Computationally restoring the potency of a clinical antibody against Omicron

The COVID-19 pandemic underscored the promise of monoclonal antibody-based prophylactic and therapeutic drugs1-3 and revealed how quickly viral escape can curtail effective options4,5. When the SARS-CoV-2 Omicron variant emerged in 2021, many antibody drug products lost potency, including Evusheld and its constituent, cilgavimab4-6. Cilgavimab, like its progenitor COV2-2130, is a class 3 antibody that is compatible with other antibodies in combination4 and is challenging to replace with existing approaches. Rapidly modifying such high-value antibodies to restore efficacy against emerging variants is a compelling mitigation strategy. We sought to redesign and renew the efficacy of COV2-2130 against Omicron BA.1 and BA.1.1 strains while maintaining efficacy against the dominant Delta variant. Here we show that our computationally redesigned antibody, 2130-1-0114-112, achieves this objective, simultaneously increases neutralization potency against Delta and subsequent variants of concern, and provides protection in vivo against the strains tested: WA1/2020, BA.1.1 and BA.5. Deep mutational scanning of tens of thousands of pseudovirus variants reveals that 2130-1-0114-112 improves broad potency without increasing escape liabilities. Our results suggest that computational approaches can optimize an antibody to target multiple escape variants, while simultaneously enriching potency. Our computational approach does not require experimental iterations or pre-existing binding data, thus enabling rapid response strategies to address escape variants or lessen escape vulnerabilities.

Acellular Perfusate is an Adequate Alternative to Packed Red Blood Cells During Normothermic Human Kidney Perfusion

Background

Brief normothermic machine perfusion is increasingly used to assess and recondition grafts before transplant. During normothermic machine perfusion, metabolic activity is typically maintained using red blood cell (RBC)-based solutions. However, the utilization of RBCs creates important logistical constraints. This study explored the feasibility of human kidney normothermic perfusion using William's E-based perfusate with no additional oxygen carrier.

Methods

Sixteen human kidneys declined for transplant were perfused with a perfusion solution containing packed RBCs or William's E medium only for 6 h using a pressure-controlled system. The temperature was set at 37 °C. Renal artery resistance, oxygen extraction, metabolic activity, energy metabolism, and histological features were evaluated.

Results

Baseline donor demographics were similar in both groups. Throughout perfusion, kidneys perfused with William's E exhibited improved renal flow (P = 0.041) but similar arterial resistance. Lactic acid levels remained higher in kidneys perfused with RBCs during the first 3 h of perfusion but were similar thereafter (P = 0.95 at 6 h). Throughout perfusion, kidneys from both groups exhibited comparable behavior regarding oxygen consumption (P = 0.41) and reconstitution of ATP tissue concentration (P = 0.55). Similarly, nicotinamide adenine dinucleotide levels were preserved during perfusion. There was no evidence of histological damage caused by either perfusate.

Conclusions

In human kidneys, William's E medium provides a logistically convenient, off-the-shelf alternative to packed RBCs for up to 6 h of normothermic machine perfusion.

Computationally restoring the potency of a clinical antibody against SARS-CoV-2 Omicron subvariants

The COVID-19 pandemic underscored the promise of monoclonal antibody-based prophylactic and therapeutic drugs1-3, but also revealed how quickly viral escape can curtail effective options4,5. With the emergence of the SARS-CoV-2 Omicron variant in late 2021, many clinically used antibody drug products lost potency, including Evusheld™ and its constituent, cilgavimab4,6. Cilgavimab, like its progenitor COV2-2130, is a class 3 antibody that is compatible with other antibodies in combination4 and is challenging to replace with existing approaches. Rapidly modifying such high-value antibodies with a known clinical profile to restore efficacy against emerging variants is a compelling mitigation strategy. We sought to redesign COV2-2130 to rescue in vivo efficacy against Omicron BA.1 and BA.1.1 strains while maintaining efficacy against the contemporaneously dominant Delta variant. Here we show that our computationally redesigned antibody, 2130-1-0114-112, achieves this objective, simultaneously increases neutralization potency against Delta and many variants of concern that subsequently emerged, and provides protection in vivo against the strains tested, WA1/2020, BA.1.1, and BA.5. Deep mutational scanning of tens of thousands pseudovirus variants reveals 2130-1-0114-112 improves broad potency without incurring additional escape liabilities. Our results suggest that computational approaches can optimize an antibody to target multiple escape variants, while simultaneously enriching potency. Because our approach is computationally driven, not requiring experimental iterations or pre-existing binding data, it could enable rapid response strategies to address escape variants or pre-emptively mitigate escape vulnerabilities.

