Dynamic associations between emotion expressions and strategy use in Chinese American and Mexican American preschoolers

Previous studies of emotion regulation in young children commonly used between-person approaches, which limit our understanding of dynamic and temporal relations between emotion expressions and strategy use. Further, previous work has mainly focused on temperamental reactivity among White children, and it is unclear whether these findings can generalize to children of Asian and Latinx origins. In the current study, we examined the within-person temporal associations between emotion expressions and strategy use among 3- to 5-year-old children in low-income Chinese American (CA) and Mexican American (MA) families. Children's emotion expressions (positive and negative) and strategy use (gaze aversion, self-soothing, fidgeting, and language) during an unfair social interaction task were coded by 10-s epoch. Executive functions were examined as between-person level predictors of strategy use. Multilevel modeling was conducted to examine whether positive and negative emotion expressions at one epoch (t-1) predicted strategy use at the following epoch (t). The results indicate that positive emotion expressions predicted an increase in fidgeting at the next epoch (β = .34, p < .01). Executive functions were unrelated to strategy use. Cultural group differences were found: CA children displayed lower intensity of positive emotion and fewer strategy use compared with MA children. The present findings inform theories on the dynamics of emotion regulation in young children and have implications for interventions with underrepresented immigrant populations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Resonant scattering of positronium in collision with CO2

The total cross sections of positronium (Ps) scattering from a carbon-dioxide molecule have been measured over the range (7-400) eV incident-Ps energy. For the first time in Ps collisions, a resonantlike structure is observed. For the present target, it occurs around 9.5 eV followed by a broader peak at ∼60 eV. Following Brawley et al. [Science 330, 789 (2010)] who have observed similarities between the total cross sections of positronium and of electrons incident upon a given target at the same velocity, a corresponding comparison is made for CO2. The comparison suggests that the former peak corresponds to the well-known 2Π(u) shape resonance which occurs for electrons at an incident velocity of 0.5 a.u. Further features are discussed and theoretical input is sought.

Electron-like scattering of positronium

Positronium (Ps), a hydrogen-like atom composed of an electron and its antimatter partner, the positron, is formed in considerable quantities whenever positrons interact with matter. It has unexpectedly been found to scatter from a wide variety of atoms and molecules in a way very similar to that of a bare electron moving at the same velocity, despite Ps being neutral and twice the mass.

Lack of association between levels of transplacentally acquired Plasmodium falciparum-specific antibodies and age of onset of clinical malaria in infants in a malaria endemic area of Nigeria

A cohort of 117 newborns was followed longitudinally for 12 months to determine the age of onset of clinical malaria and the subsequent episodes of malaria, and to investigate the possible existence of a correlation between level of transplacentally acquired Plasmodium falciparum-specific antibodies and age of onset of malaria in the infant. The mean age of onset of malaria in 49 infants was 4.48 +/- 1.54 months. Mean (+/- S.D.) age of onset of clinical malaria in haemoglobin AA infants (4.38 +/- 1.14) was significantly (P < 0.05) lower compared with haemoglobin AS (5.58 +/- 2.43) infants. No correlation was obtained between the age of onset of malaria and the level of cord serum total IgG, IgM and antibodies to P. falciparum antigens. Cord blood seropositivity for antibodies to the blood stage antigen Pf155/RESA and its C-terminal repeat sequence (EENV)6 or to the (NANP)6 peptide representing repeats of the circumsporozoite protein (CSP) did not influence the age of onset of clinical malaria. However, infants with haemoglobin AS whose cord blood was seropositive for antibodies to the (EENV)6 or (NANP)6 peptide showed delayed onset (P < 0.001) of malaria compared with AA seropositive infants. Although our results indicate that transplacentally acquired antibodies to the studied antigens alone offer no significant protection against malaria during the first few months of life, antibodies in concert with other factors such as haemoglobin genotype may contribute to the protection of the newborn.

Serum ferritin and other iron indices in adult Nigerians with chronic renal failure--review of management of anaemia

Iron studies were carried out in twenty five adult male and female patients with chronic renal failure and thirty one "healthy" individuals as control. Results showed moderately severe anaemia in all the patients with a mean haemoglobin concentration of 7.4 mg/dl (range 6-9.8 gm/dl). Transferin saturation of 28.8% in the patients was similar to the value of 29.2% in the control group. However, the mean serum ferritin value of 610 micrograms/L in the patients was significantly higher than the corresponding values of 165 micrograms/L and 58 micrograms/L in the control groups respectively. In patients with chronic renal failure, three out of ten bone marrow aspiration showed no stainable iron, and in five patients, iron was grossly increased with corresponding increases in serum ferritin values. In addition, four of the five patients had severe megaloblastic changes in the marrow.

