Aggregate-prone brain regions in Parkinson's disease are rich in unique N-terminus α-synuclein conformers with high proteolysis susceptibility.

In Parkinson's disease (PD), and other α-synucleinopathies, α-synuclein (α-Syn) aggregates form a myriad of conformational and truncational variants. Most antibodies used to detect and quantify α-Syn in the human brain target epitopes within the C-terminus (residues 96-140) of the 140 amino acid protein and may fail to capture the diversity of α-Syn variants present in PD. We sought to investigate the heterogeneity of α-Syn conformations and aggregation states in the PD human brain by labelling with multiple antibodies that detect epitopes along the entire length of α-Syn. We used multiplex immunohistochemistry to simultaneously immunolabel tissue sections with antibodies mapping the three structural domains of α-Syn. Discrete epitope-specific immunoreactivities were visualised and quantified in the olfactory bulb, medulla, substantia nigra, hippocampus, entorhinal cortex, middle temporal gyrus, and middle frontal gyrus of ten PD cases, and the middle temporal gyrus of 23 PD, and 24 neurologically normal cases. Distinct Lewy neurite and Lewy body aggregate morphologies were detected across all interrogated regions/cases. Lewy neurites were the most prominent in the olfactory bulb and hippocampus, while the substantia nigra, medulla and cortical regions showed a mixture of Lewy neurites and Lewy bodies. Importantly, unique N-terminus immunoreactivity revealed previously uncharacterised populations of (1) perinuclear, (2) glial (microglial and astrocytic), and (3) neuronal lysosomal α-Syn aggregates. These epitope-specific N-terminus immunoreactive aggregate populations were susceptible to proteolysis via time-dependent proteinase K digestion, suggesting a less stable oligomeric aggregation state. Our identification of unique N-terminus immunoreactive α-Syn aggregates adds to the emerging paradigm that α-Syn pathology is more abundant and complex in human brains with PD than previously realised. Our findings highlight that labelling multiple regions of the α-Syn protein is necessary to investigate the full spectrum of α-Syn pathology and prompt further investigation into the functional role of these N-terminus polymorphs.

PSA-NCAM Regulatory Gene Expression Changes in the Alzheimer's Disease Entorhinal Cortex Revealed with Multiplexed in situ Hybridization.

BACKGROUND: Alzheimer's disease (AD) is the most common form of dementia and is characterized by a substantial reduction of neuroplasticity. Our previous work demonstrated that neurons involved in memory function may lose plasticity because of decreased protein levels of polysialylated neural cell adhesion molecule (PSA-NCAM) in the entorhinal cortex (EC) of the human AD brain, but the cause of this decrease is unclear. OBJECTIVE: To investigate genes involved in PSA-NCAM regulation which may underlie its decrease in the AD EC. METHODS: We subjected neurologically normal and AD human EC sections to multiplexed fluorescent in situ hybridization and immunohistochemistry to investigate genes involved in PSA-NCAM regulation. Gene expression changes were sought to be validated in both human tissue and a mouse model of AD. RESULTS: In the AD EC, a cell population expressing a high level of CALB2 mRNA and a cell population expressing a high level of PST mRNA were both decreased. CALB2 mRNA and protein were not decreased globally, indicating that the decrease in CALB2 was specific to a sub-population of cells. A significant decrease in PST mRNA expression was observed with single-plex in situ hybridization in middle temporal gyrus tissue microarray cores from AD patients, which negatively correlated with tau pathology, hinting at global loss in PST expression across the AD brain. No significant differences in PSA-NCAM or PST protein expression were observed in the MAPT P301S mouse brain at 9 months of age. CONCLUSION: We conclude that PSA-NCAM dysregulation may cause subsequent loss of structural plasticity in AD, and this may result from a loss of PST mRNA expression. Due PSTs involvement in structural plasticity, intervention for AD may be possible by targeting this disrupted plasticity pathway.

