Class restriction of cephalosporin use to control total cephalosporin resistance in nosocomial Klebsiella

CONTEXT

Resistance to most or all cephalosporin antibiotics in Klebsiella species has developed in many European and North American hospitals during the past 2 decades.

OBJECTIVE

To determine if restriction of use of the cephalosporin class of antibiotics would reduce the incidence of patient infection or colonization by cephalosporin-resistant Klebsiella.

DESIGN

A before-after comparative 2-year trial.

SETTING

A 500-bed, university-affiliated community hospital in Queens, NY.

PATIENTS

All adult medical and surgical hospital inpatients.

INTERVENTION

A new antibiotic guideline excluded the use of cephalosporins except for pediatric infection, single-dose surgical prophylaxis, acute bacterial meningitis, spontaneous bacterial peritonitis, and outpatient gonococcal infection. All other cephalosporin use required prior approval by the infectious disease section.

MAIN OUTCOME MEASURE

Incidence of patient infection or colonization by ceftazidime-resistant Klebsiella during 1995 (control period) compared with 1996 (intervention period).

RESULTS

An 80.1% reduction in hospital-wide cephalosporin use occurred in 1996 compared with 1995. This was accompanied by a 44.0% reduction in the incidence of ceftazidime-resistant Klebsiella infection and colonization throughout the medical center (P<.01), a 70.9% reduction within all intensive care units (P<.001), and an 87.5% reduction within the surgical intensive care unit (P<.001). A concomitant 68.7% increase in the incidence of imipenem-resistant Pseudomonas aeruginosa occurred throughout the medical center (P<.01). All such isolates except one were susceptible to other antibiotics.

CONCLUSION

Extensive cephalosporin class restriction significantly reduced nosocomial, plasmid-mediated, cephalosporin-resistant Klebsiella infection and colonization. This occurred at the price of increased imipenem resistance in P aeruginosa, which remained susceptible to other agents. Thus, an overall reduction in multiply-resistant pathogens was achieved within 1 year.

Current global status of carotid artery stent placement

Our purpose was to review the current status of carotid artery stent placement throughout the world. Surveys were sent to major interventional centers in Europe, North and South America, and Asia. Information from peer-reviewed journals was also included and supplemented the survey. The survey asked various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. Of the centers which were sent surveys, 24 responded. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 2,048 cases, with a technical success of 98.6%. Complications that occurred during carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 63 minor strokes, with a rate of occurrence of 3.08%. The total number of major strokes was 27, for a rate of 1.32%. There were 28 deaths within a 30-day postprocedure period, resulting in a mortality rate of 1.37%. Restenosis rates of carotid stenting have been 4.80% at 6 mo. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative to vascular surgery, especially for patients that are at high risk for standard carotid endarterectomy. The periprocedural risks for major and minor strokes and death are generally acceptable at this early stage of development.

Mycobacterium tuberculosis specimen contamination revisited: the role of laboratory environmental control in a pseudo-outbreak

OBJECTIVE

To investigate suspected pseudo-outbreaks of Mycobacterium tuberculosis (MTB) during August 1994 and July 1995 among patients who did not have clinical findings consistent with tuberculosis.

DESIGN

Retrospective and prospective surveys of all clinical and laboratory data using standard epidemiological tools and DNA fingerprinting.

SETTING

A university-affiliated community hospital.

PATIENTS

Those with positive MTB cultures during periods when we noted that the number of MTB positive cultures greatly outnumbered the usual monthly average (retrospective analysis, 1994) and patients with positive MTB cultures without clinical findings consistent with tuberculosis (prospective survey, 1995).

RESULTS

Epidemiological and molecular studies revealed specimen cross-contamination in the laboratory due to a faulty exhaust hood. Improvement in laboratory ventilation and change of the implicated hood prevented further specimen contamination.

CONCLUSIONS

The identification of positive MTB cultures from patients without clinical evidence of tuberculosis should be a signal to suspect laboratory contamination and implement control measures. These should include a thorough epidemiological investigation, DNA fingerprint analysis, and an environmental inspection.

Hepatitis G virus encodes protease activities which can effect processing of the virus putative nonstructural proteins

The genome of a recently identified virus, hepatitis G virus (HGV), shows considerable homology to hepatitis C virus (HCV). Two HGV proteases similar to nonstructural proteins NS2 and NS3 of HCV were identified, and their cleavage site specificity was investigated. Amino acids essential for the protease activities were determined by mutation analysis. NS4A of HGV was demonstrated to be a cofactor for NS3-mediated proteolysis, with a region critical for activity residing between Leu1561, and Ala1598.

The effect of PTH antagonist BIM-44002 on serum calcium and PTH levels in hypercalcemic hyperparathyroid patients

BIM-44002, a pure competitive antagonist of parathyroid hormone (PTH), has a high affinity for the PTH/PTHrP receptor in vitro, and can completely inhibit the actions of a PTH agonist in rats in vivo. Toxicology studies in rats and dogs showed BIM-44002 to be devoid of any adverse effects. Therefore we undertook an investigation to evaluate the potential utility of BIM-44002 in lowering elevated serum calcium in three patients with primary hyperparathyroidism. BIM-44002 was administered by continuous intravenous infusion at dosages of 100 microg/hour (370 nmol/hour) for 12 hours, followed by 200 microg/hour for 12 hours, followed by 400 microg/hour for 12 hours. Vital signs and serum ionized and total calcium were monitored hourly and for 3 hours after cessation of the infusion. Blood for PTH determinations was obtained at the same time points. Serum calcium and PTH did not change during and after the infusion of the antagonist. No subject experienced any adverse reactions to the infusion of the antagonist. We conclude that although the PTH antagonist BIM-44002 was effective both in vitro and in vivo in animals, and it was safe in humans, it was not able to lower serum calcium in patients with hyperparathyroidism. Possible reasons for lack of clinical efficacy are discussed.

