Hyperinflation of the left anterior basal segment: a new sign of pectus excavatum severity on CT.

AIM: To describe a new finding in patients with pectus excavatum - left lower lobe anterior basal segment hyperinflation [LABSH]. A secondary objective is to determine the frequency of the new finding and association with pectus excavatum severity. MATERIAL AND METHODS: The study population included 52 children who underwent preoperative computed tomography (CT) for the evaluation of pectus excavatum. A control group of 50 children was obtained after evaluating 137 CT examinations performed for other reasons. Patient age in both groups ranged from 12 to 20 years. The Haller index was calculated for all patients. LABSH was evaluated by visual inspection of lung windows. The difference in mean radiodensity measurements in regions of interest in the left and right anterior basal segments [ΔHU] was calculated. Spirometry was performed in 44 of the patients and the results were compared to Haller index severity and the presence of LABSH. Echocardiography reports were available for 50 children in the pectus excavatum group. RESULTS: LABSH was identified by visual inspection in 15 patients [29%] and was significantly associated with a Haller index >4.0 (p=0.001). ΔHU for the patients with LABSH was 90.2 HU (standard deviation [SD]=37.7) and for the non-hyperinflated group -5.51 (SD=44.63), which was significant (p<0.0001). There was a significant association of LABSH with the pectus excavatum group as compared to the control group. The difference in mean Haller index for children with normal spirometry (4.4, SD=2.7) was not significantly different (p=0.9899) than for children with obstructive disease (4.5, SD=1). There was mild cardiac compression on two echocardiograms. CONCLUSION: LABSH is a new sign associated with pectus excavatum. The sign suggests segmental bronchial compression caused by chest deformity results in segmental air trapping.

Effect of ventilation on cerebral oxygenation in patients undergoing surgery in the beach chair position: a randomized controlled trial.

BACKGROUND: Surgery in the beach chair position (BCP) may reduce cerebral blood flow and oxygenation, resulting in neurological injuries. The authors tested the hypothesis that a ventilation strategy designed to achieve end-tidal carbon dioxide (E'(CO2)) values of 40-42 mm Hg would increase cerebral oxygenation (Sct(O2)) during BCP shoulder surgery compared with a ventilation strategy designed to achieve E'(CO2) values of 30-32 mm Hg. METHODS: Seventy patients undergoing shoulder surgery in the BCP with general anaesthesia were enrolled in this randomized controlled trial. Mechanical ventilation was adjusted to maintain an E'(CO2) of 30-32 mm Hg in the control group and an E'(CO2) of 40-42 mm Hg in the study group. Cerebral oxygenation was monitored continuously in the operating theatre using near-infrared spectroscopy. Baseline haemodynamics and Sct(O2) were obtained before induction of anaesthesia, and these values were then measured and recorded continuously from induction of anaesthesia until tracheal extubation. The number of cerebral desaturation events (CDEs) (defined as a ≥20% reduction in Sct(O2) from baseline values) was recorded. RESULTS: No significant differences between the groups were observed in haemodynamic variables or phenylephrine interventions during the surgical procedure. Sct(O2) values were significantly higher in the study 40-42 group throughout the intraoperative period (P<0.01). In addition, the incidence of CDEs was lower in the study 40-42 group (8.8%) compared with the control 30-32 group (55.6%, P<0.0001). CONCLUSIONS: Cerebral oxygenation is significantly improved during BCP surgery when ventilation is adjusted to maintain E'(CO2) at 40-42 mm Hg compared with 30-32 mm Hg. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT01546636.

Impaired in vitro interferon, blastogenic, and natural killer cell responses to viral stimulation in acquired immune deficiency syndrome.

The in vitro immune response to herpes simplex virus (HSV), type 1, strain 539, HSV type 2, strain 316D, and cytomegalovirus was studied in 20 patients (14 with acquired immune deficiency syndrome, four with the acquired immune deficiency syndrome-related symptom complex, and two sexually active asymptomatic homosexuals) and 18 heterosexual healthy controls. Peripheral blood mononuclear cells were cultured with 2 X 10(5) plaque-forming units of heat-inactivated viruses, their lymphocyte blastogenic responses were measured after 5 days in culture by [3H]-thymidine incorporation, their interferon production was measured after 24 hr and 5 days, and natural killer (NK) cell activation was measured after 24 hr and 5 days of culture. Blastogenic responses to viruses were significantly low for only HSV, type 1:1.75 X 10(3) cpm in patients' cells compared to 6.36 for controls. Interferon responses to all three viruses were significantly low at both 24 hr and 5 days; e.g., HSV, type 1:139 IU/ml in patients' cells compared to 777 for controls at 24 hr. NK cell responses of patients were lower than those of controls when tested fresh and after 24 hr of incubation: 6.1 versus 11.7% and 9.2 versus 16.8% target cell lysis, respectively. Exposure to viruses boosted NK cell responses of both patients' and controls' cells, but boosting was generally greater among the normal rather than the patients' cells. The abnormalities of response were present in all three patient groups. Addition of interleukin-2 in vitro increased the patient and control blastogenic and NK responses but did not augment the interferon responses. The in vitro responses to both HSV, type 1, and HSV, type 2, correlated significantly with our conventional assays of the percentage and absolute level of T4+-helper lymphocytes in the blood and the blastogenic responses to mitogens, such as phytohemagglutinin, pokeweed mitogen, and concanavalin A. This system should be useful for the study of host defense in acquired immune deficiency syndrome patients and those in high-risk groups, and also for the in vitro evaluation of immunomodulators.

