An improved closed cranial window technique for investigation of blood-brain barrier function and cerebral vasomotor control in the rat

A modification of the closed cranial window technique for small laboratory animals is presented. The method facilitates investigation of blood-brain barrier permeability in association with studies of the cerebrovascular response under normal and pathological conditions. Following trephination and preparation of the pia-arachnoid surface, the skull defect is closed again by sealing a cover glass onto a wall of dental cement surrounding the cranial window. The intracranial pressure can then be studied and experimentally manipulated. Care is taken to maintain normal blood-brain barrier function to a small barrier indicator (Na(+)-fluorescein, MW: 376). This is accomplished by opening the skull and dura mater under a column of paraffin oil to avoid exposure of brain tissue to atmospheric pressure. Reactivity of the cerebral surface vessels was assessed during hypercapnia at an arterial PaCO2 of 50.8 +/- 1.1 mm Hg. It was found that small arterioles of 20-50 microns phi had a significantly larger CO2-response than large arterioles of 50-100 microns phi. Pial venules did not respond at all. Superfusion of the cranial window preparation at a rate of 5 ml/h with buffered artificial CSF was tolerated for hours. No alterations of arteriolar or venular diameters nor opening of the blood-brain barrier to Na(+)-fluorescein was observed. These technical modifications enable us to employ a closed cranial window model in small laboratory animals for studies of cerebral microcirculation and blood-brain barrier function under normal as well as under pathological conditions related to brain damage.

Community-acquired pneumonia caused by Legionella dumoffii in a patient with hairy cell leukemia

A case of community-acquired pneumonia caused by Legionella dumoffii in a patient with hairy cell leukemia is described. Diagnosis was confirmed by isolation by culture of sputum and broncho-alveolar lavage specimens, positive direct fluorescent antibody stains, and antibody seroconversion from 1:16 (acute) to 1:4096 (six months). The blue white autofluorescence of the L. dumoffii colonies when viewed under ultraviolet light was particularly useful in preliminary identification. The patient recovered from his pneumonia after administration of erythromycin and rifampin. Legionella have been shown to multiply in monocytes and cell-mediated immunity appears to be the primary mechanism of host defense in man. Hairy cell leukemia is characterized by monocyte dysfunction and such patients have a predilection for infection by microbes that are controlled by cell-mediated defenses. We review other cases of community-acquired L. dumoffii pneumonia as well as other cases of Legionella infection in patients with hairy cell leukemia.

Photodynamic therapy in head and neck surgery

The results of a clinical study of photodynamic therapy (PDT) on early stage cancer in head and neck surgery are presented in this report. 30 patients with T1 malignancies of the face and oropharynx have been treated primarily with PDT. After the longest follow up of 14 months two patients revealed recurrence of the disease or residual tumor, two patients have been retreated because of residual dysplastic cells in the control biopsy, and all other patients stay histologically proven free of disease. Hence, PDT appears to be a promising cancer treatment for different histological tumors that penetrate the host tissue definitely less than a laser beam of 630 nm, which is the appropriate wavelength for PDT. Deeper-penetrating malignomas may be accessable for PDT using insertable filters when applying interstitial laser light.

Hepatitis B and hepatitis B vaccine requirements in schools of nursing in the United States: a national survey

To ascertain use of the hepatitis B vaccine and occurrence of hepatitis B infection in nursing students, 1152 U.S. nursing schools were surveyed; 54.3% responded. The vaccine was required by 4.2% and recommended by 7.7%. Baccalaureate programs tended to require the vaccine more than the associate degree or diploma programs (p = 0.062). The occurrence of exposure of nursing students to blood and body fluids in the past 5 years was reported by 89.7%. Students in the diploma program had significantly more exposures (98.6%) than those in the associate degree (92.8%) and baccalaureate programs (82.7%; p less than 0.0005). At least one case of hepatitis B in the past 5 years was reported by 6.8%. Development of positive serologic markers in students after exposure to blood was reported by 7.1%. Seropositivity tended to occur in the Southeast and West (p = 0.035) and in cities with a relatively higher incidence of acquired immunodeficiency syndrome (p = 0.075). Diploma programs were significantly more likely to institute appropriate follow-up for students after exposure to blood of patients who were known or unknown carriers of hepatitis B virus (p less than 0.0001). For students exposed to blood of patients whose hepatitis B status was unknown and patients who were known hepatitis B carriers, 19.2% and 8.9%, respectively, reported they performed no follow-up whatsoever. U.S. nursing students are inadequately protected against hepatitis B. Nursing school administrators and faculty should be educated on the risks of hepatitis B infection and the indications and use of the hepatitis B vaccine.

