Navigation-Assisted Surgery for Locally Advanced Primary and Recurrent Rectal Cancer

BACKGROUND

In some surgical disciplines, navigation-assisted surgery has become standard of care, but in rectal cancer, indications for navigation and the utility of different technologies remain undetermined.

METHODS

The NAVI-LARRC prospective study (NCT04512937; IDEAL Stage 2a) evaluated feasibility of navigation in patients with locally advanced primary (LARC) and recurrent rectal cancer (LRRC). Included patients had advanced tumours with high risk of incomplete (R1/R2) resection, and navigation was considered likely to improve the probability of complete resection (R0). Tumours were classified according to pelvic compartmental involvement, as suggested by the Royal Marsden group. The BrainlabTM navigation platform was used for preoperative segmentation of tumour and pelvic anatomy, and for intraoperative navigation with optical tracking. R0 resection rates, surgeons' experiences, and adherence to the preoperative resection plan were assessed.

RESULTS

Seventeen patients with tumours involving the posterior/lateral compartments underwent navigation-assisted procedures. Fifteen patients required abdominosacral resection, and 3 had resection of the sciatic nerve. R0 resection was obtained in 6/8 (75%) LARC and 6/9 (69%) LRRC cases. Preoperative segmentation was time-consuming (median 3.5 h), but intraoperative navigation was accurate. Surgeons reported navigation to be feasible, and adherence to the resection plan was satisfactory.

CONCLUSIONS

Navigation-assisted surgery using optical tracking was feasible. The preoperative planning was time-consuming, but intraoperative navigation was accurate and resulted in acceptable R0 resection rates. Selected patients are likely to benefit from navigation-assisted surgery.

Survival after lymphadenectomy of nodal metastases from melanoma of unknown primary site

Although the vast majority of melanomas have a primary site, 3%-4% of all melanomas in distant sites display no known primary site (MUP). This phenomenon is not fully understood and various hypotheses have been introduced. The prognostic significance of MUP has been unclear, with some studies showing no survival benefit while others find improved survival compared to stage-matched patients with melanoma of known primary site (MKP). Between 1997 and 2014, 864 patients underwent an en bloc resection of clinical nodal metastases at a referral centre for metastatic melanoma in Norway. The MUP (n = 113) and MKP (n = 751) patients were graded with stage III or IV. The overall survival (OS) was calculated with the Kaplan-Meier method, and multivariate analysis identified factors of significance for the two groups. A significant five-year OS emerged for stage III, MUP = 58% and 42% for MKP, but not for stage IV. The five-year relapse-free survival (RFS) was 41% and 31% for MUP and MKP respectively (p = 0.049). The statistically significant inter-group differences (MUP/MKP) were observed in the univariate and multivariate analyses of age, gender, number of affected nodes, tumour size and perinodal growth within stage III and tumour size within stage IV. After regional lymphadenectomy, MUP patients with clinical nodal metastases had a better outcome than MKP patients. This finding supports the theory that an endogenously mediated immune response may promote the regression of a cutaneous melanoma.

Randomized Study of Wound Drainage on Early Complications After Lymph Node Dissection for Melanoma

INTRODUCTION

The complication rate after axillary lymph node dissection (ALND) and inguinal lymph node dissection (ILND) in melanoma patients is high. The aim of this randomized non-inferiority study was to evaluate the effect of postoperative wound drainage on early complications after ALND and ILND.

MATERIALS AND METHODS

Between 2018 and 2020, 104 stage III melanoma patients operated on with ALND or ILND were randomized to a study group with complete wound drain removal 3 wk after surgery or a control group with progressive drain removal. The primary end point was overall early complications graded according to the modified Clavien-Dindo classification. Secondary endpoints were length of hospital stay and prognostic factors for early complications.

RESULTS

Of the 99 patients analyzed, ALND was performed in 58 patients and ILND in 41 patients. Overall, 62 patients (62.6%) developed early complications: 30 in the study group and 32 in the control group (P = 0.53). The confidence interval for the difference in proportions of patients without early complications in the two groups was -0.27 to 0.11 (P = 0.42), hence non-inferiority could be claimed. Length of hospital stay was 5 d in the study group compared to 6 in the control group (P < 0.01). ILND was associated with increased risk of early complications compared to ALND (75.6% versus 53.4%, P = 0.04).

