Decontamination of the digestive tract and oropharynx in ICU patients

BACKGROUND

Selective digestive tract decontamination (SDD) and selective oropharyngeal decontamination (SOD) are infection-prevention measures used in the treatment of some patients in intensive care, but reported effects on patient outcome are conflicting.

METHODS

We evaluated the effectiveness of SDD and SOD in a crossover study using cluster randomization in 13 intensive care units (ICUs), all in The Netherlands. Patients with an expected duration of intubation of more than 48 hours or an expected ICU stay of more than 72 hours were eligible. In each ICU, three regimens (SDD, SOD, and standard care) were applied in random order over the course of 6 months. Mortality at day 28 was the primary end point. SDD consisted of 4 days of intravenous cefotaxime and topical application of tobramycin, colistin, and amphotericin B in the oropharynx and stomach. SOD consisted of oropharyngeal application only of the same antibiotics. Monthly point-prevalence studies were performed to analyze antibiotic resistance.

RESULTS

A total of 5939 patients were enrolled in the study, with 1990 assigned to standard care, 1904 to SOD, and 2045 to SDD; crude mortality in the groups at day 28 was 27.5%, 26.6%, and 26.9%, respectively. In a random-effects logistic-regression model with age, sex, Acute Physiology and Chronic Health Evaluation (APACHE II) score, intubation status, and medical specialty used as covariates, odds ratios for death at day 28 in the SOD and SDD groups, as compared with the standard-care group, were 0.86 (95% confidence interval [CI], 0.74 to 0.99) and 0.83 (95% CI, 0.72 to 0.97), respectively.

CONCLUSIONS

In an ICU population in which the mortality rate associated with standard care was 27.5% at day 28, the rate was reduced by an estimated 3.5 percentage points with SDD and by 2.9 percentage points with SOD. (Controlled Clinical Trials number, ISRCTN35176830.)

Four DAZ genes in two clusters found in the AZFc region of the human Y chromosome

The DAZ genes are candidate fertility factors that lie within the human Y chromosome's AZFc region, whose deletion is a common cause of spermatogenic failure. The number of DAZ genes has been difficult to determine, in part because the nucleotide sequences of the DAZ genes are nearly identical. Here, fluorescence in situ hybridization and characterization of BAC clones revealed four full-length DAZ genes on the human Y chromosome. They exist in two clusters, each comprising an inverted pair of DAZ genes (3' <-- 5'::5' --> 3'). Analysis of genomic sequences and testicular transcripts suggested that three or four DAZ genes are translated. Each gene contains at least seven tandem copies of a previously described, 2.4-kb repeat unit that encodes 24 amino acids. In addition, two DAZ genes contain tandem copies of a 10.8-kb repeat unit that encodes the RNA-binding domain, which appears to be multimerized in some DAZ proteins. Combining our present results with previous studies, we can reconstruct several steps in the evolution of the DAZ genes on the Y chromosome. In the ancestral Y-chromosomal DAZ gene, amplification of both intragenic repeats began before the human and cynomolgus (Old World) monkey lineages diverged. During subsequent evolution, an inverted duplication of this modified gene occurred. Finally, the resulting two-gene cluster was duplicated, generating the two-cluster/four-gene arrangement found on modern human Y chromosomes.

Biventricular pacing in end-stage heart failure improves functional capacity and left ventricular function

BACKGROUND

Asynchronous patterns of contraction and relaxation may contribute to hemodynamic and functional impairment in heart failure. In 1993, we introduced biventricular pacing as a novel method to treat heart failure by synchronous stimulation of the right and left ventricles after an appropriate atrioventricular delay. The objectives of this study were to assess the early and long-term effects of this therapy on functional capacity and left ventricular function in patients with severe heart failure and left bundle branch block.

