Vasodilator component in sympathetic nerve activity destined for the skin of the dorsal foot of mildly heated humans

1. Skin sympathetic nerve activity (SSNA) was recorded in seven male subjects from the peroneal nerve by microneurography, and the temporal correspondence of spontaneously occurring SSNA bursts with vasodilatation and sweating responses on the dorsal foot was studied during a mild body heating at rest. 2. Some SSNA bursts were followed by a sweat expulsion with a latency of 2.4 +/- 0.4 s, and some bursts by a transient vasodilatation with a latency of 2.2 +/- 0.4 s (means +/- S.D.). SSNA bursts followed both by a sweat expulsion and by a vasodilatation response (Type 1), those followed only by a sweat expulsion (Type 2) and those followed only by a vasodilatation, response (Type 3) were 70%, 10% and 1% of the total bursts examined, respectively. 3. For Type 1 bursts, there was a significant, but weak linear relationship among the burst amplitude, the amplitude of the corresponding vasodilatation and the amplitude of the corresponding sweat expulsion. 4. It was concluded that SSNA contains vasodilatory activity which is synchronous with sudomotor nerve activity. The results suggest that such vasodilatory activity contributes to sustaining the sweat gland function by supplying sufficient blood.

Right paranephric abscess as a rare late complication of laparoscopic cholecystectomy

A laparoscopic cholecystectomy on a 63-year-old woman was uneventful. Twenty-one months after the operation she complained of dull right flank pain, loss of appetite, weight loss, and cough. CT of the abdomen showed an 8.5 cm mass adjacent to the posterior aspect of the upper pole of the right kidney. CT also demonstrated a small calcification (5 mm diameter) posterior to the upper pole of the right kidney. The patient underwent exploratory laparotomy 2 months after the presentation with flank pain. Examination of the mass showed a thick abscess wall and 250 mL of pus. The patient's symptoms improved after the abscess was drained.

Suicidal inactivation of human dihydropyrimidine dehydrogenase by (E)-5-(2-bromovinyl)uracil derived from the antiviral, sorivudine

An enzymatic study was performed to clarify the mechanism of 18 acute deaths in patients who had received the new oral antiviral drug, sorivudine (SRV), during anticancer chemotherapy with 5-fluorouracil (5-FU) prodrugs. Human dihydropyrimidine dehydrogenase (hDPD), playing a key role in the liver as the rate-limiting enzyme in catabolism of 5-FU, was expressed in E. coli, purified and incubated in the presence of NADPH with SRV or (E)-5-(2-bromovinyl)uracil (BVU), a metabolite of SRV produced by human gut flora. hDPD was rapidly and irreversibly inactivated by BVU, but not by SRV. Radioactivity of [14C]BVU was incorporated into hDPD in the presence of NADPH in a manner reciprocal to the enzyme inactivation. In the absence of NADPH, hDPD was not inactivated by BVU, nor radiolabeled with [14C]BVU. Thus, as we demonstrated previously with studies using the rat, the acute deaths were strongly suggested to be attributable to markedly elevated tissue 5-FU levels which were responsible for irreversible inhibition of hDPD by covalent binding of a reduced form of BVU as a suicide inactivator.

Adoptive immunotherapy of patients with metastatic renal cell cancer using lymphokine-activated killer cells, interleukin-2 and cyclophosphamide: long-term results

BACKGROUND

Initial results of adoptive immunotherapy using lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2) appeared to offer promise for treating renal cell cancer (RCC). However, lower response rates were seen in subsequent trials, and the long-term results of this treatment method have not been fully reported. In this study, we examine long-term results of adoptive immunotherapy using LAK cells, IL-2, and cyclophosphamide (LAK/IL-2/CPM therapy).

METHODS

We administered 10 courses of therapy to 9 patients with advanced RCC. One patient had liver and para-aortic lymph node metastases; the others had only lung metastases. The clinical effects were initially evaluated 4 weeks after therapy and follow-up was continued for periods of 43 to 76 months.