Synthetic hemoglobin-based oxygen carriers are an acceptable alternative for packed red blood cells in normothermic kidney perfusion

Normothermic machine perfusion presents a novel platform for pretransplant assessment and reconditioning of kidney grafts. Maintaining the metabolic activity of a preserved graft at physiologic levels requires an adequate oxygen supply, typically delivered by crystalloid solutions supplemented with red blood cells. In this study, we explored the feasibility of using a synthetic hemoglobin-based oxygen carrier (HBOC) in human kidney normothermic perfusion. Fourteen discarded human kidneys were perfused for 6 hours at a mean temperature of 37°C using a pressure-controlled system. Kidneys were perfused with a perfusion solution supplemented with either HBOC (n = 7) or packed red blood cells (PRBC) (n = 7) to increase oxygen-carrying capacity. Renal artery resistance, oxygen extraction, metabolic activity, energy stores, and histological features were evaluated. Throughout perfusion, kidneys from both groups exhibited comparable behavior regarding vascular flow (P = .66), oxygen consumption (P = .88), and reconstitution of tissue adenosine triphosphate (P = .057). Lactic acid levels were significantly higher in kidneys perfused with PRBC (P = .007). Histological findings were comparable between groups, and there was no evidence of histological damage caused by the HBOC. This feasibility experiment demonstrates that a HBOC solution can offer a logistically more convenient off-the-shelf alternative to PRBC in normothermic machine perfusion of human kidneys.

Progesterone induces the release of bull spermatozoa from oviductal epithelial cells

The mechanism that causes the detachment of spermatozoa from the oviductal reservoir around the time of ovulation remains to be elucidated. Because the cumulus cells of the bovine oocyte are known to secrete progesterone (P4), and P4 has been shown to act upon cation channels of spermatozoa (CatSper) in human spermatozoa, it was hypothesised that P4 could induce hyperactivation due to an influx of extracellular calcium, and this would facilitate detachment of spermatozoa from oviductal epithelial cells. Therefore, this study aimed to investigate the role and mechanism of action of P4 in the release of spermatozoa from bovine oviduct epithelial cells (BOEC). Initial dose–response assessments on sperm hyperactivation determined the optimum concentration of P4 (10 nM), mibefradil (a non-specific Ca2+ channel antagonist; 5µM), NNC 55-0396 dihydrochloride (NNC; a CatSper antagonist; 2µM), mifepristone (a classical and membrane P4 receptor antagonist; 400nM) and AG205 (a membrane P4 receptor antagonist; 10μM). BOEC explants were incubated with frozen–thawed bovine spermatozoa for 30min, following which loosely bound spermatozoa were removed. Two experiments were completed. In Experiment 1, BOECs were treated for 30min with either no treatment, P4, NNC, mibefradil, P4+mibefradil, P4+NNC, P4+mibefradil+NNC or P4+EGTA. In Experiment 2, BOECs were treated for 30min with either no treatment, P4, mifepristone, AG205, mifepristone+AG205, P4+mifepristone, P4+AG205 or P4+mifepristone+AG205. The number of spermatozoa remaining bound per millimetre squared of BOEC explant was determined. Progesterone stimulated the release of bound spermatozoa from BOEC explants, whereas NNC, mibefradil and EGTA inhibited this release. The release of spermatozoa by P4 was inhibited in the presence of both mifepristone and AG205, whereas the combination of both had the greatest inhibitory action on P4 release of spermatozoa. These findings suggest the presence of a P4 membrane receptor on bovine spermatozoa and that P4-induced release of spermatozoa from BOECs is likely mediated by extracellular Ca2+.

