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Biomedical subjects

C S Johnson

Publications and source records attributed to C S Johnson.

At least 109 records · Page 6Linked to original sources
PubMed1987

Electrocardiogram analysis in adult patients with sickle cell disease.

This study is an analysis of the electrocardiograms (ECGs) of 87 adult patients taken during hospital admission for sickle cell disease (homozygous S). The age range was 18 to 55 years: 38 were men and 49 were women. Seventy-two percent of all patients had abnormal ECGs. Nonspecific ST-T (NS-ST-T) wave abnormalities (53 percent) and QT interval prolongation (12 percent) were frequent. Seventy-five percent of the normal ECGs occurred in women (P < .05); and 74 percent of those with left ventricular hypertrophy (LVH) were men (P < .05). Fifteen of 21 (71 percent) patients with arrhythmias had NS-ST-T abnormalities. Systemic hypertension and ECG evidence for right-sided heart disease were rare, as was the incidence of LVH by ECG.

Adolescent↗
PubMed1987

Unsuspected pernicious anemia in a patient with sickle cell disease receiving routine folate supplementation.

Although the issue of folate supplementation in sickle cell anemia remains controversial, routine supplementation has become common. The major drawback to indiscriminate folate therapy is the potential of masking findings of vitamin B12 (cobalamin) deficiency. This has been dismissed as a problem in sickle cell anemia because of the generally young age of the patients. However, because young blacks, especially women, are at higher risk for developing pernicious anemia than whites, sickle cell anemia and pernicious anemia can be expected to coexist occasionally. In this article we describe such a patient and recommend that routine folate supplementation should not be given in sickle cell anemia before determining the vitamin B12 status.

Adult↗
PubMed1987

Pernicious anemia in Latin Americans is not a disease of the elderly.

Pernicious anemia is widely regarded as a disease of the elderly. However, it is expressed differently in black women, among the most striking differences being their younger age at presentation of the disease compared with whites. We now compared 92 Latin-American patients with 115 white and 100 black patients to see if similar age differences occur in other racial groups. Latin-American men and women were both significantly younger than white men and women, and were similar in age to blacks. Only 21% of Latin-American patients were 70 years of age or older, compared with 49% of whites. It is apparent that pernicious anemia is indeed predominantly a disease of the elderly in whites but that this is not the case in other racial groups.

Adolescent↗
PubMed1986

Pathological spectrum of liver diseases in sickle cell disease.

Most pathologic studies of liver disease in sickle cell anemia and its variants were performed retrospectively on autopsy specimens, and, because of the prominent histologic features of intrasinusoidal sickling and Kupffer cell erythrophagocytosis, hepatic dysfunction was attributed to the intrahepatic sickling of erythrocytes in this hemoglobinopathy. We compared the liver histology from 19 patients who had liver biopsies to the autopsy specimens from 32 patients who succumbed to the complications of the hemoglobinopathy. In the former, nine patients had histological evidence of viral hepatitis. Four of these patients had both serological and immunohistochemical evidence of hepatitis B surface antigen. The features of biliary tree obstruction were found in two cases and alcoholic cirrhosis and sarcoid granuloma in one case each. Only one patient, who had recovered from septic shock, showed ischemic necrosis. In five patients incidentally biopsied during cholecystectomy, no significant lesions were found. Fourteen of the autopsy specimens showed ischemic necrosis, a result which was significantly different from the biopsy group. Ten cases had no significant morphologic changes other than heavy iron deposits. There were two cases with chronic active hepatitis, two with diffuse fibrosis, and one case each of cirrhosis, acute viral hepatitis, cholestasis, and giant cell hepatitis. Intrahepatic sickling and erythrophagocytosis were seen in almost all specimens and did not correlate with liver disease or transaminase elevation. Other than the patient with septic shock, ischemic necrosis was found only in postmortem material. These histological features may represent red cell destruction rather than the etiology of liver disease in these patients.

Adolescent↗
PubMed1986

Formation and alignment of Z lines in living chick myotubes microinjected with rhodamine-labeled alpha-actinin.

