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Biomedical subjects

Y Kim

Publications and source records attributed to Y Kim.

At least 901 records · Page 50Linked to original sources
PubMed1982

Encephalomyeloneuropathy with ganglionitis of the myenteric plexuses in the absence of cancer.

A 55-year-old woman presented with rapidly progressive brainstem dysfunction which led to death within a month. She also had constipation for three weeks, and barium enema showed ileus. Subacute encephalomyelitis predominantly involving the medulla and pons correlated with the patient's initial symptoms. In addition, ganglionitis of the myenteric plexuses explained the constipation and ileus. Ganglioradiculoneuropathy was another finding. The presence of abundant neuronophagia in the brainstem, dorsal root ganglia, and myenteric plexuses raised the speculation that a putative virus, toxic agent, or immune reaction possessed special affinity for neurons and ganglion cells. The neuropathological findings were similar to paraneoplastic changes, but no neoplasm was found.

Brain Stem↗
PubMed1982

Radiation therapy before cystectomy in the management of patients with bladder cancer.

During the preceding two decades, 309 patients with bladder cancer were treated by irradiation before cystectomy at the Memorial Sloan-Kettering Cancer Center. A radical tumour dose averaging 6000 cGy (rad) in six weeks was given to 104 patients who underwent radical cystectomy +/- one year later for persistent or recurrent cancer. Pre-operative pelvic irradiation was planned in 205 patients who received either 4000 cGy in four weeks (119) or 2000 cGy in one week (86) and underwent radical cystectomy after +/- six weeks and two days, respectively. The determinate five-year survival rates (41-43%) were similar with the three irradiation regimes; mortality under five years was mainly due to cancer recurrence locally and/or distally. Incidence of recurrence with radiation-induced stage reduction (21%) was lower, especially within the pelvis, than with no stage reduction (51%). Treatment results with planned pre-operative irradiation, especially in high stage tumours, were more favourable with the shorter 2000 cGy regimen of high fractional doses than with the conventionally fractionated 4000 cGy regimen.

Adult↗
PubMed1982

Biological effects of the interaction of staphylococcal alpha-toxin with human serum.

The alpha-toxin (hemolysin) of Staphylococcus aureus is known to be an important determinant of pathogenicity although its precise role in the process of infection is not understood. In this study, the interaction of alpha-toxin with the human complement system was evaluated in terms of its effect on the opsonic activity of serum for S. aureus. Phagocytosis by human polymorphonuclear leukocytes was studied by measuring the uptake of preopsonized radiolabeled bacteria. It was found that alpha-toxin-treated serum had reduced opsonic activity and that this change was associated with complement consumption via the classical pathway. Levels of C3 to C9 were reduced in proportion to the amount of toxin added to the reaction mixture; levels of C2 were markedly reduced but those of factors B and D of the alternative pathway were unaltered in the presence of alpha-toxin. Heat-inactivated toxin, which had no hemolytic activity, also interacted with the complement system but with a significantly reduced effect. In addition, alpha-toxin behaved as a chemotaxinogen for polymorphonuclear leukocytes: human serum was activated by the toxin. These studies demonstrate that the interaction of staphylococcus alpha-toxin with human serum affects two important aspects of the host response to the staphylococcus.

Bacterial Toxins↗
PubMed1982

Abnormal morphology of bacteria in the sputa of patients treated with antibiotics.

Filaments of Klebsiella pneumoniae were observed by Gram stain in the sputum of a patient with a respiratory infection who was treated with half the usual dose of cefazolin. Identical filaments were observed in vitro when this strain was incubated with subminimum inhibitory concentrations of cefazolin. Large gram-positive cocci containing multiple cross walls were observed by electron microscopy in the sputum of a patient with a respiratory infection who was treated with ampicillin and gentamicin. Antibiotic administration was suspended the night before the sputum was obtained. The ultrastructure of these cocci was very similar to the ultrastructure of Staphylococcus aureus incubated with subminimum inhibitory concentrations of cephaloridine or oxacillin. It was suspected that the low dose of cefazolin and the intermittent therapy with ampicillin resulted in a subminimum inhibitory concentration of antibiotic in the respiratory tract which induced the the abnormal morphology of the bacteria observed in the sputum of both patients. The presence of abnormal forms of bacteria in the specimen of a patient, rather than in the culture of a specimen, has clinical significance.

Aged↗
PubMed1982

Restricted deposition of C3 on M+ group A streptococci: correlation with resistance to phagocytosis.

In this report, the mechanism of resistance to phagocytosis by group A streptococci and the participation of M protein in this process were studied. A quantitative fluorometric immunoassay was used to determine the amount of the opsonic third component of complement, C3, fixed by group A streptococci in the presence and absence of M protein. In the absence of M protein, phagocytosis was found to be dependent on the amount of C3 fixed. However, when M protein was present, the streptococci still bound sufficient C3 to have promoted phagocytosis, yet none was observed. Further investigation using immunofluorescent microscopy demonstrated that the C3 fixed to M+ chains was confined to dense patches, interspaced by areas devoid of detectable C3. This uneven distribution of C3 was dependent on the presence of a trypsin-sensitive structure; most likely the M protein. The significance of this restricted C3 deposition with respect to resistance to phagocytosis by group A streptococci is discussed.

