A gentle introduction to computer vision-based specimen classification in ecological datasets

Classifying specimens is a critical component of ecological research, biodiversity monitoring and conservation. However, manual classification can be prohibitively time-consuming and expensive, limiting how much data a project can afford to process. Computer vision, a form of machine learning, can help overcome these problems by rapidly, automatically and accurately classifying images of specimens. Given the diversity of animal species and contexts in which images are captured, there is no universal classifier for all species and use cases. As such, ecologists often need to train their own models. While numerous software programs exist to support this process, ecologists need a fundamental understanding of how computer vision works to select appropriate model workflows based on their specific use case, data types, computing resources and desired performance capabilities. Ecologists may also face characteristic quirks of ecological datasets, such as long-tail distributions, 'unknown' species, similarity between species and polymorphism within species, which impact the efficacy of computer vision. Despite growing interest in computer vision for ecology, there are few resources available to help ecologists face the challenges they are likely to encounter. Here, we present a gentle introduction for species classification using computer vision. In this manuscript and associated GitHub repository, we demonstrate how to prepare training data, basic model training procedures, and methods for model evaluation and selection. Throughout, we explore specific considerations ecologists should make when training classification models, such as data domains, feature extractors and class imbalances. With these basics, ecologists can adjust their workflows to achieve research goals and/or account for uncertainty in downstream analysis. Our goal is to provide guidance for ecologists for getting started in or improving their use of machine learning for visual classification tasks.

Crowd-sourced observations of a polyphagous moth reveal evidence of allochronic speciation varying along a latitudinal gradient

Allochronic speciation, where reproductive isolation between populations of a species is facilitated by a difference in reproductive timing, depends on abiotic factors such as seasonality and biotic factors such as diapause intensity. These factors are strongly influenced by latitudinal trends in climate, so we hypothesized that there is a relationship between latitude and divergence among populations separated by life history timing. Hyphantria cunea (the fall webworm), a lepidopteran defoliator with red and black colour morphs, is hypothesized to be experiencing an incipient allochronic speciation. However, given their broad geographic range, the strength of allochronic speciation may vary across latitude. We annotated >11,000 crowd-sourced observations of fall webworm to model geographic distribution, phenology, and differences in colour phenotype between morphs across North America. We found that red and black morph life history timing differs across North America, and the phenology of morphs diverges more in warmer climates at lower latitudes. We also found some evidence that the colour phenotype of morphs also diverges at lower latitudes, suggesting reduced gene flow between colour morphs. Our results demonstrate that seasonality in lower latitudes may increase the strength of allochronic speciation in insects, and that the strength of sympatric speciation can vary along a latitudinal gradient. This has implications for our understanding of broad-scale speciation events and trends in global biodiversity.

An integrated doctoral educational model for developing researchers in health care strategic management

Doctoral education varies according to how students that graduate from a particular program are prepared for various type of careers. PhD programs principally work to develop researchers; researchers produce and disseminate new knowledge in a given area of expertise. This manuscript looks specifically at a PhD program designed to produce researchers in healthcare strategic management. This program is based in a business school and builds on general business principles to produce strategists that do research in the healthcare context. The business school program (type B) will be analyzed according to the areas (or potential areas) of research done by its graduates. The different areas are shown in a table where one axis is research content (i.e., specifically what the functional area of research is) and the other axis is publication outlet (i.e., what journal the research is disseminated in). Advantages of the type B program are compared to advantages of a PhD program based in a healthcare administration or healthcare management school (type H program) in terms of publications in these different areas.

The paradox prescription: leading the medical group of the future

Leaders of health care organizations must constantly deal with paradox in and around their organizations. The paradox profile is a modeling technique for examining how organizations prioritize their dealings with the eight competing issues from which the four paradoxes are derived. This article demonstrates the leadership challenges that exist when a paradox is present and how these tensions differ when the integrative status of the medical group--as either part of an integrated system or not--is considered.

