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Biomedical subjects

B Jones

Publications and source records attributed to B Jones.

At least 433 records · Page 24Linked to original sources
PubMed1988

Crohn disease: perirectal and perianal findings at CT.

The computed tomographic scans of 200 consecutive patients with Crohn disease were studied to determine the frequency and patterns of perirectal and perianal involvement. In 163 patients (82%) abnormalities in the perirectal-perianal region were demonstrated; findings included inflammation of fat planes (73%), bowel wall thickening (30%), fistulas or sinus tracts (22%), and abscesses (14%). Fistulas or sinus tracts occurred with equal frequency above or below the level of the anterior symphysis pubis. Abscesses, rectal thickening, and inflammatory infiltration of fat occurred more than twice as often above the symphysis pubis. However, 37% of patients had manifestations of Crohn disease below the symphysis pubis, emphasizing the importance of extending scanning sequences to the perineum.

Anal Canal↗
PubMed1988

Tertiary care psychiatry in Zaire: DSM-III in the developing world.

In this sample of eighty consecutive admissions to the Centre-Neuro-Psycho-Pathologique (CNPP) of Kinshasa, 81% were given a DSM-III diagnosis. This demonstrates that the DSM-III is a useful tool for psychiatric research in developing sub-saharan Africa. Schizophrenia, schizophreniform psychoses, and affective disorders appeared in their familiar forms. Zairois patients tended to present with complaints of insomnia, agitation and pressured speech. The most striking observations were the relative paucity of depressed mood, self-reproach, and suicidal ideation in patients with major depression. Four cases of acute transient psychosis were noted.

Adult↗
PubMed1988

Gastrointestinal inflammation after bone marrow transplantation: graft-versus-host disease or opportunistic infection?

Gastrointestinal inflammation after allogeneic bone marrow transplantation may be due to acute graft-versus-host disease (GVHD) and/or superinfection with opportunistic organisms. Twenty-eight patients with barium studies suggesting gastrointestinal inflammation after bone marrow transplantation and either acute GVHD, viral infection, or both were studied to characterize the radiographic appearances of each disease and to determine whether acute GVHD could be distinguished from viral superinfection on the basis of radiographic findings. Thirteen patients had minimal or no acute GVHD, with viral infection proved in eight and strongly suspected in four others; the remaining patient was thought to have nonspecific inflammatory bowel disease. Five patients had pure acute GVHD, and 10 patients had viral enteritis superimposed on acute GVHD. Radiographic abnormalities were found in the gastrointestinal tract in both acute GVHD and viral infection and were more extensive than previously reported. Findings were similar in both entities, although gastric abnormalities were not seen in pure acute GVHD but only in viral infection, either alone or together with acute GVHD. Prolonged small bowel barium coating occurred in both viral infection and acute GVHD. Fold thickening evolved into fold effacement with a shaggy contour in two patients with viral infection. Colonic findings in all groups mimicked ulcerative colitis. Our data indicate that differentiation between acute GVHD and viral enteritis is not possible on the basis of radiographic findings alone. Both entities should be considered when gastrointestinal inflammation occurs after bone marrow transplantation.

Adolescent↗
PubMed1988

Prevalence of hepatitis delta (delta) virus infection. A seroepidemiologic study.

In assessing the prevalence of hepatitis delta (delta) virus (HDV) infection in 358 patients with acute hepatitis B seen in Los Angeles between 1983 and 1985 and in 196 patients with chronic hepatitis B followed between 1980 and 1985, we found that 23% of patients with chronic and 5% of patients with acute hepatitis B were infected with HDV. Among patients with chronic hepatitis B, the prevalence of HDV infection was 73% in intravenous drug users and 14% in homosexual men. Acute coinfection with the hepatitis B virus was also more frequent in drug users (8%) than in other groups. delta-Hepatitis is a common infection in hepatitis B virus carriers in Los Angeles, particularly in drug addicts, but also in homosexual men who do not abuse drugs intravenously.

California↗
PubMed1987

Differential effects of antibodies to Lyt-2 and L3T4 on cytolysis by cloned, Ia-restricted T cells expressing both proteins.