CONCLUSIONS

Complete drain removal 3 wk after ALN and ILND in stage III melanoma patients did not increase the risk of early complications compared to progressive drain removal.

Targeting AXL and the DNA Damage Response Pathway as a Novel Therapeutic Strategy in Melanoma

Receptor tyrosine kinase AXL is found upregulated in various types of cancer, including melanoma, and correlates with an aggressive cancer phenotype, inducing cell proliferation and epithelial-to-mesenchymal transition. In addition, AXL has recently been linked to chemotherapy resistance, and inhibition of AXL is found to increase DNA damage and reduce expression of DNA repair proteins. In light of this, we aimed to investigate whether targeting AXL together with DNA damage response proteins would be therapeutically beneficial. Using melanoma cell lines, we observed that combined reduction of AXL and CHK1/CHK2 signaling decreased proliferation, deregulated cell-cycle progression, increased apoptosis, and reduced expression of DNA damage response proteins. Enhanced therapeutic effect of combined treatment, as compared with mono-treatment, was further observed in a patient-derived xenograft model and, of particular interest, when applying a three-dimensional ex vivo spheroid drug sensitivity assay on tumor cells harvested directly from 27 patients with melanoma lymph node metastases. Together, these results indicate that targeting AXL together with the DNA damage response pathway could be a promising treatment strategy in melanoma, and that further investigations in patient groups lacking treatment alternatives should be pursued.

A Three-dimensional Ex Vivo Viability Assay Reveals a Strong Correlation Between Response to Targeted Inhibitors and Mutation Status in Melanoma Lymph Node Metastases

Although clinical management of melanoma has changed considerably in recent years, intrinsic treatment resistance remains a severe problem and strategies to design personal treatment regimens are highly warranted. We have applied a three-dimensional (3D) ex vivo drug efficacy assay, exposing disaggregated cells from 38 freshly harvested melanoma lymph node metastases and 21 patient derived xenografts (PDXs) to clinical relevant drugs for 7 days, and examined its potential to evaluate therapy response. A strong association between Vemurafenib response and BRAF mutation status was achieved (P < .0001), while enhanced viability was seen in some NRAS mutated tumors. BRAF and NRAS mutated tumors responded comparably to the MEK inhibitor Cobimetinib. Based on the ex vivo results, two tumors diagnosed as BRAF wild-type by routine pathology examinations had to be re-evaluated; one was subsequently found to have a complex V600E mutation, the other a double BRAF mutation (V600E/K601 N). No BRAF inhibitor resistance mechanisms were identified, but PIK3CA and NF1 mutations were identified in two highly responsive tumors. Concordance between ex vivo drug responses using tissue from PDXs and corresponding patient tumors demonstrate that PDX models represent an indefinite source of tumor material that may allow ex vivo evaluation of numerous drugs and combinations, as well as studies of underlying molecular mechanisms. In conclusion, we have established a rapid and low cost ex vivo drug efficacy assay applicable on tumor tissue from patient biopsies. The 3D/spheroid format, limiting the influence from normal adjacent cells and allowing assessment of drug sensitivity to numerous drugs in one week, confirms its potential as a supplement to guide clinical decision, in particular in identifying non-responding patients.

Fibromatosis in vertical rectus abdominis myocutaneous flap imitating tumor recurrence after surgery for locally advanced rectal cancer: case report

Background

Abdominoperineal excision is performed in patients with locally advanced, low rectal carcinoma. Reconstruction of the dorsal vagina and perineum using the vertical rectus abdominis myocutaneous flap following extensive surgery results in favorable surgical outcome and quality of life. However, the rectus abdominis muscle, as part of the anterior abdominal wall, may develop fibrous lesions also as a transplant.