RESULTS

The 4-week evaluation revealed 3 complete responses (CR), 3 partial responses (PR), 1 minor response (MR), 1 patient with no change in disease status (NC), and 2 patients whose disease progressed (PD). One CR patient remained apparently free of disease for 43 months. After tumors recurred in the lung of another CR patient further disease progression was suppressed by IL-2 administration until the patient died from other causes at 46 months. The third CR patient showed tumor recurrence in the lung and was re-treated with the same LAK/CPM/IL-2 therapy. Lung tumors decreased in size (PR), but the patient died due to brain metastasis 2 months after the second round of treatment. The 2 initial PR patients, as well as the MR and NC patients, developed regrowth or new metastatic lesions within 2 to 15 months following therapy. The 2 PD patients died 2 and 9 months after therapy.

CONCLUSION

Long-term effects of LAK/IL-2/CPM therapy were not correlated with the maximal response observed 4 weeks after therapy. Although LAK/IL-2/CPM therapy appears suitable for use as induction therapy in RCC, our data suggest that long-term suppression will require surgical removal of remnant tumors or more intensive maintenance therapy.

Hormone/antihormone withdrawal and dexamethasone for hormone-refractory prostate cancer

BACKGROUND

Flutamide withdrawal has been reported to benefit patients with hormone-refractory prostate cancer. Several studies have also demonstrated that a combination of corticosteroids and testicular androgen ablation lowers serum androgen levels and improves clinical response. The purpose of this study was to examine the effect of withdrawal of oral hormonal agents and administration of dexamethasone in stage D3 prostate cancer patients.

METHODS

Sixteen patients with hormone-refractory prostate cancer were enrolled in the study. All patients had osseous metastasis and elevated serum prostate-specific antigen. Nine had been treated with chlormadinone acetate, 4 with estramustine phosphate, and 3 with flutamide as first-line hormonal therapy. All patients had also been treated either with bilateral orchiectomy (13 cases) or a luteinizing hormone-releasing hormone (LH-RH) agonist (3 cases). Seven patients whose disease progressed following hormone withdrawal were treated with oral dexamethasone (initially 1.5 mg/day, then tapered to 0.5 mg/day).

RESULTS

Eight patients demonstrated a decrease in prostate-specific antigen of greater than 50% following hormone withdrawal. The time to cancer progression for these 8 patients was 2 to 15 months (mean, 4 months). Among the patients receiving dexamethasone, 4 showed a greater than 90% decrease in prostate-specific antigen after 3 months' treatment. The time to disease progression for these 4 patients was 3 to 11 months.

CONCLUSION

In treating hormone-refractory advanced prostate cancer, the first pharmacologic manipulation should be withdrawal of the oral component of combined hormonal therapy. Patients whose disease progresses after hormone withdrawal should then be treated with glucocorticoids such as dexamethasone.

In vitro changes in the transparency and pH of cerebrospinal fluid caused by adding midazolam

The effects of adding midazolam and bupivacaine to human cerebrospinal fluid in glass test tubes were examined by looking for changes in pH and a reduction in the transparency of the solution. Midazolam (n = 6), 0.25% bupivacaine (n = 6), 5 mg of midazolam in 6 mL of 0.25% bupivacaine (n = 6) and 5 mg of midazolam in 10 mL of saline (n = 6) were added to 1.5-mL samples (n = 24) of cerebrospinal fluid taken at the time spinal anaesthesia was begun. Transparency and pH were checked after each increment. Cerebrospinal pH was decreased to below 7.0 by adding more than 3 mg of midazolam, more than 1.9 mL of 0.25% bupivacaine or 1.3 mL of the mixture. Cerebrospinal transparency was decreased by adding more than 0.7 mg of midazolam, 1.1 mL of 0.25% bupivacaine or 0.6 mL of the mixture. Midazolam in saline neither decreased the pH below 7.0 nor reduced transparency. These results do not suggest that clinically useful doses of intrathecal or epidural midazolam are neurotoxic.

Flow sensing in mycelial fungi

Hyphae of a variety of mycelial fungi were shown to reorient their direction of growth to grow upstream in a continuous flowing current of liquid medium. Among those tested fungi, Aspergillus niger hyphae was most polarized towards the upstream. Hyphae of A. niger which had been attached to poly-L-lysine coated plates on the base of a continuous-culture flow cell were exposed to a current of medium of flow rates in the range of 0-6400 microns s-1 for 1-4 h. Hyphal tips quickly reoriented towards the upstream of the flowing medium and became aligned parallel to the flow axis as they grew larger. At flow rates above 1600 microns s-1, however, the percentage of polarization of hyphae reached a constant level. With other fungi, germ tube emergence was not polarized but hyphae and branches grew towards the upstream. There was no detectable difference in the pH and oxygen concentration of the flowing medium between inlet and outlet of the flow cell. This result suggests that hyphae of mycelial fungi sense transient flow of liquid medium over their surface and reorient their direction to grow upstream.