BC200 (BCYRN1) - The shortest, long, non-coding RNA associated with cancer

With the discovery that the level of RNA synthesis in human cells far exceeds what is required to express protein-coding genes, there has been a concerted scientific effort to identify, catalogue and uncover the biological functions of the non-coding transcriptome. Long, non-coding RNAs (lncRNAs) are a diverse group of RNAs with equally wide-ranging biological roles in the cell. An increasing number of studies have reported alterations in the expression of lncRNAs in various cancers, although unravelling how they contribute specifically to the disease is a bigger challenge. Originally described as a brain-specific, non-coding RNA, BC200 (BCYRN1) is a 200-nucleotide, predominantly cytoplasmic lncRNA that has been linked to neurodegenerative disease and several types of cancer. Here we summarise what is known about BC200, primarily from studies in neuronal systems, before turning to a review of recent work that aims to understand how this lncRNA contributes to cancer initiation, progression and metastasis, along with its possible clinical utility as a biomarker or therapeutic target.

Neonatal Discharge Planning: Could Unscheduled Reviews be reduced in the First Six Weeks of Life?

The postnatal period offers an opportunity to provide information and education to new mothers. We analysed factors associated with unscheduled presentations of newborns to local primary care, maternity and paediatric services over a 3 week period to assess whether these could be targeted with discharge planning educational interventions. Data was collected prospectively from electronic databases and manually from patient records in the maternity hospital. Two hundred and seventy six patients under 6 weeks of age presented to the three services. Half of these visits were unscheduled 137 (49%). 40 (29%) of those that were unscheduled were felt to represent benign neonatal variants whilst 28 (20%) presented with feeding problems. Eighty one (59.3%) patients were discharged home, and this was unaffected by referrer patterns; GPs 19 (56%), Nurses 13 (57%) or parents77 (67%). At least 40 (29%) of reviews were felt to be inappropriate and could have been prevented. There is room for cost saving and quality improvement of the service through education.

Low-dose antithymocyte globulin enhanced the efficacy of tacrolimus and mycophenolate for GVHD prophylaxis in recipients of unrelated SCT

We performed a retrospective analysis of the outcome of 197 consecutive unrelated donor transplant recipients who received GVHD prophylaxis either TM regimen (tacrolimus and mycophenolate) (121 patients) or TM/ATG-G regimen (TM with low-dose antithymocyte globulin (ATG) of 4.5 mg/kg, ATG-G, Genzyme) (76 patients). Cumulative incidences of grade II-IV acute GVHD for the TM and TM/ATG-G cohorts were 49% and 61% (P=0.11) and grade III-IV acute GVHD for the TM and TM/ATG-G cohorts were 27% and 14% (P=0.02), respectively. There was no difference in the incidence of relapse or disease progression between TM and TM/ATG-G-16% and 23% (P=0.64). TM/ATG-G cohort had lower incidence of non-relapse mortality (NRM; 37% vs 20%, P=0.01), chronic GVHD (56% vs 43%, P<0.001) and more favorable global chronic GVHD severity (P<0.001). Univariate analyses showed improved OS and PFS of patients who received TM/ATG-G. Multivariate analysis confirmed TM/ATG-G had a favorable influence on OS (P=0.05) but not on PFS (P=0.07). We concluded that low-dose ATG of 4.5 mg/kg given in conjunction with TM improved GVHD prophylaxis without increased risk of relapse. Lower NRM, lower incidence and severity of chronic GVHD could potentially improve survival.

Anti-glycolipid GM2-positive Guillain-Barre syndrome due to hepatitis E infection

BACKGROUND

Hepatitis E infection is most prevalent in developing countries with poor sanitation, but can also occur apparently sporadically in more developed areas.

CASE

We here report a second European case of Guillain-Barre syndrome due to hepatitis E infection in association with anti-glycolipid GM2 antibody.

INTERPRETATION

This is likely to be a specific association involving molecular mimicry, and further European cases can therefore be expected.

