Interaction of pretilachlor with PS-II activity of the cyanobacterium Desmonostoc muscorum PUPCCC 405.10

Interaction of pretilachlor with photosystem (PS)-II of the cyanobacterium Desmonostoc muscorum PUPCCC 405.10 has been studied in this paper. Pretilachlor negatively affected growth, chlorophyll a (Chl a), photosynthesis, and carbon dissimilation in a dose-dependent manner. Effects were also observed in PSs, especially PS-II (an 11–35% decrease), as well as the whole photosynthetic electron transport activity. The fluorescence emission spectrum of Chl a revealed a dose-dependent effect of pretilachlor on both the antenna and the core complex of PSs, with more severe effect on the former. Data of O-J-I-P fluorescence transient of Chl a revealed that pretilachlor interfered with electron flow between Q_A and Q_B sites of PS-II. It was further observed that pretilachlor decreased maximum fluorescence, variable and relative variable fluorescence, maximum quantum yield, quantum yield of electron transport, the rate of trapped exciton movement, quantum yield of electron transfer, and performance index of primary photochemistry; however, there was a progressive increase in the net rate of PS-II closure, quantum yield of energy dissipation, and effective antenna size per active reaction center. A decrease in photosynthetic activity leads to a decrease in carbon dissimilation, as evidenced by low activity of glucose-6-phosphate dehydrogenase and pyruvate kinase. Thus, pretilachlor, which is otherwise known to kill weeds by interfering with cell division, affected the growth of the cyanobacteria by interacting with PS-II.     

Medullary carcinoma of thyroid metastasis to breast: A cytological experience

Medullary carcinoma of thyroid is a relatively uncommon malignancy, which can be sporadic and syndromic in nature. It commonly spreads to regional lymph nodes followed by spreading to distant sites. Breast is an uncommon site of metastasis of this malignancy. Our case is a 38‐year‐old woman married parous woman presenting to the outpatient department with complaints of lump in both the breasts. Fine‐needle aspiration (FNA) was attempted, which revealed a malignancy more suggestive of a metastasis, which was confirmed on CT scan. A detailed history revealed that the patient is a known case of medullary carcinoma of thyroid. The report was given as metastatic medullary carcinoma to the breast after confirming with a calcitonin immunostain. Given the versatility of primary lesions in the breast, minimally invasive FNA cytology (FNAC) technique with adequate sampling helps in identifying metastatic lesions. Differentiating primary from metastatic lesions changes the course of management to the patient. Metastatic lesions should always be kept in mind in the occurrence of known malignancies, however rare the site of occurrence may be. Morphological clues and immunohistochemical work up aid in arriving at correct diagnosis.     

Headache as the Presenting Symptom in 2 Patients With COVID-19 and a History of Migraine: 2 Case Reports

The coronavirus disease 2019 (COVID-19) pandemic has now affected more than 5 million people globally. Typical symptoms include fever, cough, and shortness of breath. Patients with underlying medical comorbidities such as cardiovascular disease and diabetes are more likely to become severely ill. To date there is limited information on how COVID-19 affects patients with a history migraine. Here, we present the cases of 2 women with a history of migraine whose first symptom of COVID-19 was a severe persistent headache.     

Endocarditis Caused by Rhodotorula Infection

Rhodotorula is an emerging opportunistic fungal pathogen that is rarely reported to cause endocarditis. We describe a case involving a patient who developed endocarditis due to Rhodotorula mucilaginosa and Staphylococcus epidermidis, proven by culture and histopathology. The case illustrates the unique diagnostic and therapeutic challenges relevant to Rhodotorula spp.