Power Drill Craniostomy for Bedside Intracranial Access in Traumatic Brain Injury Patients.

Invasive neuromonitoring is a bedrock procedure in neurosurgery and neurocritical care. Intracranial hypertension is a recognized emergency that can potentially lead to herniation, ischemia, and neurological decline. Over 50,000 external ventricular drains (EVDs) are performed in the United States annually for traumatic brain injuries (TBI), tumors, cerebrovascular hemorrhaging, and other causes. The technical challenge of a bedside ventriculostomy and/or parenchymal monitor placement may be increased by complex craniofacial trauma or brain swelling, which will decrease the tolerance of brain parenchyma to applied procedural force during a craniostomy. Herein, we report on the implementation and safety of a disposable power drill for bedside neurosurgical practices compared with the manual twist drill that is the current gold standard. Mechanical testing of the drill's stop extension (n = 8) was conducted through a calibrated tensile tester, simulating an axial plunging of 22.68 kilogram (kg) or 50 pounds of force (lbf) and measuring the strength-responsive displacement. The mean displacement following compression was 0.18 ± 0.11 mm (range of 0.03 mm to 0.34 mm). An overall cost analysis was calculated based on the annual institutional pricing, with an estimated $64.90 per unit increase in the cost of the disposable electric drill. Power drill craniostomies were utilized in a total of 34 adult patients, with a median Glasgow Coma Scale (GCS) score of six. Twenty-seven patients were male, with a mean age of 50.7 years old. The two most common injury mechanisms were falls and motor vehicle/motorcycle accidents. EVDs were placed in all subjects, and additional quad-lumen neuromonitoring was applied to 23 patients, with no incidents of plunging events or malfunctions. One patient developed an intracranial infection and another had intraparenchymal tract hemorrhaging. Two illustrative TBI cases with concomitant craniofacial trauma were provided. The disposable power drill was successfully implemented as an option for bedside ventriculostomies and had an acceptable safety profile.

Cellular and Genetic Causes of Idiopathic Hyperaldosteronism.

Primary aldosteronism affects ≈5% to 10% of hypertensive patients and has unilateral and bilateral forms. Most unilateral primary aldosteronism is caused by computed tomography-detectable aldosterone-producing adenomas, which express CYP11B2 (aldosterone synthase) and frequently harbor somatic mutations in aldosterone-regulating genes. The cause of the most common bilateral form of primary aldosteronism, idiopathic hyperaldosteronism (IHA), is believed to be diffuse hyperplasia of aldosterone-producing cells within the adrenal cortex. Herein, a multi-institution cohort of 15 IHA adrenals was examined with CYP11B2 immunohistochemistry and next-generation sequencing. CYP11B2 immunoreactivity in adrenal glomerulosa harboring non-nodular hyperplasia was only observed in 4/15 IHA adrenals suggesting that hyperplasia of CYP11B2-expressing cells may not be the major cause of IHA. However, the adrenal cortex of all IHA adrenals harbored at least 1 CYP11B2-positive aldosterone-producing cell cluster (APCC) or micro-aldosterone-producing adenomas. The number of APCCs per case (and individual APCC area) in IHA adrenals was significantly larger than in normotensive controls. Next-generation sequencing of DNA from 99 IHA APCCs demonstrated somatic mutations in genes encoding the L-type calcium voltage-gated channel subunit α 1-D ( CACNA1D, n=57; 58%) and potassium voltage-gated channel subfamily J-5 ( KCNJ5, n=1; 1%). These data suggest that IHA may result from not only hyperplasia but also the accumulation or enlargement of computed tomography-undetectable APCC harboring somatic aldosterone-driver gene mutations. The high prevalence of mutations in the CACNA1D L-type calcium channel provides a potential actionable therapeutic target that could complement mineralocorticoid blockade and inhibit aldosterone overproduction in some IHA patients.

Aldosterone-Producing Cell Clusters Frequently Harbor Somatic Mutations and Accumulate With Age in Normal Adrenals.