A large-scale international meta-analysis of paraoxonase gene polymorphisms in sporadic ALS

BACKGROUND

Six candidate gene studies report a genetic association of DNA variants within the paraoxonase locus with sporadic amyotrophic lateral sclerosis (ALS). However, several other large studies, including five genome-wide association studies, have not duplicated this finding.

METHODS

We conducted a meta-analysis of 10 published studies and one unpublished study of the paraoxonase locus, encompassing 4,037 ALS cases and 4,609 controls, including genome-wide association data from 2,018 ALS cases and 2,425 controls.

RESULTS

The combined fixed effects odds ratio (OR) for rs662 (PON1 Q192R) was 1.09 (95% confidence interval [CI], 1.02-1.16, p = 0.01); the genotypic OR for RR homozygotes at Q192R was 1.25 (95% CI, 1.07-1.45, p = 0.0004); the combined OR for rs854560 (PON1 L55M) was 0.97 (95% CI, 0.86-1.10, p = 0.62); the OR for rs10487132 (PON2) was 1.08 (95% CI, 0.92-1.27, p = 0.35). Although the rs662 polymorphism reached a nominal level of significance, no polymorphism was significant after multiple testing correction. In the subanalysis of samples with genome-wide data from which population outliers were removed, rs662 had an OR of 1.06 (95% CI, 0.97-1.16, p = 0.22).

CONCLUSIONS

In contrast to previous positive smaller studies, our genetic meta-analysis showed no significant association of amyotrophic lateral sclerosis (ALS) with the PON locus. This is the largest meta-analysis of a candidate gene in ALS to date and the first ALS meta-analysis to include data from whole genome association studies. The findings reinforce the need for much larger and more collaborative investigations of the genetic determinants of ALS.

Elevated serum angiogenin levels in ALS

BACKGROUND

The role of hypoxia responsive genes in the pathogenesis of ALS was first suggested when deletions of the hypoxia-responsive element of vascular endothelial growth factor (VEGF) promoter caused a motor neuron disease phenotype in mice. The discovery of ALS-associated mutations in ANG, a hypoxia responsive gene coding for the protein angiogenin, has further supported this pathogenic mechanism in human ALS. In endothelium, angiogenin can regulate expression of VEGF. To date, the patterns of serum angiogenin expression among patients with ALS have not been assessed.

METHODS

Serum angiogenin and VEGF levels were quantified at diagnosis in 79 patients with definite or probable ALS and 72 healthy controls, using a quantitative sandwich enzyme-linked immunoassay.

RESULTS

Patients with ALS exhibited higher serum angiogenin (p = 0.006) but not VEGF (p = 0.55) levels than matched control subjects. Subgroup analysis showed a greater elevation in angiogenin levels for spinal- (p < 0.001) than bulbar- (p = 0.11) onset ALS vs controls. At 12 months, angiogenin levels remained elevated. No correlation was noted between angiogenin and VEGF levels (r = -0.08, p = 0.49) in ALS patient serum.

CONCLUSION

These data suggest a modest elevation in serum angiogenin in ALS at diagnosis. Further investigation will be required to assess the utility of serum angiogenin as a biomarker for ALS and as a predictor of disease progression.

The purification and properties of a cd-cytochrome nitrite reductase from Paracoccus halodenitrificans

Paracoccus halodenitrificans, grown anaerobically in the presence of nitrite, contained membrane and cytoplasmic nitrite reductases. When assayed in the presence of phenazine methosulfate and ascorbate, the membrane-bound enzyme produced nitrous oxide whereas the cytoplasmic enzyme produced nitric oxide. When both enzymes were assayed in the presence of methyl viologen and dithionite, the cytoplasmic enzyme produced ammonia. Following solubilization, the membrane-bound enzyme behaved like the cytoplasmic enzyme, producing nitric oxide in the presence of phenazine methosulfate and ascorbate, and ammonia when assayed in the presence of methyl viologen and dithionite. The cytoplasmic and membrane-bound enzymes were purified to essentially the same specific activity. Only a single nitrite-reductase activity was detected on electrophoretic gels and the electrophoretic behavior of both enzymes suggested they were identical. The spectral properties of both enzymes suggested they were cd-type cytochromes. These data suggest that the products of nitrite reduction by the cd-cytochrome nitrite reductase are determined by the location of the enzyme and the redox potential of the electron donor.

