Biomedical subjects

W F Taylor

Publications and source records attributed to W F Taylor.

At least 73 records · Page 4Linked to original sources

PubMed1984

Effect of high local temperature on reflex cutaneous vasodilation.

We examined the effect of high local forearm skin temperature (Tloc) on reflex cutaneous vasodilator responses to elevated whole-body skin (Tsk) and internal temperatures. One forearm was locally warmed to 42 degrees C while the other was left at ambient conditions to determine if a high Tloc could attenuate or abolish reflex vasodilation. Forearm blood flow (FBF) was monitored in both arms, increases being indicative of increases in skin blood flow (SkBF). In one protocol, Tsk was raised to 39-40 degrees C 30 min after Tloc in one arm had been raised to 42 degrees C. In a second protocol, Tsk and Tloc were elevated simultaneously. In protocol 1, the locally warmed arm showed little or no change in blood flow in response to increasing Tsk and esophageal temperature (average rise = 0.76 +/- 1.18 ml X 100 ml-1 X min-1), whereas FBF in the normothermic arm rose by an average of 8.84 +/- 3.85 ml X 100 ml-1 X min-1. In protocol 2, FBF in the normothermic arm converged with that in the warmed arm in three of four cases but did not surpass it. We conclude that local warming to 42 degrees C for 35-55 min prevents reflex forearm cutaneous vasodilator responses to whole-body heat stress. The data strongly suggest that this attenuation is via reduction or abolition of basal tone in the cutaneous arteriolar smooth muscle and that at a Tloc of 42 degrees C a maximum forearm SkBF has been achieved. Implicit in this conclusion is that local warming has been applied for a duration sufficient to achieve a plateau in FBF.

Adult↗

PubMed1984

Modification of the cutaneous vascular response to exercise by local skin temperature.

This study examined how local forearm temperature (Tloc) affects the responsiveness of the cutaneous vasculature to a reflex drive for vasoconstriction. We observed responses in forearm blood flow (FBF) and arterial blood pressure to a 5-min bout of supine leg exercise of moderate intensity (125-175 W) after the forearm had been locally warmed to 36, 38, 40, or 42 degrees C for 48 min. With exercise, FBF fell by 1.82 +/- 0.23, 4.06 +/- 0.58, and 3.64 +/- 1.48 ml X 100 ml-1 X min-1 at 36, 38, and 40 degrees C, respectively, and rose by 2.16 +/- 0.57 ml X 100 ml X min-1 at a Tloc of 42 degrees C (mean +/- SE). Forearm vascular conductance (FVC) fell with the onset of exercise by averages of 2.77 +/- 0.57, 7.02 +/- 0.51, 5.36 +/- 0.85, and 4.17 +/- 0.79 ml X 100 ml-1 X min-1 X 100 mmHg-1 at 36, 38, 40, and 42 degrees C, respectively. Second-order polynomial regression analysis indicated that the reductions in FVC were greatest near a Tloc of 39 degrees C and that at a Tloc of 40 or 42 degrees C the cutaneous vasoconstrictor response to the onset of exercise is attenuated. Although elevated Tloc can be used to increase base-line FBF levels to make cutaneous vasoconstrictor responses more obvious, the direct effects of Tloc on this response must also be considered. We conclude that the optimum Tloc for observing reflex cutaneous vasoconstriction is near 39 degrees C.

Adult↗

PubMed1984

Early lung cancer detection: results of the initial (prevalence) radiologic and cytologic screening in the Mayo Clinic study.

The initial (prevalence) radiologic and cytologic screening for lung cancer in the Mayo Clinic study (Mayo Lung Project) involved 10,933 outpatients. All were men at high risk for lung cancer, but none were suspected of having it when they entered the Mayo Clinic. Screening identified 91 lung cancers (8.3 per 1,000 screened). Nearly two thirds of the prevalence lung cancers were detected by chest roentgenography alone. Half of these cancers were resected. Only a fifth of the cancers were detected by sputum cytologic examination alone; however, all but 1 of these were resected. Compared with a group of lung cancers encountered in contemporary clinical practice at the Mayo Clinic, the prevalence cancers were more than twice as likely to be (1) resectable, (2) postsurgical Stage I or II (AJCC), and (3) associated with survival 5 yr after treatment.

