Leptin-induced decrease in food intake in chickens

The effect of intracerebroventricular (i.c.v.) injection of leptin was investigated using broiler and Single Comb White Leghorn (SCWL)-type chickens. These represent relatively fast- and slow-growing birds, respectively. The i.c.v. injection of leptin decreased food intake in both broilers and Leghorns in a dose-dependent manner. The most efficacious dose appeared to be 10 microg in both types of chickens. Water intake was generally not affected by leptin, indicating that this effect was not due to general malaise. It appears that leptin can act within the central nervous sytstem of birds to decrease food intake.

Enhanced transforming activity of pSV2 plasmids in human cells depends upon the type of damage introduced into the plasmid

When pSV2-gpt or pSV2-neo plasmids are introduced into human cells by calcium phosphate coprecipitation, the yield of stable transformants (Gpt+ or Neo+) is increased by irradiating the respective plasmid DNA in vitro with UV (254 nm). To identify specific lesions that can increase the transforming activity of plasmids in human cells we examined pSV2 plasmids containing different types of damage. Of the lesions tested, cyclobutane pyrimidine dimers produced the greatest increase, and can nearly fully account for the effect of 254 nm UV on transformation. The enhancement of transformation produced by UV was not altered by the additional treatment of the plasmid DNA with T4 endonuclease V, an enzyme that nicks DNA specifically at pyrimidine dimers. Treatment of plasmid DNA with osmium tetroxide to produce thymine glycols, or with acid and heat to produce apurinic sites did not affect transformation frequency. The enhancement occurred in all the human cell lines tested, whether they contained or not sequences homologous to those in the plasmids, and was independent of the repair capacity of the recipient cells.

Pituitary metastases: presentation and outcomes from a pituitary center over the last decade

PURPOSE

Highlight and characterize manifestations, diagnostic/management approaches and outcomes in a contemporary cohort of patients with pituitary metastases (PM) from a large European pituitary center-over 10 years.

METHODS

Retrospective review of PM cases between 1/2009 and 12/2018. Clinical, laboratory, imaging data at PM detection and during follow-up were analysed.

RESULTS

18 cases were identified (14 females; median age at diagnosis 61.5 years). Most common primary malignancies were lung (39%) and breast (32%). Most frequent presenting manifestation was visual dysfunction (50%). Gonadotrophin, ACTH, TSH deficiency were diagnosed in 85%, 67%, 46% of cases, respectively; diabetes insipidus (DI) was present in 17%. 33% of cases were detected during investigation for symptoms unrelated to PM. PM management included radiotherapy (44%), transsphenoidal surgery (17%), transsphenoidal surgery and radiotherapy (6%) or monitoring only (33%). One-year survival was 49% with median survival from PM detection 11 months (range 2-47).

CONCLUSIONS

In our contemporary series, clinical presentation of PM has evolved; we found increased prevalence of anterior hypopituitarism, decreased rates of DI and longer survival compared with older literature. Increased availability of diagnostic imaging, improvements in screening and recognition of pituitary disease and longer survival of patients with metastatic cancer may be contributing factors.

Feeding, drinking, and temperature responses of chickens to intracerebroventricular histamine

The present study examines the effects of intracerebroventricular injections of histamine (HA) and two HA antagonists, the H(1) receptor antagonist chloropheneramine maleate (CM) and the H(2) receptor antagonist cimetidine (CIM), on food and water consumption and body temperature in chickens. Single-Comb White Leghorns (SCWL) and broiler cockerels were utilized for these experiments. The first pair of experiments consisted of intracerebroventricular injections of HA and its effects on food and water consumption. HA was infused at dosages of 0, 25, 50, and 100 microg/10 microl of artificial cerebrospinal fluid (aCSF). HA significantly decreased food and water intake in a dose-dependent manner. The second pair of experiments examined the effects of HA on water intake while birds had no access to feed. Water intake was not significantly affected by intracerebroventricular injections of HA. The next pair of experiments examined the effects of HA on body temperature. In SCWL, body temperature was not affected by HA until 165 min postinjection when HA decreased temperature in a quadratic dose-response with maximum hypothermia being achieved at a dose of 25 microg. In contrast, HA increased body temperature in broilers beginning at 75 min postinjection. In the final series of experiments, the anorexia induced by HA was attenuated in SCWL and broilers with pretreatment of either CM or CIM. These results suggest that HA has an anorexigenic effect in SCWL and broiler cockerels, and this effect is mediated by both H(1) and H(2) receptors. Water intake is not directly affected by the intracerebroventricular injection of HA. Whereas HA increased body temperature in broilers, the response in SCWL is equivocal.

