Mutations in LZTR1 drive human disease by dysregulating RAS ubiquitination.

The leucine zipper-like transcriptional regulator 1 (LZTR1) protein, an adaptor for cullin 3 (CUL3) ubiquitin ligase complex, is implicated in human disease, yet its mechanism of action remains unknown. We found that Lztr1 haploinsufficiency in mice recapitulates Noonan syndrome phenotypes, whereas LZTR1 loss in Schwann cells drives dedifferentiation and proliferation. By trapping LZTR1 complexes from intact mammalian cells, we identified the guanosine triphosphatase RAS as a substrate for the LZTR1-CUL3 complex. Ubiquitome analysis showed that loss of Lztr1 abrogated Ras ubiquitination at lysine-170. LZTR1-mediated ubiquitination inhibited RAS signaling by attenuating its association with the membrane. Disease-associated LZTR1 mutations disrupted either LZTR1-CUL3 complex formation or its interaction with RAS proteins. RAS regulation by LZTR1-mediated ubiquitination provides an explanation for the role of LZTR1 in human disease.

Inactivation of human coagulation factor X by a protease of the pathogen Capnocytophaga canimorsus.

Essentials Capnocytophaga canimorsus causes severe dog bite related blood stream infections. We investigated if C. canimorsus contributes to bleeding abnormalities during infection. The C. canimorsus protease CcDPP7 causes factor X dysfunction by N-terminal cleavage. CcDPP7 inhibits coagulation in vivo, which could promote immune evasion and trigger hemorrhage. SUMMARY: Background Capnocytophaga canimorsus is a Gram-negative bacterium that is present in the oral flora of dogs and causes fulminant sepsis in humans who have been bitten, licked, or scratched. In patients, bleeding abnormalities, such as petechiae, purpura fulminans, or disseminated intravascular coagulation (DIC), occur frequently. Objective To investigate whether C. canimorsus could actively contribute to these bleeding abnormalities. Methods Calibrated automated thrombogram and clotting time assays were performed to assess the anticoagulant activity of C. canimorsus 5 (Cc5), a strain isolated from a fatal human infection. Clotting factor activities were measured with factor-deficient plasma. Factor X cleavage was monitored with the radiolabeled zymogen and western blotting. Mutagenesis of Cc5 genes encoding putative serine proteases was performed to identify the protease that cleaves FX. Protein purification was performed with affinity chromatography. Edman degradation allowed the detection of N-terminal cleavage of FX. Tail bleeding times were measured in mice. Results We found that Cc5 inhibited thrombin generation and increased the prothrombin time and the activated partial thromboplastin time of human plasma via FX cleavage. A mutant that was unable to synthesize a type 7 dipeptidyl peptidase (DPP7) of the S46 serine protease family failed to proteolyse FX. The purified protease (CcDPP7) cleaved FX heavy and light chains from the N-terminus, and was active in vivo after intravenous injection. Conclusions This is, to our knowledge, the first study demonstrating a detailed mechanism for FX inactivation by a bacterial protease, and it is the first functional study associating DPP7 proteases with a potentially pathogenic outcome.

Emergency medicine resident patient care documentation using a hand-held computerized device.

