Neuropsychiatric Lupus with Antibody-Mediated Striatal Encephalitis.

Systemic lupus erythematosus is a chronic autoimmune disease characterized by the production of autoantibodies resulting in tissue injury across multiple organs; up to 50% of patients develop neurologic involvement, collectively referred to as neuropsychiatric systemic lupus erythematosus. The cases in this clinical report will highlight a subtype of neuropsychiatric systemic lupus erythematosus demonstrating imaging findings of striatal inflammation responsive to plasmapheresis similar to those in the subset of N-methyl-D-aspartate receptor autoimmune encephalitis that involves the striatum. Although the cause for this striking imaging appearance is not definitely known, literature will be presented supporting the hypothesis that it is due to peripheral anti-double-stranded DNA antibodies entering the central nervous system to cross-react with N-methyl-D-aspartate receptor antigens.

TRPV1 antagonists that cause hypothermia, instead of hyperthermia, in rodents: Compounds' pharmacological profiles, in vivo targets, thermoeffectors recruited and implications for drug development.

AIM: Thermoregulatory side effects hinder the development of transient receptor potential vanilloid-1 (TRPV1) antagonists as new painkillers. While many antagonists cause hyperthermia, a well-studied effect, some cause hypothermia. The mechanisms of this hypothermia are unknown and were studied herein. METHODS: Two hypothermia-inducing TRPV1 antagonists, the newly synthesized A-1165901 and the known AMG7905, were used in physiological experiments in rats and mice. Their pharmacological profiles against rat TRPV1 were studied in vitro. RESULTS: Administered peripherally, A-1165901 caused hypothermia in rats by either triggering tail-skin vasodilation (at thermoneutrality) or inhibiting thermogenesis (in the cold). A-1165901-induced hypothermia did not occur in rats with desensitized (by an intraperitoneal dose of the TRPV1 agonist resiniferatoxin) sensory abdominal nerves. The hypothermic responses to A-1165901 and AMG7905 (administered intragastrically or intraperitoneally) were absent in Trpv1-/- mice, even though both compounds evoked pronounced hypothermia in Trpv1+/+ mice. In vitro, both A-1165901 and AMG7905 potently potentiated TRPV1 activation by protons, while potently blocking channel activation by capsaicin. CONCLUSION: TRPV1 antagonists cause hypothermia by an on-target action: on TRPV1 channels on abdominal sensory nerves. These channels are tonically activated by protons and drive the reflectory inhibition of thermogenesis and tail-skin vasoconstriction. Those TRPV1 antagonists that cause hypothermia further inhibit these cold defences, thus decreasing body temperature. SIGNIFICANCE: TRPV1 antagonists (of capsaicin activation) are highly unusual in that they can cause both hyper- and hypothermia by modulating the same mechanism. For drug development, this means that both side effects can be dealt with simultaneously, by minimizing these compounds' interference with TRPV1 activation by protons.

Autoimmune Encephalitis: Pathophysiology and Imaging Review of an Overlooked Diagnosis.

Autoimmune encephalitis is a relatively new category of immune-mediated disease involving the central nervous system that demonstrates a widely variable spectrum of clinical presentations, ranging from the relatively mild or insidious onset of cognitive impairment to more complex forms of encephalopathy with refractory seizure. Due to its diverse clinical features, which can mimic a variety of other pathologic processes, autoimmune encephalitis presents a diagnostic challenge to clinicians. Imaging findings in patients with these disorders can also be quite variable, but recognizing characteristic findings within limbic structures suggestive of autoimmune encephalitis can be a key step in alerting clinicians to the potential diagnosis and ensuring a prompt and appropriate clinical work-up. In this article, we review antibody-mediated encephalitis and its various subtypes with a specific emphasis on the role of neuroimaging in the diagnostic work-up.

Treatment of chronic haemophilic synovitis in humans with D-penicillamine.

