Age trends in lung cancer

To investigate the relationship between the stages of cancer development and the age trends in histologic type found at the time of disease diagnosis, we studied 1,669 patients with histologically proven lung cancer. These patients were examined at the National Taiwan University Hospital using Mantel-Haenszel Chi-square testing to determine a linear trend. These patients were divided into three age groups: group 1 (< 45 years), 141 patients (8%); group 2 (45-64 years), 946 patients (57%); group 3 (65 years or more), 582 patients (35%). The ratio of men to women was 1.4 in group 1, 2.5 in group 2 and 2.3 in group 3. In men, there was a significant trend for the proportion of squamous cell carcinoma to increase from 26% to 42% and that of adenocarcinoma to decrease from 52% to 34% as age increased. In women, an age trend for histologic type was not observed. There was also a significant trend for local-stage squamous cell carcinoma in men to increase from 18% in group 1 to 35% in group 2 and to 42% in group 3. In men, but not in women, local-stage large cell carcinoma increased from 20% in group 1 to 31% in group 2 and to 64% in group 3. However, the age-stage trend for other cell types was not significant in men.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrasound-guided pleural biopsy with Tru-Cut needle

We conducted a study of ultrasound (US)-guided pleural biopsy with a Tru-Cut needle and made a comparison with the results of a traditional pleural biopsy with an Abrams needle. A total of 49 patients with unilateral pleural effusion were included in this study. Twenty-four patients underwent a traditional pleural biopsy with an Abrams needle, and 25 patients underwent a US-guided pleural biopsy with a Tru-Cut needle. The age, sex, and underlying diseases in both groups were compatible. The amount of effusion was much less in the Tru-Cut group. In the patients who underwent the US-guided pleural biopsy with a Tru-Cut needle, the diagnostic sensitivity in pleural tuberculosis was 86 percent (6/7) and in pleural neoplasia it was 70 percent (7/10). In the patients who underwent traditional pleural biopsy with an Abrams needle, the diagnostic sensitivity in pleural tuberculosis was 20 percent (2/10) and in pleural neoplasia it was 44 percent (4/9). The result of US-guided pleural biopsy with a Tru-Cut needle was better than that of pleural biopsy with an Abrams needle, especially in pleural tuberculosis. No complication was found in the Tru-Cut group, but breakage and dislodgment of the tip of an Abrams needle occurred in one patient. The higher diagnostic yield in the Tru-Cut group may be attributed to the US guidance that can delineate the focal pleural abnormalities for biopsy. In conclusion, US-guided pleural biopsy by using a Tru-Cut needle was simple, safe, and well tolerated. It was particularly useful for patients with pleural tumor, thickened pleura, small amounts of pleural effusion, or loculated pleural effusion.

[Effect of combinations of anticancer drugs with interferons on human lung cancer cell lines evaluated by human tumor clonogenic assay]

Using the double agar layer method of human tumor clonogenic assay, the anticancer effect of different combinations of anticancer drugs and interferons was tested on 3 lung cancer cell lines, PC-13, PC-14, and Calu-1. The anticancer drugs and the concentrations used in this study were cisplatin (1.0 microgram/mL), adriamycin (1.0 microgram/mL), mitomycin C (0.2 microgram/mL), VP-16 (5.0 micrograms/mL) and 5-FU (5.0 micrograms/mL). Three kinds of interferon, alpha, beta and gamma in 5,000 units/mL, were tested in combination or in sequence with other anticancer drugs on lung cancer cell lines. The results demonstrate an enhanced anticancer effect on PC-14 only with sequential or simultaneous combination of VP-16 with alpha, beta and gamma interferons; and on Calu-1, only with sequential use of adriamycin and beta-interferon. Our results indicate that there is no unique way of combining anticancer drugs and interferons which can obtain an enhanced anticancer effect on all lung cancer cell lines. The best combination of interferon and anticancer drugs seems to be influenced by the biological characteristics of the cancer cells.

Evaluation of ultrasonically guided biopsies of mediastinal masses

Eighty patients with roentgenographic evidence of mediastinal abnormalities were examined with ultrasonography. Fifty-four lesions were malignant, and 26 lesions were benign. The histologic diagnoses were confirmed by ultrasonically guided fine needle aspiration/cutting needle (Tru-Cut) biopsy, surgical specimens, or transbronchial biopsy. There were no unique ultrasonographic features for diagnosis of specific tumors. Ultrasonically guided aspiration biopsies (UGAB) were performed in 44 of the malignant lesions and in 14 of the benign lesions (nine of the noncystic lesions and five of the cystic lesions). Cytologic diagnosis of malignancies was obtained in 34 (77 percent) of these 44 malignancies; however, accurate histologic classifications of malignancies were achieved in only 24 (55 percent). Accurate diagnoses were achieved in only three (33 percent) of the nine noncystic benign lesions. Ultrasonically guided cutting biopsies (UGCB) were performed in 24 malignant and five benign lesions. All attempts yielded satisfactory specimens for histologic diagnosis. Using UGAB and UGCB together, a positive diagnosis was achieved in 89 percent (39/44) of the malignancies, and accurate histologic diagnosis was achieved in 89 percent and 78 percent (7/9) in malignant and benign noncystic lesions, respectively. Correct histologic diagnosis with UGAB alone is lower in thymoma (55 percent [6/11]) and lymphoma (30 percent [3/10]) but higher in lung cancer (67 percent [8/12]) and metastatic cancer (78 percent [7/9]). There were no complications in this series. We conclude that ultrasonography with UGAB has a high diagnostic yield in diagnosing mediastinal tumors, and UGCB is necessary for thymic tumors, lymphoma, and benign lesions.

