Management of unexpected coronary artery spasm in an asymptomatic patient during anaesthesia

We report a case of life-threatening arrhythmia that was not predicted before surgery. Pulse-less ventricular tachycardia and ventricular fibrillation occurred during surgery without any changes in heart rate and blood pressure, and cardiac massage was required to maintain circulation. Although no organic stenosis was found in either the right or left coronary arteries, post-surgical angiographic examination revealed severe vasospastic angina induced by intra-luminal administration of acetylcholine. Anaesthesia with a high dose of fentanyl and vasodilators prevented the recurrence of life-threatening arrhythmia. Vasospastic angina attacks are difficult to predict with the preoperative examination routinely employed.

Analysis of rabbit articular cartilage repair after chondrocyte implantation using optical coherence tomography

OBJECTIVE

To evaluate the utility and limitations of optical coherence tomography (OCT) for immediate, high-resolution structural analysis of rabbit articular repair tissue following chondrocyte implantation without excising or sectioning the specimen.

METHODS

Full thickness articular cartilage defects were created in the patellar grooves of 30 adult rabbit knee joints. Allogenic cultured chondrocytes embedded in collagen gels were implanted into the surgical defects. A periosteal patch was then sutured over the chondrocyte-collagen composites. Six animals per time point were sacrificed at 2, 4, 8, 12 and 24 weeks after surgery. The repair tissues were sequentially analysed by arthroscopic surface imaging, OCT, and histology. The resulting images were compared to determine qualitative and quantitative features of surface roughness, repair tissue integration, and micro-architecture. Statistical analysis was performed using Student's t -testing and linear regression.

RESULTS

OCT was able to identify the bone and cartilage interface in normal rabbit articular cartilage and regenerated cartilage at 24 weeks post chondrocyte implantation. OCT was able to identify hypertrophy at 4 and 8 weeks, and subtle surface fibrillations at 24 weeks, comparable with histological analysis at low magnification (20x). More importantly, OCT was able to detect embedded gaps between the repair tissue and surrounding host cartilage.

CONCLUSION

Close correlation was observed between OCT and histological analysis of morphological features important to the assessment of articular cartilage repair. These results demonstrate that OCT is capable of providing immediate 'optical biopsy' of the rabbit articular cartilage repair tissue without damaging the specimen, and suggest that this new technique, if integrated with an arthroscope, can potentially be used in longitudinal studies of articular cartilage repair in vivo.

Induction of somatosensory evoked potentials by mechanical stimulation in reconstructed anterior cruciate ligaments

We have determined whether somatosensory evoked potentials (SEPs) were detectable after direct mechanical stimulation of normal, injured and reconstructed anterior cruciate ligaments (ACLs) during arthroscopy. We investigated the position sense of the knee before and after reconstruction, and correlated the SEP with instability.

Reproducible SEPs were detected in all 19 normal ACLs and in 36 of 38 ACLs reconstructed during a period of 13 months. Of the 45 injured ACLs, reproducible SEPs were detected in 26. The mean difference in anterior displacement in the SEP-positive group of the injured ACL group was significantly lower than that in the SEP-negative group. In the reconstructed group, the postoperative position sense was significantly better than the preoperative position sense. Our results indicate not only that sensory reinnervation occurs in the reconstructed ACL, but also that the response to mechanical loads can be restored, and is strongly related to improvement in position sense.

Arthroscopic assessment of human cartilage stiffness of the femoral condyles and the patella with a new tactile sensor

We measured the stiffness of the cartilage of the human femoral condyles via an ultrasonic tactile sensor under arthroscopic control. The stiffness and the degeneration of articular cartilage were assessed in 105 knees in 74 patients (39 men, 35 women, age: 9-72 years) who underwent arthroscopic observation or surgery. Twenty-five knees suffered from traumatic cartilage injury, 14 from osteochondritis dissecans, 13 from osteoarthritis, 11 from meniscal injury and six from ligamentous injury, bipartita patellae (three knees), and symptomatic plica synovialis (two knees). The degeneration of cartilage was classified according to Outerbridge's grading system. The relationships between the stiffness and the grade of cartilage degeneration, and gender were analyzed. The stiffness of grade I (softening) and II (fissuring less than 0.5 inches in length) was significantly lower than that of intact cartilage. In contrast, the stiffness of grade IV (exposed subchondral bone) was significantly higher than that of any other group. The cartilage stiffness of the patella in women was significantly lower than that in men. The tactile sensor was useful for determining the intraoperative stiffness of healthy and diseased human cartilage in all grades.

