Endoscopic submucosal dissection of scar-embedded rectal polyps: a prospective study (Esd in scar-embedded rectal polyps)

BACKGROUND & AIMS

Endoscopic submucosal dissection (ESD) was developed for en bloc resection of superficial neoplasm of the digestive tract. We evaluated feasibility and safety of ESD, as a salvage therapy of large refractory rectal polyps, in a tertiary care setting.

METHODS

We prospectively enrolled in the present study and treated by ESD 11 consecutive patients with rectal polyps (median diameter 3.5 cm; range 2-5 cm), who had previously undergone several attempts of endoscopic resection and not suitable for further standard endoscopic treatment. The ESD was carried out with a standard needle knife. Follow up examinations were scheduled at 3, 6, 12 and 24 months.

RESULTS

We achieved apparently complete resection of polyps in 10/11 patients. In one patient ESD was interrupted and the pathology of the resected fragment showed deep submucosal infiltration; this patient underwent surgery. Deep and lateral margins were shown to be free of neoplasm (radical resection) in six out of 11 patients. However all the 10 patients with apparently complete resection were free of recurrence after a mean follow up of 19.2 months (12-24). A T1 adenocarcinoma was radically resected by ESD, with no recurrence. We recorded 2 cases of subcutaneous emphysema, both treated conservatively.

CONCLUSIONS

Radical resection is difficult to be achieved by ESD in patients with rectal scar-embedded polyps. Nevertheless ESD may be proposed as a definitive treatment of selected patients with refractory polyps, avoiding surgery in the majority of them.

A randomized clinical trial comparing 22G and 25G needles in endoscopic ultrasound-guided fine-needle aspiration of solid lesions

BACKGROUND AND STUDY AIMS

The study aimed to investigate whether the 25G needle is superior to the 22G needle when used in endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of solid lesions.

PATIENTS AND METHODS

The study was a single-center randomized clinical trial. The setting was a tertiary referral hospital, where EUS-FNA of solid lesions was assisted by an on-site cytopathologist, who was blinded to the needle size. The main end point was the number of passes performed to obtain adequate samples. Crossover to the other type of needle was allowed after five passes, or when the gastroenterologist experienced difficulties in puncturing the lesions.

RESULTS

A total of 129 solid lesions were randomized and data regarding 127 lesions were analyzed. The mean number of passes was 3.7 (± 1.9) in the 22G needle group and 3.8 (± 2) in the 25G needle groups (difference of means: 0.1; 95% CI: -0.59 to 0.79). Fifty-eight of 63 (92.1%) and 60/64 samples (93.7%) in the 22G and 25G needle groups respectively were adequate (difference: -1.6%; 95%CI: -12.1% to 8.9%). Crossover to the other type of needle was performed in 11/63 (17.5%) and in 12/64 (18.7%) lesions in the two groups respectively (difference: -1.2%; 95%CI: -16.2% to 13.8%). A crossover to the 25G needle was successfully performed in four masses in the uncinate process; these lesions were difficult to puncture using the 22G needle.

CONCLUSIONS

Our study failed to demonstrate that the 25G is more effective than the 22G needle in EUS-FNA of solid lesions. However, targeting of lesions in the distal duodenum may be simplified by using the 25G needle.

Frequency of constitutional MSH6 mutations in a consecutive series of families with clinical suspicion of HNPCC

A large majority of constitutional mutations in hereditary non-polyposis colorectal cancer (HNPCC) are because of the MHL 1 or MSH 2 genes. In a lower fraction of cases, another gene of the mismatch repair (MMR) machinery, MSH6, may be responsible. Families with MSH6 mutations are difficult to recognize, as microsatellite instability (MSI) may not be detectable and immunohistochemistry (IHC) may give ambiguous results. In the present study, we proposed (i) to determine the frequency of MSH6 mutations in a selected population of colorectal cancer patients obtained from a tumor registry, (ii) to assess whether IHC is a suitable tool for selecting and identifying MSH6 mutation carriers. One hundred neoplasms of the large bowel from suspected HNPCC families were analyzed for MSI (BAT 25 and BAT 26 markers) and immunohistochemical expression of the MSH6 protein. We found on 12 tumors (from different families) showing instability or lack of MSH6 expression. Among these, four potentially pathogenic MSH6 mutations were detected (del A at 2984; del TT at 3119; del AGG cod 385; and del CGT cod 1242) by direct gene sequencing. These represented 12.9% of all families with constitutional mutations of the DNA MMR genes. Thus, some 5% of all HNPCC families are featured by constitutional mutation of the MSH6 gene. This appears, however, as a minimum estimate; routine use of IHC and the study of large numbers of individuals and families with little or no evidence of Lynch syndrome might reveal that mutation of this gene account for a large fraction of HNPCC.

