Neuraminidase produces a decrease of adherence of slime-forming <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> to gelatin-impregnated polyester fiber graft fabric: an experimental study

Because slime-forming microorganisms are the major causative agents of graft infections, we aimed to investigate bacterial adherence in slime-forming and nonslime-forming Staphylococcus aureus and to determine the role of neuraminidase (NANase) on adherence to gelatin-impregnated polyester fiber graft fabric. An in vitro model was developed to quantitatively measure bacterial adherence to the surface of the graft. The grafts were divided into two groups – those colonized with slime-forming S. aureus and those colonized with nonslime-forming S. aureus. The grafts were put into sterile tubes and human plasma was instilled and incubated at 37°C to perform fibrin deposition on the grafts. After 48 h of incubation, grafts were drained and inoculated with slime-forming or nonslime-forming S. aureus in triptic soy broth in the presence or absence of NANase. Following 36 h of incubation at 36°C, grafts were vortexed and cultured to perform a colony count. Bacterial counts were expressed as total colony-forming units per square centimeter of graft. Slime-forming S. aureus had greater affinity with the graft compared with nonslime-forming S. aureus (P < 0.05). The adherence of slime-forming S. aureus was impaired by NANase treatment (P < 0.001) but NANase treatment of nonslime-forming S. aureus did not change the adherence to the graft (P > 0.05). These results show that slime plays an important role in the pathogenesis of vascular graft infection. Adherence of slime-forming S. aureus can be decreased by NANase treatment. This may have implications for the development of neuraminidase-embedded vascular grafts to diminish biomaterial-related infections.     

Intracerebroventricular choline increases plasma vasopressin and augments plasma vasopressin response to osmotic stimulation and hemorrhage

Intracerebroventricular (i.c.v.) injection of choline (50-150 microg), a precursor of the neurotransmitter acetylcholine, produced a time-and dose-dependent increase in plasma vasopressin levels in conscious, freely moving rats. The increase in plasma vasopressin in response to i.c.v. choline (150 microg) was inhibited by pretreatment with the nicotinic receptor antagonist, mecamylamine (50 microg; i.c.v.), but not by the muscarinic receptor antagonist, atropine (10 microg; i.c.v). The choline-induced rise in plasma vasopressin levels was greatly attenuated by hemicholinium-3 (HC-3; 20 microg; i.c.v.), a neuronal choline uptake inhibitor. Choline (50 or 150 microg; i.c.v.) produced a much greater increase in plasma vasopressin levels in osmotically stimulated or hemorrhaged rats than in normal rats. Choline (150 microg; i.c.v.) also enhanced plasma vasopressin response to graded hemorrhage; the enhancing effect of choline was also attenuated by HC-3 (20 microg; i.c.v.). Choline and acetylcholine concentrations in hypothalamic dialysates increased significantly following i.c.v. injection of choline (150 microg). It is concluded that choline increases plasma vasopressin levels by stimulating central nicotinic receptors indirectly, through the enhancement of acetylcholine synthesis and release, and augments the ability of osmotic stimulations or hemorrhage to stimulate vasopressin release.     

MPO-ANCA-associated pulmonary-renal vasculitis in a patient with diabetes mellitus

Diabetes mellitus is one of the major causes of chronic renal failure. Typical findings of diabetic nephropathy are early hyperfiltration followed by microalbuminuria and overt proteinuria, resulting in a progressive decrease in glomerular filtration rate. Rapidly progressive glomerulonephritis has rarely been reported in patients with diabetes mellitus. Here, we describe a patient with MPO-ANCA-associated vasculitis, presenting with pulmonary-renal syndrome. Immunosuppressive treatment, including pulse methyl-prednisolone and cyclophosphamide, was administered and the disease was resolved.     

