A Systematic Review and Meta-analysis of the Impact of Radiation-Related Lymphopenia on Outcomes in High-Grade Gliomas

Supriya MallickIntroduction  Malignant gliomas are the most common primary malignant brain tumors and are typically treated with maximal safe surgical resection followed by chemoradiation. One of the unintended effects of radiation is depletion of circulating lymphocyte pool, which has been correlated with inferior overall survival outcomes. Methods  A comprehensive and systematic searches of the PubMed, Cochrane Central, and Embase databases were done to assess the studies that have reported radiation-related lymphopenia in high-grade gliomas. Hazard ratios (HRs), odds ratios (OR), and mean differences were represented with Forest plots comparing patients with severe lymphopenia and no severe lymphopenia. Review Manager Version 5.3 (The Nordic Cochrane Centre, Copenhagen, Denmark) was used for the analysis. Results  Nineteen studies were included in the final systematic review and 12 studies were included in the meta-analysis. The odds of developing severe lymphopenia were 0.39 (95% CI:0.19, 0.81, I ²  = 94%, p  = 0.01). Patients with severe lymphopenia were at increased risk of death with a pooled HR = 2.19 (95% CI: 1.70, 2.83, I ²  = 0%, p <0.00001) compared to patients with no severe lymphopenia. The mean difference in survival between patients with severe lymphopenia and no severe lymphopenia was -6.72 months (95% CI: -8.95, -4.49, I ²  = 99%, p <0.00001), with a better mean survival in the no severe lymphopenia group. Conclusion  Radiation-induced severe lymphopenia was associated with poor overall survival and increased risk of death. Photon therapy, larger planning target volume, higher brain dose, higher hypothalamus dose, and female gender were associated with increased risk of severe lymphopenia.

A systematic review and meta-analysis of the impact of radiation-related lymphopenia on outcomes in pancreatic cancer

Background: Pancreatic cancer is a devastating disease with a 5-year survival rate of 5-10%. Radiation is commonly used in neoadjuvant and adjuvant settings to improve local control. Studies have shown that circulating lymphocyte count depletion after radiation has been associated with poor tumor control and inferior overall survival (OS) outcomes. Method: To better understand the impact of radiation-associated lymphopenia in pancreatic cancer, the authors undertook this systematic review and meta-analysis of clinical studies that have reported radiation-related lymphopenia in pancreatic cancer. Results: A systematic methodology search of PubMed, Embase and the Cochrane Library resulted in 2969 abstracts. Nine studies fulfilled the inclusion criteria. Six studies reported on outcomes in patients undergoing definitive chemoradiation and three studies comparing outcomes in stereotactic body radiotherapy versus definitive chemoradiation. The patients with severe lymphopenia were at increased risk of death with a pooled hazard ratio of 2.33 (95% CI: 1.79, 3.03; I2: 36%; p < 0.001) compared with patients with no severe lymphopenia. The odds of developing severe lymphopenia were 1.12 (95% CI: 0.45, 2.79; I2: 95%; p < 0.81). The pooled mean difference for OS was -6.80 months (95% CI: -10.35, -3.24; I2: 99%; p < 0.002), suggesting that patients who develop grade 3 or 4 lymphopenia have inferior median OS outcomes. Limiting the mean splenic dose to less than 9 Gy as well as various spleen dosimetric parameters such as visit (V)10 <32%, V15 <23% and V20 <15.4% can reduce the incidence of severe lymphopenia. Conclusion: Radiation-related lymphopenia is associated with an increased hazard of death and inferior median OS. Spleen dosimetric parameters correlate with the incidence of severe lymphopenia and with sub-optimal survival outcomes. There is a need to validate these findings in prospective studies.

Impact of severe acute respiratory syndrome (SARS) on pulmonary function, functional capacity and quality of life in a cohort of survivors

OBJECTIVE

To examine the impact of severe acute respiratory syndrome (SARS) on pulmonary function, exercise capacity, and health-related quality of life (HRQoL) among survivors.

METHODS

110 survivors with confirmed SARS were evaluated at the Prince of Wales Hospital, HK at the end of 3 and 6 months after symptom onset. The assessment included lung volumes (TLC, VC, RV, FRC), spirometry (FVC, FEV1), carbon monoxide transfer factor (TLCO adjusted for haemoglobin), inspiratory and expiratory respiratory muscle strength (Pimax and Pemax), 6 minute walk distance (6MWD), chest radiographs, and HRQoL by SF-36 questionnaire.

RESULTS

There were 44 men and 66 women with a mean (SD) age of 35.6 (9.8) years and body mass index of 23.1 (4.8) kg/m2. Seventy (64%) were healthcare workers. At 6 months 33 subjects (30%) had abnormal chest radiographs; four (3.6%), eight (7.4%), and 17 (15.5%) patients had FVC, TLC, and TLCO below 80% of predicted values; and 15 (13.9%) and 24 (22.2%) had Pimax and Pemax values below 80 cm H2O, respectively. The 6MWD increased from a mean (SD) of 464 (83) m at 3 months to 502 (95) m (95% CI 22 to 54 m, p<0.001), but the results were lower than normal controls in the same age groups. There was impairment of HRQoL at 6 months. Patients who required ICU admission (n = 31) had significantly lower FVC, TLC, and TLCO than those who did not.