Phylogenetic relationship of the complete Rauscher murine leukemia virus genome with other murine leukemia virus genomes

We report the complete nucleotide sequence of the genome of Rauscher murine leukemia virus (R-MuLV), the replication-competent helper virus present in the Rauscher virus complex, and its phylogenetic relationship with other murine leukemia virus genomes. An overall sequence identity of 97.6% was found between R-MuLV and the Friend helper virus (F-MuLV), and the two viruses were closely related on the phylogenetic trees constructed from either gag, pol, or env sequences. Moloney murine leukemia virus (Mo-MuLV) was the next closest relative to R-MuLV and F-MuLV on all trees, followed by Akv and radiation leukemia virus (RadLV). The most distantly related helper virus was Hortulanus murine leukemia virus (Ho-MuLV). Interestingly, Cas-Br-E branched with Mo-MuLV on the gag and pol trees, whereas on the env tree, it revealed the highest degree of relatedness to Ho-MuLV, possibly due to an ancient recombination with an Ho-MuLV ancestor. In summary, a phylogenetic analysis involving various MuLVs has been performed, in which the postulated close relationship between R-MuLV and F-MuLV has been confirmed, consistent with the pathobiology of the two viruses.

Nature of the 5' residue in the M2 domain affects function of the human alpha 1 beta 1 GABAA receptor

The effects on the functional properties of the alpha 1 beta 1 GABAA receptor when the 5' (alpha 1 Val260; beta 1 Ile255) hydrophobic amino acids in the second transmembrane (M2) region were changed to threonine were examined. In response to a saturating concentration of GABA, the current evoked in mutant receptors showed a decreased rate of desensitization and at equilibrium was a greater fraction of the peak current than in wild-type receptors. The half-saturation concentration of the peak current response to GABA in mutant receptors was comparable to that in wild-type receptors, but the Hill coefficient was reduced to less than one. It was concluded that the 5' amino acids in the M2 region have a role in the conformational changes that occur within the alpha 1 beta 1 GABAA receptor in response to GABA.

Expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in reactive and neoplastic lymphoid cells

We have studied the expression of gelatinase A, gelatinase B, interstitial collagenase, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in reactive lymphoid cells, as well as in a series of cell lines derived from neoplasms of B- and T-cell lineage. Using both Northern blot analysis and zymography, gelatinase B activity was detected by zymography in two Burkitt cell lines and in a tonsillar cell suspension, while gelatinase A and interstitial collagenase activities were not detected by either method. TIMP-1 expression was demonstrated by Northern blot analysis in the multipotential neoplastic K-562 cell line, the high grade Burkitt's B-cell lymphoma lines, isolated tonsillar B cells and at low levels in peripheral blood T cells, but was not expressed in any of the neoplastic T-cell lines or isolated peripheral blood B cells. In contrast, TIMP-2 expression was restricted to tissues containing cells of T-cell lineage with high levels being observed in the neoplastic T-cell lines and lower levels in normal peripheral blood T cells and hyperplastic tonsil. Expression of TIMP-1 and TIMP-2 was confirmed at the protein level by reverse zymography and immunofluorescence assays using antihuman TIMP polyclonal antibodies. Expression of gelatinase B by the high grade B-cell Burkitt's lymphoma cell lines is consistent with previous findings in large cell immunoblastic lymphomas and indicates that this enzyme may play an important role in high grade non-Hodgkin's lymphomas. TIMP expression correlated with cell lineage in that TIMP-1 was primarily observed in B cells and TIMP-2 was restricted to T cells.

Ultrafast rotation and trapping of carbon monoxide dissociated from myoglobin

The nature of ligand motion within proteins has been investigated by measuring femtosecond time-resolved infrared (IR) spectra of CO photodissociated from the haem of myoglobin. Upon dissociation, the CO rotates approximately 90 degrees and becomes trapped within a ligand docking site located near the binding site. Two trajectories, distinguished spectroscopically and kinetically with time constants of 0.20 +/- 0.05 ps and 0.52 +/- 0.10 ps, lead to CO located within the docking site with opposite orientations. The protein reorganizes about the "docked' CO with a time constant of 1.6 +/- 0.3 ps and quickly establishes an energetic barrier that inhibits the reverse rebinding process.

Sudden cardiac death in cardiac transplant recipients

BACKGROUND

Sudden cardiac death (SCD) remains a significant cause of mortality in the general population. Its role in cardiac transplant patients-including its incidence, mechanism, potential risk factors, or influence on survival in this patient population-has not been well described.

METHODS AND RESULTS

We undertook a retrospective analysis of the clinical and autopsy records of 257 patient deaths. SCD was analyzed in relation to severity and frequency of rejection episodes, clinical history of arrhythmias, coronary artery disease (CAD), hypertension, diabetes, left ventricular dysfunction, and clinical history of premorbid symptoms. A total of 25 patients were identified as having died of SCD, an incidence of 9.7%: 20% died < or = 12 months after transplantation, 80% died after > 12 months, and 20% died after > or = 60 months. Patient survival ranged from 2.5 to 138 months (mean, 45.7 months). The mean number of rejection episodes per patient was 2.6, most occurring within 12 months after transplantation. Echocardiography or multigated acquisition scan revealed an ejection fraction (EF) > or = 50% in 68% of patients; however, the presence of arrhythmias, primarily atrial, was evident in 68% of patients and was equally distributed between patients with EFs > or = 50% and EFs < 50%. CAD was present in 53% of patients (10 of 19) whose angiograms were available, and the appearance of CAD after transplantation was between 29 and 85 months (mean, 51.4 months). Of the 9 patients with normal cardiac catheterization studies, 6 with available autopsy reports had documented CAD. Autopsy data in 13 of 25 patients revealed CAD in 92% and rejection in 15% (International Society for Heart and Lung Transplantation grade > 3A). Of the deaths, 64% occurred within 3 months of the last endomyocardial biopsy, 96% had normal biopsies, and the only rejection was without hemodynamic compromise.