Adenocarcinoma↗

PubMed1984

Problems in the clinical and roentgenographic diagnosis of pneumonia in young children.

The difficulty of diagnosing pneumonia by chest x-ray in children less than 4 years of age was studied by comparing the chest roentgenograms of 34 healthy children with the chest roentgenograms of 34 children previously diagnosed as having pneumonia. Review of these films without knowledge of the previous interpretation and without clinical information disclosed variations regarding the roentgenographic confirmation of pneumonia in 24 percent of the cases and variations regarding the location of the lesion in about 50 percent of the cases.

Child, Preschool↗

PubMed1984

A controlled pilot study of high-dose methotrexate as postsurgical adjuvant treatment for primary osteosarcoma.

Thirty-eight patients whose primary extremity or limb girdle osteosarcomas had been completely excised (37 amputations, one limb sparing procedure) were allocated at random to two treatment groups receiving respectively regular follow-up examinations plus a high-dose methotrexate (HDMTX) regimen or regular follow-up without primary adjuvant chemotherapy. Although the vincristine, HDMTX, leucovorin regimen was generally quite tolerable when given at three-week intervals for one year and most of the chemotherapy patients followed the planned HDMTX dose escalations from 3 to 6 to 7.5 g/m2, delayed methotrexate excretion limited dosage escalations in 25%. An estimated 52% of the 38 patients were surviving five years after randomization and an estimated 42% remained continuously relapse-free after five years. No significant differences between the outcomes of the 20 treated and the 18 untreated patients were apparent; however, power to detect differences was low. Furthermore, no significant differences in postmetastasis survival were apparent between the 12 treated and 10 untreated patients who relapsed. Approximately 20% of these failing patients appear to have been salvaged for long-term survival. This pilot study of HDMTX confirms the continuing need for controlled clinical trials in determining the therapeutic value of adjuvant chemotherapy programs for patients with primary osteosarcoma.

Adult↗

PubMed1984

Neurosurgical management of low-grade astrocytoma of the cerebral hemispheres.

The authors conducted a retrospective review of surgically treated, histologically proven cases of low-grade (Grade 1 or 2) astrocytomas. Follow-up analysis, with survival time as the end-point, was completed using multivariant statistical analysis. In the 461 cases of supratentorial low grade astrocytoma in this study, age of the patient at the time of surgery was by far the most important variable in predicting length of survival. Other variables correlating with increasing survival times were: gross total surgical removal, lack of major preoperative neurological deficit, long duration of symptoms prior to surgery, seizures as a presenting symptom, lack of major postoperative neurological deficit, and surgery performed in recent decades. The multi-variant regression analysis showed that radiation therapy was of clear benefit, primarily in older patients with incompletely removed tumors. For purposes of establishing prognosis and testing the results, a "score" was developed to predict survival times, based on the most important variables. The data in this study provide a basis for the analysis of future modes of management of low-grade gliomas.

Adolescent↗

PubMed1984

HemoQuant, a new quantitative assay for fecal hemoglobin. Comparison with Hemoccult.

HemoQuant, an assay based on heme-derived porphyrin, quantifies both total fecal hemoglobin ant that fraction already converted to porphyrin by gut flora (the intestinal converted fraction). Recovery by HemoQuant of blood added to stools exceeded 99% and was not affected by ascorbic acid, iron, or other additives. HemoQuant was used to evaluate the performance of Hemoccult on 1018 stools. Hemoccult sensitivity differed widely, remaining negative with up to 42.5 mg hemoglobin per gram of stool (about 43 mL/d of blood) but positive with only 0.04 mg of hemoglobin per gram of stool. Driest stools tended to be Hemoccult-negative and the wettest Hemoccult-positive. Hemoccult-negative stools became positive after aqueous dilution independent of hemoglobin concentration. The intestinal converted fraction, not detected by guaiac tests, often constituted most of the fecal hemoglobin equivalents and was significantly higher in Hemoccult-negative than in Hemoccult-positive stools. Hemoccult lost reactivity during fecal storage due to progressive heme degradation. Frequent false-negative and false-positive reactions of Hemoccult were explained largely by variations in stool liquidity and heme degradation.

Diagnostic Errors↗

PubMed1983

Myasthenia gravis in children: long-term follow-up.

