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Biomedical subjects

C F Abboud

Publications and source records attributed to C F Abboud.

16 recordsLinked to original sources
PubMed1990

Free alpha subunit of the pituitary glycoprotein hormones. Measurement in serum and tissue of patients with pituitary tumors.

A solid-phase radioimmunoassay was developed that measures the free alpha subunits of pituitary glycoprotein hormones (alpha PGpHs) and has negligible cross-reactivity with the intact hormones (less than 0.014% for thyroid-stimulating hormone [TSH], less than 0.1% for human chorionic gonadotropin [hCG], 0.8% for luteinizing hormone [LH], and 2.0% for follicle-stimulating hormone [FSH]). The assay is standardized with the alpha subunit of hCG but also reacts well with the alpha subunits of the other glycoprotein hormones (84% for alpha TSH, 77% for alpha FSH, and 64% for alpha LH). Concentrations as low as 0.3 micrograms/L can be reliably measured, and the 97.5% reference range in 27 healthy adults, including postmenopausal females, is less than or equal to 1.2 micrograms/L. Elevated preoperative alpha PGpH concentrations were found in 45 (9.4%) of 479 sera from patients with pituitary adenoma and 3 (4.5%) of 66 patients with nonadenomatous sellar lesions. Postoperative alpha PGpH levels were lower in 30 of 39 adenoma patients and 2 of 3 nonadenoma patients. In five (1%) of the patients with pituitary adenomas, alpha PGpH was the only elevated serum hormone marker. Serum values of alpha PGpH correlate weakly with alpha subunit immunocytochemical staining--95% of those with negative staining have normal alpha PGpH values, but only 18% of those with positive staining have elevated alpha PGpH values.

Adenoma↗
PubMed1988

Comparison of magnetic resonance imaging and computed tomography in the preoperative evaluation of pituitary adenomas.

Twenty surgically verified pituitary adenomas were imaged in a systematic comparative fashion with high field strength magnetic resonance imaging (MRI) and computed tomography (CT) before operation. The study group included 11 microadenomas, 4 macroadenomas, 2 recurrent microadenomas, and 3 recurrent macroadenomas. The MRI and CT examinations were evaluated for lesion detection, pituitary stalk displacement, cavernous sinus displacement or invasion, hemorrhage, cystic degeneration within the adenoma, bony erosion, detection of suprasellar extension, and displacement of suprasellar structures. T1 and T2 relaxation characteristics of the adenomas were evaluated on MRI examinations, and contrast enhancement characteristics were evaluated on CT examinations. MRI was superior to CT for detecting the extrasellar extent of tumor. Within the sella turcica, MRI and CT were equivalent with regard to lesion detection, except for 1 patient in whom CT was able to detect a surgically confirmed 3-mm microadenoma that was not visualized on the MRI examination.

Adenoma↗
PubMed1988

Diagnosis of pituitary tumors.

In the last two decades, significant strides have been made in the diagnosis and management of pituitary tumors. The identification, isolation, and characterization of the anterior pituitary hormones, the developments of sensitive and specific radioimmunoassays, and the significant advances in neuroradiologic, neurosurgical, and pathologic techniques have led to increasing recognition of pituitary tumors and their clinical syndromes. This article will review the current diagnostic approaches relating to prolactin, growth hormone-, thyrotropin-, and gonadotropin/alpha glycoprotein subunit-secretory, as well as nonsecretory, pituitary tumors.

Humans↗
PubMed1987

Primary idiopathic hypothalamic hypothyroidism. Report of four cases.

One man and three women with hypothalamic hypothyroidism are described; they had isolated thyrotropin-releasing hormone deficiency, otherwise normal pituitary function, and no identifiable central nervous system anatomic abnormality. Serum thyrotropin levels were low and thyrotropic response to thyrotropin-releasing hormone was uniformly present, consistent with a hypothalamic cause of hypothyroidism. In two patients, hypothyroidism was transient and spontaneously resolved; in one of them, it was recurrent. Because hypothalamic hypothyroidism is mild and potentially reversible, it is suggested that such patients have follow-up evaluation before therapy is initiated in order to avoid unnecessary treatment.

Adult↗
PubMed1987

Prolactin-secreting adenomas: the preoperative response to bromocriptine treatment and surgical outcome.

