Biomedical subjects

C McHenry

Publications and source records attributed to C McHenry.

13 recordsLinked to original sources

PubMed1989

Selective postoperative radioactive iodine treatment of thyroid carcinoma.

In a consecutive series of 234 patients with differentiated thyroid carcinoma of follicular cell origin (Hürthle cell tumors excluded), a radioactive iodine (131I) scan was obtained 3 to 6 months after thyroidectomy and 4 weeks after cessation of thyroid hormone treatments, only if extrathyroidal tumor extension or nodal or distant metastases were present. Twenty-one patients (9%) with 131I uptake of 3% or more (group 1) were treated with 150 to 200 mCi of 131I. Forty-four patients (19%) with less than 3% uptake (group 2) and 169 patients (72%) without evidence of metastases or extrathyroidal spread (group 3) were treated only with thyroid hormone. All patients initially underwent total thyroidectomy and modified neck dissection if cervical lymph node metastases were present. Three patients in group 1 and one patient in group 2 had recurrent tumor with a mean follow-up of 8.9 and 8.4 years. There were no recurrences in group 3 with a mean follow-up of 7.2 years. Death rate from thyroid carcinoma was 5% in group 1 (one patient) and 0% in groups 2 and 3. In conclusion, 131I scanning and therapy may be omitted in patients with differentiated thyroid carcinoma in the absence of local tumor extension or regional or distant metastases. Therapy with 131I is not demonstrated to be of benefit in this population of patients.

Adenocarcinoma↗

PubMed1989

Altered TSH levels associated with increased serum 1,25-dihydroxyvitamin D3: a possible link between thyroid and parathyroid disease.

The physiologic relationship between the thyroid and parathyroid glands remains poorly understood. A high incidence of coexistent thyroid disease and primary hyperparathyroidism has been well documented. Elevation of serum 1,25-dihydroxyvitamin D3 (vitamin D) has been detected in some patients with primary hyperparathyroidism. A report of specific binding sites and uptake of vitamin D by the thyrotrophs of the anterior pituitary indicates that vitamin D may modulate production or secretion of thyroid-stimulating hormone (TSH). To test this concept, we investigated the influence of elevated serum levels of vitamin D on basal and stimulated TSH. Vitamin D was administered by subcutaneously implanted sustained-release pellets at four dosages. Thyrotropin releasing hormone (TRH) stimulation tests were performed at time zero, 72 hours, 1 week, 2 weeks, and 5 weeks. Animals administered vitamin D became significantly hypercalcemic and demonstrated elevations of vitamin D, which peaked at 72 hours and remained elevated for 2 weeks after pellet implantation. TRH-stimulated TSH levels were significantly elevated at 72 hours and at 1 week and returned to normal after 5 weeks. Parathyroid hormone levels were suppressed at 72 hours and at 1 week and displayed significant elevation at 2 weeks. These results provide in vivo evidence for an interaction and a possible regulatory role of 1,25 on pituitary TSH secretion and parathyroid function.

Animals↗

PubMed1989

Adult nesidioblastosis. An unusual cause of fasting hypoglycemia.

Laidlaw coined the term nesidioblastosis in 1938 to characterize the neodifferentiation of the islet cells of Langerhans from pancreatic duct epithelium. It is well recognized in the pediatric population as a frequent cause of persistent neonatal hypoglycemia. However, its occurrence in adults is presumed to be rare and, therefore, it is not appreciated as a cause of hyperinsulinism. Three women, aged 29, 42, and 63, with adult onset hyperinsulinism secondary to nesidioblastosis are reported. All three patients required near-total pancreatectomy. The preoperative findings were consistent with hyperinsulinemic hypoglycemia as with insulinomas. Results of pancreatic imaging studies were normal in two patients and one patient had a pancreatic examination by computerized tomography and magnetic resonance imaging, with false-positive results. Two of the three patients had previously undergone a 50 per cent distal pancreatectomy in which the resected specimens were interpreted as normal in one patient and consistent with nesidioblastosis in the second. Both patients subsequently developed recurrent symptomatic hyperinsulinemic hypoglycemia that persisted despite dosage adjustments in diazoxide therapy. The oldest patient underwent a 95 per cent pancreatectomy at the initial surgical exploration because an insulinoma could not be identified. The other patients underwent a completion 95 per cent pancreatectomy. In both, histochemical examination of each specimen disclosed nesidioblastosis, characterized by clusters of islet cells interspersed throughout the exocrine tissue.

Adult↗

PubMed1989

Severity of disease correlated with fever reduction in febrile infants.