CONCLUSION

The exercise capacity and health status of SARS survivors was considerably lower than that of a normal population at 6 months. Significant impairment in surface area for gas exchange was noted in 15.5% of survivors. The functional disability appears out of proportion to the degree of lung function impairment and may be related to additional factors such as muscle deconditioning and steroid myopathy.

Sonography of the normal scapholunate ligament and scapholunate joint space

PURPOSE

The aims of this study were to assess the visibility of the normal scapholunate ligament on sonography and to establish the normal scapholunate joint space width in the neutral position and radial and ulnar deviation.

METHODS

Two hundred normal wrists in 100 subjects (55 men and 45 women; mean age, 40 years; range, 19-83 years) were examined with high-resolution sonography (5-12-MHz linear-array transducer). The visibility and thickness of the scapholunate ligament were recorded. The width of the scapholunate joint space, or interval, was measured in the neutral position and radial and ulnar deviation. The width of the distal radius was recorded as a comparative standard for the patients' body habitus.

RESULTS

The dorsal scapholunate ligament was completely (100%) visible in 95 wrists (48%), partially (> or = 50%) visible in 60 (30%), barely (< 50%) visible in 15 (8%), and not visible in 30 (15%). The volar scapholunate ligament was completely visible in 13 wrists (7%), partially visible in 17 (9%), barely visible in 15 (8%), and not visible in 151 (76%). The proximal component of the ligament was not visible in any subject. Measurement of the scapholunate interval was limited by the lack of identifiable anatomic marks for reference. The mean width of the dorsal scapholunate interval was 4.2 mm (range, 2.3-6.3 mm) in the neutral position. The interval did not differ more than 2.5 mm between the left and right wrists. No predictable change in width on ulnar or radial deviation was evident. The mean scapholunate intervals and mean distal radial width were significantly wider in men than in women and on the right side than on the left side.

CONCLUSIONS

The dorsal scapholunate ligament is completely or partially visible in 78% of normal wrists. Its detection following injury may help to exclude the possibility of scapholunate dissociation. There is a quite wide variation in scapholunate interval widths on sonography and an unpredictable response with stress testing. The absence of a visible scapholunate ligament on sonography does not indicate injury.

Evaluation of extraction methods from paraffin wax embedded tissues for PCR amplification of human and viral DNA

AIM

To evaluate the efficiency of phenol/chloroform, microwave, and Qiagen spin column based DNA extractions from paraffin wax embedded tissue for use in the polymerase chain reaction (PCR). In addition, to assess the reliability of amplifying a housekeeping gene to indicate successful viral DNA extraction.

METHODS

DNA samples extracted from 20 blocks of cervical carcinoma tissues using the three methods were subjected to PCRs targeting 509 bp and 355 bp of the beta globin gene, and 450 bp and 150 bp of human papillomavirus (HPV) DNA.

RESULTS

Microwave extraction showed the highest positive rate for beta globin PCR, whereas the spin column method was the most efficient for HPV DNA extraction. When the 509 bp beta globin and 450 bp HPV PCR results were correlated, two of 10, eight of 12, and nine of 10 beta globin positive extractions prepared by means of the phenol/chloroform, microwave, and spin column methods, respectively, yielded HPV DNA of the expected size. For the beta globin negative samples, HPV was detected in three of 10, two of eight, and four of 10 samples.

CONCLUSIONS

HPV DNA extraction was most efficient using the Qiagen spin column and had the highest positive predictive value when a housekeeping gene was used as an indicator of successful viral DNA extraction; the phenol/chloroform method was the least efficient. The potential drawbacks of some extraction methods when using a human housekeeping gene to assess the quality of viral DNA extraction need to be considered.

Association of human beta-herpesviruses with the development of cervical cancer: bystanders or cofactors

BACKGROUND/AIM

Human papillomaviruses (HPVs) are important, but not sufficient, for the development of cervical cancer. All three human beta-herpesviruses--cytomegalovirus (CMV) and human herpesviruses (HHV) types 6 and 7--have been detected in the cervix. In addition, CMV and HHV-6 can interact with HPVs in vivo. This study examined the possible role of beta-herpesviruses in cervical cancer development.

METHODS

HPV, CMV, HHV-6, and HHV-7 were detected by the polymerase chain reaction using cervical scrapes taken at colposcopy from 388 women. HPV types were identified using restriction fragment length polymorphisms. Colposcopy guided biopsies were taken from abnormal areas, and the histological findings were regarded as the final diagnoses. The associations between herpesvirus infection and the degree of cervical lesion were analysed with respect to HPV status.

RESULTS

Of the 388 women, 51.8% had a normal cervix, 14.4% had cervical intraepithelial neoplasia grade 1 (CIN1), 8.2% had CIN2, 19.3% had CIN3, and 6.2% had invasive carcinoma. Overall, the positive rates for high, intermediate, and low risk HPVs were 18.8%, 21.4%, and 5.2%, respectively. Fifteen patients harboured HPVs for which the genotype could not be identified. Positive rates for CMV, HHV-6, and HHV-7 were 9.5%, 3.6%, and 3.4%, respectively. HPV positive patients carried a higher risk for high grade lesions (CIN2/3 or carcinoma) (odds ratio (OR), 5.24; 95% confidence interval (CI), 3.19 to 8.62; chi 2 = 51.79; p < 0.001), whereas those positive for CMV, HHV-6, or HHV-7 did not. Thirteen of 131 patients with high grade lesions had HPV/herpesvirus coinfections, but no association with the cervical lesion was noted. Furthermore, positive rates for herpesviruses among HPV negative, high/intermediate risk HPV negative, and high risk HPV negative subgroups were similarly low and without a significant association.

