Stress, anxiety, and illness perception in patients experiencing delay in operative care due to the COVID-19 pandemic

Background

Amid the height of the COVID-19 pandemic in the US, the US Surgeon General ordered hospitals and healthcare systems to stop all elective surgical procedures. The aim of our study was to evaluate the additional mental health impact of surgical delay on patients awaiting surgery for benign, pre-malignant and malignant conditions within the context of the COVID-19 pandemic.

Study design

All patients over the age of 18 awaiting surgery for benign, pre-malignant or malignant conditions within the gynecologic oncology, surgical oncology and colorectal services across Northwell Health were eligible for participation. Upon successful enrollment, participants completed a baseline questionnaire consisting of the Generalized Anxiety Disorder Questionnaire, the Penn State Worry Questionnaire, and Brief-Illness Patient Questionnaire.

Results

The surgical delay was considered moderately to extremely concerning by 72 % of survey respondents, with one third indicating the highest (10/10) level of concern. Fifty-five percent of patients with a pre-operatively suspected/confirmed cancer or pre-malignant condition demonstrated mild to severe anxiety in their completion of the GAD-7 scale. The average time awaiting surgery was 117 days (range 8-292); and 63 % of respondents indicated that the delay had a moderate to severe impact on their daily life.

Conclusions

Patients awaiting surgery for confirmed, suspected or pre-malignant conditions expressed decreased sense of control and increased levels of distress compared to patients awaiting procedures for benign conditions (p < 0.05, 95 % CI [-2.65, -0.08]). Future research will focus on the effects of COVID-19 related delays in operative care on clinical outcomes, including cancer morbidity and mortality.

Abstract 2511: Autologous patient-derived organoid-immune cell co-culture platform for therapeutic discovery in high-grade endometrial cancer

Endometrial cancer is the most common gynecologic malignancy with increasing incidence and mortality rates. Recurrent endometrial cancers, which are mostly from high-grade endometrial cancers (HGEC), have limited treatment options and display extremely poor response rates upon chemotherapies, thus showing very poor prognosis. Immunotherapy revolutionized the field of cancer medicine, but the lack of scalable and sustainable pre-clinical models for HGEC poses a significant challenge in studying critical immunological aspects of HGEC. We therefore established a comprehensive endometrial cancer biobank comprising primary tissues, patient-derived organoids (PDO), and their matching immune cells from all existing HGEC types, enabling us to establish an autologous interaction between cancer and immune cells in vitro. The inactivation of antigen processing and presentation (APP) pathways is one of the major mechanisms for immune evasion in many cancer types including HGEC. Using a subset of our biobank, we performed bulk RNA-seq on 11 normal-cancer PDO pairs and found that genes involved in APP pathways are downregulated in HGEC organoids. qPCR assays confirmed that Major Histocompatibility Complexes (MHCs) are downregulated in HGEC organoids. The suppression of MHC expression could be reverted by external stimuli such as IFNg and Tazemetostat, an EZH2 inhibitor. We then assessed the effects of enhanced MHC-I and -II expression mediated by the two molecules on cancer-immune cell interactions by setting up organoid-immune cell co-cultures using autologous PBMC, CD4, and CD8 T cells. Our data show that HGEC organoids that were pre-treated with IFNg or Tazemetostat display a greater immune cell co-localization and immune cell-mediated apoptosis during the co-culture period. Using our co-culture platform, we next evaluated the efficacy of different immunotherapeutic modalities such as NK cell transfer, bi-specific T-cell engagers, and CAR-T cells on HGEC. Our proof-of-principle experiments demonstrate the utility of our co-culture system in studying the autologous cancer-immune cell interactions from the same patient ex vivo. Our sustainable and scalable testing platform could be used to assess the safety and efficacy of current therapeutics or to identify new therapeutics that enhance immune responses against advanced cancers lacking effective treatment options such as HGEC.

Citation Format: Charlie Chung, Aaron Nizam, Brian Yueh, Santhilal Subhash, Onur Eskiocak, Marina Frimer, Gary L. Goldberg, Semir Beyaz. Autologous patient-derived organoid-immune cell co-culture platform for therapeutic discovery in high-grade endometrial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2511.

Establishing patient-derived organoids from human endometrial cancer and normal endometrium

Endometrial cancer is the most common gynecologic malignancy in the United States and is one of the few malignancies that had an increasing incidence and mortality rate over the last 10 years. Current research models fail to recapitulate actual characteristics of the tumor that are necessary for the proper understanding and treatment of this heterogenous disease. Patient-derived organoids provide a durable and versatile culture system that can capture patient-specific characteristics such as the mutational profile and response to therapy of the primary tumor. Here we describe the methods for establishing, expansion and banking of endometrial cancer organoids to develop a living biobank. Samples of both endometrial tumor tissue and matched normal endometrium were collected from 10 patients. The tissue was digested into single cells and then cultured in optimized media to establish matched patient endometrial cancer and normal endometrial tissue organoids. Organoids were created from all major endometrial cancer histologic subtypes. These organoids are passaged long term, banked and can be utilized for downstream histological and genomic characterization as well as functional assays such as assessing the response to therapeutic drugs.

