Y2K medical disaster preparedness in New York City: confidence of emergency department directors in their ability to respond

OBJECTIVES

To study the preparedness New York City for large scale medical disasters using the Year 2000 (Y2K) New Years Eve weekend as a model.

METHODS

Surveys were sent to the directors of 51 of the 9-1-1-receiving hospitals in New York City before and after the Y2K weekend. Inquiries were made regarding hospital activities, contingencies, protocols, and confidence levels in the ability to manage critical incidents, including weapons of mass destruction (WMD) events. Additional information was collected from New York City governmental agencies regarding their coordination and preparedness.

RESULTS

The pre-Y2K survey identified that 97.8% had contingencies for loss of essential services, 87.0% instituted their disaster plan in advance, 90.0% utilized an Incident Command System, and 73.9% had a live, mock Y2K drill. Potential terrorism influenced Y2K preparedness in 84.8%. The post-Y2K survey indicated that the threat of terrorism influenced future preparedness in 73.3%; 73.3% had specific protocols for chemical; 62.2% for biological events; 51.1% were not or only slightly confident in their ability to manage any potential WMD incidents; and 62.2% felt very or moderately confident in their ability to manage victims of a chemical event, but only 35.6% felt similarly about victims of a biological incident. Moreover, 80% felt there should be government standards for hospital preparedness for events involving WMD, and 84% felt there should be government standards for personal protective and DECON equipment. In addition, 82.2% would require a moderate to significant amount of funding to effect the standards. Citywide disaster management was coordinated through the Mayor's Office of Emergency Management.

CONCLUSIONS

Although hospitals were on a heightened state of alert, emergency department directors were not confident in their ability to evaluate and manage victims of WMD incidents, especially biological exposures. The New York City experience is an example for the rest of the nation to underscore the need for further training and education of preparedness plans for WMD events. Federally supported education and training is available and is essential to improve the response to WMD threats.

Ischaemic heart disease may predispose to pseudophakic cystoid macular oedema

PURPOSE

Pseudophakic macular oedema (PMO) is uncommon following uncomplicated phacoemulsification and lens implantation and the cause of infrequent cases is rarely understood. This study was undertaken to determine whether a relationship exists between ischaemic heart disease (IHD) and PMO.

METHODS

Retrospective case note review was carried out of 177 (252 eyes) consecutive patients without pre-existing retinal disease who underwent phacoemulsification and intraocular lens implantation during a 12 month period. Patients with a post-operative best corrected visual acuity < 6/9 underwent slit-lamp biomicroscopy and fluorescein angiography to identify PMO. IHD was defined on clinical and electrocardiographic grounds. The incidence of IHD was compared in patients with and without PMO and statistical analysis performed using the Fisher's exact test.

RESULTS

PMO occurred in 4 patients (6 eyes), all of whom had IHD, whereas no PMO occurred in the remaining 173 patients (246 eyes) (p = 0.04).

CONCLUSIONS

Pseudophakic macular oedema represents an important complication following modern phacoemulsification and intraocular lens implantation and is associated significantly with ischaemic heart disease.

Feasibility of surveillance of changes in human fertility and semen quality

There is concern that male fertility is declining, but this is difficult to study because few men volunteer for studies of semen quality, and recruitment bias may over-represent the subfertile. The Human Reproduction Programme of the World Health Organization developed a protocol for multicentre studies of fertility involving a questionnaire for pregnant women to obtain time to pregnancy (TTP): the number of menstrual cycles taken to conceive. Male characteristics and semen quality will be determined in a subset of the partners. Our aim was to validate the TTP questionnaire, and to examine potential recruitment bias and feasibility of conducting large-scale surveillance of fertility. The questionnaire was administered to 120 pregnant women (16-32 weeks). Validation included internal reliability by consistency of responses, test-re-test reliability by repeat administration (20 women) and accuracy by comparison of gestational age from first antenatal ultrasound and menstrual dates. Internal reliability was high. Agreement between categorical responses on re-testing was very good (k > 0.8). In both the re-test and gestational age analysis, differences in TTP of 1 cycle were found (standard deviation <0.25 cycles). In this small pilot study there was no evidence of recruitment bias. Response rates indicate the feasibility of surveillance of fertility in large maternity centres.

Where genetic algorithms excel

We analyze the performance of a genetic algorithm (GA) we call Culling, and a variety of other algorithms, on a problem we refer to as the Additive Search Problem (ASP). We show that the problem of learning the Ising perceptron is reducible to a noisy version of ASP. Noisy ASP is the first problem we are aware of where a genetic-type algorithm bests all known competitors. We generalize ASP to k-ASP to study whether GAs will achieve "implicit parallelism" in a problem with many more schemata. GAs fail to achieve this implicit parallelism, but we describe an algorithm we call Explicitly Parallel Search that succeeds. We also compute the optimal culling point for selective breeding, which turns out to be independent of the fitness function or the population distribution. We also analyze a mean field theoretic algorithm performing similarly to Culling on many problems. These results provide insight into when and how GAs can beat competing methods.