[Endoscopic controlled laser lithotripsy in the treatment of sialolithiasis]

The article describes the first successful application of endoscopically controlled laserlithotripsy in the ENT field in a patient with recurrent purulent sialadenitis of the left submandibular gland due to sialolithiasis. By means of endoscopically controlled laserinduced lithotripsy of salivary gland stones, it was possible to achieve complete stone fragmentation without harming the glandular duct and the gland.

Disinfection of water distribution systems for legionella: a review of application procedures and methodologies

Hospital-acquired legionella pneumonia is emerging as a major problem; potable water distribution systems have been shown to be the primary reservoirs for the legionella organisms. As a result, disinfection measures have been developed to eradicate the organism from the hospital water supply. Each disinfection modality differs in its design and application such that choosing an appropriate cost-effective control measure requires careful analysis and planning. We assess in comparative fashion the disinfection modalities of thermal eradication ("heat-and-flush"), instantaneous steam-heating system, chlorination, ultraviolet light irradiation, ozonation and metal ionization. The theoretical bases, the actual procedure or system, the logistics of implementation, the costs and personnel requirements and the advantages and disadvantages are presented for each modality. Criteria for selection of a method, the use of combinations of methods, parameters for installation, pitfalls in implementation and a plan for subsequent environmental surveillance are discussed in detail.

Epicardial oxygen tensions during changes in arterial PO2 in pigs

Arterial hypoxemia decreased epicardial tissue PO2, measured by means of a multiwire surface electrode, as well as coronary venous PO2 and myocardial lactate extraction. Left ventricular blood flow increased, O2 delivery, O2 demand and O2 consumption of the left ventricle remained unchanged. Thus, epicardial and coronary venous PO2 indicated decreased capillary and interstitial PO2 rather than cellular hypoxia. A linear relation between mean epicardial PO2 and coronary venous PO2 proves both parameters equally effective in reflecting changes in myocardial tissue oxygenation. However, PO2 distribution curves provide additional information and epicardial PO2 is superior in models with regional changes of myocardial oxygenation.

[Pancreatic circulation in experimental biliary pancreatitis]

Measurements of pancreatic micro- and macrocirculation were performed to evaluate the pancreatitis-induced changes. Pigs were anesthetized and ventilated mechanically. Hypotension induced side-effects were avoided by adequate volume replacement. After laparatomy, splenectomy and gastroectomy the animals were enterotomized. Systemic hemodynamic parameters were monitored as well as pancreatic blood flow (Q), which was measured electromagnetically, and arterial and portal-venous blood gases. Pancreatic microcirculatory parameters were observed using fluorescence-videomicroscopy after i.v. administration of FITC dextran 150 and FITC labeled autologous erythrocytes. The pigs were randomly assigned to a control (n = 9) and a pancreatitis group (n = 10), the later being induced by the retrograde infusion of sodium-taurocholate. Systemic and pancreatic macrohemodynamic parameters remained constant in both groups, except for avdO2 and O2-consumption (O2-c) decreasing significantly in the pancreatitis group. At baseline 42% of all capillaries were perfused in both groups. In pancreatitis we detected focal areas with persistent stasis and areas which were continuously perfused. In these areas the portion of capillaries perfused by erythrocytes increased significantly to 67%. This was accompanied by an extravasation of FITC dextran. The finding of an unchanged Q beside reduced O2-c and avdO2 during pancreatitis is explained by the changes in pancreatic microcirculation. Focal stasis was observed beside areas showing typical signs of an acute inflammation: increased macromolecular permeability and capillary recruitment, e.g. oedema and hyperaemia.