Immunoglobulin levels in malaria infected Nigerians with and without abnormal haemoglobin

Comparative studies were made between malarial parasitaemia in Nigerians with and without abnormal haemoglobins. The three main classes of immunoglobulins (i.e. IgG, A and M) were assayed in these groups of patients and the mean values were compared. Those with abnormal haemoglobins S or C (HbS or HbC) were compared with those with normal control haemoglobin A (HbA). HbSS malarial patients have the highest mean values of the 3 classes of immunoglobulins. This is followed by HbAS patients while patients with normal Hb have lowest mean values for IgG and IgM. The significance of the results is discussed.

Severe morbidity among children in a trial malaria chemoprophylaxis with pyrimethamine or chloroquine in Ibarapa, Nigeria

In a controlled trial of weekly malaria chemoprophylaxis with chloroquine and pyrimethamine there were no significant differences in type and frequency of severe morbidity during chemoprophylaxis. Administration of chemoprophylaxis during the current and immediately preceding month was associated with significantly fewer episodes of severe morbidity in the chloroquine and pyrimethamine groups when each was compared with the control multivite group. After chemoprophylaxis had been stopped, significantly more episodes of severe morbidity occurred in the chloroquine group than the control group, but a similar trend in the pyrimethamine group was not statistically significant. In the control group most of the episodes of severe morbidity, including those episodes which were associated with heavy parasitaemia, occurred below the age of 4 years. In contrast, the children who received chemoprophylaxis continued to experience such illness at older ages. The difference between the chloroquine group and the control group in respect of age at time of severe morbidity was statistically significant.

Advances in burn care management: role of the speech-language pathologist

Because the inclusion of the speech-language pathologist in a burn management team is not widely practiced, we discuss our successes as members of a burn team. We also review speech-language evaluation and treatment strategies and present two patients with head and neck burns who gained from our intervention.

Correlation between in vivo and in vitro response of chloroquine-resistant Plasmodium falciparum in Calabar, south-eastern Nigeria

Since chloroquine-resistant Plasmodium falciparum (CRPF) has emerged in Nigeria, we monitored the susceptibility of the parasite strain to a standard chloroquine (C25) dose in our Children's Emergency Unit. Chloroquine (CQ) is the drug of choice for malaria chemotherapy in Nigeria. The WHO 7-day in vivo evaluation and Rieckmann's microtitre technique (in vitro test) were used. 33 children of mean age 4.9 years were enrolled in the study. 27 (81.8%) of the in vitro cultures were successful. 16 (59.3%) of the successful isolates still showed schizogony at CQ concentration of 5.7 pmol/well and above. 28 (84.8%) of the children completed the in vivo study. 15 (53.6%) were parasitaemic on day 7 and/or day 14 and were regarded as parasitologic failures. The isolates from 14 of these children showed corresponding in vitro resistance of CQ concentrations equal to or above 5.7 pmol/well. The proportion of RIII (= 13.3%) appears to have increased as compared to 5.9% recorded in 1987. We conclude that there appears to be a good correlation between in vivo evaluation of parasitologic failures (53.6%) and in vitro resistance (59.3%). It thus appears that CRPF is definitely increasing in South-Eastern Nigeria. This can be expected not only to complicate malaria chemotherapy in the Children's Emergency Unit of the University of Calabar Teaching Hospital, but will contribute immensely to the deterioration of malaria therapy and control in Nigeria.

Immunity in malaria: II. Heterophile and malarial antibodies in acute Plasmodium falciparum infection

The sera of 55 Nigerian children (30 malarious and 25 healthy) were analysed for heterophile antibodies against normal sheep erythrocytes by the passive haemagglutination technique. Fluorescent antibodies to Plasmodium falciparum were quantified by the indirect immunofluorescence method while the three major immunoglobulins (IgG, IgA and IgM) were estimated by the radial immunodiffusion technique. An increasing age gradient was demonstrated in the heterophile antibody titres within the malarious and control groups, but there was no significant difference in the levels of immunoglobulins and malarial antibodies between the two groups. An indication of higher malarial antibody titre was only observed in the malarious group, particularly in late childhood. These results show an increasing level of heterophile antibodies with age. It is concluded that malarial antigens may play a contributory, but not a dominant role in the acquisition of heterophile antibodies. There is also a need to define the exact serum factors (antibody or non-antibody) which are associated with clinical immunity to malaria in Nigerian children.

