Clinical Evidence for the Benefits of Neoadjuvant Chemotherapy and Immunotherapy in Colon Cancer: A Concise Review

Neoadjuvant chemotherapy (NAC) has long been considered technically difficult in locally advanced colon cancer (LACC). However, the introduction of oxaliplatin-based regimens led to a growing interest in NAC for patients with LACC. Several cohort studies showed that NAC was safe and reduced the rate of incomplete resection in patients with LACC. This was followed by the pivotal phase III FOxTROT trials, which showed significant benefits of NAC in this population. However, in patients with deficient mismatch repair (dMMR), the response to a neoadjuvant fluoropyrimidine regimen may be poor, limiting the benefit of NAC in this subset of patients. Neoadjuvant immunotherapy is a potential alternative for NAC in LACC patients with dMMR. In this concise review, we present the published clinical evidence evaluating the efficacy and safety of NAC and/or neoadjuvant immunotherapy in patients with LACC. Overall, the evidence suggests that NAC can be associated with significant downstaging and tumor regression, which facilitate surgical resection. However, the impact of NAC on long-term survival is still under investigation. Despite the promising results of NAC in LACC, several concerns still exist that necessitate further evidence. On the other hand, LACC patients with dMMR can benefit from neoadjuvant immunotherapy; however, further trials are still needed to confirm its effectiveness, as well as biomarkers that can predict response.

Opioid stewardship and perioperative management of pediatric tympanoplasty

OBJECTIVE

To provide insight into the intraoperative management, admission course, pain management, and graft success of microscope- and endoscope-assisted tympanoplasty.

STUDY DESIGN

Retrospective Chart Review.

METHODS

This study included children 18 years and younger who underwent ambulatory tympanoplasty at a tertiary pediatric hospital between January 2018 and December 2020. Medical records were reviewed and information about intraoperative factors, surgical approach, laterality, complications, and post-operative perforation closure success rates was collected. Multivariate analysis was performed to compare and contrast the two surgical approaches.

RESULTS

The review included 321 pediatric patients who underwent a tympanoplasty. Endoscopic tympanoplasty accounted for 17.4%, while microscopic tympanoplasty accounted for 82.6%. In both approaches, the rate of intraoperative complications, postoperative complications, audiological improvements, and perforation closure success rates were statistically similar. However, patients who underwent endoscopic tympanoplasty were 3.96 times less likely to require opioids in the post-anesthesia care unit (PACU) and had a shorter post-operative admission length. This pattern emerged regardless of the type of graft used. Obtaining an autograft was not associated with a higher opioid requirement in the PACU.

CONCLUSION

While both approaches are viable, our findings demonstrate the reduced need for opioids with similar success rates following an endoscopic tympanoplasty. Ultimately, the trade-off for the minimally invasive endoscopic approach appears to be a less painful experience for the child while promoting clinically appropriate opioid stewardship in the perioperative setting.

Locally Advanced Lung Cancer

Consolidation immunotherapy after concurrent chemoradiation has improved five-year survival rates in unresectable, locally advanced lung cancer, but disease progression and treatment personalization remain challenges. New treatment approaches with concurrent immunotherapy and consolidative novel agents are being investigated and show promising efficacy data, but at the risk of additive toxicity. Patients with PD-L1 negative tumors, oncogenic driver mutations, intolerable toxicity, or limited performance status continue to require innovative therapies. This review summarizes historical data that galvanized new research efforts, as well as ongoing clinical trials that address the challenges of current therapeutic approaches for unresectable, locally advanced lung cancer.

Incidence and Risk Factors Associated with Respiratory Compromise in Planned PICU Admissions Following Tonsillectomy

OBJECTIVES

Review the incidence and factors associated with respiratory compromise requiring intensive care unit level interventions in children with planned admission to the pediatric intensive care unit (PICU) following tonsillectomy or adenotonsillectomy (T/AT).

STUDY DESIGN

Retrospective cohort study.

METHODS

Review of all patients with PICU admissions following T/AT from 2015 to 2020 at a tertiary care pediatric hospital. Patient demographics, underlying comorbidities, operative data, and respiratory complications during PICU admission were extracted.