Induction of somatosensory evoked potentials by mechanical stimulation in reconstructed anterior cruciate ligaments

We have determined whether somatosensory evoked potentials (SEPs) were detectable after direct mechanical stimulation of normal, injured and reconstructed anterior cruciate ligaments (ACLs) during arthroscopy. We investigated the position sense of the knee before and after reconstruction, and correlated the SEP with instability. Reproducible SEPs were detected in all 19 normal ACLs and in 36 of 38 ACLs reconstructed during a period of 13 months. Of the 45 injured ACLs, reproducible SEPs were detected in 26. The mean difference in anterior displacement in the SEP-positive group of the injured ACL group was significantly lower than that in the SEP-negative group. In the reconstructed group, the postoperative position sense was significantly better than the preoperative position sense. Our results indicate not only that sensory reinnervation occurs in the reconstructed ACL, but also that the response to mechanical loads can be restored, and is strongly related to improvement in position sense.

Muscle-based gene therapy and tissue engineering

The development of new biological approaches based on cell and gene therapies, in combination with tissue engineering, may create innovative ways to treat various tissues of the musculoskeletal system. It is vital for practicing orthopaedic surgeons to understand the terminology, fundamental concepts, and current research in this burgeoning field so that they may practice their discipline in its fullest form. Such techniques, coupled with advances in cell biology and polymer chemistry, are resulting in novel approaches to treating musculoskeletal disorders in which surgeons, who have traditionally used the tools of excision and reconstruction to treat patients, may now serve as surgical gardeners who create microenvironments that are conducive for tissue regeneration. Gene therapy and tissue engineering applications for bone healing, articular disorders, and skeletal muscle diseases and injuries are currently being explored. This review is intended to update readers on the principles and current advances in muscle-based gene therapy and tissue engineering for the musculoskeletal system.

Dextran-magnetite complex: temperature dependence of its NMR relaxivity

The NMR relaxivity of proton by dextran-magnetite (DM) complex was examined at temperatures from 20 to 80 degrees C. The decrease in T1 relaxivity with increasing temperature is due to the thermal activation of motion of water molecules in and/or surrounding DM particle. The decrease in magnetization of magnetite core is the secondary effect. The temperature dependence of T1 relaxivity was found to depend on molecular weight of dextran. The motion of dextran chains binding to core may affect the thermal activation of "heavy water" interacted with dextran. The Arrhenius plots of T1 relaxivity showed different slopes at 20-40 degrees C and 50-80 degrees C, while, no change in slope was observed for Fe(NO3)3, CuSO4 and Gd-DTPA solutions.

Brain-derived neurotrophic factor enhances depolarization-evoked glutamate release in cultured cortical neurons

Brain-derived neurotrophic factor (BDNF) has been reported to play an important role in neuronal plasticity. In this study, we examined the effect of BDNF on an activity-dependent synaptic function in an acute phase. First, we found that short-term treatment (10 min) with BDNF enhanced depolarization-evoked glutamate release in cultured cortical neurons. The enhancement diminished gradually according to the length of BDNF treatment. The BDNF-enhanced release did not require the synthesis of protein and mRNA. Both tetanus toxin and bafilomycin abolished the depolarization-evoked glutamate release with or without BDNF, indicating that BDNF acted via an exocytotic pathway. Next, we investigated the effect of BDNF on intracellular Ca(2+). BDNF potentiated the increase in intracellular Ca(2+) induced by depolarization. The Ca(2+) was derived from intracellular stores, because thapsigargin completely inhibited the potentiation. Furthermore, both thapsigargin and xestospongin C inhibited the effect of BDNF. These results suggested that the release of Ca(2+) from intracellular stores mediated by the IP(3) receptor was involved in the BDNF-enhanced glutamate release. Last, it was revealed that the enhancement of glutamate release by BDNF was dependent on the TrkB-PLC-gamma pathway. These results clearly demonstrate that short-term treatment with BDNF enhances an exocytotic pathway by potentiating the accumulation of intracellular Ca(2+) through intracellular stores.

