Sex-Driven Differences in the Effectiveness of Individualized Clinical Management of Alzheimer's Disease Risk

BACKGROUND

The Comparative Effectiveness Dementia and Alzheimer's Registry (CEDAR) trial demonstrated that individualized, multi-domain interventions improved cognition and reduced the risk of Alzheimer's disease (AD). As biological sex is a significant risk factor for AD, it is essential to explore the differential effectiveness of targeted clinical interventions in women vs. men.

METHODS

Patients were recruited from an Alzheimer's Prevention Clinic. Subjects with normal cognition, subjective cognitive decline, or asymptomatic preclinical AD were classified as "Prevention". Subjects with mild cognitive impairment due to AD or mild AD were classified as "Early Treatment." The primary outcome was the change from baseline to 18-months on the modified-Alzheimer's Prevention Cognitive Composite. Secondary outcomes included a cognitive aging composite, AD and cardiovascular (CV) risk scales, and serum biomarkers. Subjects who adhered to > 60% of recommendations in the CEDAR trial were included in this a priori sub-group analysis to examine whether individualized intervention effects were modified by sex (n=80).

RESULTS

In the Prevention group, both women (p=0.0205) and men (p=0.0044) demonstrated improvements in cognition with no sex differences (p=0.5244). In the Early Treatment group, there were also no significant sex differences in cognition (p=0.3299). In the Prevention group, women demonstrated greater improvements in the Multi-Ethnic Study of Atherosclerosis risk score (MESA-RS) than men (difference=1.5, p=0.0013). Women in the Early Treatment group demonstrated greater improvements in CV Risk Factors, Aging and Incidence of Dementia (CAIDE) risk score (difference=2.3, p=0.0067), and the MESA-RS (difference=4.1, p<0.001).

CONCLUSIONS

Individualized multi-domain interventions are equally effective at improving cognition in women and men. However, personally-tailored interventions led to greater improvements in calculated AD and CV risk, and CV blood biomarkers, in women compared to men. Future study in larger cohorts is necessary to further define sex differences in AD risk reduction in clinical practice.

Satb1 deficiency licenses TFH-differentiation and Tertiary Lymphoid Structure formation in cancer

Tertiary Lymphoid Structures (TLS) are commonly identified in human tumors with improved outcome, but how they are orchestrated remains elusive. Here we show that silencing of the master genomic organizer Satb1 results in enhanced antigen-specific T Follicular Helper (TFH) differentiation. Increased TFH thereby promoted antigen-specific intra-tumoral CD19+B220+ B cell responses and spontaneous TLS assembly upon ovarian tumor challenge. Mechanistically, Satb1 deficiency drives increased TFH formation through de-repression of ICOS and PD-1. Accordingly, TGF-β1-driven downregulation of Satb1 licenses activated human CD4+ T-cells for enhanced antigen-specific T Follicular Helper (TFH) differentiation. Furthermore, Satb1 deficiency abrogates the generation of PD-1highCXCR5+Foxp3+ T Follicular Regulatory (TFR) cells during the TFH differentiation process. Importantly, functional TFH cell accumulation, in the absence of Satb1 specifically in CD4+ T cells, resulted in corresponding isotype-switched B cell responses and spontaneous formation of TLS, while B cell depletion accelerated malignant progression. Our results indicate that the formation of TLS in cancer depends on enhanced B cell responses driven by TFH cells generated through Satb1 down-regulation.

Automated chest X-ray reading for tuberculosis in the Philippines to improve case detection: a cohort study

