Intra-articular morphine versus bupivacaine for postoperative analgesia following knee arthroscopy

In a prospective, double blind, randomized study, 30 ASA I patients were allocated to three groups depending on the drug injected intra-articularly, in an attempt to establish the best postoperative analgesic protocol following knee arthroscopy. Group 1 received 3 mg of preservative-free morphine in 25 ml saline; group 2, 5 mg of preservative-free morphine in 25 ml saline; and group 3, 25 ml 0.25% bupivacaine. The degree of postoperative pain was evaluated by visual analogue scale and the need for additional analgesics at 1, 2, 3, 8 and 24 h. We conclude that bupivacaine 0.25% provides analgesia of early onset and of short duration. While 3 mg-preservative free morphine provides moderate postoperative analgesia with peak effect during the eighth postoperative hour, 5 mg preservative-free morphine provides effective and long lasting (more than 24 h) pain relief. No side effects were noted.     

Role of L-selectin in the development of autoimmune diabetes in non-obese diabetic mice

Autoimmune diabetes is characterized by an early mononuclear infiltration of pancreatic islets and later selective autoimmune destruction of insulin-producing beta cells. Lymphocyte homing receptors have been considered candidate targets to prevent autoimmune diabetes. L-selectin (CD62L) is an adhesion molecule highly expressed in naive T and B cells. It has been reported that blocking L-selectin in vivo with a specific antibody (Mel-14) partially impairs insulitis and diabetes in autoimmune diabetes-prone non-obese diabetic (NOD) mice. In the present study we aimed to elucidate whether genetic blockade of leukocyte homing into peripheral lymph nodes would prevent the development of diabetes. We backcrossed L-selectin-deficient mice onto the NOD genetic background. Surprisingly NOD/L-selectin-deficient mice exhibited unaltered islet mononuclear infiltration, timing of diabetes onset and cumulative incidence of spontaneous diabetes when compared to L-selectin-sufficient animals. CD4, CD8 T cells and B cells were present in islet infiltrates from 9-week-old L-selectin-sufficient and -deficient littermates. Moreover, total splenocytes from wild-type, heterozygous or NOD/L-selectin-deficient donor mice showed similar capability to adoptively transfer diabetes into NOD/SCID recipients. On the other hand, homing of activated, cloned insulin-specific autoaggressive CD8 T cells (TGNFC8 clone) is not affected in NOD/L-selectin-deficient recipients. We conclude that L-selectin plays a small role in the homing of autoreactive lymphocytes to regional (pancreatic) lymph nodes in NOD mice.     

A contig of non-chimaeric YACs containing the spinal muscular atrophy gene in 5q13

We have constructed a contig of non-chimaeric yeast artificialchromosomes (YACs) across the candidate region for childhoodautosomal recessive spinal muscular atrophy (SMA) In 5q13. Anovel microsatellite reduces the candidate region to approximately400kb of DNA distal to D5S435. The candidate region containsblocks of chromosome 5 specific repeats which have copies on5p as well as elsewhere on 5q. Restriction mapping of the YACsreveals at least one CpG island In the SMA gene region. TheYAC maps indicate that the contig contains minimal rearrangementsor deletions. The data show the value of screening several YAClibraries simultaneously in order to construct a set of overlappingsequences suitable for candidate gene searches and direct genomicsequencing.     

Hindrance of binding to class II major histocompatibility complex molecules by a single amino acid residue contiguous to a determinant leads to crypticity of the determinant as well as lack of response to the protein antigen.