CONCLUSIONS

SCD occurs relatively frequently in the cardiac transplant population, and CAD is present in most of the patients. Because the frequency of arrhythmias is relatively high in this group, more aggressive antiarrhythmic therapy may be beneficial for patients with allograft CAD in the prevention of SCD.

Effects of diminished and conflicting sensory information on balance in patients with cerebellar deficits

We studied the effects of altered sensory information on standing balance in 25 patients with cortical cerebellar atrophy (CCA), nine patients with olivoponto-cerebellar atrophy (OPCA), and 10 normal subjects. The total sway path and its components, the anteroposterior (AP) sway path and the lateral sway path, were measured under six conditions: (1) standing on a fixed platform with the eyes open and visual surroundings fixed, (2) standing on a fixed platform with the eyes closed, (3) standing on a fixed platform with the eyes open and visual surroundings AP sway referenced, (4) standing on an AP sway-referenced platform with the eyes open and visual surroundings fixed, (5) standing on an AP sway-referenced platform with the eyes closed, and (6) standing on an AP sway-referenced platform with the eyes open and visual surroundings AP sway referenced. Patients swayed more than normal subjects during normal stance (condition 1), when the visual information was absent (condition 2) or distorted (condition 3), and when the proprioceptive information from the ankles was distorted (condition 4). Patients swayed much more than normal, and most fell, when two sensory modalities were affected under condition 5 (proprioceptive information distorted and visual information absent) and condition 6 (both proprioceptive information and visual information distorted). When the patients' sway was normalized to that of the first condition, however, only their lateral sway was greater than the sway in normal subjects. Unlike in normal subjects, the patients' lateral sway varied with the AP sway to approximately the same degree in each condition for conditions 1-5. Clinical ratings of gait and balance were highly correlated with the sway measures. Quantitative testing of standing balance with altered sensory information has better sensitivity than normal stance testing.

Denture plaque distribution and the effectiveness of a perborate-containing denture cleanser

Formation of plaque on the surfaces of dentures is a common problem among denture wearers. A study was conducted to determine the distribution of plaque on dentures. The plaque material was disclosed with a dye solution and measured with a modified Quigley-Hein scale. A photographic method was used to determine the distribution of plaque on the dentures of a group of complete-denture wearers. The effectiveness of a perborate soak-type cleanser was also measured by studying the precleaned and postcleaned states of the denture. Denture plaque was more evident on the fitting surfaces of the dentures than on areas of the flange, teeth, and palate. The use of the soak-type cleanser alone may not be completely effective for the control of heavy plaque.

Maternal congenital heart disease and pregnancy outcome

OBJECTIVE

To study the obstetrics and neonatal outcome of women with congenital heart disease.

METHOD

This is a retrospective study of 85 women with congenital cardiac disease. Data collected include maternal characteristics, New York Heart Association Class, cardiac complications and obstetric and neonatal outcome.

RESULTS

The maternal and neonatal outcomes were excellent with no maternal and perinatal mortality. The main cardiac lesions were mitral valve prolapse (60.8%), atrial septal defect (8.6%), ventricle septal defect (6.5%) and aortic regurgitation (4.3%) and 2.1% each of tricuspid regurgitation, pulmonary regurgitation, Ebstein's anomaly, coarctation of aorta, patent ductus arteriosus, and Eisenmenger's syndrome. Six deliveries were associated with New York Heart Association deterioration. Compared to the general obstetric population, more women in the study group were primigravida, had pregnancy induced hypertension, underwent instrumental vaginal deliveries and caesarean sections and had more babies with lower birth weights.

CONCLUSION

Despite potential difficulties and complications associated with congenital heart disease, careful cardiac and obstetric management in a tertiary referal centre resulted in good maternal and fetal outcomes.

C4 and 21-hydroxylase gene deletions in nasopharyngeal carcinoma among the Chinese

Deletions around the C4 and 21-hydroxylase (21-OH) gene region occur among the Chinese, and C4B together with 21-OHA deletion is the most common. This deletion was found to be strongly associated with human leucocyte antigen (HLA) B58 DRB1*0301, particularly with DRB1*0301. The initial observation of a high frequency of this deletion in nasopharyngeal carcinoma (NPC) was secondary to the B58 DR3 association with NPC. A deletion of 21-OHA alone was observed to be associated with HLA B13 DRB1*1501.

Upregulation of the 72-kDa type IV collagenase in epithelial and stromal cells during rat tracheal gland morphogenesis

Submucosal glands secrete most of the mucus that lubricates the tracheal surface and protects it from irritants and infection. These glands develop postnatally in the rat, permitting convenient study of the mechanisms controlling this process. One such mechanism involves degradation of the supportive connective tissue matrix at the front of the growing glands. We recently showed that tracheal gland cell invasion of collagen gels in vitro is dependent on secretion of a 72-kDa type IV collagenase. In the present study, we show that the activity of this enzyme (also referred to as matrix metalloproteinase-2 or gelatinase A) is elevated at the time of gland development in vivo. That this increase is at least partly mediated at the level of steady-state mRNA was indicated by semiquantitative PCR analysis of gland-enriched, microdissected tissue samples. Immunohistochemistry revealed that the enzyme was present at the interface between the glands and extracellular matrix. In situ hybridization revealed that the cognate mRNA was present in epithelial cells of glands undergoing morphogenesis (particularly Postnatal Day 7) but not in those of adult glands or the surface epithelium. At all ages, stromal cells below the surface epithelium were labeled; labeling intensity was highest at the time and location of gland morphogenesis. These findings suggest that the 72-kDa type IV collagenase is developmentally regulated in gland and stromal cells at the level of steady-state mRNA and plays a role in the degradation of extracellular matrix during tracheobronchial gland morphogenesis.