We report observations made on 149 patients with juvenile myasthenia gravis studied from onset of disease for as long as 40 years. Median follow-up was 17 years; minimum was 4 years. Eight other patients with congenital myasthenia gravis were studied separately. Of the juvenile myasthenic patients, 85 (57%) underwent thymectomy because of diseases severity. In juvenile myasthenia gravis, a spontaneous remission rate of 22.4 per 1,000 person-years was observed, regardless of disease duration. A remission rate of 260 per 1,000 person-years was seen during the first year after thymectomy, with a rate of 95 per 1,000 person-years during the next 2 years. Early surgery, presence of bulbar symptoms, absence of ocular signs or generalized symptoms, onset of symptoms between ages 12 and 16, and presence of other immune disease were associated with increased postoperative remission rates. Epilepsy (4 patients) and neoplasia (7 patients) were the most frequent associated nonimmune disorders; rheumatoid arthritis (5 patients), juvenile-onset diabetes mellitus (3 patients), asthma (3 patients), and thyroid disease (3 patients) were the most frequent associated immune diseases.

Adolescent↗

PubMed1983

Degradation of fenprostalene in aqueous solution.

The degradation of the prostaglandin fenprostalene (III) was studied in aqueous solution. The reaction was both specific acid and base catalyzed. The only reaction found to occur was hydrolysis of the methyl ester at C-1. Activation energies for the acid- and base-catalyzed reactions were determined and are nearly identical to that for the hydrolysis of ethyl acetate, a model ester. A competing acid-catalyzed reaction of the C-1 free acid of III was found to be approximately 10 times slower than the hydrolysis of III.

Chromatography, High Pressure Liquid↗

PubMed1983

Abnormal cardiovascular regulation in the mitral valve prolapse syndrome.

Studies of patients with mitral valve prolapse syndrome have suggested autonomic nervous system dysfunction, but a precise definition of mechanisms is lacking. We measured supine and standing heart rate, blood pressure, cardiac output, oxygen consumption, plasma catecholamines, and blood volume in 23 symptomatic women with both echocardiographic and phonographic signs of MVP and in 17 normal control subjects. An analysis of the results revealed 2 distinct subgroups of patients: those with normal heart rates but increased vasoconstriction (Group I, n = 10) and those with orthostatic tachycardia (Group II, n = 13). Group II patients had heart rates at rest supine of 97 +/- 3 compared with 79 +/- 2 in Group I patients and 78 +/- 8 in control subjects. Estimated total blood volumes were lowest in Group I patients, intermediate in Group II patients, and highest in control subjects (p less than 0.05). Other measurements at rest supine were similar in patients and controls. After standing for 5 minutes, patients had a higher mean plasma epinephrine value, diastolic blood pressure (81 +/- 2 versus 74 +/- 3 mm Hg, p less than 0.05), and peripheral resistance (1,878 +/- 114 versus 1,414 +/- 92, dynes s cm-5, p less than 0.01), wider arteriovenous oxygen difference (6.7 +/- 0.4 versus 5.3 +/- 0.5 vol%), and lower stroke volume index (26 +/- 2 versus 33 +/- 2 ml/m2, p less than 0.01) than did the control subjects. Cardiac output was normal in Group II patients but reduced in Group I patients, who demonstrated marked vasoconstriction. No patient had evidence of a "hyperkinetic" circulatory state. A cycle of decreased forward stroke volume, vasoconstriction, and blood volume contraction appears to be present in at least some symptomatic patients with MVP.

Adult↗

PubMed1983

Bronchogenic carcinoma in patients younger than 40 years.

Bronchogenic carcinoma is reported to be more rapidly fatal in young persons than in older persons. We wondered whether young patients experience a more virulent form of lung cancer or whether other factors might contribute to poor survival. We reviewed the records of 113 Mayo Clinic patients younger than 40 years with histologically proven bronchogenic carcinoma diagnosed between 1956 and 1976. One hundred four patients (92%) had symptoms for a mean duration of 4 months before diagnosis. The disease was categorized as Stage I in 9 patients, Stage II in 6, and Stage III in 98. Fifty-six patients underwent thoracotomy. The procedure was curative in 17 and palliative in 14; in 25, the lesion was unresectable. Respective 1-year and 2-year survivals were 71% and 35% after curative resection and 79% and 28% after palliative resection. The 1-year survival was 82% for patients in Stage I, 40% for Stage II, and 26% for Stage III. Without resection, only 16% of patients lived 1 year or longer. Advanced disease at presentation characterized this group of young patients.

