Critical COVID-19 is associated with distinct leukocyte phenotypes and transcriptome patterns

BACKGROUND

Prognostic markers for disease severity and identification of therapeutic targets in COVID-19 are urgently needed. We have studied innate and adaptive immunity on protein and transcriptomic level in COVID-19 patients with different disease severity at admission and longitudinally during hospitalization.

METHODS

Peripheral blood mononuclear cells (PBMCs) were collected at three time points from 31 patients included in the Norwegian SARS-CoV-2 cohort study and analysed by flow cytometry and RNA sequencing. Patients were grouped as either mild/moderate (n = 14), severe (n = 11) or critical (n = 6) disease in accordance with WHO guidelines and compared with patients with SARS-CoV-2-negative bacterial sepsis (n = 5) and healthy controls (n = 10).

RESULTS

COVID-19 severity was characterized by decreased interleukin 7 receptor alpha chain (CD127) expression in naïve CD4 and CD8 T cells. Activation (CD25 and HLA-DR) and exhaustion (PD-1) markers on T cells were increased compared with controls, but comparable between COVID-19 severity groups. Non-classical monocytes and monocytic HLA-DR expression decreased whereas monocytic PD-L1 and CD142 expression increased with COVID-19 severity. RNA sequencing exhibited increased plasma B-cell activity in critical COVID-19 and yet predominantly reduced transcripts related to immune response pathways compared with milder disease.

CONCLUSION

Critical COVID-19 seems to be characterized by an immune profile of activated and exhausted T cells and monocytes. This immune phenotype may influence the capacity to mount an efficient T-cell immune response. Plasma B-cell activity and calprotectin were higher in critical COVID-19 while most transcripts related to immune functions were reduced, in particular affecting B cells. The potential of these cells as therapeutic targets in COVID-19 should be further explored.

Elevated markers of gut leakage and inflammasome activation in COVID-19 patients with cardiac involvement

BACKGROUND

A high proportion of COVID-19 patients have cardiac involvement, even those without known cardiac disease. Downregulation of angiotensin converting enzyme 2 (ACE2), a receptor for SARS-CoV-2 and the renin-angiotensin system, as well as inflammatory mechanisms have been suggested to play a role. ACE2 is abundant in the gut and associated with gut microbiota composition. We hypothesized that gut leakage of microbial products, and subsequent inflammasome activation could contribute to cardiac involvement in COVID-19 patients.

METHODS

Plasma levels of a gut leakage marker (LPS-binding protein, LBP), a marker of enterocyte damage (intestinal fatty acid binding protein, IFABP), a gut homing marker (CCL25, ligand for chemokine receptor CCR9) and markers of inflammasome activation (IL-1β, IL-18 and their regulatory proteins) were measured at three time points (day 1, 3-5 and 7-10) in 39 hospitalized COVID-19 patients and related to cardiac involvement.

RESULTS

Compared to controls, COVID-19 patients had elevated plasma levels of LBP and CCL25 but not IFABP, suggesting impaired gut barrier function and accentuated gut homing of T cells without excessive enterocyte damage. Levels of LBP were twice as high at baseline in patients with elevated cardiac markers compared with those without and remained elevated during hospitalization. Also, markers of inflammasome activation were moderately elevated in patients with cardiac involvement. LBP was associated with higher NT-pro-BNP levels, whereas IL-18, IL-18BP and IL-1Ra were associated with higher troponin levels.

CONCLUSION

Patients with cardiac involvement had elevated markers of gut leakage and inflammasome activation, suggestive of a potential gut-heart axis in COVID-19.

P6473Impact of prosthesis choice on mortality after transfemoral transcatheter aortic valve implantation in patients with reduced versus preserved left-ventricular ejection fraction

Background

Outcomes of transfemoral transcatheter aortic valve implantation (TF-TAVI) with a self-expanding (SEP) and a balloon-expandable prosthesis (BEP) seem to be comparable, though head-to-head comparisons, especially in certain patient subsets, are sparse. In addition, patients with a reduced left-ventricular ejection fraction (rEF, ≤40%) appear to be at higher risk for an increased mortality after TF-TAVI than patients with a preserved left-ventricular ejection fraction (pEF). As it remains unclear, whether outcomes of patients with rEF differ between TF-TAVI using SEP and BEP, we sought to compare all-cause mortality of patients with rEF using a SEP or a BEP.

Methods

We retrospectively analyzed data of 679 single-center TF-TAVI patients, which were stratified by baseline ejection fraction (rEF versus pEF) and type of implanted prosthesis (SEP versus BEP). Patients were censored at death or completion of 1-year follow-up, whichever occurred first.

Results

Twenty-one percent of patients had rEF, and these patients had a higher 1-year mortality compared to patients with pEF (28% vs. 19%, p=0.007). SEP were implanted in 149 patients (49 patients with rEF), while BEP were implanted in 538 patients (92 patients with rEF). All-cause 1-year mortality was similar after SEP- and BEP-implantation (16% vs 19%, p=0.516) in patients with pEF. In patients with rEF, however, 1-year mortality was higher after SEP- than after BEP-implantation (43% vs. 21%, p=0.004, see figure). Patients with rEF had a higher incidence of new permanent pacemaker implantation (26.5% vs. 13%, p=0.046) and paravalvular leak ≥2 (21% vs. 10%, p=0.07) after SEP- than after BEP-implantation, but both factors could not explain the excess mortality after SEP-implantation in multivariate analysis.

Conclusion

Patients with rEF had a higher 30-day and 1-year mortality after TF-TAVI when a SEP instead of a BEP was used. Further studies are needed to confirm and explain this finding.

