Hypernatremia and Its Rate of Correction: The Evidence So Far

Hypernatremia or high serum sodium levels can have many different causes, including insufficient free water intake, or excess free water losses. The management of hypernatremia focuses on resolving the underlying cause, replenishing free water deficit, and preventing further losses while closely monitoring serum sodium concentration. This systematic review was carried out using medical databases such as PubMed, PubMed Central, and Google Scholar for relevant medical literature. The identified articles were reviewed, eligibility criteria were applied, and seven research articles were identified. The effect of the rate of hypernatremia correction on both short- and long-term outcomes in volume-resuscitated patients was the focus of our search for randomized or observational studies. Based on our analysis of the clinical evidence, we concluded that the present recommendations for treating acute and chronic hypernatremia in resuscitated patients do not stem from high-quality research.

SARS-CoV-2 and chronic myeloid leukemia: a systematic review

Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus causing the coronavirus disease of 2019. The disease has caused millions of deaths since the first pandemic at the end of 2019. Immunocompromised individuals are more likely to develop severe infections. Numerous mutations had developed in SARS-CoV-2, resulting in strains (Alfa Beta Delta Omicron) with varying degrees of virulence disease severity. In CML (chronic myeloid leukemia) patients, there is a lot of controversy regarding the effect of the treatment on the patient outcome. Some reports suggested potential better outcomes among patients with CML, likely due to the use of TKI; other reports showed no significant effects. Additionally, it is unknown how much protection immunization provides for cancer patients.

Method

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards, we conducted a systematic review. Retrospective, prospective studies, reviews, case series, and case reports of chronic myeloid leukemia patients aged above 18 years who had SARS-CoV-2 infection were included. English literature was screened using PubMed, SCOPUS, and Google Scholar. Search terms include chronic myeloid leukemia, chronic myelogenous leukemia, and SARS-CoV-2 and Coronavirus disease 2019 (COVID-19). We searched the reference lists of the included studies for any new articles. The search included all articles published up to April 20, 2023. The review is registered in PROSPERO (registration number CRD42022326674).

Results

We reviewed 33 articles of available published literature up to April 2023 and collected data from a total of 682 CML patients with COVID-19. Most patients were in the chronic phase, seven were in the accelerated phase, and eight were in the blast phase. Disease severity was classified according to WHO criteria. Mortality was seen in 45 patients, and there were no reports of thrombotic events. Two hundred seventy-seven patients were in the era before vaccination; among them, eight were in the intensive care unit (ICU), and mortality was 30 (11%). There were 405 patients after the era of vaccination; among them, death was reported in 15 (4%) patients and ICU in 13 patients.

Limitations and conclusion

The major limitation of this review is the lack of details about the use or hold of TKIs during SARS-CoV-2 infection. Additionally, after the appearance of the different variants of the SARS-CoV-2 virus, few studies mentioned the variant of the virus, which makes it difficult to compare the outcome of the other variants of the SARS-CoV-2 virus in patients with CML. Despite the limitations of the study, CML patients with COVID-19 have no significant increase in mortality compared to other hematological malignancy. Hematological cancers are associated with an increased risk of thrombosis, which is expected to increase in patients with COVID-19. However, patient with CML has not been reported to have a significant increase in thrombosis risk. The available data indicates that COVID-19's effect on patients with chronic myeloid leukemia (CML) still needs to be better understood due to the limited data.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php? RecordID:326674.

Unmasking the Silent Threat: Cefepime-Induced Thrombocytopenia

Cefepime, a commonly prescribed fourth-generation cephalosporin, is well-known for its broad-spectrum antibacterial activity. While adverse drug reactions associated with cefepime are well documented, thrombocytopenia as a rare complication has gained attention due to its potential severity. Symptomatic patients present with purpura (bruising), petechiae (small red or purple spots on the skin), and mucosal bleeding. Drug-induced thrombocytopenia can be initiated by myelosuppression by halting platelet formation in the bone marrow or by a drug-induced immune thrombocytopenia reaction. We present a case of a 71-year-old male who experienced thrombocytopenia secondary to cefepime use. We further discussed the underlying mechanisms of cefepime-induced thrombocytopenia, highlighting the need for increased vigilance in monitoring platelet counts during cefepime administration. This case underscores the importance of recognizing and managing this uncommon but potentially life-threatening adverse reaction in clinical practice.