Evaluation of Response to Stereotactic Radiosurgery in Brain Metastases Using Multiparametric Magnetic Resonance Imaging and a Review of the Literature

AIMS

Following stereotactic radiosurgery (SRS), brain metastases initially increase in size in up to a third of cases, suggesting treatment failure. Current imaging using structural magnetic resonance imaging (MRI) cannot differentiate between tumour recurrence and SRS-induced changes, creating difficulties with patient management. Combining multiparametric MRI techniques, which assess tissue physiological and metabolic information, has shown promise in answering this clinical question.

MATERIALS AND METHODS

Multiparametric MRI techniques, including spectroscopy, diffusion and perfusion imaging, were used for the differentiation of radiation-related changes and tumour recurrence after SRS for intracranial metastases in six cases. All patients presented with enlargement of the treated lesion, an increase in perilesional brain oedema and aggravation or appearance of neurological signs and symptoms from 7 to 29 weeks after primary treatment.

RESULTS

Multiparametric imaging helped to differentiate features of tumour progression (n = 4) from radiation-related changes (n = 2). A low apparent diffusion coefficient (ADC) <1000 × 10^-6 mm²/s, high relative cerebral blood volume (rCBV) ratio > 2.1, high choline:creatine (Cho:Cr) ratio > 1.8 suggested tumour recurrence. A high ADC > 1000 × 10^-6 mm²/s, low rCBV ratio < 2.1, Cho:Cr ratio < 1.8 suggested SRS-induced radiation changes. Multiparametric MRI diagnosis was confirmed by histology or radiological and clinical follow-up.

CONCLUSION

Multiparametric MRI was helpful in the early identification of radiation-related changes and tumour recurrence and may be useful for monitoring treatment changes in intracranial neoplasms after SRS treatment.

Feasibility of Dose-escalated Hypofractionated Chemoradiation in Human Papilloma Virus-negative or Smoking-associated Oropharyngeal Cancer

AIMS

Oropharyngeal squamous cell carcinoma (OPSCC) can be divided into favourable and poor prognostic groups by association with human papilloma virus (HPV) and smoking. This study prospectively investigated a dose-intensified schedule in poor/intermediate prognosis OPSCC.

MATERIALS AND METHODS

Patients with p16/HPV-negative or p16-positive N2b OPSCC with a greater than 10 pack-year smoking history were eligible. Patients were planned to receive 64 Gy in 25 fractions with cisplatin. The primary end point was absence of grade 3 mucositis at 3 months.

RESULTS

Fifteen patients were recruited over 14 months. All patients completed a minimum of 2 years of follow-up. All patients completed full-dose radiotherapy within a median treatment time of 32 days (31-35). Grade 3 mucositis was absent in all patients at 3 months. There was one grade 4 toxicity event due to cisplatin (hypokalaemia). Complete response rates at 3 months were 100% and 93% for local disease and lymph nodes, respectively. One patient developed metastatic disease and subsequently died. Overall survival at 2 years was 93% (95% confidence interval 61-99%).

CONCLUSIONS

The schedule of 64 Gy in 25 fractions with concomitant chemotherapy is tolerable in patients with poor and intermediate prognosis OPSCC.

Can radiobiological parameters derived from squamous cell carcinoma of the head and neck be used to predict local control in anal cancer treated with chemoradiation?

OBJECTIVES

Parameters have been derived in head and neck cancer to account for the additional biological effective dose provided by synchronous chemotherapy. The purpose of this study was to establish whether such parameters could be used to predict local control differences in anal cancer.

