Epidural Anaesthesia and Urinary Dysfunction: The Risks in Total Hip Replacement

Epidural anaesthesia in total hip replacement is an established and safe practice. It may be used alone or in combination with general anaesthesia for analgesia.

Urethral catheterization in the perioperative period is known to greatly increase the complication of deep sepsis following total hip replacement. We assessed the effect on the incidence of urinary catheterization of using bupivocaine epidural anaesthesia in addition to general anaesthesia in total hip replacement. A prospective study was made of 113 total hip replacements. The incidence of catheterization in male patients who received an epidural was 67% compared to only 12% who had no epidural [ P=0.001]. In women the corresponding rates were 30% and 23%. We conclude that in men the use of supplementary epidural anaesthesia with bupivocaine is associated with a worrying increased need for urinary catheterization. This must be balanced against the claimed benefits of this form of anaesthesia.

The highly acidic C-terminal region of the yeast initiation factor subunit 2 alpha (eIF-2 alpha) contains casein kinase phosphorylation sites and is essential for maintaining normal regulation of GCN4

Regulation of the effective activity of eukaryotic initiation factor 2 (eIF-2) in protein synthesis is known to involve phosphorylation of its alpha subunit. Two mammalian enzymes, the haem-controlled repressor (HCR) and the double-stranded RNA-activated inhibitor (dsI), phosphorylate Ser-51 of the alpha subunit, thereby inhibiting the exchange of bound nucleotides on, and thus the recycling of, eIF-2. In Saccharomyces cerevisiae, the equivalent serine seems to be phosphorylated by the GCN2 protein kinase, which is activated by amino acid starvation. However, in the present paper we show that this is not the only site of phosphorylation in yeast eIF-2 alpha. We report the preparation of recombinant yeast eIF-2 alpha from Escherichia coli and its use in in vitro phosphorylation studies. Mammalian HCR and dsI are shown to phosphorylate specifically Ser-51 of yeast eIF-2 alpha, whereas extracts from yeast cells do not. Instead, at least one of three serine residue in the acidic C-terminal region of this protein is phosphorylated by fractions of yeast possessing casein kinase activities 1 and 2. A triple Ser-->Ala mutant form of yeast eIF-2 alpha was found to be no longer phosphorylated by either of the yeast (or mammalian) casein kinase activities in vitro. Isoelectric focusing of yeast extracts confirmed that the mutated sites normally act as sites of phosphorylation in vivo. The same mutant was used to show that the three sites have no essential function under normal physiological conditions in yeast. In contrast, deletion of the 13 amino acid long C-terminal region of eIF-2 alpha, including the three phosphorylation sites, led to derepression of GCN4 in vivo. Thus removal of the short, highly acidic C-terminal region of eIF-2 alpha has the same regulatory effect on translational (re)initiation as phosphorylation of the Ser-51 residue of the wild-type protein. This result provides new insight into the role of eIF-2 alpha activity in the regulation of translational (re-) initiation.

The guanine nucleotide-exchange factor, eIF-2B

Eukaryotic initiation factor eIF-2B catalyses the exchange of guanine nucleotides on another translation initiation factor, eIF-2, which itself mediates the binding of the initiator Met-tRNA to the 40S ribosomal subunit during translation initiation. eIF-2B promotes the release of GDP from inactive [eIF-2.GDP] complexes, thus allowing formation of the active [eIF-2.GTP] species which subsequently binds the Met-tRNA. This guanine nucleotide-exchange step, and thus eIF-2B activity, are known to be an important control point for translation initiation. The activity of eIF-2B can be modulated in several ways. The best characterised of these involves the phosphorylation of the alpha-subunit of eIF-2 by specific protein kinases regulated by particular ligands. Phosphorylation of eIF-2 alpha leads to inhibition of eIF-2B. This mechanism is involved in the control of translation under a variety of conditions, including amino acid deprivation in yeast (Saccharomyces cerevisiae) where it causes translational upregulation of the transcription factor GCN4, and in virus-infected animal cells, where it involves a protein kinase activated by double-stranded RNA. There is now also growing evidence for direct regulation of eIF-2B. This appears likely to involve the phosphorylation of its largest subunit. Under certain circumstances eIF-2B may also be regulated by allosteric mechanisms. eIF-2B is a heteropentamer (subunits termed alpha, beta, gamma, delta and epsilon) and is thus more complex than most other guanine nucleotide-exchange factors. The genes encoding all five subunits have been cloned in yeast (exploiting the GCN4 regulatory system): all but the alpha appear to be essential for eIF-2B activity. However, this subunit may confer sensitivity to eIF-2 alpha phosphorylation. cDNAs encoding the alpha, beta, delta and epsilon subunits have been cloned from mammalian sources. There is substantial homology between the yeast and mammalian sequences. Attention is now directed towards understanding the roles of individual subunits in the function and regulation of eIF-2B.

