Genomic origin and EGFR-TKI treatments of pulmonary adenosquamous carcinoma

BACKGROUND

Adenosquamous carcinoma (ASC) of the lung is a heterogeneous disease that is composed of both adenocarcinoma components (ACC) and squamous cell carcinoma components (SCCC). Their genomic profile, genetic origin, and clinical management remain controversial.

PATIENTS AND METHODS

Resected ASC and metastatic tumor in regional lymph nodes (LNs) were collected. The ACC and SCCC were separated by microdissection of primary tumor. The 1021 cancer-related genes were evaluated by next-generation sequencing independently in ACC and SCCC and LNs. Shared and private alterations in the two components were investigated. In addition, genomic profiles of independent cohorts of adenocarcinomas and squamous cell carcinomas were examined for comparison. We have also carried out a retrospective study of ASCs with known EGFR mutation status from 11 hospitals in China for their clinical outcomes.

RESULTS

The most frequent alterations in 28 surgically resected ASCs include EGFR (79%), TP53 (68%), MAP3K1 (14%) mutations, EGFR amplifications (32%), and MDM2 amplifications (18%). Twenty-seven patients (96%) had shared variations between ACC and SCCC, and pure SCCC metastases were not found in metastatic LNs among these patients. Only one patient with geographically separated ACC and SCCC had no shared mutations. Inter-component heterogeneity was a common genetic event of ACC and SCCC. The genomic profile of ASC was similar to that of 170 adenocarcinomas, but different from that of 62 squamous cell carcinomas. The incidence of EGFR mutations in the retrospective analysis of 517 ASCs was 51.8%. Among the 129 EGFR-positive patients who received EGFR-TKIs, the objective response rate was 56.6% and the median progression-free survival was 10.1 months (95% confidence interval: 9.0-11.2).

CONCLUSIONS

The ACC and SCCC share a monoclonal origin, a majority with genetically inter-component heterogeneity. ASC may represent a subtype of adenocarcinoma with EGFR mutation being the most common genomic anomaly and sharing similar efficacy to EGFR TKI.

Müllerian adenosarcoma: a review of cases and literature

OBJECTIVE

Mullerian adenosarcoma usually originates in the endometrium and grows as a polypoid mass in post-menopausal women presenting as abnormal vaginal bleeding. This report reviewed Miillerian adenosarcoma cases to clarify the clinical and pathologic characteristics.

MATERIALS AND METHODS

Fifteen cases ofMiillerian adenosarcoma in two medical centers covering a 15-year period were reviewed. Their clinical characteristics, pathologic findings, treatment, and outcomes were compared.

RESULTS

Of the 15 cases, three originated from the endometrium, six arose from uterine adenomyosis, three from the adnexa, and three from the cervix. There was only one post-menopausal case. One case was of breast cancer with tamoxifen (TMX) therapy. There were four Miillerian adenosarcoma with sarcomatous overgrowth (MASO) cases, three of which died within one year after surgery. Only the focal MASO case survived.

CONCLUSION

The rare variant of MASO is very aggressive and associated with poor prognosis.

Immune focusing and enhanced neutralization induced by HIV-1 gp140 chemical cross-linking

Experimental vaccine antigens based upon the HIV-1 envelope glycoproteins (Env) have failed to induce neutralizing antibodies (NAbs) against the majority of circulating viral strains as a result of antibody evasion mechanisms, including amino acid variability and conformational instability. A potential vaccine design strategy is to stabilize Env, thereby focusing antibody responses on constitutively exposed, conserved surfaces, such as the CD4 binding site (CD4bs). Here, we show that a largely trimeric form of soluble Env can be stably cross-linked with glutaraldehyde (GLA) without global modification of antigenicity. Cross-linking largely conserved binding of all potent broadly neutralizing antibodies (bNAbs) tested, including CD4bs-specific VRC01 and HJ16, but reduced binding of several non- or weakly neutralizing antibodies and soluble CD4 (sCD4). Adjuvanted administration of cross-linked or unmodified gp140 to rabbits generated indistinguishable total gp140-specific serum IgG binding titers. However, sera from animals receiving cross-linked gp140 showed significantly increased CD4bs-specific antibody binding compared to animals receiving unmodified gp140. Moreover, peptide mapping of sera from animals receiving cross-linked gp140 revealed increased binding to gp120 C1 and V1V2 regions. Finally, neutralization titers were significantly elevated in sera from animals receiving cross-linked gp140 rather than unmodified gp140. We conclude that cross-linking favors antigen stability, imparts antigenic modifications that selectively refocus antibody specificity and improves induction of NAbs, and might be a useful strategy for future vaccine design.

