Cosmesis in neurosurgery: is the bald head necessary to avoid postoperative infection?

AIM

The aims of this study were to prospectively investigate the incidence of postoperative wound infection following elective cranial surgery, when scalp hair removal was limited to the line of the incision, and to see if there was an increased risk of infection.

MATERIALS AND METHODS

This is an observational study of 57 consecutive adult elective cases operated upon without head shave (between July 1998 and December 1998). The method of scalp preparation is described.

RESULTS

During the follow-up period, there was 1 case (1.75%) of postoperative wound infection. This was compared with retrospective data, and was not found to be statistically significant.

DISCUSSION

In a review of earlier studies and a search into the history of aseptic surgery, no scientific ground for the practice of shaving was found. We suggest that there is no advantage in shaving patients in terms of reducing wound infection rates.

A fatal case of systemic brucellosis

A 65 years man presented with fever, drenching sweats, progressive dyspnoea, backache and weight loss. On examination, he had wide pulse pressure, clubbing, retinal hemorrhages, aortic and mitral regurgitation, hepatosplenomegaly, lower spinal tenderness and bilateral basal crepitations. Transthoracic 2D-echocardiography showed a large vegetation on the aortic valve. Antibody titers for brucella were positive. X-ray spine was suggestive of brucella spondylitis. Early surgical intervention was planned and the patient was given combination antibiotic therapy. The course was complicated by renal failure and the patient succumbed while being taken up for surgery.

Curricular trends in instruction of pathology: a nationwide longitudinal study from 1993 to present

Medical schools throughout the United States continue to respond to various external and internal challenges and make modifications in their curricula. Responses obtained from 66% (n = 83) of schools on a longitudinal survey conducted during the year 2000 to study trends in instruction of pathology over a 7-year period (ie, for classes entering 1993 to 1999) indicate the following. There have been steady shifts in instruction of systemic and clinical pathology from discipline-based courses to integrated formats from 1993 to 1999. The degree of integration with other disciplines varies among schools, and may take one or more of the following formats: joint course (pathology and another discipline); multidisciplinary systems course; a combination of pathology course and another integrated course; and completely integrated in the form of problem-based or case-based small group discussion. Presently, at least some degree of integration occurs in 51% of schools for instruction of systemic pathology and 65% for clinical pathology, up from 31% and 48%, respectively, in 1993. Although there has been an increased trend toward integration in instruction of general pathology as well, it is still taught predominantly in a discipline-based manner in the vast majority of schools. Although often difficult to identify with certainty, the best estimates indicate that the overall scheduled length of pathology instruction time has stabilized over the years; the mean total for the entering classes of 1999 was 196 hours versus 201 hours for the classes entering in 1993. However, internal rearrangements of time for various components of delivery of instruction continue. The lecture remains unchanged as an important mode comprising the largest component of pathology curriculum time (53% in 1999, 52.2% in 1993) during the 7-year period examined. The mean traditional laboratory instruction time has decreased slightly from 27% in 1993 to 24% in 1999. This decrease may be accounted for by a shift toward use of laboratory materials in various other formats and venues not included in the traditional laboratory instruction (eg, small group sessions, clinicopathologic correlation conferences, study of kodachrome slides, and computer programs). The use of electronic educational resources has increased remarkably, but for the most part it is not measurable because of the lack of any designated hours. Because pathology instruction occurs exclusively or primarily during year 2 in most schools, the classes entering in 1999 would have studied it during 2000 and 2001, which means the present study provides the most updated curricular trends at this time.

Facile, regioselective [4 + 2] cycloaddition involving 1-aryl-4-phenyl-1-azadienes and allenic esters: an efficient route to novel substituted 1-aryl-4-phenyl-1,4-dihydropyridines

[reaction: see text]1-Aryl-4-phenyl-1-azadienes undergo facile, regioselective [4 + 2] cycloaddition to the C2,C3 pi-bond of allenic esters in refluxing benzene, and the formed adducts undergo a 1,3-H shift to afford novel 2-alkyl-1-aryl-3-ethoxycarbonyl-4-phenyl-1,4-dihydropyridines (78-97%). However, when the reaction is carried at room temperature, besides the [4 + 2] addition, the [2 + 2] mode of addition involving C=N of azadiene and C3,C4 pi-bond of allenic esters also intervenes. The resulting N-aryl-2-ethoxy-carbonyl-methylidene-4-styrylazetidines (17-28%) undergo reorganization on silica gel to afford 2-cyclohexen-1-ones.

