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Biomedical subjects

P C Carpenter

Publications and source records attributed to P C Carpenter.

At least 19 recordsLinked to original sources
PubMed2003

Cushing's syndrome due to medullary thyroid carcinoma: diagnosis by proopiomelanocortin messenger ribonucleic acid in situ hybridization.

Medullary thyroid carcinoma (MTC) rarely causes ectopic ACTH syndrome. We describe a 38-yr-old man with renal stones who had a 5-cm MTC removed in 1992. He was RET-protooncogene positive (codon 618). Serum calcitonin was 1597 pg/ml postoperatively. In 1996 he had rib fractures, bruising, weakness, and three to four stools per day. Laboratory studies revealed an elevated 24-h urine-free cortisol (780 micro g/d), epinephrine (66 micro g/d), and calcium (558 mg/d). Baseline serum cortisol was 23.9 micro g/dl and decreased to 12.9 and 4.5 micro g/dl after 2 mg and 8 mg dexamethasone suppression, respectively. Plasma ACTH was 170 pg/ml and decreased to 75 and 24 pg/ml after dexamethasone. Bone density t-score was -4.3 (trochanter). Computed tomography scans showed multiple cervical nodes and 2-cm right adrenal nodule. Magnetic resonance imaging (MRI) scan showed a prominent, homogeneous pituitary; the adrenal MRI scan was not typical for a pheochromocytoma. Serum CRH was less than 6.6 pg/ml. Bilateral adrenalectomy revealed two adjacent right adrenal pheochromocytomas and corrected the elevated urine cortisol (30 micro g/d), epinephrine (0 micro g/d), and calcium (281 mg/d) but not plasma ACTH (125 pg/ml). Neck dissection reduced calcitonin by 96% (5300 to 120 pg/ml) and ACTH by 91% (125 to 11 pg/ml). Carcinoembryonic antigen was reduced from 32.0 to 2.3 ng/ml. Immunohistochemical stain was negative for ACTH in the MTC-positive lymph nodes and the pheochromocytoma. Proopiomelanocortin mRNA by in situ hybridization was positive in the MTC but not in the pheochromocytoma. A repeat pituitary MRI scan was normal. The differential diagnosis of ACTH-dependent Cushing's syndrome in this case included pituitary disease or ectopic ACTH, either from medullary thyroid carcinoma or pheochromocytoma. ACTH stains were unrevealing, but proopiomelanocortin mRNA in situ hybridization in MTC tissue and plasma ACTH response to neck dissection confirmed MTC as the source of ectopic ACTH.

Adrenal Glands↗
PubMed2000

Adrenocorticotropic hormone-dependent Cushing's syndrome: sensitivity and specificity of inferior petrosal sinus sampling.

BACKGROUND AND PURPOSE: Determining the cause of Cushing's syndrome can be difficult. Bilateral inferior petrosal sinus (IPS) sampling after ovine corticotropin-releasing hormone (oCRH) stimulation is an established technique for the differentiation of pituitary from nonpituitary sources of adrenocorticotropic hormone (ACTH) production. The purpose of this study was to review our experience to determine the sensitivity and specificity of bilateral IPS sampling. METHODS: Between January 1990 and February 1997, 92 patients underwent 94 IPS sampling procedures. Indications for these patients with Cushing's syndrome included no discrete lesion on MR images or CT scans, a discrete lesion present on images but equivocal peripheral ACTH sampling after oCRH stimulation, and persistent Cushing's syndrome after trans-sphenoidal surgery. RESULTS: IPS sampling yielded six false-negative results and one false-positive result, manifesting an overall sensitivity of 92.2% and a specificity of 90.0% for detection of a pituitary source of ACTH after oCRH stimulation. Microadenoma lateralization by IPS sampling after oCRH stimulation agreed with the surgical location in 70.0% of the patients. The technical success rate of initial (presampling) bilateral IPS catheterization was 93.6%. Two serious complications occurred and consisted of a venous subarachnoid hemorrhage and a lower extremity deep venous thrombosis. CONCLUSION: Bilateral IPS sampling after oCRH stimulation is helpful in the evaluation of ACTH-dependent Cushing's syndrome. False-negative results, however, suggest that the possibility of a pituitary source must still be considered when no response to oCRH is documented. Interpetrosal ACTH gradient alone is not sufficient to lateralize the tumor reliably.

Adolescent↗
PubMed1999

Venous subarachnoid hemorrhage after inferior petrosal sinus sampling for adrenocorticotropic hormone.

