Age as a criterion for eligibility in a lung cancer clinical trial

The results of a clinical trial can be generalized only if the study sample is representative of the population with the disease entity under study. A prerequisite for patient participation in a clinical trial is that all the eligibility criteria be met. In many cooperative group trials, it is common practice to use age as a criterion for eligibility on the premise that advanced age is an unfavorable prognostic factor. In this paper, we evaluate the bias introduced in a sample when this practice was followed in a lung cancer protocol. Of 653 lung cancer cases reviewed, 77 met the eligibility criteria; an additional 23 patients were ineligible for the trial solely on the basis of age. There was no significant difference in survival between these two groups of patients. This indicates that age is not an unfavorable prognostic factor for patients with lung cancer and should not be used as a criterion for eligibility in a clinical trial.

Alternative approaches to evaluating the impact of local control on survival

An important aspect of evaluating treatments aimed at local tumor control is to assess the effect of local control on survival. A common approach to this problem is to compare all patients who have failed locally with those who have not using a logrank test. However, this method of analysis does not take into account the effect of time on a patient's local disease status. Since patients in the local failure group must survive long enough to fail, this group may be biased in favor of longer survival times. The Mantel-Byar extension of the logrank test avoids this source of bias by utilizing the data on time to local failure in defining the local control and local failure groups. In this paper, the application of this technique is illustrated using data from recurrent breast cancer patients and contrasted with the results obtained using the standard logrank test.

The risk of second primaries subsequent to irradiation for cervix cancer

A review of 1048 patients with cancer of the cervix treated with radiation, either alone or combined with surgery, disclosed 32 cases of second primary malignancies occurring from 1 to 16 years subsequent to treatment. Using the person years approach, the incidence rate of second primaries was 5.49 per 1000 person years, which is not significantly different from population based rates. The anatomic locations of the new malignancies and the times from treatment of the cervix cancer to diagnosis of a new primary are presented; the possible carcinogenic effects of radiation are discussed. In this group of patients, it was concluded that under the period of observation irradiation administered at therapeutic doses did not increase the probability of second malignancy in the pelvis or at other sites.

Testicular hypoplasia in a bull with XX/XY chimerism

A 4-year-old 1/2 Hereford X Bos indicus bull displayed XX/XY chimerism associated with arrested spermatogenesis. Phenotypic examination revealed underdeveloped dorsal neck muscles, a non-pendulous scrotum, testes firm in consistency and a scrotal circumference measurement of 27 cm. On rectal palpation, small seminal vesicles were present and only azoospermic seminal fluid was collected at 3 monthly electroejaculations. Chromosome analysis on 2 monthly batches of leukocyte cultures showed a mean chimeric ratio of 80% of XX:20% XY cells. Cells cultured from skin were all male. Histopathological examination of both testes revealed reduction in size and number of tubules, marked hypoplastic germinal epithelium showing only spermatogonia and a well defined interstitium with large quantities of collagen. The small size of the testes and histological changes were suggestive of a testicular hypoplasia.

Bone scintigraphy in evaluation of Didronel therapy for Paget's disease

A case of advanced Paget's disease was successfully treated with Didronel. All indicators of disease activity have been in remission for two years post-therapy. Although sequential radiographs obtained before and after treatment showed slight changes that might have reflected a reparative process, bone scintigraphs revealed more prominent changes, so that radionuclide bone imaging could well be considered as the follow-up imaging study of choice after treatment of Paget's disease.

Clinical expressions of immotile cilia syndrome

To date three distinct morphologic types of immotile cilia disorder in man have been recognized. Patients with the disorder have variable clinical manifestations of disease of the upper and lower respiratory tract. Twenty-one patients with immotile cilia syndrome have been evaluated from the standpoint of history, clinical presentation, radiologic changes, pulmonary function tests, and mucociliary clearance. The results have been compared to the pathologic changes noted on ultrastructural examination of the cilia. Although clinical severity does not correlate with the type of abnormality found, a profile of clinical signs and symptoms suggestive of immotile cilia syndrome has emerged. The triad of productive cough, sinusitis, and otitis was a consistent finding in all. Situs inversus occurred in only half of the patients.