Case presentation

A 39-year-old female patient with low rectal cancer and extensive colorectal polyposis was treated with neoadjuvant chemoradiotherapy followed by colectomy and abdominoperineal excision with resection of the dorsal vaginal wall and subsequent reconstruction of the perineum using the vertical rectus abdominis myocutaneous flap. At the 6-month follow-up, a suspected 2 × 2 cm tumor recurrence was detected in the transposed tissue and was subsequently surgically removed. Histologic examination concluded with fibromatosis. Genetic testing revealed a known disease-causing mutation in the adenomatous polyposis coli gene, confirming the diagnosis of familial adenomatous polyposis.

Conclusions

Fibromatosis may affect the anterior abdominal wall, that is the rectus abdominis muscle, at the primary site or may develop in the muscle after its transposition into the perineum at pelvic reconstruction. Fibromatosis in the muscle flap after pelvic reconstruction may present a difficult diagnostic challenge for the multidisciplinary team.

Collagenous microstructure of the glenoid labrum and biceps anchor

The glenoid labrum is a significant passive stabilizer of the shoulder joint. However, its microstructural form remains largely unappreciated, particularly in the context of its variety of functions. The focus of labral microscopy has often been histology and, as such, there is very little appreciation of collagen composition and arrangement of the labrum, and hence the micromechanics of the structure. On transmission electron microscopy, significant differences in diameter, area and perimeter were noted in the two gross histological groups of collagen fibril visualized; this suggests a heterogeneous collagenous composition with potentially distinct mechanical function. Scanning electron microscopy demonstrated three distinct zones of interest: a superficial mesh, a dense circumferential braided core potentially able to accommodate hoop stresses, and a loosely packed peri-core zone. Confocal microscopy revealed an articular surface fine fibrillar mesh potentially able to reduce surface friction, bundles of circumferential encapsulated fibres in the bulk of the tissue, and bone anchoring fibres at the osseous interface. Varying microstructure throughout the depth of the labrum suggests a role in accommodating different types of loading. An understanding of the labral microstructure can lead to development of hypotheses based upon an appreciation of this component of material property. This may aid an educated approach to surgical timing and repair.

Phase I/II trial of melanoma therapy with dendritic cells transfected with autologous tumor-mRNA

We have developed an individualized melanoma vaccine based on transfection of autologous dendritic cells (DCs) with autologous tumor-mRNA. Dendritic cells loaded with complete tumor-mRNA may generate an immune response against a broad repertoire of antigens, including unique patient-specific antigens. The purpose of the present phase I/II trial was to evaluate the feasibility and safety of the vaccine, and the ability of the DCs to elicit T-cell responses in melanoma patients. Further, we compared intradermal (i.d.) and intranodal (i.n.) vaccine administration. Twenty-two patients with advanced malignant melanoma were included, each receiving four weekly vaccines. Monocyte-derived DCs were transfected with tumor-mRNA by electroporation, matured and cryopreserved. We obtained successful vaccine production for all patients elected. No serious adverse effects were observed. A vaccine-specific immune response was demonstrated in 9/19 patients evaluable by T-cell assays (T-cell proliferation/interferon-gamma ELISPOT) and in 8/18 patients evaluable by delayed-type hypersensitivity (DTH) reaction. The response was demonstrated in 7/10 patients vaccinated intradermally and in 3/12 patients vaccinated intranodally. We conclude that immuno-gene-therapy with the described DC-vaccine is feasible and safe, and that the vaccine can elicit in vivo T-cell responses against antigens encoded by the transfected tumor-mRNA. The response rates do not suggest an advantage in applying i.n. vaccination.

Experiences of families when a relative is diagnosed brain stem dead: understanding of death, observation of brain stem death testing and attitudes to organ donation

Brain stem death may be a difficult concept for relatives to understand. Our ITU practice follows published recommendations that the use of explanatory leaflets showing CT scans and observing brain stem death testing in some cases may help relatives to understand that death has occurred. Using this strategy, we interviewed 27 relatives 12 months after bereavement following certification by brain stem testing, investigating their understanding of brain stem death, subsequent attitudes to organ donation, grief reactions and attitudes of those who had observed the tests. Most relatives understood that the brain stem death tests indicated that survival was not possible, although three relatives had not fully understood this and valued the opportunity to discuss it again. Only five relatives observed the tests, all were pleased that they had done so as this had confirmed their understanding that death had occurred; however, these relatives had more evidence of psychological distress. No relatives who agreed to organ donation regretted this but three who did not allow donation subsequently expressed regret. Several relatives thought that observing the tests would have helped them to understand that death had occurred, making easier the decision to allow organ donation.