OBJECTIVE: To determine whether emergency medicine (EM) resident documentation of procedures, patient encounters, and patient follow-ups improved after implementation of a personal digital assistant (PDA) hand-held recording system. METHODS: All first-year EM residents were provided a PalmV (Palm, Inc., Santa Clara, CA) PDA. A customized patient procedure and encounter program was constructed using Pendragon Forms (Pendragon Software Corporation, Libertyville, IL) and loaded into each PDA. Residents were instructed to enter information on patients who had any of 21 procedures performed or were considered to be clinically unstable. These data were downloaded to the residency coordinator's desktop computer. The mean number of procedures, encounters, and follow-ups performed per resident were then compared with those of a group of 36 historical controls from the three previous first-year resident classes who recorded the same information using a handwritten card system. Data from the historical controls were combined and the means of each group were compared by Student's t-test. RESULTS: Mean documentation of three procedures was significantly increased in the PDA group versus the index card system: conscious sedation 5.8 vs. 0.03 (p < 0.000005), thoracentesis 2.2 vs. 0.0 (p = 0.002), ultrasound 6.3 vs. 0.0 (p = 0.002). The mean numbers of pericardiocenteses and unstable pediatric surgical patient evaluations were significantly decreased in the hand-held group [from 1.2 to 0.4 (p = 0.03) and from 9.1 to 2.2 (p = 0.02), respectively]. Patient follow-up documentations were not statistically different between the two groups. CONCLUSIONS: Use of a hand-held PDA was associated with an increase in first-year EM resident documentation in three of 20 procedures and a decrease in one procedure and the number of unstable surgical pediatric patient resuscitations. The overall time savings in constructing a resident procedure database, as well as the other uses of the PDAs, may make transition to a hand-held computer-based procedure log an attractive option for EM residencies.

U86, a novel snoRNA with an unprecedented gene organization in yeast.

The Xenopus laevis Nop56 gene (XNOP56), coding for a snoRNP-specific factor, belongs to the 5'-TOP gene family. XNOP56, as many 5'-TOP genes, contains an intron-encoded snoRNA. This previously unidentified RNA, named U86, was found as a highly conserved species in yeast and human. While in human it is also encoded in an intron of the hNop56 gene, in yeast it has an unprecedented gene organization: it is encoded inside an open-reading frame. Both in X. laevis and yeast, the synthesis of U86 snoRNA appears to be alternative to that of the cotranscribed mRNA. Despite the overall homology, the three U86 snoRNAs do not show strong conservation of the sequence upstream from the box D and none of them displays significant sequence complementarity to rRNA or snRNA sequences, suggesting a role different from that of methylation.

Rapid development of brain hypothermia using femoral-carotid bypass.

OBJECTIVES: Advances in the field of cardiopulmonary resuscitation have led to an increasing number of patients initially surviving sudden cardiac arrest. Unfortunately, most of these patients do not recover from the resultant anoxic brain insult. Several animal and human trials have suggested that post-resuscitative brain hypothermia may improve neurologic recovery after cardiopulmonary arrest. Present cooling methods are slow, induce only brain surface cooling, or result in systemic hypothermia. The authors tested the hypothesis that unilateral hypothermic carotid bypass would induce bilateral brain cooling without evoking systemic hypothermia or hemodynamic instability. METHODS: Anesthetized, ventilated common swine (n = 6, 24-37 kg) underwent right femoral and carotid artery bypass cannulation. Central and peripheral hemodynamic parameters were recorded every 2 minutes throughout the procedure. Thermodynamic parameters included bilateral frontal lobe, bilateral nasopharyngeal, pulmonary artery, and rectal temperatures. Hypothermic femoral-carotid bypass was accomplished by drawing blood from the right femoral artery, cooling it to 24 degrees C, and returning it to the right carotid artery at a flow rate of 5 mL/kg/min for 30 minutes. RESULTS: With initiation of cooling, brain temperatures dropped rapidly from baseline of 37.2 degrees C to 30.6 degrees C (right frontal lobe) and 33.1 degrees C (left frontal lobe) at 30 minutes. Pulmonary artery and rectal temperatures also decreased, but never reached mild hypothermic levels (34 degrees C). There was no significant change in any hemodynamic parameters during brain cooling. CONCLUSIONS: Femoral-carotid hypothermic bypass rapidly induced a state of selective brain hypothermia without causing systemic hypothermia or hemodynamic instability.

Core rewarming via warm lavage liquid ventilation in a swine model of hypothermia-associated ventricular fibrillation.

