Mild obesity does not affect perinatal outcome in gestational carrier cycles.

STUDY QUESTION: Does BMI of gestational carriers (GCs) affect perinatal outcomes after embryo transfer? SUMMARY ANSWER: Overweight and class I obesity in GCs does not affect the rate of good perinatal outcomes. WHAT IS KNOWN ALREADY: The use of GCs is increasing, but uniform guidance regarding optimal BMI for GCs is lacking. Women with obesity who conceive without fertility treatment or through autologous or donor in vitro fertilization are at higher risk of adverse maternal and fetal outcomes, but data on obesity in GCs are very limited. STUDY DESIGN, SIZE, DURATION: We performed a retrospective cohort study of 1121 GC cycles from January 2015 to December 2020 at US Fertility, the largest national partnership of fertility practices in the USA. PARTICIPANTS/MATERIALS, SETTING, AND METHODS: All GC cycles performed at a large network of fertility practices were reviewed. Same-sex partners undergoing co-IVF were excluded. The primary outcome was good perinatal outcome from the first embryo transfer, defined as a singleton live birth at ≥37 weeks of gestation with birth weight between 2500 and 4000 g. Secondary outcome measures included frequencies of live birth, clinical pregnancy, miscarriage, full-term birth, low birth weight, large for gestational age, and cesarean delivery. A generalized linear model (log-binomial) was used for each to compare outcomes across BMI groups using normal BMI (20-24.9 kg/m2) as the reference group. Risk ratios and 95% CIs were estimated for each category group relative to normal BMI. MAIN RESULTS AND THE ROLE OF CHANCE: We identified 1121 cycles in which GCs underwent first embryo transfer, of which 263 (23.5%) were in GCs with BMI >30. Demographics and reproductive history for GCs did not differ by BMI groups. The age of intended parents, use of frozen eggs, and fresh embryo transfers were higher with increasing BMI group. There were no statistically significant associations between BMI and good perinatal outcomes, live birth, clinical pregnancy, biochemical, spontaneous abortion, or low birth weight. However, among live births, higher BMI was significantly associated with birth by cesarean (P = 0.015) and large for gestational age infants (P = 0.023). LIMITATIONS, REASONS FOR CAUTION: This was a retrospective study, and there may be unmeasured confounders. The number of patients with BMI <20 or ≥35 was small, limiting the power for these groups. We were not able to assess all maternal and fetal outcomes. WIDER IMPLICATIONS OF THE FINDINGS: In this study, we did not identify any significant impact of BMI on the chances of having a good perinatal outcome. Prior research studies have been inconsistent and this is the largest study to date. STUDY FUNDING/COMPETING INTEREST(S): No external funding was received for this work. The authors do not have any conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

On the formation of fold-type oscillation marks in the continuous casting of steel.

Asymptotic methods are employed to revisit an earlier model for oscillation-mark formation in the continuous casting of steel. A systematic non-dimensionalization of the governing equations, which was not carried out previously, leads to a model with 12 dimensionless parameters. Analysis is provided in the same parameter regime as for the earlier model, and surprisingly simple analytical solutions are found for the oscillation-mark profiles; these are found to agree reasonably well with the numerical solution in the earlier model and very well with fold-type oscillation marks that have been obtained in more recent experimental work. The benefits of this approach, when compared with time-consuming numerical simulations, are discussed in the context of auxiliary models for macrosegregation and thermomechanical stresses and strains.

The Bacillus subtilis genome project: aims and progress.

The members of the bacterial genus Bacillus are important organisms for both research and industrial purposes, and a major international effort is under way to sequence the complete genome of Bacillus subtilis, the type species for this genus. In this article the organization of the project is summarized; the strategies employed for cloning, sequencing and data handling; the progress to date, and the likely benefits which will accrue to basic research and to the biotechnology industry upon completion of the sequence.

Characterisation of a repressor gene (xre) and a temperature-sensitive allele from the Bacillus subtilis prophage, PBSX.

The defective prophage of Bacillus subtilis 168, PBSX, is a chromosomally based element which encodes a non-infectious phage-like particle with bactericidal activity. PBSX is induced by agents which elicit the SOS response. In a PBSX thermoinducible strain which carries the xhi1479 mutation, PBSX is induced by raising the growth temperature from 37 degrees C to 48 degrees C. A 1.2-kb fragment has been cloned which complements the xhi1479 mutation. The nucleotide sequence of this fragment contains an open reading frame (ORF) which encodes a protein of 113 amino acids (aa). This aa sequence resembles that of other bacteriophage repressors and suggests that the N-terminal region forms a helix-turn-helix motif, typical of the DNA-binding domain of many bacterial regulatory proteins. The ORF is preceded by four 15-bp direct repeats, each of which contains an internal palindromic sequence, and by sequences resembling a SigA-dependent promoter. The nt sequence of an equivalent fragment from the PBSX thermoinducible strain has also been determined. There are three aa differences within the ORF compared to the wild type, one of which lies within the helix-turn-helix segment. This ORF encodes a repressor protein of PBSX.

The project of sequencing the entire Bacillus subtilis genome.

