Systemic lupus erythematosus presented as non-inflammatory necrotizing vasculopathy-induced ischemic glomerulopathy and small vessels-related ischemic cardiomyopathy

The clinical significance of lupus non-inflammatory necrotizing vasculopathy (NINV) is not well established. For example, since lupus renal NINV is usually reported to coexist with proliferative and active glomerulonephritis, it is difficult to demonstrate the role of NINV on renal pathophysiology. Here we report a 16-year-old SLE boy with renal NINV presenting as ischemic glomerulopathy and small vessels-related ischemic heart failure. The renal biopsy demonstrated mild proliferative glomerulonephritis and NINV initially, and one month later repeated renal biopsy showed NINV with ischemic glomerulopathy. These findings established that NINV, but not proliferative glomerulonephritis, was responsive for his acute renal failure (ARF). Another interesting question is about the pathophysiology of his myocardial dysfunction. This patient presented typical angina and congestive heart failure (CHF). Echocardiograms and ventriculography revealed dilatation of four chambers and low ejection fraction. Serial electrocardiograms demonstrated evolutionary ischemic changes. Coronary angiography revealed no abnormality of large vessels. These findings suggested small vascular lesions-induced myocardial ischemia was the underlying mechanism of dilated cardiomyopathy. As myocardial biopsy was not done in our case, we could only speculate, but not prove, that the NINV observed in renal biopsy may also involve in cardiac microvascular beds. Nevertheless, this interesting case emphasized the role of obliterative small vascular lesions in the pathophysiology of ARF and myocardial dysfunction. The patient was treated with high-dose corticosteroid, plasma infusion and hemodialysis. His cardiac function improved gradually, however the renal function did not recover.

Candidaemia in patients with dialysis-dependent acute renal failure: aetiology, predisposing and prognostic factors

BACKGROUND

Infections remain the major cause of death among patients with acute renal failure (ARF), especially in severe ARF necessitating dialysis therapy (ARF(d)). Although the clinical features and outcomes of candidaemia in various patient populations have been described, data concerning candidaemic episodes among patients with ARF(d) are scarce. This study investigated the aetiology, predisposing, and prognostic factors for candidaemia in the ARF(d) patient population. Three patient groups were investigated in this study.

METHODS

During an 8-year study period from January 1992 to December 1999, 37 candidaemic episodes that developed among 653 ARF(d) patients were assigned to ARF(d) candidaemic group, and 170 candidaemic episodes developing in patients without ARF(d) or chronic uraemia as the non-ARF(d) candidaemic group, and 28 matched ARF(d) patients without candidaemia were assigned to the ARF(d) control group. Among these groups, clinical characteristics in ARF(d) candidaemia patients, predisposing factors, and outcomes were compared. Four management strategies including central catheter removal, anti-fungal therapy, both, or neither were applied. The prognostic factors for attributable death were evaluated by univariate analysis followed by the multivariate logistic regression analysis.

RESULTS

The proportion of ARF(d) patients with candidaemia was significantly higher than in patients who had no ARF(d) or chronic uraemia (5.7% vs 0.15%, P<0.001). Compared with the non-ARF(d) candidaemic group, systemic lupus erythematosus (SLE), administration of corticosteroid, and central venous catheter-associated candidaemia were more common in the ARF(d) candidaemic group (P<0.05). In matched case-control study, multiple antibiotic usage was shown to be a predisposing factor for developing candidaemia in patients with ARF(d), and corticosteroid therapy has a marginal significance (P=0.059). The occurrence of candidaemia increased the mortality rate of ARF(d) (71% vs 39.2% in ARF(d) control group, P<0.05). By multivariate logistic analysis, the variables associated with attributable death in ARF(d) candidaemic group were identified to be an APACHE II score of >or=18, and anti-fungal therapy for >48 h. Central venous catheters were removed in 32 (86.5%) of the 37 ARF(d) candidaemic patients, among whom the 18 patients who had received anti-fungal therapy for >48 h had a lower attributable death rate than those patients who had not (27.8% vs 64.3%, P<0.05). Of the remaining five patients who did not have their catheter removed, three patients subsequently died and two patients improved only after catheter removal.