A prospective study of the effects of fever reduction on the clinical appearance of infants at risk for occult bacteremia was undertaken to study the hypothesis that infants with bacteremic illness fail to improve clinically following defervescence compared with infants with benign viral illness. A total of 154 children were enrolled in the study, including 19 with bacteremia: 13 with occult Streptococcus pneumoniae bacteremia, two with occult Haemophilus influenzae, type b bacteremia, and four with Haemophilus meningitis and bacteremia. There were no differences in degree of temperature reduction with acetaminophen between the bacteremic and nonbacteremic groups of infants. Among infants with bacteremia but without meningitis, differences from nonbacteremic children were detected in clinical appearance prior to fever reduction but not following defervescence. All patients with meningitis appeared seriously ill before and after defervescence. It was concluded that clinical improvement with defervescence is not a reliable indicator of the presence of occult bacteremia. Lack of clinical improvement with defervescence may be a reliable indicator for the presence of meningitis. Because there were differences in clinical appearance prior to fever reduction, routine administration of acetaminophen may interfere with the clinical evaluation by the physician.

Acetaminophen↗

PubMed1989

Improving postoperative recurrence rates for carcinoma of the thyroid gland.

Differentiated carcinoma of the thyroid gland is regarded as an indolent disease. However, this notion is dispelled when the population is stratified according to age, gross and microscopic tumoral characteristics and according to the occurrence of local and distant metastases in the early postoperative period. The adverse effect of local and distant recurrences on survival time has been emphasized in multiple series from the United States and Europe. However, the critical question that has yet to be answered is whether or not inadequately treated differentiated carcinomas of the thyroid gland seemingly cured in younger patients will recur as aggressive, malignant tumors when the same patients reach the graying golden years. A provisional answer to this question may indeed be found in the incidence of early postoperative nodal and distant recurrence rates. Some authors have concluded that the extent of operative treatment does not have a major influence on the course of differentiated carcinoma of the thyroid gland. This conclusion prompted the present follow-up study of 250 patients with differentiated carcinoma of the thyroid gland to examine the clinical course and results of therapy. We report a cumulative mortality rate of 2.4 per cent and a recurrence rate of 1.6 per cent, consisting of a 1.2 per cent incidence of cervical nodal recurrence and a distant recurrence rate of 0.4 per cent (one patient), after a median follow-up period of seven years and a mean of six years. Since there were no differences in treatment and outcome in 191 patients we studied who had papillary and 59 who had follicular carcinoma, they were analyzed as a single group for this report. Total thyroidectomy was the minimal treatment of all operable patients. In addition, 21.0 per cent required a modified dissection of the neck and 8.4 per cent of the patients had postoperative radioactive iodine administered to ablate either remnants of normal tissue or previously undetected metastases to cervical nodes or lungs. Potential factors contributing to improved local and distant recurrence rates included early detection of disease, especially in children who had irradiation and who were recalled and screened (34 per cent in this series); the use of needle aspiration cytologic study, leading to earlier diagnosis and treatment; total thyroidectomy, and the effective use of radioactive iodine administered as a single large dose within the first six months after thyroidectomy.

Adenocarcinoma↗

PubMed1988

Resection of parathyroid tumor in the aorticopulmonary window without prior neck exploration.

Of 522 patients with hyperparathyroidism operated on from 1973 to 1987 at our institution, there were seven (1.3%), each with an ectopic, hyperfunctioning mediastinal parathyroid adenoma, who required median sternotomy. In three of these seven patients, the tumor was located in the aorticopulmonary window. A 61-year-old woman with primary hyperparathyroidism had a preoperative thallium-technetium subtraction scan that showed thallium uptake at the base of the heart without any uptake in the neck. After further workup and without prior neck exploration, a parathyroid adenoma was found in the aorticopulmonary window through a median sternotomy. Six months later, serum calcium, phosphorus, and parathyroid hormone values remain normal. Two other cases of parathyroid adenoma in the aorticopulmonary window are presented. Of these two patients, the thallium scan was a key element in the immediate mediastinal exploration of one, who was transferred from another hospital comatose and intubated, in acute hypercalcemic crisis. Since mediastinal parathyroid tumors that necessitate median sternotomy occur in less than 2% of patients with primary hyperparathyroidism, we do not advocate routine preoperative localization studies before an initial cervical operation; localization, however, may be justified in selected cases, such as in critically ill patients or in instances of acute hyperparathyroidism, when the first operation needs to be curative.

Adenoma↗

PubMed1988

Nodular thyroid disease in children and adolescents: a high incidence of carcinoma.

Over a period of 32 years from 1954 to 1986, 65 patients under the age of 21 years, 52 girls and 13 boys, were operated for nodular thyroids: the overall incidence of carcinoma was 37 per cent. It was 46 per cent in those patients presenting with a solitary nodule. Among the 24 patients with a malignancy, the carcinoma was of the papillary variety in 63 per cent, follicular in 25 per cent and medullary in 12 per cent. Two thirds of the patients had metastatic disease at the time of presentation. All patients with thyroid carcinoma were treated with total thyroidectomy. Other measures included neck dissection and radioactive iodine. When the eight patients with a history of head and neck irradiation and the three patients with medullary carcinoma were excluded, the incidence of carcinoma was 28 per cent. In summary, in spite of the decline in radiation associated cases, the incidence of carcinoma in nodular thyroid disease in the population under 21 years, remains at the relatively high figure of 28 per cent.