CONTEXT: Aldosterone synthase (CYP11B2) immunohistochemistry and next-generation sequencing (NGS) have revealed the frequent presence of aldosterone-producing cell clusters (APCCs) harboring somatic mutations in aldosterone-regulating genes in adrenals from Americans without defined hypertension status. OBJECTIVE: Determine the frequency and somatic mutation status of APCCs in a Japanese nonhypertensive cohort. DESIGN SETTING PATIENTS AND INTERVENTIONS: Adrenals from 837 consecutive autopsies at a Japanese institution, Tohoku University Hospital, were screened to select 107 unilateral adrenal glands from nonhypertensive patients. APCC score (APCC number/adrenal cortex area per case) was assessed by CYP11B2 immunohistochemistry. DNA from all APCCs and adjacent adrenal cortex was subjected to NGS using two panels targeting aldosterone-regulating genes. PRIMARY OUTCOME MEASURE: APCC frequency and somatic mutation spectrum. RESULTS: In 107 adrenals, 61 APCCs were detected (average of 0.6 APCCs per gland). APCC score was positively correlated with age (r = 0.50, P < 0.0001). NGS demonstrated high confidence somatic mutations in 21 of 61 APCCs (34%). Notably, 16 of 21 APCCs (76%) harbored somatic mutations in CACNA1D, the most frequently mutated gene in our previous studies of APCCs in Americans and CYP11B2-positive micronodules in cross-sectional imaging (computed tomography) negative primary aldosteronism (PA), whereas no APCCs harbored mutations in KCNJ5, the most frequently mutated gene in aldosterone-producing adenoma. APCC score was significantly lower than our previous cohort of unilateral computed tomography-negative PA. CONCLUSIONS: APCCs are frequent in nonhypertensive Japanese adrenals, accumulate with age, and frequently harbor somatic mutations (most commonly in CACNA1D). The role of APCCs in PA pathobiology and non-PA hypertension warrants further investigation.

Genetic and Histopathologic Intertumor Heterogeneity in Primary Aldosteronism.

Context: Whether primary aldosteronism (PA) is the consequence of a monoclonal or multiclonal process is unclear. Case Description: A 48-year-old man with severe bilateral PA refractory to medical therapy underwent unilateral adrenalectomy of the dominant adrenal. Although computed tomography showed three left-sided cortical nodules, postsurgical histopathology and genetic analysis revealed five different adrenocortical adenomas. Two zona fasciculata (ZF)-like aldosterone-producing adenomas (APAs) each harbored distinct known somatic KCNJ5 mutations (L168R and T158A). A zona glomerulosa-like APA harbored a known CACNA1D G403R somatic mutation, whereas a zona reticularis-like adenoma, which was grossly black in pigmentation with histologic characteristics more associated with cortisol-producing adenomas, expressed CYP11B2, CYP17, and DHEA-ST by immunohistochemistry (IHC) and harbored no known somatic mutations. The fifth adenoma was ZF-type, negative for CYP11B2 and CYP17 IHC, and harbored no known somatic mutations. Conclusions: This case highlights complex intertumor heterogeneity in histology, steroidogenesis, and somatic mutations in multiple adrenocortical adenomas arising in a single patient with PA. These findings suggest that the syndrome of PA can involve heterogeneous and multiclonal functional adrenal adenomas.

Role and regulation of coordinately expressed de novo purine biosynthetic enzymes PPAT and PAICS in lung cancer.

Cancer cells exhibit altered metabolism including aerobic glycolysis that channels several glycolytic intermediates into de novo purine biosynthetic pathway. We discovered increased expression of phosphoribosyl amidotransferase (PPAT) and phosphoribosylaminoimidazole carboxylase, phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS) enzymes of de novo purine biosynthetic pathway in lung adenocarcinomas. Transcript analyses from next-generation RNA sequencing and gene expression profiling studies suggested that PPAT and PAICS can serve as prognostic biomarkers for aggressive lung adenocarcinoma. Immunohistochemical analysis of PAICS performed on tissue microarrays showed increased expression with disease progression and was significantly associated with poor prognosis. Through gene knockdown and over-expression studies we demonstrate that altering PPAT and PAICS expression modulates pyruvate kinase activity, cell proliferation and invasion. Furthermore we identified genomic amplification and aneuploidy of the divergently transcribed PPAT-PAICS genomic region in a subset of lung cancers. We also present evidence for regulation of both PPAT and PAICS and pyruvate kinase activity by L-glutamine, a co-substrate for PPAT. A glutamine antagonist, 6-Diazo-5-oxo-L-norleucine (DON) blocked glutamine mediated induction of PPAT and PAICS as well as reduced pyruvate kinase activity. In summary, this study reveals the regulatory mechanisms by which purine biosynthetic pathway enzymes PPAT and PAICS, and pyruvate kinase activity is increased and exposes an existing metabolic vulnerability in lung cancer cells that can be explored for pharmacological intervention.