Respiratory tract viral infections in inner-city asthmatic adults.

BACKGROUND: Respiratory tract viral infections (RTVIs) have been identified frequently in association with asthma exacerbations in children, but few studies have shown similar rates of viral infections in adults with asthma. Further studies using newer diagnostic techniques to evaluate the frequency of RTVIs in adults with acute exacerbations of asthma need to be performed. METHODS: Twenty-nine asthmatic adults were recruited from the pulmonary clinic of an urban county hospital and were followed up in a longitudinal cohort study for signs and symptoms of asthma and RTVI. One hundred twenty-two asthmatic adults presenting to the emergency department (ED) of the same hospital with acute symptoms of asthma underwent evaluation for RTVI in a cross-sectional prevalence study. In both studies, respiratory secretions and paired serum samples were collected from subjects with acute wheezing episodes and evaluated using virus culture, serologic testing, and reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: In the longitudinal cohort study, 138 respiratory illnesses, of which 87 were asthma exacerbations, were evaluated; 41% of all illnesses and 44% of asthma exacerbations were associated with an RTVI. In the ED study, 148 asthma exacerbations were evaluated; 55% were associated with an RTVI. An RTVI was identified in 21 (50%) of 42 of the subjects hospitalized in the ED study. Picornaviruses (rhinoviruses), coronaviruses, and influenza viruses were the most commonly identified causes of RTVI. Forty-six (60%) of the 77 picornavirus infections and 22 (71%) of the 31 coronavirus infections were identified only using RT-PCR. CONCLUSIONS: Asthmatic exacerbations in adults are frequently associated with an RTVI. Identification of such infections often requires newer diagnostic methods, such as virus-specific RT-PCR. The high frequency of RTVIs identified in association with asthmatic exacerbations in adults from the inner city suggests that strategies for the prevention of RTVI should be targeted toward this population.

Bacterial spinal epidural abscess. Review of 43 cases and literature survey.

We have reviewed our experience with 43 cases of bacterial spinal epidural abscess, as well as previously reported series of cases. We found a striking male predominance of the disease, accounting for 86% of cases. Most patients had some underlying conditions that predisposed to infection, a prior infection at a distant site, or an abnormality or trauma to the spine. Presenting symptoms included backache (72%), radicular pain (47%), weakness of an extremity (35%), sensory deficit (23%), bladder or bowel dysfunction (30%), and frank paralysis (21%). Patients cared for in public hospitals tended to seek medical attention in later stages of the disease than patients admitted to private hospitals. Spinal epidural abscess was the suspected diagnosis in only 40% of the cases; the remainder of the time various other infections, tumors, neurologic diseases, or degenerative conditions were considered. Patients in whom the diagnosis of spinal epidural abscess was not initially entertained on admission suffered delays in diagnosis and experienced neurologic deterioration. Staphylococcus aureus was the predominant pathogen (65%) and was associated with positive blood cultures in nearly every case; aerobic or facultative gram-negative bacilli were next most common. Coagulase-negative staphylococci caused infection only in patients who had previous spinal instrumentation. Although analysis of CSF was abnormal in the majority of cases, abnormalities were nonspecific, Gram stain was always negative and culture was rarely diagnostic. Abscesses extended over an average of 4 vertebrae, and the majority were located in the lumbar region followed by thoracic and cervical regions. Unlike previous series, we noted an equal frequency of anterior and posterior epidural abscesses; although differences were not statistically significant, posterior abscesses tended to be more extensive but less commonly associated with radiographic abnormalities of osteomyelitis. Myelography revealed an abnormality in every case in which it was done. Computerized tomographic scanning after intrathecal injection of contrast material always provided additional useful information. Even though magnetic resonance imaging was diagnostic in only 4 of 5 cases (80%) in our series, this test is noninvasive and clearly delineates the location and nature of spinal lesion. It should, therefore, probably replace myelography as an initial definitive study in patients suspected of having spinal infection. Plain roentgenograms and nuclear scans contributed little useful information that was not already available from other radiographic procedures. Surgical drainage together with antibiotics was the treatment of choice; 35 of our 43 patients underwent operative intervention. The preoperative status clearly predicted the final neurologic outcome.(ABSTRACT TRUNCATED AT 400 WORDS)

Herpes zoster-associated encephalitis: clinicopathologic report of 12 cases and review of the literature.