Cloned T cell lines specific for the antigen ovalbumin (OVA) in the context of self I-A or I-E class II MHC-encoded molecules were found to express equivalent levels of the Lyt-2 and L3T4 surface molecules by FACS analysis. Functionally, these cloned T cell lines will kill OVA-pulsed, class II MHC-bearing B lymphoma cells. This system allowed us to examine the relative contribution of the Lyt-2 and L3T4 molecules to recognition of antigen in the context of self class II MHC molecules. We find that anti-L3T4 is 25- to 100-fold more potent at inhibiting cytotoxicity by these cloned lines than is anti-Lyt-2, where potency is calculated as the ratio of the concentration needed for inhibition divided by the concentration needed for binding. Both antibodies can completely inhibit cytotoxicity. These results suggest that the accessory molecules Lyt-2 and L3T4 can play two different roles in antigen:MHC recognition. In class II MHC recognition, L3T4 plays a dominant role, highly sensitive to inhibition by anti-L3T4. By contrast, Lyt-2 plays a minor yet important role in the cell interaction, perhaps by adhesion strengthening. Previous analysis in several laboratories supports the concept that the ligand for L3T4 is class II MHC, whereas the ligand for Lyt-2 is class I MHC. The present results are consistent with the hypothesis that these molecules are actually part of the T cell antigen:MHC recognition complex, and play an important role in the class of MHC molecule recognized by a T cell alpha:beta heterodimeric receptor. As such, they are not accessory proteins, but a direct part of the recognition apparatus, and the term accessory protein may apply only in those cases in which the specificity of the T cell receptor is for a different class of MHC than that normally associated with the L3T4 or Lyt-2 molecule.

Animals↗
PubMed1987

Intramuscular versus low-dose intradermal hepatitis B vaccine. Assessment by humoral and cellular immune response to hepatitis B surface antigen.

The capacity of hepatitis B surface antigen (HBsAg) vaccine (which was administered by the conventional intramuscular route or as a one-tenth dose by the intradermal route) to elicit an antibody or delayed-type hypersensitivity response to HBsAg was compared for 40 paired healthy subjects, 20 per group, of whom 38 completed the vaccination protocol. The 40 subjects were allocated at random to receive three doses of 20 micrograms of vaccine intramuscularly, or three doses of 2 micrograms of vaccine intradermally. Titres of antibody to HBsAg (anti-HBs) were expressed in a radioimmunoassay by sample ratio (signal-to-noise) units (SRU). The maximal mean levels of anti-HBs (maximal one month after the third injection) were 108 SRU for the intramuscular group and 51 SRU for the intradermal group, and the levels for the intramuscular group were significantly higher at all other time-points. The levels of anti-HBs declined equally with time over 18 months in both groups. More subjects in the intramuscular group (17 of 19 subjects) showed a response to anti-HBs than in the intradermal group (14 of 19 subjects). Non-respondents in either group responded with similar frequency to further intramuscularly-administered vaccine. The frequency of delayed-type hypersensitivity to HBsAg was similar for both groups. Thus, immunization with HBsAg, when administered intradermally in a dose that is one-tenth of that recommended for intramuscular administration, induces an immune response in healthy subjects. However, since the level of antibody is lower than that after intramuscular injection, revaccination might be needed at more frequent intervals.

Adult↗
PubMed1987

The analysis of data from 2 x 2 cross-over trials with baseline measurements.

An account is given of the analysis of data from 2 x 2 cross-over trials which include baseline measurements. We show that most of the previously proposed methods can be incorporated into a general framework of least-squares estimation with a simple linear model. A simple analysis based on ordinary least-squares estimators is described which can be used with either two-sample t-tests and confidence intervals or with the corresponding non-parametric procedures. It is shown how the use of generalized least-squares estimators is equivalent to the use of covariance adjustment. These methods require no assumptions about the covariance structure of the measurements from each subject. The results of assessing the covariance structure present in examples of data from a number of trials are summarized. These results suggest that previously proposed simple covariance structures are unlikely to be appropriate in general.

Analysis of Variance↗
PubMed1987

CT abnormalities in right lower quadrant inflammatory disease: review of findings in 26 adults.

