological hyperprolactinemia, leaving few patients with unacceptable side effects or inadequate clinical response. Patients with idiopathic hyperprolactinemia or a microprolactinoma, on average, needed only half the dose of cabergoline as those with macroprolactinomas and have a higher chance of obtaining PRL normalization. Cabergoline also normalized PRL in the majority of patients with known bromocriptine intolerance or -resistance. Once PRL secretion was adequately controlled, the dose of cabergoline could often be significantly decreased, which further reduced costs of therapy.

Influence of age on the clinical presentation of prolactinomas in male patients

OBJECTIVE

Secreting pituitary adenomas are usually not considered a disease of older people. However, in male patients, prolactin-secreting pituitary tumours occur at a similar frequency throughout the entire life span, giving the opportunity to study in this gender the influence of age on the clinical presentation and response to treatment of these tumours.

METHODS

We conducted a retrospective study including 9 male patients aged >/=60 (range 60-73) years and 10 aged </=30 (range 17-30) years presenting with a prolactinoma in order to compare clinical presentation, results of pituitary function tests, and response to dopamine agonist therapy between older and younger patients.

RESULTS

Four of the 9 elderly as well as the 10 younger patients came to medical attention for typical features of male prolactinomas including visual field defect in 5 (2 elderly), headaches in 2 (1 elderly), impotence in 3 (1 elderly), gynaecomastia and/or galactorrhoea in 2, and arrested puberty in 2. The remaining 5 older people presented for other various reasons: symptoms related to cortisol deficiency in 2, lethargy with clinical signs of hypopituitarism in 1, spontaneous multiple vertebral fractures in 1, and incidental discovery of a pituitary mass in 1. Basal prolactin levels (3,051+/-4,151 vs. 3,365 +/- 4,949 microg/l) and mean tumour diameter (30 +/- 16 vs. 25 +/- 13 mm) were similar in old and young patients. Cortisol deficiency was significantly more frequent in the elderly (n = 6) than in the young (n = 1) patients (p 0.02, Fisher's exact test). Secondary hypothyroidism was found in 2 elderly only, but not in young patients. Sixteen patients (8 elderly) received bromocriptine therapy for at least 6 months with a good tolerance. Normalization of the prolactin levels was achieved in 6 older (75%) and 4 younger patients (50%).

CONCLUSIONS

The presentation of a prolactinoma in the elderly man is very heterogeneous and can be misleading. At the time of diagnosis, hypopituitarism is more frequent among older than younger patients despite a similar tumour size. We found dopamine agonists equally effective in the elderly.

After portal branch ligation in rat, nuclear factor kappaB, interleukin-6, signal transducers and activators of transcription 3, c-fos, c-myc, and c-jun are similarly induced in the ligated and nonligated lobes

Several studies have emphasized the involvement of transcription factors, cytokines, and proto-oncogenes in initiating the regenerative process after partial hepatectomy. To assess whether these events do specifically occur in a cellular system undergoing regeneration, we studied the induction of nuclear factor kappaB (NFkappaB), interleukin-6 (IL-6), signal transducers and activators of transcription 3 (Stat3), c-fos, c-myc, c-jun, after portal branch ligation (PBL), which produces atrophy of the deprived lobes (70% of the liver parenchyma), whereas the perfused lobes undergo compensatory regeneration. Nuclear extracts and total RNA were prepared from control livers as well as from atrophying and regenerating lobes at 0.5, 1, 2, 5, and 8 after PBL. NFkappaB and Stat3 induction were studied by electrophoretic mobility shift assays and Western blotting. IL-6 and proto-oncogenes expressions were assessed by reverse transcription polymerase chain reaction and Northern blotting, respectively. Assays were also performed after a sham operation. NFkappaB and Stat3 protein expression and DNA binding were rapidly and similarly induced in nuclear extracts from the atrophying and regenerating lobes. IL-6 was elevated in both lobes from 1 to 8 hours after PBL as well as c-fos, c-myc, and c-jun during the first 2 hours. IL-6 and Stat3 but not NFkappaB were also elevated after a sham operation. These findings suggest that the cellular and molecular changes occurring early in a regenerating liver are nonspecific, possibly stress-induced, cellular responses. They do not indicate the future evolution towards atrophy or regeneration.

