Radiographic Evaluation of Intermetatarsal Angle Correction Following First MTP Joint Arthrodesis for Severe Hallux Valgus.

BACKGROUND: Arthrodesis is a standard operative treatment for symptomatic arthritis of the first metatarsophalangeal (MTP) joint. Patients with degenerative joint disease (DJD), severe hallux valgus, and metatarsus primus varus may also require fusion of the first MTP joint. An important question in the latter group of patients is whether a proximal first metatarsal osteotomy is required, in addition to the first MTP joint fusion. Our hypothesis was that patients with severe hallux valgus and metatarsus primus varus, treated with first MTP joint arthrodesis alone, would have correction of the first-to-second intermetatarsal angle (1-2 IMA) and hallux valgus angle (HVA) to near population norms, without the addition of a proximal first metatarsal osteotomy. METHODS: Preoperative and postoperative radiographs of 19 feet, in 17 patients, with preoperative IMA greater than 15 were analyzed. Weight-bearing radiographs were divided into pre- and postoperative cohorts. Three independent reviewers measured these radiographs and mean 1-2 IMA and HVA were calculated. Mean follow-up was 10 months. RESULTS: The mean preoperative 1-2 IMA was 19.2 degrees (15.6-24.3). The mean preoperative HVA was 48.5 (36-56.6). The mean postoperative values for 1-2 IMA and HVA were 10.8 and 12.3 degrees, respectively. The mean change in IMA was 8.3 degrees and in the hallux valgus angle was 36.4 degrees. The differences between pre- and postoperative measurement for both angles were statistically significant (P < .001). Seven of 19 (37%) feet were corrected to an IMA of less than 9 degrees (normal), whereas in 15/19 feet the postoperative IMA was 12.3 degrees or less. The postoperative HVA was less than 15 degrees in 15/19 (79%) feet. CONCLUSION: This pre- and postoperative radiographic analysis of patients with severe bunion deformity demonstrated that HVA and 1-2 IMA were acceptably corrected without the addition of a proximal first metatarsal osteotomy. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Mass spectrometric differentiation of alpha- and beta-aspartic acid in a pseudo-tetrapeptide thrombosis inhibitor and its isomer.

The pseudo-tetrapeptide designated here as RGD (N-ethyl-N-[1-oxo-4-(4-piperidinyl) butyl] glycyl-L-alpha- aspartyl-3-cyclohexyl-L-alaninamide) and its isomer with beta-aspartic acid rather than alpha-aspartic acid were examined using electrospray ionization (ESI) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). RGD has potential as a thrombosis inhibitor and the isomer, designated here as isopeptide, is an inactive instability product; hence, means were sought to distinguish the two. Both isomers give a protonated parent on ESI and fragments typical of peptides on sustained off resonance irradiation collision-induced decomposition (SORI-CID). Cleavage at the aspartic acid (b(3)) is the dominant process in both isomers, although a significant b(2) and smaller a(2)" and c(2)" peaks are also observed. More distinctive are peaks observed at b(3)-H(2)O, b(3)-(CO + CO(2)) and, only in the case of the RGD, b(3) - (H(2)O + CO). SORI CID on the b(3) ion indicates that, of these distinctive peaks, only the b(3)-(CO + CO(2)) comes from decomposition of the b(3) ion. On this basis, a mechanism is suggested for b(3) formation, involving proton transfer from a back-bone carbonyl to the aspartic acid side-chain carboxyl group. Such an intramolecular proton transfer involves rings of different sizes for the two isomers, providing a basis for the different SORI energy dependences. A mechanism suggested for the formation of the b(3)-H(2)O fragments also involves proton transfer to the aspartic acid side chain carboxyl group. This leads to concomitant H(2)O loss and amide bond cleavage, giving the b(3)-H(2)O ions with ketene moieties resulting from the water loss. According to the suggested mechanism, the observed loss of CO (verified by SORI-CID on the b(3)- H(2)O ion) from the RGD b(3)-H(2)O peak results in a secondary carbocation stabilized by an adjacent nitrogen. The unobserved loss of CO from the b(3)-H(2)O ion, formed by the suggested mechanism from the isopeptide, would give an unstable primary carbocation lacking a neighboring nitrogen. The mechanism, thus, only rationalizes the observation of a b(3)-(H(2)O + CO) fragment in RGD and not in the isopeptide. The isomers can be distinguished on the basis of this unique peak or on the basis of the different SORI energy dependence of the formation of the b(3) ions.

Kinetics and mechanism of degradation of klerval, a pseudo-tetrapeptide.

The degradation of klerval (I) was studied as a function of pH. The extent and routes of degradation were found to be pH-dependent. Under strongly acidic conditions (pH<2), the drug predominantly undergoes specific acid-catalyzed hydrolysis of the side-chain amide bond yielding II8), the drug undergoes specific base-catalyzed hyrolysis yielding II and epimerization generating D-epimer. The epimerization appears to occur via the succinimide intermediate in neutral pH region. With increasing pH, however, the epimerization rate increases due to direct epimerization of the peptides.

Method of analysis of recombinant acidic fibroblast growth factor by capillary electrophoresis.

