Skin temperature variability is an independent predictor of survival in patients with cirrhosis

Background

Cirrhosis is a disease with multisystem involvement. It has been documented that patients with cirrhosis exhibit abnormal patterns of fluctuation in their body temperature. However, the clinical significance of this phenomenon is not well understood. The aim of this study was to determine if temperature variability analysis can predict survival in patients with cirrhosis.

Methods

Thirty eight inpatients with cirrhosis were enrolled in the study. Wireless temperature sensors were used to record patients’ proximal skin temperature for 24 hr. The pattern of proximal temperature fluctuation was assessed using the extended Poincaré plot to measure short‐term and long‐term proximal temperature variability (PTV). Patients were followed up for 12 months, and information was collected on the occurrence of death/liver transplantation.

Results

During the follow‐up period, 15 patients (39%) died or underwent transplantation for hepatic decompensation. Basal proximal skin temperature absolute values were comparable in survivors and nonsurvivors. However, nonsurvivors showed a significant reduction in both short‐term and long‐term HRV indices. Cox regression analysis showed that both short‐term and long‐term PTV indices could predict survival in these patients. However, only measures of short‐term PTV were shown to be independent of the severity of hepatic failure in predicting survival. Finally, the prognostic value of short‐term PTV was also independent of heart rate variability, that is, a measure of autonomic dysfunction.

Conclusion

Changes in the pattern of patients’ temperature fluctuations, rather than their absolute values, hold key prognostic information, suggesting that impaired thermoregulation may play an important role in the pathophysiology of cirrhosis.

“So if Mr Blue Head here clicks the link...” Risk Thinking in Cyber Security Decision Making

Cyber security decision making is inherently complicated, with nearly every decision having knock-on consequences for an organisation’s vulnerability and exposure. This is further compounded by the fact that decision-making actors are rarely security experts and may have an incomplete understanding of the security that the organisation currently has in place. They must contend with a multitude of possible security options that they may only partially understand. This challenge is met by decision makers’ risk thinking —their strategies for identifying risks, assessing their severity, and prioritising responses. We study the risk thinking strategies employed by teams of participants in an existing dataset derived from a tabletop cyber-physical systems security game.  Our analysis identifies four structural patterns of risk thinking and two reasoning strategies: risk-first and opportunity-first . Our work highlights that risk-first approaches (as prescribed by the likes of NIST-800-53 and ISO 27001) are followed neither substantially nor exclusively when it comes to decision making. Instead, our analysis finds that decision making is affected by the plasticity of teams—that is, the ability to readily switch between ideas and practising both risk-first and opportunity-first reasoning.

A systematic review protocol examining the effect of vitamin D supplementation on endothelial function

INTRODUCTION

Vitamin D has potential benefits for extraskeletal health. These could include an anti-inflammatory effect as well as a reduction in endothelial dysfunction. We aim to provide quality evidence for the hypothesis that supplementation with vitamin D will improve endothelial function (EF), possibly through the abrogation of systemic inflammation.

METHODS AND ANALYSIS

We will conduct a systematic review of all randomised controlled trials on vitamin D supplementation and EF lasting 12 weeks or more. The search will cover the period 2000-2015 and include studies that describe direct measures of EF, markers of endothelial cell (EC) activation and if concurrently reported, indicators of systemic inflammation. Study selection will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and study quality will be assessed by the Jadad score in addition to an evaluation of allocation concealment and data analysis. If sufficient data are available, a meta-analysis will be conducted. The effect sizes will be generated using Hedges' g score, for both fixed and random effect models. I(2) statistics and Galbraith plots will be used to assess heterogeneity and identify their potential sources. Potential publication and small sample size bias will be assessed by visual inspections of funnel plots and also Egger's test. Meta-regression analysis (if feasible) will be conducted with restricted maximum likelihood (REML) estimation method, controlling for potential confounders (demographics, study methods, location, etc). A backward elimination process will be applied in the regression modelling procedure. Subgroup analysis, conditional on number of studies retrieved and their sample size, will be stratified on participant disease category, total dose administered, degree of 25(OH)D change and type of supplement used.

ETHICS AND DISSEMINATION

Formal ethical approval is not required as primary data will not be collected. The results will be disseminated through a peer-reviewed publication, conference presentation and the popular press.