Familial adenomatous polyposis associated with multiple adrenal adenomas in a patient with a rare 3' APC mutation

Familial adenomatous polyposis (FAP) is characterised by hundreds of colorectal adenomas. Endocrine neoplasms have occasionally been reported, as have gastric polyps, which are usually hamartomatous in the fundus of the stomach and adenomatous in the antrum. A 57 year old man with colorectal, gastric, and periampullary adenomatous polyposis, in association with three bilateral adrenocortical adenomas, is presented. Mutation screening showed a 5960delA germline mutation in the adenomatous polyposis coli (APC) gene predicted to lead to a premature stop codon. This mutation was found in three of the four children of the patient. Western blot analysis of a lymphoblastoid cell line derived from the patient failed to detect any truncated APC polypeptide. This rare 3' mutation is responsible for an unusually complex and late onset phenotype of FAP.

Continuous administration of growth hormone does not prevent the decrease of IGF-I gene expression in zinc-deprived rats despite normalization of liver GH binding

To determine the role of reduced liver GH binding (GHR) in the decreased IGF-I observed in zinc-deficient (ZD) animals, we investigated the effects of GHR restoration on growth, insulin-like growth factor I (IGF-I) and its binding proteins (IGFBPs) in ZD rats. Rats were fed for 4 weeks a zinc-deficient diet (ZD Zn, 0 ppm) or a Zinc-normal diet (pair-fed or PF; Zn, 75 ppm). ZD rats received continuous s.c. infusion of bovine growth hormone (bGH) (100 microg/d) for the 4 weeks or for the last week of the study. Compared with pair-fed rats, zinc deficiency produced attenuated weight gain (-43%, P < 0.001), lower serum IGF-I and liver IGF-I mRNA (-52%, P < 0.001 and -44%, P < 0.05), lower serum IGFBPs (IGFBP-3 -66%, IGFBP-4 -48%, 34-29 kDa IGFBP cluster -53%, P < 0.05), lower liver GHR and its mRNA (-20 and -34%, P < 0.05) and lower serum growth hormone binding protein (GHBP) and its mRNA (-56 and -48%, P < 0.05; all comparisons vs PF rats). Exogenous bGH given continuously normalized the liver GHR, serum GHBP and their liver mRNAs, as well as circulating IGFBPs. Despite restoration of GHR and GHBP to normal, growth, serum IGF-I and its liver mRNA were not stimulated by GH infusion in ZD rats, indicating that IGF-I synthesis requires the presence of zinc in addition to GH, and that the lack of growth-promoting action of GH in zinc-deprived rats results from a defect beyond GH binding to its liver receptors.

Failure of exogenous IGF-I to restore normal growth in rats submitted to dietary zinc deprivation

Dietary zinc deficiency in rats causes growth retardation associated with decreased circulating IGF-I concentrations. To investigate the potential role of low IGF-I in this condition, we attempted to reverse the growth failure by administration of exogenous IGF-I. Rats were fed for 4 weeks a zinc-deficient diet (ZD, Zn 0 ppm) or were pair-fed a zinc-normal diet (PF, Zn 75 ppm). We compared the anabolic action of recombinant human (rh) IGF-I infused at the dose of 120 microg/day for the last experimental week in ZD, PF and freely fed control (CTRL) rats. Zinc deficiency caused growth stunting (weight gain 47% of PF; P<0.001), decreased circulating IGF-I (52% of PF; P<0.01) and liver IGF-I mRNA (67% of PF; P<0.01). Serum insulin-like growth factor-binding protein-3 (IGFBP-3) assessed by ligand blot was also reduced in ZD rats (65% of PF; P<0. 01). While exogenous IGF-I increased body weight in CTRL (+12 g; P<0. 01) and PF (+7 g; not significant) animals, growth was not stimulated in ZD rats (-1.5 g) in comparison with the corresponding untreated groups. However, circulating IGF-I and IGFBP-3 levels were restored by IGF-I infusion to levels similar to those in untreated CTRL rats. In conclusion, restoration of normal circulating levels of IGF-I and IGFBP-3 by rhIGF-I infusion fails to reverse the growth retardation induced by zinc deficiency. These results suggest that growth retardation related to zinc deficiency is not only caused by low serum IGF-I concentrations, but also by inhibition of the anabolic actions of IGF-I.