Herpes-zoster associated encephalitis (HZAE) is an uncommon complication of herpes zoster. Over 8 years, we evaluated 12 patients with this clinical diagnosis. The majority of our patients were elderly, immunosuppressed, and found to have disseminated skin lesions prior to the onset of CNS symptoms. All patients had abnormal EEGs, and CSF pleocytosis was found in most. In the seven patients who were tested, specific antibody to the varicella-zoster membrane antigen (FAMA) was detected in spinal fluid during the course of the illness. Although three patients died during the period of active infection, the virus could not be definitively implicated as the cause of death. These HZAE patients could not be distinguished from our other herpes zoster patients on the basis of age, initially involved dermatome, or mortality rate. However, among herpes zoster patients who survived, duration of hospitalization was significantly longer in those with a diagnosis of HZAE. All surviving HZAE patients had a slow but eventual return to their prior cognitive status.

Herpes simplex encephalitis treated with vidarabine (adenine arabinoside).

Vidarabine, an antiviral chemotherapeutic agent shown to have in vitro activity against the herpes group of viruses, was administered to five patients with brain biopsy-proved herpes simplex virus encephalitis. The mortality in this small number of patients (one of five or 20%) was less than that in most published reports of patients receiving other treatment modalities or no treatment other than supportive measures. No apparent toxicity was found that was attributable to vidarabine. Neuropsychological impairment of varying degree was noted in four surviving patients tested at two months after treatment and again 12 to 21 months later. Progressive improvement had occurred in three.

Cytokines and impaired CD8+ CTL activity among elderly persons and the enhancing effect of IL-12.

We have previously demonstrated that about 70% of elderly persons exhibit deficient cytotoxic T lymphocyte (CD8+ CTL) responses against influenza viruses when compared to young persons. Since IFN-gamma, a Th1 cytokine and IL-4, a Th2 cytokine, stimulate and inhibit CD8+ CTL responses respectively, their role(s) in the age-related CTL deficiency was investigated. Lymphocytes from young adults (34 +/- 5 years old) and elderly subjects (71 +/- 1 years old) were stimulated in vitro with influenza A/H3N2, A/H1N1 or influenza B virus for 6-7 days. The CD8+ CTL activity against virus-infected autologous target cells was significantly lower among the elderly than the young subjects (P < 0.01). Following stimulation with influenza virus, IL-4 production in both age groups was similar on day 3 but significantly higher among elderly persons on day 6 (P < 0.05). In contrast, T cells from the elderly produced significantly lower IFN-gamma than did those from young persons on both days (P < 0.05). Treatment of T cells from young and elderly adults with recombinant human IL-12, a pivotal cytokine that stimulates Th1 cytokines, resulted in enhancement of CD8+ CTL activity and IFN-gamma production in a dose dependent manner (P < 0.01). IL-12-dependent enhancement of CTL activity was not always abrogated by anti-IFN-gamma antibody treatment. These results suggest that deficient influenza virus-specific CTL activity among the elderly is attributable to a Th1 to Th2 cytokine production switch. Immunotherapy with IL-12 could represent a useful approach to correct the CD8+ CTL deficiency and cytokine imbalance among elderly humans.

Treatment of hospita-acquired infections with amikacin.

Amikacin was used in the treatment of 56 serious gram-negative infections in 54 patients of whom 47 survived. In six of the seven nonsurvivors, the infections were under control at the time of death. The clinical isolates were multiple drug-resistant gram-negative organisms, with Proteus rettgeri being most common. Forty-five (80%) of these infections were nosocomial in origin, and the genitourinary tract was the source in 39 (70%). Complications directly related to amikacin therapy were few and suggested renal or otologic toxicity. In this series of patients, amikacin appeared to be of therapeutic benefit in the treatment of serious gram-negative infections.

Right ventricular function and exercise performance late after primary repair of tetralogy of Fallot with the transannular patch in infancy.