Hospital-physician joint ventures: a strategic approach for both dimensions of success

Joint ventures between hospitals and the physicians on their medical staffs have produced successes and failures. Each joint venture has two very different dimensions of success--financial and collaborative. The most successful ventures are able to accomplish both of these often conflicting goals. To enhance hospital executives' success in joint ventures with physicians, a strategic approach with a series of six steps and their corresponding models or maps is proposed. The steps in this strategic approach are: (1) identify key stakeholders and linkages among them; (2) surface stakeholder conflict using problem-oriented maps; (3) diagnose the venture on both dimensions of success; (4) classify the venture using both dimensions of success; (5) select a strategy to optimize the venture's current potential for success; and (6) select an approach to transform the venture with limited potential for success.

Achieving competitive advantage through strategic human resource management

The framework presented here challenges health care executives to manage human resources strategically as an integral part of the strategic planning process. Health care executives should consciously formulate human resource strategies and practices that are linked to and reinforce the broader strategic posture of the organization. This article provides a framework for (1) determining and focusing on desired strategic outcomes, (2) identifying and implementing essential human resource management actions, and (3) maintaining or enhancing competitive advantage. The strategic approach to human resource management includes assessing the organization's environment and mission; formulating the organization's business strategy; assessing the human resources requirements based on the intended strategy; comparing the current inventory of human resources in terms of numbers, characteristics, and human resource management practices with respect to the strategic requirements of the organization and its services or product lines; formulating the human resource strategy based on the differences between the assessed requirements and the current inventory; and implementing the appropriate human resource practices to reinforce the strategy and attain competitive advantage.

Competitive forces in the medical group industry: a stakeholder perspective

Applying Porter's model of competitive forces to health care, stakeholder concepts are integrated to analyze the future of medical groups. Using both quantitative survey and qualitative observational data, competitors, physician suppliers, integrated systems new entrants, patient and managed care buyers, and hospitals substitutes are examined.

Strategic choices for medical group practices

This is the sixth in a series of articles (1) describing how to identify, assess, diagnose and strategically manage key medical group practice (MGP) stakeholders and (2) interpreting the results from the Facing the Uncertain Future (FUF) study. This article continues (from the previous article in this series) the discussion of the vital strategic stakeholder management process of choosing the most effective strategies for key stake holders based on two strategic priorities: reducing stakeholders potential for threat and enhancing their potential for cooperation. From this critical strategic priority-setting process. strategies are classified as either involving, collaborating, defending, or monitoring. Using data from the FUF project, four medical group practice (MCP) stakeholders are analyzed. These are the integrated delivery system/network (lDS/N) itself as well as its components: physicians, hospitals and managed care organizations (MCOs). The FUF project's MGP executive respondents believe these four stakeholders will be some of the most important MGP stakeholders in the year 2000. The FUF study was conducted jointly between the Center for Research in Ambulatory Health Care Administration (CRAHCA), the research and development arm of the Medical Group Management Association (MGMA), Englewood. Colo., and The Institute for Management and Leadership Research (IMLR). College of Business Administration at Texas Tech University, Lubbock, Texas. MGMA s American College of Medical Practice Executives (ACMPE), faculty of Texas Tech University's Ph.D. and M.BA programs in Health Organization Management (HOM), and faculty from the University of Alabama at Birmingham collaborated on the project. Abbott Laboratories. Abbott Park. Ill., provided funding for the FUF project The administration of Round One was completed in the fall of 1994. The administration of Round Two was completed in the summer of 1995. Selected Round One (i.e.. health care experts) and Round Two (i.e., MGP executives) results have previously been presented in educational programs and publications.

