Pharmacological modification of DDT-induced tremor and hyperthermia in rats: distributional factors

Pretreatment of rats with hydantoin (75 mg/kg, PO, an anticonvulsant), trihexyphenidyl (10 mg/kg, SC, a muscarinic cholinergic antagonist), or piperonyl butoxide (500 mg/kg, PO, a metabolic inhibitor) had no effect on the whole blood or brain tissue levels of orally administered DDT (75 mg/kg) or its metabolites DDD and DDE. Hydantoin and piperonyl butoxide decreased DDT-induced tremor and hyperthermia due to DDT when measured 12 h after DDT exposure, while trihexyphenidyl augmented some components of DDT-induced tremor. Additional experiments found that pretreatment with piperonyl butoxide increased tremor due to permethrin exposure (120 mg/kg, PO), while having no effect on tremor due to chlordecone administration (60 mg/kg, IP). Pretreatment with ellipticine (30 mg/kg, IP, a metabolic inhibitor) also decreased tremor 12 h after DDT exposure. The effects of piperonyl butoxide and ellipticine on DDT-induced tremor are postulated to occur through direct actions of these compounds on nerve or muscle tissue. Hydantoin-induced attenuation of DDT-induced neurotoxicity may be due to the ability of hydantoin to block repetitive firing of nerves by binding to the inactivation gates of sodium.

Expression of a cross-reactive idiotype on rheumatoid factor in patients with Sjogren's syndrome

Primary Sjogren's syndrome (SS) is a systemic autoimmune disorder characterized by lymphocytic infiltration of salivary and lacrimal glands. These patients have evidence of marked B cell hyperactivity, including the production of autoantibodies such as rheumatoid factor (RF) and an increased frequency of non-Hodgkin's lymphoma. We now demonstrate that RF from 12/15 SS patients contains a cross-reactive idiotype (CRI) on their kappa light chain defined by a monoclonal antibody (MoAb 17-109) and immunoblotting. This CRI was associated with immunoglobulin (Ig) A-RF, and to a lesser extent with IgM-RF molecules on the basis of direct binding studies. With the use of immunoperoxidase techniques to stain frozen tissue sections, B cells containing cytoplasmic Ig reactive with MoAb 17-109 were detected in the salivary gland biopsies from 11/12 SS patients at high frequencies, and in the blood from the same patients at much lower frequencies. One patient with pre-existant SS developed non-Hodgkin's lymphoma with tumor cells and RF paraprotein reactive with MoAb 17-109. Evaluation of serial biopsies over a 4-yr period showed a progressive increase in the proportion of B cells bearing the CRI. In contrast, synovial membrane biopsies from RA patients lacking sicca symptoms did not contain B cells expressing the CRI. Because previous studies have demonstrated that MoAb 17-109 detects a CRI on RF paraproteins from patients with lymphoma, B cells bearing this CRI may have increased frequency of neoplastic transformation. SS patients provide an opportunity to study the expression of this CRI and to understand the transition of B cell clones from autoimmune proliferation to neoplastic transformation.

Rapid identification of periodontal pathogens in subgingival dental plaque. Comparison of indirect immunofluorescence microscopy with bacterial culture for detection of Bacteroides gingivalis

A large body of research implicates Bacteroides gingivalis in the etiology of adult periodontitis, however, the application of this information to clinical diagnosis and treatment has been hampered by the need for a simple, rapid, and reliable means of detecting this microorganism. In the present study, indirect immunofluorescence microscopy using species specific, polyclonal antisera and a monoclonal antibody was evaluated in the clinical identification and quantitation of B. gingivalis in human subgingival dental plaque. One hundred and twenty subgingival plaque samples were obtained from predetermined sites by means of sterile paper points from 20 human subjects including 10 adult periodontitis patients and 10 periodontally normal subjects. The proportions of cultivable B. gingivalis in each sample were determined following anaerobic culture on nonselective blood agar media and selective media containing kanamycin. These results were then compared to quantitative estimates of B. gingivalis by indirect immunofluorescent microscopic evaluation of heat-fixed plaque smears. Using both immunofluorescence microscopy and bacterial culture, the present study confirms the importance of B. gingivalis in adult periodontitis previously described by culture. The organism was cultivable from 70% of the adult periodontitis patients but not from any of the normal adults. In contrast, indirect immunofluorescence microscopy detected the organism in up to 40% of the subgingival sites in 100% subgingival sites in 100% of the adult periodontitis patients as well as four sites in the periodontally normal subjects. The sensitivity of indirect immunofluorescence microscopy compared to culture ranged from 91 to 100% while the specificity varied from 87 to 89%.(ABSTRACT TRUNCATED AT 250 WORDS)