Organoid models for high-grade endometrial cancer to dissect tumor immune microenvironments

Inactivation of antigen processing and presentation (APP) pathways is one of the major mechanisms for immune evasion in many cancer types including high-grade endometrial cancer (HGEC). Impairments in APP pathways may contribute to the low immunotherapy response rate among the patients. However, lack of pre-clinical models for HGEC poses a significant challenge in studying critical therapeutic aspects of the cancer such as cancer-immune cell interactions. To our knowledge, we have established the largest endometrial biobank comprising primary tissues, patient-derived organoids (PDO), and their matching immune cells from all existing endometrial cancer types, enabling us to establish the interaction between cancer and immune cells in vitro.

Using a subset of our biobank, we performed RNA-seq on 68 PDOs and found that genes involved in APP pathways are downregulated in HGEC organoids compared to their matching normal pairs. We found that MHC-I and -II could be upregulated by IFNg and Tazemetostat, an EZH2 inhibitor. We further assessed the effects of enhanced MHC-I and -II expression mediated by the two molecules on cancer-immune cell interactions by setting up syngeneic organoid-immune cell co-cultures. We found that HGEC organoids that were pre-treated with IFNg or Tazemetostat displayed a greater immune cell co-localization and immune cell-mediated apoptosis during the co-culture period.

Our proof-of-principle experiments demonstrate the utility of our co-culture system in studying the cancer-immune cell interactions in vitro. Our system could be used to test the efficacy of current therapeutics or to screen potential drugs which enhance immune responses against HGEC, which lacks effective treatment options.

This research was supported by grants from The Mark Foundation for Cancer Research (20-028-EDV630), NCI CancerCenter Support Grant (5P30CA045508),and CSHL-northwell transitional research fund.

Is minimally invasive surgery for clinical stage I uterine carcinosarcoma safe?

Minimally invasive surgery (MIS) has been a mainstay of the surgical management of uterine cancer since the mid-2000s. We aim to determine the role and safety of MIS in women with uterine carcinosarcoma (UCS). An Institutional Review Board-approved study identified all patients with UCS between January 2011 and December 2017 at our institution. Demographic and outcome measures were abstracted from the medical records and tumor registry. Cox proportional hazard models, log rank tests, and comparisons of means were used to calculate significance (p < 0.05). 129 women with UCS were identified during the study period. 62 cases (48%) were open procedures and 67 cases (52%) were MIS with the majority of the MIS group having robotic surgery. 55% of the patients had pathological stage 1 disease. Thirty-eight percent of UCS tumors were heterologous. 93% of patients received adjuvant therapy in the form of chemotherapy and/or radiation therapy. There was no difference in the recurrence-free survival (RFS) or overall survival (OS) between the open surgery and the MIS groups as well as between the heterologous and homologous UCS groups (p > 0.05). UCS represents a rare and aggressive subtype of endometrial cancer. Our data suggest that MIS is a safe surgical approach for staging in women with UCS.

Clinical Implications of Genomic Loss of Heterozygosity in Endometrial Carcinoma

PURPOSE

Homologous recombination deficiency, identified by homologous recombination deficiency gene alterations or high percentage of genome-wide loss of heterozygosity (gLOH), is associated with improved prognosis, platinum sensitivity (PS), and poly (ADP-ribose) polymerase inhibitor response in high-grade ovarian cancer. Since the copy number-high (CN-H) endometrial cancer molecular subtype (EC-MS) shares molecular features with high-grade ovarian cancer, our aim was to assign EC-MS on the basis of comprehensive genomic profiling (CGP) results and evaluate the gLOH status with clinical behavior of EC.

METHODS

Eighty-two epithelial EC tumor tissues were sequenced by hybrid capture-based CGP, and results were used to assign EC-MS (ultramutated, microsatellite instability-high, CN-low; CN-high). Retrospective chart review established clinical characteristics, including PS. Relationships of PS, EC-MS, gene alterations, and gLOH were assessed statistically.

RESULTS

PS and EC-MS of CN-H showed statistically significant difference in overall survival (OS). Most notably, when the CN-H EC-MS was subcategorized by gLOH status, there was a significant difference in OS with gLOH-H being associated with longer survival. Cox semi-proportional hazard modeling showed that gLOH, stage, and race were significant in modeling OS.

CONCLUSION

The method of assigning EC-MS by CGP demonstrates similar clinical features to previous reports of EC-MS assigned by other methods. CGP can also assess gLOH status with gLOH-H most commonly seen in CN-H tumors. CN-H, gLOH-H patients showed significantly improved OS (hazard ratio, 0.100 [0.02-0.51 95% CI]). Thus, gLOH status may be a meaningful prognostic biomarker within the CN-H tumors and possibly across EC-MS.