Type II Heparin-Induced Thrombocytopenia: An Underrecognized Cause of Dialysis Catheter Dysfunction - A Case Report

Heparin-induced thrombocytopenia (HIT) is categorized into type 1 and type 2. It causes a decrease in platelet count during or shortly after exposure to heparin. Type 1 is mild and has a non-immune mechanism. Type 2 is a hypercoagulable state resulting from anti-heparin platelet factor 4 (PF4) IgG antibodies. These antibodies cause the activation of endothelium and thrombin generation. Type 2 HIT is complicated by life-threatening thromboembolic events such as deep venous thrombosis, pulmonary embolism, and myocardial infarction. HIT remains an under-recognized cause of dialysis catheter dysfunction and thrombosis. We present a case of a 66-year-old male with recurrent dialysis catheter thrombosis secondary to Type 2 HIT. Avoiding heparin-based dialysis or switching to non-heparin-based anticoagulation or peritoneal dialysis are the possible management strategies for such patients.

Veillonella Bacteremia in a Patient With Metastatic Colorectal Carcinoma

Colorectal carcinoma has increasingly been reported to be associated with gut microbial dysbiosis. Bacteroides, Fusobacterium, Faecalibacterium, Blautia, etc., are gut microbes commonly associated with colorectal carcinoma. Gut microbial dysregulation secondary to infectious, inflammatory, toxin exposure or change in dietary habits coupled with the disruption of the inner mucosal layer overlying the luminal epithelium is hypothesized as the inciting events leading to microbial invasion and subsequent tumorigenesis. Although the precise mechanism is unclear, disruption of normal host responses like inflammation, apoptosis, cellular proliferation, free radical injury, production of oncogenic toxins, etc., is postulated to play a role. We report a case of Veillonella bacteremia in a patient with metastatic colorectal carcinoma without a preceding history of periodontal disease. The patient was managed with ampicillin-sulbactam, which was followed by subsequent negative blood cultures. This case report signifies the association of gut microbiota like Veillonella with colorectal carcinoma and the importance of subsequent screening for colorectal cancer following Veillonella bacteremia.

Amiodarone-Induced Liver Attenuation on CT Scan: Alarming Signal for Toxicity and Prompt Discontinuation

Amiodarone, a class III antiarrhythmic drug, is commonly used for the management of life-threatening ventricular arrhythmias, atrial fibrillation, and other refractory supra-ventricular arrhythmias. Factors like a large volume of distribution, lipophilic property, deposition in tissues in large amounts, etc. have led to the development of amiodarone-induced multisystem adverse events. We report a case of amiodarone-induced hepatic attenuation on computed tomography (CT) of the abdomen in an elderly female patient. Amiodarone with a composition of 40% iodine by weight deposits in the liver, leading to characteristically increased radiodensity reported as increased attenuation on CT scan. Surprisingly, the severity and extent of hepatic attenuation on CT scans do not necessarily correlate with the total exposure to amiodarone over time. Individual factors may influence the liver's response to the drug, leading to varying degrees of hepatic changes. To minimize the risk of adverse events associated with amiodarone, clinicians should carefully adjust the dosage to the lowest effective level and regularly monitor liver function tests in patients. This proactive approach enables early detection of liver dysfunction and facilitates timely adjustments or discontinuation of amiodarone, thereby reducing potential harm.