To evaluate the late effects of chronic pulmonary regurgitation against the putative benefits from the current surgical trend of primary repair of tetralogy of Fallot with a transannular patch in infancy, 10 patients > 10 years after early primary repair and 7 matched normal controls underwent exercise stress test and cine magnetic resonance imaging assessment of ventricular functions. Right ventricular impaired diastolic function and decreased exercise capacity, both significantly associated with pulmonary regurgitation in patients, indicated that early primary repair of tetralogy may not prevent late ventricular dysfunction and diminished exercise performance if chronic regurgitation results from right ventricular outflow tract reconstruction.

A randomized trial of interferon alpha therapy for HIV type 1 infection.

The immunologic and virologic efficacy and safety of interferon a (IFN-alpha) administered in combination with zidovudine (ZDV) and zalcitabine (ddC) was evaluated in HIV-infected subjects with CD4+ cell counts between 300 and 500 cells/ml and no more than 14 weeks of prior antiretroviral therapy. A total of 256 subjects enrolled in an open-label, randomized controlled trial. Subjects were randomized equally into treatment groups. All subjects received ZDV and ddC, while half also receive IFN-alpha (3 MU subcutaneously every 24 hr). At 48 weeks the median average area under the curve minus baseline (AAUCMB) for plasma HIV-1 RNA for the two-drug group was -0.68 versus -0.75 log10 copies/ml for the IFN-alpha group (p = 0.046). Mean HIV-1 RNA changes from baseline to 48 weeks for these groups were -0.65 and -1.12 log10 copies/ml, respectively (p = 0.010). The median AAUCMB for CD4+ cell count for the two-drug group was 28 versus -1 cells/mm3 for the IFN-alpha group (p = 0.011). Neutropenia, anemia, and drug intolerance were more common in the IFN-alpha group. This study demonstrates that IFN-alpha inhibits HIV-1 replication but attenuates the CD4+ cell response to dual therapy with ZDV and ddC.

Malignant group B streptococcal endocarditis associated with saline-induced abortion.

A 20-year-old woman developed acute group B streptococcal endocarditis following saline-induced abortion. In the pre-antibiotic era, most cases of group B streptococcal endocarditis occurred in parturient or postabortal women. Currently, this disease is rarely described in obstetrical patients, and no previous cases following saline-induced abortion have been reported. Purulent pericarditis and a perivalvular abscess were present in our patient and represent only the second instance in which these findings have been documented in this disease.

PIP: This case report describes a 20-year-old woman who developed acute group B streptococcal endocarditis after a saline-induced abortion. She was admitted 2 weeks after an uncomplicated saline-induced abortion for a 16-week pregnancy with a 1-week history of fever, headaches, dizziness, and shortness of breath. The patient showed poor response to antibiotic therapies (initially to nafcillin and gentamicin and then to aqueous penicillin G). 6 to 6 blood cultures after hospital admission showed group B streptococcus which was penicillin sensitive by tetracycline resistant. On Day 3 of admission, a pericardial friction rub was noted and repeat chest x-rays showed marked enlargement of the cardiac shadow. Surgery was performed, and the mitral valve posterior leaflet was necrotic, and a mitral valve prosthesis was placed and an aortic embolectomy was performed. Postoperatively, she was treated with an additional 6-week course of intravenous penicillin, and subsequently, she has remained asymptomatic after 6 months. An addendum to this report, which was only the 2nd such report of endocarditis after saline abortion, describes another case of group B streptococcal endocarditis in a drug abuser after a saline-induced abortion. She required tricuspid valvulectomy and is slowly improving postoperatively.

Postoperative respiratory failure secondary to Pneumocystis carinii pneumonia.

Pneumocystis carinii pneumonia (PCP) occurs frequently in individuals infected with the HIV virus. Malignancy, immunosuppressive drugs, and congenital immune deficiency may be associated with PCP. We describe a patient with stage 1 testicular carcinoma who developed hypoxemic respiratory failure two days after retroperitoneal lymph node dissection. Pneumocystis carinii organisms were demonstrated by catheter lavage samples and confirmed on bronchoalveolar lavage. Testing for HIV antibody by ELISA and the Western blot test were negative; HIV viral culture and polymerase chain reaction were also negative. Pneumocystis carinii pneumonia is unusual in localized surgically cured malignancies without obvious immunodeficiency and, to our knowledge, has not been described as a cause of postoperative respiratory failure.

Magnetic resonance measurement of volumes using a phantom. Application to the cardiac ventricles of infants and small children.

