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Biomedical subjects

J C Long

Publications and source records attributed to J C Long.

At least 55 records · Page 3Linked to original sources
PubMed1990

Species attribution of the Swartkrans member 1 first metacarpals: SK84 and SKX 5020.

Susman (Am. J. Phys. Anthropol. 75:277-278, 79:451-474; Science 240:781-784; In FE Grine (ed): Evolutionary History of the "Robust" Australopithecines. New York: Aldine de Gruyter, pp. 149-172) has attributed the morphologically similar SK 84 and SKX 5020 hominid first metacarpals to Homo erectus and Australopithecus robustus, respectively, and has inferred that both species exhibited derived pollical morphologies, indicating refined precision grips. Consideration of the structure of his taphonomic arguments indicates that there are no adequate nonmorphological reasons to attribute these specimens securely to one or the other of the craniodentally represented species at Swartkrans. His morphological arguments fail to note any significant differences between the two specimens. Only the contrast in size between the small SK 84 and large SKX 5020 bones might warrant a species distinction; yet comparison of their length ratio to distributions of modern human first metacarpal length ratios indicates that it is not possible to reject conclusively the null hypothesis that they are conspecific. Therefore, early hominid adaptive scenarios based on a derived Homo-like manual functional morphology in A. robustus remain without a secure paleontological basis.

Animals↗
PubMed1987

Early onset periodontitis: a comparison and evaluation of two proposed modes of inheritance.

Two rare types of familial periodontitis, a localized form usually diagnosed in late adolescence, and a more generalized form with a latter mean age of diagnosis, have been analyzed with respect to genetic models currently favored in the dental literature. These include autosomal recessive and X-linked dominant (partial penetrance) inheritance. Since there is variation in severity, extent, age of onset, altered sex ratio of affected individuals, and a low population prevalence, it is not surprising that genetic mechanisms heretofore have not been revealed. We have compared the likelihoods of 33 kindreds ascertained through affected probands under the above genetic models. Our findings include (1) several families in which both forms of early onset periodontitis co-occur, making it unlikely that the clinical varieties of the disease have unrelated genetic causes; (2) the autosomal recessive model is far more likely than the X-linked dominant model. The superiority of the recessive hypothesis arises from the fact that there are only a few instances of affected individuals having affected parents and because the skewed sex ratio is shown to be incompatible with X-linked inheritance. These conclusions are largely insensitive to the assumptions of the analysis. We conclude that the X-linked dominant hypothesis is inadequate, and while the autosomal recessive model is by no means proven, it is clearly favored.

Adolescent↗
PubMed1987

The allelic correlation structure of Gainj- and Kalam-speaking people. II. The genetic distance between population subdivisions.

The patterning of allele frequency variability among 18 local groups of Gainj and Kalam speakers of highland Papua New Guinea is investigated using new genetic distance methods. The genetic distances proposed here are obtained by decomposing Sewall Wright's coefficient FST into a set of coefficients corresponding to all pairs of population subdivisions. Two statistical methods are given to estimate these quantities. One method provides estimates weighted by sample sizes, while the other method does not use sample size weighting. Both methods correct for the within-individual and between-individual-within-groups sums of squares. Genetic distances among the Gainj and Kalam subdivisions are analyzed with respect to demographic, geographic, and linguistic variables. We find that a demographic feature, group size, has the greatest demonstrable association with the patterning of genetic distances. The pattern of geographic distances among groups displays a weak congruence with the pattern of genetic distances, and the association of genetic and linguistic diversity is very low. An effect of differences in group size on genetic distances is not surprising, from basic theoretical considerations, but genetic distances have not often been analyzed with respect to these variables in the past. The lack of correspondence between genetic distances and linguistic and geographic differences is an unusual feature that distinguishes the Gainj and Kalam from most other tribal populations.

Alleles↗
PubMed1986

Genetic characterization of Gainj- and Kalam-speaking peoples of Papua New Guinea.

