Effects of one-lung ventilation on pulmonary hemodynamics and gas exchange in the newborn

For major thoracoscopic surgery, one-lung ventilation is mandatory. This is reasonably well tolerated in adults and children. The effects of one-lung ventilation on hemodynamics and gas exchange in newborns, however, are not known yet. Eight neonatal domestic pigs with a median age of 6 days (range: 3-9 days), and a mean body weight of 2.3 kg (1.7-2.8 kg) were intubated and ventilated in pressure-controlled mode (FIO2 = 1). Anesthesia was maintained with i.v. fentanyl/metomidate. After tracheotomy an endotracheal tube was positioned in the trachea, and a second tube in the left mainstem bronchus. One-lung ventilation was maintained for 120 min. Serial measurements were done before, during, and until 90 min. after one-lung ventilation. During one-lung ventilation, pulmonary artery pressure and intrapulmonary shunt increased from 15 +/- 1 to 18 +/- 1 mmHg (p = 0.004), and from 2.6 +/- 0.3 to 3.7 +/- 0.4% (p = 0.02), respectively. Arterial oxygen saturation remained unchanged at 100%. A slight increase in arterial PCO2 could easily be treated by increasing the respiratory rate. In conclusion, one-lung ventilation was not associated with major side effects in regard to hemodynamics and gas exchange in the neonatal pig.

Pharmacokinetics of the angiotensin-converting-enzyme inhibitor, benazepril, and its active metabolite, benazeprilat, in dog

1. The pharmacokinetics of the angiotensin-converting-enzyme (ACE) inhibitor benazepril were evaluated in eight healthy Beagle dogs. Benazepril was administered orally at a dosage of 7.5 mg (about 0.5 mg/kg) both as a single dose and then once daily for 14 consecutive days. The prodrug, benazepril, and its active metabolite, benazeprilat, were measured in plasma using a gas chromatography mass-spectrometry method with mass-selective detection. 2. Benazepril appeared quickly in the plasma (tmax 0.5 h) and was rapidly eliminated by metabolism to benazeprilat. Peak benazeprilat concentrations were attained later (tmax 1.25 h) and declined biphasically with a rapid elimination phase (t1/2 lambda 1 1.1 and 1.7 h after single and the last repeated dose respectively) followed by a terminal elimination phase (t1/2 lambda z 11.7 and 19.0 h after single and repeated dose respectively). The mean residence time for benazeprilat was 15.2 h after the single dose and 17.4 h after the 14th dose. 3. Repeated administration of benazepril produced moderate bioaccumulation of benazeprilat; the ratio of AUC[0-->24 h]'s after the 14th dose as compared with the single dose was 1.47, equivalent to a half-life for accumulation (t1/2acc) of 14.6 h. Steady-state benazeprilat concentrations at peak (Cmax) and trough (Cmin) were reached within three doses. 4. The pharmacodynamics of benazepril were assessed by measurement of plasma ACE activity. After both single doses and at steady-state, benazepril produced inhibition of ACE activity in all dogs that was maximal at peak effect (Emax = 100%) and long-lasting (> 85% inhibition was present at 24 h). The long duration of action of benazepril on plasma ACE is due to the presence of the terminal elimination phase of benazeprilat, even though most of the metabolite is rapidly eliminated from the plasma.

Xanthomonas maltophilia endophthalmitis after cataract extraction

PURPOSE

To report a case of Xanthomonas maltophilia endophthalmitis and to increase awareness of its potential as an intraocular pathogen.

METHOD

Case report.

RESULTS

A 76-year-old woman developed X maltophilia endophthalmitis after cataract extraction. To eradicate the infection, we performed two vitrectomies and treated the patient with numerous intravitreal antibiotic injections.

CONCLUSIONS

X maltophilia is a potential intraocular pathogen in an immunocompetent host. If the infection takes a persistent course, persistent topical and intravitreal antibiotic treatment and possibly vitrectomy are needed to eradicate the infection.