OBJECTIVES: To determine whether warm lavage liquid ventilation (LV) would provide rapid cardiopulmonary rewarming in swine with severe hypothermia and ventricular fibrillation. METHODS: Intubated common swine (n = 3; mean +/- SEM weight 26+/-1.2 kg) were cooled to a mean aortic temperature of 26.4+/-0.9 degrees C. Ventricular fibrillation was induced by transthoracic electrical shock. Rewarming was initiated by continuous endotracheal instillation of warm (44 degrees C) pre-oxygenated, perfluorocarbon liquid at 5 mL/kg/min. Endotracheal instillation of perfluorocarbon occurred while standard gas ventilation continued. Manual chest compressions were performed throughout the 30-minute rewarming process. Outcome measures were the absolute and relative rates of change of all temperatures. RESULTS: After 30 minutes of warm lavage LV, the mean aortic and pulmonary artery temperatures increased by 6.6+/-0.6 degrees C, respectively. Esophageal, nasal, and rectal temperatures did not change significantly. In one animal, normal sinus rhythm spontaneously returned after 16 minutes of rewarming. CONCLUSIONS: During cardiac arrest, warm lavage liquid ventilation may produce rapid cardiopulmonary rewarming.

"Preconditioning at a distance" in the isolated rabbit heart.

OBJECTIVE: Brief myocardial ischemia evokes a cardioprotective response, referred to as "ischemic preconditioning" (IP), that limits injury caused by a subsequent prolonged ischemic insult. The myocardial IP effect can be induced by ischemia of "distant" cardiac and noncardiac tissue, implicating the involvement of an as-yet-unidentified humoral trigger. If a preconditioning hormone exists, the authors hypothesize that the IP effect should be transferable, via administration of coronary effluent, from a preconditioned donor heart to a virgin non-preconditioned acceptor heart. METHODS: Isolated buffer-perfused rabbit hearts were assigned to one of four treatment groups in a donor/acceptor sequence. Donor hearts underwent either three IP cycles or a matched period of uninterrupted perfusion (control donors). Coronary perfusate collected from IP and control donor hearts was reoxygenated and transfused to virgin acceptor hearts. All hearts then underwent 30 minutes of global ischemia followed by 30 minutes of reperfusion. Left ventricular developed pressure (LVDP) (the authors' index of cardioprotection) was monitored throughout the protocol by a left ventricular (LV) balloon. RESULTS: In donor controls, LVDP assessed at 30 minutes post-reflow was restored to only 49 +/- 5% of baseline values. Recovery of LV function was significantly enhanced in both IP donor hearts (69 +/- 4%*) and IP acceptor hearts (70 +/- 6%*) vs donor controls (*p < 0.05), while, in acceptor controls, intermediate values of LVDP (62 +/- 7%) were obtained. CONCLUSION: The IP effect can be transferred between rabbit hearts, suggesting the presence of a humoral trigger signal for distant preconditioning. Isolating this hormone may have therapeutic and diagnostic implications in the management of acute myocardial ischemia.

A retrospective study on the efficacy of short-term perioperative prophylaxis in abdominal surgery for hernia repair in 1,254 patients.

Between 1992 and 1999 1,254 patients requiring hernioplasty came to our Department of Surgery, at San Giovanni Valdarno Hospital, Arezzo. In 94% of cases a prosthetic device was inserted. All patients received a preoperative antibiotic prophylaxis with ceftriaxone, administered intravenously in a single 2 g dose, before surgery. We have retrospectively evaluated the incidence of postoperative infections in these patients: no surgical wound infection occurred, while we observed 10 cases of systemic infections, 5 respiratory tract infections and 5 urinary tract infections, all of which were successfully treated with antibiotics. Tolerability was good: no adverse reaction to ceftriaxone was observed. In this retrospective study ceftriaxone was shown to be effective in preventing the onset of postoperative infections.

Ischemic preconditioning may be transferable via whole blood transfusion: preliminary evidence.

