Structural polymorphism of glycophorins demonstrated by immunoblotting techniques

We have explored the polymorphism of the glycophorin system in the human erythrocyte membrane using the immunoblotting techniques and examining 52 individuals selected without prior bias as to their serologic state and ten documented serologic variants of M, N, S, s blood group system. Polyclonal antisera to alpha glycophorin and to alpha glycophorin CNBr carboxyl terminal fragment C (residues 82-131) and M and N specific monoclonal antibodies (MoAbs) were used. The first two reagents detect specific regions of the alpha glycophorin molecule and all electrophoretically resolved species of glycophorins immunologically related to alpha and delta glycophorins (delta glycophorin, [alpha-delta] hybrids and other glycophorins with an alteration in the carboxyl terminal segment); the M and N MoAbs identified the glycophorin species containing or lacking the M or N determinant in the amino terminal octapeptide structures. We find that immunoblotting confirmed in all cases the serologically determined phenotype; we also find that polymorphic forms of the glycophorin system are relatively infrequent; immunoblotting, independent from serologic testing, was capable of detecting five mutants, two most likely S-s-U-phenotypes; a new glycophorin species was detected in normal red cells with both antiglycophorin and antipeptide C sera, which is not evident with MoAbs; immunoblots of known glycophorin variants (En(a-), U-, Mg, Mi I, II, III, V, and Sta) confirmed but also extended our knowledge of the abnormal glycophorins involved; and the He+ and Wrb(-) cells showed normal patterns.     

Gunshot wounds: bullet caliber is increasing, 1998-2003

In 1999, Caruso reported data from the level 1 trauma center in Newark, New Jersey, documenting "...an ominous trend toward the use of larger caliber firearms in accidents, homicides and suicides." Those data were derived from measurements of bullets removed from our trauma patients and submitted to the Surgical Pathology laboratory from 1981 through 1997. We further document this trend with measurements of similar source bullets from 1998 through 2002. During the same time, we recorded mortality among gunshot wound victims treated at our trauma center. Bullets submitted to surgical pathology during the years 1998 through 2002 were measured with a millimeter rule to determine caliber or transverse diameter. A total of 367 bullets were studied in this 5-year period. Bullets deformed beyond measurability (approximately 22%) and shotgun pellets (< 5%) were excluded from our study. Bullet calibers were expressed in terms of mean plus or minus standard error (x +/- SE). Mortality figures were derived from analysis of medical records concerning the outcomes all victims of gunshot wounds (E 922, E 965) treated at our hospital during the years studied and expressed as percentages. Linear regression of mean bullet caliber over time was performed, and analysis of variance was used to assess statistical significance of apparent differences in mortality. Bullet caliber continued to increase from 8.47 +/- 0.22 to 9.16 +/- 0.15 mm during the 5-year observation period. Linear regression reveals R = 0.9649, P < 0.01. Mortality ranged from 4.7 per cent to 10.7 per cent but the differences were not significant (P > 0.20). These data support a continued trend toward the use of larger caliber firearms in accidents, homicides, and suicides. Mortality does not change during this time and presumably because of improvements in treatment, from resuscitation to definitive surgery and its convalescence.     

An anti-EnaTS detected in the serum of an MiI homozygote

The serum of EH reacted with all red cells (RBCs) except her own, ficin- or trypsin-treated red cells, and En(a-) red cells. This reactivity defined an anti-EnaTS specificity. The red cells of the proposita typed as M-N+S-S+, Vw+Mur-Hil-Hut-Anek-Lane-, Wr(a-b+), EnaKT+. Red cells of five relatives were Vw+ and positive with her serum. Titration studies suggest that EH is genetically an MiI homozygote and that her Vw+ relatives are MiI heterozygotes. There is no history of consanguinity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting studies have agreed with the serologic observations. A variant sialoglycoprotein of faster mobility than normal glycoprotein A, but no normal glycoprotein A, was detected on her red cells. Treatment with N-glycanase did not alter the mobility, which indicated that there was no N-glycosylation of residue 26. These findings are in agreement with the reported properties of the Mi.I-specific glycoprotein A. The relatives' Vw+ red cells showed the variant sialoglycoprotein and normal glycoprotein A. EH appears to be the first reported MiI homozygote.     

Antibiotic resistance in bacteria - an emerging public health problem

The discovery and eventual introduction of anti-microbial agents to clinical medicine was one of the greatest medical triumphs of the twentieth century that revolutionized the treatment of bacterial diseases. However, the gradual emergence of populations of antibiotic-resistant bacteria resulting from use, misuse and outright abuse of antibiotics has today become a major public health problem of global proportions. This review paper examines the origins and molecular epidemiology of resistance genes, global picture of antibacterial resistance, factors that favour its spread, strategies for its control, problems of control and the consequences of failure to contain antibiotic resistance in bacteria.     

Comparison of outcomes after laparoscopic and open pyloromyotomy at a high-volume pediatric teaching hospital

Background/Purpose

Laparoscopic pyloromyotomy (LP) is used widely for treatment of hypertrophic pyloric stenosis. We examined the results of pyloromyotomy at a high-volume pediatric teaching hospital to compare outcomes of laparoscopic and open pyloromyotomy (OP).

Methods

We reviewed the records of all patients who underwent pyloromyotomy at our institution over a 5-year period. Data were collected regarding operative time, time to full feeds, length of hospital stay, complications, and frequency of postoperative emesis.

Results

There were 335 pyloromyotomies: 212 laparoscopic and 123 open. Five patients in the laparoscopic group required conversion to an open procedure. There were no significant differences in operative time (LP, 30.5 minutes; OP, 32.0 minutes), time to full feeds (LP, 22.4 hours; OP, 23.5 hours), frequency of postoperative emesis (LP, 1.8; OP, 2.2), or length of hospital stay (LP, 49.3 hours; OP, 50.5 hours). There were 5 mucosal perforations in the laparoscopic group and 2 in the open group (LP, 2.3%; OP, 1.6%). There were 3 incomplete pyloromyotomies in the laparoscopic group and none in the open group. Four perforations and all incomplete myotomies occurred in the first 2 years after the laparoscopic technique was introduced at our institution. The overall complication rate was similar (LP, 3.7%; OP, 3.2%).

Conclusions

Laparoscopic pyloromyotomy is a safe and effective alternative to OP. There appears to be an institutional learning curve when the laparoscopic technique is introduced as reflected by slightly higher rates of mucosal injury and incomplete pyloromyotomy.