Effects of recombinant human thrombopoietin alone and in combination with erythropoietin and early-acting cytokines on human mobilized purified CD34+ progenitor cells cultured in serum-depleted medium

The effects of recombinant thrombopoietin (TPO) alone and in combination with erythropoietin (EPO) and early-acting cytokines such as interleukin 3 (IL-3), stem cell factor (SCF) and GM-CSF on highly purified mobilized human CD34+ progenitor cells were studied in a serum-depleted culture system. Eight leukapheresis samples were cultured for seven days and analyzed; aliquots were replated and re-evaluated on day 12. Three-color flow cytometry was used together with morphologic analysis to determine proliferation and megakaryocytic or erythroid maturation. TPO alone was sufficient for cell survival and proliferation in serum-depleted medium. In the absence of other growth factors, almost all CD34+ cells differentiated along the megakaryocytic pathway within 12 days. Concomitantly, the progenitor cells gradually acquired the morphologic features of mature megakaryocytes. After exposure to TPO for one week, 50% of the cells still expressed CD34; by day 12 the remaining CD34+ cells (11%) were all coexpressing CD41. TPO alone did not support proliferation of glycophorin-A-positive cells. The addition of TPO to early-acting cytokines (EPO, GM-CSF, SCF and/or IL-3) not only increased the overall megakaryocyte expansion, but also generated a different maturation pattern of the CD41+ megakaryocyte progenitors. It further doubled the number of erythroid cells and c-kit+ cells in the second week of culture. Interestingly, the overall number of CD34+ cells was increased about fivefold when TPO was added to the early-acting cytokines, with a marked expansion of the CD34+/CD41+ and CD34+/CD117+ subpopulations. TPO can augment the pool of committed progenitors, thereby increasing the number of its own target cells and the number of EPO-responsive cells. These properties make TPO an interesting cytokine for the ex vivo expansion of human progenitor cells.

Pharmacokinetics of the active metabolite of benazepril, benazeprilat, and inhibition of plasma angiotensin-converting enzyme activity after single and repeated administrations to dogs

Plasma pharmacokinetic variables of benazeprilat, the active metabolite of the angiotensin-converting enzyme (ACE) inhibitor benazepril, were evaluated in healthy Beagles. Benazeprilat was administered IV at a dosage of 0.5 mg/kg of body weight (n = 9). The elimination of half-life of benazeprilat was 3.5 hours, although an additional terminal phase was observed in some dogs. Vehicle (gelatin capsules) or benazepril at dosages of 0.125, 0.25, 0.5, or 1.0 mg/kg was administered orally as a single administration, then once daily for 15 consecutive days (n = 5 or 6/group). Peak benazeprilat concentrations were rapidly attained by 2 hours. Benazeprilat concentrations accumulated moderately with repeated administration, with a peak concentration that was 23% higher and an area under the concentration-time curve that was 34% higher after the 15th dose of benazepril, compared with values after a single dose. The effective half-life for accumulation for all 4 dosages was 12 hours. Steady-state concentrations at 2 hours after administration were achieved after a median (range) of 1 (1 to 6) dose(s). Pharmacodynamic variables were assessed by measurements of plasma ACE activity after oral administration of benazepril or vehicle. All dosages of benazepril caused profound inhibition of ACE, with rapid onset of activity (time to peak effect, 2 hours) and long duration of action (single administration of all 4 doses induced inhibition of ACE that was significantly different from the value in the control [vehicle-treated] dogs for all time points between 1 and 30 hours). Maximal inhibition at all time points was induced by the 0.25-mg/kg dosage at a single administration and with the lowest dosage tested (0.125 mg/kg) at steady state. At steady state, the 0.25-mg/kg dosage caused (mean +/- SEM) 96.9 +/- 2.0% inhibition of ACE activity at maximal effect and 83.6 +/- 4.2% at trough effect (24 hours after dosing), indicating minimal variation in peak/trough effect. Steady-state inhibition of ACE activity at both peak and trough drug effect was achieved after 1 to 4 doses. The data indicate that benazepril is a potent and long-acting ACE inhibitor in dogs.