P5603Distal stent graft induced new entry: risk factors in acute and chronic type B aortic dissections

Background

Distal stent graft induced new entry (dSINE) is a rare complication occurring in acute and chronic dissections after thoracic endovascular aortic repair (TEVAR) and is linked to a high reintervention rate. We analyzed potential predicting risk factors for dSINE and analyzed the long-term outcome in patients after reintervention.

Methods

In this single-center, retrospective study we evaluated patients after TEVAR and investigated possible predictors for dSINE development. Therefore, we used a multivariate analysis to test important interventional parameters such as distal oversizing (dOS), taper ratio (TR), angle between distal stent graft and aorta, acute dissection and stent graft length. Reinterventional characteristics were analyzed and further long-term follow-ups after reintervention evaluated.

Results

We analyzed 185 patients with acute (n=77) and chronic (n=108) dissections after TEVAR with a follow-up of 68.9±32.5 months. Within the follow-up period, 12 (6.5%) patients developed dSINE after a median time of 22.2±20.7 months. We identified acute dissection as a major predicting factor for dSINE development with a 15.8 times higher odds, followed by an increased dOS and TR. The reintervention rate was higher in the dSINE group (83% vs. 20%, p=0.001), but reinterventional results were mostly satisfying, including further freedom from reintervention and/or new endoleak development up to a mean follow-up of 60.7±54.8 months. No dSINE was seen in association to tapered stent grafts.

Conclusion

We found acute aortic dissection as a major predicting factor for dSINE development, followed by increased dOS and TR. The use of tapered stent grafts might be beneficial in cases with expected high dOS and TR. In rare cases with dSINE occurrence, reintervention is often required, but has a good prognosis even after years.

[Infective endocarditis : New ESC guidelines 2015]

Infective endocarditis is an endovascular infection usually caused by bacteria. Mortality rate is still approximately 20 %. To improve patients' prognosis by implementation of current diagnostic and therapeutic evidence, the European Society of Cardiology published an updated version of the guidelines for management of infective endocarditis in 2015. It strengthens the role of imaging modalities like PET/CT for detection of infectious foci when echocardiography remains negative and highlights the use of modern tests for identification of possible pathogens. New diagnostic criteria were introduced to integrate these methods for improved diagnostic sensitivity. Complicated cases should be treated in reference centers with on-site cardiac surgery. The antibiotic and early surgical management should be discussed in a multidisciplinary endocarditis team. A few years ago, the indication for endocarditis prophylaxis was limited to high-risk patients. These recommendations were confirmed in current guidelines.

Do the early development of gestures and receptive and expressive language predict language skills at 5;0 in prematurely born very-low-birth-weight children?

It is unclear what the predictive value of very early development of gestures and language is on later language ability in prematurely born very-low-birth-weight (VLBW; birth weight ≤1500g) children. The aim of the present study was to analyse the predictive value of early gestures and a receptive lexicon measured between the ages of 0;9 and 1;3, as well as the predictive value of receptive and expressive language ability at 2;0 for language skills at 5;0 in VLBW children. The subjects were 29 VLBW children and 28 full-term children whose language development has been followed intensively between the ages of 0;9 and 2;0 using the Finnish version of the MacArthur Developmental Inventory and the Reynell Developmental Language Scales (RDLS III). At 5;0, five selected verbal subtests of the Nepsy II test and the Boston Naming Test (BNT) were used to assess children's language skills. For the first time in VLBW children, the development of gestures measured between the ages of 0;9 and 1;3 was shown to correlate significantly and positively with language skills at 5;0. In addition, both receptive and expressive language ability measured at 2;0 correlated significantly and positively with later language skills in both groups. Moreover, according to the hierarchical regression analysis, the receptive language score of the RDLS III at 2;0 was a clear and significant predictor for language skills at 5;0 in both groups. The findings particularly underline the role of early receptive language as a significant predictor for later language ability in VLBW children. The results provide evidence for a continuity between early language development and later language skills.

LEARNING OUTCOMES

After reading this article, readers will understand the associations between the very early (≤2 years of age) development of gestures and language (i.e. early receptive lexicon, expressive lexicon at 2;0, receptive and expressive language ability at 2;0) and the language skills at 5;0 in prematurely born very-low-birth-weight (VLBW) children. In addition, readers will understand the heterogeneity of the group of VLBW children. The information presented in this article is informative for those who work in a clinical context and who want to be able to identify those VLBW children who need support for their language development at an early age.

Five-year follow-up of prematurely born children with postnatally developing caudothalamic cysts

AIM

To assess the long-term developmental outcome of very low birth weight children with postnatally developing caudothalamic cysts.

METHODS

Five very low birth weight children with postnatal caudothalamic cysts were examined using cranial ultrasound and brain Magnetic Resonance Imaging as neonates, the Bayley Scales of Infant Development, 2nd edition, and the Hammersmith Infant Neurological Examination at 2 years of corrected age, and with the Wechsler Preschool and Primary Scale of Intelligence-Revised and the standardization version of NEPSY II at 5 years of age. The Magnetic Resonance Imaging of the brain was repeated at 5 years of age. The developmental outcome at 5 years of age was compared with that of 23 very low birth weight children with normal brain structure.

RESULTS

A cognitive level below normal and/or neuropsychological impairments was seen in all the children with caudothalamic cysts as well as in those with normal brain structure.

CONCLUSION

Very low birth weight children with postnatally developing caudothalamic cysts had cognitive and neuropsychological impairments similar to very low birth weight children without such cysts.