RATIONALE AND OBJECTIVES: Cine magnetic resonance (MR) is an established method for determining cardiac ventricular volumes in adults. The reported section slice thickness may be too thick for accurate measurement of ventricular volumes in infants and young children. In this article, acceptable slice thickness is established for cine MR in children. METHODS: Balloons filled with a dilute gadolinium solution were immersed in a water bath. The balloons were scanned using a fast scan technique to simulate cine MR. Scanning was performed using different slice thicknesses. Volumes were calculated using previously reported techniques. These calculated volumes were compared to direct measurement of the balloon volumes using graduated syringes. RESULTS: The balloons varied in volume from 0.9 mL to 27.3 mL. Measurements using 3- and 5-mm slice thickness sections were found to be significantly more accurate than 10-mm slice thickness sections. CONCLUSION: Section thickness should be less than 1-cm when performing cine MR in infants and small children for measurement of ventricular volumes.

Validation of right ventricular volume measurements by magnetic resonance imaging in small hearts using a fetal lamb model.

RATIONALE AND OBJECTIVES: Cine-magnetic resonance (MR) imaging is established as an accurate method of determining cardiac ventricular volumes in adults but has not been validated for the smaller ventricular volumes found in infants. The purpose of the authors study was to evaluate the accuracy and reproducibility of MR imaging to measure small ventricle volumes. METHODS: The volume of silicone-rubber casts of the right ventricle of 11 fetal lamb hearts was measured by MR imaging using different imaging planes and slice section thicknesses and by water displacement. RESULTS: The ventricle volumes of the 11 hearts ranged from 0.45 to 3.00 mL. Accurate and reproducible values for the right ventricle volumes were obtained by MR imaging. Thin sections (3 mm) in the axial plane produced the best results. CONCLUSIONS: Based on studies in the nonmoving heart, MR imaging can accurately measure the small ventricular volumes expected in infants.

Human interferon in viral diseases.

Interferons have been studied in animals and man for local and systemic viral infections that are either rare or common. Recent clinical studies in humans with purified or recombinantly derived interferons have demonstrated significant clinical response in rhinovirus common colds, herpetic keratitis, condyloma acuminata, and laryngeal papillomatosis. However, only 40 per cent of published papers with IFN have been appropriately controlled. The toxicity of these newer preparations when administered either topically or parenterally prevents their immediate licensing for general use. The toxic to therapeutic ratio for HuIFN and rIFN appears to be close to one in most clinical situations in which it has been tested. Although interferons have not proved to be the "penicillin" for viruses many thought they would become, basic in vitro work and clinical studies have contributed greatly to our understanding of host defense and immunopathology. Future studies must focus on increasing our understanding of the mechanisms of toxicity, in addition to devising controlled clinical trials with interferon alone or in combination with other antiviral agents. Thus, after 30 years of research on interferons, it would appear our work has just begun.

Viral pneumonia.

Viral pneumonias are common in infants and young children but rare in adults. Respiratory syncytial virus (RSV) and para-influenza viruses are the most frequent viral pathogens in infants and children. Influenza virus types A and B account for over one half of viral pneumonias in adults. Immunocompromised hosts are susceptible to pneumonias caused by cytomegalovirus (CMV) and other herpesviruses, as well as rubeola and adenovirus. Diagnosis of viral pneumonia depends on appropriate viral cultures and acute and convalescent sera for specific antibodies. Superinfection with bacteria is common in adults. Anti-viral therapy is available for several respiratory viruses. Ribavirin, amantadine/rimantadine, interferon alpha, and acyclovir are antiviral drugs that may be of benefit in treatment and prophylaxis. Prevention of viral pneumonia will depend upon improved viral immunization practices.

Amebic peritonitis following rupture of an amebic liver abscess. Successful treatment of two patients.

We present two successfully treated cases of amebic peritonitis. Acute peritonitis secondary to intra-abdominal rupture of an amebic liver abscess is an infrequent but serious complication of invasive amebiasis. Its diagnosis should be considered in anyone with a suspected liver abscess, jaundice, or diarrhea in whom peritonitis develops. This diagnosis should be further suggested in the United States if the patient is a male and is of Mexican origin in areas where this racial group constitutes the majority of cases of amebic disease. Use of radioisotope liver scans and the demonstration of serum precipitins to Endamoeba histolytica may provide rapid evidence of invasive disease, although surgical intervention is often necessary to make a specific diagnosis. Emetine hydrochloride alone or followed by metronidazole combined with surgical drainage is the current treatment for amebic peritonitis.

Ventricular function.

Multiple modalities contribute to the evaluation of ventricular function. The role of cineangiography, echocardiography, MR imaging, ultrafast CT, and nuclear medicine continue to evolve and improve our understanding of the physiology and pathophysiology of ventricular function. This article discusses the use and limitation of each modality.