The Role of Dual Antiplatelet Therapy (DAPT) vs Surgery in a Case of Moyamoya Disease: A Case Report and Review of the Literature

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by non-atherosclerotic and non-inflammatory progressive narrowing of the intracranial part of the carotid artery and its proximal branches. The disease process is commonly associated with the development of weak, dilated collateral blood vessels at the base of the brain. This gives it a classic smoky appearance on cerebral angiograms and hence the name "Moyamoya" which means "puff of smoke" in Japanese. When a patient has similar vasculopathy in the setting of another disease then it is known as Moyamoya syndrome (MMS). The associated diseases are sickle cell anemia, neurofibromatosis, long-standing diabetes, uncontrolled hypertension, or chemotherapy. Despite being known as a disease of the East Asian population, the disease is no longer exclusive to Asians, as evidenced by the rising incidence among non-Asian groups such as Caucasians, Hispanics, and African Americans. Patients can remain asymptomatic or present with ischemic or hemorrhagic stroke, headache, seizures, or recurrent transient ischemic attacks. Conventional cerebral angiography is considered the gold standard for diagnosing MMD. Treatment may be supportive, medical, or surgical. We present the case of a 42-year-old African American woman with several comorbidities who presented with sudden onset of ischemic stroke and upon further workup was found to have MMD. Equally important is to identify the most effective therapeutic approaches based on individual patients to achieve better clinical outcomes. Our case report highlights the importance of surgery in symptomatic MMD with a lack of supporting evidence indicating the benefits of dual antiplatelet therapy (DAPT).

Severe Urine Retention and Deep Vein Thrombosis: A Case Report and Review of the Literature on an Unusual Association

Acute urine retention is the most common urologic emergency, and it usually presents with abdominal pain and an inability to pass urine. The distended bladder in urine retention can be enormously large, raising the intra-abdominal pressure and compressing the iliac veins draining the lower limbs and pelvis. Many cases have been reported to have deep vein thrombosis (DVT)-like features with urine retention that resolves with bladder decompression. In rare cases, urine retention can lead to DVT, particularly in young patients. We report a case of a young female patient with a huge distended bladder who devolved extensive venous thrombosis bilaterally. The report sheds light on this unusual complication of acute urine retention and reviews the existing literature on the topic.

A Case Report of Cannabis Abuse: A Surprising Etiology of Elevated Troponin

Cannabis is the most commonly used additive drug after alcohol and tobacco. There has been literature proving the relationship between cannabis use and elevated troponin from myocardial infarction, with many mechanisms explaining them. However, limited data are available on elevated troponin due to cannabis-induced high myocardial oxygen demand due to vasospasm. We present a case of a 21-year-old female presenting with chest pain after cannabis abuse. She exhibited a steep rise in troponin with a normal electrocardiogram (EKG). She refused a coronary angiogram, but a bedside echocardiogram showed no wall motion abnormality. Therefore, the dramatic rise of troponin levels with the chest pain and the resolution of the symptoms were most likely explained by demand ischemia via the mechanism of reversible vasospasm.

Risk factors for community-acquired bacterial infection among young infants in South Asia: a longitudinal cohort study with nested case-control analysis

OBJECTIVE

Risk factors predisposing infants to community-acquired bacterial infections during the first 2 months of life are poorly understood in South Asia. Identifying risk factors for infection could lead to improved preventive measures and antibiotic stewardship.

METHODS

Five sites in Bangladesh, India and Pakistan enrolled mother-child pairs via population-based pregnancy surveillance by community health workers. Medical, sociodemographic and epidemiological risk factor data were collected. Young infants aged 0-59 days with signs of possible serious bacterial infection (pSBI) and age-matched controls provided blood and respiratory specimens that were analysed by blood culture and real-time PCR. These tests were used to build a Bayesian partial latent class model (PLCM) capable of attributing the probable cause of each infant's infection in the ANISA study. The collected risk factors from all mother-child pairs were classified and analysed against the PLCM using bivariate and stepwise logistic multivariable regression modelling to determine risk factors of probable bacterial infection.