CONCLUSIONS

The higher prevalence of candidaemia in ARF(d) patients is due to their underlying illnesses and multiplicity of predisposing factors, rather than ARF and dialysis therapy per se. Predisposing factors include SLE, indwelling central venous catheter, multiple antibiotic usage, and corticosteroid therapy. Prompt anti-fungal therapy and catheter removal should be mandatory for ARF(d) patients with candidaemia.

Regional anaesthesia decreases the need for postoperative mechanical ventilation in very low birth weight infants undergoing herniorrhaphy

BACKGROUND

We were interested to know whether regional anaesthesia allowed improved respiratory function postoperatively in very low birth weight babies.

METHODS

We performed a retrospective study to examine the association between regional anaesthesia and postoperative ventilation after herniorrhaphy in very low birth weight infants. Thirty-four prematurely born infants underwent herniorrhaphy from 1995 to 1997 at St Louis Children Hospital. Eighteen patients had general anaesthesia, 16 had regional anaesthesia. The mean gestational age was 26 weeks, mean postconceptual age at surgery was 38 weeks, mean birth weight was 860 g.

RESULTS

There was significant difference in postoperative ventilation support requirements between the two study groups (7/18 versus 1/16, P < 0.05).

CONCLUSIONS

Regional anaesthesia decreases the need for postoperative ventilatory support requirements in very low birth weight infants undergoing herniorrhaphy.

Decreased predominance of papG class II allele in Escherichia coli strains isolated from adults with acute pyelonephritis and urinary tract abnormalities

PURPOSE

We compared the genotypes of fimbriae or adhesions of Escherichia coli causing acute pyelonephritis in adults with and without urinary tract abnormalities.

MATERIALS AND METHODS

We studied a total of 92 E. coli strains isolated from 54 patients with acute pyelonephritis and a normal urinary tract, and 38 with urinary tract abnormalities. Of those with urinary tract abnormalities 13 with moderate to severe hydronephrosis were also considered a separate group for the purpose of analysis. The genes of 7 known fimbriae or adhesins of E. coli were detected by the polymerase chain reaction, including the papG class I to III alleles (PapG adhesins of P-fimbriae), sfa/foc (S-/F1C-fimbriae), fimH (type 1 fimbriae), and afa (afimbrial adhesin). Virulence genes associated with APN were identified by comparing the prevalence of each of these 7 genes in E. coli strains from 54 patients with acute pyelonephritis with a normal urinary tract to the prevalence in the strains from 37 patients with acute cystitis using univariate and multivariate analysis. Differences in the prevalence of the genes associated with acute pyelonephritis and the incidence of underlying illness were then compared in the 3 acute pyelonephritis groups.

RESULTS

On univariate and multivariate analysis the papG class II allele was the only virulence gene associated with acute pyelonephritis (p <0.0001 and 0.001, respectively). No significant difference was noted in the prevalence of underlying medical disease in the 3 acute pyelonephritis groups. The papG class II allele was significantly less predominant in E. coli strains isolated from acute pyelonephritis cases with versus without urinary tract abnormalities (76% versus 93%, p = 0.03). The incidence of the papG class II allele in patients with urinary tract abnormalities and moderate to severe hydronephrosis was less than in those without urinary tract abnormalities (69% versus 93%, p = 0.04).

CONCLUSIONS

Our results imply that the papG class II allele has an important role in E. coli infection in patients with acute pyelonephritis and a normal urinary tract, while urinary tract abnormalities and/or obstruction may permit ascending infection of E. coli strains with lower adhesive ability.

[The status and prospects of X-ray photographs marking technology]

This article introduces three different marking technologies used in clinical radiation photography at present and their respective theories, their advantages and disadvantages, analyzes the space-time and technology conditionality of different marking technologies in selecting mark messages. In the future, new marking technology will be fused with the cassette into one and will contain message as much as possible on photograph marks in order to satisfy the need of technicians and doctors.