Cryogen spray cooling in conjunction with pulse dye laser treatment of port wine stains of the head and neck

BACKGROUND

When a cryogen spurt is applied to the skin surface for an appropriately short period of time, the spatial distribution of cooling remains localized in the normal overlying epidermis, while leaving the temperature of deeper port wine stain (PWS) blood vessels unchanged. Furthermore, cooling continues after pulsed laser exposure as cryogen remaining on the surface evaporates and removes heat deposited by light absorption in epidermal melanin. The objective of this study was to evaluate the efficacy and advantages of cryogen spray cooling plus flashlamp-pumping in conjunction with dye laser treatment (CSC-LT) of PWS.

METHODS

From 1996 to 2000, a retrospective study was conducted on 63 patients, consisting of 43 women and 20 men, between the ages of 8 and 62 years treated with pulsed dye laser (lambda = 585 nm, tau p = 450 microseconds) over a 4-year period. The duration of cryogen spurts and the delay period between cryogen delivery and laser illumination were controlled. An infrared focal plane array thermodetector measured changes of lesion surface temperature which were recorded. The subject was asked to score discomfort during treatment using a pain scale. The primary efficacy measure was the quantitative assessment of a blanching response score.

RESULTS

The ambient skin surface temperature of PWS was 33.31 +/- 1.55 degrees C. The mean pain score for uncooled sites was 39.85 +/- 0.23 compared to 20.18 +/- 0.15 for cooled sites. There was a statistically significant difference in pain elimination between cooled and uncooled sites (p = 0.001). The mean blanching response score of CSC-LT was 3.70. A significant blanching response of PWS when receiving CSC-LT was noted.

CONCLUSION

Our clinical studies demonstrate the feasibility of selective epidermal cooling while achieving photothermolysis of blood vessels during pulsed dye laser treatment of PWS.

Total internal reflection for precision small-angle measurement

A method for precision small-angle measurement is proposed. This method is based on the total-internal-reflection effect of a light beam at a pair of glass prisms. Angular displacement of the light beam is measured when the intensity change of the reflected beam is detected as a result of the relative phase shift between the s- and the p-polarized beams. An initial phase shift between the s- and the p-polarized components is introduced to increase measurement sensitivity. For increased measurement linearity and reduced effect of laser power fluctuation on the output, a differential method is used in which the light beam is split equally into two beams, each reflected at a prism and detected by a photodiode. The output is obtained as the difference of the two detected intensities divided by their sum. A prototype device was built, which demonstrated a nonlinearity error of 1.3% in a measurement range of ?0.6 degrees or 0.4% in ?0.3 degrees . The peak-to-peak noise level was found to be at approximately 0.5 arc sec. This noise level can be reduced further and resolution increased by a reduction of the measurement range.

Drug-targeting strategies in cancer therapy

Genetic changes in cell-cycle, apoptotic, and survival pathways cause tumorigenesis, leading to significant phenotypic changes in transformed cells. These changes in the tumor environment - elevated expression of surface proteases, increased angiogenesis and glucuronidase activity - can be taken advantage of to improve the therapeutic index of existing cancer therapies. Targeting cytotoxics to tumor cells by enzymatic activation is a promising strategy for improving chemotherapeutics.

Automatic gait recognition via statistical approaches for extended template features

A gait recognition system using extended template features is presented. A proposed statistical approach is applied for feature extraction from spatial and temporal templates. This method can be used to reduce data dimensionality and to optimize the class separability of different gait sequences simultaneously. Dimensionality reduction is achieved by template extraction followed by principal component analysis. Gait recognition is achieved in the canonical space using a measure of accumulated distance as the metric. By incorporating spatial and temporal information into an extended feature, gait recognition becomes more robust and accurate than using spatial or temporal features alone.

