Deficient IgA and IgG2 anti-pneumococcal antibody levels and response to vaccination in otitis prone children

OBJECTIVE: To evaluate the isotype and IgG subclass distribution of anti-pneumococcal antibodies and response to polysaccharide vaccination in otitis prone children. METHODS: IgG1, IgG2 and IgA antibodies to pneumococcal serotypes 3, 4, 6B, 9V, 14, 19F and 23F were determined in otitis prone children and in an age-matched healthy control population. Patients were immunized with a 23-valent pneumococcal polysaccharide vaccine. The antibody response was measured 4 weeks later. RESULTS: Geometric mean IgA and IgG2 antibody levels for all seven pneumococcal serotypes tested were significantly lower in otitis prone children than in the control population. After immunization, there was no significant increase in geometric mean IgG2 anti-serotype 6B, 19F and 23F pneumococcal polysaccharide (weak immunogenic), but also no increase for IgG2 anti-serotype 4 and 14. Post immunization IgG2 antibody titers for serotypes 6B, 9V and 19F even remained below titers of non-vaccinated controls. Nine out of 29 otitis prone children were colonized nasopharyngeally with Streptococcus pneumoniae during the time of vaccination; these children had an even more severely impaired systemic antibody response. CONCLUSIONS: Otitis prone children, while having normal IgG1 antibody levels, have low IgG2 and IgA anti-polysaccharide antibody levels and fail to respond in these subclasses upon vaccination with pneumococcal polysaccharide vaccine.     

Modulation of T-cell CD3-zeta chain expression in early pregnancy

PROBLEM: To assess the modulation of T-cell CD3-zeta chain expression by a factor in the sera of women, prior to egg retrieval and 14 days after an in vitro fertilization (IVF) and to delineate the mechanism of this modulation. METHOD OF STUDY: In this prospective study, blood samples were obtained from 17 patients during an IVF cycle, prior to human chorionic gonadotropin (hCG), and 14 days after embryo return. Serum was incubated with cultured T-lymphocytes (Jurkat cells) for 96 hr and expression of CD3-zeta chain was evaluated. RESULTS: Eight patients had a positive serum hCG titer 14 days after retrieval, while nine patients had a negative hCG titer. Serum from pregnant patients significantly suppressed CD3-zeta chain expression as compared with their sample prior to retrieval (85.6 +/- 6.2%), while subjects not becoming pregnant failed to suppress zeta expression (99.1 +/- 0.9%, P < 0.0001). CONCLUSION: A factor capable of suppressing TcR/CD3-zeta expression can be detected in the sera of pregnant women 14 days after embryo retrieval. Loss of zeta chain was associated with the induction of apoptosis.     

Expression and prognostic role of tumor suppressor gene PTEN/MMAC1/TEP1 in hepatocellular carcinoma

BACKGROUND: Inactivation of the tumor suppressor gene PTEN/MMAC1/TEP1, located on chromosome 10q23, is a common event in advanced stages of diverse human malignancies. However, the prognostic role of PTEN expression in patients with hepatocellular carcinoma (HCC) has not been characterized. METHODS: One hundred five resected specimens were collected from patients with HCC. Expression levels of PTEN and p53 in clinical samples were analyzed by immunohistochemistry. RESULTS: Immunohistochemical analysis of 105 HCC tissue specimens revealed that decreased or absence of PTEN immunostaining was found in 43 specimens (40.9%). Reduced PTEN expression levels were correlated with increased tumor grade (P = 0.017), advanced disease stage (P = 0.016), and elevated serum alpha-fetoprotein (alphaFP) levels (P = 0.001). Kaplan-Meier analysis indicated that patients with reduced PTEN levels had shorter overall survival (P = 0.001) and higher recurrence rates (P = 0.0007) compared with patients who had intact PTEN expression. Examining p53 expression unveiled an inverse correlation between p53 overexpression and reduced PTEN expression in patients with HCC (P = 0.004). In addition, patients with p53 overexpression had shorter overall survival compared with patients who were without p53 overexpression (P = 0.0014). Univariate and multivariate analyses revealed that reduced PTEN expression was an independent prognostic factor for survival in patients with HCC. CONCLUSIONS: The current study demonstrated that reduced PTEN expression levels are involved in the pathogenesis of HCC. Moreover, decreased PTEN expression was correlated with tumor progression, high alphaFP levels, p53 overexpression, and poor prognosis in patients with HCC.     

Acute toxicities of betel nut: rare but probably overlooked events

Background: Betel nut chewing has long been a social habit in Taiwan and other Asian and tropical countries. It produces various autonomic and psychoneurologic effects including tachycardia, flushing, warmth, cholinergic activation, alertness, and euphoria. Although the oral carcinogenic effects are well known, data concerning its acute toxicity are few. To better understand the toxicity of betel nut, cases reported to the Taiwan Poison Control Center as probable or possible betel nut-related toxicity (January 1988-June 1998) were reviewed. In the 17 cases suitable for review (14 males, 3 females, age 21 to 60 years), the most common manifestations were tachycardia/palpitations (7); tachypnea/dyspnea (6); hypotension and sweating (5); vomiting, dizziness, and chest discomfort (4); abdominal colic, nausea, numbness, and coma (3); and acute myocardial infarction and related manifestations (2). The reported quantity of betel nut used was low (1 to 6 nuts), except an extract of 100 betel nuts was used in 1 case and 66 chewed in another. Most cases recovered within 24 hours after the exposure. One patient developed probable acute myocardial infarction and ventricular fibrillation and died despite repeated cardiac defibrillation. Although betel nut chewing is widespread, significant toxicity as reported to a poison center is rare. Because most betel nut-related effects are transient and mild in nature, the incidence of such events is likely to be underreported. Nevertheless, betel nut chewing can produce significant cholinergic, neurological, cardiovascular, and gastrointestinal manifestations. It is possible that it may aggravate cardiac diseases in susceptible patients but this hypothesis must be further investigated. Treatment is symptomatic. With timely support, rapid and complete recovery is anticipated but a small risk of major complications cannot yet be discounted.     

In-situ photopolymerization of oriented liquid-crystalline acrylates, 3. Oriented polymer networks from a mesogenic diacrylate

Synthesis, mesomorphism, orientation and photo-initiated chain crosslinking of the liquid-crystalline diacrylate 1,4-phenylene bis{4-[6-(acryloyloxy)hexyloxy]benzoate} ( 1 ) are studied. Monomer 1 exhibits a broad nematic phase between 108 and 155°C and a monotropic smectic phase below 88°C. The monomer is uniaxially oriented in its nematic phase at a substrate which has been coated with polyimide and unidirectionally rubbed with tissue. At the transition temperature to the smectic phase the order parameter is measured to be 0,7. During polymerization, the ordering of the mesogens is frozen-in, yielding a uniaxially crosslinked network. The clear films of oriented poly( 1 ) exhibit a birefringence Δn between 0,12 and 0,15, depending on the polymerization temperature. In the highest oriented state of 1 a small reduction of the degree of order is observed during the crosslinking reaction, whereas at higher temperatures and lower ordering of 1 , the uniaxially orientation increases upon reaction. A special feature of the oriented networks is that the ordering is maintained while heating at high temperatures. The polymerization of the acrylate groups in the mesomorphic phases proceeds fast and to high conversion. Below 90°C the polymerization behaviour is similar to that of conventional isotropic diacrylates. Above 90°C the polymerization reaction of the liquid-crystalline diacrylate proceeds faster than that of an isotropic diacrylate.