Nosocomial COVID-19 infection in women undergoing elective cesarean delivery: a prospective cohort study

BACKGROUND

The COVID-19 pandemic placed obstetricians in a difficult position of continuing to perform elective cesarean delivery without the knowledge of the risk of the spread of nosocomial infection of the COVID-19 virus.

OBJECTIVE

This study aimed to determine the nosocomial infection rate in women undergoing elective cesarean delivery at 2 academic institutions.

STUDY DESIGN

This nonrandomized prospective cohort trial evaluated patients undergoing elective cesarean delivery during the reopening phase of the COVID-19 pandemic in the state of New York at 2 large volume labor and delivery units. Eligible patients with a negative preoperative reverse transcriptase-polymerase chain reaction test and immunoglobulin G antibody test for COVID-19 were retested 6 to 9 days after discharge. The primary objective was the COVID-19 test conversion rate defined as a positive polymerase chain reaction test for SARS-CoV-2 after discharge with a negative preoperative test. This was used as a proxy for the nosocomial infection rate.

RESULTS

A total of 136 patients were screened for participation. Of these patients, 2 tested positive for COVID-19 on preoperative testing, and 25 declined to participate. Overall, 111 patients consented to participate, and 96 patients underwent both preoperative and postoperative testing. No patient with a negative polymerase chain reaction test preoperatively, had a positive polymerase chain reaction test for the COVID-19 virus postoperatively.

CONCLUSION

With strict and methodical perioperative and postpartum protocols, we can limit nosocomial COVID-19 infection in women undergoing elective cesarean delivery.

Abstract LB236: Utilizing endometrial tumor organoids to model cancer immunomodulation

Endometrial cancer is the most common gynecologic malignancy in the United States. Most women present with early stage disease and have a favorable prognosis. However, the treatment options for recurrent endometrial cancer is limited. Immunotherapy has become increasingly popular in the treatment of recurrent endometrial cancer. A hallmark of malignant cells is immune-evasion at both the genetic level and in the tumor microenvironment. We hypothesized that an endometrial cancer organoid model could be utilized to study the tumor immune microenvironment.

Major Histocompatibility Complex (MHC) is a protein receptor recognized with its antigen by immune cells to screen either non-self or tumorous cells. It has a crucial role in eliminating non-self cells, such as cancer cells. We first assessed the genes involved in the regulation of MHC I and II in cultured normal and tumor organoids. RNA-Sequencing of fifty-six patients from our living organoid biobank were analyzed and we found an immunologic cluster of high-grade endometrial cancers that display significant downregulation in both MHC I and II. This was confirmed with real time-PCR which showed that high-grade cancers organoids had downregulated MHC I and II compare to organoids derived from low-grade cancer tissues and benign tissues. We next sought to demonstrate that both normal and endometrial cancer organoids retain the ability to present external antigen by using DQ-Ovalbumin. We demonstrated that endometrial organoids retain the ability to present antigen, but cancer organoids display reduced efficiency in the antigen processing. Next, we stimulated endometrial cancer organoids with interferon-gamma (IFNg), a well known cytokine for enhancing immunological response, to increase the expression of MHC I and II in cancer organoids. IFNg led to a 2-6 fold increase in MHC expression in low-grade cancer organoids, but a 5-40 fold increase in expression in high-grade cancer organoids utilizing real time-PCR. Finally, we implement the organoid-immune cell co-culture system with patient-derived organoids and CD8+ cytotoxic T-Cells in the allogeneic and syngeneic settings. Endometrial cancer organoids and matched patient-derived cytotoxic T-Cells were co-cultured for 48 hours and imaged for 16 hours. Both migratory effect and tumor killing effect were compared. As expected, in the allogeneic setting CD8+ T-Cells efficiently colocalized and killed cancer cells in the vehicle and IFNg stimulated groups. In the syngeneic setting, CD8+ T-Cells did not colocalize or kill cancer cells in the vehicle, whereas they significantly colocalized and killed cancer cells when stimulated with IFNg.

Our data demonstrate that high-grade endometrial cancer cells downregulate MHC I and II, suggesting that they can evade the host immune system. We also showed that this effect is patient-specific and can be overcome by stimulating with interferon-gamma. Furthermore, we demonstrated that increasing MHC I and II among cancer organoids enhances the target cell recognition and apoptosis induction by CD8+ T-cells. Collectively, our finding offers an approach to study the tumor microenvironment that can be individualized for each patient through the use of patient-derived cancer organoids. This technology can be further developed to study targeted therapies and provides a much needed pre-clinical model for the study of endometrial cancer.

Citation Format: Aaron Nizam, Charlie Chung, Gary L. Goldberg, Semir Beyaz. Utilizing endometrial tumor organoids to model cancer immunomodulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB236.