Controversy exists regarding the effects of bromocriptine on the success of transsphenoidal surgery for patients with prolactinomas. Various studies on this drug have reported adverse effects, improvement, and no effect upon the subsequent surgical outcome. The authors have retrospectively reviewed the case histories of 55 patients with immunocytochemically confirmed prolactin-secreting pituitary adenomas operated on by a transsphenoidal approach between 1981 and 1985. All patients had received bromocriptine in a variety of doses and for variable durations prior to surgery. Thirty-nine patients were women and 16 were men, with an age range of 8 to 72 years. Basal prolactin levels prior to bromocriptine treatment ranged from 38 to 100 ng/ml in 11 patients, from 101 to 200 ng/ml in 12, and greater than 200 ng/ml in 29. The "cure" rates were 54%, 58%, and 38%, respectively. Thirty-one patients had microadenomas, with a postoperative cure rate of 68%; 12 had diffuse expansive adenomas, with a 17% cure rate; and 12 had grossly invasive tumors, with a 17% cure rate. A response to preoperative bromocriptine therapy was defined as a return of the basal prolactin level to normal: 18 patients were responders and 29 were hyporesponders; in eight the data were not available. The postoperative cure rate was 50% for the responders and 31% for the hyporesponders. Taking into account the distribution of tumor type, there was no actual difference in outcome between the responder and the hyporesponder groups. The total bromocriptine dose received preoperatively was nearly identical for all groups. No significant differences in the frequency or extent of fibrosis, calcification, or prolactin immunoreactivity were observed in the 55 patients when compared with 26 control prolactinomas not treated with bromocriptine. It is concluded that short-term bromocriptine treatment does not adversely affect surgical outcome in any of the prolactin-secreting adenoma groups, nor does response or lack of response to bromocriptine predict surgical outcome.

Adenoma↗
PubMed1986

Laboratory diagnosis of hypopituitarism.

Hypopituitarism can be caused by failure or loss of one or more of the eight identifiable hormones in the anterior lobe of the pituitary gland. The endocrine manifestations of hypopituitarism are related to the type and degree of hormonal deficiency and the stage in life during which the deficiency occurs. In patients with suspected hypopituitarism, the diagnostic approach consists of determining the extent and the cause of the hormonal loss. Specific provocative tests for the diagnosis of hypopituitarism are reviewed in detail in this article.

Adrenocorticotropic Hormone↗
PubMed1979

Pituitary adenoma and oral contraceptives: a case-control study.

A search of the centralized data resource available at the Mayo Clinic for all cases of pituitary adenoma diagnosed in the population of Olmstead County, Minnesota, disclosed an increasing incidence of this tumor in women of childbearing age. The sex, age, and temporal relationships suggest that, if this increase is real, oral contraceptives should be considered as one of the possible etiologic factors. A case-control study, however, did not reveal an association of prior use of oral contraceptives with pituitary tumor--relative risk, 0.5; 95% confidence interval, 0.1 to 2.2. No association was found with other possible risk factors, i.e., prior head injury, radiation therapy, seizures, and smoking. Thus, unless other etiologic agents can be identified, it appears that the increasing incidence is due to advances in diagnostic and surgical technology rather than to a specific etiologic factor.

Adenoma↗
PubMed1979

Neurosurgical management of acromegaly. Results in 82 patients treated between 1972 and 1977.

A consecutive series of 82 acromegalic patients who underwent transsphenoidal surgery during a 5-year period is presented. Preoperative and postoperative values for human growth hormone (HGH) were available in 80 cases. Microadenomas were present in 18 patients with a mean preoperative HGH value of 25.2 ng/ml, diffuse adenomas in 39 patients with mean of 53.8 ng/ml, and invasive adenomas in 25 with mean of 68.0 ng/ml. There was no operative mortality. The results reflected the classification of the tumors, with apparent cures accomplished in 87.5% of previously untreated patients with microadenoma, all of whom had anterior pituitary function preserved. The percentages of apparent cures in cases of diffuse adenoma (68%) and invasive adenoma (54%) were much less satisfactory. Transsphenoidal microsurgery is capable of achieving good results, particularly in patients with microadenoma.

Acromegaly↗
PubMed1978

Primary hyperparathyroidism and peptic ulcer disease.