CONCLUSIONS

The ubiquitous nature of herpesviruses may pose difficulty in elucidating their pathogenic role. These results indicate that CMV, HHV-6, and HHV-7 are bystanders rather than cofactors in the oncogenesis of cervical cancer.

Importance of atrial flutter isthmus in postoperative intra-atrial reentrant tachycardia

BACKGROUND

In survivors of congenital heart surgery, intra-atrial reentrant tachycardia (IART) often develops. Previous reports have emphasized the atriotomy scar as the central barrier around which a reentrant circuit may rotate but have not systematically evaluated the atrial flutter isthmus in such patients. We sought to determine the role of the atrial flutter isthmus in supporting IART in a group of postoperative patients with congenital heart disease.

METHODS AND RESULTS

Nineteen postoperative patients with IART underwent electrophysiological studies with entrainment mapping of the atrial flutter isthmus for determining postpacing intervals. Radiofrequency ablation was performed at the identified isthmus in an effort to create a complete line of block. Twenty-one IARTs were identified in 19 patients, with a mean tachycardia cycle length of 293+/-73 ms. The atrial flutter isthmus was part of the circuit in 15 of 21 (71. 4%). In the remaining 6 of 21, the ablation target zone was at sites near atrial incisions or suture lines. Ablation was successful in 19 of 21 (90.4%) IARTs and in 14 of 15 (93.3%) cases at the atrial flutter isthmus.

CONCLUSIONS

In most of our postoperative patients, the atrial flutter isthmus was part of the reentrant circuit. The fact that the atrial flutter isthmus is vulnerable to ablation suggests that whenever IART occurs late after repair of a congenital heart defect, the atrial flutter isthmus should be evaluated. These data support the theory that some form of conduction block between the vena cava is essential for the establishment of a stable substrate for the atrial flutter reentrant circuit.

Data-dependent systems profilometry of two-dimensional surfaces

Fourier-transform profilometry (FTP) and data-dependent systems profilometry (DDSP) are two methods that are available for recovering one-dimensional fine surface profiles from the phase of a single interferogram. FTP has already been extended to two-dimensional surfaces; a similar extension of DDSP is introduced here. Inasmuch as this extension involves autoregressive modeling of the rows or columns of an interferogram, the feasibility of using a common model order is explored. The common order reduces not only the amount of computation but also the errors caused by the heterodyned phase-removal procedure. As autoregression requires masking the first few data values, the length of the mask is determined by means of a Green's function. A comparison shows that DDSP outperforms FTP in roughness measurements in terms of rms and center-line average. The comparison also shows that DDSP is able to recover a detailed surface, whereas FTP outlines only the global features. An interferogram regeneration procedure provides a reference surface for the verification of results.

Comparison of fourier-transform and data-dependent system profilometry by use of interferometric regeneration

Fourier-transform profilometry (FTP) and data-dependent system profilometry (DDSP) are the two major phase-extraction methods that use a single interferogram. The difficulty in verifying surface profiles obtained by these methods is that the exact spot on an actual surface cannot be measured with two different instruments. An interferogram regeneration procedure is developed to solve this problem. The surface profile is then extracted from the regenerated interferogram by both FTP and DDSP. Comparisons of the actual surface profile with the extracted surface profiles show that both methods perform equally well in measuring the root mean square and the center line average, but only DDSP is able to reproduce the detailed surface profile of the reference surface.

Effects of doxorubicin on diastolic function, contractile reserve, and ventricular-vascular coupling in piglets

The use of doxorubicin as an anticancer drug is limited by its cardiac toxicity. To examine the adverse effects of doxorubicin on cardiac function and ventricular-vascular coupling in piglets, eight piglets received five doses of intravenous doxorubicin, 1.5 mg/kg/dose, every 4-7 days starting at 3 weeks of age. A control group consisted of eight normal piglets. Using conductance and manometric catheters, indices of cardiac function, including end systolic elastance (Ees), preload-recruitable stroke work, dP/dtmax, tau, dP/dtmin, dV/dtmax, and end systolic stiffness, were calculated from volume and pressure measurements at rest and during infusion of isoproterenol. Ventricular-vascular coupling was examined by measuring arterial elastance (Ea) and Ea/Ees. Significant differences in relaxation were found between groups. Indices of diastolic stiffness and of contractile function were not different between groups. Baseline contractile efficiency was increased in the doxorubicin group. Ea and Ea/Ees were lower in the doxorubicin group. Ea/Ees was near 1 at baseline in the doxorubicin group, indicating that conditions were optimized for performance of external stroke work. Therefore, the reserve to increase external cardiac work was diminished. The finding of altered diastolic function suggests the importance of screening of diastolic indices to detect the earliest disturbances in cardiac function caused by doxorubicin.