The human acrosome reaction

We developed tests of sperm-oocyte interaction: sperm-zona binding, zona-induced acrosome reaction, spermzona penetration and sperm-oolemma binding, using oocytes which failed to fertilise in clinical in vitro fertilization (IVF). Although oocyte defects contribute to failure of sperm oocyte interaction, rarely are all oocytes from one woman affected. Low or zero fertilization in standard IVF was usually caused by sperm abnormalities. Poor sperm-zona pellucida binding was frequently associated with failure of standard IVF and obvious defects of sperm motility or morphology. The size and shape of the acrosome is particularly important for sperm binding to the oocyte. The proportion of acrosome intact sperm in the insemination medium was related to the IVF rate. Inducing the acrosome reaction with a calcium ionophore reduced sperm-zona binding. Blocking acrosome dispersal with an acrosin inhibitor prevented spermzona penetration. Sperm-zona penetration was even more highly related to IVF rates than was sperm-zona binding. Some patients had low or zero fertilization rates with standard IVF but normal sperm by conventional tests and normal sperm-zona binding. Few of their sperm underwent the acrosome reaction on the surface of the zona and none penetrated the zona. In contrast, fertilization and pregnancy rates were high with intracytoplasmic sperm injection. We call this condition defective zona pellucida induced acrosome reaction. Discovery of the nature of the abnormalities in the signal transduction and effector pathways of the human zona pellucida induced acrosome reaction should result in simpler tests and treatments for the patients and also provide new leads for contraceptive development.

Non-erythroid form of acute intermittent porphyria caused by promoter and frameshift mutations distant from the coding sequence of exon 1 of the HMBS gene

Acute intermittent porphyria (AIP) is a low-penetrant, autosomal dominant disorder caused by mutations in the HMBS gene. The gene is transcribed from two promoters to produce ubiquitous and erythroid isoforms of porphobilinogen deaminase, which differ only at their NH2 ends. In the classical form of AIP, both isoforms are deficient, but about 5% of families have the non-erythroid variant in which only the ubiquitous isoform is affected. Previously identified mutations in this variant have been within or close to the coding region of exon 1 of the HMBS gene, the only exon that is expressed solely in the ubiquitous isoform. Here, we describe mutations in the ubiquitous promoter (-154delG) and in exon 3 (41delA) that cause the non-erythroid variant. Reporter gene and electrophoretic mobility shift assays show that the G nucleotide at position -154, the most 5' of several transcription-initiation sites in the ubiquitous HMBS promoter, which lies immediately 3' to a transcription-factor IIB binding motif, is essential for normal transcription. The frameshift mutation in exon 3 introduces a stop codon into mRNA for the ubiquitous isoform only. Our investigations identify two new mechanisms for production of the non-erythroid variant of AIP and demonstrate that mutational analysis for diagnosis of this variant needs to include wider regions of the HMBS gene than indicated by previous reports. Furthermore, they show that deletion of one of several transcription initiation sites in the promoter of a housekeeping gene that lacks both TATA and initiator elements can produce disease.

Efficacy and acceptability of testosterone implants, alone or in combination with a 5alpha-reductase inhibitor, for male hormonal contraception

Testosterone (T) treatment suppresses serum gonadotropins and reduces sperm output sufficiently for contraceptive efficacy in approximately 70% of Caucasian men. In the remaining 30% of men, an increase in 5alpha-reductase activity may maintain testicular androgen activity, thus accounting for the failure of sperm suppression. The form of T therapy is a major consideration in the safety and acceptability of T-based contraception. As compared to T ester injections, T implants provide a more physiological serum T profile and fewer side effects, but have not yet been used in contraceptive efficacy studies. We have used T implants (800-1200 mg every 3 months) in 29 normal men for 3-16 months. T implants produced long-term suppression of sperm densities below 1 million/mL in approximately 70% of men without significant androgenic side effects. No pregnancies occurred in 214 months of exposure. In 16 men failing to suppress within 3 months of T 800 mg, no evidence of enhanced spermatogenic suppression was seen with the co-administration of the type 2 5alpha-reductase inhibitor, finasteride, for 3 months when compared to placebo. We conclude that: 1) T implants provide adequate spermatogenic suppression in approximately 70% of Caucasian men, a rate comparable to intramuscular T injections but with minimal side effects; and, 2) the inclusion of a type 2 5alpha-reductase inhibitor does not enhance spermatogenic suppression.