Medical practice and physician executives face the uncertain future. Strategic stakeholder management III

This article, third in a series addressing stakeholder management, presents preliminary findings of Round Two data from the "Facing the Uncertain Future" study. One purpose of this study is to determine how experts define key stakeholders of medical group practices now and how these stakeholders might change by the year 2000. This analysis highlights a comparison of two expert panels: medical practice executives (MPEs) and physician executives (PEs). The purpose was to ascertain whether or not MPE and PE perspectives for the present and predictions for the future differed on a series of key issues. The key issues discussed are: organizational goals, who will be responsible for managing the organization towards these goals, assessment of the external environment and identification of key stakeholders. MPEs and PEs, with the exception of the physician manager and several current organizational goals, view the present similarly and also showed convergence in their predictions for 2000. Despite different training and career experiences, our analysis found that MPEs and PEs view the present and future in surprisingly similar ways. As a result, MPEs and PEs are encouraged to be less preoccupied with perceived differences in perspective and, instead, focus their energies on developing clear strategies and specific tactics to strengthen their organization's position in this turbulent environment.

Integrated delivery systems/networks in the uncertain future. Strategic stakeholder management, Round One continued

This article presents an analysis of Round One data with a focus on integrated delivery systems/networks (IDS/Ns). These complex, multifaceted organizations are growing in importance in the turbulent health care industry. The emergence of these multi-organizational forms requires that all health care industry organizations--medical groups, hospitals, payer organizations, suppliers--adapt to the ever-increasing demands placed on them as the industry experiences revolutionary changes. The findings presented in this article were compiled from the responses of 580 health care industry experts about the uncertain future facing health care executives. These respondents represented virtually every health care organizational form, including medical groups, physicians, hospitals, payer organizations, academic researchers, pharmaceutical firms and other health care industry suppliers. Each of these health care respondent panels answered hundreds of questions pertaining to both the present (1994) and the future (1999). These analyses seek to describe the different relationships between medical groups, their stakeholders and IDS/Ns, and how they will change over the years of 1994 to 1999. We also present experts' perceptions and predictions about five other key stakeholders of medical groups--managed care organizations, governments, employers, system hospitals and patients.

Strategic stakeholder management. First round results from 'Facing the Uncertain Future'

Authors summarize preliminary results from the first round of a two-round modified Delphi study called "Facing the Uncertain Future." Health care experts were asked to comment on the status of the health care industry in 1994 when the study began and their predictions for change by 1999. Major findings based on the 580 responses received include: (1) the continued movement of the U.S. health care industry from a primarily private insurance industry to one in which medical groups and hospitals will be members of integrated delivery systems/networks (IDS/N); (2) the increasing dominance of the components of IDS/Ns in 1999 (components are defined as: medical practices, system hospitals, managed care organizations and IDS/Ns); and (3) the potential effects of IDS/Ns on the health care industry, including: increases in cost effectiveness, quality of administrative management and the quality of physician leadership, as well as decreases in availability of advanced medical technology and the duplication of ancillary services, facilities and equipment. The study is being conducted jointly by the Medical Group Management Association and Texas Tech University with funding from Abbott Laboratories.

Urban-rural hospital affiliations: assessing control, fit, and stakeholder issues strategically

Urban-rural hospital affiliations are an outgrowth of both the external pressures on rural hospitals to survive and the need for urban hospitals to maintain or increase their share of the tertiary referral market. This article discusses the significant role of stakeholders in these affiliations, develops a fourfold typology of urban-rural hospital affiliations based on the notions of organizational control and fit, suggests four generic strategies for forming affiliations, and analyzes four actual cases of affiliation.

Negotiating with interactive scenarios and strategies

Physician executives need to negotiate effectively with a wide range of parties. In those negotiations, they should consider the relative importance of both substantive and relationship outcomes in selecting initial negotiation strategies. Of course, these strategies may or may not be successful, depending on the strategies used by the other party. Hence, the physician executive must consider the other party's strategy and how it and his or her initial strategy are likely to interact both before and during negotiations.

Negotiating for more than a slice of the pie

Negotiation is an important way for physician executives to manage conflict and to accomplish new projects. Because of the rapidly changing nature of the health care environment, as well as conflicts and politics within their organizations, managers need to effectively negotiate with a wide range of other parties. Managers should consider the relative importance of both the substantive and relationship outcomes of any potential negotiation. These two factors may guide the executive's selection of initial negotiation strategies.