BACKGROUND: DetecTB (Diagnostic Enhanced Tools for Extra Cases of TB), an intensified tuberculosis (TB) case-finding programme targeting prisons and high-risk communities was implemented on Palawan Island, the Philippines.OBJECTIVE: To evaluate the performance of TB detection based on computerised chest radiography (CXR) readings.DESIGN: Data from 14 094 subjects were analysed from September 2012 to June 2014. All CXRs were read by a physician and by software. Individuals with TB symptoms or CXR abnormalities according to the physician underwent Xpert^® MTB/RIF testing, the remaining persons were considered TB-negative (screening reference). A subset of 200 CXRs was read by an independent human reader (radiological reference). This reader also re-read a subset of the most abnormal cases as identified using the software but read as normal by the physician (discordant cases).RESULTS: A total of 10 755 individuals were included in the analysis, 2534 of whom had a positively assessed CXR; 298 cases were Xpert-positive. Using the screening reference, the area under the receiver operating characteristic curve for software readings was 0.93 (95%CI 0.92-0.94), with a sensitivity of 0.98 (95%CI 0.97-0.99) and a specificity of 0.69 (95%CI 0.40-0.98). Based on the radiological reference, the physician performed slightly worse than the software (sensitivity, 0.82, 95%CI 0.74-0.89 and specificity, 0.87, 95%CI 0.81-0.96 vs. sensitivity, 0.83, 95%CI 0.71-0.93 and specificity, 0.87, 95%CI 0.75-0.95), although this was not statistically significant. Of the 291 discordant cases, 70% were assessed as positive, resulting in a 22% increase in TB detection when extrapolated to the full cohort.CONCLUSION: The performance of automated CXR reading is comparable to that of the attending physicians in DetecTB, and its use as a second reader could increase TB detection.

Determination of Atropine (Hyoscyamine) Sulfate in Commercial Products by Liquid Chromatography with UV Absorbance and Fluorescence Detection: Multilaboratory Study

A liquid chromatographic (LC) method with 2 detection systems for determining atropine (hyoscyamine) sulfate in commercial products was tested in a multilaboratory study. Depending on the type of product, sample solutions are prepared in methanol or methanol–water (1 + 1). The standard solution contains about 1.0 mg atropine sul-fate/100 mL and is prepared in the same solvent used in sample preparation. LC separations are performed on a 7.5 cm Novapak silica column. The mobile phase is prepared by mixing 970 mL methanol with 30 mL of a 1% aqueous solution of 1-pentanesulfonic acid, sodium salt. Detection is by 2 systems, UV absorbance detection at 220 nm and fluorescence detection with excitation at 255 nm and emission at 285 nm. The injection volume is 100 or 200 μL. The following materials were used for the study: 2 separate samples of tablets labeled to contain 0.4 mg atropine sulfate, 2 separate samples of extended-release tablets labeled to contain 0.375 mg hyoscyamine sulfate, one sample of atropine sulfate injection labeled to contain 2 mg/mL, and one sample of 1% (v/v) atropine sul-fate ophthalmic. Eight participants analyzed 2 separate portions of the 6 samples by both detection systems. A ninth participant analyzed the samples in duplicate but only by UV absorbance detection because of the unavailability of a fluorescence detector. The relative standard deviation (RSD) between laboratories ranged from 1.4 to 3.3% for samples of tablets and injections but higher for ophthalmic solutions (5.1–5.2%). A linearity study was conducted in the originating laboratory before the multilaboratory study with 5 solutions ranging in concentration from 0.80 to 1.20 mg atropine sul-fate in 100 mL. Average recoveries were 100.0% by UV absorbance detection and 99.9% by fluorescence detection; the RSDs were 1.1 and 1.2%, respectively.

Accuracy of an automated system for tuberculosis detection on chest radiographs in high-risk screening

SETTING:

Tuberculosis (TB) screening programmes can be optimised by reducing the number of chest radiographs (CXRs) requiring interpretation by human experts.

OBJECTIVE:

To evaluate the performance of computerised detection software in triaging CXRs in a high-throughput digital mobile TB screening programme.

DESIGN:

A retrospective evaluation of the software was performed on a database of 38 961 postero-anterior CXRs from unique individuals seen between 2005 and 2010, 87 of whom were diagnosed with TB. The software generated a TB likelihood score for each CXR. This score was compared with a reference standard for notified active pulmonary TB using receiver operating characteristic (ROC) curve and localisation ROC (LROC) curve analyses.

RESULTS:

On ROC curve analysis, software specificity was 55.71% (95%CI 55.21–56.20) and negative predictive value was 99.98% (95%CI 99.95–99.99), at a sensitivity of 95%. The area under the ROC curve was 0.90 (95%CI 0.86–0.93). Results of the LROC curve analysis were similar.

CONCLUSION:

The software could identify more than half of the normal images in a TB screening setting while maintaining high sensitivity, and may therefore be used for triage.

Automatic versus human reading of chest X-rays in the Zambia National Tuberculosis Prevalence Survey

SETTING

Tuberculosis (TB) prevalence survey in Zambia between 2013 and 2014.

