Surgical training of minimally invasive mitral valve repair on a patient-specific simulator improves surgical skills

OBJECTIVES

Minimally invasive mitral valve repair (MVR) is considered one of the most challenging operations in cardiac surgery and requires much practice and experience. Simulation-based surgical training might be a method to support the learning process and help to flatten the steep learning curve of novices. The purpose of this study was to show the possible effects on learning of surgical training using a high-fidelity simulator with patient-specific mitral valve replicas.

METHODS

Twenty-five participants were recruited to perform MVR on anatomically realistic valve models during different training sessions. After every session their performance was evaluated by a surgical expert regarding accuracy and duration for each step. A second blinded rater similarly assessed the performance after the study. Through repeated documentation of those parameters, their progress in learning was analysed, and gains in proficiency were evaluated.

RESULTS

Participants showed significant performance enhancements in terms of both accuracy and time. Their surgical skills showed sizeable improvements after only 1 session. For example, the time to implant neo-chordae decreased by 24.64% (354 s-264 s, P < 0.001) and the time for annuloplasty by 4.01% (54 s-50 s, P = 0.165), whereas the number of irregular stitches for annuloplasty decreased from 52% to 24%.The significance of simulation-based surgical training as a tool for acquiring and training surgical skills was reviewed positively.

CONCLUSIONS

The results of this study indicate that simulation-based surgical training is a valuable and effective method for learning reconstructive techniques of minimally invasive MVR and overall general dexterity.The novel learning and training options should be implemented in the surgical traineeship for systematic teaching of various surgical skills.

An ex-vivo and in-vitro dynamic simulator for surgical and transcatheter mitral valve interventions

PURPOSE

Minimally invasive mitral valve surgery (MIMVS) and transcatheter edge-to-edge repair (TEER) are complex procedures used to treat mitral valve (MV) pathologies, but with limited training opportunities available. To enable training, a realistic hemodynamic environment is needed. In this work we aimed to develop and validate a simulator that enables investigation of MV pathologies and their repair by MIMVS and TEER in a hemodynamic setting.

METHODS

Different MVs were installed in the simulator, and pressure, flow, and transesophageal echocardiographic measurements were obtained. To confirm the simulator's physiological range, we first installed a biological prosthetic, a mechanical prosthetic, and a competent excised porcine MV. Subsequently, we inserted two porcine MVs-one with induced chordae tendineae rupture and the other with a dilated annulus, along with a patient-specific silicone valve extracted from echocardiography with bi-leaflet prolapse. Finally, TEER and MIMVS procedures were conducted by experts to repair the MVs.

RESULTS

Systolic pressures, cardiac outputs, and regurgitations volumes (RVol) with competent MVs were 119 ± 1 mmHg, 4.78 ± 0.16 l min-1, and 5 ± 3 ml respectively, and thus within the physiological range. In contrast, the pathological MVs displayed increased RVols. MIMVS and TEER resulted in a decrease in RVols and mitigated the severity of mitral regurgitation.

CONCLUSION

Ex-vivo modelling of MV pathologies and repair procedures using the described simulator realistically replicated physiological in-vivo conditions. Furthermore, we showed the feasibility of performing MIMVS and TEER at the simulator, also at patient-specific level, thus providing new clinical perspectives in terms of training modalities and personalized planning.

Search for a τ^{+}τ^{-} Resonance in e^{+}e^{-}→μ^{+}μ^{-}τ^{+}τ^{-} Events with the Belle II Experiment

We report the first search for a nonstandard-model resonance decaying into τ pairs in e^{+}e^{-}→μ^{+}μ^{-}τ^{+}τ^{-} events in the 3.6-10  GeV/c^{2} mass range. We use a 62.8  fb^{-1} sample of e^{+}e^{-} collisions collected at a center-of-mass energy of 10.58 GeV by the Belle II experiment at the SuperKEKB collider. The analysis probes three different models predicting a spin-1 particle coupling only to the heavier lepton families, a Higgs-like spin-0 particle that couples preferentially to charged leptons (leptophilic scalar), and an axionlike particle, respectively. We observe no evidence for a signal and set exclusion limits at 90% confidence level on the product of cross section and branching fraction into τ pairs, ranging from 0.7 to 24 fb, and on the couplings of these processes. We obtain world-leading constraints on the couplings for the leptophilic scalar model for masses above 6.5  GeV/c^{2} and for the axionlike particle model over the entire mass range.

