Postoperative muscle paralysis after rocuronium: less residual block when acceleromyography is used

BACKGROUND

Residual muscle paralysis after anesthesia is common after pancuronium, but less common following the intermediate-acting drugs vecuronium and atracurium. Therefore, many anesthetists do not monitor neuromuscular function when using an intermediate-acting agent. The purpose of this prospective, randomised and double-blind study was to establish the incidence and degree of postoperative residual block following the use of rocuronium in patients not monitored with a nerve stimulator, and to compare it with results obtained in patients monitored using acceleromyography (AMG).

METHODS

During propofol/opioid anesthesia, 120 adult patients were randomised to two groups, one monitored with AMG, the other using only clinical criteria without a nerve stimulator. Postoperatively, TOF-ratio was measured with mechanomyography; a TOF-ratio < 0.80 indicated residual muscle paralysis.

RESULTS

Residual muscle paralysis was found in 10 patients in the group without neuromuscular monitoring (16.7%) (95% confidence interval, 12-21%) and in two patients in the AMG-monitored group (3%) (95% CI, 0-8%); (P = 0.029, Fisher's exact test). Time from end of surgery to tracheal extubation was significantly longer in the AMG-monitored group (12.5 min) than in the group not monitored with AMG (10 min).

CONCLUSION

Clinical evaluation of recovery of neuromuscular function does not exclude significant residual paralysis following the intermediate-acting muscle relaxant rocuronium, but the problem of residual block can be minimized by use of AMG.

Accuracy of digital tympanic, oral, axillary, and rectal thermometers compared with standard rectal mercury thermometers

OBJECTIVE

To compare a number of electronic tympanic, oral, axillary, and rectal measurements with those taken with a standard rectal mercury thermometer.

DESIGN

Prospective open study.

SETTING

County hospital, Denmark.

SUBJECTS

200 patients.

INTERVENTIONS

Each of 200 patients had 6 electronic measurements of body temperature: 3 in the auditory canal using Ivac Core Check 2090A, Diateck 9000, and Genius 3000A, 1 in the axilla using Terumo Digital C202. 1 in the mouth using Terumo Digital C402, and 1 in the rectum using a Terumo Digital C402. These were compared with readings from a standard mercury glass thermometer in the rectum.

MAIN OUTCOME MEASURES

Accuracy of electronic thermometry.

RESULTS

The rectal electronic measurements were closest to the rectal mercury readings, with a mean (SD) of -0.05 degrees C (0.12), whereas the other measurements gave unacceptable SDs of temperature differences ranging from 0.41 degrees C to 0.53 degrees C.

CONCLUSIONS

We conclude that electronic rectal temperature measurements are the most accurate. We do not recommend electronic tympanic, oral, or axillary measurements.

Comparison of the cardiovascular effects of cisatracurium and vecuronium in patients with coronary artery disease

PURPOSE

Cisatracurium besylate (Nimbex Injection, Glaxo Wellcome Inc., Research Triangle Park, NC) is an intermediate-acting bis-benzylisoquinolinium neuromuscular blocking drug that is one of the stereoisomers of atracurium. At doses < or = 8 x ED95, it caused no clinically important cardiovascular side effects or histamine release in healthy patients. The purpose of the present study was to investigate the haemodynamic effects of high doses of cisatracurium in patients with coronary artery disease.

METHODS

One hundred patients undergoing myocardial revascularization participated in a pilot study (seven patients) and a double-blinded, randomized, controlled trial comparing the haemodynamic effects of cisatracurium with vecuronium at three centres. The patients were anaesthetized using oxygen 100%, with etomidate, fentanyl and a benzodiazepine, and tracheal intubation was facilitated using succinylcholine. After baseline haemodynamic measurements, the study drug was administered over 5-10 sec according to group assignment: Group A (pilot) cisatracurium, 0.20 mg.kg-1 (4 x ED95), (n = 7); Group B-cisatracurium, 0.30 mg.kg-1 (6 x ED95), (n x ED95), (n = 31); Group C-vecuronium, 0.30 mg.kg-1 (6 x ED95), (n = 31); Group D cisatracurium, 0.40 mg.kg-1 (8 x ED95), (n = 21); Group E-vecuronium, 0.30 mg.kg-1 (6 x ED95), (n = 10). The haemodynamic measurements were repeated at 2, 5, and 10 min after cisatracurium or vecuronium.