OBJECTIVE

To compare the performance of automatic software (CAD4TB 5) in chest X-ray (CXR) reading with that of field (general practitioners) and central (radiologists) readers.

DESIGN

A retrospective study comparing the performance of human and automatic reading was conducted. Two scenarios for central reading were evaluated: abnormalities not consistent with TB were considered to be 'normal' or 'abnormal'. Sputum culture was defined as the reference standard. Measures derived from receiver operating characteristic analysis were used to assess readers' performances.

RESULTS

Of 46 099 participants, 23 838 cases included all survey information; of these, 106 cases were culture-confirmed TB-positive. The performance of CAD4TB 5 was similar to that of field and central readers. Although there were significant differences in specificity when compared with field readings (P = 0.002) and central readings considering the first scenario (P < 0.001), these differences were not substantial (93.2% vs. 92.6% and 98.4% vs. 99.6%, respectively).CONCLUSIONp: The performance of automatic CXR readings is comparable with that of human experts in a TB prevalence survey setting using culture as reference.

Quantifying the relative effects of environmental and direct transmission of norovirus

Norovirus is a common cause of outbreaks of acute gastroenteritis in health- and child-care settings, with serial outbreaks also frequently observed aboard cruise ships. The relative contributions of environmental and direct person-to-person transmission of norovirus have hitherto not been quantified. We employ a novel mathematical model of norovirus transmission, and fit the model to daily incidence data from a major norovirus outbreak on a cruise ship, and examine the relative efficacy of potential control strategies aimed at reducing environmental and/or direct transmission. The reproduction number for environmental and direct transmission combined is [Formula: see text] [6.1,9.5], and of environmental transmission alone is [Formula: see text] [0.9,2.6]. Direct transmission is overwhelmingly due to passenger-to-passenger contacts, but crew can act as a reservoir of infection from cruise to cruise. This is the first quantification of the relative roles of environmental and direct transmission of norovirus. While environmental transmission has the potential to maintain a sustained series of outbreaks aboard a cruise ship in the absence of strict sanitation practices, direct transmission dominates. We find that intensive promotion of good hand washing practices may prevent outbreaks. Isolation of ill passengers and cleaning are beneficial, but appear to be less efficacious at outbreak control.

Localized Energy-Based Normalization of Medical Images: Application to Chest Radiography

Automated quantitative analysis systems for medical images often lack the capability to successfully process images from multiple sources. Normalization of such images prior to further analysis is a possible solution to this limitation. This work presents a general method to normalize medical images and thoroughly investigates its effectiveness for chest radiography (CXR). The method starts with an energy decomposition of the image in different bands. Next, each band's localized energy is scaled to a reference value and the image is reconstructed. We investigate iterative and local application of this technique. The normalization is applied iteratively to the lung fields on six datasets from different sources, each comprising 50 normal CXRs and 50 abnormal CXRs. The method is evaluated in three supervised computer-aided detection tasks related to CXR analysis and compared to two reference normalization methods. In the first task, automatic lung segmentation, the average Jaccard overlap significantly increased from 0.72±0.30 and 0.87±0.11 for both reference methods to with normalization. The second experiment was aimed at segmentation of the clavicles. The reference methods had an average Jaccard index of 0.57±0.26 and 0.53±0.26; with normalization this significantly increased to . The third experiment was detection of tuberculosis related abnormalities in the lung fields. The average area under the Receiver Operating Curve increased significantly from 0.72±0.14 and 0.79±0.06 using the reference methods to with normalization. We conclude that the normalization can be successfully applied in chest radiography and makes supervised systems more generally applicable to data from different sources.

PCR offers no advantage over culture for microbiologic diagnosis in cellulitis

PURPOSE

Most cases of cellulitis are traditionally attributed to β-hemolytic Streptococcus and Staphylococcus species, although in most cases, no organism is identified. Development of PCR using the conserved bacterial 16 S rRNA DNA permits identification of bacteria independent of conventional culture approaches and prior use of antibiotics.

METHODS

We used PCR-based techniques to identify cellulitis etiology using aspirate samples from affected skin. Saline was infiltrated and aspirated at the site of greatest erythema or at the cellulitic border. Samples were tested for 16 S rRNA DNA, and organism-specific probes used to identify bacteria commonly seen in skin infections.