TRIAL REGISTRATION NUMBER

International Prospective Register for Systematic Reviews (PROSPERO) number CRD42014013523.

Vitamin D supplementation and body weight status: a systematic review and meta-analysis of randomized controlled trials

Vitamin D is anticipated to have many extra-skeletal health benefits. We questioned whether supplementation with the vitamin influenced body weight and composition. A systematic review and meta-analysis was conducted on high-quality, randomized controlled trials (RCTs) that had supplemented vitamin D without imposing any caloric restriction. Eighteen trials reporting either body weight, body mass index (BMI), fat mass (FM), percentage fat mass (%FM) or lean body mass (LBM) met our criteria. Twelve studies provided the required data for the meta-analysis. Vitamin D supplementation did not influence the standardized mean difference (SMD) for body weight, FM, %FM or LBM. A small but non-significant decrease in BMI (SMD = -0.097, 95% confidence interval: [-0.210, 0.016], P = 0.092) was observed. Meta-regression confirmed that neither the absolute vitamin D status achieved nor its change from baseline influenced the SMD of any obesity measure. However, increasing age of the subjects predicted a shift in the SMD for FM towards the placebo treatment, whereas a greater percentage of women in these studies favoured a decrease in FM following vitamin D. Vitamin D supplementation did not decrease measures of adiposity in the absence of caloric restriction. A potential confounding by age and gender was encountered.

Academic and personal problems among Australian university students who drink at hazardous levels: web-based survey

ISSUE ADDRESSED

Australian university students consume large amounts of alcohol. There is little published information about personal and academic problems associated with this behaviour. We sought to estimate the prevalence, and identify variables associated with, alcohol-related problems among undergraduate hazardous drinkers.

METHODS

The control group members (942 undergraduates, 53.3% male, mean age 19.4 years) of an internet-based intervention trial, who scored ≥8 on the Alcohol Use Disorders Identification Test, completed two validated questionnaires about their experience of alcohol-related problems in the preceding 4 weeks. Regression models were used to identify associations between individual characteristics and alcohol-related problems.

RESULTS

One-quarter of participants had missed a class (25.6%) and/or had been unable to concentrate in class (25.7%), and 45% reported that their drinking had impacted negatively on their learning or grades. The most frequent non-academic problems were hangovers (74.8%), blackouts (44.8%), emotional outbursts (30.5%), vomiting (28.1%), arguments (20.2%) and drink-driving (23.2%). Male gender, lower age, being a smoker, being in the Faculty of Health (versus Humanities) and living in shared housing (versus with parents/guardians) were each associated with alcohol-related problems, whereas year of study had no association.

CONCLUSIONS

There is a high prevalence of preventable alcohol-related problems among undergraduates drinking at hazardous levels and a need for restriction of the availability and promotion of alcohol as well as intervention for individuals at high risk. SO WHAT?: Universities have a duty of care to large populations of young people drinking at hazardous levels and should make greater efforts to address hazardous alcohol consumption.

Ice crystal concentration in cumulus clouds: influence of the drop spectrum

Secondary ice crystals are thrown off when supercooled cloud drops are captured and freeze on a moving target in a cloud at -5 degrees C. The rate of production of these ice crystals is proportional to the rate of accretion of drops of the diameter >/=24 micrometers.

Aberdeen Colles' fracture brace as a treatment for Colles' fracture. A multicentre, prospective, randomised, controlled trial

We carried out a randomised, prospective, multicentre clinical trial of the treatment of Colles' fractures. A total of 339 patients was placed into two groups, those with minimally displaced fractures not requiring manipulation (151 patients) and those with displaced fractures which needed manipulation (188 patients). Treatment was by either a conventional Colles' plaster cast (a control group) or with a prefabricated functional brace (the Aberdeen Colles' fracture brace). Similar results were obtained in both groups with regard to the reduction and to pain scores but the brace provided better grip strength in the early stages of treatment. This was statistically significant after five weeks for both manipulated and non-manipulated fractures. At the tenth day the results were statistically significant only in manipulated fractures. There was no significant difference in the functional outcome between the two treatment groups. However, younger patients and those with less initial displacement had better functional results.

Antibodies against human putamen in adolescents with anorexia nervosa

OBJECTIVE

To examine whether antiputamen antibodies are present in adolescents with anorexia nervosa (AN).

