The Z lattice in canine cardiac muscle.

Filtered images of mammalian cardiac Z bands were reconstructed from optical diffraction patterns from electron micrographs. Reconstructed images from longitudinal sections show connecting filaments at each 38-nm axial repeat in an array consistent with cross-sectional data. Some reconstructed images from cross sections indicate two distinctly different optical diffraction patterns, one for each of two lattice forms (basket weave and small square). Other images are more complex and exhibit composite diffraction patterns. Thus, the two lattice forms co-exist, interconvert, or represent two different aspects of the same details within the lattice. Two three-dimensional models of the Z lattice are presented. Both include the following features: a double array of axial filaments spaced at 24 nm, successive layers of tetragonally arrayed connecting filaments, projected fourfold symmetry in cross section, and layers of connecting filaments spaced at intervals of 38 nm along the myofibril axis. Projected views of the models are compared to electron micrographs and optically reconstructed images of the Z lattice in successively thicker cross sections. The entire Z band is rarely a uniform lattice regardless of plane of section or section thickness. Optical reconstructions strongly suggest two types of variation in the lattice substructure: (a) in the arrangement of connecting filaments, and (b) in the arrangement of units added side-to-side to make larger myofilament bundles and/or end-to-end to make wider Z bands. We conclude that the regular arrangement of axial and connecting filaments generates a dynamic Z lattice.

Optical diffraction of the Z lattice in canine cardiac muscle.

Optical diffraction patterns from electron micrographs of both longitudinal and cross sections of normal and anomalous canine cardiac Z bands have been compared. The data indicate that anomalous cardiac Z bands resembling nemaline rods are structurally related to Z bands in showing a repeating lattice common to both. In thin sections transverse to the myofibril axis, both electron micrographs and optical diffraction patterns of the Z structure reveal a square lattice of 24 nm. This lattice is simple at the edge of each I band and centered in the interior of the Z band, where two distinct lattice forms have been observed. In longitudinal sections, oblique filaments visible in the electron micrographs correspond to a 38-nm axial periodicity in diffraction patterns of both Z band and Z rod. We conclude that the Z rods will be useful for further analysis and reconstruction of the Z lattice by optical diffraction techniques.

Three-dimensional structure of the Z band in a normal mammalian skeletal muscle.

The three-dimensional structure of the vertebrate skeletal muscle Z band reflects its function as the muscle component essential for tension transmission between successive sarcomeres. We have investigated this structure as well as that of the nearby I band in a normal, unstimulated mammalian skeletal muscle by tomographic three-dimensional reconstruction from electron micrograph tilt series of sectioned tissue. The three-dimensional Z band structure consists of interdigitating axial filaments from opposite sarcomeres connected every 18 +/- 12 nm (mean +/- SD) to one to four cross-connecting Z-filaments are observed to meet the axial filaments in a fourfold symmetric arrangement. The substantial variation in the spacing between cross-connecting Z-filament to axial filament connection points suggests that the structure of the Z band is not determined solely by the arrangement of alpha-actinin to actin-binding sites along the axial filament. The cross-connecting filaments bind to or form a "relaxed interconnecting body" halfway between the axial filaments. This filamentous body is parallel to the Z band axial filaments and is observed to play an essential role in generating the small square lattice pattern seen in electron micrographs of unstimulated muscle cross sections. This structure is absent in cross section of the Z band from muscles fixed in rigor or in tetanus, suggesting that the Z band lattice must undergo dynamic rearrangement concomitant with crossbridge binding in the A band.

Aragonite twinning in the molluscan bivalve hinge ligament.

Molluscan bivalve hinge ligaments are composed of long needle-shaped aragonite crystals embedded in a protein matrix. These crystals are twinned and, in general, the twin forms a thin lamella through the center of the crystal.

Doxorubicin-containing regimens for the treatment of stage II breast cancer: The National Surgical Adjuvant Breast and Bowel Project experience.

