Structural study and preliminary crystallographic data for the hemoglobin from reindeer (Rangifer tarandus tarandus)

The ferric form of reindeer hemoglobin (Rangifer tarandus tarandus) has been crystallized in an orthorhombic crystalline form from polyethylene glycol solutions, at pH 8.2. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit cell edges a = 84.2 A, b = 59.9 A, c = 119.5 A; one hemoglobin tetramer is contained in the asymmetric unit. The crystals diffract X-rays to a limit spacing of 3.0 A. Inspection of amino acid sequences in the N-terminal region of beta-chains, and analysis of hemoglobin three-dimensional models, allows one to rationalize, on a molecular basis, the reduced O2 affinity and the decreased effect of organic phosphates observed in ruminant hemoglobins. By analogy, the analysis is extended to birds and reptiles, whose hemoglobin beta-chains display, as in ruminants, the deletion of the N-terminal residue and a methionine at the NA2 position.

Mechanism of loss of thermodynamic control in mitochondria due to hyperthyroidism and temperature

Incubation of normal mitochondria at 45 degrees C results in increases of respiration and of total apparent proton conductance (TAPC, respiration/proton motive force) and in an upward shift of the flow-force relationships. Similar effects are observed during operation of the redox proton pumps at different sites of the respiratory chain. These effects are accompanied by an almost equivalent increase of the passive proton conductance (PPC, proton leakage/proton motive force). In mitochondria from 3,3,5-triiodo-L-thyronine (T3)-treated rats there are also increases of respiration and of TAPC and an upward shift of flow-force relationships, more pronounced at the level of the cytochrome oxidase proton pump. However, at variance from the incubation at 45 degrees C, in mitochondria from T3-treated rats there is only a slight increase of PPC. Addition of bovine serum albumin to normal mitochondria incubated at 45 degrees C results in a marked depression of TAPC in the nonlinear range of the flow-force relationships. An equivalent effect is not observed in mitochondria from T3-treated rats. The experimental results have been compared with computer simulations obtained on the basis of a chemiosmotic model of energy transduction. The increase of TAPC following incubation at high temperature is apparently due to changes of the proton conductance mainly at the level of PPC, while the increase of TAPC following T3 administration is rather due to changes presumably at the level of the redox or ATPase proton pumps.

Quantitation of red cell-bound IgG by an enzyme-linked antiglobulin test in human immunodeficiency virus-infected persons

Anemia, thrombocytopenia, and neutropenia have been observed in patients with acquired immune deficiency syndrome (AIDS) and AIDS-related complex. To investigate whether red cells (RBCs) of patients with human immunodeficiency virus infection were coated with IgG and/or complement (C3), blood samples of 239 patients were tested. The prevalence of a positive direct antiglobulin test on RBCs was 16.7 percent. By use of an enzyme-linked antiglobulin test (ELAT) to measure more accurately the number of IgG molecules per RBC in a group of 67 patients, 30 of the 67 individuals were observed to have increased numbers (mean, 155) compared to normal controls and to patients with hypergammaglobulinemia due to multiple myeloma or chronic liver disease. Hemoglobin level was correlated with the number of IgG molecules per RBC (p = 0.008), but no correlation could be demonstrated between those numbers and serum immunoglobulin (p = 0.10) or circulating immune complexes (p = 0.38). Our results with ELAT suggest that some AIDS patients may have specific binding of IgG on the surface of their RBCs, rather than nonspecific uptake; further clinical correlations are necessary to confirm these findings.

Activation of respiration and loss of thermodynamic control in hyperthyroidism. Is it due to increased slipping in mitochondrial proton pumps?

T3 administration increases the extent of non-linearity in the flow-force relationship between pump proton conductance and protonmotive force. The effect is present also at the ATPase proton pump. These effects are not accompanied by changes in passive proton conductance. Incubation of mitochondria at 45 degrees C also causes an increased non-linearity, accompanied by a partial increase of proton conductance. It appears that the increase of respiratory activity following T3 administration is due to loss of thermodynamic control within or at the proton pumps, an effect which might be attributed to increased slipping.