RESULTS

Two patients in Group D had > 20% decreases in MAP, but only one required therapy for hypotension. The haemodynamic changes from pre- to post-injection in the cisatracurium patients were minimal and similar to patients receiving vecuronium.

CONCLUSIONS

In patients with coronary artery disease, rapid cisatracurium (4-8 x ED95) boluses and vecuronium (6 x ED95) result in minor, clinically insignificant haemodynamic side effects.

[Leiomyosarcoma of the spermatic cord]

Sarcoma of the spermatic cord is a rare disease with less than 300 cases reported in the literature. A case of leiomyosarcoma is presented, and an analysis of the therapeutic approaches of radical orchidectomy, and in some cases retroperitoneal lymph node dissection, chemotherapy and radiation is given. The total numbers of different types of sarcomas in the spermatic cord, reported to The Danish Department of Cancer Registration are briefly presented as well.

[Plasma cholinesterase and abnormal reaction to suxamethonium injection. 20-year experience with the Danish Cholinesterase Registry]

For more than 20 years, the Danish Cholinesterase Research Unit (DCRU) has collected information about patients showing an abnormal response to succinylcholine. The purpose of this study was to evaluate our clinical findings in patients referred because of prolonged response following succinylcholine. Also, we wanted to evaluate the results of our prospective controlled studies of the effect of succinylcholine in patients with normal and abnormal plasma cholinesterase genotypes. An explanation for the apparent abnormal response to succinylcholine was only found in roughly 60% of the 1247 patients referred to the Unit. In the remaining nearly 40% of the patients the reason for the abnormal response remained obscure, though our results indicate that the anaesthetic technique, including hyperventilation or central respiratory depression, was most likely to be the reason. The significance of the different genotypes, including two newly discovered genotypes (AK, AH), for the reaction to succinylcholine was evaluated and found to be comparable to previous findings. Our results indicate that it is a problem for many anaesthetists to correctly diagnose a prolonged response to succinylcholine. We therefore urge the anaesthetist to use a peripheral nerve stimulator when faced with a case of apparent abnormal response to succinylcholine.

Plasminogen activators and plasminogen activator inhibitor in portal blood from patients with and without gastric malignancy

BACKGROUND

Plasminogen activators (PA) may be released by the gut and eliminated by the liver. Patients with liver disorders or malignancy often have abnormal plasma levels of PAs. Some tumours may produce PAs.

METHODS

In patients undergoing gastric surgery for malignant (n = 18) or benign (n = 21) disorders., blood drawn from the portal vein and a peripheral vein was analysed for tissue-type plasminogen activator antigen and activity (tPA: Ag, tPA: Act), single-chain urokinase-type plasminogen activator activity (scuPA: Act), and plasminogen activator inhibitor antigen and activity (PAI: Ag, PAI: Act).

RESULTS AND CONCLUSIONS

In both groups tPA: Act and scuPA: Act levels were significantly higher in portal blood than in peripheral blood, but tPA: Ag and PAI: Act levels did not differ. PAI: Act levels were significantly lower in patients with malignant disease, but levels of the other markers did not differ in the two groups.

Good clinical research practice (GCRP) in pharmacodynamic studies of neuromuscular blocking agents

Based on an international consensus conference held in Copenhagen in the autumn of 1994, a set of guidelines for Good Clinical Research Practice (GCRP) in pharmacodynamic studies of neuromuscular blocking agents are presented. The guidelines are intended to be a help for people working in this research field, and it is hoped that the guidelines will assist researchers, editors, and drug companies to enhance the quality of their pharmacodynamic studies of neuromuscular blocking agents.