METHODS AND RESULTS

Twelve patients with end-stage congestive heart failure, sinus rhythm and complete left bundle branch block were treated with biventricular stimulation at optimized atrioventricular delay. The NYHA functional class and maximal bicycle exercise capacity were assessed. Systolic and diastolic left ventricular function were studied with echocardiography and radionuclide angiography. Data was collected at various intervals during 1-year follow-up. Cumulative survival [95% CI] was 66.7% [40.0,93.4] at 1 year and 50 % [21.8, 78.2] at 2 and 3 years. Median NYHA class improved from class IV to class II at 1 year (p=0.008). After 6 weeks an increase in exercise capacity occurred, which was sustained. A less restrictive left ventricular filling pattern, an increase in dP/dt and left ventricular ejection fraction, and a decrease in mitral regurgitation were observed early and long-term.

CONCLUSIONS

Biventricular pacing at optimized atrioventricular delay results in improvement in functional capacity, which is associated with improved systolic and diastolic left ventricular function, and a decrease in mitral regurgitation during short- and long-term follow-up.

Infusion of vecuronium controlled by a closed-loop system

Closed-loop control of neuromuscular blockade, using a semi-continuous infusion of vecuronium, is described. In 28 patients, the average neuromuscular transmission was between 13 and 17% of control. Requirements for vecuronium averaged 1.1 micrograms kg-1 min-1 (0.8-1.5 micrograms kg-1 min-1), being in the same range as for repeated bolus injections. No side effects were observed. After the infusion was stopped recovery was rapid. Only three patients required induced reversal of blockade.

Neuromonitoring in defibrillation threshold testing. A comparison between EEG, near-infrared spectroscopy and jugular bulb oximetry

OBJECTIVES

The aim was to study the physiological effects of induced ventricular fibrillation and subsequent circulatory arrest for defibrillation threshold testing on the brain using the EEG, jugular bulb oxymetry and near-infrared spectroscopy.

METHODS

Thirteen patients undergoing surgery for implantable cardioverter-defibrillator implantation or replacement under general anesthesia were included. We continuously monitored the jugular bulb oxygen saturation (SjO2), regional oxygen saturation (rSO2) and the EEG.

RESULTS

59 episodes of circulatory arrest were studied. In all cases the rSO2 fell instantly while the EEG changed within 12 +/- 4 seconds after induction. The EEG indicated ischemic changes, ranging from occurrence of rhythmic delta activity to cessation of all electrical activity. On successful defibrillation the rSO2 increased to values in excess of pre-arrest levels and restored towards baseline; the SjO2 initially fell followed by a similar overshoot. Recovery times increased in proportion to arrest duration.

CONCLUSION

Short lasting episodes of circulatory arrest have serious, but transient effects on brain function. The rSO2 is an effective non-invasive tool for monitoring cerebral oxygenation during DFT-testing.

Pharmacokinetic profiles of nevirapine and indinavir in various fractions of seminal plasma

Limited data are available on antiretroviral drug concentrations in seminal plasma during a dosing interval. Further, since human ejaculate is composed of fluids originating from the testes, the seminal vesicles, and the prostate, all having different physiological characteristics, drug concentrations in total seminal plasma do not necessarily reflect concentrations in the separate compartments. Five human immunodeficiency virus type 1-infected patients on nevirapine (NVP; 200 mg twice a day [b.i.d.]) and/or indinavir (IDV; 800 mg b.i.d. with ritonavir, 100 mg b.i.d.) regimens used a split ejaculate technique to separate seminal plasma in two fractions, representing fluids from the testes and prostate (first fraction) and fluids from the seminal vesicles (second fraction). Split-ejaculate samples were provided at 0, 2, 5, and 8 h after drug ingestion, on separate days after 3 days of sexual abstinence. NVP and IDV showed time-dependent concentrations in seminal plasma, with peak concentrations in both fractions at 2 and 2 to 5 h, respectively, after drug ingestion. The NVP concentrations were not significantly different between the first and second fractions of the ejaculate at all time points measured and were in the therapeutic range, except for the predose concentration in two patients. The median (range) predose IDV concentrations in the first and second fractions of the ejaculate were 448 (353 to 1,015) ng/ml and 527 (240 to 849) ng/ml, respectively (P = 0.7). In conclusion, NVP and IDV concentrations in seminal plasma are dependent on the time after drug ingestion. Furthermore, our data suggest that NVP and IDV achieve therapeutic concentrations in both the testes and prostate and the seminal vesicles throughout the dosing interval.