Assessment of childhood diabetes-related quality-of-life in West Sweden

AIM

To investigate health-related quality-of-life (HrQoL) in childhood diabetes and the level of agreement between West Sweden and European reference data for the new multi-cultural European questionnaire - DISABKIDS.

METHOD

Twenty percent of the Swedish paediatric diabetes population was included in the survey. Child-parent pairs completed the DISABKIDS chronic generic (37 questions) and diabetes modules (10 questions) during their routine clinic visit. A one-page results summary, based on positive domains, was used to provide feedback to clinicians.

RESULTS

Three hundred and sixty-one child-parent pairs were included in the analysis. In Sweden, diabetes was perceived by the children as having less impact than the European average. Swedish parents rated the HrQoL of their children lower than did the European parents. Swedish girls had a lower HrQoL than boys and greater difficulty accepting their diabetes; adolescents had greater difficulty accepting the diagnosis than younger children. Parents reported greater impact of diabetes on their children than the children themselves but reported no difference between boys and girls. Parents reported better acceptance of treatment in boys. The child's reported quality-of-life (QoL) is related to age and gender.

CONCLUSION

Our results confirm the applicability of DISABKIDS to the Swedish paediatric diabetes population.

Jaundice, renal failure and pulmonary haemorrhage in a canal boat owner

Leptospirosis is a rare notifiable disease with three major clinical manifestations: subclinical disease, a self limiting illness (90% cases) and Weil's disease, a fulminant, life-threatening condition with renal and hepatic failure, haemorrhagic pneumonitis and cardiovascular collapse. Diagnosis is by the detection of IgM antibodies to leptospira produced 7 to 14 days after the onset of illness. It is important for acute physicians to consider this condition in their initial differential diagnosis since early treatment reduces the severity and duration of symptoms and hospital stay. A history of environmental or occupational exposure to animals or potentially infected water should raise suspicions of leptospirosis. This article aims to remind clinicians of the diagnosis and management of this condition. The typical symptoms and signs are illustrated by a recent case which presented to our department.

Public perception of emergency research: a questionnaire

BACKGROUND AND OBJECTIVE

Emergency research (e.g. into cardiac arrest or head injury) needs to start immediately, often before the patient, or relative, can give consent. A recent European Directive will prevent or severely limit emergency research. Little is known about the public view of emergency research.

METHODS

Patients attending the outpatient department of a university teaching hospital were invited to complete a self-administered questionnaire. Research Ethics Committee approval was obtained and participants gave written informed consent.

RESULTS

Three hundred and five of 362 respondents (84%) thought emergency research should start in the absence of consent but should be obtained as soon as possible from the nearest relative (82%) or the patient (90%). If consent was refused 62% felt the data could still be used, as did 81% if the patient died. Despite 62% approving of public meetings to publicize emergency research only 35% would attend one. A previously recommended list of preconditions was endorsed: no other consentable group (47%); advance consent impossible (55%); unable to delay treatment (73%); consent to be obtained as soon as possible (88%); an adequately designed protocol (74%); Ethics Committee approval (71%); patient may benefit (85%); future patients may benefit (92%) and that the treatment was necessary and could not be delayed (91%).

CONCLUSIONS

Emergency research must occur to improve the outcome from life-threatening illness or injury. The majority of people are aware of the importance of this research and that the normal rules of consent are not applicable. Alternative methods of recruitment need to be investigated.

Wohnortnahe Rehabilitation

In recent years new avenues of medical rehabilitation have been made possible in order to allow a more flexible and better care for patients. This includes day care and outpatient treatment additional to inpatient services. A further new development are centers which provide "residential rehabilitation". It allows a continuous cooperation with physicians and therapists who send patients or take care of them after discharge. Cooperation with acute care hospitals is easier. Inpatient care, day care and outpatient care can be better integrated. The social network of the patient can easier be taken into account in treatment planning. Patients can be supported when going back to work. Contact with self-help groups can be arranged while the patient is still in treatment.

The effect of the transfusion of stored RBCs on intestinal microvascular oxygenation in the rat

BACKGROUND

Although it is known that the transfusion of stored RBCs does not always improve tissue O(2) consumption under conditions of limited tissue oxygenation, the efficiency of O(2) delivery to the microcirculation by stored RBCs has never been determined.

STUDY DESIGN AND METHODS

In a rat hemorrhagic shock model, the effects of resuscitation with fresh or 28-day-old RBCs stored in CPD plasma, saline-adenine-glucose-mannitol, and CPDA-1 plasma were investigated. Systemic hemodynamic and intestinal oxygenation measures were monitored. Intestinal microvascular PO(2) was determined with the O(2)-dependent quenching of palladium-porphyrin phosphorescence, and the RBC deformability was measured with a Laser-assisted optic rotational cell analyzer.

RESULTS

Hemodynamic and oxygenation measures were significantly decreased during hemorrhagic shock. Intestinal oxygen consumption and mesenteric venous pO(2) were restored with the transfusion of both fresh and stored RBCs, except for CPD-stored RBCs. The intestinal microvascular pO(2) improved only with the transfusion of fresh RBCs. Deformability of the stored RBCs was significantly decreased.

CONCLUSION

In contrast to that of fresh RBCs, the transfusion of stored RBCs did not restore the microcirculatory oxygenation, possibly because of impaired O(2) unloading, but, except for CPD-stored RBCs, the storage-induced changes were not enough to impair intestinal VO(2) and mesenteric venous pO(2).

Adolescent enrollees in Medicaid managed care: the provision of well care and sexual health assessment

PURPOSE

(1) To estimate the proportion of adolescents receiving outpatient care, well care, and sexual health assessment during 12 months of continuous enrollment in Medicaid managed care. (2) To investigate factors associated with provision of these categories of service.

