Check-in Kiosks in the Outpatient Clinical Setting: Fad or the Future?

OBJECTIVES

Check-in kiosks are increasingly used in health care. This project aims to assess the effects of kiosk use upon check-in duration, point of service (POS) financial returns, and patient satisfaction.

METHODS

Six kiosks were implemented in a large academic orthopedic clinic, and check-in duration for 8.5 months following implementation and POS returns for 10.5 months before and after implementation were analyzed. Consumer Assessment of Healthcare Providers and Systems Clinician and Group survey and self-devised surveys recorded patient satisfaction.

RESULTS

Cumulatively, 28,636 kiosk-based patient encounters were analyzed. Compared with historical norms, check-in duration decreased 2 minutes, 47 seconds (P < 0.001). Daily gross and individual POS returns increased $532.13 and $1.89, respectively (P < 0.001). Satisfaction surveys were completed by 719 of 1376 consecutive patients (52% response rate), revealing 12% improvement (P < 0.001), but Consumer Assessment of Healthcare Providers and Systems Clinician and Group survey responses demonstrated no change (P = 0.146, 0.928, and 0.336).

CONCLUSIONS

Kiosks offer to reduce check-in duration and increase POS revenue without negatively affecting patient satisfaction.

The rising use of total hip arthroplasty for femoral neck fractures in the United States

BACKGROUND

We examined the trends in the treatment of femoral neck fractures with arthroplasty in the United States from 2004-2013.

METHODS

We used the National Inpatient Sample database in conjunction with codes from the International Classification of Diseases, Ninth Revision, to identify patients receiving hemiarthroplasty (HA) or total hip arthroplasty (THA) for the treatment of closed femoral neck fracture from 2004-2013. We evaluated the trend of these 2 treatments along with demographics, comorbidities, length of stay and same admission mortality.

RESULTS

Our study identified 1,059,414 patients who underwent arthroplasty for the treatment of femoral neck fracture. We found a 42% increase in the use of THA during the study period from 8.4% in 2004 to 12.9% in 2013. While the large majority of patients received HA (87.1%), there was an overall decline in the use of HA (89,132 in 2004 to 85,635 in 2013) and increase in the use of THA (8,177 in 2004 to 11,375 in 2013). Patients receiving THA were younger (mean age 74.7 THA vs. 80.4 HA, p < 0.001) with fewer comorbidities, higher likelihood of discharge to home (24% THA vs. 10% HA, p < 0.001) and lower inpatient mortality rates (1.5 % THA vs. 2.4 % HA, p < 0.001) in comparison to HA.

CONCLUSION

There has been a significant increase in the use of THA over the last decade. Patients receiving THA were younger and healthier with fewer comorbidities, less likely to sustain a same admission mortality and more likely to discharge to home in comparison to HA patients.

Trends and Risk Factors in Orthopedic Lawsuits: Analysis of a National Legal Database

Orthopedic surgeons frequently encounter medical malpractice claims. The purpose of this study was to assess trends and risk factors in lawsuits brought against orthopedic surgeons using a national legal database. A legal research service was used to search publicly available settlement and verdict reports between 1988 and 2013 by terms "orthopaedic or orthopedic" and "malpractice." Temporal trends were evaluated, and logistic regression was used to identify independent risk factors for case outcomes. A total of 1562 publicly reported malpractice cases brought against orthopedic surgeons, proceeding to trial during a 26-year period, were analyzed. The plaintiffs won 462 (30%) cases, with a mean award of $1.4 million. The frequency of litigation and pay-outs for plaintiffs increased 215% and 280%, respectively, between the first and last 5-year periods. The mean payout for plaintiff-favorable verdicts was highest in pediatrics ($2.6 million), followed by spine ($1.7 million) and oncology ($1.6 million). Fracture fixation (363 cases), arthroplasty (290 cases), and spine (231 cases) were the most commonly litigated procedures, while plaintiffs were most successful for fasciotomy (48%), infection-treating procedures (43%), and carpal tunnel release (37%). When analyzing data by state and region, adjusted for population, northeastern states had a higher frequency of lawsuits. Malpractice liability has increased during the past 3 decades while orthopedic surgeons continue to win most of the cases making it to court. As patients search for medical care via publicly available information, it is important for orthopedic surgeons to understand what aspects of their own practice carry different risks of litigation. [Orthopedics. 2019; 42(2):e260-e267.].

Adoption of Intramedullary Nail Fixation for Proximal Humerus Fractures: Assessment of Surgical Efficiency and Complications

Fixation of proximal humerus fractures (PHFs) with intramedullary (IM) nails potentially is a newer, less invasive technique. The purpose of this study was to report on the early adoption results of IM nail use for PHF. Retrospective chart reviews were performed on the first 60 patients treated with IM nails for acute PHFs by two shoulder surgeons. The first 15 patients treated by each surgeon were compared with the subsequent 15 patients. Surgical and fluoroscopic times, fracture type, union, and varus collapse were compared. The average operating time decreased (p = .002). Fluoroscopy time, radiographic alignment, union rate, complications, and reoperations were not influenced. Three- and four-part fractures had a higher complication rate than two-part fractures (53% vs. 20%). When considering implementing use of IM nails for treatment of PHFs, initial cases can have outcomes and complications similar to those performed with greater experience. IM nailing appears a good treatment option for two-part PHFs. (Journal of Surgical Orthopaedic Advances 28(2):121-126, 2019).

Methamphetamine-Induced Cardiomyopathy (MACM) in a Middle-Aged Man; a Case Report

The development of methamphetamine-associated cardiomyopathy (MACM) represents a severe complication of chronic methamphetamine abuse. MACM-induced irreversible structural and functional changes in the heart can eventually lead to decompensated heart failure, ultimately requiring heart transplantation. In this case report we present a 47-year old male with a previous history of chronic amphetamine abuse who presented to the emergency room with severe dyspnea at rest associated with mild substernal non-radiating chest pain. He denied any previous cardiac history but had a positive urinary toxicology for methamphetamine. A complete cardiac workup ruled out all other etiologies. The patient required a 3-week intensive pharmacotherapy intervention to stabilize acute heart failure symptoms. At discharge he was classified as having New York Association Class III (NYHA-III) heart failure. His medical symptoms did not improve and he was considered for heart transplantation. With the increase in availability and abuse of methamphetamine, case of MACM such as ours are more frequently being encountered in the emergency departments. In addition to raising awareness, our case provides an outline of how MACM patients likely may present and the subsequent morbid sequela. Clinicians should maintain a high degree of suspicion when assessing all patients with a history of methamphetamine abuse. Early cardiac evaluation can help identify ventricular compromise in asymptomatic patients providing an opportunity to intervene prior to the development of irreversible MACM.

Trends in Joint Replacement Surgery in Patients with Rheumatoid Arthritis

Objective.

