Comparison of Clinical, Economic, and Humanistic Outcomes Between Blood Collection Approaches: A Systematic Literature Review

BACKGROUND

A systematic literature review was performed to understand the prevalence, advantages, and disadvantages of blood collection using different approaches (direct venipuncture or vascular access devices), and interventions used to mitigate the disadvantages.

METHODS

The review included a broad range of study designs and outcomes. Database searches (Embase, MEDLINE, Cochrane library, and Centre for Reviews and Dissemination) were conducted in March 2021 and supplemented by hand searching.

RESULTS

One hundred forty-one publications were included. The data indicate that blood sampling from vascular access devices is common in emergency departments, trauma centers, and intensive care units. Studies showed that hemolysis and sample contamination place a considerable economic burden on hospitals. Significant cost savings could be made through enforcing strict aseptic technique, or using the initial specimen diversion technique.

CONCLUSIONS

Hemolysis and sample contamination are far from inevitable in vascular access device-collected or venipuncture samples; both can be reduced through adherence to strict blood sampling protocols and utilization of the initial specimen diversion technique. Needle-free blood collection devices offer further hope for reducing hemolysis. No publication focused on the difficult venous access population; insertion success rates are likely to be lower (and the benefits of vascular access devices higher) in these patients.

Defining difficult intravenous access (DIVA): A systematic review

BACKGROUND

The term "difficult intravenous access" (DIVA) is commonly used but not clearly defined. Repeated attempts at peripheral intravenous catheter (PIVC) insertion can be a traumatic experience for patients, leading to sub-optimal clinical and economic outcomes. We conducted a systematic literature review (SLR) to collate literature definitions of DIVA, with the aim of arriving at an evidence-driven definition.

METHODS

The SLR was designed to identify clinical, cost, and quality of life publications in patients requiring the insertion of a PIVC in any setting, including studies on US-guidance and/or guidewire, and studies with no specific intervention. The search was restricted to English language studies published between 1st January 2010 and 30th July 2020, and the Ovid platform was used to search several electronic databases, in addition to hand searching of clinical trial registries.

RESULTS

About 121 studies were included in the SLR, of which 64 reported on the objectives relevant to this manuscript. Prevalence estimates varied widely from 6% to 87.7% across 19 publications, reflecting differences in definitions used. Of 43 publications which provided a definition of DIVA, six key themes emerged. Of these, themes 1-3 (failed attempts at PIV access using traditional technique; based on physical examination findings for example no visible or palpable veins; and personal history of DIVA) were covered by all but one publication. Following a failed insertion attempt, the most common number of subsequent attempts was 3, and it was frequently reported that a more experienced clinician would attempt to gain access after multiple failed attempts.

CONCLUSIONS

Considering the themes identified, an evidence-driven definition of DIVA is proposed: "when a clinician has two or more failed attempts at PIV access using traditional techniques, physical examination findings are suggestive of DIVA (e.g. no visible or palpable veins) or the patient has a stated or documented history of DIVA."

Coping with the COVID-19 Pandemic: An adapted approach to preclinical teaching of Pathology- Pathophysiology

Introduction/Objective

The COVID-19 pandemic affected all aspects of medicine, from patient care to medical education. Pandemic-related restrictions regarding in-person teaching activities at our medical college required adoption of an online, live, virtual format for all activities in our preclinical Pathology-Pathophysiology (PP) courses. Adaptation of teaching approaches using available technology allowed for uninterrupted learning and may serve to contribute to future innovations in medical education.

Methods/Case Report

Using Zoom as a platform, all lectures and interactive group exercises were converted to a live virtual format. Live Zoom lectures were also recorded and, subsequently, made available to students, in order to provide additional opportunities for engaged learning. Interactive, case-based and self-directed exercises, and gross specimen reviews were also held using the live virtual format. Fourth year students enrolled in our education concentration helped provide intermittent virtual peer reviews for the 2^nd year students. All exams were administered via an electronically monitored virtual format.

Results (if a Case Study enter NA)

Overall, performance of the 2020-2021 class on in-house, multiple choice question (MCQ) exams in our PP courses was typically at or above the performance of prior classes, while class performance on a standardized national subject exam (NBME) in Pathology was above the national average, which was consistent with prior class performances, and significantly higher (p = 0.01) on average in 2021 than in 2019 (2.28 points) and 2020 (2.27 points). Additional analyses are being conducted on demographic subgroups within each cohort (sex, MCAT score, socioeconomic status, underrepresented in medicine, registered for disability accommodations) to determine if any particular group’s performance was impacted by this change of format.

Conclusion

Despite the restrictions imposed by the pandemic, student performance on in-house and standardized national exams in the NYMC Pathology-Pathophysiology courses were similar to recent pre-pandemic years. Our endeavors to provide a strong preclinical educational experience in Pathology-Pathophysiology during the pandemic resulted in learning outcomes on a par with those in recent years, despite the rapid transition to a completely online, live virtual format.Our data suggest that continued use of virtual teaching methods is a viable option in on-going medical curricula

Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera-electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.

Hoptel equalizes length of stay for homeless and domiciled inpatients

BACKGROUND

There is growing evidence that homeless individuals have longer inpatient lengths of stay with significantly higher medical costs than domiciled individuals. We compared adjusted mean lengths of stay among domiciled patients and homeless patients discharged to a hospital hotel (hoptel). Because the hoptel allowed homeless patients to be discharged when medically indicated, we hypothesized no significant differences in lengths of stay between the 2 groups after adjustment for severity of illness.