The inferior vena caval pseudo thrombus sign: diagnosis by dynamic CT after arm vein injection

Pseudothrombus of the inferior vena cava has been observed after pedal infusion. Previously it has been suggested that this pitfall results from technique and that this finding would not be observed following fast computed tomographic scanning after arm vein injection. However, we have observed similar flow artifacts using the latter technique. A scan obtained up to 14 minutes after the start of the bolus or reinjection with delayed dynamic scanning can exclude thrombus without further investigation.

Simultaneous high-performance liquid chromatography assay of acetylsalicylic acid and salicylic acid in film-coated aspirin tablets

A reversed-phase high-performance liquid chromatography (HPLC) method has been developed for the simultaneous assay of acetylsalicylic acid (I) and salicylic acid (II) in film-coated aspirin tablets. As little as 0.1% II (relative to I) can be quantitatively determined. Using a 5-microns octadecylsilane column with water-acetonitrile-phosphoric acid (76:24:0.5) as the mobile phase enabled the chromatographic separation to be completed in 4 min. Due to the slow rate of decomposition of I to II in the extraction solvent, acetonitrile-methanol-phosphoric acid (92:8:0.5), the analysis of many samples was routinely performed by means of automated HPLC equipment. Other compounds (non-aspirin salicylates, caffeine and acetaminophen) were also separated by the chromatographic system.

Gene dosage and complementation analysis of ataxia telangiectasia lymphoblastoid cell lines assayed by induced chromosome aberrations

An approach of general applicability to mammalian radiosensitive mutants has been used in the analysis of gene dosage and complementation in ataxia telangiectasia (A-T). Thymidine residues in DNA of one parental lymphoblastoid cell line were substituted with bromodeoxyuridine before fusion with a second parental cell line, to allow differential staining of the two sets of chromosomes. Following gamma-irradiation, induced chromosome aberrations were scored in diploid and homokaryon cells from each parental line as well as in heterokaryons. Four complementation groups were ascertained among 7 A-T cell lines. Analysis of heterokaryons formed between appropriate combinations of normal, A-T homozygote and A-T heterozygote cells, gave a quantitative measure of gene dosage and demonstrated increasing radiosensitivity with increasing numbers of A-T alleles.

L1210(A) mouse lymphoma cells depleted of glutathione with L-buthionine-S-R-sulfoximine proliferate in tissue culture

L1210(A) mouse lymphoma cells have been adapted to long-term tissue culture in the presence of L-buthionine-S-R-sulfoximine in concentrations of 1-10 mM. As a result of the inhibitory action of this compound on the synthesis of gamma-glutamylcysteine, the dipeptide precursor of glutathione, the cells are depleted of more than 90% of their normal cellular glutathione content. The residual 10% seems to resist depletion at high concentrations of buthionine sulfoximine. Glutathione depleted cells proliferate at a rate similar to that of non-depleted cells, and show full viability. Upon transfer of cells into inhibitor-free medium, they fully regain their original glutathione content. It is concluded that these cells contain at least two pools of glutathione: a large cytoplasmic pool and a smaller, possibly mitochondrial, pool. It is further concluded that the large pool of cytoplasmic glutathione is not obligatory for cell growth and mitosis.

Establishment and characterization of a human monocytoid leukemia cell line, CTV-1

A new human monocytoid leukemic cell line, CTV-1, was established from a patient with relapsed acute monoblastic leukemia. The characteristics of this cell line were evaluated by morphologic and cytochemical analyses, electron-microscopy, chromosome study, surface marker analysis and a study of differentiation potential with tumor-promoting agents.

