New abnormalities in the morphology, cell surface receptors, and electrolyte metabolism of In(Lu) erythrocytes

The In(Lu) phenotype is inherited as an autosomal dominant trait and is characterized by suppression of the Lutheran, P1, i, and Aua erythrocyte blood group antigens. We have developed a monoclonal antibody (L21) that strongly agglutinates all erythrocytes except In(Lu), and we have identified eight In(Lu) individuals among 42,000 blood donors tested. Studies of two families confirmed the dominant mode of inheritance and revealed several new features of this phenotype. The erythrocytes of all five affected individuals from the two families exhibited diminished hemagglutination by the lectin concanavalin A, although they reacted normally with several other lectins. The erythrocytes of two affected individuals in one family exhibited marked acanthocytosis. The erythrocytes of the proposita of the other family exhibited a mild degree of poikilocytosis, but the cells of the other two affected individuals in this family had normal morphology. The osmotic fragility of fresh In(Lu) erythrocytes was normal, but after incubation for 24 hours at 37 degrees C in plasma the In(Lu) cells exhibited a marked increase in resistance to osmotic lysis. During the incubation period the erythrocytes lost K+ and their total cation content was diminished. These data indicate that in addition to the suppression of blood group antigens noted previously, the In(Lu) phenotype includes a variety of morphological abnormalities and a defect in electrolyte metabolism. The use of L21 and similar monoclonal antibodies provides a more sensitive means of detecting In(Lu) erythrocytes than typing with human anti-Lub antisera.     

The Relationship Between Nocturnal Blood Pressure and Hemorrhagic Stroke in Chinese Hypertensive Patients

To study the relationship between nocturnal blood pressure (BP) variation and spontaneous intracerebral hemorrhage (ICH) among Chinese hypertensive patients and its clinical significance, the authors retrospectively screened 371 patients with primary hypertension (189 patients with ICH, 182 patients without ICH) in Shanghai and analyzed their demographics, clinical information, nocturnal blood pressure variability and medication. Compared with the control group, the levels of blood glucose, triglycerides, and creatinine were significantly increased in the ICH group, along with a marked reduction in nocturnal BP drop (P<.05). Multivariate logistic regression indicated that blood glucose, creatinine, and nocturnal mean arterial pressure were risk factors for ICH, and the magnitude of nocturnal BP drop was negatively related to the risk for ICH. There was no significant difference in the prevalence of reverse dippers between the large hematoma volume group and the small hematoma volume group (χ²=2.529, P=.112), nor among the patients taking angiotensin‐converting enzyme inhibitors, angiotensin receptor blockers, or calcium channel blockers (χ²=1.981, P=.371). Reverse dipping is associated with the risk for ICH, suggesting that appropriate antihypertensive drug and chronotherapy might be effective to normalize the rhythm of abnormal circadian variation in hypertensive patients.     

Elevated Serum Uric Acid is Associated With Angiotensinogen in Obese Patients With Untreated Hypertension

This study investigated the correlation between elevated serum uric acid (SUA) and angiotensinogen in obesity patients with hypertension. A total of 162 obese and 162 nonobese men with hypertension were recruited in this study. Plasma angiotensinogen levels were measured by enzyme‐linked immunosorbent assay. Fasting insulin (FINS) was evaluated by radioimmunoassay. Compared with nonobese patients, obese patients exhibited higher levels of angiotensinogen, FINS, and homeostasis model assessment index‐insulin resistance (HOMA‐IR) (P<.001 for all). Moreover, these indexes significantly increased in obese patients in the highest tertile of SUA when compared with those in the lowest tertile of SUA (P<.001, P=.002, P=.007, respectively). In the obese group, SUA levels were significantly related to angiotensinogen, FINS, and HOMA‐IR, respectively. Furthermore, it was demonstrated that obesity × uric acid was an independent contributor to angiotensinogen (β=0.257, P<.001). In conclusion, elevated SUA is strongly related to angiotensinogen in an obesity‐dependent manner in hypertension.     

Calcium Channel Blocker Compared With Angiotensin Receptor Blocker for Patients With Hypertension: A Meta‐Analysis of Randomized Controlled Trials

To explore the clinical effects of a calcium channel blocker compared with an angiotensin II receptor blocker in hypertensive patients, the authors collected data from randomized controlled trials. The pooled outcomes were all‐cause mortality, stroke, myocardial infarction, and heart failure. Eight head‐to‐head trials enrolling 25,084 patients were included. There was no significant mortality difference in the two arms (relative risk, 0.99; 95% confidence interval, 0.91–1.07). However, calcium channel blockers were more effective in reducing stroke (relative risk, 0.87; 95% confidence interval, 0.76–0.99) and myocardial infarction incidence (relative risk, 0.86; 95% confidence interval, 0.76–0.98). There was no significant difference with heart failure incidence between the two arms but a lower trend in patients with angiotensin II receptor blockers was noted (relative risk, 1.4; 95% confidence interval, 0.99–1.98). The meta‐analysis suggested that initially use of a calcium channel blocker might be superior to an angiotensin II receptor blocker for prevention of stroke and myocardial infarction.     

Development of Lectin-Linked Immunomagnetic Separation for the Detection of Hepatitis A Virus

The accuracy and sensitivity of PCR-based methods for detection of hepatitis A virus (HAV) are dependent on the methods used to separate and concentrate the HAV from the infected cells. The pH and ionic strength affect the binding affinity of the virus to cells. In this study, we initially investigated the effects of pH (4.0–10.0) and metal ions (Fe²⁺, Co²⁺, Cu²⁺, Mg²⁺, K⁺, and Ca²⁺) on the binding of HAV to oyster digestive cells. The lowest relative binding (RB) of HAV to the cells was found at pH 4.0 and in FeSO₄ solution (64.6% and 68.1%, respectively). To develop an alternative to antibody-dependent immunomagnetic separation prior to detection of HAV using RT-PCR, the binding of HAV to five lectins, peanut agglutinin (PNA), Dolichos biflorus agglutinin (DBA), Helix pomatia agglutinin (HPA), Ulex europaeus agglutinin (UEA-1) and soybean agglutinin (SBA), was evaluated using ELISAs. SBA showed significantly higher RB to HAV than the other lectins tested. In addition, HAV could be concentrated within 30 min using SBA-linked magnetic bead separation (SMS) prior to the RT-PCR assay. Our findings demonstrate the feasibility of using SMS combined with RT-PCR to detect HAV at dilutions ranging from 10⁻¹–10⁻⁴ of a HAV stock (titer: 10⁴ TCID₅₀/mL).