Prevention of chronic experimental pyelonephritis by suppression of acute suppuration.

In order to evaluate the importance of suppuration, persistent infection, and scar formation in the evolution of Escherichia coli chronic pyelonephritis, we treated rats with different antibiotic regimens at different stages of the disease. The results show that (a) if acute suppurative pyelonephritis is aborted with early antibiotic therapy, chronic pyelonephritis is prevented; (b) chronic pyelonephritis can develop even after eradication of infection if acute suppuration persists beyond 3 days; (c) persistent infection does not lead to chronic pyelonephritis, if the acute suppuration is suppressed; and (d) residual infection, antigen-load, antibody, and(or) cell-dependent autoimmune processes did not play a significant role. We interpret these results as evidence that the pathologic entity recognized as chronic pyelonephritis results from kidney damage, scarring and shrinkage secondary to acute suppuration.

In vivo modification of plant membrane phospholipid composition.

Tomato seedlings treated with ethanolamine showed altered phospholipid composition. The changes included altered acyl chain composition as well as changes in the relative amounts of the phospholipid classes. Specifically, there was an increase in phosphatidylethanolamine and phosphatidylserine with a concomitant decrease in phosphatidylcholine and no overall increase in phospholipids. Treatment with ethanolamine increased the relative amount of C18 acyl chains (especially 18 : 2) in phosphatidylethanolamine and phosphatidylcholine at the expense of 16 : 0 and 16 : 1. Acyl composition of other phospholipid classes were unchanged. Labeled ethanolamine was incorporated mostly into phosphatidylethanolamine and phosphatidylcholine. Ethanolamine-stimulated incorporation of labeled oleate was entirely into acyl chains and appeared only as 18 : 1 and 18 : 2. There was greater incorporation, but less conversion of 18 : 1 to 18 : 2 with choline. Stearate was incorporated but desaturated.

Differences in growth characteristics and elementary body associated cytotoxicity between Chlamydia trachomatis oculogenital serovars D and H and Chlamydia muridarum.

AIM: In vitro growth and elementary body (EB) associated cytotoxicity of two Chlamydia trachomatis strains belonging to serovars D and H and C muridarum were compared to identify difference(s) that correlate with virulence variations between these strains in the mouse model of human female genital tract infection, and phenotypic characteristics that could explain human epidemiological data on serovar prevalence and levels of shedding during serovar D and H infection. METHODS: Replication cycle kinetics, inclusion characteristics, and EB associated cytotoxicity were assessed in McCoy cell monolayers using culture, light microscopy, and lactate dehydrogenase release. RESULTS: Over 72 hours, more rapid production and release of inclusion forming units (ifu) allowed C muridarum to initiate two replication rounds, resulting in 4-8 times more ifu/input unit of infection than with serovars D and H. Although C muridarum EBs were significantly more cytotoxic to McCoy cell monolayers than serovar D at moderate and high multiplicity of infection ratios (MOI), serovar H EBs were significantly more cytotoxic than C muridarum, even at the lowest MOI tested. CONCLUSIONS: These phenotypic differences are consistent with the more invasive course and severe pathological outcome of infection in mice infected with C muridarum, providing an objective basis for questioning the appropriateness of C muridarum as a surrogate for the human biovar of C trachomatis in the murine model of female genital tract infection. The differences seen between the human strains could help explain human epidemiological data relating to differences in prevalence and level of shedding that occurs during infection with oculogenital serovars D and H.

A role for G protein-coupled lysophospholipid receptors in sphingolipid-induced Ca2+ signaling in MC3T3-E1 osteoblastic cells.