Impact of surgery on the development of duodenal cancer in patients with familial adenomatous polyposis

PURPOSE

Precancerous duodenal lesions in patients with familial adenomatous polyposis can be detected with duodenoscopy and treatment may prevent the development of cancer. We proposed to determine the frequency, natural history, cumulative risk, and risk factors of the precancerous duodenal lesions in a series of patients diagnosed in northern Italy.

METHODS

A prospective, endoscopic, follow-up protocol was performed in 50 patients examined by gastroduodenoscopy at two years of interval or less. The presence and severity of precancerous lesions of the duodenal mucosa were evaluated by Spigelman score. Twenty-five patients (50 percent) had proctocolectomy and ileoanal anastomosis, 15 (30 percent) had colectomy and ileorectal anastomosis, and 5 (10 percent) had proctocolectomy and definitive ileostomy from 0 to 3 years before the admission to the surveillance program. All patients showed more than a thousand adenomas in the colorectal mucosa. No patients with attenuated polyposis were found.

RESULTS

At the first endoscopy, duodenal adenomas could be detected in 19 of 50 patients (38 percent), whereas at the end of the follow-up, 43 (86 percent) had duodenal lesions. The final mean Spigelman score increased during the follow-up period (P<0.001 respect to baseline values). No duodenal cancer could be detected. Eleven patients had or developed severe precancerous duodenal lesions (Stage IV) treated with endoscopic or surgical resection. The distribution of patients with Stage IV according to the surgery of the colon was: 2 of 25 treated with ileoanal anastomosis and 8 of 15 with ileorectal anastomosis (P=0.0024, Fisher's exact test).

CONCLUSIONS

Patients with familial adenomatous polyposis are at risk of significant neoplasia. The natural history of precancerous lesions might be related to surgical treatment of colorectal neoplasms.

Comparison of three different risk scoring systems in non-variceal upper gastrointestinal bleeding

BACKGROUND AND AIMS

To prospectively validate in patients with non-variceal upper gastrointestinal bleeding three risk scoring systems (the Baylor College scoring system, the Rockall's risk scoring system and the Cedars-Sinai Medical Centre predictive index) previously proposed to be predictive of rebleeding/death after upper gastrointestinal bleeding.

PATIENTS AND METHODS

We calculated values of the scores for 343 patients, who underwent endoscopy after non-variceal upper gastrointestinal haemorrhage during the years 1997-1999. We compared the observed outcomes with the ones expected upon the original series contributed by the authors. Discriminative ability was evaluated by calculating the area under the receiver operating characteristic curve.

RESULTS AND CONCLUSIONS

Rockall's score accurately predicted rebleeding in low- and intermediate-risk categories (< 6), but not in high-risk patients. The rates of rebleeding were significantly higher than the ones predicted by the low-risk categories of either Cedars-Sinai index (< or = 2) or Baylor score (< or = 6). The predicted and the observed mortality was not significantly different throughout all the categories of Rockall's score, except for patients with a score of 4. All the scores had better discriminative ability for mortality than for rebleeding. The Rockall's score identifies a low-risk group of patients (Rockall's score < or = 2) for rebleeding and mortality.

Gastric carcinoma risk index, type III intestinal metaplasia and Helicobacter pylori status on antrum and body biopsies in a prospective general population study

BACKGROUND

To evaluate the utility of 2 biopsies of antrum and gastric body on routinary endoscopy for the assessment of type III intestinal metaplasia (IM-3) and Helicobacter pylori (Hp) status, 1750 patients (pts) (895 males and 855 females, mean age 60.2) were considered from June 1998 to June 2000.

METHODS

Specimens were graded 0 to 3 for atrophy, IM-3 and Hp status. 620 pts treated previously with antibiotics or not eligible for biopsy were excluded from initial 2360 pts.

RESULTS

IM-3 (score >0), was found in 118 pts (6.7%), 86 pts (4.9%) only in the antrum. Ten of 355 pts (2.8%) with normal endoscopy findings and 47 of 702 (6.6%) with non erosive endoscopic gastritis resulted IM-3 positive in the antrum. 709 pts (40.5%) were found positive for Hp in antrum or/and corpus. The presence of Hp and IM-3 in the antrum was not correlated (p=0.99; spearman test). A positive correlation (p=0.000) between duodenal ulcer and Hp was found when antral Hp positivity was taken into account. Gastric carcinoma risk index (GCRI) was found in 358 pts (20.4%); in this group 131 pts (36.6%) were Hp positive, 82 pts (23%) have IM-3, 184 pts (51.4%) have atrophy.

