Methods for improved detection of oxacillin resistance in coagulase-negative staphylococci: results of a multicenter study

A multilaboratory study was undertaken to determine the accuracy of the current National Committee for Clinical Laboratory Standards (NCCLS) oxacillin breakpoints for broth microdilution and disk diffusion testing of coagulase-negative staphylococci (CoNS) by using a PCR assay for mecA as the reference method. Fifty well-characterized strains of CoNS were tested for oxacillin susceptibility by the NCCLS broth microdilution and disk diffusion procedures in 11 laboratories. In addition, organisms were inoculated onto a pair of commercially prepared oxacillin agar screen plates containing 6 microg of oxacillin per ml and 4% NaCl. The results of this study and of several other published reports suggest that, in order to reliably detect the presence of resistance mediated by mecA, the oxacillin MIC breakpoint for defining resistance in CoNS should be lowered from >/=4 to >/=0.5 microg/ml and the breakpoint for susceptibility should be lowered from </=2 to </=0.25 microg/ml. In addition, a single disk diffusion breakpoint of </=17 mm for resistance and >/=18 mm for susceptibility is suggested. Due to the poor sensitivity of the oxacillin agar screen plate for predicting resistance in this study, this test can no longer be recommended for use with CoNS. The proposed interpretive criteria for testing CoNS have been adopted by the NCCLS.

Systematic decalcification prophylaxis during treatment with fixed appliances

In a practical setting, 4 different prophylactic methods were compared with regard to their effects on the incidence of decalcification during orthodontic fixed appliance therapy and on the frequency of premature debonding resulting from imminent or already manifest decalcification. This study showed that the use of a system in which selection and care were oriented solely along the clinical impression was associated with the highest rate of decalcification and premature debonding. The findings were significantly better (p < 0.05), when a prophylactic regimen of oral hygiene was implemented which was based on patient selection (API < 30%) and regular oral hygiene check-ups during the treatment. When the DMFT index was considered in addition to the API value, and the number of the initial lesions at the beginning of treatment were included for selecting patients, the incidence of decalcification was significantly reduced even further (p < 0.05). A more comprehensive or "optimized prophylaxis" utilizing saliva test parameters and active prophylactic interventions implemented by a dental hygienist during the treatment phase also had a favorable impact on the main outcome parameters. The present findings indicate that decalcification can be markedly reduced by using a treatment regimen that targets the decalcification risk and a systematic, individualized prophylaxis during active treatment with fixed appliances.

The emergence of decreased susceptibility to vancomycin in Staphylococcus epidermidis

BACKGROUND

Coagulase-negative staphylococci (CNS) are the major cause of nosocomial bloodstream infection. Emergence of vancomycin resistance among CNS is a serious public health concern, because CNS usually are multidrug-resistant, and glycopeptide antibiotics, among which only vancomycin is available in the United States, are the only remaining effective therapy. In this report, we describe the first bloodstream infection in the United States associated with a Staphylococcus epidermidis strain with decreased susceptibility to vancomycin.

METHODS

We reviewed the hospital's microbiology records for all CNS strains, reviewed the patient's medical and laboratory records, and obtained all available CNS isolates with decreased susceptibility to vancomycin. Blood cultures were processed and CNS isolates identified by using standard methods; antimicrobial susceptibility was determined by using minimum inhibitory concentration (MIC) and disk-diffusion methods. Nares cultures were obtained from exposed healthcare workers (HCWs) to identify possible colonization by CNS with decreased susceptibility to vancomycin.

RESULTS

The bloodstream infection by an S. epidermidis strain with decreased susceptibility to vancomycin occurred in a 49-year-old woman with carcinoma. She had two blood cultures positive for CNS; both isolates were S. epidermidis. Although susceptible to vancomycin by the disk-diffusion method (16-17 mm), the isolates were intermediate by MIC (8-6 microg/mL). The patient had received an extended course of vancomycin therapy; she died of her underlying disease. No HCW was colonized by CNS with decreased susceptibility to vancomycin.