Noninvasive stool antigen assay can effectively screen Helicobacter pylori Infection and assess success of eradication therapy in hemodialysis patients

Helicobacter pylori (H pylori) stool antigen (HpSA), serological antibody against H pylori (immunoglobulin G [IgG]), and urea breath test (UBT) are noninvasive methods used to detect H pylori infection that can allow a patient to avoid the discomfort and risk of invasive endoscopy. However, because the UBT has proven not highly reliable in patients with end-stage renal disease (ESRD), this study attempts to investigate the diagnostic efficacy of HpSA and IgG for H pylori detection in 80 patients with ESRD and 80 dyspeptic patients without renal function impairment as a control group. All patients in both study groups underwent panendoscopy to obtain gastric biopsy specimens for histological examination and H pylori culture. With H pylori infection defined as a positive result on either histological examination or culture, we evaluated the reliability of HpSA and serum IgG in detecting H pylori infection. Forty of the patients with ESRD (50%) and 48 patients in the control group (60%) were proven to be infected with H pylori. To eradicate H pylori infection, these patients were administered a 1-week course of triple therapy. To evaluate the success of H pylori eradication, 38 patients in the ESRD group and 44 patients in the control group underwent a follow-up endoscopy and provided stool samples for HpSA 6 to 8 weeks later. Success of H pylori eradication was found in 86.8% of the patients with ESRD (33 of 38 patents) and 84.1% of the control patients (37 of 44 patients). Before therapy, HpSA for H pylori detection was 97.5% sensitive and 97.5% specific in patients with ESRD, as effective as that in the control group. After therapy, HpSA was 100% sensitive and more than 96% specific to detect the failure of H pylori eradication therapy in both the ESRD and control groups. Conversely, the use of IgG as a screening method for H pylori infection proved to be less effective because it showed a sensitivity of 87.5% and specificity of 80% in this study. Monitoring the success of triple therapy, IgG had a specificity of only 21.9% in the ESRD group and 24.3% in the control group. In summary, HpSA is a noninvasive and reliable tool to screen H pylori infection before therapy and assess the success of eradication therapy in patients with ESRD.

Body warmer and upper extremities position affect the accuracy of cutaneous thermometers during anesthesia

STUDY OBJECTIVE

To evaluate whether axillary skin temperature can accurately reflect distal esophageal temperature.

DESIGN

Prospective, randomized study.

SETTING

Teaching hospital.

PATIENTS

48 ASA physical status I and II adult patients undergoing abdominal surgery.

INTERVENTIONS

Patients received standard general anesthesia. 19 patients had abducted upper extremities and an upper body surface warmer, 19 patients had abducted upper extremities with no upper body surface warmer, and 10 patients had adducted upper extremities with no upper body surface warmer.

MEASUREMENTS AND MAIN RESULTS

The temperatures were measured 60 minutes after the induction of general anesthesia. There was no significant difference between axillary skin temperature (36 +/- 1.7) (degrees C) and core temperature (36 +/- 0.7) (degrees C) when the upper body surface warmer was used. There was no difference between axillary skin temperature (35.5 +/- 0.4) (degrees C) and core temperature (35.8 +/- 0.4) (degrees C) when upper extremity was adducted 0 degrees.

CONCLUSIONS

At 0 degrees of arm adduction, or at 90 degrees using the upper body, forced-air surface warmer, axillary skin temperature accurately identified the core temperature in patients during general anesthesia.

Incidence, transmission, and clinical significance of hepatitis G virus infection in hemodialysis patients