CONCLUSIONS

The incidence of IM-3 is low (6.7%) in routinary endoscopy. Normal endoscopy does not exclude the presence of IM-3. The biopsy is necessary to discover IM-3 in the antrum in 5.3% of pts with normal or aspecific endoscopic gastritis. Application of the GCRI might be useful to identify a group of patients carrying a higher risk for gastric carcinoma.

What is the utility of selected clinical and endoscopic parameters in predicting the risk of death after caustic ingestion?

BACKGROUND AND STUDY AIMS

Despite the increasing use of early esophagogastroduodenoscopy, the prognostic evaluation and triage of patients who have ingested caustic material is challenging. We evaluated the usefulness of selected clinical and endoscopic parameters in predicting the risk of death after ingestion of caustic substances.

PATIENTS AND METHODS

Clinical and endoscopic parameters were obtained from the records of all the patients admitted to our endoscopy unit because of ingestion of caustic material between 1 March 1982 and 30 June 1999. Parameters significantly associated with the risk of death by univariate analysis were entered into a multivariate logistic model. The independent predictors of death by multivariate analysis were used to build a risk score system.

RESULTS

Out of 210 patients, 13 underwent emergency surgery (6.2 %) and 25 died (11.9 %). Multivariate analysis identified the following as independent predictors of death: age (10-year intervals; odds ratio [OR] 2.4; 95 % confidence interval 1.4 - 4.1), ingestion of strong acids (OR 7.9; 1.8 - 35.3), white blood cell count at admission > or = 20 000 units/mm3 (OR 6.0; 1.3-28), deep gastric ulcers (OR 9.7; 1.4 - 66.8), and gastric necrosis (OR 20.9; 4.7 - 91.8). The values of the risk score system devised from the results of the multivariate analysis ranged from 1 to 16. No patient scoring < 10 points died and just one of the patients scoring > 14 points survived.

CONCLUSION

Age, ingestion of a strong acid, leucocytosis, deep gastric ulcers, and gastric necrosis are predictive of death after caustic ingestion. A risk score system including these predictors may be useful in prognostic evaluation.

Variant liver estrogen receptor transcripts already occur at an early stage of chronic liver disease

Variant estrogen receptors may be found in hepatocellular carcinoma and may influence its natural history. Because it is not known whether their occurrence is an early or a late event during the course of chronic liver disease or whether they cluster in some subgroups of patients, we investigated a series of patients in different stages of chronic liver disease. One hundred eleven consecutive patients were studied for variant estrogen receptor transcripts by reverse-transcription polymerase chain reaction of RNA extracted from liver biopsy specimens. In chronic active hepatitis, variant estrogen receptor transcripts were coexpressed with wild-type significantly more often in men than in women (P = .029) and in hepatitis B surface antigen (HBsAg)-positive subjects than in subjects positive for antibody to hepatitis C virus (P = .0006). In hepatocellular carcinoma, again in men (P = .004) and in HBsAg-positive patients (P = .0015), the variant estrogen receptor transcript was overexpressed or remained the only one expressed. Patients with liver cell dysplasia presented with the same estrogen receptor pattern than patients with hepatocellular carcinoma. This further reinforces the significance of liver cell dysplasia as a preneoplastic condition. The significantly higher occurrence of variant estrogen receptor in men (especially in HBsAg-positive men) already at an early stage of disease, like chronic active hepatitis, suggests that the alteration of estrogen receptors, favoring uncontrolled proliferation and development of hyperplasia, might constitute a prominent mechanism facilitating neoplastic transformation especially in men.

Hepatic tocopherol content in primary hepatocellular carcinoma and liver metastases