To determine whether primary hyperparathyroidism is related to peptic ulcer disease, we evaluated 46 cases of concomitant primary hyperparathyroidism and peptic ulcer disease. Among these patients, there was no sex preponderance. The pathologic findings at parathyroid surgery, as well as the features of peptic ulcer disease, were the same as in patients with primary hyperparathyroidism or with peptic ulcer disease alone. The ulcer symptoms of 58% of the patients with adequate follow up improved after parathyroidectomy. Sixty-six percent of the patients who had active peptic ulcer disease at surgery improved as compared with only 44% of the patients who had complicated peptic ulcer disease. None of the factors studied (age, sex, serum calcium and serum parathyroid hormone levels, location, and duration of ulcer) had any effect on the peptic ulcer symptoms after parathyroidectomy. Our results and a critical review of the experimental and clinical literature suggest that the association between primary hyperparathyroidism and peptic ulcer disease is no more than coincidental.

Follow-Up Studies↗
PubMed1978

Pituitary adenoma in Olmsted County, Minnesota, 1935--1977. A report of an increasing incidence of diagnosis in women of childbearing age.

There has been a recent, rapid increase in the number of pituitary adenomas diagnosed in women of childbearing age in Olmsted County, Minnesota. The incidence rates in men of all ages and in women aged 45 and over have remained stable and are similar to rates reported from elsewhere. Since 1970 the mean annual incidence per 100,000 women aged 15 through 44 years has been 7.1, whereas it was 0.7 in the population of the same age and sex during the period 1935 through 1969.

Adenoma↗
PubMed1977

Radioimmunoassay of human homologous prolactin in serum with commercially available reagents.

A clincally useful and reproducible radioimmunoassay for human homologous prolactin, established with commercially available reagents, was studied and validated. We present detailed conditions for iodination and purification of labeled prolactin and the optimal conditions for the assay. By the method, we found values (microgram/liter) as follows for serum prolactin: normal men. 8.9 +/- 5.2 (mean +/- SD); normal women, 11.8 +/- 5.5; normal women taking contraceptive pills, 9.2 +/- 5.0; pregnant women in the third trimester, 188 +/- 69.5; patients with various diseases other than of the hypothalamic-pituitary axis, 9.3 +/- 6.3; in some patients with amenorrhea and galactorrhea of diverse origin, 78.2 +/- 87.4; and in some patients with surgically proven pituitary tumor, 1414 +/- 1980. Results under provocative testing are also presented for a patient with normal hypothalamic-pituitary function.

Chlorpromazine↗
PubMedDate not supplied

Anesthesia for transsphenoidal surgery of the hypophyseal region.

For pituitary surgery--by either the transcranial or the transsphenoidal approach--anesthetic management conforms to the general principles of neuroanesthesia as discussed in texts and review articles. In addition, the endocrine functions and the anatomic situation of the pituitary gland must be considered. Preoperative and perioperative evaluation of the patient's endocrine status and appropriate therapeutic measures are important. Preservation of neurohypophyseal function and, frequently, of adequate adenohypophyseal function is an advantage of the transsphenoidal approach to the sella. Potential problems with the transsphenoidal technic include damage to suprasellar and parasellar structures and harzards associated with intraoperative or postoperative bleeding. Anesthetic aspects peculiar to the transsphenoidal approach include positioning of the patient, surgical use of solutions containing epinephrine and topical cocaine, intraoperative air studies, and management of emergence. Anesthesia for the transsphenoidal approach to the sella is discussed on the basis of our experience with 148 surgical procedures in 142 patients.

Adolescent↗
PubMedDate not supplied

Assay of somatomedin C by cartridge extraction prior to radioimmunoassay with antiserum developed against synthetic somatomedin C.

The whole molecule of human somatomedin C (SM-C) prepared by the total synthesis method was used as an antigen to produce an antiserum for a radioimmunoassay. Since plasma proteins that bind SM-C interfere with the assay, a method was developed that uses acid dissociation followed by C-2 cartridge extraction to strip SM-C from its binding proteins before assay. This assay has no cross-reactivity with human proinsulin or insulin-like growth factor II (IGF-II). The SM-C values in 339 normal subjects showed age-dependence, increasing from childhood to a peak at age 14 to 16 years and decreasing sharply before adulthood. In adults, the SM-C values decreased gradually with age. All 13 patients with acromegaly who were tested had an increased SM-C value, with no overlap with the normal range. The 12 patients with prolactinoma but non-growth-hormone-producing pituitary tumor had no increase in SM-C. Two children with pituitary deficiency had low SM-C values; one of these children received growth hormone therapy, and his SM-C value increased from undetectable to normal. By three weeks after discontinuation of the therapy, his SM-C value was again undetectable. Of 20 children with short stature and constitutional delay of growth and development, SM-C was below normal in 70 percent and normal in 30 percent. Two patients with malnutrition had below-normal SM-C values.

Adolescent↗