METHODS

Demographic, diagnosis, and length of stay data were obtained for all patients discharged from all inpatient wards at a large, urban Veterans Affairs Medical Center during the first 32 months of hoptel operation (1996 through 1998). Adjusted mean lengths of stay for domiciled patients and homeless patients discharged to the hoptel were compared. ANCOVA was used to adjust for demographic characteristics (age, income, race/ethnicity), diagnosis-related group (DRG), principal diagnosis, and substance abuse comorbidity. Three types of hospitalizations were analyzed on the basis of major DRG categories: general medical, psychiatric, and all hospitalizations.

RESULTS

No significant differences were found in adjusted mean lengths of stay between domiciled patients and homeless patients discharged to the hoptel. Homeless hoptel patients stayed an average 0.7, 0.3, and 0.4 days longer than domiciled patients for all, general medical, and psychiatric hospitalizations (P = 0.504, 0.627, and 0.839), respectively.

CONCLUSIONS

These data suggest that hoptels may help equalize inpatient lengths of stay among domiciled and homeless patients discharged to a hoptel. Public health care systems seeking innovative ways of reducing inpatient lengths of stay among homeless patients ought to consider establishing hoptels.

Reducing psychiatric hospitalization among mentally ill veterans living in board-and-care homes

OBJECTIVE

The effectiveness of a community-based case management program at the Veterans Affairs West Los Angeles Healthcare Center in reducing hospital readmission of mentally ill veterans living in privately operated board-and-care homes was evaluated.

METHODS

A retrospective cohort design was used. The sample consisted of 321 patients identified by hospital records as living in one of 24 board-and-care homes in the Los Angeles area that were approved by the community residential care program. A total of 214 subjects who received monthly home visits from case managers (program group) were compared with 107 subjects who did not receive monthly home visits (comparison group). The median number of psychiatric bed-days used was calculated for the two years before and after follow-up. The number of days from the start of follow-up to the first psychiatric hospitalization was also calculated.

RESULTS

Among subjects in the program group, the median number of psychiatric bed-days used decreased significantly, from 59 days to 50 days. No significant change in the median number was observed for comparison subjects. Comparison subjects were rehospitalized 1.7 times more often than program subjects. Overall, program subjects under age 62 (younger subjects) were rehospitalized 2.5 times more often than older subjects. In the program group, those who had received home visits for more than two years were hospitalized three times more often than those who had received visits for less than two years, and younger subjects were rehospitalized 1.8 times more often than older subjects.

CONCLUSIONS

The findings suggest that home visits conducted by case managers in a community residential care program helped reduce psychiatric hospitalization among veteran patients living in privately operated board-and-care homes.

[Is there justification for limited percutaneous surgical drainage in severe neonatal necrotizing enterocolitis in low birth weight premature infants?]

The usual treatment of complicated neonatal necrotizing enterocolitis (NEC) is resection of the necrotic bowel, lavage of the peritoneal cavity and diversion enterostomy. Low-birth-weight premature neonates with this condition are in special danger if general anesthesia and full exploratory surgery is contemplated. A relatively simple alternate procedure is percutaneous insertion under local anesthesia of a soft abdominal drain, most often in the right lower quadrant. The procedure is done in the neonatal intensive care unit without moving the whole set-up to the operating room. 4 such cases have been treated within the past year. 3 were discharged home as they did not require additional surgical treatment, not having developed intestinal stenosis or obstruction. 1 recovered from the acute episode, but succumbed to a severe intraventricular hemorrhage and respiratory failure 7 days after the procedure. Our limited but most gratifying experience, in addition to similar experience of others, encourages us to recommend this simple surgical approach in the very sick low-birth-weight premature with fulminant NEC.

Effector protease receptor 1 mediates the mitogenic activity of factor Xa for vascular smooth muscle cells in vitro and in vivo

The binding of 125I-factor Xa to human aortic smooth muscle cell (SMC) monolayers was studied. At 4 degreesC, 125I-factor Xa bound to a single class of binding sites with a dissociation constant value of 3.6+/-0.7 nM and a binding site density of 11,720+/-1,240 sites/cell (n = 9). 125I-factor Xa binding was not affected by factor X, thrombin, or by DX9065, a direct inhibitor of factor Xa, but was inhibited by factor Xa (IC50 = 5.4+/-0.2 nM; n = 9) and by antibodies specific for the effector cell protease receptor 1 (EPR-1), a well-known receptor of factor Xa on various cell types. A factor X peptide duplicating the inter-EGF sequence Leu83-Leu88-(Gly) blocked the binding of 125I-factor Xa to these cells in a dose-dependent manner (IC50 = 110+/-21 nM). Factor Xa increased phosphoinositide turnover in SMCs and when added to SMCs in culture was a potent mitogen. These effects were inhibited by DX9065 and by antibodies directed against EPR-1 and PDGF. Increased expression of EPR-1 was identified immunohistochemically on SMCs growing in culture and in SMCs from the rabbit carotid artery after vascular injury. When applied locally to air-injured rabbit carotid arteries, antibodies directed against EPR-1 (100 mug/ artery) strongly reduced myointimal proliferation 14 d after vascular injury (65-71% inhibition, P < 0.01). DX9065 (10 mg/kg, subcutaneous) inhibited myointimal proliferation significantly (43% inhibition, P < 0.05). These findings indicate that SMCs express functional high affinity receptors for factor Xa related to EPR-1, which may be of importance in the regulation of homeostasis of the vascular wall and after vascular injury.