This research was designed to test the hypothesis that ischemic preconditioning can be transferred between animals via whole blood transfusion. Preconditioning at a distance refers to the reduction in myocardial infarct size seen when coronary artery occlusion is preceded by brief ischemic episodes of noncardiac tissue. Isolation of the trigger signal responsible for this effect may be useful in the diagnosis and treatment of acute coronary occlusive syndromes. Rabbits were paired by crossmatching blood samples prior to experimentation. Crossmatched pairs were placed into either preconditioned (P) or control sets. Rabbits in the preconditioned sets were further divided into donor (PD) and acceptor (PA) animals. PD animals underwent five episodes of circumflex and renal artery occlusion followed by reperfusion. Before and after each preconditioning episode, a whole blood exchange was performed between PD and PA animals. Alternatively, control rabbits underwent the same surgical procedures and time-sequenced transfusion without preconditioning. All animals then underwent prolonged circumflex occlusion (60 minutes) followed by reperfusion (30 minutes). The area of myocardium at risk (R) was determined by isotope-labeled microsphere injection. Infarct size (I) was determined by NBT staining. The percent infarct within the risk area (I/R) was then compared. The I/R was significantly lower in the PA (14.0% +/- 12.2) and PD (14.3% +/- 11.2) groups as compared with controls (61% +/- 20. 6). There was no significant difference between the tPA and TPD groups. In conclusion, the ischemic preconditioning effect can be transferred to nonpreconditioned animals via whole blood transfusion, suggesting a humoral mechanism for preconditioning at a distance.

[Ileal duplication in adults. A very rare nosological entity]. / La duplicazione ileale dell'adulto. Una rarissima entità nosologica.

The report presents a rare case of intestinal duplication in a 43-year old female. Intestinal duplication is a rare congenital malformation and is extremely exceptional in adults. A lot of etiopathogenic theories have been advanced to explain this malformation that can occur anywhere along the alimentary tract, even if the ileum remains the most common. It may be cystic or tubular. An important aspect of mucosal histology is the possibility of gastric heterotopy, conditioning a particular treatment. The literature shows 14 cases with clinical very different presentations and instrumental exams were rarely helpful for correct diagnosis. Treatment of choice is surgical complete resection of the duplication. When contiguous structures are involved intestinal bypass or Roux-on-Y anastomosis may be necessary with mandatory stripping of the mucosa when heterotopic gastric mucosa is present in order to prevent the risk of gastrointestinal haemorrhage or malignant transformation, an event possible in about 25% of the cases reported in the literature.

The use of neuromuscular blocking agents in the emergency department to facilitate tracheal intubation in the trauma patient: help or hindrance?

PURPOSE: The purpose of this study is to examine the relationship between the occurrence of a difficult intubation and (1) the use of neuromuscular blocking agents (NMB) and (2) the presence of airway injuries. It is a retrospective analysis of data from a trauma registry. MATERIALS AND METHODS: Registry records of patients (n = 160) who required emergent endotracheal intubation or establishment of a surgical airway over a 3.5-year period in the emergency department were reviewed. Risk factors for difficult intubations were identified and analyzed using multivariate logistic regression analysis. RESULTS: NMB were used in 75% of patients requiring intubation. Fifteen percent of the intubations were considered difficult. No association was found between the presence of airway injuries and difficult intubations; however, the use of succinylcholine was associated with a lower risk of difficult intubations compared with intubations where a nondepolarizing NMB was used. CONCLUSIONS: The use of succinylcholine may result in fewer difficult intubations in the trauma patient than when a nondepolarizing NMB is used. The presence of airway injuries did not appear to predispose to difficult intubations.

[The solitary rectal ulcer today. A review of the literature]. / L'ulcera solitaria del retto oggi. Revisione della letteratura.

The solitary rectal ulcer (SRU) is a benign lesion of adults of either sex, which presents with chronic constipation, peculiar defecatory disorders, rectal prolapse and smaller psychological abnormalities. The characteristic appearance of this disease is a "neither being always ulcerate, nor always solitary" lesion, but often with polypoid or granular feature, typically localized in anterior rectal wall, a few inches from anal channel. Distinctive histopathological specimens are localized mucosal distortion, hypertrophic proliferation of muscularis mucosae and obliteration of lamina propria by fibroblasts and muscle fibres from the muscularis mucosae. Very few intermittent or recurrent symptoms are rectal bleeding and mucous discharge with defecations, difficulty of a complete ampullar evacuation and sometimes pelvic or rectoperineal pain. Clinical picture and endoscopic biopsies led to diagnosis. Barium enema, defecography, transrectal ultrasound, manometry and electromyography have an additional role. Medical treatment is performed by high-fiber diet, but biofeedback training is very helpful. Surgical management is as an excisional surgery, as a rectopexy if there is prolapse. Fecal diversion and rectocolic resection are considered only for patients with obstinate and severe symptoms. Even in patients who seem to advocate a surgical approach it is important to heal a dyskinetic puborectalis muscle.