CONCLUSIONS

This is the first report in the United States of bloodstream infection due to S. epidermidis with decreased susceptibility to vancomycin. Contact precautions likely played a role in preventing nosocomial transmission of this strain, and disk-diffusion methods may be inadequate to detect CNS with decreased susceptibility to vancomycin.

Attempting to enhance the enrollment of adolescents into AIDS clinical trials: the design of ACTG Protocol 220

The epidemic of HIV infection continues to grow in adolescents and young adults. Unfortunately, because treatment regimens have been developed based on data derived from clinical trials, little data are available on adolescents because they are infrequently included in these trials. In an effort to facilitate the enrollment of more adolescents into AIDS Clinical Trials Group (ACTG) clinical trials, we designed a nontreatment protocol to familiarize adolescents with clinical trials requirements. Two hundred fifty-six adolescents (150 females, 106 males) between the ages of 13 and 21 years were enrolled at 43 different clinical trials sites throughout the United States. The majority of patients (50%) were enrolled at sites that had specific programs for adolescents. Most of the young women (85%) had acquired their infection via heterosexual transmission, whereas the largest transmission categories in men were blood or factor transfusions (43%) or same-sex contact (34%). Admission CD4 counts were lower in males (mean = 396 cells/mm3) than in females (mean = 513 cells/mm3) (p = 0.01). Psychosocial profiles revealed a variety of ongoing risk behaviors in HIV-infected adolescents. Two years into the study, 223 patients are still being observed. We conclude that adolescents can be enrolled in an observational protocol. The success of this trial will be determined by how many ACTG Protocol 220 participants are ultimately enrolled in therapeutic trials.

[Intravenous immunoglobulins (IVIG) in treatment of an antiphospholipid syndrome in pregnancy]

A patient with a history of early onset preeclampsia and repeated fetal death, high titer IgG anticardiolopin antibodies and prolonged aPTT was treated during her third pregnancy with intravenous immunoglobulins (IVIG) from the seventh month of pregnancy onwards. Every month--after a loading dose of 30 g immunoglobulins--a daily infusion of 3 g immunoglobulin was for three days was given during six consecutive cycles. The patients pregnancy ended preterm with a life birth, delivered by cesarean section, because of a severe preeclampsia. The 1600 g weighing boy was in good health. Each treatment with IVIG resulted in a reduction of anticardiolipin-antibodies. During the seventh months observation period, a gradual increase in PAI activity/factor VIIIR:Ag was found. A partial transient reduction of antiphospholipid-antibody levels was observed immediately following each treatment course resulting in an accelerated fetal outcome.

Antidepressant efficacy and cardiovascular safety of venlafaxine in young vs old patients with comorbid medical disorders

OBJECTIVE

To determine whether venlafaxine exerts a differential effect on blood pressure in young versus old depressed patients.

METHOD

We compared thirty-four consecutive patients treated with 50-250 mg/day venlafaxine for major depressive disorder or another major mood disorder at our medical college's ambulatory neuropsychiatry program. We obtained baseline and follow-up blood pressure measurements. Each patient also received a baseline and final Clinical Global Impressions (CGI) score; global improvement was determined by consensus of two clinicians.

RESULTS

Sixteen nongeriatric patients (age, 13 to 56 years) were compared with eighteen elderly patients (age, 65 to 86 years). Most patients (88%) had serious medical comorbidities or histories. Despite a higher mean daily venlafaxine dosage for patients in the young group, no significant changes in systolic blood pressure were noted in either group. For the older group, we found a non-statistically significant 4.7 mm Hg mean increase in diastolic blood pressure. No patient became hypertensive. We also found a negative correlation between baseline diastolic blood pressure and change in diastolic blood pressure during treatment with venlafaxine. This inverse relationship was statistically significant in the older patients.