Development of a binding assay for p53/HDM2 by using homogeneous time-resolved fluorescence

The p53 tumor suppressor protein is activated and stabilized in response to DNA damage, resulting in cell cycle arrest or apoptosis. HMD2 is a negative regulator of p53. Binding of p53 by HDM2 traffics p53 from the nucleus to the cytoplasm where it is recognized and targeted for ubiquitin-mediated degradation (D. A. Freedman, L. Wu, and A. J. Levine, 1999, Cell. Mol. Life Sci. 55, 96-107). Several reports have suggested that disruption of this complex in normal cells results in p53 signaling (V. Böttger, A. Böttger, A. Sparks, W.-L. Liu, S. F. Howard, and D. P. Lane, 1997, Curr. Biol. 7, 860-869; C. Wasylyk, R. Salvi, M. Argentini, C. Dureuil, I. Delumeau, J. Abecassis, L. Debussche, and B. Wasylyk, 1999, Oncogene 18, 1921-1934). A homogeneous time-resolved fluorescence (HTRF) assay has been developed to monitor p53/HDM2 binding. This assay employs a site-specific biotinylated p53 protein, a GST-fused HDM2 protein, and two fluorophore-conjugated detection reagents, streptavidin-XL665 and europium cryptate-labeled anti-GST antibody ¿Eu(K)-anti-GST. Binding of p53 to HDM2 brings the fluorophores into close proximity, allowing fluorescence resonance energy transfer to occur. Development of this assay and comparison to a traditional ELISA are described in this report. The HTRF assay was then utilized to assess the effect of serine phosphorylation within the p53 N-terminus on HDM2 binding, and to determine the relative affinity of a p73 peptide for HDM2.

Blood alcohol concentration among injured drivers in Hualien County

Vehicle-related injuries are the major cause of death and injuries in Hualien County. Driving under the influence of alcohol plays a major role in such crashes. From December 1997 to May 1998, we determined the blood alcohol concentrations of 750 injured drivers from vehicle crashes, visiting the two emergency rooms of teaching hospitals in Hualien. The objectives of this study were to investigate the incidence of alcohol used in vehicle crashes, to identify the prevalence groups for prevention and to discuss alcohol testing at emergency services. Sixty-four percent were male; 27.5% were aborigines. The mean age was 36.5 +/- 16.5 years. About 54.1% tested positive for blood alcohol concentration (BAC), which ranged from 13 to 611 mg/dL; 38.6% had BAC levels exceeding 50 mg/dL and 21.1% exceeding 200 mg/dL. The mean BAC was 85.9 mg/dL (+/- 118.5). Middle-aged males and aborigines were more likely to drive under the influence of alcohol. We recommend blood alcohol testing to be mandatory at the emergency service and to be used as evidence for prosecution in a court of law. Preventing drunk driving through community programs is imperative, especially in the aboriginal communities.

Use of thin films for high-sensitivity angle measurement

We propose to use thin films to provide a drastic improvement of measurement sensitivity in the recently developed small-angle measurement method, namely, angle measurement based on the internal-reflection effect. By designing the thin films (single layer or multiple layers) so that they provide an antireflection effect in the vicinity of the critical angle, we show that the sensitivity of angle measurement can be increased exponentially with the increase of the number of thin-film layers. This method provides a new means of designing angle sensors with increased sensitivities without having to increase the number of reflections and therefore the physical size and the required fabrication accuracy of the reflection prisms. We describe the design of the thin films for this particular application and the analysis of measurement sensitivity and range as determined by the material and the number of layers of the thin films. Selection of the optimal initial angle for high linearity performance is also discussed.

Small-angle measurement by use of a single prism

A new method of angle measurement based on the internal reflection effect is proposed that uses a single right-angle prism. We measure the angular displacement between a laser beam and the prism by detecting the changes in reflectance as a function of the angle of incidence. We achieve high linearity of measurement by taking the inverse of reflectance as the output. The inverse of reflectance is obtained from the intensities of the reflected and the transmitted beams measured by two photodiodes. Experiments with a prototype device have demonstrated that angle measurement with a range of ?500 arc sec, a nonlinearity error of ?0.1%, and a resolution of 0.1 arc sec can be readily achieved. The measurement range can be further increased with some sacrifice of linearity.

Oncogene products as therapeutic targets for cancer

Enormous progress has been made in the last several years in delineating signal transduction pathways associated with cell proliferation and apoptosis. The components of these pathways, which include both oncogenes and tumor suppressors, may provide viable targets for therapeutic intervention for the treatment of cancer and other diseases. This review highlights some of these recent biologic and pharmacologic advances, focusing on the ras pathway and on p53-dependent apoptosis.

Angle measurement based on the internal-reflection effect using elongated critical-angle prisms

Elongated critical-angle prisms that provide multiple reflections have been used to increase measurement sensitivity while retaining excellent linearity in the recently developed angle-measurement method, angle measurement based on the internal-reflection effect.

