Umbilical cord cyst: a diagnostic dilemma

Umbilical cord cyst refers to any cystic lesion associated with the umbilical cord. Cord cysts can be defined as true or false cysts and may occur in any location along the cord. They are irregular in shape and are located between the cord vessels. Authors are reporting the case of an infant with an umbilical cord tumor which had twice been misdiagnosed previously as a hemangioma, based on ultrasound image of its cystic and solid component with good vascular supply. The ultrasound image most likely suggestive of a hemangioma as a differential diagnosis led to caesarean section in our patient (based on large size of the lesion and fear of rupture of same during process of labour). The definitive diagnosis was made only after birth of the baby. Final diagnosis of true umbilical cord cyst was made after histopathological examination. Thus, there can be confusion in the diagnosis between umbilical cord hemangiomas and umbilical cord cysts based on ultrasound

Cysteine proteases in nodulation and nitrogen fixation

1124-1132<span style="font-size: 14.0pt;mso-bidi-font-size:9.0pt;font-family:" times="" new="" roman","serif""="">The cysteine proteinases or cysteine endopeptidases (EC 3.4.22) are known to occur widely in plant cells. They are involved in almost all aspects of plant growth and development including germination, circadian rhythms, senescence and programmed cell death. They are also involved in mediating plant cell responses to environmental stress (such as water stress, salinity, low temperature. wounding. Ethylene, and oxidative conditions) and plant-microbe interactions (including <span style="font-size: 14.0pt;mso-bidi-font-size:9.0pt;font-family:" times="" new="" roman","serif""="">nodulation). In the development and function of legume root nodules,  cysteine proteases could be involved in several important processes:-(i) a defence response to root invasion by microorganisms; <span style="font-size:13.0pt;mso-bidi-font-size:8.0pt; font-family:" times="" new="" roman","serif""="">(ii) <span style="font-size:14.0pt; mso-bidi-font-size:9.0pt;font-family:" times="" new="" roman","serif""="">protein turnover required during the <span style="font-size:14.0pt;mso-bidi-font-size:9.0pt;line-height:115%; font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">formation of new tissue; <span style="font-size:13.0pt;mso-bidi-font-size:8.0pt; line-height:115%;font-family:" times="" new="" roman","serif";mso-fareast-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="">(iii) <span style="font-size:14.0pt;mso-bidi-font-size: 9.0pt;line-height:115%;font-family:" times="" new="" roman","serif";mso-fareast-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="">cellular homeostasis and metabolism; (iv) adaptation of host cells to physiological stresses; (v) control of nodule senescence. Because of their central importance to plant physiology,  cysteine proteases could serve as important targets for the study of nodule development and functioning at the molecular level. Because of their widespread occurrence in nodulating plants they could also serve as candidate genes for targeted plant breeding programmes.</span

Dark-induced changes in legume nodule functioning

10 pages, figures and tables statistics.Exposure of nodulated leguminous plants to prolonged periods of continuous darkness has been used as a convenient tool to investigate host plant control on nitrogen fixing systems in legume root nodules. Foliar dark treatment of plants results in a rapid decline in N2-fixation in terms of acetylene reduction activity (ARA) and predisposes the nodules to metabolic and structural senescence. After 2 d of darkness, a significant decrease is seen in nitrogenase (N2-ase) proteins of common bean nodules. The effect of dark treatments on nodule respiration varies with plant species. A variable decrease in nodule carbohydrates is observed in different plant species under dark treatments, but no direct correlation between N2-ase activity and gross levels of carbohydrates present in the nodules has been detected. Usually nodule leghemoglobin (Lb) shows a decrease of variable intensity depending on plant species. The mRNA of Lb, sucrose synthase and glutamine synthetase shows a significant decline within 24 h of complete darkness. Dark-induced acceleration of proteolytic activity and decreased plant growth are reflected in decreased nodule proteins and accumulation of free amino acids following a drop in ARA. Antioxidants such as ascorbic acid and glutathione, along with the enzymes of their oxidation–reduction cycle, show a considerable decrease in their content and activity in nodules from dark-treated plants. Among H2O2 scavengers, nodule catalase activity decreases in most of the plants studied, but peroxidase activity shows an increase. Dark-induced adverse effects on N2-fixation are completely or partially reversible on shifting the plants back to a normal light/dark regime. Significant changes in nodule ultrastructure are induced by dark treatment. Attempts have been made to explain the mechanisms underlying dark-induced changes in nodule functioning.We are grateful to Dr R. K. Behl, Professor Plant Breeding, Dr I. S. Sheoran, Professor and Head, Department of Botany and Plant Physiology, Dr S. K. Sawhney, Professor Biochemistry and Dr S.C. Goyal, Associate Professor Botany, Department of Botany and Plant Physiology, CCS Haryana Agricultural University, Hisar for useful discussions and comments on the manuscript.Peer reviewe