The importance of relationships in hospital negotiation strategies

Negotiation is one important way for hospital executives to manage conflict and to accomplish new projects. Because of the rapidly changing nature of the health care environment, as well as conflicts and politics within their organizations, managers need to negotiate effectively with a wide range of other parties. Hospital managers should consider the relative importance of both the substantive and relationship outcomes of any negotiation. These two factors, when viewed both in terms of the priorities of the hospital executive and the other party may guide the executive's anticipation of negotiation scenarios and selection of appropriate negotiation strategies.

Assessing key stakeholders: who matters to hospitals and why?

A key stakeholder perspective, informed by illustrative quantitative and qualitative data, is developed for hospital administrators. These data provide answers to the questions, Who matters to hospitals? and Why do they matter? A tool kit for assessing stakeholders also is presented to help hospital executives identify their institutions' key stakeholders, determine the power of these stakeholders and their core values, and define who within their institutions should be responsible for the routine management of different stakeholders. These tools facilitate the management of each key stakeholder, ensuring that each strategic decision is examined in terms of the likely reaction of key stakeholders and is supplemented with plans for gaining stakeholder acceptance. Managers should recognize that the answers to Who matters? and Why? will vary by type of hospital and by the specific issue being addressed.

Stakeholder strategies for the physician executive

If physician executives are to be effective in confronting the environmental turbulence and uncertainty facing their organizations, they must effectively manage their stakeholders. This article extends the stakeholder approach described in the May-June 1989 issue of Physician Executive as a tool for the physician executive in the development of practical strategies to cope with turbulence and uncertainty. We suggest four generic strategies physician executives can use: involve supportive stakeholders, monitor marginal stakeholders, defend against nonsupportive stakeholders, and collaborate with mixed-blessing stakeholders. As an overarching strategy, a physician executive should try to change the organization's relationships with a stakeholder from a less favorable category to a more favorable one. The stakeholder can then be managed using the generic strategy most appropriate for the category.

Stakeholder issues for the physician executive

If physician executives are to cope with the environmental turbulence and uncertainty facing their organizations, they must effectively manage their "stakeholders." The stakeholder approach helps integrate managerial concerns that are frequently treated separately, such as strategic management, marketing, human resource management, "organizational politics," and social responsibility. The stakeholder perspective enables medical managers to relate important issues to the development of strategies for handling potentially conflicting demands for effectiveness and efficiency from various stakeholders. Medical managers should minimally satisfy the needs of marginal stakeholders while they maximally satisfy the needs of key stakeholders. To identify key stakeholders, a physician executive should critically assess each stakeholder's potential to threaten the organization and its potential to cooperate. This assessment should account for such factors as the stakeholder's relative power, the specific context and history of the organization's relations with it, the specific issues under consideration, and other key stakeholders influencing the organization.

Too many on the seesaw: stakeholder diagnosis and management for hospitals

If hospital managers are to cope with the environmental turbulence and uncertainty facing hospitals, they must effectively manager their stakeholders. The stakeholder approach helps integrate managerial concerns normally treated separately, such as strategic management, marketing, human resource management, organizational politics, and social responsibility. This approach enables hospital executives to develop strategies for handling conflicting demands for effectiveness and efficiency from various stakeholders. Four generic strategies hospital managers can use depending on the type of stakeholder are detailed, and an overarching strategy for hospital managers is discussed.

Stakeholder supportiveness and strategic vulnerability: implications for competitive strategy in the HMO industry

A conceptual and empirical analysis of the strategic vulnerability of HMOs shows that they are strategically vulnerable on the social dimension of stakeholder supportiveness. One of the major implications of this finding is that HMOs' cost leadership strategy cannot be sustained, given the competition from such substitutes as PPAs.