Angle measurement based on the internal-reflection effect and the use of right-angle prisms

A new development in angle measurement based on the internal-reflection effect (AMIRE) is described in which a pair of right-angle prisms is used to replace the previously used elongated critical-angle prisms, resulting in lower costs and a more compact size. Excellent linearity is achieved through careful alignment of the right-angle prisms. The measurement sensitivity and range can be selected through the use of light sources with different polarization states. Experiments with a prototype sensor demonstrated a measurement range of 1.6°, a resolution of 0.04 arcsec, and a nonlinearity error of ±0.1%. Both analytical and experimental results are presented.

An SH3 domain is required for the mitogenic activity of microinjected phospholipase C-gamma 1

Phospholipase activity is elevated in dividing cells. In response to growth factor stimulation, phospholipase C-gamma (PLC-gamma) binds to activated tyrosine kinase receptors via SH2 binding domains, resulting in phosphorylation of PLC-gamma and activation of its enzyme activity. These observations suggest that PLC-gamma participates in the signal transduction pathway employed by growth factors to promote mitogenesis. Consistent with this hypothesis, microinjection of purified bovine PLC-gamma into quiescent fibroblasts has been previously reported to initiate a mitogenic response [Smith et al. (1989) Proc. Natl. Acad. Sci. 86, 3659]. We have reproduced this result using recombinant rat PLC-gamma protein. Surprisingly, however, a catalytically inactive mutant of PLC-gamma, H335Q, also elicited a full mitogenic response. The capacity to induce mitogenesis by microinjection of PLC-gamma was mapped to the 'Z' domain of the protein, which contains PLC-gamma's SH2 and SH3 motifs. Inactivation of the phosphorylated tyrosine binding properties of both SH2 domains had no effect on the mitogenic activity of the Z-domain peptide. However, deletion of the SH3 domain resulted in a complete loss of activity. These results suggest that PLC-gamma's mitogenic properties do not require the enzyme's phospholipase activity, but are instead mediated by a novel pathway for mitogenic stimulation which is dependent upon an intact SH3 domain.

Retinoblastoma protein reverses DNA bending by transcription factor E2F

E2F is a mammalian transcription factor involved in cell cycle regulation. The retinoblastoma gene product, pRB, binds to E2F in a cell cycle-dependent manner and appears to turn E2F from a transcriptional activator into a repressor. We show here that in vitro binding of pRB has three major effects on the DNA binding properties of E2F affinity-purified from HeLa cells; pRB binding increases the half-life of E2F.DNA complexes 10-15-fold, it reduces E2F specific DNA binding in the presence of nonspecific DNA by sequestering E2F, and it partially reverses the DNA bending induced by E2F. Upon specific DNA binding, E2F induces a DNA bend with a flexure angle of 125 degrees. Both full-length pRB105 and the N-terminally truncated pRB60 bind to the E2F.DNA complex with a Kd,app of 150 pM and reduce the apparent DNA bending to less than 80 degrees. DNA footprinting analysis indicates that the nonspecific DNA binding activity of pRB is not involved in this effect. Our biochemical data suggest that transcriptional activation by E2F may involve DNA bending and that the reversal of bending upon binding of pRB may turn E2F into a repressor.

Transcription factor E2F binds DNA as a heterodimer

E2F is a mammalian transcription factor that appears to play an important role in cell cycle control. DNA affinity column-purified E2F from HeLa cells reproducibly exhibits multiple protein bands when analyzed by SDS/PAGE. After electrophoretic purification, electroelution, and refolding of the individual protein components, the E2F DNA binding activity of the individual proteins was poor. However, upon mixing the individual components together, a dramatic (100- to 1000-fold) increase in specific DNA binding activity was observed. The five protein bands isolated can be separated into two groups based on apparent molecular mass. Optimal reconstitution of activity requires one of the two proteins found in the group of larger molecular mass (approximately 60 kDa) and one of the three proteins in the smaller-sized group (approximately 50 kDa). The reconstituted heterodimer is identical to authentic affinity-purified E2F by three criteria: DNA-binding specificity, DNA pattern, and binding to the retinoblastoma gene product. A recently cloned protein with E2F-like activity, RBP3/E2F-1, is related to the protein components of the group of larger molecular mass, as determined by Western blot analysis and reconstitution experiments. These data suggest that E2F, like many other transcription factors, binds DNA as an oligomeric complex composed of at least two distinct proteins.