DNA ligase IV-deficient cells are more resistant to ionizing radiation in the absence of Ku70: Implications for DNA double-strand break repair

Vertebrate cells have evolved two major pathways for repairing DNA double-strand breaks (DSBs), homologous recombination (HR) and nonhomologous DNA end-joining (NHEJ). To investigate the role of DNA ligase IV (Lig4) in DSB repair, we knocked out the Lig4 gene (LIG4) in the DT40 chicken B-lymphocyte cell line. The LIG4(-/-) cells showed a marked sensitivity to X-rays, bleomycin, and VP-16 and were more x-ray-sensitive in G(1) than late S or G(2)/M, suggesting a critical role of Lig4 in DSB repair by NHEJ. In support of this notion, HR was not impaired in LIG4(-/-) cells. LIG4(-/-) cells were more x-ray-sensitive when compared with KU70(-/-) DT40 cells, particularly at high doses. Strikingly, however, the x-ray sensitivity of KU70(-/-)/LIG4(-/-) double-mutant cells was essentially the same as that of KU70(-/-) cells, showing that Lig4 deficiency has no effect in the absence of Ku. These results indicate that Lig4 is exclusively required for the Ku-dependent NHEJ pathway of DSB repair and that other DNA ligases (I and III) do not substitute for this function. Our data may explain the observed severe phenotype of Lig4-deficient mice as compared with Ku-deficient mice.

Uraemia suppresses central dopaminergic metabolism and impairs motor activity in rats

OBJECTIVE

Uraemia often provokes various neurological disorders, such as mental changes, malperception, confusion, seizures and coma. Since changes in neurotransmissions induce neurological symptoms, we investigated changes in the monoamine metabolism and motor activity in uraemic rats.

DESIGN

Prospective, randomised, controlled animal study.

SUBJECTS

Male Wistar rats.

INTERVENTIONS

Acute renal failure was induced by occlusion of bilateral renal arteries for 60 min, and the motor activity and brain monoamine turnover were examined 48 h later. The brain monoamine turnover was evaluated by the depletion of norepinephrine (NE) and dopamine (DA) induced by alpha-methyl-p-tyrosine (alpha-MT), or the accumulation of 5-hydroxyindoleacetic acid (5-HIAA) induced by probenecid.

MEASUREMENTS AND RESULTS

Marked damage in renal function was found in animals subjected to renal ischaemia 48 h after the operation. The motor activity of the uraemic rats was impaired. The turnover of DA in the striatum, mesencephalon and hypothalamus was decreased in these rats. The turnover of NE and 5-hydroxytryptamine (5-HT) was unchanged in all regions examined.

CONCLUSIONS

Suppression of the central DA turnover appears to be involved in the impairment of motor activity in uraemic rats.

Brain-derived neurotrophic factor triggers a rapid glutamate release through increase of intracellular Ca(2+) and Na(+) in cultured cerebellar neurons