Use of amifostine as a chemoprotectant during high-dose chemotherapy in autologous peripheral blood stem cell transplantation

This report describes two patients with germ cell tumors who underwent tandem autologous peripheral stem cell transplants. The chemotherapy consisted of high-dose carboplatin and etoposide. Both patients developed chemotherapy-related toxicities, which included nephrotoxicity in one case and febrile neutropenia, thrombocytopenia, ototoxicity and mucositis in both. During the second transplant, both patients received amifostine 15 min before and 2 h after each dose of carboplatin. The patients had less mucositis and nephrotoxicity. The duration of neutropenia and thrombocytopenia was less in both cases resulting in a decreased use of antibiotics and platelet transfusions. These cases suggest that the use of amifostine may be of benefit in minimizing toxicities associated with high-dose chemotherapy.

Chemical specificity of the PDR5 multidrug resistance gene product of Saccharomyces cerevisiae based on studies with tri-n-alkyltin chlorides

To understand the chemical basis of action for the PDR5-encoded multidrug resistance transporter of Saccharomyces cerevisiae, we compared the relative hypersensitivities of the wild-type (RW2802) and null mutant strains toward a series of tri-n-alkyltin compounds. These compounds differ from each other in a systematic fashion-either by hydrocarbon chain length or by anion composition. Using zone-of-inhibition and fixed-concentration assays, we found that the ethyl, propyl, and butyl compounds are strong PDR5 substrates, whereas the methyl and pentyl compounds are weak. We conclude that hydrophobicity and anion makeup are relatively unimportant factors in determining whether a tri-n-alkyltin compound is a good PDR5 substrate but that the dissociation of the compound and the molecular size are significant.

Sequence determinants for regulated degradation of yeast 3-hydroxy-3-methylglutaryl-CoA reductase, an integral endoplasmic reticulum membrane protein

The degradation rate of 3-hydroxy-3-methylglutaryl CoA reductase (HMG-R), a key enzyme of the mevalonate pathway, is regulated through a feedback mechanism by the mevalonate pathway. To discover the intrinsic determinants involved in the regulated degradation of the yeast HMG-R isozyme Hmg2p, we replaced small regions of the Hmg2p transmembrane domain with the corresponding regions from the other, stable yeast HMG-R isozyme Hmg1p. When the first 26 amino acids of Hmg2p were replaced with the same region from Hmg1p, Hmg2p was stabilized. The stability of this mutant was not due to mislocalization, but rather to an inability to be recognized for degradation. When amino acid residues 27-54 of Hmg2p were replaced with those from Hmg1p, the mutant was still degraded, but its degradation rate was poorly regulated. The degradation of this mutant was still dependent on the first 26 amino acid residues and on the function of the HRD genes. These mutants showed altered ubiquitination levels that were well correlated with their degradative phenotypes. Neither determinant was sufficient to impart regulated degradation to Hmg1p. These studies provide evidence that there are sequence determinants in Hmg2p necessary for degradation and optimal regulation, and that independent processes may be involved in Hmg2p degradation and its regulation.

Role of a BRCT domain in the interaction of DNA ligase III-alpha with the DNA repair protein XRCC1

The BRCT domain (for BRCA1 carboxyl terminus) is a protein motif of unknown function, comprising approximately 100 amino acids in five conserved blocks denoted A-E. BRCT domains are present in the tumour suppressor protein BRCA1 [1-3], and the domain is found in over 40 other proteins, defining a superfamily that includes DNA ligase III-alpha and the essential human DNA repair protein XRCC1. DNA ligase III-alpha and XRCC1 interact via their carboxyl termini, close to or within regions that contain a BRCT domain [4]. To examine whether the primary role of the carboxy-terminal BRCT domain of XRCC1 (denoted BRCT II) is to mediate the interaction with DNA ligase III-alpha, we identified the regions of the domain that are required and sufficient for the interaction. An XRCC1 protein in which the conserved D-block tryptophan was disrupted by point mutation retained the ability to interact with DNA ligase III-alpha, so this tryptophan must mediate a different, although conserved, role. XRCC1 in which the weakly conserved C-block was mutated lost the ability to interact with DNA ligase III-alpha. Moreover, 20 amino acids spanning the C-block of BRCT II conferred full DNA ligase III-alpha binding activity upon an unrelated polypeptide. An XRCC1 protein in which this 20mer was deleted could not maintain normal levels of DNA ligase III-alpha in transfected rodent cells, a phenotype associated with defective repair [5]. In summary, these data demonstrate that a BRCT domain can mediate a biologically important protein-protein interaction, and support the existence of additional roles.

