A mortality study of workers at seven beryllium processing plants

The International Agency for Research on Cancer (IARC) has found that the evidence for the carcinogenicity of beryllium is sufficient based on animal data but "limited" based on human data. This analysis reports on a retrospective cohort mortality study among 9,225 male workers employed at seven beryllium processing facilities for at least 2 days between January 1, 1940, and December 31, 1969. Vital status was ascertained through December 31, 1988. The standardized mortality ratio (SMR) for lung cancer in the total cohort was 1.26 (95% confidence interval [CI] = 1.12-1.42); significant SMRs for lung cancer were observed for two of the oldest plants located in Lorain, Ohio (SMR = 1.69; 95% CI = 1.28-2.19) and Reading, Pennsylvania (SMR = 1.24; 95% CI = 1.03-1.48). For the overall cohort, significantly elevated SMRs were found for "all deaths" (SMR = 1.05; 95% CI = 1.01-1.08), "ischemic heart disease" (SMR = 1.08; 95% CI = 1.01-1.14), "pneumoconiosis and other respiratory diseases" (SMR = 1.48; 95% CI = 1.21-1.80), and "chronic and unspecified nephritis, renal failure, and other renal sclerosis" (SMR = 1.49; 95% CI = 1.00-2.12). Lung cancer SMRs did not increase with longer duration of employment, but did increase with longer latency (time since first exposure). Lung cancer was particularly elevated (SMR = 3.33; 95% CI = 1.66-5.95) among workers at the Lorain plant with a history of (primarily) acute beryllium disease, which is associated with very high beryllium exposure. The lung cancer excess was not restricted to plants operating in the 1940s, when beryllium exposures were known to be extraordinarily high. Elevated lung cancer SMRs were also observed for four of the five plants operating in the 1950s for workers hired during that decade. Neither smoking nor geographic location fully explains the increased lung cancer risk. Occupational exposure to beryllium compounds is the most plausible explanation for the increased risk of lung cancer observed in this study. Continued mortality follow-up of this cohort will provide a more definitive assessment of lung cancer risk at the newer plants and among cohort members hired in the 1950s or later at the older plants. Further clarification of the potential for specific beryllium compounds to induce lung cancer in humans, and the possible contribution of other exposures in specific processes at these plants, would require a nested case-control study. We are currently assessing whether available industrial hygiene data would support such an analysis.

Pathogenesis-related protein 4 is structurally homologous to the carboxy-terminal domains of hevein, Win-1 and Win-2

The extracellular, acidic pathogenesis-related protein, PR-4, was purified to homogeneity from leaves of Nicotiana tabacum infected with tobacco mosaic virus (TMV) and characterized by partial amino acid sequencing. Complementary DNA clones encoding PR-4 were isolated using an oligonucleotide probe based on the sequence of one of the peptides. The deduced PR-4 protein sequence was found to be related to a family of proteins including hevein and Win-1, which have an amino-terminal lectin domain and a carboxy-terminal domain of unknown function. PR-4 is homologous to the carboxy-terminus of these proteins but does not contain the lectin domain. Thus, the organization of the PR-4 family of proteins is similar to that of the plant chitinase family, in that both contain structural subclasses characterized by the presence or absence of an amino-terminal lectin domain. This observation is consistent with the proposal that the DNA encoding the lectin domain may be capable of transposing to form new genes encoding proteins of more complex, multi-domain structure. The expression of PR-4 mRNA was found to increase dramatically in response to TMV infection and the time course of RNA accumulation was similar to that of other PR proteins.

Lung cancer incidence among patients with beryllium disease: a cohort mortality study

