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R Comtois

Publications and source records attributed to R Comtois.

At least 37 records · Page 2Linked to original sources
PubMed1991

The clinical and endocrine outcome to trans-sphenoidal microsurgery of nonsecreting pituitary adenomas.

From 1962 to 1987, 126 patients underwent trans-sphenoidal surgery for primary treatment of pituitary adenomas unassociated with clinical or biochemical evidence of hormonal overproduction. There were 73 male and 53 female patients (mean age, 50 +/- 12 years). Before surgery, 56% of the patients (70 of 124) had headaches, 74% (94 of 126) had deterioration of vision, and 12% (15 of 126) had ophthalmoplegia. Endocrine evaluation revealed the presence of hypogonadism in 75% (87 of 115), adrenal insufficiency in 36% (46 of 126), and hypothyroidism in 18% (21 of 122). Plasma prolactin was increased in 65% (56 of 86) with a mean level of 39 +/- 14 micrograms/l (normal, 3 to 20 micrograms/l). Radiologic enlargement of the sella turcica was documented in all cases: 67% (84 of 126) had enclosed and 33% (42 of 126) had invasive adenomas. After surgery, vision was normalized or improved in 75% (71 of 94) of the patients. Thyroid, adrenal, and gonadal functions were improved in 14% (three of 22), 41% (19 of 46), 11% (ten of 87), were unchanged in 82% (100 of 122), 77% (97 of 126), 89% (102 of 115), and worsened in 15% (19 of 22), 8% (ten of 126), 3% (102 of 115), respectively. Permanent diabetes insipidus occurred in 5% (seven of 126). Two patients died during the immediate postoperative period. The recurrence rate in patients with a mean follow-up of 6.4 +/- 4.2 years was 21% (15 of 71). These data indicate that trans-sphenoidal microsurgery is an effective and safe initial treatment for patients with nonsecreting pituitary adenoma and may reverse hypopituitarism.

Adenoma↗
PubMed1991

Reversible hypertriiodothyroninaemia due to adrenal insufficiency.

It is well known that an excess of glucocorticoids affects thyroid tests. The effect of adrenal deficiency on thyroid hormones is less well defined. We here describe the case of a 33-year-old woman with Cushing's disease who was cured by trans-sphenoidal surgery. During the postoperative period, a secondary adrenal insufficiency developed. The thyroid blood tests then revealed elevated L-triiodothyronine (T3) levels and a decrease in reverse T3. These findings suggest that secondary adrenal deficiency may be associated with high T3 levels, which may be due to an increase in the peripheral conversion of thyroxine (T4) to T3.

Adrenal Insufficiency↗
PubMed1990

Surgical management of giant pituitary adenomas.

During the past 25 years, 77 giant pituitary adenomas have been treated surgically, including suprasellar extensions of type C in 66 cases and of type D in 11 cases. Non-secreting adenomas were present in 53 and secreting adenomas in 24 cases. All patients except 3 presented with significant visual field defects; including bitemporal hemianopia, superior quadranopia or unilateral temporal hemianopia, contralateral blindness in 73% of the cases, and one case with sudden bilateral blindness due to acute pituitary apoplexy. A single transsphenoidal procedure was carried out in 74% of the patients while 11 patients (7%) required re-operations for recurrent or residual tumor. Only 3 patients required a subsequent transcranial procedure. Complications included 1 CSF-leak, 1 empty-sella syndrome and 4 fatal post-operative hematomas. We prefer the transsphenoidal route even in very large or giant pituitary adenomas, since it allows rapid and adequate decompression of the optic nerves and chiasm, avoids major pituitary insufficiency in 60% of the cases and is associated with low morbidity-mortality rates.

Adenoma↗
PubMed1990

Long term treatment with CV 205-502 in patients with prolactin-secreting pituitary macroadenomas.