Pseudomonas aeruginosa infections associated with use of povidone-iodine in patients receiving continuous ambulatory peritoneal dialysis

Fifteen episodes of infection due to Pseudomonas aeruginosa, including peritonitis and catheter site infections, occurred in nine patients receiving continuous ambulatory peritoneal dialysis over a 27-month period. Eight episodes were associated with catheter loss. Occurrence of P aeruginosa infection was significantly associated with use of povidone-iodine solution to cleanse the catheter site. There was no association with use of povidone-iodine solution to disinfect tubing connections, use of other skin care products or exposure to other environmental sources of P aeruginosa. Cultures of available povidone-iodine products were negative. Local irritation and alteration in skin flora caused by antiseptic solution or low-level contamination of povidone-iodine solution are potential mechanisms of infection.

[Photodynamic laser tumor therapy with a hematoporphyrin derivative in spinocellular carcinoma of the external ear]

Haematoporphyrine-derivative (hpd) selectively photosensitises malignant tumours following intravenous application. 48 hours after injection of hpd an integral laser-light application of the tumour and the surrounding normal tissue was performed. We report on the successful administration of this photodynamic therapy in a patient with a spinocellular carcinoma of the auricle. 16 days after therapy the tumour showed a complete response without damage of the also irradiated surrounding normal tissue. Apart from a temporary sensitivity to light no side effects of the therapy were seen.

Myocardial surface PO2--an indicator of myocardial tissue oxygenation?

The validity of myocardial surface tissue PO2 (PtO2) as a reliable indicator of transmural myocardial tissue oxygenation was studied in six anaesthetised, open chest pigs. Epicardial surface PtO2 was correlated with other variables of myocardial tissue oxygenation such as regional blood flow, coronary venous PO2, O2 saturation, PCO2 and regional myocardial lactate extraction. The study design was based on an experimental model in which the effects of a pacing induced tachycardia on tissue oxygenation of ischaemic and normally supplied myocardium were measured. Two platinum multiwire surface electrodes were placed on the epicardium, on the areas supplied by the left anterior descending coronary artery (LAD) and the left circumflex coronary artery (CX). The LAD was constricted to reduce mean surface PtO2 in the LAD area to about 50% of its baseline value. This did not affect surface PtO2 in the CX area. The reduction of surface PtO2 in the LAD area was associated with decreases in coronary venous PO2 and O2 saturation and with increases in coronary venous lactate and PCO2. Subendocardial regional blood flow and the subendocardial to subepicardial flow ratio were significantly lower than in the CX area. Increasing the heart rate by pacing (+45 beats.min-1) led to an increased degree of ischaemia as shown by fall in surface PtO2 in the LAD area to values around zero kPa, by marked increase in coronary venous lactate and PCO2, by reduction in total (-10%) and subendocardial (-40%) LAD flow and by deterioration of the subendocardial to subepicardial flow ratio. The increased degree of ischaemia was not accompanied by an increase in O2 extraction. The marked decrease in surface PtO2 occurred in spite of a slight increase in the subepicardial regional blood flow (+10%); thus the increase in O2 delivery was not sufficient to meet the increase in O2 demand. Total flow was increased by 27% in the CX area without changes in the subendocardial to subepicardial flow ratio and in the surface PtO2 values. When pacing was stopped, surface values of PtO2 in the LAD area returned to prepacing values, as did lactate extraction and coronary venous PCO2. Clear and close relationships with surface PtO2 were found for regional lactate extraction, coronary venous PCO2 and the normalised subendocardial RBF. Poor or no correlations were found for the normalised subepicardial regional blood flow, the coronary venous O2 saturation and the absolute values of subendocardial and subepicardial regional blood flow.(ABSTRACT TRUNCATED AT 400 WORDS)