Despite numerous reports of findings obtained following the use of doxorubicin (Adriamycin [A]; Adria Laboratories, Columbus, OH) for the postoperative treatment of patients with primary breast cancer and positive axillary nodes, no clear consensus exists regarding its worth when used in that setting. In June 1981, the National Surgical Adjuvant Breast and Bowel Project (NSABP) implemented two randomized clinical trials aimed at evaluating the worth of doxorubicin when administered in conjunction with melphalan (L-PAM) and fluorouracil (5-FU) (PF). A prior NSABP study identified cohorts of patients who did or did not benefit from tamoxifen (TAM, T) when used with chemotherapy. That information was employed in the design of the present studies. Women considered responsive to TAM (1,106) were randomized between PFT and PAFT, and those nonresponsive to TAM (707) were randomized between PF and PAF. Findings through 6 years of follow-up (mean duration of potential time on study, 64 months and 63 months, respectively) indicate that non-TAM-responsive patients who received PAF had a significantly better disease-free survival (DFS) (P = .003) and survival (P = .05) than did those receiving PF. By contrast, there was no significant difference in DFS (P = .6) or survival (P = .7) between PFT- and PAFT-treated patients. No disparity in the amount of drug received, whether related to the median amount or to dose-intensity, is present to account for the difference in findings between the studies. Aside from alopecia and emesis, the toxicity from the doxorubicin-containing regimens was similar to those in which doxorubicin was omitted. Cardiomyopathy was not a significant finding; there were no deaths from cardiac toxicity. The incidence of arterial and venous complications in patients receiving TAM was less than reported by others.

Pathologic findings from the National Surgical Adjuvant Breast and Bowel Project: prognostic significance of erbB-2 protein overexpression in primary breast cancer.

In order to investigate the prognostic significance of erbB-2 overexpression, immunohistochemical staining for the erbB-2 protein was performed on sections from paraffin blocks of 292 primary invasive breast cancers obtained from women enrolled in the National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol B-06. Positive reaction indicative of erbB-2 overexpression was observed on tumor cells in 62 (21%) samples. Women whose cancers were judged to have erbB-2 overexpression had a significantly worse overall survival (P = .0012) with twice the mortality rate of women without detectable erbB-2 expression. No statistically significant effect was evident for disease-free survival (P = .22). In multivariate analysis, detection of erbB-2 overexpression was the second most predictive independent variable for survival after nodal status. Overexpression of erbB-2 was more common among tumors of poor nuclear grade (29%) than those of good nuclear grade (12%). The association of erbB-2 overexpression with decreased survival was evident only among women with tumors of good nuclear grade. In this subgroup, erbB-2 overexpression was associated with an approximately fivefold increase in mortality rate (P = .00001). The combined predictive value of erbB-2 overexpression and nuclear grade was evident regardless of their lymph node status. These results provide evidence that detection of erbB-2 overexpression may be an independent prognostic variable for patient survival. Moreover, when combined with evaluation of nuclear grade, it may be possible to use immunostaining for erbB-2 protein to identify patients at increased risk from within a relatively low-risk group.

Structural states in the Z band of skeletal muscle correlate with states of active and passive tension.

In skeletal muscle Z bands, the ends of the thin contractile filaments interdigitate in a tetragonal array of axial filaments held together by periodically cross-connecting Z filaments. Changes in these two sets of filaments are responsible for two distinct structural states observed in cross section, the small-square and basketweave forms. We have examined Z bands and A bands in relaxed, tetanized, stretched, and stretched and tetanized rat soleus muscles by electron microscopy and optical diffraction. In relaxed muscle, the A-band spacing decreases with increasing load and sarcomere length, but the Z lattice remains in the small-square form and the Z spacing changes only slightly. In tetanized muscle at sarcomere lengths up to 2.7 micron, the Z lattice assumes the basketweave form and the Z spacing is increased. The increased Z spacing is not the result of sarcomere shortening. Further, passive tension is not sufficient to cause this change in the Z lattice; active tension is necessary.