Unaltered maximum reflex vasodilatory capacity of the perfused hindquarters of spontaneously hypertensive rats

Hindquarter reflex vasodilation (RVD delta mmHg decrease in perfusion pressure) in response to arterial pressure elevations by intravenous norepinephrine (NE) was examined in young (2 1/2-3 months) and mature (8-10 months) spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto (WKY) normotensive rats to ascertain whether maximum reflex vasodilatory capacity is altered in the developmental and/or established stages of spontaneous hypertension. The maximal RVD was not significantly different in young or mature SHR (young 26.2 +/- 1.9 and mature 36.2 +/- 3.2) compared to age-matched WKY controls (young 23.9 +/- 1.8 and mature 29.6 +/- 2.3) (P greater than 0.05 between SHR vs. WKY at both ages). However, the rise in mean systemic arterial pressure by NE which produced maximal RVD was greater in mature SHR (116.0 +/- 7.4 mmHg) than in WKY controls (78.3 +/- 6.2 mmHg) (P less than 0.01), whereas no such differences were found between young SHR (85.1 +/- 6.5 mmHg) and its WKY controls (87.5 +/- 2.3 mmHg). There was no difference in the dose of NE that required maximal responses of reflex vasodilation in young or mature SHR compared to WKY controls. In each age group of SHR or WKY rats, RVD was linearly related to the arterial pressure increments. The slope (a +/- SEM) of the regression line for the correlation between the pressure rises and resultant RVD was similar in young SHR (a = 0.424 +/- 0.061) and WKY controls of (a = 0.458 +/- 0.013). In contrast, the slope of the regression line for these two parameters in mature SHR (a = 0.250 +/- 0.004) was significantly smaller than that of either WKY controls (a = 0.364 +/- 0.010) or young SHR (P less than 0.01). The direct hindquarter vasodilation of mature SHR in response to intra-arterial administration of histamine or nitroglycerin was not different compared to that of WKY controls. The results indicate an unaltered maximum hindquarter reflex vasodilatory capacity during the developmental and established stages of genetic hypertension in SHR. An additional finding in the present study was the abnormal responsiveness of the baroreceptor reflex vasodilator system of mature SHR to a wide range of arterial pressure elevations. This abnormal responsiveness may contribute to the maintenance of high blood pressure in the established stage of hypertension.

Circadian rhythms of plasma renin, aldosterone and cortisol on habitual and low dietary sodium intake

To examine the effects of reducing sodium intake upon the renin-angiotensin-aldosterone system (RAAS), 5 healthy men and 5 healthy women, 17-37 years old, living under standardized conditions, were sampled around the clock, once on habitual and once on restricted sodium intake. Plasma renin activity (PRA), aldosterone (PA) and cortisol (PC) were determined by radioimmunoassay. All three variables were found to exhibit a statistically significant circadian rhythm, both on habitual and restricted salt intake. After salt restriction, an increase in midline-estimating statistic of rhythm (mesor) of PRA and PA, but not of PC, was observed. The acrophase (an estimate of the time of high values) for PC lagged behind that for PRA and PA. This difference in acrophase was of specially high statistical significance when subjects were on a sodium-restricted diet. These results demonstrate the importance of inferential statistical so-called rhythmometric methods: parameters such as the acrophase can also be used for the assessment of novel effects and for a quantification in time. The derivation of confidence intervals for each rhythm parameter allows one to verify that a given variable exhibits values bracketing an average not only between a higher and a lower, but also between an earlier and a later limit. Changes that may involve only the acrophase, such as a lead or lag, as here noted, are then detected and are of factual as well as methodological interest.