Genome amplification and long-distance movement functions associated with the central domain of tobacco etch potyvirus helper component-proteinase

The tobacco etch potyvirus (TEV) helper component-proteinase (HC-Pro, 460 amino acid residues) is a multifunctional protein involved in aphid-mediated transmission, genome amplification, polyprotein processing, and long-distance movement. To investigate the interrelationships between three of these functions, 25 alanine-scanning mutations affecting clusters of charged residues were introduced into the HC-Pro coding sequence. The resulting mutants were analyzed with respect to HC-Pro proteolytic activity in vitro, genome amplification in protoplasts, and long-distance movement in tobacco plants. Three classes of mutants were identified. Class I mutants (total of 17) were capable of genome amplification, long-distance movement, and HC-Pro proteolysis with efficiencies similar to parental virus. The class III mutant (total of 1) encoded a proteolytically debilitated HC-Pro and was replication-defective. Class II mutants (total of 7) encoded proteolytically active HC-Pro, but each exhibited a suppressed amplification phenotype that was characterized by a progressive shutoff during the course of infection in protoplasts. The class II mutants also exhibited defects in long-distance movement, accumulating to relative levels of 0 to 7.5% in noninoculated tissue. Wild-type HC-Pro supplied in trans was able to partially rescue the class II mutant amplification defects in protoplasts and long-distance movement defects in plants, although the extent of complementation of movement function varied for each mutant. Six of the seven class II mutations affected the central region of HC-Pro between residues 126 and 300, whereas only one affected the C-terminal proteolytic domain. These results indicate that the central region of HC-Pro is necessary for efficient genome amplification and long-distance movement, and that the one or more HC-Pro functions involved in these processes is at least partially trans-active. Additionally, the long-distance movement properties of a previously characterized HC-Pro-defective mutant (TEV-GUS/CCCE) were characterized further using grafted nontransgenic and HC-Pro-expressing transgenic plants. The results indicated that HC-Pro is required in both inoculated and noninoculated tissues to complement the TEV-GUS/CCCE movement defects.

Analysis of the VPg-proteinase (NIa) encoded by tobacco etch potyvirus: effects of mutations on subcellular transport, proteolytic processing, and genome amplification

A mutational analysis was conducted to investigate the functions of the tobacco etch potyvirus VPg-proteinase (NIa) protein in vivo. The NIa N-terminal domain contains the VPg attachment site, whereas the C-terminal domain contains a picornavirus 3C-like proteinase. Cleavage at an internal site separating the two domains occurs in a subset of NIa molecules. The majority of NIa molecules in TEV-infected cells accumulate within the nucleus. By using a reporter fusion strategy, the NIa nuclear localization signal was mapped to a sequence within amino acid residues 40 to 49 in the VPg domain. Mutations resulting in debilitation of NIa nuclear translocation also debilitated genome amplification, suggesting that the NLS overlaps a region critical for RNA replication. The internal cleavage site was shown to be a poor substrate for NIa proteolysis because of a suboptimal sequence context around the scissile bond. Mutants that encoded NIa variants with accelerated internal proteolysis exhibited genome amplification defects, supporting the hypothesis that slow internal processing provides a regulatory function. Mutations affecting the VPg attachment site and proteinase active-site residues resulted in amplification-defective viruses. A transgenic complementation assay was used to test whether NIa supplied in trans could rescue amplification-defective viral genomes encoding altered NIa proteins. Neither cells expressing NIa alone nor cells expressing a series of NIa-containing polyproteins supported increased levels of amplification of the mutants. The lack of complementation of NIa-defective mutants is in contrast to previous results obtained with RNA polymerase (NIb)-defective mutants, which were relatively efficiently rescued in the transgenic complementation assay. It is suggested that, unlike NIb polymerase, NIa provides replicative functions that are cis preferential.

