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Biomedical subjects

M H Stevens

Publications and source records attributed to M H Stevens.

At least 37 records · Page 2Linked to original sources
PubMed1987

Lack of effect of parathyroidectomy or calcium channel blockade on serum gastrin concentration and gastric acid secretion in a patient with hyperparathyroidism and Zollinger-Ellison syndrome.

Management of patients with multiple endocrine neoplasia type I (Wermer's syndrome) who have concurrent hypercalcemia and hypergastrinemia is controversial. The usual therapeutic approach has been to perform parathyroidectomy first before surgery for ulcer disease in an effort to decrease serum calcium concentration and presumably remove one of the stimuli for both gastrin and gastric acid secretion. We present the history of a 48-year-old man with primary hyperparathyroidism and Zollinger-Ellison syndrome who underwent acid secretory studies and secretin stimulation tests before and after parathyroidectomy. We also studied the effect of calcium channel blockade on gastrin and gastric acid secretion, since calcium influx into endocrine cells, such as the gastrinoma cell, is thought to be critical in hormone secretion. Although parathyroidectomy reduced serum calcium and parathormone levels to normal, basal serum gastrin concentration and basal acid output remained unchanged. The peak rise in serum gastrin concentration after secretin injection was less after parathyroidectomy than before parathyroidectomy but was still abnormal. During administration of verapamil, a calcium channel antagonist, no change was seen in the serum gastrin concentration, secretin test response, or acid secretion. Basal acid output was 45.4 mmol/hr before parathyroidectomy or verapamil and 54.0 and 50.4 mmol/hr after parathyroidectomy or verapamil, respectively. In contrast, a small but significant decrease (p less than 0.05) in serum parathormone concentration occurred during treatment with verapamil, an observation that to the best of our knowledge has not been previously reported in humans.

Calcium Channel Blockers↗
PubMed1986

Inhibitory effects of beta-adrenergic agonists on gastric acid secretion in dogs.

We evaluated the effect of two beta-adrenergic agonists, isoproterenol (nonselective agonist) and terbutaline (selective beta 2-agonist), on gastric acid secretion stimulated by intravenous pentagastrin, bethanechol, or histamine in dogs with gastric fistulas. Intravenous infusion of isoproterenol or terbutaline inhibited pentagastrin-stimulated acid secretion to a significantly greater extent than they inhibited bethanechol- or histamine-stimulated acid secretion. For example, isoproterenol (12 micrograms X kg-1 X h-1) reduced mean pentagastrin-, bethanechol-, and histamine-stimulated acid output by 86, 63, and 14%, respectively. Percent inhibition of acid secretion with terbutaline (30 micrograms X kg-1 X h-1) averaged 60, 17, and 24% for pentagastrin, bethanechol, and histamine, respectively. Terbutaline also inhibited pentagastrin-stimulated acid secretion from vagally denervated fundic pouches in a dose-related manner. Plasma somatostatin-like immunoreactivity was significantly higher during infusion of terbutaline plus pentagastrin than during infusion of pentagastrin alone. However, an intravenous infusion of 0.3 microgram X kg-1 X h-1 somatostatin-14 had no effect on pentagastrin-stimulated acid secretion from the gastric fistula, even though this infusion increased plasma somatostatin-like immunoreactivity to the same extent as terbutaline plus pentagastrin infusion. Thus the amount of somatostatin released during terbutaline infusion was not sufficient to explain the inhibition of pentagastrin-stimulated acid secretion observed.

Adrenergic beta-Agonists↗
PubMed1985

Computed tomography of cervical lymph nodes. Staging and management of head and neck cancer.

Forty patients with head and neck cancer had a computed tomographic (CT) scan followed by lymphadenectomy and pathologic confirmation. The overall accuracy of clinical examination of the neck was 70% vs 93% by CT. The CT correctly "upstaged" the neck in nine patients. One was upstaged from NO to N1, and four each from NO to N2 and N1 to N2. It correctly "downstaged" the neck in one patient (from N2 to N1). Eight patients had extranodal disease on CT confirmed by pathology. The CT findings were correct in ten of 11 previously treated patients. Because CT is more accurate than the clinical examination, it should be included in the staging of not only the primary tumor but also nodal disease of the neck. It can have an important role in the management of head and neck cancer.

Adult↗
PubMed1983

Head and neck cancer survival and life-style change.

A retrospective analysis using patient and family questionnaires and chart review was done on 269 patients with head and neck neoplasms. Sixty-nine with tumors at sites known to be unrelated to tobacco and alcohol use served as controls. Two hundred patients with epidermoid carcinoma of the oral cavity, pharynx, and larynx constituted the study group. Alcohol use alone increased the risk of acquiring the study cancer 3.6 times; smoking alone increased the risk 5.8 times. Both factors combined increased the risk 19 times. Those who continued to smoke after diagnosis had a fourfold increase in the recurrence rate over those who did not smoke, and double that of those who stopped smoking. Survival was also the lowest in those who continued to smoke, while persistent alcohol use did not affect survival.