Electron microscopy of tissue adherent to explanted electrodes in dystonia and Parkinson's disease

Deep brain stimulation (DBS) is used to treat a variety of severe medically intractable movement disorders, including Parkinson's disease, tremor and dystonia. There have been few studies examining the effect of chronic DBS on the brains of Parkinson's disease patients. Most of these post mortem studies concluded that chronic DBS caused mild gliosis around the lead track and did not damage brain tissue. There have been no similar histopathological studies on brains from dystonic patients who have undergone DBS. In this study, our objective was to discover whether tissue would be attached to DBS electrodes removed from patients for routine clinical reasons. We hoped that by examining explanted DBS electrodes using scanning (SEM) and/or transmission (TEM) electron microscopy we might visualize any attached tissue and thus understand the electrode-human brain tissue interaction more accurately. Initially, SEM was performed on one control DBS electrode that had not been implanted. Then 21 (one subthalamic nucleus and 20 globus pallidus internus) explanted DBS electrodes were prepared, after fixation in 3% glutaraldehyde, for SEM (n = 9) or TEM (n = 10), or both (n = 2), according to departmental protocol. The electrodes were sourced from two patients with Parkinson's disease, one with myoclonic dystonia, two with cervical dystonia and five with primary generalized dystonia, and had been in situ for 11 and 31 months (Parkinson's disease), 16 months (myoclonic dystonia), 14 and 24 months (cervical dystonia) and 3-24 months (primary generalized dystonia). Our results showed that a foreign body multinucleate giant cell-type reaction was present in all TEM samples and in SEM samples, prewashed to remove surface blood and fibrin, regardless of the diagnosis. Some of the giant cells were >100 microm in diameter and might have originated from either fusion of parenchymal microglia, resident perivascular macrophage precursors and/or monocytes/macrophages invading from the blood stream. The presence of mononuclear macrophages containing lysosomes and sometimes having conspicuous filopodia was detected by TEM. Both types of cell contained highly electron-dense inclusions, which probably represent phagocytosed material. Similar material, the exact nature of which is unknown, was also seen in the vicinity of these cells. This reaction was present irrespective of the duration of implantation and may be a response to the polyurethane component of the electrodes' surface coat. These findings may be relevant to our understanding of the time course of the clinical response to DBS in Parkinson's disease and various forms of dystonia, as well as contributing to the design characteristics of future DBS electrodes.

Noise exposure and hearing loss among student employees working in university entertainment venues

OBJECTIVES

Most studies to date on sound levels in entertainment establishments have concentrated on exposure levels for the attending public, rather than employees who may be at greater risk of hearing loss. Of particular concern are young employees. The aim of this pilot study was to (i) estimate typical sound levels in different areas where amplified music was played, (ii) measure temporary threshold shift (TTS) and (iii) estimate the dependence of hearing threshold shifts on measured noise levels.

METHODS

This study focused on students working part-time (up to 16 h/week) in music bars and discotheques in a university entertainment venue. All 28 staff were invited to participate in the study. Pre- and post-exposure audiometry was used to determine hearing threshold at both high and low frequencies. Personal dosemeters and static measurements were made to assess noise levels and frequency characteristics. A questionnaire was used to determine patterns of noise exposure and attitudes to noise levels and hearing loss.

RESULTS

Of the 28 student employees working in the three areas, 14 (50%) agreed to take part in the study, giving 21 pre- and post-shift audiograms. The mean personal exposure levels for security staff were higher than those of bar staff, with both groups exceeding 90 dB(A). The maximum peak pressure reading for security staff was 124 dB. Although TTS values were moderate, they were found to be highly significant at both low and high frequencies and for both ears. Twenty-nine per cent of subjects showed permanent hearing loss of more than 30 dB at either low or high frequencies. The correlation between TTS and personal exposure was higher at 4 kHz than the low and high frequencies.