METHOD

Using enzyme-linked immunosorbent assay (ELISA) with an extract of human putamen as an antigen, sera samples obtained from 22 adolescents with active AN and from 22 healthy adolescents (control group) were assayed for antibodies to neuronal components

RESULTS

Mean optical density (OD) readings for serum antibodies against human putamen in adolescents with AN was significantly greater than the mean OD readings in the control group (0.492 +/- 0.086 vs. 0.275 +/- 0.028, p =.02). When serum positivity was defined as an OD level greater than 2 SD above the mean control group value (0.541), antiputamen antibodies were detected in the blood of 6 AN patients (27%) whereas they were detected in the blood of 1 patient (5%) in the control group (p <.05; Fisher's exact test).

DISCUSSION

The detection of antiputamen antibodies in adolescents with AN suggests an underlying immune process at the putamen level in some patients with this eating disorder.

Investigation into the tribological condition of acetabular tissue after bipolar joint replacement hip surgery

The aim of this research was to investigate the tribological condition of acetabular tissue before and after bipolar hip surgery. Articular cartilage was taken from the femoral head of patients undergoing primary joint replacement as a control. Tissue was also taken from the acetabular cups of patients undergoing revision hip surgery after primary bipolar surgery and compared with the control cartilage. The biomechanical characteristics of the two tissue types were tested using friction and compression tests. The friction tests were carried out on a sliding friction rig under nominal contact stresses of 0.5 and 4 MPa. The compression tests were carried out under a 0.8 MPa contact stress. The majority of the bipolar patients produced friction coefficients that were significantly higher than those produced by the control group, and the compression tests highlighted that the tissue from the bipolar patients produced a much greater rate of increase in displacement compared with the control cartilage. Histology showed major differences between the control cartilage and the bipolar tissue. The control cartilage showed a healthy collagen structure with a good distribution of proteoglycan whereas the majority of the bipolar tissue had lost tissue architecture and had a sparse fibrous structure. The high friction coefficients with the bipolar tissue imply that the frictional torque at the outer head of the bipolar prosthesis would be large compared with the inner bearing frictional torque. It was therefore predicted that the motion of the bipolar prosthesis should occur at the inner bearing.

Anomalous diffraction theory for arbitrarily oriented finite circular cylinders and comparison with exact T-matrix results

A general method is developed to formulate extinction and absorption efficiency for nonspherical particles at arbitrary and random orientations by use of anomalous diffraction theory (ADT). An ADT for finite circular cylinders is evaluated as an example. Existing ADT's for infinite cylinders at arbitrary orientations and for finite cylinders at the normal incidence are shown to be special cases of the new formulation. ADT solutions for finite cylinders are shown to approach the rigorous T-matrix results when the refractive indices approach unity. The importance of some physical processes that are neglected in the ADT approximation are evaluated by comparisons between ADT and rigorous calculations for different particle geometries. For spheres, van de Hulst's ADT and Mie theory are used, whereas the ADT that we present and T-matrix calculations are used for cylinders of different diameter-to-length ratios. The results show that the differences in extinction between ADT and exact solutions generally decrease with nonsphericity. A similar decrease occurs for absorption at wavelengths of relatively strong absorption. The influence of complex refractive index is evaluated. Our results suggest that ADT may provide a useful approximation in parameterization and remote sensing of cirrus clouds in the Christiansen bands where the real part of the refractive index approaches unity and/or where relative absorption is strong.

Corona-producing ice clouds: a case study of a cold mid-latitude cirrus layer

A high (14.0-km), cold (-71.0 degrees C) cirrus cloud was studied by ground-based polarization lidar and millimeter radar and aircraft probes on the night of 19 April 1994 from the Cloud and Radiation Testbed site in northern Oklahoma. A rare cirrus cloud lunar corona was generated by this 1-2-km-deep cloud, thus providing an opportunity to measure the composition in situ, which had previously been assumed only on the basis of lidar depolarization data and simple diffraction theory for spheres. In this case, corona ring analysis indicated an effective particle diameter of ~22 mum. A variety of in situ data corroborates the approximate ice-particle size derived from the passive retrieval method, especially near the cloud top, where impacted cloud samples show simple solid crystals. The homogeneous freezing of sulfuric acid droplets of stratospheric origin is assumed to be the dominant ice-particle nucleation mode acting in corona-producing cirrus clouds. It is speculated that this process results in a previously unrecognized mode of acid-contaminated ice-particle growth and that such small-particle cold cirrus clouds are potentially a radiatively distinct type of cloud.

