Impact of Magnetic Resonance Imaging Markers on the Diagnostic Performance of the International Parkinson and Movement Disorder Society Multiple System Atrophy Criteria.

BACKGROUND: Multiple system atrophy is a neurodegenerative disease with α-synuclein aggregation in glial cytoplasmic inclusions, leading to dysautonomia, parkinsonism, and cerebellar ataxia. OBJECTIVE: The aim of this study was to validate the accuracy of the International Parkinson and Movement Disorder Society Multiple System Atrophy clinical diagnostic criteria, particularly considering the impact of the newly introduced brain magnetic resonance imaging (MRI) markers. METHODS: Diagnostic accuracy of the clinical diagnostic criteria for multiple system atrophy was estimated retrospectively in autopsy-confirmed patients with multiple system atrophy, Parkinson's disease, progressive supranuclear palsy, and corticobasal degeneration. RESULTS: We identified a total of 240 patients. Sensitivity of the clinically probable criteria was moderate at symptom onset but improved with disease duration (year 1: 9%, year 3: 39%, final ante mortem record: 77%), whereas their specificity remained consistently high (99%-100% throughout). Sensitivity of the clinically established criteria was low during the first 3 years (1%-9%), with mild improvement at the final ante mortem record (22%), whereas specificity remained high (99%-100% throughout). When MRI features were excluded from the clinically established criteria, their sensitivity increased considerably (year 1: 3%, year 3: 22%, final ante mortem record: 48%), and their specificity was not compromised (99%-100% throughout). CONCLUSIONS: The International Parkinson and Movement Disorder Society multiple system atrophy diagnostic criteria showed consistently high specificity and low to moderate sensitivity throughout the disease course. The MRI markers for the clinically established criteria reduced their sensitivity without improving specificity. Combining clinically probable and clinically established criteria, but disregarding MRI features, yielded the best sensitivity with excellent specificity and may be most appropriate to select patients for therapeutic trials. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Impact of early aggressive fluid resuscitation in acute pancreatitis.

BACKGROUND/OBJECTIVES: Acute pancreatitis management guidelines recommend early aggressive hydration to improve clinical outcomes. We aim to evaluate the influence of early fluid therapy (total intravenous fluids in the first 24 h [IVF/24hrs]) on clinical outcomes in patients with acute pancreatitis. METHODS: This was a retrospective chart review of all patients admitted for acute pancreatitis between July 2011 to December 2015. IVF/24hrs was categorized into 3 groups according to tertiles. Logistic regression was performed to evaluate predictors of persistent organ failure and in-hospital mortality. RESULTS: A total of 310 patients were included: Conservative (IVF/24hrs < 2.8L, n = 102), Moderate (IVF/24hrs 2.8-4.475L, n = 105) and Aggressive (IVF/24hrs ≥ 4.475, n = 103). Most patients (80.6%) were African Americans, 91.3% had mild acute pancreatitis (BISAP score ≤ 2). The Aggressive IVF group had higher incidence of persistent organ failure (16.5% vs 4.9% and 7.6%, p = 0.013), and longer length of hospital stay (9.2 ± 10.7 vs 6.5 ± 7.3 and 6.8 ± 5.7 days, P = 0.032). However, IVF/24hr did not correlate with length of hospital stay (PCC 0.08, p = 0.174). On multivariate analysis, only organ failure at admission was an independent predictor of persistent organ failure (OR 16.1, p < 0.001). Persistent organ failure and local complications were found to be the only independent predictors in-hospital mortality (OR 27.6, p < 0.001 and OR 16.95, p = 0.001 respectively). There was no difference in clinical outcomes in African Americans compared to other races. CONCLUSIONS: More aggressive early IVF therapy in a predominantly mild acute pancreatitis cohort, was not associated with improvement in persistent organ failure, length of hospital stay, or in-hospital mortality.

Same-Admission Cholecystectomy Compared with Delayed Cholecystectomy in Acute Gallstone Pancreatitis: Outcomes and Predictors in a Safety Net Hospital Cohort.