Immunity in malaria: depression of delayed hypersensitivity reaction in acute Plasmodium falciparum infection

The effect of acute Plasmodium falciparum malaria infection on the cell-mediated immune response of 30 Nigerian children attending the General Out-patient (GOP) Clinic of the University College Hospital, Ibadan, Nigeria, was assessed in a controlled study. Delayed-type hypersensitivity skin reaction to five tuberculin units (5 TU) of purified protein derivative (PPD) was used as an indicator of cell-mediated immunity. The results showed marked depression of delayed hypersensitivity reaction to PPD in 27 (90%) of the malarious children, compared with four (16%) of the 25 control healthy subjects (P less than 0.0005). This depression was observed despite evidence of previous BCG vaccination in 38 (69.1%) of the 55 children in the study. The possible clinical significance of these observations in tropical paediatric practice, and the immunopathological implications, are discussed.

The effect of substance(s) associated with malarial parasites on C3b inactivator

The effects of a substance or substances associated with malarial parasites on the inhibitory role of C3b inactivator in immune adherence were investigated. The test system involved adherence of immune complexes of complement-bearing sheep erythrocytes and rabbit antibody, using human group O erythrocytes and human renal glomerular tissues as indicators. Malarial antigen and other soluble by-products of the malarial parasites, presumably present in spent culture medium, did not interfere with the inhibitory role of C3b inactivator. However, malarial pigment, both crude and purified, enhanced immune adherence in the presence of C3b inactivator. It is suggested that malarial pigment, by inhibiting the action of C3b inactivator, may play a significant role in the immunopathogenesis of renal lesions associated with malarial infections.

Granulocyte chemotaxis in acute human Plasmodium falciparum malaria

The non-lymphoid elements of the peripheral leucocyte pool were examined in the present study to determine their response to chemotactic stimulation. Our results indicate that granulocytes are effectively mobilized during malaria infections and are not deactivated by complement-derived chemotactic factors. These findings provide further evidence for the restriction of immunosuppression to some specific T and B-cell related functions only.

Range of normal serum immunoglobulin (IgG, IgA and IgM) values in Nigerians

The serum levels of immunoglobulins G, A and M of 703 apparently healthy Nigerians resident in Ibadan and aged 1-50 years were studied. The differences in values that are related to age, sex and season were also computed. Normal values of the immunoglobulins varied with age and sex. IgG mean values for the different age groups ranged from 688 to 1251 mg/100 ml in the males and from 720 to 1038 mg/100 ml in the females. For the IgA class the mean values ranged from 81 to 211 mg/100 in the males and from 90 to 206 mg/100 ml in the females. Mean values of IgM varied from 65 to 132 mg/100 ml in the males and from 96 to 114 mg/100 ml in the females. There was a general increase in IgG levels with advancing age especially in the first 20 years of life. IgA increased progressively with age from 1 to 50 years. The male IgM levels generally rose with increasing age while there was no significant elevation in female IgM values. Females had higher levels of IgG, IgA and IgM in the first 10-20 years of life after which the levels were either the same or higher in the males. The possible reason for this observation is discussed. A significant seasonal influence on the three immunoglobulin concentrations could not be demonstrated.

The immunogenicity of malarial antigen obtained from infected human placenta

Malarial placenta antigen (MPA) was obtained from heavily parasitized human placenta. The immunogenicity of this antigen was tested by immunizing rabbits. The rabbit antiserum to malarial placenta antigen (anti-MPA) was absorbed with homogenate from nonparasitized human placenta. The anti-MPA serum was also absorbed with malarial placenta extract. Evaluation of the anti-MPA serum was done using the Ouchterlony immunodiffusion technique and by immunoelectrophoresis in agar. The results show that human malarial placenta antigen can stimulate the formation of anti-plasmodium antibodies. Although the antiserum produced also contained antibodies to some placental components, absorption studies showed that some malarial specific precipitinogens were produced. The significance of this in efforts to develop an effective malarial vaccine is discussed.