We have conducted a cohort mortality study on 689 patients with beryllium disease who were included in a case registry. An earlier mortality study on 421 of these patients was limited to males and resulted in a determination of a nonsignificant twofold lung cancer excess based on only seven lung cancer deaths. We have extended this earlier study by including females and by adding 13 years of follow-up. Comparison of the 689 beryllium disease patients with the U.S. population resulted in a lung cancer standardized mortality ratio (SMR) of 2.00 (95% confidence interval = 1.33-2.89) based on 28 observed lung cancer deaths. Adjustment for smoking did not change these results. All causes of mortality were also significantly elevated (SMR = 2.19), largely because of the very high rate of deaths due to pneumoconioses (primarily beryllium disease) (SMR = 34.23; 158 deaths). No other causes of death were significantly elevated. The excess of lung cancer was consistent for both sexes and did not appear to increase with duration of exposure to beryllium or with time elapsed since first exposure to this element. The case registry included those with acute beryllium disease, which resembles a chemical pneumonitis, and those with chronic beryllium disease, which resembles other pneumoconioses. The lung cancer excess was more pronounced among those with acute disease (SMR = 2.32) than among those with chronic disease (SMR = 1.57).

Structural and functional conservation of histidinol dehydrogenase between plants and microbes

The partial amino acid sequence of histidinol dehydrogenase (L-histidinol:NAD+ oxidoreductase, EC 1.1.1.23) from cabbage was determined from peptide fragments of the purified protein. The relative positions of these peptides were deduced by aligning their sequences with the sequence of the HIS4C gene product of Saccharomyces cerevisiae. cDNA encoding histidinol dehydrogenase was then amplified from a library using a polymerase chain reaction primed with degenerate oligonucleotide pools of known position and orientation. By using this amplified fragment as a probe, an apparently full-length cDNA clone was isolated that is predicted to encode a proenzyme having a putative 31-amino acid chloroplast transit peptide and a mature molecular mass of 47.5 kDa. The predicted protein sequence was 51% identical to the yeast enzyme and 49% identical to the Escherichia coli enzyme. Expression of the cDNA clone in an E. coli his operon deletion strain rendered the mutant able to grow in the presence of histidinol.

Excess number of bladder cancers in workers exposed to ortho-toluidine and aniline

A retrospective cohort study of the incidence of bladder cancer was conducted in response to a union request for an evaluation of a possible excess number of cases of bladder cancer at a chemical plant in western New York State. Workers at the plant were exposed to two potential bladder carcinogens--ortho-toluidine (o-toluidine) and aniline. Incidence rates of bladder cancer among workers at the plant were compared with those of the population of New York State (excluding New York City). Among all 1749 workers at the plant, 13 cases of bladder cancer were observed versus 3.61 expected [standardized incidence ratio (SIR) = 3.60; 90% confidence interval (CI) = 2.13-5.73]. Among the 708 workers who worked in areas in which o-toluidine and aniline were used, 7 cases were observed versus 1.08 expected (SIR = 6.48; 90% CI = 3.04-12.2). Among the 288 maintenance, shipping, and janitorial workers thought to have been possibly exposed, 4 cases were observed versus 1.09 expected (SIR = 3.66; 90% CI = 1.25-8.37). Among the remaining 753 workers who were probably not exposed, 2 bladder cancers were observed versus 1.43 expected (SIR = 1.39; 90% CI = 0.25-4.39). Increased risk of bladder cancer was strongly associated with increased duration of employment in the department where o-toluidine and aniline were used (P less than .001). Among workers with 10 or more years of employment in the department, the SIR was 27.2 (90% CI = 11.8-53.7). o-Toluidine is an animal carcinogen more potent than aniline and is known to produce bladder tumors in rats; hence, it is more likely that o-toluidine is responsible for the observed excess number of cases of bladder cancer, although aniline may have played a role.

Evidence for a third structural class of beta-1,3-glucanase in tobacco

Glucan endo-1,3-beta-glucosidases (beta-1,3-glucanases) have been implicated in several developmental processes and they may also play a direct role in the plant's defense against fungal pathogens. In an effort to characterize the glucanase gene family, complementary DNA clones encoding an acidic form of beta-1,3-glucanase have been isolated from tobacco. The cDNA was expressed in E. coli and shown to encode a beta-1,3-glucanase activity. The protein sequence encoded by the cDNA was found to match the partial protein sequence of PR-35, a previously characterized beta-1,3-glucanase. The protein encoded by the cDNA was purified from the extracellular fluid of TMV-infected tobacco leaves and found by immunological methods to correspond to glucanase PR-Q'. From a detailed analysis of the cDNA it is clear that this glucanase represents a third structural class of enzyme which differs substantially from both the basic, vacuolar glucanase and the acidic, extracellular forms (PR-2, PR-N and PR-O). It has previously been demonstrated that the basic form of beta-1,3-glucanase is synthesized as a pre-pro-enzyme and upon maturation the 21 amino acid signal peptide and a 22 amino acid carboxy-terminal peptide are removed. This processing event has been proposed to be involved with the vacuolar localization of the enzyme. By comparing the deduced protein structure of PR-Q' to that of the basic form it is evident that this extracellular enzyme is missing the carboxy-terminal 22 amino acids. The role of a conserved phenylalanine-glycine dipeptide in the processing of glucanases and other pathogenesis-related proteins from tobacco is discussed.