Sphingolipids have been proposed to modulate cell function by acting as intracellular second messengers and through binding to plasma membrane receptors. Exposure of MC3T3-E1 osteoblastic cells to sphingosine (SPH), sphingosine-1-phosphate (SPP), or sphingosylphosphorylcholine (SPC) led to the release of Ca2+ from the endoplasmic reticulum (ER) and acute elevations in cytosolic-free Ca2+ ([Ca2+]i). Desensitization studies suggest that SPP and SPC bind plasma membrane endothelial differentiation gene (Edg) receptors for lysophosphatidic acid (LPA). Consistent with the coupling of Edg receptors to G proteins, SPP- and SPC-induced Ca2+ signaling was inhibited by pretreatment of the cells with pertussis toxin (PTx). Of the Edg receptors known to bind SPH derivatives in other cell types, MC3T3-E1 cells were found to express transcripts encoding Edg-1 and Edg-5 but not Edg-3, Edg-6, or Edg-8. In contrast to SPP and SPC, the ability of SPH to elicit [Ca2+]i elevations was affected neither by prior exposure of cells to LPA nor by PTx treatment. However, LPA-induced Ca2+ signaling was blocked in MC3T3-E1 cells previously exposed to SPH. Elevations in [Ca2+]i were not evoked by SPP or SPC in cells treated with 2-aminoethoxydiphenylborate (2-APB), an inhibitor of inositol 1,4,5-trisphosphate (IP3)-gated Ca2+ channels in the ER. No effect of 2-APB was observed on SPH-or LPA-induced [Ca2+]i elevations. The data support a model in which SPP and SPC bind Edg-1 and/or Edg-5 receptors in osteoblasts leading to the release of Ca2+ from the ER through IP3-gated channels.

Proximal muscle weakness and selenium deficiency associated with long term parenteral nutrition.

A 33-yr-old white female with short bowel syndrome secondary to trauma was maintained on home parenteral nutrition for 4 yr when her plasma, red cell, white cell, and platelet glutathione peroxidase (GSHPx) activities were found to be extremely low, as were her plasma and red cell selenium levels. During her first year on parenteral nutrition she noted the onset of an inability to rise from a squatting position, rapid tiring when stair climbing, and weakness when attempting to lift large or moderately heavy objects. Treatment with 400 micrograms/d of selenious acid intravenously was associated with a disappearance of her symptoms and an increase in proximal muscle strength within 6 wk. The plasma and red cell selenium levels, and the plasma and white cell GSHPx activities rose to normal levels within 6 wk. Red cell GSHPx activity returned to normal by 3 mo.

Delayed sternal closure after neonatal cardiac operations.

We retrospectively compared the use of primary elective open sternum coupled with delayed sternal closure with the use of primary sternal closure in neonates after cardiac operations. Primary elective open sternum/delayed sternal closure was selectively used in patients who demonstrated hemodynamic or respiratory deterioration, or both, during an intraoperative trial of sternal closure; otherwise primary sternal closure was used. Primary elective open sternum was used in 55 (61.8%) and primary sternal closure in 34 (38.2%) of the 89 patients studied. Eleven (20%) patients having primary elective open sternum died compared with 5 (14.7%) patients having primary sternal closure (p = 0.6). Six (10.9%) of the patients with primary elective open sternum died before delayed sternal closure; the remaining 49 patients comprise the primary elective open sternum/delayed sternal closure group. The durations of mechanical ventilation (9.7 +/- 0.9 days [mean plus or minus standard error of the mean], median 7.7 versus 9.9 +/- 3.4 days, median 4.9; p = 0.0005) and hospital stay (21.1 +/- 1.4 days, median 17.7 versus 19.6 +/- 4.1 days, median 12.9; p = 0.004) were shorter in the primary sternal closure group. The overall morbidity and duration of inotropic support were not significantly different between the two groups, although seven (20.6%) of the patients with primary sternal closure did have to undergo delayed sternal reopening for refractory postoperative low cardiac output. There was one superficial wound infection in the primary elective open sternum/delayed sternal closure group. Primary elective open sternum/delayed sternal closure is an effective treatment for postoperative neonatal mediastinal compression for the following reasons: (1) the morbidity is low; (2) the mortality of the critically ill group of neonates in whom primary elective open sternum/delayed sternal closure was used was similar to that of the less critically ill primary sternal closure group; and (3) 20.6% of the primary sternal closure group eventually had to undergo delayed sternal reopening to treat refractory postoperative low cardiac output.

Chlamydia trachomatis serovar E isolates from patients with different clinical manifestations have similar courses of infection in a murine model: host factors as major determinants of C trachomatis mediated pathogenesis.