Value of assessment of ploidy in rectal cancers.

Flow cytometry was performed on available archival material from 232 patients with rectal cancer enrolled in the National Surgical Adjuvant Breast and Bowel Project protocol R-01. Tumor ploidy was not found to be significantly related to such pathologic and clinical parameters as Dukes' stage; nodal status; nuclear or histologic grades; patient's age, sex, or overall survival rate with an average study time of 79 months. A trend was evident that patients with poor histologic grade, or those with Dukes' B and C tumors that were aneuploid fared worse than those with diploid cancers. However, measurements of survival were found to be more strongly and consistently related to such conventional prognostic parameters as tumor differentiation, Dukes' stage, and nodal status. Further, numbers of nodes with metastases (ie, 1 to 4 or 5+) more significantly discriminated Dukes' C cases than estimation of tumor ploidy. Although tumor ploidy may reflect some features of rectal cancers, their natural history and prognosis are explained better by assessment of conventional parameters used for these purposes.

The dark side of Taiwan's globalization success story.

Government regulators and researchers in Taiwan (Republic of China) express optimism about their country's economic success in its transition from a traditional society to a first world, industrialized nation. But this economic success, as measured by the standards and ideology of globalization, also has a dark side for many ordinary workers, especially Taiwan's 300,000 foreign workers. The promise of growth and future prosperity is conditional upon global economic practices and an adherence to a science-technology ideological perspective that shapes political content. Multiple centers of opposition and critical thinking have no public presence in Taiwan; nor do organizational defiance and resistance by trade unions. Instead, individuals and small human rights groups seek to reveal areas of human degradation and suffering in a response to poverty and the American dream. Meanwhile, the dominant ideological perspective as articulated by globalism seeps into and directs all public policy on the work environment so that it is coherent with the neoliberal political agenda of multinational corporations. This direction is being questioned by students of the work environment and by labor activists in North America, who report the deterioration of working conditions and worsening of government regulatory instruments for protecting workers from physical, mental, and social risk and harm in the workplace.

Agricultural "killing fields": the poisoning of Costa Rican banana workers.

The poisoning of Costa Rican banana workers by multinational corporations' excessive use of pesticides is not a local issue; it is embedded in a dominant ideology expressed by the phenomenon of globalization. This ideology seeps into every aspect of our social institutions--economic, political, and legal. The practice of this ideological perspective is evident in the industrialization of global agriculture and the shift from "developmentalism"--liberal welfarism, industrialization, and urbanization--to a dominant, undemocratic, global financial elite with "economism" and a neoliberal political agenda overriding the nation-state polis. A specific effect is to transform the agricultural workers of developing countries, such as Costa Rican banana workers, into politically superfluous flesh-and-blood human beings.

A conversation about the work environment.

The author looks at work environment matters from the perspective of public policy-making and the policy instruments used to deal with workplace health and safety: standard setting; joint health and safety committees; compliance, enforcement, and prosecution; workers' compensation as an economic incentive; and collective bargaining. While regarding all as necessary, the author considers them as separately and collectively, fundamentally flawed and therefore insufficient, because liberal public policy-making itself is problematic. He proposes an alternative way of thinking about this subject from the perspective of the "politics of meaning."

The Work Environment Board and the limits of social democracy in Canada.

A Work Environment Board was established to deal with all workplace health and safety issues within the Potash Corporation of Saskatchewan from 1978 to 1982. The Board was an experiment, established because of the observed deficiencies of the mandatory joint occupational health and safety committees that were legislated by the province in 1972. The administrators of the occupational health and safety program observed the problems faced by workers on these committees. An experiment was therefore established in one of the province's crown corporations that would transform the joint committee into a Work Environment Board with wider powers to deal with work environment matters within the corporation. In addition, a Work Environment Fund was established to enable the worker members on the Board to do their own research and to get the information they wanted. The Work Environment Board was frustrated by the fact that corporate leaders were not prepared to extend worker rights on the health and safety committees within the respective mines. Rather, they viewed health and safety reforms as part of an overall strategy of quality of work life. The social democratic government was not prepared to extend worker rights and to threaten management prerogatives. Now that there are three New Democratic Party (social democratic) governments in Canada, it appears that these governments are prepared to initiate technical improvements, but not the extension of worker rights in work environment matters.