The high incidence of hepatocellular carcinoma (HCC) in cirrhosis, where previous studies have indicated a severe reduction in several antioxidant vitamin factors, prompted us to compare plasma liposoluble vitamins with tocopherol content in healthy and neoplastic liver tissue in humans. This, with a view to a more positive preventive dietary approach, given the conflicting results obtained by liposoluble vitamin dietary supplementation in different malignancies. Eleven patients with cirrhosis, 18 patients affected by cirrhosis with HCC, and 10 patients with liver metastases (LM) from digestive tract adenocarcinomas were compared with controls who had undergone perlaparoscopic cholecistectomy. Plasma alpha- and beta-carotene, retinol and tocopherol, together with liver tocopherol, from both nonmalignant portions and malignant nodules of the same organ, were determined by high-performance liquid chromatography following a well-assessed technique. The results confirm a trend towards a reduction in circulating carotenoids and tocopherol in cirrhosis and in patients affected by cirrhosis with HCC. Tocopherol content in liver tissue is significantly decreased in cirrhosis (0.26 + 0.03 micromol/g prot., mean + SEM, P < .001) and in cirrhotic areas of the HCC group (0.31 + 0.02, P < .002), with respect to its content in liver specimens of healthy controls (0.46 + 0.03) and in healthy areas of the same organ in patients with LM (0.41 + 0.03). Tocopherol concentration is further reduced by 50% in malignant liver nodules of HCC, with respect to surrounding cirrhotic tissue, whereas in metastatic liver nodules from digestive neoplasms the tocopherol content is almost twice that of healthy surrounding areas. This unpredictable tocopherol behavior in liver specimens, of secondary as opposed to primary malignancies of the liver, affords further insight into the conflicting effects of liposoluble vitamins employed in the chemopreventive treatment of different malignant diseases, where hepatic tocopherol concentration show opposite trends: halved in primary HCC and doubled in LM of digestive adenocarcinomas, with respect to healthy controls.

Type of estrogen receptor determines response to antiestrogen therapy

Failure of tamoxifen treatment for unresectable hepatocellular carcinomas (HCCs) might be caused by variant estrogen receptors (ERs) in some of these tumors. We therefore planned a study in which antihormonal therapy was done with 80 mg/day tamoxifen or 160 mg/day megestrol according to the presence of wild-type or exon 5-deleted variant ER transcripts. Growth rate (evaluated by MRI) of HCCs characterized by variant ER transcripts was 4 times more rapid than that of HCCs with wild-type ERs. Tumor volume in all patients with wild-type ERs was halved after 9 months of tamoxifen treatment, whereas megestrol in patients with variant ERs only slowed down tumor growth. Choosing antihormonal treatment according to the presence of wild-type or variant ERs in the tumor definitely improves the response rate to tamoxifen; in patients with tumors bearing variant ERs, megestrol causes only a temporary inhibition of tumor growth.

Alpha but not beta interferon is useful in chronic active hepatitis due to hepatitis C virus. A prospective, double-blind, randomized study

Interferon-alpha has been widely used in chronic hepatitis C, but controlled studies with intramuscular interferon-beta are lacking. We therefore performed a prospective, double-blind, randomized study comparing intramuscular IFN-alpha and -beta in patients with chronic hepatitis C. Sixty patients were randomly assigned to receive 3 MU thrice weekly intramuscularly of either recombinant IFN-alpha or leukocyte IFN-alpha or fibroblast IFN-beta for six months. Nine of 20 patients (45.0%) in the recombinant IFN, 5/19 (26.3%) in the leukocyte IFN, and none in the IFN-beta group had a complete response during therapy (recombinant IFN vs IFN-beta: P < 0.01). Only in IFN-alpha-treated patients, was infection with a single HCV genotype (type 2a or 2b) associated with significantly better long-term outcome. IFN-alpha is useful in chronic hepatitis C while intramuscular IFN-beta interferon does not exert any beneficial effect. This is probably due to an insufficient bioavailability of IFN-beta when given intramuscularly.

Long-term follow-up of hepatitis C virus (HCV) infection in liver transplant patients

Chronic hepatitis represents a frequent event after orthotopic liver transplantation (OLT). To ascertain the influence of HCV infection on the clinical and histological outcome of these patients, we have investigated the long-term outcome of 22 patients with end-stage chronic liver disease undergoing liver transplant focusing the attention on the role of different HCV genotypes in determining recurrence and severity of post-OLT liver disease. For all patients blood samples taken before OLT and 3 months, 1, 2 and 3 years after OLT were tested for antiHCV antibodies by two different enzyme-linked immuno-assays and by recombinant immuno-blot II and for the presence and type of HCV RNA by nested PCR (5' untranslated region and core gene primers). Of the 16 pre-OLT antiHCV-positive patients, 14 (87.5%) had recurrence of HCV infection while 2 cleared HCV. Pre-OLT genotype recurred in 11 of these 14 patients (2 genotype I) 8 genotype II - in 1 case associated with genotype III - and 1 genotype IV). Of the 6 pre-OLT antiHCV-negative patients, only 1 (16.6%) became persistently HCV-infected, with genotypes I and II. The recurrence of genotype II strictly related with development of severe chronic hepatitis while genotype I and IV were associated with milder forms of liver disease and were more easily cleared.