Detection of the plasma cholinesterase K variant by PCR using an amplification-created restriction site

Ten individuals registered at the Danish Cholinesterase Research Unit were examined at the DNA level for the presence of the K allele of plasma cholinesterase, using amplification-created restriction sites (ACRSs). A further nine members of a family registered at the unit were tested for mutations of the K and atypical variants. The frequency of the K allele was calculated from examination of normal material from 25 individuals, representing 50 random alleles. The results show that the ACRS method successfully demonstrates the presence of the K variant, whose frequency in the Danish population was found to be 0.18. We conclude that this technique is a reliable and rapid non-radioactive diagnostic assay for detecting the plasma cholinesterase K variant.

Dose-response relationship for mivacurium in patients with phenotypically abnormal plasma cholinesterase activity

During thiopentone-fentanyl-nitrous oxide anaesthesia and using a cumulative design, we studied the dose-response relationship of mivacurium in 8 patients: 7 patients phenotypically homozygous for the atypical plasma cholinesterase gene and 1 patient homozygous for the silent gene. The estimated mean ED50 and ED95 were 15 and 20 micrograms.kg.bw-1 in patients homozygous for the atypical gene, and 13 and 16 micrograms.kg.bw-1 in the patient homozygous for the silent gene, respectively. The results indicate that mivacurium is 4-5 times more potent in patients homozygous for the atypical or the silent gene than in patients with normal plasma cholinesterase activity and phenotype.

Plasminogen activators and plasminogen activator inhibitor before and after surgery in patients with and without gastric malignancy

Pre- and postoperative plasma levels of tissue-type plasminogen activator (t-PA), single-chain urinary plasminogen activator, and plasminogen activator inhibitor 1 (PAI-1) were measured in 40 patients undergoing gastric surgery in order to compare patients operated for benign (n = 21) and malignant (n = 19) disease. On the 1st postoperative day, the PAI-1 activity was significantly increased and the t-PA activity significantly decreased in the malignant group, whereas only insignificant changes were seen in the benign group. In contrast, the t-PA activity was significantly increased 1 week after surgery in patients without malignancy. In both groups, the single-chain urinary plasminogen activator activity decreased on the 1st postoperative day, but was significantly increased 1 month after operation. Thus, the two groups reacted differently, but it remains to be determined whether this bears any relationship to the well-known high risk of postoperative venous thromboembolism in cancer patients.

Identification of human plasma cholinesterase variants using molecular biological techniques

Genetic variation is one of several factors determining the level and quality of plasma cholinesterase activity (butyrylcholinesterase, BChE). The many genetic variants known today, and the resulting large number of genotypes and phenotypes, have complicated the problem of identifying individual BChE genotypes and phenotypes on the basis of enzymatic analyses alone. Modern molecular biological techniques have, however, permitted the development of diagnostic tests which allow BChE variants to be identified at the DNA level. Today, at least 20 genetic variants have been identified in this way. This review is an introduction to the principles of molecular biology used to identify the variants forms of the BCHE gene.

Plasma cholinesterase and abnormal reaction to succinylcholine: twenty years' experience with the Danish Cholinesterase Research Unit

For more than 20 years, the Danish Cholinesterase Research Unit (DCRU) has collected information about patients showing an abnormal response to succinylcholine. The purpose of this study was, on the basis of the 20 years' experiences with the Unit, to evaluate our clinical findings in patients referred because of prolonged response following succinylcholine. Also, we wanted to evaluate the results of our prospective controlled studies of the effect of succinylcholine in patients with normal and abnormal plasma cholinesterase genotypes. An explanation for the apparent abnormal response to succinylcholine was found in 61.1% of the 1,247 patients referred to the Unit. Of the 1,247 patients, 28.5% were genotypically normal and 46.5% had an abnormal genotype. In the remaining 24.9% of the patients, the genotype could not be established. The time to sufficient recovery of neuromuscular function following succinylcholine 1.0-1.5 mg kg-1 was 15-30 min in patients heterozygous for one abnormal gene, 35-45 min in patients heterozygous for two abnormal genes and 90-180 min in patients homozygous for the atypical gene. Patients with two newly discovered genotypes (AK (5 patients) and AH (1 patient) showed slightly prolonged (20 min) and markedly prolonged (90 min) duration of action of succinylcholine, respectively. Our results indicate that it is a problem for many anaesthetists to correctly diagnose a prolonged response to succinylcholine. We therefore urge the anaesthetist always to use a peripheral nerve stimulator when faced with a case of apparent abnormal response to succinylcholine.