CONCLUSIONS

Venlafaxine was not associated with significant, sustained changes in blood pressure in any patient receiving dosages of 50-250 mg/day. Minimal changes in diastolic blood pressure were no more likely to occur in older venlafaxine-treated patients than in younger ones. Higher baseline diastolic blood pressure in older patients, but not in younger ones, seemed to protect against diastolic adrenergic blood pressure effects of venlafaxine.

Evaluation of pharmacokinetics, safety, tolerance, and activity of combination of zalcitabine and zidovudine in stable, zidovudine-treated pediatric patients with human immunodeficiency virus infection. AIDS Clinical Trials Group Protocol 190 Team

A double-blind phase II trial compared zalcitabine (0.03 mg/kg/day) in combination with zidovudine (720 mg/m2/day) and zidovudine monotherapy in 250 clinically stable, previously zidovudine-treated, human immunodeficiency virus-infected children. The combination was well-tolerated except for an increased incidence of neutropenia (14%) compared with that in children receiving monotherapy (5%). No differences were noted for time to first AIDS-defining illness or death, neuropsychologic status, or weight Z scores. In patients in the combination arm, the CD4 cell count decline was slower (13% per year) than in patients receiving monotherapy (25% per year) (P = .03), and quantitative peripheral blood mononuclear cell virus load remained lower at all time points (P = .08). Deaths were fewer in patients receiving combination therapy (4) compared with those in patients receiving monotherapy (10) (P = .083). Thus, administration of zidovudine with zalcitabine to children with prior zidovudine treatment did not result in a significant increase in toxicity compared with that resulting from zidovudine monotherapy and demonstrated improvement in immunologic and virologic surrogate markers.

Generation of progenitor-cell precursors in long-term bone-marrow cultures after marrow purging with ether lipids

Alkyl-lysophospholipid derivates (ALP) are currently being tested as bone marrow (BM) purging agents prior to autologous BM transplantation in different malignancies. We evaluated the toxicity of the ALP ET-18-OCH3 (ET-18; Edelfosine, 1-0-octadecyl-2-0-methyl-rac-glycero-3-phosphocholine) towards early hematopoietic precursors by testing progenitor regeneration of non-purged and ET-18-purged BM (75 mu g and 125 mu g ET-18/ml/2x10(7) BM cells) in autologous long-term bone marrow cultures (LTBMC) from 3 different patients in complete remission. LTBMC feeder layers were irradiated with 875 rad for complete elimination of hematopoietic progenitors and recharged with cryopreserved purged and non-purged BM. In weekly intervals, adherent layer and supernatant LTBMC cells were completely removed and evaluated in colony forming unit (CFU)-assays. We have seen sufficient CFU-regeneration out of ET-18-purged BM up to 8 weeks of LTBMC (>40 CFU/flask). Total CFU-counts from LTBMC with purged BM were slightly reduced compared to non-purged control. High dose purging with 125 mu g ET-18/ml partly inhibited initial CFU-proliferation, but demonstrated elevated CFU-counts after 4 and 8 weeks of LTBMC compared to control. In conclusion, in our LTBMC series ET-18-purging yielded tolerable toxicity towards committed BM-progenitors, but no remarkable decline of early hematopoietic precursors regenerating CFU-progenitors for up to 8 weeks of culture.

Tuberculosis in human immunodeficiency virus-exposed or -infected United States children