RESULTS

Seven hundred and seventy-two patients were admitted to the PICU following T/AT, age 6.1 ± 4.6 years. All children were diagnosed with obstructive sleep apnea or sleep-disordered breathing (mean pre-operative apnea-hypopnea index 29 ± 26.5 and O2 nadir 77.1% ± 11.1). Neuromuscular disease, enteral feed dependence, and obesity were common findings (N = 240 (31%), N = 106 (14%), and N = 209 (27%) respectively). Overall, 29 patients (3.7%) developed respiratory compromise requiring PICU-level support, defined as new-onset continuous or bilevel positive airway pressure support (n = 25) or reintubation (n = 9). Three patients were diagnosed with pulmonary edema. Multivariable regression analysis demonstrated pre-operative oxygen nadir and enteral feed dependence were associated with respiratory compromise (OR = 0.97, 95% CI 0.94-0.99, P = .04; OR = 6.3, 95% CI 2.36-52.6, P = .001 respectively).

CONCLUSIONS

Our study found respiratory compromise in 3.7% of patients with planned PICU admissions following T/AT. Oxygen nadir and enteral feeds were associated with higher respiratory compromise rates. Attention should be given to these factors in planning for post-operative disposition.

Disparities in Healthcare: Evaluation of Equity in Access to Surveillance Colonoscopy After Hemicolectomy in Patients With Colon Cancer During the COVID-19 Pandemic

Introduction: Surveillance colonoscopy is rcommended for patients with colon cancer who obtain a hemicolectomy for tumor resection. Guidelines from many organizations require this colonoscopy to be performed within one year after resection. The objective of this study was to evaluate the difference in surveillance colonoscopy rates between white people and African Americans who had their colon tumors resected. The second objective was to determine whether the COVID-19 pandemic affected these colonoscopy rates. The study goal was to shed light on the issue of low colonoscopy rates among African Americans with colon cancer after tumor removal by hemicolectomy and on how the pandemic exacerbated this issue.

Methods: A total of 800 patient charts from Brooklyn Methodist Hospital were reviewed. The selected patients had a history of colon cancer and received hemicolectomy in the past. The patients were divided according to race and their expected surveillance colonoscopy dates. One group included patients with an expected one-year follow-up date for colonoscopy after hemicolectomy before the start of the pandemic. Another group included patients with colonoscopies due to be performed during the pandemic. A two-sample proportions test was used to compare the colonoscopy rates before and during the pandemic for African Americans. The two-sample equal variance t-test was used to compare the average distance from the patients' home to hospital between African Americans and whites.

Results: The surveillance colonoscopy rates among African Americans were 54% before and 45% during the pandemic. This difference was significant (p < 0.001). The colonoscopy rates between whites and African Americans differed. The surveillance colonoscopy rates among whites were 97% before and 84% during the pandemic. The distance between the patients' homes and the hospital where the procedure was performed also significantly differed. The average travel distance for whites was 1.33 miles and that for African Americans was 3.98 miles (p < 0.001). A total of 215 of the 416 African American patients included had tumors in the cecum and ascending colon.

Conclusion: A significant difference was observed in the colonoscopy rates for African Americans before and during the pandemic. A substantial difference was found in the colonoscopy rates between whites and African Americans, which increased during the pandemic. The distance from the patients' home to the hospital performing the colonoscopy was twice as far for African Americans than whites in the borough of Brooklyn. These data support the hypothesis that a significant difference in colonoscopy rates exists between African Americans and whites, probably because of a healthcare disparity in access to this procedure. The study objective was to highlight the long-standing issue of low colonoscopy rates in African Americans and how the pandemic further decreased these low rates.

The Development of Therapeutic Radiographers in Imaging and Adaptive Radiotherapy Through Clinical Trial Quality Assurance

AIMS

Adaptive radiotherapy (ART) is an emerging advanced treatment option for bladder cancer patients. Therapeutic radiographers (RTTs) are central to the successful delivery of this treatment. The purpose of this work was to evaluate the image-guided radiotherapy (IGRT) and ART experience of RTTs before participating in the RAIDER trial. A plan of the day (PoD) quality assurance programme was then implemented. Finally, the post-trial experience of RTTs was evaluated, together with the impact of trial quality assurance participation on their routine practice.

MATERIALS AND METHODS

A pre-trial questionnaire to assess the experience of the RTT staff group in IGRT and ART in bladder cancer was sent to each centre. Responses were grouped according to experience. The PoD quality assurance programme was implemented, and the RAIDER trial commenced. During stage 1 of the trial, RTTs reported difficulties in delivering PoD and the quality assurance programme was updated accordingly. A follow-up questionnaire was sent assessing experience in IGRT and ART post-trial. Any changes in routine practice were also recorded.

