Abstract : The San Francisco Estuary, in central California, has several long-running monitoring programs that have been used to reveal human-induced changes throughout the estuary in the last century. Here, we pair synoptic records of particulate organic matter (POM) composition from 1990–1996 and 2007–2016 with more robust long-term monitoring program records of total suspended sediment (TSS) concentrations generally starting in the mid-1970s to better understand how POM and TSS sources and transport have shifted. Specifically, POM C:N ratios and stable isotope values were used as indicators of POM source and to separate the bulk POC pool into detrital and phytoplankton components. We found that TSS and POC sources have shifted significantly across the estuary in time and space from declines in terrestrial inputs. Landward freshwater and brackish water sites, in the Delta and near Suisun Bay, witnessed long-term declines in TSS (32 to 52%), while seaward sites, near San Pablo Bay, recorded recent increases in TSS (16 to 121%) that began to trend downwards at the end of the record considered. Bulk POM C:N ratios shifted coeval with the TSS concentration changes at nearly all sites, with mean declines of 12 to 27% between 1990–1996 and 2007–2016. The widespread declines in bulk POM C:N ratios and inferred changes in POC concentrations from TSS trends, along with the substantial declines in upstream TSS supply through time (56%), suggest measurable reductions in terrestrial inputs to the system. Changes in terrestrial TSS and POM inputs have implications for biotic (e.g., food web dynamics) and abiotic organic matter cycling (e.g., burial, export) along the estuarine continuum. This work demonstrates how human-generated environmental changes can propagate spatially and temporally through a large river-estuary system. More broadly, we show how underutilized monitoring program datasets can be paired with existing (and often imperfect) synoptic records to generate new system insight in lieu of new data collection.

Psoriasis is a relevant topic for publication in general medical journals. We conducted a search of the Thomson Reuters’ Science Citation using the search term of “psoriasis” in five high-impact general medical journals. All citation classics from 1970 to 2012 were included and each author’s total number of citations was summated. A total of 51 citation classics were collected. The most common topic of publication was psoriasis treatment (37), especially biologic agents (16). A total of 1037 authors of psoriasis articles were identified in our study and the top 25 most-cited authors were compiled. We hope our citation analysis provides a historical perspective and highlights the work of our colleagues and predecessors.

We analyzed trends in the frequency of original publications into common dermatologic topics in two premier European journals, the British Journal of Dermatology and the Journal of the European Academy of Dermatology and Venereology. Most notably, we found that psoriasis publications peaked around the mid-to-late 1980’s as well as demonstrated an upward trend since the 21st century. Skin cancer research witnessed a gradual increase in the frequency of publications since 1970. These findings were consistent with a prior study analyzing trends in two American dermatology journals. We attempted to analyze these results from a historical perspective as well as provide an outlook on the future of research into these common dermatologic topics.

Schwannomatosis is a distinct syndrome characterized by multiple peripheral nerve schwannomas that can be sporadic or familial in nature. Cases affecting the lower cranial nerves are infrequent. Here, the authors present a rare case of schwannomatosis affecting the left spinal accessory nerve. Upon genetic screening, an in-frame insertion at codon p.R177 of the Sox 10 gene was observed. There were no identifiable alterations in NF1, NF2, LZTR1, and SMARCB1. This case demonstrates a rare clinical presentation of schwannomatosis in addition to a genetic aberration that has not been previously reported in this disease context.

Aged ovariectomized (OVX) female monkeys, a model for menopause in humans, show a decline in spine density in the dorsolateral prefrontal cortex (dlPFC) and diminished performance in cognitive tasks requiring this brain region. Previous studies in our laboratory have shown that long-term cyclic treatment with 17β-estradiol (E) produces an increase in spine density and in the proportion of thinner spines in layer III pyramidal neurons in the dlPFC of both young and aged OVX rhesus monkeys. Here we used 3D reconstruction of Lucifer yellow-loaded neurons to investigate whether clinically relevant schedules of hormone therapy would produce similar changes in prefrontal cortical neuronal morphology as long-term cyclic E treatment in young female monkeys. We found that continuously delivered E, with or without a cyclic progesterone treatment, did not alter spine density or morphology in the dlPFC of young adult OVX rhesus monkeys. We also found that the increased density of thinner spines evident in the dlPFC 24h after E administration in the context of long-term cyclic E therapy is no longer detectable 20days after E treatment. When compared with the results of our previously published investigations, our results suggest that cyclic fluctuations in serum E levels may cause corresponding fluctuations in the density of thin spines in the dlPFC. By contrast, continuous administration of E does not support sustained increases in thin spine density. Physiological fluctuations in E concentration may be necessary to maintain the morphological sensitivity of the dlPFC to E.