METHODS

Chart reviews were completed for a statewide random sample of adolescent Medicaid enrollees in Washington State. Multivariate logistic regression models included age, gender, race, language, residence, enrollment plan, and service level as independent variables. Dependent variables were receipt of outpatient care, well care, and sexual health assessment.

RESULTS

Of 2000 enrollees' records, 78.3% provided evidence of outpatient service, 30.5% included well care, and 20.8% documented a sexual health assessment. Among adolescents who obtained service, younger enrollees and non-Whites were more likely to receive well care; females, older enrollees, and those with well care were more likely to have sexual health assessments. Use of standardized charting tools increased the likelihood that sexual health assessments would be documented. The variable most strongly associated with provision of outpatient service was plan of enrollment. Plan rankings on provision of outpatient care were not associated with organizational descriptions, such as for-profit status or plan structure.

CONCLUSION

The low rates of well care and sexual health assessment documented for adolescents in Medicaid managed care suggest that interventions are needed.

[New drugs in the treatment of advanced colorectal cancer]

BACKGROUND

Colorectal cancer is one of the leading cancers in industrialised countries in terms of incidence and mortality. Advanced colorectal cancer has traditionally been treated with 5-fluorouracil, alone or in combination with leucovorin. This treatment has shown response rates of 10-25%; however, little effect has been observed on survival.

MATERIAL, METHODS AND RESULTS

In recent years, a number of new drugs for advanced colorectal cancer have been developed and tested. We have made a comprehensive survey of the literature and find that phase II and phase III clinical studies show improved response rates compared to the traditional use of 5-fluorouracil and leucovorin. Thymidylate-synthase inhibitors, oxaliplatine and topoisomerase inhibitors, used singly or in combination, improve response rates and show a significant effect on survival in patients with metastatic colorectal disease.

INTERPRETATION

Several new drugs now available in hospital treatment of metastatic colorectal cancer show improved response and increased survival compared to traditional 5-fluorouracil regimens.

[Fluorinated pyrimidines in oral treatment of advanced colorectal cancer]

BACKGROUND

For several years, fluorinated pyrimidines have been used in the treatment of advanced colorectal cancer, mainly in the form of intravenous injections of 5-fluorouracil (5-FU), alone or in combination with leucovorin. Oral treatment with 5-FU has been difficult because of high toxicity and low bioavailability.

MATERIAL, METHODS AND RESULTS

Increased knowledge of the metabolism of 5-FU, reviewed in this article, has led to the development of a number of new oral drugs for the treatment of advanced colorectal cancer. Administration of prodrugs and inhibitors of 5-FU-catabolic enzymes has led to stable and high levels of active drug. Several drugs have shown promising results in new clinical trials.

INTERPRETATION

New 5-FU related drugs for oral administration show results comparable to those of the cytotoxic drugs that have been administered in hospital. In the future, general practitioners could possibly treat and follow up a larger proportion of these patients.

A comparison of the cutaneous microvascular properties of the spontaneously hypertensive rat and the Wistar-Kyoto rat

The Spontaneously Hypertensive rat (SHR) and its non-hypertensive companion strain, the Wistar-Kyoto (WKY) rat, provide an excellent comparative model to permit study of the differential properties of cutaneous microvascular beds. We explored the possibility that chronically elevated vascular pressures in the SHR rat might affect the microvascular constitution of the skin. We measured skin blood flow at the back and at the paw of a group of 20-week-old WKY rats and a contrast group of SHR rats. We then performed skin biopsies at these two locations and used the NIH Image program to count and measure the size of capillaries, arterioles, and venules. We also determined microvascular density as percentage of total tissue area. At basal temperature, skin blood flow was similar in the two rat strains at both the back and paw. Heat induced vasodilatation resulted in a 50% increase in blood flow at the back, reaching the same level in the two rat groups. However, at the paw site, thermal stimulation resulted in significantly greater flow (39.3 +/- 3.1 ml/100 gm tissue per min) in the SHR rats than the WKY rats (28.6 +/- 1.9 ml/100 gm tissue per min, P < 0.05). The ratio of systemic arterial pressure to skin blood flow was computed as an index of vascular resistance to flow. At basal temperature, this index was 50% greater for the SHR rats at both skin sites. At 44 degrees C, the resistance index decreased at both sites in both rat groups but was still approximately 50% higher at the back of the SHR than the WKY rats. In contrast, the resistance index at 44 degrees C at the paw site fell to the same level in both the SHR and WKY rats. There were twice as many capillaries at the back of the WKY rats than at the back of the SHR rats (9.2 +/- 2.0 per mm2 vs. 4.7 +/- 1.2 per mm2, P < 0.05). Expressed as a percentage of total tissue area, the capillary density at the back in the WKY rats was 0.064 +/- 0.010% as compared to 0.034 +/- 0.008% in the SHR rats (P < 0.05). There were five times more arterioles at the paw compared to the back in both rat groups with no significant difference between the groups. We measured the diameter of the lumen and the thickness of the wall of each arteriole and computed their ratio as an index of possible media hypertrophy. There were minimal differences seen in these parameters between the two rat groups at the back and paw sites. The venular density was significantly higher at the paw than at the back in both rat groups with no significant difference between them. Reduced capillary density at the back of the SHR rats may be a developmental adaptation to high blood pressure. Such a reduction in the pathways of blood flow may help account for increased flow resistance at that site, independent of arteriolar vasoconstriction.