[Which laryngoscope is the most stressful in laryngoscopy; Macintosh, Miller, or McCoy?]

Stress responses during laryngoscopy were compared among the situations using three different laryngoscopes, Macintosh (curved standard blade), Miller (straight blade), or McCoy (levering). Blood pressure, heart rate (in 58 patients) and plasma concentration of catecholamines (in 29 patients) were measured before, during and after laryngoscopy without tracheal intubation. Systolic blood pressure after laryngoscopy was significantly higher in the Miller group than in other two groups. Plasma epinephrine concentrations after laryngoscopy in the McCoy group were lower than other two groups. Heart rate and plasma norepinephrine concentration were not different among the three groups. These results suggest that the stress response during laryngoscopy without intubation is the biggest in using the Miller laryngoscope and the smallest in using the McCoy laryngoscope.

Characterization of the transcriptional initiation regions of genes for the major secreted protein antigens 85C and MPB51 of Mycobacterium bovis BCG

The component of mycobacterial 85 complex (85A, 85B, and 85C) and MPB51 are very important from immunological, biochemical, and antimycobacterial points of view. In this study, the transcriptional properties of genes encoding three components of 85 complex and MPB51 from BCG were analysed. The authors' analyses revealed that genes for 85A and MPB51 were transcribed as a single unit despite the one operon-like structure and these four genes were probably under a different regulatory control. These findings may help to understand the immunological and physiological roles of these antigens.

Evaluation of a new method for identification of bacteria based on sequence homology of 16S rRNA gene

A new identification method for bacteria based on partial sequences of divergent regions of the 16S rRNA gene was evaluated. The method involves PCR-based amplification of 16S rRNA gene fragments, followed by sequencing and comparison of sequences of about 300 nucleotides with those in the database of NCBI (National Center for Biotechnology Information) via the Internet. Most of the bacteria tested could be identified at the species level even if some unread nucleotides were present in the sequence. Although this method still requires improvement, it has the potential to be a highly reliable and practical identification method for bacteria.

Interactions between nicardipine and enflurane, isoflurane, and sevoflurane

PURPOSE

During nicardipine induced hypotension, different inhalational anaesthetics may have different effects on haemodynamic variables, sympathetic function and drug metabolism. Therefore, the haemodynamic effects and pharmacokinetics of nicardipine were studied in the presence of the three inhalation anaesthetics enflurane, isoflurane and sevoflurane.

METHODS

Thirty patients scheduled for neurosurgery were randomly assigned to one of three anaesthetic techniques: enflurane, isoflurane or sevoflurane. Nicardipine (0.017 mg.kg-1) was administered during stable anaesthesia and the following measurements made for 30 min: blood pressure, heart rate, and plasma concentration of norepinephrine, epinephrine and nicardipine.

RESULTS

With sevoflurane, plasma concentrations of nicardipine, five minutes after administration, (39.8 +/- 3.5 ng.ml-1, mean +/- SEM) were higher (P < 0.05) than in the other two groups (28.3 +/- 2.9 ng.ml-1, 32.6 +/- 4.3 ng.ml-1, enflurane and isoflurane, respectively). With isoflurane, the approximated half-life of nicardipine (14 +/- 4 min) was shorter and clearance (2.1 +/- 0.3 l.min-1) more rapid. Peak heart rates were similar in all groups but elevated rates continued longer with isoflurane (> 30 min). Nicardipine-induced reduction in blood pressure was greater with sevoflurane but low pressures persisted for longer with isoflurane. Plasma catecholamine concentrations increased with isoflurane and enflurane, but not with sevoflurane: considerably higher epinephrine concentrations were seen with isoflurane.

CONCLUSION

This study showed that the action of nicardipine is modified by different inhalational anaesthetic agents. Nicardipine has a prolonged duration of action in the presence of isoflurane and produces greater initial hypotension with sevoflurane.

Same day drainage and removal of a giant ovarian cyst

PURPOSE

An unusual case of a giant ovarian cyst was successfully anaesthetized with a combination of epidural followed by general anaesthesia. The method was chosen to avoid circulatory depression and re-expansion pulmonary oedema in removal of a giant tumour in a woman who did not understand the nature of her disease.