We have used fluorescence analogue cytochemistry in conjunction with time lapse recording to study the dynamics of alpha-actinin, a major component of the Z line, during myofibrillogenesis. Rhodamine-labeled alpha-actinin microinjected into living cultured chick skeletal myotubes became localized in discrete cellular structures within 1 h and remained specifically associated with structures for up to 4 d, allowing individual identified structures to be followed during development. In the most immature cells used, alpha-actinin was found in diffuse aggregates, some of which displayed sarcomeric periodicity. Aggregates were observed to coalesce into better defined structures (Z bands) that were approximately 1.0-micron wide. Z bands condensed into narrow, more intensely fluorescent Z lines in 4-48 h. During this period, Z lines grew laterally, primarily by the addition of small beads of alpha-actinin to existing Z lines or by the merging of small Z lines. In more mature cells, alpha-actinin added to Z lines without going through a visible intermediary structure. Mean sarcomere length did not change significantly during the stages examined, although the variability of sarcomere length did decrease markedly over time for identified sets of sarcomeres. At early stages, myofibrils frequently shifted position in both the longitudinal and lateral directions. Neighboring myofibrils were frequently associated for one or more sarcomeres sporadically along their length, such that the intervening sarcomeres were often misaligned. Associations between myofibrils were often transitory. Shifts in myofibril location in conjunction with the formation, breaking, and reformation of lateral associations between myofibrils facilitated the alignment of Z lines through a trial and error process.

Actinin↗
PubMed1986

Infection of haematopoietic stem cells in mice with Friend virus induced erythroleukaemia.

Animals infected with conventional anaemia (FVA) or polycythemia-inducing (FVP) strains of the Friend virus develop lethal erythroleukaemia. A variant strain, RFV, induces an initially identical disease except that it spontaneously regresses in 50% of infected mice. To determine whether pluripotent stem cells as measured by spleen colony forming units (CFU-s) in leukaemic mice are productively infected with virus and whether their infection influences the outcome of the disease, we tested CFU-s from leukaemic mice for susceptibility to cytotoxicity by monospecific antiviral gp70 antiserum. Spleen CFU-s from progressively leukaemic (FVP, FVA and RFV) mice were productively infected with virus. CFU-s in RFV progressors became infected by 40 days post-virus inoculation. FVA and FVP progressors became infected between 15 and 21 days post virus. Infection of CFU-s was accompanied by an increase in the proportion of replicating (S phase) CFU-s in these populations. Spleen CFU-s from fully regressed RFV regressor mice were uninfected and remained so throughout the course of their disease. Bone marrow CFU-s in both regressors and progressors remained uninfected and were not induced to increased cell cycling.

Animals↗
PubMed1986

Induction of leukemia regression in mice by immunotherapeutic transfer of T-lymphocytes.

The erythroleukemia induced in susceptible mice by Friend virus (FV) is a progressive, lethal disease. A variant strain of Friend virus (regressing FV) produces a histopathologically identical leukemia except that the disease spontaneously regresses in 50% of leukemic mice. Normal T-cell and macrophage function are required for regression to occur and in animals that are going to regress, specifically reactive T-cells are found in the spleen. Passive transfer of sensitized T-cells from regressing FV immunized or regressed mice caused regression of the conventional lethal leukemia induced by FV. To expand the effector cell populations, characterize them and improve their therapeutic efficacy, sensitized T-cells were cultured in vitro. The T-cells, isolated from regressed or immunized mice, were grown and expanded in vitro with interleukin 2 and antigen (mitomycin C treated regressing FV-infected cell lines). The T-cells demonstrated high levels of in vitro cytotoxicity against FV antigens but exhibited no blastogenic response to the same antigens. When fully FV-induced leukemic mice (14 days post virus inoculation; spleen weight, greater than 0.75 g) were given one injection of 5 X 10(6) in vitro cultured T-cells and no other treatment the mice experienced permanent regressions of their disease. From T-cell cultures depleted of specific cell populations with monoclonal antisera, helper Lyt-1+ cells were shown to be responsible for permanent regressions (cures), whereas cytotoxic Lyt-2+ cells caused temporary leukemia remissions. This model thus provides an experimental system of highly effective passive cellular immunotherapy against an autochthonous, fully developed leukemia, requiring no adjunctive treatment for activity.

Animals↗
PubMed1986

Mechanism of macrophage reversal of Friend erythroleukemia: macrophage regulation of normal and leukemic erythropoiesis.

The acute erythroleukemia induced in mice by the anemia-inducing strain of the Friend virus complex is caused to regress by normal macrophages. We examined the possibility that reversal of leukemia is related to a macrophage regulatory function in erythropoiesis. We found that the ability of macrophages to induce leukemia regression correlates with nonimmunological, in vivo suppression of normal and susceptible leukemic erythroid progenitors. The macrophage effect on erythropoiesis appears to be due to changes in a humoral regulator, related to but independent of erythropoietin. The results suggest a novel regulatory system for erythropoiesis, operative in vivo, and involving macrophages as accessory or suppressor cells. This regulation appears to be disrupted in erythroleukemic mice, but can be restored, and the disease can be made to regress by treatment with normal macrophages.