Halm-Zielke instrumentation for primary stable anterior scoliosis surgery: operative technique and 2-year results in ten consecutive adolescent idiopathic scoliosis patients within a prospective clinical trial

Halm-Zielke instrumentation (HZI) was developed to eliminate the disadvantages of Zielke instrumentation (VDS) in terms of lack of primary stability and a kyphogenic effect. HZI is an anterior double-rod system. The system is composed of a lid-plate, which is fixed at the lateral aspect of the vertebral body with two screws, a sunk screw anteriorly and a VDS screw posteriorly. The lid-plate design provides the lowest possible implant profile. The longitudinal components consist of a threaded VDS rod and a solid, fluted rod. Correction is performed with the threaded rod and the solid rod. The solid rod allows internal derotation and relordosation, eliminates the Zielke three-point lever system and augments the system. The fluted design of the rod provides rotatory stability. This is a report of the first ten consecutive adolescent idiopathic scoliosis patients in a prospective clinical trial using HZI with a minimum follow-up of 2 years. Curves ranged from 36 degrees to 77 degrees. Correction of the frontal plane averaged 77.5% and 72.2% postoperatively and at follow-up, respectively. Thoracolumbar kyphosis was present in three patients and corrected in all from an average of +18 degrees to +1.7 degrees at follow-up. Implant-related complications were not observed. All patients were treated without any additional external immobilization. In our opinion, HZI is a major improvement on the original Zielke VDS. It eliminates the kyphogenic effect and provides primary stability.

Oral fluid therapy. A promising treatment for vasodepressor syncope

OBJECTIVE

To investigate the predictive value of an intravenous fluid bolus during tilt table testing on clinical outcome and to evaluate of oral therapy is an effective treatment for patients with vasodepressor syncope.

DESIGN

Retrospective cohort.

SETTING

Regional pediatric cardiology outpatient clinic.

PATIENTS

Patients (N = 58) with a positive baseline tilt table testing result who were treated with oral fluid therapy between February 1991 and March 1996.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Patients with a positive tilt table test result were given an intravenous bolus of isotonic saline solution. Responders were identified as having a negative tilt table test result after the bolus. Patients were prescribed a protocol of oral fluid therapy. Data were obtained from the medical record and a mailed survey.

RESULTS

Of the 58 subjects, 90% had no recurrent syncope while receiving oral fluid therapy. During tilt table testing, the mean decrease in mean arterial pressure seen with symptomatic events was lower after the intravenous fluid. The heart rate, which dropped during the initial test, increased during the rests after the intravenous bolus. In the nonresponders, symptomatic episodes occurred significantly later in the tilt table test when given fluids. The response to intravenous fluid bolus had positive predictive value of 92% and negative predictive value of 11% of clinical outcome.

CONCLUSIONS

Our data suggest that oral fluid therapy is an effective treatment for vasodepressor syncope in our population. Fluid bolus response during tilt table testing has a high positive but a low negative predictive value of response to oral fluid therapy. We now recommend oral fluid therapy as a primary intervention and reserve tilt table testing for oral fluid therapy failures.

Left ventricular systolic function, arterial elastance, and ventricular-vascular coupling: a developmental study in piglets

Circulatory changes occur during perinatal life that increase cardiac output and left ventricular contractile reserve. To examine postnatal changes in left ventricular systolic function and ventricular-vascular coupling, piglets underwent cardiac catheterization at 1, 2, 4, and 6 wk of age. We measured end-systolic elastance (Ees), preload-recruitable stroke work, dP/dt(max), the dP/dt(max) end-diastolic volume relation, cardiac index, heart rate, arterial elastance (Ea), and the ratio Ea/Ees, at rest, during isoproterenol infusions (0.05-1.0 microg/kg/min), and after propranolol (1 mg/kg i.v.). Resting heart rate and cardiac index decreased between 1 and 6 wk. In 1 wk olds, resting Ees was at maximum and was unchanged during isoproterenol infusion; isoproterenol increased other contractility indices. Two, 4, and 6 wk olds demonstrated reserve using all contractility indices. Contractile efficiency was not different between ages. In 1 wk olds, Ea decreased during isoproterenol infusion; isoproterenol did not change Ea at 6 wk. Ea/Ees was higher at rest at 6 wk than at 1 wk, and fell significantly on isoproterenol; isoproterenol did not change Ea/Ees at 1 wk. With beta-adrenergic stimulation, 1 wk olds increased cardiac index by increasing heart rate and decreasing afterload, 6 wk olds increased cardiac index by increasing heart rate and contractility; no change in contractile efficiency was found in either group. In summary, contractile reserve is limited at 1 wk when measured by Ees, but other indices demonstrated reserve. Indexed Ea falls in response to beta-adrenergic stimulation in all ages but 6 wk. Ventricular-vascular coupling is optimized at 1 wk even under baseline conditions.

Digital acoustic analysis of precordial innocent versus ventricular septal defect murmurs in children

This study examines whether digital acoustic analysis of individual cardiac sound components for intensity, timing, and frequency could differentiate between innocent and pathologic murmurs. With use of this new technology, sensitive and specific criteria can be established for a fast and easy screening procedure to help differentiate between innocent and ventricular septal defect murmurs in children with suspected heart disease.

Effects of commonly used adrenergic agonists on left ventricular function and systemic vascular resistance in young piglets

This study compared the effects of high-dose infusions of various adrenergic agonists on cardiovascular function in piglets. We hypothesized that agonists would have different effects on systolic, diastolic, and vascular functions. Nine anesthetized 3-week-old piglets underwent cardiac catheterization. Manometric and conductance catheters measured pressures and volumes. Data were acquired at rest and during infusions of epinephrine, norepinephrine, dopamine, dobutamine, isoproterenol, and phenylephrine. End-systolic elastance, preload-recruitable stroke work, cardiac output, the maximum and minimum derivatives of left ventricular pressure, the relaxation constant tau, peak filling rate, and end-diastolic stiffness were obtained. Contractile efficiency and the cardiac output/pressure-volume area ratio were calculated. Regression was used for analysis of variance; p < 0.05 was considered significant. All agonists increased indexes of contractility. beta-Adrenergic agonists enhanced relaxation. Isoproterenol and dopamine increased efficiency. No drug changed diastolic stiffness. Therefore both alpha-adrenergic and beta-adrenergic agonists have inotropic effects in the 3-week-old piglet. Some beneficial effects of beta-agonists on cardiac output may be due to enhancement of relaxation and to afterload reduction. Various agents exert different effects on the cardiovascular system, and these differences may be clinically important.