Variant estrogen receptor messenger RNA species detected in human primary hepatocellular carcinoma

The development of hepatocellular carcinoma (HCC) in addition to cirrhosis affects males in a significantly higher proportion than females. Liver estrogen receptors increase when HCC develops in males; however, these tumors usually respond poorly to antiestrogens. We have, therefore, hypothesized that, similar to breast cancer, estrogen receptors in males with HCC may be mutated. Variant estrogen receptor transcripts (lacking exon 5 of the hormone binding domain) were investigated by reverse transcription-PCR in 14 patients (7 males and 7 females) with HCC. While females mostly displayed the wild-type transcript (both in peritumoral and in tumor liver tissue), males showed both transcripts in the cirrhotic tissue and almost only the variant in the tumor. As the variant ER transcripts when translated could give rise to truncated receptors still able to constitutively activate transcription, they may be key factors in favoring deregulated proliferation in the male liver.

Oligomeric structures of cytosoluble estrogen-receptor complexes as studied by anti-estrogen receptor antibodies and chemical crosslinking of intact cells

The structure of estrogen-receptor complexes recovered in cytosolic extracts of MCF-7 cells treated with hormone at 2 degrees was probed by chemical crosslinking of intact cells and sample analysis with four monoclonal anti-estrogen receptor antibodies. When MCF-7 cells were treated with either glutaraldehyde or dithiobis(succinimidyl propionate), cytosoluble estrogen-receptor complexes consisted of two major forms sedimenting as 4 S monomers and 8-9 S salt-resistant oligomers. By high salt sucrose density gradient centrifugation, we could observe that the four monoclonal anti-estrogen receptor antibodies bound different forms of receptor complexes from crosslinked cells. While H222 and H226 antibodies could interact with any form we detected, the D75 and D547 monoclonals could only recognize those showing sedimentation coefficients lower than 7 S. When cytosolic extracts from [35S]-methionine-labeled cells were subjected to immunoprecipitation with H222 and D75 anti-estrogen receptor antibodies, electrophoretic analysis of material extracted from immunoprecipitates revealed the presence of 65 kDa estrogen receptors. If extracts were prepared from crosslinked cells, instead, two more components with estimated molecular masses of 220 and 100 kDa were specifically immunoprecipitated by the H222 antibody, whereas only the 100 kDa component and the estrogen receptor were found in immunoprecipitates obtained with the D75 monoclonal. When estrogen-receptor complexes were immunopurified from extracts prepared after cells had been crosslinked with dithiobis(succinimidyl propionate), and the oligomers were dissociated by treatment with beta-mercaptoethanol, electrophoretic analysis of our samples showed that only the 65 kDa estrogen receptor and a 50 kDa protein were selectively immunoprecipitated by anti-estrogen receptor antibodies. We concluded that the structures of cytosoluble estrogen-receptor complexes in MCF-7 cells treated with hormone at 2 degrees C, include oligomeric forms which contain a 50 kDa non-steroid binding protein.

Serotonergic control of TSH and PRL secretion in obese men

To evaluate whether the inhibitory control of TSH and the stimulatory control of prolactin (PRL) secretion exerted by endogenous serotonin was altered in obesity, 22 obese men and 10 normal controls were tested with TRH (200 micrograms IV bolus) in the presence (experimental test) and absence (control test) of the serotonergic agonist fenfluramine (60 mg PO 90 min before TRH). Control and experimental tests were also performed in seven male patients with subclinical hypothyroidism and were repeated in the same obese subjects after substantial weight loss. Basal TSH levels were similar in control and obese men. Normal TSH responses to TRH (peak less than or equal to 14 mU/L) were observed in all normal controls (mean peak +/- SE 9.8 +/- 0.6 mU/L). In contrast, obese men were divided into two groups: nine in whom the TRH-induced TSH rise was higher than normal (group I: mean peak = 16.5 +/- 0.5 mU/L) and 13 in whom it was normal (group II: mean peak = 10.6 +/- 0.7 mU/L). The hypothyroid men all had elevated basal and TRH-stimulated TSH levels. Basal PRL concentrations were similar in the normal controls and both groups of obese subjects. The PRL response to TRH was lower in both group I and group II obese men than in normal controls and was similar between group I and group II.(ABSTRACT TRUNCATED AT 250 WORDS)

The infusion of somatostatin reduces the arginine-vasopressin response to insulin-induced hypoglycemia in man

The effect of an iv infusion of somatostatin (SRIH) (4.1 micrograms/min x 90 min) on the basal secretion of arginine-vasopressin (AVP) and on the AVP response to insulin (0.15 IU/Kg) - induced hypoglycemia was studied in 6 normal men. Basal AVP secretion was not modified by SRIH administration. The blood glucose decrements induced by insulin were similar in the control insulin-tolerance test (ITT) and in the ITT + SRIH test, whereas the AVP response to hypoglycemia was significantly lower in the presence of SRIH. The mean peak AVP increase was three times higher than the basal value in the control ITT, but only two times during SRIH administration. Infusion of higher doses of SRIH (7 micrograms/min x 90 min) produced similar results. These data suggest the involvement of a somatostatinergic mechanism in regulation of AVP response to hypoglycemia.