Flux ratios and pump stoichiometries at sites II and III in liver mitochondria. Effect of slips and leaks

Addition of bovine serum albumin to state 4 mitochondria results in a depression of the proton leak and of the resting respiration of 70 and 25%, respectively. The conductance membrane potential diagram, both in the ohmic and in the non-ohmic region, shows that in the presence of bovine serum albumin the level of ohmic conductance is lowered while that of non-ohmic conductance is increased toward higher delta psi values. The same effect is observed during operation of the different proton pumps. Addition of chloroform affects the conductance membrane potential diagram in the following manner: there is no effect in the ohmic region with all pumps, while there is an effect in the non-ohmic region either at site III or at sites II plus III but not at site II. This suggests a possible effect of chloroform at the level of the cytochrome oxidase proton pump. During titration with oligomycin of the ATPase proton pump the conductance potential diagram shows a region of non-ohmicity only in the presence but not in the absence of an ATP-regenerating system. Protonophoric uncouplers such as carbonyl cyanide p(trifluoromethoxy)phenylhydrazone and intrinsic uncouplers such as chloroform have different effects on the relationship between rates of charge translocation and of oxygen consumption, and thus on the pump stoichiometries, in that the slope of the diagram is modified by the latter but not by the former. The differential effects of protonophores and of intrinsic uncouplers on the stoichiometries have been analyzed by computer simulations and represent an additional criterion to distinguish between extrinsic and intrinsic mechanisms of uncoupling.

Secondary sclerosing cholangitis: an experimental study

An experimental study on rabbit sclerosing cholangitis (SC) secondary to direct injection into the biliary tract of the chemical substances commonly employed for intraoperative sterilization of the hydatid cyst content is reported. Among the various substances utilized, 10% formalin and 30% hypertonic solution caused gross and microscopic lesions compatible with less advanced forms of sclerosing cholangitis. The authors present their hypothesis on the development of SC in operated hydatid cysts of the liver.

Endometriosis and infertility: our experience over five years

During a 5-year period, we diagnosed endometriosis by laparoscopy in 163 infertile patients (7.9% of the infertile population). Seventy-one women presented with minimal endometriosis, 32 women a mild form, 38 women a moderate form and 22 women a severe form. Only 40 patients (24.5%) were found to have endometriosis as the only abnormality in a complete fertility work-up. One hundred and twenty patients were treated with Danazol (600 mg daily for 4-6 months) and 33 of them conceived (27.5%). Twenty-eight patients received conservative surgical treatment associated with Danazol therapy and 11 of them conceived (39.2%). In the 15 patients with minimal endometriosis, who had no therapy but expectant management, there were two conceptions within one year (13.3%). The anticipation of minimal disease in patients with endometriosis as the only abnormality produced about the same results as achieved by active treatment (pregnancy rate of 33.3% after expectant management and 36.3% after treatment). These results suggest that minimal endometriosis can be anticipated only when there are no co-existing factors of infertility.

Pregnancy in women with different types of von Willebrand disease

The course and outcome of pregnancy in women with different types of von Willebrand disease (3 type I, 1 subtype IIA, and 1 subtype IIB) are described. In all patients, factor VIII increased and reached normal levels before delivery, whereas the bleeding time remained prolonged; in subtypes IIA and IIB the abnormal multimeric structure of von Willebrand factor remained unchanged. Deliveries were uneventful in all patients, with two spontaneous vaginal deliveries and three cesarean sections, despite the fact that no replacement therapy was given. Hence, the most important determinant of abnormal hemorrhage during delivery is low factor VIII; the prolonged bleeding time can be compensated for by meticulous surgical hemostasis and efficient contraction of the uterus. Replacement therapy with plasma derivatives can usually be avoided providing that normal factor VIII levels have been attained at delivery.

Biliary cystadenoma: an uncommon cause of recurrent cholestatic jaundice

The clinical history of a patient with intermittent jaundice is presented. The diagnostic work up, including ultrasound, laparoscopy, and endoscopic retrograde cholangiography, revealed a multiloculated cystic mass in the left lobe of the liver. At laparotomy, a multicystic lesion invading the left hepatic duct and protruding into the common bile duct was found. Histological examination revealed a biliary cystadenoma. Complete excision is the treatment of choice of such lesions.

Results of screening for colorectal cancer

Screening for colorectal cancer and its precursors was performed from '68 to '78 within the framework of a multiphasic cancer detection program on 35,700 "healthy" individuals of both sexes in the "high-risk" age groups. Fecal occult blood as determined by the benzidine test after diet was positive in 3,676 individuals (10.3%). Out of this group, 2,599 subjects were submitted to g.i. consultation and proctosigmoidoscopy, as well as 567 of the occult blood negative group selected on the basis of various clinical signs and symptoms. The lesions detected were 153 neoplastic polyps and 21 cancers, mostly in the Dukes A and B stages. Among the most significant results are the high compliance (70%) to proctosigmoidoscopy, the low sensibility (51%) and specificity (18%) of the benzidine test for occult blood, which makes it obsolete as a screening procedure, the increased (50%) diagnostic yield obtained by flexible sigmoidoscopy and the relevance of clinical signs and symptoms as selection parameters for further diagnostic work up.