Binding of CO to myoglobin from a heme pocket docking site to form nearly linear Fe-C-O

The relative orientations of carbon monoxide (CO) bound to and photodissociated from myoglobin in solution have been determined with time-resolved infrared polarization spectroscopy. The bound CO is oriented < or = 7 degrees from the heme normal, corresponding to nearly linear FE-C-O. Upon dissociation from the Fe, CO becomes trapped in a docking site that orientationally constrains it to lie approximately in the plane of the heme. Because the bound and "docked" CO are oriented in nearly orthogonal directions CO binding from the docking site is suppressed. These solutions results help to establish how myoglobin discriminates against CO, a controversial issue dominated by the misconception that Fe-C-O is bent.

Comparison of techniques for transscleral diode photocoagulation in the rabbit

PURPOSE

To assess the optimum probe design and treatment parameters for transscleral diode laser retinopexy.

METHODS

Transscleral diode photocoagulation was performed on the eyes of Dutch-belted rabbits using three different transscleral probes: a straight, 400-microns diameter probe; a prism-tipped 400-microns diameter probe; and a prism-tipped 900-microns diameter probe.

RESULTS

Transscleral diode photocoagulation with all three probe types was an effective method of ablating the retina and creating chorioretinal adhesions. Both the burn diameter and the mean radiant output energy requirement increased as the burn duration and probe aperture diameter was increased. Explosive retinal holes were encountered in 12% of the burns created with the straight probe. The use of the prism-tipped probes significantly reduced the incidence of retinal holes to < 4% (P < 0.005). Histopathologically, all burns were grade III in intensity with severe choroidal injury. In many of the burns, there was histopathologic evidence of thermal injury to the inner sclera. The frequency of these inner scleral changes was reduced with a long burn duration (5 seconds).

CONCLUSION

This study confirms that diode transscleral photocoagulation is a feasible method of thermal retinopexy. The use of the prism-tipped probes and long duration burns resulted in the fewest adverse reactions.

Differential susceptibility of plasma proteins to oxidative modification: examination by western blot immunoassay

Plasma proteins are exposed to oxidants in a variety of circumstances in vivo, such as during tissue injury and inflammation. In this report, the relative susceptibility of each of the major plasma proteins to oxidative modification was assessed by exposing whole plasma to a metal-catalyzed radical generating system and detecting oxidation (protein carbonyl groups) using a novel Western blot immunoassay. Proteins were derivitized with dinitrophenylhydrazine, separated by SDS-gel electrophoresis, and screened with antibodies against dinitrophenyl groups. As little as 1 pmol of protein-associated carbonyls could be detected (100 ng of a 50 kD protein containing 0.5 mol carbonyl/mol protein). Individual plasma proteins were identified by their comigration with standards, crossreactivity with specific antibodies, and by comparison of plasma to serum. Using this approach, we found that plasma fibrinogen was much more susceptible to oxidative modification compared to the other major plasma proteins, albumin, immunoglobulins, and transferrin. The results emphasize the utility of this method for studying oxidation of proteins in cell extracts and tissues and indicate that experiments on the effects of oxidation on fibrinogen function are merited.

Diet measurement in Vietnamese youth: concurrent reliability of a self-administered food frequency questionnaire

Dietary patterns of Asian Americans change with increasing acculturation, leading to increased consumption of Western foods including those high in fat. Strategies to preserve the healthy aspects of traditional diets need to be developed and dietary assessment methods evaluated. Little is known about reliability of brief dietary measures in the general population or among minority youth. The concurrent reliability of a brief food frequency questionnaire (FFQ) was determined among Vietnamese youth using diet reports. Students in a bilingual high school program were given a FFQ. Students then completed daily diet reports one day each week over seven weeks. The data from the FFQ were compared to the daily food reports. The reliability of the FFQ was highest for frequently eaten food types like rice (r = 0.626, P < 0.01), fruit (r = 0.513, P < 0.01), meat (r = 0.525, P < 0.01) and vegetables (r = 0.474, P < 0.01) and was lower for less commonly eaten types including fish/shellfish (r = 0.227, P = 0.20) and fried foods (r = 0.310, P = 0.07). These results suggest that a few simple FFQ items, particularly for indicator foods such as rice, are reliable for dietary assessment in this population.

Phase 1 clinical trial of chimeric monoclonal anti-CD4 antibody in multiple sclerosis

We conducted an open trial of cM-T412, a chimeric monoclonal anti-CD4 antibody, in 29 patients with MS. This antibody caused a prompt and long-lasting depletion of circulating CD4 (helper/inducer) lymphocytes. The mean (+/- SE) CD4 count for the group decreased from 870 (+/- 66) cells/mm3 at baseline to 76 (+/- 11) 3 hours after treatment, and then increased to 425 (+/- 38) at 1 month after treatment and 475 (+/- 39) at 6 months after treatment. Numbers of CD8 (cytotoxic/suppressor) lymphocytes, B lymphocytes, granulocytes, and monocytes changed transiently but showed no significant long-term effects. The most common side effects were headache, nausea, myalgia, fever, and tachycardia occurring in the first few hours after treatment. No serious or unexpected infections or other significant adverse effects occurred. Kurtzke EDSS scores remained stable, and MRI scans showed less contrast enhancement 1 week after treatment. We conclude that treatment of MS patients with cM-T412 chimeric anti-CD4 antibody is well tolerated at the doses tested and produces a long-lasting, selective depletion of CD4 lymphocytes.