Chronic proliferative synovitis secondary to haemathroses is a major complication in patients with severe haemophilia. Current management strategies include prophylactic infusions of the missing coagulation factor, corticosteroids, synoviorthesis and/or synovectomy with variable degrees of benefit. In addition, patients with coagulation factor inhibitors are not amenable to the invasive therapeutic modalities. The gross and microscopic findings of the synovitis in haemophilic arthritis are remarkably similar to those seen in patients with rheumatoid arthritis, although the pathophysiology of these two conditions are quite different. Haemophilic arthropathy, in the later stages, resembles degenerative rather than inflammatory joint disease. Oral D-penicillamine, a drug effective in the proliferative synovitis of rheumatoid arthritis, was evaluated in 16 patients. Ten patients had an unequivocal response, while three had a reduction in palpable synovium and three had no response. Thus 81% of the patients had a beneficial response. Minor reversible drug side-effects occurred in two patients (proteinuria in one and a rash in the second). The results of this study suggest that D-penicillamine is an effective and safe drug for the treatment of haemophilic chronic synovitis.

Hemolytic-uremic syndrome.

The hemolytic-uremic syndrome (HUS) has been recognized for more than 45 years and consists of the combination of hemolytic anemia, thrombocytopenia, and acute renal failure. HUS occurs predominantly in children younger than 4 years of age. It is the most frequent cause of acute renal failure in children. The most common form of the syndrome (D+ HUS) occurs in healthy young children (>6 mo to <5 y of age) and is preceded by watery diarrhea that can evolve to hemorrhagic colitis. The diarrhea precedes the hemolysis and thrombocytopenia by 5 to 7 days; oliguria/anuria follows several days later. Although the pathogenesis is unknown, available evidence strongly suggests that endothelial cell damage is necessary. The outcome for most patients who have D+ HUS is favorable: 65% to 85% recover completely, 5% to 10% die (usually during the acute illness), recurrence is uncommon, and only a few patients slowly progress to end-stage renal disease (ESRD).

Tissue-type plasminogen activator, plasminogen activator inhibitor, and histidine-rich glycoproteins in stressed human newborns.

Normal newborns have reduced levels of tissue-type plasminogen activator (tPA). Stressed newborns have an increased prevalence of thrombotic diseases. An impaired release of tPA and/or increased plasminogen activator inhibitor (PAI) is associated with thrombotic risk in the adult patient. The purpose of this study was to assay the plasma levels of tPA, PAI, histidine-rich glycoprotein (HRG), and other fibrinolytic proteins in 15 severely stressed newborns. The stressed babies showed significantly higher (p less than .001) levels of tPA antigen compared with normal newborns. Also, PAI activity and PAI-1 antigen levels were increased. Levels of both HRG and plasminogen were higher in the stressed group but the ratio of HRG to plasminogen was the same as that in the normal control newborns (1:3), suggesting an insignificant effect of HRG. D-dimers were significantly elevated in the stressed newborns. However, 8 patients died and 4 of these were found to have massive thrombotic disease on autopsy. These results show that the newborn when stressed will increase tPA levels and activate the lytic system. However, the activity is suboptimal inasmuch as PAI activity did not decrease and thrombotic disease was observed.

A variant form of thrombasthenia.

We encountered two siblings with abnormal bruising since infancy. Studies revealed functional platelet defects characterized by a lack of platelet aggregation and adenosine triphosphate release on exposure to adenosine diphosphate and collagen as well as variable responses with ristocetin (at concentrations of less than or equal to 1.25 g/L) and arachidonic acid. In addition, little or no platelet aggregation was observed after exposure to hexadimethrine bromide (Polybrene), the calcium ionophore A23187, and the thromboxane/endoperoxide analogue U46619. The membrane proteins IIIa and Ib were present, as determined with monoclonal antibody testing, and no platelet-associated IgG was found. Platelet analysis with routine electron microscopy and ultrastructural cytochemistry revealed normal morphologic features and no deficiencies in the number of alpha granules dense bodies and other organelles. The platelet abnormality may represent a new variant of thrombasthenia.

Measurement of serum granulocyte colony-stimulating factor in a patient with congenital agranulocytosis (Kostmann's syndrome).

A 12-month-old boy with Kostmann's syndrome was admitted with cavitary pulmonary disease. He had also had bacterial conjunctivitis, periorbital cellulitis, pneumonitis, and otitis media since the age of 10 days. His umbilical cord had not fallen off until he was 3 weeks old. Neutropenia was diagnosed at 4 weeks of age. Antineutrophil antibody studies were negative. A bone marrow aspirate showed granulocytic hypoplasia and a maturation arrest at the promyelocyte stage. Hematopoietic cell culture showed normal numbers of colony-forming units-granulocyte macrophage. Serum granulocyte-macrophage colony-stimulating factor level, was 0.24 ng/mL (normal, greater than 0.05 ng/mL). Serum granulocyte colony-stimulating factor levels, measured by enzyme immunoassay, were undetectable. The patient was successfully treated with filgrastim (granulocyte colony-stimulating factor), with an increase in the absolute neutrophil count to 10.0 x 10(9)/L. Thus, our case of Kostmann's syndrome appears to represent a defect in regulation or production of granulocyte colony-stimulating factor.