Birth planning and fertility transition

In 1971 the government of the People's Republic of China launched the third birth control campaign. The goals were to raise the age at marriage, lengthen the birth interval, and limit the number of births per family to two in the cities and three in the countryside. A birth-quota and pregnancy-authorization system was instituted. The campaign was greatly facilitated by the nationwide network of free community-based contraceptive and abortion services and generous incentives. By the early 1980s the contraceptive prevalence rate rose to 70 percent, and the total fertility rate fell to about 2.5 children per woman of reproductive age. The year 1979 saw the introduction of the one-child campaign. By 1982 first births accounted for 47 percent of total births, and 42 percent of the one-child families had pledged to have no more children. The successful implementation of the one-child campaign will, however, lead to a rapid aging of the population. The percentage of the population older than 64 years of age will increase rapidly, from 5 percent in 1982 to 7.3-7.7 percent in 2000 and to 23-27 percent in 2050. With such a high aged-dependency ratio, caring for the aged will entail heavy fiscal outlay in the twenty-first century.

Familial melanoma associated with dominant ultraviolet radiation sensitivity

Sensitivity to ultraviolet radiation was studied in lymphoblastoid cell lines derived from 32 members of two families with histories of multiple primary melanomas in several generations. As assayed by colony formation in agar or by trypan blue exclusion following irradiation, cellular sensitivity showed a bimodal distribution. All persons with melanoma or multiple moles were in the sensitive group, while some family members exhibited responses similar to those of controls. Cells from four cases of sporadic melanoma showed normal levels of sensitivity. The data are consistent with a dominantly inherited ultraviolet light sensitivity associated with these examples of familial melanoma. Spontaneous and ultraviolet light-induced sister chromatid exchange frequencies were similar to those in control cell lines. No defect in excision repair was detected in any of the above cell lines, but the sensitive group showed postirradiation inhibition of DNA replication intermediate between controls and an excision-deficient xeroderma pigmentosum cell line.

Differences in lymphoproliferative responses to the bacterium Actinomyces viscosus in various mammalian species

A water-soluble extract of Actinomyces viscosus (AVS) was tested for its capacity to induce DNA synthesis in lymphocytes from man, monkeys, mice and guinea pigs. The results indicated that the AVS induced an in-vitro lymphoproliferative response, as assessed by tritiated thymidine incorporation, in mouse-spleen cells, in the majority of human peripheral blood samples tested and in macaque monkey spleen cells. The AVS also elicited a blastogenic response from spleen, lymph node and peripheral blood lymphocytes from guinea pigs immunized with A. viscosus. The AVS did not elicit a lymphoproliferative response from human-cord blood cells, monkey peripheral blood lymphocytes, or peripheral blood and spleen lymphocytes from non-immunized guinea pigs. Thus there was a difference in the ability of A. viscosus to induce DNA synthesis in lymphocytes from the different animal species tested.

Cell-mediated and humoral immune responses of guinea-pigs to the oral bacterium Actinomyces viscosus

Actinomyces viscosus is a Gram-positive facultative rod indigenous to most human mouths. The guinea-pig was evaluated as a model for assessing cellular immune responses to a human strain of A. viscosus. Guinea-pigs, immunized with heat-killed A. viscosus cells or a water-soluble extract from A. viscosus (AVS), were tested for delayed-type hypersensitivity responses to A. viscosus 4 weeks after immunization. A week later, the guinea-pigs were terminated. Lymphocytes from peripheral blood, lymph node and spleen were tested for in-vitro blastogenic responses to heat-killed A. viscosus or the water-soluble extract. Plasma from these guinea-pigs were tested for the presence of precipitating antibodies. Positive in-vivo delayed-type hypersensitivity reactions and antibody responses to AVS occurred only in immunized guinea-pigs. A strong in-vitro blastogenic response to AVS or heat-killed A. viscosus occurred in lymphocytes from immunized guinea-pigs, but a weak response was detected in un-immunized animals. These data suggest that the guinea-pig can be used to evaluate different parameters of the immune response to oral bacteria such as A. viscosus.