Two-dimensional echocardiography and Doppler ultrasound in managing obstetric patients

OBJECTIVE

To test the usefulness of ultrasound-derived measurements of intracardiac filling pressures and cardiac performance in the noninvasive management of obstetric patients with an indication for hemodynamic monitoring.

METHODS

We included patients with oliguria unresponsive to crystalloid boluses, with hypertension unresponsive to hydralazine, and at high risk for pulmonary edema who were determined to be candidates for invasive monitoring. They were first studied with two-dimensional echocardiography and Doppler ultrasound using a technique previously validated at our institution. Cardiac dimensions, filling pressures, and function were assessed at the bedside. Subsequently, management decisions were made based on these findings.

RESULTS

Fourteen patients were studied. Two received a pulmonary artery catheter after noninvasive evaluation indicated a need for continuous monitoring. The 12 patients managed without the need for a pulmonary artery catheter included women with intractable hypertension (one patient), pulmonary edema (two patients), complex cardiac lesions (two patients), oliguria (five patients), intractable hypertension and oliguria (one patient), and unexplained dyspnea with peripheral arterial oxygen desaturation (one patient). Although some patients received as much as 8 L of crystalloid, none developed pulmonary edema or left ventricular failure. In all 12 cases, the ultrasound monitoring allowed successful noninvasive management of the patient.

CONCLUSION

This pilot study suggests that two-dimensional echocardiography and Doppler examination may be an effective alternative to invasive monitoring in the management of selected pregnant patients.

Simvastatin inhibits myointimal hyperplasia following carotid artery injury in cholesterol-fed rabbits

The effect of simvastatin, a potent inhibitor of 3-hydroxy 3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) was evaluated in an experimental model of myointimal hyperplasia in cholesterol-fed rabbits. Myointimal hyperplasia was induced by an air-drying injury of the left carotid artery followed by a 2%-cholesterol diet for 14 days. A 2-week oral treatment with simvastatin (6 mg/kg/day, p.o.) significantly lowered the circulating levels of cholesterol and triglycerides (41% and 49% inhibition respectively) as well as the low density lipoprotein (LDL)-cholesterol and high density lipoprotein (HDL)-cholesterol levels. Simvastatin also strongly affected the uptake of cholesterol in the arteries occurring as a consequence of vascular injury (44% inhibition, P < 0.001). Morphometric analysis revealed that both the intima and the media areas increased substantially 2 weeks after the lesion and showed a considerable smooth muscle cell accumulation in the neointima together with the presence of numerous foam cells. A 16-day oral treatment with simvastatin strongly reduced smooth muscle cells hyperplasia occurring in both the media and the intima following deendothelialization (19% and 60% inhibition respectively) suggesting that simvastatin may be a useful inhibitor of restenosis which occurs following vascular injury.

Ovarian fibroma in a prepubertal girl

Ovarian fibroma rarely occurs in prepubertal girls. However, we found such an asymptomatic, large, uncalcified pelvic mass in an otherwise healthy 12-year-old girl. The plain films (radiographs), US and CT findings are presented.

Synthesis of a novel biotin-estradiol conjugate and its use for the development of a direct, broad range enzyme immunoassay for plasma estradiol

The synthesis and purification by high pressure liquid chromatography of a novel biotinoyl-diaminodioxaoctane-estradiol conjugate is described. The conjugate was used for the development of an enzyme immunoassay (EIA) for the direct determination of estradiol in human plasma. This assay was characterized by a low limit of detection (77 pM) and a broad working range. Estradiol concentrations ranging from 77 to 24300 pM, i.e. from the lower levels observed in the follicular phase of the normal menstrual cycle to the very high levels attained during hyperstimulation for in vitro fertilization, could be determined directly in undiluted plasma samples. Intra-assay variation ranged from 3.6 to 10.9% and interassay variation from 6.1 to 12%. The results obtained by the present EIA correlate well with target values obtained by isotope-dilution gas chromatography-mass spectrometry (r = 0.96) and with results obtained by a direct RIA (r = 0.97). The EIA requires no special apparatus, is simple, fast and robust, and could be applied in any clinical laboratory.

A direct non-competitive idiometric enzyme immunoassay for serum oestradiol

We report a novel non-competitive enzyme immunoassay for oestradiol based on the use of two types of anti-idiotypic antibody that recognize different epitopes within the hypervariable region of the primary anti-oestradiol idiotypic antibody (Ab1). The first anti-idiotype, the betatype, competes with the analyte for an epitope of the primary antibody at the binding site. On the other hand, the second anti-idiotype, the alphatype, binds to the Ab1 in the presence of analyte but does not bind to the betatype/Ab1 complex because of steric hindrance. In the present format the biotinylated alphatype was captured onto anti-biotin IgG which was adsorbed on the surface of microtitre wells. Reaction mixtures containing the Ab1 complexed sequentially with an enzyme labelled second antibody reagent, with oestradiol standards or serum samples and with the betatype anti-idiotypic antibody were then allowed to react with the immobilized alphatype anti-idiotypic antibody. The enzyme activity of the bound fraction measured at 405 nm increased with increasing oestradiol concentrations over the range 0.06-2.5 ng/ml. The detection limit of the assay was 28 pg/ml. The intra-assay variation ranged from 3.5 to 12.4%, and inter-assay variation from 6 to 13.4%. The results obtained by the colorimetric idiometric immunoassay correlated well with those obtained by a direct radioimmunoassay (n = 85, r = 0.97). This non-competitive immunoassay, termed idiometric assay, for haptens permits the development of sensitive immunoassays with a wide working range, and a variety of end-point determinations depending on the label used (e.g., enzyme, chemiluminescent or fluorogenic compound).