OBJECTIVES: Recent studies have shown a decrease in gallstone-related complications if same-admission cholecystectomy (SAC) is performed in mild gallstone pancreatitis (GSP); however, SAC often is not performed in resource-limited settings such as safety net hospitals. The aims of this study were to evaluate the rate of SAC and compare a composite endpoint of recurrent biliary events in patients undergoing SAC with patients in the delayed cholecystectomy (DC) group. Secondary aims included evaluating the rate of recurrent pancreatitis in patients in the DC group, identifying the predictors for DC and the reasons for not undergoing SAC. METHODS: We reviewed 310 patients admitted in the past 5 years with the diagnosis of acute pancreatitis. Eighty patients were admitted for gallstone pancreatitis; 75% were African American, 18% were white, and the average age was 44 years with a mean body mass index of 30. Forty patients did not receive cholecystectomy before discharge. The DC and SAC groups were similar in body mass index, ethnicity, severity of pancreatitis, and complications. RESULTS: The DC group was significantly more likely to be older and with higher comorbidity indexes compared with the SAC group. Bedside Index of Severity in Acute Pancreatitis scores and revised Atlanta classification definitions were used to define severe acute pancreatitis; 10% (4) of patients had organ failure at 48 hours, whereas 17.5% (7) had a Bedside Index of Severity in Acute Pancreatitis scores ≥3. A total of 14 recurrent biliary events occurred in the DC group (14 of 40), which was 35% compared with 2 of 40 (5%) in the SAC group (P < 0.001). Of the 9 patients who developed recurrent pancreatitis, 8 were in the DC group (8 of 40, 20%, P = 0.02). Of the 40 patients in the DC group, only 14 patients eventually received a cholecystectomy documented in our hospital, with median-length postdischarge follow-up of approximately 6.5 months. On regression analysis, a Charlson Comorbidity Index >2 was the only significant predictor of DC. The most common reason for DC was no surgical consultation during the inpatient stay (22%). CONCLUSIONS: Our findings support existing evidence that DC is associated with a significantly increased risk of recurrent biliary events and pancreatitis. Furthermore, we report a 56% adherence to the current guidelines for SAC and report that the most common reason for not undergoing SAC was the absence of surgical consultation. We conclude that ensuring SAC in eligible patients should be a priority for safety net hospitals because it may help decrease hospital costs in the long term, and active efforts should be made to identify patients who may be less likely to receive SAC.

A two-stage genome-wide association study of sporadic amyotrophic lateral sclerosis.

The cause of sporadic amyotrophic lateral sclerosis (ALS) is largely unknown, but genetic factors are thought to play a significant role in determining susceptibility to motor neuron degeneration. To identify genetic variants altering risk of ALS, we undertook a two-stage genome-wide association study (GWAS): we followed our initial GWAS of 545 066 SNPs in 553 individuals with ALS and 2338 controls by testing the 7600 most associated SNPs from the first stage in three independent cohorts consisting of 2160 cases and 3008 controls. None of the SNPs selected for replication exceeded the Bonferroni threshold for significance. The two most significantly associated SNPs, rs2708909 and rs2708851 [odds ratio (OR) = 1.17 and 1.18, and P-values = 6.98 x 10(-7) and 1.16 x 10(-6)], were located on chromosome 7p13.3 within a 175 kb linkage disequilibrium block containing the SUNC1, HUS1 and C7orf57 genes. These associations did not achieve genome-wide significance in the original cohort and failed to replicate in an additional independent cohort of 989 US cases and 327 controls (OR = 1.18 and 1.19, P-values = 0.08 and 0.06, respectively). Thus, we chose to cautiously interpret our data as hypothesis-generating requiring additional confirmation, especially as all previously reported loci for ALS have failed to replicate successfully. Indeed, the three loci (FGGY, ITPR2 and DPP6) identified in previous GWAS of sporadic ALS were not significantly associated with disease in our study. Our findings suggest that ALS is more genetically and clinically heterogeneous than previously recognized. Genotype data from our study have been made available online to facilitate such future endeavors.

Effective Treatment of Nonalcoholic Fatty Liver Disease Using a Community-Based Weight Management Program.