Screening workers exposed to 4,4'-methylenebis(2-chloroaniline) for bladder cancer by cystoscopy

A bladder cancer incidence study was conducted among 540 workers exposed to the potential bladder carcinogen 4,4'-methylenebis(2-chloroaniline) from 1969 to 1979. Among the 385 workers who participated in a urine screening examination, none had suspicious or positive cytology. Twenty-one workers had at least one reading of atypia and 60 had either a positive dipstick for heme or greater than five red blood cells per low power field. The study protocol initially involved referral to private physicians for follow-up of any suspicious laboratory results. However, the diagnosis by cystoscopy of a bladder tumor in a nonsmoking man less than 30 years old with low-level hematuria prompted us to offer cystoscopy to all members of the cohort. A total of three tumors were identified in 200 persons who received cystoscopy. All were low-grade, papillary tumors and two occurred in men with completely normal urine screening results. These findings suggest that cystoscopy of asymptomatic persons should be considered in designing bladder cancer screening programs in high-risk cohorts.

Neuroblastoma and parental occupation

A matched case-control study of neuroblastoma investigated parental occupational risk factors. Cases diagnosed in 1970-1979 were identified through tumor registries in the Greater Philadelphia area. Controls were selected by random digit dialing and were matched to cases on race, birth date, and telephone exchange. Parents of 104 matched pairs were interviewed by telephone. In contrast to results of a previous study, no significant associations were noted for paternal employment in a job cluster of occupations in electricity, electronics, insulation, utility, and printing; in jobs with electromagnetic field exposure; or in jobs as workers in electronics. Six cases and one control, however, had a father or mother who worked in electrical or electronic products assembly.

Biological monitoring of a worker acutely exposed to MBOCA

A 30 year-old male polyurethane worker was exposed to an accidental spill of 4,4'-methylene-bis-2-chloroaniline (MBOCA) at a plant producing MBOCA-cured plastic products. Exposure to MBOCA is significant in that this compound is a known animal carcinogen and a suspected human carcinogen. The employee was sprayed over his upper body and extremities with molten MBOCA while cleaning out a clogged hose from a MBOCA and polymer mixing machine. The subsequent environmental and medical evaluation of this episode included serial urinary MBOCA samples from the worker over a 2 week period to allow the calculation of a biological half-life for this compound. This worker experienced a very high dose of MBOCA as judged by his urinary MBOCA levels (peak value of 1,700 ppb 4 hours after exposure). There were no acute symptoms or other laboratory abnormalities noted. The kinetic evaluation resulted in a biological half-life for MBOCA in urine of approximately 23 hours. Assuming a one-compartment model, approximately 94% of an initial MBOCA dose will be eliminated within four days. This is the first report of kinetic analysis on urinary MBOCA excretion in humans. This information suggests that biological monitoring of the urine MBOCA concentrations in exposed workers may miss peak levels following an acute exposure unless the analyses of the urinary MBOCA are performed in a timely fashion. Recommendations to the company included: 1) installation of a warning system or lock-out device on the mixing machine to prevent the opening of the MBOCA hose prior to the release of pressure; and 2) annual medical surveillance of this individual for bladder cancer with urinalysis and urine cytology.