RESULTS

Aspirates from 32 patients were studied, and 16 S rRNA DNA was detected in nine of these patient samples (28.1%). Bacterial species were identified by PCR methods in six of these nine samples (66.6%), with S. aureus and methicillin-resistant S. aureus (MRSA) identified in four and two, respectively, of these samples. Of the patients with positive aspirate bacterial cultures (3/9, 33.3%), S. aureus and coagulase-negative Staphylococcus (CoNS) were present on cultures of two of the three (both 66.6%) positive samples. Only in one of the three positive bacterial cultures did the PCR method detect the same organism as was detected by culture. Among patients with positive provider-collected clinical cultures, MRSA was the predominant organism (11/18, 61.1%) and when present, it was found as the sole organism. Where S. aureus or Streptococcus species were detected by molecular methods, clinical cultures yielded a positive result as well.

CONCLUSIONS

PCR-based techniques do not appear to be more sensitive than aspirate cultures for the detection of pathogens in cellulitis.

Sticks and stones may break my bones: work-related orthopaedic injuries sustained during obstetrics and gynaecology training

Backache is a common cause of morbidity among doctors and 50% of the obstetricians and gynaecologists suffering from this attribute it to work practice and posture. Occupational injuries remain poorly studied among obstetricians and gynaecologists and we have therefore tried to assess the extent and demographics of work-related injuries sustained during training by sending an eight-item questionnaire to 418 Registrar grade trainees in the London area. A low 23.2% response rate (97/418) was obtained, despite second questionnaires being sent to initial non-responders. Out of the 97 responders, 28 (28.7%) had suffered injuries at work at least once throughout their career. There was female preponderance in those reporting injuries, with a female to male ratio of 3:1. Of the 28 positive responders, 11 were UK graduates, 7 EU and the remaining 10 from Colombia, West Indies, India and Sudan. The mean age was 32.5 +/- 4.2 years, with 21 of the 28 (75%) being senior trainees (post-MRCOG). The injuries reported were: forearm (4); wrist (7); thumb (3); hands (1) shoulder and neck (9), ankle (1) and lower back (6). Of these, 18 sought medical help and received treatment for these injuries, which included long-term physiotherapy, although no-one required surgery. Eight were forced to take time off work, with a cumulative total of 80 days; one had to prolong her training by 3 months. Seven trainees sustained their injuries (e.g. ligamentous strain of wrist and scaphoid fracture) while performing caesarean sections, while forceps deliveries were the cause of six occupational injuries (e.g. ligamentous strain of sacroiliac joint). Work-related injuries can have adverse effects on training and workforce. Awareness of correct surgical techniques and adoption of ergonomic posture when performing procedures may help to minimise the risk of a work-related injury.

Extended hepatic resection: a 6-year retrospective study of risk factors for perioperative mortality

BACKGROUND

Extended hepatic resection (more than four liver segments) is a major operative procedure that is associated with significant risk. The purpose of this study was to assess the impact of perioperative variables on in-hospital mortality after extended hepatectomy.

STUDY DESIGN

Consecutive patients who underwent extended hepatic resection were studied. The prognostic value of 29 perioperative variables was evaluated using in-hospital mortality as the endpoint. For each variable, the odds ratio (95% confidence interval) for in-hospital mortality was calculated. Those variables with a lower confidence limit > 1 were considered important risk factors. The population was stratified into categories of patients having the same number of risk factors, and mortality was estimated for each group. These data were used to develop a risk assessment algorithm.

RESULTS

There were 14 deaths (6%) in 226 patients. Three preoperative variables (cholangitis, creatinine > 1.3 mg/dL, and total bilirubin > 6 mg/dL) and two operative variables (blood loss > 3 L and vena caval resection) appear to be important factors for in-hospital mortality. The mortality associated with the presence of any two of the five factors was 100% (5 of 5), and the mortality associated with the absence of these factors was 3% (6 of 191).

CONCLUSIONS

Perioperative evaluation of patients undergoing extended hepatic resection should include the quantitation of mortality risk factors. The combination of any two factors among preoperative cholangitis, elevated serum creatinine, elevated serum bilirubin, high operative blood loss, and vena cava resection may carry a high mortality risk. These results require prospective validation.