Search for an Invisible Z^{'} in a Final State with Two Muons and Missing Energy at Belle II

The L_{μ}-L_{τ} extension of the standard model predicts the existence of a lepton-flavor-universality-violating Z^{'} boson that couples only to the heavier lepton families. We search for such a Z^{'} through its invisible decay in the process e^{+}e^{-}→μ^{+}μ^{-}Z^{'}. We use a sample of electron-positron collisions at a center-of-mass energy of 10.58 GeV collected by the Belle II experiment in 2019-2020, corresponding to an integrated luminosity of 79.7  fb^{-1}. We find no excess over the expected standard-model background. We set 90%-confidence-level upper limits on the cross section for this process as well as on the coupling of the model, which ranges from 3×10^{-3} at low Z^{'} masses to 1 at Z^{'} masses of 8  GeV/c^{2}.

Search for Lepton-Flavor-Violating τ Decays to a Lepton and an Invisible Boson at Belle II

We search for lepton-flavor-violating τ^{-}→e^{-}α and τ^{-}→μ^{-}α decays, where α is an invisible spin-0 boson. The search uses electron-positron collisions at 10.58 GeV center-of-mass energy with an integrated luminosity of 62.8  fb^{-1}, produced by the SuperKEKB collider and collected with the Belle II detector. We search for an excess in the lepton-energy spectrum of the known τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ} and τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decays. We report 95% confidence-level upper limits on the branching-fraction ratio B(τ^{-}→e^{-}α)/B(τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ}) in the range (1.1-9.7)×10^{-3} and on B(τ^{-}→μ^{-}α)/B(τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}) in the range (0.7-12.2)×10^{-3} for α masses between 0 and 1.6  GeV/c^{2}. These results provide the most stringent bounds on invisible boson production from τ decays.

Comparative evaluation of three commercially available markerless depth sensors for close-range use in surgical simulation

PURPOSE

Minimally invasive surgeries have restricted surgical ports, demanding a high skill level from the surgeon. Surgical simulation potentially reduces this steep learning curve and additionally provides quantitative feedback. Markerless depth sensors show great promise for quantification, but most such sensors are not designed for accurate reconstruction of complex anatomical forms in close-range.

METHODS

This work compares three commercially available depth sensors, namely the Intel D405, D415, and the Stereolabs Zed-Mini in the range of 12-20 cm, for use in surgical simulation. Three environments are designed that closely mimic surgical simulation, comprising planar surfaces, rigid objects, and mitral valve models of silicone and realistic porcine tissue. The cameras are evaluated on Z-accuracy, temporal noise, fill rate, checker distance, point cloud comparisons, and visual inspection of surgical scenes, across several camera settings.

RESULTS

The Intel cameras show sub-mm accuracy in most static environments. The D415 fails in reconstructing valve models, while the Zed-Mini provides lesser temporal noise and higher fill rate. The D405 could reconstruct anatomical structures like the mitral valve leaflet and a ring prosthesis, but performs poorly for reflective surfaces like surgical tools and thin structures like sutures.

CONCLUSION

If a high temporal resolution is needed and lower spatial resolution is acceptable, the Zed-Mini is the best choice, whereas the Intel D405 is the most suited for close-range applications. The D405 shows potential for applications like deformable registration of surfaces, but is not yet suitable for applications like real-time tool tracking or surgical skill assessment.

