A robust experimental and computational analysis framework at multiple resolutions, modalities and coverages.

The ability to study cancer-immune cell communication across the whole tumor section without tissue dissociation is needed, especially for cancer immunotherapy development, which requires understanding of molecular mechanisms and discovery of more druggable targets. In this work, we assembled and evaluated an integrated experimental framework and analytical process to enable genome-wide scale discovery of ligand-receptors potentially used for cellular crosstalks, followed by targeted validation. We assessed the complementarity of four different technologies: single-cell RNA sequencing and Spatial transcriptomic (measuring over >20,000 genes), RNA In Situ Hybridization (RNAscope, measuring 4-12 genes) and Opal Polaris multiplex protein staining (4-9 proteins). To utilize the multimodal data, we implemented existing methods and also developed STRISH (Spatial TRanscriptomic In Situ Hybridization), a computational method that can automatically scan across the whole tissue section for local expression of gene (e.g. RNAscope data) and/or protein markers (e.g. Polaris data) to recapitulate an interaction landscape across the whole tissue. We evaluated the approach to discover and validate cell-cell interaction in situ through in-depth analysis of two types of cancer, basal cell carcinoma and squamous cell carcinoma, which account for over 70% of cancer cases. We showed that inference of cell-cell interactions using scRNA-seq data can misdetect or detect false positive interactions. Spatial transcriptomics still suffers from misdetecting lowly expressed ligand-receptor interactions, but reduces false discovery. RNAscope and Polaris are sensitive methods for defining the location of potential ligand receptor interactions, and the STRISH program can determine the probability that local gene co-expression reflects true cell-cell interaction. We expect that the approach described here will be widely applied to discover and validate ligand receptor interaction in different types of solid cancer tumors.

Sudden unexpected death from an undiagnosed histiocytic sarcoma in an adolescent female.

A previously well 15-year-old female who was awaiting medical investigations for a proptosed right eye collapsed and died suddenly while walking. Postmortem examination revealed diffuse distortion and infiltration of multiple organs by a suspected neoplastic process. Histology confirmed the invasion of multiple organs by atypical cells and myocardial infiltration was the likely cause of death. An extensive panel of immunohistochemistry established the diagnosis of a histiocytic sarcoma. Sudden unexpected death due to a clinically undiagnosed neoplasia in childhood and adolescence is uncommon. This is the first report of a histiocytic sarcoma causing sudden unexpected death and highlights the importance of considering undiagnosed hematological malignancies when examining a case of sudden death at postmortem.

Molecular pharmacology of the calcitonin receptor.

The peptide hormone calcitonin is widely used therapeutically in the treatment of bone disorders such as Paget's disease, osteoporosis, and the hypercalcemia of some malignancies. However, emerging evidence suggests the actions of calcitonin via its G protein-coupled receptor, the calcitonin receptor, may not be limited to bone. Calcitonin receptors have also been identified in the central nervous system, testes, skeletal muscle, lymphocytes, and the placenta. We are now becoming aware that the complexity of the calcitonin response mediated by the calcitonin receptor can be influenced by accessory proteins, receptor isoforms, genetic polymorphisms, developmental and/or transcriptional regulation, feedback inhibition, and the specific cellular or tissue background. This article discusses what is known about the molecular and pharmacological actions of the calcitonin receptor and highlights areas of current research.

Deaths of amateur scuba divers.

Four scuba diving deaths investigated by the Forensic Medicine Unit, University of Edinburgh Medical School, are reported. The pathological investigation of such deaths requires that a detailed history of the events prior to death is obtained and that the site of the accident is fully examined with underwater photographic recording where possible. The diving suits, breathing apparatus and other diving accessories also have to be examined carefully by experts and a complete autopsy with toxicological and histological examination is essential. The causes and mechanisms of death are discussed, as are the importance of special autopsy techniques and investigations. Possible interpretative problems are highlighted.

Endomyocardial fibrosis in a scuba diving death.

A death of an amateur SCUBA diver with undiagnosed late phase endomyocardial fibrosis is reported. This 27-year-old man found himself in difficulties during a Sub-Aqua Club outing and drowned. Autopsy revealed features of drowning in addition to severe endomyocardial fibrosis (EMF) with collagenization of the left ventricle and interventricular septum with foci of chronic myocarditis. Other organs were essentially normal and toxicological studies were negative. Examination of the air tank revealed a normal oxygen circulation with elevation of the carbon dioxide content above recommended limits. Sudden ventricular arrhythmia underwater due to EMF is believed to have precipitated drowning. Stricter medical monitoring of amateur divers should prevent similar accidents in the future.

An unusual accidental death from reverse suspension.

Deaths involving prolonged suspension head downwards have received little or no attention in the English-language literature, doubtless because they are extremely rare. An example, involving alcoholic intoxication as the sole complicating factor, is reported. The mechanism of death is also considered since this is plainly a subject of some interest and likely to provoke further thought and discussion.

Two deaths from intravenous nifedipine abuse.

An incident is reported in which 2 intravenous drug abusers died as the result of uncontrolled experimentation with intravenous injection of the common anti-hypertensive and anti-anginal drug Nifedipine (Adalat t.m. Bayer), probably in mistake for the commonly abused short-acting benzodiazepine drug Temazepam. Large quantities of Nifedipine were identified in the blood of both decreased men by gas chromatography. Apart from intense gastric mucosal congestion, pulmonary oedema and general visceral congestion, the autopsy findings were entirely nonspecific. The similarity in colour, shape and texture between capsules of Nifedipine and those of Temazepam is likely to have prompted the mistake.

Episodic macroglossia in Down's syndrome.

We report a unique case of recurrent gross enlargement of the tongue associated with lymphangiectasia and tongue protrusion in an adult male with Down's syndrome. There were three episodes of acute macroglossia with no clinically identifiable cause. Spontaneous resolution always occurred after five to six days. Histological examination of the tongue, at post mortem, revealed a primary lesion of the lingual lymphatics. The possible mechanisms of acute macroglossia and the surgical techniques which could have been used to reduce the tongue bulk are discussed.

The mechanism of fatal cardiopulmonary injury caused by a blow from a golf club.

In the course of a scuffle, a youth of 18 years was struck a single blow across the chest with a golf club. He collapsed dead on the spot. At autopsy, a precisely located and highly distinctive patterned imprint abrasion of the precordial region was revealed providing an excellent match with the weapon. The heart showed multiple internal ruptures and there was a laceration of the lingula of the left lung. Injury to the chest wall was confined to the soft tissues, the rib cage and sternum being intact. We postulate a novel mechanism to explain the cardiac rupture.