Surgical complications related to insertion of penile prostheses with emphasis on infection and cost

We initiated a prospective study of penile prosthesis implant surgery to evaluate risk factors for infection and other complications. Twenty-one patients admitted for surgery or related complications were evaluated over a seven-month period. The two types of penile prostheses implanted were (1) inflatable and (2) semi-rigid. Nine of 21 patients (43%) developed postoperative complications. Although cephapirin and gentamicin were given prophylactically, four of nine patients had four wound infections and one case of pneumonia. One case of Bacteroides fragilis bacteremia was due to stool incontinency during surgery. In two of the wound infections, removal and reinsertion of the prosthesis was necessary. Other complications included hypotension during surgery, prosthesis malfunction and malposition, and urethral tears. There were no significant associations between infection and age, length of surgery, or type of prosthesis used. These complications contributed to prolonged hospital stay and readmission (87 extra days for the infected patients at a cost of $44,000). Antibiotic costs to treat the infections totaled $1,900. Prospective evaluation by infection control practitioners of various elective surgeries can be useful in quantitating the complication rate and targeting patients at risk, with the goal of minimizing hospital costs.

Ethinylestradiol stimulates a biliary cholesterol-phospholipid cosecretion mechanism in the hamster

The mechanism of ethinylestradiol-induced biliary secretion of excess cholesterol, a potential causative factor of cholesterol gallstones, is not yet known. It might be related to altered bile acid metabolism, since the rate of cholesterol and phospholipid secreted into bile is thought to be influenced by the hydrophobicity of the bile acid species secreted. We therefore studied the effect of ethinylestradiol on bile acid metabolism and on secretory relationships between taurocholate and cholesterol/phospholipids in bile. Litter-matched Syrian female hamsters (80 to 100 gm body weight) were injected subcutaneously with either 0.2 ml per day corn oil (controls) or a pharmacologic dose of 5 mg per kg per day ethinylestradiol in corn oil (EE-hamsters; n = 6) for 5 days. On Day 6, bile was collected for 60 min (basal secretory rate) via a bile duct fistula after exclusion of the gallbladder. Then, a graded infusion of taurocholate was given for 110 to 130 min. Secretory rates (nmoles.min-1.-1 liver) for bile acids, cholesterol and phospholipids were determined and their mutual "linkage coefficients" (nmoles of secretory increment per 1 nmole of bile acid secreted) calculated by linear regression analysis. EE-hamsters had higher (p less than 0.02) basal secretory rates of cholesterol (0.71 +/- 0.21 vs. 0.45 +/- 0.10) and phospholipids (5.74 +/- 1.04 vs. 4.21 +/- 0.73) than controls at comparable bile flow and bile salt secretion rates. Cholic acid pool size and the fractional composition of bile acid species in bile were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Staphylococcus aureus nasal carriage and infection in patients on hemodialysis. Efficacy of antibiotic prophylaxis

We conducted a five-year prospective controlled study of prophylaxis of Staphylococcus aureus nasal carriage and infection among patients in a hemodialysis unit. Carriers tended to have chronic colonization with a single phage type. S. aureus infections occurred significantly more frequently in carriers than in noncarriers and, in 93 percent of the infected carriers, were caused by the same phage type as that carried in the nares. Neither intravenous vancomycin nor topical bacitracin was found to be efficacious in eradicating nasal carriage. However, oral rifampin given for five days decreased S. aureus carriage over a one-month follow-up period, but within three months colonization of the nares recurred in most carriers, often with an S. aureus of the original phage type. Carriers were then randomly assigned to receive either rifampin or no prophylaxis. Rifampin was readministered at three-month intervals if culture of the anterior nares yielded S. aureus. Infections with S. aureus occurred significantly more frequently in carriers given no prophylaxis than in those given a full course of rifampin. S. aureus resistant to rifampin was isolated from the anterior nares of four patients, but these isolates were not implicated in any infections. The incidence of infection at the dialysis access site, skin, and soft tissue of patients on hemodialysis can be decreased by interventions directed at nasal carriage of S. aureus.