Huntington's disease: implications of associated cellular radiosensitivity

Ionizing radiation sensitivity was studied in a series of Huntington's Disease (HD) patients and controls by measurement of radiation-induced chromosome aberrations in lymphocytes and by clonogenic survival of lymphoblastoid cell lines. As a group, HD patients were found to be significantly more radiosensitive than controls (p less than 0.001), but there was an overlap between values for the two groups such that an absolute distinction is not possible. These data are consistent with an association between HD and radiosensitivity but not with identity between HD and a radiosensitive phenotype, so that cellular radiosensitivity cannot be used for individual diagnosis. Analysis of three families including 5 HD patients and 11 first-degree relative confirmed this conclusion and demonstrated that even within a given family presymptomatic diagnosis cannot be based on measurement of radiosensitivity. However, the common association of cellular radiosensitivity with HD probands and their families provides a potential lead to the identification of HD gene(s) and so to an eventual understanding of the aetiopathogenesis of this disease at the molecular level.

Plasmodium falciparum strains from Papua New Guinea: culture characteristics and drug sensitivity

Seven strains of Plasmodium falciparum from Papua New Guinea have been established in continuous in vitro culture. Samples with a high initial parasitaemia were more likely to form continuous lines, possibly due to the time required for transport of infected blood samples from Papua New Guinea to laboratories in Australia. Most but not all established lines were resistant to chloroquine and all were resistant to pyrimethamine, possibly reflecting the parasite strain characteristics in that region.

Antigen structural requirements for immunoglobulin isotype switching in mice

L-Tyrosine-p-azobenzene-p-arsonate (RAT) is immunogenic and serves as a carrier for anti-hapten antibody responses in guinea pigs, rats, and mice. However, the murine anti-N-2,4-dinitrophenyl (DNP) plaque-forming cell (PFC) response to the bifunctional antigen 2,4-dinitrophenyl-6-amino-caproyl-L- tyrosine-p-azobenzene-p-arsonate (DNP-SAC-RAT; or BI-1) is extremely weak (2,000-4,000 PFC/spleen) and exclusively IgM in both primary and secondary responses. The 6-amino-caproyl group serves as a spacer in this antigen between the DNP haptenic and RAT carrier epitopes. In view of recent evidence indicating that different T helper cells synergize for optimal antibody responses, a trifunctional antigen, N-2,4- dinitrophenyl-6-amino-caproyl-L-tyrosine-p-azobenze-p-arsonate-(proline)9-L- tyrosine-p-azobenzene-p-arsonate (DNP-SAC-RAT-PRO(9)-RAT; or TRI), was prepared to investigate the effect of adding a second RAT epitope to BI-1. The nonaproline spacer between the two RAT epitopes in TRI is assumed to be a rigid rod of approximately 28 A. TRI induced about twice as many PFC as BI-1 in primary responses of A/J mice, and induced both IgM and IgG PFC in secondary responses. Furthermore, TRI induced IgG PFC responses in mice primed with p-azobenzene-p-arsonate-keyhole limpet hemocyanin, BI-1, or RAT, whereas boosting with BI-1 failed to induce IgG PFC, even in mice primed with TRI. These findings indicate that the minimum antigen structural requirements for inducing IgG PFC in mice are two carrier epitopes and one haptenic epitope. In addition, priming with a mono-epitope carrier (RAT) is sufficient preparation for IgG responses to a trifunctional immunogen. Because TRI differs from BI-1 by the (proline)(9) spacer as well as the additional RAT epitope, two other compounds, N-2,4-dinitrophenyl-6-amino- caproyl-(proline)(9)-L-tyrosine-p-azobenzene-p-arsonate (DNP-SAC-PRO(9)-RAT; or BI-2) and N-2,4-dinitrophenyl-6-amino-caproyl-(proline)(9)-L-tyrosine-p- azobenzene-arsonate (DNP-SAC-RAT-PRO(10); or BI-3), were prepared to evaluate the possible role of the spacer in the observed responses. BI-2, but not BI-3, induced IgG as well as IgM PFC in TRI-primed mice. However, BI-2 failed to induce IgG responses in RAT-primed mice, indicating that TRI and BI-2 were not equivalent immunogens. Because anti-prolyl antibodies had been found in guinea pigs immunized with N-2,4-dinitrophenyl-(proline)10-L-tyrosine-p- azobenzene-p-arsonate (DNP-PRO(10)-RAT), it seemed possible that priming with TRI might induce anti-prolyl antibodies, which, in turn, could cross-link BI-2 molecules into aggregates containing at least two carrier epitopes. To help resolve this question, mice were immunized with acetyl-(proline)10-L- tyrosine-p-azobenzene-p-arsonate and boosted with BI-2. IgG PFC responses were detected, suggesting that anti-prolyl antibodies were indeed responsible, because priming with RAT and boosting with BI-2 did not induce IgG formation. Accordingly, the observations that IgG responses in RAT-primed mice were induced only by TRI and not by any of the bifunctional antigens indicate that two carrier epitopes per antigen molecule are indeed required for IgG induction. They also provide indirect evidence for synergistic help in the switching of immunoglobulin isotypes.