Efficiency and safety of optically modified fiber tips for laser angioplasty

To evaluate the safety and efficiency of optically modified fiber tips, craters were created in human cadaver atherosclerotic arterial walls using sapphire contact probes and lensed fibers connected to a continuous wave neodymium yttrium aluminum garnet (Nd-YAG) laser. Laser energy was emitted at a constant level of 50 J. The sapphire contact probe catheter consisted of a round 2.2 mm diameter synthetic sapphire attached to an 8F catheter into which a 0.2 mm diameter optical fiber was inserted with the distal tip maintained at 3 mm from the sapphire. The lensed fiber catheter consisted of a 0.2 mm optical fiber at the end of which a 1 mm diameter lens was made. The fiber was inserted into a 5F low profile balloon catheter with the lens maintained 3 mm beyond the catheter tip. During laser emissions the catheter tips were maintained in a stationary position in contact with tissue targets immersed in blood at an angle of 90 degrees. The diameter of holes at the entry and exit of craters, the depth of craters and thermal injury to adjacent tissue (rim of carbonization and vacuolization) were measured with microscopy. The volume of tissue removed was derived from these values. Controlled effect index was determined as the ratio of diameter of holes and the extent of thermal injury. Efficiency was determined as the ratio of volume of tissue removed and the energy required to vaporize tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Development and experimental application of contact probe catheter for laser angioplasty

A sapphire contact probe laser catheter was developed to increase the dimensions of tunnels created by laser angioplasty. The device consisted of a round sapphire probe (2.2 mm diameter) attached to an 8F catheter into which a 0.2 mm optical fiber was inserted with a tip maintained at 3 mm from the sapphire. The fiber was connected to a continuous wave neodymium yttrium aluminum garnet (Nd-YAG) laser. A saline perfusate was circulated through the catheter during laser emissions to prevent excessive heating of the fiber tip. The system was used in vitro on 16 sections of atherosclerotic calcified human cadaver aortic walls, using diluted blood as a medium, at powers ranging from 10 to 40 W and exposure times from 1 to 4 seconds. Six craters were created at each energy level. The system was also used on six human cadaver, agar-embedded, obstructed iliac and femoral arteries, using 40 W and 2 second laser emissions. Dimensions of probe-created craters were compared with those obtained using bare fibers. The shape of the probe craters was that of a truncated cone with the entry hole wider than the exit, as opposed to the cylindrical shape created with unmodified bare fibers. At 120 J (seconds X watts), areas of entry and exit probe-formed holes were greater than those created with the bare fibers (6.7 +/- 0.5 and 3.4 +/- 0.6 versus 0.2 +/- 0.01 mm2, respectively, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Histopathology after Nd-YAG laser percutaneous transluminal angioplasty of peripheral arteries

Laser recanalization of occluded femoral or popliteal arteries was performed in 12 patients using a continuous wave neodymium yttrium aluminum garnet (Nd-YAG) laser. The histologic findings of the laser-irradiated arterial segments in two of these patients are reported. The specimens were obtained 2 and 4 weeks after the laser procedure. The laser-irradiated vessel in Patient 1 had been partially recanalized with reduction of the atherosclerotic occlusion from 3 to 1 cm. The lased arterial lumen manifested thermal injury to the inner quarter of the arterial wall with vacuolization and a rim of carbonization occupying 10% of the width of the arterial wall, but without thrombus formation. Histologic examination in Patient 2 revealed no fibrin deposits, atherosclerotic debris or thrombi at the intimal arterial edge. At the crater site, thermal injury was apparent with vacuolization of the intimal fibrous tissue. The histologic sections obtained 4 weeks after the procedure revealed new fibrous intimal tissue without endothelialization in some of the heavily calcified tissue sections. Where the plaques were noncalcified, reendothelialization was noted with only minimal damage to the surrounding tissue. No medial or elastic fiber disruption was seen, and no aneurysmal dilation had occurred. Intimal splitting with a cleft between the tunica media and the intima was noted at the site of previous balloon angioplasty. In conclusion, the follow-up histologic findings 2 and 4 weeks after laser angioplasty in two patients using a specially designed catheter delivery system and cooling blood perfusate revealed thermal injury to the inner quarter of the arterial vessel wall and no evidence of thrombus formation.