Identification of human plasma cholinesterase variants in 6,688 individuals using biochemical analysis

In 1973, a Cholinesterase Research Unit was established in Denmark (DCRU). The primary aim was to provide a central service for determining genotypes and activity of plasma cholinesterase (BChE) in patients showing abnormal response after succinylcholine. The purpose of the present study was, on the basis of 20 years experience with this Unit, to establish accurate reference intervals for BChE activity and inhibition values for the different genotypes of BChE. Also we wanted to evaluate the influence of age and sex on the BChE activity in genotypically normal patients. Plasma cholinesterase activity was measured using benzoylcholine as substrate. The genetic variations of the enzyme were identified using differential inhibitors, i.e.: Dibucaine, Sodium Fluoride, Succinylcholine, Urea and Ro-2-0683. We investigated 6,688 patients. The reference values for the 13 genotypes represented agree with previous findings. In genotypically normal patients, no age or sex differences were found in BChE activity in children below the age of 10 years. From the age of 10 years the activity decreased significantly in both males and females, the activity in females being significantly lower than in males. In females the activity was lowest in the age group 30-40 years, returning to prepuberty level at about 60 years of age. In males the activity decreased slightly up to 50-60 years of age. Hereafter the activity was stable or tended to increase slightly. Most genotypes could be recognized using the results of the different inhibition studies. We found the inhibitors Dibucaine, Sodium fluoride, Urea and Ro-2-0683 most helpful, whereas succinylcholine was of less value.(ABSTRACT TRUNCATED AT 250 WORDS)

[Chronic volvulus of the stomach]

Gastric volvulus is an abnormal rotation of the stomach. The incidence seems to be equal for men and women, and all ages are represented. Gastric volvulus may present as an emergency or as a chronic condition. Acute volvulus is potentially lethal if unrecognized, while a chronic volvulus may cause symptoms for years if not treated. Gastric volvulus may be more common than previously estimated. Approximately 700 cases have thus far been documented. Two case reports of chronic gastric volvulus are presented, of which one was treated by laparoscopic surgery.

Clinical importance of plasma cholinesterase for the anaesthetist

Plasma cholinesterase is a glycoprotein synthesized in the liver and is found in plasma, liver, intestinal mucosa and other tissues. Six percent to 7% of patients in most surgical populations have an abnormal plasma cholinesterase activity and about 65% of all cases of prolonged neuromuscular blockade following succinylcholine are due to genetic factors. This review focuses on the causes and clinical significance of plasma cholinesterase for the hydrolyses of succinylcholine. Diagnosis and treatment of prolonged response to succinylcholine in phenotypically normal patients, heterozygous abnormal patients and patients homozygous for the atypical gene is mentioned. Also presented is the relationship between plasma cholinesterase and the new relaxant mivacurium, and bambuterol, a prodrug to terbutaline. Additionally, the recent developments in the identification of the plasma cholinesterase genotypes are presented.

Haemostatic activation before and after surgery in patients with and without gastric malignancy

Pre- and postoperative plasma levels of Prothrombin Fragment 1 + 2 (F1 + 2), Thrombin-antithrombin III complex (TAT), Fibrinopeptide A (FpA), Fibrin and Fibrinogen Degradation Products (FbDP, FgDP) and Soluble Fibrin (SF) were measured in 40 patients undergoing gastric surgery in order to compare patients operated for benign (n = 21) and malignant (n = 19) disease. Plasma levels of F1 + 2, TAT, FbDP and SF on the first postoperative day were significantly higher than before operation. F1 + 2 and FbDP levels were further increased one week after surgery, at which time FgDP levels were also higher than preoperatively. A significant postoperative increase in FpA levels was found only in patients with malignant disease. When age was taken into consideration, significant differences between patients with and without malignancy were found only in the late postoperative period, as cancer patients had higher FpA and FbDP levels one week after surgery and higher FbDP levels one month after discharge from hospital.