RESULTS

The experience of RTTs in IGRT and ART pre-trial varied. For centres deemed to have RTTs with more experience, the initial PoD quality assurance programme was streamlined. For RTTs without ART experience, the full quality assurance programme was implemented, of which 508 RTTs completed. The quality assurance programme was updated (as the trial recruited) and it was mandated that at least one representative RTT (regardless of pre-trial experience) participated in the update in real-time. The purpose of the updated quality assurance programme was to provide further support to RTTs in delivering a complex treatment. Engagement with the updated quality assurance programme was high, with RTTs in 24/33 centres participating in the real-time online workshop. All 33 UK centres reported all RTTs reviewed the updated training offline. Post-trial, the RTTs' experience in IGRT and ART was increased.

CONCLUSION

Overall, 508 RTTs undertook the PoD quality assurance programme. There was a high engagement of RTTs in the PoD quality assurance programme and trial. RTTs increased their experience in IGRT and ART and subsequently updated their practice for bladder cancer and other treatment sites.

Curating and translating the evidence about SARS-CoV-2 and COVID-19 for frontline public health and clinical care: The Novel Coronavirus Research Compendium (NCRC)

The public health crisis created by the SARS-CoV-2 pandemic has spurred a deluge of scientific research aimed at informing public health and medical response to the COVID-19 pandemic. However, those working in frontline public health and clinical care had insufficient time to parse the rapidly evolving evidence and use it for decision making. Academics in public health and medicine were well-placed to translate the evidence for use by frontline clinicians and public health practitioners. The Novel Coronavirus Research Compendium (NCRC), a group of >50 faculty and trainees, began in March 2020 with the goal to quickly triage and review the large volume of preprints and peer-reviewed publications on SARS-CoV-2 and COVID-19, and to summarize the most important, novel evidence to inform pandemic response. From April 6, 2020 through January 1, 2021, 54,192 papers and preprints were screened by NCRC teams and 527 were selected for review and uploaded to the NCRC website for public consumption. The majority of papers reviewed were peer-reviewed publications (n=395, 75%), published in 102 journals; 25% (n=132) of papers reviewed were of preprints. The NCRC is a successful model of how academics can support practitioners by translating scientific knowledge into action and help to build capacity among students for this work. This approach could be used for health problems beyond COVID-19, but the effort is resource intensive and may not be sustainable over the long term.

The Indirect Costs of the SARS-CoV-2 Pandemic: A Case of Severe Malaria in Brooklyn

Severe malaria due to the infection of Plasmodium falciparum is a critical infection that may lead to multisystem abnormalities if not promptly and adequately treated. We present a case of severe malaria in a patient recently repatriated from Conakry, Guinea, West Africa, marooned during the recent coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While the direct costs of the SARS-CoV-2 pandemic and its indirect effect on neighboring industries have been analyzed, the indirect costs of other ailments in medicine have yet to be fully established. This case explores the ramifications of the SARS-CoV-2 pandemic on what would otherwise have been routine prophylaxis of malaria in a traveler. Given the pandemic, the healthcare industry has had fundamental changes that have impacted access to healthcare, particularly in the outpatient setting.

Cancer patients and COVID-19: Mortality, serious complications, biomarkers, and ways forward

The SARS-CoV-2 (COVID-19) pandemic has particularly serious consequences for cancer patients, as they are at high risk for severe complications and mortality due to the virus since cancer patients are immunocompromised. Preliminary evidence suggests that patients with hematological, and metastatic malignancies are particularly susceptible to developing severe COVID-19 illness, which leads to poor prognosis. Biomarkers including C-reactive protein and interleukin-6 may be predictors of outcome and, therefore, crucial in assessing COVID-19 illness severity in cancer patients. A patient-specific risk and benefit inventory should be completed, and expert guidelines consulted when deciding to continue or postpone therapeutic interventions. This review presents preliminary evidence of COVID-19 infection and its impact on cancer, as well as discussion of general guidelines for the treatment and management of cancer patients with COVID-19.