CONCLUSIONS

Contemporary music may be an important yet little considered contributor to total personal noise exposure, especially amongst young employees. Employees need to be better informed of risks of hearing loss and the need to report changes in hearing acuity. Suggestions are made on strategies for improving the assessment of noise exposure in entertainment venues.

Human hepatocyte cell lines proliferating as cohesive spheroid colonies in alginate markedly upregulate both synthetic and detoxificatory liver function

BACKGROUND/AIMS

Bio-artificial liver support systems for treatment of hepatic failure require maintained expression of hepatocyte function in vitro. We studied cultures of human hepatocyte cell-lines proliferating within alginate beads, investigating the hypothesis that 3-dimensional cohesive colonies of hepatocyte cell-lines would achieve polarity and cell-to-cell contact resulting in upregulation of function.

METHODS

HepG2 and HHY41 human cell lines in alginate beads were cultured for >20 days.

RESULTS

Proliferation was maintained for 20 days. Production of albumin, prothrombin, fibrinogen, alpha-1-acid glycoprotein and alpha-1-antitrypsin was maintained throughout, maximal at days 8-10, when upregulation was 300-1100% compared with monolayer cultures at similar cell number per unit volume. Detoxificatory functions: ethoxyresorufin deethylase activity, androstenedione metabolism, and urea synthesis from arginine was also increased several-fold. Function returned to pre-freezing levels within 18 h of thawing after cryopreservation of cells in alginate. Electron microscopy revealed spherical colonies of cells of cuboidal shape, with cell-to-cell contact via desmosomes and junctional complexes, abundant microvilli, and cytoplasmic appearances suggesting transcriptionally active hepatocytes.

CONCLUSION

Hepatocyte cell-lines, proliferating in alginate express a range of liver-specific functions at levels approaching those found in vivo, relevant to their use in liver support systems.

Parallel genotyping of human SNPs using generic high-density oligonucleotide tag arrays

Large scale human genetic studies require technologies for generating millions of genotypes with relative ease but also at a reasonable cost and with high accuracy. We describe a highly parallel method for genotyping single nucleotide polymorphisms (SNPs), using generic high-density oligonucleotide arrays that contain thousands of preselected 20-mer oligonucleotide tags. First, marker-specific primers are used in PCR amplifications of genomic regions containing SNPs. Second, the amplification products are used as templates in single base extension (SBE) reactions using chimeric primers with 3' complementarity to the specific SNP loci and 5' complementarity to specific probes, or tags, synthesized on the array. The SBE primers, terminating one base before the polymorphic site, are extended in the presence of labeled dideoxy NTPs, using a different label for each of the two SNP alleles, and hybridized to the tag array. Third, genotypes are deduced from the fluorescence intensity ratio of the two colors. This approach takes advantage of multiplexed sample preparation, hybridization, and analysis at each stage. We illustrate and test this method by genotyping 44 individuals for 142 human SNPs identified previously in 62 candidate hypertension genes. Because the hybridization results are quantitative, this method can also be used for allele-frequency estimation in pooled DNA samples.

Three-dimensional in vitro cell culture leads to a marked upregulation of cell function in human hepatocyte cell lines--an important tool for the development of a bioartificial liver machine

Upregulating hepatocyte function in proliferating human liver cell lines could provide cells for a bio-artificial liver. Ideally, a means of mimicking the biological extracellular matrix with a relatively inert, bio-compatible matrix is required. Alginate encapsulation of primary hepatocytes is biocompatible. This study aimed to characterize cells grown in a 3D configuration in alginate. A human-derived liver cell line encapsulated in 1% alginate was assessed for synthetic and detoxification functions. Secreted proteins measured (e.g., albumin, fibrinogen, alpha-1-antitrypsin etc.) were increased in alginate compared with monolayers. Cytochrome P450 1A1 activity increased three- to fourfold, whilst urea synthesis, undetectable in monolayer cultures, was synthesized by cells in alginate at levels approaching in vivo production. TEM revealed good ultrastructure reminiscent of normal hepatocytes. Alginate promotes 3D colonies of proliferating cells with upregulated liver functions. Rapid recovery of function of cryopreserved cells (< 18 h) provides added advantages for this system to support the biological component of an artificial liver for patients with fulminant hepatic failure.