BACKGROUND: Some investigators have proposed an association between certain Chlamydia trachomatis serovars and the clinical course of infection in humans. A recent study of over 1100 patients with culture confirmed and serotyped C trachomatis urogenital infection detected no such association. AIMS: To corroborate these results using a murine model of female genital tract infection. METHODS: Various parameters of infection were assessed in mice intravaginally infected with human genital isolates of C trachomatis serovar E from four cases with either a clear symptomatic or asymptomatic clinical course in both the patient and their partner. RESULTS: No differences were seen among the strains in the incidence or duration of infection, polymorphonuclear granulocyte responses, or upper genital tract progression. CONCLUSIONS: An investigation to determine the correlation between the clinical manifestations of different isolates of C trachomatis serovar E in humans and certain parameters of microbial pathogenesis in a mouse model failed to reveal an association between the measured parameters and the tendency of serovar E to produce symptomatic versus asymptomatic infections in humans. These findings suggest that differences in the clinical course of infection in humans seen with these strains may be more related to host factors than to genetic variation among strains.

Risk factors for failure of aortic valvuloplasty in aortic insufficiency with ventricular septal defect.

BACKGROUND: Aortic insufficiency (AI) associated with ventricular septal defect (VSD) is often repaired using a modification of Trusler's aortic valvuloplasty technique. The purpose of this study was to identify the risk factors for failure of aortic valve (AV) repair in patients who underwent repair of associated VSD. METHODS: A univariate analysis was performed in this retrospective study to identify the possible risk factors for failure of the repair resulting in the need for AV replacement (AVR). RESULTS: The study included 24 patients, 15 (62%) boys and 9 (38%) girls, with a mean age of 9.1 +/- 1.2 (SEM) years. The VSD was perimembranous in 15 (62%) and subarterial in 9 (38%). The prolapsed aortic cusp was the right in 13 (54%), the noncoronary in 6 (25%), and both in 5 (21%). Plication was performed at one end of the free edge of the prolapsed cusp(s) in 12 (50%) and at more than one end in 12 (50%) of the patients. The VSD was closed by use of a patch in 21 (88%) and by direct suture closure in 3 (12%). At the mean follow up of 7.3 +/- 1.3 years, the degree of AI was none in 6 (25%), trivial in 5 (21%), mild in 9 (38%), moderate in 1 (4%), and severe in 3 (12%). The 15-year actuarial freedom from reoperation was 81% +/- 19% (95% confidence limit). By univariate analysis, the possible risk factors for AV repair failure were the degree of AI at hospital discharge (p = 0.004), direct closure of the VSD (p = 0.061), smaller size of the VSD (p = 0.081), and plication of more than one end of the prolapsed cusp(s) (p = 0.095). CONCLUSIONS: Trusler's AV repair is an effective and durable technique for the surgical treatment of patients with VSD-AI syndrome. The adequacy of the initial repair is the most important determinant of the long-term results.

Coronary sinus ostial atresia with persistent left superior vena cava.

BACKGROUND: Atresia of the coronary sinus orifice with a persistent left superior vena cava is an intrinsically benign cardiac anomaly with important surgical implications. METHODS: THe medical records of 5 patients with atresia of the coronary sinus orifice with a persistent left superior vena cava were reviewed retrospectively, and a computer search of the world literature describing this cardiac malformation was undertaken. RESULTS: The 5 patients ranged in age from 9 months to 5 years. In 2, the diagnosis was made preoperatively by angiocardiography, and in 3, the abnormality was found incidentally at the time of cardiotomy for repair of associated congenital heart disease. Four of the 5 patients underwent repair of associated cardiac lesions. During operation, care was taken to avoid disruption of left superior vena cava flow to prevent coronary venous obstruction. All patients survived and are doing well at follow-up. CONCLUSIONS: Atresia of the coronary sinus orifice with persistent left superior vena cava is, in itself, a benign anomaly without physiologic consequence. However, the recognition of this lesion during repair of associated cardiac lesions is of vital importance to the cardiac surgeon. Interruption of this sole route of coronary venous drainage can potentially lead to myocardial ischemia and necrosis.

Arch growth after staged repair of interrupted aortic arch using carotid artery interposition.