METHODS

In anal cancer two randomised trials of radiotherapy vs chemoradiotherapy and two trials randomising between different synchronous chemotherapy regimens were identified. To predict differences in local control between the arms of the first two studies, a global value of 9.3 Gy for the chemotherapy biologically effective dose was employed. For the last two trials, values specific to differing chemotherapy schedules were derived. These values were added to the calculated biological effective dose for the radiotherapy component in order to predict local control outcomes in anal cancer trials.

RESULTS

The predicted difference in local control using the global value of 9.3 Gy for the addition of synchronous chemotherapy in the trials of radiotherapy vs radiotherapy and synchronous chemotherapy was 24.6% compared with the observed difference of 21.4%. Using schedule-specific values for the contribution of chemotherapy, the predicted differences in local control in the two trials of differing synchronous chemotherapy schedules were 7.2% and 12% compared with the observed 18% and 0%.

CONCLUSION

The methods initially proposed require modification to result in adequate prediction. If the decreased cisplatin dose intensity employed in anal cancer is modelled, more satisfactory predictions for such trials can be achieved.

ADVANCES IN KNOWLEDGE

This revised modelling may be hypothesis generating.

Improving Equitable Collection and Analysis of PROMIS Global Health Data Over Time Following Spine Surgery: Characterizing Survey Non-Response and Missing Data

BACKGROUND CONTEXT

Patient-reported outcome measures (PROMs), the gold standard for outcome assessment in spine surgery, exhibit variability over time. Incomplete PROM collection, however, introduces non-response bias and limits the generalizability of time-based analyses of outcomes.

PURPOSE

This study compared PROM-respondents and non-respondents in spine surgery to characterize survey non-response and improve equitable patient representation in time series PROM analyses.

STUDY DESIGN

Retrospective Study PATIENT SAMPLE: : Patients undergoing surgery at a large, tertiary care center in the United States between July 2009 and February 2023 for lumbar spinal stenosis without spondylolisthesis (LSS), lumbar spinal stenosis with spondylolisthesis (LSP), or cervical spondylotic myelopathy (CSM).

OUTCOME MEASURES

The primary outcome was completeness of available PROM records, which was defined as having Patient-Reported Outcomes Measurement Information System (PROMIS)-Global Health scores once within two years preoperatively and twice within two years postoperatively.

METHODS

Demographic variables of age, sex, race, marital status, employment, insurance, body mass index (BMI), smoking, and Area Deprivation Index (ADI) were obtained from the electronic medical record. These characteristics were compared by PROM-completeness within each pathology group. Comparative analyses between the PROM-complete and PROM-incomplete patients within each pathology group were conducted using the Satterthwaite t-test for continuous variables, Pearson's chi-square test for categorical variables, and Mann-Whitney U test for ordinal variables. Among patients with complete PROMs, availability of PROMIS-Global Health within two years pre- and postoperatively was plotted in bins of 84- and 168-days width to characterize the distribution of time points represented in PROM data for these patients. To visualize geographic variation in likelihood of representation in time series PROMs analyses, census block-level heatmaps were generated for each pathology group showing predicted probability of PROM-completeness by logistic regression with age, sex, race, marital status, employment status, insurance category, BMI, and smoking status as predictor variables RESULTS: : 4,938 patients (1,751 LSS, 1,711 LSP, 1,476 CSM) were analyzed. PROM-complete patients varied significantly from PROM-incomplete patients in demographic distributions. PROM-complete patients were more likely of White race, married, retired, and less likely to be current smokers. LSS and CSM PROM-complete patients were more likely to have Medicare insurance than PROM-incomplete patients.

CONCLUSION

Patients completing PROMs for spine surgery may differ from those who do not, with greater representation of White race, being married, retiree status, and Medicare insurance among those with complete PROMs. As PROMs are further incorporated into physician evaluation, value-based reimbursement, and predictive analytics for surgical outcomes, understanding survey non-response will be critical for generating equitable, individualized, and informed applications to support healthcare decisions.