CLINICAL FEATURES

A 58-yr-old woman (107.6 kg, 150 cm and abdominal girth: 163.5 cm) was admitted for removal of a giant ovarian cyst. There was gross-pitting oedema of both legs and an elevated diaphragm but no pleural effusion. She did not understand the severity of her disease. It was decided to drain the cyst gradually, followed by total surgical removal on the same day. An epidural catheter was inserted at the L3-4 interspace with the patient in the left lateral position and, under epidural anaesthesia, 44.3 L fluid were drained over two hours without producing circulatory depression or pulmonary oedema. General anaesthesia was induced, with the patient in the supine position, by slow injection of 10 mg midazolam, 100 micrograms fentanyl and inhalation of nitrous oxide 50% in oxygen, and maintained with adding epidural block using lidocaine 1.5% and bupivacaine 0.5%, and sevoflurane 0.4 to 0.8%. During surgery, the volume of infused fluid was carefully controlled with central venous pressure monitoring. Ulinastatin, a protease inhibitor, was infused to prevent pulmonary oedema. No circulatory depression nor pulmonary oedema occurred perioperatively.

CONCLUSION

For the removal of a giant ovarian cyst, slow drainage over two hours under epidural anaesthesia may safely precede later removal of the cyst on the same day under general anaesthesia.

Haemodynamic and catecholamine changes during rapid sevoflurane induction with tidal volume breathing

PURPOSE

To compare haemodynamic and plasma catecholamine changes with rapid (three minute) inhalational anaesthesia induction with tidal volume breathing of sevoflurane 7%, conventional (seven minute) slow inhalation induction with increasing sevoflurane concentration up to 5%, and induction with thiamylal i.v.

METHODS

Twenty-four patients were randomly divided into three groups of eight. In Group A, anaesthesia was induced with tidal volume breathing of sevoflurane 7% (inspiratory concentration) and nitrous oxide 50% in oxygen (total flow; 6 l.min-1) for three minutes: Group B received conventional slow induction for seven minutes and increasing sevoflurane concentration by 0.5% every two or three breaths up to 5% with nitrous oxide 50% in oxygen: and Group C received 5 mg.kg-1 thiamylal with an inhalation of 100% oxygen. Blood pressure, heart rate, rate pressure product, and plasma concentrations of epinephrine and norepinephrine were measured.

RESULTS

There were no changes in blood pressure before or after intubation in Group A (sevoflurane 7%) whereas both were increased in patients in Group C (thiamylal). Changes in heart rate and rate pressure product were not different for the two inhalation groups. Plasma epinephrine concentrations decreased in all the three groups. Norepinephrine concentrations were increased before intubation in both inhalation groups but not in the thiamylal group.

CONCLUSION

Rapid induction of anaesthesia with sevoflurane 7% and tidal volume breathing for three minutes induced less haemodynamic changes than the other methods studied and has no inhibitory effect on sympathetic activity.

[Effects of cardiac output on PETCO2 and PaCO2 during combined inhalational-epidural anesthesia]

We investigated the effects of cardiac output on PETCO2 in anesthetized patients. We studied 8 adult patients undergoing long-lasting lower abdominal surgery. Anesthesia was maintained with epidural combined with inhalational anesthesia. The minute ventilation volume was kept constant at 10 ml.kg-1 x 10 cycles.min-1. PETCO2, PaCO2, and cardiac index, (CI) by thermodilution method were measured simultaneously. PaCO2 was corrected for body temperature for comparison with PETCO2. Approximate value of alveolar dead space to tidal volume ratio was calculated as VD/ VTalv = (PaCO2-PETCO2)/PaCO2. The measurements were repeated every 10 to 20 minutes under the steady body temperature. One hundred and six sets of data were obtained from these patients. PETCO2 as well as PaCO2 correlated positively with CI, while VD/VTalv did not correlate with CI. PETCO2 correlated positively with PaCO2, while it did not correlate with VD/VTa1v. When examined in individual patients, PETCO2 correlated positively with CI in 7 patients. PaCO2 correlated positively with CI in 6 patients, while VD/VTa1v correlated negatively with CI only in 2 patients, in whom CI showed a large fluctuation. PaCO2 correlated positively with PETCO2 in 8 patient, while VD/VTa1v correlated negatively with PETCO2 only in 1 patient. By multiple regression analysis, VD/VTa1v change accounted for only 20.0 +/- 15.3% of PETCO2 change, while PACO2 or PaCO2 change accounted for 79.3 +/- 16.7%. Decreased CI was associated with a decrease in oxygen uptake (VO2), and PaCO2 correlated positively with VO2. Decreased CI was also associated with an increase in VA/Q, and PaCO2 correlated negatively with VA/Q. Thus, PETCO2 decreased with decreasing cardiac output. A decrease in PACO2 explained the decrease in PETCO2 better than an increase in VD/VT did. Decreased cardiac output caused hypocapnia through decreased CO2 production and/or increased ventilation to perfusion ratio i.e. relative hyperventilation.

