Hypertrophy without increased isometric strength after weight training

Summary Eight men (20–23 years) weight trained 3 days week^–1 for 19 weeks. Training sessions consisted of six sets of a leg press exercise (simultaneous hip and knee extension and ankle plantar flexion) on a weight machine, the last three sets with the heaviest weight that could be used for 7–20 repetitions. In comparison to a control group (n = 6) only the trained group increased (P<0.01) weight lifting performance (heaviest weight lifted for one repetition, 29%), and left and right knee extensor cross-sectional area (CAT scanning and computerized planimetry, 11%, P<0.05). In contrast, training caused no increase in maximal voluntary isometric knee extension strength, electrically evoked knee extensor peak twitch torque, and knee extensor motor unit activation (interpolated twitch method). These data indicate that a moderate but significant amount of hypertrophy induced by weight training does not necessarily increase performance in an isometric strength task different from the training task but involving the same muscle group. The failure of evoked twitch torque to increase despite hypertrophy may further indicate that moderate hypertrophy in the early stage of strength training may not necessarily cause an increase in intrinsic muscle force generating capacity.     

Proliferation rates in epidermis of patients with graft-versus-host disease, non-specific inflammation and normal skin.

There is evidence that epidermal stem cells or their early progeny may be the targets in graft-versus-host disease (GVHD). The early progeny should be a proliferating group of daughter cells more concentrated in areas just above or adjacent to stem cell regions. We have, therefore, compared proliferative rates of keratinocytes within relevant subregions of the epidermis using the AgNOR stain on biopsies from patients with GVHD, non-specific inflammatory infiltrates (NSI) and normal skin. We concurrently evaluated T cell infiltration using immunohistology on paraffin-embedded tissue with UCHL-1 antibody. Fifty-one bone marrow transplant patients were evaluated in each of three temporal groups (days 7-20 post-transplant, days 20-40 post-transplant, and days 80-100 post-transplant). In each of these groups, 5-9 patients with a histological diagnosis of GVHD were compared to similar numbers of patients with a histological diagnosis of non-specific dermatitis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Endothelial changes in cutaneous graft-versus-host disease: a comparison between HLA matched and mismatched recipients of bone marrow transplantation

Histological features of endothelial and vascular changes seen in cell mediated immune reactions were evaluated in skin biopsies from 44 HLA matched and mismatched recipients of bone marrow transplantation. The mismatched group (n = 24) was further subdivided into 'D-mismatched' (n = 14) and 'AB-mismatched' (n = 10). All patients had clinical grade III and histological grade II graft-versus-host disease (GVHD). Comparison groups consisted of skin biopsies from 10 non-GVHD cases. Histological evidence of endothelial damage including perivascular factor VIII related antigen deposition was assessed and compared between the groups. The results showed that all patients post-transplant had evidence of a non-specific vascular response consisting mainly of a perivascular lymphocytic infiltrate, perivascular oedema and factor VIII related antigen extravasation. However, a significant difference between matched and mismatched patients who developed GVHD was the more frequent observation of perivascular nuclear dust in the HLA mismatched group (p less than 0.01) suggesting a greater degree of endothelial cell damage in these patients.     

Direct ultrastructural evidence of target-directed polarization by cytotoxic lymphocytes in lesions of human graft-vs-host disease

Cytotoxic lymphocytes are thought to kill target cells by means of potent cytotoxic granules that congregate near the microtubular organizing center and the Golgi apparatus at one pole of the killer cell. We searched for evidence of this type of polarization in 12 lip biopsy specimens from patients with acute and/or chronic graft-vs-host disease (GVHD) compared with two lip specimens from normal individuals. Lymphocytes with such polarization were found in contact with epithelial cells of the squamous mucosa in all 12 cases of GVHD, and cells of the cuboidal minor salivary duct epithelium were found in two of 11 evaluable cases. The data add support to the hypothesis that cytolytic lymphocytes attack epithelial cells in GVHD.     

Modulation of the constitutive or cytokine-induced bronchial epithelial cell functions in vitro by fluticasone propionate