Differentiation of lung abscess and empyema by ultrasonography

To assess the value of chest ultrasonography in the differentiation between a lung abscess and empyema, 50 patients, including 24 cases of lung abscess and 26 cases of empyema, were studied. The ultrasonographic characteristics of a lung abscess included an irregular wall width, a blurred outer margin, an oval or round shape, an acute chest wall angle and a negative pleural separation. The ultrasonographic characteristics of empyema were an uniform wall width, a sharp outer margin, a lenticular shape, an obtuse chest wall angle and a positive pleural separation. A new ultrasonographic scoring system was proposed; a positive finding for each of the features: sharp outer margin, lenticular shape, obtuse chest wall angle and positive pleural separation was assigned a score of 1, while a negative finding was assigned a score of zero. The total scores for the four features were then assessed. Ninety-six percent of the empyema cases scored 2 or more, while 96% of the lung abscess cases scored 1 or zero. The efficacy of differential diagnosis was 96%. We conclude that chest ultrasonography is a useful tool in the differentiation between lung abscess and empyema and that ultrasonography alone is sufficient to make a correct diagnosis in most cases.

Tissue polypeptide antigen and carcinoembryonic antigen as tumor markers in lung cancer

Simultaneous measurements of serum tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA) were conducted on 106 patients with bronchogenic carcinoma and 19 patients with inflammatory pulmonary disease. The distribution of cell types was 63 with adenocarcinoma, 26 with epidermoid carcinoma, 9 with small cell carcinoma, 4 with large cell carcinoma and 4 with adenosquamous carcinoma. There were 20 patients in stage 1, 6 in stage 2, 38 in stage 3 and 42 in stage 4 of their disease. The cut-off values of TPA and CEA were 110 U/L and 3 ng/ml, respectively. The diagnostic sensitivity of TPA and CEA was 61% (65/106) and 47% (50/106), respectively. The diagnostic specificity of TPA and CEA was 90% (17/19) and 95% (18/19), respectively. In combination with TPA and CEA the diagnostic sensitivity and specificity to indicate at least one positive result was 73% and 84%, respectively. Both TPA and CEA revealed significantly higher mean serum levels in stage 4 patients than in stage 1 patients. The intermarker correlation between the serum levels of TPA and CEA was low in this study. Serial measurements of serum TPA after surgical resection were found to be useful in the monitoring of recurrence of tumors.

Lung abscesses: US examination and US-guided transthoracic aspiration

Examinations with ultrasound (US) and US-guided transthoracic aspiration were conducted in 35 patients to enable diagnosis of lung abscesses. Thirty-three of the abscesses (94%) were demonstrated at US, while two lesions were not depicted. At US, lung abscesses were depicted as hypoechoic lesions with irregular outer margins and an abscess cavity that was manifested as a hyperechoic ring. Twenty-five abscesses (71%) had local adhesion to parietal pleura (lesion-pleura symphysis). US-guided transthoracic needle aspiration of fluid from the abscess cavity was performed successfully in 31 of 33 patients (94%). A total of 65 pathogens were isolated from 31 aspirates (41 anaerobes and 24 aerobes), not-withstanding the fact that 23 of the patients had been previously treated with antibiotics. Only two of 65 pathogens (3%) could be recovered from blood culture, seven (11%) from sputum culture, and two from bronchoalveolar lavage (3%). Two patients developed minimal pneumothorax. The authors conclude that US examination and US-guided transthoracic aspiration are useful and safe diagnostic methods of collecting specimens to enable accurate diagnosis of lung abscesses.

Sonographic patterns of ribs with tumor involvement

We analyzed the sonographic appearance of the ribs when there was tumor involvement in 16 patients (12 men and 4 women). The tumors included 11 carcinomas, 3 nonepithelial malignancies and 2 benign tumors. Three sonographic patterns on the cross section of abnormal ribs were identified. Pattern I was an eccentrical hyperechoic plate-like shadow inside a hypoechoic tumor. Pattern II was a round hyperechoic shadow or ring in the center of a hypoechoic tumor. Pattern III was a hypoechoic tumor only. The Pancoast tumor manifested pattern I. Metastatic cancer, mostly squamous cell carcinoma, manifested pattern II, and both malignant and benign tumors could manifest pattern III. In sonography, the margin and shape of the tumors, the change in the acoustic shadow of the rib and the pleural line did not differentiate the malignant tumors from benign tumors. When we routinely took a biopsy of these tumors under sonar guidance, the diagnostic yield was 100% without any complications. We conclude that the rib should be evaluated in chest sonography, and that pattern recognition and biopsy under sonar guidance are most useful.

