Brolucizumab as treatment of wet age-related maculopathy.

Given the success in stabilizing vision with current anti-vascular endothelial growth factor (VEGF) options, one main target for future anti-VEGF drug development includes creating medications with longer durations of action. Achieving this goal will decrease the number of overall injections and follow-up visits required to ensure better patient compliance. The smallest anti-VEGF created so far is brolucizumab (Beovu; Novartis). It is a 26-kDa IgG single-chain antibody fragment that delivers 11 times more anti-VEGF per injection than aflibercept. Brolucizumab was approved by the U.S. Food and Drug Administration (FDA) in late 2019 for the treatment of wet age-related macular degeneration, and has been also approved for the same indication in Japan and the European Union in 2020. In this article, we compare brolucizumab to current FDA-approved anti-VEGF treatments, address the studies associated with brolucizumab, discuss brolucizumab's side effects, and conclude with recommendations.

Common side closure type, but not stapler brand or oversewing, influences side-to-side anastomotic leak rates.

BACKGROUND: Anastomotic leak (AL) increases costs and cancer recurrence. Studies show decreased AL with side-to-side stapled anastomosis (SSA), but none identify risk factors within SSAs. We hypothesized that stapler characteristics and closure technique of the common enterotomy affect AL rates. METHODS: Retrospective review of bowel SSAs was performed. Data included stapler brand, staple line oversewing, and closure method (handsewn, HC; linear stapler [Barcelona technique], BT; transverse stapler, TX). Primary endpoint was AL. Statistical analysis included Fisher's test and logistic regression. RESULTS: 463 patients were identified, 58.5% BT, 21.2% HC, and 20.3% TX. Covidien staplers comprised 74.9%, Ethicon 18.1%. There were no differences between stapler types (Covidien 5.8%, Ethicon 6.0%). However, AL rates varied by common side closure (BT 3.7% vs. TX 10.6%, p = 0.017), remaining significant on multivariate analysis. CONCLUSION: Closure method of the common side impacts AL rates. Barcelona technique has fewer leaks than transverse stapled closure. Further prospective evaluation is recommended.

Large scrotal hernia: a complicated case of mesh migration, ascites, and bowel strangulation.

A 30-year-old male with 1 1/2-year history of an asymptomatic, large, reducible right indirect scrotal hernia presented to the emergency department complaining of a 2-week history of increasing abdominal distension and daily emesis. He had recently undergone an emergent exploratory laparotomy in which his asymptomatic hernia was repaired with a mesh plug from an intra-abdominal approach. The mesh plug subsequently migrated into the patient's scrotum resulting in a strangulating bowel obstruction. This paper discusses a serious complication that may result from inappropriate use and placement of a mesh plug and our approach to correct the situation utilizing a bioabsorbable mesh prosthesis.

Transgenic analysis of the Smad family of TGF-beta signal transducers in Drosophila melanogaster suggests new roles and new interactions between family members.

Smad signal transducers are required for transforming growth factor-beta-mediated developmental events in many organisms including humans. However, the roles of individual human Smad genes (hSmads) in development are largely unknown. Our hypothesis is that an hSmad performs developmental roles analogous to those of the most similar Drosophila Smad gene (dSmad). We expressed six hSmad and four dSmad transgenes in Drosophila melanogaster using the Gal4/UAS system and compared their phenotypes. Phylogenetically related human and Drosophila Smads induced similar phenotypes supporting the hypothesis. In contrast, two nearly identical hSmads generated distinct phenotypes. When expressed in wing imaginal disks, hSmad2 induced oversize wings while hSmad3 induced cell death. This observation suggests that a very small number of amino acid differences, between Smads in the same species, confer distinct developmental roles. Our observations also suggest new roles for the dSmads, Med and Dad, in dActivin signaling and potential interactions between these family members. Overall, the study demonstrates that transgenic methods in Drosophila can provide new information about non-Drosophila members of developmentally important multigene families.

Of mice and men and elephants: metabolic rate sets glomerular filtration rate.