Administered activity of 99Tcm-DMSA for kidney scintigraphy in children

Kidney scintigraphy using 99Tcm-dimercaptosuccinic acid (DMSA) is a common gamma camera investigation in paediatric patients. The present study deals with methods of calculating the activity to be administered to children. Our aim is to find a method of calculation which gives the same count density in the gamma camera images for all ages. Four different methods, based on body weight, height, body surface area and a theoretical model, are compared. The count density in the images of the kidneys was studied retrospectively in 85 patients aged between 3 weeks and 19.5 years. Fourteen young adults aged 22.0-31.9 years were also studied. Two of the calculation methods, based on body surface area and the theoretical model, showed no apparent age dependency (i.e. a constant count density was observed for all ages). The variation between individuals was similar with both methods, but only the body surface area method gave a count density comparable to that for the young adults. As the method based on body surface area is also easy to implement, this method is recommended.

Relation between fibre composition and daily duration of spontaneous activity in ankle muscles of the cat

This study concerns the relation between use and fibre type composition among limb muscles. The histochemical properties were investigated for ankle muscles from cats that had previously been studied in 24 hr electromyographic (EMG) recordings of daily spontaneous activity. We then reported average daily "duty times" (i.e. the percentage of total sampling time filled with EMG activity) of 1.9% for extensor digitorum longus (EDL), 2.1 and 4.0% for anterior and posterior sites of tibialis anterior (TA), 6.6 and 9.5% for anterior and posterior sites of peroneus longus (PL), and 13.9% for soleus (SOL). In the present experiments, muscles from which these data had been obtained were sectioned in a cryostat and stained for myofibrillar ATPase. Fibres were classified as type I (presumably slow) or II (presumably fast), the latter fibres being further categorized as IIA, IIB and a minor portion of transitional IIAB fibres. As expected, SOL was 100% type I. Among the muscles of mixed fibre-type composition ("mixed muscles"), a statistically significant difference in the mean percentages of type I fibres was found between TA or EDL (2.9-6.0%) vs. PL (11.8-14.6%). For TA the percentage of type I fibres was higher in posterior (deep) than in anterior (superficial) sampling regions; for PL no clear antero-posterior difference was found. A significant correlation was obtained between the percentage of type I fibres and the total duration of daily activity recorded from corresponding mixed muscle sites (5 different recording sites in 4 cats, totally 15 cases of successfully combined physiological and histochemical measurements, r = 0.76, P < 0.001). Similarly, within TA the total duration of daily activity was higher for sites with high (posteriorly) than for those with low (anteriorly) percentages of type I fibres.

IN CONCLUSION

a "coarse-grain" relationship was found between fibre type composition and the duration of daily activity among mixed muscles. Possible mechanisms underlying this relationship are discussed.

The relationship of laser-Doppler skin blood flow measurements to the cutaneous microvascular anatomy

The hairless plantar paw surface of the rat shows high skin blood flow with a substantial response to thermal stimulation. This contrasts with hair-covered areas such as the back, where there is much lower basal flow and thermal response. These properties are similar to the differences seen in humans between skin sites which have a high density of arterioles and venules (AV areas) and sites with predominantly nutritive (NUTR) capillary perfusion. However, there has been no previous study of the microvascular anatomy of rodent skin. We used NIH Image, a quantitative imaging program, to count the capillaries, arterioles, and venules in the skin of the plantar paw surface and the back of 14 Wistar-Kyoto rats. We also used laser-Doppler techniques to determine skin blood flow at these sites. We found significantly more vessels per unit area at the paw. There were twice as many capillaries in the paw (19.6 +/- 2.4 per mm2) compared to the back (9 +/- 1.5 per mm2) (P < 0.001). Similarly, there were three times as many venules (11.8 +/- 1.2 per mm2 vs 3. 48 +/- 0.45 per mm2; P < 0.001). The largest difference was in the number of arterioles (7.76 +/- 0.74 per mm2 vs 0.79 +/- 0.13 per mm2 at the back; P < 0.001). The greater microvascular density at the paw was reflected in a threefold higher basal blood flow (6.6 +/- 0. 44 ml/min/100 g) compared to that in the back (1.99 +/- 0.07 ml/min/100 g) (P < 0.001). Microvascular volume at the back was 0.14 +/- 0.01 x 10(6) RBC/ml in the basal state compared to 0.31 +/- 0.01 x 10(6) RBC/ml at the paw. Thus, the increased number of vessels at the paw resulted in a twofold increase in microvascular volume. The plantar paw surface has considerably more vessels than the back. As might be expected, there is a higher proportion of arterioles and venules compared to capillaries at the paw than at the back. Thus, the plantar paw surface is an AV site compared to the back, which is a NUTR site. Although our prior studies have largely assumed that we could use the paw and back as contrast sites comparable to AV and NUTR sites in humans, we have now for the first time conclusively established this fact. The increased microvascular density at the paw results in higher skin blood flow at this site.

Side effects associated with influenza vaccination in healthy working adults. A randomized, placebo-controlled trial

BACKGROUND

Concern about side effects is a barrier to influenza vaccination. This randomized, double-blind, placebo-controlled trial assessed side effects following vaccination among healthy working adults.

METHODS

Healthy working adults were recruited during October and November 1994 and were randomized to receive influenza vaccine or placebo injections. Local and systemic symptoms during the week following the injection were evaluated through structured telephone interviews.