Model for interacting instabilities and texture dynamics of patterns

A simple model to study interacting instabilities and textures of resulting patterns for thermal convection is presented. The model, consisting of a twelve-mode dynamical system derived for periodic square lattice, describes convective patterns in the form of stripes and patchwork quilt. The interaction between stationary zigzag stripes and standing patchwork quilt pattern leads to spatiotemporal patterns of twisted patchwork quilt. Textures of these patterns, which depend strongly on Prandtl number, are investigated numerically using the model. The model also shows an interesting possibility of a multicritical point, where stability boundaries of four different structures meet.

A coiled coil with a fluorous core

The design, synthesis, and structural characterization of a highly fluorinated peptide system based on the coiled coil region of the yeast transcription factor GCN4 is described. All four leucine residues (a position) and three valine residues (d position) were replaced by the unnatural amino acids 5,5,5-trifluoroleucine and 4,4,4-trifluorovaline, respectively. The peptide is highly alpha-helical at low micromolar concentrations as judged by circular dichroism spectra, sediments as a dimeric species in the 5-30 microM concentration range, and exhibits a dimer melting temperature that is 15 degrees C higher than a control peptide with a hydrocarbon core. Furthermore, the apparent free energy of unfolding as calculated from guanidinium hydrochloride denaturation experiments is larger by approximately 1.0 kcal/mol for the fluorinated peptide than its hydrocarbon counterpart. We conclude that additional stability is derived from sequestering the more hydrophobic trifluoromethyl groups from aqueous solvent. These studies introduce a new paradigm in the design of molecular self-assembling systems, one based on orthogonal solubility properties of liquid phases.

Absent p53 immunohistochemical staining in a pituitary carcinoma

BACKGROUND

Carcinomatous transformation of pituitary adenomas is uncommon, and is generally accompanied by nuclear accumulation of p53 protein. Pituitary carcinoma lacking accumulation of p53 protein is very rare, only two such cases being previously reported.

METHODS

A patient presented with visual disturbance and cranial nerve palsies and was found to have a suprasellar mass. He underwent both transphenoidal and transfrontal excision of a nonfunctioning pituitary adenoma which recurred several times. The third recurrence was accompanied by multiple dural-based metastases. Despite aggressive surgical management, he continued to develop additional intracranial lesions and died two years after the discovery of metastatic disease. Specimens from 1984, 1995, 1997 and 1998 were available for histological and immunocytochemical analysis. Antibodies recognizing the pituitary hormones (ACTH, PRL, GH, FSH, LH and TSH), as well as cytokeratin, epithelial membrane antigen (EMA), glial fibrillary acidic protein (GFAP) and chromogranin A were applied to investigate the lineage of the neoplasm. Antisera specific for Ki-67 (MIB-1) and p53 protein were also applied to further delineate the biology of the tumour.

RESULTS

Although cytokeratin and chromogranin A were detected in neoplastic cells. no expression of pituitary hormones was demonstrable, indicative of a nonfunctioning, null-cell pituitary adenoma. Nuclear pleomorphism and mitotic activity increased with subsequent resections. Abnormal accumulation of p53 protein was not observed, neither in early resections nor in the metastatic deposits.

CONCLUSIONS

Failure to demonstrate p53 protein accumulation does not ensure a favourable outcome for pituitary adenoma. Accordingly, pituitary carcinoma may occur in the absence of p53 accumulation. The factors which underlie aggressive behaviour of pituitary neoplasms are uncertain but are under investigation.

Genetic and molecular characterization of Skb15, a highly conserved inhibitor of the fission yeast PAK, Shk1

The p21-activated kinase, Shk1, is essential for viability, establishment and maintenance of cell polarity, and proper mating response in the fission yeast, Schizosaccharomyces pombe. Here we describe the characterization of a highly conserved, WD repeat protein, Skb15, which negatively regulates Shk1 in fission yeast. A null mutation in the skb15 gene is lethal and results in deregulation of actin polymerization and localization, microtubule biogenesis, and the cytokinetic machinery, as well as a substantial uncoupling of these processes from the cell cycle. Loss of Skb15 function is suppressed by partial loss of Shk1, demonstrating that negative regulation of Shk1 by Skb15 is required for proper execution of cytoskeletal remodeling and cytokinetic functions. A mouse homolog of Skb15 can substitute for its counterpart in fission yeast, demonstrating that Skb15 protein function has been substantially conserved through evolution.