The immune system has evolved the potential to respond to a wide variety of antigens, yet unresponsiveness to many foreign determinants is encountered frequently. Here, we report a lack of response to a particular determinant, hen egg lysozyme (HEL)-(46-61)-peptide (p46-61), in C57BL/6 (H-2b) mice, whereas a strong T-cell response to this determinant is obtained in major histocompatibility complex (MHC)-identical C3H.SW mice. However, (C3H.SW x C57BL/6)F1 mice respond well to p46-61, suggesting the absence of a p46-61-specific "hole" in the T-cell repertoire in C57BL/6 mice. We further show that p46-61 cannot bind the I-Ab class II MHC molecule, whereas p46-60 lacking Arg61 exhibits good binding and is immunogenic in both strains. Thus, the presence of the hindering residue, Arg61, renders p46-61, a dominant determinant in C3H.SW, into a silent, cryptic determinant in C57BL/6 mice. Upon i.p. immunization with HEL, no T-cell responses to either HEL or p46-61 could be demonstrated in spleens of HEL-primed C57BL/6 mice, whereas a predominant response to p46-61 and HEL was demonstrated in C3H.SW mice. Evidently, C57BL/6 mice differ from C3H.SW in their ability to process p46-61 into an actual I-Ab binding determinant, indicating a putative enzymatic defect in the C57BL/6 strain. Furthermore, our results suggest that the inability of C57BL/6 mice to respond in the spleen to HEL is based upon its failure to generate a dominant immunogenic determinant from HEL, coupled with its pattern of susceptibility to regulatory effects.     

Effect of pipecuronium and pancuronium on intracranial pressure and cardiovascular parameters in patients with supratentorial tumours

A prospective, randomised, single blind study was conducted to evaluate and compare the intracranial pressure (ICP) and cardiovascular effects of pipecuronium (PPC) and pancuronium (PNC) in 20 patients undergoing supratentorial surgery. Patients were randomly divided into two groups. Patients in Group I (n = 10) received pancuronium (0.1 mg kg(-1)) and in Group II (n = 10) pipecuronium (0.07 mg kg(-1)) for intubation. Intracranial pressure (ICP), heart rate (HR), systolic, diastolic and mean arterial pressures (SAP, DAP, MAP), central venous pressure (CVP), nasopharyngeal temperature and arterial blood gases (ABG) were monitored at the following time periods: before induction (0 minutes); 3 minutes after thiopentone and muscle relaxant; immediately after intubation; and 4, 6, 8, 10, 20 and 30 minutes following intubation. The rise in intracranial pressure at intubation was significantly greater in group I (21.10+/-3.97 torr, 122.59%) when compared to group II patients (1.80+/-0.70 torr, 10.04%) (p<0.0 1). Cardiovascular parameters also showed a significantly greater degree of rise in group I when compared to group II patients. Heart rate increased by 29+/-6.32 beats min(-1) (33.52%) and systolic arterial pressure by 11.60+/-7.37 torr (9.47%) in group I. These parameters did not change significantly in group II. No significant alterations were observed in the other measured parameters in either of the two groups.     

Ulnar nerve elongation and excursion in the cubital tunnel after decompression and anterior transposition

We studied the elongation and excursion of cadaveric ulnar nerves during elbow flexion in control conditions and after in situ decompression and anterior subcutaneous transposition. We found that the normal nerve had the greatest elongation (23%) and excursion (14 mm) in the epicondylar groove. Decompression did not alter the excursion, but significantly reduced the elongation in the groove (6%) and increased it proximally (19%). After anterior subcutaneous transposition, the nerve segment which was originally in the groove elongated with elbow extension to the same extent as occurred with the normal nerve during flexion.     

Feasibility of partial A2 and A4 pulley excision: residual pulley strength

We investigated residual digital flexor pulley strengths after 75% excision of the A2 and A4 pulleys. For direct pull-off tests, A2 and A4 pulleys from cadaveric fingers were tested by pulling on a loop of flexor digitorum profundus tendon through the pulley. For functional loading tests, fingers were positioned with the metacarpophalangeal joint flexed to 90 degrees for A2 testing, and with the proximal interphalangeal joint in 90 degrees flexion for A4 testing (with all other joints in full extension). Excision of 75% of A2 and A4 pulleys reduced pulley strengths determined by both testing methods. For the functional loading tests, which are more clinically relevant, mean tendon forces at failure after partial excision of A2 and A4 pulleys were 224 and 131 N respectively, which is sufficient to withstand flexor tendon forces expected during activities of daily living.     