Sudden cardiac death in hypertrophic cardiomyopathy. Variability in phenotypic expression of beta-myosin heavy chain mutations

BACKGROUND

Recent identification of mutations in the beta-myosin heavy chain gene (MYH7), a major responsible gene for HCM, has provided the opportunity to characterize genotype-phenotype correlation in HCM families. In this study we analysed the phenotypic expression of two beta-myosin heavy chain (beta MHC) mutations in three unrelated HCM families.

METHODS

Living individuals from three unrelated HCM families (Families 1, 2, and 3) were screened by history, physical examination, electrocardiography, and two-dimensional echocardiography. Blood was collected from all individuals for DNA extraction. Polymerase chain reaction (PCR), restriction endonuclease digestion and chemical cleavage were utilized for detection of mutations. All mutations were confirmed by sequence analysis.

RESULTS

Identification of mutations: A missense mutation in exon 13 of the beta MHC gene (Arg403 Gln) was detected in HCM patients from Families 1 and 2. PCR amplification of the exon 13 DNA, followed by Ddel digestion of the PCR product and gel electrophoresis, showed two fragments of 84 and 70 bp in normal individuals and four fragments of 84, 70, 52 and 32 bp in HCM patients. Sequence analysis showed substitution of an adenine for guanine at coding position 1208. In Family 3, a missense mutation in exon 16 of the beta MHC gene (Val606 Met) was detected in HCM patients. Chemical cleavage of the PCR products showed an uncleaved product of 337 bp in the normal individuals, while in the affected individuals, in addition to the uncleaved product, a 90 bp cleaved product was also detected, indicating the presence of a mismatch in one allele. Sequence analysis showed substitution of an adenine for guanine in coding position 1817.

CLINICAL CHARACTERISTICS

Seven members of Family 1 had HCM, of whom five are alive. One patient died from sudden cardiac death (SCD) and another from recurrent cerebral emboli. In Family 2, 15 individuals had HCM of whom nine have died, seven from SCD. The mean age at the time of SCD was 33 years. The third family is comprised of 11 affected individuals and one obligate carrier, of whom one patient died at age 17 from progressive heart failure. Two additional individuals in this family have also succumbed to SCD to age 60. A variety of clinical and echocardiographic manifestations of HCM were present in each family. Logrank test of Kaplan-Meier survival curves indicates that Arg403 Gln mutation was associated with a poor prognosis in HCM families as compared to Val606 Met (P = 0.034).

CONCLUSIONS

beta MHC mutations despite showing variable clinical and echocardiographic manifestations of HCM are predictors of survival in HCM families.

Influence of pH, salt and nitrite on the heme-dependent catalase activity of lactic acid bacteria

A screening of commercial starter cultures used for the production of dry sausage showed a maximum heme-dependent catalase activity in the range of 60 mumol/l hematin for Lactobacillus sake, Lactobacillus plantarum, Lactobacillus pentosus and Pediococcus acidilactici. Pseudocatalase activity was not detected. In standard dry sausage production, 2-3% (w/w) nitrite salt (0.6% sodium nitrite per 100 g NaCl) is normally added, which corresponds to 4-6% salt in the water phase. In vitro experiments with L. sake and L. plantarum have shown that such a high concentration of salt caused a significant reduction of catalase activity and bacterial growth. In the case of P. acidilactici, the catalase activity remained constant at a salt concentration up to 6% (w/w); at 7% (w/w) the activity decreased sharply. The pH also affected the catalase activity, which remained constant up to pH 5.1 and decreased dramatically at lower values. The effect of nitrite has also been investigated. L. pentosus and P. acidilactici were not affected by the addition of 160 ppm nitrite (NO2-); L. plantarum, on the other hand, showed a significantly reduced catalase activity. In practice, optimum fermentation characteristics combined with an optimum catalase activity which are not inhibited by salt concentrations higher than 6% (w/v) and a residual nitrite content of about 160 ppm (w/v), are of the utmost importance in screening and selection of lactic acid bacteria for starter cultures.

[Hirschprung's disease in the Negev]

We treated 65 children with proven Hirschprung's disease between 1970-1992. After definitive surgery, 35 were over 10 years of age and 13 were over 18. The male:female ratio was 4:1. All but 3 were born full-term. 44% were of Bedouin origin, with a higher prevalence in 3 families of 2 tribes. 38 (58%) were diagnosed in the neonatal period: by barium enema and rectal muscle biopsy in 42 (65%), and by barium enema alone in 23 (35%). In the latter the diagnosis was verified by intra-operative biopsy. Severe constipation, intestinal obstruction or enterocolitis were the presenting features. 19 associated anomalies were found in 12 children, but none was life-threatening; 5 (8%) had cardiac anomalies; none had Down's syndrome. The rectosigmoid colon was the most common aganglionic segment involved (only 1 had total colonic aganglionosis). 7 of the 8 with short segment involvement responded well to posterior rectal myectomy. 55 patients had an abdominoperineal pull-through: 48 by Swenson's procedure and 5 by the Soave and 2 by the Duhamel modifications. In 43 a protective colostomy was performed at the end of the procedure. 53 had complete diversion colostomy at the time of initial diagnosis (neonatal and early infancy). There was no intra- or immediate post-operative death. 1 patient died 2 months after operation of complications following enterocolitis and total parenteral nutrition. 2 died a few hours after admission of severe sepsis due to enterocolitis before operation was possible. There were early postoperative complications in 11% of the 151 operations, mostly minor wound infections.(ABSTRACT TRUNCATED AT 250 WORDS)