Effects of a corporate health promotion program

The effects of a pilot health promotion program at AT&T Communications were evaluated. The study group was given an initial health risk appraisal and offered health education modules. A control group was given the health risk appraisal with no modules; a second control group was neither given the health risk appraisal nor offered modules. The health promotion program was found to lower health risks and improve health-related and job-related attitudes among the study group. Participants in specific intervention modules experienced gains in positive health behaviors.

Potential in-hospital modes of transmission of Legionella pneumophila. Demonstration experiments for dissemination by showers, humidifiers, and rinsing of ventilation bag apparatus

The mode of transmission of nosocomial legionellosis remains uncertain. Aerosolization of Legionella pneumophila by showers, humidifiers, and respiratory equipment rinsed in tap water was evaluated using plate-settling culture and air aspirator methods. All protocols simulated the actual hospital setting including use of humidifier equipment used in hospital patient rooms and water from faucets and showerheads in hospitals with nosocomial Legionnaires' disease. Protocols for humidifier and shower experiments mimicked the procedure actually used in hospitals by health care personnel. Showering failed to produce aerosols of L. pneumophila; however, portable humidifiers readily generated aerosols of L. pneumophila that disseminated throughout a two-bed patient room. Intensity of aerosolization directly correlated with the degree of L. pneumophila contamination of the tap water used to fill the humidifier. Rinsing of ventilation bag apparatus with tap water led to isolation of L. pneumophila from culture plates after the ventilation bags were squeezed. Thus, L. pneumophila could be aerosolized or directly instilled into a patient's bronchial tree following routine measures for cleaning ventilation bag apparatus with tap water. On the basis of these results, the use of humidifiers filled with tap water has been discontinued and sterile water is recommended for rinsing ventilation bag apparatus and tubing.

[Liver perfusion and oxygenation with isoflurane]

The influence of 0.7, 1.4 or 2.1 vol % isoflurane on hepatic blood flow and hepatic tissue oxygenation was studied in 12 dogs under basal anaesthesia with i.v. piritramid. Blood flow was measured by the microsphere method (phi = 15 micron). Tissue pO2 was determined by a platinum multiwire electrode and by measuring hepatic venous pO2. Isoflurane effected a marked fall in arterial blood pressure in these surgically not stimulated animals. However, cardiac output fell only moderately due to a considerable reduction in systemic vascular resistance. Both local tissue pO2 and venous pO2 were decreased with isoflurane. A potentially hazardous reduction in hepatic tissue pO2 was found predominantly with high isoflurane concentrations. The decrease in hepatic tissue pO2 results from disadvantageous effects on hepatic O2-balance: total hepatic blood flow decreases, whereas splanchnic O2 consumption increases. The lower blood flow is due to a reduction of portal blood flow whereas arterial perfusion remains unchanged. The increase in splanchnic O2 consumption possibly results from an elevated O2 consumption of the liver. Further studies have to clarify whether the disadvantageous effects of high isoflurane concentrations fail to appear when pain-induced stimulation of the sympathico-adrenergic system counteracts the fall in arterial blood pressure.

Isolation of Legionella pneumophila from blood with the BACTEC system: a prospective study yielding positive results

In a prospective study of 16 patients with Legionnaires disease confirmed by cultural isolation of Legionella pneumophila from the respiratory tract, 38% (6 of 16) had positive blood cultures. Daily subcultures were made onto buffered charcoal-yeast extract plates from 6B aerobic and 7C anaerobic BACTEC blood culture bottles (Johnston Laboratories, Inc., Towson, Md.). Isolation of L. pneumophila was achieved from both aerobic and anaerobic bottles. L. pneumophila growth indices failed to exceed the BACTEC threshold limits; thus, the organism would have been overlooked despite its presence in the blood culture bottles. Bacteremic patients had statistically significant higher quantities of L. pneumophila isolated from sputum and visualized on direct fluorescent antibody stains. Thus, the potential exists for improved diagnosis of Legionella infection by a relatively noninvasive procedure (blood culture) with an instrument already in use in many hospital laboratories.