A high prevalence of hepatitis G virus (HGV) infection has been noted in patients receiving chronic hemodialysis (HD) therapy, yet the incidence rate and transmission route have rarely been reported. Serum samples from 160 chronically uremic patients in a HD unit were initially collected at the time chronic HD therapy was begun, and thereafter annually in July and, finally, in November 1999. Serum HGV RNA was detected using nested reverse transcription polymerase chain reaction, and HGV E2 antibody was determined using an enzyme immunoassay. Nucleotide sequences of the 5'-noncoding region were studied in the HD patients with HGV viremia. Forty healthy staff members were also enrolled as control subjects. Three of the 40 (7.5%) healthy staff members were positive for HGV RNA or HGV E2 antibodies, in contrast to 40 of the 160 (25%) HD patients, including 14 (8.8%) who were positive for HGV RNA only, 25 (15.6%) who were positive for HGV E2 antibody only, and 1 (0.6%) who had both markers. HGV exposure did not correlate with gender, age, duration of HD therapy, or history of blood transfusions. At least 20 of the 40 (50%) patients with HGV exposure had been infected before the start of chronic HD therapy. Nevertheless, at least nine (22.5%) patients acquired new HGV infections after starting chronic HD therapy, with an incidence rate of > or = 2.6% per year. Three patients with newly acquired HGV viremia after HD therapy was started and two with pre-existing HGV viremia before HD therapy was started had the same nucleotide sequences. HGV and HCV infections (with a prevalence of 14.4%) might have been transmitted independently in HD patients. In addition, HGV infection was not found to cause significant elevation of alanine aminotransferase levels in the group exposed to HGV. To conclude, the incidence of new HGV infections was at least 2.6% per year. In addition to transmission through blood transfusion, HGV may have been transmitted nosocomially patient-to-patient within the HD unit. The compliance with standard universal precautions should be carefully re-examined, but it is not necessary to routinely screen for HGV infection among patients on chronic HD.

Generalized argyria in two chronic hemodialysis patients

Silver can be absorbed through ingestion, topical administration, or inhalation. Generalized argyria results from deposition of silver in the skin, nails, mucous membranes, and internal organs and is characterized by a diffuse bluish-gray discoloration in sun-exposed areas. We report two cases of generalized argyria in patients on maintenance hemodialysis (HD) therapy for more than 15 years. They presented with diffuse hyperpigmentation of the face that was mistaken to be related to uremia and bluish-gray discoloration of all nails believed to be cyanosis. Histopathologic examination of skin biopsy specimens showed characteristic findings of argyria, which was further confirmed by radiograph microanalysis. Their serum silver levels were also elevated. No definite silver source could be determined. However, their argyria might be related to their long-term HD therapy because (1) they had been on HD therapy for more than 15 years and the discoloration appeared several years afterward, and (2) the water used for HD was not well processed in the early 1980s in TAIWAN: Argyria should be suspected in chronic HD patients presenting with a diffuse bluish-gray discoloration of the skin and nails and evaluated carefully by skin biopsy.

The heterogeneity in risk factors of lung cancer and the difference of histologic distribution between genders in Taiwan

OBJECTIVE

The difference in histologic patterns of lung cancer between men and women in Taiwan may be associated with the heterogeneity in causal factors of lung cancer between the sexes. A sex- and age-matched case-control study was designed to investigate such a relationship.

METHODS

Cases consisted of 236 male and 291 female incident cases with newly diagnosed and histologically confirmed primary carcinoma of the lung, and were compared to one or two individually matched controls.

RESULTS

Cigarette smoking, occupations, and previous tuberculosis history were found to independently correlate with an elevated risk of squamous/small cell carcinoma and adenocarcinoma for male patients. However, there was little difference in the effect of these risk factors except smoking. The use of fume extractors in the kitchen, and the habit of waiting to fry after the fumes were emitted, separately explained the majority of the attributable fraction of female squamous/small cell carcinoma (28.2%) and adenocarcinoma (47.7%). With the exception of a kitchen with fume extractors and a clinical history of tuberculosis, the environmental causal factors of lung cancer were heterogeneous between these two histologic cell groups.

CONCLUSIONS

Our results suggested that the causal factors of lung cancer might be specific for the type of tumor concerned. The gender-specific risk factors of lung cancer could partly explain the difference in cell-type distribution between men and women.

