[Pneumococcal endocarditis: apropos of 3 cases]

Streptococcus pneumoniae is a common pathogen in man. The incidence of endocarditis caused by this organism has diminished in the last decades, and now it is an exceptional condition. Three patients with pneumococcal endocarditis are reported. Their clinical and epidemiological features are reviewed and compared with previous literature. One of the instances was due to a strain with high resistance to penicillin; vancomycin was a valid alternative therapy.

[Etiology of acute infections of the lower respiratory tract in hospitalized infants: bacterial antigens]

Demonstration of bacterial antigens in biological fluids has been used for early detection of bacterial infections. Recent evidence suggests that higher detection rates of these antigens can be obtained from concentrated urine than from serum samples of patients. Evidence of bacterial infection by antigen detection was looked for from 50 fold concentrated urine samples by means of an ultrafilter system (Minicom) and latex agglutination for Haemophilus influenzae B (HiB) and Streptococcus pneumoniae (Sp) in three groups of patients. Group A (Positive controls), included 7 patients whose blood culture were positive for HiB (n = 5) and Sp (n = 2). Group B (Healthy controls) involved 16 children without clinical and laboratory signs of infection, coming from ambulatory well baby clinics and surgical wards, and group C was formed by 77 patients with negative blood cultures but with clinical and X ray evidence of lower respiratory tract infection. The corresponding antigen was demonstrated in urine samples from all group A patients. Three group B subjects gave positive results for HiB antigen. HiB antigen was detected from 10 and Sp antigen from 2 group C patients. These results suggest that the search for bacterial antigens in urine would be useful for etiological diagnosis and management of patients with bacterial pneumoniae. There is no definite explanation for the finding of HiB antigen in urine from apparently healthy children but the possibility of previous or actual asymptomatic infections must be taken into account.

Cholesterol increase in mitochondria: a new method of cholesterol incorporation

In this study, we report a new method for cholesterol incorporation in mitochondria. This method is based on the coupling of cholesterol to bovine serum albumin (BSA) to form a structure with a spherical shape (designated C-BSA-C). The results show that C-BSA-C induces a specific cholesterol incorporation in mitochondria without interference from BSA. The cholesterol increase is complete in 1 minute, and is dose-related and pH-dependent. Temperature also has an effect. In mitochondria from dog adrenal glands, pregnenolone biosynthesis induced by C-BSA-C is increased, indicating that only cholesterol is transferred to the membrane.

Biochemical effects of gossypol in isolated mitochondria: monovalent cations and ATPase activity

1. The effect of gossypol acetic acid upon the energy-producing system of isolated liver mitochondria was studied. Gossypol was found to exert an uncoupling effect. 2. Oxygen consumption and ATPase activity were stimulated only when a monovalent alkali metal cations was present. 3. The mitochondrial proton gradient, produced by the enzymatic hydrolysis of ATP, was lower in the gossypol-treated mitochondria than in the control experiments. 4. It is proposed that gossypol stimulates oxygen consumption and the ATPase activity in mitochondria by a protonophoretic effect and a cation translocation process.

Decreased exchange of adenine nucleotides in human placental mitochondria

The purpose of this work was to study the exchange of adenine nucleotides in mitochondria isolated from human placenta tissue. The results indicate that ADP and ATP are translocated at a lower rate than those reported for rat liver mitochondria. It is proposed that the limited transport is due to the particular lipid composition of placental mitochondria membrane, which induces an arrest in membrane fluidity with the consequent restriction in adenine nucleotide translocase mobility.

[Peritoneal dialysis in the newborn (author's transl)]

In the period 1972-1978, forty peritoneal dialysis were performed in thirty seven newborn infants. Their weights were comprised between 1,250 and 5,600 gr., being under 2,000 gr. in eight cases. Peritoneal dialysis was considered as a therapeutic method integrated on the whole treatment approche applied to each critically ill newborn. Its indication was due to renal failure in twenty seven cases and to severe water and electrolyte disturbances in ten cases. Except for one newborn infant with a likely lactic acidosis, our aims in setting an adequate blood depuration and maintenacne of the water and electrolye balance were attained. In two cases we could correlate an aggravation of the clinical state with final death to complications partially due to the procedure. Other incidents in relation with peritoneal dialysis were less relevant and did not interfere with the clinical course followd by the patients. In our experience, peritoneal dialysis was a simple and highly useful method in the treatment of neonates with renal failure or severe metabolic disturbances.