Cell Type-Specific Nuclei Markers: The Need for Human Brain Research to Go Nuclear.

Identifying and interrogating cell type-specific populations within the heterogeneous milieu of the human brain is paramount to resolving the processes of normal brain homeostasis and the pathogenesis of neurological disorders. While brain cell type-specific markers are well established, most are localized on cellular membranes or within the cytoplasm, with limited literature describing those found in the nucleus. Due to the complex cytoarchitecture of the human brain, immunohistochemical studies require well-defined cell-specific nuclear markers for more precise and efficient quantification of the cellular populations. Furthermore, efficient nuclear markers are required for cell type-specific purification and transcriptomic interrogation of archived human brain tissue through nuclei isolation-based RNA sequencing. To sate the growing demand for robust cell type-specific nuclear markers, we thought it prudent to comprehensively review the current literature to identify and consolidate a novel series of robust cell type-specific nuclear markers that can assist researchers across a range of neuroscientific disciplines. The following review article collates and discusses several key and prospective cell type-specific nuclei markers for each of the major human brain cell types; it then concludes by discussing the potential applications of cell type-specific nuclear workflows and the power of nuclear-based neuroscientific research.

Three-port laparoscopic cholecystectomy is safe and efficient in the treatment of surgical biliary disease: a retrospective cohort study.

Multiple studies have suggested that three-port laparoscopic cholecystectomy is both feasible and safe. However, this approach has failed to gain acceptance outside of clinical trials, leaving adopters of this approach vulnerable to medico-legal scrutiny. We hypothesized that the three-port approach to laparoscopic cholecystectomy (LC) is safe and efficient in experienced hands. All LC (including robotic) cases were performed on patients 18 years and older between November 2018 and March 2020. Operations utilizing three ports were compared to those performed using more than three ports. The primary outcomes measured were total operative time, conversion-to-open rate, and the complication rate. A two-sample test was performed to compare operative times, and a Fisher's exact test was used to compare conversion-to-open and complication rates. Linear regression models were used to account for the effect of confounders. 924 total LCs were performed by 30 surgeons in the study period (71 three-port, 853 four or more ports). The mean operative time was 10 min shorter in the three-port group in comparison (64.1 ± 1.4 min vs. 74.4 ± 1.8 min, p < 0.01), despite a threefold higher rate of intraoperative cholangiogram in these cases (23.0% vs. 7.9%, p < 0.001). There was no significant difference in either the conversion-to-open rate (1.6% vs. 5.1%, p = 0.35), or the overall complication rate (7.1% vs. 8.7%, p = 0.82). Operative time for LC performed through three ports was significantly less than those performed through the traditional four port approach, despite utilizing intraoperative cholangiogram nearly three times as often. There was no difference in the conversion-to open rate or complication rate. These results provide considerable evidence that three-port laparoscopic cholecystectomy is comparable to four-port laparoscopic cholecystectomy in operative duration, conversion-to-open rate, and complication rate.

Predictors of morbidity in revisional bariatric surgery and bariatric emergencies at an MBSAQIP-accredited community hospital.

INTRODUCTION: Bariatric surgery revisions and emergencies are associated with higher morbidity and mortality compared to primary bariatric surgery. No formal outcome benchmarks exist that distinguish MBSAQIP-accredited centers in the community from unaccredited institutions. METHODS: A retrospective chart review was conducted on 53 bariatric surgery revisions and 61 bariatric surgical emergencies by a single surgeon at a high-volume community hospital accredited program from 2018 to 2020. Primary outcomes were complications or deaths occurring within 30-days of the index procedure. Secondary outcomes included operative time, leaks, surgical site occurrences (SSOs), and deep surgical site infections. RESULTS: There were no significant differences in the demographic characteristics of the study groups. Mean operative time was significantly longer for revisions as compared to emergency operations (149.5 vs. 89.4 min). Emergencies had higher surgical site infection (5.7% vs. 21.3%, p < 0.05) and surgical site occurrence (SSO) (1.9% vs. 29.5%, p < 0.05) rates compared to revisions. Logistic regression analysis identified several factors to be predictive of increased risk of morbidity: pre-operative albumin < 3.5 g/dL (p < 0.05), recent bariatric procedure within the last 30 days (p < 0.05), prior revisional bariatric surgery (p < 0.05), prior duodenal switch (p < 0.05), and pre-operative COPD (p < 0.05). CONCLUSION: Bariatric surgery revisions and emergencies have similar morbidity and mortality, far exceeding those of the primary operation. Outcomes comparable to those reported by urban academic centers can be achieved in community hospital MBSAQIP-accredited centers.