Observation of e^{+}e^{-}→ωχ_{bJ}(1P) and Search for X_{b}→ωϒ(1S) at sqrt[s] near 10.75 GeV

We study the processes e^{+}e^{-}→ωχ_{bJ}(1P) (J=0, 1, or 2) using samples at center-of-mass energies sqrt[s]=10.701, 10.745, and 10.805 GeV, corresponding to 1.6, 9.8, and 4.7  fb^{-1} of integrated luminosity, respectively. These data were collected with the Belle II detector during special operations of the SuperKEKB collider above the ϒ(4S) resonance. We report the first observation of ωχ_{bJ}(1P) signals at sqrt[s]=10.745  GeV. By combining Belle II data with Belle results at sqrt[s]=10.867  GeV, we find energy dependencies of the Born cross sections for e^{+}e^{-}→ωχ_{b1,b2}(1P) to be consistent with the shape of the ϒ(10753) state. These data indicate that the internal structures of the ϒ(10753) and ϒ(10860) states may differ. Including data at sqrt[s]=10.653  GeV, we also search for the bottomonium equivalent of the X(3872) state decaying into ωϒ(1S). No significant signal is observed for masses between 10.45 and 10.65  GeV/c^{2}.

Measurement of the Λ_{c}^{+} Lifetime

An absolute measurement of the Λ_{c}^{+} lifetime is reported using Λ_{c}^{+}→pK^{-}π^{+} decays in events reconstructed from data collected by the Belle II experiment at the SuperKEKB asymmetric-energy electron-positron collider. The total integrated luminosity of the data sample, which was collected at center-of-mass energies at or near the ϒ(4S) resonance, is 207.2  fb^{-1}. The result, τ(Λ_{c}^{+})=203.20±0.89±0.77  fs, where the first uncertainty is statistical and the second systematic, is the most precise measurement to date and is consistent with previous determinations.

Search for a Dark Photon and an Invisible Dark Higgs Boson in μ^{+}μ^{-} and Missing Energy Final States with the Belle II Experiment

The dark photon A^{'} and the dark Higgs boson h^{'} are hypothetical particles predicted in many dark sector models. We search for the simultaneous production of A^{'} and h^{'} in the dark Higgsstrahlung process e^{+}e^{-}→A^{'}h^{'} with A^{'}→μ^{+}μ^{-} and h^{'} invisible in electron-positron collisions at a center-of-mass energy of 10.58 GeV in data collected by the Belle II experiment in 2019. With an integrated luminosity of 8.34  fb^{-1}, we observe no evidence for signal. We obtain exclusion limits at 90% Bayesian credibility in the range of 1.7-5.0 fb on the cross section and in the range of 1.7×10^{-8}-200×10^{-8} on the effective coupling ϵ^{2}×α_{D} for the A^{'} mass in the range of 4.0  GeV/c^{2}<M_{A^{'}}<9.7  GeV/c^{2} and for the h^{'} mass M_{h^{'}}<M_{A^{'}}, where ϵ is the mixing strength between the standard model and the dark photon and α_{D} is the coupling of the dark photon to the dark Higgs boson. Our limits are the first in this mass range.

Precise Measurement of the D^{0} and D^{+} Lifetimes at Belle II

We report a measurement of the D^{0} and D^{+} lifetimes using D^{0}→K^{-}π^{+} and D^{+}→K^{-}π^{+}π^{+} decays reconstructed in e^{+}e^{-}→cc[over ¯] data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The data, collected at center-of-mass energies at or near the ϒ(4S) resonance, correspond to an integrated luminosity of 72  fb^{-1}. The results, τ(D^{0})=410.5±1.1(stat)±0.8(syst)  fs and τ(D^{+})=1030.4±4.7(stat)±3.1(syst)  fs, are the most precise to date and are consistent with previous determinations.

Search for B^{+}→K^{+}νν[over ¯] Decays Using an Inclusive Tagging Method at Belle II

A search for the flavor-changing neutral-current decay B^{+}→K^{+}νν[over ¯] is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63  fb^{-1} collected at the ϒ(4S) resonance and a sample of 9  fb^{-1} collected at an energy 60 MeV below the resonance. Because the measurable decay signature involves only a single charged kaon, a novel measurement approach is used that exploits not only the properties of the B^{+}→K^{+}νν[over ¯] decay, but also the inclusive properties of the other B meson in the ϒ(4S)→BB[over ¯] event, to suppress the background from other B meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of B^{+}→K^{+}νν[over ¯] of 4.1×10^{-5} is set at the 90% confidence level.