This study analyzed trends in large total joint arthroplasties (TJA) and in the proportion of these procedures performed on patients with rheumatoid arthritis (RA).

Methods.

The US Nationwide Inpatient Sample (2002–2012) was used to identify the incidences of total shoulder (TSA), elbow (TEA), knee (TKA), hip (THA), and ankle (TAA) arthroplasty and the proportion of these performed with coexisting RA.

Results.

The prevalence of RA among patients with TJA increased 3.0%. The prevalence of RA among cases of TEA and TSA decreased by 50% (p < 0.0001) and 18% (p = 0.0016), respectively; a 38.0% decrease occurred in the prevalence of RA among TAA (p = 0.06); and nonsignificant increases were seen among THA and TKA. The average age difference between RA and non-RA patients undergoing TJA narrowed by 2 years (p < 0.0001). There was a greater reduction in the proportion of TSA, TEA, and TAA groups among women with RA than men with RA. In the TSA and TEA groups, there was a reduction in the proportion of whites with RA, but not blacks. The proportion of privately insured TSA and TAA patients with RA decreased, while patients with RA undergoing TSA, TEA, or TAA who were receiving Medicaid (government medical insurance) remained relatively stable over time.

Conclusion.

The prevalence of RA has decreased among TSA and TEA patients. A nonsignificant decline occurred among TAA patients. The average age of TJA patients with RA is beginning to mirror those without RA. Sex ratios for TSA, TEA, and TAA patients are following a similar pattern. These results may be evidence of the success of modern RA treatment strategies.

Arthroscopic Versus Open Rotator Cuff Repair: Which Has a Better Complication and 30-Day Readmission Profile?

PURPOSE

To provide a comparative 30-day postoperative analysis of complications and unplanned readmission rates, using the National Surgical Quality Improvement Program database, after open or arthroscopic rotator cuff repair (RCR).

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was reviewed for postoperative complications after open or arthroscopic RCR over an 8-year period, from 2007 through 2014. Patients were identified by use of Current Procedural Terminology codes. The open group contained 3,590 cases (21.8%) and the arthroscopic group had 12,882 cases (78.2%), for a total of 16,472 patients undergoing RCR. The risk of complications was compared between the 2 groups, along with patient demographic characteristics, operative time, length of stay, and unplanned readmission within 30 days. We compared dichotomous variables using the Fisher exact test and continuous variables with 1-way analysis of variance. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated when appropriate.

RESULTS

The open RCR group had a higher prevalence of patients aged 65 years or older and comorbidities such as hypertension, diabetes, chronic obstructive pulmonary disease, smoking, and alcoholism (P < .05). Patients undergoing open RCR had a higher risk of any adverse event when compared with arthroscopic RCR patients (1.48% vs 0.84%; RR, 1.17; 95% CI, 1.05-1.30; P = .0010). They were also at higher risk of return to the operating room within 30 days (0.70% vs 0.26%; RR, 1.36; 95% CI, 1.09-1.69; P = .0004). Open RCR was associated with a longer average hospital stay (0.48 ± 2.7 days vs 0.23 ± 4.2 days, P = .0007), whereas arthroscopic RCR had a longer average operative time (90 ± 45 minutes vs 79 ± 45 minutes, P < .0001).

CONCLUSIONS

Although both open and arthroscopic approaches to RCR had low morbidity, arthroscopy was associated with lower risks of any adverse event and return to the operating room during the initial 30-day postoperative period.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Competitive bass anglers: a new concern in sports medicine

OBJECTIVE

Competitive bass angling involves sport fishing against other anglers while targeting a species of fish known as the black basses. Due to the rapidly growing popularity of high school competitive bass angling in Alabama and the nature of the casting motion similar to that of overhead athletes, we sought to examine the prevalence of sports type injuries in this population.

METHODS

In spring 2016, an anonymous survey was distributed across two large scale competitive high school fishing tournaments, allowing for a broad sampling of anglers throughout the state of Alabama. Survey items included demographic information, relevant past medical history, and various pains associated with the shoulder, elbow and wrist. Results were recorded and analyzed electronically using Microsoft Excel and IBM SPSS statistical software.

RESULTS

A total of 257 surveys were recorded. The response rate was 61%. The mean age of participating anglers was 15 ± 1.61 years. The majority (42%) of anglers fished year round. On average, anglers casted nearly 1,000 more times while competing versus fishing recreationally. Approximately 15% of anglers experienced shoulder, elbow, and wrist pain. The most common factors associated with pain included higher tournament cast counts, number of competitive years, number of tournaments/year, number of tournaments, and use of light weight lures.

CONCLUSION

A large portion of high school competitive anglers experience upper extremity pain. Knowledge of angling factors associated with pain allow for the creation of a modifiable routine to help reduce pain in affected anglers and prevent pain in healthy anglers.

Readability of Orthopaedic Patient-reported Outcome Measures: Is There a Fundamental Failure to Communicate?

BACKGROUND

Patient-reported outcome measures (PROMs) are increasingly used to quantify patients' perceptions of functional ability. The American Medical Association and NIH suggest patient materials be written at or below 6th to 8th grade reading levels, respectively, yet one recent study asserts that few PROMs comply with these recommendations, and suggests that the majority of PROMs are written at too high of a reading level for self-administered patient use. Notably, this study was limited in its use of only one readability algorithm, although there is no commonly accepted, standard readability algorithm for healthcare-related materials. Our study, using multiple readability equations and heeding equal weight to each, hopes to yield a broader, all-encompassing estimate of readability, thereby offering a more accurate assessment of the readability of orthopaedic PROMS.

QUESTIONS/PURPOSES

(1) What proportion of orthopaedic-related PROMs and orthopaedic-related portions of the NIH Patient Reported Outcomes Measurement Information System (PROMIS®) are written at or below the 6th and 8th grade levels? (2) Is there a correlation between the number of questions in the PROM and reading level? (3) Using systematic edits based on guidelines from the Centers for Medicare and Medicaid Services, what proportion of PROMs achieved American Medical Association and NIH-recommended reading levels?

METHODS

Eighty-six (86) independent, orthopaedic and general wellness PROMs, drawn from commonly referenced orthopaedic websites and prior studies, were chosen for analysis. Additionally, owing to their increasing use in orthopaedics, four relevant short forms, and 11 adult, physical health question banks from the PROMIS®, were included for analysis. All documents were analyzed for reading grade levels using 19 unique readability algorithms. Descriptive statistics were performed using SPSS Version 22.0.