Ultrastructural evaluation of lung maturation in a sheep model of diaphragmatic hernia and tracheal occlusion

In fetuses with diaphragmatic hernia (DH) lung development is impaired, and pulmonary hypoplasia is one of the main factors responsible for the poor outcome of the disease. A possible treatment consists of occluding trachea during lung development to retain pulmonary fluid and to force the lung to expand. Although it appeared promising at first, this technique has recently been reported to decrease type II cell number and to induce surfactant deficiency. The aim of this study was to investigate lung maturation further through ultrastructural examination in a fetal lamb model of DH created at 85 d, followed or not by endoscopic balloon tracheal occlusion (TO) at 120 d of gestation. The proportion of alveolar epithelial type I and type II cells was altered by both treatments: the type I/type II cell ratio, which was about 2 in control lungs, was decreased 4.5-fold in DH lungs but was increased 4.5-fold in DH+TO lungs. The proportion of undifferentiated cells was increased in DH lungs. Indeterminate cells sharing features of type II and type I cells that were not observed in controls were seldom seen in DH lungs and were numerous in DH+TO lungs. The number of lamellar bodies per type II cell was decreased in both DH and DH+TO groups. In DH lungs, wall structure presented an immature appearance, with cellular connective tissue and poor secondary septation of saccules. In DH+TO lungs, primary septa appeared more mature, with reduced connective tissue, but secondary septa were still buds, although elastin was present at their tips. A single capillary layer was found in all three groups (control, DH, and DH+TO) with no sign of septal capillary pairing. This first investigation in DH and DH+TO lungs through transmission electron microscopy thus enabled us to show that compression and forced expansion of the lung are both responsible for alterations in type II cell differentiation and septal development.

Behavior of a cell line derived from normal human hepatocytes on non-physiological and physiological-type substrates: evidence for enhancement of secretion of liver-specific proteins by a three-dimensional growth pattern

The behavior of a recently described cell line, HH25, derived from normal human hepatocytes, has been investigated on several different substrates--tissue-culture plastic, glass, a thin layer of rat-tail collagen I, and thin layers or thick gels of extracellular matrix derived from the Engelbreth-Holm-Swarm murine sarcoma (EHS matrix). Cellular morphology, proliferation, and secretion of three hepatocyte-specific proteins (albumin, alpha1 acid glycoprotein, and alpha1 antitrypsin) have been examined. There were no differences in morphology, proliferation, or differentiated function in the cells on either plastic, glass, collagen, I, or a thin layer of EHS matrix, but on a thick EHS matrix gel the cells altered their morphology (forming three-dimensional colonies with canalicular-like structures) and their production of albumin and alpha1 acid glycoprotein was enhanced. This suggests that the enhanced differentiated function is associated with the morphological change (occurring only on the thick EHS gel) rather than with receptor-mediated cell-matrix interactions (which can also occur on the thin layer of EHS matrix). This cell line is therefore a good in vitro cellular model for the investigation of the roles of morphological changes and of cell-cell and cell-matrix interactions in the control of human hepatocyte behavior without the need for an extensive source of primary tissue.