Psychosocial aspects in the treatment of children with myelomeningocele: an assessment after a decade

The aim of this study was to recognize the possible psychological advantages when children with a severe CNS disorder like myelomeningocele (MMC) are given very early rehabilitation treatment. One hundred and seven newborns with MMC seen between 1971-1992 were prospectively analysed with respect to two different therapeutic approaches. The children born during the period 1971-1980 did not receive very early therapeutic rehabilitation treatment, whereas those born during the period 1981-1992, received this treatment. In the latter group, special attention was paid to support an improvement in the difficult relationship between the parents and the child with MMC as well as between parents and caregivers. The following statistically significant differences between the two treatment programmes were found: (1) all children achieved independent locomotion at 5 years, in the very early intervention group, compared to only 35% (P < 0.001) in the group without this programme. Orthopaedic operations in the first-mentioned group were markedly reduced; (2) urological surgery decreased drastically in the group with very early urodynamic rehabilitation. Thus, there were 0.6 operations per patient in the older group, but only 0.06 operations per patient in the younger one (P < 0.001); (3) normal schooling was reached by 76% (22/29) and social continence by 80% (23/29) of the children with very early interventional therapy. In the older group only 54% reached normal schooling (P < 0.05) and 29% social continence (P < 0.001). The very early co-ordinated medical and physiotherapeutic rehabilitation treatment of children with MMC usually reduces the psychosocial stress and improves the quality of life of these children and of their families.

Dose-ranging study of recombinant human granulocyte-macrophage colony-stimulating factor in small-cell lung carcinoma

PURPOSE

This randomized, multicenter, dose-finding study was undertaken to determine the dose of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) that can safely reduce neutropenia after cyclophosphamide, doxorubicin, and etoposide (CAVP-16) chemotherapy in patients with small-cell lung cancer (SCLC). Secondary clinical end points included incidence of infection, intravenous (IV) antimicrobial use, and chemotherapy delivered.

PATIENTS AND METHODS

A total of 290 newly diagnosed SCLC patients were to receive six cycles of standard CAVP-16 chemotherapy on days 1 to 3 of every 21 days alone or with rhGM-CSF at 5, 10, or 20 micrograms/kg, administered subcutaneously (SC) on days 4 to 13 of each cycle.

RESULTS

In cycle 1, median absolute neutrophil count (ANC) nadirs were twofold to threefold higher in patients who received rhGM-CSF, although all values were less than 500/microliters, and recovery from neutropenia was faster at all rhGM-CSF dosages versus observation (P < or = .01). In cycle 2, 56% of all patients given rhGM-CSF received full chemotherapy dosages (87.5% to 112.5% of projected dose) versus 36% of observation patients. During days 5 to 21 of cycle 1, fewer patients who received 10 micrograms/kg of rhGM-CSF required antibiotics compared with observation patients (11% v 29%, P < or = .01). Adverse events that occurred more frequently in rhGM-CSF-treated patients included injection-site reaction, edema, asthenia, paresthesia, diarrhea, myalgia, musculoskeletal pain, Pruritus, and rash (P < or = .10). Fever occurred more frequently in the 10- and 20-micrograms/kg rhGM-CSF groups than in the observation groups. The incidence in the 5-microgram/kg group was comparable to that in observation patients. Patients who received rhGM-CSF had a higher incidence of thrombocytopenia.

CONCLUSION

rhGM-CSF at 5 to 10 micrograms/kg reduces chemotherapy-associated neutropenia and should be the dose range used in future studies.

Reproducibility of patch tests. A multicenter study of synchronous left-versus right-sided patch tests by the German Contact Dermatitis Research Group

BACKGROUND

The efficiency and reproducibility of patch tests remain controversial.

OBJECTIVE

Our purpose was to determine the efficiency and reproducibility of patch tests and to identify factors influencing these features.

METHODS

We double-tested 1285 patients concomitantly with 10 standard allergens by manually filled test chambers. Additional information was obtained from all patients with a standardized protocol.