Long-distance movement factor: a transport function of the potyvirus helper component proteinase

Transport of viruses from cell to cell in plants typically involves one or more viral proteins that supply dedicated movement functions. Transport from leaf to leaf through phloem, or long-distance transport, is a poorly understood process with requirements differing from those of cell-to-cell movement. Through genetic analysis of tobacco etch virus (TEV; potyvirus group), a novel long-distance movement factor was identified that facilitates vascular-associated movement in tobacco. A mutation in the central region of the helper component proteinase (HC-Pro), a TEV-encoded protein with previously described activities in aphid-mediated transmission and polyprotein processing, inactivated long-distance movement. This mutant virus exhibited only minor defects in genome amplification and cell-to-cell movement functions. In situ histochemical analysis revealed that the mutant was capable of infecting mesophyll, bundle sheath, and phloem cells within inoculated leaves, suggesting that the long-distance movement block was associated with entry into or exit from sieve elements. The long-distance movement defect was specifically complemented by HC-Pro supplied in trans by a transgenic host. The data indicate that HC-Pro functions in one or more steps unique to long-distance transport.

Busulfan-based regimens and allogeneic bone marrow transplantation in patients with myelodysplastic syndromes

Preparative regimens containing busulfan (BU) followed by allogeneic bone marrow transplantation (BMT) were used in 27 consecutive patients with myelodysplastic syndromes (MDS). The median age was 33 years (range, 4 to 54). Ten were female and 17 male. Sixteen patients had primary MDS, 11 other patients had antecedent hematologic diseases or developed MDS after cytotoxic and/or radiation therapy. Six patients had leukemic transformation and received antileukemic therapy before BMT. Pre-BMT cytogenetic studies showed complex chromosomal abnormalities in 13 patients, a simple abnormality in 5 patients, and normal chromosome in 8 patients. Three BU-based preparative regimens were used: 1 patient received BU 4 mg/kg orally (PO) daily for 4 days and cyclophosphamide (CY) 50 mg/kg intravenously (IV) daily for 4 days (BUCY-4); 24 patients received BU 4 mg/kg PO daily for 4 days, cytosine arabinoside (ara-C) 2 g/m2 IV every 12 hours for 4 doses, and CY 60 mg/kg IV daily for 2 days (BAC); and 2 patients with preceding Fanconi anemia received BU 2 mg/kg PO daily for 4 days followed by total lymphoid irradiation of 5 Gy. Seventeen of 27 patients are alive with no evidence of disease. Ten patients have died: 2 from hepatic veno-occlusive disease, 3 from sepsis, 1 from a cerebral bleed, 1 from a massive gastrointestinal (GI) bleed associated with acute graft-versus-host disease, 1 from hemolytic uremic syndrome with adult respiratory distress syndrome, 1 from bronchiolitis obliterans, and the only patient who did not engraft died from acute myeloid leukemia. Regimen-related toxicities (RRT) include GI tract (diarrhea, 14; stomatitis, 11), liver (9), cardiac (1), and skin (5). Patients who received a genotypically matched marrow graft had a significantly better disease-free survival (DFS) than patients who received a nongenotypic marrow graft (P = .02). The Kaplan-Meier analysis projects an overall DFS of 56% +/- 13% and 78% +/- 10% for patients who received a genotypically matched marrow graft. With the exception of a child who did not engraft, there was no relapse of MDS or leukemia. Excellent DFS, acceptable RRT, and the ease of administration are advantages of this regimen.

