Prediction of large-for-gestational-age infant by fetal growth charts and hemoglobin A1c level in pregnancy complicated by pregestational diabetes.

OBJECTIVES: To compare the ability of three fetal growth charts (Fetal Medicine Foundation (FMF), Hadlock and National Institutes of Child Health and Human Development (NICHD) race/ethnicity-specific) to predict large-for-gestational age (LGA) at birth in pregnant individuals with pregestational diabetes, and to determine whether inclusion of hemoglobin A1c (HbA1c) level improves the predictive performance of the growth charts. METHODS: This was a retrospective analysis of individuals with Type-1 or Type-2 diabetes with a singleton pregnancy that resulted in a non-anomalous live birth. Fetal biometry was performed between 28 + 0 and 36 + 6 weeks of gestation. The primary exposure was suspected LGA, defined as estimated fetal weight ≥ 90th percentile using the Hadlock (Formula C), FMF and NICHD growth charts. The primary outcome was LGA at birth, defined as birth weight ≥ 90th percentile, using 2017 USA natality reference data. The performance of the three growth charts to predict LGA at birth, alone and in combination with HbA1c as a continuous measure, was assessed using the area under the receiver-operating-characteristics curve (AUC), sensitivity, specificity, positive predictive value and negative predictive value. RESULTS: Of 358 assessed pregnant individuals with pregestational diabetes (34% with Type 1 and 66% with Type 2), 147 (41%) had a LGA infant at birth. Suspected LGA was identified in 123 (34.4%) by the Hadlock, 152 (42.5%) by the FMF and 152 (42.5%) by the NICHD growth chart. The FMF growth chart had the highest sensitivity (77% vs 69% (NICHD) vs 63% (Hadlock)) and the Hadlock growth chart had the highest specificity (86% vs 76% (NICHD) and 82% (FMF)) for predicting LGA at birth. The FMF growth chart had a significantly higher AUC (0.79 (95% CI, 0.74-0.84)) for LGA at birth compared with the NICHD (AUC, 0.72 (95% CI, 0.68-0.77); P < 0.001) and Hadlock (AUC, 0.75 (95% CI, 0.70-0.79); P < 0.01) growth charts. Prediction of LGA improved for all three growth charts with the inclusion of HbA1c measurement in comparison to each growth chart alone (P < 0.001 for all); the FMF growth chart remained more predictive of LGA at birth (AUC, 0.85 (95% CI, 0.81-0.90)) compared with the NICHD (AUC, 0.79 (95% CI, 0.73-0.84)) and Hadlock (AUC, 0.81 (95% CI, 0.76-0.86)) growth charts. CONCLUSIONS: The FMF fetal growth chart had the best predictive performance for LGA at birth in comparison with the Hadlock and NICHD race/ethnicity-specific growth charts in pregnant individuals with pregestational diabetes. Inclusion of HbA1c improved further the prediction of LGA for all three charts. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Longitudinally-graded optical fibers.

Optical fibers have become ubiquitous tools for the creation, propagation, manipulation, and detection of light. However, while the intensity of light propagating through the fiber can increase or decrease along the length through amplification or attenuation, respectively, the properties of the fiber itself generally do not, thus removing an opportunity to further control the behavior of light and performance of fiber-based devices. Shown here are optical fibers that exhibit significant changes in their longitudinal optical properties, specifically a tailored longitudinal numerical aperture change of about 12% over less than 20 meters of length. This is about 1900 times greater than previously reported. The Brillouin gain coefficient was found to decrease by over 6 dB relative to a standard commercial single mode fiber. Next generation analogs are expected to exhibit more than a 10 dB reduction in SBS gain using larger, yet still reasonably manufacturable gradients over practical lengths.

Linkage of oxygen deficiency defects and rare earth concentrations in silica glass optical fiber probed by ultraviolet absorption and laser excitation spectroscopy.