A master protocol to investigate a novel therapy acetyl-L-leucine for three ultra-rare neurodegenerative diseases: Niemann-Pick type C, the GM2 gangliosidoses, and ataxia telangiectasia

BACKGROUND

The lack of approved treatments for the majority of rare diseases is reflective of the unique challenges of orphan drug development. Novel methodologies, including new functionally relevant endpoints, are needed to render the development process more feasible and appropriate for these rare populations and thereby expedite the approval of promising treatments to address patients' high unmet medical need. Here, we describe the development of an innovative master protocol and primary outcome assessment to investigate the modified amino acid N-acetyl-L-leucine (Sponsor Code: IB1001) in three separate, multinational, phase II trials for three ultra-rare, autosomal-recessive, neurodegenerative disorders: Niemann-Pick disease type C (NPC), GM2 gangliosidoses (Tay-Sachs and Sandhoff disease; "GM2"), and ataxia telangiectasia (A-T).

METHODS/DESIGN

The innovative IB1001 master protocol and novel CI-CS primary endpoints were developed through a close collaboration between the Industry Sponsor, Key Opinion Leaders, representatives of the Patient Communities, and National Regulatory Authorities. As a result, the open-label, rater-blinded study design is considerate of the practical limitations of recruitment and retention of subjects in these ultra-orphan populations. The novel primary endpoint, the Clinical Impression of Change in Severity© (CI-CS), accommodates the heterogenous clinical presentation of NPC, GM2, and A-T: at screening, the principal investigator appoints for each patient a primary anchor test (either the 8-m walk test (8MWT) or 9-hole peg test of the dominant hand (9HPT-D)) based on his/her unique clinical symptoms. The anchor tests are videoed in a standardized manner at each visit to capture all aspects related to the patient's functional performance. The CI-CS assessment is ultimately performed by independent, blinded raters who compare videos of the primary anchor test from three periods: baseline, the end of treatment, and the end of a post-treatment washout. Blinded to the time point of each video, the raters make an objective comparison scored on a 7-point Likert scale of the change in the severity of the patient's neurological signs and symptoms from video A to video B. To investigate both the symptomatic and disease-modifying effects of treatment, N-acetyl-L-leucine is assessed during two treatment sequences: a 6-week parent study and 1-year extension phase.

DISCUSSION

The novel CI-CS assessment, developed through a collaboration of all stakeholders, is advantageous in that it better ensures the primary endpoint is functionally relevant for each patient, is able to capture small but meaningful clinical changes critical to the patients' quality of life (fine-motor skills; gait), and blinds the primary outcome assessment. The results of these three trials will inform whether N-acetyl-L-leucine is an effective treatment for NPC, GM2, and A-T and can also serve as a new therapeutic paradigm for the development of future treatments for other orphan diseases.

TRIAL REGISTRATION

The three trials (IB1001-201 for Niemann-Pick disease type C (NPC), IB1001-202 for GM2 gangliosidoses (Tay-Sachs and Sandhoff), IB1001-203 for ataxia telangiectasia (A-T)) have been registered at www.clinicaltrials.gov (NCT03759639; NCT03759665; NCT03759678), www.clinicaltrialsregister.eu (EudraCT: 2018-004331-71; 2018-004406-25; 2018-004407-39), and https://www.germanctr.de (DR KS-ID: DRKS00016567; DRKS00017539; DRKS00020511).

Divergence of annual and perennial species in the Brassicaceae and the contribution of cis-acting variation at FLC orthologues