Protein domains governing interactions between E2F, the retinoblastoma gene product, and human papillomavirus type 16 E7 protein

Human papillomaviruses (HPVs) are the etiological agents for genital warts and contribute to the development of cervical cancer in humans. The HPV E7 gene product is expressed in these diseases, and the E7 genes from HPV types 16 and 18 contribute to transformation in mammalian cells. Mutation and deletion analysis of this gene suggests that the transforming activity of the protein product resides in the same domain as that which is directly involved in complex formation with the retinoblastoma gene product (pRB). This domain is one of two conserved regions (designated CRI and CRII) shared by E7 and other viral oncoproteins which bind pRB, including adenovirus E1A protein. Binding of HPV type 16 E7 protein to pRB has previously been shown to affect pRB's ability to bind DNA and to form complexes with other cellular proteins. In the current study, we map the functional interaction between E7 protein and pRB by monitoring the association between a 60-kDa version of the pRB, pRB60, and the cellular transcription factor E2F. We observe that CRII of E7 (amino acids 20 to 29), which completely blocks binding of full-length E7 protein, is necessary but not sufficient to inhibit E2F/pRB60 complex formation. While CRI of E1A (amino acids 37 to 55) appears to be sufficient to compete with E2F for binding to pRB60, the equivalent region of E7 is neither necessary nor sufficient. Only E7 fragments that contained both CRII and at least a portion of the zinc-binding domain (amino acids 60 to 98) inhibited E2F/pRB60 complex formation. These results suggest that pRB60 associates with E7 and E2F through overlapping but distinct domains.

Angle measurement based on the internal-reflection effect: a new method

We describe a new method of angle measurement that is based on the internal-reflection effect at an air-glass boundary. The method uses a differential detection scheme to largely reduce the inherent nonlinearity of the reflectance versus the angle of incidence in internal reflection. With nonlinearity reduced, the displacement of the angle of incidence can be determined accurately by measuring the reflectance. The resolution and measurement range are determined by the initial angle of incidence, the polarization state of the light, and the number of reflections. Compared with interferometers and autocollimators, this method has the advantage of a simple sensor design for applications ranging from a wide measurement range to extremely high resolution. Other advantages are compact size, simple structure, and low cost. A theoretical analysis of the method and some experimental results of a prototype sensor are presented. The possible applications of the method are also discussed.

A Multi-Degree-of-Freedom Measuring System for CMM Geometric Errors

A precision multi-degree-of-freedom measuring (MDFM) system has been developed and implemented for the simultaneous measurement of straightness, pitch, yaw, and roll errors of the moving axes of a CMM. The system is based on the principles of laser alignment and autocollimator. Its measurement principles and the influence of laser beam drifts on its measurement quality have been investigated and some improvement schemes have been implemented. Through the measurements of actual as well as artificially created geometric errors of the CMM, it has been found that the system’s accuracy of measuring straightness error components is better than 1 μm and its accuracy for angular error measurements is better than 0.5 arcsec.

Malignant carcinoid tumor metastatic to the dura mater simulating a meningioma

A 50-year-old man, transferred from another hospital, was admitted because of adult onset seizures. Nine months earlier, he had undergone an esophagogastrectomy; the lesion was confirmed to be a carcinoid tumor. Laboratory tests, chest x-rays, and electrocardiogram were normal. A second liver and spleen scan was performed. A computed tomographic scan revealed a well-circumscribed homogeneous enhancement of a lesion in the left frontal superficial area. On the 10th day, the patient underwent a left frontal parietal craniotomy. Postoperatively, he manifested no residual neurological deficits and was discharged on the 6th postoperative day. A week later, he was readmitted for treatment of aphasia and right hemiparesis; he was treated and discharged. The patient survived 16 more months. The occurrence of central nervous system metastasis from carcinoid tumor is rare. This tumor resembled, in many respects, a parasagittal meningioma. Radiological findings on the computed tomographic scan were typical of these tumors. This patient was diagnosed as having metastatic disease just 9 months after the diagnosis of the primary tumor and 13 months from the onset of any symptoms. This is a short period of time compared with that reported in other cases.