Adult↗

PubMed1983

Influence of thiotepa and doxorubicin instillation at time of transurethral surgical treatment of bladder cancer on tumor recurrence: a prospective, randomized, double-blind, controlled trial.

The influence of the instillation of thiotepa or doxorubicin hydrochloride into the bladder at the end of transurethral surgical treatment on the recurrence of bladder cancer was evaluated. We studied in a randomized, double-blind, controlled fashion 89 patients with transitional cell epithelioma (carcinoma in situ or papillary carcinoma) whose tumors were considered to have been completely removed. Of these patients 28 (the control group) received a placebo (sterile water), 30 received thiotepa and 31 received doxorubicin. By 3 to 4 months postoperatively 71 per cent of the control group, and 30 and 32 per cent, respectively, of the patients treated with thiotepa and doxorubicin had recurrences (p less than 0.01). Additional treatment during the followup interval was ineffective in all groups. Patients studied also were classified according to grade, histological findings, multiplicity of tumors and history of bladder tumor. Treatment was most effective in reducing recurrence in patients with low grade, papillary or multiple tumors and in patients with a history of bladder cancer. No effect was observed in patients with single tumors and only modest effects were found in those with high grade tumors, carcinoma in situ or new tumors. The results support the concept that recurrences may arise from tumor cell implantation at the time of transurethral management of bladder tumors and may be reduced effectively by concomitant intravesical chemotherapy.

Adult↗

PubMed1983

Haemodynamic responses to static and dynamic handgrip before and after autonomic blockade.

1. Six healthy men performed static and dynamic handgrip to local muscular fatigue in approximately 6 min under control conditions, i.e. without drugs and after combined parasympathetic and beta-adrenergic blockade with atropine and metoprolol. 2. From rest to exercise at fatigue, systolic, diastolic and mean arterial pressures increased by 32 +/- 4 and 39 +/- 3 mmHg, 24 +/- 3 and 26 +/- 4 mmHg, and 26 +/- 3 and 30 +/- 3 mmHg respectively for static and dynamic handgrip. There were no significant differences between the pressor responses for the two modes of contraction. Cardiac output increased significantly only during dynamic exercise. Total peripheral resistance increased by 2.3 +/- 1.0 units for static handgrip (P less than 0.05) and by 0.7 +/- 0.8 unit (P greater than 0.05) for dynamic handgrip. Autonomic blockade abolished the heart rate response to both static and dynamic handgrip. For both modes of contraction the systolic arterial pressure responses were 9-12 mmHg lower (P less than 0.05) after autonomic blockade, but the diastolic and mean pressure responses were not significantly affected. A significant increase in cardiac output persisted during dynamic exercise. The increase in peripheral resistance during static exercise tended to be greater after blockade. Plasma noradrenaline and adrenaline levels showed only minor elevations in response to static and dynamic handgrip and were not changed by autonomic blockade. 3. These data indicate that when performed to a common end-point with identical small muscle groups static and dynamic exercise produce an equally large pressor response, which is only slightly attenuated by autonomic blockade.

Adult↗

PubMed1983

Cardiovascular responses to exercise as functions of absolute and relative work load.

The roles of absolute and relative oxygen uptake (VO2 and percent of muscle group specific VO2 max) as determinants of the cardiovascular and ventilatory responses to exercise over a wide range of active muscle mass have not previously been defined. Six healthy men performed four types of dynamic exercise--one-arm curl, one-arm cranking, and one- and two-leg cycling at four different relative work loads--25, 50, 75, and 100% of VO2 max for the corresponding muscle group. VO2 during maximal one-arm curl, one-arm cranking, and one-leg cycling averaged 20, 50, and 75%, respectively, of that for maximal two-leg cycling. Cardiac output was linearly related to VO2 with a similar slope and intercept for each type of exercise. Heart rate at a given %VO2 max was higher with larger active muscle mass. In relation to %VO2 max, systemic resistance was lower and plasma catecholamine levels were higher with larger active muscle mass. The cardiovascular responses to exercise are determined to a large extent by the active muscle mass and the absolute oxygen uptake, with the principal feature appearing to be the tight linkage between systemic oxygen transport and utilization.