Variation in life history contributes to reproductive success in different environments. Divergence of annual and perennial angiosperm species is an extreme example that has occurred frequently. Perennials survive for several years and restrict the duration of reproduction by cycling between vegetative growth and flowering, whereas annuals live for 1 year and flower once. We used the tribe Arabideae (Brassicaceae) to study the divergence of seasonal flowering behaviour among annual and perennial species. In perennial Brassicaceae, orthologues of FLOWERING LOCUS C (FLC), a floral inhibitor in Arabidopsis thaliana, are repressed by winter cold and reactivated in spring conferring seasonal flowering patterns, whereas in annuals, they are stably repressed by cold. We isolated FLC orthologues from three annual and two perennial Arabis species and found that the duplicated structure of the A. alpina locus is not required for perenniality. The expression patterns of the genes differed between annuals and perennials, as observed among Arabidopsis species, suggesting a broad relevance of these patterns within the Brassicaceae. Also analysis of plants derived from an interspecies cross of A. alpina and annual A. montbretiana demonstrated that cis-regulatory changes in FLC orthologues contribute to their different transcriptional patterns. Sequence comparisons of FLC orthologues from annuals and perennials in the tribes Arabideae and Camelineae identified two regulatory regions in the first intron whose sequence variation correlates with divergence of the annual and perennial expression patterns. Thus, we propose that related cis-acting changes in FLC orthologues occur independently in different tribes of the Brassicaceae during life history evolution.

Donor vigilance data of a blood transfusion service: A multicenter analysis

BACKGROUND

Donor vigilance is an important part of the quality management system of blood transfusion services. The evaluation of donor side effects helps to improve the donation process and donor compliance. The aim of the present study was to evaluate donor vigilance data in whole blood and plasmapheresis donors of a blood donor service.

MATERIALS AND METHODS

Donors fulfilling current national and European eligibility criteria underwent whole blood and plasmapheresis donation (PCS and MCS+ (Haemonetics, Braintree, USA), A 200 (Fenwal, Round Lake, USA). Whole blood was collected at fixed and mobile sites while plasmaphereses were performed at 8 plasma centers. From 2011 to 2013 donor information was provided for gender, age, body weight, height, first and repeat donation. Donors were monitored for venipuncture and circulatory associated side effects.

RESULTS

The total incidences of adverse events were 5004 (0.56%) in repeat donors and 2111 (2.78%) in first time donors for whole blood donation and 3323 (1.01%) and 514 (7.96%) for plasmaphereses, respectively. Circulatory associated events were 2679 (0.30%) for whole blood donation and 1624 (0.49%) for plasmaphereses.

CONCLUSION

Our donor vigilance data of a blood transfusion service show that whole blood and plasmapheresis are safe with low incidences of adverse events. Repeat donation and age are predictors for low rates of adverse events. On the other hand, first time donation and female gender were associated with higher incidences of adverse events.

Activating SRC mutation in a subset of advanced human colon cancers

The discovery of Rous sarcoma virus (RSV) led to the identification of cellular Src (c-Src), a non-receptor tyrosine kinase, which has since been implicated in the development of numerous human cancers. c-Src has been found to be highly activated in colon cancers, particularly in those metastatic to the liver. Studies of the mechanism of c-Src regulation have suggested that c-Src kinase activity is downregulated by phosphorylation of a critical carboxy-terminal tyrosine (Tyr 530 in human c-Src, equivalent to Tyr 527 in chicken Src) and have implied the existence of activating mutations in this C-terminal regulatory region. We report here the identification of a truncating mutation in SRC at codon 531 in 12% of cases of advanced human colon cancer tested and demonstrate that the mutation is activating, transforming, tumorigenic and promotes metastasis. These results provide, for the first time, genetic evidence that activating SRC mutations may have a role in the malignant progression of human colon cancer.

Surgical Approaches to Esophageal Cancer

BACKGROUND: Esophageal cancer is a highly lethal malignancy. Esophageal resection remains the primary treatment in most centers. A number of approaches to esophageal resection have been described. METHODS: The authors review the current approaches to esophageal resection and adjuvant therapy for esophageal cancer. RESULTS: Transthoracic, transhiatal, and minimally invasive techniques are currently employed in esophageal surgery for malignancy. A number of authors favor extended mediastinal and cervical lymphadenectomy in hopes of improving survival. Combined chemotherapy and radiotherapy in the neoadjuvant setting appears to offer some promise. CONCLUSIONS: No consensus of opinion exists regarding the optimal approach or extent of esophageal resection for cancer. Prospective, randomized trials of neoadjuvant therapy may determine its efficacy. Newer approaches may enhance quality of life.