Cloning of cDNAs for cellular proteins that bind to the retinoblastoma gene product

The E7 transforming protein of human papilloma virus-16 binds to the retinoblastoma gene product (pRb) through a nine-amino-acid segment of E7 (21-29). This segment of E7 is homologous to the pRb-binding domains of the simian virus 40 large T and adenovirus E1A transforming proteins. Each of these viral transforming proteins bind to the same region of pRb. To isolate cellular proteins that interact with this viral protein-binding domain on pRb, we used recombinant pRb to screen a human complementary DNA expression library. Two cDNAs were isolated that encode retinoblastoma binding proteins (RBP-1 and RBP-2). We report here that these RBP genes exist in separate loci and produce discrete messenger RNAs. The predicted amino-acid sequence of these genes showed no homology to known proteins, but both RBPs contain the pRb binding motif conserved between E7, large T and E1A14. In vitro expression of the RBP cDNAs yielded proteins that specifically bound to pRb. Recombinant E7 protein, the E7 21-29 peptide and the homologous RBP-1 peptide inhibited RBP-pRb binding. Mutations introduced into the putative pRb-binding segment in RBP-1 impaired its binding activity. These studies indicate that the cellular RBP-1, RBP-2 and viral E7 proteins interact with pRb through similar domains.

Diffuse intravascular coagulation associated with brain tumor surgery in children

There have been numerous reported cases of diffuse intravascular coagulation (DIC) or defibrination syndrome associated with head trauma, but very few reported cases associated with primary brain tumor. This report concerns the findings in a case of DIC associated with brain tumor surgery in an infant. The patient died 2 days after surgery from acute renal and respiratory failure as a result of postoperative DIC. Therapy for DIC is controversial and shows mixed results.

Klippel-Feil syndrome in association with a craniocervical dermoid cyst presenting as aseptic meningitis in an adult: case report

Intracranial tumors associated with Klippel-Feil syndrome usually occur in children, with spinal tumors being more common in adults affected by the syndrome. A rare case of a dermoid cyst at the craniocervical junction presenting as aseptic meningitis in an adult with Klippel-Feil syndrome is described. A review of the literature on tumors associated with this syndrome is also presented.

[Immunohistochemical and cytochemical analysis of lymphocytes and plasma cells in nasopharyngeal carcinoma]

Cytoplasmic IgA+, IgG+ and IgM+ in plasma cells, present in biopsy tissue of 68 patients with nasopharyngeal carcinoma (NPC) and 40 patients with chronic nasopharyngitis (CN), were studied by immunoperoxidase (PAP) technique. EB virus VCA-IgA serum antibody in all these patients was determined. At the same time, the activity of T lymphocytes of 41 patients (23 with NPC and 18 with CN) was investigated by alpha-naphthyl acetate esterase (ANAE) method. The number of T lymphocytes in NPC was far less than that in CN. This suggests that the impediment or deficiency in cellular immunity may promote the development and growth of tumor. The number of IgA+ plasma cells in NPC was obviously more than that in CN. As the increase in the level of VCA-IgA serum antibody in NPC patients corresponded to the increase in the number of IgA+ plasma cells in the tumor tissue, it was presumed that part of the IgA+ plasma cells might participate in the production and introduction of VCA-IgA antibody. We suggest that the examination of VCA-IgA serum antibody be a reliable screening test for NPC. No significant difference was found in the numbers of IgG+ plasma cells between NPC and CN. IgM+ plasma cells were rare in both.

Augmentation of pulmonary surfactant secretion by lung expansion at birth

To study the effect of lung expansion at birth on surfactant secretion, we delivered by hysterotomy 11 litters of rabbit pups at 30 days of gestation and divided them into three groups that were killed: 1) after 30 min air-breathing, 2) after 30 min nitrogen-breathing, and 3) after 30 min tracheal occlusion. Each group was compared to a littermate group killed at birth. Groups 2) and 3) continued respiratory efforts for 30 min despite progressive asphyxia. Six additional litters were pretreated with atropine; at delivery one-half of each litter was killed, the remaining pups were subjected to 30 min of hypoxic gas breathing. After sacrifice, alveolar surfactant was recovered by saline lavage and estimated quantitatively on a surface-tension balance. Surfactant concentration at birth was 1.40 +/- 0.22 mg/g dry lung and increased to 1.86 +/- 0.19 (+/- SEM) after 30 min air-breathing (P less than 0.01). Also, surfactant was increased in the nitrogen-breathing pups (from 1.61 +/- 0.35 in littermate controls to 2.41 +/- 0.58; P less than 0.03), but not to a significant degree in the occluded group (1.34 +/- 0.33 vs. 1.41 +/- 0.28), or the atropine pretreated breathing pups (1.77 +/- 0.29 vs. 1.89 +/- 0.25).

Intermittent erection in spinal canal stenosis

A case of intermittent erection in a patient with spinal canal stenosis is reported. The symptoms disappeared after lumbar laminectomy. The mechanism of erection remains speculative.