Dopaminergic, but not cholinergic, involvement in regulation of hypoglycemia-induced oxytocin release in man

The plasma oxytocin response to insulin-induced hypoglycemia was evaluated in 20 normal male subjects in the basal state (insulin tolerance test (ITT) alone) and after pretreatment with the muscarinic antagonist pirenzepine (40 mg IV 10 min before the ITT in six subjects), the nicotinic antagonist trimethaphan (0.3 mg/min IV for 30 min before the ITT in six subjects), and the dopaminergic receptor agonist bromocriptine (2.5 mg PO 1 hr before the ITT in eight subjects). The drugs did not modify arterial blood pressure nor produce side effects capable of altering oxytocin secretion. Neither pirenzepine nor trimethaphan administration changed the oxytocin response to hypoglycemia, whereas bromocriptine significantly reduced the oxytocin increase during the ITT. These data suggest the involvement of dopaminergic, but not of cholinergic, muscarinic or nicotinic, receptors in the oxytocin response to hypoglycemia.

Effect of lysine vasopressin on basal and TRH stimulated TSH and PRL release in normal men

In order to test the possible effects of lysine vasopressin (LVP) on basal and TRH stimulated TSH and PRL release, an iv bolus of LVP (0.06 IU/kg bw) was injected alone or just before TRH (20 or 400 micrograms iv) in 18 normal male subjects. The administration of LVP modified neither the basal secretion of TSH and PRL nor the TSH and PRL release induced by 20 or 400 micrograms TRH. These data suggest that in humans, vasopressin is not involved in the control of TSH and PRL release at the anterior pituitary level.

Serotonin regulation of aldosterone secretion

The circulating levels of aldosterone (A), cortisol (F), prolactin, ACTH and potassium and the PRA were studied in 8 (6 males and 2 females) healthy normotensive subjects after 5-hydroxy-tryptophan (5OHT), or pizotifen (Piz) or placebo oral administration. In the same subjects 5OHT was administered twice: after placebo and after dexamethasone pretreatment. The results showed a significant increase of A, ACTH and F after 5OHT plus placebo administration without any change of PRA, potassium or prolactin levels; dexamethasone pretreatment suppressed ACTH and F but was uneffective on the response of A to 5OHT. Only A levels showed a significant decrease after Piz administration, the other studied parameters were unaffected by the blockade of the 5HT2 receptors by Piz. The administration of placebo induced a slight but not significant decrease of the studied parameters. Our results suggest the existence of a physiologic serotonergic control of A secretion, a pituitary factor could be one of the putative links between the central serotonergic activation and the adrenal secretory response.

Lysine-vasopressin does not affect basal and LH-RH-stimulated LH and FSH release during the menstrual cycle of normal women

In order to test possible effects of lysine-vasopressin (LVP) on basal and LH-RH-stimulated LH and FSH release, an intravenous bolus of LVP (0.06 IU/kg body weight) was injected alone or 10 min before LH-RH (100 micrograms i.v.) in 33 normal women in the follicular, periovulatory and luteal phase of their menstrual cycle. The administration of LVP modified neither the basal secretion of the gonadotropins nor the LH-RH-induced LH and FSH release. These data suggest that in humans, vasopressin is not involved in the control of gonadotropin release at the level of the anterior pituitary.

Muscarinic cholinergic and histaminergic H1 and H2 receptors are not involved in the LH response to naloxone in man

The role of muscarinic-cholinergic and H1-, H2-histaminergic receptors as possible mediators of the LH response to the opioid antagonist naloxone was evaluated in 18 normal men. Subjects were divided in 3 groups of 6 men; the increment of LH in the plasma elicited by naloxone was evaluated after giving naloxone alone or together with dexchlorpheniramine, cimetidine or pirenzepine (respectively H1-, H2-histaminergic and muscarinic-cholinergic receptor antagonists). LH release was significantly stimulated by naloxone in all subjects; this response was not altered by histaminergic or cholinergic blockade. These results confirm the stimulatory effect of naloxone on LH release in man, without evidence of the involvement of H1-, H2-histaminergic or muscarinic-cholinergic pathways.