BACKGROUND: Between 1980 and 1990, our practice was to perform carotid artery interposition as part of a staged repair of interrupted aortic arch with various associated cardiac defects. METHODS: This procedure was used in 16 patients with IAA type B. The median age at operation was 4.5 days and the median weight, 3.2 kg. Ten of the patients had an associated ventricular septal defect. Six more had complex anatomy. There were two death at carotid interposition, two interim deaths, and two deaths after intracardiac repair. Preoperative echocardiographic and angiographic studies were compared with postoperative studies in 11 survivors of arch repair to assess sequential growth of the interposed carotid artery. Measurements of the carotid artery were normalized to the descending aorta. RESULTS: Preoperatively, the left carotid artery had a median diameter of 3.7 mm and was 42.9% of the descending aortic diameter. Postoperative studies performed at a median age of 5.7 months disclosed that the interposed carotid artery had grown to a median diameter of 7.0 mm and was 69.6% of the diameter of the descending aorta (normal > or = 81%). On follow-up at a median time of 4 years, 6 of 9 patients have no gradient by blood pressure measurements or echocardiographic Doppler studies, and 3 have modest gradients. No patient has required revision of the arch repair. CONCLUSIONS: Survival is good after carotid artery interposition for interrupted aortic arch and growth of the carotid artery approaches that of a normal arch. Carotid artery interposition is a viable alternative for repair of this lesion should primary definitive repair not be feasible.

Pediatric cardiac surgical ECMO: multivariate analysis of risk factors for hospital death.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has emerged as an effective technique for the mechanical support of many pediatric postcardiotomy patients with medically refractory cardiac failure. METHODS: We retrospectively reviewed the records of 73 pediatric patients with congenital heart disease who were placed on ECMO support between August 1984 and February 1994. The patients were divided into groups defined by the timing of ECMO cannulation relative to the time of operation. Group 1 patients (n = 7, 9.6%) were placed on ECMO preoperatively. Group 2 patients (n = 66, 90.4%) were a heterogeneous population placed on ECMO at any interval after cardiac repair. Subgroup 2A consisted of patients (n = 17, 25.8%) who could not be weaned from cardiopulmonary bypass and were converted directly to ECMO support immediately after repair. Subgroup 2B patients (n = 49, 74.2%) were cannulated postoperatively after an initial period of clinical stability. RESULTS: Hospital survival for all study patients (42/73) and for group 2 patients (38/66) was 58%. Only 4 group 2A patients (23.5%) survived their hospitalization compared with 34 group 2B patients (69.4%) (p = 0.001). Multivariate analysis identified elevated right atrial pressure after ECMO decannulation (p = 0.049) and, possibly, membership in group 2A (p = 0.061) as independent risk factors for hospital death. CONCLUSIONS: Extracorporeal membrane oxygenation is most effective in salvaging pediatric cardiac surgical patients who demonstrate medically refractory hemodynamic deterioration at some interval after being successfully weaned from cardiopulmonary bypass. The right atrial pressure after extracorporeal membrane oxygenation decannulation is an independent predictor of hospital death.

The Ross procedure in children and young adults with congenital aortic valve disease.