CV 205-502, a new long-acting nonergot dopamine agonist, was given to 15 patients (6 women and 9 men) with PRL-secreting pituitary macroadenomas. The compound was administered in a single daily dose for a period of 6-12 months. The treatment resulted in normalization of plasma PRL levels (less than or equal to 20 micrograms/L) in 5 of 6 women at a mean dose of 135 micrograms (range, 75-300 micrograms) and in 6 of 9 men at a mean dose of 192 micrograms (range, 75-300 micrograms). Among patients for whom computed tomographic scans were available before and after at least 6 months of therapy, definite tumor shrinkage occurred in 6 of 7 patients. Libido was improved in 5 of 6 women and in 6 of 8 men, galactorrhea disappeared in all cases (3 women and 1 man) and menses resumed in 3 of 5 women. Plasma testosterone rose to normal levels in 3 of 6 men who were not receiving testosterone injections. The PRL response to TRH was blunted in 4 of 6 patients with normalized basal PRL. Serum total cholesterol was reduced by CV 205-502 treatment in women from 5.35 +/- 0.49 to 4.63 +/- 0.51 mmol/L (P = 0.031) and in men from 5.93 +/- 0.89 to 5.28 +/- 0.82 mmol/L (P = 0.045). Side-effects included mainly headache, nausea, and dizziness. One side-effect or more occurred transiently and with mild intensity in 14 patients. No patient discontinued the therapy because of side-effects. In conclusion, CV 205-502 appears to be a safe and valuable compound in the treatment of patients with PRL-secreting macroadenomas.

Adult↗
PubMed1989

Clinical usefulness of estimation of serum fructosamine concentration as screening test for gestational diabetes.

Serum fructosamine levels and fructosamine/protein ratios were measured in 100 pregnant women who underwent glucose tolerance tests because of clinical risk. Compared with normal pregnant women, the 13 study participants with gestational diabetes had higher fructosamine/protein levels (39 +/- 3.9 mumol/gm versus 37 +/- 3.2 mumol/gm, p less than 0.05), fasting serum glucose levels (107 +/- 13.7 mg/dl versus 82 +/- 8.6 mg/dl, p less than 0.001), and area under curve of glucose tolerance test (36 +/- 5 gm x min x dl-1 versus 22 +/- 3.6 gm x min x dl-1, p less than 0.001). The serum fructosamine levels were not significantly different between the two groups of participants (2.3 +/- 0.26 mmol/L versus 2.2 +/- 0.17 mmol/L); 10 of the 13 women with diabetes had a fructosamine/protein ratio within 2 SD of the mean of the groups of normal pregnant women. Spontaneous caloric intakes (r = 0.72, p less than 0.005) and the hospital mean daily capillary glucose levels during diabetic diet (r = 0.72, p less than 0.005) correlated better with the fructosamine/protein ratio than with fasting serum glucose levels (r = 0.58, p less than 0.05) and area under curve (r = 0.57, p less than 0.05). Consequently, serum fructosamine and fructosamine/protein ratio levels should be considered insensitive as a screening test in pregnant patients with clinical risk of gestational diabetes.

Adult↗
PubMed1989

Technical and clinical evaluation of fructosamine determination in serum.

We evaluated a serum fructosamine (glycated serum proteins) assay for efficacy in the diagnosis and follow-up of diabetic patients. A Roche reagent kit, based on nitroblue tetrazolium reduction in alkaline medium, was used in COBAS FARA centrifugal analyzer. We demonstrated that this method is precise, linear and unaffected by serum hemolysis. However, bilirubin affected the test positively and lipemia negatively. Fructosamine (F) correlated positively with total protein (P) (r = 0.809) and albumin (r = 0.746) in a group of 48 non-diabetic individuals. A good correlation was observed between F and glycated hemoglobin from the sera of 514 patients (r = 0.794). A better correlation (r = 0.838) was obtained when F was corrected for P concentration (F/P). Different F and F/P means were calculated only in patients with overt diabetes, compared to normals. Gestational diabetes was associated with a highly significant F increase. However, its low sensitivity (21%) precludes the use of F as an effective screening test for that condition. Nevertheless, because of its simplicity, low cost and rapidity in reflecting changes in the metabolic control of diabetes, F should be considered a valuable test to assess glycemic control in diabetic patients.

Adult↗
PubMed1989

Hypersecretion of gonadotropins by a pituitary adenoma: pituitary dynamic studies and treatment with bromocriptine in one patient.

Pituitary adenomas secreting gonadotropins are often diagnosed as nonsecreting tumors on the basis of clinical findings. We now describe a middle-aged woman who developed visual disturbances and was found to have a large infiltrating pituitary adenoma secreting large quantities of follicle-stimulating hormone (FSH) with moderate elevation of luteinizing hormone (LH). The patient twice underwent transsphenoidal microsurgery to partially remove the adenoma. Thereafter, a trial with bromocriptine was initiated. Normal levels of FSH and LH were observed after 6 weeks of treatment as well as improvement of visual field examination. This case illustrates the fact that some gonadotropin-secreting adenomas can be extremely sensitive to dopamine agonist adenomas can be extremely sensitive to dopamine agonist therapy.