Ultraviolet absorption measurements and laser excitation spectroscopy in the vicinity of 248 nm provide compelling evidence for linkages between the oxygen deficiency center (ODC) and rare earth concentrations in Yb and Er-doped glass optical fibers. Investigations of YAG-derived and solution-doped glass fibers are described. For both Yb and Er-doped fibers, the dependence of Type II ODC absorption on the rare earth number density is approximately linear, but the magnitude of the effect is greater for Yb-doped fibers. Furthermore, laser excitation spectra demonstrate unambiguously the existence of an energy transfer mechanism coupling an ODC with Yb(3+). Photopumping glass fibers with a Ti:sapphire laser/optical parametric amplifier system, tunable over the 225-265 nm region, or with a KrF laser at 248.4 nm show: 1) emission features in the 200-1100 nm interval attributable only to the ODC (Type II) defect or Yb(3+), and 2) the excitation spectra for ODC (II) emission at ~280 nm and Yb(3+) fluorescence (λ ~1.03 µm) to be, within experimental uncertainty, identical. The latter demonstrates that, when irradiating Yb-doped silica fibers between ~240 and 255 nm, the ODC (II) defect is at least the primary precursor to Yb(3+) emission. Consistent with previous reports in the literature, the data show the ODC (II) absorption spectrum to have a peak wavelength and breadth of ~246 nm and ~19 nm (FWHM). Experiments also reveal that, in the absence of Yb, incorporating either Al(2)O(3) or Y(2)O(3) into glass fibers has a negligible impact on the ODC concentration. Not only do the data reported here demonstrate the relationship between the ODC (II) number density and the Yb doping concentration, but they also suggest that the appearance of ODC defects in the fiber is associated with the introduction of Yb and the process by which the fiber is formed.

Silica-clad crystalline germanium core optical fibers.

Silica-clad optical fibers comprising a core of crystalline germanium were drawn using a molten core technique. With respect to previous fibers drawn using a borosilicate cladding, the present fibers exhibit negligible oxygen despite being fabricated at more than twice the melting point of the germanium. The counterintuitive result of less oxygen when the fiber is drawn at a higher temperatures is discussed. The measured propagation loss for the fiber was 0.7 dB/cm at 3.39 µm, which is the lowest loss reported to date.

Brillouin spectroscopy of YAG-derived optical fibers.

We present Brillouin spectroscopy of YAG-derived optical fibers. It is found that the addition of yttria and alumina both tend to raise the acoustic velocity when added to silica, with the change due to yttria being much weaker. The temperature-dependence of the Stokes's shift in the YAG-derived fibers is also measured, disclosing a lesser temperature dependence than conventional Ge-doped fibers. These fibers are found experimentally to have a substantially larger acoustic attenuation coefficient relative to that of bulk silica, and assuming a photoelastic constant of amorphous YAG similar to that of pure crystalline YAG, a much-reduced Brillouin gain coefficient as a result. A 40 weight percent yttria and alumina fiber has a Brillouin gain coefficient estimated to be roughly one sixth of pure silica. We also show that the addition of Er to the YAG-derived system decreases the acoustic velocity and broadens the Brillouin spectrum.

Toward a photoconducting semiconductor RF optical fiber antenna array.

Recently, optical fibers comprising a crystalline semiconductor core in a silica cladding have been successfully drawn by a conventional drawing process. These fibers are expected to exhibit a photoconductive response when illuminated by photons more energetic than the band gap of the core. In the photoconducting state, such a fiber can be expected to support driven RF currents so as to function as an antenna element, much as a plasma antenna. In this paper, we report the first device-related results on a crystalline semiconductor core optical fiber potentially useful in a photoconducting optical fiber antenna array; namely, optically induced changes to the electrical conductivity of a glass-clad germanium-core optical fiber. Since DC photoconduction measurements were masked by a photovoltaic effect, RF measurements at 5 MHz were used to determine the magnitude of the induced photoconductive effect. The observed photoconductivity, though not large in the present experiment, was comparable to that measured for the bulk crystals from which the fibers were drawn. The absorbed pumping light generated photo-carriers, thereby transforming the core from a dielectric material to a conductor. This technology could thus enable a class of transient antenna elements useful in low observable and reconfigurable antenna array applications.