Safety of thoracic transverse process fixation: an anatomical study

An anatomical study of the passage of the implant placed around thoracic transverse process was undertaken in human cadavers to investigate the safety of thoracic transverse process fixation. A simulated surgical procedure for implant placement around the transverse processes of T1-T10 was carried out in eight fresh human cadavers using a mock plastic implant, 7.0 mm wide and 1.5 mm thick. A total of 80 implanted thoracic vertebrae were dissected systematically. One implanted spinal column was sectioned sagittally through the costotransverse space. The parietal pleura, the intercostal vessels, and intercostal nerves were not injured by the implants in any of the specimens. All the implants were located posterior to the intercostal nerves and vessels, lateral to the pedicles, and outside the spinal canal. The transverse processes of T1-T10 are safe structures for implant anchorage in posterior spinal instrumentation.

Surgical approaches for the correction of unstable thoracolumbar burst fractures: a retrospective analysis of treatment outcomes

The authors retrospectively studied 49 nonparaplegic patients who sustained acute unstable thoracolumbar burst fractures. All patients underwent surgical treatment and were followed for an average of 27 months. All but one patient achieved solid radiographic fusion. Three treatment groups were studied: the first group of 16 patients underwent anterior decompression and fusion with instrumentation; the second group of 27 patients underwent posterior decompression and fusion; and the third group of six patients had combined anterior-posterior surgery. Prior to surgical intervention, these groups were compared and found to be similar in age, gender, level of injury, percentage of canal compromise, neurological function, and kyphosis. Patients treated with posterior surgery had a statistically significant diminution in operative time and blood loss and number of units transfused. There were no significant intergroup differences when considering postoperative kyphotic correction, neurological function, pain assessment, or the ability to return to work. Posterior surgery was found to be as effective as anterior or anterior-posterior surgery when treating unstable thoracolumbar burst fractures. Posterior surgery, however, takes the least time, causes the least blood loss, and is the least expensive of the three procedures.

Coronary artery fistula in the pediatric age group: a 19-year institutional experience

Ten patients with coronary artery fistulae were identified from records at Columbus Children's Hospital between 1974 and 1993. Clinical presentations of patients were quite variable, from 1 day to 20 years of age. Symptoms ranged from none to severe cardiorespiratory failure requiring extracorporeal membrane oxygenation. Long term follow-up revealed one sudden death and one spontaneous closure of the fistula. This lesion should be ruled out in patients who present as extracorporeal membrane oxygenation candidates. Patients with mild forms of this lesion may be followed up medically if the left to right shunt is inconsequential, because spontaneous closure is a possibility. Because of the risk of sudden death, close long-term follow-up is mandatory even for operated patients, and antiplatelet therapy should be considered for these patients.

Effects of renin-angiotensin system in mediating endothelin-induced renal vasoconstriction: therapeutic implications

PURPOSE

Experiments were designed to determine whether angiotensin converting enzyme inhibition with quinaprilat can prevent endothelin-mediated decreases in renal blood flow and the glomerular filtration rate in the anesthetized dog.

METHODS

To mimic the activation of the renal endothelin system that occurs in a number of cardiorenal disease states, endothelin was administered intrarenally in a group of mongrel dogs. Quinaprilat, the major active metabolite of quinapril, was infused in a separate group. One kidney (group 1) or both kidneys (group 2) were exposed in order to measure renal blood flow by an electromagnetic flow probe. Mean arterial blood pressure was measured through a catheter in a femoral vein. Blood samples were taken to determine plasma renin activity. Urine was collected.

RESULTS

The infusion of endothelin decreased renal blood flow and the glomerular filtration rate and increased renal vascular resistance. These renal vascular responses were associated with increased plasma renin activity, indicating activation of the renal renin-angiotensin system. Quinaprilat attenuated the renal vascular responses.

CONCLUSIONS

These studies provide further evidence of the importance of the renal renin-angiotensin system in mediating the renal vasoconstrictor actions of endothelin and indicate the therapeutic potential for quinapril in opposing the actions of endothelin in states of excessive endothelin activation.

Use of cardiac catheterization in pediatric cardiac surgical decisions

Current practice patterns relating to pediatric cardiac catheterization (Cath) have considerable economic implications. The decreased cost and risk of noninvasive methods such as echocardiography (ECHO) and magnetic resonance imaging (MRI) make them attractive alternative diagnostic methods if they can sufficiently define cardiac anatomy and the need for surgical intervention. We reviewed a recent cardiac surgical series of 465 cases in 1.5 years to determine how often a Cath was performed prior to surgery. Overall, 59.4% of the procedures were preceded by a Cath (76% of open heart operations, and 26.7% of closed heart operations). We specify the situations where we feel enough information is available for preoperative decision making from non-invasive testing, and we present some diagnostic pitfalls that have been encountered.