Outcomes of Patients With Five or More Brain Metastases Treated With Stereotactic Radiosurgery From 2014 to 2019: A UK Series

AIMS

Treatment with stereotactic radiosurgery/radiotherapy (SRS/SRT) is standard practice in selected patients with small numbers of brain metastases (BMs). It is less accepted in those with ≥5 BMs, due to the lack of a prospective evidence base. While randomised trials are ongoing, we present the experience of a single UK cancer centre in using SRS/SRT for patients with 5 or more BMs without whole brain radiotherapy (WBRT).

MATERIALS AND METHODS

Patients undergoing treatment at a single centre between 2014 and 2019 were prospectively identified. All follow-up imaging was reviewed to identify any evidence of local failure or distant brain progression, which was analysed using a death-censored approach.

RESULTS

A total of N = 88 patients were included, with a median of seven BMs (range: 5-37). Post-SRS/SRT toxicity events occurred in 42%, most commonly reliance on steroids for ≥4 weeks (36% of the cohort). Median survival was 10 months, with median freedom from local failure and distant brain progression of 12 and 8 months, respectively; none of these outcomes differed significantly by the number of BMs. Brain-directed salvage treatment was required after a median of 21 months, and was not significantly associated with the number of BMs.

CONCLUSION

SRS/SRT alone may have a role in the management of selected patients with multiple BMs. Since the number of BMs were not significantly associated with overall survival or disease control, the National Health Service (NHS) commissioning criteria should continue to be based on tumour volume.

Review of mechanisms of expandable spine surgery devices

INTRODUCTION

Expandable devices such as interbody cages, vertebral body reconstruction cages, and intravertebral body expansion devices are frequently utilized in spine surgery. Since the introduction of expandable implants in the early 2000s, the variety of mechanisms that drive expansion and implant materials have steadily increased. By examining expandable devices that have achieved commercial success and exploring emerging innovations, we aim to offer an in-depth evaluation of the different types of expandable cages used in spine surgery and the underlying mechanisms that drive their functionality.

AREAS COVERED

We performed a review of expandable spinal implants and devices by querying the National Library of Medicine MEDLINE database and Google Patents database from 1933 to 2024. Five major types of mechanical jacks that drive expansion were identified: scissor, pneumatic, screw, ratchet, and insertion-expansion.

EXPERT OPINION

We identified a trend of screw jack mechanism being the predominant machinery in vertebral body reconstruction cages and scissor jack mechanism predominating in interbody cages. Pneumatic jacks were most commonly found in kyphoplasty devices. Critically reviewing the mechanisms of expansion and identifying trends among effective and successful cages allows both surgeons and medical device companies to properly identify future areas of development.

The Use of Cranial Aneurysm Clips for Repair of Incidental Lumbar Durotomy: Operative Technique and Case Series

BACKGROUND

Incidental durotomy is a common complication of posterior lumbar spine surgery; however, effective and durable methods for primary repair remain elusive. Multiple existing techniques have previously been reported and extensively described, including sutured repair and the use of nonpenetrating titanium clips. The use of cranial aneurysm clips for primary repair of lumbar durotomy serves as a safe and effective alternative to obtain watertight closure of a dural tear.

METHODS

We performed a retrospective review of patients at a single institution who underwent primary repair of an incidental lumbar durotomy with the use of an aneurysm clip during open posterior lumbar surgery between 2012 and 2023. Patient demographics, operative details, and postoperative metrics were collected and examined to evaluate the safety and efficacy of the novel technique.

RESULTS

A total of 51 patients were included for analysis. Four patients underwent durotomy repair with an aneurysm clip alone, 27 patients were repaired with an aneurysm clip and fibrin glue, and 20 patients underwent repair with an aneurysm clip, fibrin glue, and a collagen dural substitute. Three patients (5.9%) reported headaches: 2 (3.9%) with pseudomeningocele and 1 (2%) with wound leakage. Two patients (3.9%) had treatment failure with a return to the operating room for repair of a cerebrospinal fluid leak.