Lymphoproliferative responses to oral bacteria in humans with varying severities of periodontal disease

We assessed in vitro the lymphocyte blastogenic resp onsess of peripheral blood lymphocytes to antigen extracts of a large battery of oral microorganisms in a population of humans with varying severities of periodontal disease. When the magnitudes and frequencies of statistically positive blastogenic responses to various oral microorganisms were compared, three general patterns emerged. The Actinomyces species proved to be potent stimulators of lymphocyte blastogenesis in most subjects tested, whereas Streptococcus sanguis, Campylobacter, and Eikenella corrodens stimulated few individuals. The response to these organisms correlated poorly with the severity of periodontal disease in the tested patients. However, several gram-negative anaerobic organisms, including Bacteroides asaccharolyticus and Treponema denticola, elicited statistically more frequent positive response in subjects with destructive periodontitis compared with patients with gingivitis. These results, taken together with recent microbiological findings, suggest that the specificity of the lymphocyte blastogenic response to antigens of oral bacteria correlates with the presence of these organisms in the subgingival microflora during various periodontal disease states.

Immunological properties of Actinomyces viscosus: comparison of blastogenic and adjuvant activities

A water-soluble extract of Actinomyces viscosus was tested for its capacity to induce deoxyribonucleic acid synthesis in spleen cells from normal mice and to augment the in vitro antibody-forming cell (AFC) response to the T-cell-dependent antigen, sheep erythrocytes (SRBC) by T-cell-deficient adherent spleen cell monolayers from the same mice. Our results indicated that the water-soluble extract induced an in vitro blastogenic response, as assessed by tritiated thymidine incorporation into mouse spleen cells. The water-soluble extract also augmented the antibody response to SRBC. However, after fractionation of the water-soluble extract on Biogel P-300, not all of the fractions induced a blastogenic response and augmented an AFC response to SRBC. This difference in the ability of A. viscosus fractions to induce in vitro responses suggests that the water-soluble extract has multiple immunological properties. Chemical analysis of the water-soluble extract indicated an enrichment for amino acids and amino sugar common to peptidoglycan.

Macrophage-T cell interaction mediated by immunogenic and non-immunogenic forms of a monofunctional antigen

As an approach to the elucidation of the essential steps in the immune pathway, the uptake and retention of immunogenic and non-immunogenic analogs of a monofunctional antigen by guinea pig macrophages and the efficiency of macrophages pulsed with the compounds to present antigen to sensitized T lymphocytes were compared. L-Tyrosine-azobenzene-p-arsonate (RAT) and its non-immunogenic analog, 4-hydroxyphenyl-n-propane-3-azobenzene-p-arsonate (RAN), react similarly with antiarsonate antibody, but RAN, unlike RAT, is unable to induce cellular immunity in guinea pigs. The uptake and retention patterns of the two compounds by macrophages differed in that, at a given time, more RAN than RAT was retained and detectable on cell surfaces by anti-arsonate antibody. Equivalent numbers of T lymphocytes from guinea pigs sensitized to RAT formed antigen-dependent clusters with macrophages pulsed with either RAT or RAN after 24 hr in culture, but not with macrophages pulsed with an azobenzenoid compound of unrelated specificity. On the other hand, T lymphocytes from guinea pigs immunized with RAN showed no significant capacity to bind to macrophages which had been pulsed with any of the compounds. The number of lymphocytes from RAT-sensitized animals which bound to RAT-pulsed macrophages remained relatively stable over a 48 hr period, whereas clusters of the same lymphocytes with RAN-pulsed macrophages dissocitated to background levels within that time. Early cluster formation mediated by RAN, as well as its ability to induce transient specific T cell unresponsiveness to RAT in vivo, indicate that T cells are capable of recognizing (binding) the non-immunogen. However, such early, and perhaps weak, interaction with RAN-pulsed macrophages did not induce DNA synthesis by T cells. Anti-Ia serum completely blocked cluster formation mediated by either RAT or RAN. Thus, the only significant distinction disclosed by these studies between the immunogenic and non-immunogenic compounds was the stability of macrophage-T cell interaction as determined by the persistence of antigen mediated cell clusters in culture, suggesting that this may be a factor in immunogenic discrimination.