RESULTS

The majority of the independent PROMs (64 of 86; 74%) were written at or below the 6th grade level, with 81 of 86 (94%) written at or below the 8th grade level. All item banks (11 of 11) and short forms (four of four) of the PROMIS® were written below the 6th grade reading level. The median reading grade level of the 86 independent PROMs was 5.0 (interquartile range [IQR], 4.6-6.1). The PROMIS® question banks had a median reading grade level of 4.1 (IQR, 3.5-4.8); the Adult Short Forms had a median reading grade level of 4.2 (IQR, 4.2-4.3) There was no correlation appreciated between the median reading grade level and the number of questions contained in a PROM (r = -0.081; p = 0.460). For PROMs above NIH-recommended levels, following edits, all (five of five) achieved NIH reading level goals and three (three of five) achieved American Medical Association goals. Editing of these PROMs improved readability by 4.3 median grade level (before, 8.9 [IQR, 8.4-9.1], after 4.6 [IQR, 4.6-6.4], difference of medians, 4.3; p = 0.008).

CONCLUSIONS

Patient literacy has great influence on healthcare outcomes, and readability is an important consideration in all patient-directed written materials. Our study found that more than 70% of PROMs commonly used in orthopaedics, and all orthopaedic-related portions of the PROMIS® are written at or below the most stringent recommendations (≤ 6th grade reading level), and more than 90% of independent PROMs and all PROMIS® materials are written at or below an 8th grade level. Additionally, the use of the Centers for Medicare and Medicaid Services guidelines for editing high reading level PROMs yields satisfactory results.

CLINICAL RELEVANCE

Fears of widely incomprehensible PROMs may be unfounded. Future research to identify the most appropriate readability algorithm for use in the healthcare sector, and revalidation of PROMs after readability-improving edits is warranted.

Behind the Match Process: Is There Any Financial Difference Lurking below the Specialty of Choice?

The Match was developed in response to a chaotic residency selection process. While the match has remained relatively unchanged since it was introduced, the number of medical school graduates has increased at a rate outpacing the number of residency positions leading to a more competitive process for applicants. In May 2014, an 18-question mixed-response questionnaire was distributed to fourth year allopathic medical students via an E-mail distribution list for student affairs representatives. The individual surveys were accessible via SurveyMonkey and available for completion over the course of a 4-week period. Approximately 65.1 per cent of students performed at least one audition rotation and documented average expenditures of $2494 on housing, food, and transportation. The average applicant applied to 32 programs and attended 12 interviews while spending $4420 on the interview trail. Applicants for surgical programs applied to approximately 42 programs and attended 13 interviews compared with primary care applicants who averaged 23 programs ( P < 0.001) and attended 12 interviews ( P = 0.002). Surgical applicants averaged 20 days on the interview trail while spending $5500 ($423/interview) on housing, food, and transportation compared with primary care applicants averaged 19 days away from home ( P < 0.05) and spending $3400 ($283/interview) on these same items ( P < 0.001). The findings in our study indicate that the “Match process” contributes to the financial burden of graduating medical students and it is more expensive and time consuming for the candidates interested in surgical specialties.

Behind the Match Process: Is There Any Financial Difference Lurking Below the Specialty of Choice?

The Match was developed in response to a chaotic residency selection process. While the match has remained relatively unchanged since it was introduced, the number of medical school graduates has increased at a rate outpacing the number of residency positions leading to a more competitive process for applicants. In May 2014, an 18-question mixed-response questionnaire was distributed to fourth year allopathic medical students via an E-mail distribution list for student affairs representatives. The individual surveys were accessible via SurveyMonkey and available for completion over the course of a 4-week period. Approximately 65.1 per cent of students performed at least one audition rotation and documented average expenditures of $2494 on housing, food, and transportation. The average applicant applied to 32 programs and attended 12 interviews while spending $4420 on the interview trail. Applicants for surgical programs applied to approximately 42 programs and attended 13 interviews compared with primary care applicants who averaged 23 programs (P < 0.001) and attended 12 interviews (P = 0.002). Surgical applicants averaged 20 days on the interview trail while spending $5500 ($423/interview) on housing, food, and transportation compared with primary care applicants averaged 19 days away from home (P < 0.05) and spending $3400 ($283/interview) on these same items (P < 0.001). The findings in our study indicate that the "Match process" contributes to the financial burden of graduating medical students and it is more expensive and time consuming for the candidates interested in surgical specialties.

Natural history of meticillin-resistant Staphylococcus aureus colonisation among residents in community long term care facilities in Spain

The spread of meticillin-resistant Staphylococcus aureus (MRSA) is a major problem for both acute care hospitals and among residents in long term care facilities (LTCFs). We performed a cohort study to assess the natural history of MRSA colonisation in LTCF residents. Two cohorts of residents (231 MRSA carriers and 196 non-carriers) were followed up for an 18 month period, with cultures of nasal and decubitus ulcers performed every six months. In the MRSA carrier cohort, 110 (47.8%) residents had persistent MRSA colonisation for six months or longer, 44 (19.0%) had transient colonisation and nine (3.9%) were intermittently colonised. No risk factors for persistent MRSA colonisation could be determined. The annual incidence of MRSA acquisition was around 20% [95% confidence interval (CI): 14.3-25.5]. Antibiotic treatment was independently associated with MRSA acquisition (odds ratio: 2.27; 95% CI: 1.05-4.88; P=0.03). Just two clones were distinguishable by pulsed-field gel electrophoresis and multilocus sequence typing: CC5-MRSA IV, which is widely disseminated in Spanish hospitals, and ST22-MRSA IV. This study adds to the knowledge of the epidemiology of MRSA in community LTCFs, which are important components of long term care in Spain.

Soluble oligomeric forms of beta-amyloid (Abeta) peptide stimulate Abeta production via astrogliosis in the rat brain

The aim of this study was to investigate the interaction between beta-amyloid (Abeta) peptide and astrogliosis in early stages of Abeta toxicity. In Wistar rats, anaesthetised with equitesine, a single microinjection of Abeta1-42 oligomers was placed into the retrosplenial cortex. Control animals were injected with Abeta42-1 peptide into the corresponding regions of cerebral cortex. Immunocytochemical analysis revealed an intense Abeta immunoreactivity (IR) at the level of Abeta1-42 injection site, increasing from the first 24 h to later (72 h) time point. Control injection showed a light staining surrounding the injection site. In Abeta oligomers-treated animals, Abeta-immunopositive product also accumulates in cortical cells, particularly in frontal and temporal cortices at an early (24 h) time point. Abeta-IR structures-like diffuse aggregates forms were also observed in hippocampus and in several cortical areas, increasing from the first 24 h to later (72 h) time point. In control animals no specific staining was seen neither in cortical cells nor in structures-like diffuse aggregates forms. Injections of Abeta oligomers also induce activation of astrocytes surrounding and infiltrating the injection site. Astrocyte activation is evidenced by morphological changes and upregulation of glial fibrillary acidic protein (GFAP). By GFAP immunoblotting we detected two immunopositive protein bands, at 50 and 48 kDa molecular mass. Confocal analysis also showed that GFAP co-localized with Abeta-IR material in a time-dependent manner. In conclusion, our results indicate that astrocyte activation might have a critical role in the mechanisms of Abeta-induced neurodegeneration, and that should be further studied as possible targets for therapeutic intervention in AD.