Glass-clad single-crystal germanium optical fiber.

Long lengths (250 meters) of a flexible 150 microm diameter glass-clad optical fiber containing a 15 microm diameter crystalline and phase-pure germanium core was fabricated using conventional optical fiber draw techniques. X-ray diffraction and spontaneous Raman scattering measurements showed the core to be very highly crystalline germanium with no observed secondary phases. Elemental analysis confirmed a very well-defined core-clad interface with a step-profile in composition and nominally 4 weight-percent oxygen having diffused into the germanium core from the glass cladding. For this proof-of-concept fiber, polycrystalline n-type germanium of unknown dopant concentration was used. The measured infrared transparency of the starting material was poor and, as a likely outcome, the attenuation of the resultant fiber was too high to be measured. However, the larger Raman cross-section, infrared and terahertz transparency of germanium over silicon should make these fibers of significant value for fiber-based mid- to long-wave infrared and terahertz waveguides and Raman-shifted infrared light sources once high-purity, high-resistivity germanium is employed.

Silicon optical fiber.

Described herein are initial experimental details and properties of a silicon core, silica glass-clad optical fiber fabricated using conventional optical fiber draw methods. Such semiconductor core fibers have potential to greatly influence the fields of nonlinear fiber optics, infrared and THz power delivery. More specifically, x-ray diffraction and Raman spectroscopy showed the core to be highly crystalline silicon. The measured propagation losses were 4.3 dB/m at 2.936 microm, which likely are caused by either microcracks in the core arising from the large thermal expansion mismatch with the cladding or to SiO(2) precipitates formed from oxygen dissolved in the silicon melt. Suggestions for enhancing the performance of these semiconductor core fibers are provided. Here we show that lengths of an optical fiber containing a highly crystalline semiconducting core can be produced using scalable fiber fabrication techniques.

Ablative thyroid treatment for thyrotoxicosis due to thyrotropin-producing pituitary tumours.

BACKGROUND: Thyrotropin (TSH)-secreting pituitary adenomas (TSHomas) are rare tumours that can be invasive. It has been suggested that thyroid surgery or radioiodine treatment should not be considered in patients with such tumours as these treatments may facilitate rapid and aggressive tumour expansion. AIM: To study the effects of thyroid ablative treatment on tumour size and thyroid status in two patients with TSHomas in whom the size of the adenoma was clearly documented before treatment was started. METHODS: Patients studied were: (1) a female patient with a TSHoma who declined to undergo pituitary surgery and underwent a total thyroidectomy instead and (2) a male patient who opted for radioiodine treatment for his recurrent TSHoma. Changes in tumour size on serial magnetic resonance imaging scans, and restoration of euthyroidism were studied. RESULTS: No marked changes in tumour size or features of aggressiveness occurred in these patients over periods of 8 and 12 years. Euthyroidism was restored and maintained in both patients. CONCLUSIONS: Ablative thyroid treatment can be a safe and successful option to treat TSHomas, but long-term and close follow-up of these patients is mandatory to ensure that the size and behaviour of the tumours do not change markedly.

Sonographic measurement of fetal humeral soft tissue thickness in pregnancy complicated by GDM.

Sonographic measurement of fetal humeral soft tissue thickness (STT) was performed in 93 women with gestational diabetes mellitus during the third trimester. STT measurements revealed accelerated growth in large for gestational age infants at 31 wk gestation. This new measurement proved to be the most accurate predictor of excessive fetal size compared with other standard ultrasound parameters (sensitivity 82%, specificity 95%, positive predictive value 90%). Asymmetrical growth was more evident in infants with large STT measurements in utero. Humeral STT measurement may distinguish large fetuses with truncal obesity from those that are symmetrically large, thereby allowing prediction of risk for birth trauma before delivery.