Cabergoline in the treatment of acromegaly: a study in 64 patients

Cabergoline is a new, long acting, dopamine agonist that is more effective and better tolerated than bromocriptine in patients with hyperprolactinemia. Because dopamine agonists still have a place in the medical management of acromegaly, cabergoline might be a useful treatment. We, therefore, evaluated the effect of long term administration of cabergoline in a large group of unselected acromegalic patients. Sixty-four patients were included in a multicenter, prospective, open labeled study. A subgroup of 16 patients had GH-/PRL-cosecreting pituitary adenomas. Cabergoline was started at a dose of 1.0 mg/week and was gradually increased until normalization of plasma insulin-like growth factor I (IGF-I) levels, occurrence of unacceptable side-effects, or a maximal weekly dose of 3.5 mg (7.0 mg in 1 case) was reached. Treatment with cabergoline suppressed plasma IGF-I below 300 micrograms/L in 39% of cases and between 300-450 micrograms/L in another 28%. With pretreatment plasma IGF-I concentrations less than 750 micrograms/L, a suppression of IGF-I below 300 micrograms/L was obtained in 53% of cases, and a suppression between 300-450 micrograms/L was obtained in another 32%. By contrast, with pretreatment plasma IGF-I concentrations above 750 micrograms/L, only 17% of cases showed a suppression of IGF-I below 300 micrograms/L, and there was IGF-I suppression between 300-450 micrograms/L in another 21%. In GH-/PRL-cosecreting adenomas, 50% of cases suppressed plasma IGF-I levels below 300 micrograms/L, and another 31% did so between 300-450 micrograms/L, in contrast to only 35% and 27%, respectively in GH-secreting adenomas. Similar results were obtained concerning the secretion of GH. Tumor shrinkage was demonstrated in 13 of 21 patients, with a mass reduction by more than half in 5 GH-/PRL-cosecreting adenomas. Except for slight gastrointestinal discomfort and orthostatic hypotension in a few patients at the beginning of therapy, cabergoline treatment was well tolerated. Only 2 patients stopped medication because of nausea. The weekly dose of cabergoline ranged between 1.0-1.75 mg. A further increase in the dose was only effective in 1 GH-/PRL-cosecreting adenoma. The results of this study suggest that cabergoline is an effective, well tolerated therapy that should be considered in the management of acromegaly, especially if the pituitary adenoma cosecretes GH and PRL or if pretreatment plasma IGF-I levels are below 750 micrograms/L.

Cushing's disease: a comparison of pituitary corticotroph microadenomas and macroadenomas

Cushing's disease appears as a functionally heterogeneous disease, but criteria that are able to distinguish between different clinical forms remain elusive. We compared two subgroups of patients with proven Cushing's disease according to the size of the pituitary adenoma, evaluated by computed tomography or magnetic resonance imaging. Our series comprised 11 patients with a microadenoma and 10 with a macroadenoma (median volumes (range): 173 (13-270) and 3022 (500-10312) mm3 respectively; P < 0.0001). The clinical presentation was similar in the two groups, but the time elapsed before diagnosis was longer, and visual impairment was less frequent in the patients with a microadenoma (1.5+/-0.8 years and 0%) than in those with a macroadenoma (0.7+/-0.6 years and 40%; P < 0.05). Morning and evening peripheral concentrations of ACTH were greater in patients with macroadenoma (134+/-78 and 130+/-7 ng/l respectively) than in those with microadenoma (52+/-28 and 56+/-19 ng/l, P < 0.05). Hypokalaemia and lymphopenia were also more pronounced in patients with macroadenoma (3.4+/-0.3 mmol/l and 1273+/-401 lymphocytes/mm3) than in those with microadenoma (3.8+/-0.3 mmol/l and 1852+/-668 lymphocytes/mm3 P < 0.05), although morning and evening plasma cortisol concentrations were similar in both groups. In patients with macroadenoma, there was less relative nycthemeral variation of ACTH concentrations (28+/-24%, compared with 62+/-39% in those with microadenoma; P < 0.05), less suppression of plasma cortisol by high doses of dexamethasone (-30+/-14%, compared with -61+/-25%; P < 0.05), and a reduced concentration ratio of mean basal cortisol to ACTH (7+/-3, compared with 12+/-5; P < 0.05). Plasma IGF-I concentration and the TSH peak response to TRH were significantly lower in patients with macroadenoma than in those with microadenoma (0.4+/-0.2 x 10(3) IU/I and 2.3+/-1.8 mIU/I, compared with 1.8+/-0.6 x 10(3) IU/I and 5.2+/-1.6 mUI/l; P < 0.05). Thus, in comparison with microadenomas, corticotroph macroadenomas are characterized by a greater and more autonomous ACTH secretion, inducing more pronounced biological signs of hypercorticism, and are more often accompanied by visual field defects and impairment of other pituitary hormonal secretions.