Changes in cerebral oxygen uptake and cerebral electrical activity during defibrillation threshold testing

During cardioverter-defibrillator implantation, repeated episodes of ventricular fibrillation (VF) are induced. Insufficient recovery of oxygen metabolism may cause neurological sequelae. In this prospective clinical study, we monitored the electroencephalogram (EEG), middle cerebral artery blood flow velocity (Vmca), and jugular bulb oxygen saturation and estimated cerebral oxygen uptake. Results were analyzed for tests requiring a single shock (Group 1) and tests requiring multiple shocks for defibrillation (Group 2). Immediately after the induction of VF, the mean arterial blood pressure (MAP) decreased to < 30 mm Hg, and the Vmca decreased to 0 cm/s. The EEG showed ischemic changes consisting of a decrease of fast, and an increase of slow, activity, progressively declining to isoelectricity within 11 +/- 2 s. After defibrillation, the MAP recovered rapidly regardless of the arrest duration (3 +/- 2 s). The EEG recovered within 17 +/- 9 and 22 +/- 12 s, respectively, for Groups 1 and 2 (P < 0.05) and did not reveal ischemic changes until induction of a subsequent arrest. In Group 1, the cerebral oxygen uptake increased to 191% +/- 31% of baseline values and returned to baseline in 16 +/- 7 s, whereas in Group 2, it increased to 229% +/- 38% (P < 0.05), followed by a significant decrease to less than baseline (85% +/- 18%; P < 0.005), and returned to baseline simultaneously with the Vmca. We conclude that, although restoration to normal of the EEG and cerebral oxygen uptake coincide in short arrests, EEG recovery underestimates metabolic recovery after tests requiring multiple shocks.

IMPLICATIONS

Short test intervals have been mentioned as a cause of neurological sequelae after cardioverter-defibrillator implantation. This study demonstrates that although all systemic hemodynamic variables and the electrocardiogram may have returned to normal, cerebral oxygen uptake may still be depressed for a considerable time, especially after tests requiring two or more shocks.

Absence of deleted in azoospermia (DAZ) genes in spermatozoa of infertile men with somatic DAZ deletions

OBJECTIVE

To determine the presence or absence of the deleted in azoospermia (DAZ) gene clusters in the Y-bearing spermatozoa in semen of severely oligozoospermic men or in testicular biopsy samples of azoospermic men with somatic DAZ deletions.

DESIGN

Prospective study.

SETTING

Academic hospital.

PATIENT(S)

Nineteen patients attending our clinics for therapeutic intracytoplasmic injection of sperm.

INTERVENTION(S)

Peripheral blood lymphocytes were used to obtain somatic DNA for analysis using the polymerase chain reaction. Analysis of chromosomes X and Y and the detection of the DAZ gene clusters were carried out with the fluorescence in situ hybridization technique in spermatozoa remaining after intracytoplasmic sperm injection.

MAIN OUTCOME MEASURE(S)

Presence or absence of the DAZ gene clusters in matched somatic DNA and Y-bearing spermatozoa.

RESULT(S)

Seven patients appeared to have a somatic DAZ deletion. Three-color fluorescence in situ hybridization showed that all Y-bearing spermatozoa examined from these men carried the same deletion.

CONCLUSION(S)

The DAZ deletions present in the seven men would all have been transmitted if they had fathered sons through artificial fertilization techniques using the sperm cells examined in this study.

Semen parameters of a semen donor before and after infection with human immunodeficiency virus type 1: Case report

Semen samples from a donor who seroconverted for human immunodeficiency virus type 1 (HIV-1) during the period that he was donating at our clinic were stored before and after infection. Semen analysis was done on all of these samples before cryopreservation. Retrospectively, both qualitative and quantitative HIV-1 testing was performed on the cryopreserved semen samples to determine the time of primary HIV-1 infection. After HIV-1 infection, semen volume, sperm motility and the percentage of spermatozoa with normal morphology were reduced compared with the same parameters before HIV-1 infection. HIV-1 RNA was intermittently detectable in semen. HIV-1 infection led to a reduction in semen volume, sperm motility and normal sperm morphology in this donor. However, the clinical significance of these findings is unclear. A longitudinal cohort study on the effects of HIV-1 infection on semen quality is necessary to confirm these findings.