Amitraz-induced glucose intolerance in rats: antagonism by yohimbine but not by prazosin

Amitraz (N'-[2,4-dimethylphenyl]-N-[(2,4-dimethylphenyl)imino]-N- methylmethanimidamide) is a formamidine insecticide/acaricide that increases plasma glucose and decreases plasma insulin concentrations in dogs when applied topically. Because amitraz activates alpha 2-adrenoceptors in numerous tissues, in this study we used rats as a model to determine whether these effects of amitraz are mediated by alpha 2-adrenoceptors. The i.v. injection of amitraz (0.1, 0.3, and 1 mg/kg) followed by i.v. glucose injection (1 g/kg) induced a dose-dependent glucose intolerance characterized by hypoinsulinemia. At 1 mg/kg, amitraz completely blocked the insulin release induced by i.v. glucose administration. The alpha 2-adrenoceptor antagonist yohimbine (1 mg/kg, i.v.) prevented the effects of amitraz, but the alpha 1-adrenoceptor antagonist prazosin (0.3 mg/kg, i.v.) did not. The results suggested that one mechanism by which amitraz prolongs glucose-induced hyperglycemia is via inhibition of insulin release and this effect is mediated by alpha 2-adrenoceptors.

Ultrasonic evaluation of cervical lymphadenopathy

Seventy-seven patients with various underlying diseases underwent real-time ultrasonographic study of the neck. The sonography of lymph nodes can be round or ovoid shaped, discrete hypoechoic nodules, or multiple confluent lobulated heterogeneous or homogeneous hypoechoic masses. Venous invasion by a malignant lymph node can also be demonstrated by ultrasonography as a loss of echogenicity in the vessel wall. Twenty-five patients with malignant cervical lymph nodes showed homogeneous discrete hypoechoic nodules. Eleven patients with malignant lymph nodes showed a multiple confluent lobulated hypoechoic picture, among them, 2 patients also had discrete hypoechoic nodules. Eight patients with multiple confluent lymph nodes showed evidence of venous invasion. Among 42 patients with a clinically palpable neck mass, 1 showed venous thrombosis in the internal jugular vein, 2 had abscesses, and 3 had normal musculo-skeletal tissues. Among 35 patients with clinically impalpable cervical lymph nodes, 5 patients had cervical lymphadenopathy. All 41 patients with sonographically detectable lymph nodes underwent aspiration cytology or biopsy, and 36 of these showed malignancy, 4 TB lymphadenitis and 1 nonspecific inflammation. No complication was observed in this series. We conclude that ultrasonography is a valuable tool to evaluate cervical lymphadenopathy and to clarify the histopathological features of the affected lymph nodes with the aid of aspiration cytology.

Lung tumors associated with obstructive pneumonitis: US studies

Eleven patients who had lung tumors associated with obstructive pneumonitis and who failed to yield diagnostic material at conventional bronchoscopic biopsy underwent real-time ultrasonographic (US) studies and US-guided aspiration biopsy. Sonography of the consolidated lung showed a wedge-shaped hypoechoic lesion containing a fluid bronchogram. The presumed obstructing tumor was seen as a hypoechoic nodule near the hilum or as a well-defined hyperechoic mass inside the partially consolidated lung. Computed tomography (CT) was superior to US in demonstrating the bronchial obstruction (P less than .05). However, there were no significant differences between CT and US in demonstrating the obstructing tumor (P greater than .10). In all 11 patients the diagnosis was made by means of US-guided transthoracic aspiration biopsy and in eight patients also by means of Trucut biopsy. No complications were observed in the studies. It is concluded that US and US-guided aspiration biopsy are useful adjunct diagnostic techniques for lung tumor patients with obstructive pneumonitis.

Serum macro creatine kinase type 2 as a tumor marker in lung cancer: comparison with carcinoembryonic antigen

Macro creatine kinase type 2 (MCK-2), an atypical cathodically migrating creatine kinase isoenzyme, was first detected in the serum of a breast cancer patient in 1978. In recent years, MCK-2 was also found in the sera of several malignancies and has been proposed as a potential tumor marker. Forty two patients with lung cancer. The rates of MCK-2 presence in serum were 56.8%, 29.6%, and 0%, respectively, for primary lung cancer, inflammatory lung disease and normal controls. In primary lung cancer, the rate of presence of MCK-2 was higher than CEA (40.0%), and appeared more frequently in epidermoid cancer (71.3%) and in stages 3 and 4 (65.4%). Serial examinations postoperatively showed that MCK-2 became negative after resection. Carcinoembryonic antigen, MCK-2 or a combination of both was evaluated as a diagnostic aid in 37 patients with a peripheral pulmonary nodule. Sensitivity, specificity and accuracy were 32.0%, 90.9%, 50.0%, 36.4%, 93.3%, 59.5%; 43.8%, 90.5%, 70.3%, respectively, for CEA, MCK-2, and CEA plus MCK-2. It is concluded that MCK-2 is comparable to CEA as a tumor marker in lung cancer. The combination of MCK-2 and CEA is of value as a diagnostic aid in patients with a peripheral pulmonary nodule.