Efficacy of tolterodine as a first-line treatment for non-neurogenic voiding dysfunction in children

OBJECTIVE: To assess the effect of antimuscarinic treatment with tolterodine combined with behavioural modification as a first-line treatment, before invasive investigation, in children with non-neurogenic voiding dysfunction but no obvious anatomical or neurogenic cause. PATIENTS AND METHODS: The study comprised 44 children presenting with voiding dysfunction (30 girls and 14 boys, mean age 7 years, range 5-14); all had a noninvasive evaluation consisting of a history, urine analysis, renal and bladder ultrasonography and physical examination, with specific emphasis on the voiding pattern. Anticholinergic treatment with tolterodine (1 mg twice daily) was started in all patients; they were also informed about conservative management, including timed voiding, double voiding and relaxation of the pelvic floor during voiding. At the start and after 3 months, the dysfunctional voiding symptom score (DVSS) was completed twice by all patients. RESULTS: For all patients the mean (sd) DVSS was 14.0 (2.67) and 6.68 (3.67) before and after treatment, respectively; the difference was statistically significant (P < 0.001). The mean scores for girls and boys, respectively, were 13.8 (2.79) and 14.5 (2.44) before and 6.43 (3.79) and 7.50 (3.34) after treatment. CONCLUSION: Tolterodine combined with behavioural modification for dysfunctional voiding in children with no neurological or anatomical abnormality can be recommended as a first-line treatment before invasive evaluation. Additionally, the DVSS appears to provide accurate and objective data for monitoring the effect of treatment in such children.     

Differential expression of VASP in normal lung tissue and lung adenocarcinomas

BACKGROUND: Vasodilator stimulated phosphoprotein (VASP) is associated with focal adhesions and is thought to have an important role in actin filament assembly and cell motility. We hypothesise that an increase in the expression of VASP is involved in the progression and invasion of lung adenocarcinomas in parallel to tumour progression. A study was undertaken to analyse VASP expression in normal lung tissue and lung adenocarcinomas. METHODS: Human lung tissues with adenocarcinomas (n = 26) were used. Normal lung tissue specimens (n = 14) were taken from areas a standard distance (3 cm) from resected adenocarcinomas of patients who underwent surgical lung resection. Adenocarcinomas were classified according to pathological staging and histopathological grades. Tissues were stained for VASP using immunohistochemistry. RESULTS: Normal lung pneumocytes showed no VASP expression while alveolar macrophages had the strongest immunoreactivity for VASP. Bronchial epithelium (surface epithelium, goblet cells) and bronchial gland cells had a very weak immunoreactivity for VASP. Adenocarcinomas had significantly greater VASP expression than normal epithelium (p < 0.001). Moreover, VASP expression in adenocarcinomas increased significantly with more advanced tumour stage (p < 0.001). CONCLUSIONS: The spatial and differential expression of VASP in normal lung tissue and lung adenocarcinomas suggests that it is likely to be involved in the differentiation of normal lung cells to adenocarcinomas. The significant increase in the expression of VASP in adenocarcinomas in parallel to pathological staging suggests that it may regulate the invasive behaviour of lung adenocarcinomas as adenocarcinoma invasion is increased in more advanced tumours.     

Ocular surface disorders and tear function changes in nodulo-cystic acne

The aim of this study was to investigate the ocular surface disorders and tear function changes in patients with nodulo-cystic acne. Eighty-seven patients with nodulo-cystic acne vulgaris and 50 healthy subjects were included in the study. All subjects underwent full ocular examinations. Subjective ocular complaints were recorded. Corneal staining with fluorescein, tear film break-up time (BUT), and Schirmer test were applied. Abnormal tear film BUT and abnormal Schirmer scores were significantly more common in the acne group than in the control group. The tear film BUT was abnormal in 18 (20.7%) cases in the patient group and in 2 (4%) subjects in the control group (p=0.007). The mean Schirmer score was abnormal in 7 (8%) and decreased in 18 (20.7%) acne patients, and it was decreased in only 3 (6%) control subjects (p=0.005). Corneal punctuate epithelial erosions were detected in 3 (3.4%) acne patients, but not any of the control subjects. However, the difference between the groups was not statistically significant (p=0.184). Subjective ocular complaints were present in 28 cases (32.2%) in the patient group. Five (10%) subjects in the control group had such complaints (p=0.003). Tear function tests are also significantly altered in patients with nodulo-cystic acne. Our data suggest that severe acne patients should be referred to an ophthalmologist.     