[Study on base insertion/deletion of CAG-rich region in insulin receptor substrate-1 5'-regulatory sequence]

To study the relationship of the polymorphism of the insulin receptor substrate-1 (IRS-1) gene 5'-flanking regulatory sequence and Type 2 diabetes, the IRS-1 gene 5'-flanking regulatory sequence was scanned by PCR-SSCP in 78 healthy control subjects and 76 Type 2 diabetic subjects. Applying PCR-denatured polyacrylamide gel electrophoresis and silver staining, the insertion/deletion polymorphism of the CAG-rich region was analyzed. The genome DNA of the normal and variant subjects was amplified with high-fidelity pfu DNA polymerase. The purified and digested target fragments were then subcloned into the pCAT Basic vector. Each allele was identified according to the mobility by the restrictive endonuclease digestion of the recombinant combined with denatured polyacrylamide gel electrophoresis and silver staining, and finally the constructive plasmids containing different alleles were analyzed by DNA sequencing. Firstly, we found several insertion/deletion variations in the CAG-rich region of IRS-1 gene. Secondly, 7 genotypes and 6 alleles(T1-T6) in this site were detected. Moreover, T5 and T6 were only observed in Type 2 diabetic group.

Extreme metabolic alkalosis treated with normal bicarbonate hemodialysis

Metabolic alkalosis (MA), defined as a primary increment in plasma bicarbonate concentration, is a common complication in hospitalized patients and is associated with high morbidity and mortality in severe cases. One of the major routes of compensation for MA (ie, the secretion of an alkaline urine) is lost in renal failure patients. We report three cases involving four episodes of extreme MA with an arterial pH value greater than 7.60, serum bicarbonate concentration greater than 55 mmol/L, and stupor or seizure. Profound vomiting or massive gastric drainage combined with concurrent oliguric renal failure was the underlying mechanism for severe MA. Hydration and normal central venous pressure failed to improve the MA. The extreme MA was reversed quickly and safely by conventional hemodialysis with normal bicarbonate dialysate of 25 to 28 mmol/L. To our knowledge, this is the first reported successful use of normal bicarbonate dialysate in the treatment of severe MA. We also found that either H(2) blockers or proton-pump inhibitors have a prophylactic effect on the formation of MA.

Cost analysis in vitrectomy: monitored anesthesia care and general anesthesia

A retrospective study was performed to compare differences in hospital charges between monitored anesthesia care with retrobulbar block and general anesthesia among patients having vitrectomy. Of 128 consecutive patients undergoing vitrectomy between July 1996 and July 1997, group 1 received general anesthesia (n = 41), group 2 received monitored care anesthesia with retrobulbar block (n = 59), and 28 patients were eliminated from the study. There were significant differences in anesthesia charges, operating room charges, pharmacy charges, and total hospital charges between groups 1 and 2. Charges associated with monitored care anesthesia with retrobulbar block are 20% less than charges associated with general anesthesia. Fewer patients in group 2 required postoperative intravenous narcotics than in group 1.

Preoperative oral rofecoxib does not decrease postoperative pain or morphine consumption in patients after radical prostatectomy: a prospective, randomized, double-blinded, placebo-controlled trial

STUDY OBJECTIVES

To evaluate the analgesic efficacy of the rofecoxib po before radical prostatectomy.

DESIGN

Prospective, randomized, double-blinded, placebo-controlled trial.

SETTING

Teaching hospital.

PATIENTS

Anesthetic management was standardized. Patients received either a 50-mg rofecoxib capsule or a placebo capsule po 1 hour before induction of anesthesia.

MEASUREMENTS AND MAIN RESULTS

Patient-generated 10-cm visual analog scale (VAS) scores for pain were assessed at 1, 2, 4, 6, 8, and 24 hours after surgery. Morphine consumption was recorded from a patient-controlled analgesia device at the same time. A patient-generated overall pain relief score was obtained at 24 hours after surgery. We were unable to detect any differences between study groups with respect to postoperative morphine consumption, VAS score, or overall pain relief score.

CONCLUSIONS

When rofecoxib is used po in maximum recommended doses before surgery, it does not provide significant analgesia that results in reduction in pain scores or analgesic requirements for patients after radical prostatectomy.