RESULTS

Among 63 114 infants born, 14 655 were assessed and 6022 had signs of pSBI; of these, 81% (4859) provided blood samples for culture, 71% (4216) provided blood samples for quantitative PCR (qPCR) and 86% (5209) provided respiratory qPCR samples. Risk factors associated with bacterial-attributed infections included: low (relative risk (RR) 1.73, 95% credible interval (CrI) 1.42 to 2.11) and very low birth weight (RR 5.77, 95% CrI 3.73 to 8.94), male sex (RR 1.27, 95% CrI 1.07 to 1.52), breathing problems at birth (RR 2.50, 95% CrI 1.96 to 3.18), premature rupture of membranes (PROMs) (RR 1.27, 95% CrI 1.03 to 1.58) and being in the lowest three socioeconomic status quintiles (first RR 1.52, 95% CrI 1.07 to 2.16; second RR 1.41, 95% CrI 1.00 to 1.97; third RR 1.42, 95% CrI 1.01 to 1.99).

CONCLUSION

Distinct risk factors: birth weight, male sex, breathing problems at birth and PROM were significantly associated with the development of bacterial sepsis across South Asian community settings, supporting refined clinical discernment and targeted use of antimicrobials.

Infectious aetiologies of neonatal illness in south Asia classified using WHO definitions: a primary analysis of the ANISA study

Background

Globally, neonatal mortality accounts for almost half of all deaths in children younger than 5 years. Aetiological agents of neonatal infection are difficult to identify because the clinical signs are non-specific. Using data from the Aetiology of Neonatal Infections in south Asia (ANISA) cohort, we aimed to describe the spectrum of infectious aetiologies of acute neonatal illness categorised post-hoc using the 2015 WHO case definitions of critical illness, clinical severe infection, and fast breathing only.

Methods

Eligible infants were aged 0–59 days with possible serious bacterial infection and healthy infants enrolled in the ANISA study in Bangladesh, India, and Pakistan. We applied a partial latent class Bayesian model to estimate the prevalence of 27 pathogens detectable on PCR, pathogens detected by blood culture only, and illness not attributed to any infectious aetiology. Infants with at least one clinical specimen available were included in the analysis. We assessed the prevalence of these aetiologies according to WHO's case definitions of critically ill, clinical severe infection, and infants with late onset, isolated fast breathing. For the clinical severe definition, we compared the prevalence of signs by bacterial versus viral aetiology.

Findings

There were 934 infants (992 episodes) in the critically ill category, 3769 (4000 episodes) in the clinical severe infection category, and 738 (771 episodes) in the late-onset isolated fast breathing category. We estimated the proportion of illness attributable to bacterial infection was 32·7% in infants in the critically ill group, 15·6% in the clinical severe infection group, and 8·8% among infants with late-onset isolated fast breathing group. An infectious aetiology was not identified in 58–82% of infants in these categories. Among 4000 episodes of clinical severe infection, those with bacterial versus viral attribution had higher proportions of hypothermia, movement only when stimulated, convulsions, and poor feeding.

Interpretation

Our modelled results generally support the revised WHO case definitions, although a revision of the most severe case definition could be considered. Clinical criteria do not clearly differentiate between young infants with and without infectious aetiologies. Our results highlight the need for improved point-of-care diagnostics, and further study into neonatal deaths and episodes with no identified aetiology, to ensure antibiotic stewardship and targeted interventions.

Funding

The Bill and Melinda Gates Foundation.

A systematic review and meta- analysis of randomized controlled trials to evaluate the risk of hematological toxicities in patients with cancer treated with poly adenosine diphosphate ribose polymerase (PARP) inhibitors

