A WC/WO star exploding within an expanding carbon-oxygen-neon nebula.

The final fate of massive stars, and the nature of the compact remnants they leave behind (black holes and neutron stars), are open questions in astrophysics. Many massive stars are stripped of their outer hydrogen envelopes as they evolve. Such Wolf-Rayet stars1 emit strong and rapidly expanding winds with speeds greater than 1,000 kilometres per second. A fraction of this population is also helium-depleted, with spectra dominated by highly ionized emission lines of carbon and oxygen (types WC/WO). Evidence indicates that the most commonly observed supernova explosions that lack hydrogen and helium (types Ib/Ic) cannot result from massive WC/WO stars2,3, leading some to suggest that most such stars collapse directly into black holes without a visible supernova explosion4. Here we report observations of SN 2019hgp, beginning about a day after the explosion. Its short rise time and rapid decline place it among an emerging population of rapidly evolving transients5-8. Spectroscopy reveals a rich set of emission lines indicating that the explosion occurred within a nebula composed of carbon, oxygen and neon. Narrow absorption features show that this material is expanding at high velocities (greater than 1,500 kilometres per second), requiring a compact progenitor. Our observations are consistent with an explosion of a massive WC/WO star, and suggest that massive Wolf-Rayet stars may be the progenitors of some rapidly evolving transients.

A kilonova as the electromagnetic counterpart to a gravitational-wave source.

Gravitational waves were discovered with the detection of binary black-hole mergers and they should also be detectable from lower-mass neutron-star mergers. These are predicted to eject material rich in heavy radioactive isotopes that can power an electromagnetic signal. This signal is luminous at optical and infrared wavelengths and is called a kilonova. The gravitational-wave source GW170817 arose from a binary neutron-star merger in the nearby Universe with a relatively well confined sky position and distance estimate. Here we report observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817 and with a weak, short γ-ray burst. The transient has physical parameters that broadly match the theoretical predictions of blue kilonovae from neutron-star mergers. The emitted electromagnetic radiation can be explained with an ejected mass of 0.04 ± 0.01 solar masses, with an opacity of less than 0.5 square centimetres per gram, at a velocity of 0.2 ± 0.1 times light speed. The power source is constrained to have a power-law slope of -1.2 ± 0.3, consistent with radioactive powering from r-process nuclides. (The r-process is a series of neutron capture reactions that synthesise many of the elements heavier than iron.) We identify line features in the spectra that are consistent with light r-process elements (atomic masses of 90-140). As it fades, the transient rapidly becomes red, and a higher-opacity, lanthanide-rich ejecta component may contribute to the emission. This indicates that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process elements.

Whipple's disease infection surgical treatment: presentation of a rare case and literature review.

The Whipple' Disease (W.D.) is a very rare disease with an incidence of 1 per 1.000.000 inhabitants; it is a systemic infection that may mimic a wide spectrum of clinical disorders, which may have a fatal outcome and affects mainly male 40-50 years old. The infective agent is an actinomycete, Tropheryma Whipplei (T.W.) that was isolated 100 years after first description by Wipple, and identified in macrophages of mucosa of the small intestine by biopsy which is characterized by periodic acid-Schiff-positive, products of the inner membrane of his polysaccharide bacterial cell wall. The multisystemic clinical manifestations evolve rapidly towards an organic decay characterized by weight loss, malabsorption, diarrhea, polyathralgia, opthalmoplegia, neuro-psychiatric disorders and sometimes associated to endocarditis. Early antibiotic treatment with trimethoprim and sulfometathaxazole reduces the fatal evolution of the disease. The authors present a rare experience about a female subject in which the clinical gastrointestinal signs were preceded by neuro-psychiatric disorders, and evolved into obstruction and intestinal perforation which required an emergency surgery with temporary ileostomy, recanalized only after adequate medical treatment with a full dose of antibiotic and resolution of clinical disease for the high risks of fistulae for the edema and lymphadenopathy of mucosa. The diagnosis was histologically examined by intestinal biopsy performed during surgery, which showed PAS-positive histiocytes, while PRC polymerase RNA was negative, which confirms the high sensibility of PAS positive and low specificity of RNA polymerase for T.W.

Surgical management of symptomatic simple hepatic cysts.

The authors present three cases of symptomatic, large, benign, nonparasitic hepatic cysts. The diagnosis was determined by US and CT scan, the latter enabling differential diagnosis with neoplastic or hydatid cysts. All patients were treated with open hepatic resection. In 2 cases, laparoscopy was performed to enable complete diagnosis. The authors used LigaSure™ (Covidien, USA) instrument, avoiding bleeding complications and reducing surgery time. Histological examination confirmed the diagnosis of benign cysts. CT follow-up at 6 months and 1 year demonstrated the efficacy of the surgery, with no recurrences.