We reported previously that BDNF induced glutamate release was dependent on intracellular Ca(2+) but not extracellular Ca(2+) in cerebellar neurons (Numakawa et al., 1999). It was revealed that the release was through a non-exocytotic pathway (Takei et al., 1998; Numakawa et al., 1999). In the present study, we monitored the dynamics of intracellular Ca(2+) and Na(+) in cerebellar neurons, and investigated the possibility of reverse transport of glutamate mediated by BDNF. As reported, BDNF increased the intracellular Ca(2+) level. We found that the Ca(2+) increase induced by BDNF was completely blocked by xestospongin C, an IP(3) receptor antagonist, and U-73122, a PLC-gamma inhibitor. Xestospongin C and U-73122 also blocked the BDNF-dependent glutamate release, suggesting that the BDNF-induced transient increase of Ca(2+) through the activation of the PLC-gamma/ IP(3) pathway was essential for the glutamate release. We found that BDNF induced a Na(+) influx. This was blocked by treatment with TTX. U-73122 and xestospongin C blocked the BDNF-induced Na(+) influx, suggesting that the Na(+)influx required the BDNF-induced Ca(2+) increase. Next, we examined the possibility that a co-transporter of Na(+) and glutamate was involved in the BDNF-induced glutamate release. BDNF-induced glutamate release was blocked by L-trans-pyrollidine-2,4-dicalboxylic acid (t-PDC), a glutamate transporter inhibitor, whereas neither the 4-aminopyridine (4AP)- nor high potassium (HK(+))-induced release was blocked by t-PDC. In addition, DL-threo-beta-benzyloxyaspartate (DL-TBOA) also blocked the BDNF-mediated glutamate release, suggesting that reverse transport of glutamate may be involved. All the results therefore suggest that Na(+)-dependent reverse transport contributes to BDNF-mediated transmitter release through the PLC-gamma/IP(3)-mediated Ca(2+) signaling.

Dexamethasone reduces energy utilization in ischemic gerbil brain

Glucocorticoids have been reported to aggravate ischemic neuronal damage. Because energy failure is a crucial factor in the development of ischemic neuronal injury, the effects of dexamethasone on histologic outcome and energy metabolism were investigated in gerbil brain. Dexamethasone (3 microg, i.c.v.) was administered 1 h prior to ischemia, and its effect on delayed neuronal death caused by 2 min of bilateral common carotid artery occlusion was observed in hippocampal CA1 pyramidal neurons. The brain concentration of ATP after various durations of decapitation ischemia was determined, and the effect of dexamethasone (3 microg, i.c.v.) was examined. Na+,K+-activated adenosine triphosphatase (Na+,K+-ATPase) activity was evaluated after the administration of the agent. Forebrain ischemia for 2 min produced neuronal damage in animals pretreated with dexamethasone, although neuronal damage was not observed in vehicle-injected animals. Decapitation ischemia for 0.5 and 1 min reduced the brain ATP concentration to 44% and 15% of the basal level, respectively. Dexamethasone attenuated the ischemia-induced reduction in ATP, and the values were 58% and 25% of the basal level, respectively. Na+,K+-ATPase activity at pH 6.7 was suppressed to 47% by dexamethasone treatment (3 microg, i.c.v.), whereas the activity at pH 7.4 was not influenced by the agent. The results show that a contributing factor to the aggravation of ischemic neuronal damage may be a disturbance in Na+,K+-ATPase despite adequate levels of ATP.

Dentatorubral-pallidoluysian atrophy (DRPLA) presenting with psychosis

The authors report on four DRPLA patients who manifested delusions. All patients demonstrated autosomal dominant DRPLA confirmed by standard gene analysis. Patients with DRPLA can exhibit a variety of psychiatric symptoms in addition to extrapyramidal and cerebellar symptoms.

New pain following cordotomy: clinical features, mechanisms, and clinical importance

OBJECT

The clinical features, possible causes, and contributing factors associated with novel spontaneous pain following unilateral cordotomy were investigated to clarify the mechanism and clinical importance of this pain.

METHODS

Forty-five patients who underwent cordotomy for severe unilateral cancer pain were included in this study. New pain occurred in 33 (73.3%) of 45 patients. Pathological conditions of tissue demonstrated on imaging corresponded to new pain in eight patients, referred pain in five, and neither of these in 15 patients. New pain was centered opposite the site of the original pain in a mirror-image location in 28 patients and rostral to the original pain in five patients. It was temporary in seven patients, weaker than the original pain in 25, and as severe as the original pain in one patient. The incidence of moderate or severe pain was significantly higher in patients with confirmed tissue disease (six of eight patients) than in those without (six of 20 patients). An important contributing factor to the occurrence of new pain was the achievement of analgesia by performing the cordotomy.