Allometric scaling deals with the functional consequences of changes in size or scale among geometrically dissimilar animals (ie, animals differing in proportions). For adult mammals ranging in size and proportion from mouse to elephant, the data describe an interdependent set of functions consisting of metabolism (measured as metabolic rate), glomerular filtration rate (GFR), effective renal plasma flow, excretion of nitrogenous waste products, cardiac output, and pulmonary function-related variables. Within this set of functions, evidence indicates that metabolic rate is the primary process. One important design feature is given by the ratio of GFR to metabolic rate. Because this ratio is independent of size, it can be generalized to all mammals in this series. The numeric value of this ratio gives the optimal GFR for each unit of metabolic rate. A simple hypothesis is proposed: metabolic rate, the primary process, sets GFR. This relationship is unidirectional. A decrease in GFR, for example, caused by nephron loss, should not lead to a change in metabolic rate. This hypothesis was tested in four natural experiments: human growth and development, thyroid dysfunction, chronic renal failure, and hibernation. The results are consistent with this hypothesis.

Ammonia functions as a regulatory molecule to mediate adjustments in glomerular filtration rate in response to changes in metabolic rate.

In mammals, varying in size from mouse to elephant there is a close linkage between metabolic rate (MR) and glomerular filtration rate (GFR). This linkage has evolved because of the necessity to excrete nitrogenous wastes generated predominately by amino acid catabolism. A similar linkage is observed in birds, reptiles and fish, although in the latter vertebrate group gill excretion rate and GFR need to be considered as an interdependent co-ordinated system. A change in the rate of amino acid catabolism will result in a change in the rate of production of nitrogenous wastes requiring excretion and hence GFR (or GFR plus gill excretory rate in fish) must be appropriately re-set. It is hypothesized that ammonia functions as a regulatory molecule to mediate adjustments in excretory rate (GFR or GFR plus gill excretory rate) in response to such changes in amino acid catabolism.

Crossveinless 2 contains cysteine-rich domains and is required for high levels of BMP-like activity during the formation of the cross veins in Drosophila.

The BMP-like signaling mediated by the ligands Dpp and Gbb is required to reinforce the development of most veins in the Drosophila wing. However, the formation of the cross veins is especially sensitive to reductions in BMP-like signaling. We show here that the formation of the definitive cross veins occurs after the initial specification of the longitudinal veins in a process that requires localized BMP-like activity. Since Dpp and Gbb levels are not detectably higher in the early phases of cross vein development, other factors apparently account for this localized activity. Our evidence suggests that the product of the crossveinless 2 gene is a novel member of the BMP-like signaling pathway required to potentiate Gbb of Dpp signaling in the cross veins. crossveinless 2 is expressed at higher levels in the developing cross veins and is necessary for local BMP-like activity. The Crossveinless 2 protein contains a putative signal or transmembrane sequence, and a partial Von Willebrand Factor D domain similar to those known to regulate the formation of intramolecular and intermolecular bonds. It also contains five cysteine-rich domains, similar to the cysteine-rich domains found in Chordin, Short Gastrulation and Procollagen that are known to bind BMP-like ligands. These features strongly suggest that Crossveinless 2 acts extracelluarly or in the secretory pathway to directly potentiate Dpp or Gbb signaling.

Mouse to elephant: biological scaling and Kt/V.

The construct Kt/V is used by the nephrology community in prescribing dialysis dose. The concerns that have been raised as to what value of V to use in the calculation of Kt/V touch on the more central question of whether filtration rate should be normalized by a parameter other than V. Within the animal kingdom, a number of physiological variables scale to body size according to an equation of the form Y = YoMb, where Yo is a constant, M is body mass, and b is a scaling exponent. Glomerular filtration rate (GFR) in mammals weighing from 30 g to 503 kg scales to body weight with an exponent of 0.77. Hence, GFR per unit body weight (or Kt/V) decreases significantly with increasing body size. Metabolic rate also scales to body size in a wide range of mammals according to the same general equation and with a scaling exponent of 0.75. Because GFR and metabolic rate scale to body mass with virtually the same exponent, a ratio of the two yields a constant independent of body size. We propose that the ratio (filtration rate/metabolic rate) replace Kt/V. Such a ratio would underscore the linkage between filtration rate (and dialysis therapy) and the metabolic demands of the body.