Anatomic evaluation of cisternal puncture

Cisternal puncture, although less frequently used since the advent of computed tomography and magnetic resonance imaging, is an important tool in the neurodiagnostic armamentarium. An anatomic study of cisternal puncture was conducted on fresh cadavers by direct visualization and fluoroscopic guidance of cisternal puncture. Anatomic and radiographic analyses demonstrated a dramatic dynamic anatomy of the cisternal space during cisternal puncture and indicated that "tenting" of the dura mater over the needle occurs reliably during cisternal puncture. Lateral fluoroscopy may decrease the risk of cisternal puncture by allowing visualization of needle depth in the cisternal space.

Emergency department detection and follow-up of high blood pressure: use and effectiveness of community health workers

This study introduced trained paraprofessionals, community health workers (CHWs), into the emergency department (ED) to supplement providers' routine efforts in high blood pressure (HBP) detection, treatment, and follow-up among high-risk black men. In a demonstration project over a 2-year period, CHWs provided (1) BP and pulse measurements, and educational counseling regarding HBP and cardiovascular risk factors; (2) telephone preappointment reminders to improve ED follow-up visit rates; and (3) recontact of patients failing to show for their ED follow-up visits to improve return rates even after missed BP appointments. Results of preappointment reminders by CHWs showed a 19% improvement in appointment keeping (P less than .001). With a sample of patients who had failed to return for a follow-up visit, CHW contact was also effective, showing an overall improvement rate of 7% (P less than .001). The results reported support the idea that individuals from the community, trained as paraprofessionals, can improve appointment keeping as well as be useful in assisting in screening and counseling for chronic conditions within the ED. These CHWs are seen as having the additional advantage of enhancing the integration of the ED, the community, and continuing care sites. The approaches used in this study should be applicable and may serve as a model for the approach to other chronic conditions experienced in urban high-risk communities.

A user evaluation of four Kodak Ektachem slide assays

Evaluations of magnesium, theophylline, creatinine, and creatine kinase isoenzyme MB assays by the Kodak Ektachem multilayer-film technique are reported.

A user evaluation of four Kodak Ektachem slide assays

Evaluations of magnesium, theophylline, creatinine, and creatine kinase isoenzyme MB assays by the Kodak Ektachem multilayer-film technique are reported.

Study of mortality among chemical workers in the Kanawha Valley of West Virginia

To assess the mortality experience of a cohort of chemical workers in the Kanawha Valley of West Virginia, 29,139 males who worked at any one of three facilities over a 39-year period were followed-up for vital status. The facilities include two chemical manufacturing plants and a research and development center. From this cohort, 5,785 men were found to have died as of the study end, December 31, 1978. This was less than the 6,148.5 men expected to have died, based upon the United States white male population (standardized mortality ratio (SMR) = 94, 95% confidence interval (CI) = 92-96). Eighty-six specific causes of death were examined. Statistically significant increased deaths were observed for two causes; cancers of the liver (not specified as primary or secondary) (SMR = 174; CI = 102-280) and lympho- and reticulosarcoma (SMR = 140; CI = 104-187). When all biliary and liver cancer was examined by duration and time since initial employment, the SMR for those who worked at least 25 years and whose deaths occurred 30 years or more after first employment was 301 (95% confidence limit = 168-497). The identification and follow-up of this complete cohort provides the basis for future study of subcohorts with specific chemical and process exposures and case control studies of specific causes of death.

Bladder tumors in two young males occupationally exposed to MBOCA

MBOCA (4,4' methylenebis (2-chloroaniline) is a structural analogue of benzidine and is carcinogenic in mice, rats, and dogs. MBOCA has not yet been demonstrated to be carcinogenic in humans and is not regulated as an occupational carcinogen in the United States. We report two noninvasive papillary tumors of the bladder identified in a screening study of 540 workers exposed to MBOCA during its production at a Michigan chemical plant from 1968 to 1979. Both tumors occurred in men under 30 years old who had never smoked. Although the prevalence of grade 1-2 tumors among asymptomatic males in this age group is unknown, the incidence of clinically apparent tumors on U.S. males aged 25-29 is only 1 per 100,000 per year. The detection of the two tumors in young, nonsmoking males is consistent with the hypothesis that MBOCA induces bladder neoplasms in humans.

