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.

Hepatocellular carcinoma and intermediate alpha1-antitrypsin deficiency (MZ phenotype).

A case history of a 16-year-old boy with hepatocellular carcinoma and an intermediate deficiency of alpha1-antitrypsin (MZ phenotype) is presented. Previous reports have suggested that hepatocellular carcinoma may be associated with the Z variant of antitrypsin and either a severe or intermediate antitrypsin deficiency. The present case is unusual because of the rather high level of the serum trypsin inhibitory capacity for an MZ heterozygote (1.633 units), which may be due to involvement of the liver by the tumor or to a recent partial hepatectomy. PAS-positive antitrypsin globules were seen in the primary tumor and in nodules metastatic to the mesentery, as well as in nonneoplastic portions of the liver. Hepatocellular carcinoma is another disease state that may occur preferentially in individuals with either severe or intermediate deficiencies of alpha1-antitrypsin.

Nonpalpable breast lesions discovered by mammography.

Specimen mammography has been used at our medical center since January 1976, for the purpose of localizing and confirming the removal of mammographically identified, nonpalpable breast lesions. Forty patients were studied between Jan 1, 1976 and MFay 31, 1979, and 11 of these were found to have carcinoma. Nine of this group had surgical procedures that included axillary lymph node excision and there were no patients with positive axillary nodes. Frozen-section diagnosis was used in 22 patients and found to correlate well with permanent section diagnosis, providing the frozen section was obtained from the most suspicious area of the specimen. Needle localization was used in 15 patients and found to be of definite value in assuring excision of the mammographic abnormality. Three patients had a persistent mammographic lesion after the procedure was done and each of these was successfully managed by repeated biopsy using specimen roentgenography with needle localization.

Glassy cell carcinoma of the cervix. Cytologic and clinicopathologic analysis.

A clinicopathologic analysis of 15 patients with glassy cell carcinoma confirmed that this is a rare disease, having an incidence of 1.2%. It is a rapidly progressive and biologically aggressive disease with early extrapelvic metastasis. The five-year survival and the median survival in our series were 28% and 14 months, respectively. The majority of patients (87%) were understaged, which may have played a role in the poor prognosis. Four of 12 patients (33%) were initially diagnosed as having a benign disease (false-negatives). Defining of cytologic characteristics and differential features of this tumor may facilitate an early and more accurate diagnosis to improve prognosis.