Reversal of diastolic cerebral blood flow in infants without brain death

The reversal of diastolic cerebral blood flow has been regarded as a characteristic waveform of brain death and a useful confirming sign. We report 2 patients who had diastolic flow reversal but survived. One, a 1-month-old boy with status epilepticus, had reversal of diastolic cerebral blood flow detected by Doppler ultrasound soon after admission. Reversal disappeared after medical management for increased intracranial pressure and seizure control. He recovered without sequelae. The other, a 6-month-old girl with choroid plexus papilloma, had reversal of diastolic flow during abrupt clinical deterioration. Emergent surgical removal of the tumor was performed and she survived with hemiparesis and psychomotor retardation. Our patients demonstrated that even in the presence of diastolic reversal of cerebral blood flow, prompt and effective treatment can avoid a fatal outcome.     

Laparoscopic nephrectomy in a porcine model.

Laparoscopic nephrectomy was performed in 15 male pigs, the procedure was successful in 14. Extraction of the intact kidney through a 5-cm lower abdomen incision was done in 7 animals; complete destruction and evacuation of the kidney was accomplished by a round-knife suction device through a 1-cm port in another 7 pigs. Grossly, the specimen consisted of sausage-like tubular renal tissue and a small amount of tissue debris. Pathology revealed that the glomerular and tubular structures were well preserved, no interstitial hematoma could be found. Four ports were usually used, one 1-cm umbilical camera port, one 0.5-cm port for ureter traction, and two 1-cm working ports along the midclavicular line. All the pigs recovered uneventfully. The average operation time was 3 h 20 min. The application of endo-GIA (United States Surgical Corporation) for renal hilum reduced the operative time to 2 h 20 min. Complications included renal vein tear during endoclip application and cutting in the first case, mild subcutaneous emphysema in 2 cases. This first pig received exploratory laparotomy for the repair and ligation of the renal vein. No more major complications occurred with increasing experience. From this porcine experiment, we conclude that the combination of laparoscopy, a tissue destroyer and an endobag for the entrapment of kidney seem to be a promising technique for clinical nephrectomy.     

Metastatic septic endophthalmitis in pyogenic liver abscess

In a consecutive series of 180 patients with pyogenic liver abscess, three patients (two men and one woman, between 46 and 75 years of age) had metastatic Klebsiella endophthalmitis. The incidence of metastatic endophthalmitis was 1.7% in patients with pyogenic liver abscess, 5.2% in patients with Klebsiella liver abscess, and 7.8% in patients with Klebsiella liver abscess having Klebsiella bacteremia. Despite aggressive therapeutic measures, the men permanently lost their vision and the woman eventually required an evisceration of her right eye. Delayed recognition and/or treatment as well as the nature of bacteria probably contributed to the tragic outcome. The findings suggest that a high index of suspicion is critical and a combined effort of the internist and ophthalmologist is mandatory.     

Glucokinase gene is genetic marker for NIDDM in American blacks.

Glucokinase (ATP:D-glucose-6-phosphotransferase), expressed exclusively in liver and pancreatic islet beta-cells, catalyzes the first step of glycolysis and acts as glucose sensor and metabolic signal generator in these tissues. The enzyme plays a key role in glucose homeostasis and as such is an excellent candidate for inherited defects predisposing to non-insulin-dependent diabetes mellitus (NIDDM). A compound-imperfect dinucleotide (CA)n repeat element was found approximately 10-kb 3' of the human glucokinase gene on chromosome 7p, which revealed polymorphism with alleles differing in size by 2-15 nucleotides in unrelated individuals. A polymerase chain reaction assay was developed, and genomic DNA from 275 biologically unrelated American black individuals was typed for glucokinase alleles. The differences in allelic frequencies between individuals with NIDDM and nondiabetic individuals were compared. After typing 112 diabetic and 163 nondiabetic subjects, we found five different-sized alleles, with Z defined as the most common allele, Z + 2, Z + 4, Z + 10, and Z - 15. The Z allele was more common in nondiabetic subjects than in diabetic patients (60.4 vs. 49.6%, P = 0.012). The Z + 4 allele was more common in diabetic patients than in nondiabetic subjects (20.1 vs. 12.0%, P = 0.009). After adjusting for age, sex, and body mass index, the Z + 4 allele continued to have a positive association with NIDDM (P = 0.0018), and the Z allele had a negative association with NIDDM (P = 0.0334). The Z + 4 allele, transmitted as an autosomal dominant trait, appeared to be the most significant one at this locus.(ABSTRACT TRUNCATED AT 250 WORDS)     

An effective treatment of comminuted fractures of the distal radius

One hundred cases of comminuted fracture of the distal radius were treated by a simple uniform method consisting of distraction by an external fixator for 3 weeks followed by functional bracing. During the application of the external fixator, autogenous cancellous bone chips were taken from the iliac crest and packed into the fracture site to realign the juxtaarticular fragments and to fill up the bone gap. Complications have been minimal. The results, after an average follow-up period of 20 months, taking into consideration subjective assessment of pain, objective measurement of wrist motion, and radiologic angles, have been excellent.     

Chromosomal screening of mentally retarded school children in Taipei.