Effect of flunarizine on pituitary secretion by healthy men and in woman with migraine

Flunarizine is widely used in the prophylaxis of migraine. It is both a calcium blocker and a histamine antagonist at H1-receptors and either of these effects could alter hormonal secretion. The effect of administration of flunarizine to 8 women with common migraine on pituitary secretion has been studied. The dopamine antagonist domperidone (10 mg) and gonadotropin releasing hormone (100 micrograms) were injected iv before and after one month of flunarizine therapy (10 mg orally at bedtime). The basal prolactin level was significantly increased by the drug, and the peak induced by domperidone stimulation was reduced. Basal TSH concentrations were not affected, but the increase after domperidone was blunted. After 90 days of therapy there were no significant differences from the baseline concentration. Neither basal nor gonadotropin releasing hormone-stimulated secretion of FSH and LH were affected by flunarizine. Twelve healthy men were given placebo and flunarizine (10 mg at bedtime) for 5 days in single-blind fashion. Flunarizine caused a significant increase in prolactin and TSH with no effect on basal gonadotropin and thyroid hormone levels. These results can be accounted for by the calcium blocking effect of the drug, although weak interference with dopaminergic transmission is a further possibility explanation.

Different effects of metoclopramide and domperidone on arginine-vasopressin secretion in man

This study was performed in order to investigate the dopaminergic mechanism involved in the control of arginine-vasopressin (AVP) secretion in normal men. Plasma AVP concentrations were measured before and after the administration of an i.v. bolus of 10 mg metoclopramide or domperidone to twelve healthy males. Metoclopramide, a cerebral and peripheral antagonist of dopaminergic receptors, significantly stimulated AVP secretion, whereas domperidone, a dopamine antagonist which does not cross the blood-brain barrier, was without effect. These data suggest that metoclopramide stimulates the release of AVP by blocking dopaminergic receptors in structures located inside the blood-brain barrier. Alternatively, it is possible that the stimulation of AVP release induced by metoclopramide does not occur through inhibition of dopamine receptors but rather through interaction with other neuroendocrine pathways.

Evidence for an association of high blood pressure and hyperinsulinemia in obese man

An association between hyperinsulinemia and hypertension has been suggested by epidemiological surveys. To assess whether this association is independent of the presence of other hyperinsulinemic states, such as obesity and glucose intolerance, we measured the insulin response to oral glucose in a group of middle-aged moderately obese [144 +/- 4% overweight (mean +/- SEM)] patients (n = 18) with essential hypertension (174 +/- 5/104 +/- 2 mm Hg) and normal glucose tolerance. Normotensive subjects (n = 17) with normal glucose tolerance, matched for age and degree of overweight, served as the control group. The mean insulin response to glucose was twice as high in the hypertensive patients (25.8 +/- 0.2 mU/ml X 2 h) as in the normotensive subjects (11.3 +/- 0.2; P less than 0.001), yet the glucose incremental area was 3-fold higher in the former (10.9 +/- 1.0 g/dl X 2 h) than in the latter (3.5 +/- 0.7; P less than 0.001), thus indicating more severe insulin resistance. In the hypertensive group, systolic blood pressure levels were directly correlated with the 2-h plasma insulin values (r = 0.75; P less than 0.001). Furthermore, the 2-h plasma insulin value and the degree of overweight accounted for 65% of the variation in the systolic blood pressure in a multiple regression model (r = 0.81; P less than 0.001). We conclude that in obesity, the occurrence of hypertension marks the presence of additional hyperinsulinemia and insulin resistance, independent of any impairment of glucose tolerance.

Muscarinic cholinergic modulation of insulin response to an intravenous glucose tolerance test in normal man

The effect of pirenzepine, a specific muscarinic cholinergic receptor antagonist, on insulin and glucagon responses to an intravenous injection of glucose was investigated in eight normal adult subjects. These volunteers received two iv glucose tolerance tests (0.33 g/kg) before and after the oral administration of 125 mg of pirenzepine (three doses of 25 mg during the day before the experiment and a fourth dose of 50 mg 2 h before glucose injection). Treatment with pirenzepine neither altered basal blood glucose levels nor affected glucose tolerance after the injection of the glucose load. In addition, it did not modify basal plasma insulin and glucagon levels and the decrement of glucagon in response to glucose injection. In contrast, pirenzepine significantly decreased insulin release induced by glucose administration. In man, during the present experimental conditions, the muscarinic cholinergic system modulates insulin, but not glucagon response to an iv glucose injection.

