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The effects of coronary blood flow, tissue water content and hematocrit variation on the Integrated Myocardial Backscatter Rayleigh 5 (IBR5) and Fourier coefficient of amplitude modulation (FAM, an index of cardiac cylce-dependent variation in IBR5) were measured in five open chest dogs. Data were obtained at baseline, during adenosine infusion and after two hours of crystalloid hemodilution (Hct 15%). IBR5 of −46.4 ± .94 dB at baseline did not change significantly during adenosine infusion (−45 ± .85 dB) and after hemodilution (−46.4 ± 2.0 dB). FAM at baseline was (4.0 ± 1.0 dB) (3.8 ± -1.0 dB) during adenosine infusion and after hemodilution (5.0 ± 1.8 dB). Myocardial water content increased significantly (p〈.05) from 78 ± .20% at baseline to 80.7 ± .17% after hemodilution. Coronary blood flow demonstrated a three-fold increase with adenosine and two-fold increase with hemodilution. Electronmicroscopy demonstrated an increase in intracellular and extracellular water content. In conclusion, IBR5 and FAM did not change significantly despite significant increases in coronary blood flow and myocardial water content. Myocardial cellular derangements seen with nonischemic cell swelling, increased blood flow and a fall in hematocrit are insufficient to affect integrated backscatter.

Rabbits injected with pure human placental transcobalamin II-receptor (TC II-R) failed to thrive with no apparent tissue or organ damage, but a 2-fold elevation of the metabolites, homocysteine, methylmalonic acid, and the ligand, transcobalamin II, in their plasma. Exogenously added transcobalamin II-[57Co]cyanocobalamin bound very poorly (2-5%) to the affected rabbit liver, kidney, and intestinal total or intestinal basolateral membrane extracts relative to the binding by membrane extracts from normal rabbit tissues. The activity was restored to normal values following a wash of affected rabbit tissue membranes with pH 3 buffer containing 200 mM potassium thiocyanate. Immunoblot analysis of normal and affected rabbit kidney and liver total membranes revealed similar amounts of 124-kDa TC II-R dimer protein. The neutralized and dialyzed extract from the affected rabbit membranes inhibited the binding of the ligand to pure TC II-R and the harvested affected rabbit serum inhibited the uptake of TC II-[57Co]cobalamin (Cbl) from the basolateral side of human intestinal epithelial (Caco-2) cells and decreased the utilization of [57Co]Cbl as coenzymes by the Cbl-dependent enzymes. The loss of exogenously added ligand binding or the binding of 125I-protein A occurred with the intestinal basolateral, but not the apical membranes. Based on these results, we suggest that circulatory antibodies to TC II-R cause its in vivo functional inactivation, suppress Cbl uptake by multiple tissues, and thus cause severe Cbl deficiency and the noted failure to thrive.

Quantitative lactate determinations were performed on cerebrospinal fluids to assess their value in the rapid diagnosis of bacterial and mycotic meningitis and to evaluate their value in assessing the prognosis in these patients. Cerebrospinal fluid lactate concentrations were elevated in all patients with untreated bacterial or fungal meningitis. Lactate concentrations proved very valuable in following patients with mycotic meningitis and in differentiating aseptic from bacterial meningitis. Elevated cerebrospinal fluid lactate is not specific for meningitis. Lactate is also elevated in situations where there is central nervous system ischemia and necrosis and in patients with brain tumors. Lactate concentration is normal in chronic degenerative brain diseases. Thus, the clinical situation must be taken into account when interpreting the lactate concentrations.

Seven antigens of Borrelia hermsii, B. parkeri, and B. turicatae with isoelectric points in the range of 4.4 to 5.0 and molecular masses of 40 to 43 kilodaltons played a role in the relapse phenomenon of relapsing fever. Based upon location of the antigens in the outer envelope, the molecular weight, and Western blot analysis, the antigens from each phase of spirochetemia appeared to be a mixture of the serotype-specific antigens of cloned B. hermsii.

Levels of C-reactive protein and lactate were determined on 562 consecutive cerebrospinal fluid (CSF) samples from adult patients with a wide variety of central nervous system diseases to compare the sensitivity and specificity of CSF lactate and C-reactive protein for the rapid diagnosis of bacterial meningitis. Neither test alone, together, or in combination with elevated CSF leukocyte count and protein had a predictive value over 60% for a positive test in this group of patients with diverse central nervous system problems. Neither test is useful as a screening test for bacterial or mycotic meningitis. Also, in patients with partially treated bacterial meningitis, the tests are often negative. CSF lactate may be useful in differentiating aseptic from septic meningitis in selected patients.