Fibroblast growth factors are a series of well characterized proteins that have intriguing pharmacological properties. Acidic fibroblast growth factor (aFGF) recently appeared in the literature for its efficacy in spinal cord repair in rats. The protein has proven difficult to analyze by capillary electrophoresis, because it has a tendency to unfold, aggregate and precipitate, especially near and above physiological temperatures. By studying the turbidity of capillary electrophoresis running buffers and aFGF at 50 degrees C, conditions were found that stabilize the aFGF solution, thereby allowing the capillary electrophoretic separation of the protein from its recombinant production impurities. The buffer system employs 50 mM phosphate buffer at pH 2.5 with 0.25% hydroxypropylmethylcellulose (HPMC) additive. This system provided the best efficiency and selectivity of the systems studied and was developed for pharmaceutical purity analysis.

Cross-correlation in flow-injection analysis with parallel flow streams and amperometric detection.

Cross-correlation was implemented for flow-injection analysis by using two parallel flow lines, each with amperometric detectors, and driven by peristaltic pumps. One flow line was used to generate the reference signal for an analog correlator circuit and the other to generate the analyte signal. Cross-correlation was performed by multiplying these signals together at a time delay of zero, followed by low pass filtering. Using dopamine as a test system, improvements in signal-to-noise ratios of about two orders of magnitude were found for the correlation signal over the direct measurement of the electrode current.

Amylase mRNA synthesis and ageing in rat parotid glands following isoproterenol-stimulated secretion.

In the parotid, as well as in other exocrine glands, secretory protein synthesis declines with age. However, whether this decline in the steady-state rate of protein synthesis reflects the reduced digestive activity of the animal or actual cellular alterations that affect synthesis is unknown. Here the ability to synthesize amylase and its mRNA during the period of enhanced protein synthesis following secretion induced by isoproterenol was compared in acinar cells of 2-and 24-month-old rats. In unstimulated glands, rates of synthesis of total protein and amylase, as well as amounts of amylase mRNA, were significantly less in the older rats than in their younger counterparts. After stimulation with isoproterenol, which induced the secretion of about 50% of stored proteins, rates of synthesis of total protein, as well as amylase, were increased by about 2.5 x the unstimulated rates in both age groups. However, the amount of amylase mRNA did not increase in parallel with the increase in the rate of amylase protein synthesis in both young and old rats. The molecular size of the mRNA was the same in stimulated and unstimulated glands of both age groups. Thus, it appears that parotid acinar cells from old rats can be stimulated to synthesize secretory proteins at an increased rate. It remains to be determined what causes the reduced rate of protein synthesis in unstimulated glands in old rats.

Effects of diabetes and insulin on alpha-amylase messenger RNA levels in rat parotid glands.

Previous studies have shown that amylase levels are reduced significantly in the pancreas and parotid gland of diabetic rats and that insulin reverses this effect and increases the secretory protein levels. In the pancreas, these changes in amylase protein levels are accompanied by parallel changes in amylase mRNA levels. In the present study, the effects of diabetes and subsequent insulin treatments on contents (per cell) of amylase protein and its mRNA in parotid glands were compared in rats rendered diabetic with an injection of a beta-cell toxin, streptozotocin (STZ). Both amylase protein and its mRNA contents were reduced significantly in diabetic rats, compared with control rats, and this reduction was reversed following insulin injections of diabetic rats. In insulin-injected diabetic rats, amylase protein contents increased before a detectable increase in amylase mRNA levels was seen. The mRNA contents of a non-secretory protein, actin, did not change during diabetogenesis or subsequent insulin treatments. The reductions in parotid contents of amylase and its mRNA in diabetic rats and the reversal of these changes by insulin are similar to those changes that occur in the pancreas under the same conditions. However, the magnitude of these changes in parotid glands was much smaller than in the pancreas, and the effect of insulin on amylase mRNA synthesis was not as immediate as in the latter gland.

Translocation(X;Y)(p22.33;p11.2) in XX males: etiology of male phenotype.

Analysis of G-banded prometaphase chromosomes from three XX males revealed extra bands on the distal end of one X short arm. These bands were similar both in size and staining properties to the distal Y short arm of their fathers (in the two cases examined) and also to other chromosomally normal males. The extra material on the abnormal X chromosomes was not C- or G-11 positive in the two cases examined, suggesting that the proximal Y long arm was not present. Previous karyotype-phenotype correlations with structurally altered Y chromosomes provided evidence for localization of male determinants on the Y short arm. The present findings in XX males provide support for more precise localization, to bands p11.2 leads to pter of Y short arm.

Trisomy 5: delineation of clinical features.

Partial trisomy for the short arm of chromosome No. 5 appears to result in an identifiable syndrome. Major features include characteristic facial appearance, mental and growth retardation, seizures, and an excess of ulnar loops. Less certain features may include strabismus and an absence of major congenital malformations. The translocation present in this family from the short arm of chromosome No. 5 to the short arm of No. 4 has, to the best of our knowledge, not been reported previously [6].

Continuing medical education. The philosphy and use of audit.

In 55 audits of 37 topics totaling 5,499 patient records, 94% of deficiencies were in the area of performance, while only 6% occurred in the area of lack of knowledge. In addition to defining problems, audit serves as an educational experience and a stimulus to improve practice.