Comparison of three solid phase supports for promoting three-dimensional growth and function of human liver cell lines

An extracorporeal liver support system will require that liver cells maintain their normal differentiated function. This is more likely to be achieved utilizing a three-dimensional culture configuration rather than a simple monolayer culture. We present data on a human liver cell line attached and maintained on different three-dimensional supports, porous glass (Siran), silicon (Immobasil), and calcium-alginate beads. Albumin, fibrinogen, prothrombin, alpha1-acid glycoprotein and alpha1-antitrypsin secretions were measured. Proliferation was slower on each of the three-dimensional supports than on the monolayer culture. The protein secretion of all 5 proteins was highest in cells encapsulated in alginate; silicon beads supported greater protein secretion than glass. Cells on silicon or within alginate were rounded; those on glass grew in 2 configurations as flattened monolayers and as rounded colonies. Cells in alginate secreted as much protein as the whole liver (e.g., albumin, 14.88 g/10(12) cells/day compared to the whole liver, approximately 12 g/day). Three-dimensional culture of a human liver cell line leads to both proliferation and a high synthetic capacity, an important feature of cells suitable for an extracorporeal liver support system.

Influence of superovulation on endometrial and embryonic development

The authors have studied the temporal relationship between follicular rupture and endometrial development in 13 women during a natural ovarian cycle (length 25 to 35 days), and subsequently after standard treatment with clomiphene citrate, human menopausal gonadotropin and human chorionic gonadotropin (hCG) to induce multiple folliculogenesis for oocyte recovery, in vitro fertilization, and embryo freezing (cycle length 23 to 27 days). An endometrial biopsy was taken during both cycles 1.5 to 2.0 days after the oocytes had been released or removed. The samples were examined by light and transmission electron microscopy. Samples of peripheral blood were taken at defined times for hormone analysis. After treatment 11 subjects (85%) had advanced morphological development of the endometrium (8 women by 3 to 4 days, 3 women by 1 to 2 days). The concentrations of plasma estradiol (E2) and progesterone (P) on the days of follicular rupture and endometrial biopsy were significantly raised in the treatment cycles. The concentration of total urinary estrogens on the day of hCG administration and the mean change in the concentration of plasma E2 (treatment/control) on the days of endometrial biopsy were positively correlated with the extent of endometrial advancement. In addition, the mean change in the concentration of plasma P (treatment/control) was markedly increased on the days of follicular rupture and endometrial biopsy in those subjects with an advanced endometrium. Embryonic development was not so obviously related to the extent of superovulation. Asynchronous endometrial and embryonic development may therefore contribute to the low pregnancy rate in these patients.

Morphology of human and experimental hydrosalpinges: a comparative study

Infection, and possibly raised intra-luminal pressure, may be responsible for the morphological changes and associated infertility that occur with hydrosalpinx formation. Biopsies from human hydrosalpinges were studied by light microscopy and scanning and transmission electron microscopy. Loss of mucosal folds, atrophied epithelium and varying degrees of deciliation were the main features found. Mechanical hydrosalpinges were produced in rabbits by double clip application (duration of clip application varied from 8 to 52 weeks). Morphological study of animal hydrosalpinges showed partial or complete loss of mucosal folds, atrophied epithelium and varying degrees of deciliation. The severity of morphological changes was related to duration of clip application. It is concluded that raised intra-luminal pressure plays a role in the morphological changes seen in human hydrosalpinges and infertility in women after anatomically successful salpingostomy. The rabbit would appear to provide a suitable model for the study of human hydrosalpinges. The significance of these findings is discussed in relation to the clinical management of hydrosalpinges.

Energy requirements for gestation and lactation in a delayed implanter, the American badger

1. Two adult female badgers were water-deprived and/or fasted during the last one-half to two-thirds of pregnancy while a third pregnant female received water ad libitum and was fed meat and dog food. 2. The litter size, birth weights, post partum energy consumption, growth rate, development of homeothermy, tooth eruption and date of weaning, as well as other developmental characteristics, were not significantly different between cubs born to the fed or fasted mothers. 3. The energy demands for gestation are apparently small and are accommodated by fat reserves during periods of food deprivation. However, the calculated energy for lactation is 16 times that of gestation, which is quadruple the expenditure for most mammals. 4. As a result of delayed implantation, the length of gestation and litter weights of badgers are considerably below those predicted from allometric equations. 5. The period of lactation is therefore extremely critical to the survival of both the cubs and lactating adults which require heavy fat stores and possibly torpor to ensure sufficient energy availability during prolonged winter food shortage.