Lymphocyte subpopulations and antibody levels in immunized malnourished children

1. The proportions of lymphocyte subpopulations (by rosette tests) and the serum antibody levels (using haemagglutination techniques) were estimated in malnourished and well fed Nigerian children before and up to 21 d after immunization with tetanus toxoid or measles virus vaccine. 2. Significantly diminished (P less than 0.01) mean percentage T lymphocyte levels and considerably higher mean percentage null cell levels were observed in the malnourished children before immunization with either of the vaccines. 3. There was comparable in vivo increases in percentage T lymphocytes in malnourished and control children following the administration of each antigen. 4. The mean percentage B lymphocyte levels were similar in the control and malnourished children before and after the immunization. 5. There was a slight depression in the tetanus antibody levels (P greater than 0.2) but a significant diminution (P less than 0.01) in measles virus antibody concentrations in the malnourished children. 6. Rise in mean percentage T lymphocytes corresponded with the elevation in mean tetanus antibody levels in both malnourished and control children following tetanus toxoid immunization. This was however not the situation in the malnourished children following immunization with measles virus. 7. The observed depressed T lymphocyte number in malnourished children may in practice affect their handling of antigens such as measles virus in vivo.

IgG subclass levels in malaria-infected Nigerians

IgG class and subclass levels were measured in the sera of malaria-infected patients who had high serum antibody titres (greater than or equal to 1 in 5,120) as well as in uninfected controls with low serum malaria antibody titres (less than or equal to 1 in 320). The malaria-infected patients had higher IgG and IgGI subclass levels than the uninfected controls (p less than 0.005). There was a slight diminution in the mean IgG3 concentration in the malaria-infected patients.

The occurrence and properties of E rosette inhibitory substance in the sera of malnourished children

In vitro sheep erythrocyte (E) rosette inhibitory activity was observed in the sera of nine out of 22 (41%) children with kwashiorkor, three of 15 (20%) marasmic children, neither of the two children with marasmic-kwashiorkor and in one of 42 (2%) well nourished control children. Sera of children with kwashiorkor containing the E rosette inhibitory substance did not inhibit in vitro rosette formations by autologous lymphocytes whereas rosette formations by homologous lymphocytes were inhibited. Inhibition of E rosette formation occurred when lymphocytes were pretreated with serum having the inhibitory substance before incubation with sheep red cells, but there was no such inhibition when sheep red cells were pretreated with the same serum before incubation with lymphocytes. The inhibitory substance was observed to be stable at 4 degrees C up to about 1 week and migrated electrophoretically with the alpha-2 globulins. It was digested by papain. It is probable that the E rosette inhibitory substance demonstrated in the present study is attached to markers on T lymphocyte surfaces in some malnourished children thereby making the lymphocytes unreactive in vitro and presumably in vivo as well.

Positive correlation between degree of parasitemia, interferon titers, and natural killer cell activity in Plasmodium falciparum-infected children

Natural killer (NK) cell activity and interferon levels have been measured in the peripheral blood of children acutely ill with Plasmodium falciparum infection. The NK cell levels were found to be raised in the malaria-infected children, with a positive correlation between the degree of parasitemia and lytic activity. Comparatively high titers of antiviral activity was discovered in sera from the majority of P. falciparum-infected children, again positively correlating with the degree of parasitemia and NK levels. The characteristics of the antiviral factor indicated alpha-type interferon to be the dominating agent involved. Addition of exogenous interferon in vitro potentiated the NK levels of PBL from normal children while having no significant impact on cells from malaria-infected children.

Positive correlation between degree of parasitemia, interferon titers, and natural killer cell activity in Plasmodium falciparum-infected children

Natural killer (NK) cell activity and interferon levels have been measured in the peripheral blood of children acutely ill with Plasmodium falciparum infection. The NK cell levels were found to be raised in the malaria-infected children, with a positive correlation between the degree of parasitemia and lytic activity. Comparatively high titers of antiviral activity was discovered in sera from the majority of P. falciparum-infected children, again positively correlating with the degree of parasitemia and NK levels. The characteristics of the antiviral factor indicated alpha-type interferon to be the dominating agent involved. Addition of exogenous interferon in vitro potentiated the NK levels of PBL from normal children while having no significant impact on cells from malaria-infected children.