The major concern of the national population policy in Taiwan in recent years has been to lower the incidence of hereditary diseases and mental retardation in the general population. It has been estimated that there are around 10,000 mentally retarded school children in Taiwan. If effective chromosomal screening can be extended to these children, some of the family members who are carriers of balanced chromosomal rearrangements may benefit from follow-up studies and genetic counseling. The present report is the result of a pilot study conducted from 1988 to 1991 to explore the possibility of chromosomal screening of mentally retarded school children in Taipei. A total of 871 blood samples were collected from 1,147 children registered in 46 schools or residing in homes for the retarded. Chromosomal analysis was successfully accomplished on 674 out of 871 blood samples. The following chromosomal abnormalities were observed: 28 Down's syndrome, four Klinefelter syndrome, one XYY, one triple X, 11 translocations, seven inversions, four mosaics, three duplications, one deletion and one with an extra marker chromosome. After follow-up cytogenetic analyses of 13 families with probands with structural chromosomal anomalies, three of these families were shown to have one or two carriers of balanced translocated chromosomes. It seems that the present screening system would not be practical or cost-effective if it were applied island-wide in the future.     

Effects of hypothermia on hemodynamic responses to dopamine and dobutamine.

Hemodynamic characteristics, arrhythmogenicity, and dose-related hemodynamic responses to intravenous dopamine (group I) and dobutamine (group II) were examined in 16 swine at three different core body temperatures (38.5 degrees C, 35 degrees C, and 30 degrees C). The animals were anesthetized with isoflurane and mechanically ventilated. Cooling and re-warming were accomplished by a femoral-jugular A-V shunt. The animals were cooled down to 30 degrees C and stabilized for 1 hour before intravenous infusion of dopamine (group I, n = 8) or dobutamine (group II, n = 8) was started at 2, 5, 10, 15, 20, and 30 micrograms/kg/min. Hemodynamic responses to the two inotropes were continuously monitored with a bedside monitor equipped with a PC mode for customized data collection and analysis. Computerized arrhythmia detection was performed. Our findings were: (1) profound hypothermia (30 degrees C) causes significant depression of hemodynamic functions; (2) IV infusion of dopamine and dobutamine can be used safely and effectively for inotropic support during profound hypothermia, and the optimal dosage for improving cardiac output is 10-20 micrograms/kg/min; (3) no risk of inducing arrhythmia was noted with IV infusion of both inotropes up to a maximum dosage of 30 micrograms/kg/min, even though significant sinus tachycardia was consistently seen at 30 micrograms/kg/min.     

Molecular epidemiology and control of nosocomial methicillin-resistant Staphylococcus aureus infection in a teaching hospital.

BACKGROUND AND PURPOSE: Nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection is difficult to control. Due to a dramatic increase in the nosocomial MRSA infection rate at our hospital from 2000 to 2001, this study was conducted to identify the source of these infections and the effectiveness of control measures. METHODS: 179 healthcare workers (HCWs) were screened for carriage of MRSA. Starting in April 2001, all patients with MRSA infection or colonization were put in strict contact and cohort isolation. The bacterial isolates of HCW carriers and patients with MRSA infection from April 2001 to September 2001 were subjected to antimicrobial susceptibility testing by disk-diffusion method and molecular typing by pulsed-field gel electrophoresis (PFGE). RESULTS: Fifteen HCWs were found to be carriers of MRSA. They were all given topical mupirocin treatment. After these interventions, the nosocomial MRSA infection rate decreased from 1.23 to 0.53 per 1000 patient-days. All 61 MRSA isolates available for antimicrobial susceptibility testing and molecular typing were multidrug resistant. PFGE study revealed 2 predominant types, type C and type Y, comprising 36 and 12 isolates, respectively. CONCLUSIONS: The current study demonstrates the importance of measures to control nosocomial MRSA infections in hospitals that already have a high incidence of endemic MRSA infection. Elimination of carriage by healthcare workers, and strict contact and cohort isolation are the main effective measures.     

Omega-3 fatty acids in major depressive disorder. A preliminary double-blind, placebo-controlled trial.

Patients with depression have been extensively reported to be associated with the abnormality of omega-3 polyunsaturated fatty acids (PUFAs), including significantly low eicosapentaenoic acid and docosahexaenoic acid in cell tissue contents (red blood cell membrane, plasma, etc.) and dietary intake. However, more evidence is needed to support its relation. In this study, we conducted an 8-week, double-blind, placebo-controlled trial, comparing omega-3 PUFAs (6.6 g/day) [corrected] with placebo, on the top of the usual treatment, in 28 patients with major depressive disorder. Patients in the omega-3 PUFA group had a significantly decreased score on the 21-item Hamilton Rating Scale for Depression than those in the placebo group (P < 0.001). From the preliminary findings in this study, omega-3 PUFAs could improve the short-term course of illness and were well tolerated in patients with major depressive disorder.     

Surface stiffness affects impact force during a fall on the outstretched hand

Falls on the outstretched hand are among the most common causes of traumatic bone fracture. However, little is known regarding the biomechanical factors that affect the risk for injury during these events. In the present study, we explored how upper-extremity impact forces during forward falls are affected by modification of surface stiffness, an intervention applicable to high-risk environments such as nursing homes, playgrounds, and gymnasiums. Results from both experimental and linear biomechanical models suggest that during a fall onto an infinitely stiff surface, hand contact force is governed by a high-frequency transient (having an associated peak force F_max1), followed by a low-frequency oscillation (having an associated lower magnitude peak force F_max2). Practical decreases in surface stiffness attenuate F_max1 but not F_max2 or the magnitude of force transmitted to the shoulder. Model simulations reveal that this arises from the compliant surface's ability to decrease the velocity across the wrist damping elements at the moment of impact (which governs F_max1) but inability to substantially reduce the peak deflection of the shoulder spring (which governs F_max2). Comparison between model predictions and previous data on fracture force suggests that feasible compliant surface designs may prevent wrist injuries during falls from standing height or lower, because F_max1 will be attenuated and F_max2 will remain below injurious levels. However, such surfaces cannot prevent F_max2 from exceeding injurious levels during falls from greater heights and therefore likely provide little protection against upper-extremity injuries in these cases.