[A trial of laparoscopic assisted radical nephrectomy]

BACKGROUND

We tried a new procedure of gas-less laparoscopy assisted radical nephrectomy.

METHODS

Prior to insertion of laparoscope, pararectal incision approximately 7 cm in length was made to enter into the intraabdominal cavity. A 12 mm trocar was placed just below the umbilicus and a flexible electroscope was inserted through it. A 10 cm size disposable fan for lifting up the abdominal wall was indwelled through the under space of trocar port. After appropriately lifting up the abdominal wall, a 10 mm trocar for working channel was placed at mid-axillar line. Under laparoscopic and trans-laparotomic views, radical nephrectomy was performed using the combined technique of laparoscopic and open surgery.

RESULTS

Seven patients have been successfully treated with this procedure. The mean operating time of this procedure was significantly shorter than that of totally laparoscopic nephrectomy. The recovery time from the operation was as short as usual laparoscopic nephrectomy.

CONCLUSION

We thought that this procedure could open a new scope of laparoscopic surgery.

[Clinical use of midazolam]

Midazolam is widely used in anesthesia. This paper shows characteristics of midazolam and how to use midazolam in clinical anesthesia. As a premedication, midazolam should be injected i. m. 15 min before entering an operating room in a dose of 0.04 mg.kg-1 to 0.08 mg.kg-1 according to the patient's age. For anesthesia induction, midazolam should be used together with barbiturate or propofol to take advantage of synergistic effects. Continuous infusion of midazolam in total intravenous anesthesia with fentanyl results in hemodynamic stability and good postoperative analgesia. During spinal or epidural anesthesia, i.v. midazolam of 0.05 mg.kg-1 has anti-anxietic and sedative effects. Midazolam inhibits awakening during cardiopulmonary bypass and it has little cardiodepressant effect. In aged, hepatic damaged or renal damaged patients, the effects of midazolam are slightly increased. Therefore, lower doses may be required in such patients. In conclusion, midazolam is usable in premedication, induction, maintenance in general anesthesia and in sedation in local anesthesia.

[Assessment of the practice of endotracheal intubation by levering Laryngoscope in teaching of undergraduate medical students]

Twenty-nine inexperienced medical students tried to intubate endotracheal tubes using both levering laryngoscope (McCoy laryngoscope) and Macintosh laryngoscope in adult mannikin the Cormack and Lehane Grade 2. The number of successful intubations by McCoy type was close to those by Macintosh type. Improvement in time necessary from insertion of the laryngoscope to confirmation of placement of the endotracheal tube McCoy type was also close to that by Macintosh type. But the grade of handling difficulty of McCoy type was significantly higher than that of Macintosh type, because Macintosh type was simpler to handle than McCoy type. It was suggested that Macintosh laryngoscope was more useful than McCoy laryngoscope for teaching of inexperienced medical students.

Analysis of the genes encoding the antigen 85 complex and MPT51 from Mycobacterium avium

The components of the fibronectin-binding antigen 85 complex (85A, 85B, and 85C) and the related protein MPB/MPT51 are major secreted proteins in Mycobacterium tuberculosis and Mycobacterium bovis BCG. The fbpA, fbpC, and mpt51 genes encoding 85A, 85C, and MPT51, respectively, were isolated from Mycobacterium avium and sequenced in this study. The structures of these genes, and that of the fbpB gene encoding the 85B protein, were conserved in these three species. The secreted amounts of 85A, 85B, 85C, and MPB/MPT51 were compared for M. tuberculosis, BCG, and M. avium. These four proteins were found in large amounts in the culture filtrates from M. tuberculosis and BCG. In contrast, in the culture filtrate from M. avium, 85B and MPT51 were abundant whereas 85A and 85C were hardly found, in spite of the presence of the encoding genes. The difference in the secretion amounts might be regulated at the transcription level. These facts might reflect host immunopathogenesis, the protective immunities against infections, and the drug susceptibilities of these organisms.