Tumor markers of lung cancer: carcinoembryonic antigen and TuMark

To assess the value of tumor marker determinations in diagnosing lung cancer and monitoring the response to therapy in lung cancer patients, we tested the serum concentration of TuMark-reactive protein and carcinoembryonic antigen (CEA) in 78 patients with lung cancer and 81 patients with non-malignant diseases. The sensitivity of TuMark in detecting the presence of lung cancer was 63.8%, compared to 37.2% for CEA (p less than 0.05). The specificity was 91.3% for TuMark and 97.5% for CEA. The combination of TuMark and CEA increased the sensitivity to 74.3%. The sensitivity of TuMark for non-small cell carcinoma was significantly higher than that for small cell carcinoma (67.6% vs 30.0%) (p less than 0.05). The incidence of positive TuMark reactivity did not correlate with the stages of lung cancer. Since the incidence of positive CEA reactivity was lower in the limited stage than in the extensive stage of lung cancer (20.0% vs 43.1%), the sensitivity of TuMark with regard to the detection of early stage lung cancer appeared far superior to CEA (65.0% vs 20.0%, p less than 0.05). Serial monitoring of TuMark levels in 32 patients with all types of lung cancer showed that 84% correlated with their clinical courses. Six patients with stage I or II disease received complete surgical resection of tumors. All showed a decline of the TuMark level to normal levels in 17 to 48 days (average of 32 days). These results suggested that the TuMark test may be a useful new marker for diagnosing lung cancer and monitoring response to therapy, especially for non-small cell lung cancer.

Ultrasonography in complete chest X-ray opacification of hemithorax

To assess whether ultrasonography is valuable in the diagnosis and management of patients with complete chest X-ray opacification of hemithorax, chest ultrasonography was conducted in 65 patients. There were 54 patients (83.1%) with massive pleural effusion with or without other pathology, six (9.2%) with tumors, two (3.1%) with organized fibrothorax, two (3.1%) with consolidation or atelectasis and one (1.5%) with pseudocyst of the pleura in the sonographic diagnosis. Sonography differentiated effusion from tumor, consolidation and fibrosis. The effusion showed a hypoechoic area with floating fibrin strands and changed shape on respiration. The tumor revealed a homogeneous iso- or hypoechoic mass with a sharp margin. Consolidation or atelectasis showed a lobar or segmental area of heterogeneous isoechoic density with air-bronchogram. The pleural showed an area of hypoechoic density without floating fibrin or a changed shape on respiration. In 24 (37%) patients we could demonstrate complex pathology addition to the pleural effusion. Twenty-one patients had a hidden tumor beneath the effusion. Three patients had consolidation or atelectasis with effusion. In 13 patients, aspiration biopsy was performed under ultrasonic guidance from the tumor and the histological diagnosis was confirmed in 12 patients. We conclude that ultrasonography is a very useful, noninvasive tool in the differential diagnosis of complete chest X-ray opacification of hemithorax. Complex pathology is also easily detected by sonography. Sonographic findings can also be used as a guideline for an appropriate approach to the patient's management.

A new class of orally active glycol renin inhibitors containing phenyllactic acid at P3

We prepared a new series of renin inhibitors based on dipeptide glycols, replacing the P4-P3 subsites with an O-(N-morpholinocarbonyl)-3-L-phenyllactic acid residue. This modification proved bioisosteric with Boc-L-phenylalanine, giving rise to highly potent human renin inhibitors (1-5 nM), e.g., SC-46944 (IC50 = 5 nM). Moreover, this change produced compounds that are orally efficacious in reducing plasma renin activity in salt-depleted marmosets.

Pathologic prognostic factors for cutaneous malignant melanoma: the Western Canada Melanoma Study

An analysis of data for histopathologic factors influencing survival was conducted on 798 cases of invasive cutaneous malignant melanoma. On univariate analysis, a number of factors influenced survival; however, when these factors were examined using a proportional-hazards model, sex and log of depth of penetration were the only factors governing survival. Moreover, these factors were only important in patients with lesions up to 4 mm in depth with no evidence of other disease. For patients with solitary lesions deeper than 4 mm, or patients with regional or distant disease, none of the factors examined in our study was of predictive value for survival assessment.

Immunological surveillance in a pseudorabies quarantined herd using gilts and their progeny as sentinels

Specific pathogen free gilts and their progeny were evaluated to use as sentinels in a pseudorabies virus (PRV) infected herd by immunologically monitoring for PRV seroconversions. Time intervals targeted were pre- and post-PRV vaccinations, herd exposure, and farrowing to finishing. Post-PRV vaccinations, gilts showed low PRV lymphocyte stimulation and humoral responses. Following herd exposure, control gilts PRV seroconverted and PRV vaccinated gilts increased (2 to 4 times) in virus neutralization (VN) titers. Sixty-seven percent (4/6) of the progeny from a control gilt were PRV seropositive at finishing. Progeny from PRV vaccinated gilts were depleted of passive immunity by week 7, and were seronegative until week 9. At finishing 47% (14/30) of them were PRV seropositive indicating exposure to PRV. The VN test was not sensitive enough to detect weak positive serums, noted as positives by latex agglutination (LA) test, ELISA, and Western blots. The gilts and progeny detected PRV, respectively, in the herd housing quarters and in the farrow to finish facilities. A strategy for future sentinel experimental surveillances using primarily the LA test is proposed.