CONCLUSIONS

The present results indicate that new pain occurs frequently after unilateral cordotomy. Nonetheless, cordotomy may still be indicated for unilateral uncontrollable pain because new pain, when present, was weaker and more easily controlled than the original pain in nearly all cases. The authors speculate that new pain may represent a type of referred pain from the original painful area or may arise from sensitization of contralateral spinal nociceptive circuits due to metastasis or tumor infiltration, and that new pain is potentiated by the interruption of descending inhibitory pathways.

Genetic mutations in exons 3 and 4 of the pancreatic secretory trypsin inhibitor in patients with pancreatitis

PURPOSE

We hypothesized that mutations in the pancreatic secretory trypsin inhibitor (PSTI) gene could promote autodigestion, leading to acute or chronic pancreatitis. Our investigation involved mutation analysis of the PSTI gene in patients with acute or chronic pancreatitis.

METHODS

Mutation analysis for the PSTI gene was performed in patients with acute or chronic pancreatitis. Unrelated healthy volunteers and family members of a chronic pancreatitis patient with point mutations in the PSTI gene were also analyzed.

RESULTS

Two types of single-point mutation in the PSTI gene were observed in one patient with chronic pancreatitis: 34Asn (AAT)-to-Ser (AGT) (101 A > G N34S: N34S) in exon 3, and 67Arg (CGC)-to-Cys (TGC) (199 C > T R67C: R67C) in exon 4. No mutations with amino-acid substitution were found in other patients or in the volunteer group. In the patient with the PSTI gene mutations, no additional mutations were observed in the cationic trypsinogen gene. The family study revealed that the mother and a maternal uncle were homozygotes for the N34S mutation, while the father and brother were compound heterozygotes for the N34S and R67C mutations. The uncle (N34S/N34S) showed clinical manifestations of pancreatitis, but the other family members did not.

CONCLUSIONS

The N34S mutation may cause a predisposition to pancreatitis, with incomplete penetrance. However, with the limited information available, it is not known whether the R67C mutation promotes pancreatitis.

Blockade of central histaminergic H2 receptors aggravates ischemic neuronal damage in gerbil hippocampus

OBJECTIVE

Histaminergic H2 antagonists have been reported to provoke central nervous system dysfunction in humans. They also aggravate ischemic neuronal damage in experimental animals. Because energy failure and glutamate release are crucial factors in ischemic neuronal damage, the effects of ranitidine on energy state and the extracellular concentration of glutamate were investigated in gerbil brain.

DESIGN

Prospective, randomized, controlled animal study.

SETTING

University animal laboratory.

SUBJECTS

Male Mongolian gerbils.

INTERVENTIONS

The changes in the direct-current potential shift in the hippocampal CA1 area produced by transient forebrain ischemia for 2.5 mins were compared in gerbils pretreated with saline or ranitidine (10 nmol) intracerebroventricularly. The histologic outcome was evaluated 7 days after ischemia by observing the delayed neuronal death in these animals. In a second study, brain concentrations of adenosine 5'-triphosphate after various durations of decapitation ischemia were determined, and the effect of ranitidine was evaluated. In a third experiment, changes in the extracellular concentrations of excitatory amino acids during forebrain ischemia were examined by a microdialysis procedure.

MEASUREMENTS AND MAIN RESULTS

The forebrain ischemia produced a sudden shift in the membrane potential 62 +/- 5 secs (mean +/- sd, n = 6) after the start of ischemia. The preischemic administration of ranitidine facilitated onset of depolarization (38 +/- 8 secs; p <.01). The histologic outcome was aggravated by ranitidine (p <.01). Decapitation ischemia reduced brain adenosine 5'-triphosphate concentration rapidly. Ranitidine facilitated the ischemic reduction in adenosine 5'-triphosphate, and the value after 1 min was 55% of that in the corresponding saline group (p <.01). Ranitidine enhanced the ischemic increase in the glutamate concentration, and the peak value in the ranitidine group was 316% of that in the saline group (p <.05).