Animals↗
PubMed1986

Influence of oxygen tension on the viscoelastic behavior of red blood cells in sickle cell disease.

Although the rheological behavior of sickle cell suspensions and of hemoglobin S solutions is known to be strongly dependent on oxygen tension (PO2), little data exist concerning the influence of PO2 on the viscoelasticity of individual HbSS RBC. We have used micropipette aspiration techniques to test the deformation response of both HbSS and control HbAA RBC over a wide range of PO2 at 23 degrees C. Sickled, spiculed HbSS cells were present for PO2 approximately less than 35 mm Hg; for a number of these cells, the deformation response was essentially elastic and an effective membrane rigidity (EMR) was calculated. EMR increased with decreasing PO2 and was approximately 5 to 50 times higher than the equivalent rigidity of oxygenated HbSS RBC. In addition, the rate of membrane deformation was very slow for sickled cells; the half-time for the deformation process increased as PO2 was lowered and was about two orders of magnitude longer than the equivalent time for normal RBC. Other sickled cells exhibited plastic deformation when subjected to comparable deforming forces and experienced irreversible membrane deformation and budding. At all PO2 levels tested, some HbSS RBC remained as discocytes; these cells had normal membrane elasticity and membrane viscosity. Furthermore, changes in PO2 did not affect the membrane properties of HbAA RBC. Thus, gross abnormalities in the deformation response of HbSS RBC were only detected after morphological sickling had occurred. These abnormalities most likely arose from changes in the cytoplasmic HbS viscoelasticity and, if present in vivo, would be expected to impair the flow of HbSS cells in the microcirculation.

Anemia, Sickle Cell↗
PubMed1985

Racial differences in serum total bilirubin levels in health and in disease (pernicious anemia).

Common usage prescribes a single normal range for serum bilirubin levels. However, we have not only confirmed that men have higher levels than women but have discovered significant racial differences as well. Among 1,538 healthy Americans, blacks had lower mean bilirubin levels than whites of European origin, Latin Americans, and Asians. These racial differences, which were more pronounced among women than men, were maintained in pernicious anemia. Even though bilirubin levels rose in our 174 patients with this disease, they continued to be lower among blacks than among whites and Latin Americans. Moreover, the actual bilirubin level changes caused by pernicious anemia were themselves smaller among blacks. The racial differences, thus, persisted in pernicious anemia despite similar degrees of anemia, whereas the sex differences disappeared. We suggest that the lower serum bilirubin levels in blacks in health and disease do not stem primarily from lower bilirubin production than in whites.

Anemia, Pernicious↗
PubMed1985

Tracer diffusion coefficients of proteins by means of holographic relaxation spectroscopy: application to bovine serum albumin.

Holographic relaxation spectroscopy has been used to measure tracer diffusion coefficients for photochromically labeled bovine serum albumin in solutions having total bovine serum albumin concentrations in the range 3.25 to 257 g/liter. In the limit of zero concentration, the diffusion coefficient (20 degrees C, 0.1 M NaCl, 0.05 M Tris, pH 8.0) was found to be (5.9 +/- 0.1) X 10(-7) cm2/s and the initial slope was zero. The concentration dependence of the diffusion coefficient was not significantly affected by the fraction of protein molecules which were labeled. Holographic relaxation spectroscopy permits rapid, accurate determination of tracer diffusion coefficients for proteins in mixtures.

Animals↗
PubMed1985

Isoimmunization in pregnancy to Gerbich antigen.

A case of hemolytic disease of the newborn due to Gerbich, a public antigen, is presented. The antibody which was IgG1 reacted in vitro with mononuclear phagocytes. Serial sonographic and amniotic fluid examinations were followed and a mildly jaundiced neonate was delivered. Further investigation may establish a relationship between severity of disease and IgG subclasses, a mononuclear phagocyte assay, and sonographic measurements. Sources of compatible blood for possible maternal, fetal, or neonatal transfusion include blood bank rare donor files, relatives, and autologous donation.

Adult↗
PubMed1985

Air gap technique for digital subtraction angiography of the extracranial carotid arteries.

The technique of applying an air gap between the patient and the x-ray detector reduces scattered radiation from the patient's neck sufficiently to allow performance of DSA of the extracranial carotid arteries with the antiscatter grid removed. When compared with the conventional grid technique, air gap allows 25 to 88% reduction of mA without increasing the kVp or exposure time and without loss of spatial resolution or diagnostic image quality. These considerable patient radiation-exposure savings can be implemented on DSA systems that use ordinary under-table x-ray tube fluoroscopic equipment without the purchase of additional hardware.

