Induced luteolysis in the primate: rapid loss of luteinizing hormone receptors

The molecular mechanisms involved in luteolysis are still unclear in the primate. This study aimed to investigate the effect of induced luteolysis on the ovarian luteinizing hormone (LH) receptor and the steroidogenic enzyme, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in the marmoset monkey. Luteolysis was induced in the mid-luteal phase either directly by systemic prostaglandin F2alpha (PGF2alpha), or indirectly by LH withdrawal using systemic gonadotrophin releasing hormone antagonist (GnRHant) treatment. The LH receptor was studied by isotopic mRNA in-situ hybridization and in-situ ligand binding and 3beta-HSD expression was studied using isotopic mRNA in-situ hybridization and immunohistochemistry. Induced luteolysis was associated with a reduction in the expression of LH receptor (P < 0.0001) and 3beta-HSD mRNA, closely followed by a reduction in the LH receptor (P < 0.05) and 3beta-HSD protein concentrations within 24 h. There were no differences in the findings whether luteolysis was induced with PGF2alpha or GnRHant. This study shows that disparate mechanisms to induce luteolysis in the primate result in an identical rapid loss of the LH receptor and 3beta-HSD. In conclusion, induced luteolysis leads to rapid loss of the steroidogenic pathway in luteal cells.      

X-linked liver glycogenosis type II (XLG II) is caused by mutations in PHKA2, the gene encoding the liver alpha subunit of phosphorylase kinase

X-linked liver glycogenosis type II (XLG II) is a recently described X- linked liver glycogen storage disease, mainly characterized by enlarged liver and growth retardation. These clinical symptoms are very similar to those of XLG I. In contrast to XLG I patients, however, XLG II patients do not show an in vitro enzymatic deficiency of phosphorylase kinase (PHK). Recently, mutations were identified in the gene encoding the liver alpha subunit of PHK (PHKA2) in XLG I patients. We have now studied the PHKA2 gene of four unrelated XLG II patients and identified four different mutations in the open reading frame, including a deletion of three nucleotides, an insertion of six nucleotides and two missense mutations. These results indicate that XLG II is due to mutations in PHKA2. In contrast to XLG I, XLG II is caused by mutations that lead to minor structural abnormalities in the primary structure of the liver alpha subunit of PHK. These mutations are found in a conserved RXX(X)T motif, resembling known phosphorylation sites that might be involved in the regulation of PHK. These findings might explain why the in vitro PHK enzymatic activity is not deficient in XLG II, whereas it is in XLG I.      

Optical Manipulation of Objects and Biological Cells in Microfluidic Devices

In this paper, we review optical techniques used for micro-manipulation of small particles and cells in microfluidic devices. These techniques are based on the object's interaction with focused laser light (consequential forces of scattering and gradient). Inorganic objects including polystyrene spheres and organic objects including biological cells were manipulated and switched in and between fluidic channels using these forces that can typically be generated by vertical cavity surface emitting laser (VCSEL) arrays, with only a few mW optical powers. T-, Y-, and multi-layered X fluidic channel devices were fabricated by polydimethylsiloxane (PDMS) elastomer molding of channel structures over photolithographically defined patterns using a thick negative photoresist. We have also shown that this optical manipulation technique can be extended to smaller multiple objects by using an optically trapped particle as a handle, or an optical handle. Ultimately, optical manipulation of small particles and biological cells could have applications in biomedical devices for drug discovery, cytometry and cell biology research.     

Reduced oxidative function in gingival crevicular neutrophils in periodontal disease.