Markers of coagulation and fibrinolysis in portal blood from patients with and without gastric malignancy

BACKGROUND

The origin of coagulation and fibrinolysis abnormalities in cancer patients is unknown. The aim of this study was to measure markers of coagulation and fibrinolysis in portal and peripheral blood from patients with and without gastric malignancy.

METHODS

Blood samples were drawn from the portal vein and a peripheral vein in 39 patients undergoing elective gastric surgery, 18 for gastric malignancy and 21 for benign disorders, and analyzed for prothrombin fragment 1 + 2 (F1 + 2), thrombin-anti-thrombin III complex (TAT), fibrinogen and fibrin degradation products (FgDP, FbDP), and fibrinopeptide A (FpA).

RESULTS AND CONCLUSIONS

In portal blood, levels of F1 + 2, TAT, FpA, FgDP, and FbDP did not differ in the two groups. In peripheral blood, levels of FpA and FbDP were higher in cancer patients, but in a multiple regression model malignancy did not contribute significantly to variation in peripheral FpA or FbDP levels. In both groups FpA levels were higher in portal blood than in peripheral blood.

Absorption kinetics of two highly concentrated preparations of growth hormone: 12 IU/ml compared to 56 IU/ml

The purpose of this study was to compare the relative bioavailability of two highly concentrated (12 IU/ml versus 56 IU/ml) formulations of biosynthetic human growth hormone administered subcutaneously. After pretreatment with growth hormone for at least four weeks, nine growth hormone deficient patients with a mean age of 26.2 years (range 17-43) were studied two times in a randomized design, the two studies being separated by at least one week. At the start of each study period (7 p.m.), growth hormone was injected subcutaneously in a dosage of 3 IU/m2. The 12 IU/ml preparation of growth hormone was administered on one occasion, and the 56 IU/ml preparation on the other. Serum profiles of growth hormone were monitored by frequent measurements for 24 hr. Bioavailability and absorption dynamics were evaluated by the absorption fraction, F56 IU/12 IU, calculated from the mean integrated levels (AUC) of growth hormone, and the observed time, Tmax, to reach maximum concentration, Cmax. Levels of serum IGF-I, IGFBP-3, insulin and blood glucose were measured to study the short term metabolic effects of growth hormone. The absorption fraction, F (S.D.) was 1.034 (0.163). The 90% confidence interval was 0.934-1.144, which is included in the interval 0.8-1.25, implying that the two preparations are bioequivalent. Neither AUC (P = 0.90), Cmax (p = 0.47) or Tmax (P = 0.86) for the two formulations of growth hormone were significantly different. Similar levels of serum IGF-I, IGFBP-3, insulin and blood glucose were obtained.(ABSTRACT TRUNCATED AT 250 WORDS)

Mivacurium-induced neuromuscular blockade in patients with atypical plasma cholinesterase