Association of clinical factors and recent anticancer therapy with COVID-19 severity among patients with cancer: a report from the COVID-19 and Cancer Consortium

BACKGROUND

Patients with cancer may be at high risk of adverse outcomes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We analyzed a cohort of patients with cancer and coronavirus 2019 (COVID-19) reported to the COVID-19 and Cancer Consortium (CCC19) to identify prognostic clinical factors, including laboratory measurements and anticancer therapies.

PATIENTS AND METHODS

Patients with active or historical cancer and a laboratory-confirmed SARS-CoV-2 diagnosis recorded between 17 March and 18 November 2020 were included. The primary outcome was COVID-19 severity measured on an ordinal scale (uncomplicated, hospitalized, admitted to intensive care unit, mechanically ventilated, died within 30 days). Multivariable regression models included demographics, cancer status, anticancer therapy and timing, COVID-19-directed therapies, and laboratory measurements (among hospitalized patients).

RESULTS

A total of 4966 patients were included (median age 66 years, 51% female, 50% non-Hispanic white); 2872 (58%) were hospitalized and 695 (14%) died; 61% had cancer that was present, diagnosed, or treated within the year prior to COVID-19 diagnosis. Older age, male sex, obesity, cardiovascular and pulmonary comorbidities, renal disease, diabetes mellitus, non-Hispanic black race, Hispanic ethnicity, worse Eastern Cooperative Oncology Group performance status, recent cytotoxic chemotherapy, and hematologic malignancy were associated with higher COVID-19 severity. Among hospitalized patients, low or high absolute lymphocyte count; high absolute neutrophil count; low platelet count; abnormal creatinine; troponin; lactate dehydrogenase; and C-reactive protein were associated with higher COVID-19 severity. Patients diagnosed early in the COVID-19 pandemic (January-April 2020) had worse outcomes than those diagnosed later. Specific anticancer therapies (e.g. R-CHOP, platinum combined with etoposide, and DNA methyltransferase inhibitors) were associated with high 30-day all-cause mortality.

CONCLUSIONS

Clinical factors (e.g. older age, hematological malignancy, recent chemotherapy) and laboratory measurements were associated with poor outcomes among patients with cancer and COVID-19. Although further studies are needed, caution may be required in utilizing particular anticancer therapies.

CLINICAL TRIAL IDENTIFIER

NCT04354701.

Anti-NMDA receptor encephalitis with neurologic sequelae refractory to conservative therapy with complete response to adjuvant therapy

•

The presence of Anti-NMDA receptor encephalitis has rarely been described in patients with an immature teratoma.

•

Neurologic symptoms in this case were refractory to standard surgical resection and initial immunotherapy.

•

Systemic chemotherapy caused a complete response in neurologic symptoms.

•

Early detection of lesions and treatment can significantly improve long-term sequelae of Anti-NMDA receptor encephalitis.

Background

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis has been described in increasing frequency in association with benign, mature ovarian teratoma. Affected patients typically present with paraneoplastic limbic encephalitis with flu-like symptoms followed by altered mental status, acute psychiatric symptoms, seizures and amnesia. These symptoms can rapidly progressive if not treated aggressively with surgical resection. Profound neurological symptoms may require immunotherapy.

Case

We present a case of anti-NMDA receptor encephalitis associated with a malignant immature teratoma in which symptoms were refractory to surgical management and initial immunotherapy. A complete neurologic response was only seen after initiating adjuvant chemotherapy.

Conclusion

Anti-NMDA receptor encephalitis has rarely been described with immature ovarian teratomas. In these cases, a complete response may not be observed until systemic chemotherapy is started.

Overall Survival and Adjuvant Therapy in Women with Ovarian Carcinosarcoma: A Single-Institution Experience

BACKGROUND

Carcinosarcoma of the ovary (CSO) is a rare and aggressive variant of ovarian cancer. Due to the rare nature of the disease there is insufficient evidence to make recommendations regarding standard management and overall prognosis.

METHODS

An Institutional Review Board-approved study identified all our patients with CSO between January 2011 and May 2018. Demographic and outcome measures were abstracted from the medical records and tumor board files. Cox proportional hazard models, log rank tests, and comparisons of means were used to calculate significance (p < 0.05).

RESULTS

27 women with CSO were identified. The median age at diagnosis was 65 years (range 48-91). Five women (18%) presented with early stage disease (Stage I or II) and 22 patients (82%) presented with late stage III or IV disease. Twenty patients (74%) received intravenous platinum-based combination chemotherapy. Seven patients did not receive chemotherapy during their treatment course. The median overall survival was 23 months (range 2-68 months). Overall survival was not significantly worsened by the stage of disease at diagnosis. There was no difference in survival based on the age at diagnosis, tobacco status or ethnicity (p > 0.05).