A missense mutation in the beta myosin heavy chain gene is a predictor of premature sudden death in patients with hypertrophic cardiomyopathy

BACKGROUND

Familial hypertrophic cardiomyopathy (FHCM) is an autosomal dominant disease with protean clinical manifestations, ranging from asymptomatic to that of severe heart failure or sudden death. There is no known parameter in individuals with hypertrophic cardiomyopathy (HCM) that predicts a specific clinical event. This is particularly troublesome for premature sudden death that frequently occurs in young athletes without prior symptoms. Recent identification of mutations in the beta myosin heavy chain (beta MHC) gene that co-segregate with the inheritance of the disease provides an opportunity to determine whether certain mutations are more likely to induce a particular clinical event. In this study we analyzed the genotype and phenotype of individuals from two unrelated families with HCM in which the affected individuals have the same missense mutation in exon 13 (G1208A) of the coding sequence for beta MHC.

METHODS

Individuals from two unrelated families with the diagnosis of FHCM were screened by history, physical examination, electrocardiography, and two dimensional echocardiography. After extraction of DNA from the blood of these individuals, the exon 13 of the beta MHC gene was amplified by polymerase chain reaction (PCR), and the PCR product was digested with Ddel restriction endonuclease. The digestion products were separated by gel electrophoresis and identified by ethidium bromide staining.

RESULTS

We studied 54 individuals from the two families, 21 were affected with HCM of which eleven died prematurely, eight from sudden cardiac death. While most of the nine affected individuals studied had septal hypertrophy, three had concentric hypertrophy and six, left ventricular outflow tract obstruction. Onset of symptoms was in the second decade of life. Electrophoretic separation of the digested DNA (exon 13) from unaffected individuals provided two fragments of 84 and 70 bp in size, as expected. In contrast, DNA from individuals affected with HCM showed four fragments of 84 bp, 70 bp, 52 bp and 32 bp indicating they inherited the mutation. In only one 10 year old male was the mutation present without evidence of HCM which gives an overall penetrance of 86%.

CONCLUSIONS

The missense mutation in exon 13 of the beta MHC gene in individuals with FHCM is associated with high penetrance, highly variable expressivity, severe disease, early in onset and a high incidence of premature sudden death. Based on these results we recommend individuals from families with HCM be screened for this missense mutation and if positive, be counselled to avoid combative sports, as it is these activities that often precipitate sudden death.

Hypertrophic cardiomyopathy mutation is expressed in messenger RNA of skeletal as well as cardiac muscle

BACKGROUND

The beta-myosin heavy chain (beta-MHC) gene has been identified as a major locus for familial hypertrophic cardiomyopathy (FHCM). We recently showed that one of the common mutations associated with FHCM is expressed in the cardiac muscle messenger RNA (mRNA) of an affected individual. Since beta-MHC is a major sarcomeric protein of cardiac and skeletal muscle, studies were performed to determine whether the mutation is also expressed in skeletal muscle.

METHODS AND RESULTS

Biopsies were obtained of skeletal muscle (biceps brachii) from a proband with FHCM known to have the missense mutation in exon 13 of the beta-MHC gene. RNA was extracted from skeletal muscle and lymphocytes by the RNAzol method. First-strand complementary DNA was synthesized by reverse transcription using an antisense primer to exon 16. Polymerase chain reaction (PCR) was performed using primers to exons 12 and 14 to amplify the segment encompassing exon 13. The PCR products were digested with Ddel restriction endonuclease. Undigested PCR product in the control and the proband was 321 base-pairs (bp). Ddel digestion of the PCR product from normal skeletal and lymphocytes showed two DNA fragments of 181 and 140 bp as expected, whereas digestion of the PCR product from the proband's skeletal muscle and lymphocytes showed four DNA fragments of 181, 149, 140, and 32 bp due to the mutation in exon 13. This indicates that the mutation in affected individuals is also expressed in the mRNA of skeletal muscle and lymphocytes.

CONCLUSIONS

To our knowledge, this is the first documentation of a beta-MHC gene mutation expressed in skeletal muscle. This finding is provocative. Does it impair skeletal muscle function? If so, how? If not, why not? Is the impairment, or lack of it, a clue to the molecular defect of cardiac muscle? Furthermore, skeletal muscle provides a readily accessible source of mRNA for expression studies and for purification of the beta-MHC protein, which is probably essential to future investigation designed to unravel the molecular basis of this disorder.