Adult-onset minimal change disease among Taiwanese: clinical features, therapeutic response, and prognosis

There are some racial differences in the prevalence and prognosis of idiopathic nephrotic syndrome; however, reports about minimal change disease (MCD) in Chinese were rare. We retrospectively analyzed 123 Chinese adults with idiopathic nephrotic syndrome, who received percutaneous renal biopsy in our institution within the last 10 years. In total, 46 patients (37.4%) were compatible with the pathological diagnosis of MCD. The male to female ratio was 1.2:1. The mean age of onset was 30.9 years, and 80% of the patients with MCD were less than 40 years. The mean daily proteinuria was 10.2 g, and serum albumin was 1.8 mg/dl. Azotemia occurred in 16 (35%) of 46 cases; hypertension, 13%; and microscopic hematuria, 13%. High selectivity index for proteinuria (SI <0.1) was noted in 12 (39%) of 31 cases; and high IgE level was found in 83.7% of the study subjects, although only one case had allergic history. Complete remission in 36 MCD patients treated with corticosteroid was achieved by 42% (15/36), 80% (29/36), and 94% (34/36) within 4, 8, and 12 weeks, respectively. The time interval to remission was similar between the younger group (<40 years old, 1.7 months) and older group (>40 years old, 1.6 months). Nineteen (56%) of 34 cases with steroid response did not relapse, and the other cases (44%) had a mean relapse rate of 1.5 times per patient within a period of 45 months. The age of onset in MCD cases was not significantly correlated with steroid-responsive rate, and the time interval to remission. However, a tendency existed between the onset in the young age and the sequentially relapsing rate (p = 0.06). Two cases with primary steroid resistance and 5 cases with frequent relapse or steroid dependence responded well to intravenous pulse therapy of cyclophosphamide, except one refractory case. No thrombotic episode was ever noted in our group. Regarding infectious complications, primary peritonitis occurred in one, pneumonia in one, and cellulitis in 6 cases during active nephrotic stage. Two mortality cases, one with E. coli-related necrotizing fasciitis and one from pneumonia, were noted. In brief, compared with children, adult patients with MCD had lesser high selectivity index for proteinuria, the same steroid-responsive rate (94%), but slower response, and significantly lesser relapsing rate. The intravenous pulse therapy of cyclophosphamide may be an alternative regimen for adult patients with steroid resistance or dependency. In addition, the Asian adult-onset MCD had younger age, male predominance, and lesser relapsing rate in comparison to those of the Western population.

Blood pressure and left ventricular hypertrophy in patients on different peritoneal dialysis regimens

OBJECTIVE

To examine the relation between the results of ambulatory 24-hour blood pressure monitoring (ABPM) and left ventricular mass index (LVMI), then to find the independent determinant for left ventricular hypertrophy (LVH) in peritoneal dialysis (PD) patients. Finally, to evaluate the differences in the clinical and cardiovascular characteristics between patients on continuous ambulatory PD (CAPD) and continuous cyclic PD (CCPD).

DESIGN

An open, nonrandomized, cross-sectional study.

SETTING

Divisions of nephrology and cardiology in a medical center.

PATIENTS

Thirty-two uremic patients on maintenance PD therapy (22 patients on CAPD, and 10 on CCPD) without anatomical heart disease or history of receiving long-term hemodialysis.

INTERVENTIONS

Home blood pressure (BP) and office BP were measured using the Korotkoff sound technique by sphygmomanometer. ABPM was employed for continuous measurement of BP. Echocardiography was performed for measurement of cardiac parameters and calculation of LVMI.

MAIN OUTCOME MEASURES

Multivariate logistic regression analysis was performed for independent determinant of LVH in PD patients. The differences in clinical and cardiovascular characteristics between CAPD and CCPD patients were compared.

RESULTS

Simple regression analysis showed positive correlations between LVMI and the duration of hypertension, ambulatory nighttime BP/BP load/BP load > 30%, serum phosphate, calcium-phosphate product, ultrafiltration (UF) volume, and percentage of UF volume during the nighttime. A negative correlation was noted between LVMI and dipping. In multiple regression analysis, the duration of hypertension was the only variable linked to LVMI. In multivariate logistic regression analysis, only ambulatory nighttime systolic BP load > 30% had an independent association with LVH. There were correlations between office/home BP and ambulatory 24-hour BP. In addition, CCPD patients had higher LVMI, UF volume during the nighttime, and percentage of UF volume during the nighttime than those of CAPD patients.