Ex vivo partial nephrectomy and partial kidney autotransplantation for renal pelvic carcinoma in a functionally solitary kidney: case report

A 46-year-old Japanese man was diagnosed with a left renal pelvic carcinoma and a contralateral hypoplastic kidney. The tumor was adjacent to the renal pelvis and was considered too difficult to completely resect in situ. The patient was treated by ex vivo partial nephrectomy of the left kidney followed by autotransplantation of the remaining renal segment. A pathologic evaluation revealed a transitional cell carcinoma, G2, pT3. Graft function recovered satisfactorily postautotransplantation and no significant complications developed during the postoperative period. The patient is alive and doing well 12 months postoperatively with no evidence of tumor recurrence.

Lethal drug interactions of sorivudine, a new antiviral drug, with oral 5-fluorouracil prodrugs

Rats were orally co-administered sorivudine (SRV: 1-beta-D-arabinofuranosyl-(E)-5-(2-bromovinyl)uracil), a new oral antiviral drug for herpes zoster, with the oral anticancer drug tegafur (FT: 1-(2-tetrahydrofuryl)-5-fluorouracil as a prodrug of 5-fluorouracil (5-FU) once daily to investigate a toxicokinetic mechanism of 15 Japanese patients' deaths recently caused within a brief period by the drug interaction of these drugs. All the rats showed extremely elevated levels of 5-FU in plasma and tissues, including bone marrow and small intestine, and died within 10 days, whereas the animals given the same dose of SRV or FT alone were still alive over 20 days without any appreciable toxic symptom. Before their death, there was marked damage of bone marrow, marked atrophy of intestinal membrane mucosa, marked decreases in white blood cells and platelets, diarrhea with bloody flux, and severe anorexia as reported with the Japanese patients. Data obtained by in vivo and in vitro studies strongly suggested that (E)-5-(2-bromovinyl)uracil generated from SRV by gut flora was reduced in the presense of NADPH to a reactive form by hepatic dihydropyrimidine dehydrogenase (DPD), a key enzyme determining the tissue 5-FU levels, bound covalently to DPD as a suicide inhibitor, and markedly retarded the catabolism of 5-FU.

[Combined spinal and epidural anesthesia for laparotomy in a geriatric patient with severe obstructive lung disease]

Asthma and heavy smoking are the risk factors for postoperative respiratory distress, especially after general anesthesia. We experienced a case of sigmoidectomy in a geriatric patient with severe obstructive lung disease accompanied by asthma and a long history of smoking. The patient was a 70 year old man with 1 second volume of less than 0.6 l, because of asthma and long smoking history of 40 pieces of cigarettes a day for 50 years. We considered that general anesthesia with tracheal intubation might worsen the respiratory state after surgery and chose combined spinal and epidural anesthesia. He received sigmoidectomy under spinal anesthesia with 0.3% dibucaine 2.4 ml combined with epidural anesthesia. As the level of analgesia went up to Th4, the patient complained of dyspnea and he discharged a plenty of sputum. Without any special treatment his dyspnea disappeared spontaneously. During and after the surgery, no exacerbation occurred in his respiratory state. It is suggested that spinal anesthesia combined with epidural anesthesia is useful for a patient with severe obstructive lung disease.

Cerebrovascular CO2 reactivity in elderly and younger adult patients during sevoflurane anaesthesia

PURPOSE

General anaesthetic agents and aging affect cerebrovascular CO2 reactivity (CCO2R). The purpose of this study was to investigate the effect of aging on CCO2R in patients during sevoflurane anaesthesia.

METHODS

Twenty-four patients were divided into two groups of 12 according to age; 20-40 yr and 50-70 yr. Anaesthesia was induced with 5 mg.kg-1 thiopentone and maintained with sevoflurane 1.0 to 1.5% (end-tidal) and nitrous oxide 66% in oxygen to maintain anaesthesia. End-tidal CO2 tension (PETCO2) was altered from 20 to 50 mmHg in 5 mmHg steps by changing the respiratory rate. Middle cerebral blood flow velocity (CBFV) and pulsatility index (PI) were measured by transcranial Doppler (TCD) at each step change in PETCO2. The CCO2R was calculated as the change of CBFV per mmHg at each 5 mmHg interval.