Thyrotropin-releasing hormone does not inhibit lysine vasopressin-induced growth hormone secretion in normal men

In order to establish whether thyrotropin-releasing hormone (TRH) inhibits lysine-vasopressin (LVP)-induced growth hormone (GH) release, six normal men were tested with LVP alone or in combination with TRH. LVP strikingly increased serum GH levels; this response was not altered by TRH. These results indicate that in man TRH is not involved in the control of GH secretion in response to LVP.

Effect of naloxone on oxytocin-induced cortisol decrease in normal men

iv administration of oxytocin decreases plasma ACTH-cortisol levels in normal men. In contrast, naloxone, a specific opioid antagonist, stimulates cortisol release, suggesting that opioid peptides exert an inhibitory control on ACTH-cortisol secretion. The present study was carried out in an attempt to determine whether an opioid pathway mediates oxytocin action; therefore, we evaluated the effect of naloxone on the decrease of cortisol induced by oxytocin. Six normal men were treated iv with oxytocin (2 IU as a bolus), naloxone (4 mg as a bolus plus 10 mg infused for 2 h) or a combination of the 2 drugs. Plasma cortisol levels were determined in samples taken before and 2 h after drug treatment. As expected, administration of oxytocin significantly decreased cortisol secretion, while naloxone had a stimulatory effect on plasma cortisol levels. When oxytocin injection was followed by administration of naloxone, cortisol levels remained unchanged; thus, naloxone abolished a cortisol decrement in response to oxytocin. These findings show that in man oxytocin requires an active opioid system in order to produce its inhibitory action on ACTH-cortisol secretion, suggesting that this effect of oxytocin could be mediated by an opioid pathway.

Nicotine from cigarette smoking enhances clonidine-induced increase of serum growth hormone concentrations in men

In order to determine whether nicotine exerts its stimulant effect on serum concentrations of growth hormone (GH) by interacting with an adrenergic pathway, we evaluated the effect of cigarette smoking on the response of GH to the administration of clonidine, a specific alpha-adrenoceptor agonist. In six normal volunteers, clonidine significantly increased serum levels of GH. When subjects smoked two non-filter cigarettes, GH response to the alpha-adrenoceptor agonist was greatly enhanced. These findings suggest that in man nicotinic cholinergic and adrenergic mechanisms might interact in the stimulation of GH secretion.

Evaluation of oxytocin administration on luteinizing hormone and follicle-stimulating hormone response to luteinizing hormone-releasing hormone during the menstrual cycle of normal women

In order to determine whether oxytocin modifies luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion in response to LH-releasing hormone (LH-RH), a group of normal women, 23 to 30 years of age, was studied in the follicular, periovulatory, and luteal phases. LH and FSH response to LH-RH was evaluated in the serum under control conditions and after oxytocin infusion. Oxytocin administration failed to modify LH and FSH release induced by LH-RH. These results suggest that this neuropeptide is not involved in the control of LH and FSH at the level of the anterior pituitary.

Effect of pharmacological doses of oxytocin on insulin response to glucose in normal man

In this study we have examined the effect of the administration of oxytocin on basal blood concentrations of insulin, glucagon, cortisol, growth hormone, and on the dynamic secretory response of these hormones to intravenous glucose administration (0.33 g/kg) in basal condition and after the injection of 3 IU (1 plus 2 IU/1 h) or 6 IU (2 plus 4 IU/1 h) of oxytocin (6 subjects for each group). The highest dose of oxytocin (6 IU) used significantly increased insulin secretion in response to intravenously administered glucose. No significant change of insulin secretion was observed with 3 IU of oxytocin. Glucagon, cortisol, and growth hormone response to intravenous injection of glucose was not affected by oxytocin (3 or 6 IU) administration. These results suggest that high doses of oxytocin affect beta-cell function in normal man.

Radioimmunoassayable myoglobinaemia and Duchenne carrier detection

1 case of Duchenne Muscular Dystrophy (DMD) definite carrier, 3 probable and 17 possible (all analytically positive: "possible +") carriers were classed as Group A, 23 DMD possible carriers (all analytically negative "possible") as Group B and 26 normal subjects as Controls. The three groups were subjected to serum myoglobin (MGB) radioimmunoassay. Since the differences between MGB levels of Group A vs. Controls and Group A vs. Group B were statistically significant, it is suggested that the determination of MGB should be included among the tests for DMD carrier detection.