A Novel Synthesis of Enantiomerically Pure 5,5,5,5‘,5‘,5‘-Hexafluoroleucine

[reaction in text] A novel, short, and efficient synthesis of (S)-5,5,5,5',5',5'-hexafluoroleucine (6) in greater than 99% ee starting from the protected oxazolidine aldehyde 1 is described. The enantiomeric excess of the product was calculated from an NMR analysis of a dipeptide formed by reaction with a protected L-serine derivative. Furthermore, a racemic sample of N-acylated hexafluoroleucine was enzymatically resolved by treatment with porcine kidney acylase I and was found to have the same optical rotation as a synthetic sample of 6.

Probing functional perfection in substructures of ribonuclease T1: double combinatorial random mutagenesis involving Asn43, Asn44, and Glu46 in the guanine binding loop

Combinatorial random mutageneses involving either Asn43 with Asn44 (set 1) or Glu46 with an adjacent insertion (set 2) were undertaken to explore the functional perfection of the guanine recognition loop of ribonuclease T(1) (RNase T(1)). Four hundred unique recombinants were screened in each set for their ability to enhance enzyme catalysis of RNA cleavage. After a thorough selection procedure, only six variants were found that were either as active or more active than wild type which included substitutions of Asn43 by Gly, His, Leu, or Thr, an unplanned Tyr45Ser substitution and Glu46Pro with an adjacent Glu47 insertion. Asn43His-RNase T(1) has the same loop sequence as that for RNases Pb(1) and Fl(2). None of the most active mutants were single substitutions at Asn44 or double substitutions at Asn43 and Asn44. A total of 13 variants were purified, and these were subjected to kinetic analysis using RNA, GpC, and ApC as substrates. Modestly enhanced activities with GpC and RNA involved both k(cat) and K(M) effects. Mutants having low activity with GpC had proportionately even lower relative activity with RNA. Asn43Gly-RNase T(1) and all five of the purified mutants in set 2 exhibited similar values of k(cat)/K(M) for ApC which were the highest observed and about 10-fold that for wild type. The specificity ratio [(k(cat)/K(M))(GpC)/(k(cat)/K(M))(ApC)] varied over 30 000-fold including a 10-fold increase [Asn43His variant; mainly due to a low (k(cat)/K(M))(ApC)] and a 3000-fold decrease (Glu46Ser/(insert)Gly47 variant; mainly due to a low (k(cat)/K(M))(GpC)) as compared with wild type. It is interesting that k(cat) (GpC) for the Tyr45Ser variant was almost 4-fold greater than for wild type and that Pro46/(insert)Glu47 RNase T(1) is 70-fold more active than the permuted variant (insert)Pro47-RNase T(1) which has a conserved Glu46. In any event, the observation that only 6 out of 800 variants surveyed had wild-type activity supports the view that functional perfection of the guanine recognition loop of RNase T(1) has been achieved.

Continuous intrathecal morphine treatment for chronic pain of nonmalignant etiology: long-term benefits and efficacy

BACKGROUND

To analyze, prospectively, the long-term effects of continuous intrathecal morphine infusion therapy in 16 patients with chronic nonmalignant pain syndromes.

METHODS

Twenty-five patients with severe, chronic, nonmalignant pain that had proven refractory to conservative management were considered candidates for trial of intrathecal spinal morphine. Sixteen patients achieved more than 50% pain relief after a trial period of intrathecal morphine infusion. They were implanted with fully implantable and programmable pumps through which morphine was delivered intrathecally on a continuous basis. These patients were followed prospectively and underwent careful evaluation of their functional and mental status, and pain intensity measurements using standardized techniques before treatment and every 6 months thereafter in the follow-up period. The follow-up period ranged from 13 months to 49 months (mean 29.14 months +/- 12.44 months) for the patients who had implanted morphine pumps.