Maturation of the tyrosine kinase c-src as a kinase and as a substrate depends on the molecular chaperone Hsp90.

Although Hsp90 displays general chaperone activity in vitro, few substrates of the chaperone have been identified in vivo, and the characteristics that render these substrates dependent on Hsp90 remain elusive. To investigate this issue, we exploited a paradoxical observation: several unrelated oncogenic viral tyrosine kinases, including v-src, attain their native conformation after association with Hsp90, yet their nearly identical cellular homologs interact only weakly with the chaperone. It has been controversial whether Hsp90 is vital for normal maturation of the cellular kinases or is simply binding a misfolded subfraction of the proteins. By modulating Hsp90 levels in Saccharomyces cerevisiae, we determined that Hsp90 is indeed necessary for the maturation of c-src (the normal homolog of v-src). c-src maturation is, however, less sensitive to Hsp90 perturbations than is v-src maturation. Dependence of the two proteins on Hsp90 does not correspond to their relative efficiency in reaching their final destination (the plasma membrane); we observed that in yeast, unlike in vertebrate cells, neither c-src nor v-src concentrate in the membrane. Expression of different v/c-src chimeras in cells carrying wild-type or temperature-sensitive Hsp90 alleles revealed that the difference between the proteins instead arises from multiple, naturally occurring mutations in the C-terminal region of v-src.

Physical functioning and mental health in patients with chronic medical conditions.

There is evidence to suggest that a decline in physical functioning with advancing age is independent of mental health, which appears to remain relatively stable. There is additional evidence to suggest that those with a chronic disease also experience a decline in physical function while the mental health remains relatively stable. Using a cross-sectional design, data from the US population norms for the Medical Outcomes Study SF-36 are examined and compared to SF-36 data collected for four patient groups. Patient groups include kidney dialysis patients, multiple sclerosis patients, kidney transplant patients and patients with severe osteoarthritis of the hip prior to total hip replacement. Overall scores and scores within 10-year age groupings are examined in order to compare the physical functioning and mental health scores of the general population with those of the four patient groups. Results support the hypothesis that physical functioning declines with advancing age and with the development of chronic disease, but mental health remains remarkably stable regardless of chronic disease and/or advancing age. This observation suggests a process of psychological adjustment or adaptation to the physical difficulties encountered with advanced age or disability, and implies that this adjustment process may in fact be quite strong.

Thermotolerance in Saccharomyces cerevisiae: the Yin and Yang of trehalose.

Trehalose, a sugar produced by a wide variety of organisms, has long been known for its role in protecting certain organisms from desiccation. Recent work in yeast indicates that trehalose also promotes survival under conditions of extreme heat, by enabling proteins to retain their native conformation at elevated temperatures and suppressing the aggregation of denatured proteins. The latter property, however, seems to impair the recovery of cells from heat shock if they fail to degrade trehalose after the stress has passed. These multiple effects of trehalose on protein stability and folding suggest a host of promising applications.

Multiple effects of trehalose on protein folding in vitro and in vivo.

The disaccharide trehalose is produced in large quantities by diverse organisms during a variety of stresses. Trehalose prevents proteins from denaturing at high temperatures in vitro, but its function in stress tolerance in vivo is controversial. We report that trehalose stabilizes proteins in yeast cells during heat shock. Surprisingly, trehalose also suppresses the aggregation of denatured proteins, maintaining them in a partially-folded state from which they can be activated by molecular chaperones. The continued presence of trehalose, however, interferes with refolding, suggesting why it is rapidly hydrolyzed following heat shock. These findings reconcile conflicting reports on the role of trehalose in stress tolerance, provide a novel tool for accessing protein folding intermediates, and define new parameters for modulating stress tolerance and protein aggregation.