RESULTS

Of 849 subjects enrolled in the study, 425 received a placebo and 424 received influenza vaccine. Baseline characteristics were similar between the groups, and 99% of subjects completed interviews to assess side effects after the study injection. No differences were seen between the 2 groups for the systemic symptoms of fever, myalgias, fatigue, malaise, or headaches. Overall, 35.2% of placebo and 34.1% of vaccine recipients reported at least 1 of these systemic symptoms (P = .78, chi 2). Vaccine recipients reported a higher rate of arm soreness at the injection site than did placebo recipients (63.8% vs 24.1%, P < .001). Local reactions were mild in both groups and infrequently resulted in decreased use of the arm. After logistic regression, female sex (odds ratio [OR], 1.5;95% confidence interval [CI], 1.1-2.1), age younger than 40 years (OR, 1.6;95% CI, 1.2-2.2), and coincidental upper respiratory tract illness (OR, 4.6; 95% CI, 3.2-6.6) were independently associated with higher rates of systemic symptoms. In the multivariate model, vaccine again was not associated with systemic symptoms (OR, 0.9; 95% CI, 0.7-1.2).

CONCLUSIONS

Influenza vaccination of healthy working adults is not associated with higher rates of systemic symptoms when compared with placebo injection. These findings should be useful to physicians and other health care providers as they counsel patients to take advantage of an important opportunity for disease prevention and health protection.

The effectiveness of vaccination against influenza in healthy, working adults

BACKGROUND

Although influenza causes substantial morbidity and mortality in all age groups, current recommendations emphasize annual immunization for people at high risk for complications of influenza. We conducted a double-blind, placebo-controlled trial of vaccination against influenza in healthy, working adults.

METHODS

In the fall of 1994, we recruited working adults from 18 to 64 years of age from in and around the Minneapolis-St. Paul area and randomly assigned them to receive either influenza vaccine or placebo injections. The primary study outcomes included upper respiratory illnesses, absenteeism from work because of upper respiratory illnesses, and visits to physicians' offices for upper respiratory illnesses. The economic benefits of vaccination were analyzed by estimating the direct and indirect costs associated with immunization and with upper respiratory illnesses.

RESULTS

We enrolled a total of 849 subjects. Baseline characteristics were similar in the two groups. During the follow-up period, consisting of the 1994-1995 influenza season (December 1, 1994, through March 31, 1995), those who received the vaccine reported 25 percent fewer episodes of upper respiratory illness than those who received the placebo (105 vs. 140 episodes per 100 subjects, P < 0.001), 43 percent fewer days of sick leave from work due to upper respiratory illness (70 vs. 122 days per 100 subjects, P = 0.001), and 44 percent fewer visits to physicians' offices for upper respiratory illnesses (31 vs. 55 visits per 100 subjects, P = 0.004). The cost savings were estimated to be $46.85 per person vaccinated.

CONCLUSIONS

Vaccination against influenza has substantial health-related and economic benefits for healthy, working adults.

Relative degree of stimulation-evoked glycogen degradation in muscle fibres of different type in rat gastrocnemius

1. The relative degree of glycogen degradation, caused in different fibre types by supramaximal electrical activation of the muscle nerve, was investigated in m. gastrocnemius medialis of young adult rats under general pentobarbitone anaesthesia. Four different protocols of intermittent maximal tetanic activation were used, each lasting 6 s (33% duty cycle; fast and slow isovelocity concentric (shortening) contractions, brief- and long-burst isometric contractions; 6 rats per group). All contractions were evoked under ischaemic conditions. 2. Work output finally dropped to 29% of the initial value for the fast concentric and to 87% for the slow concentric contractions. In isometric protocols evoked by the same stimulation patterns, the force x time area rose to 110% for brief-burst contractions and dropped to 95% for the long-burst contractions. 3. Following the physiological procedures, the experimental muscle and its contralateral control were removed and prepared for histochemical analysis. Serial sections were stained for glycogen (periodic acid-Schiff (PAS) method) and myofibrillar ATPase (mATPase), the latter reactions being used for classifying the fibres as types I, IIA, IIBd and IIBm. 4. For deep 'red' regions of non-stimulated contralateral control muscles the optical density of PAS staining was ranked between fibre types such that I < IIA < IIBd < IIBm. In superficial 'white' regions of the same muscles, no significant difference in PAS staining density was found between IIBd and IIBm fibres (types I and IIA not present). 5. All contractile protocols produced a significant glycogen degradation in IIBm fibres, and the fast concentric activation procedure was associated with a significant decline of PAS staining in all fibre types. For all activation protocols, the relative degree of glycogen degradation within a given region was ranked such that IIBm > IIBd > IIA > I. For IIBm vs. IIBd fibres, the differences in relative degradation were greater and more consistently significant for superficial white regions than in the deeper red muscle portions. 6. The results are discussed in relation to glycogen degradation measurements in studies of motor unit recruitment. Furthermore, the results from red vs. white muscle regions underline that fibres of seemingly the same mATPase type may differ considerably in other properties.

Palpable lymph nodes of the neck in Swedish schoolchildren

We studied 3592 Swedish schoolchildren, 8 or 9 years old, examined for palpable submandibular, cervical and supraclavicular lymph nodes. All children were skin tested with 2 TU PPD RT23 and with 0.1 microgram of Mycobacterium avium sensitin or 0.1 microgram of M. scrofulaceum sensitin. A total of 991 children had palpable lymph nodes in any of the three locations. Among them, 811 had lymph nodes in one location, 162 in two locations and 18 in three. In 312 children, the lymph nodes were > or = 5 mm in size in any location. The most common location was submandibular. Boys had a significantly higher prevalence of palpable lymph nodes than girls. There was also seasonal variation. Children infected by atypical mycobacteria (sensitin reaction > or = 6 mm) did not have a higher prevalence of palpable lymph nodes than those not infected.