Introduction  There are many reported modifications to the retrosigmoid approach including variations in skin incisions, soft tissue dissection, bone removal/replacement, and closure. Objective  The aim of this study was to report the technical nuances developed by two senior skull base surgeons for retrosigmoid craniectomy with reconstruction and provide anatomic dissections, surgical video, and outcomes. Methods  The regional soft tissue and bony anatomy as well as the steps for our retrosigmoid craniectomy were recorded with photographs, anatomic dissections, and video. Records from 2017 to 2019 were reviewed to determine the incidence of complications after the authors began using the described approach. Results  Dissections of the relevant soft tissue, vascular, and bony structures were performed. Key surgical steps are (1) a retroauricular C-shaped skin incision, (2) developing a skin and subgaleal tissue flap of equal thickness above the fascia over the temporalis and sub-occipital muscles, (3) creation of subperiosteal soft tissue planes over the top of the mastoid and along the superior nuchal line to expose the suboccipital region, (4) closure of the craniectomy defect with in-lay titanium mesh and overlay hydroxyapatite cranioplasty, and (5) reapproximation of the soft tissue edges during closure. Complications in 40 cases were pseudomeningocele requiring shunt ( n  = 3, 7.5%), wound infection ( n  = 1, 2.5%), and aseptic meningitis ( n  = 1, 2.5%). There were no incisional cerebrospinal fluid leaks. Conclusion  The relevant regional anatomy and a revised technique for retrosigmoid craniectomy with reconstruction have been presented with acceptable results. Readers can consider this technique when using the retrosigmoid approach for pathology in the cerebellopontine angle.

Background Posterior fossa craniotomies can be complicated by cerebrospinal fluid (CSF) leaks, infection, meningitis, neurologic deficits, and intracranial hypotension caused by defective closure of the dura. Secondary dural closures such as pericranial graft, muscle graft, glue, sealants, or fat graft are used. However, there have been few studies examining the use of sealants with a polyethylene glycol and polyethylenimine component. Objective We studied the effect of one such sealant, Adherus® (HyperBranch Medical Technology, Durham, NC, USA), as an adjunct to secondary closure methods in the reduction of the use of abdominal fat grafting and lumbar puncture/drains. Methods We retrospectively reviewed the surgical records of all patients undergoing posterior fossa cranial surgery during a two-year period at a tertiary university affiliated medical center. Results Overall, data a total of 122 patients (62 in the no Adherus and 60 in the Adherus group) were collected. There was no statistically significant difference in the 30-day incisional CSF leak rate (4.1% vs. 6.5%; p=0.183), 30-day non-incisional CSF leak rate (11.3% vs. 5.0%; p=0.205), and 30-day pseudomeningocele rate (16.1% vs. 13.3%; p=0.663) in the no Adherus and Adherus groups, respectively. However, there was a significant reduction in the use of abdominal fat grafting (0% vs. 30.7%; p<0.001) and intraoperative CSF diversion techniques (58.1% vs. 23.3%; p<0.001). Every instance of the use of Adherus saved on average, $809.36. Conclusions A statistically significant reduction in the use of CSF shunting procedures during posterior fossa craniotomy/craniectomy was achieved after the introduction of Adherus with no increase in CSF leak rate.

Purpose

Rigid occipitocervical (O-C) instrumentation can reduce the anterior pathology and has a high fusion rate in children with craniovertebral instability. Typically, axis (C2) screw fixation utilizes C1-C2 transarticular screws or C2 pars screws. However, anatomic variation may preclude these screw types due to the size of fixation elements or by placing the vertebral artery at risk for injury. Pediatric C2 translaminar screw fixation has low risk of vertebral artery injury and may be used when the anatomy is otherwise unsuitable for C1-C2 transarticular screws or C2 pars screws.

Methods

We retrospectively reviewed a neurosurgical database at UCSF Benioff Children's Hospital Oakland for patients who had undergone a cervical spinal fusion that utilized translaminar screws for occipitocervical instrumentation between 2002 and 2020. We then reviewed the operative records to determine the parameters of C2 screw fixations performed. Demographic and all other relevant clinical data were then recorded.

Results

Twenty-five patients ranging from 2 to 18 years of age underwent O-C fusion, with a total of 43 translaminar screws at C2 placed. Twenty-three patients were fused (92%) after initial surgery with a mean follow-up of 43 months. Two patients, both with Down syndrome, had a nonunion. Another 2 patients had a superficial wound dehiscence that required wound revision. One patient died of unknown cause 7 months after surgery. One patient developed an adjacent-level kyphosis.

Conclusion

When performing occipitocervical instrumentation in the pediatric population, C2 translaminar screw fixation is an effective option to other methods of C2 screw fixation dependent on anatomic feasibility.