Childhood oligodendrogliomas presenting with seizures and low-density lesions on computed tomography

Three children with cerebral oligodendrogliomas causing partial complex or generalized seizures presented with completely normal neurologic examinations. CT showed low-density, nonenhancing surface lesions. Although these CT features are usually associated with infarcts or cysts, neoplasm was suspected because of irregularity of the margins and erosion of the adjacent inner table of the skull. Oligodendrogliomas often enlarge slowly and may cause seizures years before they produce focal neurologic signs. CT of all children with seizures not responsive to anticonvulsant medication and focal clinical or EEG abnormalities will hasten diagnosis of slowly growing intracranial mass lesions.

What is the benefit of preoperative sperm preservation for patients who undergo restorative proctocolectomy for benign diseases?

PURPOSE

In patients with benign colorectal diseases undergoing a restorative proctocolectomy with an ileal pouch-anal anastomosis, semen cryopreservation seems rational to enable the possibility of procreation in case surgery leads to sexual disorders or impotence. The aim of this study was to determine the preoperative and postoperative semen quality in patients undergoing ileal pouch-anal anastomosis. In addition, the study sought to determine the incidence of surgery-induced sexual dysfunction to evaluate the economic efficiency of semen cryopreservation as compared with alternatives such as microsurgical epididymal sperm aspiration.

METHODS

Preoperative and postoperative semen analyses were offered to 97 patients with ileal pouch-anal anastomosis with benign colorectal diseases since 1989. The direct costs of the semen cryopreservation program were determined and compared with those of alternatives.

RESULTS

In 34 of 40 consecutive patients with ileal pouch-anal anastomosis who made use of preoperative semen preservation, normal sperm concentrations, motility, and morphology were found. Mean semen characteristics of all 23 patients who returned for postoperative analysis were not different from preoperative values, but they were for total sperm number. Two patients developed temporary retrograde ejaculation postoperatively. None of the preserved semen samples was used, thus semen cryopreservation benefited none of these patients. The total costs of semen cryopreservation are between 2.2 and 5 times higher than the costs for one microsurgical epididymal sperm aspiration procedure.

CONCLUSIONS

Preoperative semen cryopreservation in patients undergoing ileal pouch-anal anastomosis because of benign colorectal diseases is quite feasible. However, most likely because of improved surgical techniques and the increasing number of effective alternatives, preoperative semen cryopreservation in patients with ileal pouch-anal anastomosis is no longer cost effective.

Capnography does not reliably detect double-lumen endotracheal tube malplacement

Two patients are described in whom double-lumen endotracheal tube malplacement and its ventilatory consequences were not detected by infrared capnography. Problems were suspected on auscultation, and the malplacement was diagnosed by means of bronchospirometry. We conclude that bronchospirometry helps detect problems with endotracheal intubation.