Neurologic complications associated with inferior petrosal sinus sampling for adrenocorticotropic hormone in the diagnosis of Cushing syndrome are rare. Previously reported complications include brain stem infarction and pontine hemorrhage. We report a case of venous subarachnoid hemorrhage with subsequent acute obstructive hydrocephalus occurring during inferior petrosal sinus sampling for Cushing syndrome.

Adrenocorticotropic Hormone↗
PubMed1997

Issues concerning androgen replacement therapy in postmenopausal women.

A decrease in blood androgen levels is well documented in women who experience natural or surgical menopause. This change may be associated with various negative effects on bone metabolism in addition to psychosocial and sexuality aspects of life. A review of published information on androgen replacement therapy shows that major benefits may be achieved; unfortunately, only minimal quality information is available to help clinicians make decisions about this type of therapy. In this review, we point out the potential benefits and risks to bone, lipid and carbohydrate metabolism, and sexuality; in addition, we discuss potential risks of neoplasms and virilizing somatic changes. Long-term, physiologic, and well-designed androgen replacement studies should be performed to obtain the knowledge needed to guide therapy in this important area.

Androgens↗
PubMed1997

Clinical care management and workflow by episodes.

This paper describes the implementation of clinically defined episodes of care and the introduction of an episode-based summary list of patient problems across Mayo Clinic Rochester in 1996 and 1997. Although Mayo's traditional paper-based system has always relied on a type of 'episode of care' (called the "registration") for patient and history management, a new, more clinically relevant definition of episode of care was put into practice in November 1996. This was done to improve care management and operational processes and to provide a basic construct for the electronic medical record. Also since November 1996, a computer-generated summary list of patient problems, the "Master Sheet Summary Report," organized by episode, has been placed in all patient histories. In the third quarter of 1997, the ability to view the episode-based problem summary online was made available to the 3000+ EMR-capable workstations deployed across the Mayo Rochester campus. In addition, the clinically oriented problem summarization process produces an improved basic "package" of clinical information expected to lead to improved analytic decision support, outcomes analysis and epidemiological research.

Episode of Care↗
PubMed1997

Standardized problem list generation, utilizing the Mayo canonical vocabulary embedded within the Unified Medical Language System.

UNLABELLED: VOCABULARY: The Mayo problem list vocabulary is a clinically derived lexicon created from the entries made to the Mayo Clinic's Master Sheet Index and the problem list entries made to the Impression/ Report/Plan section of the Clinical Notes System over the last three years. The vocabulary was reduced by eliminating repetition including lexical variants, spelling errors, and qualifiers (Administrative or Operational terms). Qualifiers are re-coordinated with other terms, at run-time, which greatly increased the number of input strings which our system is capable of recognizing. IMPLEMENTATION: The Problem Manager is implemented using standard windows tools in a Windows NT environment. The interface is designed using Object Pascal. HTTP calls are passed over the World Wide Web to a UNIX based vocabulary server. The server returns a document, which is read into Object Pascal structures, parsed, filtered and displayed. STUDY: This paper reports the results of a recent Usability Trial focused on assessing the viability of this mechanism for standardized problem entry. Eight clinicians engaged in eleven scenarios and responded as to their satisfaction with the systems performance. These responses were observed, videotaped and tabulated. Clinicians in this study were able to find acceptable diagnoses in 91.1% of the scenarios. The response time was acceptable in 92.5% of the scenarios. The presentation of related terms was stated to be useful in at least one scenario by seven of the eight participants. All clinicians wanted to make use of shortcuts which would minimize the amount of typing necessary to encode the concept they were searching for (e.g. Abbreviations, Word Completion). CONCLUSIONS: Clinicians are willing to choose a canonical term from a suggested list (as opposed to their own wording). Clinicians want an "intelligent" system, which would suggest terms within a category (e.g. Types of "Migraine"). They are able to make functional use of our system, in its current state of development. Finally, all clinicians appreciate the value of encoding their problems in a standardized vocabulary, toward improved research, education and practice.

Computer Communication Networks↗
PubMed1995

Adrenal surgery for hypercortisolism--surgical aspects.

BACKGROUND: Patients with endogenous hypercortisolism are thought to be at high risk for adrenalectomy and may experience significant postoperative surgical mortality/morbidity. METHODS: From 1981 through 1991, 91 patients underwent adrenal resection for endogenous hypercortisolism. Causes were adrenal-dependent Cushing's syndrome (50%), pituitary-dependent Cushing's syndrome (27%), and an ectopic adrenocorticotropic hormone-secreting tumor (23%). Causes of adrenal-dependent Cushing's syndrome were adrenocortical adenoma (72%), bilateral nodular hyperplasia (20%), and adrenocortical carcinoma (8%). Comparative mean length of hospitalization for patients undergoing unilateral anterior versus posterior approach was 8 versus 6 days, and bilateral anterior versus posterior was 11 versus 6 days. RESULTS: Operative mortality was 2.6%. Only one patient had a wound infection, and no patient had either a venous thrombosis or a pulmonary embolism. Delayed wound healing occurred in three patients. CONCLUSIONS: (1) Adrenal surgery can be performed today with low morbidity/mortality. (2) Although there is an effect of hypercortisolism on wound healing, infection, diabetes, hypertension, coronary artery disease, and pulmonary embolism, it was possible to perform adrenalectomy surgically with acceptable morbidity and mortality. (3) These results may serve as a standard against which laparoscopic adrenalectomy may be compared.