Droplet size spectra and water-vapor concentration of laboratory water clouds: inversion of Fourier transform infrared (500-5000 cm(-1)) optical-depth measurement

Infrared extinction optical depth (500-5000 cm(-1)) has been measured with a Fourier transform infrared spectrometer for clouds produced with an ultrasonic nebulizer. Direct measurement of the cloud droplet size spectra agree with size spectra retrieved from inversion of the extinction measurements. Both indicate that the range of droplet sizes is 1-14 mum. The retrieval was accomplished with an iterative algorithm that simultaneously obtains water-vapor concentration. The basis set of droplet extinction functions are computed once by using numerical integration of the Lorenz-Mie theory over narrow size bins, and a measured water-vapor extinction curve was used. Extinction and size spectra are measured and computed for both steady-state and dissipating clouds. It is demonstrated that anomalous diffraction theory produces relatively poor droplet size and synthetic extinction spectra and that extinction measurements are helpful in assessing the validity of various theories. Calculations of cloud liquid-water content from retrieved size distributions agree with a parameterization based on optical-depth measurements at a wave number of 906 cm(-1) for clouds that satisfy the size spectral range assumptions of the parameterization. Significance of droplet and vapor contribution to the total optical depth is used to evaluate the reliability of spectral inversions.

An immunoassay for anti-neuronal antibodies associated with involuntary repetitive movement disorders

Tourette's syndrome (TS) is a complex neurobehavioral disorder emerging in childhood and is characterized by motor and vocal tics of at least one year in duration. In a portion of patients with TS, environmental (non-genetic) factors may either have an etiologic role or act to modulate the phenotype. One possible environmental factor may be antibodies to central nervous system cells, as sera from several children diagnosed with either TS or Sydenham's chorea contained anti-neuronal antibodies. Using enriched membrane preparations isolated from HTB-10 neuroblastoma cells, a sensitive and specific assay was developed for the determination of human anti-neuronal antibodies associated with involuntary repetitive movement disorders. This assay exhibited between-run and within-run precision of 11.3 percent and 5.9 percent, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of this assay for the diagnosis of TS and TS or chorea are 79.1 percent, 61.2 percent, 61.6 percent, 78.8 percent, and 71.1 percent, 60.9 percent, 68.6 percent, and 63.6 percent, respectively. In addition, there was a significant difference (p < 0.0001) between the mean optical density in the patients with TS and children determined to be clinically "normal".

Infected lower extremity extra-anatomic bypass grafts: management of a serious complication in high-risk patients

To determine optimal management and outcome of infected extra-anatomic bypass grafts (EABG), we reviewed 28 patients (19 men and 9 women; mean age 70 years) treated over a 13-year period. Mean follow-up was 42 months. There were 16 axillofemoral (AF), 10 femorofemoral (FF), and two axillopopliteal (AP) grafts. Risk factors included previous prosthetic graft infection in 13 patients, enterocutaneous fistula in two, and mycotic aortic aneurysm in one. Initial management involved complete graft excision in 12 patients, partial graft excision in 10, and nonresectional therapy in six. Failure of nonresectional therapy and partial excision in three patients each required further operative intervention with graft excision. Reconstruction in patients eventually requiring graft excision (n = 25) entailed placement of a new prosthetic AF or AP graft in eight, an autogenous FF graft in five, combined prosthetic AF and autogenous FF bypass in two, autogenous iliofemoral bypass in one, obturator bypass in one, or no reconstruction in eight. Four autogenous FF reconstructions thrombosed immediately postoperatively, and three prosthetic reconstructions became infected. The mortality rate was 18% (FF = 20%, AF = 19%, AP = 0%). The amputation rate was 25% (AP = 100%, AF = 25%, FF = 10%) and was higher without arterial reconstruction (56% vs. 12%, p = 0.02). Two patients required hemipelvectomies and one had bilateral hip disarticulation. We conclude that EABG infections can be successfully treated but carry significant morbidity and mortality. Optimal management includes EABG resection and prompt revascularization, bearing in mind the risk of early thrombosis in autogenous grafts and reinfection in prosthetic grafts.