This study was designed to provide a preliminary assessment of the occurrence of tuberculosis exposure, infection and disease within a national sample of infants and children with human immunodeficiency virus (HIV) exposure or infection, and to determine the prevalence of Mycobacterium tuberculosis isolates resistant both to isoniazid and rifampin in these patients or their adult source contacts. A retrospective questionnaire survey was conducted of infants and children with HIV exposure or infection evaluated by pediatric HIV referral centers in the United States comprising the pediatric units or subunits of the Pediatric Acquired Immunodeficiency Syndrome Clinical Trials Group (PACTG). Seventy of 72 sites during a mean period of 5 (range, 1 to 12) years participated in this study and had provided care for 14,038 patients. There were 75 cumulative total cases of tuberculosis disease seen since each site was established. Therapy for asymptomatic infection was given to another 40 children and for tuberculosis exposure to 71 children. Annualized case rates were 478/100,000 for sites established in 1990 to 1992, 117/100,000 for 1988 to 1989, 63/100,000 for 1986 to 1987 and 58/100,000 for 1981 to 1985 (P = 0.05, Spearman's p test for trend). By comparison, the 1992 age-specific tuberculosis case rate for all U.S. children < 5 years was 5.5/100,000. Twenty percent of isolates from PACTG patients and 15% of isolates from adult source contacts were resistant to isoniazid and rifampin.(ABSTRACT TRUNCATED AT 250 WORDS)

The clinical effects and cost-avoidance of a change in perioperative bronchodilator use

The clinical effects and financial impact of a change in prescribing habits from routine to occasional use of perioperative bronchodilators, following the presentation of drug information, were assessed retrospectively by comparing the outcomes of patients admitted for major thoracic surgery. Eighteen of 24 (75%) patients in Period A (prior to change) received salbutamol bronchodilator therapy versus 10 of 17 (59%) in Period B (following the change) (p = .448). Of the patients who did receive salbutamol aerosols, the mean dose in grams per patient was greater in Period A than in Period B (6.85 +/- 5.96 vs. 2.64 +/- 4.44 respectively p < 0.05). Two patients from Period A and one from Period B were receiving digoxin prior to admission. In the remaining patients, 5 of 22 (23%) in Period A and 1 of 16 (6%) in Period B developed atrial fibrillation requiring digoxin (p = .36). The proportion of patients with obstructive airways disease (OAD) who developed an arrhythmia was not different between the two groups. However, in those patients without OAD an arrhythmia was reported in 9 of 16 patients (56%) receiving salbutamol, versus only 1 of 11 (9%) of those not receiving it (p = 0.032). The number of days patients were hospitalized during Period A and Period B were 10.2 +/- 4.97 and 9.4 +/- 3.68 respectively (p = 0.85). A potential average cost-avoidance of $68.46 per patient could be realized with this new practice. We conclude that a change in prescribing habits had no adverse clinical outcome and resulted in a considerable cost-avoidance.

[Mucinous cystadenomas and cystadenocarcinomas of the pancreas--the pancreaticoscopy as a new device for endoscopic and histological diagnosis]

Recent advances in diagnostic imaging procedures offer the opportunity for detection of rare cystic neoplasms of the pancreas. Cystadenomas of the pancreas have been reported to represent 10% of cystic pancreatic lesions. Serous microcystic cystadenoma, megacystic mucinous and duct-ectatic mucinous cystadenoma were distinguished. While the serous cystadenoma is benign, in general the megacystic and the duct-ectatic mucinous cystadenoma have a significant malignant potential. With pancreatoscopy, a rather new endoscopic technique, five cases of mucinous megacystic cystadenoma were diagnosed preoperatively by macroscopic and microscopic means. In one case, development of malignant neoplasm was diagnosed, one patient did not undergo surgery because of her age. Three patients were operated (total pancreatectomy in one case, duodeno-hemipancreatectomy in two cases) and are without any further signs of recurrence and free of symptoms in a one year to four year clinical follow-up.