Attending Surgeon Influences Operative Time More Than Resident Level in Laparoscopic Cholecystectomy.

BACKGROUND: Prior studies on laparoscopic cholecystectomy (LC) have concluded that resident involvement lengthens operative time without impacting outcomes. However, the lack of effect of resident level on operative duration has not been explained. We hypothesized that attending-specific influence on average operative time for LC is more pronounced than resident post-graduate year level. MATERIALS AND METHODS: We retrospectively analyzed all LC cases performed on patients 18 y and older between November 2018 and March 2020 at 2 academic medical center-affiliated hospitals. Regression models were used to compare operative times, conversion to open rates, and complication rates by attending surgeon and resident level. RESULTS: Nine hundred twenty-five LCs were performed over the study period, 862 (93.1%) with resident participation. Of the 44.5% variation in operative time was explained by differences in attending surgeon, as compared to 11.0% attributable to differences in resident level (P < 0.0001). This effect persisted after adjusting for patient and disease factors (33.0% versus 7.1%, P < 0.0001). Neither attending surgeon (P = 0.80), nor the level of the involved resident (P = 0.94) demonstrated a significant effect on the conversion-to-open rate (4.9%). Similarly, neither the attending surgeon (P = 0.33), nor resident level (P = 0.81) significantly affected the complication rate (8.58%). CONCLUSIONS: Operative time for LC is primarily determined by patient- and disease-specific factors; resident level has no effect on conversion to open or complication rates. Attending influence on operative time was more pronounced than resident level influence. These findings suggest attending surgeon-related factors are more important than resident experience in determining operative duration for LC.

Non-super-selective venous sampling for persistent hyperparathyroidism using a systemic hypocalcemic challenge.

PURPOSE: To describe a new protocol employing an acute systemic hypocalcemic challenge (SHC) aimed at augmenting the parathyroid hormone (PTH) gradient to enable non-super-selective venous sampling (VS) in patients with persistent primary hyperparathyroidism (PHPT). MATERIALS AND METHODS: In a retrospective study, 37 patients (39 studies-20 SHC, 19 super-selective VS) who underwent VS for persistent or recurrent PHPT were examined. Study patients were pretreated with intravenous hydration, diuretics, and bicarbonate to induce temporary relative hypocalcemia and then underwent non-super-selective VS targeted at large vessels within the neck and chest with rapid PTH testing. The traditional VS protocol involved super-selective VS with arteriography. RESULTS: SHC decreased ionized calcium by 0.098 mmol/L ± 0.18 (P = .07) and increased peripheral PTH by 10.2 pg/mL (P = .58). Positive VS gradients, defined as a ≥ 1.4-fold difference from baseline to after SHC, were detected in 95% of patients. VS findings guided successful surgery in 77% of SHC cases and 90% of super-selective VS cases; the peak gradient site was concordant with operative findings in 46% of SHC cases and 80% of super-selective VS cases. Avoidance of super-selective sampling decreased mean fluoroscopy time from 91 minutes to 33 minutes and decreased contrast material administered from 204 mL to 63 mL (both P < .0001). CONCLUSIONS: The SHC protocol to enable non-super-selective VS in patients with persistent PHPT had the same ability as super-selective VS to detect a positive (≥ 1.4-fold) PTH gradient, was associated with decreased accuracy in identifying the site of the adenoma compared with super-selective VS, and significantly decreased contrast material used and fluoroscopy time.