CONCLUSION

This is one of the largest single institution experiences with CSO. The majority of our patients presented with advanced stage disease and received adjuvant platinum-based chemotherapy after cytoreductive surgery. The median overall survival of 23 months was not affected by the stage of the disease. The optimal management of this rare disease needs further study with collaborative, prospective multi-institutional trials.

Recurrence, death, and secondary malignancy after ovarian conservation for young women with early-stage low-grade endometrial cancer

OBJECTIVE

To examine the association between ovarian conservation and oncologic outcome in surgically-treated young women with early-stage, low-grade endometrial cancer.

METHODS

This multicenter retrospective study examined women aged <50 with stage I grade 1-2 endometrioid endometrial cancer who underwent primary surgery with hysterectomy from 2000 to 2014 (US cohort n = 1196, and Japan cohort n = 495). Recurrence patterns, survival, and the presence of a metachronous secondary malignancy were assessed based on ovarian conservation versus oophorectomy.

RESULTS

During the study period, the ovarian conservation rate significantly increased in the US cohort from 5.4% to 16.4% (P = 0.020) whereas the rate was unchanged in the Japan cohort (6.3-8.7%, P = 0.787). In the US cohort, ovarian conservation was not associated with disease-free survival (hazard ratio [HR] 0.829, 95% confidence interval [CI] 0.188-3.663, P = 0.805), overall survival (HR not estimated, P = 0.981), or metachronous secondary malignancy (HR 1.787, 95% CI 0.603-5.295, P = 0.295). In the Japan cohort, ovarian conservation was associated with decreased disease-free survival (HR 5.214, 95% CI 1.557-17.464, P = 0.007) and an increased risk of a metachronous secondary malignancy, particularly ovarian cancer (HR 7.119, 95% CI 1.349-37.554, P = 0.021), but was not associated with overall survival (HR not estimated, P = 0.987). Ovarian recurrence or metachronous secondary ovarian cancer occurred after a median time of 5.9 years, and all cases were salvaged.

CONCLUSION

Our study suggests that adoption of ovarian conservation in young women with early-stage low-grade endometrial cancer varies by population. Ovarian conservation for young women with early-stage, low-grade endometrial cancer may be potentially associated with increased risks of ovarian recurrence or metachronous secondary ovarian cancer in certain populations; nevertheless, ovarian conservation did not negatively impact overall survival.

Abstract TP148: The Hydration Influence on the Risk of Ischemic Stroke Outcomes (THIRST-EXPANSION STUDY)

Introduction: Extensive studies have not been done in patients presenting with ischemic stroke regarding hydration status. It is unclear whether all of the elements of hydration status affect disability on discharge. Our past study suggests that high serum osmolality has a negative impact on ischemic stroke severity. This continuation of our prior study aims to test the effect of all laboratory elements of dehydration on severity and outcome of ischemic stroke patients.

Methods: We conducted a retrospective analysis of ischemic stroke patients admitted between 2004 and 2009 at a community teaching hospital. Serum BUN/Creatinine and serum osmolality (sOsm) was calculated at initial presentation. sOSm, BUN/Cr, hematocrit and bicarbonate levels were analyzed for association with NIHSS and mRS. Patients were divided into two groups by sOsm as follows: (1) sOsm < 295, (2) sOsm ≥ 295; and two groups by BUN/Cr as follows: (3) BUN/Cr < 20, (4) BUN/Cr ≥ 20. Discharge mRS score was compared between (1) and (2); and (3) and (4) to determine the effect of sOsm and BUN/Cr on stroke outcomes. All data was analyzed using SPSS software version 20.

Results: Of 1350 patients, 543 (mean age = 72.5 +/-14.2, 56% female) were included. There was a significant difference between the mean admission NIHSS in (1) 8.57, n = 222 and (2) 7.09, n = 319, p < .05 and between (3) 8.90, n = 219 and (4) 6.87, n = 322, p < .05. There was a significant difference in the mean mRS score between (1) 2.92, n = 222 and (2) 2.54, n = 317, p < .05, and (3) 2.92, n = 218 and (4) 2.56, n = 321, p < .05. The same results were found when comparing discharge sOsm values to predict patient outcome. Discharge sOsm correlated with mRS (r = .147, p < .05). Initial BUN/Cr correlated with NIHSS (r = .128, p < .05) and mRS (r = .107, p < .05) and final BUN/Cr with mRS (r = .161, p < .001). Bicarbonate levels at admission correlated with NIHSS at admission (r = -0.134), p < 0.05. Hematocrit levels at discharge correlated with mRS (r= -0.183), p <0.001.

Conclusion: Our study suggests that patients with BUN/Cr and sOsm above normal levels at admission and dishcarge have worse outcome at discharge. We also found a correlation between other laboratory variables of dehydration status, namely hematocrit levels and outcome. A future prospective randomized study is warranted.