Alcohol Drinking↗
PubMed1983

Computed tomography of cervical and retropharyngeal lymph nodes: normal anatomy, variants of normal, and applications in staging head and neck cancer. Part I: normal anatomy.

The retropharyngeal and cervical lymph-node-bearing areas in 30 patients were examined with computed tomography (CT) to determine the range of normal variation in these nodal groups. The data agree with those in the pathologic, anatomic, and surgical literature, and indicate that CT can very precisely determine the size and gross morphology of normal nodes in the retropharyngeal region and the neck. This should have important applications in the management of patients with head and neck cancer.

Head↗
PubMed1983

Computed tomography of cervical and retropharyngeal lymph nodes: normal anatomy, variants of normal, and applications in staging head and neck cancer. Part II: pathology.

Forty-one patients were examined (39 prospectively and 2 retrospectively) with computed tomography (CT) to determine its value in staging cervical and retropharyngeal nodal metastases. Precise surgical confirmation of CT findings was available in 25 patients. CT correctly increased the stage of the disease in six necks, and showed extranodal extent more precisely than the clinical examination in six others. The clinical evaluation proved superior to CT at predicting the extent of extranodal disease in two patients. Both CT and the clinical examination failed to detect microscopic tumor in normal-size nodes in two patients and falsely predicted tumor in enlarged nodes in one. CT offers information important for management and prognosis that is not available from the clinical examination in patients who have already been treated for cancer of the neck, and in patients with extranodal spread or retropharyngeal adenopathy. In the untreated neck CT will increase the stage of the disease from N0 to N1 about 5% of the time. Simple criteria for integrating CT into current clinical-diagnostic staging systems based on this and other experience are presented.

Diagnostic Errors↗
PubMed1981

Primary fungal infections of the paranasal sinuses.

There has been an increase in the number of primary and secondary fungal infections of the paranasal sinuses in recent years. Aspergillosis and mucormycosis are the most common fungal infections involving the paranasal sinuses. In the past, fungal infections usually occurred in patients with uncontrolled metabolic diseases or compromised defense mechanisms as an acute, rapidly progressing process, often leading to the patient's demise. Primary fungal infections may also be aggressive in otherwise healthy individuals. Physicians should be aware of these microorganisms in order to establish an early diagnosis by biopsy and to institute prompt surgical debridement and medical therapy.

Adult↗
PubMed1981

Synchronous tuberculous involvement of both ears and the larynx in a patient with active pulmonary disease.

Since the incidence of pulmonary tuberculosis in the United States has declined dramatically, this diagnosis is often overlooked in the differential diagnosis of puzzling extra-pulmonary disease. Recent publications emphasize that tuberculosis still needs to be considered in patients with chronic ear, nose, and throat complaints. A patient with tuberculosis involving both middle ears, the larynx, and the lung was correctly diagnosed only after a prolonged delay and several visits for chronically draining ears. As a result of the infection, subtotal bilateral tympanic membrane perforations and a profound hearing loss in both ears occurred. This case emphasized the importance of a high index of suspicion in the evaluation and treatment of patients with symptoms of chronic diseases who fail to respond to conventional therapy.

Aged↗
PubMed1980

Action of general anesthesia on middle ear effusions.

An investigation was made of the incidence of "negative myringotomy" or the absence of middle ear effusion when preoperative impedance testing and examination predicted such fluid. The effect of general anesthesia on the clearance of middle ear fluid was studied by comparing preanesthesia and postanesthesia tympanograms with the findings at myringotomy. The effect of nitrous oxide and positive pressure ventilation without nitrous oxide to increase middle ear pressure are mechanisms that could clear low viscosity fluid from the middle ear.

Anesthesia, General↗
PubMed1978

Aspergillosis of the frontal sinus.

Aspergillus is the most common fungal infection of the paranasal sinuses and usually appears as a chronic disease in an otherwise healthy person. Previously reported cases have involved the maxillary sinus alone in the majority of cases. To my knowledge, isolated frontal sinus aspergillosis has not been previously reported. A frontal osteoplastic flap approach was used to expose a fungus ball in the right frontal sinus of a healthy 69-year-old man. Histologic preparations and fungal cultures showed Aspergillus fumigatus. Follow-up substantiated prior experience that surgical removal of the fungal mass with drainage of the involved sinus is the treatment of choice in healthy patients with Aspergillus involving the paranasal sinuses.

Aged↗
PubMed1977

Unusual parotid tumors.

The patient presenting with a mass lesion of the parotid gland is frequently found to have a mixed tumor of salivary tissue origin. However, less common lesions occur in the anatomical region of the parotid gland. These pathological entities deserve consideration in the differential diagnosis. This report presents nine patients with unusual lesions occurring in the parotid region. These regions include cervicofacial actinomycosis, branchial cleft cyst, parapharyngeal tumors, bony lesion of the mandible, non-parotid origin malignant tumor, and metastatic malignant tumors. Each class of lesions demonstrated is also discussed.