Abnormal abdominal computed tomographic (CT) examinations, performed on 26 adults who presented with clinical evidence of right lower quadrant inflammatory disease, were retrospectively studied. Final diagnoses, established surgically in each case, included complicated appendicitis (15 patients), diverticulitis of the ileum or right colon (4), previously undiagnosed Crohn's disease (3), perforated cecal neoplasm (2), right tuboovarian abscess (1), and paracolic abscess of unknown cause (1). The CT features in each diagnostic group are presented in detail. Solid or ring calcification within a pericecal inflammatory mass was specific for appendicitis, occurring in 40% of the 15 patients. Without calcification, the differentiation of complicated appendicitis from Crohn's disease or diverticulitis, based on CT features alone, may be difficult in some cases.

Adolescent↗
PubMed1987

Granular small bowel mucosa: a reflection of villous abnormality.

Diffuse mucosal granularity was reported recently in small bowel Crohn's disease. The radiographic appearance corresponded on histopathologic examination to villous hypertrophy, fusion, or epithelial bridge formation. We have observed similar granularity in Crohn's disease but also in several other conditions, including radiation enteritis, pancreatic glucagonoma, protein-losing enteropathy, and small bowel ischemia. Histopathologic examination demonstrated various alterations in villous morphology, such as edema, hyperplasia, clubbing, or fusion. In Crohn's disease, this appearance was sometimes an indication of early inflammatory disease but was also seen following extensive small bowel resection, possibly due to villous enlargement resulting from intestinal adaptation. These findings suggest that granular mucosa in the small bowel is a nonspecific finding reflecting an alteration in villous structure.

Adult↗
PubMed1987

Pneumatosis intestinalis in children after allogeneic bone marrow transplantation.

Four children, ages 3 to 8 years, developed pneumatosis intestinalis (PI) after allogeneic bone marrow transplantation (BMT) for acute leukemia or severe aplastic anemia. PI was detected at a median of 48 days (range, 10-63 days) after BMT and was associated with abdominal symptoms and clinical signs. All patients had severe systemic and/or high-grade cutaneous acute graft-versus-host disease (AGVHD) at some time after BMT and were receiving corticosteroids at the time of development of PI; however, PI was associated with concomitant severe AGVHD in only one patient. One patient with PI had Hafnia alvei bacteremia and another patient had gastroenteritis due to rotavirus and adenovirus. All patients were treated with supportive care and systemic broad-spectrum antibiotics, and PI resolved 2-16 days after onset. Two patients died with BMT-associated complications unrelated to PI. Multiple factors contribute to the development of PI after BMT, and the prognosis for recovery from PI is good with medical management alone. Overall survival in these patients is dependent on the frequency and severity of other conditions, such as AGVHD and opportunistic infections, after BMT.

Acute Disease↗
PubMed1987

The effect of phorbol esters on human erythrocyte morphological discocyte-echinocyte transitions.

12-O-Tetradecanoylphorbol-13-acetate (TPA) (100 nM) when incubated with human erythrocytes under conditions of ATP depletion, delayed the onset of the morphological transition from discocytes to echinocytes so that at 2 h, when control incubations were estimated to contain 65% echinocytes, those treated with TPA contained 23% echinocytes. TPA did not alter the subsequent rate of the transition which was complete by 3 h in control cells and 5 h in TPA-treated cells. Addition of 100 nM TPA to ATP-depleted erythrocytes at 2.5 h (greater than 80% echinocytes) for 0.5 h at 37 degrees C resulted in 17% reversal to a discocyte morphology, but as the time of incubation under conditions of ATP depletion was extended, the level of the reversal fell. TPA had no significant effect on the fall in ATP concentrations over the time course of the experiments (5 h). Preincubation of discocytes with TPA for 10 min also prevented, by approx. 50%, the echinocytosis induced by the calcium (0.2 mM) loading of discocytes using 5 microM A23187. TPA was unable to reverse the echinocyte morphology of calcium-loaded cells back to discocytes. The less potent tumour promotor 4-phorbol-12,13-didecanoate had no effect on this discocyte-echinocyte transition. Incubation of discocytes with the diacylglycerol 1-oleoyl-2-acetylglycerol (OAG) (1-10 microM) had complex effects on morphology, and the ATP-induced morphological transition, ranging from stomatocyte formation to echinocyte formation, depending upon the concentration of the agent and the time of incubation.

Adenosine Triphosphate↗