Reflex cardiovascular responses induced by electrical stimulation of glossopharyngeal nerves in the rat

Reflex cardiovascular responses to electrical stimulation of glossopharyngeal nerves (GPN) were studied in Dial-Urethane anesthetized rats. GPN stimulation at 3 V, 0.3 msec and 50 Hz produced maximal reflex depressor (34 +/- 2 mmHg) and bradycardia (21 +/- 2 beats/min) responses that were altered as follows: pentolinium (0.25 mg/kg, i.a.) blocked approximately 72% and 89% of control values of depressor and bradycardia responses, respectively; tripelennamine (5 mg/kg, i.a.) significantly reduced depressor responses (76%); whereas atropine (0.4 mg/kg i.a.) blocked only bradycardia (85%). Regional blood flow studies showed that GPN stimulation reduced systemic arterial pressure (approximately 25%), and increased iliac artery blood flow (5%), and decreased blood flow through the renal (14%) and superior mesenteric (13%) arteries. Hence, decreases in vascular resistance during GPN stimulation were greater in the hindlimb vascular bed (28%) than in the renal (14%) or the mesenteric vasculatures. In addition, the magnitude of decreases in hindlimb vascular resistance by GPN stimulation was reduced (80%) by pretreatment with tripelennamine, but not by atropine. The results suggest that reductions in arterial blood pressure and hindlimb vascular resistance of the rat in response to GPN stimulation may be mediated via a histaminergic vasodilator mechanism, and that there may be a differential pattern of reflex vascular adjustments of blood flow and vascular resistance among regional vasculatures of the rate.

Carcinoma of the pyriform sinus: predictors of TNM relapse and survival

To determine predictors of TNM relapse and survival for 108 patients with epidermoid carcinoma of the pyriform sinus, the histopathologic features of tumor-related and host-related characteristics were correlated with primary and/or cervical nodal failure, distant metastases, and actuarial three-year survival. Patients in this study received preoperative irradiation and partial laryngopharyngectomy (PLP) or total laryngopharyngectomy (TLP) with en bloc radical neck dissection. Higher rates of local failure were observed in patients with keratinizing tumors (34 vs. 15%), with tumors having an "infiltrating" tumor-stromal interface (30 vs. 14%), with positive surgical margins in PLP or TLP specimens (30 vs. 16%), and with extranodal extension of tumor (39 vs. 22%). The development of distant metastases was significantly correlated with nonkeratinizing carcinomas (30 vs 11%, P = 0.02), and was observed more often in patients with positive lymph nodes (17 vs. 7%). Patients with negative surgical margins in PLP or TLP excision (50 vs. 21%, P = 0.01) survived significantly longer.

Altered cardiovascular responses to glossopharyngeal nerve stimulation in the spontaneously hypertensive rat

Alterations in arterial blood pressure and heart rate in response to electrical stimulation of glossopharyngeal nerve (GPN) were examined in 6-10 months old, male spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto (WKY) normotensive rats. GPN stimulation resulted in frequency-dependent decreases in arterial blood pressure in both SHR and WKY rats. SHR were more sensitive to GPN stimulation than WKY controls. Vasodepressor responses to GPN stimulation were greater in SHR than in WKY rats over a wide range of stimulus frequencies. At the frequency which produced the maximum response (50 Hz) the vasodepressor response was 68% greater in SHR than in WKY control. The results, indicate that neurogenically-induced vasodepression is enhanced in SHR, suggesting that decreased vasodepressor capacity mediated through the central nervous system is not involved in the maintenance of elevated blood pressure in SHR. In contrast to increased vasodepressor responses in SHR, GPN stimulation produced less bradycardia in SHR than it did in WKY rats. This difference may be central in origin because peripheral vagal stimulation produced essentially equal bradycardia in SHR and WKY normotensives.

Relationships of S-phase fraction of breast carcinoma in relapse to duration of remission, estrogen receptor content, therapeutic responsiveness, and duration of survival

The fractions of tumor cells in S phase (DNA synthesis) were measured by in vitro thymidine labeling and autoradiography in 48 breast carcinomas after relapse. The S-phase fractions (SPF's), expressed as S-phase cells/100 cells, had a lognormal distribution with a geometric mean of 6.5 and a median of 7.4. Paired SPF measurements on the primary and relapsed breast carcinomas of 14 patients showed that the SPF usually increased over time. The SPF after relapse correlated negatively with the interval between primary therapy and relapse and with duration of survival after relapse. Low SPF's were associated with older age, minimal nuclear anaplasia, and estrogen receptor positivity, but SPF was the only variable that could be shown to have independent prognostic significance. Therefore, the prognostic powers of the estrogen receptor status and nuclear grade appear to result from their correlations with the SPF. Either low SPF or presence of estrogen receptor predicted response to hormonal therapy.