Workplace health and safety: report from Canada.

This article represents a critical analysis of the major policy responses to workplace health and safety in Canada. It examines the deficiencies inherent in the legislative development of Joint Health and Safety Committees in most Canadian jurisdictions, the limitations regarding standard-setting of worker exposure to contaminants, and disincentive for employers to positively improve the workplace because of Workers Compensation legislation. Collective bargaining agreements in Canada have had only limited positive effects, while the ultimate legal sanction of criminal prosecution by the regulatory agencies has weakened enforcement and compliance of existing regulations. There has never been a successful criminal prosecution of an employer in Canada, even for multiple deaths. The article suggests the following four reasons for this "underdevelopment" of occupational health and safety in Canada: the concealment of the dimension of the incidence of industrial disease based on Workers Compensation Board statistics; the application of an incorrect theory of causation of both industrial disease and injury by both managers and government administrators of occupational health and safety programs; the resistance of both senior and middle managers against increased worker participation in both work organization and job design questions; and the general "moral underdevelopment," rather than ignorance, of managers in favoring economic considerations or values at the expense of worker health and safety. In light of the magnitude of the problem and the deficiencies of existing policy approaches, the author proposes the need for greater workplace democratization of production and industry as a necessary and sufficient reform of workplace health and safety.

A message to the labor movement: stop and think!

Trade unions and workers in North America have been objectified and instrumentalized by all political regimes, including the social-democratic New Democratic Party in Canada. And it is means-end non-thinking that characterizes government policies. Liberal elites and policy-making have marginalized ordinary workers making them "superfluous" without any vision of an "ethical community" and demonstrating contempt for democratic initiatives. There are oppositionary voices to the dominant social structures that oppress and undermine community and solidarity. However, trade unions and occupational health and safety "activists" have yet to reassess their strategies on workplace health and safety reforms, but are on the defensive in North America. Further, they are complicit with the dominant ideology and the occupational health and safety establishment, including the various and diverse professionals, who shape how we think about work environment matters; and they accommodate government regulators in mediating worker experiences and expectations with employer interests. The author suggests the beginning of a strategy that does not succumb to present-day liberal public policy-making and the atrophy of alternative options. In part, this strategy calls for a rudimentary phenomenology of moral judgment and a reconstruction of labor "tradition".

Labor policy and social democracy: the case of Saskatchewan, 1971-1982.

This article analyzes labor policy, especially that of occupational health and safety, initiated by the Saskatchewan New Democratic Party (NDP) from 1971 to 1982. The NDP was perceived by Canadian provincial labor federations and the Canadian Labour Congress as the government most approximating a European labor party. The provincial labor legislation was seen as exemplary, and the occupational health and safety legislation as a "beacon" for the rest of Canada. This article suggests that the advances in occupational health and safety statute and regulations were a direct response to the government's policy to develop uranium mining. In order to pursue a vigorous renewable and nonrenewable resource policy, the government maintained that uranium could be mined "safely." This resulted in "progressive" health and safety legislation and the reinforcement of the colonial status of people of Indian ancestry. This policy of growth and development also resulted in joint venture relationships with multinational corporations and increasing investments in the north for nonrenewable resource development. Prior to the landslide defeat of the NDP in 1982 by the Conservative Party, the richest 5 percent of Saskatchewan people earned as much, in total, as the poorest 50 percent. Meanwhile, ordinary workers experienced declining real wages and increased employment insecurity.

The unwritten story of women's role in the birth of occupational health and safety legislation.