Retraction pockets in chronic suppurative otitis media- our experience

Retractions of the tympanic membrane constitute a large proportion of ear diseases causing concern to the otologist. The clinical features in a case of retraction pocket are varied and cholesteatoma. Also, that a retraction pocket in the posterosuperior region and pars ftaccida is a precursor of cholesteatoma is now well recognized. We have studied 60 cases of retraction pockets during a period of 5 years and have attempted to find out the etiology as well as the most effective treatment in such cases. Though over the years along with a dysfunctional eustachian tube, a sclerotic mastoid has been implicated as one of the causes of Retraction Pockets, we in our study have seen a large sized mastoid antrum (beyond 2 mm vf Lateral Semicircular Canal) as a consistent feature in most of our cases. This was subjectively assessed as a surgical finding in tympanomastoidectomy and objectively assessed by a high Resolution Computed Tomography of the temporal bone. We have found that a canal wall down mastoidectomy was the most effective in preventing the recurrence of retraction pockets. In a coutry like India, canal wall down mastoidectomy offers an acceptable solution to the problem of retraction pocket as not only is the follow up of patients poor but also the “Second- Look” procedure is not always possible. The use of 1- 0 chromic catgut in the middle ear instead of the more conventionally used silastic in preventing recurrent retractions can be considered as an effective single-staged procedure.     

Outcomes of simultaneous kidney-pancreas transplantation in African-American recipients: a case-control study

INTRODUCTION: Previous studies have suggested that African-American (AA) ethnicity is a risk factor for rejection and graft loss after kidney transplantation. However, little data is available regarding outcomes after simultaneous kidney pancreas transplantation (SKPT) in AA recipients. The objective of this study was to compare the outcomes of SKPT in AA patients to matched Caucasian patients as controls. METHODS: From January 1996 to September 1999, we performed 79 SKPTs, including 10 in AA recipients. Ten Caucasian controls were selected and matched for age, gender, weight, timing and technique of transplantation, and immunosuppressive regimen. Clinical outcomes were collected and compared between the two groups. RESULTS: The two groups were well matched for donor and recipient demographic, immunologic and transplant characteristics, including 2 patients in each group with type 2 diabetes. All patients received tacrolimus (TAC), mycophenolate mofetil (MMF) and steroids, and about half in each group received antibody induction therapy. Patient survival was 100% in both groups with a mean follow-up of 18 months (range 6 47). Kidney and pancreas graft survival rates were both 80% in the AA and 100% in the Caucasian groups, respectively (p = 0.14). All but one kidney (in the AA group) and all pancreas grafts experienced immediate function. There were two immunologic kidney and two immunologic pancreas graft losses in the AA group. No grafts were lost due to technical problems. The mean length of initial hospital stay was 16 d in the AA group compared to 10 d in the Caucasian group (p = 0.07). The AA group had a slight increase in the number of readmissions (mean 2.2 AA vs. 1.6 Caucasian, p = 0.08). The incidence of biopsy-proven pancreas acute rejection was significantly higher in the AA group (50%) compared to the Caucasian group (10%) (p = 0.05). The incidence of either kidney or pancreas acute rejection was also higher in the AA group (60% AA vs. 20% Caucasian, p = 0.06). TAC levels were comparable at specific times after transplantation, al-though there was a trend toward higher doses of TAC in the AA group to achieve therapeutic levels. The incidences of relaparotomy (30% AA vs. 20% Caucasian) and major infection (40% AA vs. 60% Caucasian) were similar between groups. Renal and pancreas allograft functions were comparable between groups at specific times after transplantation. CONCLUSIONS: These results suggest that SKPT in AA recipients may be associated with a higher incidence of rejection and immunologic graft loss compared to matched Caucasian controls.