Animals↗
PubMed1982

Systemic lupus erythematosus in the first two decades of life.

Seventy patients with systemic lupus erythematosus (SLE) in the first two decades of life have been followed from 1958 to 1981. The patients were treated with corticosteroids alone (17 patients) or corticosteroids and immunosuppressives (53 patients). Twenty-one patients (30%) had evidence of CNS lupus. Eighty-seven percent of patients had evidence of renal involvement, and 34% of these patients had diffuse proliferative lupus nephritis (DPLN). A high frequency of pathologic transition was found to occur. Analysis of 20 pregnancies in 12 women with SLE reveals that patients with active SLE and/or renal disease are at a high risk for complications of pregnancy in contrast to patients in remission. The occurrence of infection, aseptic necrosis and cataracts is shown to be related to SLE itself and to its treatment. By life table analysis overall survival was 90% at 1 yr, 85% at 10 yr. and 77% at 15 yr. Survival of patients who entered the study before age 16 and of patients with CNS lupus could not be distinguished from that of the total group. Patients who entered the study from 1974-1981 had 5-yr survival similar to that of the total group. Survival of 21 patients with DPLN did not deviate from that of the entire group until 14 yr after study entry (7 yr if dialysis and transplantation are considered as deaths). In conclusion, the prognosis of SLE and especially of DPLN in the younger patient appears to be better than indicated by prior reports. Thus, analysis of outcome in this disease may require a long duration of follow-up.

Adolescent↗
PubMed1982

Opsonization of encapsulated Staphylococcus aureus: the role of specific antibody and complement.

Previous studies of encapsulated Staphylococcus aureus have shown that the opsonins of normal, nonimmune human serum (complement factor C3 and IgG) bind beneath the capsule, i.e., on the cell wall, and when bound at this site these opsonins are not effective in promoting phagocytosis of the bacteria by polymorphonuclear leukocytes (PMN). In this investigation immune antibody was added to human serum to effect opsonization of encapsulated S. aureus. Opsonization was assessed by quantitating the uptake of 3H-labeled staphylococci by human PMN, and the amount of C3 fixation to bacteria was measured in a quantitative fluorescent immunoassay. Low levels of immune antibody (IgG) effectively opsonized encapsulated S. aureus when added to fresh but not to heated serum; phagocytosis of the staphylococci was mediated via pronase-sensitive membrane receptors (presumably C3b receptors) of PMN. Experiments with C2-, C3-, or C5-deficient human sera revealed that C3 was required for opsonization and that activation of C3 was mediated via the alternative complement pathway. Encapsulated S. aureus bound significantly less C3 than unencapsulated strains in diluted normal serum; addition of immune antibody, however, increased C3 fixation 4.7-fold (p less than 0.005). Immunoelectron microscopy localized C3 throughout the capsule as well as on the staphylococcal cell wall when bacteria had been opsonized in human serum with immune antibody. Without immune antibody, C3 binding was restricted to the cell wall. At approximately 10-fold higher levels of immune antibody, opsonization and phagocytosis of encapsulated S. aureus was independent of complement and pronase-sensitive receptors on PMN. These studies show that, in addition to immune antibody, the alternative pathway of complement plays an important role in the opsonization of encapsulated S. aureus strains and suggest that complement may be crucial to the in vivo clearance of these organisms.

Antibodies, Bacterial↗
PubMed1981

Influence of age and sex on serum complement components in children.

Concentrations of eight complement components were determined on sera from 419 healthy children (198 boys and 221 girls) aged from 1 to 19 years. A significant correlation between concentration and age for all complement components (C1q, C1s, C4, C3, C5, factor B, properdin, and C1 inhibitor) was observed for girls; in the male population, a significant correlation was present only for C1q, C4, C3, C5, and properdin. The presence of a significant relationship to age suggests that this variable must be considered in establishing normal values of serum complement for children.

Adolescent↗
PubMed1981

Fetal macrosomia in experimental maternal diabetes.

Fetal macrosomia in diabetic pregnancy has been shown to accompany increases in the fetal levels of deoxyribonucleic acid (DNA) and proteins in animal model systems. In order to elucidate the underlying mechanisms of this macrosomia, the synthesis of DNA and proteins, the transport of the precursors, and the tissue level of DNA polymerase activities in macrosomic fetuses from mildly diabetic rats were compared with those in normal fetuses on 20.5 and 19.5 days of gestation. Increases in the influx of precursors and stimulation of synthesis of the macromolecules were observed in macrosomic fetuses as early as 19.5 days of gestation. However, stimulation of DNA polymerase activities in macrosomic fetuses did not occur until 20.5 days of gestation. Therefore, stimulation of DNA polymerase may participate in maintenance of macrosomia but does not initiate macrosomia. Whether or not increases in both the influx of substrates and the synthesis activities precede the macrosomia has yet to be determined.

Animals↗