METHODS: Thirty-three children and young adults with congenital aortic valve disease underwent pulmonary autograft replacement of the aortic valve between October 1993 and March 1997. There wer six females and 27 males; at operation, median age was 16 years (range: 3 to 41 years) and median body weight 60 kg (range: 14 to 121 kg). Fifteen patients (46%) had undergone one or more previous cardiac surgical procedures. A bicuspid aortic valve was present in 31 patients (94%); moderate to severe aortic stenosis and regurgitation was present in 10 (30%) and 26 (79%), respectively. RESULTS: All patients underwent the Ross procedure while in NYHA class I (64%) or class II (36%). A preoperative shortening fraction of 41 +/- 1.4% suggested well-preserved systolic function, but the mean left ventricular end-diastolic pressure of 16.6 +/- 1.3 mmHg was consistent with preoperative left ventricular pressure and volume overload. The aortic root was replaced using an interrupted suture technique in two patients and with three separate running sutures in 31. The right ventricular outflow tract was reconstructed in all classes with a cryopreserved pulmonary homograft valved conduit (median diameter 23 mm; range 19 to 30 mm). Intraoperative complications included transient atrioventricular dissociation (one), permanent atrioventricular dissociation (one), and left coronary artery distortion relieved by shortening the distal ascending aorta (one). Postoperatively, postpericardiotomy syndrome developed in six patients (18%), supraventricular tachycardia in three (9%), and ventricular tachycardia in one (3%). At three days after surgery, one patient developed ischemic left ventricular dysfunction requiring repositioning of the distorted left coronary artery higher on the neo-aortic root. Hospital survival rate was 100%. During a median follow-up of 17 months (range: 1 to 41 months) one patient suffered a non-cardiac death due to blunt trauma. there has been a significant postoperative improvement in NYHA class among surviving patients (class I, 94%; class II, 6%; p = 0.004 versus preoperative). Postoperative aortic regurgitation was absent or trivial in 17 (60%) and mild in the remaining 11 (40%) patients for whom follow-up echocardiographic data are available. One patient required reoperation 16.5 months after the Ross procedure to replace a rapidly degenerating pulmonary homograft, and one with moderately severe homograft stenosis and five with mild homograft stenosis are being monitored. Postoperatively, a gradual early expansion in the diameter of the neo-aortic root and reduction in echocardiographic indices of left ventricular hypertrophy and dilatation occurred. CONCLUSIONS: Pulmonary autograft replacement of the aortic valve in young patients with congenital aortic valve disease has produced excellent short-term anatomic/physiologic results and symptomatic relief with no mortality. Indices of left ventricular dilatation and hypertrophy regress after repair when the Ross operation precedes important deterioration in preoperative ventricular function. Important technical considerations include: (i) the native distal ascending aorta should be sufficiently shortened before performing the distal aortic anastomosis; and (ii) the left coronary anastomosis should be positioned relatively high on the neo-aortic root with a slight amount of tension. Both of these maneuvers reduce the likelihood of coronary artery distortion. Rapid degeneration of the pulmonary homograft and the propensity towards progressive dilatation of the neo-aorta are important postoperative considerations. Until more is known about the etiology and natural history of these two potential complications, postoperative anti-inflammatory and/or immunosuppressive therapy and strict control of hypertension should be strongly considered.

Home parenteral nutrition with full-time home care nurses.

A group of patients exists who cannot manage home parenteral nutrition (HPN) due to debilitating conditions and/or lack of family resources. They are limited to either nursing home placement or extended hospitalization unless home nursing care is provided. A 58-year-old single female with malabsorption secondary to scleroderma was sent home on cyclic HPN under the supervision of full-time home care nurses. A comprehensive patient-centered nurse training program was designed to teach nursing personnel from a private nursing service the theory and practice of HPN. Each nurse must achieve at least 80% in the theory posttest and demonstrate the competent performance of central venous catheter care, mixing of parenteral nutrition solutions, use of infusion pump, and application of the heparin lock. The results of the pre- and posttests have shown that the home care nurses have been able to learn the theory necessary for implementing HPN. The mean pretest value was 46% while the mean posttest value was 90% (n = 12, p = 0.01). The patient has been doing very well at home for 5 months in this psychologically, medically, and financially effective program covered by third party payers. To the best of our knowledge, this program has never before been accomplished.

Characterization of fatty acids from root and shoot lipids ofCapsicum species.

Lipids were extracted from the roots and shoots of four species of theCapsicum (pepper) genus and separated into three fractions: triglycerides; free fatty acids, mono- and diglycerides; and phospholipids. The component fatty acids were determined by subjecting the methyl esters to gasliquid chromatography. The predominate fatty acids obtained were palmitic (16ratio0) and linoleic (18ratio2), with lesser amounts of linolenic (18ratio3), stearic (18ratio1), and oleic (18ratio0). Differences existed in the neutral lipid fractions which might be of value from taxonomic interests; however, the phospholipids from each of the species and plant parts did not differ so greatly. A comparison of the amount of unsaturated fatty acids in the phospholipid fractions indicates that differences exist which might be of value in determining the relative sensitivity of the several species to chilling temperatures.

Sediment quality in Los Angeles Harbor, USA: a triad assessment.