Tine test cards for TB screening: rates of return and associated factors

OBJECTIVE

Screening for tuberculosis in children can be done with the multiple-puncture Tine test. Determination of the extent of induration following the test may be reported by a child's caregiver via a mailed Tine card. We report the rate of return of these cards, and factors associated with return, in a family medicine health center.

METHODS

Retrospective review of the medical charts of 152 mother and child pairs seen in the health center over a two-year period.

RESULTS

Of the 98 children who had received a Tine test by age one, 16.3% of their Tine cards were returned to the health center. Children whose delivery was insured by Medicaid were less likely to have a Tine card returned than were those without Medicaid (OR for non-return = 4.3, 95% CI = 1.2, 15.4). Physicians often documented a tuberculosis screening result without a Tine card.

CONCLUSIONS

Given the low return rates, health care professionals responsible for tuberculosis screening should be cautious when relying on caregivers to interpret, record and return tuberculosis screening results, particularly in the most disadvantaged populations. More valid data are likely to be obtained from a clinical reading of tuberculosis tests.

Nonexponential protein relaxation: dynamics of conformational change in myoglobin

The picosecond evolution of the tertiary conformation of myoglobin (Mb) after photodissociation of MbCO was investigated at room temperature by probing band III, a weak iron-porphyrin charge-transfer transition near 13,110 cm-1 (763 nm) that is sensitive to the out-of-plane displacement of the iron. Upon photolysis, the iron moves out of the plane of the porphyrin, causing a blue-shift of band III and a concomitant change in the protein conformation. The dynamics for this functionally important motion are highly nonexponential, in agreement with recent molecular dynamics simulations [Kuczera, K., Lambry, J.-C., Martin, J.-L. & Karplus, M. (1993) Proc. Natl. Acad. Sci. USA 90, 5805-5807]. The conformational change likely affects the height of the barrier to ligand rebinding and may explain nonexponential NO rebinding.

A prospective randomised study of local versus general anaesthesia for cataract surgery

One hundred and sixty-nine patients (aged 65-98 years) were randomised to receive either local or general anaesthesia for cataract surgery. Cognitive function was assessed using a battery of psychometric tests performed pre-operatively, and at 24 h, 2 weeks and 3 months postoperatively. Oxygen saturation, blood pressure and heart rate were monitored and the results recorded throughout the anaesthetic and immediate recovery period. In the general anaesthetic group, 19% of patients experienced at least one episode of oxygen desaturation during the procedure compared with none in the local anaesthetic group. Pulse rate and blood pressure were stable in the local anaesthetic group compared with the general anaesthetic group where marked fluctuations were noted; 61% of patients in the general anaesthetic group experienced falls in systolic blood pressure greater than 30% of the pre-induction value. No evidence of long-term postoperative cognitive dysfunction was detected and there was no significant difference between the performances of the two groups.

A review of patients with a 'normal' coronary angiogram over a 3-year period

Over a period of 36 months, we detected 54 patients with normal coronary arteries or non-critical coronary artery stenosis within our study series of coronary angiography. We studied these patients to determine their clinical, electrocardiographic, stress testing and angiocardiographic characteristics. We detected among them a preponderance of female sex and a higher incidence of ethnic Indians. The majority of the patients studied had one or more coronary risk factors. 52% had a normal resting ECG. In those with a positive stress test and reports available for review, there is a near equal distribution of horizontal and J-type ST depression. Those patients with a positive treadmill tend to have a higher left ventricular end diastolic pressure (LVEDP) at cardiac catheterization. We also noted in this group of patients a higher proportion with a small distal left anterior descending artery. These patients also tend to have higher LVEDP even in the presence of normal left ventriculogram. Our current series suggests the possibility of raised left ventricular end-diastolic pressure and the presence of a "small distal left anterior descending artery" syndrome in association with patients with a 'false positive' treadmill test.

Overestimation of severity of mitral stenosis during cardiac catheterization due to a large left atrial thrombus

We report a case of mitral stenosis with a large left atrial thrombus which was obstructing pulmonary venous inflow where the conventional use of the pulmonary capillary wedge pressure as an approximation of the left atrial pressure during diagnostic cardiac catheterisation led to the over-estimation of the severity of mitral stenosis.

[Postspinal headache. A comparison of the 24G Sprotte syringe and a 29G Quincke needle]

PATIENTS AND METHODS

A randomised study was performed to compare the frequency of postdural puncture headache in 56 patients who underwent spinal anaesthesia for extra-corporeal shockwave lithotripsy using either a Sprotte 24 G (n = 28) or Vygon 29 G or Quincke type needle (n = 28). Frequency of headache was recorded in a similar group of 28 patients who received general anaesthesia.

RESULTS

Dural puncture was easier with the Sprotte 24 G cannula than with the less stable Quincke needle, as documented by a significantly shortened time for insertion of the cannula (4.6 +/- 2.6 vs 8.6 +/- 6.3 min, P less than 0.005). The total frequency of post-operative headache was 57% in the Vygon 29 G group and 25% in the Sprotte 24 G group; 21% of patients in the general anaesthesia group complained of headache. Frequency of postdural puncture headache, classified as being posture-related, was 25% in the 29 G Vygon group, compared with 11% in the 24 G Sprotte group (P = 0.148). When only moderate and severe postdural puncture headache was considered, there was a significant difference (25% vs. 4%; P = 0.026) in favour of the Sprotte cannula.

DISCUSSION AND CONCLUSIONS

Thus, the 24 G Sprotte needle was at least as effective as the 29 G Vygon needle, and there is a suggestion that the former is more effective in minimising the incidence of moderate or severe postdural puncture headache.