Detection of a new mutation in the beta-myosin heavy chain gene in an individual with hypertrophic cardiomyopathy

Familial hypertrophic cardiomyopathy (FHCM) is an autosomal dominant disease affecting primarily the myocardium. The gene responsible for FHCM has been localized to chromosome 14 in some families and several mutations have been described in the beta-myosin heavy chain (beta MHC), a candidate gene for the disease. We recently identified a family with HCM in whom we did not detect any of the known mutations in the beta MHC gene (the alpha/beta MHC hybrid gene and the missense mutation in exons 13 and 9). However, we did observe a novel 9.5-kb BamHI restriction fragment length polymorphism detected by a beta MHC probe on Southern blots of DNA from the proband of this family. Similarly, a novel 3.8-kb TaqI polymorphism and a novel 4.3-kb HindIII polymorphism were detected on Southern blots of DNA from the same proband. Polymerase chain reaction (PCR) was used to amplify the segment of the beta MHC that was detected by pSC14 probe. PCR amplification of the distal 3'-end of the beta MHC gene yielded an additional product in the DNA template from the proband which was subsequently cloned and sequenced. The sequence analysis showed a 2.4-kb nucleotide deletion involving one allele of the beta MHC gene. The deletion includes part of the intron 39, exon 40 including the 3'-untranslated region and the polyadenylation signal, and part of the beta-alpha MHC intergenic region. This deletion was inherited in Mendelian fashion in an additional three members of this small family of which only the proband has developed clinically diagnosed HCM at a very late onset (age 59 yr), the other three family members are younger and have not developed the disease at the ages of 10, 32, and 33 yr.

The natural history of community-acquired hepatitis C in the United States. The Sentinel Counties Chronic non-A, non-B Hepatitis Study Team

BACKGROUND

Chronic liver disease develops in more than half of patients with post-transfusion hepatitis C, but little is known about the natural history of community-acquired hepatitis C.

METHODS

In 1985 and 1986 we identified adults with acute non-A, non-B hepatitis in four counties in the United States and followed them prospectively. We used three markers to detect hepatitis C virus (HCV) infection in stored samples of serum: antibody to HCV (anti-HCV) detected by second-generation serologic assays; HCV RNA detected by polymerase-chain-reaction assay; and antibody to HCV antigen (anti-HCVAg) detected by fluorescent-antibody-blocking assay.

RESULTS

Of 130 patients with non-A, non-B hepatitis, 106 (82 percent) had HCV infection, 93 were positive for anti-HCV, and 13 were positive only for HCV RNA or anti-HCVAg. Chronic hepatitis developed in 60 (62 percent) of 97 HCV-infected patients followed for 9 to 48 months, with no relation to the risk factors for infection. Ten of the 30 patients who had liver biopsies had chronic active hepatitis. In samples collected 42 to 48 months after the onset of hepatitis, HCV RNA was detected in 12 of 13 tested patients with chronic hepatitis and in all 15 tested patients with hepatitis that had resolved. Anti-HCV persisted in all but two of the initially positive patients, for a rate of antibody loss of 0.6 per 100 person-years.

CONCLUSIONS

Patients with community-acquired hepatitis C have a high rate of chronic hepatitis. HCV may be a major cause of chronic liver disease in the United States, and in most patients HCV infection seems to persist for at least several years, even in the absence of active liver disease.

[Traumatic rupture of the diaphragm in an infant]

Traumatic rupture of the diaphragm can be caused by both penetrating and blunt trauma. High kinetic energy applied to the abdomen during blunt abdominal trauma creates pressure differences between the abdominal and chest cavities. These sudden changes in pressure rupture the diaphragm. We present a 13-month-old infant admitted after being injured by a car. In addition to rupture of the diaphragm there were pelvic fractures. Chest x-ray on admission was diagnostic for diaphragmatic rupture. The possibility of congenital diaphragmatic hernia was rejected because of increasing ventilatory embarrassment.

Expression of a missense mutation in the messenger RNA for beta-myosin heavy chain in myocardial tissue in hypertrophic cardiomyopathy

We have determined that a missense mutation in exon 13 of the beta-myosin heavy chain (beta MHC) gene is expressed in the messenger RNA (mRNA) isolated from a right ventricular endomyocardial biopsy obtained from the proband of a family with hypertrophic cardiomyopathy. The mutation is the result of a substitution of an adenine for a guanine residue in one allele of the beta MHC gene and creates a second recognition site for the restriction endonuclease Ddel in exon 13. The mutation is inherited in a Mendelian fashion and co-segregates with hypertrophic cardiomyopathy in this family. Complementary DNAs synthesized from RNA isolated from the endomyocardial biopsy were cloned into a plasmid vector and sequenced to confirm the expression of both the normal and mutant allele in mRNA of myocardial tissue. This is the first report of the transcription of a mutant beta MHC gene allele into mRNA of the myocardium.

Isolation of a human chromosome 14-only somatic cell hybrid: analysis using Alu and LINE-based PCR

Interspecific somatic cell hybrids containing single human chromosomes are valuable reagents for localization of cloned genes and DNA fragments to specific chromosomes, for the development of chromosome-specific libraries, and for generation of hybrid cell lines containing subchromosomal regions. A CHO somatic cell hybrid containing a single, intact human chromosome 14 (MHR14) was developed and confirmed by LINE PCR amplification gel pattern, by Alu-517 PCR product dot blot hybridization, and by cytogenetic analysis. MHR14 will serve as the chromosome source for the development of a radiation map of human chromosome 14.