Activities of beta-lactams against Acinetobacter genospecies as determined by agar dilution and E-test MIC methods.

The agar dilution MIC method was used to test activities of ticarcillin, ticarcillin-clavulanate, amoxicillin, amoxicillin-clavulanate, ampicillin, ampicillin-sulbactam, piperacillin, piperacillin-tazobactam, inhibitors alone, ceftazidime, and imipenem against 237 Acinetobacter genospecies. A total of 93.2% of strains were beta-lactamase positive by the chromogenic cephalosporin method. Overall, ampicillin-sulbactam was the most active combination against all strains (MIC at which 50% of the isolates are inhibited [MIC50] and MIC90, 4.0 and 32.0 microg/ml; 86.9% susceptible at < or = 16 microg/ml), followed by ticarcillin-clavulanate (16.0 and 128.0 microg/ml; 85.7% susceptible at < or = 64 microg/ml), piperacillin-tazobactam (16.0 and 128.0 microg/ml; 84.8% susceptible at < or = 64 microg/ml), and amoxicillin-clavulanate (16.0 and 64.0 microg/ml; 54.4% susceptible at < or =16 microg/ml). Ceftazidime and imipenem yielded MIC50s and MIC90s of 8.0 and 64.0 microg/ml (ceftazidime) and 0.5 and 1.0 microg/ml (imipenem), respectively; 71.3% of strains were susceptible to ceftazidime at < or = 16 microg/ml, and 99.2% were susceptible to imipenem at < or = 8 microg/ml. Sulbactam was the most active beta-lactamase inhibitor alone (MIC50 and MIC90, 2.0 and 16.0 microg/ml); clavulanate and tazobactam were less active (16.0 and 32.0 microg/ml for both compounds). Enhancement of beta-lactams by beta-lactamase inhibitors was not always seen in beta-lactamase-positive strains, and activity of combinations such as ampicillin-sulbactam was due to the inhibitor alone. Acinetobacter baumannii was the most resistant genospecies. By contrast, Acinetobacter haemolyticus, Acinetobacter calcoaceticus, Acinetobacter johnsonii, Acinetobacter junii, Acinetobacter radioresistens, and other non-Acinetobacter baumannii strains were more susceptible to all compounds tested. E-test MICs were within 1 dilution of agar dilution MICs in 38.4 to 89.6% of cases and within 2 dilutions in 61.6 to 98.6% of cases.

Topic and systemic administration of natural alfa interferon in the treatment of female and male HPV genital infections.

The aim of the study was to evaluate the effectiveness and tolerance of topic and systemic administration of natural alfa-interferon from normal human leukocytes in the treatment of HPV lesions of the lower genital tract. From May 1991 through May 1992, 70 women (mean age = 29; range 16-42) and 51 men (mean age = 28; range 18-48) with histologically proven HPV genital lesions were studied. 43 patients and 32 male partners with subclinical infection underwent cream therapy (4 applications/day for 30 days) composed of natural alfa interferon and containing 1,000,000 IU/gr. 27 women and 19 men affected by florid infection underwent systemic i.m. therapy with natural alfa interferon in doses of 3,000,000 IU on alternate days for 30 days. The percentage of therapeutical success amounted to 55.8% for women and 78.1% for men subjected to topic therapy; for the 27 patients and 19 male partners treated with systemic therapy the final percentages of success were 70.3% respectively. Natural alfa interferon from normal human leucocytes seems to be a drug of good efficacy and tolerance in the treatment of HPV genital pathology.