Introduction Obesity-related gastrointestinal disorders including nonalcoholic fatty liver disease (NAFLD) and gastroesophageal reflux disease (GERD) are more frequent and usually present earlier than type 2 diabetes mellitus (T2DM) and cardiovascular disorders. This provides an opportunity for the gastroenterologist to intervene early with an effective weight-loss therapy. We evaluated the outcomes of a multifaceted, community-based gastroenterologist-supervised weight management program compared with patient-directed weight-loss efforts after physician advice. The program is aimed at achieving a 10% total body weight (TBW) loss at three months, a known determinant for NAFLD regression. Methods This is a retrospective pre- and post-intervention study of NAFLD patients, who participated in a medically supervised weight management program in the period between May 2017 and May 2019. The program is comprised of a very-low-calorie (800 kcal/day) meal replacement diet, a recommended medical fitness program, and weekly behavioral support groups. Patients are followed on monthly basis and slowly transitioned to a whole food plant-based or Mediterranean diet after three months of participation. Patients' weight trends driven by self-directed efforts to lose weight after physician advice were collected based on historical data up to two years prior to program participation. The primary outcome was defined as percentage TBW loss at three months under medical supervision (post-intervention) compared with patient-directed weight-loss efforts (pre-intervention). The secondary outcomes included percentage TBW loss in relation to behavioral support group attendance and improvement in GERD and T2DM disease status after program participation. Linear mixed and linear regression models were used to assess for a statistically significant difference in percentage TBW loss. Statistical significance was defined as p < 0.05. Results A total of 114 NAFLD patients (mean age 55 years, mean BMI 39 kg/m2, 77 females, and 37 males) completed at least three months of follow-up and were included in the study. Of those, 89 patients had a documented three-month office visit. At three months, 65% of patients had lost at least 10% of their TBW. Percentage TBW loss under medical supervision was noted to be significantly higher and occurred at a faster rate over three months when compared with patient-directed efforts after physician advice (p < 0.001). Patients who attended the behavioral support groups ≥ 50% of the time had a 3% higher TBW loss at three months compared with patients who attended <50% of the time (p = 0.006). Approximately, 52% of patients with GERD and 38% of patients with T2DM had symptoms improvement and/or medication reduction at their three-month follow-up visit. Conclusion A multifaceted, community-based, gastroenterologist supervised weight management program is effective in achieving a clinically significant TBW loss of at least 10% within three months of participation. This weight loss was greater and occurred at a faster rate when compared with patient-directed efforts. Additionally, improvement in GERD and T2DM disease status was noted in 52% and 38% of patients with these conditions, respectively. Further community-based studies of a larger scale are needed to determine the sustainability of this weight loss over one year.

A Prospective Study of Neurologic Disorders in Hospitalized Patients With COVID-19 in New York City.

OBJECTIVE: To determine the prevalence and associated mortality of well-defined neurologic diagnoses among patients with coronavirus disease 2019 (COVID-19), we prospectively followed hospitalized severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive patients and recorded new neurologic disorders and hospital outcomes. METHODS: We conducted a prospective, multicenter, observational study of consecutive hospitalized adults in the New York City metropolitan area with laboratory-confirmed SARS-CoV-2 infection. The prevalence of new neurologic disorders (as diagnosed by a neurologist) was recorded and in-hospital mortality and discharge disposition were compared between patients with COVID-19 with and without neurologic disorders. RESULTS: Of 4,491 patients with COVID-19 hospitalized during the study timeframe, 606 (13.5%) developed a new neurologic disorder in a median of 2 days from COVID-19 symptom onset. The most common diagnoses were toxic/metabolic encephalopathy (6.8%), seizure (1.6%), stroke (1.9%), and hypoxic/ischemic injury (1.4%). No patient had meningitis/encephalitis or myelopathy/myelitis referable to SARS-CoV-2 infection and 18/18 CSF specimens were reverse transcriptase PCR negative for SARS-CoV-2. Patients with neurologic disorders were more often older, male, white, hypertensive, diabetic, intubated, and had higher sequential organ failure assessment (SOFA) scores (all p < 0.05). After adjusting for age, sex, SOFA scores, intubation, history, medical complications, medications, and comfort care status, patients with COVID-19 with neurologic disorders had increased risk of in-hospital mortality (hazard ratio [HR] 1.38, 95% confidence interval [CI] 1.17-1.62, p < 0.001) and decreased likelihood of discharge home (HR 0.72, 95% CI 0.63-0.85, p < 0.001). CONCLUSIONS: Neurologic disorders were detected in 13.5% of patients with COVID-19 and were associated with increased risk of in-hospital mortality and decreased likelihood of discharge home. Many observed neurologic disorders may be sequelae of severe systemic illness.

