A case of recurrent pneumothorax related to oral methylphenidate

Primary spontaneous pneumothorax (PSP) commonly occurs in young, tall, and thin males, without any identifiable cause except for emphysema-like changes (ELCs). However, other risk factors may be overlooked. Herein, we report the case of a 19-year-old male who presented with recurrent spontaneous pneumothorax while taking oral methylphenidate.     

Reactogenicity and immunogenicity of reduced antigen content diphtheria-tetanus-acellular pertussis vaccine (dTpa) administered as a booster to 4-6 year-old children primed with four doses of whole-cell pertussis vaccine

A trial to compare the reactogenicity and immunogenicity of a reduced antigen content diphtheria-tetanus-acellular pertussis (dTpa) vaccine with diphtheria-tetanus-whole-cell pertussis (DTPw) vaccine was conducted in Thailand. Three hundred and thirty children aged 4-6 years, primed with four doses of DTPw, received a single injection of either dTpa or DTPw. There was a significantly lower incidence of local and general reactions following dTpa than DTPw (P<0.001). One month after vaccination, 99.4 and 100% of all subjects had protective anti-diphtheria and -tetanus titers, respectively. The vaccine response rate to pertussis antigens was similar in both groups, with 96.9% versus 92.5% for anti-pertussis toxin (PT), 96.9% versus 97.5% for anti-filamentous hemagglutinin (FHA) and 95.1% versus 90.8% for anti-pertactin (PRN) in the dTpa and DTPw groups, respectively. For anti-BPT, the vaccine response in the dTpa group was 29.6% versus 94.4% for DTPw. In conclusion, the dTpa vaccine was as immunogenic and significantly better tolerated than DTPw. The new dTpa vaccine could improve coverage for routine booster vaccination in children and provide a good replacement for DTP vaccines at 4-6 years of age.     

Developmental regulation of embryonic genes in plants

Somatic embryogenesis from cultured carrot cells progresses through successive morphogenetic stages termed globular, heart, and torpedo. To understand the molecular mechanisms underlying plant embryogenesis, we isolated two genes differentially expressed during embryo development. The expression of these two genes is associated with heart-stage embryogenesis. By altering the culture conditions and examining their expressions in a developmental variant cell line, we found that these genes were controlled by the developmental program of embryogenesis and were not directly regulated by 2,4-dichlorophenoxyacetic acid, the growth regulator that promotes unorganized growth of cultured cells and suppresses embryo morphogenesis. These genes are also expressed in carrot zygotic embryos but not in seedlings or mature plants.     

Chronic Klebsiella pneumonia: a rare manifestation of Klebsiella pneumonia

K. pneumoniae can present as two forms of community-acquired pneumonia, acute and chronic. Although acute pneumonia may turn into necrotizing pneumonia, which results in a prolonged clinical course, it often has a rapidly progressive clinical course. In contrast, chronic Klebsiella pneumonia runs a protracted indolent course that mimics other chronic pulmonary infections and malignancies. Herein, we present two cases of chronic Klebsiella pneumonia. The diagnosis was made by microorganism identification, as well as absence of other potential causes. Clinical and radiographic findings improved after a prolonged course of antibiotic therapy.     

Primary vaccination with a new heptavalent DTPw-HBV/Hib-Neisseria meningitidis serogroups A and C combined vaccine is well tolerated.

OBJECTIVE: Safety and reactogenicity of a new heptavalent DTPw-HBV/Hib-MenAC (diphtheria, tetanus, whole cell pertussis-hepatitis B virus/Haemophilus influenzae type b-Neisseria meningitidis serogroups A and C) vaccine was compared with a widely used pentavalent DTPw-HBV/Hib vaccine. METHODS: Three phase III randomized studies comparable in design and methodology, in which healthy infants received DTPw-HBV/Hib-MenAC (N=1334) or DTPw-HBV/Hib (N=446) at 2, 4, and 6 months, were pooled for analysis. Solicited symptoms were recorded for 4 days, and unsolicited adverse events for 31 days after each dose. Serious adverse events (SAEs) were recorded throughout the studies. RESULTS: There were no significant differences between the two groups in the proportion of subjects with fever >39.5 degrees C or >40.0 degrees C (p<0.005). Compared to group DTPw-HBV/Hib, a significantly higher percentage of subjects in group DTPw-HBV/Hib-MenAC reported fever >39 degrees C (21.2% vs. 14.8%, p=0.004). Fever subsided quickly, did not lead to differences in attendance to medical services and did not increase from dose to dose. Sixty-seven SAEs were reported, 56/1334 (4.2%) in group DTPw-HBV/Hib-MenAC and 11/446 (2.5%) in the DTPw-HBV/Hib group. CONCLUSION: Overall, the heptavalent and pentavalent vaccines had similar safety profiles. The difference observed in percentage of subjects with fever >39 degrees C did not lead to differences in medically attended visits for fever.     

Thoracic manifestations of paradoxical immune reconstitution inflammatory syndrome during or after antituberculous therapy in HIV-negative patients

Immune reconstitution inflammatory syndrome (IRIS) is a consequence of exaggerated and dysregulated host’s inflammatory response to invading microorganism, leading to uncontrolled inflammatory reactions. IRIS associated with tuberculosis (TB) is well recognized among human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy, but it is less common among HIV-negative patients. IRIS can manifest as a paradoxical worsening or recurring of preexisting tuberculous lesions or development of new lesions despite successful antituberculous treatment. Hence, the condition might be misdiagnosed as superimposed infections, treatment failure, or relapse of TB. This pictorial essay reviewed diagnostic criteria and various thoracic manifestations of the paradoxical form of TB-associated IRIS (TB-IRIS) that might aid in early recognition of this clinical entity among HIV-negative patients. The treatment and outcomes of TB-IRIS were also discussed.Immune reconstitution inflammatory syndrome (IRIS) is a consequence of exaggerated and dysregulated host’s inflammatory response to invading microorganisms, typically Mycobacterium tuberculosis. It can also be found in other infections, e.g., cryptococcosis and cytomegalovirus infection, especially among human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy (1). Tuberculosis-associated IRIS (TB-IRIS) among HIV-negative patients has been increasingly observed, particularly in those with extrapulmonary TB (2). This clinical entity can be misdiagnosed as superimposed infections, treatment failure, or TB relapse (3).There are two clinical scenarios related to IRIS, namely unmasking of an occult opportunistic infection and paradoxical worsening or recurring of a prior infection despite successful antimicrobial treatment (1). The pathogenesis of IRIS is not well understood in the latter. IRIS is postulated to be a consequence of immune recovery following appropriate antimicrobial therapy. The recovery results in an abrupt shift of the host’s immune response from an immunosuppressive state towards a pathogenic hyperinflammatory state by increased production of proinflammatory cytokines from Th1 and Th17 cells and simultaneous suppression of anti-inflammatory cytokines from regulatory T cells and Th2 cells (4–6).This pictorial essay reviewed diagnostic criteria and various thoracic manifestations that might aid in early recognition of TB-IRIS among HIV-negative patients. The treatment and outcomes of TB-IRIS were also discussed.