Calcium uptake studies of 1,4-dihydropyridine agonists into rabbit aortic smooth muscle cells in culture

The effects of the three dihydropyridine calcium channel agonists (+/-)BAY K 8644, (+)202-791 and (+/-)CGP 28392 on 45Ca++ uptake were studied in cultures of rabbit aortic smooth muscle cells. At 10(-7) M each agonist enhanced 45Ca++ uptake in 15-50 mM K+ but had no effect on the basal 45Ca++ uptake at 5 mM K+. At the uptake threshold of 15 mM K+ each agonist potentiated 45Ca++ uptake in a dose-dependent manner with half maximal effects at 2.4 nM for (+/-)BAY K 8644, 22 nM for (+)202-791 and 18 nM for (+/-)CGP 28392. The agonists showed no significant antagonistic activity. Responses were antagonized competitively by nifedipine and non-competitively by (+/-)D-600. The 45Ca++ uptake dose-response curves and the half maximal effects of the three agonists were over the same range of concentrations as their inhibition of [3H]nitrendipine binding to rat ventricular receptor membrane preparations. The data suggest that these cells mimic the calcium uptake by the intact aorta better than commercial vascular smooth muscle lines or cardiac cells.

Differences in the sex ratio of laryngeal cancer incidence rates by anatomic subsite

The incidence data from nine population-based cancer registries participating in the Surveillance, Epidemiology and End Results program in the U.S. suggest that squamous cell carcinoma arising from different parts of the larynx have different etiologic influences. The male to female rate ratio for laryngeal cancers was substantially higher in the glottic region (9.2 among whites and 11.8 among blacks) than in other subsites (approx. 3-5 in both races). The sex rate ratios were uniformly higher for glottic tumors in all age groups, and these ratios increased more rapidly with age for glottic than for supraglottic tumors. Factors that are closely related to sex other than smoking and drinking behavior are responsible for the considerably high ratio of male to female rates of the glottic tumors. Future etiologic studies should investigate the possible differential effect of hormonal or other sex-related factors on different anatomic subsites within the larynx.

Ultrasonography of Pancoast tumor

Eleven patients with Pancoast tumor, who failed to yield diagnostic materials by conventional sputum cytology and fiberoptic bronchoscopy, were studied by real-time linear-array and sector ultrasonography. The sector scanner through the supraclavicular approach adequately visualized the external profile and the internal texture of the lesions in all 11 patients, which is a significant improvement (p less than 0.05) over what can be accomplished with linear-array scanner through the intercostal approach. All patients received percutaneous transthoracic aspiration under ultrasound guidance. Positive cytologic diagnosis was established in ten of the 11 patients (91 percent). Additional biopsies performed in seven patients under similar ultrasonic guidance also provided concordant results. No complications were observed in this series. This study has clearly shown that ultrasound-guided aspiration biopsy can be a safe and useful means for obtaining materials for pathologic confirmation of Pancoast tumor. It may also assist in defining the tumor extension to pleura and adjacent structures.

Epidemiological characteristics of adenocarcinoma of the gastric cardia and distal stomach in the United States, 1973-1982

Data from the Surveillance, Epidemiology, and End Results (SEER) programme of the National Cancer Institute were utilized to estimate the incidence of adenocarcinoma of the gastric cardia and distal stomach in the US in order to determine whether the epidemiological features of these diseases differ. Based upon 12,562 histologically confirmed cases identified, the annual incidence of gastric cardia adenocarcinoma was 1.1 per 100,000 people and for the distal stomach 3.8 per 100,000. The male-to-female ratio for adenocarcinoma arising in the cardia was 7.0, versus 2.2 for that arising in the distal stomach. The sex ratio shifted across age groups for the gastric cardia and was highest for the 50-59 year age group, but remained relatively stable across age groups for cancers of the distal stomach. Over the decade studied, the sex ratio decreased from 8.0 to 4.6 for gastric cardia tumours, but remained constant for adenocarcinoma of the distal stomach. Blacks were 2.5 times more likely to develop adenocarcinoma of the distal stomach than whites, but had a 50% lower risk of gastric cardia tumours than whites. These results support an emerging concept that adenocarcinoma of the gastric cardia, gastro-oesophageal junction and distal oesophagus may comprise a group of disease which is aetiologically distinct from distal gastric tumours.