RESULTS

The mean morphine dosage initially administered was 1.11 mg/day (range 0.2--6.5 mg/day); after 6 months, it was 3.1 mg/day (range 0.4--8.75 mg/day). In long-term observation, no patient had a constant dosage history. The patients who received intrathecal morphine for longer than 2 years all showed an increase in morphine dosage to more than 10 mg/day. The best long-term results were seen with deafferentation pain and mixed pain, with 75% and 61% pain reduction (visual analog scale), respectively. Nociceptive pain patients had best pain relief initially (78% pain reduction) but it tended to decrease over the follow-up period to 57% pain reduction at final follow-up. The average pain reduction for all groups after 6 months was 67.5% and at last follow-up, it was 57.5%. Ten patients were satisfied with the delivery system and eleven reported improvement in their quality of life. In two patients, morphine was not able to adequately control the pain without producing undesirable side effects requiring the addition of clonidine to their infusion medication. In this series, 12 patients were considered successes and 4 patients were considered failures. In two patients, the intrathecal opioid therapy was unable to produce satisfactory pain relief and in the other two patients the pumps had to be explanted because of intolerable side effects.

CONCLUSIONS

In our experience, the administration of intrathecal opioid medications for nonmalignant pain is justified in carefully selected patients.

Giant cell tumour of hyoid bone: case report

Giant cell tumours of bones are uncommon and are usually found in the epiphyses of long bones. They are rare in flat bones (<10%). The tumour has to our knowledge never been described in the hyoid bone, although 18 cases have been reported in the cartilagenous laryngeal skeleton. We report a giant cell tumour of the hyoid bone in a 45-year-old man, which we excised along with the left half of the hyoid bone. It recurred locally one year later and was cured by excision and split course radiotherapy. The patient is disease-free after 30 months of follow-up.

Biodiversity of Anabaena azollae isolates from different Azolla cultures

The random amplified polymorphic DNA (RAPD) profile of A. azollae strains isolated from four different Azolla cultures was studied by using different primers. The objective of this study was to determine whether polymerase chain reaction (PCR) with different primers could differentiate the isolated A. azollae strains from one another. The primers amplified specific sequences of the isolates and generated fingerprinting pattern characteristic of each isolate. Clear polymorphism was noticed among all the strains which depends on the primer sequence.

Benign pituitary adenoma with multiple dural metastases: a case report

BACKGROUND

Pituitary adenomas are considered benign tumors and metastases are seen when the tumor shows malignant transformation.

CASE DESCRIPTION

We present a case of a benign pituitary adenoma with multiple dural metastasis without malignant transformation throughout its course. At all times, the pituitary adenoma remained benign as seen by a lack of nuclear pleomorphism, nuclear atypia, vascular invasion, and absence of immunohistochemical staining for p53 protein.

CONCLUSION

This is a rare example of dural metastasis from a benign pituitary adenoma. The authors believe this is the fourth reported case of this type in the literature.

Correction of cubitus varus by French or dome osteotomy: a comparative study

BACKGROUND

The purpose of this study was to compare the outcomes of two different techniques of supracondylar osteotomy, French osteotomy and dome osteotomy, for the correction of posttraumatic cubitus varus.

METHODS

A comparative randomized study was undertaken of 25 patients (average age 10 years) with an established posttraumatic cubitus varus deformity (mean time from injury to corrective osteotomy, 1.7 years). Patients were followed-up with for 1 year, and carrying angle, Baumann's angle, and internal rotation deformity were measured. Postoperative complications were assessed.

RESULTS

A significant (p < 0.01) correction of carrying angle and Baumann's angle was achieved with both techniques, with no statistically significant differences between them. Although internal rotation deformity was corrected by both techniques, the correction was significantly greater with the dome osteotomy (p < 0.01). However, the persistence of internal rotation did not seem to affect the final outcome. There was a higher incidence of postoperative complications in the dome osteotomy group, including infection (1), inadequate correction (1), nerve palsy (1), loss of motion (5), and circulatory compromise (1).

CONCLUSION

The dome osteotomy is technically more difficult than the French osteotomy and has a higher incidence of complications. We suggest that the French osteotomy be used for the correction of cubitus varus after supracondylar fractures of the elbow in children.

Asymmetric squares as standing waves in rayleigh-Benard convection

Possibility of thermal convection in the form of asymmetric squares in a thin layer of Boussinesq fluids of large lateral extension confined between stress-free and conducting flat boundaries is investigated numerically using a seven mode Lorenz-like model. For fluids with moderate and high Prandtl numbers (4<sigma<20) and in a narrow window of high Rayleigh numbers (12<R/R(c)<15), which depend on Prandtl number, the stationary rolls become unstable and asymmetric squares appear as standing waves at the onset of secondary instability. Asymmetric squares, two-dimensional rolls, and again asymmetric squares with their corners shifted by half a wavelength form a stable limit cycle. The oscillatory bifurcation is supercritical.