Reversing the substrate specificities of phenylalanine and tyrosine hydroxylase: aspartate 425 of tyrosine hydroxylase is essential for L-DOPA formation

The catalytic domains of the pterin-dependent enzymes phenylalanine hydroxylase and tyrosine hydroxylase are homologous, yet differ in their substrate specificities. To probe the structural basis for the differences in specificity, seven residues in the active site of phenylalanine hydroxylase whose side chains are dissimilar in the two enzymes were mutated to the corresponding residues in tyrosine hydroxylase. Analysis of the effects of the mutations on the isolated catalytic domain of phenylalanine hydroxylase identified three residues that contribute to the ability to hydroxylate tyrosine, His264, Tyr277, and Val379. These mutations were incorporated into full-length phenylalanine hydroxylase and the complementary mutations into tyrosine hydroxylase. The steady-state kinetic parameters of the mutated enzymes showed that the identity of the residue in tyrosine hydroxylase at the position corresponding to position 379 of phenylalanine hydroxylase is critical for dihydroxyphenylalanine formation. The relative specificity of tyrosine hydroxylase for phenylalanine versus tyrosine, as measured by the (V/K(phe))/(V/K(tyr)) value, increased by 80000-fold in the D425V enzyme. However, mutation of the corresponding valine 379 of phenylalanine hydroxylase to aspartate was not sufficient to allow phenylalanine hydroxylase to form dihydroxyphenylalanine at rates comparable to that of tyrosine hydroxylase. The double mutant V379D/H264Q PheH was the most active at tyrosine hydroxylation, showing a 3000-fold decrease in the (V/K(phe))/(V/K(tyr)) value.

Flow triggering added to pressure support ventilation improves comfort and reduces work of breathing in mechanically ventilated patients

PURPOSE

The purpose of this study was to measure the effect of flow triggering (FT), added to pressure support ventilation (PSV), during spontaneous breathing in intubated patients.

MATERIALS AND METHODS

A prospective observational study was conducted at a Comprehensive Cancer Center, University Hospital. Fourteen consecutive critically ill, mechanically ventilated patients on PSV with positive end-expiratory pressure were studied. Flow triggering was added to PSV in spontaneously breathing ventilated patients.

RESULTS

Respiratory rate (f), minute ventilation (Vepsilon), patient work of breathing (WOBp), respiratory drive (P0.1), rapid shallow breathing index (f/Vt), tidal volume (Vt) and a visual analog scale of breathing effort and comfort all improved. There was a large decrease in WOBp and P0.1 when flow triggering was added to PSV (P<.001). There was a moderate decrease in f/V1 during the same procedure (P<.01). Twelve patients felt subjectively better with the intervention.

CONCLUSIONS

Flow triggering offers an excellent complement to PSV because it improves patient comfort and reduces the magnitude of the inspiratory effort as well as the delay time between inspiratory muscle contraction and gas flow. It augments gas exchange at no metabolic cost to the patient while reducing the work of breathing.

Detection of DNA hybridization using the TISPR-1 surface plasmon resonance biosensor

Biotinylated oligonucleotide probes were immobilized to the gold sensor surface of the TISPR-1 miniature integrated surface plasmon resonance liquid sensor system for the purpose of detecting specific DNA hybridization. The immobilization of the oligonucleotide capture probes was carried out through streptavidin-biotin binding technology. The sensor detected the immobilization of unlabeled DNA through shifts in index of refraction as the molecules entered and remained selectively bound to the surface in the vicinity of the exponentially decaying surface plasmon resonance wave. The surface immobilization chemistry was proven to be stable for long periods of time, reproducible, and practical for detecting DNA hybridization with the TISPR-1. DNA hybridization was detected as a slow, positive, and small (when compared to protein-protein or antibody-antigen binding experiments) increase in the measured index of refraction under passive hybridization conditions by the TISPR-1 sensor. The DNA hybridization signal was significant (index of refraction change of 0.001) when large fragment PCR-amplified DNA products were hybridized to the oligonucleotide probes (S/N = 6-10). The DNA hybridization techniques were demonstrated using DNA sequences from the HIV genome which encode the Tat and Rev genes.