The research presented focuses on genetic variation in the Gainj- and Kalam-speaking peoples of highland Papua New Guinea. The primary data are typings at 51 genetic loci observed on 600 individuals who reside in 21 census units, called parishes. These data are augmented by cultural and demographic information that has also been collected. Parish sizes are small, ranging from 20 to about 200 individuals. Direct Western contact with these people has been occurring only for the past three decades. Although Westernization is currently increasing, we find that much of the traditional settlement pattern and mate exchange system is preserved. There are segregating variants at 27 loci. Four rare variants are initially described: NP 4-Kalam, ADA 6-Kalam, PEPA 3-Kalam, and FUM 2-Kalam. We find evidence for a new Gm haplotype, a;-, that is recessive to all other Gm haplotypes. It occurs at a high enough frequency, f(a;-) = 0.119, to be considered a "private polymorphism." Average per locus heterozygosity is estimated to be 0.053. This value is not statistically different from levels observed on two modern urban populations. Thus, there is no evidence for a reduced level of genetic variation in these people, despite small parish sizes and a relatively unacculturated social structure.

Adolescent↗
PubMed1986

The allelic correlation structure of Gainj- and Kalam-speaking people. I. The estimation and interpretation of Wright's F-statistics.

The internal patterning of allelic correlations in the Gainj and Kalam swidden horticulturalists of highland Papua New Guinea is examined within the context of Sewall Wright's F-statistic model. A multiallelic extension of the model is given first, and multivariate variance-component estimators for the parameters are suggested. Then, it is shown that the expectation of the F-statistic set depends on the age structure of the population and that knowledge of the population and sample age structure is critical for meaningful analysis. The array of F-statistics estimated jointly over five polymorphic enzyme loci reveals the following features of Gainj and Kalam population structure: (1) significant departures from panmictic expectations and (2) characteristics of a continuously distributed breeding population, rather than those expected for populations subdivided into demes with discrete boundaries. Finally, the F-statistics estimated for the Gainj and Kalam are briefly compared to estimates obtained from other tribal populations. It is seen that the level of differentiation observed in the Gainj and Kalam is only about one-third that observed in South American swidden horticulturalists. Consequently, some conventional wisdom regarding the interrelationship of socioecological settings and genetic structures may require reevaluation.

Alleles↗
PubMed1983

Intertribal gene flow between the Ye'cuana and Yanomama: genetic analysis of an admixed village.

Genetic exchange with a neighboring village of Ye'cuana Indians had introduced two alleles, Dia and ACPa, into the Yanomama Indian Village of Borabuk. After several generations, these alleles had reached frequencies of 0.08 and 0.10, respectively. These frequencies are puzzling because they are higher in Borabuk than in the Ye'cuana village from which they were derived. Single allele estimates of ancestral proportions obtained from either of these traits are biologically unrealistic and suggest that admixture is not a good explanation for genetic variation in Borabuk. Nevertheless, multiallelic admixture models are seen to produce credible estimates of ancestral proportions and to explain a large amount of allele frequency variation in Borabuk. When these results are compared with expectations derived froma formal pedigree analysis, good agreement is seen. Comparison of single allele estimates of ancestral proportions obtained from alleles at 11 loci, with multiallelic estimates obtained from the same 11 loci and with the pedigree-derived estimates, demonstrates the superiority of the multiallelic approach.

Alleles↗
PubMed1980

Mammographic appearance of malignant lymphoma of the breast.

The spectrum of mammographic findings in 12 patients with malignant lymphoma of the breast is presented. Five patients had primary breast lymphoma, and seven had secondary involvement. The abnormal densities varied from fairly discrete nodules to diffuse involvement of the parenchyma and skin. Correlations between the mammographic findings and histopathological classification are explored.

Adult↗
PubMed1980

Endogenous pyrogen production by Hodgkin's disease and human histiocytic lymphoma cell lines in vitro.