RESULTS

Patch test efficiency was good (> or = 0.94) with all 10 allergens. In contrast, nonreproducibility of patch tests was strongly allergen dependent, ranging from 0.2 for nickel sulfate to 0.6 for formaldehyde. The likelihood of nonreproducible allergic reactions increased when more than four positive reactions were seen at the same time, and with another positive reaction located in close proximity to an allergic reaction. Sex and age of patients, atopy, dermatitis at distant sites, sleeping habits, and the time of allergen exposure (24 or 48 hours) did not affect the rate of nonreproducible results.

CONCLUSION

To increase patch test reproducibility, specific preparations of patch test allergens need to be improved. Furthermore, amplification effects by synchronous neighboring positive reactions should be excluded.

Casino gaining offense inmates: What are these men like?

The characteristics of 28 men convicted for casino gaming offenses in Nevada were determined. Twenty-seven of these inmates cheated using slot or video poker machines. Most of the subjects used slugs. The other cheated at cards. Compared to other inmates, a disproportionate number of inmates were white. There were no black inmates incarcerated for this crime. Eighteen (57%) of the gaming offenders were over the age of 40 when convicted, in significant comparison to 27% of the general population inmates. They had significantly more aliases than the general population inmates. None of the gaming offenders had a history of violent felony convictions. They had, however, a history of great social, marital, occupational, and financial instability in addition to a criminal life style.

Prostatic utricle: an unusual case report

A 3-year-old white patient was hospitalized for the second recurrence of an epididymitis but this time with a left scrotal abscess. He was known to have a perineoscrotal hypospadias associated with bilateral undescended testis. Cystoscopy with cytourethrography releaved the presence of a "prostatic utricle". At operation after treatment of the infection the utricle was exised. Surprisingly a vagina masculinus (vagina, uterus and fallopian tubes without ovaries) more than a conventional utricle was found.

Immobilization, a risk factor for urinary tract stones in children. A case report

Immobilization causes bone dissolution leading to hypercalcemia and hypercalciuria in children. We report the case of a 10-year-old boy who developed 2 stones in the pelvis off his left healthy kidney after only 8 days of immobilization. He was on bedrest after pyeloplasty done for a ureteropelvic junction obstruction on the right side. Compared to references in literature our patient showed stone formation very early during the course of immobilization. Temporary hypercalciuria and stone formation are well documented because of underlying kidney disease. The risk factors of immobilization-induced hypercalciuria and hypercalcemia are discussed together with possible treatment and prophylaxis of this pathology.

Urolithiasis in childhood: when to do what?

Between 1983 and 1992 22 children with urolithiasis were treated at the Department of Paediatric Surgery and Paediatrics of the University Hospital of Berne. There were 8 girls and 14 boys with a mean age of 7.3 years. Metabolic disease was found in 6 children. There were 12 renal stones, 12 ureteral stones, 1 bladder stone and 1 urethral stone. Conservative therapy, ESWL, and surgery were used as treatment each in one third of the children. Studying our patient-group and analyzing the recent literature, the place of the different therapeutic methods of the childhood stones will be discussed.

Reinfusion potassium blood cardioplegia versus cold blood reinfusion alone in elective revascularization

The purpose of this study was to determine if the addition of potassium to reinfusion cold blood cardioplegia (CBC) offers an advantage over cold blood alone. Forty patients matched for age, left ventricular function, extent of coronary disease and number of vessels bypassed were prospectively randomized. Each patient received an initial dose of CBC (10 cc/kg) with potassium. Group I patients (n = 23) received subsequent infusions of CBC (5 cc/kg) containing potassium while Group II patients (n = 17) received cold blood only. The cross-clamp time, mean infusate volume and temperature were not significantly different in the two groups. Following reperfusion, the cardiac index and the CPK isoenzyme release at 0.5, 1, 8, and 12 h after cross-clamp release were not significantly different between the groups. The postoperative appearance of new Q-waves, inotropic agent requirement, and reversal of the lactate dehydrogenase (LDH) isoenzyme ratio were also not significantly different in the two groups. The study demonstrated that following initial arrest with potassium, cold blood is equally as effective as potassium blood cardioplegia in protecting the ischemic myocardium.

