Human sperm-specific peptide vaccine that causes long-term reversible contraception

A novel dodecamer peptide sequence, YLP(12), was identified on human sperm that is involved in oocyte binding. We investigated its immunocontraceptive effects in a murine model. A vaccine was prepared by conjugating the synthetic YLP(12) peptide with the binding subunit of recombinant cholera toxin. Vaccination of female mice by i.m. or intranasal routes without any additional adjuvant induced a sperm-specific immune response in serum and the vaginal tract that caused a long-term contraceptive state. Fertility was fully regained when antibody reactivity diminished at 305-322 days. The contraceptive effect was also completely reversed voluntarily by intravaginal administration of the peptide. Antibodies affected fertility at the prefertilization stage by inhibiting sperm capacitation and the acrosome reaction, and sperm-oocyte binding. The peptide sequence is an epitope of a 50 +/- 5-kDa membrane protein localized on the acrosome and tail of spermatozoa. Thus, the sperm-specific YLP(12) is an attractive candidate for contraceptive vaccine.     

Automated image morphometry of lobular breast carcinoma

OBJECTIVE: To analyze the role of automated image morphometry (AIM) in distinguishing infiltrating lobular carcinoma (ILC) of the breast from benign, borderline and infiltrating ductal carcinoma (IDC). STUDY DESIGN: Only histopathologically proven lobular carcinoma, ductal carcinoma, borderline lesions and benign breast lesions were selected for the study. There were 19 cases of ILC and 30 cases of IDC, 20 cases of benign lesions (fibroadenoma, 18; fibrocystic disease, 1; and fibroadenosis, 1); 10 cases were borderline lesions (mild epithelial hyperplasia, 3; moderate epithelial hyperplasia, 2; florid epithelial hyperplasia 4; intraductal papillary carcinoma, 1). In all cases hematoxylin and eosin-stained slides were used for AIM. At least 100 cells from each case were subjected to analysis randomly with an image cytometer with Leica Quantimet 600 software (Cambridge, England). Nuclear area, diameter, perimeter, convex perimeter, convex area and roundness were measured in each case with random, unbiased selection of cells and 40 x objectives (one pixel = 0.46 microm). AIM data on the cases were analyzed in relation to final cytologic diagnosis. RESULTS: All the nuclear morphometric features of ILC were much lower than those of IDC and borderline lesions, whereas nuclear morphometric data on ILC were only marginally more than those on benign cases. ANOVA showed that mophometric data were significant (P < .05) in all the variables between ILC and IDC. However, there was no significant difference between ILC, and borderline and benign cases. CONCLUSION: Image morphometry may be useful in distinguishing ILC from IDC on cytologic smears. However, morphometric data may not be helpful in distinguishing benign and borderline lesions from ILC.     

Instability of CGG repeats in transgenic mice

Dynamic mutation resulting in the expansion of CGG repeats in the untranslated region (UTR) of the first exon of the FMR1 gene in humans results in fragile X syndrome. Long stretches of CGG repeats that are known to be highly unstable in humans have so far failed to show similar intergenerational instability in transgenic mice. We generated transgenic lines that show a dramatic increase from 26 to >300 repeats in three generations. One of the salient features of our transgene is the inclusion of the origin of replication of simian virus-40 (SV40), which is known to exclude nucleosomes. Three founder mice in FVB/NJ background show expansion of CGG repeats present in the transgene, supporting a postzygotic mechanism for CGG expansion that is independent of a genomic imprinting effect. We discuss here the results of analyzing one of the lines established.     

Olfactory axon pathfinding: who is the pied piper?

Mammalian olfactory sensory neurons that express a particular odorant receptor (OR) project axons to the same few glomeruli in the olfactory bulb. In this issue of Neuron, Vassalli et al. use OR minigenes that coexpress histochemical markers and show that the determinants in the sensory neurons required to generate the stereotyped olfactory bulb map are the same as those needed for appropriate expression of the OR.     

Sequence conserved for subcellular localization

The more proteins diverged in sequence, the more difficult it becomes for bioinformatics to infer similarities of protein function and structure from sequence. The precise thresholds used in automated genome annotations depend on the particular aspect of protein function transferred by homology. Here, we presented the first large-scale analysis of the relation between sequence similarity and identity in subcellular localization. Three results stood out: (1) The subcellular compartment is generally more conserved than what might have been expected given that short sequence motifs like nuclear localization signals can alter the native compartment; (2) the sequence conservation of localization is similar between different compartments; and (3) it is similar to the conservation of structure and enzymatic activity. In particular, we found the transition between the regions of conserved and nonconserved localization to be very sharp, although the thresholds for conservation were less well defined than for structure and enzymatic activity. We found that a simple measure for sequence similarity accounting for pairwise sequence identity and alignment length, the HSSP distance, distinguished accurately between protein pairs of identical and different localizations. In fact, BLAST expectation values outperformed the HSSP distance only for alignments in the subtwilight zone. We succeeded in slightly improving the accuracy of inferring localization through homology by fine tuning the thresholds. Finally, we applied our results to the entire SWISS-PROT database and five entirely sequenced eukaryotes.     

Correlation between VEGF expression and angiogenesis in breast carcinoma

OBJECTIVE: To analyze the role of vascular endothelial growth factor (VEGF) secreted by tumor cells in angiogenesis of breast carcinoma using image morphometry. STUDY DESIGN: Thirty-four cases of node-negative breast carcinoma were used in the study. There were 6 grade 1, 20 grade 2 and 8 grade 3 tumors. For each case, 2 consecutive sections from the same block were cut. Immunostaining for VEGF and CD31 was carried out, and areas of highest staining density were marked. Those marked "hot spots" for CD31 and VEGF for each case were subsequently compared morphometrically. The area and intensity of immunostaining on each slide were also scored. RESULTS: The total scores for VEGF and CD31 were 5.15 and 3.79, respectively. All 34 cases showed cytoplasmic positivity for VEGF within the tumor cells. The average number of hot spots for VEGF and CD31 were 2.41 and 2.47, respectively, and the average number of hot spots that matched between these 2 groups were 0.79. Statistical analysis using Pearson's coefficient of correlation showed no significant match between the hot spots for CD31 and VEGF. Also, there was no significant difference between the total scores of CD31 and VEGF. CONCLUSION: VEGF is expressed in most breast carcinomas. However, the lack of topographic correlation between microvessel density and VEGF expression supports the notion that multiple angiogenic factors may play a role along with VEGF in the angiogenic process.     

Utility of mean nuclear volume in predicting disease-free survival in locally advanced invasive cervical squamous cell carcinoma

OBJECTIVE: To evaluate mean nuclear volume (MNV) as a prognostic indicator in invasive squamous cell carcinoma of the uterine cervix. STUDY DESIGN: Forty-nine consecutive cases of invasive squamous cell carcinoma of the cervix diagnosed in 1995 were analyzed retrospectively for MNV and correlated with outcome at the end of a 5-year follow-up period. RESULTS: The average MNV among patients with a 5-year disease-free survival (DFS) and patients with disease recurrence within the same period was 1424.11 microm3 and 1401.49 microm3, respectively (P = .984, Mann-Whitney test), indicating a poor relationship between MNV and 5-year DFS. CONCLUSION: Estimation of MNV alone in cases of invasive squamous cell carcinoma of the cervix is not predictive of DFS.