[Giant and bilateral adrenal myelolipoma. Case report]. / Mielolipoma surrenalico bilaterale gigante. Caso clinico.

The adrenal myelolipoma is a relatively rare benign tumour of adipose cell and bone marrow elements, non functioning and asymptomatic. Giant and bilateral adrenal myelolipoma is quite rare. The Authors report a case of bilateral adrenal myelolipoma, a giant one (> 15 cm) on the left side and a small one (> 4 cm) on the right with constant pain in a 57-year-old man, shown by computerized tomography. The hormonal blood tests were normal. Surgical excision was performed for large left symptomatic mass, by open laparotomy, and biopsy for right minor adrenal lesion. Histology confirmed diagnosis of myelolipoma for both masses. Follow-up to 6-12 months did'nt show any change of the right myelolipoma. The authors agree with the need to remove the giant adrenal myelolipoma, because the lesion > 10 cm have a high risk of cancer and hemorrhagic complication, while for small myelolipoma (< 6 cm) 6-12 months follow-up is the appropriate choice.

Pentoxifylline in the treatment of venous leg ulcers.

A double-blind, placebo-controlled study was carried out in 12 patients suffering from chronic venous insufficiency and persistent leg ulcers to assess the efficacy of pentoxifylline treatment as an adjunct to compression bandaging in the conservative management of venous leg ulcers. Six patients were allocated at random to receive twice-daily infusions of 200 mg pentoxifylline intravenously and 400 mg pentoxifylline orally 3-times daily for 7 days then 400 mg oral doses 3-times daily for a further 60 days. The control group received matching placebo in an identical regimen. Treatment outcome was assessed by changes between the start and end of the study in venous ulcer surface area, and continuous wave Doppler ultrasound was used to monitor ankle/arm systolic pressure ratio, venous pressure at the ankle, valvular competence and possible venous reflux at intervals throughout the study period. The results showed that in the patients treated with pentoxifylline complete ulcer healing took place in 4 out of 6 and there was a significant reduction in mean ulcer surface area. In the control group, complete ulcer healing was recorded in 1 out of 6 patient only and the ulcer area was only moderately reduced in the others. There was no statistically significant differences between the two groups in the variables monitored by Doppler ultrasound but the difference between treatment outcome was significant. Treatment was well-tolerated.

Effects of L-carnitine on adriamycin-induced cardiomyopathy in rabbit.

The authors conducted an investigation in order to ascertain whether or not L-carnitine, by promoting the utilization of FFA for energy and neutralizing FFA toxicity occurring after ischaemia, could prevent or confine adriamycin-induced cardiotoxicity in rabbits. The results show that L-carnitine determines a higher survival rate and reduced onset of cardiomyopathy. Histopathological examination of myocardial tissue under light and electron microscopy revealed a marked decrease in mitochondrial lesions.

Cytoprotective therapy of gastric ulcers: a controlled clinical evaluation of triletide versus carbenoxolone.

Two parallel groups, each of 10 out-patients with endoscopically confirmed benign gastric ulcer, were randomly assigned to receive either 1.5 g/day of triletide, a new tripeptide shown to increase the synthesis of gastroduodenal mucus and to antagonize thromboxane A2, or 0.3 g/day of carbenoxolone. Both drugs were given orally in 3 divided doses for 4 weeks, according to the controlled design. Endoscopy showed that a greater proportion of patients treated with triletide benefited from treatment (60%) in comparison with those who had carbenoxolone (40%), but the difference was not significant. Weekly monitoring of epigastric pain, heartburn and antacid intake showed both treatments to be effective, and triletide to be overall faster acting (p less than 0.01 for epigastric pain). Subjective complaints of possible side-reactions were not recorded with either treatment; routine physical examination, haematology and haematochemistry remained unaffected by triletide, whereas treatment with carbenoxolone was associated with a significant increase in both systolic and diastolic blood pressure and with a significant decrease (p less than 0.05) in blood potassium levels. Triletide, therefore, appeared to be an effective and well-tolerated means for the therapy of gastric ulcer, and by virtue of its significantly greater symptomatic action and greater tolerance in comparison with a standard cytoprotective treatment such as carbenoxolone, it is suggested that triletide deserves consideration in the management of peptic ulcer.