Adenocarcinoma↗

PubMed1988

Carcinoma of the thyroid in patients with autonomous nodules.

Over a period of 25 years (1961-1986), 30 consecutive patients were operated upon for solitary "HOT" nodules. The autonomy of these nodules was substantiated by cytomel nonsuppressibility on 131I or 123I scanning, or TSH stimulated enhancement of the remaining suppressed thyroid tissue (n = 24); or as a solitary toxic hot nodule with suppression of the remaining thyroid tissue (n = 6). Seventeen of these patients were euthyroid and 13 were thyrotoxic and required preoperative preparation with antithyroid medication. Five patients had a history of head and neck irradiation. The population consisted of 24 women and six men. Their ages ranged from 14 to 68 years. The tumors ranged in size from 1.5 to 7 cm. The pathologic findings consisted of "colloid" adenoma in nine patients, follicular adenoma in 19 patients, and a follicular carcinoma in two patients, for an incidence of 6 per cent. It is of interest that neither of the patients with thyroid carcinoma were toxic or had a history of radiation exposure. These findings support the concept that the incidence of carcinoma in truly autonomous "HOT" thyroid nodules is not negligible.

Adenocarcinoma↗

PubMed1987

Thyroid neoplasia following radiation therapy for Hodgkin's lymphoma.

The question of thyroid neoplasia following high-dose radiation treatment to the neck and mediastinum for malignant neoplasms such as Hodgkin's lymphoma in children and young adults has been raised recently. Five patients, 19 to 39 years old, were operated on for thyroid neoplasms that developed following cervical and mediastinal radiation therapy for Hodgkin's lymphoma. Three patients had papillary carcinomas and two had follicular adenomas. The latency period between radiation exposure and the diagnosis of thyroid neoplasm ranged from eight to 16 years. This limited series provided strong support for the recommendation that children and young adults who are to receive high-dose radiation therapy to the head, neck, and mediastinum should receive suppressive doses of thyroxine prior to radiation therapy in order to suppress thyrotropin (thyroid-stimulating hormone) and then be maintained on a regimen of suppression permanently.

Adenoma↗

PubMed1987

The incidence of thyroid carcinoma in Hashimoto's thyroiditis.

The incidence of thyroid carcinoma in Hashimoto's thyroiditis has been a widely debated issue. Previous authors have reported on this topic by analyzing series of patients with Hashimoto's thyroiditis or patients with thyroid carcinoma, but not both of those populations in the same series. The population consists of a consecutive series of 800 patients operated on for thyroid nodules not associated with a radiation history. Among 161 patients with the diagnosis of thyroid carcinoma, 61 (38%) had coexistent Hashimoto's thyroiditis. In comparison, among 161 sex- and age-matched patients with colloid nodules in the same population, 18 (11%) had Hashimoto's thyroiditis. Furthermore, in the series as a whole, the incidence of Hashimoto's thyroiditis in 423 patients with colloid nodules was 10 per cent. From the perspective of the Hashimoto's thyroiditis population in the same series of 800 thyroidectomies, among 267 patients with Hashimoto's thyroiditis 61 (23%) had coexistent carcinoma. In comparison, among 267 age- and sex-matched patients with colloid nodules there were only ten coexistent carcinomas for an incidence of 4 per cent. The high incidence of carcinoma of the thyroid in Hashimoto's thyroiditis lends credence to the hypothesis that Hashimoto's thyroiditis is a predisposing factor in the development of thyroid carcinoma.

Adolescent↗

PubMed1977

DNA polymerase III holoenzyme of Escherichia coli. Purification and resolution into subunits.

DNA polymerase III holoenzyme has been purified from Escherichia coli HMS-83, using, as an assay, the conversion of coliphage G4 single-stranded DNA to the duplex replicative form. The holoenzyme consists of at least four different subunits: alpha, beta, gamma, and delta of 140,000, 40,000, 52,000, and 32,000 daltons, respectively. The alpha subunit is DNA polymerase III, the dnaE gene product. The holoenzyme has been resolved by phosphocellulose chromatography into an alpha - gamma - delta complex and a subunit beta (copolymerase III*); neither possesses detectable activity in the G4 system but together reconstitute holoenzyme-like activity. The alpha - gamma - delta complex has been further resolved to yield a gamma - delta complex which reconstitutes alpha - gamma - delta activity when added to DNA polymerase III. The gamma - delta complex contains a product of the dnaZ gene and has been purified from a strain which contains a ColE1-dnaZ hybrid plasmid.

Centrifugation, Density Gradient↗

PubMedDate not supplied

Silent suffering.

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Body Image↗

PubMedDate not supplied

Handy work.

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Activities of Daily Living↗