17Beta-hydroxysteroid dehydrogenase type 1, 2, 3, and 4 expression and enzyme activity in human anterior pituitary adenomas.

17Beta-hydroxysteroid dehydrogenase (17betaHSD) isoforms reversibly catalyze the final step in the formation of estradiol (E2) from estrone (E1) and the formation of testosterone from androstenedione. We have investigated 17betaHSD type 1, 2, 3, and 4 gene expression and 17betaHSD estrogenic activity in human anterior pituitary adenomas. 17BetaHSD messenger ribonucleic acid (mRNA) expression was studied by RT-PCR in 42 pituitary tumors and 3 normal pituitaries, 17betaHSD activity was studied in 11 tumors and 17betaHSD type 1 was immunolocalized in vitro in 6 tumors. 17BetaHSD type 1 gene expression was detected in 34 of 42 adenomas in all tumor subtypes; 17betaHSD type 2 mRNA was detected in 18 of 42 adenomas, but not in prolactinomas; 17betaHSD type 3 mRNA was detected in 12 of 42 adenomas, but not in corticotropinomas; 17betaHSD type 4 was expressed in 20 of 42 adenomas by all adenoma subtypes. Reversible 17betaHSD activity was found in 9 of 11 adenomas, and 17betaHSD type 1 immunopositivity was cytoplasmically distributed in all 6 adenomas in vitro. All 4 17betaHSD isoforms are variably expressed in human anterior pituitary adenomas, which also show 17betaHSD enzyme activity, suggesting that 17betaHSD may play an important role in regulating the local cellular levels of estradiol.

Effects of basic fibroblastic growth factor on the function and proliferation of human clinically non-functional pituitary adenomas which secreted glycoprotein hormones in vitro.

The effects of human recombinant basic fibroblastic growth factor (bFGF) on the secretion, viability, proliferation, attachment and morphology of ten dispersed human clinically non-functional (NF) adenomas were examined in vitro. Four clinically NF adenomas secreting FSH and/or LH in vitro were unaffected by 10 nM bFGF over a 4-h period. Over 4 days 10 nM bFGF stimulated LH secretion (66% and 72%, P < 0.01) from two out of seven clinically NF adenomas secreting LH, whilst FSH (three tumours) and alpha-subunit secretion (three tumours) were unaffected. One adenoma co-secreting LH and alpha-subunit and one secreting LH alone were studied over 21 days; LH secretion fell progressively, but the decline was significantly less (P < 0.05) with bFGF (10 nM) treatment after 14 and 21 days in both adenomas, whilst the fall in alpha-subunit secretion was unaffected by bFGF treatment. A 24-h GnRH test performed at the start and end of the 21-day period in one of these tumours showed an increase in both basal and stimulated LH secretion in the bFGF-treated group over control (124%, P < 0.001). There was no effect of bFGF (10 nM) on viability, S-phase proliferation, attachment or morphology of adenoma cells over a 4-day period. These results suggest that bFGF has a role in tumorous LH secretion from these adenomas, but is not mitogenic (at least over 4 days) and is without effect on other parameters of in vitro differentiated function.

Apoptosis and p53 suppressor gene protein expression in human anterior pituitary adenomas.

Human anterior pituitary adenomas proliferate and express the p53 tumour suppressor gene protein, but it is not known if apoptosis (programmed cell death) occurs. Therefore, the detection of apoptosis was undertaken in tumorous human anterior pituitary tissue and compared with p53 protein expression, tumour type and tumour size. Apoptosis (detected by the in situ end labelling technique) and p53 suppressor gene protein (detected by DO.1-antibody immunocytochemistry) were determined in formalin-fixed and paraffin-embedded tissue from 37 human pituitary adenomas (2 macroprolactinomas, 9 somatotrophinomas and 26 non-functioning adenomas). Two normal anterior pituitaries were also included in this study. Pre-operative tumour size was scored 1 to 4 from magnetic resonance imaging radiology. Apoptosis was found in 7 of 29 tumours (24%), 11% of somatotrophinomas and 33% of non-functioning adenomas, although this difference was not significant. The p53 tumour suppressor protein was found in 7 of 31 tumours (23%), 33% of somatotrophinomas and 19% of non-functioning adenomas. Apoptosis and p53 protein expression were not found in normal anterior pituitary. In conclusion, apoptosis occurs in human anterior pituitary adenomas, but no significant association was found between apoptosis and p53 protein expression, tumour type or tumour size.