Incidence of cancer of the esophagus in the US by histologic type

Data from nine US population-based cancer registries participating in the Surveillance, Epidemiology, and End Results (SEER) program from 1973 through 1982 were analyzed to examine demographic characteristics related to the occurrence of the two major types of cancer of the esophagus. The overall annual incidence rate per 100,000 persons was 2.6 for squamous cell carcinoma and 0.4 for adenocarcinoma. The sex ratio for adenocarcinoma varied from one age group to the next and was highest in the 50- to 59-year-old group. It was relatively the same for squamous cell carcinoma. The male-to-female ratio was higher for adenocarcinoma (seven in whites and 10 in blacks) than for squamous cell carcinoma (three and four, respectively). The highest sex-specific ratio for adenocarcinoma occurred in the lower third of the esophagus. Blacks had a fourfold to fivefold higher rate of squamous cell carcinoma than whites, but the rate of adenocarcinoma in blacks was 30% of the rate in whites. The incidence of squamous cell carcinoma in black men and women increased by approximately 30% between 1973 and 1982, and the rate of adenocarcinoma among white men increased 74%. Nearly half of the squamous cell carcinomas occurred in the middle of the esophagus, whereas the majority (79%) of the adenocarcinomas arose in the lower third. These data suggest that the two major histologic types of esophageal cancer may be of different etiologic origin.

Enhanced potency dipeptide glycol renin inhibitors: studies in vitro and in the conscious rhesus

We prepared a series of novel dipeptide amides of the formula Boc-Phe-Leu-X, where X is a 3-amino-3-alkyl-1,2-propanediol with lower alkyl substitutions at C-1, in order to probe accessory binding sites in the enzyme renin. This approach was successful in generating potent inhibitors of human and hog renin in vitro. Moreover, these inhibitors were able to effect in vivo reduction of plasma renin activity (PRA) in the conscious salt-depleted rhesus monkey (i.v. route); this effect was related to the size of the C-1 alkyl group.

Calcium channel blockers: correlation among receptor binding, calcium uptake and contractility in vitro

Ten known calcium channel blockers were studied for inhibition of K+-induced 45Ca++ uptake into rabbit aortic smooth muscle cells in culture, and for displacement of [3H]nitrendipine [2,6-dimethyl-3-carbomethoxy-5-carbomethoxy-4-(3-nitro)phenyl-1, 4-dihydroxypyridine] binding to rat ventricular membrane preparations, in order to relate their effects on receptor binding with their inhibitory activities on 45Ca++ uptake and on contractile responses of vascular smooth muscle. Steady-state 45Ca++ uptake increased with K+ concentration in a dose-dependent manner. With 25 to 50 mM K+, Ca++ uptake was 0.6 nmol of Ca++ per one million cells. All calcium channel blockers inhibited K+-induced 45Ca++ uptake and [3H]nitrendipine binding in a dose-dependent fashion. The enatiomeric dihydropyridines 202-791 [isopropyl-4-(2,1,3-benzoxadiazol-4-yl)-1,4-dihydro-2, 6-dimethyl-5-nitro-3-pyridinecarboxylate] exhibited marked stereoselectivity in both studies, the agonist (+)-202-791 significantly enhancing 45Ca++ uptake at 15 to 50 mM K+. The similarity between the order of potency in inhibiting 45Ca++ uptake and displacing [3H]nitrendipine resulted in a highly significant linear (1:1) correlation. An equally significant correlation was also established for the 10 blockers between their inhibitory potencies on 45Ca++ uptake and the contractile response of rabbit aortic strips as cited in the literature. These findings support the hypothesis that calcium channel blockers block contraction of vascular muscle by inhibiting cellular calcium uptake through voltage-dependent calcium channels as a result of binding to receptors associated with these channels. The aortic cells possess channels that are functionally similar to those found in intact vascular tissue.

Selective vasodilation produced by renal denervation in adult spontaneously hypertensive rats

The kidneys of adult male spontaneously hypertensive rats (SHR) were denervated, and systemic and regional blood flows were measured 3 to 5 hours or 5 days after denervation. Arterial pressure was reduced 20 to 27% in denervated SHR during both periods compared with that in sham-operated SHR (iliolumbar blood vessels painted with phenol). This hypotensive response was produced by a 32 to 35% reduction in total peripheral resistance. At 3 to 5 hours and at 5 days, a major decrease in total peripheral resistance was produced by vasodilation in the kidneys and splanchnic organs. Acute urine output, sodium excretion, and plasma renin activity in response to a saline load were not different between sham-operated and denervated SHR. The decreased total peripheral resistance in denervated SHR may have been secondary to a decreased central sympathetic nerve activity revealed by a decreased maximum response to ganglionic blockade. The results suggest that a pathophysiological link may exist between the kidneys and splanchnic organs in genetic hypertension and that specific efferent antiadrenergic or antiafferent nerve therapy, or both, in the kidney may lead to substantial specific decreases not only in renal vascular resistance but also in splanchnic vascular resistance and total peripheral resistance.