The duration of action of mivacurium was evaluated during a modified neurolept anaesthesia in 17 patients heterozygous for the usual and the atypical plasma cholinesterase (pChe) gene (E1uE1a) and in five patients homozygous for the atypical gene (E1aE1a). The response to train-of-four nerve stimulation was recorded using a Myograph 2000. Five heterozygous patients were given a small dose of mivacurium 0.03 mg kg bw-1 intravenously (Group 1). The mean (range) suppression of the first twitch in the train-of-four response (T1) was 91% (69-100%). The time to 90% T1 recovery was 23.9 min (14.0-31.3 min). Twelve other heterozygous patients (Group 2) received mivacurium 0.2 mg kg bw-1 (2.5 x ED95). In these patients the time to 100% T1 suppression was 1.4 min (1.1-2.0 min). The time to reappearance of the T1 response, to 90% T1 recovery, and the recovery index (25.3 min (14.5-34.5), 45.5 min (30.9-59.2), and 9.8 min (6.8-19.6), respectively) were significantly longer than reported in phenotypically normal patients. Five patients homozygous for the atypical gene (Group 3) were given 0.03 mg kg bw-1 mivacurium. The time to reappearance of T1 response following this low dose of mivacurium ranged from 26-128 min. In all five patients the neuromuscular block was successfully antagonized with neostigmine preceded by atropine. In conclusion, mivacurium-induced neuromuscular blockade was moderately prolonged in patients heterozygous for the usual and the atypical gene for plasma cholinesterase. Patients homozygous for the atypical plasma cholinesterase gene appear to be markedly sensitive to mivacurium.

Reaction to succinylcholine in two patients segregating for the plasma cholinesterase allele Ek

Recently, several new alleles have been identified at plasma cholinesterase locus E1. We have had the opportunity for the first time to monitor the response to succinylcholine in two patients with the newly discovered genotype Ea1Ek1. The duration of action and type of neuromuscular block following succinylcholine 1.0 and 1.5 mg kg-1 i.v., respectively, were evaluated using train-of-four nerve stimulation and a Myograph 2000. One patient was anaesthetized with halothane, and the other was given a modified neurolept anaesthesia. Time to first response to nerve stimulation was 15 and 16 min, and time to 50% twitch height recovery was 19 and 20 min, respectively in the two patients. Both showed a depolarizing block. One of the patients received three bolus doses of succinylcholine 1 mg kg-1. This patient gradually developed a phase II block, which was easily reversed by edrophonium. The results indicate that patients with genotype Ea1Ek1 are slightly more sensitive to succinylcholine than are genotypically normal patients (Eu1Eu1) and patients heterozygous for the normal and the atypical gene (Eu1Ea1).

Structural basis of the butyrylcholinesterase H-variant segregating in two Danish families

The rare H-variant of human butyrylcholinesterase is a quantitative variant that reduces serum butyrylcholinesterase activity by about 90%. Individuals who are heterozygous for both the H-variant and the atypical variant are abnormally sensitive to the muscle relaxant succinylcholine. By using standard phenotypic serum assays, the Danish Cholinesterase Research Unit identified four individuals from two unrelated pedigrees who were heterozygous for both the H-variant (H) and the atypical (A) variant. DNA of these A/H individuals was extracted from white blood cells. Using the polymerase chain reaction and subsequent DNA sequencing, a point mutation was found at nucleotide 424 which changed amino acid 142 from valine to methionine. The previously identified atypical mutation, Asp 70 to Gly, was also seen, which segregated apart from the H-variant mutation in family studies. These two mutations were found in all four A/H individuals.

Influence of plasma cholinesterase activity on recovery from mivacurium-induced neuromuscular blockade in phenotypically normal patients

The significance of plasma cholinesterase (pChe) activity for the duration of action of mivacurium in phenotypically normal patients was evaluated in 35 patients during neurolept anaesthesia. The response to train-of-four nerve stimulation was recorded using a Myograph 2000. Ten patients with normal pChe (Group I) and five patients with decreased pChe activity (Group 2) were given a small test dose of mivacurium 0.03 mg kg-1. Mivacurium 0.1 mg kg-1 was administered following spontaneous recovery from the first dose. The mean suppression of the height of the first (T1) of the train-of-four responses following mivacurium 0.03 mg kg-1 patients with normal and decreased enzyme activity was 40% and 56%, respectively, and the mean T1 suppression after mivacurium 0.1 mg kg-1 was 100% in both groups. The times to different levels of twitch height recovery following the 0.1 mg kg-1 dose did not differ between the two groups of patients. Another 20 patients with normal or decreased pChe activity (Group 3) were given mivacurium 0.2 mg kg-1. In this group the time to maximum block was 1.4 min (1.0-4.0) mean (range) and the time to reappearance of the T1 response was 15.0 min (7.4-22.7) (range). An inverse relationship was found between the patients' pChe activity and the time to first response. It is concluded that mivacurium is short-acting in patients with normal pChe phenotype and normal to low-normal pChe activity. No patient with very low pChe activity was included in the study. A prolonged response to mivacurium may, however, be expected in these patients.