Genetic adaptation of Pseudomonas aeruginosa to the airways of cystic fibrosis patients is catalyzed by hypermutation

In previous work (E. E. Smith, D. G. Buckley, Z. Wu, C. Saenphimmachack, L. R. Hoffman, D. A. D'Argenio, S. I. Miller, B. W. Ramsey, D. P. Speert, S. M. Moskowitz, J. L. Burns, R. Kaul, and M. V. Olson, Proc. Natl. Acad. Sci. USA 103:8487-8492, 2006) it was shown that Pseudomonas aeruginosa undergoes intense genetic adaptation during chronic respiratory infection (CRI) in cystic fibrosis (CF) patients. We used the same collection of isolates to explore the role of hypermutation in this process, since one of the hallmarks of CRI is the high prevalence of DNA mismatch repair (MMR) system-deficient mutator strains. The presence of mutations in 34 genes (many of them positively linked to adaptation in CF patients) in the study collection of 90 P. aeruginosa isolates obtained longitudinally from 29 CF patients was not homogeneous; on the contrary, mutations were significantly concentrated in the mutator lineages, which represented 17% of the isolates (87% MMR deficient). While sequential nonmutator lineages acquired a median of only 0.25 mutation per year of infection, mutator lineages accumulated more than 3 mutations per year. On the whole-genome scale, data for the first fully sequenced late CF isolate, which was also shown to be an MMR-deficient mutator, also support these findings. Moreover, for the first time the predicted amplification of mutator populations due to hitchhiking with adaptive mutations in the course of natural human infections is clearly documented. Interestingly, increased accumulation of mutations in mutator lineages was not a consequence of overrepresentation of mutations in genes involved in antimicrobial resistance, the only adaptive trait linked so far to hypermutation in CF patients, demonstrating that hypermutation also plays a major role in P. aeruginosa genome evolution and adaptation during CRI.

Humoral and cellular monitoring to predict the development of infection in Crohn's disease patients beginning treatment with infliximab

Although severe infectious complications are rare, it is important to properly screen patients for predisposing conditions before beginning treatment with infliximab. We assessed immunity markers that might provide prognostic value for the development of infection in Crohn's disease patients after treatment with infliximab. In a prospective study, 34 fistulizing Crohn's disease patients (mean age 37 years) were studied. Patients were scheduled to receive three infusions of infliximab (5 mg/kg) at weeks 0, 2, and 6. Immunologic studies: Serum immunoglobulin (IgG, IgA, IgM), IgG-subclasses, and complement (C3, C4, factor B) determined by nephelometry; CD3+, CD3+CD4+, CD3+CD8+, CD19+, and CD56+CD3- lymphocyte subsets performed by flow cytometry. During a mean follow-up of 56 months, 1 patient had disseminated tuberculosis and 2 patients had severe bacterial infections. The presence of infection was associated with significantly higher IgM (246 vs. 121 mg/dL; Mann-Whitney test, P = 0.01), lower C3 (64 vs. 118, P = 0.02), lower C4 concentrations (12 vs. 25, P = 0.02), and with decreased levels of CD19 B cells (47 vs. 290, P = 0.03) in the baseline study. Further prospective studies in a larger number of patients are suggested to examine whether early monitoring of immunocompetence might help to identify the risk of infection in patients treated with infliximab.

PICK1 targets activated protein kinase Calpha to AMPA receptor clusters in spines of hippocampal neurons and reduces surface levels of the AMPA-type glutamate receptor subunit 2

The PICK1 protein interacts in neurons with the AMPA-type glutamate receptor subunit 2 (GluR2) and with several other membrane receptors via its single PDZ domain. We show that PICK1 also binds in neurons and in heterologous cells to protein kinase Calpha (PKCalpha) and that the interaction is highly dependent on the activation of the kinase. The formation of PICK1-PKCalpha complexes is strongly induced by TPA, and PICK1-PKCalpha complexes are cotargeted with PICK1-GluR2 complexes to spines, where GluR2 is found to be phosphorylated by PKC on serine 880. PICK1 also reduces the plasma membrane levels of the GluR2 subunit, consistent with a targeting function of PICK1 and a PKC-facilitated release of GluR2 from the synaptic anchoring proteins ABP and GRIP. This work indicates that PICK1 functions as a targeting and transport protein that directs the activated form of PKCalpha to GluR2 in spines, leading to the activity-dependent release of GluR2 from synaptic anchor proteins and the PICK1-dependent transport of GluR2 from the synaptic membrane.

Synthesis, structure, luminescence, and theoretical studies of tetranuclear gold clusters with phosphinocarborane ligands

Treatment of the tetranuclear gold cluster [Au4((PPh2)2C2B9H10)2(AsPh3)2] (1), which contains the nido-carborane-diphosphine [7,8-(PPh2)2C2B9H10]-, with various tertiary phosphines leads to derivatives [Au4((PPh2)2C2B9H10)2-(PR3)2] (PR3 = PPh3 (2), P(4-MeC6H4)3 (3), P(4-OMeC6H4)3 (4)). The X-ray crystal structure of complex 4 shows a tetrahedral framework of gold atoms, two of which are chelated by the diphosphine, and two are coordinated to one monophosphine ligand each. These compounds are very stable and are obtained in high yield. MP2 calculations suggest that the two types of chemically nonequivalent gold atoms can be formally assigned as Au(I) (those attached to the arsines or phosphines) and Au(0) (those bonded to the anionic diphosphine) and emphasize the role of correlation in the gold-gold interactions. The compounds are luminescent. The emission is assigned to a gold-centered spin-forbidden transition; the assignment of the oxidation state of the gold centers on this basis leads to results coincident with those obtained by theoretical calculations.

Mutagenesis reveals a role for ABP/GRIP binding to GluR2 in synaptic surface accumulation of the AMPA receptor

We studied the role of PDZ proteins GRIP, ABP, and PICK1 in GluR2 AMPA receptor trafficking. An epitope-tagged MycGluR2 subunit, when expressed in hippocampal cultured neurons, was specifically targeted to the synaptic surface. With the mutant MycGluR2delta1-10, which lacks the PDZ binding site, the overall dendritic intracellular transport and the synaptic surface targeting were not affected. However, over time, Myc-GluR2delta1-10 accumulated at synapses significantly less than MycGluR2. Notably, a single residue substitution, S880A, which blocks binding to ABP/GRIP but not to PICK1, reduced synaptic accumulation to the same extent as the PDZ site truncation. We conclude that the association of GluR2 with ABP and/or GRIP but not PICK1 is essential for maintaining the synaptic surface accumulation of the receptor, possibly by limiting its endocytotic rate.