Nosocomial legionellosis in surgical patients with head-and-neck cancer: implications for epidemiological reservoir and mode of transmission

A prospective pneumonia study was conducted simultaneously on head-and-neck surgery wards at two hospitals over 2 years; one hospital had a water supply contaminated with Legionella pneumophila but no record of having had a case of legionella pneumonia, and the other had just decontaminated its water supply because of known endemic nosocomial legionellosis. Special laboratory tests for legionella were done on all cases of nosocomial pneumonia irrespective of clinical impression. Over the first 18 months, the rate of nosocomial legionellosis was 30% at the first hospital and 0% at the second. Patients who underwent laryngectomy did not acquire the disease. Hyperchlorination at the first hospital was followed by a fall (p less than 0.01) in legionella pneumonias. Thus legionella pneumonias can be overlooked if special laboratory tests are not applied routinely, and surgical patients with head-and-neck cancer may be at high risk of nosocomial legionellosis because of the potential for pulmonary aspiration of contaminated water or orophyaryngeal microflora and/or frequent manipulation of the respiratory tract. This study demonstrates the benefits of examining the environment for legionella despite the absence of documented disease.

A pseudo-outbreak of Streptomyces infections linked to laboratory construction

Over a four-week period, nine isolates of Streptomyces species were identified from seven blood cultures, one infected gortex graft, and one cerebrospinal fluid (CSF) specimen. None of the patients were clinically infected or received antimicrobial therapy. Blood culture collecting tubes, iodoform prep solutions, BAC-TEC filters, and alcohol prep pads were cultured but did not reveal a source of contamination. Six additional clinical specimens became positive, and the occurrence of construction in the laboratory was considered as a source of the contaminating organism. Blood agar plates were placed for 20 minutes in an area undergoing construction. Streptomyces grew in heavy concentrations on nine of ten plates in the construction site, but only one colony on ten plates grew from a hallway not undergoing construction. Isolation of the organism ceased with cessation of the construction. The authors conclude that the Streptomyces pseudo-outbreak was related to construction around the laboratory, with probable airborne contamination of clinical specimens.

Pseudomonas stutzeri bacteremia associated with hemodialysis

Pseudomonas stutzeri bacteremia developed in six patients undergoing hemodialysis. Fever, shaking chills, nausea, and vomiting were observed. All patients recovered, although only two received specific antibiotic therapy. The infections occurred sporadically over a period of nine months. Pseudomonas stutzeri was subsequently isolated from the dialysate that circulates within the hemodialysis machine. The ultimate source was the deionized water that is combined with the liquid concentrate to form the dialysate. Pseudomonas stutzeri could be localized to the top cannister of the dialysis machine but was also isolated throughout the machine, including the bottom reservoir and the recirculating pump. The emphasis on handwashing, strict compliance with disinfection procedures, and elimination of prolonged sitting times for the filled machine after disinfection resulted in no further cases of P stutzeri infection.

Legionellaceae in the hospital water-supply. Epidemiological link with disease and evaluation of a method for control of nosocomial legionnaires' disease and Pittsburgh pneumonia

An epidemiological link was found between contamination of a hospital water-supply by Legionella pneumophila and by Pittsburgh pneumonia agent (PPA) and subsequent cases of nosocomial legionnaires' disease and Pittsburgh pneumonia. The extent of L pneumophila isolation from the water-supply paralleled the occurrence of disease. Whenever L pneumophila was isolated from more than 30% of ten selected water sites, nosocomial legionellosis occurred. The temperature of the hot water tanks was raised to 60-77 degrees C for 72 h, and water outlets were flushed for 30 min with hot water. A decline in numbers of L pneumophila and PPA in the water-supply was followed by a fall in the incidence of legionnaires' disease and Pittsburgh pneumonia. In addition, intermittent raising of the temperature in the hot water system decreased both the number of months in which disease occurred and the proportion of nosocomial pneumonias caused by these organisms.