Arm function after stroke: measurement and recovery over the first three months

Four short, simple measures of arm function, suitable for use with patients recovering from acute stroke, are described. These tests are: the Frenchay Arm Test, the Nine Hole Peg Test, finger tapping rate and grip strength. Good interobserver and test-retest reliability was demonstrated for all tests, and the Frenchay Arm Test was shown to be valid. Normal values for all tests were established on 63 controls. It was found that the limited sensitivity of the Frenchay Arm Test could be improved using the Nine Hole Peg Test and grip strength. Recovery of arm function has been studied in a sample of 56 patients seen regularly over the first 3 months after their stroke, using these standard measures. The results demonstrated a wide variation in recovery curves between patients. The use of the Nine Hole Peg Test enabled further recovery to be detected after patients achieved a top score on the Frenchay Arm Test. Failure to recover measureable grip strength before 24 days was associated with absence of useful arm function at three months. Measurement of finger tapping rate was not useful.

Medical and drug risk factors associated with neuroblastoma: a case-control study

A matched case-control study of prenatal risk factors for neuroblastoma was conducted, including 104 cases diagnosed over the period 1970-79 in the Greater Delaware Valley. Significantly elevated odds ratios (ORs) were associated with maternal use of a neurally active drug during pregnancy (OR = 2.83), sex hormone exposure 3 months prior to or during pregnancy (OR = 2.25), frequent alcohol consumption during pregnancy (OR = 9.0), and maternal use of diuretic drugs during pregnancy (OR = 5.75). Significantly more case mothers than control mothers reported use of hair coloring products during pregnancy (OR = 3.0). No association was found between cigarette smoking, coffee consumption, or medical irradiation and case-control status.

The nucleotide sequence of the tnpA gene of Tn21

The nucleotide sequence of the tnpA gene of Tn21 is presented. The transposase encoded by this gene is exactly the same length (988 amino acids) as the Tn501 transposase (4), and shows 72% homology overall with this protein, with greater homology towards the C-terminus. The sequence of the transposase is discussed in the context of the evolution of Class II transposable elements and of the characteristics of the enzyme's action.

4,4'-Methylenebis (2-chloroaniline): an unregulated carcinogen

4,4'-Methylenebis (2-chloroaniline) (MBOCA) is a confirmed animal carcinogen. It is used commercially as a curing agent for polymers containing isocyanate. There are no adequate studies documenting a carcinogenic risk for MBOCA in humans; however, studies in rats and dogs have shown that MBOCA is a carcinogen. Also, MBOCA is structurally similar to aromatic amines, which cause bladder cancer in workers with occupational exposure. Manufacture of MBOCA in the United States ceased in 1979. However, estimates of the number of workers potentially exposed range from 1,400 to 33,000 in the manufacture of MBOCA-cured products. Presently, there are no federal regulations limiting occupational exposure to MBOCA. An occupational standard for MBOCA proposed by the Occupational Safety and Health Administration was remanded by the Third Circuit Court of Appeals on procedural grounds in 1974. NIOSH recommended in 1978 that MBOCA be treated as a potential human carcinogen and that worker exposure be controlled so that it does not exceed 3 micrograms/m3 of air determined as a time-weighted average concentration for up to a 10-hour workshift (the lowest level that can be reliably measured). In this paper, we will review the literature in regard to MBOCA's carcinogenicity, describe industrial use and extent of worker exposure, and review MBOCA's status in relation to occupational regulations in the United States and abroad.

Efficacy of urinary monitoring for 4,4'-methylenebis (2-chloroaniline)

The aromatic amine 4,4'-methylenebis (2-chloroaniline) (MBOCA), an animal carcinogen, is used commercially as a curing agent for isocyanate-containing polymers. It is structurally similar to other aromatic amines that cause bladder cancer in occupationally exposed workers. Since the late 1970s, MBOCA users have relied on urinary monitoring as the primary method of assessing MBOCA exposure in the workplace. This paper (1) outlines uncertainties about MBOCa's metabolism in humans that complicate interpretation of urinary MBOCA results; (2) describes alternative laboratory techniques for measuring MBOCA in urine; and (3) discusses observations from site visits concerning the practical application of urinary monitoring. Recommendations to improve the efficacy of monitoring programs for urinary MBOCA are outlined.