Aortic valve replacement in patients with aortic stenosis and severe left ventricular dysfunction

BACKGROUND

The outcome of aortic valve replacement for severe aortic stenosis is worse in patients with impaired left ventricular function. Such dysfunction in aortic stenosis may be reversible if caused by afterload mismatch, but not if it is caused by superimposed myocardial infarction.

METHODS

From our echocardiography database, 55 patients with severe aortic stenosis (valve area < or =0.75 cm2) and ejection fractions of 30% or lower who subsequently underwent aortic valve replacement were included. The operative mortality and clinical follow-up were detailed.

RESULTS

There were 10 perioperative deaths (operative mortality, 18%). Twenty (36%) of the 55 patients had a prior myocardial infarction. In the 35 patients without prior myocardial infarction, there was only 1 death (3%). In contrast, 9 of 20 patients with prior myocardial infarction died (mortality rate, 45%; P< or =.001). The factors significantly associated with perioperative death on univariate analysis (functional class, mean aortic gradient, and prior myocardial infarction) were entered into a model for stepwise logistic regression. This multivariate analysis showed that only prior myocardial infarction was independently associated with perioperative death (odds ratio, 14.9; 95% confidence interval, 2.4-92.1; P = .004).

CONCLUSIONS

The risk of aortic valve replacement in patients with severe aortic stenosis and severely reduced left ventricular systolic function is extremely high if the patients have had a prior myocardial infarction. This information should be factored into the risk-benefit analysis that is done preoperatively for these patients, and it may preclude operation for some.

Molecular tracking of coagulase-negative staphylococcal isolates from catheter-related infections

Three molecular typing methods (pulsed-field electrophoresis, localization of the mecA gene, and probing the vicinity of mec) have been used for the characterization of 40 catheter-related isolates of coagulase-negative staphylococci (CNS) in 14 patients admitted to the same hospital. The 40 isolates yielded 14 different SmaI banding patterns and corresponding unique localizations of mecA, each associated with a unique ClaI mecA polymorph. In 6 of the 14 patients the contaminated skin at the catheter entry site was the source of 4 local infections and 2 cases of bacteremia. A contaminated hub was the origin of 2 local infections and 4 cases of bacteremia in 6 more patients. The remaining 2 patients had positive cultures from both skin and catheter hub. In each bacteremic patient, the CNS recovered from catheter-related sites (tip, skin, and/or hub) and the CNS recovered from blood were identical, but each of these matching isolates was unique to the particular patients, indicating a low rate of cross-infection from patient to patient. Although classical methods for typing CNS (e.g., biotype and antibiotype) are readily available for most hospital laboratories, they have limitations concerning reproducibility and discriminatory power. Molecular epidemiologic techniques can provide powerful support to traditional techniques in determining the etiologic role of CNS in the disease process.

Analysis of the discontinuation of protease inhibitor therapy in routine clinical practice

We evaluated the frequency of and reasons for discontinuation of protease inhibitor therapy in a cohort of HIV-infected patients in a prospective observational study. We included 230 HIV-infected patients who had started protease inhibitor therapy between November 1996 and July 1997. Mean baseline CD4 count was 138 cells/microl and HIV-RNA 4.5 log10. Forty-five percent of patients had prior AIDS and 77% had been treated with nucleoside analogues. Saquinavir-treated patients were at a less advanced stage of HIV disease. Overall, 41.3% of patients discontinued therapy, and their last HIV-RNA measured higher than that of patients who continued therapy: 4.07 vs. 2.70 log10 (p < 0.0001). Reasons for discontinuation of therapy were poor adherence (including abandonment) (18.6%), drug intolerance (12.1%), virological failure (7%) and physician decision (3.5%). In a multivariate model, factors associated with drug discontinuation were not taking indinavir (OR 0.26, 95% CI 0.12-0.59) and being pretreated with nucleoside analogues (OR 3.42, 95% CI 1.58-7.42). We concluded that in routine clinical practice a high proportion of patients discontinued protease inhibitors during the first 6 months of therapy, the main reason being the patient's own decision (abandonment or poor adherence). Psychological support and counselling are warranted in patients when initiating protease inhibitor therapy.

Venographic comparison of subcutaneous low-molecular weight heparin with oral anticoagulant therapy in the long-term treatment of deep venous thrombosis

PURPOSE

The primary objective of this study was to evaluate with venography the rate of thrombus regression after a fixed dose of low-molecular weight heparin (LMWH) per day for 3 months compared with oral anticoagulant therapy for deep venous thrombosis (DVT). Secondary endpoints were the comparisons of the efficacy and safety of both treatments.

METHODS

This study was designed as an open randomized clinical study in a university hospital setting. Of the 165 patients finally enrolled in the study, 85 were assigned LMWH therapy and 80 were assigned oral anticoagulant therapy. In the group randomized to oral anticoagulant therapy, the patients first underwent treatment in the hospital with standard unfractionated heparin and then coumarin for 3 months. Doses were adjusted with laboratory monitoring to maintain the international normalized ratio between 2.0 and 3.0. Patients in the LMWH group were administered subcutaneous injections of fixed doses of 40 mg enoxaparin (4000 anti-Xa units) every 12 hours for 7 days, and after discharge from the hospital, they were administered 40 mg enoxaparin once daily at fixed doses for 3 months without a laboratory control assay. A quantitative venographic score (Marder score) was used to assess the extent of the venous thrombosis, with 0 points indicating no DVT and 40 points indicating total occlusion of all deep veins. The rate of thrombus reduction was defined as the difference in quantitative venographic scores after termination of LMWH or coumarin therapy as compared with the scores obtained on the initial venographic results. The efficacy was defined as the ability to prevent symptomatic extension or recurrence of venous thromboembolism (documented with venograms or serial lung scans). The safety was defined as the occurrence of hemorrhages.

RESULTS

After 3 months of treatment, the mean Marder score was significantly decreased in both groups in comparison with the baseline score, although the effect of therapy was significantly better after LMWH therapy (49.4% reduction) than after coumarin therapy (24.5% reduction; P <.001). LMWH therapy and male gender were independently associated with an enhanced resolution of the thrombus. A lower frequency of symptomatic recurrent venous thromboembolism was also shown in patients who underwent treatment with LMWH therapy (9.5%) than with oral anticoagulant therapy (23.7%; P <.05), although this difference was entirely a result of recurrence of DVT. Bleeding complications were significantly fewer in the LMWH group than in the coumarin group (1. 1% vs 10%; P <.05). This difference was caused by minor hemorrhages. Coumarin therapy and cancer were independently associated with an enhanced risk of complications. Subcutaneous heparin therapy was well tolerated by all patients.

CONCLUSION

The patients who were allocated to undergo enoxaparin therapy had a significantly greater improvement in their quantitative venographic score, a significantly lower recurrence rate of symptomatic venous thromboembolism, and a significantly lower incidence of bleeding than patients who underwent treatment with coumarin. LMWH can be used on an outpatient basis as a safer and more effective alternative to classical oral anticoagulant therapy for the secondary prophylaxis of selected patients with DVT.