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Background: Poly adenosine diphosphate ribose polymerase (PARP) inhibitors have shown to benefit in DNA repair-deficient tumors by enhancing synthetic lethality in cancer cells and are currently employed in many solid tumors. Nevertheless, the risk of hematological toxicities remains significant. We performed a systematic review and meta-analysis of randomized controlled trials (RCT) to determine the risk of hematological toxicities. Methods: We conducted a comprehensive literature search using MEDLINE, EMBASE databases and meeting abstracts from inception through June 2018. Phase III RCTs that mention hematological toxicities as adverse effects were incorporated in the analysis. Mantel-Haenszel (MH) method was used to calculate the estimated pooled risk ratio (RR) with 95% confidence interval (CI). Random effects model was applied. Results: Seven phase III RCTs with a total of 3,188 patients with breast, ovarian and gastric cancer were eligible. Studies compared olaparib or niraparib or rucaparib versus placebo, olaparib vs single agent chemotherapy, iniparib + gemcitabine / carboplatin (GC) versus GC, veliparib + C versus C and olaparib + paclitaxel vs paclitaxel. The RR of all-grade side effects were as follows: anemia, 2.38 (95% CI: 1.42 – 4.00, p = 0.001); thrombocytopenia, 2.96 (95% CI: 1.37 – 6.40, p = 0.006); neutropenia, 1.47 (95% CI: 1.06 – 2.05, p = 0.02); and leukopenia, 1.08 (95% CI: 0.77 – 1.50, p = 0.63). The RR of high-grade adverse effects were as follows: anemia, 3.63 (95% CI: 1.53 – 8.57, p = 0.003); thrombocytopenia, 2.65 (95% CI: 0.89 – 7.85, p = 0.07); neutropenia, 1.27 (95% CI: 0.87 – 1.86, p = 0.21); and leukopenia, 1.20 (95% CI: 0.90 – 1.58, p = 0.19). Conclusions: Our meta-analysis demonstrated that patients on PARP inhibitors experienced a significant increase in the risk of all grades of anemia with a relative risk of 3.63 for grade 3 and 4 anemia, along with any-grade thrombocytopenia and neutropenia. Proper supportive care is essential, and it will ultimately reduce drug dosing inconsistencies and financial burden among patients undergoing treatment.

Risk of health-related quality-of-life events and pulmonary toxicities in patients with cancer treated with poly adenosine diphosphate ribose polymerase inhibitors: A meta-analysis of seven phase III trials

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Background: Poly adenosine diphosphate ribose polymerase (PARP) enzymes aide in the repair of DNA damage. PARP inhibitors showed synthetic lethality in cancer cells and were utilized in many solid tumors with notable toxicities. Fatigue and pain are the major determinants of health-related quality of life (HRQOL) in cancer patients undergoing chemotherapy. We undertook a systematic review and meta-analysis of randomized controlled trials (RCT) to determine the risk of HRQOL events and pulmonary toxicities. Methods: MEDLINE, EMBASE databases and meeting abstracts from inception through June 2018 were queried. Phase III RCTs that mention HRQOL events and pulmonary toxicities as adverse effects were included. Mantel-Haenszel (MH) method was used to calculate the estimated pooled risk ratio (RR) with 95% confidence interval (CI). Random effects model was applied. Results: 3188 patients from 7 phase III RCTs with breast, ovarian, and gastric cancer were eligible. Studies compared olaparib or niraparib or rucaparib versus placebo, olaparib vs single agent chemotherapy, iniparib + gemcitabine / carboplatin (GC) versus GC, veliparib + C versus C and olaparib + paclitaxel versus paclitaxel. The RR of all-grade side effects were as follows: fatigue, 1.26 (95% CI: 1.07 – 1.49, P = 0.006); decreased appetite, 1.42 (95% CI: 1.18 – 1.71, P < 0.001); arthralgia, 1.05 (95% CI: 0.83 – 1.34, P = 0.65); headache, 1.35 (95% CI: 0.99 – 1.84, P = 0.05); cough, 1.75 (95% CI: 1.17 – 2.62, P = 0.006); dyspnea, 1.40 (95% CI: 0.90 – 2.18, P = 0.12); and upper respiratory infections, 1.70 (95% CI: 0.97 – 3.00, P = 0.06). The RR of high-grade side effects were as follows: fatigue, 1.94 (95% CI: 1.24 – 3.04, P = 0.004); arthralgia, 1.37 (95% CI: 0.29 – 6.51, P = 0.68); headache, 1.09 (95% CI: 0.47 – 2.55, P = 0.83); and dyspnea, 1.02 (95% CI: 0.44 – 2.36, P = 0.95). Conclusions: The risk of developing all grades of fatigue as well as any-grade cough and decreased appetite was high in PARP inhibitors group, compared to control arm. Recognizing these toxicities and providing good supportive care is vital in enhancing patients’ quality of life.