The effect of malarial chemoprophylaxis on immunoglobulin levels of pregnant Nigerian women and the newborn

Immunoglobulins G, M and A were estimated at various stages of gestation in a group of 60 Nigerian primigravidae who were given malarial chemoprophylaxis throughout pregnancy. Immunoglobulin levels were also determined in paired maternal and cord sera of the same women at the time of delivery. Corresponding values for the malarial fluorescent antibody titres were also obtained. There was a fall in both the IgG levels and the fluorescent antibody titres with increasing gestation. The mean IgG and malarial fluorescent antibody titres were generally lower than those previously reported in Nigerian women not on malarial chemoprophylaxis. The mean cord IgG in this study was lower than the mean paired maternal IgG value. This agrees with reported studies in the African population but differs from those reported in Caucasians. The cord IgG values were correlated to the paired maternal IgG levels and those were found to be correlated with the corresponding malarial antibody titres. The factors that influence the fetomaternal IgG gradient are discussed. It is concluded that the newborn of mothers on prolonged malarial chemoprophylaxis may have a lowered acquired immunity to malaria.

Malarial immunity in pregnant Nigerian women and their newborn

The levels of malarial fluorescent antibody titers (MFAT) were estimated throughout pregnancy and at delivery in 20 urban Nigerian primigravidas who received malarial chemoprophylaxis. There was a statistically significant (p < 0.001) fall in the MFAT levels as pregnancy progressed. The mean logarithmic MFAT levels were 2.8664 +/- 0.3326 and 2.2794 +/- 0.1656 in the first and last trimesters of pregnancy, respectively. The MFAT level in the newborn was positively correlated to the maternal MFAT level at delivery (r = 0.9468; p < 0.001). If malarial prophylactics are used for a prolonged period, the maternal MFAT level will fall, leaving newborns with lowered immunity to malaria.

Studies on the immunopathology of the nephrotic syndrome associated with Plasmodium malariae. 1. Serum levels of an immune adherence inhibitor

A comparative study of the serum levels of an immune-adherence inhibiting factor was carried out on serum samples from eighty-seven nephrotic syndrome children, twenty-eight nephrotic adults, 202 normal school children, 116 blood donors, twenty-five falciparum malaria children and 172 patients with miscellaneous diseases. Low titres (1/32 and below) of the factor were present in sera from 63.2% of the nephrotic children 60.7% of nephrotic adults and 60.0% of children malaria, as compared with 30.7% of the normal children, 25.5% of the patients with miscellaneous diseases and 41.4% of the blood donors. There is a significant difference between nephrotic children and normal children with low titres (P less than 0.05). Furthermore, 36.8% of the nephrotic children had serum titres of 1/4 or less, as compared with 6.4% of normal children. The serum factor is tentatively referred to as 'C3b-inase'. Its similarity to conglutinogen-activating factor (KAF) and its possible role in the pathogenesis of the immune-complex nephropathy of childhood nephrotic syndrome associated with malaria are discussed.

Serum levels of immunoglobulin G subclasses in Nigerians

IgG subclass levels were determined in 128 apparently normal Nigerian subjects aged 6--42 years, using a modified radial immunodiffusion technique. IgG1 constituted the major subclass with about 70% of the total IgG. IgG4 subclass was the least with about 0.5%. The concentrations of IgG2 and IgG3 were 27% and 1.5% of the total IgG respectively. There was no systematic effect of age on all the subclasses. IgG1 and IgG2 levels were higher in females than in males but there were no marked differences in the IgG3 and IgG4 levels between the sexes.

Immunoglobulin levels in apparently normal and hypertensive Nigerian mothers at delivery

Immunoglobulin (Ig) levels in 68 apparently normotensive and 29 hypertensive mothers were estimated at parturition. There was a significantly higher incidence of elevated IgG levels in the hypertensive group (p less than 0.005) even though there were no differences in their mean concentrations. The mean IgA levels were not different in the two groups. IgM levels were higher in the hypertensive than in the normotensive mothers. The significance of these findings is discussed.