CONCLUSION

The deleterious effect of ranitidine on ischemic neuronal damage may involve the increase in the extracellular concentration of glutamate and facilitation of energy depletion in an anaerobic state.

Decreased topoisomerase IIalpha expression confers increased resistance to ICRF-193 as well as VP-16 in mouse embryonic stem cells

To elucidate the relationship between topoisomerase (topo) II expression and sensitivity to anti-topo II drugs in mammalian cells, we generated mouse embryonic stem cell mutants heterozygous for the topo IIalpha gene by gene targeting. The level of topo IIalpha in the heterozygous cells reduced to one-half of that found in wild-type cells, while topo IIbeta levels were similar in both cell types. Importantly, the heterozygous cells exhibited an increased resistance to ICRF-193 as well as VP-16, suggesting that ICRF-193, like VP-16, exerts its cytotoxicity through converting topo II to a poison.

Nosocomial rotavirus in a pediatric hospital

We describe a nosocomial rotavirus outbreak among pediatric cardiology patients and the impact of a prospective, laboratory-based surveillance program for rotavirus in our university-affiliated, quartenary-care pediatric hospital in New York City. Improved compliance with infection control and case-finding among patients and healthcare workers halted the outbreak.

A fatal case of infantile scurvy

We report a case of infant death due to scurvy, which is very rare in Japan. We initially had little knowledge of the disease and suspected that the bleeding in the body was caused by domestic violence. The case did not fall under the category of the battered child syndrome but the death was caused by ignorance with respect to child care. In addition the parents usually locked the child alone in a room during the day and this is probably a case of neglect.

[Evaluation of efficiency of ACD-CPR and STD-CPR; a multi-institutional study]

We compared the efficacy of ACD-CPR and STD-CPR based on 64 multi-institutional reports. No significant differences were observed in the rate of restoration of spontaneous circulation (ROSC) and in cardiopulmonary parameters during CPR using the two methods. There were 5 cases in which cardiopulmonary parameters improved after switching from STD-CPR to ACD-CPR and, eventually, in two of them spontaneous circulation was restored. In the ROSC cases of both groups, ETCO2 and values of SpO2, PaO2, and systolic BP at 30 minutes were higher than those of non-ROSC cases. ETCO2 never exceeded 20 mmHg in the non-ROSC cases, but it was higher in the ROSC cases. ACD-CPR is a good choice when trained persons are present or when extra hands are available to continue the CPR.

Intraosseous hypertension and venous congestion in osteonecrosis of the knee

To determine whether an angiogenic factor affects the pathogenesis of the idiopathic osteonecrosis of the medial femoral condyle, intraosseous pressure and venogram in 11 knees with osteonecrosis were compared with intraosseous pressure and venogram in 11 knees with the medial type of osteoarthritis. Patients were matched by age, gender, obesity index, blood pressure, tibiofemoral angle, and clinical evaluation. The intraosseous pressure of the medial condyle of the knees with osteonecrosis (62.8 +/- 27.3 mm Hg) was significantly higher than that in the lateral condyle of the knees with osteonecrosis (25.4 +/- 18.9 mm Hg) and those of both condyles of the knees with osteoarthritis (medial, 31.6 +/- 17.4 mm Hg; lateral, 29.5 +/- 11.0 mm Hg). In contrast, there was no significant difference in the pressure between the medial and lateral condyles of the knees with osteoarthritis. Venography showed a marked disturbance of venous drainage in all patients with osteonecrosis. In addition, the average clearance time of the medium in the medial femoral condyle was significantly more prolonged in patients with osteonecrosis (17.7 +/- 6.1 minutes) than in patients with osteoarthritis (5.5 +/- 1.6 minutes). These data support the hypothesis that venous stasis within the medullar canal in the condyle increases intraosseous pressure and decreases arteriovenous pressure difference, leading to osteonecrosis.