Causes and incidence of community-acquired serious infections among young children in south Asia (ANISA): an observational cohort study

BACKGROUND

More than 500 000 neonatal deaths per year result from possible serious bacterial infections (pSBIs), but the causes are largely unknown. We investigated the incidence of community-acquired infections caused by specific organisms among neonates in south Asia.

METHODS

From 2011 to 2014, we identified babies through population-based pregnancy surveillance at five sites in Bangladesh, India, and Pakistan. Babies were visited at home by community health workers up to ten times from age 0 to 59 days. Illness meeting the WHO definition of pSBI and randomly selected healthy babies were referred to study physicians. The primary objective was to estimate proportions of specific infectious causes by blood culture and Custom TaqMan Array Cards molecular assay (Thermo Fisher, Bartlesville, OK, USA) of blood and respiratory samples.

FINDINGS

6022 pSBI episodes were identified among 63 114 babies (95·4 per 1000 livebirths). Causes were attributed in 28% of episodes (16% bacterial and 12% viral). Mean incidence of bacterial infections was 13·2 (95% credible interval [CrI] 11·2-15·6) per 1000 livebirths and of viral infections was 10·1 (9·4-11·6) per 1000 livebirths. The leading pathogen was respiratory syncytial virus (5·4, 95% CrI 4·8-6·3 episodes per 1000 livebirths), followed by Ureaplasma spp (2·4, 1·6-3·2 episodes per 1000 livebirths). Among babies who died, causes were attributed to 46% of pSBI episodes, among which 92% were bacterial. 85 (83%) of 102 blood culture isolates were susceptible to penicillin, ampicillin, gentamicin, or a combination of these drugs.

INTERPRETATION

Non-attribution of a cause in a high proportion of patients suggests that a substantial proportion of pSBI episodes might not have been due to infection. The predominance of bacterial causes among babies who died, however, indicates that appropriate prevention measures and management could substantially affect neonatal mortality. Susceptibility of bacterial isolates to first-line antibiotics emphasises the need for prudent and limited use of newer-generation antibiotics. Furthermore, the predominance of atypical bacteria we found and high incidence of respiratory syncytial virus indicated that changes in management strategies for treatment and prevention are needed. Given the burden of disease, prevention of respiratory syncytial virus would have a notable effect on the overall health system and achievement of Sustainable Development Goal.

FUNDING

Bill & Melinda Gates Foundation.

Relationship between pain and depression among patients with cancer at a community teaching hospital

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Background: While depression is often under-diagnosed in the general population, the rate of under-diagnosis among patients with cancer may be far higher. The American Cancer Society reports that a quarter of all patients with cancer may suffer from depression. We seek to identify a link between pain and depression among patients with cancer which may signal an enhanced need both for the involvement of mental health services and for more effective pain management. Methods: This is an observational cross-sectional study evaluating depression among patients with cancer in an outpatient setting. From June of 2015 to January of 2016, 29 patients from our institution’s affiliated cancer clinics were interviewed by study staff members about their pain and various other cancer-related concerns. Subjects were also administered the depression screening tool Patient Health Questionnaire 9 (PHQ-9). Data was collected and analyzed using Spearman’s rho. Results: The inclusion criteria included a confirmed cancer diagnosis and willingness to participate in a clinical study. There were no exclusion criteria. Age ranged from 43 to 87 and women comprised 75% of participants. Of the 18 patients who complained of pain (62.1% of the total), 14 reported pain of at least 7 of 10 in severity (77.8%). Severity of pain was found to correlate positively with the questions of “Poor appetite or overeating” as well as “Moving or speaking so slowly...Or the opposite — being so fidgety or restless...” (R = 0.41, P = 0.03; R = 0.40, P = 0.03, respectively). Presence of pain likewise correlated positively with the latter question (R = 0.46, P = 0.01). Conclusions: The effects of depression on patients with cancer may contribute to life-shortening complications related to reduced compliance with treatment and lifestyle modifications, as well as the exacerbation of heart disease and other comorbid conditions. Our findings demonstrate that pain, particularly severe pain, may signal an elevated risk of depression and call for the swift involvement of mental health services. Likewise, the high proportion of patients complaining of pain in general and severe pain in particular suggests a need for more aggressive pain management among patients with cancer within our cohort.