Mojave rattlesnake (Crotalus scutulatus scutulatus) venom: in vitro effect on platelets, fibrinolysis, and fibrinogen clotting.

Rattlesnake envenomation commonly produce defects in the hemostatic mechanism. However, Mojave rattlesnake (Crotalus scutulatus scutulatus) envenomation has been reported not to cause a systemic bleeding diathesis. In this study, whole venom from the Mojave rattlesnake was tested in vitro for fibrinogen clotting activity, ability to induce platelet aggregation, and for fibrinolytic activity. The Mojave venom caused no fibrinogen clotting and it displayed very weak ability to cause platelet aggregation and fibrinolytic activity. These in vitro studies support the clinical observation that Mojave envenomation does not cause a coagulopathy.

Histidine-rich glycoprotein and plasminogen plasma levels in term and preterm newborns.

The newborn's fibrinolytic system is not the same as that in the adult. Hypoplasminogenemia with normal (adult) levels of alpha 2-plasmin inhibitor and plasminogen activator inhibitor are characteristic of the newborn's lytic system. This combination suggests that the newborn may have an impaired lytic system that may explain, in part, the thrombotic events that are frequently observed. Histidine-rich glycoprotein (HRG), another fibrinolytic inhibitor, retards fibrinolysis by interfering with plasminogen's binding to fibrin. Levels of HRG have been reported to be reduced in term newborns. This finding has not been studied recently and to our knowledge, there are no reports of HRG levels in premature infants. The purpose of this study was to measure the plasma levels of HRG and plasminogen in three groups of patients: normal adults (n = 48), normal term newborns (n = 43), and normal premature newborns (n = 18). The protein levels were determined by electroimmunoassay. Cross-immunoelectrophoresis was also performed for HRG. Cord blood was employed for obtaining newborn citrated plasma. The newborns had significantly lower plasminogen and HRG levels when compared with those of the adults. Also, the HRG levels of the premature newborns were lower than those of the term newborns. In conclusion, the newborns had lower levels of HRG than adults, with premature newborns having the lowest levels. This may allow for more plasminogen to be available for fibrin binding even though newborns have hypoplasminogenemia.

Effects of chronic beta-carotene supplementation on vitamin K status in adults.

Plasma vitamin K concentrations and prothrombin coagulation activity were determined in 26 normal adults who had received daily beta-carotene supplementation (0, 15, 30, or 60 mg) for six months. Neither plasma vitamin K nor coagulation activity were significantly decreased at any supplementation level. Thus, chronic beta-carotene supplementation, even at high daily doses, is not expected to result in clinical vitamin K deficiency. The data suggest separate mechanisms for intestinal absorption of beta-carotene and vitamin K.

Hepatic impairment in fetuses of preeclamptic mothers.

Cord blood from preeclamptic and normal gestations were analyzed for the vitamin K-dependent proteins, factors II, VII, IX, X, and protein C, and for fibrinogen and albumin. Factor II, factor IX, protein C, and albumin protein levels were reduced in the preeclamptic group, whereas there was no significant change in the fibrinogen or factor X protein levels. The data suggest that these findings are probably due to decreased synthesis and are not indicative of vitamin K deficiency.

Newborn's fibrinolytic mechanism: components and plasmin generation.

Plasminogen activity and antigen, tissue-type plasminogen activator (tPA) activity and antigen, plasminogen activator inhibitor (PAI) activity, and plasmin generation rates were determined in 32 normal newborn plasmas and 25 normal adult plasmas. The newborns showed reduced levels of plasminogen activity and antigen and tPA antigen, and activity, normal levels of PAI activity, and slower plasmin generation rates. The slower generation was shown to be due to the hypoplasminogenemia. The in vitro plasmin generation studies also showed that the newborn needed 11 times the usual concentration of urokinase and 5 times the usual concentration of tPA to achieve the minimal activation rate of the adult.