Adenoma↗
PubMed1989

Growth hormone rebound after cessation of sms 201-995 treatment in acromegaly.

We studied a 42-year-old woman who had persistent active acromegaly despite conventional therapies. She was treated for 6 months with SMS 201-995. Her mean plasma growth hormone GH values decreased during treatment from 9.1 +/- 1.2 to 6.6 +/- 1.2 micrograms/L. One month after the withdrawal of SMS 201-995, the plasma GH level increased to 24.4 micrograms/L (P less than 0.001). This elevation was clinically silent and transitory, as GH levels decreased 8 months later to 6.9 +/- 1.3 micrograms/L. Furthermore, at the beginning of therapy, her intractable headache was completely relieved; however, it progressively resumed under therapy. In conclusion, cessation of SMS 201-995 may be followed in some acromegalic patients by a rebound of plasma GH levels. This rebound suggests that SMS 201-995 decreases GH levels by an inhibition of its release from the pituitary. Furthermore, SMS 201-995 may relieve intractable headache in some acromegalic patients, but tolerance to the analgesic effect may develop.

Acromegaly↗
PubMed1989

Clinical pancreas transplantation: a learning curve of its management.

In this evolving experience, acceptable patient and graft survival after PTX appear best secured by the use of whole duodenopancreatic grafts, enteric drainage, triple immunosuppression induced by OKT3, and the monitoring of postprandial blood glucose and serum amylase for detection of rejection.

Adult↗
PubMed1988

Low serum urea level in dehydrated patients with central diabetes insipidus.

Dehydrated patients usually present with an elevated serum urea level, owing in part to increased renal reabsorption of urea mediated by antidiuretic hormone (ADH). We carried out a study to examine whether, during dehydration, the variations in the serum urea level could discriminate patients with central diabetes insipidus (CDI) from those with dehydration not due to CDI. We studied retrospectively 27 episodes of dehydration in 23 patients with CDI and 14 episodes in 14 patients without CDI. The mean serum urea level was 2.9 mmol/L in the CDI group and 15.4 mmol/L in the patients without CDI (p less than 0.001); the mean serum sodium level was 155 mmol/L in both groups. All the patients with CDI had a sodium/urea ratio greater than 24.2, whereas the ratio was less than 21.7 in all the patients without CDI. In the patients with CDI a positive correlation was found between the magnitude of diuresis and the percentage decrease in the serum urea level compared with the level before dehydration (p less than 0.001). In the patients with CDI the serum urea level returned to the level before dehydration after the administration of vasopressin; a striking increase in the clearance of urea, which exceeded the creatinine clearance, was observed during dehydration in the three patients in whom clearance studies were done. The results suggest that serum urea values can be used to distinguish patients dehydrated because of CDI from those with hypertonic dehydration but without ADH deficiency and that during dehydration the net reabsorption of urea is dependent on the renal action of ADH.

Adult↗
PubMed1988

Defective dopaminergic regulation of prolactin secretion in patients with hyperprolactinemia.

In order to evaluate the dopaminergic control of the lactotroph, we examined the plasma prolactin response to metoclopramide (a dopamine receptor blocker, 10 mg iv bolus) and to dopamine (1 microgram/Kg/min iv infusion for 120 min) in 52 hyperprolactinemic female patients and 19 healthy volunteer women. Three diagnostic categories were included: "idiopathic" hyperprolactinemia (21), microadenoma (24), and macroadenoma (7). Patients from all groups showed a marked blunting of the prolactin response to metoclopramide as compared to the prolactin rise in normal women (p less than 0.001). However, normal responses were observed in 8 patients with idiopathic hyperprolactinemia and in one patient with adenoma. The magnitude of the prolactin response to metoclopramide (percent of baseline level) correlated negatively with the level of basal prolactin in each group except for macroadenoma patients. Dopamine infusion significantly (p = 0.015) reduced the mean plasma prolactin levels in hyperprolactinemic patients and normal women. However, patients with idiopathic hyperprolactinemia were hyposensitive to dopamine (p less than 0.05). Furthermore, microadenoma patients were less responsive to dopamine suppression than were the patients with macroadenoma (p less than 0.05). The results indicate the presence of a relative resistance to dopamine in patients with idiopathic hyperprolactinemia and in patients with microadenoma. They also suggest that in these patients, the decrease in prolactin response to metoclopramide may be explained by the relative refractoriness to endogenous dopamine.