Studies of autofluorescence in experimentally induced cerebral necrosis in pigs

Lesions of cerebrocortical necrosis experimentally induced in pigs by transcalvarial freezing with liquid nitrogen were slightly fluorescent 48 hours after surgery. Fluorescence increased greatly thereafter and was most marked grossly under ultraviolet illumination with a wavelength of 366 nm at 7 days. Fluorescence of the necrotic focus persisted up to 35 days after surgery. Detection of cerebrocortical necrosis by ultraviolet illumination of fresh specimens during gross inspection is useful in determining the extent and distribution of lesions. This would aid more accurate selection of brain sections for histological examination in various encephalopathies.

Blood pressure in a high school population. II. Clinical profile of the juvenile hypertensive

One-hundred-fourteen hypertensive high school students were evaluated to determine whether a distinctive clinical profile could be identified; 71 normotensive students served as controls. Selected blood chemistry determinations, urinalysis, and chest roentgenograms were done to help rule out secondary causes of hypertension. Left ventricular function was assessed by echocardiography and systolic time intervals. The hemodynamic response to exercise was also evaluated. A significant number of the subjects 14 to 18 years of age with persistent systolic and/or diastolic pressure 1.65 SD above the mean for age and sex showed the following: obesity; elevated serum triglyceride concentration; basilar hypertrophy by electrocardiogram/vectorcardiogram; electromechanical systole and pre-ejection period shorter, and the ratio of the pre-ejection period over the left ventricular ejection time lower, than mean for age and sex as determined by systolic time intervals; volume indices depressed and cardiac contractile functions elevated as determined by echocardiography; higher blood pressure at start of exercise stress test and higher peak systolic and diastolic pressures during test, and a slower return of heart rate to base line level after the test. The above findings should be useful in following the course of a young individual with essential hypertension and may provide a means of evaluating therapeutic intervention.

A review of pseudorabies (Aujeszky's disease) in pigs

The main features in terms of etiology, clinical signs, pathogenesis, pathology, diagnosis, epizootiology and control and prevention that are known about pseudorabies are briefly reviewed. Areas still lacking in information which may provide more effective and reliable means of dealing with pseudorabies are mentioned and recommendations using available tools and knowledge to deal with the problem of pseudorabies are given.

False-positive studies in early 67Ga-citrate scintigraphy

Two cases of false-positive early 67Ga-citrate scintigraphs are presented. In both cases, the initial accumulation of the radiotracer in the region of the right iliac fossa could not be substantiated on the delayed study. It is suggested that the results of an early gallium scan be interpretated cautiously, especially when any apparent abnormality is within the region of the normal colonic anatomy. A delayed study should be performed whenever possible.

Therapeutic activity of pretazettine, a narcissus alkaloid, on spontaneous AKR leukemia

A narcissus alkaloid, pretazettine hydrochloride (PTZ) has been shown to be active against spontaneous AKR leukemia. The long-term treatment with PTZ begining at 5--7 months of age of a group of AKR mice containing 10--20% of advanced leukemic mice significantly prolonged the life span of the group. The therapeutic effectiveness of PTZ has been compared with several standard antileukemic drugs. PTZ decreased the AKR virus titer in the circulating blood of mice and its antiviral activity in AKR virus infected NIH/3T3 cells has been confirmed by XC assay.

Therapeutic activity of pretazettine on Rauscher leukemia: combination of antiviral activity and cellular protein inhibition

Pretazettine hydrochloride (PTZ) has been found to inhibit protein synthesis, without being inhibitory to DNA and RNA, in Rauscher leukemic blood cells in mice for at least 6 h after its administration. With comparison to Virazole and cycloheximide, the specific anti-Rauscher virus activity of PTZ has been demonstrated only in acutely-infected NIH/3T3 cells but not in chronically-infected cells. It is not certain that the inhibitory action of PTZ on reverse transcriptase is contributory to its therapeutic activity in leukemic mice.