Assessment of the threatened carnivore community in the recently expanded rainforest protected area Anjanaharibe-Sud Special Reserve, Madagascar

Madagascar is an island nation renowned for its biodiversity and species endemism, yet it is still largely understudied despite intense anthropogenic threats including forest loss and edge effects. Anjanaharibe-Sud Special Reserve is a recently expanded rainforest protected area that is lacking detailed surveys and assessments of the native carnivore community of the endemic family Eupleridae. To identify which terrestrial carnivores occupy the reserve and what anthropogenic disturbances and factors best explain their occurrence patterns, we deployed 35 motion-activated cameras to detect native and introduced carnivores. From November 2018 to February 2019, we collected 2918 unique capture events (all species) and confirmed the presence of 5 euplerids: Galidia elegans, Galidictis fasciata, Eupleres goudotii, Fossa fossana, and Cryptoprocta ferox. These results extend the known range of E. goudotii and G. fasciata. In the reserve, F. fossana and G. elegans were the most common and widespread native carnivores, while E. goudotii was the rarest. We highlight the negative impact of edge effects on G. fasciata and F. fossana and the threat posed by the free-ranging non-native carnivore C. familiaris. This study represents the first detailed survey and occurrence estimates of the carnivore community of this protected area, allowing comparison with other protected areas in Madagascar. Our empirical findings show that anthropogenic disturbance negatively impacts carnivore existence within the Anjanaharibe-Sud Special Reserve and provide important management recommendations for protecting the carnivore community and the co-occurring wildlife living within this area.

Positive Expiratory Pressure Therapy With And Without Oscillation And Hospital Length Of Stay For Acute Exacerbation Of Chronic Obstructive Pulmonary Disease

Introduction

Pharmacologic management of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is well-established. Our aim in the current study is to determine if therapy with a positive expiratory pressure (PEP) device with or without an oscillatory mechanism (OM) in addition to standard care results in a reduction in hospital length of stay (LOS) among patients hospitalized for AECOPD.

Methods

Two studies were performed and are reported here. Study 1: Patients admitted with AECOPD and sputum production were enrolled in a prospective trial comparing PEP therapy versus Oscillatory PEP (OPEP) therapy. Study 2: A retrospective historical cohort, matched in a 2 to 1 manner by age, gender, and season of admission, was compared with the prospectively collected data to determine the effect of PEP ± OM versus standard care on hospital LOS.

Results

In the prospective trial (Study 1; 91 subjects), median hospital LOS was 3.2 (95% CI 3.0–4.3) days in the OPEP group and 4.8 (95% CI 3.9–6.1) days in the PEP group (p=0.16). In fully adjusted models comparing the prospective trial data with the retrospective cohort (Study 2; 182 subjects), cases had a median hospital LOS of 4.2 days (95% CI 3.8–5.1) versus 5.2 days (95% CI 4.4–6.0) in controls, consistent with a shorter hospital LOS with adjunctive PEP±OM therapy versus standard care (p=0.04).

Conclusion

Adjunctive therapy with a PEP device versus standard care may reduce hospital LOS in patients admitted for AECOPD. Although the addition of an OM component to PEP therapy suggests a further reduction in hospital LOS, comprehensive multicenter randomized controlled trials are needed to confirm these findings.

Clinical trial registration number

NCT03094806.

Ondansetron induced torsades de pointes

A single dose of oral Ondansetron can precipitate torsades de pointes and other arrhythmias in patients with risk factors that may prolong QTc interval.

A Rare Presentation of Biclonal Gammopathy in Multiple Myeloma with Simultaneous Extramedullary Involvement: A Case Report

Multiple myeloma is characterized by an abnormal clone of plasma cell infiltration in the bone marrow and presence of a high level monoclonal immunoglobulin (M-protein) in the serum or urine in most cases. The monoclonal protein is usually detected as a discrete band in the gamma globulin region by serum protein electrophoresis. Rarely, it may show a simultaneous presence of two distinct bands, which could be either from a single clone, or two separate clones. We report a very unusual presentation of biclonality with lambda restricted IgG predominant cells from cervical lymph node and kappa restricted IgA cells from the bone marrow simultaneously.

A Case of Vanishing Metastatic Mass: Right Atrial Mass in the Setting of Primary Epithelioid Hemangioendothelioma of the Spine

Epithelioid hemangioendothelioma (EHE) is a rare low-grade vascular neoplasm that is characterized as intermediate between benign hemangioma and high-grade angiosarcoma affecting 1 in 1,000,000 people worldwide. It has been described throughout the body with lung, liver, skin, and bone being the most frequent sites. Primary EHE of the spine has been reported in 56 cases so far with no correlation of age and sex. Our case highlights a rare clinical presentation, etiopathogenesis, diagnosis, and treatment of EHE of the spine with metastasis to the right atrium. This is the first documented case of EHE of the spine with metastatic spread to the heart treated with bevacizumab leading to resolution of the heart metastatic mass. Further studies are warranted to develop a treatment formula for this rare tumor, to consider combination chemotherapy and new adjuvant targeted immunotherapies to prevent progression of disease.