Actinomycosis↗
PubMed1975

Stenting in experimental laryngeal injuries.

This experimental pilot project studies acute laryngeal injuries in 20 dogs and compares the use of three types of stenting materials with using no stent at all following the production of a "controlled airway deforming injury." Each injury was repaired meticulously using stainless steel wire to immobilize the cartilage separations, and fine catgut to close the mucosal lacerations. Animals were killed after observation for periods of two to six weeks postoperatively. Marked infection, ulceration, and granulation tissue formation were observed in most of the stented animals, with the nonstented animals showing the most complete and uncomplicated healing. In this experimental model, acute laryngeal "fractures" were adequately stabilized by suturing and a stable cartilaginous framework supported the healing intralaryngeal soft tissues. Avoidance of stenting in this animal series appears to decrease infection, ulceration, and granulation tissue formation resulting in improved healing.

Acute Disease↗
PubMedDate not supplied

Quantitative effects of nasal surgery on olfaction.

A prospective study of 100 patients undergoing nasal surgery was done to quantitate the effects of nasal surgery on olfaction. Patients were evaluated pre- and postoperatively with regard to their subjective olfaction, and pre- and postoperative olfactograms were obtained using a simple office olfactometer. Thirty-two patients had normal olfaction during the course of study. Forty-nine improved following surgery. Eight patients had a decrease in olfaction after surgery. Two of these were related to allergic rhinitis. One patient had a total loss of olfaction following a septorhinoplasty. The authors conclude that most patients undergoing nasal surgery will have either an improvement or no change in olfaction after surgery.

Adolescent↗
PubMedDate not supplied

Intubation success rates by air ambulance personnel during 12-versus 24-hour shifts: does fatigue make a difference?

OBJECTIVES: To determine whether the skill performance and psychomotor agility, as measured by the endotracheal intubation success rate, of air ambulance medical personnel would be affected by the potential fatigue incurred when increasing the length of their shifts from 12 to 24 hours. METHODS: This was a retrospective review of all flight and intubation records from a large air medical transport system from 1997, when 24-hour shifts were in place, and six months (March-August) of 1996, during which 12-hour shifts were scheduled. Records of all intubation efforts during both periods, including multiple attempts per patient, and outcomes of all attempts, were recorded. Results of successes and failures were tabulated for both ultimate intubation outcome per patient and all attempts per patient for each calendar day and for the 12 hours between 19:00 and 07:00 when fatigue might play a role. Results from the two study periods were compared using Fisher's exact test. RESULTS: During the six months of 1996, 190 of 199 (95.5%) patients were ultimately successfully intubated. These patients required 237 attempts (80.1% successful). During 1997, 362 of 376 (96.3%) patients were successfully intubated, and required 438 attempts (82.6% successful). There was no statistically significant difference in the number of ultimately successful intubations (p = 0.66) or total intubation attempts (p = 0.37) between 1996 and 1997. Analysis of intubations between 19:00 and 07:00 revealed 81 of 84 (96.4%) patients successfully intubated in 1996, with 81 of 103 (78.6%) attempts successful. During 1997, 173 of 180 (96.1%) patients were ultimately successfully intubated, with 173 of 212 (81.6%) attempts successful. Again, there was no significant difference in the number of successful intubations (p = 0.99) or intubation attempts (p = 0.55) between 1996 and 1997. CONCLUSION: Psychomotor agility of air ambulance medical personnel, as measured by the success rate of endotracheal intubation, was not affected by the potential additional fatigue incurred as a result of increasing shift length from 12 to 24 hours.

Air Ambulances↗
PubMedDate not supplied

Acquired and congenital subglottic stenosis in the infant.

During the calendar year of 1974, the Intermountain Newborn Intensive Care Center at the University of Utah Medical Center had 603 admissions. A representative group of 293 charts were reviewed which indicated that 44% of these children were intubated from hours to weeks. The overall mortality rate for the 293 children was 29%. Eighteen of the 603 children were diagnosed as having subglottic stenosis. Fifteen of these children appeared to have acquired subglottic stenosis secondary to endotracheal intubation. Three children had congenital subglottic stenosis. Tracheostomy was necessary in the management of 15 patients. Ten of the 18 patients have survived and two of these patients still have tracheostomy tubes in place. The survival and thickness of the stenotic area are inversely proportional to the birth weight and the duration of intubation. Endoscopic excision, dilatation and stenting were techniques utilized in the treatment of these stenotic lesions. The extubation technique utilized is described. The factors involved in the production of acquired subglottic stenosis are presented along with suggestions to decrease the incidence of this problem in the intubated child.

Glottis↗
PubMedDate not supplied

Basal cell carcinoma of the temporal bone.

A case of a 57-year-old man with a 25-year history of untreated basal cell carcinoma of the ear is presented. The lesion resulted in auricular destruction and temporal bone invasion. This case emphasizes the potential destructive ability of basal cell carcinoma. Extensive resection and reconstruction were required for control.

Basal Cell Carcinoma↗