A genome-wide association study of sporadic ALS in a homogenous Irish population.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive limb or bulbar weakness. Efforts to elucidate the disease-associated loci have to date produced conflicting results. One strategy to improve power in genome-wide studies is to genotype a genetically homogenous population. Such a population exhibits extended linkage disequilibrium (LD) and lower allelic heterogeneity to facilitate disease gene mapping. We sought to identify associated variants for ALS in the Irish, a stable population of relatively homogenous genetic background, and to replicate these findings in larger genetically out-bred populations. We conducted a genome-wide association study in 432 Irish individuals using Illumina HumanHap 550K single nucleotide polymorphism chips. We demonstrated extended LD and increased homogeneity in the Irish sample when compared to an out-bred population of mixed European ancestry. The Irish scan identified 35 loci associated with P-values below 0.0001. For replication, we identified seven chromosomal regions commonly associated in a joint analysis of genome-wide data on 958 ALS cases and 932 controls from Ireland and the previously published datasets from the US and The Netherlands. When pooled, the strongest association was a variant in the gene encoding DPP6, a component of type A neuronal transmembrane potassium channels. Further confirmation of the candidate loci is warranted in additional genome-wide datasets. We have made our individual genotyping data publicly available, contributing to a powerful world-wide resource to refine our understanding of the genetics of sporadic ALS.

Sigma ligands, but not N-methyl-D-aspartate antagonists, reduce levodopa-induced dyskinesias.

Levodopa (L-DOPA) is the 'gold standard' to treat Parkinson's disease. Unfortunately, dyskinesias detract from its efficacy. Current dyskinesia treatments, including amantadine and dextromethorphan, are thought to work via N-methyl-D-aspartate (NMDA) antagonism, but this hypothesis has not been tested. The NMDA antagonists MK-801 and HA-966 failed to suppress expression of dyskinesias in the 6-hydroxydopamine rat. Dyskinesias, however, were suppressed by the NMDA and sigma (sigma)-1 receptor ligand dextromethorphan and by the sigma-1 antagonist BMY-14802. Antidyskinetic effects of dextromethorphan may be mediated via mechanisms other than NMDA, including the sigma-1 receptor and other binding sites common to dextromethorphan and BMY-14802.

Service Members Prefer a Psychotherapist Who Is a Veteran.

The military is experiencing high rates of mental illness, yet service members and veterans with mental health problems often choose not to seek treatment. Based on clinical-psychology models of client-therapist matching and cultural competency, we hypothesized that willingness to seek treatment among military personnel is higher when the potential psychotherapist is a discharged veteran. Seventy-seven military personnel (73% men, 70% White, Mage = 34.2) took part in the study. As hypothesized, the majority of participants indicated that they would prefer to see a psychologist who is a veteran. When responding to vignettes, ratings of the psychotherapist's ability to understand the client (a soldier post-deployment), of his ability to help such a client, and of whether the client should seek treatment from this psychotherapist were higher when the psychotherapist was a veteran compared to when he had no military experience. There were no between-group differences in age, years of service, deployment history, or attitudes toward psychotherapy in general. Similarly, gender and education level had no effect on the results. These findings imply that having the opportunity to receive treatment by a psychotherapist who is a veteran may remove barriers for treatment and encourage more service members and veterans to seek and obtain the help that they need. This can be done by communicating these findings to the military population and by encouraging therapists who have military experience to make this fact known to their potential clients.

Localized Myosin II Activity Regulates Assembly and Plasticity of the Axon Initial Segment.

The axon initial segment (AIS) is the site of action potential generation and a locus of activity-dependent homeostatic plasticity. A multimeric complex of sodium channels, linked via a cytoskeletal scaffold of ankyrin G and beta IV spectrin to submembranous actin rings, mediates these functions. The mechanisms that specify the AIS complex to the proximal axon and underlie its plasticity remain poorly understood. Here we show phosphorylated myosin light chain (pMLC), an activator of contractile myosin II, is highly enriched in the assembling and mature AIS, where it associates with actin rings. MLC phosphorylation and myosin II contractile activity are required for AIS assembly, and they regulate the distribution of AIS components along the axon. pMLC is rapidly lost during depolarization, destabilizing actin and thereby providing a mechanism for activity-dependent structural plasticity of the AIS. Together, these results identify pMLC/myosin II activity as a common link between AIS assembly and plasticity.

By any other name: ambiguity in marketing proprietary anti-infective agents.

In 55 instances, a single proprietary (trade) name has been used to market > or = 2 distinct generic anti-infective agents. In some cases, one trade name represents 2 different drugs in the same country--or even marketed by the same manufacturer. Some unrelated drugs and poisonous substances are also manufactured under trade names assigned to anti-infectives. The use of proprietary names in the prescribing of anti-infective drugs could result in considerable confusion or harm to patients.