Comparison of operative versus nonoperative treatment of lumbar burst fractures

The outcomes of traumatic two- and three-column lumbar burst fracture patients treated operatively and nonoperatively were investigated with respect to treatment complications, resumption of employment, and quality of life. Data were obtained from hospital records, radiographs, and written questionnaires. Of 93 patients diagnosed with lumbar fracture between January 1987 and December 1989, 22 met the criteria for study (12 operative, ten nonoperative). Exclusion was based on single-column compression or chance fractures, neurologic compromise, and nontraumatic fractures. The patient groups had distinctly different fracture patterns based on degree of anterior column compression (ACC). Trends toward significant differences in kyphotic angulation and canal compromise were noted. There were no preoperative complications. Varying modes of external immobilization were used in both groups. One patient in each group used narcotic medications for pain at final follow-up evaluation. When comparing the operatively and nonoperatively treated lumbar burst fracture patients in this study group, no significant difference in treatment outcome was established. Nonoperative treatment remains a viable alternative to operative intervention in selected lumbar burst fracture patterns.

Influence of pedicle fixation on postoperative pain

From October 1988 through November 1990, 29 lumbar and lumbosacral spine fusion patients, 11 instrumented and 18 noninstrumented, were observed. Seventeen were men and 12 were women, with a mean age of 42.6 years (range, 22-83). The narcotic equivalent (NE) in milligrams/kilogram/day of medication used was analyzed. Age, sex, height, and weight were compared to the type, dose, mode, and duration of medication administration. Morphine was the reference point narcotic at 1.0:1.0. Levels fused, use of instrumentation, and prior surgery were related to NE. No significant differences in age, total body weight, height, levels fused, or hospital stay were established. There were 89.6% of patients over the ideal body weight by a mean 17.47 kg or 38.3 lb. The mean population NE was 3.76 mg/kg/day. Prior surgery patients tended to request narcotics intramuscularly for a longer period, while older patients tended to receive less medication. Patient obesity was related to lower NE. This study could not demonstrate a decrease in postoperative pain as it relates to the amount of narcotic medication received with the use of pedicle instrumentation.

Nonoperative treatment in burst fractures of the lumbar spine (L2-L5) without neurologic deficits

A retrospective review of 20 patients treated nonoperatively for burst fractures of the lumbar spine (L2-L5) was performed. All patients were neurologically intact at the time of injury. Follow-up averaged 3.9 years with a range of 2.1 to 9.1 years. Fourteen patients were men and six were women. The average age at injury was 35.8 years (8-67 years). Sixty-five percent of the injuries were the result of motor vehicle accidents and 35% falls from height. Fifty-five percent were two-column injuries and 45% three-column injuries. Kyphotic deformity averaged 8 at injury (-7 to 30) and 9.6 at follow-up (-8 to 33). Computed tomography scans were performed in nine patients during evaluation of injury. Spinal canal compromise averaged 40% (18-75%). Eighteen patients (90%) were considered to have a good to excellent functional outcome, whereas two patients had a fair outcome. No patient had a poor outcome. In no patient did neurologic deterioration or symptomatic spinal stenosis develop. Twenty-five percent of patients had no back pain, 70% mild back pain, and 5% moderate back pain. No patient was totally incapacitated by pain. Of those employed, all returned to full-time work. Nonoperative treatment should be considered as an alternative in the treatment of lumbar burst fractures (L2-L5) in patients presenting without initial neurologic deficits.

Renal-specific actions of angiotensin II receptor antagonism in the anesthetized dog

The role of angiotensin II (AII) in the regulation of systemic hemodynamic and renal function and sodium excretion, although important in states characterized by the activation of the renin-angiotensin system, remains unclear under basal conditions. The current studies were designed to define the role of AII in the basal regulation of cardiovascular and renal function using a specific AII receptor antagonist, DuP 753, in the normal anesthetized dog. No changes in mean arterial pressure, cardiac output, or systemic vascular resistance were observed during the infusion of DuP 753. In contrast, a significant increase in glomerular filtration rate (19.7 +/- 0.9 to 26.1 +/- 2.0 mL/min) and renal blood flow (151 +/- 20 to 188 +/- 26 mL/min), with a decrease in renal vascular resistance (0.85 +/- 0.10 to 0.66 +/- 0.06 mm Hg/mL/min) was observed. Associated with the renal hemodynamic changes, a diuretic (0.16 +/- 0.05 to 0.57 +/- 0.21 mL/min) and natriuretic (31.2 +/- 7.0 to 100.5 +/- 22.2 microEq/min) response was also demonstrated. Renal hemodynamic changes were also associated with a decrease in tubular sodium reabsorption characterized by an increase in the fractional excretion of sodium (1.10 +/- 0.3 to 2.61 +/- 0.62%), with an associated decrease in whole-kidney proximal tubular reabsorption indicated by an increase in fractional excretion of lithium (31.2 +/- 2.2 to 40.8 +/- 3.9%). In addition, a kaliuretic (17.9 +/- 2.1 to 27.1 +/- 2.4 microEq/min) response was observed despite a concurrent decrease in plasma aldosterone (10.8 +/- 1.5 to 8.1 +/- 1.0 ng/dL).(ABSTRACT TRUNCATED AT 250 WORDS)

Posterior upper cervical fusion in rheumatoid arthritis

The purpose of this study was to determine fusion rates in patients who underwent posterior cervical fusion for instability of the upper cervical spine secondary to rheumatoid arthritis. A retrospective review of clinical and radiographic data was conducted. Nineteen patients underwent posterior cervical fusions limited to the upper cervical spine. There were 11 C1-C2 fusions and 8 occiput-C2 fusions. Instability with pain or neurologic deficits were the main indications. A uniform technique was used in all cases. Preoperative reduction in halo vest or cast was followed by a Gallie type fusion using autogenous iliac bone graft and wire, and postoperative halo vest or cast immobilization for 3 months. A fusion rate of 94% was achieved. The average follow-up was 5 years. Complete or partial relief of pain was obtained in all patients; 30% of those with preoperative deficits improved after surgery. A high fusion rate may be achieved with C1-C2 and occiput-C2 fusions in rheumatoid arthritis, with relief of pain and prevention of neurologic deterioration.