A proteomic approach for the rapid, multi-informative and reliable identification of blood

Blood evidence is frequently encountered at the scene of violent crimes and can provide valuable intelligence in the forensic investigation of serious offences.

P3-07-42: Lymphovascular Invasion Best Correlates with Presence of Nodal Metastasis in Sentinel Lymph Node Biopsy

Background. Sentinel lymph node biopsy (SLNB) biopsy is routinely practised for axillary staging with 25–30% having positive SLN. Tumour size is the most important parameter taken into consideration in decision making in node negative patients with a size cut off for 4–5cm dependant on different units. Lymphovascular invasion (LVI) and Ki-67 a cell-cycle antigen are known important prognostic markers along with the tumour grade, oestrogen receptor and herceptin receptor status.

Aim. To examine whether lymphovascular invasion, Ki-67 or any other factors can be used as a predictor for axillary lymph node involvement and hence prognosis.

METHODS. A prospective study of 264 patients with invasive breast cancer undergoing SLN biopsy between January 2009 and December 2010.

Histopathology reports were reviewed regarding LVI, Ki-67, grade, oestrogen, Progesterone and Herceptin receptor and SLN status. Stats direct was used to analyse data. Logistic regression was used and p-value calculated.

RESULTS. LVI (p value=0.0001) and size(p value=0.0273) were the two most significant factors associated with node positivity. Grade of tumour had a p-value of 0.0825 and Ki67 had a p-value of 0.5217 which were not significant.

Co-exposure to nickel and cobalt chloride enhances cytotoxicity and oxidative stress in human lung epithelial cells

Nickel and cobalt are heavy metals found in land, water, and air that can enter the body primarily through the respiratory tract and accumulate to toxic levels. Nickel compounds are known to be carcinogenic to humans and animals, while cobalt compounds produce tumors in animals and are probably carcinogenic to humans. People working in industrial and manufacturing settings have an increased risk of exposure to these metals. The cytotoxicity of nickel and cobalt has individually been demonstrated; however, the underlying mechanisms of co-exposure to these heavy metals have not been explored. In this study, we investigated the effect of exposure of H460 human lung epithelial cells to nickel and cobalt, both alone and in combination, on cell survival, apoptotic mechanisms, and the generation of reactive oxygen species and double strand breaks. For simultaneous exposure, cells were exposed to a constant dose of 150 μM cobalt or nickel, which was found to be relatively nontoxic in single exposure experiments. We demonstrated that cells exposed simultaneously to cobalt and nickel exhibit a dose-dependent decrease in survival compared to the cells exposed to a single metal. The decrease in survival was the result of enhanced caspase 3 and 7 activation and cleavage of poly (ADP-ribose) polymerase. Co-exposure increased the production of ROS and the formation of double strand breaks. Pretreatment with N-acetyl cysteine alleviated the toxic responses. Collectively, this study demonstrates that co-exposure to cobalt and nickel is significantly more toxic than single exposure and that toxicity is related to the formation of ROS and DSB.

Gastric emptying of hexose sugars: role of osmolality, molecular structure and the CCK₁ receptor

BACKGROUND

It is widely reported that hexose sugars slow gastric emptying (GE) via osmoreceptor stimulation but this remains uncertain. We evaluated the effects of a panel of hexoses of differing molecular structure, assessing the effects of osmolality, intra-individual reproducibility and the role of the CCK(1) receptor, in the regulation of GE by hexoses.

METHODS

Thirty one healthy non-obese male and female subjects were studied in a series of protocols, using a (13) C-acetate breath test to evaluate GE of varying concentrations of glucose, galactose, fructose and tagatose, with water, NaCl and lactulose as controls. GE was further evaluated following the administration of a CCK(1) receptor antagonist. Three subjects underwent repeated studies to evaluate intra-individual reproducibility.