Postretrieval propranolol disrupts a cocaine conditioned place preference.

The current study examined whether a postretrieval drug memory could be disrupted by the beta-adrenoceptor antagonist propranolol, administered following reactivation in a cocaine-mediated conditioned place preference paradigm. Following cocaine conditioning, rats were given a test of conditioned place preference, followed immediately by intraperitoneal administration of propranolol or saline. Rats that received propranolol following the preference test showed no preference for the cocaine-paired floor during a subsequent test, while vehicle-treated rats continued to express a preference for the cocaine-paired floor. These deficits in behavior were specific to retrieval of the cocaine-mediated memory, suggesting that postretrieval propranolol induced an impairment of drug-seeking behavior that is consistent with the disruption of a reconsolidation phase following retrieval.

Analysis of IFT74 as a candidate gene for chromosome 9p-linked ALS-FTD.

BACKGROUND: A new locus for amyotrophic lateral sclerosis--frontotemporal dementia (ALS-FTD) has recently been ascribed to chromosome 9p. METHODS: We identified chromosome 9p segregating haplotypes within two families with ALS-FTD (F476 and F2) and undertook mutational screening of candidate genes within this locus. RESULTS: Candidate gene sequencing at this locus revealed the presence of a disease segregating stop mutation (Q342X) in the intraflagellar transport 74 (IFT74) gene in family 476 (F476), but no mutation was detected within IFT74 in family 2 (F2). While neither family was sufficiently informative to definitively implicate or exclude IFT74 mutations as a cause of chromosome 9-linked ALS-FTD, the nature of the mutation observed within F476 (predicted to truncate the protein by 258 amino acids) led us to sequence the open reading frame of this gene in a large number of ALS and FTD cases (n = 420). An additional sequence variant (G58D) was found in a case of sporadic semantic dementia. I55L sequence variants were found in three other unrelated affected individuals, but this was also found in a single individual among 800 Human Diversity Gene Panel samples. CONCLUSION: Confirmation of the pathogenicity of IFT74 sequence variants will require screening of other chromosome 9p-linked families.

Pseudo-borreliosis in patients with malaria.

Malaria and relapsing fever are arthropod-borne infections characterized by fever, myalgia, headache, and a tendency to relapse. Both are diagnosed through examination of stained blood films, and both might respond to tetracycline therapy. In at least four published case reports, the presence of malarial microgametes possibly resulted in misdiagnosis of borreliosis in patients with malaria. An additional case is presented, and the mechanism of microgamete production in clinical specimens is discussed.

GIDEON: a comprehensive Web-based resource for geographic medicine.

GIDEON (Global Infectious Diseases and Epidemiology Network) is a web-based computer program designed for decision support and informatics in the field of Geographic Medicine. The first of four interactive modules generates a ranked differential diagnosis based on patient signs, symptoms, exposure history and country of disease acquisition. Additional options include syndromic disease surveillance capability and simulation of bioterrorism scenarios. The second module accesses detailed and current information regarding the status of 338 individual diseases in each of 220 countries. Over 50,000 disease images, maps and user-designed graphs may be downloaded for use in teaching and preparation of written materials. The third module is a comprehensive source on the use of 328 anti-infective drugs and vaccines, including a listing of over 9,500 international trade names. The fourth module can be used to characterize or identify any bacterium or yeast, based on laboratory phenotype. GIDEON is an up-to-date and comprehensive resource for Geographic Medicine.

Asthma in adventure travelers: a prospective study evaluating the occurrence and risk factors for acute exacerbations.

BACKGROUND: Exacerbation of asthma during travel to remote regions may lead to devastating consequences. The course of asthma in travelers and the risk factors for disease exacerbation during travel have not been studied. METHODS: We screened 5835 consecutive travelers and identified 203 patients with asthma. Before travel, all enrollees were assessed for presumed risk factors for asthma exacerbation by means of an interview and an exercise test combined with spirometry. After travel, data regarding travel characteristics and asthma severity were recorded by means of a structured telephone interview. RESULTS: The 203 enrollees visited 56 countries for a median duration of 13 weeks, 147 were engaged in high-altitude trekking, and 88 had asthma attacks. Among these, 40 reported worsening asthma during travel, 32 experienced the worst asthma attack ever, and 11 reported a life-threatening asthma attack. Two independent risk factors for attacks during travel were identified: frequent use (> or = 3 times weekly) of inhaled bronchodilators before travel (relative risk [RR], 3.35; 95% confidence interval [CI], 1.75-6.39) and participation in intensive physical exertion during treks (RR, 2.04; 95% CI, 1.04-3.98). When both risk factors were present, the RR for asthma attacks increased to 5.52 (95% CI, 2.81-10.84). CONCLUSIONS: Asthma frequently worsens during travel and should not be ignored as a potentially life-threatening condition requiring pretravel consideration. Asthmatic travelers who frequently use inhaled bronchodilators before travel or participate in intensive trekking during travel are at increased risk to develop asthma attacks. Therapy should be intensified to achieve better disease control; intensive trekking should be discouraged.