Lovastatin increases arachidonic acid levels and stimulates thromboxane synthesis in human liver and monocytic cell lines

The effect of lovastatin (LOV), the inhibitor of 3-hydroxy-3-methyl-glutaryl coenzyme A reductase, on linoleic acid (LA, 18:2n-6) metabolism was examined in human monocytic Mono Mac 6 (MM6) and hepatoma Hep G2 cells. The desaturation of LA was examined after LOV (72 h, 10 microM) or dimethylsulfoxide (LOV carrier, < 0.1%) and [14C]LA (last 18 h, 0.3 microCi, 5 microM). In both cell lines, LOV reduced the percentage of 14C label associated with LA and increased the percentage of label in the 20:4n-6 and the 22:5n-6 fractions. In Hep G2 but not MM6 cells, this effect was fully reversible by means of coincubation with mevalonic acid (500 microM), but not with cholesterol or lipoproteins. In both cell lines, the LOV-mediated increase in LA desaturation resulted in dose-dependent reductions of LA and elevations of AA in cellular phospholipids. The lipids secreted by LOV-treated Hep G2 cells were also enriched in arachidonic acid (AA). In the MM6 cells, LOV increased release of thromboxane upon stimulation with the calcium ionophore A23187. In summary, our findings of higher LA desaturation and AA enrichment of lipids secreted by the Hep G2 cells suggest that LOV treatment may increase the delivery of AA from the liver to extrahepatic tissues. The changes in membrane fatty acid composition can influence a variety of cellular functions, such as eicosanoid synthesis in monocytic cells. The mechanism appears to be related to the reduced availability of intermediates of cholesterogenesis.

Crystal and molecular structures of beta-cellobiosylnitromethane and of beta-maltosylnitromethane heptaacetate

The structures of the title compounds have been determined by X-ray crystallography, using direct methods, and have been refined to conventional final residual factors of R = 0.063 and R = 0.046, respectively.

Correlations between the loss of acoustic TMJ symptoms and alterations in mandibular mobility after surgical mandibular advancement

A longitudinal clinical-axiographic study including 10 patients who had undergone surgical mandibular advancement to correct a dental and skeletal Class II anomaly, produced evidence of correlations between alterations of acoustic symptoms and of mandibular mobility. In 7 of 11 movements, where TMJ-sounds disappeared, post-operative mandibular mobility was reduced to such a degree that the point at which the acoustic symptom originated pre-operatively could no longer be attained. On the other hand, in all cases, where TMJ sounds remained uninfluenced by the surgical intervention, reductions in mobility occurred only beyond this point. Even the persistence of losses of TMJ sounds during the further post-operative follow-up period could, in the majority of cases (4 of 7) be well explained by the persistence of mobility restriction. Accordingly, in the future a differentiation between mobility- and non-mobility-dependent alterations of TMJ symptoms should be made.

[Temporomandibular joint function after orthognathic surgery--the individual factors]

Case studies presented in the literature present evidence that individual factors may influence mandibular mobility unfavorably after mandibular advancement osteotomies. These factors are, respectively: high preoperative dysfunction index, preoperative articular pain in movement, preoperative reciprocal clicking, advanced patient age, and significant overjet reduction. This study identifies these individual factors, which can influence postoperative functional condition, and documents conclusively the importance of individual, function oriented preoperative planning in orthognathic surgery. Taken together these factors indicate that the adaptation ability of the effected tissue should be given greater attention in planning the operation.

Effects of tolazoline and prostacyclin on pulmonary hypertension in infants after cardiac surgery

OBJECTIVE

To evaluate the hemodynamic effects of tolazoline and prostacyclin in infants with pulmonary vasospasm after cardiac surgery.

DESIGN

Prospective cohort study.

SETTING

Pediatric ICU.

PATIENTS

The cohort consisted of 42 infants and children with congenital heart disease and pulmonary hypertension who underwent corrective surgery and were monitored postoperatively using pulmonary artery catheters. Fourteen infants (2 to 12 months old) in this group required postoperative treatment with tolazoline or prostacyclin.

INTERVENTIONS

Tolazoline was administered as a bolus of 0.5 mg/kg for treatment of persistent pulmonary hypertension or acute pulmonary hypertensive crisis. If its effectiveness was proved after 30 mins by hemodynamic measurements, a continuous iv infusion of 0.5 mg/kg/hr was established. Higher doses of tolazoline were avoided. If tolazoline treatment did not fulfill the criteria for pulmonary vasodilation, prostacyclin was given by continuous iv infusion at a starting rate of 5 ng/kg/min, followed by 10 ng/kg/min. In three patients, the infusion rate was increased to 15 ng/kg/min.