Diarrheagenicity evaluation of attenuated Vibrio cholerae O1 and O139 strains in the human intestine ex vivo

The recent spread of El Tor cholera in Latin America highlights the need for a safe and economical vaccine. The main approach for developing live recombinant vaccines has been to disarm known pathogenic strains of cholera toxin leaving intact antigens involved in protection. These recombinant vaccine candidates do not cause severe diarrhea, but they are too reactogenic for wide scale usage. We describe here a test capable of determining the diarrheagenic potential of attenuated V. cholerae strains. The functional test consists in the simultaneous recording of net water movement, electrical potential difference and short-circuit current across the human intestine ex vivo. We found that human tissues incubated with supernatants from the attenuated 638, 413 and 251a V. cholerae strains caused no changes in the ion conductances and water absorption in ileal and colon tissues allowing them to be assayed in volunteers.

The effect of the ingestion of ethanol on obstruction of the left ventricular outflow tract in hypertrophic cardiomyopathy

BACKGROUND

Ethanol causes vasodilation, which might have an adverse effect, due to increased obstruction of the left ventricular outflow tract, in patients with hypertrophic obstructive cardiomyopathy. We assessed the hemodynamic effects of the ingestion of ethanol, in an amount commonly consumed socially, in patients with hypertrophic cardiomyopathy.

METHODS

We performed echocardiography in 36 patients before and several times after the ingestion of either 50 ml of 40 percent ethanol or an isocaloric placebo with the aroma of rum. Each patient received both ethanol and placebo, on different days. The patients, but not the physicians, were blinded to the content of the drink. We measured the sizes of the left atrium and left ventricle, the left-ventricular-wall thickness, blood pressure, heart rate, the degree of systolic anterior motion of the mitral valve, and the pressure gradient across the left ventricular outflow tract.

RESULTS

The ingestion of ethanol regulated in a significant drop in the mean (+/- SD) systolic blood pressure (from 130.5 +/- 18.6 to 122.5 +/- 20.3 mm Hg, P<0.001), a significant increase in systolic anterior motion of the mitral valve (from a grade of 2.1 to a grade of 2.5, P<0.001), and a 63 percent increase in the mean gradient across the left ventricular outflow tract (from 38.1 +/- 26.5 to 62.2 +/- 42.4 mm Hg, P<0.001). These changes, which were not associated with symptoms, did not occur after the ingestion of placebo.

CONCLUSION

The ingestion of a small amount of ethanol caused an increase in the gradient across the left ventricular outflow tract in patients with hypertrophic obstructive cardiomyopathy, which could have and adverse clinical effect.

Identification of two isoforms of the Cak receptor kinase that are coexpressed in breast tumor cell lines

The Cak receptor kinase is a member of a novel family of receptors that are characterized by the unique structure of the ectodomains. We have identified a new isoform of Cak that differs from the original isolate by the deletion of 37 amino acids in the cytoplasmic juxtamembrane sequence. Analysis of the genomic sequence suggests that the two isoforms arise by exon skipping. The isoform-specific insert contains the motif NPXY, which was previously shown to be involved in diverse signaling function in a number of receptors. By RNase protection analyses, we found that the long isoform, Cak I is expressed at three- to sevenfold the abundance of the short isoform (Cak II). By Western blotting, Cak I receptor was found to be expressed in mouse embryos and in adult brain. Cak II protein was not detected in mouse embryos or adult tissues, but is abundantly expressed in some breast tumor cell lines. The expression profile of Cak suggests that its primary function is likely to be in developmental regulation. The coexpression of the Cak isoforms in some epithelial cell lines suggests that heterodimer formation may be a key feature in the function of the receptor.

Valve strands are strongly associated with systemic embolization: a transesophageal echocardiographic study

OBJECTIVES

We attempted to determine the prevalence of strands on native and prosthetic valves, as detected by transesophageal echocardiography, and to assess the relative risk for systemic emboli associated with these strands.

BACKGROUND

Fine threadlike strands, seen on native and prosthetic valves by transesophageal echocardiography, have been implicated in systemic embolization.

METHODS

During a 2-year period, 1,559 patients underwent transesophageal echocardiography at our center. Of these, 41 patients had strands and no other identifiable source of systemic emboli. They were matched for age, gender, history of hypertension and history of smoking with a control group of 41 patients without strands who also had no identifiable source of emboli. The risk of embolization in the two groups was compared.

RESULTS

Of 1,559 patients studied by transesophageal echocardiography, 86 (5.5%) had strands. Strands were far more common on mitral valves than on aortic valves. Of the patients with strands, 38% had had an event consistent with a systemic embolus, whereas 62% had not. Of 597 patients with an embolic event, 63 (10.6%) had strands, whereas only 23 (2.3%) of 962 patients without emboli had strands. In the case-control study, 33 (83%) of the 41 patients with strands without another source of embolism had emboli compared with only 12 (29%) of the 41 control patients without another source (odds ratio 10.0, 95% confidence interval 3.6 to 27.8, p = 0.00001).

CONCLUSIONS

Valvular strands visualized by transesophageal echocardiography are associated with systemic embolization.

Protruding atheromas of the aortic arch in symptomatic patients with carotid artery disease

Protruding aortic arch atheromas are associated with otherwise unexplained strokes and transient ischemic attacks. Therefore aortic atheromas also may be important in patients with carotid artery disease. Forty-five patients with > or = 50% carotid stenosis and stroke or transient ischemic attack within 6 weeks underwent transesophageal echocardiographic examination (TEE). They were matched for age, sex, and hypertension with 45 control subjects who had also had a recent cerebral event but in whom significant carotid stenosis was absent. Protruding aortic arch atheromas were present in 17 (38%) of 45 patients with carotid disease and only 7 (16%) of 45 of control subjects (p = 0.02). Mobile atheromas (with the greatest embolic potential) were present almost exclusively in case patients, 6 (13%) of 45, versus 1 (2%) of 45 control subjects (p = 0.05). Case patients with mobile atheromas had the most severe carotid stenosis ( > or = 80%). Cerebral symptoms were discordant with the side of the carotid stenosis in 10 case patients, and 4 had atheromas. In conclusion, protruding atheromas of the aortic arch are present in significant numbers of symptomatic patients with carotid artery disease. These atheromas may represent an additional cause of symptoms in patients with carotid stenosis. TEE to look for protruding aortic atheromas may be considered in patients with neurologic events despite the presence of significant carotid stenosis, especially if the symptoms are discordant with the side of carotid stenosis.