Junction sequences generated by 'one-ended transposition'

In the presence of the cognate transposase, plasmids containing a single inverted repeat (IR) sequence of Tn21 or of Tn1721 can fuse efficiently with other plasmids ('one-ended transposition'). The junctions across the sequences of donor and recipient DNA in recombinants generated by this process have been determined. These show that the segment of donor DNA starts precisely at the IR sequence (it is variable at the other end), and is flanked by a direct repeat of host DNA (usually 5bp) that was present only once in the original host sequence. These are characteristics of recombinants generated by transposition of Tn21 and Tn1721 themselves, suggesting that the mechanism of one-ended transposition is very similar to that of the corresponding entire elements.

A genetic component in human lysosomal enzyme excretion

Acid hydrolases are present in normal human urine in appreciable amounts. Their source appears to be lysosomes released by kidney proximal tubule epithelial cells. For a given lysosomal enzyme the total amount excreted is the product of two parameters, a general one describing the rate of lysosome secretion and a specific one describing the relative concentration of that enzyme in lysosomes. There is considerable population variation in both parameters. Studies of beta-glucuronidase, beta-galactosidase, beta-hexosaminidase, and alpha-galactosidase in monozygotic and dizygotic twins show that an appreciable part of this variation is genetic in origin. This appears to be true for both total enzyme excretion and lysosome composition. Although it was not possible to test directly whether this is also true for the rate of lysosome secretion, the fact that the two former parameters are both heritable strongly suggests that the rate of lysosome excretion is also a heritable trait. Taken together with previous data, the results suggest polygenic control of these biochemical traits. It is particularly significant that beta-glucuronidase excretion in normal individuals is a heritable trait since the excretion of this enzyme has frequently been used as a measure of normal and pathological physiological changes.

Plasmids containing one inverted repeat of Tn21 can fuse with other plasmids in the presence of Tn21 transposase

In the presence of the Tn21 transposase, plasmids that contain a single Tn21 inverted repeat sequence fuse efficiently with other plasmids. This reaction occurs in recA strains, is independent of the transposon-encoded resolution system, and results in insertions into different sites in the recipient plasmid. All fusion products studied contained at least one complete copy of the donor plasmid; most also contained some duplication of it as well. The data are consistent with processive models of transposition.

Absence of seasonal variation in antipyrine metabolism

The induced activity of aryl hydrocarbon hydroxylase (AHH), measured by the metabolism of benzo[a]pyrene to fluorescent products in cultured human lymphocytes, shows a strong seasonal variation. The in vivo metabolism of antipyrine, which is also catalyzed by microsomal cytochrome P-450-dependent monooxygenases, has been reported to be correlated with AHH inducibility in human lymphocytes. To determine whether antipyrine metabolism also showed seasonal changes, we measured antipyrine half-life (t 1/2) in 10 nonsmokers and eight smokers at the two times of the year that correspond to the high and low peaks of inducible AHH activity as measured in lymphocytes. The mean antipyrine t 1/2 determined in all 18 subjects in summer was almost identical to that found in winter (mean +/- SEM = 10.90 +/- 0.65 and 10.96 +/- 0.78 hr). AHH activity in cultured human lymphocytes from the nonsmoking subjects was determined in control and 3-methylcholanthrene-induced cells to obtained inducibility ratios of 4.2 +/- 0.56 (SEM) in the summer and 1.4 +/- 0.14 (SEM) in winter. These results indicate that the seasonal variation in AHH inducibility in human lymphocytes is not reflected by a corresponding seasonal variation in antipyrine metabolism in vivo.

Detection of antibodies to Epstein-Barr virus capsid antigen by immune adherence hemagglutination

The immune adherence hemagglutination assay was found to be as sensitive and specific as the indirect immunofluorescence technique for titration of antibodies to Epstein-Barr virus capsid antigen. Satisfactory virus capsid antigen-specific and negative control antigens for the immune adherence hemagglutination assay were prepared from cell extracts of the Epstein-Barr virus producer P3HR-1 and the Epstein-Barr virus genome-negative BJAB lymphoblastoid cell lines, respectively. As the immune adherence hemagglutination assay can be used to titrate antibodies to both the heterophil antigen of the Paul-Bunnell type and to virus capsid antigen, it offers a promising alternative to the immunofluorescence methods in the serodiagnosis of Epstein-Barr virus infections which can be performed by most diagnostic laboratories.