Serum immunoconglutinin levels in healthy subjects, malaria nephrosis and other conditions

Serum immunoconglutinin (I-K) levels were estimated and compared in 189 normal school children, ninety blood donors, eight-seven nephrotic children, twenty-eight nephrotic adults, twenty-five falciparum malaria children and 126 miscellaneous patients. Low levels (1/32 or less) were recorded in 75.1% of normal school children and 68.9% of blood donors. Similarly 95.4% of nephrotic children and 71.4% of nephrotic adults had low titres. The trend was the same in other disease groups in which 88.0% of falciparum malaria children and 65.1% miscellaneous patients had low titres. The relevance of the I-K levels obtained in the study groups is discussed.

Immunoglobulin allotypes in African populations. I. Gm--Am haplotypes in a Nigerian population

The study of immunoglobulin allotypes in various Negro populations has shown that their polymorphism is different from that in other populations. This particularly true for the alleles of the gamma3 and alpha2 locus. Numerous investigations have been made in which a limited number of markers were determined. It seems to be of importance to compare the results of the determination of all markers known at present in different tribes from various African countries. Such information may ultimately lead to additional support for theories on the origin and migration of early African inhabitants. In this paper we resent the results of the study of the first of a series of studies on African populations.

Role of complement components in the susceptibility to Plasmodium berghei infection among inbred strains of mice

Inbred strains of mice, sensitive and resistant to Plasmodium berghei infections, including a complement deficient strain were infected with P. berghei. Daily levels of parasitaemia were determined and serum levels of complement components (C3 and C5) measured by standard haemolytic assay. Serum levels of C3 and C5 were depressed in all strains of mice infected with P. berghei. There was no difference in the infectivity and course of P. berghei infection in the co-isogenic C5 deficient and non-deficient strains. The significance of these observations is discussed.

Precipitation of serum proteins by phytohaemagglutinin

Phytohaemagglutinin (PHA) produced precipitin lines in agar diffusion tests with all the 506 serum samples obtained from normal Nigerians. A few (3%) of the normal sera reacted weakly; in contrast a good proportion (29%) of the lymphoma and leukaemia sera tested were either negative or poorly reacting. Immunoelectrophoretic analysis showed that PHA reacts with some of the α-, β- and γ- globulins of human and animal sera, and that there were marked species differences in the degree of reactivity of the three classes of proteins. The γ-globulins of normal rabbit serum reacting with PHA were different from the specific antibodies produced in PHA-immunized rabbits. There is evidence resulting from absorption studies that the haemagglutinin, leucoagglutinin and mitogenic factors of PHA have the same electrophoretic mobility, are recognized by the same antibodies, and together constitute the precipitin factor(s) of PHA.

Distribution of malarial antibody in maternal and cord sera

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Malarial antigen from human brain

A method is described for purifying malarial antigen from human brain. The antigen appears to be highly specific for malarial antibodies. On double diffusion in agar gel a precipitin reaction was produced only with sera from persons with malarial parasites in their peripheral blood and those with high malarial fluorescent antibody titre. No precipitin lines were formed with sera from persons who were known to be free from malarial infection.

Immunoglobin synthesis by fresh biopsy cells and established cell lines from Burkitt's lymphoma

(1) Freshly dispersed cells from four Burkitt's lymphoma biopsies, and three `lymphoblast' cell lines (OB2, OB3 and OB6) derived from the tumour were tested for capacity to synthesize immunoglobulins in vitro.

Using labelled amino acid incorporation, electrophoretic, radio-immunoelectrophoretic and ultracentrifugation techniques, it was possible to demonstrate the release of labelled proteins with antigenic characteristics of immunoglobulins by all four biopsy samples, and the two cell lines tested by these techniques. Newly synthesized labelled proteins were demonstrable in the culture medium within 1 hour of incubation.

In a separate series of experiments, absorption and immunodiffusion techniques were used in the characterization of proteins synthesized by two cell lines (OB2 and OB3) growing as healthy continuous cultures.

(2) Freshly isolated cells from Burkitt's lymphoma are capable of immunoglobulin synthesis in vitro. Cells from all four fresh biopsy materials produced IgG. One cell line (OB2) produced IgG and type-κ light chains, while OB6 cell line produced IgA. Immunoglobulin synthesis was not detected in OB3 cell line by immunodiffusion technique.

(3) Cells from each biopsy specimen or cell line produced not more than one type of immunoglobulin, although there was a wide variation in the sedimentation coefficient of the protein molecules synthesized by one (OB6) and presumably all other cell lines.