Catheter deadspace: a source of error during tonometry

Tonometry of PCO2 is a promising method for assessing the oxygen supply to demand ratio of the gastrointestinal mucosa in critically ill patients. A balloon-tipped tonometer is introduced into the stomach or sigmoid colon, and saline is instilled into the balloon. After a time to allow partial equilibration with intraluminal PCO2, saline is aspirated and PCO2 is measured. Intermittent instillation and aspiration of saline allows serial PCO2 measurements, provided correction factors are used to calculate the PCO2 value expected at full equilibration from the PCO2 values measured after short dwell times. The technique is not yet widely applied, partly because of methodological controversies. We evaluated the role of the catheter deadspace as a source of error during PCO2 tonometry. The increase in PCO2 in sigmoid-type tonometers with a normal length (normal tonometer (NT)) and in those with a 50% increase in length and thus deadspace (extended tonometer (ET)), in a saline bath at a PCO2 of 4.8 kPa was assessed. Saline dwell times were 10, 20, 30, 45, 60 and 90 min and the time-dependent PCO2 increase was determined at deadspace PCO2 values of approximately 4.0 and 8.0 kPa following contamination of the catheter deadspace after immersion in saline baths at PCO2 values of 4.8 and 9.6 kPa, respectively, before each measurement cycle. In another experiment, the tonometer was rinsed between measurement cycles to remove deadspace saline containing carbon dioxide and to obviate contamination of instilled saline. PCO2 was measured in a blood-gas analyser, taking into account measurement bias in saline. Failure to remove deadspace saline between measurement cycles resulted in an overestimation of 10% and 6% for the NT and 16% and 10% for the ET, at saline dwell times of 10 and 20 min, respectively, at a deadspace PCO2 of approximately 4.0 kPa. At a deadspace PCO2 of approximately 8.0 kPa, PCO2 was overestimated by 17%, 11% and 5% for the NT and 31%, 20% and 11% for the ET, at dwell times of 10, 20 and 30 min, respectively. Rinsing the NT/ET resulted in accurate assessment of PCO2 at all dwell times, but the dwell time-dependent increase in PCO2 was slightly slower in the ET, particularly at 10 min, after a sink effect of the increased deadspace. Hence, a previously unrecognized deadspace effect caused error during PCO2 tonometry, particularly with short dwell times. This potentially large error can be avoided by rinsing the tonometer before each measurement cycle, allowing accurate PCO2 tonometry even at 10-min saline dwell times, provided that correction factors are used that are specific for catheter size. These findings may help to widen the clinical applicability of tonometry.

Severe amniotic band syndrome occurring with unrelated syndactyly

A patient with severe amniotic band syndrome and true proximal syndactyly of the hand and foot is presented. The occurrence of these two seemingly unrelated anomalies may be pathologically linked with amniotic band syndrome in some as yet unexplained way or less likely may occur with amniotic band syndrome coincidentally.

Neurophysiological effects of pediatric balloon dilatation procedures

Balloon dilatation of valvar and vascular stenoses has become routine therapy in pediatric cardiology. Repeated balloon inflations cause many episodes of low cerebral oxygen delivery. This study is a prospective study to assess the effects of balloon dilatation on cerebral perfusion and oxygenation. The study included 11 patients scheduled for elective catheterization and balloon dilatation at a university pediatric hospital. Blood flow velocity in the middle cerebral artery (Vmca) and regional cerebral oxygen saturation (rSO2) were monitored by means of transcranial Doppler sonography and near infrared spectroscopy, respectively. In group 1, consisting of 6 patients without an intracardiac shunt, inflation of the balloon resulted in a decrease in Vmca followed by a minor decrease in rSO2. In group 2, consisting of 5 patients with an interatrial communication, inflation resulted in an increase in right-to-left shunt fraction, arterial desaturation. and a major decrease in rSO2 with minor changes in Vmca. Balloon dilatation causes an important decrease in cerebral oxygen delivery by different mechanisms. This may lead to serious morbidity and even mortality. Neuromonitoring is a useful tool in assessing the cerebral effects of balloon dilatation and brain recovery.

A randomized trial between GIFT and ovarian stimulation for the treatment of unexplained infertility and failed artificial insemination by donor

This study was designed to investigate the surplus effect of gamete intra-Fallopian transfer (GIFT) over ovarian stimulation alone, in patients with unexplained infertility. A total of 50 patients with unexplained infertility of at least 3 years duration, or unexplained failure of artificial insemination by donor (AID) for at least 12 cycles, meeting strict inclusion criteria, were randomly selected for either two GIFT cycles or two ovarian stimulation cycles. Ovarian stimulation was combined with timed intercourse, or timed cervical donor insemination. In 38 completed GIFT cycles, five clinical pregnancies (13.2% per cycle) occurred and in 44 ovarian stimulation cycles four clinical pregnancies occurred (9.1% per cycle). Five remaining GIFT cycles were converted into in-vitro fertilization leading to two pregnancies. Of the 50 patients suffering from unexplained infertility, the 23 who did not have AID gave rise to four pregnancies out of 39 cycles (10.3%); from the remaining 27 patients who underwent AID, seven pregnancies were achieved out of 48 cycles (14.6%). No statistical differences between GIFT and ovarian stimulation treatment were found. Therefore, the GIFT success rates can be explained at least in part, if not fully, by the effect of ovarian stimulation alone. Consequently, ovarian stimulation should be considered in unexplained infertility before more elaborate forms of assisted reproduction are used.