Adenoma↗
PubMed1995

Long term follow-up of transsphenoidal surgery for the treatment of Cushing's disease in childhood.

Transsphenoidal removal of pituitary adenomas has become the accepted treatment for Cushing's disease. As Cushing's disease is rare in childhood, few reports describe extended follow-up after transsphenoidal surgery for this disease in children. Twenty-two patients less than 19 yr of age were diagnosed with Cushing's disease by standard testing. All patients underwent transsphenoidal surgery (TSS) as primary treatment at Mayo Clinic between 1975 and 1990. Follow-up was available in all patients and averaged 6.7 yr. Adenomas were identified pathologically in 19 patients and visualized by the surgeon in the remainder. There was 1 macroadenoma. Ten patients are considered cured with a mean follow-up of 5.5 yr. Five patients had evidence of persistent disease within 6 months of TSS and required further treatment. Seven patients had remission lasting greater than 6 months with subsequent relapse (mean time to recurrence, 7.0 yr). In children treated with TSS for Cushing's disease, the rate of cure with extended follow-up is only approximately 50%. This rate is much lower than that in adults and may indicate that Cushing's disease is more aggressive in childhood. As TSS is associated with low morbidity, we feel it is still the treatment of choice for Cushing's disease in children.

Adenoma↗
PubMed1995

Implementing an EMR: paper's last hurrah.

The implementation of an electronic medical record system in any large organization is as complex a task as the design of the system. During implementation, it is necessary that health care providers using the electronic system are able to communicate with colleagues who are continuing to work with the paper record. The Mayo Clinic in Rochester, Minnesota, is well along the path to implementing an electronic medical record system. One of the key issues addressed has been the need for the electronic system to integrate with the paper record. This need to function in the dual electronic/paper environment has placed new demands on printers, required revision of some paper forms, and required the electronic system to create facsimilies of paper record forms. In addition, new security issues have been raised. Dual paper/electronic environment issues are an important challenge in the implementation of an electronic medical record.

Computer Systems↗
PubMed1994

The electronic medical record: perspective from Mayo Clinic.

On 1 January 1993, the Electronic Medical Record Task Force at Mayo Clinic published its report. Charged by the Mayo Foundation to define the Electronic Medical Record (EMR) for Mayo, the task force mapped the goals, strategies and time-lines for implementation of the EMR in that institution. The task force was composed predominantly of caregivers (physicians and nurses) with assistance from members of Mayo's information systems and administrative departments. The focus of the effort was care of the patient with the consensus belief that the EMR will improve that process and, if designed robustly, will serve the other information needs of claims, research, education and practice management. The recommendations of this report have been accepted by the Mayo Foundation leadership resulting in the generation of a master plan and the creation of the governance structure for implementation at Mayo. This paper abstracts key portions of the report.

Computer Systems↗
PubMed1994

Hirsutism.

Explore the source record for details and available documents.

Androgen Antagonists↗
PubMed1993

The Universal Patient Identifier: a discussion and proposal.

The broad-based need for a standard, robust patient identifier is reviewed. Advantages and difficulties of the Social Security Number are considered. An alternative number, composed of birthdate, location, and check digits, is proposed. Logistic extensions of the geographically based schema are made for provider and facility identification. Several variations of representation are described in base 34, which make the composite number short, easily derived and decoded, and robust.

Humans↗
PubMed1992

The Cushing syndrome induced by bronchial carcinoid tumors.