Fever not explained by infection may occur in patients with malignant lymphoma presumably caused by a release of endogenous pyrogen. Although pyrogen has been found in some tumors with a mixed cell population, production of endogenous pyrogen by the neoplastic cells has not been demonstrated. This report documents the apparently spontaneous synthesis and release of such pyrogen by two human tumor cell lines derived from patients with Hodgkin's disease and histiocytic lymphoma. The endogenous pyrogen from the two cell lines was similar and closely resembled that produced by normal human monocytes in antigenic properties as well as heat and pronase sensitivity. The Hodgkin's disease and histiocytic lymphoma cell lines do not require specific stimulation for the production of endogenous pyrogen suggesting that the mechanism of pyrogen release by neoplastic macrophage-related cells differs from that of normal phagocytic cells. The tumor-associated fever in some patients with malignant lymphoma may be caused by a release of endogenous pyrogen by proliferating neoplastic cells.

Cell Line↗
PubMed1979

Electron microscopy of Hodgkin's disease tissue cultures.

Cells from 9 monolayer tissue cultures prepared from Hodgkin's disease tumors in the spleen were examined in the electron microscope. Three established culture lines (carried in vitro for greater than 3 years and passaged greater than 200 times) that contained aneuploid karyotypes were composed of oval cells with numerous interdigitating surface microvilli. The nuclei were complex and convoluted with multiple large nucleoli and dispersed chromatin. The cytoplasm contained lysosomes, microfilaments, a complex Golgi apparatus, nondilated rough endoplasmic reticulum, polyribosomes, fat, and glycogen. One Hodgkin's disease monolayer with aneuploid chromosomes examined from the 4th to 48th passage in culture was composed of larger cells with fewer microvilli and numerous multinuclear giant cells. Two monolayers derived from transplanted tumors in nude mice inoculated with Hodgkin's disease cultured cells were similar to the original cell lines. The ultrastructural features of these 6 cultures with aneuploid karyotypes differed from those of 3 monolayers which, although prepared from Hodgkin's disease splenic tumors, were composed of fibroblastic cells with diploid chromosomes. The aneuploid Hodgkin's disease cultures did not resemble 6 normal spleen, thymus, or lung monolayers, Raji lymphoblastoid suspension cultures, or Hela cells. Our electron microscopic studies indicate that adherent cells which replicate in some monolayer tissue cultures derived from Hodgkin's disease tumors are related to and possibly derived from neoplastic macrophages.

Aneuploidy↗
PubMed1979

Terminal deoxynucleotidyl transferase positive lymphoblastic lymphoma: a study of 15 cases.

The investigation was undertaken to define the features of lymphoblastic lymphoma. Fifteen lymph node biopsies from a group of 82 specimens studied for the enzyme terminal deoxynucleotidyl transferase (TdT) fulfilled morphological criteria for this diagnosis. These criteria required a diffuse infiltrate of relatively uniform, immature lymphoid cells with basophilic cytoplasm; round, oval or lobulated nuclei with evenly dispersed chromatin; rare or inconspicuous nucleoli; and numerous mitotic figures. Examination of 1-micron thick, plastic-embedded, Giemsa-stained tissue sections revealed convoluted nuclei in more than 50% of neoplastic cells in four cases: in six specimens there was an admixture of cells with grooved, hyperlobulated, and round nuclei, and in five the round or oval nuclei were non-convoluted. Specimens from all 15 patients were positive for TdT by fluorescent antibody and biochemical assays. The percentage of cells from involved nodes reacting by indirect immunofluorescence with an antiserum against bovine TdT ranged from 4 to 90% (mean of 52%), and the mean level of biochemically measured enzyme activity was 8.7 units/g of tissue (range of 1.9 to 27.5). Cytochemical stains for acid phosphatase were positive in 13 of the 15 cases. In eight samples more than 50% of cells formed rosettes with sheep erythrocytes, while the E rosettes varied from 14 to 38% in the other seven. The percentage of cells with complement receptors varied widely (range of 6 to 80), but cells bearing surface immunoglobulin or IgGfc receptors were not increased. All patients presented with supradiaphragmatic lymphaedenopathy, eight with an anterior mediastinal mass. Two-thirds of the patients were male, and the mean age was 20 years (range 4 to 46 years). None were leukemic at the time of diagnosis, but eight patients subsequently developed acute lymphoblastic leukemia. Involvement of the central nervous system was observed in four of the 15, and of the testes in two. Ten patients have died of their disease with a median survival of 8 months (range 4 to 20), and five are alive 3--8 months after diagnosis. We observed no differences in clinical findings at presentation, incidence of mediastinal involvement or leukemic dissemination, content of TdT, acid phosphatase staining, or immunologic cell surface characteristics between the convoluted and non-convoluted types of lymphoblastic lymphoma. Distinctive morphologic, cell surface, biochemical, and clinical features of lymphoblastic lymphoma can be identified irrespective of the presence or absence of convoluted nuclei.