CONCLUSIONS

To the best of our knowledge, we report the largest series of patients undergoing primary repair of incidental durotomy with the use of an aneurysm clip. Use of an aneurysm clip is noted to be a safe, quick, and effective method of primary repair compared with existing repair techniques such as sutured repair or nonpenetrating titanium clips.

Using Resource Utilization in Spine Healthcare to Complement Patient-Reported Outcome Measurements in Assessing Surgical Success

OBJECTIVE

Patient-reported outcome measures (PROMs) are utilized to assess surgical success but are limited by data collection, response bias, and subjectivity. The large volume of digital healthcare data offers a new method to utilize healthcare utilization as a longitudinal, individualized, and objective proxy for health needs among surgical patients. This study aimed to design and evaluate a novel resource utilization in spine healthcare (RUSH) clustering method that complements PROMs in evaluating postoperative patient outcomes.

METHODS

This retrospective cross-sectional study conducted at a large, tertiary healthcare system included all adult patients undergoing cervical or lumbar surgery between 2014 and 2020 with at least 3 months follow-up. Postoperative healthcare utilization was analyzed using clinic visits, inpatient encounters, telephone encounters, MyChart messages, opioid use, physical therapy, injections, and imaging. Latent profile analysis determined RUSH clusters and changes in PROM Information System Physical Health (PROMIS-PH) scores preoperation and 12-months postoperation.

RESULTS

This study included 5602 surgeries (mean age 61.3 ± 13.1 years, 49.9% female). Four RUSH groups were identified: low utilizers (21.5%), moderate utilizers without advanced imaging (34.7%), moderate utilizers with advanced imaging (10.7%), and high utilizers (33.1%). Utilization patterns varied by surgery type, with lower-utilization patterns among non-fusion procedures and a consistent sub-population of high utilizers across all surgery types. High RUSH utilizers had the lowest pre-operative PROMIS-PH scores and the worst average postoperative change.

CONCLUSIONS

RUSH clustering provides a novel, data-driven approach to measure surgical success, complementing traditional PROMs, and leveraging big data to monitor and respond to surgical outcomes.

Surgical Operations in short-stay Hospitals United States-1968

Out of the universe of 6,965 hospitals, 413 hospitals participated during all or part of the 1968 data year and approximately 210,000 abstracts of sample discharges were received and processed; A detailed description of the sample design, data collection procedures, and the estimation process may be found in appendix I. An estimated 28.1 million inpatients were discharged from the Nation's short-stay hospitals during 1968. Thirty-nine percent of these patients had one or more surgical operations or procedures as defined herein. The highest proportions of patients treated surgically in 1968 were in the Northeast and West Regions. Fifty-one percent of the nonobstetrical inpatients discharged from short-stay hospitals having 300-499 beds had one or more surgical operations. More than one-half of the inpatients under the age of 15 years were treated surgically, with. an average of 1.2 operations per surgical patient in that age group. Only 37 percent of the adult patients (15 and over) had an operation.However, adult patients accounted for 84 percent of the estimated volume of operations and procedures performed for inpatients discharged in 1968.

Tumor markers in non-small cell lung cancer spine metastasis: an assessment of prognosis and overall survival

PURPOSE

The identification of gene mutations in the modern medical workup of metastatic spine tumors has become more common but has not been highly utilized in surgical planning. Potential utility of these genetic markers as surrogates for cancer behavior in current prognosis scoring systems and overall survival (OS) remains underexplored in existing literature. This study seeks to investigate the association of frequently identified tumor markers, EGFR, ALK, and PD-L1, in metastatic non-small cell lung cancer (NSCLC) to the spine with Tokuhashi prognosis scoring and OS.

METHODS

Patients with NSCLC metastasis to spine were identified through chart review. EGFR, ALK, and PD-L1 wild type vs. mutant type were identified from targeted chemotherapy genetic testing. Multiple linear regression was performed to assess gene profile contributions to Tokuhashi score. Cox Proportional Hazards models were generated for each tumor marker to assess the relationship between each marker and OS.