Extinction efficiency in the infrared (2-18 µm) of laboratory ice clouds: observations of scattering minima in the Christiansen bands of ice

Extinction measurements with a laser diode (0.685 µm) and a Fourier transform infrared spectrometer (2-18 µm) were performed on laboratory ice clouds (5 µm ≤ D ≤ 70 µm) grown at a variety of temperatures, and thus at a variety of crystal habits and average projected crystal area. Ice clouds were grown by nucleation of a supercooled water droplet cloud with a rod cooled with liquid nitrogen. The ice crystals observed were mainly plates and dendrites at the coldest temperatures (≈-15 °C) and were mainly columns and needles at warmer temperatures (≈-5 °C). The crystals were imaged with both a novel microscope equipped with a video camera and a heated glass slide and a continuously running Formvar replicator. The IR spectral optical-depth measurements reveal a narrow (0.5-µm-width) extinction minimum at 2.84 µm and a wider (3-µm-width) minimum at 10.5 µm. These partial windows are associated with wavelengths where the real part of the index of refraction for bulk ice has a relative minimum so that extinction is primarily due to absorption rather than scattering (i.e., the Christiansen effect). Bulk ice has absorption maxima near the window wavelengths. IR extinction efficiency has a noticeable wavelength dependence on the average projected crystal area and therefore on the temperaturedependent crystal properties. The average-size parameters in the visible for different temperatures ranged from 64 to 128, and in the IR they ranged from 2.5 to 44. The extinction efficiency and the single-scatter albedo for ice spheres as computed from Mie scattering also show evidence of the Christiansen effect.

The endoscopic diagnosis of iliac colonic fistula and review of literature

Although the efficacy of upper gastrointestinal endoscopy in the diagnosis of a graft-enteric fistula is defined, the clinical utility of colonoscopy in this problem is not well described. We report a case of a 65-yr-old white male with gastrointestinal bleeding and a suspected graft-enteric fistula which was diagnosed by an immediate preoperative colonoscopic examination. The colonoscopy performed under general anesthesia in the operating room not only documented the presence and location of the graft colonic fistula but also illustrated the necessity for a more radical surgical resection before any planned revascularization. The current literature on the various methods of diagnosis and management of graft-enteric fistula was reviewed.

Multiple aortic aneurysms: the results of surgical management

During the past 2 decades 102 consecutive patients (77 men and 25 women) with multiple aortic aneurysms underwent 201 aortic reconstructions. These procedures (174 elective and 27 emergent) represented 3.4% of the 5837 aortic aneurysm operations performed. Seventy-five (30.9%) of the 243 aneurysms occurred in the infrarenal aorta, 65 occurred in the descending aorta (26.7%), 56 occurred in the thoracoabdominal aorta (23.0%), and 47 occurred in the ascending aorta or arch (19.3%). Ages ranged from 20 to 81 years (mean 63.3 years). Smoking history and abnormal electrocardiographic tracings were present in 84.3% of the patients, hypertension was present in 77.5%, and obstructive lung disease was present in 60.8%. Multiple aortic aneurysms were present at the time of the first repair in 55 patients (53.9%). Twelve patients had one procedure, 81 had two, and nine had three. Sixteen (17.8%) of the 90 patients who had multiple operations had a subsequent operation for complications of the unrepaired aneurysm (rupture 12, symptoms 4). Fourteen perioperative deaths occurred among the 174 elective repairs (8.0%), and 11 occurred among the 27 emergent procedures (40.7%). Procedure mortality increased with the ordinal number of elective operations and was 4.4% for the first, 10.4% for the second, and 33.3% for the third. Seven of 21 patients (33.3%) who had simultaneous repair of at least two aortic aneurysms died in the perioperative period. Overall, 77 of the 102 patients (75.5%) survived all surgical procedures to repair their multiple aortic aneurysms; of these, 63 had complete resection of all known aneurysms. Follow-up was complete in all patients and averaged 6.3 years (ranges: 1 month to 19 years). There were 30 late deaths; the most frequent cause was myocardial infarction. Kaplan-Meier 5-year survival including perioperative deaths for all patients after the first operation was 76% and after the last operation 40%. We conclude that multiple aortic aneurysms can be safely managed, usually with staged repairs, and that long-term survival is probably. After the first aortic operation the presence of multiple aneurysms mandates close observation with timely surgical intervention.