Construction of biosensors using a gold-binding polypeptide and a miniature integrated surface plasmon resonance sensor

Surface plasmon resonance (SPR) biosensors were constructed on miniature integrated sensors. Recognition elements were attached to the sensor surface using a gold-binding repeating polypeptide. Biosensors with fluorescyl groups attached to their surfaces were functional for at least 1 month of daily use with little decrease in response to the binding of an anti-fluorescyl monoclonal antibody. The coupling of protein A to the gold-binding polypeptide on the sensor surface enabled the biosensor to detect the binding of antibodies to the protein A and provided a sensor with convertible specificity. The system described herein provides a simple and rapid approach for the fabrication of highly specific, durable, portable and low cost SPR-based biosensors.

Quantitative methanol-burning lung model for validating gas-exchange measurements over wide ranges of FIO2

The methanol-burning lung model has been used as a technique for generating a predictable ratio of carbon dioxide production (VCO2) to oxygen consumption (VO2) or respiratory quotient (RQ). Although an accurate RQ can be generated, quantitatively predictable and adjustable VO2 and VCO2 cannot be generated. We describe a new burner device in which the combustion rate of methanol is always equal to the infusion rate of fuel over an extended range of O2 concentrations. This permits the assembly of a methanol-burning lung model that is usable with O2 concentrations up to 100% and provides continuously adjustable and quantitative VO2 (69-1,525 ml/min) and VCO2 (46-1,016 ml/min) at a RQ of 0.667.

Internucleosomal DNA cleavage in HeLa cells exposed to cisplatin

Exposure of HeLa cells to Cisplatin resulted in cell death characteristic of a suicide process known as apoptosis, as stated by morphologic features, extensive and specific DNA fragmentation and in situ end labeling of DNA breaks. The apoptotic cell death was induced timely in a dose-dependent manner, without any primary necrosis at the concentrations used. In contrast to other reports, the death in this cell line was accompanied by low-molecular weight DNA fragmentation. These results and their relevance to the apoptotic process are discussed.

One hundred consecutive hepatic resections. Blood loss, transfusion, and operative technique

BACKGROUND

Hepatic resection is prone to significant blood loss. Adverse effects of blood loss and transfusion mandate improvements in surgical techniques to reduce blood loss and transfusion requirements.

METHODS

One hundred hepatic resections were carried out using a standard surgical technique that includes control of the hilar structures, extrahepatic control of the hepatic veins, and use of the Pringle maneuver. Low central venous pressure and Trendelenburg positioning were used during parenchymal transection. Data were collected retrospectively in the first 36 patients, whereas data were collected prospectively in the remaining 64 patients.

RESULTS

Hospital mortality was 3%. Median blood loss was 450, 700, 1000, 1100, and 1500 mL for segmental, nonanatomic, lobar, extended right, and extended left resections, respectively. Major resections were more likely than minor resections to be transfused with albumin (P = .008), fresh frozen plasma (P = .009), and packed red blood cells or whole blood (P = .04). Overall transfusion of packed red blood cells or whole blood occurred in 59 of 100 patients. In the 64 patients who were followed up prospectively, the predeposit of autologous blood decreased the need for homologous transfusions from 56% to 38%. A further reduction in the transfusion rate of 25% could have been possible if all patients in the prospective group had donated 2 U of autologous blood. Patients who predeposited blood were more likely to receive transfusions and to have had a transfusion more than 24 hours after surgery than were patients who did not donate blood.

CONCLUSIONS

The surgical techniques used results in acceptable blood loss and transfusion requirements for hepatic resection. This approach is safe, cost-effective, reproducible, and applicable for widespread use.

Immunolocalization of proacrosin/acrosin in rabbit sperm during acrosome reaction and in spermatozoa recovered from the perivitelline space

The participation of acrosin in mammalian sperm penetration through the zona pellucida has been amply debated. In this paper we report the immunolocalization--by silver enhanced immunogold technique using ACRO-8C10 monoclonal antibody to human acrosin--of proacrosin/acrosin on ejaculated rabbit spermatozoa incubated in vitro in a capacitating medium and on spermatozoa recovered from the perivitelline space. After incubation in a capacitating medium, four different patterns were observed: (1) no labeling on acrosome intact spermatozoa; (2) labeling on the rim of the head; (3) labeling on the whole acrosome area; and (4) no labeling on acrosome reacted spermatozoa. At the start of incubation, spermatozoa with pattern 1 were the most abundant, whereas at the end of the 32 h incubation period, patterns 2 and 3 were the most frequent. On the other hand, 625 perivitelline spermatozoa were recovered from 17 fertilized rabbit eggs, of which 26% were labeled with the antiacrosin monoclonal antibody ACRO-8C10 in two different areas: (1) only on the equatorial region; and (2) only on the postacrosomal area. These results are consistent with the idea that proacrosin/acrosin remains associated to the acrosome reacted spermatozoa for long periods of time, and that proacrosin/acrosin associated to perivitelline spermatozoa could be responsible for the second penetration of fresh rabbit eggs by perivitelline spermatozoa.