RESULTS

A total of 119 patients with NSCLC spine metastasis were identified. We employed a multiple linear regression analysis to investigate the influence of EGFR, ALK, and PD-L1 genotypes on the Tokuhashi score, revealing statistically significant relationships overall (p = 0.002). Individual genotype contributions include EGFR as a non-significant contributor (p = 0.269) and ALK and PD-L1 as significant contributors (p = 0.037 and p = 0.001 respectively). Overall survival was not significantly associated with tumor marker profiles through Kaplan-Meier analysis (p = 0.46) or by multivariable analysis (p = 0.108).

CONCLUSION

ALK and PD-L1 were significantly associated with Tokuhashi score while EGFR was not. Tumor markers alone were not predictive of OS. These findings indicate that genetic markers found in NSCLC metastases to the spine may demonstrate prognostic value. Therefore, employing standard tumor markers could enhance the identification of appropriate surgical candidates, although they demonstrate limited effectiveness in predicting overall survival.

Exploring tribology and material contact science in spine surgery: implications for implant design

Tribology, an interdisciplinary field concerned with the science of interactions between surfaces in contact and their relative motion, plays a well-established role in the design of orthopedic implants, such as knee and hip replacements. However, its applications in spine surgery have received comparatively less attention in the literature. Understanding tribology is pivotal in elucidating the intricate interactions between metal, polymer, and ceramic components, as well as their interplay with the native human bone. Numerous studies have demonstrated that optimizing tribological factors is key to enhancing the longevity of joints and implants while simultaneously reducing complications and the need for revision surgeries in both arthroplasty and spinal fusion procedures. With an ever-growing and diverse array of spinal implant devices hitting the market for static and dynamic stabilization of the spine, it is important to consider how each of these devices optimizes these parameters and what factors may be inadequately addressed by currently available technology and methods. In this comprehensive review, the authors' objectives were twofold: 1) delineate the unique challenges encountered in spine surgery that could be addressed through optimization of tribological parameters; and 2) summarize current innovations and products within spine surgery that look to optimize tribological parameters and highlight new avenues for implant design and research.

Clinical Outcomes and Relevance of Composite V12 Gy in Patients With Four or More Brain Metastases Treated With Single Fraction Stereotactic Radiosurgery

AIMS

Tissue V12Gy (total brain volume receiving 12Gy including target) can predict for late toxicity in single target benign disease treated with stereotactic radiosurgery (SRS). The value of this metric remains uncertain for multiple brain metastases. This retrospective cohort study reports the outcomes and evaluates the predictors of toxicity in patients with four or more brain metastases treated with single-fraction SRS.

MATERIALS AND METHODS

Two hundred twenty-six patients with 2160 metastases treated from 2014-21 were retrospectively studied. Symptomatic late toxicity (new/progressive neurological symptoms ≥3 months post SRS) with magnetic resonance imaging (MRI) changes suggestive of treatment effect were analysed. Kaplan-Meier and competing risk analysis was used to assess survival and toxicity respectively.

RESULTS

median number of metastases/patient was 6 (range: 4-41) and median composite tissue V12Gy (inclusive of planning target volume (PTV)) was 11.3 cc (IQR: 6.1 cc-17.1 cc). Sixteen out of the 226 patients developed symptomatic late radiation adverse event (R-AE), and the cumulative incidence was 4.9% at 1 year and 6.9% at 2 years. The total target volume was significantly predictive of the risk of late R-AE. Volume of the largest lesion, V12Gy and V15Gy did not predict for late R-AE, but plotted graphs showed suggestions of linear relationships between dosimetric parameters and late R-AE.

CONCLUSION

Within the limitations of this study, the cumulative incidence of symptomatic toxicity remains acceptable despite routinely accepting a composite tissue V12Gy in excess of 10 cc to treat multiple brain metastases.

ADVANCES IN KNOWLEDGE

V12Gy has limitations as a plan quality metric in multiple brain metastases treated with SRS. There is insufficient evidence to have a defined target limit as <10 cc.