Acid Phosphatase↗
PubMed1979

The immunopathology of Hodgkin's disease.

Answers are beginning to emerge to the questions posed in the introduction to the preceding section. In vitro techniques that allow characterization of malignant cells have particular relevance when, as in Hodgkin's disease, the precise identity of the cells remains in doubt. Monolayer tissue cultures derived from Hodgkin's disease tumours and maintained as established cell lines have proven amenable to a variety of cytogenetic, immunological, enzymatic, and ultrastructural studies. Tissue culture experiemnts, in conjunction with meticulous immunological studies of individual Reed-Sternberg cells from non-cultured tumours, suggest that neoplastic cells of Hodgkin's disease are related to, and possibly derived from, cells of the monocyte-macrophage system. The lymphocytes that comprise an integral part of the cellular proliferation and form the basis for histological subclassification of the tumour could be a manifestation of cell-mediated immunity against this non-lymphoid malignant cell. The immunodeficiency of patients with untreated Hodgkin's disease of limited anatomical extent is not the primary event of the disorder and probably not related to the site at which the aetiological agent acts. The deficit does not result solely from impaired T-cell function and appears to arise as a consequence of excessive suppressor cell activity. Inhibitory monocyte-lymphocyte interactions may be one of the causes of defective cell-mediated immunity in Hodgkin's disease. The possible significance of elevated levels of circulating immune complexes in the serum of patients with Hodgkin's disease is indicated by the finding that such complexes react with cells of long-term monolayer tissue cultures derived from the tumour. Circulating immune complexes may be one source for intracellular immunoglobulin in non-cultured Hodgkin's disease cells. The presence of polyclonal immunoglobulin G on the membrane and within the cytoplasm of Reed-Sternberg cells could be due to in vivo binding and ingestion of immune complexes by such cells. The specificity of the interaction between soluble complement-containing immune complexes and neoplastic cells of Hodgkin's disease depends on the nature of the complexed antigen. The complexes could non-specifically attach via an Fc receptor or, if the complexed antigen is identical to a tumour cell antigen, the binding could be specific. If the immune complexes are tumour specific they could provide a source for isolation and identification of tumour-associated antigens. However, the aetiological significance of antigens and putative oncogenic viruses thus far identified in association with Hodgkin's disease remains to be clarified.

Antigen-Antibody Complex↗
PubMed1979

Reaction of immune complexes with Hodgkin's disease tissue cultures: radioimmune assay and immunoferritin electron microscopy.