Measurable amounts of viable and functional polymorphonuclear neutrophils (PMNs) are recovered from pooled washings of the gingival crevice of healthy individuals. In the present study, we have assessed the ability of the PMNs removed from single healthy or diseased pocket sites to mount an oxidative burst when challenged with phorbol myristate acetate (PMA) and compared these activities with each other and with those obtained with autologous peripheral-blood PMNs. The oxidative burst after PMA stimulation was evaluated by using methods developed for the flow cytometer. The results showed that the PMNs collected from untreated disease sites were minimally responsive to PMA when compared with peripheral-blood PMNs collected at the same time from the same individual. Thus, whereas the peripheral-blood PMNs exhibited significantly lower resting oxidative product formation and a 500% increase when stimulated with PMA, all gingival-crevicular PMNs exhibited significantly higher resting formation of oxidized products but only a 150% increase after PMA stimulation. PMNs obtained from a consistently healthy site had significantly higher resting production of oxidized products and were able to mount the greatest absolute increase in oxidized products after PMA stimulation when compared with PMNs collected from diseases sites. Mechanical debridement of these diseased sites, which both reduced the bacterial numbers and restored clinical health, resulted in the recovery of gingival-crevicular PMNs that exhibited an oxidative burst more typical of that observed in PMNs obtained from healthy gingival sites and from the peripheral blood. This suggested that the PMNs collected from the diseased sites either had been exhausted by the large numbers of bacteria present in these sites or had been specifically inhibited by these bacteria.     

Bacteriocins from Neisseria gonorrhoeae and their possible role in epidemiological studies

Although no consistent results can be demonstrated when freshly isolated strains of Neisseria gonorrhoeae are tested for bacteriocin activity on chocolate blood agar, such activity can be demonstrated on GC base medium (Difco), enriched with a defined supplement. At the present time, using six indicator strains, 75% of isolates of N. gonorrhoeae show characteristic patterns of inhibition. These observations are encouraging and suggest that ;gonocin' typing may be possible.     

Epidermal lipid in several cetacean species: ultrastructural observations

The ultrastructure of the skin of four cetacean species, bottlenose dolphin (Tursiops truncatus) long-finned pilot whale (Globicephala melaena), humpback whale (Megaptera novaeangliae), and fin whale (Balaenoptera physalus) was investigated with particular reference to epidermal lipid. It has already been established that massive lipid reservoirs exist in whales, that the biochemical structures of cetacean lipids are unique, and that unusual intracellular lipid droplets appear in the epidermis. We report here some novel findings on scanning electron microscopic morphology of epidermal lipid, and on its ultrastructural morphology in general and specialized integumentary sites, including species not previously investigated. The intracellular epidermal lipid droplets were more extensive than lamellar body-derived intercellular lipid which is within the interstices of stratum externum cells. The intracellular droplets were spherical, highly variable in size ranging from 0.24 m to 3.0 m in diameter, appeared singly or were aggregated in cytoplasmic cavitations, and often were closely associated with epidermal cell nuclei. Evidence for exocytosis of the intracellular droplets was not observed. Significant numbers of intracellular lipid droplets are not observed in the epidermis of terrestrial mammals, so their presence is one of several aquatic specializations of the cetacean integument. Its full significance remains obscure, but it is more probably associated with epidermal cell metabolism than with secretion of lipid.     

Continuous Glucose Monitoring Use in Clinical Trials for On-Market Diabetes Drugs

To the best of our knowledge, there are no published data on the historical and recent use of CGM in clinical trials of pharmacological agents used in the treatment of diabetes. We analyzed 2,032 clinical trials of 40 antihyperglycemic therapies currently on the market with a study start date between 1 January 2000 and 31 December 2019. According to ClinicalTrials.gov, 119 (5.9%) of these trials used CGM. CGM usage in clinical trials has increased over time, rising from <5% before 2005 to 12.5% in 2019. However, it is still low given its inclusion in the American Diabetes Association’s latest guidelines and known limitations of A1C for assessing ongoing diabetes care.