Mothers against dpp participates in a DDP/TGF-beta responsive serine-threonine kinase signal transduction cascade.

Mothers against dpp (Mad) is the prototype of a family of genes required for signaling by TGF-beta related ligands. In Drosophila, Mad is specifically required in cells responding to Decapentaplegic (DPP) signals. We further specify the role of Mad in DPP-mediated signaling by utilizing tkvQ199D, an activated form of the DPP type I receptor serine-threonine kinase thick veins (tkv). In the embryonic midgut, tkvQ199D mimics DPP-mediated inductive interactions. Homozygous Mad mutations block signaling by tkvQ199D. Appropriate responses to signaling by tkvQ199D are restored by expression of MAD protein in DPP-target cells. Endogenous MAD is phosphorylated in a ligand-dependent manner in Drosophila cell culture. DPP overexpression in the embryonic midgut induces MAD nuclear accumulation; after withdrawal of the overexpressed DPP signal, MAD is detected only in the cytoplasm. However, in three different tissues and developmental stages actively responding to endogenous DPP, MAD protein is detected in the cytoplasm but not in the nucleus. From these observations, we discuss possible roles for MAD in a DPP-dependent serine-threonine kinase signal transduction cascade integral to the proper interpretation of DPP signals.

Signaling through both type I DPP receptors is required for anterior-posterior patterning of the entire Drosophila wing.

The imaginal disk expression of the TGF-beta superfamily member DPP in a narrow stripe of cells along the anterior-posterior compartment boundary is essential for proper growth and patterning of the Drosophila appendages. We examine DPP receptor function to understand how this localized DPP expression produces its global effects upon appendage development. Clones of saxophone (sax) or thick veins (tkv) mutant cells, defective in one of the two type I receptors for DPP, show shifts in cell fate along the anterior-posterior axis. In the adult wing, clones that are homozygous for a null allele of sax or a hypomorphic allele of tkv show shifts to more anterior fates when the clone is in the anterior compartment and to more posterior fates when the clone is in the posterior compartment. The effect of these clones upon the expression pattern of the downstream gene spalt-major also correlates with these specific shifts in cell fate. The similar effects of sax null and tkv hypomorphic clones indicate that the primary difference in the function of these two receptors during wing patterning is that TKV transmits more of the DPP signal than does SAX. Our results are consistent with a model in which a gradient of DPP reaches all cells in the developing wing blade to direct anterior-posterior pattern.

Impact of portable APD on patient perception of health-related quality of life.

We assessed the impact of the introduction of a portable automated peritoneal dialysis (APD) system (Homechoice, Baxter Healthcare) on health-related quality of life (HRQOL). We evaluated HRQOL in 26 patients using the RAND 36-item Health Survey 1.0, which measures physical functioning, role limitations (physical and emotional), social functioning, emotional well-being, pain, energy, and general health perceptions. Questionnaires were administered prior to changing to the new system and 3 months later. Kt/V and albumin levels were measured at both time points. Eight patients had been on continuous ambulatory peritoneal dialysis (CAPD), and 18 had been using other APD systems (PacXtra, Baxter and AMP80, Fresenius). Kt/V increased significantly (p = 0.026); albumin was unchanged (p = 0.09). There was an improvement in the pain score (p = 0.079), although this did not reach statistical significance in the overall sample. Subgroup analysis showed that most of the improvement was from the group that had used the AMP80. No other statistically significant differences were found overall in the domains of HRQOL. Questioning of a random sample of patients indicated that perceived advantages of the new system were ease of setup and portability within the home. Neither of these translated into improvement in role-functioning domains of HRQOL. The improvement in pain score may reflect the capacity of newer cyclers to switch from drain to fill after a set proportion of dialysate has drained, leaving the patient empty for less of the time. Portable APD systems did not bring about predicted improvements in HRQOL. The HRQOL instrument may be insensitive, but technologically convenient advances may have limited impact on HRQOL due to its multifactorial nature.

Quantity of dialysis: quality of life--what is the relationship?