[Testicular varicocele. Reason for surgery and recurrence frequency]

In the period 1979-1989, 63 patients were operated on for testicular varicocele. The study was a retrospective follow-up from case records and from a questionnaire. Thirty-eight had local complaints, 19 were operated on because of infertility and six had an asymptomatic varicocele. 10% had minor, reversible complications. 92% answered the questionnaire and 38% had a personal contact. 21% had recurrence of the varicocele although to a minor degree. In the infertility group, 42% succeeded in conception after operation.

DNA mutation associated with the human butyrylcholinesterase K-variant and its linkage to the atypical variant mutation and other polymorphic sites

Genomic DNA from two families exhibiting the K-variant phenotype of serum butyrylcholinesterase was amplified by PCR and sequenced to determine the molecular basis of this variant. The K-variant phenotype was found to be associated with a DNA transition from guanine to adenine at nucleotide 1615, which caused an amino acid change from alanine 539 to threonine (GCA----ACA; Ala539----Thr). There was a 30% reduction of serum butyrylcholinesterase activity associated with this mutation. Amplification and sequencing of DNA from a random sample of 47 unrelated people gave a frequency of .128 for the K-variant allele. Thus, 1 person in 63 should be homozygous for the K-variant, making the K-variant the most common butyrylcholinesterase variant. The K-variant mutation was also found to be present in 17 (89%) of 19 butyrylcholinesterase genes containing the point mutation which causes the atypical phenotype of butyrylcholinesterase (GAT----GGT; Asp70----Gly). The presence of the K-variant in the same molecule as the atypical variant does not contribute to the qualitative change in the atypical enzyme, but it most likely accounts for the approximately one-third reduction in Vmax of butyrylcholinesterase activity in atypical serum. Two additional point mutations located in noncoding regions of the gene were also observed to be in linkage disequilibrium with the K-variant mutation. As many as four different point mutations have been identified within a single butyrylcholinesterase gene. Inhibition tests of the enzyme in plasma are usually used to distinguish the K-variant from the usual enzyme when the former is present with the heterozygous atypical variant (AK phenotype vs. UA phenotype). Inhibition tests were performed on plasma enzyme from the four possible genotypic combinations of the heterozygous atypical mutation with or without the K-variant mutation on either allele; we found that the AK phenotype was caused by three genotypes (A/K, AK/K, and U/A) and that the UA phenotype was caused by two genotypes (U/A and U/AK).

Transurethral prostatectomy compared with incision of the prostate in the treatment of prostatism caused by small benign prostate glands

In a prospective, randomized study 60 patients with prostatism caused by small prostate glands (estimated weight < 20 g) had either transurethral prostatectomy (TURP, n = 31) or transurethral incision of the prostate (TUI, n = 29). Operating time and blood loss were significantly less in the group that underwent TUI. There were no differences between the groups in number of days with an indwelling catheter or days in hospital after operation. Eight patients in the TUI group required further operation, as did four in the TURP group, one of whom was discharged with a permanent indwelling catheter. In addition one patient developed a urethral stricture. Nine of the failures of treatment occurred within the first month. Fifty-one patients were followed up at 3 months and 47 were also seen at 12 months. Both operations significantly improved symptom scores and maximum flow rates compared with preoperatively, but the improvement in maximum flow rate was significantly better in the TURP group than in the TUI group. At 12 months TURP had also improved micturition time and voided volume, which TUI had not. Neither operation caused any significant change in sexual activity or erective potency postoperatively. Retrograde ejaculation was, however, seen in more than half of the patients in the TURP group, and only one in the TUI group. We recommend TUI for the treatment of prostatism caused by small prostate glands in patients who want to preserve normal ejaculation or are at poor surgical risk.