Cytomegalovirus ventriculoencephalitis in AIDS patients

We report 4 autopsy-proven cases of cytomegalovirus ventriculoencephalitis (CMV-VE) and a further case with dramatic clinical and radiological response to ganciclovir therapy. The diagnoses were based upon clinical features, cerebrospinal fluid (CSF) examination and either brain computerized tomography (CT) or magnetic resonance imaging (MRI), and confirmed by autopsy findings in 4 cases. All patients had previously had an AIDS-defining condition. CMV retinitis was diagnosed in 3 patients, 2 of them before the onset of encephalitis. CMV viremia was present in 4 patients. Examination of CSF demonstrated elevated protein and hypoglycorachia in all cases. CSF culture was negative for CMV in 3 of 3 patients. Periventricular enhancement was detected by MRI in 2 of 3 patients, but in only 1 of 5 patients by CT. Three patients received ganciclovir and 2 patients foscarnet therapy. All 4 patients died. Pathologic examination revealed periventriculitis with ependymal necrosis and CMV intranuclear inclusion bodies all 4 patients. One showed a marked neurological improvement and radiological resolution by MRI after 4 weeks of ganciclovir therapy. We conclude that CMV-VE should be suspected in HIV-infected patients who present with altered neurological status, CMV viremia or retinitis, hypoglycorachia and ventriculitis as demonstrated by MRI. Although more effective therapy is needed, ganciclovir may be beneficial, as shown in one of our patients.

High risk for vascular events in patients with protruding aortic atheromas: a prospective study

OBJECTIVES

The purpose of this study was to prospectively evaluate the risk of vascular events in patients with protruding aortic atheromas.

BACKGROUND

Protruding atheromas of the thoracic aorta have been shown to be associated with embolic disease in previous retrospective studies.

METHODS

During a 1-year period, 521 patients had transesophageal echocardiography. Of these, 42 patients had protruding atheromas and no other source of emboli. They were followed up for up to 2 years (mean follow-up 14 months) and compared with a control group without atheromas, matched for age, gender and hypertension.

RESULTS

Of 42 patients with atheromas, 14 (33%) had 19 vascular events during follow-up (5 brain, 2 eye, 4 kidney, 1 bowel, 7 lower extremity). Of 42 control patients, 3 (7%) had vascular events (2 brain, 1 eye). Univariate analysis identified only protruding atheromas as significantly correlating with events (p = 0.003). There was no positive correlation of events with age, gender, hypertension, smoking, family history, atrial fibrillation, valve replacement, antithrombotic drug use, diabetes or coronary disease. Multivariate analysis showed that only protruding atheromas independently predicted events (p = 0.005, odds ratio 4.3, 95% confidence interval 1.2 to 15.0). Nine patients died in the atheroma group versus six in the control group, but this was not statistically significant (p = 0.39).

CONCLUSIONS

Protruding atheromas seen on transesophageal echocardiography predict future vascular events.

Identification and chromosomal mapping of a receptor tyrosine kinase with a putative phospholipid binding sequence in its ectodomain

We have cloned a novel receptor tyrosine kinase that has an unusual ectodomain. The extracellular sequence consists of 416 amino acids and has none of the structural motifs that have been found in other receptor tyrosine kinases. The 150 amino acids in the amino terminus of the receptor is homologous to a putative phospholipid-binding sequence that is found also in other cell adhesion molecules such as the neuronal A5 antigen and coagulation factors V and VIII. The kinase domain has a short cytoplasmic tail and contains a short insert between subdomains I and II. The structure of this receptor kinase suggests that it belongs to a new family of receptors involved in cell-cell interactions. The cell adhesion kinase (Cak) is expressed at low levels in most adult tissues and expression is highest in the brain and lung. Using fluorescence in situ hybridization and interspecific backcross mapping, the Cak gene was localized to human chromosome 6 and mouse chromosome 17.

Sézary syndrome in an 11-year-old girl

All forms of cutaneous T-cell lymphoma are rare in children. We describe an 11-year-old girl who had generalized exfoliative erythroderma, intense pruritus, peripheral lymphadenopathy, mycosis cells in the skin and lymph nodes, and Sézary cells in the peripheral blood. Results of a biopsy specimen of involved skin showed changes consistent with mycosis fungoides. A classic case of Sézary syndrome has not previously been reported in childhood or preadolescence.

Trends in antimicrobial resistance of clinical isolates of Streptococcus pneumoniae in Bellvitge Hospital, Barcelona, Spain (1979-1990)

From January 1979 to December 1990 we studied the susceptibility of 1,492 pneumococcal strains isolated from adult patients in Bellvitge Hospital, Barcelona, Spain, to nine antimicrobial agents. Among clinically significant pneumococci, the incidence of penicillin-resistant strains increased from 4.3% in 1979 to 40% in 1990, and that of erythromycin-resistant strains also rose from 0% in 1979 to 9.4% in 1990. On the other hand, the incidence of strains resistant to tetracycline decreased from 76.1% to 37.6%, as did that of chloramphenicol-resistant strains, from 56.5% to 29.4%. The incidence of co-trimoxazole-resistant strains was about 40% throughout the study. Even more alarming was the finding that about 70% of penicillin-resistant strains showed multiple resistance to non-beta-lactam antibiotics. All pneumococci were susceptible to vancomycin, and all but six were susceptible to rifampin. We observed that isolates from cerebrospinal fluid and the respiratory tract were significantly more resistant to penicillin than were isolates from blood. The majority of strains (95%) belonged to serogroups or serotypes included in the 23-valent pneumococcal vaccine and 77.6% of penicillin-resistant strains belonged to groups 23, 6, 9, and 19.

Protruding atheromas in the thoracic aorta and systemic embolization

OBJECTIVE

To determine whether protruding atheromas in the thoracic aorta are a risk factor for systemic embolization.

DESIGN

Case-control study.

SETTING

A referral hospital.

PATIENTS

A total of 122 patients with a history of stroke, transient ischemic attack, or peripheral emboli and an equal number of age- and sex-matched control patients.

MEASUREMENTS

Evaluation using transesophageal echocardiography was done in case patients to detect protruding atheromas in the thoracic aorta and in control patients for cardiac indications other than emboli.

MAIN RESULTS

Matched logistic regression showed that the presence of protruding atheromas was strongly related to the occurrence of embolic symptoms (odds ratio, 3.2; 95% Cl, 1.6 to 6.5; P less than 0.001). Furthermore, atheromas with mobile components were present only in case patients. When known risk factors for stroke (hypertension and diabetes) were added to the model, the presence of protruding atheromas remained an independent risk factor for embolic symptoms (odds ratio, 3.8). Hypertension was also independently associated with embolic symptoms (odds ratio, 2.7), but diabetes was not (odds ratio, 1.0).

CONCLUSION

Protruding atheromas in the thoracic aorta can be detected by transesophageal echocardiography and should be considered as a cause of strokes, transient ischemic attacks, and peripheral emboli.