KEY RESULTS

At 250 mOsmol, a hexose-specific effect was apparent: tagatose slowed GE more potently than water, glucose and fructose (P < 0.05). Fructose (P < 0.05) also slowed GE, but with substantial inter-, but not intra-, individual differences. As osmolality increased further the hexose-specific differences were lost. At 500 mOsmol, all hexoses slowed GE compared with water (P < 0.05), whereas lactulose and saline did not. The slowing of GE by hexose sugars appeared to be CCK(1) receptor-dependent.

CONCLUSIONS & INFERENCES

The effects of hexose sugars on GE appear related to their molecular structure rather than osmolality per se, and are, at least in part, CCK(1) receptor-dependent.

p38 kinase is activated in the Alzheimer's disease brain

The p38 mitogen-activated protein kinase is a stress-activated enzyme responsible for transducing inflammatory signals and initiating apoptosis. In the Alzheimer's disease (AD) brain, increased levels of phosphorylated (active) p38 were detected relative to age-matched normal brain. Intense phospho-p38 immunoreactivity was associated with neuritic plaques, neuropil threads, and neurofibrillary tangle-bearing neurons. The antibody against phosphorylated p38 recognized many of the same structures as an antibody against aberrantly phosphorylated, paired helical filament (PHF) tau, although PHF-positive tau did not cross-react with the phospho-p38 antibody. These findings suggest a neuroinflammatory mechanism in the AD brain, in which aberrant protein phosphorylation affects signal transduction elements, including the p38 kinase cascade, as well as cytoskeletal components.

Determination of water in forages and animal feeds by Karl Fischer titration

Oven methods for determining moisture (volatiles) in forages and other animal feeds are empirical. The moisture concentration obtained depends upon the time and temperature the sample was dried and is influenced by the presence of other volatiles than water. A validated reference method to measure water in forages and animal feeds could be used to evaluate the appropriateness of oven methods for various types of animal feeds and forages. Karl Fischer titration is a well-established method for determining water. However, thorough extraction of water from forages and feeds is a challenge because they often contain cellular structures that release water slowly. Water was successfully extracted into methanol-formamide (50 + 50) by high-speed homogenization and then titrated directly at 50 degrees C with a one-component Karl Fischer reagent based on imidazole. The method is described in detail, results of day-to-day repeatability and laboratory-to-laboratory reproducibility are reported, and preliminary comparison data between oven methods are provided.

N-terminal heterogeneity of parenchymal and cerebrovascular Abeta deposits

The goals of this study were twofold: to determine whether species differences in Abeta N-terminal heterogeneity explain the absence of neuritic plaques in the aged dog and aged bear in contrast to the human; and to compare Abeta N-terminal isoforms in parenchymal vs cerebrovascular Abeta (CVA) deposits in each of the species, and in individuals with Alzheimer disease (AD) vs nondemented individuals. N-terminal heterogeneity can affect the aggregation, toxicity, and stability of Abeta. The human, polar bear, and dog brain share an identical Abeta amino acid sequence. Tissues were immunostained using affinity-purified polyclonal antibodies specific for the L-aspartate residue of Abeta at position one (AbetaN1[D]), D-aspartate at N1 (AbetaN1[rD]), and pyroglutamate at N3 (AbetaN3[pE]) and p3, a peptide beginning with leucine at N17 (AbetaN17[L]). The results demonstrate that each Abeta N-terminal isoform can be present in diffuse plaques and CVA deposits in AD brain, nondemented human, and the examined aged animal models. Though each Abeta N-terminal isoform was present in diffuse plaques, the average amyloid burden of each isoform was highest in AD vs polar bear and dog (beagle) brain. Moreover, the ratio of AbetaN3(pE) (an isoform that is resistant to degradation by most aminopeptidases) vs AbetaN17(L)-x (the potentially nonamyloidogenic p3 fragment) was greatest in the human brain when compared with aged dog or polar bear. Neuritic plaques in AD brain typically immunostained with antibodies against AbetaN1(D) and AbetaN3(pE), but not AbetaN17(L) or AbetaN1(rD). Neuritic deposits in nondemented individuals with atherosclerotic and vascular hypertensive changes could be identified with AbetaN1(D), AbetaN3(pE), and AbetaN1(rD). The presence of AbetaN1(rD) in neuritic plaques in nondemented individuals with atherosclerosis or hypertension, but not in AD, suggests a different evolution of the plaques in the two conditions. AbetaN1(rD) was usually absent in human CVA, except in AD cases with atherosclerotic and vascular hypertensive changes. Together, the results demonstrate that diffuse plaques, neuritic plaques, and CVA deposits are each associated with distinct profiles of Abeta N-terminal isoforms.