CONCLUSIONS

In this study, ambulatory nighttime systolic BP load > 30% had an independent association with LVH. Office and home BP measurements were correlated with ABPM in PD patients. The result that CCPD patients had a higher LVMI than CAPD patients may be due to a relative volume overload during the daytime in CCPD patients.

Correlation-based correction of sound velocity inhomogeneities using delta-sigma modulators

Delta-sigma (deltasigma) modulator based beamformers have been proposed for high-quality ultrasonic imaging. Due to the high sampling rate and single bit data width, the cost and complexity of the receive beamformer can be significantly reduced. It was shown that with proper dynamic focusing controls, equivalent image quality could be achieved with an adequate signal-to-quantization noise ratio (SQNR). In this paper, deltasigma modulator based beamformers are used for correlation-based phase aberrations correction of sound velocity inhomogeneities in the body. It is shown that the correction can be efficiently implemented at a performance level similar to that of a conventional radio frequency (rf) beamformer. In addition, more than 6 dB contrast improvement is demonstrated. The different dynamic focusing techniques are also investigated in the context of phase aberration correction. It is shown that the single bit dynamic focusing approach does not affect the overall performance of phase aberration correction.

A dynamic focusing technique for delta-sigma-based beamformers

Beamformation using oversampling delta-sigma (deltasigma) modulators has been proposed for diagnostic ultrasound. Such a beamformer can reduce the size, complexity and cost of an imaging system while providing adequate signal-to-quantization noise ratio (SQNR). High quality images can also be generated if dynamic receive delays are applied correctly. Several dynamic focusing techniques were previously proposed. Generally, an additional bit or extra compensation circuit is required to preserve the power and frequency distribution of the signal. Without preserving the power and frequency distribution, the image background noise is increased. In this paper, an alternative technique is presented. The new technique exploits the symmetry of focusing delays relative to the center of a transducer array. By properly synchronizing the delays and selecting the inserted values, no noise is added to the beam sum signal and the image background level is not increased. Using real ultrasound data, it is shown that the proposed technique provides the same imaging performance as the previous approaches with reduced system complexity by using only a single bit to encode the output of the deltasigma modulator.

Clinical presentations and prognostic factors of a glyphosate-surfactant herbicide intoxication: a review of 131 cases

OBJECTIVE

Suicide attempts with agricultural chemicals are common in southern Taiwan. Among them, glyphosate-surfactant herbicide (GlySH) intoxication has been encountered with increasing frequency. Although a number of reports have described the clinical course and outcomes following ingestion, predictors of serious complications and mortality have not been elucidated. The purpose of this study was to define predictors of serious complications and probable mortality.

METHODS

This was a retrospective study of 131 GlySH-intoxicated patients treated at the National Cheng Kung University Hospital from 1988 to 1995. Medical charts were reviewed and clinical and laboratory variables were abstracted, looking for predictors of mortality.

RESULTS

The most common symptoms included sore throat (79.5%), and nausea with or without vomiting (73.8%). The most common laboratory findings were leukocytosis (68.0%), low serum bicarbonate (48.1%), and acidosis (35.8%). Overall, 11 of 131 patients (8.4%) died; the mean +/- SEM time to death was 2.8 +/- 0.8 days after presentation. When comparing the clinical and laboratory characteristics among the survivor and fatality groups, significant differences were identified. Respiratory distress, pulmonary edema, respiratory distress necessitating intubation, shock (systolic blood pressure less than 90 mm Hg), altered consciousness, abnormal chest x-ray, renal failure necessitating hemodialysis, larger amount of ingestion (>200 mL), and hyperkalemia were predictors highly associated with poor outcomes and mortality. Using multiple logistic regression, three predictors were identified, which may predict mortality in severely intoxicated patients.