[A case of male breast cancer with an unusual clinical course]

A case of male cancer of the breast with an unusual clinical course is presented. The local manifestations which simulated dermaphytosis are described.

[Experience from the first year of treatment of renal calculi with extracorporeal piezoelectric shockwave lithotripsy]

The experience of the first year with piezoelectric extracorporeal lithotripsy is described. One hundred and eighty-eight patients commenced treatment of 194 renoureteric stone units (a total of 328 stones). Twelve per cent required analgesics during therapy. The median number of treatments was two (1-6) and median number of shock waves 4,200 (450-24,606). One hundred and twenty-three stone units had concluded treatment and control schedules at the follow up end date. After six months, 59% of the stone units were stone-free, while 17% had residual fragments up to 2 mm, and additional 15% had residual fragments between 2 and 6 mm. Only few and insignificant complications were observed. Extracorporeal shock wave lithotripsy by the Wolf Piezolith 2300 is a well-tolerated, effective, relative painless and not complicated treatment of renal stones, and an important part of modern treatment of staghorn- and ureteric stones.

[Herpes zoster induced reversible neurogenic bladder dysfunction. Urodynamic documentation of reversible bladder paralysis]

A case of sacral herpes zoster with reversible neurogenic bladder dysfunction causing urinary retention is presented. Gradual reversibility of the motoric paralysis of the detrusor was demonstrated in cystometrograms. It is stressed that treatment should be primarily conservative and that repeated urodynamic examinations is essential.

[Lengthening of the femur and tibia using Wagner's method]

Thirty-nine patients (19 girls and 20 boys with an average age of 14 years) were submitted to 41 lengthening osteotomies by Wagner's method. The average preoperative shortening was 6.4 cm (3.5-25) and the average lengthening achieved in the femur was 6.4 cm (2.0-10.3) while the lengthening achieved in the tibia was 5.5-5.6 cm. In five patients, residual anisomelia varied between 3.5 to 10 cm and two of these patients have subsequently been submitted to supplementary lengthening. Complications occurred in 12 patients and, in particular, the postoperative course was complicated in two patients over the age of 20 years. It is concluded that lengthening of the femur and tibia by Wagner's method, and undertaken before growth has ceased, is a safe method of correction of considerable anisomelia.

[Colonoscopic appendectomy. Removal of a persisting iatrogenic invaginated appendix with colonoscopy]

A case in which the appendix was invaginated with the object of incidental appendectomy but survived is described. Colonoscopic appendectomy was successfully performed.

Growth hormone administration by means of an injection pen

We have evaluated the pharmacokinetics, reliability and patient tolerability of a newly developed injection pen for cartridged growth hormone (GH). The cartridge contains 25 IU GH in 2 ml solvents. The pen, which is basically a needle, syringe and vial in one piece, is operated by a turning movement and allows doses from 0.25-4 IU. Nine GH deficient patients were hospitalized twice for overnight bloodsampling following subcutaneous injections (at 8 p.m.) of GH: i.e. when using traditional syringe and vial and after 6 weeks of use of the pen. Serum GH antibodies were measured immediately prior to, and 3 and 6 months following pen treatment. GH containers were collected regularly from the patients for chemical analysis. A questionnaire was completed during and at the end of the study. The absorption rate and bioavailability of GH tended to be higher with syringe and vial (2 P = 0.07) but there were no differences in the profiles of IGF-I, insulin, glucagon or pertinent metabolic parameters following the 2 injection modes. No GH antibodies occurred during 6 months of pen treatment. The content of polymeric GH was lower in the cartridges (2 P less than 0.001). Seven of the patients reported less injection pain when using the injection pen, which they all strongly preferred and wished to continue using. We conclude that the GH injection pen is a reliable tool which seems to be more convenient for the patients.

Urethral cancer presenting with scrotal abscess formation. A differential diagnosis of acute epididymitis

Primary urethral cancer in male subjects is briefly described, and a case is presented in which the formation of a scrotal abscess was the unusual presenting symptom.