Triple modality testing by endoscopic retrograde cholangiopancreatography for the diagnosis of cholangiocarcinoma.

OBJECTIVES: Brush cytology has a low sensitivity for the diagnosis of cholangiocarcinoma. This study aimed to compare the standard approach (brush cytology) with a triple modality approach utilizing brush cytology, forceps biopsy and fluorescence in situ hybridization in terms of sensitivity and specificity for the diagnosis of cholangiocarcinoma. METHODS: In a retrospective study at a single academic center, 50 patients underwent triple modality testing. Additionally, 61 patients underwent brush cytology alone. Intervention was endoscopic retrograde cholangiopancreatography with brush cytology, fluorescence in situ hybridization, and forceps biopsy. The main outcome measures included sensitivity, specificity, positive predictive value and negative predictive value. RESULTS: Overall, 50 patients underwent triple tissue sampling, and 61 patients underwent brush cytology alone. Twenty-two patients were eventually diagnosed with cholangiocarcinoma. Brush cytology had a sensitivity of 42%, specificity of 100%, positive predictive value of 100% and negative predictive value of 88%. Triple tissue sampling had an overall sensitivity of 82%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 87%. Within the triple test group, brush cytology had a sensitivity of 27%, forceps biopsy had a sensitivity of 50%, and fluorescence in situ hybridization analysis had a sensitivity of 59%. CONCLUSIONS: A triple modality approach results in a marked increase in sensitivity for the diagnosis of cholangiocarcinoma compared with single modality testing such as brush cytology and should be considered in the evaluation of indeterminate or suspicious biliary strictures.

Insight into the intrinsic sensitivity of the PCR assay used to detect CMV infection in amniotic fluid specimens.

BACKGROUND: PCR detection of human cytomegalovirus (HCMV) DNA in amniotic fluid (AF) is the most sensitive tool for diagnosis of fetal infection, but has sub-optimal sensitivity. It has been suggested that inhibition by AF reduces the sensitivity of this assay, however this assumption has never been thoroughly studied. Several PCR assays have been shown to improve sensitivity, but comparative studies are insufficient to choose the optimal approach. OBJECTIVES: To assess the effect of AF inhibition on PCR sensitivity and to determine the most sensitive assay for diagnosing fetal infection. STUDY DESIGN: Plasmid containing HCMV DNA was tested by PCR, in water and in non-infected AF, to assess the inhibitory effect of AF. Twenty-three AF-infected samples were tested by various PCR protocols. AF supernatant, with or without DNA extraction, and AF cells, were assayed by single-round and semi-nested PCR. Viral load was measured in the supernatant by a commercial quantitative PCR kit. RESULTS: The plasmid model demonstrated that single-round PCR was 2000-fold less sensitive in AF compared with water. Semi-nested PCR was only 10-fold less sensitive. Single-round PCR was 30% sensitive in HCMV-infected AF supernatants, and detected viral loads higher than 2.3 x 10(6) viral copies/ml. Extraction of DNA from the supernatant increased the sensitivity of this assay to 89% and the detection limit to 5.2 x 10(4) copies/ml. Semi-nested PCR performed on supernatant, with and without DNA extraction, was 96% and 100% sensitive, respectively, with a detection threshold of 3.8 x 10(3) copies/ml. Single-round and semi-nested PCR were 89% and 100% sensitive, respectively, in cells. The commercial quantitative PCR assay was 100% sensitive. CONCLUSIONS: AF supernatant is inhibitory to PCR. The two most sensitive assays were semi-nested PCR performed on DNA extracted from the supernatant and the commercial quantitative PCR kit. Of these two, the latter is standardized, non-labor-intensive, and allows minimal opportunity for contamination, thereby making it the preferred method for diagnosis.