High frequency jet ventilation: use of the Bain system for entrainment

The use of a Bain system to convey anaesthetic gases for entrainment during high frequency jet ventilation (HFJV) was evaluated by examining the effect of varying the fresh gas flow (Vf) on the end-tidal carbon dioxide (PECO2) in 46 ASA physical status I and II patients undergoing extracorporeal shock-wave lithotripsy (ESWL). Anaesthesia was induced with methohexitone (1-2 mg.kg-1), fentanyl (1-1.5 micrograms.kg-1) and vecuronium (0.1 mg.kg-1). After endotracheal intubation with a Mallinckrodt Hi-Lo Jet cuffed endotracheal tube, the patient was immersed in a water bath and HFJV at 150 breaths per minute was instituted with an Acutronic AMS 1000 jet ventilator attached to the side channel of the Hi-Lo tube. A Bain system was attached to the proximal end of the endotracheal tube to provide gases for entrainment. Anaesthesia was maintained with an intravenous infusion of methohexitone (5 mg.kg-1.h-1) and 50% nitrous oxide in oxygen for both the jetted and entrained gases. PECO2 was determined at 5-min intervals by a single-breath technique using a calibrated Engstrom Eliza capnograph. Thirty patients were randomly allocated to receive Vf's of 50 (Group 1), 75 (Group 2) and 100 (Group 3) ml.kg-1.min-1, respectively. A further eight patients (Group 4) received a Vf of 100 ml.kg-1.min-1 for 15 min, 75 ml.kg-1.min-1 for the next 15 min and 50 ml.kg-1.min-1 thereafter. In a further group of eight patients (Group 5), Vf was initially 25 ml.kg-1.min-1 for 10 min and was then switched off for the remainder of the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of granulocyte colony stimulating factor and granulocyte-macrophage colony stimulating factor genes in human astrocytoma cell lines and in glioma specimens

Expression of granulocyte (G) and granulocyte-macrophage (GM) colony stimulating factor (CSF) genes in human cells of astroglial lineage was studied. Primers for CSFs were used to analyze RNA transcripts in 5 cultured human astrocytoma cell lines and 8 fresh brain specimens by polymerase chain reaction. Constitutive expression of mRNA transcripts of GM-CSF could be detected in all astrocytoma and one neuroblastoma cell lines, and two out of 5 unstimulated astrocytomas, U87MG and U138 MG, expressed G-CSF genes. After stimulation with interleukin (IL)-1 beta + tumor necrosis factor (TNF)-alpha, all cell lines expressed G-CSF. In addition to the cultured cells, we examined gene expression within human malignant astrocytoma, peritumoral brain and autopsied normal brains. The results show that some of the tumor and its surrounding reactive lesions express G- and GM-CSF genes but normal brains do not. The concentration of G- and GM-CSF in supernatants of cultured cells was assessed at the protein level by ELISA. A low level of GM-CSF activity was constitutively present in all astrocytomas. G-CSF was detected in unstimulated U87MG and U138MG and other cell lines could synthesize G-CSF after the stimulation of IL-1 beta and TNF-alpha at the level of mRNA. Furthermore, the concentration of CSFs increased markedly upon stimulation with IL-1 beta and/or TNF-alpha in both a time- and dose-dependent fashion. From these results, it is suspected that astroglial cell-derived CSFs may participate in local immune reactions accompanying infection, degeneration and malignancies in the brain.

Chemical synthesis of 10 kDa chaperonin. Biological activity suggests chaperonins do not require other molecular chaperones

Molecular chaperones are required for the correct folding and assembly of certain other polypeptides. It is not known whether molecular chaperones themselves require other chaperones to become functional. A 97-amino acid chaperone, the chaperonin 10 protein was chemically synthesised so that during synthesis and purification there was no contact of the chaperone with any other protein. The purified, synthetic chaperonin 10 protein formed oligomeric structures spontaneously and was biologically active as a chaperonin. This is the first description of a chemically synthesised chaperonin, and suggests that no other chaperones are required for correct folding, polymerisation and biological activity of this chaperone.

HPV DNA typing of adult-onset respiratory papillomatosis

Respiratory papillomatosis is a recalcitrant, human papillomavirus-induced disorder of the upper airways. Using in situ hybridization and biotinylated deoxyribonucleic acid (DNA) probes, the type of human papillomavirus (HPV) in nine adults was determined both at presentation and during subsequent recurrences. Fifty-three biopsies obtained from seven men and two women over a 10-year period were examined for HPV 6, 11, 16 and 18. All patients had either type 6 or 11. One dual infection was found. Despite intensive therapy with lasers with or without alpha interferon, no elimination or change in viral type occurred. Despite identical histologies, the amount of HPV DNA present in a given patient's papillomata varied markedly. The results suggest that adult-onset respiratory papillomatosis is due to HPV 6 and/or HPV 11, and that its recurrent nature, despite therapy, is due to persistence of a viral reservoir.

Atropine-induced heart rate changes: a comparison between midazolam-fentanyl-propofol-N2O and midazolam-fentanyl-thiopentone-enflurane-N2O anaesthesia