The availability of reliable continuous glucose monitoring (CGM) systems has proven to be a major innovation in diabetes management and research. Most current CGM systems are approved for 7- to 14-day use and use a wire-tipped glucose oxidase sensor inserted in subcutaneous tissue to monitor glucose concentrations in interstitial fluid. One implanted CGM system is approved for longer-term use (90–180 days); it operates with fluorescence-based technology. CGM sensors record a glucose data point every 1–15 minutes (depending on the system), collecting far more granular data and information on glycemic patterns than self-monitoring of blood glucose (SMBG) alone. Real-time CGM or intermittently scanned CGM systems send data continuously or intermittently to dedicated receivers or smartphones, whereas professional CGM systems provide retrospective data, either blinded or unblinded, for analysis and can be used to identify patterns of hypo- and hyperglycemia. Professional CGM can be helpful to evaluate patients when other CGM systems are not available to the patient or the patient prefers a blinded analysis or a shorter experience with unblinded data.In the 20 years since CGM systems first became available to people with diabetes, technological improvements, particularly pertaining to accuracy and form factor, have made CGM increasingly viable for both patient use and clinical investigation (1,2). Average sensor MARD (mean absolute relative difference; a summary accuracy statistic) has decreased from >20 to <10% (3–10), including two systems that do not require fingerstick calibrations and three that are approved to be used for insulin dosing (11). Concurrently, size, weight, and cost of CGM systems have all decreased, while user-friendliness and convenience have increased (12).To encourage use of CGM-derived data, researchers and clinicians have worked to develop a standard set of glycemic metrics beyond A1C. In 2017, two international groups of leading diabetes clinical and research organizations published consensus definitions for key metrics, including clinically relevant glycemic cut points for hypoglycemia (<70 and <54 mg/dL), hyperglycemia (>180 and >250 mg/dL), and time in range (TIR; 70–180 mg/dL) (13,14).CGM-derived metrics provide far greater precision and granularity than is possible with SMBG or A1C data alone (Table 1), enabling clinicians and investigators to better represent inter- and intraday glycemic differences with metrics such as TIR, glycemic variability, and time in hypoglycemia and hyperglycemia (15). Crucially, CGM also allows for the accurate measurement and detection of nocturnal glycemia (16). The use of these metrics enables a more comprehensive understanding of glycemic management that can facilitate individualized treatment for people with diabetes or prediabetes. Although A1C is a useful estimate of mean glucose over the previous 2–3 months, especially when evaluating population health, it is important to include other glycemic outcomes in clinical trials. Furthermore, there is emerging evidence suggesting that TIR predicts the development of microvascular complications at least as well as A1C (17,18).TABLE 1Benefits of CGM Compared With A1C Alone in Assessing Glycemia

A screening study of antidepressant treatment rates and mood symptoms in pregnancy

Summary Study design: As part of a large screening study of perinatal depression, pregnant women were screened for demographic, depression and treatment variables in obstetrics clinics. Women taking antidepressant medication prior to conception were included in the sample as the study aimed to document rates of antidepressant medication use, and relationship to depressive symptomatology.Results: Among women who reported using antidepressant medications within 2 years prior to screening (n = 390, or 11% of all women), 22% reported current use of these medications. Women who reported using antidepressant medications (52%) and those who discontinued them (49%) evidenced elevated depressive symptoms during pregnancy.Conclusions: Both women who discontinue and some who continue antidepressants during pregnancy demonstrate depressive symptoms, suggesting sub-optimal management of both groups. Future studies should carefully assess the adequacy of treatments prescribed as well as the monitoring and adherence of recommended treatments. Full symptom remission should be the goal for antenatal and postnatal depression in order to minimize risk to mother and baby.     

Characterization of the Mycobacterium bovis restriction fragment length polymorphism DNA probe pUCD and performance comparison with standard methods

In this study, the newly described Mycobacterium bovis restriction fragment length polymorphism (RFLP) typing probe pUCD was characterized by sequence analysis and the previously observed polymorphic banding pattern was reproduced with a combination of three oligonucleotide probes in a single, mixed hybridization. In addition, the ability of pUCD to distinguish between 299 M. bovis isolates from the Republic of Ireland was assessed in relation to established methods and a statistical function for objective comparison of RFLP probes was derived. It was found that typing with pUCD alone produced greater discrimination between M. bovis isolates than typing with the commonly used mycobacterial DNA probes IS6110, PGRS, and DR and also by the spoligotyping technique. pUCD and DR in combination produced the highest level of discrimination while maintaining a high level of concordance with known epidemiological data relating to the samples. The reduction of pUCD to the level of oligonucleotides should in future allow pUCD and DR to be included together in a mixed hybridization, thus producing a high level of M. bovis strain type discrimination from a single round of RFLP analysis.