Abstract TP285: Serum Potassium Levels Influence Ischemic Stroke Outcome

Introduction: In cardiac literature hypokalemia has been shown to be assoicated with poor outcomes. It remains unclear whether specific electrolytes, namely potassium, influence stroke outcomes. Our goal in this retrospective study was to test whether the serum electrolyte level at admission and discharge is related to NIHSS and discharge mRS.

Methods: We conducted a retrospective analysis of ischemic patients admitted to Neuro-ICU between December 2004 and December 2009 at a community teaching hospital. Patient electrolyte levels were documented at admission and discharge as well as discharge mRS. Patients were then divided into groups based on their admission potassium levels as follows: hypokalemic patients (K+ less than 3.5), normokalemic patients (K+ 3.5-5.0), and hyperkalemic patients (K+ greater than 5) and their means were compared in respect to discharge mRS using SPSS software version 20.

Results: Of 1350 patients, 543 (mean age = 72.5 +/- 14.2, 56% female) were included. Mean potassium level at admission and discharge were 4.31+/- 0.77 mEq/L and 4.12 +/- 0.50 mEq/L, respectively. There was a significant difference between admission and discharge potassium levels, p <0.001. Hypokalemic patients had a significantly higher mRS score than normokalemic patients, p < .05 at admission (p < 0.05) and at discharge (p < 0.05). Hypokalemic patients had a significantly higher NIHSS than normokalemic patients, p < .05. Hypokalemic patients of age ≥ 65 at admission (p <0.05) and at discharge (p < 0.05) had a significantly higher mRS than normokalemic patients. This effect was not seen in patients < 65 years of age.

Conclusion: Our study suggests that patients with serum potassium levels below normal levels initially and at discharge have worse outcomes , especially in elderly patients. A larger prospective study is warranted to study the effect of endogenous potassium in long term outcomes of patients with ischemic stroke.

Isoeccentric locations are not equivalent: the extent of the vertical meridian asymmetry

Performance in visual tasks is limited by the low-level mechanisms that sample the visual field. It is well documented that contrast sensitivity and spatial resolution decrease as a function of eccentricity and that those factors impair performance in "higher level" tasks, such as visual search. Performance also varies consistently at isoeccentric locations in the visual field. Specifically, at a fixed eccentricity, performance is better along the horizontal meridian than the vertical meridian, and along the lower than the upper vertical meridian. Whether these asymmetries in visual performance fields are confined to the vertical meridian or extend across the whole upper versus lower visual hemifield has been a matter of debate. Here, we measure the extent of the upper versus lower asymmetry. Results reveal that this asymmetry is most pronounced at the vertical meridian and that it decreases gradually as the angular distance (polar angle) from the vertical meridian increases, with eccentricity held constant. Beyond 30° of polar angle from the vertical meridian, the upper to lower asymmetry is no longer reliable. Thus, the vertical meridian is uniquely asymmetric and uniquely insensitive. This pattern of results is consistent with early anatomical properties of the visual system and reflects constraints that are critical to our understanding of visual information processing.

Speech disorders in operated cleft lip and palate children in Northeast Malaysia

The aim of this study was to determine the prevalence and association of speech disorders among operated cleft lip and palate children (CLP) in Northeast Malaysia. A comparative cross sectional study was performed on 98 operated CLP and 109 non-cleft subjects that aged between 3- 12-years-old. Data collection was done clinically and also by recording speech samples of each subject from both groups using a portable cassette recorder. Results showed that the prevalence of speech abnormality was 61.2% (95% CI: 51.41-71.04) and the risk of having speech abnormality was 174.5 times (95% CI: 23.04, 1320.67; P value < 0.001) in CLP children compared to non-cleft children. Therefore it was found that children with appropriately repaired CLP in Northeast Malaysia failed to have normal speech.

A comparative study of osseointegration phenomenon in coated and non-coated NiTi implants in a rabbit model

There was a significant increased in Absolute Contact Length measurements of endosteal bone growth along the Nickel-Titanium (NiTi) implant coated with the natural coral powder and Hydroxyapatite (HA) compared to the non-calcium coated implants. This study demonstrated that coated implants seemed to show earlier and higher osseointergration phenomena compared to non coated ones. Furthermore, there was significantly greater bone-to-implant contact at the apical 1/3rd of the coated implants.

Tensile strength and water absorption of alumina filled poly (methyl methacrylate) denture base material

The aim of this study was to evaluate the tensile properties and water absorption of denture base material prepared from high molecular weight poly methyl methacrylate (PMMA) and alumina (Al2O3) as particulate filler. Specimens for mechanical testing were prepared by adding composite powder to the monomer followed by hand mixing as in dental laboratory procedure. The tensile strength of the prepared denture base material was slightly higher than commercial denture base material, while the water absorption was almost the same for all formulation of denture base materials.