Sediment quality in the Los Angeles and Long Beach Harbor area of southern California, USA, was assessed from 1992 to 1997 as part of the California State Water Resources Control Board's Bay Protection and Toxic Cleanup Program and the National Oceanic and Atmospheric Administration's National Status and Trends Program. The assessment strategy relied on application of various components of the sediment quality triad, combined with bioaccumulation measures, in a weight-of-evidence approach to sediment quality investigations. Results of bulk-phase chemical measurements, solid-phase amphipod toxicity tests, pore-water toxicity tests with invertebrate embryos, benthic community analyses (presented as a relative benthic index), and bioaccumulation measures indicated that inner harbor areas of this system are polluted by high concentrations of a mixture of sediment-associated contaminants and that this pollution is highly correlated with toxicity in laboratory experiments and degradation of benthic community structure. While 29% of sediment samples from this system were toxic to amphipods (Rhepoxynius abronius or Eohaustorius estuarius), 79% were toxic to abalone embryos (Haliotis rufescens) exposed to 100% pore-water concentrations. Statistical analyses indicated that amphipod survival in laboratory toxicity tests was significantly correlated with the number of crustacean species and the total number of species measured in the benthos at these stations. Triad measures were incorporated into a decision matrix designed to classify stations based on degree of sediment pollution, toxicity, benthic community degradation, and, where applicable, tissue concentrations in laboratory-exposed bivalves and feral fish.

Parkinson's disease. Update in diagnosis and symptom management.

Parkinson's disease (PD) is a progressive neurodegenerative disorder with a high burden of morbidity. Because no diagnostic test exists for PD, clinical knowledge and skill are key to making an early, accurate diagnosis. Diagnostic criteria for PD require at least two of three motor signs: tremor, rigidity, or bradykinesia. Levodopa and the dopamine agonists are considered first-line drug therapy. Recent studies have shown a lower incidence of dyskinesia in patients who began therapy with a dopamine agonist, although levodopa may be better tolerated by patients age 70 or older. Combinations of medications and rehabilitative, alternative, and surgical therapies can often help patients achieve adequate control of PD motor symptoms and maintain a high quality of independent living.

Inductive coupling of hearing aids and telephone receivers.

The present investigation sought to determine the effects of hearing loss, signal level, telephone receiver type, and telecoil location on the aided word-discrimination abilities of hearing impaired subjects using electromagnetic coupling of their hearing aids to the telephone. As expected, significant deterioration in discrimination scores was observed with increasing hearing loss. In addition, significant improvement in discrimination scores was observed, for all subject groups, as the signal level increased from 80 dB SPL to 105 dB SPL. Of the four receiver conditions, the U1 and BARC receivers resulted in the best discrimination scores. Also, the results suggest that the U1 and BARC receivers are indeed equivalent in terms of word discrimination scores. Finally, the telecoil location in individual hearing aids appeared to have little influence on the speech discrimination capabilities of the subjects in this study. However caution must be used in interpreting that result, since subjects were allowed to adjust the telephone handset position to maximize the signal level in any given condition. This occasionally resulted in inappropriate handset locations for conventional telephone use.

Temperature-induced phase transitions in nematode lipids and their influence on respiration.

Temperature-induced phase transitions estimated by electron spin resonance (ESR) technique were ohscrved in the lipids of several nematode species. In both Meloidogyne javanica and Caenorhahditis elegans, there was a phase transition in their phospholipids from a liquid-crystalline state to a solid gel state at about 10 C. Aphelenchus avenae also had a phase transition, but at about 20 C. With this species, the spin-label motion parameters indicated the transition was from the liquid-crystalline state below 20 C to a more liquid or disordered state above 20 C. Anguina tritici and Meloidogyne hapla, in contrast, had no phase transitions over the entire temperature range studied. Each phase transition detected by ESR was reflected in the respiratory rates of the nematodes, and the temperature of the transition coincides with the environmental adaptation of these species.

Laparoscopy: new applications of an established technique.

The safety and cost-effectiveness of any new procedure is, of course, brought into question in this era of heightened fiscal concerns. In general, a review of initial results with laparoscopic pelvic lymph node dissection appears to reveal sufficient patient benefits to warrant further work with these less invasive techniques. The principal benefits include the following: Decreased patient morbidity, early and latent; Shorter hospitalization; Faster recovery and return to normal daily functions; Equivalent efficacy to open surgical alternatives; Overall cost-effectiveness Cosmetic effect; minimizes loss of body image; Reproducible results. Perfecting the skills necessary for complicated laparoscopic surgery requires a commitment of time and work on the part of the surgeon. This is not a procedure that will be learned by auditing a few cases. Laparoscopic surgery requires diligence in mentally and physically preparing the skills needed for surgery and caution in the application of these skills. Nurses can help to minimize this learning curve by taking an active interest in the current and future practice of laparoscopic surgery and by sharing their knowledge and enthusiasm.