We examined the binding of soluble immune complexes in sera from patients with Hodgkin's disease to established tissue cultures derived from the tumor. Circulating immune complex levels were determined by the Raji cell assay, and the reaction of serum with cultured cells was examined with a radioimmune assay and by immunoferritin electron microscopy. Serum with elevated immune complexes was found to react with cells of Hodgkin's disease monolayers when tested with radioiodine-labeled antisera against human IgG heavy and light chains and the complement 3 (C3) component. When examined with the electron microscope, monolayers incubated with Hodgkin's disease serum containing immune complex and labeled with ferritin-conjugated antiserum to C3 contained surface-bound ferritin particles with a uniform but discontinuous pattern. Absorption of Hodgkin's disease serum with monolayer cells reduced immune complexes and decreased reactivity of the sample with cultured cells by radioimmune assay. Sera of patients with other disorders and aggregated gamma-globulin with complement, despite markedly elevated immune complex levels, did not react positively with monolayers derived from Hodgkin's disease tumors, and none of the sera reacted with normal cultured spleen. The approximate size of serum components reacting with Hodgkin's disease monolayers was estimated by sucrose density gradient centrifugation. Sedimentation fractions in the 19S region reacted with monolayer cells when tested with 125I-labeled antisera to both IgG and C3 and contained immunoglobulin-complement complexes by gel diffusion and immunoabsorption. A component sedimenting at 7-9S contained immunoglobulin not complexed with complement; this component reacted with monolayer cells when tested with anti-IgG antiserum but did not react when tested with antibody to C3. The reaction of Hodgkin's disease monolayers with serum containing immune complexes differed from that of two suspension culture lines composed of cells with surface complement and IgG Fc receptors. Inasmuch as cells of our long-term Hodgkin's disease monolayers do not contain these surface receptors, possibly the antibody component of the immune complex reacts with antigens on the surface of cultured cells.

Antigen-Antibody Complex↗
PubMed1978

Circulating immune complexes in Hodgkin's disease.

Levels of circulating immune complexes (CIC) in the serum of patients with Hodgkin's disease were measured by the Raji cell radioimmunoassay. Elevated levels of immune complexes (mean value of 49 microgram/ml +/- 21 SE) were detected in 20 of 40 (50 per cent) untreated patients. After treatment, the level of CIC was normal (less than 15 microgram/ml) in 39 of 41 patients. Recurrent disease developed in two of the 39 patients with normal post-treatment levels of CIC and in one of the two patients with elevated post-treatment levels during the follow-up period of six months to six years. Elevated levels of CIC were detected in patients with Hodgkin's disease in stages I, II and III but not in stage IV. No significant correlations were found in the frequency of elevated levels of CIC or the values observed, and the presence or absence of symptoms (fever, sweats, weight loss) or the histologic subtype of the tumor. Our data indicate that the measurement of CIC by the sensitive and specific raji cell assay may prove useful in the management of patients with Hodgkin's disease. In particular, serial measurement of the level of CIC could be employed to monitor the response to treatment and to detect recurrent diseases.

Antigen-Antibody Complex↗
PubMed1978

Terminal deoxynucleotidyl transferase in the diagnosis of leukemia and malignant lymphoma.

Neoplastic cells from 253 patients with leukemia and 46 patients with malignant lymphoma were studied for the presence of terminal deoxynucleotidyl transferase (TdT) by biochemical and fluorescent antibody technics. TdT was detected in circulating blast cells from 73 of 77 patients with acute lymphoblastic leukemia, 24 of 72 patients with chronic myelogenous leukemia examined during the blastic phase of the disorder and in cell suspensions of lymph nodes from nine of nine patients with diffuse lymphoblastic lymphoma. Blast cells from six of 10 patients with acute undifferentiated leukemia were TdT positive, but the enzyme was found in only two of 55 patients with acute myeloblastic leukemia. TdT was not detected in other lymphocytic or granulocytic leukemias or in other types of malignant lymphomas. The fluorescent antibody assay for TdT permits rapid and specific identification of the enzyme in single cells. The TdT assay is clinically useful in confirming the diagnosis of acute lymphoblastic leukemia, evaluating patients with blastic chronic myelogenous leukemia, and distinguishing patients with lymphoblastic lymphoma, whose natural history includes rapid extranodal dissemination, from patients with other poorly differentiated malignant lymphomas.

Adolescent↗