Congenital peritoneal mesothelioma

Only three primary peritoneal mesotheliomas in children have been previously reported. We describe a 6-wk-old girl with a papillary peritoneal mesothelioma of low grade malignancy. This is probably a congenital mesothelioma and is the youngest patient reported to date.

Brief clinical report: deletion of the long arm of chromosome 11, [del(11)(q23)]

We report sporadic occurrence of deletion of the long arm of chromosome 11 (q23 leads to qter) in a male newborn infant with intrauterine growth retardation, craniofacial, cardiac, and orthopedic abnormalities and neonatal death but without genital abnormalities. This deletion is seen predominantly in females; here we emphasize the importance of an XX sex chromosome constitution as a factor determining phenotypic expression of and survival in the del(11q) syndrome. We also provide a description of the cardiovascular system from postmortem examination. The cardiac findings are similar to those of two previously autopsied cases and will assist in early clinical diagnosis of the 11q-syndrome.

Tampon-related toxic-shock syndrome. Histopathologic and clinical findings in a fatal case

Toxic-shock syndrome (TSS) is consistently associated with penicillin-resistant Staphylococcus aureus in the vagina of menstruating women who use tampons. Increasing evidence implicates Staphylococcal toxin(s) in the pathogenesis of the condition, but the nature and biological effects of such toxin(s) are not established. Comprehensive postmortem studies and histopathologic data are few and largely unknown. The autopsy of a 15-year-old girl with this syndrome showed extensive superficial ulcerations and thrombophlebitis of the vagina, with bacteria on the mucosal surface only. Systemic phlebitis and capillaritis, visceral interstitial edema and acute inflammation involving various organs suggest a toxic effect, which is primarily manifested by widespread vascular damage. The histogenesis of the vaginal ulcerations remains unclarified, although they probably contribute to the absorption of toxin(s).

Heterotopic growth of dysplastic cerebellum in frontal encephalocele in an infant of a diabetic mother

An infant of a diabetic mother lived 13 days after birth. She had a small dysplastic 12.6 gm. brain, partly forming a frontal encephalocele. The uncleaved forebrain contained a mass of poorly organized heterotopic cerebellar cortex. The cerebellum itself had normal lamination, but was small and continuous with the dysplastic tissue. The ventricular system was absent except for a few midline ependymal rosettes, and the cerebral cortex was not developed. The cerebellar dysplasia resembled a proliferative and invasive lesion by its rostral extension.

Generalized dermal melanocytosis

A female infant was born with generalized blue-gray discoloration of the skin. Light microscopy demonstrated the diffuse distribution of dihydroxyphenylalanine-positive, dermal melanocytes. Electron microscopy confirmed the identification of the pigment-bearing cells as melanocytes and demonstrated individual melanocytes to be invested with a filamentous extracellular sheath. To our knowledge, comparable, generalized, dermal melanocytosis has not previously been reported in a newborn.

De novo partial 2p duplication with postmortem description

An unbalanced karyotype most likely consisting of a partial duplication of the short arm of chromosome 2 (p13 leads to pter) was found in a newborn infant with intrauterine growth retardation, facial, skeletal, and cardiac abnormalities. There was no evidence of a translocation in either parent. At autopsy, striking histopathologic abnormalities were detected in the central nervous system and ovaries.

Ethmoidal fibro-osseous lesion in a child. Diagnostic and therapeutic problems

A 4-year-old Caucasian male presented with marked proptosis of the right eye of 3 months' duration. A large soft tissue mass occupied fully the right ethmoid sinus; radiologic evidence of extensive bone destruction suggested a malignant tumor. Unexpectedly, a biopsy of the ethmoid tumor was interpreted as benign. Over the next 2 months, this lesion progressed rapidly, with further bone destruction and extension into the anterior cranial fossa. The histopathologic features of a resection specimen were so variable that a wide range of diagnoses was offered by several consultants who examined the material. This lack of agreement among experts in the field of bone diseases considerably influenced the treatment program selected for this patient.