Locally produced bovine bone sponge as a haemostatic agent

The aim of this study was to evaluate the morphological and biological properties of a locally produced "Bovine Bone Sponge" for use in dentistry. Bovine bone sponge was prepared from local calf bone. Endotoxin level and surface properties were investigated. The pore size and water uptake ability were measured and results were compared with the commercial haemostatic agent. The material was tested for its haemostatic property and its inhibition of alveolar bone resorption in a sheep model following dental extraction. Results revealed a significant difference in haemostatic effect, and a shorter bleeding time and a lower rate of alveolar bone resorption in bovine bone sponge compare to a commercial haemostatic agent.

Effect of powder to liquid ratio on tensile strength and glass transition temperature of alumina filled poly methyl methacrylate (PMMA) denture base material

The aim of this study was to evaluate the mechanical properties and glass transition temperature (Tg) of a denture base material prepared from high molecular weight poly methyl methacrylate (PMMA) and alumina (Al2O3). The glass transition temperature was studied by using differential scanning calorimetry (DSC). The effect of powder-to-liquid ratio was investigated. The result showed that the tensile properties and the Tg were slightly effected by the powder-to-liquid ratio. The ratio of 2.2:1 by weight of powder to liquid was found to be the best ratio for mixing the material to give the best result in this formulation.

Mechanical and thermal properties of hydroxyaptite filled poly (methyl methacrylate) heat processed denture base material

The aim of this study was to evaluate the effect of powder-to-liquid ratio on the glass transition temperature (Tg) and the tensile properties of denture base material prepared from poly (methyl methacrylate) (PMMA) and hydroxyapatite (HA) previously treated with 3-trimethoxysilylpropyl methacrylate (gamma-MPS). Specimens for mechanical testing were prepared by adding composites powder (PMMA, BPO and HA) to the monomer (MMA and EGDMA) followed by hand mixing as in dental laboratory description usage. The glass transition temperature was studied by using differential scanning calorimetry (DSC). It was observed that the tensile properties and the Tg were affected by the powder-to-liquid ratio. The mechanical characterization of the materials were performed by using single edge notch-tension (SEN-T) specimens; the fracture toughness was slightly higher in formulation which contained HA filler compared to commercial denture base material.

Age and sequence of eruption of permanent teeth in Kelantan, North-eastern Malaysia

The aim of this study was to determine the age and sequence of eruption of permanent teeth, as well as gender differences, in children and adolescents in Kelantan, Malaysia. Cross-sectional data on permanent teeth eruption were collected by examining pre-school, primary and secondary school children of 5-17 years of age. The subjects were drawn by multistage random sampling from the school registers. There were 2,382 subjects in the sample, 1,062 boys and 1,320 girls. The data were subjected to probit regression analysis. The mean age of eruption of lower first molar was 6.0 (95%CI: 5.8, 6.2) years. The median age of eruption of each tooth was earlier in girls than in boys. Although the range of years during which the permanent teeth erupted was similar in both sexes, i.e. 6-12 years, the sequence of the tooth eruption differed. All mandibular teeth, with the exception of first and second premolars in both males and females, tended to erupt earlier than their maxillary counterparts. The findings seem to correspond to earlier studies done in the other parts of the world.

Estimation of the efficacy of live, attenuated influenza vaccine from a two-year, multi-center vaccine trial: implications for influenza epidemic control

The authors provide an analysis of data from a two-year (1996-1998), multicenter (ten US cities), double-blinded, placebo-controlled influenza vaccine trial in children. The vaccine was the trivalent cold-adapted influenza vaccine. Estimates are made of the vaccine efficacy for susceptibility to culture-confirmed influenza (VE(S)) while taking inter-center variability in the risk of infection into account. Our overall estimate of VE(S) against influenza is 0.92 (95% confidence interval (CI) 0.89-0.94). In addition, for the second year, although the vaccine contained antigen for A/Wuhan-like (H3N2), the estimated VE(S) for epidemic variant A/Sydney-like (H3N2) was 0.89 (95% CI 0.81-0.94). Thus, the vaccine showed a high degree of protection against a variant not closely matched to the vaccine antigen. With regard to natural immunity, an influenza A infection in the first year reduces the estimated risk of an influenza A infection in the second year by a factor of 0.88 (95% CI 0.21-0.98). When comparing year 1 to year 2, there is a negative correlation of -0.50 in the center-specific attack rates in the placebo groups. This is consistent with the theory that natural immunity provides overall community protection to children. The authors argue that mass vaccination of 70% of the children with the cold-adapted influenza vaccine could provide substantial protection to the community at large.

Estimation of vaccine efficacy in the presence of waning: application to cholera vaccines

The authors present a nonparametric method for estimating vaccine efficacy as a smooth function of time from vaccine trials. Use of the method requires a minimum of assumptions. Estimation is based on the smoothed case hazard rate ratio comparing the vaccinated with the unvaccinated. The estimation procedure allows investigators to assess time-varying changes in vaccine-induced protection, such as those produced by waning and boosting. The authors use the method to reanalyze data from a vaccine trial of two cholera vaccines in rural Bangladesh. This analysis reveals the differential protection and waning effects for the vaccines as a function of biotype and age.