Dipeptide glycols: a new class of renin inhibitors

The discovery of a new class of novel renin inhibitors consisting of protected dipeptide amides derived from aminoglycols (Formula I) prompted a study of structure-activity in vitro and efficacy in vivo. Thus, Boc-L-Phe-N-[(1S,2R)-1-benzyl-(2,3-dihydroxy)propyl]-L-leucinamide (1) and the corresponding histidinamide (2) inhibit human renin in vitro (IC50: 8.7 X 10-6 M and 2.6 X 10-6 M, respectively). Compound 1 has a slight inhibitory effect on pepsin and compound 2 does not inhibit pepsin at all (at 10-4M); these compounds are inactive against rat renin. Compound 1 is efficacious in lowering plasma renin activity in the Rhesus monkey (i.v.). Results indicate that this new class of low molecular weight inhibitors is specific for human renin and thus constitutes a new source of drug candidates.

Growth rate of asymptomatic hepatocellular carcinoma and its clinical implications

The growth rate of 31 asymptomatic hepatocellular carcinomas (diameter less than or equal to 5 cm) discovered in 28 patients by a prospective screening program was determined by real-time ultrasonography over 36-860 days. Except for one tumor that shrank on follow-up, the doubling time ranged from 29 to 398 days, with a median of 117 days, an arithmetic mean of 136 days, and a geometric mean of 110 days. In 17 tumors with more than two measurements, the growth rate remained exponential in nine, declined in growth in seven, and showed an initial lag period in one. Doubling time correlated with initial tumor diameter but was independent of the patient's age, sex, hepatitis B surface antigen status, tumor location, liver function tests, stage of liver cirrhosis, histologic type, or grade of malignancy. Although initial alpha-fetoprotein levels did not correlate well with growth rate, in 14 patients with an exponential increase of serum alpha-fetoprotein, the alpha-fetoprotein doubling time was closely related to the tumor doubling time. Based on the above data, the median detectable subclinical period of hepatocellular carcinoma was deduced to be 3.2 yr, and the suitable screening interval for its early detection in our area was 4-5 mo.

Early detection of hepatocellular carcinoma by real-time ultrasonography. A prospective study

For early detection of hepatocellular carcinoma (HCC), real-time ultrasonography (US) was performed prospectively in 528 patients, including 236 with cirrhosis, 81 with chronic hepatitis, 168 asymptomatic hepatitis B surface antigen carriers, and 43 with a family history of HCC. Simultaneous measurement of serum alpha-fetoprotein (AFP) level was also done. In addition, 233 patients had regular controls at 3- to 6-month intervals, with an average follow-up period of 1.4 years. On initial screening, a total of 17 patients were found to have HCC: 13 in the cirrhotic group, 3 in the HCC family group, and 1 in the asymptomatic carriers. Of these HCCs, 7 were smaller than 3 cm, 6 were between 3 to 5 cm, and 4 were larger than 5 cm. In patients with tumors smaller than 5 cm, the AFP levels were normal in 46.2%, between 20 to 400 ng/ml in another 46.2%, and only 7.6% were over 400 ng/ml. On follow-up, another seven patients, all in the cirrhotic group, were found to have HCCs varying from 1.6 to 4.7 cm; three of them had normal serum AFP level. The authors conclude that real-time US is more sensitive than AFP assay in early detection of HCC, and the high-risk subjects should receive this procedure at regular intervals.

Peripheral pulmonary lesions: ultrasonography and ultrasonically guided aspiration biopsy

Twenty-five patients, each of whom had peripheral intrathoracic lesions that were smaller than 5.0 X 5.0 cm in size and not diagnosed by conventional methods, underwent real-time sonography and ultrasonically guided aspiration biopsy. The lesions included 18 nodules, two infiltrates, and five cavitary lesions. Sonography showed homogeneous hypoechoic or isoechoic density with well-defined margins in 16 of the nodules, and heterogeneous echogenicity with irregular margins in infiltrates. The cavitary lesions showed a hyperechoic ring with a central sonolucent area. Biopsy specimens were successfully obtained by percutaneous aspiration under ultrasound guidance in 24 (96%) of the patients, and a positive diagnosis was established in 21 (84%) by cytology and/or histology. All 17 malignant lesions were diagnosed by aspiration biopsy, while only four of seven benign lesions were diagnosed by this method. Two patients (8%) experienced minimal pneumothorax after aspiration biopsy. We conclude that real-time sonography, including ultrasonically guided aspiration biopsy, is a useful and safe method for examination of peripheral intrathoracic lesions and has a high diagnostic yield.

Hepatocellular carcinoma: US evolution in the early stage

To study the sonographic evolution of hepatocellular carcinoma (HCC) in its early stage, 26 HCCs in 24 patients were observed regularly with real-time ultrasound for a period of 90 to 691 days. In the beginning, 21 tumors were hypoechoic, two isoechoic, and three diffusely hyperechoic. On follow-up, two of the 21 initially hypoechoic HCCs remained the same echodensity, 12 increased in internal echoes but were still hypoechoic, one became isoechoic, four changed to hyperechoic, and the remaining two shifted from hypoechoic to isoechoic and then to hyperechoic. The two initially isoechoic HCCs also gained echogenicity and became hyperechoic. By contrast, the three initially hyperechoic HCCs kept the same echo patterns. The "acquired" hyperechoic HCCs were inhomogeneous in echodensity and larger in size whereas the three originally hyperechoic HCCs were homogeneous and smaller. It is concluded that most small HCCs evolve progressively from hypoechoic to isoechoic and then to inhomogeneously hyperechoic patterns as they grow; a few HCCs have diffusely high echogenicity from the beginning and retain the same features thereafter.