8;21 translocation in myelodysplasia secondary to essential thrombocythemia

A case is presented of a 73-year-old woman who received busulphan for essential thrombocythemia and subsequently developed a myelodysplastic syndrome (MDS), which transformed to acute nonlymphoblastic leukaemia within 1 month. Cytogenetic studies showed a 46,XX,t(8;21) (q22;q22) karyotype in all metaphases examined at diagnosis. The karyotypic abnormality is previously unreported in secondary myelodysplasia and may have specific clinical implications in this setting, such as early transformation to acute leukaemia and short survival. This finding contrasts with the generally favourable prognosis of the 8;21 translocation in patients with de novo acute nonlymphoblastic leukemia. A possible explanation for this difference may be the involvement of a committed progenitor in acute nonlymphoblastic leukaemia, while in myelodysplasia the more primitive multipotent stem cell may be affected.

Solute effects on ice recrystallization: an assessment technique

Reliable assessment of the effect of a solute upon ice recrystallization is accomplished with "splat cooling," the impaction of a small solution droplet onto a very cold metal plate. The ice disc has extremely small crystals, and recrystallization can be followed without confusing effects caused by grain nucleation. This method confirms the exceptionally strong recrystallization inhibition effect of antifreeze protein from Antarctic fish and shows that grain growth rate is a sensitive function of both grain size and solute concentration.

Epiphyseal replacement using developing tissue donors in a murine model: a combined histologic and radiographic study

Epiphyseal transplantation has long been a goal of orthopaedic surgeons. While microvascular surgery has raised hopes that this goal could be achieved, factors other than blood supply also appear capable of affecting the function of the epiphysis. Basic research into the biology of the epiphysis appears to be required. This would be facilitated with a model of epiphyseal transplantation using a small mammal. The purpose of this experiment was to develop such a model in the mouse. Developing CD1 mouse or Lewis rat limb tissue was used to replace knee tissue that had been resected from CD1 postnatal mouse hosts. Donor tissue ranged from 14-day embryonic mouse to 9-day postnatal mouse or 18- and 19-day fetal rat, which has a gestation similar to the mouse. The murine tissue is known to be avascular prior to the sixth postnatal day. The limbs were analyzed radiographically and histologically. The results show that epiphyseal replacement could be studied using developing tissue donors in a murine model. The results suggest that donor tissue prior to vascularization and tissue combinations with the least developmental time mismatch (the least heterochronicity) produced relatively the best, although still abnormal epiphyses.

Ice growth in supercooled solutions of antifreeze glycoprotein

Inhibition of ice growth in supercooled solution by certain proteins is vital to the survival of many living organisms. Some fish, native to both subzero northern and southern waters, have special proteins or glycoproteins in their blood serum that inhibit ice formation. Whereas these proteins have only a very small effect on the melting temperature of ice, the temperature of these fish can fall to nearly 1 K below the melting point before ice crystals grow. This phenomenon is called freezing hysteresis, in contrast to the normal colligative effect of solutes that depresses the equilibrium temperature, around which small changes lead to crystal growth or melting depending on sign. Some insects also exhibit a serum freezing hysteresis. We report the effects of different degrees of supercooling on the habit and rates of growth of ice crystals from solutions of these antifreeze glycoproteins (AFGPs). We find that the crystallization rate is up to five times greater than that in pure water.

Cytogenetic and endocrine studies of a freemartin heifer and its bull co-twin

The study of a bovine freemartin and its male co-twin has shown that the sex-reversed gonads of the female are secreting testosterone. Therefore, we suggest that the masculinisation of the freemartin’s reproductive tract may be due to sex hormones secreted by its own gonads, rather than by those from its male co-twin. On the evidence at present available, we favour the view that the female gonad is sex-reversed by a humoral inductor substance coming from the male co-twin that causes retention of the medullary sex cords. A study of the male co-twin suggests that its gonads may also be abnormal in that they secrete reduced amounts of androgen. Both twins showed extensive 60, XX/60, XY chimaerism, with a metacentric marker chromosome associated with the XY cell line only. This was derived from the dam. The proportion of XY cells varied markedly between tissues in both the twins. We were unable to find any germ cells in the female gonad, and, with the exception of one possible female pachytene, all the germ cells examined in the male’s testes were XY.