Squamous-cell carcinoma of the pelvis in a giant condyloma acuminatum: use of neoadjuvant chemoradiation and surgical resection: report of a case

A 60-year-old bisexual male was referred to our institution for management of an unresectable squamous-cell carcinoma of the pelvis arising in a giant condyloma acuminatum. He received neoadjuvant chemoradiation consisting of 5-fluorouracil and mitomycin C with concurrent external beam radiation, followed by posterior pelvic exenteration. The surgical specimen had no residual cancer. In situ hybridization was performed using a human papilloma virus omniprobe for human papilloma virus subtypes 6, 11, 16, 18, 31, 33, and 35. Two years after diagnosis the patient is doing well with no evidence of recurrent disease.

CD44V6 expression in human colorectal carcinoma

CD44 is an adhesion molecule involved in cell-to-cell and cell-to-matrix interactions. This transmembrane glycoprotein exists in either standard or variant forms, originated by alternative splicing. One of the isoforms (CD44V6) has been shown, in some systems, to modify the metastatic potential of tumor cells. To investigate the role of this biomarker as possible prognostic antigen in colorectal cancer, we immunohistochemically analyzed the distribution of CD44V6 expression on formalin-fixed, paraffin-embedded tissues from resected colorectal cancers of 34 patients. The monoclonal antibody VFF7 against the amino acid sequence encoded by exon CD44V6 was applied using the avidin-biotin-peroxidase method. For each resected specimen, normal (N), adenomatous (AD), and carcinomatous (CA) colonic mucosa were tested. In 68% of the resected cases, these areas were present in the same slide, and in 76% of cases, nodal or liver metastases (MT) were available for evaluation. Adenomatous polyp biopsy specimens of 10 carcinoma-free patients were also tested. In selected cases, CD44V6 expression was also determined using the Western blot immunoprecipitation technique. CD44V6 immunoreactivity was detected in 100% of the ADs, and in 91% of CAs, but was mostly weak in only 38% of MTs (n=26). In 49% (n=35) of ADs, 11% (n=34) of CAs, and 4% of MTs (n=26), the stain was moderate to strong. CD44V6 immunoreactivity was predominantly membranous in ADs and cytoplasmic in MTs. In the CAs, both staining patterns were noted. Interestingly, the normal mucosa had a weak subnuclear localization of the stain. In the cases evaluated by Western blotting immunoprecipitation analysis, the level of CD44V6 protein expression was similar to that obtained by immunohistochemistry. No correlation was found with tumor type, stage, or patient survival. The predominant CD44V6 expression in ADs and CAs, but not in MTs, suggests that, in many cases, the expression of this adhesion molecule may be lost during the acquisition of migratory function by the tumor cells.

Elevated c-Src protein expression is an early event in colonic neoplasia

The molecular events regulating the development and progression of colonic neoplasia are currently being delineated. Recent studies have implicated c-Src protein kinase activation as an early event in the malignant transformation of colonic epithelial cells. However, increased c-Src activity has also been reported in colon carcinomas as well as in metastatic hepatic and extrahepatic colon carcinomas. To further investigate the potential role of c-Src in the progression of colonic neoplasia, we analyzed c-Src levels by immunohistochemistry in 27 colorectal resection specimens. Mouse monoclonal antibody to c-Src protein was applied to 3-micron sections from formalin-fixed, paraffin-embedded tissues using the avidin-biotin-peroxidase method. The combination of adenomatous (AD) and adjacent carcinomatous mucosa (CA) specimens were present in 20 of 27 patients. In 15 cases, synchronous metastatic (MT) lesions were available for evaluation. Strong c-Src expression was evident in 95% of AD (n = 20), in contradistinction to 32% of MT (n = 19) and 14% of CA (n = 22). Weak-to-moderate c-Src expression was seen in adjacent normal colonic mucosa (NM) in 96% of cases. Signed rank test univariate analysis revealed a statistically significant difference in c-Src expression between NM/AD (p = 0.0001), NM/CA (p = 0.0001), NM/MT (p = 0.0006), AD/CA (p = 0.0001), and AD/MT (p = 0.0002). No significant correlation between levels of c-Src expression and patient survival, tumor size, histologic grade, or tumor configuration was observed using the Cox's Regression Model. Similar results were obtained by analysis of c-Src protein levels and c-Src kinase activity as measured by Western blot and in vitro kinase assays of representative cases. Our results indicate that: (a) elevated c-Src expression is an important early event during colorectal carcinogenesis; (b) its activation may be involved in tumor progression in a subset of colonic carcinomas; and (c) additional molecular events are necessary for invasion to occur.