Surgery for primary hyperparathyroidism: are the consensus guidelines being followed?

OBJECTIVE: To determine parathyroidectomy (PTx) rates in patients who satisfy the consensus guidelines for surgical treatment of primary hyperparathyroidism (PHPT). BACKGROUND: Surgery for PHPT is recommended for all symptomatic patients and select asymptomatic patients meeting established consensus criteria. Adherence to the consensus guidelines has not been examined systematically, because of inadequate information regarding patients managed nonoperatively. METHODS: All nonuremic patients with PHPT during the period 1995-2008 were identified using the Kaiser Permanente-Southern California laboratory database, encompassing 3.5 million individuals annually. Multivariate logistic regression was used to examine predictors of PTx. RESULTS: We found 3388 patients with PHPT, of whom 265 (8%) were symptomatic (nephrolithiasis). Nephrolithiasis was predictive of PTx (OR 2.94 vs asymptomatic), with 51% of symptomatic patients undergoing surgery. Among asymptomatic patients, the proportion meeting consensus criteria was 39% during the early period (1995-2002) and 51% during the late period (2003-2008). The PTx rate for these patients exceeded that for asymptomatic patients not meeting consensus criteria but remained low (early 44% vs 19%, P < 0.0001; late 39% vs 16%, P < 0.0001). The following individual criteria were predictive of PTx: calcium >11.5 mg/dL (OR 2.27), hypercalciuria (OR 3.28, P < 0.0001), and age < 50 years (OR 1.54, P < 0.0001). However, the absolute PTx rates associated with satisfaction of these criteria were in the 50% range. Bone density scores did not influence likelihood of PTx and renal impairment predicted against PTx (OR 0.35, P < 0.0001). CONCLUSIONS: The consensus guidelines regarding PHPT have not been followed in our study population. PTx appears to be underutilized in both asymptomatic and symptomatic patients.

The effect of a dedicated endocrine surgery program on general surgery training: a single institutional experience.

BACKGROUND: The endocrine surgery program was established at the University of California, Los Angeles, in 2006 to enhance the educational experience of surgical residents in this area. The impact of this program on subjective and objective measures of resident education was prospectively tracked. METHODS: Resident case logs, American Board of Surgery In-Training Examination scores, self-assessment surveys, and annual rotation evaluations from July 2005 to June 2009 were reviewed. RESULTS: The mean number of endocrine cases reported by graduates doubled during the study period (from 18 to 36, P < .001). Self-assessment scores increased for thyroid (from 4.53 to 5.76, P = .04) and parathyroid (from 4.46 to 5.90, P = .03) disorders. The mean rating for the endocrine rotation (from 3.23 to 3.95, P = .005) improved, with specific increases in the quantity (from 3.05 to 3.74, P = .02) and quality (from 3.25 to 3.95, P = .002) of operative experience. Since 2006, trainees have coauthored 17 peer-reviewed reports and 3 textbook chapters on endocrine topics. CONCLUSIONS: The establishment of a dedicated endocrine surgery program has a measurable impact on resident education within this core content area.

Population-level predictors of persistent hyperparathyroidism.

BACKGROUND: Systematic study of outcomes of initial surgery for primary hyperparathyroidism (PHPT) has been limited by selection and self-reporting biases. To avoid these biases, we evaluated parathyroidectomy (PTx) outcomes within an integrated health care system encompassing 3.25 million enrollees. METHODS: All patients undergoing PTx for PHPT from 1995 to 2010 were studied. Persistent and recurrent disease were defined by a serum calcium level >10.5 mg/dL before or after 6 months postoperatively, respectively. The effect of demographic, clinical, and hospital volume-related variables was assessed by the use of multivariate logistic regression. RESULTS: A total of 1,190 initial operations for PHPT were performed at 14 hospitals. Follow-up calcium levels were available in 97% of subjects. The overall success rate was 92%, and 5% of patients developed recurrent disease. Age ≥ 70 years was predictive of persistent disease (odds ratio 1.80, P < .05). High-volume hospital (>100 cases) predicted against persistent disease (odds ratio 0.42, P < .05) and carried 96% success rate. Negative or equivocal sestamibi scan was associated with a lower success rate (success rate 89% vs 95% for positive scan, P < .05). Reoperation was performed in 12% of patients with persistent or recurrent PHPT. CONCLUSION: The success rate of PTx is influenced by patient age, hospital volume, and sestamibi scan result. Surgical outcomes may be optimized by designating high-volume centers in the community setting.

