Interference of pentobarbitone with the contraction of vascular smooth muscle in goat middle cerebral artery

Pentobarbitone (10^?5 to 10^?3 M) decreased the basal tone of vascular smooth muscle of goat middle cerebral artery in a dose-dependent manner as well as relaxing established contractions induced by noradrenaline (NA) (10^?5 M), 5-hydroxytryptamine (5-HT) (10^?5 M) and KCl(120 mM). Preincubations with pentobarbitone reduced the contractions evoked by these three agents in a dose-dependent way. It also decreased Ca²⁺-induced contractile responses in K⁺-depolarized arteries and 5-HT-Ca²⁺ and NA-Ca²⁺ contractions dose-dependently. Contractions induced by K⁺ were more sensitive to the depressant actions of the drug than those produced by NA and 5-HT. The small contractions evoked by K⁺ and 5-HT in Ca²⁺-free medium were also reduced in its presence. The antagonism Ca²⁺-pentobarbitone was insurmountable. These results suggest that the drug interferes with Ca²⁺ entry and Ca²⁺ release from cell stores, and therefore with the smooth muscle contractions.     

Generalized plane xanthoma and idiopathic Bence–Jones proteinuria

Generalized (diffuse) plane xanthoma (GPX) is a nor-molipacmic xanthomatosis that is very frequently associated with a haematological disorder, and especially with monoclonal gammapathies, which it may precede by several months or years. Here, we report a case of GPX associated with idiopathic Bence–Jones proteinuria, a very rare type of monoclonal gammopathy of undetermined significance. To our knowledge, this association has not been previously described.     

Pyridoxine-Responsive Anemia: Report of 2 Cases in Brothers and a Review of the Literature

The clinical and laboratory findings in two brothers with severe anemiaare presented. These findings were very similar in both cases. Evidence thatat least one of them suffered from a pyridoxine-responsive anemia is presented.It was assumed that the other had the same disorder since, in addition to thestriking similarity in the clinical and laboratory abnormalities, the latter’s anemia disappeared completely with the parenteral administration of vitamin Bcomplex, which provided him with 2 mg. of pyridoxine daily. These patientshave not relapsed 1.5 and 6 years after stopping the therapy.

A review of the reported cases with anemia responding to vitamin B₆ administration is presented. Common factors observed in some of these casesare: (1) severe anemia, microcytic and hypochromic in type, chiefly due to astriking maturation erythroblastic arrest at the basophilic stage with no defectin leukocytes or thrombocytes; (2) hyperferremia and hemosiderosis; (3) anabnormal tryptophan-loading test; and (4) complete or almost complete correction of all abnormalities with administration of vitamin B₆, even at smalldoses. These data were considered to suggest that the patients had a true deficiency in pyridoxine.

In other patients, no increased excretion of xanthurenic acid has been observed after a tryptophan-loading dose, and pyridoxine administration hasimproved the anemia only partially and has not reversed the serum iron parameters to normality. All of these other patients suffered from a familial hypochromic anemia not due to iron deficiency or from a "sidero-achrestic" or "refractory normoblastic" anemia.

The cause of the disorder in patients in the first group is unknown, but, byexclusion, increased requirement of vitamin B₆ seems to be the most likelypossibility.

Submitted on November 22, 1960 Accepted on February 14, 1961     

Comparative Analysis of Syngeneic and Allogeneic Mixed Lymphocyte Reaction of ''Naturally'' Activated and Resting T Cells

'Naturally' activated (NA) or resting T lymphocytes obtained from the spleen of normal BALB/c mice were compared in their capacity to mount a syngeneic mixed lymphocyte reaction (SMLR). Both T-cell subsets were able to proliferate and secrete IL-3/GM-CSF in SMLR cultures. IL-2 was present in 'resting' T-cell SMLR supernatants, and barely detectable in NA T-cell SMLR supernatants. Both NA and 'resting' T-cell SMLRs were inhibited with anti-class II, anti-CD4, or anti-IL-2R MoAbs. NA T cells exhibited a background proliferative and secretory activity in the absence of syngeneic accessory cells. This autonomous activity was susceptible to anti-CD4, but poorly inhibited with anti-class II MoAbs. Both NA and 'resting' T lymphocytes displayed strong responsiveness to allogeneic stimuli. The analysis of the relative frequency of proliferating cells in the SMLR (BALB/c), or allo-MLR (B10, B10.A, B10.D2) from NA or 'resting' T cells indicated an enrichment for syngeneic reactivity among NA T lymphocytes. The meaning of these results for NA T-cell function and repertoire is discussed.     

Excess Hemolysis in Subjects with Severe Iron Deficiency Anemia Associated and Nonassociated with Hookworm Infection

An excess hemolysis was found in subjects with iron deficiency anemia associated with hookworm infection. Red cell survival, measured with Cr⁵¹ andDFP³² in the subjects before deworming, showed a marked disproportionbetween the decrease of the survival and the amount of daily intestinal bloodloss in most cases. Excess of hemolysis was still present after more than 90 percent of the parasites were removed. Red cell survival became normal aftercorrection of anemia through iron treatment. Excess of hemolysis was alsopresent in noninfected subjects with iron deficiency anemia due to othercauses.

The reduction in the survival of the erythrocytes from infected subjectstransfused into normal recipients shows that the hemolytic process is due toan intrinsic defect of the red cells. The low values of hemoglobinemia andthe presence of haptoglobins in the plasma indicate that hemoglobin has notbeen liberated in excess intravascularly. Finally, the fact that the red cellsfrom an infected patient taken after deworming survived normally in splenectomized recipients indicates that the spleen is probably the principal siteof the red cell destruction. The clinical and autopsy findings suggest thatsplenic function is not pathologically increased, but rather that this organ isacting physiologically at a more rapid rate, "culling" the abnormal circulatingred cells and thus leading to a decrease in red cell survival.

The studies presented here also indicate that the hookworm infection perse does not induce hemolysis.

Submitted on January 13, 1964 Accepted on April 24, 1964