OBJECTIVES: To define the clinical spectrum of bronchial carcinoid tumors in patients presenting with the Cushing syndrome, to evaluate the role of chest radiographs and computed tomography in their diagnosis, to review the characteristic histologic features, and to determine patient outcome. DESIGN: Retrospective analysis of consecutive patients. SETTING: A referral-based medical center. PATIENTS: Fifteen consecutive patients with the Cushing syndrome evaluated at the Mayo Clinic with histologically proven bronchial carcinoid tumors. MEASUREMENTS: Clinical, radiographic, and histologic features. RESULTS: The Cushing syndrome was the initial clinical presentation, and bronchial carcinoid tumors were found later in all 15 patients. The diagnosis of carcinoid tumor was proved histologically in all cases. Ten biopsies showed typical carcinoid tumors, three were histologically atypical, and three were metastatic. Corticotropin was detected by immunostaining in seven of these tumors. Biochemical analysis showed marked elevations of circulating corticotropin with a mean serum value of 156 +/- 58 pmol/L (normal, 4 to 22 pmol/L). Additional clinical features included hypokalemia in six patients and glucocorticoid response to either high-dose dexamethasone or metyrapone in 6 of 13. These hormonally active carcinoid tumors were frequently radiographically occult, with 10 of 15 patients initially having normal chest radiographs. Computed tomography was successful in locating carcinoid tumors in five patients with negative chest radiographs evaluated after 1980. All five remaining patients with normal chest radiographs evaluated before 1980 eventually developed nodular lesions on standard chest radiography from 1 to 10 years later. Ten patients achieved complete remission and two patients, partial remission of the Cushing syndrome after surgical resection. Three patients continued to have symptomatic glucocorticoid excess due to metastatic disease. CONCLUSIONS: Although uncommon, the Cushing syndrome may be the initial clinical manifestation of an otherwise indolent bronchial carcinoid tumor. Radiographic imaging of occult lesions can be successfully accomplished with computed tomography. Surgical resection is curative in most patients with this disorder.

ACTH Syndrome, Ectopic↗
PubMed1990

Ovine corticotropin releasing hormone stimulation test: normal value study.

We determined the pituitary-adrenal response to 1 microgram/kg of ovine corticotropin releasing hormone (oCRH) administered as an intravenous bolus injection in 50 normal subjects. Brief facial flushing was noted in 44% of the subjects; no other side effects were reported. Plasma corticotropin levels increased from a median of 30.2 pg/ml at baseline to a median peak level of 77.8 pg/ml after administration of oCRH; the peak response occurred at the 30- to 45-minute or the 45- to 60-minute time point. Plasma cortisol levels increased from a median of 10.8 micrograms/dl at baseline to a median peak level of 22.0 micrograms/dl after administration of oCRH; the peak response occurred at the 45- to 60-minute time point. Plasma beta-endorphin levels increased from a median of 9.5 pg/ml at baseline to a median peak level of 23.0 pg/ml after administration of oCRH; the peak response occurred at the 15- to 30-minute or the 30- to 45-minute time point. The responsiveness to oCRH was unaffected by age, sex, or body mass index of the subjects.

Adrenocorticotropic Hormone↗
PubMed1988

Cushing's syndrome due to primary multinodular corticotrope hyperplasia.

In this report, a case of Cushing's syndrome due to primary multinodular corticotrope hyperplasia is described. The patient had typical features of Cushing's syndrome and dynamic pituitary-adrenal testing, which suggested an ectopic adrenocorticotropic hormone (ACTH) syndrome. Results of petrosal sinus catheterization indicated that the pituitary gland was the source of excess ACTH. Total hypophysectomy resulted in complete remission of Cushing's syndrome. Light microscopic and immunohistochemical studies revealed multinodular corticotrope hyperplasia. Plasma corticotropin releasing hormone (CRH) was undetectable, and computed tomography of the chest and abdomen disclosed no neoplastic source of CRH. We speculate that either an abnormality in hypothalamic CRH secretion or corticotrope hypersensitivity to CRH might have been responsible for Cushing's syndrome in this patient.

Adrenocorticotropic Hormone↗
PubMed1988

Estrogen replacement therapy: current recommendations.

Estrogen replacement therapy is effective for the prevention and treatment of postmenopausal osteoporosis and should be offered to all women at high risk for osteoporosis. Such therapy is particularly beneficial for prevention of spinal compression fractures; in addition, it alleviates menopausal symptoms (hot flushes, genitourinary symptoms, and changes in mood). In each patient, these benefits must be weighted against the potential risks of endometrial hyperplasia and carcinoma, breast tenderness, hypertension, vascular headaches, and the inconvenience of menstrual bleeding if the uterus is intact. The risk of endometrial cancer associated with estrogen replacement therapy can be considerably reduced by the addition of a progestin, and other side effects can be diminished or eliminated by use of the new transdermal estrogen preparations. Thus, estrogen replacement therapy should be considered in all women who have experienced natural or surgically induced menopause, and it is advisable in women who have osteoporosis or an increased risk for this disorder and no contra-indications to its use. Estrogen replacement therapy should be instituted as soon after menopause as possible and seems to be well tolerated until at least 75 years of age.

Aged↗