Health related quality of life (HRQOL) is increasingly being used to evaluate physical and psychosocial parameters in patients receiving dialysis. In patients with chronic illness, these indices are important adjuncts to biochemical measurements. Inadequate dialysis with low urea clearance (Kt/Vurea) has been linked to adverse outcomes in dialysis patients. Little is known about the relationship between dialysis adequacy and patient reported HRQOL. We evaluated HRQOL in 55 hemodialysis and 60 peritoneal dialysis patients using the RAND 36 Item Health Survey 1.0, measuring the following: physical functioning; role limitations (physical); role limitations (emotional); social functioning; emotional well being; pain; energy; and general health perceptions. Kt/V was also calculated for each patient. Mean HD Kt/V was 1.44 +/- 0.31 (range, 0.5-2.0); mean weekly PD Kt/V was 2.28 +/- 0.90 (range, 1.13-6.02). The relationship between Kt/V and HRQOL was tested using Pearson's correlation. No significant association was found for either treatment group between Kt/V and any of the domains of HRQOL. Thus, HRQOL seems to be influenced by factors other than dialysis adequacy, enhancing its role as an independent measure of patient problems otherwise undetected by traditional objective parameters.

HSP100/Clp proteins: a common mechanism explains diverse functions.

The HSP100/Clp proteins are a newly discovered family with a great diversity of functions, such as increased tolerance to high temperatures, promotion of proteolysis of specific cellular substrates and regulation of transcription. HSP100/Clp proteins are also synthesized in a variety of specific patterns and, in eukaryotes, are localized to different subcellular compartments. Recent data suggest that a common ability to disassemble higher-order protein structures and aggregates unifies the molecular functions of this diverse family.

Self-delivery of hemodialysis care: a therapy in itself.

Patient autonomy, sense of control, and well-being are thought to be enhanced by self-care hemodialysis as a therapy for end-stage renal disease. Dialysis in a satellite setting reduces travel time and can diminish therapy intrusiveness. Health-related quality of life (HRQOL), in terms of functional status and well-being, was measured in a group of patients trained for self-care, and then measured again after these patients were transferred to a satellite unit. Comparison was made with an age- and comorbidity-matched cohort of full-care patients. Patients trained for self-care tended to score higher than the full-care patients in the psychosocial domains of HRQOL, such as role function, social function, and emotional well-being, before and after transfer to the satellite unit. Physiological measurements did not differ significantly between groups at any time during the study, indicating that differences in HRQOL were not attributable to differences in metabolic stability. We conclude that patients trained for self-care hemodialysis experience better subjective quality of life than their full-care counterparts. This study highlights both the usefulness of measuring HRQOL as an outcome of hemodialysis therapy and the potential benefits of therapies such as self-care and satellite dialysis.

Measurement of health-related quality of life in multiple sclerosis patients.

BACKGROUND: Patient outcomes in multiple sclerosis (MS) have generally been measured by their neurological impairment using specific scales such as the Kurtzke Expanded Disability Status Scale (EDSS). However, this scale does not measure the multiple dimensions of health-related quality of life (HRQOL) such as functional status and general well-being, which are also important outcomes along with disease-specific measurements. METHODS: HRQOL was measured in a group of 97 MS patients using the RAND 36-item Health Survey 1.0. The EDSS score was assigned by the clinic neurologist. Additional data were collected from the clinical record for each patient. RESULTS: MS patients scored poorly in a number of HRQOL domains such as physical and role functioning and energy or vitality. Disability as quantified by the EDSS correlated only with the physical functioning domain. Regression models were developed to measure the relationship between patient characteristics (independent variables) and HRQOL domains (dependent variables). DISCUSSION: A number of patient characteristics were associated with higher or lower scores on the HRQOL domains. Of particular interest is the finding that a family history of MS was associated with poorer physical and social functioning as well as more pain and less vitality. The occurrence of seizures had a negative impact on role functioning, social functioning and general health perceptions. HRQOL gives caregivers a broader measure of disease burden than the EDSS alone, and should be useful in planning and monitoring interventions.