Nucleotide sequence of the oncogene encoding the p21 transforming protein of Kirsten murine sarcoma virus

The transforming protein of Kirsten murine sarcoma virus (Ki-MuSV) is a virally encoded 21-kilodalton protein called p21 kis. The sequences encoding p21 kis were genetically localized to a 1.3-kilobase segment near the 5' end of the viral genome by assaying the capacity of a series of defined deletion mutants of molecularly cloned Ki-MuSV DNA to induce focal transformation of mouse cells. Nucleotide sequencing of a portion of this region has led to the identification of an open reading frame of 567 nucleotides coding for p21 kis protein.

Actions of progestins on the morphology and biochemistry of the endometrium of postmenopausal women receiving low-dose estrogen therapy

Endometrial biopsies were obtained from postmenopausal women receiving 0.625 mg Premarin daily and either 2.5 or 5 mg norethindrone daily or 150 or 500 microgram dl-norgestrel daily for 10 days each month. Sample were taken during the estrogen-only phase of treatment and on the sixth day of combined estrogen/progestin administration. Progestin exposure caused marked morphologic and biochemical changes as well as features comparable with the premenopausal luteal phase. Thus, progestins oppose the stimulation of premarin to the postmenopausal endometrium. However, the currently recommended dosage of norethindrone and dl-norgestrel greatly exceed those necessary to suppress endometrial proliferation effectively. The recommended daily dosage may be lowered without losing protective effect. This reduction will probably minimize the risk of dose-dependent progestin side effects.

Role of RNA transcripts in replication incompatibility and copy number control in antibiotic resistance plasmid derivatives

The genes required for autonomous replication and incompatibility in the antibiotic resistance plasmids R100 and R1 have been located within a 2.5-kilobase region of the 90-kilobase genome, within which the incompatibility gene occupies a 1.3-kilobase region excluding the replication origin. We now report that three RNA species are synthesized in vitro from the 2.5-kilobase region, which R100 and R1 have in common. One, a long RNA molecule which is transcribed in the direction of DNA replication, probably acts as a messenger or a protein required for plasmid replication. The second RNA species, only 91 nucleotides long, is transcribed in the opposite direction, from a region of the DNA entirely contained within the first and known to specify incompatibility and copy control functions. The third RNA species, 150 bases long, is transcribed from a region including the replication origin; it may be a primer of DNA synthesis or, in conjunction with the second of the three RNA species, an influence in the control of replication.

Genes and sites involved in replication and incompatibility of an R100 plasmid derivative based on nucleotide sequence analysis

The nucleotide sequence of the entire region required for autonomous replication and incompatibility of an R100 plasmid derivative, pSM1, has been determined. This region includes the replication region and all plasmid encoded information required for replication. Numerous reading frames for possible proteins can be found in this region. The existence of one of these proteins called RepA1 (285 amino acids; 33,000 daltons) which is encoded within the region known by cloning analysis to be required for replication is supported by several lines of evidence. These include an examination of the characteristic sequences on the proximal and distal ends of the coding region, a comparison of the sequence of the replication regions of pSM1 and the highly related R1 plasmid derivative Rsc13 as well as other biochemical and genetic evidence. The existence of two other proteins, RepA3 (64 amino acis; 7000 daltons) and RepA2 (103 amino acids; 11,400 daltons) is also consistent with most of the criteria mentioned above. However, the region encoding RepA3, which by cloning analysis is within the region responsible for both replication and incompatibility, has never been demonstrated to produce a 7,000 dalton polypeptide. Since a large secondary structure can be constructed in this region, it is possible that the region contains structure or other information that is responsible for incompatibility. RepA2, encoded entirely within the region identified by cloning analysis to be responsible for incompatibility but not for replication can be visualized in vivo and in vitro. However, the nucleotide sequence of the region encoding RepA2 is completely different in mutually incompatible plasmid derivatives of R1 and R100. It is therefore unlikely that RepA2 plays a major role in incompatibility. Thus, we predict that RepA2 is required to initiate DNA synthesis at the replication origin and that the region proximal to RepA2 either encodes a gene product or structure information that is responsible for incompatibility.