Risk factors for acute non-A, non-B hepatitis in the United States and association with hepatitis C virus infection

The Centers for Disease Control conducted intensive surveillance for acute non-A, non-B hepatitis in four sentinel counties over a 7-year period. Testing for antibody to hepatitis C virus was performed with the newly developed enzyme immunoassay. The incidence of non-A, non-B hepatitis remained relatively stable (average, 7.1 cases per 100,000, but there were significant changes in disease transmission patterns. The proportion of patients with a history of blood transfusion declined from 17% to 6%, but the proportion with a history of parenteral drug use increased from 21% to 42%. The proportion of patients with histories of sexual exposure (6%), household exposure (3%), occupational exposure to blood (2%), or hemodialysis (0.6%) did not change over time. Antibody to hepatitis C virus was found in 45% of patients within 6 weeks of onset of illness and in 68% of patients followed up for at least 6 months. Patients with no history of transfusions were just as likely to be positive for antibody to hepatitis C virus as patients with transfusion-associated hepatitis, indicating that hepatitis C virus is the major causative agent of all non-A, non-B hepatitis in the United States.

Persistent müllerian duct remnant in a newborn

Müllerian duct remnant in a newborn is a rare finding. The presented case illustrates well the ultrasonic and radiologic features of the entity.

The changing epidemiology of hepatitis B in the United States. Need for alternative vaccination strategies

To determine trends in the incidence and epidemiology of acute hepatitis B in the United States we conducted intensive surveillance for viral hepatitis in four sentinel counties from October 1, 1981, to September 30, 1988. The overall incidence of hepatitis B remained relatively constant throughout the study period (average, 13.2 cases per 100,000 population), but disease transmission patterns changed significantly. The proportions of hepatitis B cases accounted for by homosexual activity and health care employment decreased 62% and 75%, respectively; the proportions of cases accounted for by parenteral drug use and heterosexual exposure increased 80% and 38%, respectively. The percentage of patients for whom no risk factor was identified (30% to 40%) did not change over time. These patients tended to belong to minority populations, and their socioeconomic level was low. The decline in the number of hepatitis B cases among homosexual men probably results from the modification of high-risk sexual behavior; the decline among health care workers is due mostly to hepatitis B immunization. The current strategy for prevention of hepatitis B, which targets high-risk groups for immunization, has failed to have a significant impact on the incidence of disease.

Diversity in supercoupling of beta 2-adrenergic receptors in orthostatic hypotension

Orthostatic hypotension is a clinical condition that frequently involves abnormal adrenergic control of cardiovascular function. Adrenergic function was studied in six patients with symptomatic orthostatic hypotension and in 11 age-matched healthy subjects. The patients demonstrated higher supine mean arterial pressures (MAP; 103 +/- 8 versus 86 +/- 4 mm Hg) and orthostatic hypotension (delta MAP -70 +/- 5 versus +15 +/- 2 mm Hg, p less than 0.001) compared with normal subjects. The delta MAP in phase II of the Valsalva maneuver was significantly greater (-31 +/- 4 versus -7 +/- 4 mm Hg, p less than 0.002) and phase IV heart rate response was blunted (-5 +/- 3 versus -30 +/- 8 beats/min, p less than 0.02) in these patients. More isoproterenol was required to increase heart rate by 25 beats per minute in patients with hypotension (810 +/- 670 versus 3.1 +/- 1.3 micrograms, p less than 0.05), indicating marked chronotropic hyposensitivity. Leukocyte beta 2-adrenergic receptor densities were similar in patients and controls. beta 2-Adrenergic receptor coupling, however, was elevated in patients with hypotension when compared with control subjects (ratio of the low-affinity and high-affinity dissociation constants [KL/KH] 140 +/- 7.4 versus 66 +/- 4.3, p less than 0.001). There were negative correlations between the KL/KH value and the dose of isoproterenol required to decrease MAP by 20 torr (p less than 0.02) and between the KL/KH value and the product of the hormone receptor and MAP (p less than 0.01). However, the patients could be subdivided into a group who could mount a nearly normal hormone receptor times MAP response on standing (group 1A), and a group who could not (group 1B). The group 1A patients had elevated plasma norepinephrine responses associated with milder beta 2-adrenergic receptor supercoupling, whereas group 1B patients had essentially no orthostatic plasma norepinephrine response and had much higher KL/KH values. Thus, though a state of biochemical supersensitivity existed in both patient subgroups, diminished catecholamine exposure was associated, as expected, with beta 2-adrenergic hypersensitivity in group 1B, whereas there was no diminution of catecholamine exposure in the beta 2-adrenergic hypersensitivity observed in group 1A patients.

Spectrum of dysautonomia in mitral valvular prolapse

PURPOSE

Symptoms suggesting altered autonomic regulation of cardiovascular function have been noted in some patients with mitral valvular prolapse (MVP) but may also occur in patients with other disorders. We evaluated cardiovascular responses to autonomic stimuli in 118 patients with symptoms of dysautonomia, 78 of whom had MVP, and 40 of whom did not, to determine if unique patterns of these responses distinguished patients in one symptomatic subgroup from another.

SUBJECTS AND METHODS

The responses of patients to standing, quantitated Valsalva maneuver, facial immersion in ice water, and administration of isoproterenol, phenylephrine, and tyramine were compared with those in 12 asymptomatic patients with MVP and 23 normal volunteers.