When exposed to proinflammatory mediators, human bronchial epithelial cells (HBECs) upregulate the 'constitutive' adhesion molecule expression and cytokine/chemokine release. We tested whether and to what extent the inhibitory effect of fluticasone propionate on HBECs could involve the 'constitutive' and 'cytokine-induced' proinflammatory functions. Stimulation of the HBECs with interleukin (IL)-4 plus tumour necrosis factor (TNF)-alpha was more effective in upregulating intercellular adhesion molecule (ICAM)-1 ( approximately 2.2-fold increase) than vascular adhesion molecule (VCAM)-1 ( approximately 1.6-fold increase) expression (P<0.05) and in increasing the release of 'regulated on activation normal T cell expressed' (RANTES, 5.7-fold increase) than of IL-8 (3.5-fold increase) and granulocyte macrophage-colony stimulating factor (GM-CSF, 2.8-fold increase), (P<0.01). Fluticasone propionate, at the two concentrations tested (10 and 100 nM), was more effective in inhibiting the 'IL-4 plus TNF-alpha-induced' ICAM-1 expression than VCAM-1 expression (P<0.05) and in downregulating RANTES than IL-8 or GM-CSF secretion (P<0.05). The degree of inhibition demonstrated by fluticasone propionate appeared to be related to the degree of cell activation. In addition, for both adhesion molecules, the effect of fluticasone propionate at both concentrations tested appeared to be related to a complete inhibition of 'IL-4 plus TNF-alpha-induced' expression with no involvement of the 'constitutive' expression. Slightly different results were observed for cytokine/chemokine release. Indeed, evaluating RANTES, a complete inhibition of the 'IL-4 plus TNF-alpha-induced' release with a partial inhibition also of the 'constitutive' release at both concentrations of the drug tested was found, whereas for GM-CSF and IL-8, only a partial inhibition of the 'IL-4 plus TNF-alpha-induced' release in the presence of fluticasone propionate 10 and 100 nM. Thus, HBECs can constitutively or upon activation express adhesion molecules and secrete proinflammatory proteins at various levels and the different ability of fluticasone propionate to modulate the HBEC functions appears to be mostly related to the different inhibition of the various 'IL-4 plus TNF-alpha-induced' responses.     

Effect of postactivation potentiation on dynamic knee extension performance

Six men and four women performed, in separate trials, maximal dynamic knee extensions with loads of 15%, 30%, 45% and 60% of maximal isometric knee extension peak torque (MVC). The dynamic extensions were done after postactivation potentiation (PAP) had been induced with a 10-s MVC, and in a control trial without PAP. PAP, measured as the increase in evoked twitch torque, was 53 (4)% (SE) and 43 (3)% at the time of the first and second extensions with each load. PAP failed to increase the attained peak velocity with any load; on the contrary, there was a trend for peak velocity to decrease in the first extension, which occurred ≅15 s after the 10-s MVC. The results suggest that fatigue produced by the 10-s MVC suppressed any benefit that could be derived from the induced PAP. A surface electromyogram (EMG) recorded from one muscle of quadriceps femoris gave no indication of activation failure in the first knee extension; however, activation impairment specific to the rate of force development cannot be ruled out. It is concluded that the strategy employed, namely of having knee extensions performed soon after the 10-s MVC to maximize PAP at the time of performance, was unsuccessful because there had been insufficient time for recovery from fatigue. It is possible that a longer recovery time, even at the cost of a diminished PAP, may have proved beneficial. Accepted: 27 July 2000     

The CQI paradigm: a pathway to nurse empowerment in a community hospital

Anderson Area Medical Center instituted continuous quality improvement (CQI) hospitalwide two years ago. Three teams were challenged with identifying and improving processes related to accounts receivable. X-ray report turn-around-time, and emergency department patient satisfaction. Nursing participation was sought for all three teams. An eight-step CQI process was used to identify, analyze, and improve these three processes. Substantial nursing participation in these pilot CQI teams led to further participation in many other CQI teams optimizing clinical processes. Nursing personnel gained opportunities to make significant contributions to the enhancement of clinical and administrative processes in a large hospital. Nurses learned to work with other members of the health care team outside of their traditional domains, and this, combined with formalized training in the team process, is empowering.     

Exercise induces a change in plasma fibrinogen concentration: fact or fiction?

This study examined the effect of exercise on plasma fibrinogen concentrations with simultaneous measurements of plasma volume changes. Eight moderately active males aged 26.6±3.6 years (mean±SD) completed maximal (VO₂max) and submaximal (75% VO₂max for 30 minutes) exercise trials separated by 7 days. Venous blood samples were obtained at rest, immediately postexercise, and following 30 minutes of recovery. Whole blood was analysed for haematocrit and haemoglobin, while citrated plasma was assayed for fibrinogen levels. Values of haematocrit and haemoglobin before and after exercise were utilised for the estimation of plasma volume changes. Plasma volume decreased (p<0.05) immediately following both maximal (−17.7±5.1%) and submaximal (−14.3±4.1%) exercise. Exercise resulted in decreased plasma fibrinogen levels (maximal exercise: from 266.3±14.5 to 222.2±23.9 mg·dL⁻¹; submaximal exercise: from 239.5±45.4 to 209.7±42.4 mg·dL⁻¹) only when postexercise raw data were corrected for the contraction of plasma volume. It is concluded therefore that changes in plasma volume in response to exercise should be taken into account when interpreting exercise effects on plasma fibrinogen concentration.     

Benign clear cell tumor of lung with necrosis.

A case of benign clear cell tumor ("sugar tumor") of the lund with extensive necrosis is reported. Electron microscopic study established the diagnosis by virtue of the characteristic cytoplasmic membrane-bound glycogen. Ultrastructural study may be necessary in cases containing necrosis to differentiate this lesion decisively from metastatic renal cell carcinoma.