The inwardly pointing knee. An unrecognized problem of external rotational malalignment

Twelve patients with inwardly pointing knees had chronic knee pain and disability suggestive of patellofemoral subluxation. None had responded well to conservative measures or surgical correction at the level of the soft tissues. Their pattern of limb alignment was studied roentgenographically and was found to differ significantly from the control group of 49 healthy young adults. The deformities primarily related to the tibia were external tibial torsion, excess varus angulation of the tibial plateau, and varus knees. Angulation of the femoral condyles was normal and femoral anteversion did not appear to contribute significantly to the deformity. Surgery in seven cases (nine knees) was by derotation valgus Maquet osteotomy of the tibia and lateral release realignment of the patellae. Outcome assessments after a three-year follow-up period (five knees) were excellent. Early results on the remaining cases were satisfactory.

Laparoscopic laser cholecystectomy and choledocholithiasis

The management of common bile duct stones during laparoscopic laser cholecystectomy (LLC) is uncertain. Open common bile duct exploration is the least desirable option since it defeats the purpose of LLC. Endoscopic retrograde cholangiopancreatography (ERCP) with papillotomy has become the procedure of choice since it has a high rate of success and results in minimal morbidity. Intraoperative techniques using balloon catheters and the flexible choledochoscope via the cystic duct may obviate the need for ERCP in selected cases.

Effects of temazepam premedication on cognitive recovery following alfentanil-propofol anaesthesia

The effects of temazepam 20 mg and placebo were compared for premedication in patients anaesthetized with propofol and alfentanil and undergoing day surgery. Temazepam 20 mg significantly reduced preoperative anxiety and increased recovery time. A series of computerized cognitive tasks revealed significant deficits in attention and memory following anaesthesia, which were increased in range and magnitude by temazepam, which were apparent 30 min after surgery and had largely, but not completely, recovered at 4 h. This study has demonstrated that computerized cognitive testing can identify a wider profile of impairments produced by temazepam than has been found in previous work using non-computerized techniques.

Demographic predictors of the use of injectable versus oral antipsychotic medications in outpatients

The authors examined the records of 397 outpatients maintained on antipsychotic medication to identify demographic characteristics that predicted use of depot medication. Patients maintained on long-acting antipsychotics tended to be young, male, and black. The age effect was largely restricted to white patients.

Responses of the pig isolated renal artery to transmural electrical stimulation and drugs

Pig isolated renal arteries contract in response to addition of noradrenaline, 5-hydroxytryptamine, histamine, angiotensin II, vasopressin and carbachol, whereas cholecystokinin, adenosine, and inosine produce relaxation. Transmural stimulation of the tissue causes contraction of circular muscle in the arterial wall which produces apparent elongation of the vessel. The effects of transmural stimulation are partially blocked by prazosin and potentiated by propranolol, indicating that noradrenaline acts through both alpha- and beta-adrenoceptors. Guanethidine (10(-5) M) reduces the size of responses to transmural stimulation in the presence of both prazosin (10(-6) M) and propranolol (10(-7) M). Both saralasin (10(-7) M), and desensitization of angiotensin II receptors by prolonged contact with the peptide, produced a reduction in response to transmural stimulation, indicating that angiotensin II may be involved in neurotransmission. This effect was blocked by tetrodotoxin. Transmural stimulation produces relaxation of renal arteries in the presence of maximal doses of saralasin, prazosin, and propranolol, suggesting that a third unidentified substance is also released from autonomic nerves.

Woringer-Kolopp disease (pagetoid reticulosis). Four cases with histopathologic, ultrastructural, and immunohistologic observations

Four patients had localized lesions of Woringer-Kolopp disease (pagetoid reticulosis). The clinical appearances and histopathologic features with light microscopy of the four cases were similar. However, electron microscopy in all four cases and enzyme histochemistry studies and immunophenotyping with monoclonal antibodies in three cases disclosed two subgroups of patients. The features of the predominant cells in the intraepidermal infiltrate of three cases were most consistent with those of helper T lymphocytes with cerebriform nuclei, as found in many cases of mycosis fungoides. In one case, however, the epidermis contained a predominant population of small, medium, and large lymphoid cells of cytotoxic/suppressor T-lymphocyte cell phenotype. It remains to be determined whether Woringer-Kolopp disease is a variant of mycosis fungoides (ie, within the spectrum of the cutaneous T-cell lymphomas), a benign reactive process, or a syndrome with various causes.

Rate of endothelial cell loss in the early postoperative period after cataract surgery

Central corneal endothelial cell density was estimated in 33 consecutive patients preoperatively and at monthly intervals for 6 months after cataract surgery. The patients were divided into 3 groups by a random procedure to have either intracapsular extraction or intracapsular extraction plus Federov 4-loop iris clip lens, or extracapsular extraction with Binkhorst 2-loop iridocapsular lens. In all groups the greatest cell loss had occurred by one month and thereafter no accelerated loss was apparent except in individual patients. The limitations of such a method of assessment are discussed.

Diffusion of CO2 and O2 through the walls of plastic syringes

The diffusion of O2 and CO2 through the walls of two types of plastic syringes was measured. When the syringes were filled with 16% O2, 5% CO2, and the balance N2, the average outward diffusion of CO2 was 0.076% per hour and the average inward diffusion of O2 was 0.06% per hour in room air at room temperature. When the syringes were surrounded by room air cooled in ice the average loss of CO2 was 0.137% per hour and the average increase in O2 content 0.10% per hour. From the measurements we conclude that diffusion of gases through the walls of disposable syringes cannot be responsible for the low [Formula: see text] values of "normal" arterial blood reported by clinical laboratories.