Feasibility of surveillance of changes in human fertility and semen quality

To show that male fertility is declining is not simple. Few men volunteer and recruitment bias may lead to over-representation of the subfertile. Semen analysis has errors arising from counting and poorly standardized criteria, which may be overcome by automation. Time to pregnancy (TTP)-the number of menstrual cycles taken to conceive-measures fertility and allows male recruitment bias to be estimated. We review automated measurement of sperm concentration, motility and morphology and present a preliminary report on a study to assess a retrospective TTP questionnaire, recruitment bias and feasibility for large-scale surveillance of fertility.

Nine novel L1 CAM mutations in families with X-linked hydrocephalus

Mutations in the gene for neural cell adhesion molecule L1 are responsible for the highly variable phenotype found in families with X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type I. To date, 32 different mutations have been observed, the majority being unique to individual families. Here, we report nine novel mutations in L1 in 10 X-linked hydrocephalus families. Four mutations truncate the L1 protein and eliminate cell surface expression, and two would produce abnormal L1 through alteration of RNA processing. A further two of these mutations are small in-frame deletions that have occurred through a mechanism involving tandem repeated sequences. Together with a single missense mutation, these latter examples contribute to the growing number of existing mutations that affect short regions of the L1 protein that may have particular functional significance.

Validation of self-reported chronic conditions and health services in a managed care population

BACKGROUND

Self-reported data are commonly used to estimate the prevalence of health conditions and the use of preventive health services in the population, but the validity of such data is often questioned.

METHODS

The Behavioral Risk Factor Survey (BRFS) was admin istered by telephone to a stratified, random sample of health maintenanc e organization (HMO) subscribers in Colorado in 1993, and self-reports w ere compared with HMO medical records for 599 adults aged >21. Sensitivity and specificity were calculated for three chronic conditions and use of six preventive services.

RESULTS

Sensitivity was highest for hypertension (83%), moderate for diabetes (73%), and lowest for hypercholesterolemia (59%); specificity was >80% for all three conditions. Sensitivity ranged from 86% to 99% for influenza immunization, clinical breast examination, blood cholesterol screening, mammography, Pap test, and blood pressure screening; specificity was <75% for all preventive services.

CONCLUSIONS

Self-reports are reasonably accurate for certain chronic conditions and for routine screening exams and can provide a useful estimate for broad measures of population prevalence.

Mutations in the human delta homologue, DLL3, cause axial skeletal defects in spondylocostal dysostosis

Spondylocostal dysostosis (SD, MIM 277300) is a group of vertebral malsegmentation syndromes with reduced stature resulting from axial skeletal defects. SD is characterized by multiple hemivertebrae, rib fusions and deletions with a non-progressive kyphoscoliosis. Cases may be sporadic or familial, with both autosomal dominant and autosomal recessive modes of inheritance reported. Autosomal recessive SD maps to a 7.8-cM interval on chromosome 19q13.1-q13.3 that is homologous with a mouse region containing a gene encoding the Notch ligand delta-like 3 (Dll3). Dll3 is mutated in the X-ray-induced mouse mutant pudgy (pu), causing a variety of vertebrocostal defects similar to SD phenotypes. Here we have cloned and sequenced human DLL3 to evaluate it as a candidate gene for SD and identified mutations in three autosomal recessive SD families. Two of the mutations predict truncations within conserved extracellular domains. The third is a missense mutation in a highly conserved glycine residue of the fifth epidermal growth factor (EGF) repeat, which has revealed an important functional role for this domain. These represent the first mutations in a human Delta homologue, thus highlighting the critical role of the Notch signalling pathway and its components in patterning the mammalian axial

Impact of infants born at the threshold of viability on the neonatal mortality rate in Colorado

OBJECTIVE

To determine the contribution of infants born at the threshold of viability (< 750 gm) on neonatal mortality in Colorado.

STUDY DESIGN

For the period of January 1991 to December 1996, all Colorado live births who expired were evaluated for gestational age, birth weight, gender, hospital level of care, age at time of death, delivery room resuscitation, mechanical ventilation, medical and surgical complications, and serious malformations.

RESULTS

Although infants weighing < 750 gm represent only 0.31% of all live births, they account for 46.3% of deaths. While those infants weighing < 500 gm and with a gestation of < 24 weeks almost always died (94.7%), the majority born in the 500- to 745-gm category (55.8%) survived. The vast majority (88.5%) of deaths occurred on the first day of life. A total of 38.4% of births in which the infant weighed < 750 gm occurred outside bona fide regional perinatal centers.

CONCLUSION

Future attempts to reduce the Colorado neonatal mortality rate would best focus on the 500- to 750-gm weight group through the re-regionalization of high-risk perinatal care.