The addict's perceptions of their own drug-taking: implications for the treatment of drug dependence

The attitudes, beliefs and expectations of the addict have received surprisingly little research attention. The present study looks at the relationship between the addict's perception of their own drug taking and their behaviour in treatment. The subjects who took part in the study were receiving treatment at a London drug dependence unit: 60 were inpatients, 40 were outpatients. All completed an attitude questionnaire and a personality inventory, the EPQ). Several attitudinal differences were found between inpatient and outpatient groups, the outpatients being more generally resistant to the prospect of giving up drugs. Among the inpatients, those subjects who saw their addiction as a sort of sickness were least likely to remain in treatment. The attitude items related more clearly to the addict's behaviour in treatment than did the personality measures. The implications of these findings for the treatment of drug addicts are discussed.

Seasonal variation of aryl hydrocarbon hydroxylase activity in human lymphocytes

A seasonal variation was observed when aryl hydrocarbon hydroxylase (AHH) activity was measured in the cultured lymphocytes of 977 donors over a period of 2 1/2 years. The variation was strongest in AHH activity induced by 3-methylcholanthrene and was less apparent for AHH activity in lymphocytes grown without any inducer. The period of the seasonal variation is 1 year, and maximal induced AHH activity occurs during late summer and early fall with minimal activity 6 months later. Based on the average of all individuals tested during the highest and lowest weeks, induced AHH activity can be as much as 10-fold higher during the peak season. It is not possible to tell from these experiments whether the seasonal variation is tissue specific, occurring only in lymphocytes, or characteristic of microsomal oxidases in other tissues as well.

Aryl hydrocarbon hydroxylase inducibility is not altered in bladder cancer patients or their progeny

We investigated the possible influence of aryl hydrocarbon hydroxylase (AHH) on susceptibility to bladder cancer in humans. AHH inducibility was measured in the cultured lymphocytes of 16 patients who were being followed after successful treatment for bladder cancer, in 53 progeny of bladder cancer patients, and in matched controls. In both the progeny and patient populations, no evidence was found for a difference between the distribution of AHH inducibility or induced AHH activity compared to the distribution among control individuals. Thus, AHH acitivity or inducibility does not appear to be a major determinant of bladder cancer risk in humans.

Aryl hydrocarbon hydroxylase in persons with lung or laryngeal cancer

To test whether the distribution of AHH inducibility is shifted toward the high end of the range in patients who had lung and laryngeal cancer, we measured this trait in 59 patients (32 lung and 27 laryngeal) who had resectable tumors and had been disease-free for a period of time. The advantage of selecting patients who were free of clinical disease was that measurement of their AHH inducibility should not have been affected by the disease state. Patient and control populations showed no difference in basal and induced AHH activity of AHH inducibility. The mean AHH inducibility in patients who had lung cancer was 3.20 +/- 0.20; in patients who had laryngeal cancer 2.96 +/- 0.18, and for all controls 3.29 +/- 0.04 (no significant difference at p = 0 05). Further analysis of the distribution of AHH inducibility in the patient group compared to controls showed no suggestion of a shift toward the higher end of the range in patients who had lung and laryngeal cancer.

Cytophotometric and cytogenetic analyses of mouse lymphomas

Simultaneous cytophotometric and cytogenetic analyses of spontaneous mesenteric lymphomas from three female mice are reported. No statistically significant deviation from normal lymph node cells could be detected for any of the tumors with respect to nucleic acid content. However, all three tumors demonstrated trisomy as the major cytogenetic anomaly. Chromosome 7 or 8 was found to be the extra chromosome in two of the lymphomas while identification of chromosomes was not possible in the third.

Aryl hydrocarbon hydroxylase in cultured lymphocytes of twins

Measurement of aryl hydrocarbon hydroxylase (AHH) in cultured lymphocytes of 18 monozygotic and 30 dizygotic twin pairs showed that basal and induced AHH activity and AHH inducibility are heritable traits. The data are consistent with AHH inducibility being determined by a single or a very few polymorphic genes.