Strategic impact of a new academic endocrine surgery program.

BACKGROUND: A minority of medical centers possess a dedicated endocrine surgery program. Here we assess the short-term impact of a new endocrine surgery program on institutional case volumes and financial endpoints. METHODS: We studied all endocrine procedures performed over a 5-year period spanning the inception of the endocrine surgery program at UCLA. Institutional and state-level data on patient geographic origin, discharges for endocrine diagnosis-related groups (DRGs), and hospital-side charges and costs were examined. RESULTS: Total endocrine case volume increased 112% (264 to 559 cases annually) over the study period. The relative increase was greater for parathyroid (56 to 196, 250%, P < 0.0001) and adrenal (11 to 31, 181%, P = 0.06) procedures compared to thyroid procedures (317 to 442, 39%). The endocrine case volume of nonspecialist surgeons remained stable over the study period. Growth in referrals arose from previously unrepresented zip codes and was associated with an increase in the mean distance traveled for care (2006, 44 miles vs. 2009, 92 miles, P < 0.01). In each DRG, UCLA attained the top market position within one year of the program's inception, corresponding to an overall 27% increase in regional market share. Total hospital charges for endocrine DRGs rose 161% to $14.7 million annually, while the cost of parathyroid surgery fell 34% (P < 0.001). CONCLUSIONS: The establishment of an academic endocrine surgery program can cause fundamental shifts in referral patterns within a competitive, densely populated metropolitan environment. Hospitals should consider the inclusion of an endocrine surgery program in strategic planning initiatives.

Coarctation of the aorta presenting as spontaneous subarachnoid haemorrhage in the absence of cerebral aneurysm: a report of a rare clinical entity.

Subarachnoid haemorrhage (SAH) is a common neurologic event characterised by bleeding into the space immediately surrounding the brain. In non-traumatic SAH, the predominant cause is aneurysmal rupture of the cerebral vasculature. A significant number occur in the absence of vascular anomalies. This report describes a case of a 35-year-old male who presented with a subarachnoid haemorrhage in the absence of intracranial aneurysm. Subsequent workup demonstrated severe proximal hypertension due to congenital aortic coarctation as the cause of this event. This case demonstrates the importance of considering congenital abnormalities when evaluating patients with cerebrovascular events in the absence of common aetiologies.

An algorithm informed by the parathyroid hormone level reduces hypocalcemic complications of thyroidectomy.

BACKGROUND: Measurement of the parathyroid hormone (PTH) level following total thyroidectomy (TTx) may allow prediction of postoperative hypocalcemia. We present an algorithmic method of managing hypocalcemia pre-emptively, based on the PTH level 1 h after operation. MATERIALS AND METHODS: We examined 423 consecutive patients undergoing TTx at a single institution. A subset of patients were managed using an algorithm involving routine postoperative oral calcium administration and the early addition of oral calcitriol in patients with a low 1-h postoperative PTH level. Algorithm patients were compared to a concurrent, conventionally managed group. Outcomes measured included serum calcium levels, symptoms of hypocalcemia, postoperative complications, and receipt of intravenous (i.v.) calcium. RESULTS: The algorithm was applied in 135 patients, and 288 patients were managed conventionally. Critically low calcium levels (total calcium <7.5 mg/dl [1.88 mmol/l] or ionized calcium <0.94 mmol/l) were less common in algorithm patients (10.6% vs. 25.3%; p < 0.005). Much of this difference was attributable to the protective impact of the algorithm on patients undergoing TTx for cancer, 30% of whom developed critically low calcium levels when managed conventionally. Among patients requiring i.v. calcium, algorithm patients received fewer doses (1.29 vs. 1.86; p < 0.05). Low 1-h PTH levels were found in 21% (28/133) of algorithm patients, but these did not correlate with low calcium levels, suggesting that the algorithm compensated adequately for temporary hypoparathyroidism. No patients developed hypercalcemia. CONCLUSIONS: An algorithmic approach incorporating early postoperative PTH levels and routine administration of oral calcium reduces the risk of severe hypocalcemia after total thyroidectomy.