Expression of hepatocyte nuclear factor 6 in rat liver is sex-dependent and regulated by growth hormone

Growth hormone (GH) binding to its receptor modulates gene transcription by influencing the amount or activity of transcription factors. In the rat, GH exerts sexually dimorphic effects on liver gene transcription through its pattern of secretion which is intermittent in males and continuous in females. The expression of the CYP2C12 gene coding for the female-specific cytochrome P450 2C12 protein is dependent on the continuous exposure to GH. To identify the transcription factor(s) that mediate(s) this sex-dependent GH effect, we studied the interactions of the CYP2C12 promoter with liver nuclear proteins obtained from male and female rats and from hypophysectomized animals treated or not by continuous GH infusion. GH treatment induced the binding of a protein that we identified as hepatocyte nuclear factor (HNF) 6, the prototype of a novel class of homeodomain transcription factors. HNF-6 competed with HNF-3 for binding to the same site in the CYP2C12 promoter. This HNF-6/HNF-3 binding site conveyed both HNF-6- and HNF-3-stimulated transcription of a reporter gene construct in transient cotransfection experiments. Electrophoretic mobility shift assays showed more HNF-6 DNA-binding activity in female than in male liver nuclear extracts. Liver HNF-6 mRNA was barely detectable in the hypophysectomized rats and was restored to normal levels by GH treatment. This work provides an example of a homeodomain-containing transcription factor that is GH-regulated and also reports on the hormonal regulation of HNF-6.

Maternal protein restriction early in rat pregnancy alters brain development in the progeny

We assessed the effects of a dietary protein restriction (5% vs. 20% casein in diet) initiated at conception and imposed during the first 2 weeks of rat gestation on postnatal brain development. At the end of the malnutrition period, protein-restricted animals exhibited significantly smaller fetal body weight and brain cortical thickness than controls. At birth and thereafter, body weight was normalized in the progeny. Similarly, brain weight and cytoarchitecture were normal in postnatal animals. In contrast, we observed, during the first 2 postnatal weeks, several abnormalities of brain development which affected all the studied areas for most of the studied parameters: (i) delayed astrocytogenesis as shown by a reduced GFAP staining; (ii) delayed production of hyaluronan in the extracellular matrix studied with binding of biotinylated hyaluronectin; (iii) abnormal neuronal differentiation as shown by reduced expression of MAP-5 and increased expression of MAP-1; (iv) abnormal synaptogenesis as shown by the increased expression of synaptophysin in the basal ganglia; (v) decreased programmed cell death. In adult prenatally protein-restricted animals, all the above parameters were normalized excepted MAP-1 labeling which remained high. In addition, we observed slight alterations of the ventilatory response to hypoxia in adult animals. The present study demonstrates that early protein malnutrition during embryonic development induces multiple, transient alterations of brain development. However, the almost complete normalization in adults of brain architecture and differentiation as well as our physiological data strongly suggest a remarkable plasticity of the developing brain following an early aggression.

Postnatal catch-up growth induced by growth hormone and insulin-like growth factor-I in rats with intrauterine growth retardation caused by maternal protein malnutrition

In this study, we examined the effects of exogenous IGF-I and GH on postnatal growth of rat pups with intrauterine growth retardation due to gestational protein restriction. From birth until weaning (d 23), pups born from dams fed ad libitum a low (5% casein; P5 pups) or a normal protein diet (20% casein; P20 controls) were cross-fostered to well nourished lactating dams. On d 2, the litters (n = 6/dietary group) were reduced in size to 6 pups, and littermates received, through postnatal d 23, two daily s.c. injections of bovine GH (2.5 microg/g of body weight (BW)/day), human IGF-I (1.8 microg/g of BW/day), or saline. At birth, BW and tail length (TL) of P5 pups were markedly decreased (to 72 and 70% of controls, respectively; p < 0.001). Despite food rehabilitation, stunting of body growth was still apparent on d 23 in the saline-injected P5 rats (BW and TL: 76 and 83% of age-matched saline-injected controls; p < 0.01). Serum IGF-I (-51%; p < 0.001) and weight of liver, heart, kidney, brain, and thymus (-13 to -35%; p < 0.01) were also reduced. Administration of GH in P5 rats raised their serum IGF-I (1-fold) to levels observed in saline-injected controls, and restored normal BW and TL (94 and 98% of controls, respectively), and organ weight (91-107% of those of controls). Injections of IGF-I in P5 rats increased after 1 h their serum IGF-I to levels 3 times greater than in saline-injected controls, and resulted in normalization of BW and TL (94 and 96% of controls), and organ weight (92-111% of controls). In P20 controls, 3-wk GH and IGF-I injections significantly increased serum IGF-I (0.6- and 2-fold increases, respectively), BW (14 and 11%), TL (12 and 11%), and organ weight (+10 to 30%) compared with saline-injected rats (p < 0.01). We conclude that under conditions of adequate nutrition, both GH and IGF-I may equally promote postnatal catch-up growth in rats with intrauterine growth retardation caused by gestational protein malnutrition.