Human parvovirus B19-induced epidemic acute red cell aplasia in patients with hereditary hemolytic anemia

From March to August 1984, 26 patients with hereditary hemolytic anemia in northeastern Ohio developed acute, profound red cell aplasia. The patients included 14 males and 12 females 2 to 23 years old, with sickle cell anemia (20 cases), hemoglobin SC-disease (4 cases), sickle- beta-thalassemia (1 case), or hereditary spherocytosis (1 case). All had an acute onset of severe reticulocytopenia and anemia and prodromal symptoms of illness including fever, abdominal symptoms, headache, and arthralgias. Twenty-two received transfusions. Reticulocytosis occurred spontaneously within 2 to 14 days of presentation. In five acute-phase sera, 10(8) to 10(12) viral particles/mL were detected by electron microscopy. Human parvovirus B19 DNA was demonstrated in high concentration by hybridization in the same five acute-phase sera and in low concentration in sera of eight additional patients. The five highly viremic sera inhibited erythroid colony formation in vitro. B19- specific IgM was detected in sera of 24/26 patients, and B19-specific IgG in 21 of 22 patients tested. Our results indicate that human parvovirus B19 was the etiologic agent in this large epidemic of life- threatening acute red cell aplasia in patients with hereditary hemolytic anemia.     

Histamine plays no part in schedule-induced polydipsia in the rat

Twelve Sprague-Dawley male albino rats were tested with or without combined antagonism of peripheral H1 (using 2 mg/kg dexbrompheniramine IP) and H2 (using 32 mg/kg cimetidine IP) receptors for histamine prior to (a) drinking after 2.5 mg/kg histamine SC, (b) drinking after 24-hr water deprivation, and (c) drinking during the acquisition and maintenance of schedule-induced polydipsia (SIP) with a 45 mg Noyes pellet delivered every 90 sec. Such antagonism of histamine receptors abolished drinking elicited by exogenous histamine without inhibiting drinking after water deprivation. Moreover, histaminergic antagonism failed to prevent the acquisition and maintenance of SIP and failed to alter the distribution of contacts with the drinking spout during interpellet intervals. These findings demonstrate no role for endogenous systemic histamine in SIP.     

Serum and salivary antibodies to a mycobacterial 65‐kDa stress protein are elevated in HIV‐positive patients and modified by oral candidiasis

Serum immunoglobulin G (IgG) and IgA, and salivary IgA antibodies to a mycobacterial stress protein (mSP65) were determined in human immunodeficiency virus (HIV)–positive patients, acquired immunodeficiency syndrome (AIDS) patients and HIV‐negative controls with or without oral candidiasis. Serum IgG antibodies were elevated in patients with HIV infection and AIDS and especially in subjects with candidiasis compared with controls (P<0.02, P<0.005). This was not apparent with serum IgA. In the absence of candidiasis, salivary IgA antibodies were elevated in HIV‐positive patients compared with AIDS (P<0.005) patients and healthy controls (P=0.001). The relative avidity of serum IgG antibodies to mSP65 in controls with candidiasis was lower than healthy controls (P<0.0001). In saliva there was a decrease in the relative avidity of IgA antibodies in AIDS patients with candidiasis compared with HIV patients (P< 0.03). In patients without candidiasis, the relative avidity was higher in HIV patients than healthy controls (P=0.02). The results suggest that HIV infection leads to raised serum and salivary antibodies to heat shock proteins. Concurrent Candida infection may modify both the titer and relative avidity differently for serum and saliva.     

Accuracy of Self-reported Human Papillomavirus Vaccination Status Among Gay and Bisexual Adolescent Males: Cross-sectional Study

BackgroundMen who have sex with men are a risk group for anal human papillomavirus (HPV) and anal cancer. Australia introduced a universal school-based HPV vaccination program in 2013. Self-reported HPV vaccination status has been widely used in clinical and research settings, but its accuracy is understudied.ObjectiveWe aimed to examine the accuracy of self-reported HPV vaccination status among gay and bisexual adolescent males.MethodsWe included 192 gay and bisexual males aged 16-20 years from the Human Papillomavirus in Young People Epidemiological Research 2 (HYPER2) study in Melbourne, Australia. All participants had been eligible for the universal school-based HPV vaccination program implemented in 2013 and were asked to self-report their HPV vaccination status. Written informed consent was obtained to verify their HPV vaccination status using records at the National HPV Vaccination Program Register and the Australian Immunisation Register. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of self-reported HPV vaccination status.ResultsThe median age of the 192 males was 19 (IQR 18-20) years. There were 128 males (67%) who had HPV vaccination records documented on either registry. Self-reported HPV vaccination had a sensitivity of 47.7% (95% CI 38.8%-56.7%; 61/128), a specificity of 85.9% (95% CI 75.0%-93.4%; 55/64), a positive predictive value of 87.1% (95% CI 77.0%-93.9%; 61/70), and a negative predictive value of 45.1% (95% CI 36.1%-54.3%; 55/122).ConclusionsSelf-reported HPV vaccination status among Australian gay and bisexual adolescent males underestimates actual vaccination and may be inaccurate for clinical and research purposes.     

Medical treatment of hepatic amebic abscess: rare need for percutaneous drainage

Although amebic liver abscess can virtually always be successfully treated medically, percutaneous drainage has been advocated recently. In 96 recently treated patients, therapeutic aspiration and percutaneous drainage were rarely needed. Most cases were correctly diagnosed by means of clinical, laboratory, and sonographic findings. Abscesses in only 13 (13.5%) patients were diagnostically aspirated. An abscess in one patient was therapeutically aspirated because the patient was responding slowly to medical therapy. No patient required catheter drainage. The key to successful amebic abscess management is medical therapy. Therapeutic drainage is rarely needed. Successfully treated patients occasionally respond slowly to medical therapy, and successfully treated amebic abscesses may enlarge or become bizarre-appearing on sonograms. This should not prompt therapeutic drainage. Diagnostic aspiration is appropriate when amebic and pyogenic abscesses are indistinguishable using clinical and imaging findings. Rare indications for therapeutic aspiration or drainage include pyogenic superinfection and large, juxtacardiac abscesses (potential intrapericardial rupture).