Comparison of cardiac catheterization and Doppler echocardiography in the decision to operate in aortic and mitral valve disease

Clinical decisions utilizing either Doppler echocardiographic or cardiac catheterization data were compared in adult patients with isolated or combined aortic and mitral valve disease. A clinical decision to operate, not operate or remain uncertain was made by experienced cardiologists given either Doppler echocardiographic or cardiac catheterization data. A prospective evaluation was performed on 189 consecutive patients (mean age 67 years) with valvular heart disease who were being considered for surgical treatment on the basis of clinical information. All patients underwent cardiac catheterization and detailed Doppler echocardiographic examination. Three sets of two cardiologist decision makers who did not know patient identity were given clinical information in combination with either Doppler echocardiographic or cardiac catheterization data. The combination of Doppler echocardiographic and clinical data was considered inadequate for clinical decision making in 21% of patients with aortic and 5% of patients with mitral valve disease. The combination of cardiac catheterization and clinical data was considered inadequate in 2% of patients with aortic and 2% of patients with mitral valve disease. Among the remaining patients, the cardiologists using echocardiographic or angiographic data were in agreement on the decision to operate or not operate in 113 (76% overall). When the data were analyzed by specific valve lesion, decisions based on Doppler echocardiography or catheterization were in agreement in 92%, 90%, 83% and 69%, respectively, of patients with aortic regurgitation, mitral stenosis, aortic stenosis and mitral regurgitation. Differences in cardiac output determination, estimation of valvular regurgitation and information concerning coronary anatomy were the main reasons for different clinical management decisions. These results suggest that for most adult patients with aortic or mitral valve disease, alone or in combination, Doppler echocardiographic data enable the clinician to make the same decision reached with catheterization data.

Stiffness and strength tailoring of a hip prosthesis made of advanced composite materials

This work is concerned with the design of hip prostheses using advanced fiber reinforced composite materials. The major focus of the study is to evaluate how the stiffness and strength of composite hip prostheses can be affected by variations in ply orientation and stacking sequence for a selected manufacturing method. This investigation involved both analytical and experimental work. An analytical model was developed which consists of a stress analysis and a failure analysis. A finite element program was developed during the course of the investigation for analyzing stresses, strains, and deformations of composite stems with a simplified configuration. Failure and mode of failure were predicted by appropriately selected failure criteria. Experiments were also performed on T300/976 graphite/epoxy composites to verify the analysis and the computer calculations. Both testing and analysis accounted for the various combinations of in-plane and out-of-plane (torsion) loading that can act on the prosthetic hip. Simplified composite stems with a 120 layer thickness were fabricated and tested. An excellent agreement was found between the measured strain data and the numerical calculations. Using the program, parametric studies were performed. It was found that an optimal design of hip stems can be achieved by using advanced fiber-reinforced composite materials, but great care must be taken when selecting the appropriate ply orientation and stacking sequence for a chosen fabrication method.

Odor and taste aversions conditioned in anesthetized rats

Conditioned flavor aversions (CFA) are acquired by anesthetized rats but effects of various anesthetics on acquisition of aversions for separate odor and taste components are unknown. In Experiment 1, rats drank tomato juice and then were tranquilized with "Innovar-Vet" or "Rompun" before receiving injections of lithium chloride. Neither drug interfered with acquisition of aversions. Innovar-Vet alone produced no aversions; Rompun alone produced mild aversions but did not enhance aversions when combined with lithium. In Experiments 2 and 3, rats received a compound odor/taste cue as they drank and then were anesthetized with pentobarbital before lithium injections. Anesthesia alone produced negligible aversions but facilitated taste-lithium aversions. During odor tests, odor aversions were weaker than taste aversions. These data extend previous work and suggest that CFA does not result from ordinary classical conditioning. A tripartite notation that unites CFA and classical conditioning is discussed.

Efficient malignant transformation of rat embryo fibroblasts by genomic DNA from Walker carcinoma cells

DNA isolated from Walker carcinoma ascites cells was transfected into primary rat embryo fibroblasts (REF), selecting transformed cells by growth in soft agar after prolonged propagation in monolayer. Both high molecular weight genomic DNA and a partially purified mitochondrial DNA fraction were able to transform REF with high efficiency, whereas pure mitochondrial DNA failed to elicit a transformed phenotype. Hybridization experiments showed that the mitochondrial DNA fraction contained DNA species of presumably extramitochondrial origin. Colonies were cloned into morphologically transformed, foci-forming, immortalized cell lines, showing different degrees of chromosomal alterations, tumorigenicity, and production of cell growth factors. These results indicate that although REF are refractory to genomic neoplastic DNA or to single cloned oncogenes in the absence of enhancers, they can be efficiently transformed by chromosomal DNA from a highly malignant tumor under conditions selecting against the remaining normal cells.

Odor and taste aversions conditioned in anesthetized rats

Conditioned flavor aversions (CFA) are acquired by anesthetized rats but effects of various anesthetics on acquisition of aversions for separate odor and taste components are unknown. In Experiment 1, rats drank tomato juice and then were tranquilized with "Innovar-Vet" or "Rompun" before receiving injections of lithium chloride. Neither drug interfered with acquisition of aversions. Innovar-Vet alone produced no aversions; Rompun alone produced mild aversions but did not enhance aversions when combined with lithium. In Experiments 2 and 3, rats received a compound odor/taste cue as they drank and then were anesthetized with pentobarbital before lithium injections. Anesthesia alone produced negligible aversions but facilitated taste-lithium aversions. During odor tests, odor aversions were weaker than taste aversions. These data extend previous work and suggest that CFA does not result from ordinary classical conditioning. A tripartite notation that unites CFA and classical conditioning is discussed.

Comparative susceptibilities of penicillin-resistant pneumococci to co-trimoxazole, vancomycin, rifampicin and fourteen beta-lactam antibiotics

Eighty-four isolates of penicillin-resistant pneumococci were tested for susceptibility to vancomycin, rifampicin, cotrimoxazole, and 14 beta-lactam antibiotics by agar and microbroth dilution methods. Twenty-three were from adult patients with pneumococcal disease, 57 from nasopharingeal carriers (preschool children) and four were resistant South African isolates. For all isolates tested, imipenem (N-formimidoyl thienamycin), rifampicin, ceftriaxone and cefotaxime had the greatest activity ( MIC90 : 0 X 12, 0 X 25, 0 X 5 mg/l, respectively). Cefoxitin and latamoxef were the least active of the drugs studied. The remaining beta-lactams tested had less activity than that of penicillin. All strains were inhibited by 1 mg/l of vancomycin and all but one were resistant to cotrimoxazole. The excellent in-vitro activities of the newer beta-lactam agents (ceftriaxone, cefotaxime and, particularly, imipenem ) and vancomycin against penicillin-resistant pneumococci offer a considerable promise for their use in the treatment of pneumococcal meningitis caused by these strains.