Minimal access surgical management of large juvenile polyps in children.

BACKGROUND: Juvenile polyps have a reported incidence of up to 2% in individuals younger than of 18 years. Most polyps are small, occur in the distal colon and rectum, and present with bleeding or prolapse. Giant juvenile polyps have been rarely reported. CASE REPORTS: We encountered 2 unique presentations of very large juvenile polyps in children. A 9-year-old boy presented with recurrent rectal bleeding and anemia because of a single large polyp at the hepatic flexure. A 14-year-old boy presented with abdominal pain secondary to 2 large polyps in the cecum. The polyps were seen on colonoscopy as pedunculated masses larger than 5 cm and were not subjected to biopsy. Both patients underwent laparoscopic colon mobilizations with extracorporeal segmental resection in the first patient and colotomy and polypectomy in the second. Both patients had short hospital stays and excellent outcomes. CONCLUSIONS: Giant juvenile polyps are rare in children and may not be amenable to colonoscopic removal. They can be resected effectively with minimal access surgical techniques.

Cystic pancreatic neoplasm in pregnancy: a case report and review of the literature.

Mucinous cystic neoplasms of the pancreas are rare tumors that tend to occur in young women. They are thought to be responsive to sex hormones. We report a case of a 32-year-old pregnant woman with a 7-month history of pain and a left upper quadrant abdominal mass. She arrived at the emergency department with exacerbation of her symptoms during week 15 of gestation. Findings from ultrasonography and magnetic resonance imaging suggested a pancreatic cyst. Percutaneous aspiration of the cyst fluid yielded mucinous fluid with an elevated carcinoembryonic antigen level. The patient underwent a spleen-preserving distal open pancreatectomy. We present herein a brief review of the current literature on mucinous cystic neoplasms during pregnancy. On the basis of our experience and the existing knowledge of this condition, we advocate resection during the second trimester with splenic preservation.

Splenectomy for trauma increases the rate of early postoperative infections.

Little is known what effect splenectomy for trauma has on early postoperative infectious complications. Our aim was to determine if splenectomy increases early postoperative infections in trauma patients undergoing laparotomy. We reviewed all trauma patients undergoing splenectomy from June 2002 through December 2004. Each splenectomy patient was matched to a unique trauma patient who underwent laparotomy without splenectomy based on age, gender, mechanism of injury, injury severity score, and presence of colon or other hollow visceral injury. Outcomes included infectious complications including pneumonia, urinary tract infection, bacteremia, and intra-abdominal abscess, as well as mortality. There were 98 splenectomy patients and 98 controls. The splenectomy patients had more overall infectious complications (45% vs 30%, P = 0.04) trended toward more urinary tract infections (12% vs 5%, P = 0.12), and more often had pneumonia (30% vs 14%, P = 0.02). Additionally, more splenectomy patients developed multiple infections (20% vs 7%, P = 0.01). There was no difference in mortality (11% vs 8%, P = 0.63). Splenectomy is associated with an increase in infectious complications after laparotomy for trauma. More specifically, splenectomy patients more often develop pneumonia and multiple infections. This increase in infections is not associated with increased mortality.