Role of prostaglandins in delayed cerebral ischemia after subarachnoid hemorrhage.

Prostaglandin E2, thromboxane B2, and 6-oxo-prostaglandin F1 alpha were assayed in blood and cerebrospinal fluid samples from patients after subarachnoid hemorrhage (SAH) and from a control population. The levels found in samples obtained from patients after SAH were compared with those found in controls and were also correlated with a number of clinical and radiological variables, many of which are either significantly associated with or represent evidence of cerebral ischemia. The levels of prostaglandin E2, thromboxane B2, and 6-oxo-prostaglandin F1 alpha in blood samples from patients after SAH and from controls were below the level of sensitivity of the assays. Levels of prostaglandin E2, thromboxane B2, and 6-oxo-prostaglandin F1 alpha in cerebrospinal fluid from patients after SAH were significantly elevated when compared with those found in control samples. There was no significant correlation, however, between the level of each prostaglandin measured and the following variables: clinical grade on admission as assessed by the Glasgow Coma Score and the World Federation of Neurological Surgeons grading system; the amount of subarachnoid blood seen on computed tomographic scan; the occurrence of ischemic deterioration; the occurrence of low density change on computed tomographic scan; the presence of vasospasm on angiography; clinical outcome as assessed by the Glasgow Coma Score 3 months after the ictus; and the incidence of ischemia as a cause of death or disability as assessed 3 months after the ictus. A primary role for prostaglandins in the etiology of delayed cerebral ischemia after SAH is not therefore confirmed.

Vascular malformation simulating a glioma on computerized tomography. Case report.

A patient with an arteriovenous malformation and giant venous aneurysm was erroneously diagnosed as having an oligodendroglioma on computerized tomography (CT). This case highlights some of the problems of interpretation of CT scans and the dangers of misinterpretation, particularly in the surgical context.

Shunt catheter impacted in the vena cava. Case report.

A shunt-dependent patient had an atrial catheter firmly adherent in the superior vena cava. Thoracotomy was required for its removal.

A comparison of proliferation indices in human anterior pituitary adenomas using formalin-fixed tissue and in vitro cell culture.

The authors compared detection methods for cell proliferation in human anterior pituitary adenomas using histological sections and dispersed cell culture. After tumor cells had been grown for 4 days in dispersed culture, bromodeoxyuridine (BUdR), proliferating cell nuclear antigen (PCNA), and Ki-67 were compared by double immunostaining and contrasted with single staining of PCNA and Ki-67 indices in the corresponding histological sections from 12 human pituitary adenomas. In vitro, the BUdR labeling index was positive in six of 12 tumors (range < 0.1-5.1%), 10 of 12 tumors were PCNA-positive (range < 0.1-100%), and Ki-67 was positive in 10 of 12 adenomas (range < 0.1-8%). In vitro, BUdR and Ki-67 gave similar proliferative indices for 10 of 12 adenomas. In vivo, the PCNA labeling index was positive in 12 of 12 adenomas (range 0.9-95%) and Ki-67 was positive in 11 of 12 adenomas (range < 0.1-2%). Tumors with a labeling index less than 0.1% were considered to be negative for proliferation. High PCNA values were found in vitro and in vivo, whereas Ki-67 labeling indices were similar in vitro and in vivo for nine of 12 adenomas. It is concluded that Ki-67 proliferative indices in vivo reflect those found in vitro, at least after 4 days in dispersed culture, but that PCNA overestimates pituitary adenoma proliferation in histological sections as well as in dispersed culture.