Carboxy terminal of beta-amyloid deposits in aged human, canine, and polar bear brains

Immunocytochemistry, using antibodies specific for different carboxy termini of beta-amyloid. A beta 40 and A beta 42(43), was used to compare beta-amyloid deposits in aged animal models to nondemented and demented Alzheimer's disease human cases. Aged beagle dogs exhibit diffuse plaques in the absence of neurofibrillary pathology and the aged polar bear brains contain diffuse plaques and PHF-1-positive neurofibrillary tangles. The brains of nondemented human subjects displayed abundant diffuse plaques, whereas the AD cases had both diffuse and mature (cored) neuritic plaques. Diffuse plaques were positively immunostained with an antibody against A beta 42(43) in all examined species, whereas A beta 40 immunopositive mature plaques were observed only in the human brain. Anti-A beta 40 strongly immunolabeled cerebrovascular beta-amyloid deposits in each of the species examined, although some deposits in the polar bear brain were preferentially labeled with anti-A beta 42(43). beta-amyloid deposition was evident in the outer molecular layer of the dentate gyrus in the aged dog, polar bear, and human. Within this layer, A beta 42 was present as diffuse deposits, although these deposits were morphologically distinct in each of the examined animal models. In dogs, A beta 42 was cloud-like in nature; the polar bear demonstrated a more aggregated type of deposition, and the nondemented human displayed well-defined deposits. Alzheimer's disease cases were most frequently marked by neuritic plaques in this region. Taken together, the data indicate that beta-amyloid deposition in aged mammals is similar to the earliest stages observed in human brain. In each species, A beta 42(43) is the initially deposited isoform in diffuse plaques.

Familial influence on plaque formation in the beagle brain

Aged canines exhibit central neuropathological changes strikingly similar to those seen in patients with Alzheimer's disease. In this study, brain tissue from pure bred beagles raised in a controlled environment were examined for Alzheimer-like pathology. The mean age of the animals was 15.6 years. The incidence of plaques among these 29 dogs was 65.5%. Of the 19 samples that demonstrated Alzheimer-like pathology, 18 were characterized as diffuse and one as neuritic. Plaque density was found to be independent of age. Plaque numbers were highest in the perirhinal cortex and the adjacent temporal cortex. Familial influence on plaque development is supported by congruence within 15 of the 16 litters examined (p < 0.001). In this environmentally controlled group the diffuse plaques were rarely converted to the dense neuritic plaques found in Alzheimer's disease.

Bile acid profiles in peroxisomal 3-oxoacyl-coenzyme A thiolase deficiency

Fast atom bombardment mass spectrometry and gas chromatography-mass spectrometry were used to analyze bile acids in the body fluids of an infant (L.C.) whose liver contained no immunoreactive peroxisomal 3-oxoacyl-CoA thiolase. The profiles were compared with those of six patients with undetectable peroxisomes (Zellweger syndrome) and two siblings (N.B. and I.B.) whose defect of peroxisomal beta-oxidation could not be localized by morphological studies of peroxisomes or by immunoblotting of peroxisomal beta-oxidation proteins. 3 alpha, 7 alpha, 12 alpha-Trihydroxy-5 beta-cholestan-26-oic acid (THCA) was present in bile and plasma of all patients. However, bile from L.C., N.B. and I.B. contained unconjugated varanic acid (3 alpha, 7 alpha, 12 alpha, 24-tetrahydroxy-5 beta-cholestan-26-oic acid) as the major C27 bile acid, whereas bile from Zellweger patients contained only small amounts of varanic acid. In the bile from L.C. two isomers of varanic acid were present; in the bile from N.B. and I.B. a single isomer predominated. L.C., N.B., and I.B. all produced bile containing small amounts of (24E)-3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholest-24-en-26-oic acid [( 24E]-delta 24-THCA), its [24Z]- isomer, 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholest-23-en-26-oic acid and 3 alpha, 7 alpha, 12 alpha-trihydroxy-27-nor-5 beta-cholestan-24-one. The results provide evidence for peroxisomal pathways for cholic acid synthesis in man via THCA, delta 24-THCA and varanic acid and show that bile acid analyses can be used to diagnose peroxisomal thiolase deficiency.