[Blue nevus of the endocervix]. / Nevo blu dell'endocervice.

We report a case of blue nevus of the uterine cervix discovered in a cone removed for other reasons. The lesion can be interpreted as a visceral analogue of the cutaneous blue nevus. Histological and Immunohistological studies suggest the melanocytic nature of the lesion.

Cervical intraepithelial neoplasia: carbon dioxide laser vaporization and conization. Our experience.

Between 1984 and 1992, the CO2 laser was used to treat 341 patients affected by CIN of various degrees. On the basis of specific indications these patients underwent vaporization or conization. Two hundred and twenty eight patients underwent vaporization of intraepithelial lesions, 221 (96.92%) of whom were free of disease after one laser treatment, as observed during the subsequent years of follow-up. In 105 out of the 113 patients treated with conization the cone margin was free of disease. One hundred and one (96.19%) of the these 105 patients had no evidence of disease after one year of follow-up. In the remaining 8 (7.07%) cases examination of the cone revealed the presence of invasive carcinoma. The major complication was vaginal discharge observed in 115 (33.72%) patients. The CO2 laser is a very effective therapeutic procedure for the treatment of intraepithelial lesions of the cervix and permits to preserve reproductive function and anatomic integrity.

Pulse oximetry is accurate in acute anemia from hemorrhage.

HYPOTHESIS: Pulse oximetry is an accurate, noninvasive assay of oxygen saturation percentage (SaO2) in acutely severe anemia (less than 5 g/dL). DESIGN: A paired comparison of SaO2 by pulse oximetry (SpO2) and arterial blood gas analysis (SaO2) in patients with either acute gastrointestinal bleeding or blunt trauma with hematocrit of less than 20%. SETTING: An academic emergency department in a tertiary referral hospital with a Level I trauma center. PARTICIPANTS: Seventeen nonhypoxic patients were identified with initial hematocrit of less than 20% over a 9-month period. MEASUREMENTS AND MAIN RESULTS: Determination of SaO2 by pulse oximetry and arterial blood analysis was not statistically significantly different (P < .05) over a range of hemoglobin levels from 2.3 to 8.7 g/dL. The observed mean difference between SpO2 and SaO2 was 0.53 +/- 0.23% (mean +/- SEM; n = 17). The 95% confidence interval associated with this difference score ranged from 0.044 to 1.014. CONCLUSION: Despite reports that pulse oximetry is inaccurate below a hemoglobin concentration of 5 g/dL, our study suggested that this technology is accurate and reliable at 2.3 g/dL for nonhypoxic SaO2 values (SaO2 of more than 93%). The anemic endpoint where pulse oximetry either becomes inaccurate or simply fails to work has not been determined. Pulse oximetry overestimates SaO2 on average by 0.53% over a range of hemoglobin concentrations from 2.3 to 8.7 g/dL.

Management of human papilloma virus vulvo-perineal infection with systemic beta-interferon and thymostimulin in HIV-positive patients.

OBJECTIVES: To evaluate the effect of a combined therapy based on beta-interferon and thymostimulin in HIV-seropositive women with florid vulvoperineal condylomatosis. METHODS: Nineteen HIV-seropositive women affected by HPV florid vulvo-perineal infection were studied. Their ages ranged from 19 to 32 years (mean = 26); all were smokers; 11 (57.89%) were intravenous drug users with a mean period of drug addiction of 5 years. No patient was on AZT therapy. All patients underwent a combined medical therapy based on beta-interferon administration with doses of 3,000,000 IU i.m. daily for 7 days and subsequently on alternate days for 2 weeks associated with the administration of 70 mg i.m. of thymostimulin per day on alternate days for 30 days. RESULTS: Seven (36.84%) patients showed complete recovery at the end of follow-up; 5 (26.31%) patients showed partial recovery and 7 (36.84%) did not respond to therapy. CONCLUSION: A pro-host immunotherapy seems to be indicated in patients affected by immunodeficiency syndrome.