CONCLUSIONS

In managing patients who have larger amount of GlySH ingestion, airway protection, early detection of pulmonary edema, and prevention of further pulmonary damage and renal damage appear to be of critical importance.

Diagnostic efficacy of (13)C-urea breath test for Helicobacter pylori infection in hemodialysis patients

The noninvasive urea breath test (UBT) avoids the discomforts and risks of invasive endoscopic methods of Helicobacter pylori detection. This study investigated the diagnostic efficacy of carbon 13 ((13)C)-labeled UBT for H pylori detection in 70 patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD) and 70 dyspeptic controls without renal impairment. With H pylori infection defined as a positive result on either histological examination or culture of gastric biopsy specimen, we evaluated the reliability of the (13)C-UBT in detecting H pylori infection in both groups. To ascertain whether HD therapy affects the diagnostic efficacy of the UBT, the test was performed twice in patients with ESRD (before and after HD) at least 72 hours apart. In each UBT session, the baseline, 10-minute, and 15-minute (Delta15) gas samples were obtained to analyze excess (13)CO(2)/(12)CO(2) ratio (ECR). Histological stain and/or culture studies found that 33 of the patients with ESRD (47. 1%) and 42 of the control patients (60%) had H pylori infection. (13)C-UBT for H pylori detection in patients with ESRD was found to be only 93.8% sensitive and 85.3% specific. These results were achieved by gas sampling (Delta15) after HD therapy with a cutoff ECR value greater than 5. Conversely, the UBT in the control group achieved the greatest diagnostic efficacy (sensitivity, 97.6%; specificity, 96.4%) with a comparatively lower ECR cutoff value of 4. We conclude that the diagnostic accuracy for H pylori detection in patients with ESRD could be improved by performing (13)C-UBT (Delta15) after HD therapy and assessing the UBT with a cutoff ECR value greater than 5. However, the diagnostic efficacy of the UBT for patients with ESRD remained less accurate than that for dyspeptic patients without renal impairment.

Quality of life and outcomes after pancreaticoduodenectomy

OBJECTIVE

To assess the quality of life (QOL) and functional outcome of patients after pancreaticoduodenectomy.

SUMMARY BACKGROUND DATA

Pancreaticoduodenectomy is gaining acceptance and is being performed in increasing numbers for various malignant and benign diseases of the pancreas and periampullary region. There is a general impression that pancreaticoduodenectomy can severely impair QOL and alter normal activities. Only a few small studies have evaluated QOL after pancreaticoduodenectomy.

METHODS

A standard QOL questionnaire was sent to 323 patients surviving pancreaticoduodenectomy who had undergone surgery at The Johns Hopkins Hospital between 1981 and 1997. Thirty items on a visual analog scale were categorized into three domains: physical (15 items), psychological (10 items), and social (5 items). Scores are reported as a percentile, with 100% being the highest possible score. The same QOL questionnaire was also sent to laparoscopic cholecystectomy patients and healthy controls. A separate component of the questionnaire asked about functional outcomes and disabilities.

RESULTS

Overall QOL scores for the 192 responding pancreaticoduodenectomy patients in the three domains (physical, psychological, social) were 78%, 79%, and 81%, respectively. These QOL scores were comparable to those of the 37 laparoscopic cholecystectomy patients and the 31 healthy controls. The pancreaticoduodenectomy patients were subgrouped into chronic pancreatitis, other benign disease, pancreatic adenocarcinoma, and other cancers. Patients who underwent resection for chronic pancreatitis and pancreatic adenocarcinoma had significantly lower QOL scores in the physical and psychological domains compared with the laparoscopic cholecystectomy patients and the healthy controls. Common problems after pancreaticoduodenectomy were weight loss, abdominal pain, fatigue, foul stools, and diabetes.

CONCLUSIONS

This is the largest single-institution experience assessing QOL after pancreaticoduodenectomy. These data demonstrate that as a group, patients who survive pancreaticoduodenectomy have near-normal QOL scores. Many patients report weight loss and symptoms consistent with pancreatic exocrine and endocrine insufficiency. Most patients have QOL scores comparable to those of control patients and can function independently in daily activities.