Characteristics of a two-site immunoradiometric assay for human skeletal alkaline phosphatase in serum

This two-site IRMA includes specific monoclonal antibodies for measuring skeletal alkaline phosphatase (B-ALP) in human serum. Assay calibration is based on mass units (micrograms per liter) and was established with purified B-ALP from a human osteosarcoma cell line, SAOS-2. Precision studies demonstrated intra- and interassay CVs of 3-5% and 5-7%, respectively. Relative reactivity studies showed that the assay has a sevenfold preference for detecting B-ALP compared with the liver isoenzyme in serum. The normal reference interval for 478 healthy adults was 5-22 micrograms/L. Method comparison studies showed good correlation between this B-ALP assay (y) and commercially available electrophoretic methods (x) (y = 0.3540x + 20.5, R2 = 0.929) in a pagetic population. Temporal profiles for total ALP, this IRMA B-ALP assay, and B-ALP by electrophoresis in three pagetic patients were parallel. We conclude that this assay demonstrates good analytical performance and would be useful for the clinical assessment of metabolic bone disorders.

Characteristics of a two-site immunoradiometric assay for human skeletal alkaline phosphatase in serum

This two-site IRMA includes specific monoclonal antibodies for measuring skeletal alkaline phosphatase (B-ALP) in human serum. Assay calibration is based on mass units (micrograms per liter) and was established with purified B-ALP from a human osteosarcoma cell line, SAOS-2. Precision studies demonstrated intra- and interassay CVs of 3-5% and 5-7%, respectively. Relative reactivity studies showed that the assay has a sevenfold preference for detecting B-ALP compared with the liver isoenzyme in serum. The normal reference interval for 478 healthy adults was 5-22 micrograms/L. Method comparison studies showed good correlation between this B-ALP assay (y) and commercially available electrophoretic methods (x) (y = 0.3540x + 20.5, R2 = 0.929) in a pagetic population. Temporal profiles for total ALP, this IRMA B-ALP assay, and B-ALP by electrophoresis in three pagetic patients were parallel. We conclude that this assay demonstrates good analytical performance and would be useful for the clinical assessment of metabolic bone disorders.

Effects of trans fatty acids on lipid accumulation in 3T3-L1 cells

Previous work had shown that dietary trans fatty acids (tFA) resulted in decreased fat deposition in adipose tissue. This study was conducted to see if tFA influence lipid accumulation in Swiss mouse fibroblast 3T3-L1 cells, which are widely used as an adipocyte model. Cells were cultured in the presence of experimental or control growth media supplemented with fatty acids complexed to bovine serum albumin. Fatty acid compositions of experimental and control growth media were similar except that the octadecenoates in the control growth media were cis fatty acids, whereas those in the experimental media contained both cis and trans fatty acids. Cell-conditioned media and cellular lipids at the preadipocyte and differentiating adipocyte stages were analyzed. At both stages of development, less fat accumulated in cells cultured in the presence of tFA, due primarily to a decrease in the nonpolar lipid content of cells exposed to tFA, and linoleate to arachidonate ratios were higher in cells supplemented with tFA. Calculations comparing sums of saturated and monounsaturated fatty acids in cells at the differentiating adipocyte stage suggested that tFA may have replaced monounsaturated fatty acids in the nonpolar lipid fraction and saturated fatty acids in the polar lipid fraction. The results of these studies are in good agreement with the in vivo effects of tFA seen in previous work with mouse adipose tissue. It was concluded that the 3T3-L1 in vitro model is an appropriate system for further studies of tFA and lipid metabolism in adipose tissue.