The routine analysis of breast milk for drugs of abuse in a clinical toxicology laboratory

Drug screening of breast milk in a clinical toxicology laboratory is reported. Findings from three cases include cocaine, ethylbenzoylecgonine (cocaethylene), ethanol, oxycodone, codeine, and nicotine. We believe this to be the first report of ethylbenzoylecgonine in human breast milk. One other specimen submitted for analysis was screened with negative results. Screening and confirmation procedures adapted for use with breast milk are described. Finally, the potential for cocaine intoxication from mother to baby is discussed. Estimates of infant blood cocaine concentration are given which may increase awareness of the need to monitor milk and blood cocaine concentrations in the infant when the situation warrants.

Sensitivity to sensitins and tuberculin in Swedish children. Part 5: A study of school children in an inland rural area

SETTING

Since 1986 we have tested approximately 7000 non-BCG-vaccinated Swedish children with tuberculin and with Mycobacterium avium or M. scrofulaceum sensitin. In Göteborg, an urban coastal area, 25% of 8-9-year-old school children reacted to M. avium sensitin and 32% of M. scrofulaceum sensitin using a 6 mm cut-off.

OBJECTIVE

To evaluate if geographical factors have an influence on the prevalence of children reacting to tuberculin and sensitins.

DESIGN

2000 schoolchildren of the same age as those in Göteborg but living in an inland rural area were Mantoux-tested in a similar way (simultaneously on separate arms with PPD RT23 and either of the two sensitins).

RESULTS

15% reacted to PPD RT23, 9.7% to M. avium and 13.9% to M. scrofulaceum sensitin. None of the children with a PPD RT23 reaction > = 6 mm showed signs of tuberculosis or had any known exposure. A reaction to PPD RT23 was usually combined with a still larger sensitin reaction.

CONCLUSION

There was a considerable geographic difference in sensitin reactivity, low in an inland rural area compared to a coastal urban area. Children reacting to PPD RT23 had probably not been infected by M. tuberculosis but more likely by atypical mycobacteria. The reactions should be interpreted as cross-reactions.

Age-related changes in force and efficiency in rat skeletal muscle

We investigated the effect of age on (the reduction of) work output, efficiency and muscle fibre type composition. Rat medial gastrocnemius muscles of three age-groups performed a series of 15 repeated contractions within 6 s (blood flow was arrested). Stimulation and shortening velocities were chosen as optimal for each group, while all muscles shortened over the same relative fibre lengths. The fibre type composition showed a higher proportion of the oxidative type IIBd fibres in the middle-aged group [5 months old; 39.8 +/- 6.8 vs. 23.6 +/- 4.2% of the fibre area in the young rats (1.3 months old)] in contrast to the type IIBm fibres (52.9 vs. 67.9%, respectively), while the old group (22 months old) was not different from the middle-aged group. Work output in the last contraction (relative to the first contraction) was not different between the age-groups (53.1 +/- 18.1; 48.0 +/- 6.5 and 61.1 +/- 6.2%, respectively). High-energy phosphate utilization was not different between the groups (150.6 +/- 11.2; 154.6 +/- 15.6 and 157.2 +/- 7.0 mumol g-1 dry wt, respectively). However, the efficiency was approximately 30% lower in the muscles of the youngest group, which corresponds with a lower specific power and specific tension. Since the change in fibre type composition is unlikely to be the cause of the low efficiency in the young animals, the causes remain unclear, but may be related to the rapid growth of the young rats in our study.

Changes in morphological and functional characteristics of male rat EDL muscle during growth

Morphological and functional changes as well as changes in fibre-type composition were investigated in the left extensor digitorum longus (EDL) muscles of male Wistar rats of approximately 40, 60, 120 and 700 days old. A number of morphological changes occurred in the EDL muscle during growth. While from 40 to 120 days muscle mass and cross-sectional area (CSA) increased by 247 and 192%, changes in muscle and fibre lengths were much smaller (44 and 17%, respectively). Besides morphological changes tetanic force was also found to increase (approximately 307%) up to 120 days. Because this increase in force was greater than the increase in CSA, specific force increased by approximately 29% between 40 and 60 days. Thereafter, specific force stayed rather constant. From 40 until 60 days changes were also found in the force-frequency and force-velocity curve, which indicate a slowing of the muscles (until 60 days). Changes in fibre-type composition of the EDL muscle were found to occur later during growth between 60 and 120 days. In this period an increase in the relative total area of Type IIBd fibres and a decrease in the relative total area of Type IIBm fibres (corresponding to the Type 2X and IIB fibres, respectively), were found; this was apparently due to a conversion of many Type IIBm into Type IIBd fibres and not to a difference in cross-sectional growth between these fibres.(ABSTRACT TRUNCATED AT 250 WORDS)

Sensitivity to sensitins and tuberculin in Swedish children. IV. The influence of BCG-vaccination

BCG-vaccinated schoolchildren, 8-9 yrs of age, were simultaneously tested on separate arms with tuberculin and a sensitin. Using the 6 mm cut-off they reacted in 49% to two tuberculin units purified protein derivative (PPD RT23), in 67% to 0.1 micrograms Mycobacterium avium sensitin RS10, and in 58% to 0.1 micrograms M. scrofulaceum sensitin RS95. The corresponding figures for non-BCG-vaccinated schoolchildren of the same age tested at the same time were 3, 25 and 32%, respectively. The results indicate a stimulating influence of BCG-vaccination on tuberculin and sensitin reactivity. Since the sensitin reactions were the larger ones, these reactions were not only due to the vaccination. The BCG-vaccinated schoolchildren seem to have acquired infections by atypical mycobacteria despite vaccination.