The results obtained during the first year of the project involving the sequencing of the Bacillus subtilis genome are presented. Different gene libraries using a yeast artificial chromosome vector and bacteriophage vectors, lambda FixII and phi 105J124, have been constructed. A total of 300 kbp have been cloned using the lambda FixII vector, 68 kbp of which have been fully sequenced. Several open reading frames showing homologies with genes of other organisms were found. Two genes, previously unknown in this organism, have been identified.

Synthesis and anti-HIV activity of some haloalkyl phosphoramidate derivatives of 3'-azido-3'-deoxythymidine (AZT): potent activity of the trichloroethyl methoxyalaninyl compound.

Phosphate triester derivatives of AZT have been prepared as membrane-soluble pro-drugs of the bio-active nucleotides, and have been evaluated against HIV-1 in vitro. In particular, the phosphorus centre carries a trichloro- or trifluoroethyl group and a carboxyl-protected, amino-linked amino acid. The compounds are prepared using phosphorochloridate chemistry, and are characterized by a range of techniques. They display potent anti-HIV activity and low host toxicity, but surprisingly this activity does not increase on the introduction of the haloalkyl moiety. The trichloroethyl methoxyalaninyl compound is exceptional: here the activity is enhanced 50-fold by the introduction of the trichloroethyl group.

Aryl phosphate derivatives of AZT retain activity against HIV1 in cell lines which are resistant to the action of AZT.

Novel aryl phosphate derivatives of the anti-HIV nucleoside analogue AZT have been prepared by phosphorochloridate chemistry. These materials are designed to act as membrane-soluble pro-drugs of the bio-active free nucleotides. In vitro evaluation revealed the compounds to have a pronounced, selective antiviral activity, which, in one case, was more potent than the parent nucleoside AZT. The magnitude of the biological effect varied considerably with the nature of the phosphate-blocking group. Moreover, one of the compounds, a phosphoramidate, is particularly active in a cell line restrictive to the activity of AZT, due to poor phosphorylation therein. These data support the suggestion that the phosphate derivatives exert their biological effects via intracellular release of the nucleotide forms.

Synthesis and anti-HIV evaluation of some phosphoramidate derivatives of AZT: studies on the effect of chain elongation on biological activity.

A series of phosphoramidate derivatives of the anti-HIV drug AZT has been prepared as membrane soluble pro-drugs of the bio-active nucleotide forms and evaluated in vitro against HIV-1. Terminal substituted alkyl amines have a pronounced anti-HIV effect: this effect declines upon increasing the length of the methylene spacer. The results are consistent with a mechanism of action involving intracellular cleavage of the phosphoramidate bond, and release of the nucleotide, or a derivative thereof. Full spectroscopic data are included on the products and their phosphorochloridate precursors.

Surgical salvage after radiation for laryngeal cancer.

From January, 1962, through December, 1973, 1,084 patients with cancer of the intrinsic larynx were treated at the Mayo Clinic. Of the 1,084 patients, 136 were retreated after radiation therapy failed to cure their cancer (105 glottic, 30 supraglottic, and one subglottic cancers). Recurrence of glottic cancer was generally recognized later than recurrences in the supraglottic area; likewise, glottic cancers were more advanced at recurrence than supraglottic growths. When feasible, conservation surgery was carried out on both glottic and supraglottic growths. Unfortunately, many growths were too advanced for conservation surgery by the time recurrence was recognized. The concept of "radiate-and-watch" for early glottic and supraglottic cancers is designed to save larynges. The concept is not supported by this study.

Inverting papilloma of the nose and paranasal sinuses.

Inverting papilloma of the nose and paranasal sinuses has been classified as a true neoplasm by most authors. It is distinct from the ordinary nasal polyps in that it has a different cause, different histologic features, a higher recurrence rate, and is occasionally associated with carcinoma. This study includes 57 patients seen over a 30-year period who had inverting papilloma and for whom the history, clinical and radiologic findings, treatment methods, pathologic sections, and recurrences were analyzed. Features associated with higher recurrence rate were epithelial atypia and extent of lesions. Females showed higher recurrence rates than males. External approaches (lateral rhinotomy) reduced recurrence remarkably compared with transnasal removal (13 percent versus 45 percent). Four patients had associated carcinoma with inverting papilloma, and more extensive operations were perfomred in these cases; one patient died of the tumor. Radical aggressive treatment and careful follow-up are advocated because of the higher recurrence rate after inadequate removal and because of possible malignant transformation.

Verrucous carcinoma of the larynx.

Verrucous carcinoma, because of its oftentimes unusual clinical appearance, may be misdiagnosed if there is not good communication between the surgeon and the pathologist. We have reviewed our series of 20 cases of verrucous carcinoma from 1964 through 1974 and have analyzed the results of our therapy. We have concluded that verrucous carcinoma is a slow-growing, locally invasive lesion that does not metastasize to the cervical lymph nodes. Radiation therapy does not seem to be an effective method of treatment; the recurrence rate is high. Conservative laryngeal surgery is the preferred method of treatment in these patients and should prevent loss of life and spare laryngeal function.