Histopathologic abnormalities of the sinus node compared with electrocardiographic evidence of sinus node dysfunction after the modified Fontan operation: an autopsy study of 14 cases

Autopsy specimens from 14 patients who had undergone a modified Fontan operation were evaluated to correlate the extent of histopathologic disruption of the sinus node with electrocardiographic findings of sinus node dysfunction. Patients with sinus node dysfunction (n=7) and those without (n=7) were similar in age, complexity of cardiac malformation, and number of postoperative days at time of death. The degree of fibrosis, local hemorrhage, necrosis, lymphocytic infiltration, and focal calcification of the sinus node and perinodal tissue was also similar in both groups. These findings, which showed a comparable amount of sinus node disruption in patients with normal sinus rhythm and in those with sinus node dysfunction, indicate a lack of correlation between the extent of histopathologic abnormality of the sinus node and electrocardiographic evidence of sinus node dysfunction.

Incidence of prematurity and low birth-weight in an immigrant Chinese population

This paper analyses the incidences of prematurity (gestation less than 37 weeks) and low birth-weight (birth-weight between 500 and 2,500g) in liveborn singleton infants born in Australia to mothers of the Chinese race. The incidence of prematurity was lower in infants born to mothers from Hong Kong (4.6%), to those from an almost exclusive Chinese population (5.5%) and to those that comprised a predominantly Chinese population (6.1%) when compared to that in a mainly non-Chinese population (7.7%). The incidence of low birth-weight was lower in infants born to mothers from Hong Kong (3.5%) and to those born to an almost exclusive Chinese population (4.1%) but not to those born to a predominantly Chinese population (5.9%) when compared to that in those born to a mainly non-Chinese population (5.9%). The incidence of major fetal malformations was similar in these Chinese and non-Chinese populations. This study confirms that Chinese have a significantly low incidence of prematurity and that this finding remains true when they live in Australia. Detailed prospective studies are required in immigrant Chinese to determine why they have such a low incidence of prematurity and to determine the incidence of fetal malformations which is said to be different than in Caucasian populations.

Treatment of hematogenous pyogenic vertebral osteomyelitis with anterior debridement and primary bone grafting

From 1971 to 1984 at the University of Rochester Medical Center, 23 adult patients underwent surgical treatment via an anterior approach for pyogenic vertebral osteomyelitis. Data from 21 patients with greater than 2-year follow-up is presented in this report. Surgical debridement via an anterior approach was performed in all 21 patients. Bone grafting with iliac crest or rib strut was done in 19 patients. Clinical follow-up averaged 4 years, with a range of 2 years to 9 years, 9 months. No patient had a recurrence of osteomyelitis. All patients with neurologic deficits recovered without functional motor or sensory deficits. Of the 19 patients grafted, 18 showed roentgenographic evidence of fusion, and one went on to a pseudarthrosis. The average increase in kyphosis at the infection site was 3 degrees. In selected patients with pyogenic vertebral osteomyelitis requiring surgical treatment, anterior debridement and primary bone grafting in conjunction with appropriate antibiotics is successful in treating the infection and promoting osseous fusion in a high percentage of cases.

Multiparameter pilot study of adolescent idiopathic scoliosis

Seventy-two adolescent females with idiopathic scoliosis were studied to determine the possible relationships between parameters previously studied by others, as well as several new parameters. Dichotic listening tests showed that patients with less right-ear advantage for language were more likely to have progressive curves than patients with greater right-ear advantage, implying a difference in hemispheral dominance between the two groups. This finding, if confirmed with larger populations, could lead to a prognostic test for the determination of therapeutic modality. Platelet aggregation was found to be lower than in a group of controls; however, similar findings were also obtained from a group of patients with chronic orthopaedic conditions. Mitral valve prolapse, the electroencephalogram and the mother's age at patient's birth were all found to be nonspecific for the patients as compared to control groups. The level of autonomic system activity in the patients was found to be higher than that observed in controls.

Ventral derotation spondylodesis. A review of 22 cases

Twenty-two patients with major lumbar or thoracolumbar curves were treated with Zielke's modification of the Dwyer instrumentation, termed the "ventral derotation spondylodesis (VDS) system. In 16 patients, this was followed by planned second-stage posterior Harrington instrumentation and fusion. Six patients with adolescent idiopathic scoliosis were treated with VDS instrumentation and fusion alone. In neuromuscular and adult idiopathic scoliosis, a combined approach resulted in excellent curve correction and a high rate of successful fusion. In adolescent idiopathic scoliosis, VDS instrumentation alone resulted in excellent curve correction while permitting a shorter fusion length than conventional posterior Harrington instrumentation.