Women's role in the formation of trade unions and development of collective bargaining, as well as in labor's historical struggle to improve day-to-day working conditions, has been conspicuously underplayed, if not ignored. Yet, when one reviews the history of the reduction of working hours, prohibition of child labor, elimination of homework in tenement slums, reform of factory legislation, and investigations into accidents precipitating early workers' compensation legislation, the literature is rich with women's investigative reports and studies on unhealthy and unsafe working conditions. This was the case from the late 19th century in North America up until the 1950s and the Cold War. The women's movement and political activities requiring factory reforms then seemed to go underground, re-emerging in full force during the 1960s. Women's involvement in the environmental movement, especially in the United States, has been significant in politicizing occupational health as well. Their efforts led to the 1970 passage of the U.S. Occupational Health and Safety Act.

The implications of work organization for occupational health policy: the case of Canada.

This article examines occupational health and safety developments in Canada during the decade of the 1970s when most government jurisdictions replaced former factory Acts with new health and safety legislation recognizing the right of workers to be involved in work environment matters. During the latter part of the 1970s, health and safety "activists" and trade unionists began to perceive the need for a wider conception of occupational health and safety. Canadian reformers were influenced by Scandinavian developments, especially the research of Dr. Bertil Gardell and his associates. Unfortunately, during the late 1970s Canada experienced a recession and a political shift to conservatism. Consequently, during the 1980s there have been no meaningful workplace health and safety reforms. Further, the article suggests that there is strong resistance by management and government to extension of worker rights in occupational health and safety. All major political parties ground their work environment policies in utilitarian concepts that trade worker health and safety for economic considerations. The author, therefore, argues for the development of an "ethics of the work environment" based upon egalitarian principles, and the transformation of the primary work group into a community of workers who can shape the character of their work environment. Ideally, the relationship between the major "actors" in our industrial relations system ought to be based on obligation instead of the present language of worker protest based on rights. Nonetheless, there is a need to extend and deepen worker rights in the workplace. Finally, the author argues that the appropriate relationship in industry to reflect a democratic work environment is "partnership"--the coming together of the primary work groups as equals.

A strategic response to the occupational health establishment.

The experiences of occupational health and safety "activists" in Canada reveal the limits of achieving reform in working conditions by technical efforts in combination with rank-and-file activation. The author argues that the way union "activists" approach occupational health and safety limits workers in dealing with their actual experiences and understanding about workplace hazards and risks, then discusses the condition for the awakening of their critical consciousness as a basis of acting on hazardous working conditions. The first movement in the way the worker apprehends the work environment is a movement of negation and is the prior condition to a critical and disclosive discourse about workplace hazards. It is the positive side of "No!" and the taking seriously of workers' rights. It is this negation of the negative that holds out the greatest hope for solidarity and a liberatory community in workplaces, since legislated workers' rights as the basis of protection have become a facade. Workers can respond with the power of saying "No!" in solidarity with suffering workers, and then work through appropriate principles, ends, or strategies avoiding entrapment by a "telos" in the first instance. By laying out these "ends" or a strategic paradigm, one introduces a "conversation stopper" for workers and atrophies their activation.

Accident proneness: science or non-science?

The "accident proneness" thesis has been with us since the early 1900s. The early statistical studies that reputedly provided the scientific basis for this notion are examined and found to be lacking due to methodological errors and a fragmented view of industrial life. Accident proneness, as originally envisioned, has no empirical foundations. It has, however, become part of the tactical armanentarium used in "blaming the victim" for industrial accidents. It focuses on the personal characteristics of workers in relation to accident causation, while de-emphasizing the role of dangerous work environments. In this respect, it has acted as a barrier in the development of preventive occupational health and safety principles and practices. The notion has endured not only because it is tactically advantageous, but also because many members of the professions that deal with workplace accidents have accepted it without reservation and lent it credence. For the purposes of industrial accident prevention, however, it would be more appropriate to discard this notion in favor of a more integrated and broader understanding of the nature of the interaction between workers and their socio-technical work environment.