RESULTS

In each group, there were no changes in blood pressure, heart rate, end-tidal sevoflurane concentration, or PI as the PETCO2 was increased from 20 to 50 mmHg. The CCO2R at PETCO2 of 35 to 50 mmHg in the younger group (0.80 +/- 0.27 (SD) cm.sec-1.mmHg-1) was larger than that in the elderly group (0.31 +/- 0.16 cm.sec-1.mmHg-1) (P < 0.01).

CONCLUSION

It is concluded that, during sevoflurane anaesthesia, CCO2R is well preserved, and that the CCO2R at PETCO2 of 35 to 50 mmHg in the 20 to 40 yr age group is greater than that in the 50 to 70 yr age group.

[A simple, lightweight device for measurement of hemoglobin; the HemoCue Blood Hemoglobin Test]

In some situations such as a sudden bleeding during surgery, rapid testing of blood hemoglobin concentration is necessary. The HemoCue Blood Hemoglobin Test uses a lightweight photometer, which is easily movable anywhere. The HemoCue needs only 10 microliters of blood and it takes only about 45 seconds to produce the result. Therefore, the device might be useful in the operating suite and the emergency unit. To evaluate the accuracy of the HemoCue, we compared the blood hemoglobin concentrations measured by the HemoCue with those measured by the ABL 300. A positive correlation was found between the variables by the HemoCue (Y) and those by the ABL 300 (X); Y = 0.944X - 0.208, r = 0.97, P < 0.001. It is concluded that the HemoCue is a reliable device for measurement of blood hemoglobin concentration.

[Anesthesia induction for laryngeal mask insertion--comparison of propofol with midazolam and propofol with thiopental]

We compared the patient's response to laryngeal mask (LM) insertion and hemodynamics among three anesthesia induction methods; P group using 2.5 mg.kg-1 propofol with 0.2 microgram.kg-1 fentanyl, M group using 0.2 mg.kg-1 midazolam with 0.2 microgram. kg-1 fentanyl, B group using 5 mg.kg-1 thiopental with 0.2 microgram.kg-1 fentanyl. Each 30 patients, 35 to 65 years, for elective mastectomy were entered in three groups. Preanesthetic medication was i.m. injection of 0.5 mg atropine and 5 mg midazolam 30 min before the induction. Anesthesia was induced with intravenous injection of each dose of P, M or B in 20 sec followed by fentanyl. When verbal response disappeared, a laryngeal mask was inserted. The number of patients with difficult insertion or showing body movement or gagging were larger in the order of M group > B group > P group. Blood pressure and heart rate in the P group were significantly lower than those in the other two groups. It was concluded that P allowed the most smooth insertion of LM among the three groups, but it also induced hypotension and bradycardia.

Lethal drug interactions of sorivudine, a new antiviral drug, with oral 5-fluorouracil prodrugs

Rats were orally co-administered sorivudine (SRV: 1-beta-D-arabinofuranosyl-(E)-5-(2-bromovinyl)uracil), a new oral antiviral drug for herpes zoster, with the oral anticancer drug tegafur (FT: 1-(2-tetrahydrofuryl)-5-fluorouracil) as a prodrug of 5-flourouracil (5-FU) once daily to investigate a toxicokinetic mechanism of 15 Japanese patients' deaths recently caused within a brief period by the drug interaction of these drugs. All the rats showed extremely elevated levels of 5-FU in plasma and tissues, including bone marrow and small intestine, and died within 10 days, whereas the animals given the same dose of SRV or FT alone were still alive over 20 days without any appreciable toxic symptom. Before their death, there was marked damage of bone marrow, marked atrophy of intestinal membrane mucosa, marked decreases in white blood cells and platelets, diarrhea with bloody flux, and severe anorexia as reported with the Japanese patients. Data obtained by in vivo and in vitro studies strongly suggested that (E)-5-(2-bromovinyl)uracil generated from SRV by gut flora was reduced in the presense of NADPH to a reactive form by hepatic dihydropyrimidine dehydrogenase (DPD), a key enzyme determining the tissue 5-FU levels, bound covalently to DPD as a suicide inhibitor, and markedly retarded the catabolism of 5-FU.