New class of inhibitors specific for human renin

Seven active tetrapeptide amides characterized by a C-terminal phenylalanyl aminoadamantane (PheNHAd) sequence, were identified by selective testing for human renin inhibitory activity among compounds with adjacent hydrophobic groups and molecular size equivalent to 3-5 amino acid residues. The new inhibitors were compared with known renin inhibitors (RIP, pepstatin, H-77) and opioid analgesic agents (Met-enkephalin, morphine), with the following results: The new inhibitors were active against human renin (IC50 approximately 10-5M), but inactive against rat renin and pepsin. Although active in opiate receptor binding studies (IC50 approximately 10(-7)M), they were, with few exceptions, inactive in the mouse writhing and hot plate tests for analgesia. SAR studies suggested a separation of the renin inhibitory from the analgesic activity of enkephalin analogs. Preliminary experiments with sodium-depleted rhesus monkeys indicated hypotensive activity for three of the new inhibitors at 3 mg/kg i.v., and RIP at 1 mg/kg. The recently reported clinical hypotensive properties of RIP (Zusman et al., Trans. Assoc. Am. Physicians 96:365, 1983) along with the present comparative studies suggest that the new inhibitors may lead to clinically useful agents.

Thermal melting of chromatin from the pancreas and liver of guinea pigs treated with 1-methyl-1-nitrosourea

The carcinogen 1-methyl-1-nitrosourea (MNU) can cause pancreatic cancer in guinea pigs. We have examined the relative damage produced by MNU treatment on the chromatin from pancreas and liver of these animals. Thermal denaturation of chromatin from guinea pig pancreas and liver was studied following parenteral administration of MNU in several doses. Estimates of single strand breakage were also obtained by examination of the fluorescence of intercalated ethidium bromide. Oligomeric chromatin melted with a main Tm at 78 degrees C, with additional components at 48 degrees C, 55 degrees C and 65 degrees C. Repetitive treatment with MNU at several doses between 20 mg/kg and 70 mg/kg produced destabilization of pancreatic chromatin as shown by a shift from 78 degrees C to lower melting components. The liver by contrast was relatively unaffected. In addition, pancreatic chromatin showed an increase in alkali-induced strand unwinding with MNU treatment, probably due to an increase in single strand breaks, while there was no change in this regard in the liver. The data indicate that the pancreas is more susceptible to damage by MNU than the liver.

Adenylyl cyclase activities in ovarian tissues. I. Homogenization and conditions of assay in graafian follicles and corpora lutea of rabbits, rats, and pigs: regulation by ATP, and some comparative properties

Responsiveness of ovarian adenylyl cyclases to luteinizing hormone (LH), found to be 5 to 10-fold in cell-free preparations under optimal conditions, required gentle homogenizations and storage in sucrose-containing media. Assay conditions required the use of an ATP-regenerating system consisting of creatine kinase, creatine phosphate, and myokinase for the preservation of ATP levels. LH-stimulated adenylyl cyclase (AC) in rabbit CL showed the following properties: 1) The pH optimum of basal activity was about 8.0; that of LH-stimulated activity was about 7.5. 2) The relative response to LH was low (1.5 to 2-fold) at 0.1 mM ATP and increased with increasing ATP, but not with increasing GTP. At low (0.1 mM) ATP, GTP increased catalytic efficacy of the system, both in the absence and in the presence of LH (no effect on relative stimulation). 3) The optimal relative stimulation by LH was obtained at about 1.0 mM MgCl2 in excess of added magnesium-binding ingredients. 4) The sensitivity to stimulation by LH (about 0.2 mug/ml NIH-LH-B8) was unaffected by either pH, nucleotides (ATP and GTP), or MgCl2 concentration. 5) Under the assay conditions used, activity was stimulated by prostaglandin E1 (PGE1) about 1.5 to 2-fold, and by epinephrine about 3 to 4-fold. In all aspects tested, LH-stimulated AC in rat CL resembled that in rabbit CL, except that about 5-fold higher concentrations of NIH-LH-B8 were needed for half-maximal stimulation. The AC activity in pig Graafian follicles, however, differed from that in rabbit CL in that 1) the ATP concentration needed for optimal stimulation by LH was lower (in the micromolar rather than the millimolar range); 2) catecholamines elicited only a 1.3 to 1.4-fold stimulation; and 3) NIH-LH-B8 elicited half-maximal stimulation at 0.008 to 0.020 mug/ml. We were unable to detect LH-responsive AC activity in either homogenates or washed particles of CL from either cycling or pregnant pigs. LH fractions of three origins (human, bovine, and ovine) and of varying specific activities (from 0.041 to 2.0 NIH-LH-S18 units/mg) were tested and the relative potencies by OAAD assay were found to correlate well with the relative potencies in the adenylyl cyclase assays (rat CL, rabbit CL, and pig follicles), consistent with the possibility that AC receptors are responsible for biologic actions of LH.