Properties of amphiphilic oligonucleotide films at the air/water interface and after film transfer

The self-assembly of amphiphilic hybrid materials containing an oligonucleotide sequence at the air/water interface was investigated by means of pressure-molecular area (Π-A) isotherms. In addition, films were transferred onto solid substrates and imaged using scanning force microscopy. We used oligonucleotide molecules with lipid tails, which consisted of a single stranded oligonucleotide 11 mer containing two hydrophobically modified 5-(dodec-1-ynyl)uracil nucleobases (dU11) at the 5'-end of the oligonucleotide sequence. The air/water interface was used as confinement for the self-assembling process of dU11. Scanning force microscopy of films transferred via Langmuir-Blodgett technique revealed mono-, bi- (Π ≥ 2 mN/m) and multilayer formation (Π ≥ 30 mN/m). The first layer was 1.6 ± 0.1 nm thick. It was oriented with the hydrophilic oligonucleotide moiety facing the hydrophilic substrate while the hydrophobic alkyl chains faced air. In the second layer the oligonucleotide moiety was found to face the air. The second layer was found to cover up to 95% of the sample area. Our measurements indicated that the rearrangement of the molecules into bi- and multiple bilayers happened already at the air/water interface. Similar results were obtained with a second type of oligonucleotide amphiphile, an oligonucleotide block copolymer, which was composed of an oligonucleotide 11 mer covalently attached at the terminus to polypropyleneoxide (PPO).

Impact of crop-manure ratios on energy production and fertilizing characteristics of liquid and solid digestate during codigestion

The influence of maize silage-manure ratios on energy output and digestate characteristics was studied using batch experiments. The methane production, nutrients availability (N and P) and heavy metals' content were followed in multiflask experiments at digestion times 7, 14, 20, 30 and 60 days. In addition, the available nutrient content in the liquid and solid parts of the digestate was evaluated. Aanaerobic digestion favoured the availability of nutrients to plants, after 61 days 20-26% increase in NH4+ and 0-36% increase in PO4(3-) were found in relation to initial concentrations. Digestion time and maize addition increased the availability of PO4(3-). Inorganic nutrients were found to be mainly available in the liquid part of the digestate, i.e. 80-92% NH4+ and 65-74% PO4(3-). Manure had a positive effect on the methane production rate, whereas maize silage increased the total methane production per unit volatile solids in all treatments.

Experience with MTR fuel at the HOR reactor

In the last three years 3 events were observed in which the release rate of fission products from the fuel plates into the pool water increased significantly. Although intervention levels laid down in the permit and safety analysis were never reached, the ALARA principle was the incentive to analyse the situation and take appropriate actions.

Immunocytochemical localization of acrosin and hyaluronidase in epididymal and ejaculated porcine spermatozoa

Acrosin and hyaluronidase demonstrated different release patterns following treatment of living spermatozoa with the Ca2+-ionophore A 23187. One hour after the acrosomal reaction about 50% of the acrosin was still associated with the spermatozoal membranes, while hyaluronidase could no longer be detected in the spermatozoal remnants. Strong fixation conditions with acrolein and glutaraldehyde were used to prevent redistribution and leakage of these sperm proteins. Lost antigenicity was restored with sodium-borohydride and pronase E treatment. Immunofluorescent localization showed hyaluronidase to be confined to the anterior portion of the acrosome. Acrosin was localized throughout the entire acrosome including the equatorial segment. By immunoelectron microscopy, hyaluronidase was exclusively found in the acrosomal matrix. The equatorial segment was devoid of hyaluronidase. Acrosin was found in the acrosomal matrix as well as on the outer acrosomal membrane. Furthermore, labeling for acrosin in the equatorial segment was clearly demonstrated. Localization of hyaluronidase was the same for epididymal and ejaculated sperm cells but in approximately 70% of the epididymal spermatozoa acrosin could not be detected in the equatorial segment. In most of these epididymal cells acrosin was confined to the anterior part of the acrosome comparable with hyaluronidase. These observations support the motion that the appearance of acrosin in the equatorial segment is part of the maturation process during passage through the epididymis.