Carotid Arteries↗
PubMed1985

Liver involvement in sickle cell disease.

In an effort to clarify the features of hepatic dysfunction in sickle cell disease, we obtained serial tests of liver function in 100 consecutive patients with sickle cell anemia and in 30 consecutive patients with hemoglobinopathy SC during a five-year period. There were 32 patients with chronic abnormalities in tests of liver function. These abnormal tests were explained by a variety of lesions in 30 cases, and the liver disease remained unexplained in only 2 patients who declined liver biopsy. The diagnoses in these 30 patients included hepatitis, chronic passive congestion, common duct obstruction, alcoholic liver disease, pregnancy, collagen-vascular disease, and sarcoidosis. Evidence for hepatitis B infection was present in 19 of those with sickle cell anemia and in 6 of those with hemoglobinopathy SC. The bilirubin levels in sickle cell anemia appeared to have a trimodal distribution, with six patients exhibiting markedly elevated levels of indirect bilirubin suggesting a difference in bilirubin metabolism. There was no evidence of liver disease in 72 patients with sickle cell anemia, nor in 24 patients with hemoglobinopathy SC, as these patients exhibited only mild elevation of their serum indirect bilirubin levels owing to chronic hemolysis. Intrasinusoidal sickling and Kupffer cell erythrophagocytosis were nearly universal findings at liver biopsy, irrespective of the clinical disorder, and were not related to the degree of liver test abnormalities. Liver and biliary tract dysfunction in sickle cell disease have been attributed to anoxia secondary to sinusoidal obstruction by sickled erythrocytes and Kupffer cell erythrophagocytosis. However, some causes of liver disease in sickle cell patients can be explained by clinical disorders other than the hemoglobinopathy alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1984

Inhibition of CFU-E colony formation by resident peritoneal macrophages from hybrids of BALB/c mice.

In previous studies, macrophages have been shown to influence in vitro colony formation by erythroid progenitors (CFU-E). To determine whether the origin of the macrophages influences their effects on in vitro erythropoiesis, plasma clot cultures of CFU-E were grown over adherent monolayers of macrophages from various strains of mice. Macrophages were separated from the plasma clot cultures by an intermediary layer of agar. Normal resident macrophages from BALB/c mice and several other inbred strains had no effect on CFU-E colony formation. In contrast, macrophages from a strain of mice termed BWF, which were originally identified as BALB/c but subsequently shown to be a hybrid of BALB/c and outbred CFW mice, strongly inhibited erythroid colony formation. Resident macrophages from the parental outbred CFW mice inhibited CFU-E in 50% of the animals tested. Inhibition was obtained in both homologous and autologous macrophage-CFU-E combinations and was therefore not due to histoincompatibility effects, nor was inhibition related to prostaglandin production by the macrophages or to effects on erythropoietin levels in the assay system. The results demonstrate that normal resident macrophages influence in vitro erythropoiesis and that the effects observed are dependent on the genotype of the mice from which the cells are derived.

Animals↗
PubMed1984

Stimulation of normal erythropoiesis in vitro by macrophages from erythroleukemic mice.

The erythroleukemia induced in mice by the Friend virus complex is caused to regress by macrophages. To determine whether the effect of macrophages on leukemia is due to their role in the regulation of erythropoiesis, investigators examined the influence of macrophages from normal and leukemic mice on in vitro colony formation by erythroid progenitor cells [colony-forming units of erythroid progenitor cells (CFU-E)]. Plasma clot cultures of CFU-E were grown over monolayers of macrophages separated from the CFU-E cultures by a layer of agar. Macrophages from progressors (those leukemic mice that will not undergo leukemia regression) significantly stimulated CFU-E, whereas macrophages from regressors (those that will undergo leukemia regression) had no effect on colony formation. Monolayers of normal resident macrophages did not affect in vitro erythropoiesis, while less mature macrophages (peripheral blood mononuclear cells) or nonspecifically activated macrophages (exudate induced) in monolayer stimulated CFU-E. Stimulation by macrophages from leukemic mice was dependent on the presence of virus-producing cells. CFU-E from erythroleukemic mice were resistant to stimulation by leukemic macrophages. These results demonstrated that macrophages from progressively leukemic mice influenced normal colony formation of CFU-E in vitro and that these effects could be related to the ability of macrophages to cause leukemia regression.

Animals↗