Fetal hemoglobin in polycythemia vera: cellular distribution in 50 unselected patients

Fetal hemoglobin was studied in 50 unselected patients with polycythemia vera with chemical determinations of Hb F and measurements of F-cell levels using fluorescent anti-Hb F antibodies. Although in the majority of the patients Hb F production did not differ from that in normal controls, in 20% of the patients F-cell values were above the normal range. There was no correlation between F-cell values and duration of disease, treatment modality, presence of myelofibrosis, or hematologic parameters at the time of study. In 5 of 50 patients 30%--45% of the erythrocytes contained Hb F; such striking elevations of F cells may reflect a distorted differentiation of erythroid precursor cells in certain patients with this disorder.

A Nuclear Magnetic Resonance Study of Water in Cold-acclimating Cereals

Continuous wave nuclear magnetic resonance (NMR) studies indicated that the line width of the water absorption peak (Deltav(1/2)) from crowns of winter and spring wheat (Triticum aestivum L.) increased during cold acclimation. There was a negative correlation between Deltav(1/2) and crown water content, and both of these parameters were correlated with the lowest survival temperature at which 50% or more of the crowns were not killed by freezing (LT(50)). Regression analyses indicated that Deltav(1/2) and water content account for similar variability in LT(50). Slow dehydration of unacclimated winter wheat crowns by artificial means resulted in similarly correlated changes in water content and Deltav(1/2). Rapid dehydration of unacclimated crowns reduced water content but did not influence Deltav(1/2). The incubation of unacclimated winter wheat crowns in a sucrose medium reduced water content and increased Deltav(1/2). The increase in Deltav(1/2) appears to be dependent in part on a reduction in water content and an increase in solutes.Longitudinal (T(1)) and transverse (T(2)) relaxation times of water protons in cereals at different stages of cold acclimation were measured using pulse NMR methods. The T(1) and T(2) signals each demonstrated the existence of two populations of water, one with a short and one with a long relaxation time. During the first 3 weeks of acclimation, the long T(2) decreased significantly in winter-hardy cereals, and did not change in a spring wheat until the 5th week of hardening. There was no change in the long T(1) until the 3rd week of hardening for the winter cereals and until the 7th week of hardening for the spring wheat. No simple relationship could be established between T(1) or T(2) and cold hardiness. Neither continuous wave or pulsed NMR spectroscopy can be used as a diagnostic tool in predicting the cold hardiness of winter wheats. An increase in Deltav(1/2) or a reduction in relaxation times does not provide evidence for ordering of the bulk of the cell water.

Dependence on cloning method of survival of human melanoma cells after ultraviolet and ionizing radiation

The resistance of a human melanoma cell line (MM96) to both ultraviolet and ionizing irradiation was compared by two different methods of cloning, on plates and in agar. A high level of resistance to both ultraviolet (D0 = 320 ergs/sq mm) and ionizing irradiation (D0 = 4300 rads) was observed when viability of cells was determined by cloning in agar. In contrast, melanoma cells were found to be as sensitive as were other cells when viability after irradiation was determined by cloning on plastic plates. The difference in sensitivity to radiation between the two methods of cloning can be explained in a model involving damage to membranes as well as to DNA. At least for ionizing radiation, this effect is not restricted to melanoma cells since a HeLa subline, HeLa-QB1, showed a similar response. In contrast, a human lymphoblastoid line (JHP) cloned in agar was sensitive under these conditions (D0 = 120 rads).