The protean clinical features of polymorphic reticulosis (lethal midline granuloma).

Confusion surrounds the entity known as "lethal midline granuloma". Partly responsible is the lack of specificity in this term. "Polymorphic reticulosis" has been used as a term to describe the morphology of the disease. Thirty-two cases illustrate the protean features of this disease. Although it commonly presents in the head and neck, other sites such as the lungs, kidneys, skin, and gastrointestinal tract may be involved, either alone or in conjunction with lesions of the head and neck. Clinically, it is easily confused with Wegener's granulomatosis. Histopathologic differentiation, however, is both feasible and important. Wegener's granulomatosis is treatable with steroids with or without cyclophosphamide; polymorphic reticulosis confined to one site responds to irradiation. In polymorphic reticulosis, thhe best results of treatment are obtained in localized lesions of the upper airway treated early with irradiation; a poorer outcome is associated with multifocal involvement, which necessitates systemic therapy.

Competencies in biomechanics for the physical therapist. Suggestion for entry-level curricula.

The purpose of this paper is to identify competencies needed in the area of biomechanics for physical therapists. The discussion is divided into the following three areas: prevention of movement dysfunction, patient evaluation, and patient treatment. Clinical examples for each area are included. Physical therapists must understand normal biomechanical development, pathomechanical development, biomechanics of normal movement, and pathomechanics of the musculoskeletal system. In addition, physical therapists should be experts in biomechanics of exercise and be able to analyze biomechanically various types of activities.

Electromyographic activity recorded from an unexercised muscle during maximal isometric exercise of the contralateral agonists and antagonists.

The purpose of this study was to determine if integrated electromyographic activity recorded from an unexercised muscle during contralateral exercise was dependent upon the contralateral muscle (agonist or antagonist) being exercised and upon the position of the unexercised limb. Twenty normal subjects participated in the study. Electromyographic activity was recorded, using surface electrodes, from the right rectus femoris and the right vastus lateralis muscles during four experimental conditions. Statistical analysis revealed that 1) integrated electromyographic activity recorded from the rectus femoris muscle during contralateral, isometric exercise was not significantly influenced by the position of the unexercised knee or the exercised contralateral muscle and 2) integrated electromyographic activity recorded from the vastus lateralis muscle during contralateral, isometric exercise was significantly greater when the unexercised knee was initially positioned in 10 degrees of flexion and the contralateral agonists were exercised. Integrated electromyographic activity recorded during contralateral exercise appeared to be related to the associated movement of the unexercised limb.

Mucoepidermoid carcinoma of the oral cavity.

From 1950 through 1975, 54 patients with mucoepidermoid carcinoma of the oral cavity were treated at the Mayo Clinic. Metastatic disease occurred in 13 patients; nine patients died of their disease. Mucoepidermoid tumors of the hard palate should be treated by partial maxillectomy. Complete neck dissection is necessary for tumors larger than 2 cm in the base of the tongue. Other intraoral mucoepidermoid carcinomas are treated by wide surgical excision.

Nontraumatic, nonneoplastic subglottic stenosis.

During a 20-year period, 12 patients with nontraumatic, nonneoplastic subglottic stenosis were seen at the Mayo Clinic. The etiologic factors were relapsing polychondritis, amyloidosis, sarcoidosis, and Wegener's granulomatosis. Because of the diverse initial presentation of the disease, the clinician should consider that the stenosis is a manifestation of a systemic disorder and carry out an otolaryngologic and physical examination with the appropriate roentgenograms and blood and urine tests. Treatment, if a systemic disease is proved, consists of appropriate medication. Surgery may be necessary, depending on the nature of the lesion. Small strictures may not need to be treated.

Granular cell tumors of the larynx.

Granular cell tumors of the larynx are relatively uncommon, always benign, and most commonly located in the posterior portion of the larynx. They are easily identified and should be differentiated from other lesions. A possible problem in the differential diagnosis is the presence of pseudoepitheliomatous hyperplasia, which overlies the granular cell tumor and which may mimic squamous cell carcinoma. Careful histopathologic differentiation is important because the laryngeal granular cell lesion should be managed conservatively, with transoral local excision usually being adequate. The histogenesis of these lesions remains in doubt, with a neural or epithelial derivation being the most likely possibility.

Symposium. ENT for nonspecialists. The patient has a lump in the neck.

When a patient presents with a hard, painless lump in the neck, one should assume that it is a cancer and that it is metastatic from a primary lesion located above the clavicle. A careful physical examination with the appropriate instruments most often will determine the site of the primary lesion. Laryngograms or lateral soft-tissue roentgenograms should not be used as a substitute for visual inspection and careful examination. Examination with the patient under anesthesia is not needed unless the office examination cannot be done or a specimen from the suspected region cannot be obtained and examined microscopically in the office. Taking blind biopsies from normal-appearing mucosa is seldom worthwhile. Excisional biopsy is usually done with the patient under general anesthesia; needle biopsy is seldom used. Pathologic diagnosis by examination of frozen section is mandatory. Definitive treatment depends on the surgical and pathologic findings.