Dipyridamole and postoperative ischemic deficits in aneurysmal subarachnoid hemorrhage.

Recent evidence has suggested that the delayed cerebral ischemic deficits that often follow surgery for aneurysmal subarachnoid hemorrhage (SAH) may be due to a proliferative vasculopathy. This vascular pathology may result from an interaction between the platelets and the vessel wall. A single-blind controlled trial of dipyridamole administration in 677 patients presenting with SAH (of whom 348 came to surgery) was undertaken to test the hypothesis that the modification of platelet behavior might reduce the incidence of ischemic deficits. Blind independent assessment of the outcome in the surgical group based on the Glasgow Outcome Scale and the specific neurological deficits revealed no significant differences between the control and treatment groups.

Report of a controlled clinical trial comparing automated percutaneous lumbar discectomy and microdiscectomy in the treatment of contained lumbar disc herniation.

STUDY DESIGN: The results of a randomized controlled trial comparing automated percutaneous lumbar discectomy (APLD) with lumbar microdiscectomy for the treatment of small contained lumbar discal herniations are reported. All patients gave full informed consent and were assessed by an independent observer. Seventy-one patients with radiologically confirmed small contained lumbar disc herniations were randomly assigned to undergo either APLD or lumbar microdiscectomy. All patients were formally assessed by the independent assessor using the Macnab outcome classification at 3 weeks, 2 months, and 6 months after the procedure with follow-up being continued for the duration of the study. OBJECTIVE: The objective was to complete the first randomized and blinded study with sufficient numbers to provide a valid statistical evaluation of these procedures. SUMMARY OF BACKGROUND DATA: No previous randomized controlled study comparing these methods has been previously reported. METHODS: Each procedure was performed by the same surgeon using standard techniques. Statistical analysis was by the chi-square method. RESULTS: In the APLD group only 9 of 31 (29%) had satisfactory outcomes as compared to 32 of 40 (80%) for the microdiscectomy group. Of those patients in the APLD group who had an unsatisfactory outcome and who then opted to undergo surgery (20 of 22 patients), the final success rate was only 65%. Thus, the cumulative success rate of the group initially randomized to APLD including those undergoing either APLD alone or APLD and microdiscectomy after unsuccessful APLD was 22 of 31 (71%). CONCLUSION: In this group of patients, APLD is seen to be ineffective in the treatment of contained lumbar disc herniation.

Vestibular schwannomas in children.

OBJECTIVE: This article highlights the clinical presentation and management issues of unilateral vestibular schwannomas in children. We demonstrate how the presentation differs from neurofibromatosis type 2 (NF2) and from adult unilateral vestibular schwannomas. STUDY DESIGN: This article is composed of a series of three cases and a literature review. SETTING: The study was performed at a university hospital (tertiary referral center). PATIENTS: Three children, aged 9, 11, and 13 years, with histologically confirmed vestibular schwannomas were studied. All children under 16 years of age in the world literature with unilateral vestibular schwannomas were reviewed. INTERVENTION: Analysis of presentation and surgical management of these three children and those children reported in the literature. MAIN OUTCOME MEASURE: Pattern of presentation relative to children with NF2 and people with adult unilateral vestibular schwannomas. RESULTS: Two patients had multiple cranial nerve weakness and recurrence, and one patient had successful removal of the tumor with preservation of all functions of the cranial nerves, including the facial nerve. CONCLUSION: Vestibular schwannomas in children are very uncommon. It is likely that it is the first manifestation of NF2, but it may also be a variant of sporadic vestibular schwannomas. A presentation of three cases and a review of 36 other cases in the literature demonstrates how the presentation is different from adult sporadic vestibular schwannomas and NF2 because it lacks primary audiological symptoms. The study also provides evidence of non-NF2 vestibular schwannomas presenting in children and suggests that it is likely that these are a variant of unilateral sporadic vestibular schwannomas. The search for the features of NF2 in these cases remains mandatory.