Mechanism of adjuvant activity of dental plaque: in vitro activation of residual helper T-cell precursors in T-cell-deficient murine spleen cell cultures

The immunoenhancing activity of a water-soluble extract of dental plaque (DP), which contains a mixture of microbial antigens, has been investigated. DP was tested for its capacity to augment the in vitro antibody-forming cell (AFC) response to sheep erythrocyte by adherent spleen cells from thymectomized, lethally irradiated, and bone marrow-transplanted (TxB) mice. Although DP was found to induce a small polyclonal AFC response, most of the increase in AFC induced by DP was antigen dependent. The latter enhancing effect is an indicator of the adjuvanticity of DP. This adjuvant activity of DP was T-cell-dependent, since removal of the residual prethymic and/or thymic-derived lymphocytes (T-cells) by anti-T-cell serum (anti-theta) and guinea pig complement abrogated the capacity of DP to augment the in vitro AFC response. This view was further supported by the synergistic restorative effect obtained by culturing anti-theta-treated adherent spleen cells with both DP and a population of unactivated T-cells that by themselves were unable to significantly enhance AFC responsiveness. Moreover, DP was found to be mitogenic for thymocytes. The cumulative results suggest that the adjuvant activity of DP is dependent on both the T- and B-cell-activating components present in DP.

Immune response of guinea pigs to Schistosoma mansoni. II. In vitro blastogenesis and macrophage migration inhibition factor production in response to cercarial, adult worm and egg antigens

Guinea pigs infected with Schistosoma mansoni were tested for in vitro lymphocyte response to schistosome antigens and nonspecific mitogens at various times after infection. Production of macrophage migration inhibition factor by peritoneal exudate cells in response to cercarial, adult, and egg antigens reached a peak between 4 and 8 weeks post-infection and diminished rapidly thereafter. In contrast, peak blastogenic responses of blood lymphocytes appeared later than 8 weeks for all antigens and persisted until at least the 24th week. Blastogenic responses to concanavalin A and phytohemagglutinin P were not significantly different in normal and infected animals.

Bacteriophage T4 RNA ligase is gene 63 product, the protein that promotes tail fiber attachment to the baseplate

RNA ligase and tail fiber attachment activities, normally induced following bacteriophage T4 infection of Escherichia coli, are not induced when gene 63 amber mutants of T4 infect nonpermissive host cells. Both activities are induced when these mutants infect permissive hosts, or when revertants of these mutants infect nonpermissive hosts. When one of these mutants infects a host that carries supF, both activities are more than normally heat labile. RNA ligase, purified to homogeneity, promotes the tail fiber attachment reaction in vitro with a specific activity similar to that of the most highly purified preparations of gene 63 product isolated on the basis of tail fiber attachment activity. We conclude that T4 RNA ligase is gene 63 product. The RNA ligase and tail fiber attachment reactions differ in requirements and in response to some inhibitors, suggesting that the two activities of the gene 63 product may be mechanistically unrelated.

The relationship of cellular immunity to prognosis in acute leukemia

Forty-five patients with acute leukemia were compared on cellular immunity measures versus prognosis. The patients were treated according a multicombination therapy protocol. The purified protein derivative (PPD) test and dinitrochlorobenzene (DNCB) test on admission indicated low positive percentages. In acute non-lymphocytic leukemia (ANLL) patients, the 50% survival durations were 11 months in the PPD positive group and 6 months in the PPD negative group. In acute lymphocytic leukemia (ALL) patients, the 50% survival durations were 21 months in the PPD positive group and 13 months in the PPD negative group. Peripheral lymphocyte blastogenesis by phytohemagglutinin (PHA) stimulation was examined at various clinical stages. The stimulation indices were generally low, and no correlation was found between the PHA test and clinical stages. These cellular immunity measures appeared to reflect one aspect of the clinical condition in acute leukemia patients, and further studies are needed for predicting prognosis.