Adenoma↗
PubMed1987

Distinctive features of prolactin secretion in acromegalic patients with hyperprolactinaemia.

We have investigated the relationship between the plasma PRL concentrations of 98 untreated acromegalic patients and the GH levels during basal and dynamic conditions. Hyperprolactinaemia was present in 27 patients. In patients with marked hyperprolactinaemia (PRL greater than 80 ng/ml or greater than 1600 mU/l), basal plasma PRL and the TRH-induced response correlated with basal plasma GH (correlation coefficients of 0.9, P less than 0.001 and 0.74, P less than 0.02, respectively). The PRL response to TRH also correlated with GH response to TRH (r = 0.38, P less than 0.01). In contrast, in patients with moderately elevated PRL (20 to 80 ng/ml), and in those with normal plasma PRL (less than 20 ng/ml or less than 400 mU/l), no such correlations were found. Immunostaining for PRL was positive in 24 out of 25 adenomas of patients with hyperprolactinaemia, while no PRL was found in the tumour tissue of 10 normoprolactinaemic patients. In conclusion, our data suggest the existence of two populations of acromegalic patients with hyperprolactinaemia, one group with correlations between GH and PRL secretion, and the other without.

Acromegaly↗
PubMed1986

Capnocytophaga ochracea and group F beta-hemolytic streptococcus suppurative thyroiditis.

The route of infection in acute suppurative thyroiditis is unknown in most cases; when demonstrated, pyriform sinus fistula appears to be the most frequent one. We report the clinical and laboratory findings of a child in whom culture of the thyroid pus yielded two bacteria which are part of the normal oropharyngeal flora: capnocytophaga ochracea and group F Beta-hemolytic streptococcus. The preliminary results of the culture, which showed a mixed flora, prompted us to search and to find a pyriform sinus fistula. Apart from the onset in infancy, the left lobe involvement and the frequent recurrence, the recovery from the thyroid pus of bacteria from normal oropharyngeal flora should be included in the characteristic features of thyroiditis resulting from an infection through the pyriform sinus fistula.

Adolescent↗
PubMed1985

Acromegaly: biochemical assessment of cure after long term follow-up of transsphenoidal selective adenomectomy.

This study reports the clinical and biological follow-up 5-11 yr after transsphenoidal selective adenomectomy in 25 patients with acromegaly. Eight patients had microadenomas, and 17 had macroadenomas. Initial normalization of plasma GH levels (basal values, less than 5 ng/ml; glucose-suppressed concentrations, less than 2.5 ng/ml) was achieved in all 8 patients with microadenomas and in 13 patients with macroadenomas. Of these, 3 patients with normal GH levels and dynamics had relapse of GH hypersecretion after intervals between 1-6 yr after microadenoma removal. Recurrence of pituitary adenoma was documented by surgery in 1 patient and by computed tomographic scanning in 2 others. Normal basal and glucose-suppressed plasma GH concentrations were maintained 7.4 +/- 0.5 (+/- SEM) yr after adenomectomy in 7 patients with microadenomas and in all 10 patients with macroadenomas. Thus, 88% of the patients with microadenomas and 59% of the patients with macroadenomas were cured, and the overall cure rate was 68%. We conclude that recurrence of acromegaly after successful surgery may occur late after adenoma removal and that it cannot be predicted by normal postoperative GH levels and dynamics. However, in view of the overall cure rate, transsphenoidal adenomectomy remains a most valuable treatment for acromegaly.

Acromegaly↗
PubMed1982

Antibody response to rubella virus proteins in different physical forms.

The immunogenicity of different antigens, containing rubella virus hemagglutinating (HA) membrane protein, was studied using live virus, beta-propiolactone-inactivated virus, detergent and lipid-free octamers and virosomes. Whole virus particles, live or inactivated, induced hemagglutination inhibition (HAI) antibodies in rabbits after one subcutaneous injection of 0.16 micrograms of HA protein. Hemagglutinin rosettes or virosomes failed to induce antibodies even at a dose of 120 micrograms. Apparently, the extraction of viral membrane hemagglutinin, for the preparation of a rubella subunit vaccine, led to destruction of the antigenicity responsible for the induction of hemagglutination inhibiting antibodies. These results are discussed in the light of earlier studies on the preparation of a rubella subunit vaccine.

Animals↗