Age-related Refractive Shifts in Simple Myopia

BACKGROUND

An understanding of physiologic age-related shifts in myopic refractive errors is important to the refractive surgeon for the interpretation of long-term results, surgical planning, and patient counseling. This study characterizes the refractive stability of adult simple myopia with a retrospective study of 413 eyes.

METHODS

Approximately 74,000 patient records were analyzed to identify 208 adults with -1.00 to -6.00 diopters (D) of myopia who were followed for more than 20 years at the Spokane Eye Clinic. Amounts of myopic shift (increase in myopia) and hyperopic shift (decrease in myopia) were identified and analyzed within the population. The results were compared to long-term studies of radial keratotomy.

RESULTS

The mean changes per patient age decade were: 20s, -0.60 D; 30s, -0.39 D; 40s, -0.29 D; 50s, +0.28 D; 60s, +0.41 D. Reanalyzed Prospective Evaluation of Radial Keratotomy (PERK) study 10-year postoperative data demonstrated progressively increasing hyperopic shifts per decade, at least to age 50.

CONCLUSION

The normal adult population with simple myopia differs from the general population and consists of a population subgroup that is relatively stable and other subgroups that experience significant refractive shift. The hyperopic shift after radial keratotomy appears to be surgically induced and may be larger than previously thought.

Morning-to-evening change in refraction, corneal curvature, and visual acuity 11 years after radial keratotomy in the prospective evaluation of radial keratotomy study. The PERK Study Group

PURPOSE

Previous reports demonstrate morning-to-evening changes in ophthalmic measurements at 3 months, 1 year, and 4 years after radial keratotomy. The authors determine whether diurnal change in refractive error persists 11 years after radial keratotomy surgery in the Prospective Evaluation of Radial Keratotomy (PERK) study.

METHODS

Seventy-one patients were examined in the morning and evening a mean of 11.1 +/- 0.6 years (range, 10-12.7 years) after undergoing radial keratotomy under a standardized protocol using a diamond blade.

RESULTS

Between the morning and evening examinations, the mean change in the spherical equivalent of refraction was a 0.31 +/- 0.58-diopter (D) increase in minus power in first eyes. Thirty-six (51%) eyes had an increase in minus power of the manifest refraction of 0.50 to 1.62 D; 22 (31%) had a change in refractive cylinder power of 0.50 to 1.25 D; 9 (13%) had a decrease in uncorrected visual acuity of two to seven Snellen lines; and 25 (35%) showed central corneal steepening measured by keratometry of 0.50 to 1.94 D. Two (3%) eyes lost two lines of spectacle-corrected visual acuity, whereas one (1%) eye gained two lines. In patients whose both eyes underwent surgery, a high degree of symmetry was observed in morning-to-evening refractive change.

CONCLUSION

In some patients after radial keratotomy, morning-to-evening change of refraction and visual acuity persists for at least 11 years, although in most patients the magnitude of this change is small. Thus, diurnal fluctuation may be a permanent sequela of radial keratotomy in some individuals.

Stability of refraction and visual acuity during 5 years in eyes with simple myopia. The PERK Study Group

BACKGROUND

Normal ranges of variability of refraction and visual acuity in adult myopic eyes are needed as a reference standard for assessing the stability of refractive corneal surgery.

METHODS

We measured the changes in spectacle-corrected visual acuity and cycloplegic refraction during 5 years for the unoperated eye of 82 patients aged 21 to 57 years in the Prospective Evaluation of Radial Keratotomy Study. The changes were compared for contact lens and non-contact lens wearers. We also compared the 5-year cycloplegic and manifest refractions for these unoperated eyes.

RESULTS

Of 77 eyes, 44% gained or lost one Snellen line and 48% experienced no change in spectacle-corrected visual acuity between baseline and 5 years. Only one eye (1%) lost two lines, and 7% gained two lines. The refractive change was less than 1.00 D for 84% of the 37 non-contact lens wearing eyes. Only 13% became more myopic by at least 1.00 D (maximum increase in myopia, 2.00 D), and 3% became less myopic by 1.00 D. Of 45 contact lens wearing eyes, 38% became more myopic by at least 1.00 D. The 5-year manifest refraction was 0.50 D to 1.50 D more myopic than the cycloplegic refraction for 37% of eyes.

CONCLUSIONS

We recommend using two or more Snellen lines as the standard for a meaningful change in spectacle-corrected visual acuity in operated eyes, and 1.00 D as a meaningful cutoff for stability of refraction. The wearing of contact lenses can confound the results of stability studies. The difference between the cycloplegic and manifest refractions suggests that the cycloplegic refraction should be used in planning for refractive surgery.