A new radiological technique for the forefoot

Based on a study of 50 subjects seen at the University of Rochester Medical center, a new axial weightbearing radiological technique of the forefoot is described. The technique is simple, inexpensive, and easily reproducible. It has the advantage of not distorting the forefoot, relationships, unlike currently employed techniques. Since it is performed under weightbearing conditions, the results correlate closer to clinical situations. The subjects under this study, which excluded those with neuromuscular or malalignment problems, were found to fall into two categories: the pain-free and callous-free feet group, who have a well defined arch in the forefoot, and the group of subjects with pain and/or callous under the forefoot, who have a depressed arch. There is also a statistical significance between the relative heights of the tibial and fibular sesamoids. A new classification for hallux valgus based on observations of this technique is proposed.

Lumbosacral transitional vertebrae and their relationship with lumbar extradural defects

The relationship between herniated lumbar disc and abnormalities of the transverse process of the lumbosacral junction was investigated. Two hundred consecutive patients with positive myelographic findings of herniated lumbar disc were reviewed. Sixty patients presented abnormalities of the transverse process to satisfy the criteria for lumbosacral transitional vertebra. A new classification of lumbosacral transitional vertebra is presented based upon the morphologic and clinical characteristics with respect to herniated nucleus pulposus. Type I represents a "forme fruste" of lumbosacral transitional vertebra and shows no difference in the incidence of the location of herniations. In types III and IV, there are no herniations at the level of the lumbosacral transitional vertebra and no increase in the incidence of herniations just proximal to the lumbosacral transitional vertebra. The Type II lumbosacral transitional vertebra presents herniated lumbar disc at the level of transition. It also presents a greater than normal incidence of herniations at the level just above the lumbosacral transitional vertebra.

Normal cardiac rhythm during hypocaloric diets of varying carbohydrate content

Cardiac arrhythmias have been implicated in the deaths of 17 morbidly obese individuals subsisting on a collagen hydrolysate preparation ("liquid protein") during a modified fasting regimen for weight loss. Serious cardiac arrhythmias have been noted in three of six subjects studied prospectively within 28 days of starting a similar regimen, which used an inadequate protein source and was nearly devoid of all essential minerals. A comparative study of three 28-day weight loss diets of varying carbohydrate, protein, and energy content (450 to 820 kcal/day) but employing protein of good quality and adequate in micronutrients did not disclose substantial diet-related arrhythmias in five subjects on each of the three diets. The incidence of arrhythmia seen with liquid protein diets is not likely to be related to the absolute energy or carbohydrate content of the modified fasting regimen itself.

Bilateral carcinoma of the breast

A review of patients treated at the Peter MacCallum Clinic, Melbourne, between 1968 and 1973 inclusive, revealed 76 cases of primary carcinoma involving the opposite breast. Twenty-one of these occurred synchronously, when they were usually associated with elderly patients, a strong family history and an increased delay in presentation. The behaviour of these tumours was unremarkable, though the survival of the patients may have been less than those with single lesions, and in accord with the doubled risk of distant spread and local recurrence. Fifty-five patients with metachronous lesions did not present initally with features which would help to identify them as being prone to this double pathology. About 50% of the second carcinomas occurred within five years, but the remainder developed at intervals which were in several cases longer than 20 years. The patients did not present earlier on the second occasion, and several had advanced lesions. There was no evidence that the behaviour of the second carcinoma was influenced by immunological factors or patient susceptibility. Implications with regard to management are outlined, and the importance of long-term follow-up with regular examination is emphasized.

Women's attitudes to mastectomy for breast cancer

One hundred patients who had been subjected to mastectomy for carcinoma were interviewed retrospectively to gauge their attitudes to any physical and/or emotional disabilities relating to their operation or disease. It was found that 40% of the patients had delayed for longer than a month after the onset of symptoms before seeking medical advice, but the reasons for this were not readily forthcoming. However, fear of mastectomy was not a common cause. Anxiety and embarassment due to an absent breast occurred in about one-third of patients, and did not diminish with time. Knowledge and the use of mammary prostheses was far from universal, and disturbingly only two-thirds were counselled in these matters by their medical advisers. Physical complications were common, particularly lymphoedema of the arm, and as expected this was closely related to the type and extent of treatment undertaken.

Guidelines for the management of lumbosacral spondylolisthesis associated with scoliosis

Lumbosacral spondylolisthesis, when it is associated with scoliosis, presents special problems which require special consideration in management. Lumbosacral spondylosisthesis associated with a major thoracic curve, presents two separate problems. Treatment of the lumbosacral spondylolisthesis depends upon the severity of the lesion and symptoms. The thoracic curve is treated as required, depending upon the severity of the scoliosis and the stage of spinal maturation. Lumbosacral spondylolisthesis associated with a thoracolumbar or lumbar curve requires treatment of the curves above, along with the spondylolisthesis. Do not fuse the lumbosacral joint in an uncorrected position.

Thoracoomphalopagus diagnosed before delivery

Twins may be dizygotic or monozygotic. Of the monozygotic twins, 25% to 30% are dichorionic and 70% to 75% are monochorionic. Whilst all the dichorionic twins are diamniotic, very occasionally some monochlorionic ones may be monoamniotic; some of these may be conjoined. A case of conjoined twins was diagnosed during pregnancy. The two girls were delivered by elective classical caesarean section. They were joined together from just above the xiphisternum to the umbilicus and were successfully separated. Recent literature is reviewed.