[The value of conservative therapy in kidney trauma in childhood]

Between 1975 and 1991 74 children with a renal injury after blunt abdominal trauma were treated at the Department of Pediatric Surgery of the University Hospital of Berne. There were 22 girls and 52 boys with a mean age of 9.4 years. 55 patients were treated conservatively and 19 operatively. The mean follow-up was for the operated patients 2.6 years and for the not operated 2.5 years. The conservatively treated patients had a shorter hospitalization time, were fewer days on the ICU, needed less blood transfusions and had a minor complication rate compared with the operated ones.

Congenital intracranial cysts: clinical findings, diagnosis, treatment and follow-up. A multicenter, retrospective long-term evaluation of 72 children

A multicenter, retrospective evaluation of 72 children born between 1973 and 1987 with intracranial cysts was performed: 37 had an arachnoid cyst, 25 a Dandy-Walker malformation and 10 a porencephalic cyst. The following criteria were evaluated: history, clinical findings, diagnostic work-up (neuroradiology, CSF and intracystic pressures), surgical therapy and follow-up (outcome and cyst volumes).

Correlates of pathological gambling propensity in prison inmates

The South Oaks Gambling Inventory was administered to 136 consecutively admitted inmates in a medium-security prison in Nevada. According to the criteria of the authors of this instrument, 22.79% of these inmates had some problem and 26% were probable pathological gamblers. Significant positive correlations with the F, depression, psychopathic deviate, psychasthenia, paranoia, schizophrenia, and Mac Andrew alcoholism scales of the Minnesota Multiphasic Personality Inventory (MMPI) were found. Gambling score was negatively correlated with the Raven's Standard Progressive Matrices measure of intelligence. Clinical implications are suggested.

Hybrid hybridomas producing bispecific antibodies to CEA and peroxidase isolated by a combination of HAT medium selection and fluorescence activated cell sorting

A combination of fluorescence-activated cell sorting and HAT medium selection has been used to establish bispecific antibody (biAbs)-producing hybrid hybridomas. For this purpose hypoxanthine-guanine phosphoribosyl transferase (HGPRT)-deficient mutants were isolated from a hybridoma line (D11-DG2) producing anti-CEA antibodies by 8-azaguanine treatment. The resulting HAT-sensitive hybrid cells were stained with the fluorescence marker tetramethyl rhodamine isothiocyanate (TRITC) and fused by polyethylene glycol (PEG) with HAT-non-sensitive unstained hybrid cells producing antibodies to horseradish peroxidase (POD). Fluorescent fused hybrid hybridomas as well as non-fused stained anti-CEA cells were separated from the unstained anti-POD cells using a fluorescent activated cell sorter (FACS). Finally, non-fused enzyme-deficient anti-CEA cells were eliminated by cultivation in HAT selection medium which permits only an outgrowth of HAT-resistant hybrid hybridoma cells containing the genes for producing both antibodies.

Pharmacokinetics and pharmacodynamics of benazepril hydrochloride in patients with major proteinuria

We have investigated whether the pharmacokinetics and pharmacodynamics of the ACE inhibitor benazepril hydrochloride are altered with proteinuria by studying 8 patients with major proteinuria of different causes who were given a single dose of 10 mg p.o. The maximum plasma concentration of benazepril was found between 0.5 and 2 h after dosing (median 1 h). Its elimination was almost complete within 6 h. Peak plasma levels of benazeprilat, the active metabolite of benazepril, were observed between 1 and 6 h (median 2.5 h). The elimination of benazeprilat from plasma was biphasic, with mean initial and terminal half-lives of 3.0 and 17.3 h, respectively. On average, the pharmacokinetic parameters of benazepril and benazeprilat in the patients did not differ from those in a historical control group of healthy volunteers, but intersubject variability in the AUC and half-lives of benazeprilat was greater in the patients. Plasma ACE was completely inhibited from 1.5 to 6 h after dosing, and at 48 h the mean inhibition was still 42%. Plasma renin showed substantial intersubject variation. Mean supine blood pressure (systolic/diastolic) was reduced from baseline by a maximum of 18/13 mm Hg at 6 h. Proteinuria was diminished after benazepril in 7 patients. In conclusion, the results of this study suggest that proteinuria in the nephrotic range does not require a change in benazepril dosage.