Two lineages of Lemna aequinoctialis (Araceae, Lemnoideae) based on physiology, morphology, and phylogeny.

Lemna aequinoctialis Welw. is a widely spread species that has diverse physiological and molecular properties. Flower characteristics are important factors in deducing taxonomical status; however, owing to the rarity of flowering observations in Lemna, studying them has been a prolonged challenge. In this study, physiological and morphological analyses were conducted by inducing flowering, and molecular analysis was done based on the two chloroplast DNA loci (matK, atpF-atpH intergeneric spacer) of L. aequinoctialis sensu Landolt (1986) from 70 strains found in 70 localities in Japan, Korea, Thailand, and the US. In total, 752 flowering fronds from 13 strains were observed based on axenic conditions. Two different trends in flower organ development-protogyny and adichogamy-were detected in these strains. Their physiological traits were divided into two groups, showing different morphological features based on frond thickness, root cap, and anther sizes. Molecular analysis showed two lineages corresponding to two physiological groups. These were identified as L. aequinoctialis sensu Beppu et al. (1985) and L. aoukikusa Beppu et Murata based on the description of the nomenclature of L. aoukikusa. These were concluded as independent taxa and can be treated as different species. Furthermore, the distribution of L. aoukikusa is not only limited to Japan.

Diagnostic challenges in a patient with dengue shock syndrome presenting with acute meningoencephalitis.

Dengue is a systemic viral infection, and clinical findings vary from asymptomatic to life-threatening, including shock and neurological complications. Despite efforts in vector control, the disease continues to spread worldwide, and the number of annual dengue infections is estimated to be 390 million. For patients with severe dengue, early diagnosis is important; however, owing to the wide range of symptoms and severity, diagnosis can be difficult. Herein, we report the case of a 24-year-old man from Vietnam who was found to have dengue shock syndrome complicated by meningoencephalitis, even though he did not show the typical clinical manifestations of dengue infection. He was transported to our hospital by ambulance because of fever and altered mental status. Brain magnetic resonance imaging revealed hyperintensities in the bilateral thalamus and brainstem on the T2 sequence. After hospitalization, polymerase chain reaction testing of cerebrospinal fluid, serum, and urine revealed the presence of dengue virus serotype 2. This confirmed the diagnosis of dengue encephalitis. The patient was discharged on day 49 with impaired abduction of the left eye and urinary retention. In this case, the initial differential diagnosis was broad because the patient was unable to provide any medical history owing to altered mental status. In addition, the fact that he did not show the characteristic symptoms of dengue infection initially made the diagnosis very difficult. In conclusion, dengue fever should always be considered as a part of the differential diagnosis when a patient from an endemic area presents with fever and impaired consciousness.