Adult↗

PubMed1983

Application of Epstein-Barr virus serology to the diagnosis and staging of North American patients with nasopharyngeal carcinoma.

From 1978 to 1981, 151 patients with nasopharyngeal carcinoma (NPC) were enrolled in a prospective, collaborative study of North American patients, most of them white. Thirty-seven had World Health Organization (WHO) type 1 tumors, and 114 had WHO types 2 and 3 tumors. The anti-Epstein-Barr virus (EBV) profile of elevated antibody titers directed against viral capsid antigen and early antigen was seen in 85% of the patients with WHO types 2 and 3 tumors but in only 16% of the patients with WHO type 1 tumors. Geometric mean titers tended to be higher in higher stages of the disease in several staging systems. Low antibody-dependent cellular cytotoxicity at diagnosis appears to reflect a poorer prognosis, and the determination of antibody titers by this assay may prove to be useful for identifying persons in whom recurrent disease is likely to develop after conventional therapy. Anti-EBV titers can aid in diagnosis and treatment planning in patients with NPC, particularly those with occult primary NPC.

Adolescent↗

PubMed1983

Barium enemas of carcinoma of the colon: sensitivity of double- and single-contrast studies.

A total of 1,140 primary colorectal carcinomas found in 1084 patients during a 5 1/2-year period (1976 to mid-1981) at the Mayo Clinic was reviewed to evaluate the accuracy of detection by the double- and single-contrast barium enema examinations. Both methods were equally sensitive in detecting colon cancer above the proctoscopic level. The error rate (ulcerative colitis excluded) was 4.8% for the single-contrast enema and 4.7% for the double-contrast study. Neither type of examination was superior in finding smaller lesions or earlier staged lesions. Several causes for error were identified: fluoroscopic inexperience, technical factors, misinterpretation of radiologic findings, and distraction.

Adenocarcinoma↗

PubMed1983

The surgical management of medullary thyroid carcinoma.

Medullary carcinoma of the thyroid may occur in three patient groups: multiple endocrine neoplasia, type 2b (MEN2b), MEN2a, and sporadic. The prognosis is best in MEN2a and worst in MEN2b. Multicentric disease occurs in approximately 90% of patients in the MEN groups and in 20% of the patients in the sporadic group. The minimal surgical procedure advocated is total thyroidectomy with dissection of the central compartment nodes. When neck dissection is performed, there appears to be no advantage in resecting the internal jugular vein or the sternomastoid muscle. Primary relatives of all patients with medullary carcinoma should be screened by measurement of plasma immunoreactive calcitonin to identify C-cell disease in a generally unsuspecting group/reservoir and because it results in earlier diagnosis, which leads to a less extensive surgical procedure and a higher percentage of patients with a disease-free state.

Adolescent↗

PubMed1983

Roentgenographically occult lung cancer. A ten-year experience.

During the past 10 years, 54 patients, all men, were found to have roentgenographically occult lung cancer. The mean age was 61 years (range 45 to 76 years). All patients had abnormal findings on sputum cytologic study (carcinoma in 41 patients and squamous cell atypia in 13). The cancer was localized by bronchoscopy in all patients (range one to five examinations, mean 1.5). Seventy-five percent of the tumors were localized within 169 days of the abnormal sputum cytologic examination. Pulmonary resection for cure was performed in all patients: lobectomy in 38, pneumonectomy in nine, and bilobectomy in seven. Operative mortality was 5.6% (three patients). Fifty-eight cancers were resected, all squamous cell carcinomas (two had a component of large cell cancer). Tumor TNM classification (AJC) was TIS N0 M0 in 19 patients, T1 N0 M0 in 25, T1 N1 M0 in five, T2 N1 M0 in four, and T3 N0 M0 in one. Overall 5 year actuarial survival rate (lung cancer deaths only) was 90%. Five-year survival rate for the 44 patients with TIS N0 M0 and T1 N0 M0 neoplasms was 91%. Currently, 21 patients have died, but only 10 of lung cancer. Subsequent additional lung cancer developed in 12 patients (22%). Eleven of these patients had a second primary squamous lung cancer, six of which again were occult. We conclude that patients with occult lung cancer have a strong likelihood of long-term survival if treated early. Close surveillance is indicated because of the high incidence of a second primary lung cancer.

Aged↗