Growth-related change in specific force but not in specific power of rat fast skeletal muscle

The effect of growth on the dynamic performance of rat medial gastrocnemius muscle was studied. From approximately 1.5 to 5 months of age specific force increased by 18%. Reductions were found in both optimal stimulation frequency (from 120 to 100 Hz) and optimal shortening velocity (by 16%) indicating that the fibres became slower. Specific power did not change during growth but was obtained at a lower shortening velocity. Possible mechanisms for the observed changes are discussed.

Sensitivity to sensitins and tuberculin in Swedish children. IV. The influence of BCG-vaccination

BCG-vaccinated schoolchildren, 8-9 yrs of age, were simultaneously tested on separate arms with tuberculin and a sensitin. Using the 6 mm cut-off they reacted in 49% to two tuberculin units purified protein derivative (PPD RT23), in 67% to 0.1 micrograms Mycobacterium avium sensitin RS10, and in 58% to 0.1 micrograms M. scrofulaceum sensitin RS95. The corresponding figures for non-BCG-vaccinated schoolchildren of the same age tested at the same time were 3, 25 and 32%, respectively. The results indicate a stimulating influence of BCG-vaccination on tuberculin and sensitin reactivity. Since the sensitin reactions were the larger ones, these reactions were not only due to the vaccination. The BCG-vaccinated schoolchildren seem to have acquired infections by atypical mycobacteria despite vaccination.

Sensitivity to sensitins and tuberculin in Swedish children. III. Sequential versus simultaneous skin testing

The aim of this study was to determine whether simultaneous and sequential skin testing with tuberculin and sensitins give consistent results. A total of 475 8- or 9-year-old schoolchildren were skin tested sequentially, at an interval of 3 days, with PPD tuberculin and with either Mycobacterium scrofulaceum or M. avium sensitin. The results were compared with those of 470 simultaneously tested children chosen from the same living area. There were no statistically significant differences between the frequencies of the reactions of sequentially and simultaneously tested children. When the sequential testing procedure was employed, 3.1% reacted to tuberculin, 19% to M. avium sensitin and 30% to M. scrofulaceum sensitin, taking a 6 mm cut-off. The corresponding figures for the simultaneously tested children were 4.7, 21 and 36%, respectively. Thus, there was no indication that the simultaneous testing procedure in itself influenced the results, neither was there any sign of a booster effect when testing in sequence with an interval of 3 days in non-BCG-vaccinated children.

Myofibrillar ATPase histochemistry of rat skeletal muscles: a "two-dimensional" quantitative approach

In histochemical investigations of skeletal muscle, the fibers are commonly classified into three types according to their staining for myofibrillar ATPase (mATPase). In serial sections of skeletal muscles from normal Wistar rats, we compared two common staining methods for mATPase: (a) an ac-ATPase technique, with pre-incubation at pH 4.7, and (b) a fixed alk-ATPase technique, using treatment with 5% paraformaldehyde followed by pre-incubation at pH 10.4. In addition, the same fibers were stained in subsequent serial sections for succinate dehydrogenase (SDH) activity. Staining intensities were objectively evaluated by microphotometric measurements of optical density. Combining both mATPase methods in consecutive serial sections ("two-dimensional approach") led to the identification of four distinct clusters of fibers: Types I, IIA, and two subgroups of Type IIB, as separated by their staining densities for fixed alk-ATPase (IIBd dark, IIBm moderate). The mean intensity of SDH staining per fiber type, as measured in the central core of the fibers, was ranked such that IIA greater than I greater than IIBd greater than IIBm. The analyzed muscles (tibialis anterior, biceps brachii) were markedly heterogeneous with respect to the topographic distribution of different fiber types. In comparison to other muscle portions, the regions containing Type I fibers ("red" portions) showed a higher IIBd vs IIBm ratio and more intense SDH staining for either subtype of the IIB fibers. The IIBd fibers probably correspond to the Type 2X fibers of Schiaffino et al.

Sensitivity to sensitins and tuberculin in Swedish children. I. A study of schoolchildren in an urban area

Non-BCG-vaccinated schoolchildren (8 or 9 years of age) were simultaneously tested on separate arms with 2 IU PPD RT23 and 0.1 microgram Mycobacterium avium sensitin RS10 or 0.1 microgram Mycobacterium scrofulaceum sensitin RS95. None of the 2819 analysed children had any known exposure to tuberculosis. A total of 3.4% reacted with an induration greater than or equal to 6 mm to PPD RT23. Half the number of children were tested with M. avium sensitin and 25.4% reacted while the remaining were tested with M. scrofulaceum sensitin and 32.4% reacted when the cut-off was 6 mm. For about 90% of the children the sensitin reaction was larger than or equal to the tuberculin (PPD RT23) reaction. Correlation analyses showed that moderate and high PPD RT23 values were combined with still higher sensitin values, indicating that the tuberculin reactions were mainly cross-reactions due to the antigenic similarity between tuberculin and sensitins. The presence of birds, dogs and cats in the homes was combined with an increased frequency of children reacting to the sensitins used. The children with reactions to PPD RT23 greater than or equal to 6 mm were examined and chest X-rays were performed. None of them showed any signs or symptoms of mycobacterial disease. In non-BCG-vaccinated Swedish schoolchildren without clinical signs of tuberculosis and without known contact with a contagious tuberculous person, indurations less than 12 to 14 mm on tuberculin testing are probably caused by atypical mycobacteria. In such cases sensitin tests should be performed to verify the suspicion.