Atropine-induced heart rate (HR) changes were studied in 19 patients (ASA physical status I) during anaesthesia-maintained predominantly with propofol-N2O or thiopentone-enflurane-N2O. Ten patients (Group A) received midazolam (0.07 mg.kg-1), fentanyl (1 microgram.kg-1), propofol (2 mg.kg-1) and succinylcholine (1 mg.kg-1). Following tracheal intubation, anaesthesia was maintained with propofol (6 mg.kg-1.hr-1), N2O (67 per cent) and O2 (33 per cent). In nine patients (Group B) thiopentone (4 mg.kg-1) was substituted for propofol and anaesthesia maintained with N2O (67 per cent) O2 (33 per cent), and enflurane (0.5 per cent inspired concentration). The study was non-randomised because Group B patients were only included if HR before administration of atropine less than 90 beats.min-1. IPPV was performed in all patients using a Manley ventilator (minute vol. 85 ml.kg-1; tidal vol. 7 ml.kg-1). Ten minutes after tracheal intubation, incremental doses of atropine (equivalent cumulative doses: 1.8, 3.6, 7.2, 14.4, 28.8 micrograms.kg-1) were administered at two-minute intervals and HR responses calculated during the last 45 sec of each intervening period. No differences were observed between the groups following 1.8 and 3.6 micrograms.kg-1 atropine, but propofol-N2O anaesthesia was associated with reduced responses (P less than 0.01) following 7.2, 14.4 and 28.8 micrograms.kg-1 atropine. These results suggest that there is a predominance of parasympathetic influences during propofol-N2O anaesthesia compared with thiopentone-enflurane-N2O anaesthesia.

Ascorbic acid potentiates the inhibitory effect of dopamine on prolactin release: a putative supplementary agent for PIF

Dopamine has a catechol group which can be easily oxidized by mild oxidizing agents. Ascorbic acid has been routinely added to a dopamine solution in order to protect it from oxidation. We have examined the effect of ascorbic acid on dopaminergic inhibition of prolactin release. Male rat pituitary cells were dispersed using trypsin and cultured for 5-7 days before experiments. Ascorbic acid did not stimulate nor inhibit prolactin release in both static monolayer culture and dynamic perifusion systems, but potentiated by approximately 100 times the inhibitory effect of dopamine on prolactin release. In order to differentiate chemical protection from potentiation, we tested the potentiation effect of isoascorbic acid which is an epimer of biologically active L-ascorbic acid but is biologically less active. Our results indicated that isoascorbic acid caused less potentiation of the dopaminergic effect on prolactin release than did ascorbic acid. In a perifusion system, a high concentration of dopamine (100 nmol/l) was unable to inhibit prolactin release for a 1 h experimental period, but a low concentration of dopamine (10 nmol/l) plus ascorbic acid (10 mumol/l) inhibited prolactin release for the entire 1 h perifusion period. There is a strong possibility that ascorbic acid may be a physiological supplementary agent for the prolactin-release inhibiting factor (PIF) since the blood concentration of ascorbic acid is rather high (23-85 mumol/l).

Multiple T and B cell epitopes in the S1 subunit ("A"-monomer) of the pertussis toxin molecule

The immunogenicity and reactogenicity of Bordetella pertussis vaccine are mediated in part by the S1 subunit of pertussis toxin (PT). To identify the immune epitopes in the S1 subunit of PT, synthetic peptides were prepared and tested for their capacity to induce antibodies in mice with different MHC genotypes. In BALB/c mice, peptides corresponding to sequences 1-17, 70-82 and 189-199 generate T cell proliferative responses, induce the production of antibodies capable of neutralization of the toxin in the Chinese hamster ovary-cell assay, and protect mice from a shock-like syndrome caused by alternate injections of BSA and PT. Protection and neutralization correlated with the ability of these peptides to elicit high anti-PT titers. Different B cell epitopes were detected in other inbred mouse strains. The antibody reactivity against synthetic peptides from two infants vaccinated with pertussis vaccine was tested. These infants had antibodies reactive to a variety of epitopes in the S1 subunit, including peptides 1-17, 70-82, 99-112, 135-145, and 189-199. Thus, it appears that there are multiple T and B cell epitopes in the S1 subunit of PT.

Multiple T and B cell epitopes in the S1 subunit ("A"-monomer) of the pertussis toxin molecule

The immunogenicity and reactogenicity of Bordetella pertussis vaccine are mediated in part by the S1 subunit of pertussis toxin (PT). To identify the immune epitopes in the S1 subunit of PT, synthetic peptides were prepared and tested for their capacity to induce antibodies in mice with different MHC genotypes. In BALB/c mice, peptides corresponding to sequences 1-17, 70-82 and 189-199 generate T cell proliferative responses, induce the production of antibodies capable of neutralization of the toxin in the Chinese hamster ovary-cell assay, and protect mice from a shock-like syndrome caused by alternate injections of BSA and PT. Protection and neutralization correlated with the ability of these peptides to elicit high anti-PT titers. Different B cell epitopes were detected in other inbred mouse strains. The antibody reactivity against synthetic peptides from two infants vaccinated with pertussis vaccine was tested. These infants had antibodies reactive to a variety of epitopes in the S1 subunit, including peptides 1-17, 70-82, 99-112, 135-145, and 189-199. Thus, it appears that there are multiple T and B cell epitopes in the S1 subunit of PT.

Triiodothyronine regulates insulin-like growth factor-I binding to cultured rat pituitary cells

Abstract Triiodothyronine (T(3)) stimulates the synthesis of growth hormone and enhances the growth of neoplastic rat pituitary somatomam-motrophs (GH cells) in culture. Moreover, T(3) has been shown to stimulate the production and secretion of an autocrine growth factor by these cells. We have previously demonstrated the presence of specific receptors for insulin-like growth factors (IGF) on GH cells. Since GH(3) cells contain mRNA encoding IGF-I, it has been suggested that IGF-I might act in an autocrine fashion in these cells. Therefore, it was of interest to learn how T(3) affects IGF-I binding to GH(3) cells. T(3) increased [(125)I]IGF-I binding in a time - and dose-dependent manner. After 48 h of exposure to T(3), an increase in IGF-I binding was seen with 10(-11)M T(3), maximizing with 10(-8)M T(3). When cells were exposed to 10(-8) T(3), [(125)I]IGF-I binding reached a maximum of 218 +/- 20.8% of control (+/-SEM, P < 0.002) after 72 h of incubation. Scatchard analysis indicated that T(3) did not alter the K(d) of IGF-I for its receptor, but that the total receptor number was increased. Dexamethasone (10(-7)M) inhibited the T(3)-induced increase in IGF-I binding, but glucocorticoid alone did not substantially alter receptor number. No significant change in insulin or IGF-II binding was seen after hormone treatment. 10(-8) M T(3) or IGF-I increased the growth of the GH(3) cells by >/=30%. Our data indicate that T(3) upregulates IGF-I binding in GH(3) cells without altering insulin binding and thereby provides a means for enhancing potential autocrine regulation in this cell line.