RESULTS

Bolus administration of tolazoline resulted in a distinct pulmonary vasodilation in seven infants: mean pulmonary artery pressure and pulmonary vascular resistance decreased by an average of 35% and 45%, respectively. In these patients, tolazoline was infused over the following 12 to 72 hrs. One infant who received tolazoline for 72 hrs developed a clinically important gastrointestinal hemorrhage. In seven nonresponders to tolazoline, prostacyclin (PGI2) at an infusion rate of 5 ng/kg/min led to pulmonary vasodilation in five patients, at an iv infusion rate of 10 ng/kg/min in all seven infants studied. The latter dose of PGI2 reduced the mean pulmonary artery pressure by an average of 37%, and pulmonary vascular resistance by 43%. Transient withdrawal of prostacyclin in five infants demonstrated its short half-life and clinical effectiveness. Apart from a facial flush, no side-effects were encountered using PGI2 as an infusion over durations ranging from 12 to 504 hrs.

CONCLUSIONS

These data suggest that, if tolazoline in a relatively low dose proves to be inefficient, prostacyclin can still be used as a safe and effective drug for treatment of pulmonary vasospasm. Prostacyclin offers more than a pharmacologic alternative to increased tolazoline dosages.

Battered child syndrome: cerebral ultrasound and CT findings after vigorous shaking

Child abuse by whiplash-shaking can lead to severe cerebral damage, neurological defects and mental retardation. Cerebral damage has been found with and without external evidence of head injury. We report the sonographic findings in two children after traumatization due to repetitive vigorous whiplash shaking. Cerebral sonography revealed cerebral edema at admission or within 48 hours thereafter. Follow-up studies demonstrated development of marked brain atrophy in both cases. The sonographic findings were confirmed by cranial computerized tomography. Doppler sonography was used to monitor cerebral perfusion by measuring intracranial blood flow. The clinical history of the patients demonstrates that cerebral sonography in combination with Doppler sonography not only serves as a diagnostic tool but also allows adjustment of therapy to the actual clinical status of the patient.

Changes in mandibular mobility after different procedures of orthognathic surgery

A prospective study including 63 adult Class II and Class III patients was carried out in order to examine short- and long-term effects of four different treatment methods on mandibular mobility. The patients were treated either (Group A, control-group) orthodontically alone or (Group B) by a LeFort I-osteotomy, a (Group C) mandibular advancement or (Group D) a two-jaw surgery/mandibular set-back. In the surgery-groups (B, C, and D) maximum opening, protrusion and lateral excursions were measured 2 days pre-operatively (T0), and 3, 8, 14.5, and 25.5 months post-operatively (T1-T4). In the control-group (A) at T0 and T4 was measured, only. Significantly differing effects of the four treatment methods on mandibular mobility were detected. (A) Orthodontic treatment alone, (B) maxillary advancement by LeFort I osteotomy, and (D) two-jaw surgery/mandibular set-back osteotomy did not influence mandibular mobility permanently. Temporary decreases in groups B and D (P less than or equal to 0.05) were observed, however. In contrast, permanent reductions after (C) mandibular advancement took place (P less than or equal to 0.001). Longitudinal survey showed that in all surgery groups recoveries were limited to a short period of 3-14.5 months, depending on the movement. Surprisingly, a closer similarity between the LeFort-I group (B) and the two-jaw surgery group (D), rather than between the sagittal-split groups (C and D), was seen indicating that the problem of reduced mobility after orthognathic surgery can be limited to Class II therapy. It was concluded that in Class III therapy, the application of rigid fixation in combination with a method of maintaining condyle-position, thereby dispensing with maxillomandibular fixation, prevents permanent reductions in mobility and guarantees a rapid recovery to pre-operative mobility levels.