Cerebral embryopathy in late first trimester: possible association with swine influenza vaccine

An infant girl was born with cerebral malformations characterized by developmental arrest late in the first trimester of gestation. These features included persistent pontine flexure, cerebellum developed only around the rhombic lip, failure of migration of inferior olive, absence of basis pontis and of corticospinal and corticopontine tracts, and agenesis of olfactory bulbs. The cerebral cortex was thin and poorly laminated, and primary and secondary sulci had failed to form. The choroid plexus contained vascular malformations, hemorrhages, and infarcts. The leptomeninges contained foci of primitive mesenchyme. The mother had received an inoculation of swine influenza vaccine six weeks after conception, followed by a 2-week illness. The temporal relation to the timing of the cerebral malformation suggests a teratogenic effect of the vaccine, but may have been coincidental.

alpha1-Antitrypsin deficiency and liver disease in children

This report describes the clinical, biochemical, and hepatic morphologic findings in ten children with severe serum alpha1-antitrypsin deficiency. Genetic protease inhibitor (Pi) phenotyping, using acid-starch gel and crossed antigen-antibody electrophoresis, demonstrated Pi phenotype ZZ in all our cases. In eight patients, manifestations of liver disease appeared during the first year of life. The case reports show that alpha1-antitrypsin deficiency should be suspected in any child with neonatal hepatitis, unexplained hepatomegaly or splenomegaly, or cirrhosis. In our report, one infant is normal at age 6 months, and one infant had progressive hepatic damage that culminated in liver failure and death at age 6 months. The variable clinical course and prognosis for infants with severe alpha1-antitrypsin deficiency is well illustrated by these two infants.

The liver in GM1 gangliosidosis types 1 and 2. A light and electron microscopical study

The livers from two cases of GM1 gangliosidosis types 1 and 2 were examined by histochemistry, light and electron microscopy. Type 1 GM1 gangliosidosis is characterized by large amounts of a water soluble substance in the hepatocytes, presumed to be keratan sulfate-like mucopolysaccharide, with similar material and probably a ganglioside in the Kupffer cells. In type 2 GM1 gangliosidosis, there is minimal storage of water soluble material and abundant presumed ganglioside in the Kupffer cells. The histochemical and ultrastructural features support the chemical findings and indicate a quantitative and morphologic difference in storage between the two types. These morphologic differences may provide an additional diagnostic parameter in the delineation of the two clinical variants.

Immunopathologic studies of systemic lupus erythematosus (SLE). I. Tissue-bound immunoglobulins in relation to serum antinuclear immunoglobulins in systemic lupus and in chronic liver disease with LE cell factor

We studied the composition of tissue-bound immunoglobulins and of antinuclear factors by immunofluorescent techniques in five patients with systemic lupus and two with chronic liver disease associated with positive LE cell tests. Renal glomeruli in all seven demonstrated deposits of bound gammaG-globulin and complement, although the presence of gammaA- and gammaM-immunoglobulins was variable. Blood vessel walls contained primarily gammaG-globulin and complement in the systemic lupus patients, but such deposits were absent from vessels in the two with chronic liver disease. We observed antinuclear factors, demonstrated by immunofluorescence, in all three immunoglobulin classes. In six of the seven patients, evidence was obtained of a correspondence between the classes of bound immunoglobulins in glomeruli and vessels and the serum titers of antinuclear immunoglobulins. These observations are consistent with the concept that immunoglobulin deposits in tissues may be derived at least in part from antinuclear factors. Neither bound immunoglobulins nor complement was observed in liver parenchyma of the two patients with chronic liver disease or in two patients with systemic lupus and liver pathology. It thus seems doubtful that serum antibodies play a primary role in the pathogenesis of forms of chronic liver disease associated with positive LE cell tests.