RESULTS

Constitutional, cardiovascular, and neuropsychiatric symptoms occurred with similar frequency in the two symptomatic patient groups. The most common pattern of abnormal responses in symptomatic patients with or without MVP was (1) an increased heart rate and elevated plasma norepinephrine levels while supine and then while standing quietly for five minutes, (2) an exaggerated increase in heart rate during phase II of Valsalva, (3) a diminished bradycardic response during phase IV of Valsalva, and (4) an exaggerated heart rate response to administration of isoproterenol. The increased heart rate during Valsalva, but not the exaggerated sensitivity to isoproterenol, was correlated with the magnitude of the chronotropic response to standing only in symptomatic patients with MVP. Exaggerated hypertensive overshoot during phase IV of Valsalva was observed in only a few symptomatic patients. No consistent pattern of these abnormalities, however, was noted in any of the patient subgroups. Hemodynamic responses to autonomic stimuli in asymptomatic MVP patients were generally indistinguishable from those observed in normal subjects.

CONCLUSION

These findings suggest that abnormal cardiovascular responses to autonomic stimuli may occur in any patient with symptoms of dysautonomia regardless of the presence or absence of MVP and that the pattern of these abnormal responses may be diverse. It is therefore important to characterize the pattern of altered autonomic regulation of cardiovascular function in each patient when considering mechanistic implications or making therapeutic decisions about these patients.

Mitral valve prolapse with symptoms of beta-adrenergic hypersensitivity. Beta 2-adrenergic receptor supercoupling with desensitization on isoproterenol exposure

Autonomic nervous system dysfunction has recently been identified in a subset of patients with mitral valve prolapse. These autonomic nervous system abnormalities may correspond, in part, to biochemical alterations in beta-adrenergic receptors. Nine women with mitral valve prolapse and symptoms and signs of beta-adrenergic hypersensitivity and seven normal volunteer women were studied. Quiet standing (five minutes) increased both heart rate and plasma norepinephrine (p less than 0.05) in symptomatic patients with mitral valve prolapse compared with normal subjects. The dose of isoproterenol required either to increase heart rate 25 beats/minute (0.5 +/- 0.3 microgram versus 1.0 +/- 0.3 microgram) or to decrease mean arterial pressure 20 mm Hg (11.1 +/- 4.8 versus 78.2 +/- 25.2 micrograms) was significantly less in the patients with mitral valve prolapse than in the volunteers. Symptomatic patients with mitral valve prolapse were desensitized by a four-hour isoproterenol infusion, whereas sensitivity in normal control subjects did not change. In the patients with mitral valve prolapse, baseline beta-adrenergic receptor coupling was elevated compared with that in control subjects (220 +/- 7 versus 81 +/- 2; p less than 0.001). Isoproterenol infusion induced uncoupling in these patients (KL/KH = 35 +/- 3, p less than 0.05) but did not alter coupling in normal volunteers. This study demonstrates physiologic and pharmacologic beta-adrenergic hypersensitivity in vivo directly corresponding to biochemical supercoupling in a subset of patients with mitral valve prolapse.

The effect of underreporting on the apparent incidence and epidemiology of acute viral hepatitis

To determine if passively reported cases of acute viral hepatitis are representative of the affected population, an active surveillance system was set up that identified all persons in Pierce County, Washington, who had been diagnosed by a physician as having acute viral hepatitis in the period March 1 through August 31, 1984. In this county, this was part of an ongoing epidemiologic study of viral hepatitis that had previously included some stimulation of reporting. The active surveillance system covered all primary sources of medical care, including all private physicians who were most likely to see persons with hepatitis. Secondary sources, those that did not provide direct medical care but might be aware of new cases, were also surveyed. The results of active surveillance showed that passive reporting was about 65% complete in Pierce County. No change occurred in the number of hepatitis A cases reported, but hepatitis B cases increased by 50%, and non-A, non-B hepatitis cases increased by 138%. Most of the increase was a result of enhanced reporting from private physicians. The two risk groups most affected by underreporting were homosexual men with hepatitis B and blood transfusion recipients with non-A, non-B hepatitis. During active surveillance, the proportion of persons with hepatitis B who reported homosexual activity was 52% compared with 20% from passive surveillance. Transfusion recipients represented 24% of the non-A, non-B hepatitis reported from active surveillance compared with 9% reported from passive surveillance. Although Pierce County may not be representative of all counties in the United States, persons responsible for public health prevention programs should recognize that data acquired through passive surveillance may not accurately reflect the magnitude of the risk for specific populations or the amount of disease that can be prevented.

[2 or 4 daily doses of cimetidine in the treatment of gastric ulcer?]

In a randomized multicentre study of 149 patients with gastric ulcer the effect of 1000 mg cimetidine daily applied in four separate doses was compared to that of 400 mg cimetidine twice a day. In both patient groups similar healing rates were observed. 80.3% and 74.0%, respectively, of the ulcers healed within 6 weeks, and 93.8% and 90.3%, respectively, within 10 weeks. Abdominal pain and antacid consumption decreased under both regimens to a similar degree. Drug safety was good. Lower cost and simplicity in the administration make the b. i. d. regimen of cimetidine preferable to the q. i. d. regimen in the acute treatment of gastric ulcer.

Congenital partial gastric antral obstruction, an elusive cause of abdominal pain and vomiting

The patient with partial gastric antral obstruction due to a diaphragm may present with obstructive symptoms at any age in life. Including the four patients presented, there are now 50 reported cases. Since the diagnosis has been unduly delayed in many adults, it is particularly important that those physicians and surgeons caring for infants and children be aware of this entity. If properly treated in infancy and childhood, many years of suffering and debility can be obviated.