High rates of survival and fertilization of mouse and hamster oocytes after vitrification in dimethylsulphoxide

A high proportion (> 70%) of mouse and hamster oocytes exposed for 3-5 min to 1.5 M dimethylsulfoxide (DMSO) and washed briefly in 3.9 M DMSO before vitrification in 6.0 M DMSO appeared morphologically normal on recovery. Significantly fewer (< 46%) mouse oocytes appeared normal when the time of exposure to 1.5 M DMSO was reduced to 1 min or less. The rate of fertilization in vitro of vitrified oocytes was reduced compared to the rate for untreated controls (mouse: 79% vs. 94%; hamster: 73% vs. 87%). After removal of the zona pellucida, fertilization was similar in vitrified and control hamster oocytes inseminated with hamster (> 90%) or human (21% vs. 23%) sperm. Sperm nuclear decondensation and pronuclear formation appeared to be delayed in the cytoplasm of vitrified hamster oocytes. Seventy-nine percent of 2-cell-stage mouse embryos derived from vitrified oocytes implanted after transfer to pseudopregnant recipients, but only 40% developed to normal fetuses compared to 61% of controls. The reason for this high rate of postimplantation loss is unknown.

Golden hamster perivitelline spermatozoa do not show proacrosin/acrosin at the inner acrosomal membrane

It has been suggested that acrosin may function in penetration of the zona pellucida and of the highly structured extracellular matrix of the perivitelline space. In this study we investigated whether golden hamster perivitelline spermatozoa contain proacrosin/acrosin, as evidenced by the silver enhanced immunogold technique using the monoclonal antibody antiacrosin C2E5. None of the 197 spermatozoa recovered from the perivitelline space showed proacrosin/acrosin associated with the acrosomal region, suggesting that acrosin would not play a role in the penetration of the perivitelline extracellular matrix.

Anesthetic Implications for Children Undergoing Computerized Tomography-Guided Stereotactic Brain Biopsy

Anesthesiologists spend much of their time administering anesthesia to children outside of the operating room, especially for neuroradiological evaluation. Neuroradiological procedures include magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography, myelography, pneumoencephalography, and arteriography. Each of these procedures presents a "working environment" that compromises the ability to deliver a safe and well-monitored anesthetic (1). CT-guided stereotactic brain biopsy in children requires two anesthetic locations (2). The stereotactic guidance apparatus renders the airway inaccessible both during CT and during transport to the operating room. We report a case of a child undergoing CT-guided stereotactic brain biopsy to elucidate the anesthetic considerations of this logistically difficult procedure.

Upper abdominal cancer surgery in the very elderly

From January 1981 to December 1987, 59 major upper abdominal operations were performed on 57 patients aged 80 to 90 years at Memorial Sloan-Kettering Cancer Center. Procedures for primary adenocarcinoma of the stomach, distal esophagus, pancreas, or hepatobiliary system were performed with curative intent or for palliation in 34 of 59 patients (58%) and bypass with limited or no resection in 13 of 59 patients (22%) patients. Emergency operations were performed in six (10%) patients for gastric bleeding, perforation, or outlet obstruction. Six (10%) patients underwent laparotomy for benign biliary obstruction (1), splenectomy for secondary thrombocytopenia (2), or gastrectomy for sarcoma (2) or lymphoma (1). Hospital mortality was 15% overall and 9% for major resections, 15% for bypass, and 67% for emergency procedures. Major complications occurred in 10 (20%) elective procedures. Mortality was associated with respiratory or cardiac failure while complications most commonly included arrhythmias and wound infection. Mean postoperative hospitalization was 18 days overall and 45 patients (76%) were discharged home. Median survival following major resection was 17.5 months but less than 2 months after bypass procedures. A protocol of pre-operative evaluation, intra-operative hemodynamic monitoring and postoperative intensive care has been formalized for use in elderly or poor-risk patients.