Investigation of the mechanism of nicotine induced relaxation in rabbit corpus cavernosum in vitro

In order to determine whether nicotine acts on corporal smooth muscle, the mechanism of its effect on strips of rabbit corpus cavernosum was studied in vitro. Rabbit corpus cavernosum muscle strips were mounted in an organ bath with modified Krebs-Henseleit solution and aerated with 95% O₂ and 5% CO₂. Tension was measured with isometric force transducers, and muscle relaxation was expressed as the percent decrease of precontraction induced by phenylephrine. Nicotine produced concentration dependent relaxation when preparations were precontracted by phenylephrine (10^–5 M). The maximum nicotine-induced relaxation was 60.4±4.2% of the phenylephrine contraction and was not affected by indomethacin (10^–5 M), N^w-nitro L-arginine methyl ester (3×10^–5 M), methylene blue (10^–5 M), glibenclamide (10^–5 M), clotrimazole (10^-6 M), tetraethylammonium (3×10^–4 M), or 4-aminopyridine (10^–3 M). Nicotine did not exhibit a calcium antagonizing effect. From these results, we conclude that nicotine-induced relaxation of the rabbit corpus cavernosum is not mediated by the release of nitric oxide, prostaglandins or a related substance, by the activation of potassium channels, or by the stimulation of nicotinic cholinoceptors. Further work is needed to determine the cellular mechanism(s) of the action by which nicotine acts on corporal smooth muscle.     

Surgical management of childhood bronchiectasis due to infectious disease

BACKGROUND: The purpose of this study was to estimate operative risk and to identify indicators of adverse prognosis in patients undergoing resection for childhood bronchiectasis. METHODS: From January 1985 to February 2001, patients undergoing resection for bronchiectasis were studied. The indications for operation were failure of medical therapy in 33 patients (94.2%) and hemoptysis in 2 (5.7%). The mean duration of symptoms was 4.2 years (range, 1-9 years). Surgical treatment included lobectomy in 17 patients (48.5%), pneumonectomy in 7 (20%), lobectomy plus segmentectomy in 5 (14.2%), bilobectomy in 2 (5.7%), and segmentectomy in 4 (11.4%). RESULTS: The operative mortality rate was 2.8%, and the morbidity rate was 17.6%. The mean follow-up in 34 patients was 5.4 years (range, 1-12 years). Overall, 22 patients (64.7%) were asymptomatic after surgery. Clinical improvement was noticed in 8 patients (23.5%), and no improvement was noticed in 4 (11.7%). Complete resection resulted in a significantly better clinical outcome than incomplete resection (P <.05). CONCLUSIONS: Surgery for childhood bronchiectasis can be performed with low mortality and morbidity. Complete resection should be performed when possible.     

The hypotension evoked by visceral nociception is mediated by delta opioid receptors in the periaqueductal gray

This study tested the hypothesis that the ventrolateral column of the midbrain periaqueductal gray (vlPAG) region mediates the hypotension and bradycardia evoked by visceral nociception. To test this, the local anesthetic lidocaine (2%; 0.5 microl) was microinjected into the vlPAG of halothane-anesthetized rats bilaterally and visceral nociception was induced 2 min later by injecting 5% acetic acid (0.5 ml) intraperitoneally. Acetic acid injection caused an abrupt fall in arterial pressure (-12.2+/-2.1 mm Hg) and heart rate (-37+/-93 bpm) lasting approximately 15 min. Lidocaine injection into the vlPAG prevented the fall in arterial pressure and heart rate completely. Cobalt chloride (5 mM; 0.2 or 0.5 microl) injection into the vlPAG also prevented nociceptive hypotension but it did not affect the fall in heart rate significantly. Lidocaine pretreatment also inhibited the depressor response caused by intramuscular formalin (5%; 0.2 ml) administration, a model of deep somatic nociception, although it did not prevent the response completely. To determine if opioid receptors mediate the response, selective mu, delta or kappa opioid receptor antagonists were microinjected into the vlPAG 5 min before intraperitoneal (ip) acetic acid administration. Naltrindole, a delta receptor antagonist, inhibited the response significantly but mu and kappa antagonists were completely ineffective. Lidocaine and naltrindole had no effect when injected into the dorsolateral PAG and did not influence cardiovascular function when injected into the vlPAG of saline treated control animals. These data support the hypothesis that the vlPAG mediates the depressor response evoked by visceral nociception and indicate that delta opioid receptors participate in the response.