Allogeneic bone marrow transplantation in high-risk myeloid disorders using busulfan, cytosine arabinoside and cyclophosphamide (BAC)

Twenty-one patients (median age = 34, range = 10-49; F:M = 7:14) received a preparative regimen consisting of busulfan 4 mg/kg/day x 4, cytosine arabinoside 2 g/m2/12 h x 4 and cyclophosphamide 60 mg/kg/day x 2 ('BAC' regimen) for allogeneic bone marrow transplantation. Out of 12 patients with acute myeloid leukemia (AML), two were in first remission, six were in second remission and four had resistant, relapsed disease or prolonged marrow aplasia after induction chemotherapy. Five of the 12 patients with AML had secondary AML. Four patients had transfusion-dependent myelodysplastic syndrome. Three patients with chronic myeloid leukemia were in the accelerated phase and two were in the blastic phase. Organ toxicities related to the preparative regimen were graded. Liver toxicity occurred in 11 patients, two of these were fatal veno-occlusive disease (VOD) (10%). Nineteen of the 21 patients had grade 2 or less diarrhea, and 13 also had mucositis. One patient developed grade 3 cardiac toxicity, and one other patient had grade 1 skin toxicity. Four patients had gross hematuria related to treatment (19%). No renal, pulmonary or CNS toxicities were encountered. Ten patients have died, two from regimen-related hepatic VOD. Of the remaining eight deaths, four were from respiratory failure in four patients (one case each of Pneumocystis pneumonia, CMV pneumonia, bronchiolitis obliterans associated with chronic graft-versus-host disease, and interstitial pneumonitis complicated pulmonary emboli), and one patient each from GI bleeding, cardiac arrhythmia, sepsis and CNS bleeding. Thus far, only one patient transplanted for secondary AML in second remission relapsed at day 230.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of transdermal scopolamine on heart rate variability in normal subjects

A decrease in cardiac parasympathetic tone is a recognized finding in patients with ischemic heart disease, sudden cardiac death and heart failure, correlating closely with disease severity and overall survival. To study the clinical potential of vagomimetic intervention, the effect of transdermal scopolamine on fluctuations in heart rate was studied in 32 healthy adult subjects using both time-domain (mean RR interval, standard deviation of the mean RR interval, mean of the differences between consecutive RR intervals) and frequency-domain measures (spectrum analysis of 128 consecutive RR intervals) of heart rate variability. After an exposure of 24 hours, transdermal scopolamine resulted in a significant increase in all indexes tested. The increase was most pronounced in the 0.25-Hz respiratory peak of the RR interval power spectrum, compatible with a strong vagomimetic mode of action of transdermal scopolamine. Results indicate that transdermal scopolamine may have potential merit as a selective vagotonic agent in certain patients with myocardial infarction, heart failure or ventricular arrhythmias.

Prostaglandin F2-alpha bladder irrigation for control of intractable cyclophosphamide-induced hemorrhagic cystitis

We report a case of intractable cyclophosphamide-induced hemorrhagic cystitis. Conservative therapy, including suprapubic cystostomy with through-and-through bladder irrigation, failed to slow the bleeding. We then instilled 200 cc of a 0.7 mg. per cent solution of prostaglandin F2-alpha into the bladder for 4 hours daily. The bleeding ceased completely by the end of treatment 5 and the patient remains free of hematuria. There were no side effects noted during the 5 days of treatment. This form of therapy offers an effective, safe and easy alternative to more caustic bladder irrigants and methods of treatment.

The practice of pharmacy in England

The practice of pharmacy in England is described. Community pharmacies have a contract with the Department of Health and Social Security to fill National Health Service prescriptions. A large proportion of the general public obtain their prescriptions free. Funding for the health service comes from taxes and automatic contributions from employers and employees. Aspects of hospital pharmacy practice and salaries are discussed, e.g., a junior pharmacist may expect to earn between $9000 and $12,000. There is very little unit-dose dispensing, and many hospitals are unable to provide 24-hour services. Hospital pharmacies function with fewer pharmacists than their U.S. counterparts, utilizing larger numbers of technicians. Clinical pharmacy practice centers around drug monitoring (ward pharmacy). Pharmacokinetic services are provided in a few places. Master of science degrees in clinical pharmacy are available. However, the future of clinical pharmacy practice in England depends on staffing levels and competition between and acceptance from other health disciplines.