Characteristics of prostatic infarcts and their effect on serum prostate-specific antigen and prostatic acid phosphatase

OBJECTIVES

To determine how prostatic infarcts affect serum prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) levels.

METHODS

Two hundred eighteen clinically benign, whole prostates were obtained at autopsy, completely sectioned, and examined histologically. PSA and PAP levels were determined from premortem serum.

RESULTS

Six of the 218 (2.8%) prostates had infarcts. The infarcts were usually multiple and usually located in the central and/or middle concentric zones of the middle third of the prostate without a preference for a particular lobe. Serum PSA by immunoradiometric assay were elevated in all 6 cases. Serum PAP by both enzymatic assay (ACA), and immunoradiometric assay were available for 5 cases and were elevated by both methods in 2 cases, approached elevated levels by both methods in 1 case, and were normal by both methods in 2 cases. The PSA and PAP levels appeared to be affected more by the age than by the size of the infarct.

CONCLUSIONS

Prostatic infarcts elevate PSA levels more frequently than PAP levels, and prostatic infarcts may be responsible for some unexplained elevations of serum PSA and PAP levels.

Chronic pressure ulcer carcinomas

Carcinomas arising from chronic pressure ulcers, Marjolin's ulcers, are an uncommon occurrence. They are virulent cancers that require aggressive surgical treatment. We present 3 such cancers including the first report of a squamous cell carcinoma arising in a distal extremity pressure ulcer. Carcinomas arising in chronic pressure ulcers behave more aggressively than other types of Marjolin's ulcers and, therefore, they need to be treated more aggressively. Extensive surgical excisions with wide surgical margins are necessary and elective lymph node dissections should be considered for optimal therapy.

[Building blocks for oligonucleotide syntheses with uniformly fragmentable beta-halogenated protective groups]

5'-Dimethoxytrityl-3'-phosphite amides of deoxynucleosides are synthesized. Phosphite/phosphate is protected by the 2,2,2-trichloro-1,1-dimethyl-ethyl (TCB) group, heterocyclic bases by the 2,2,2-trichloro-2,2-dimethyl-ethoxycarbonyl (TCBOC) group. Deoxyguanosine is also blocked by 6-O-trichloroethyl thus avoiding the difficulties observed with monoprotected guanine residues.

[Comparison between cimetidine-pirenzepine and antacids for the prevention of stress hemorrhage in intensive care patients. A controlled clinical study on 125 patients]

In a controlled clinical trial, the efficacy of an intravenous combination of cimetidine and pirenzepine (group A: 62 patients) was compared with that of an intragastric administration of a magnesium-aluminium-hydroxide concentrate (group B: 58 patients) in preventing visible and occult upper gastrointestinal tract bleeding in intensive-care patients. It was found that both forms of therapy had the same favourable effect on the extent and incidence rate of visible and occult gastric bleeding. The antacid was more effective than the cimetidine-pirenzepine combination in raising the pH level to 4 or higher (P less than 0.05). Intensive-care patients should, therefore, be treated with the antacid whenever possible, since it is equally effective as the cimetidine-pirenzepine combination in preventing bleeding from the upper gastrointestinal tract, whereas it is superior in elevating the gastric pH. Besides, the use of the antacid is also less costly.

Surgical implications of antithrombin III deficiency

Antithrombin III is a potent coagulant inhibitor in plasma. Congenital deficiency of antithrombin III may predispose to thrombotic events and may complicate surgical management. We describe a patient with congenital antithrombin III deficiency who developed superior mesenteric vein thrombosis after the cessation of warfarin therapy which resulted in venous gangrene of the small intestine. Initial treatment of this deficiency with fresh frozen plasma and subsequent long-term management with warfarin therapy has been effective in avoiding further thrombotic events.