Cell adhesion to substrates containing adsorbed or attached IgG

When most mammalian cells are propagated in tissue culture, they are attached to a solid surface. This surface is commonly covered with a layer of serum protein. In this study we looked at the effect of the protein layer on the interaction between the cells and the surface by precoating the surface with various pure protein molecules. We found no differences between surfaces covered with pure protein layers and those covered with serum proteins except when antibody molecules were used. In all cases the cell types used avoided surfaces covered with antibody molecules. Previously, other investigators have established that some cells belonging to the immunology system are attracted to such surfaces.

Questionable relation of aryl hydrocarbon hydroxylase to lung-cancer risk

To test whether the genetically determined trait, aryl hydrocarbon hydroxylase inducibility, affects susceptibility to lung cancer, we measured this trait in cultured lymphocytes from a normal population, patients with lung cancer and progeny of such patients. We found very low aryl hydrocarbon hydroxylase activity (19 per cent of normal) in about half the patients with lung cancer. Only part of this activity can be accounted for by reduced cell growth and by reduced protein synthesis. In an indirect assessment of inducibility, both 57 progeny and 27 matched controls had a mean inducibility of 2.95 and a similar distribution into low, intermediate and high groups (chi-square = 0.3 P = 0.9). No differences in basal or induced activity were observed. Thus, if patients with lung cancer possess altered aryl hydrocarbon hydroxylase inducibility or activity these characteristics are not transmitted to their progeny.

Distribution of aryl hydrocarbon hydroxylase inducibility in cultured human lymphocytes

We measured aryl hydrocarbon hydroxylase (AHH) in cultured human lymphocytes. A striking seasonal variation in AHH activity was observed with induced AHH activity levels from January through May measuring approximately 20% of the values during the remainder of the year. AHH inducibility was determined by comparing lymphocytes from the same person cultured with and without the inducer 3-methylcholanthrene. If measurements are limited to the summer and fall seasons when AHH activity is high, AHH inducibility is reproducible for most persons with repeat determinations on the same person averaging 11% from the mean. The values of AHH inducibility in 53 persons ranged from 0.9 to 5.0, but the distribution of values did not fall into three distinct, nonoverlapping classes as reported by others. We were not able to determine the distribution of AHH inducibility in lung cancer patients since lymphocytes from less than half of the patients tested could be successfully cultured.

Antigen, host and adjuvant requirements for induction of hyperacute experimental autoimmune encephalomyelitis

A hyperacute form of experimental autoimmune encephalomyelitis (HEAE) was induced in Lewis rats using small doses (3.2 mug) of guinea pig myelin basic protein as immunogen and B. pertussis vaccine as adjuvant. Myelin basic proteins from species other than guinea pig (rat, man, monkey, pig, ox, rabbit and sheep) induced only ordinary EAE with this adjuvant. HEAE was more readily distinguished from ordinary EAE by clinical criteria (early onset, with a rapid and severe course, and high incidence of cerebral signs and mortality) than by histologic signs which, although characteristic of HEAE. were not pathognomonic for HEAE, HEAE was transferred to x-irradiated syngeneic recipient rats with lymph node cells from appropriately immunized donors. The Brown Norway (BN) strain of rat was found susceptible to induction of ordinary EAE, but not HEAE, using large doses of either rat or guinea pig myelin basic proteins. The unique immunogenicity of the guinea pig basic protein must be due to a different antigenic determinant from the determinant(s) which is shared by rat and guinea pig myelin basic proteins and which without B. pertussis induces ordinary EAE. The adjuvant action of B. pertussis in inducing HEAE in the Lewis rat is most likely mediated through an immunocompetent T lymphocyte.

Evidence for diaphragms in the pores of annulate lamellae and the nuclear membrane

Interpretation of cross and tangential sections of the annulate lamellae and nuclear membrane of Rana pipiens oocytes provides evidence in these structures for the existence of disphragms spanning the pores. The evidence appears to rule out explanations ascribing such diaphragms to an optical artifact. More detailed description is given of a component of the pore complex only briefly described heretofore and now called the "intracisternal ring." The varied results and interpretations of studies of the pore complex in various cells are discussed.