Production of osteoclast-activating factor by normal human peripheral blood rosetting and nonrosetting lymphocytes

This study has tested the ability of human mononuclear cells and the subpopulations of lymphocytes that rosette (E-RFC) or do not rosette (non-E-RFC) with sheep red blood cells to synthesize DNA and to produce a mediator with bone resorbing activity (osteoclast-activating factor, OAF) in response to stimulation with phytohemagglutinin (PHA). Mononuclear cells were stimulated by PHA both to synthesize DNA and to produce a factor that caused bone resorption. E-RFC enriched for T lymphocytes and depleted of macrophages synthesized considerable DNA in response to stimulation with PHA, but were unable to produce significant bone resorbing activity in tissue culture unless macrophages were re-added to the E-RFC. In contrast, mononuclear cells depleted of E-RFC (non-E-RFC enriched for B cells) did not synthesize DNA in response to stimulation with PHA, but did produce a mediator that caused significant bone resorption in tissue culture. In most of the experiments, unstimulated non-E-RFC produced as much OAF as the PHA-stimulated non-E-RFC. These results suggest that both activated T lymphocytes (E-RFC) and B lymphocytes (non-E-RFC) can produce OAF.

Lessons from the Chinese experience: China's planned birth program and its transferability

This article describes the most salient developments in the planned birth program of the People's Republic of China during the 1970s and discusses the potential for transfer of some features to other countries. Many Chinese activities are of interest because they are designed for a country with scarce resources for development and a low-income population. Some particular program features worth noting are: the encouragement of local initiative and experimentation: specific methods for the diffusion of innovation; and total integration of the health system with other development-political, administrative, economic, and social-at the grass-roots level.

Relationship between pacemaker fibrillation thresholds and electrode area

Energy thresholds for electrical pacing of the heart are lower with small electrodes than with large. Because pacing of the heart during the vulnerable period may produce ventricular fibrillation, it is also pertinent to know if fibrillation threshold is affected by the electrode size. Electrodes of different surface area but of the same material were implanted in 40 dogs and the pacing thresholds were recorded. Ventricular fibrillation was electrically induced by discharging a 2-msec d.c. cathodal pulse of progressively increasing energy into the vulnerable period. It was found that small electrodes required more energy to produce ventricular fibrillation than large electrodes, and the ratio of fibrillation to stimulation threshold was higher for the small-surface-area electrode. The difference between the thresholds and ratios obtained with the various electrodes was statistically significant. A similar experiment was performed in animals with chronically implanted electrodes, producing comparable results. The results indicate that, in regard to pacing and fibrillation thresholds, small electrodes are preferable to large.

Immune response of guinea pigs to Schistosoma mansoni. I. In vitro effects of antibody and neutrophils, eosinophils and macrophages on schistosomula

Schistosomula of Schistosoma mansoni were rapidly killed in vitro by IgG2 antibodies from serum of schistosome-infected guinea pigs and heat-labile factors present in normal serum. Addition of polymorphonuclear neutrophilic leukocytes greatly increased the rate and degree of killing. Eosinophils and macrophages did not increase the level of killing, though they did react with schistosomula already damaged or killed by antiserum. Neutrophils and eosinophils reacted with schistosomula only in the presence of specific antibody, while macrophages nonspecifically attacked dead schistosomula. Serum antibody levels reached a plateau at approximately 6 weeks after a single infection. Attempts to precoat schistosomula with antibody prior to exposure to complement were largely unsuccessful.

A Unified Theory for the Finitely and Infinitesimally Separated Position Problems of Kinematic Synthesis

A rigid body is studied in a series of different positions. These positions can be finitely separated, infinitesimally separated, or a combination of the two. A general method for determining the locations of points or lines (in the rigid body) which have their different multiple positions satisfying the constraints of binary links or combined link chains is developed. In a companion paper [10] equations governing the locations of these special points and lines are derived.

Design Equations for the Finitely and Infinitesimally Separated Position Synthesis of Binary Links and Combined Link Chains

A general method for synthesizing spatial linkages (derived in a previous paper [1]) is applied to the design of various types of binary links and combined link chains. Equations governing those special points and lines which define the link dimensions are derived. Types and order of loci of such special points and lines and the maximum number of design positions for each link are given. Numerical method for computing these special points and lines are discussed, and a numerical example is presented.