Effect of vecuronium on atropine-induced changes in heart rate

The effect of vecuronium on the heart rate response to atropine has been studied by comparing dose-response relationships in two groups of patients who underwent extracorporeal shock wave lithotripsy. One group received vecuronium (0.1 mg/kg) and the other acted as control. Incremental doses of atropine (1.8, 1.8, 3.6, 7.2 and 14.4 micrograms/kg) were administered and changes in heart rate recorded. No significant differences were observed between the two groups following each incremental dose of atropine.

Prevention of postdural puncture headache after spinal anaesthesia for extracorporeal shockwave lithotripsy. An assessment of prophylactic epidural blood patching

The prevention of postdural puncture headache after spinal anaesthesia for extracorporeal shockwave lithotripsy was investigated by a controlled clinical trial which compared epidural injection of 10 ml of autologous blood with 10 ml of normal saline immediately after intrathecal injection of local anaesthetic. The incidence of postdural puncture headache was 8.3% in the group that received blood compared with 45% in the group that received saline, a significant reduction (p less than 0.01). The incidences of backache and lower limb paraesthesiae were similar in both groups. No serious complications were reported.

Treatment of the chest wall

Irradiation of the chest wall is sometimes given following radical or modified radical mastectomy. The aim of treatment planning in such cases is to deliver a uniform dose to a superficial layer of tissue a few centimeters thick with an acceptably low dose to underlying tissues, particularly the lung. Both tangential photon beams and appositional electron beams have been used for this purpose, the choice between them being determined by the radiation modalities available, the extent and thickness of the designated target volume and the curvature of the patient's contour in the region. In this paper we will consider a few examples of both types of treatment with emphasis on the use of multiple electron fields. Dose distributions for the following plans were calculated using the system developed at the Cross Cancer Institute in Edmonton. In this system electron dose calculations are based on the Fermi-Eyges theory of multiple Coulomb scattering using the programs developed by Hogstrom and his co-workers.

MHC-restricted recognition of immunogenic T cell epitopes of pertussis toxin reveals determinants in man distinct from the ADP-ribosylase active site

The S1 subunit of Pertussis toxin (PT) is responsible for the reactogenicity and in part the immunogenicity of Bordetella pertussis vaccine. The critical residues associated with the immunomodulatory effects of PT were located around Glu140 in the S1 subunit. In man, T cell responses to PT are directed at S1 peptides distinct from Glu140. Two such epitopes, p64-75 and p151-161, are immunogenic in a panel of individuals covering a wide range of HLA genotypes. The response to PT peptides is HLA class II restricted. The response to p64-75 is blocked by an anti-HLA-DQ mAb, while that to p151-161 is blocked by an anti-HLA-DR mAb. These findings may allow for the development of a B. pertussis vaccine free from reactogenicity.

CT treatment planning of the liver

The article deals with CT treatment planning of the liver to maximize the dose to the liver but minimize the dose to the right kidney, spinal cord, and bowels. (The left kidney is out of the field due to the oblique angles of the fields.) This is achieved by right kidney shielding reconstruction from multislice CT treatment planning and by the oblique angles of the fields. Without CT, it is not possible to utilize oblique fields to cover the liver. With conventional AP-PA fields, not only is the whole liver treated but also most of the right kidney, half of the left kidney, bowels and spinal cord. Tolerance dose to the kidneys is exceeded if adequate dose is delivered to the liver. Some new computer algorithms display a bird's eye view of the shielding but this paper presents for the first time, a technique for actual shielding reconstruction from multislice CT treatment planning for use by the radiation oncologist when shielding blocks are drawn on the simulator films.

Characterization of a major encephalitogenic T cell epitope in SJL/J mice with synthetic oligopeptides of myelin basic protein

The C-terminal 89-169 amino acid fragment of myelin basic protein (MBP) causes experimental allergic encephalomyelitis (EAE) in SJL/J mice. In order to identify the encephalitogenic T cell epitope, we have examined the fine specificity of encephalitogenic SJL/J T cell clones with synthetic peptides derived from the C-terminal 89-169 amino acids of MBP. These peptides were examined for their immunogenic and encephalitogenic activity in the SJL/J mouse. The SJL/J-derived, encephalitogenic T cell clone, 4b.14a, was shown to be responsive to rat myelin basic protein synthetic peptides pR89-101 (VHFFKNIVTPRTP) as well as to intact MBP. Its response was effectively blocked by mAb 10-2.16 (anti-I-As) as was the response to intact MBP. Furthermore, pR89-101 was revealed to be highly immunogenic for the (PLSJ)F1 mouse in terms of lymphocyte proliferation, but not for the PL/J mouse, in spite of the fact that there exists a strong bias to H-2u restricted responses in the (PLSJ)F1 mouse at the T cell level. By using pR89-101, T cells of (PLSJ)F1 origin were revealed to recognize the peptide in association with the I-As molecule on (PLSJ)F1 antigen presenting cells (APC). When examined for encephalitogenicity for the SJL/J mouse, pR89-101 was found to be as encephalitogenic as intact rat MBP. These results demonstrated that MBP peptide pR89-101 is a major encephalitogenic determinant for the SJL/J mouse.