Detection of craniospinal dissemination of intracranial germ cell tumours based on serum and cerebrospinal fluid levels of tumour markers

Nineteen intracranial germ cell tumours treated during the past 11 years were evaluated retrospectively. The tumours were classified into three groups according to the level of alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (HCG) in serum and cerebrospinal fluid, and the optimal treatment for each group was determined. Group A consisted of patients with normal titres of AFP and HCG, group B of patients with relatively high titres (< 10 times normal), and group C comprised patients with higher titres ( 10 times normal levels). In group A, an appropriate field and dose of irradiation was necessary to prevent craniospinal dissemination. In group B, none of four patients who underwent total or subtotal resection of the tumour had craniospinal disseminatio n or tumour recurrence, whereas dissemination occurred in four further patients, including two who had received radiochemotherapy only, and two who had undergone partial resection of the tumour. While patients in group C had dissemination at the time of initial diagnosis, most patients in group B developed dissemination more than 10 months after initial treatment, suggesting that the type of treatment received as first line therapy is important in patients in this group. The prognosis of patients in group C, however, was unaffected by the priority given to either surgery, radiation or chemotherapy as first line treatment. Craniospinal dissemination can be prevented in patients with germ cell tumours who have a relative increase in levels of AFP and HCG by aggressive removal of the tumours as first line therapy, regardless of the type of adjuvant therapy given.

[Effects of intravenous nicardipine, prostaglandin E1, nitroglycerin, sodium nitroprusside, and epidural lidocaine on hepatic and renal blood flow during hypotensive anesthesia]

We studied the effects of intravenous nicardipine (NIC), prostaglandin E1 (PGE1), nitroglycerin (TNG), sodium nitroprusside (SNP) and epidural lidocaine (LID) on hepatic and renal blood flow during general anesthesia (nitrous oxide-oxygen-sevoflurane) in 46 female patients undergoing unilateral total hip arthroplasty. During operations, hepatic blood flow, glomerular filtration rate, renal plasma flow, and renal tubular injury were measured by R 15 ICG (15 minutes retention rate of indocyanine green), CCR (creatinine clearance), CPAH (para-aminohippuric acid clearance), and urinary excretion of NAG and beta 2-microglobulin. Significant elevation of R 15 ICG was observed in the hypotensive state in the TNG group and the elevation of R 15 ICG indicates that blood flow to the liver has decreased during hypotensive anesthesia. Urine volume in the PGE1 group was larger than that in the TNG, SNP or LID group. CCR in the PGE1 group was larger than that in the NIC, TNG or SNP groups. CPAH in the PGE1 group was larger than that in the SNP or LID group. The value of urine NAG in the TNG group was larger than that in the NIC or PGE1 group. The value of urine beta 2-microglobulin in the NIC group was larger than that in the PGE1 or SNP group. The results of urine volume, CCR, CPAH, urine NAG, and urine beta 2-microglobulin indicate that blood flow to the kidneys was greater in the PGE1 group as compared to other groups. This study indicates that prostaglandin E1 is the best hypotensive drug for hepatic and renal blood flow during hypotensive anesthesia.

Proprioceptive improvement in knees with anterior cruciate ligament reconstruction

The correlation between the prospective course of proprioceptive improvement and knee stability after anterior cruciate ligament reconstruction was investigated in 38 patients. Proprioception, on the basis of the patient's capacity to reposition the limb accurately, was evaluated at 3-month intervals for 24 months after hamstring graft anterior cruciate ligament surgery. Knee stability was evaluated concurrently with a KT-2000 knee arthrometer. Thirty patients experienced improvement in postoperative position sense in at least one of the examinations, although eight patients had no improvement at any time. Of the 30 patients who had improvement, 28 maintained improved position sense from 18 months to the final followup. Thirty patients maintained significantly better knee stability for a postoperative period of at least 24 months. These results indicated that a minimum of 18 months after anterior cruciate ligament reconstruction may be needed for complete restoration of the proprioceptive function in knees, although the mean position sense in all patients gradually improved from 9 months. Improvement in postoperative knee stability may have facilitated recovery of proprioception.