Comparison of human cervical mucus and artificial sperm penetration media

The cervical mucus penetration tests aid research and determine the clinical importance of positive sperm antibody tests. Limited availability and variability of human cervical mucus have instigated the search for mucus substitutes for these tests. This study compares sperm migration in cervical mucus with that in artificial media including hyaluronate solution, egg white and albumin Tyrode solution. Results were quantified by measuring the migration distance (the maximum distance of capillary migration from a semen reservoir by spermatozoa after 1 h) and the sperm concentration at half the migration distance. The mean of both measures for cervical mucus and hyaluronate solution were equivalent [4.4 +/- 1.1 (SD) versus 4.3 +/- 1.0 cm and 118 +/- 51 versus 111 +/- 44x10(3)/ml], and higher than in egg white and albumin Tyrode solution. Antisperm antibodies impaired sperm penetration in cervical mucus and hyaluronate solution in a similar manner (r = 0.92). These results suggest that hyaluronate solution sufficiently resembles human cervical mucus in terms of penetrability that it may be used as a substitute for mucus in capillary tube tests of sperm function. The higher penetrability of cervical mucus and hyaluronate solution is probably related to a channelling effect due to their polymeric structure.

The spectrum of Silver-Russell syndrome: a clinical and molecular genetic study and new diagnostic criteria

The Silver-Russell syndrome (SRS) is characterised by severe intrauterine growth retardation, with a preserved head circumference, leading to a lean body habitus and short stature. Facial dysmorphism and asymmetry are considered typical features of the syndrome, although the range of phenotypic variance is unknown. Fifty seven subjects varying in age from 0.84 to 35.01 years, in whom the diagnosis of SRS had been considered definite or likely, were re-evaluated in a combined clinical and molecular study by a single observer (SMP). In 50 patients the clinical findings complied with a very broad definition of SRS. Notable additional findings included generalised camptodactyly seen in 11 (22%), many with distal arthrogryposis. Thirteen of the 25 males required genital surgery for conditions including hypospadias and inguinal hernia. Fourteen (36.8%) subjects above school age have received a statement of special educational needs. Molecular genetic analysis was performed in 42 subjects and has identified maternal uniparental disomy of chromosome 7 in four. The phenotype was generally milder with birth weights for one patient above and three below -2 SD from the mean. Two children had classical facial dysmorphic features, and two had a milder facial phenotype. Of relevance to the possible molecular mechanism underlying this condition, none of the four disomic patients had significant asymmetry.

Neonatal diabetes mellitus and cerebellar hypoplasia/agenesis: report of a new recessive syndrome

Classical neonatal diabetes mellitus is defined as hyperglycaemia occurring within the first six weeks of life in term infants. Cerebellar agenesis is rare. We report three cases of neonatal diabetes mellitus, cerebellar hypoplasia/agenesis, and dysmorphism occurring within a highly consanguineous family. This constellation of abnormalities has not previously been described. Two of these cases are sisters and the third case is a female first cousin. The pattern of inheritance suggests this is a previously undescribed autosomal recessive disorder. Prenatal diagnosis of the condition in this family was possible by demonstration of the absence of the cerebellum and severe IUGR.

A gene for autosomal recessive spondylocostal dysostosis maps to 19q13.1-q13.3

In spondylocostal dysostosis (SD), vertebral-segmentation defects are associated with rib anomalies. This results in short-trunk short stature, nonprogressive kyphoscoliosis, and radiological features of multiple hemivertebrae and rib fusions. SD can be familial, and both autosomal dominant and autosomal recessive (AR) inheritance have been reported, but no genes have been identified or localized for nonsyndromic SD in humans. We performed genomewide scanning by homozygosity mapping in a large consanguineous ARSD Arab Israeli family with six definitely affected members. Significant linkage was found to chromosome 19q13, with a LOD score of 6.9. This was confirmed in a second Pakistani family with three affected members, with a LOD score of 2.4. The combined-haplotype data identify a critical region between D19S570 and D19S908, an interval of 8.5 cM on 19q13.1-19q13.3. This is the first study to localize a gene for nonsyndromic SD. ARSD is clinically heterogeneous and is likely to result from mutations in developmental genes or from regulating transcription factors. Identification of these genes will improve the understanding of the molecular processes contributing to both normal and abnormal human vertebral development.

Quantitative sperm mucus penetration: modified formulae for calculating penetration efficiency

In 1980 Katz et al. derived a formula for the percentage of successful collisions (PSC) as a quantitative measure of sperm-cervical mucus penetration efficiency. The use of PSC waned after its validity was questioned by reports of values >100% and the observation that PSC varied with the cross-sectional area of the mucus column. The aim of the present study was to develop a more accurate measure of mucus penetration efficiency by correcting the original formula for the effects of sperm depletion in the semen reservoir. Two formulae were derived using different models for the sperm-mucus interaction: (i) each motile spermatozoon was assumed to have an equal chance of mucus penetration on collision; (ii) a select subpopulation of spermatozoa was assumed to penetrate with 100% efficiency on collision. Both modified formulae gave PSC values higher than the original estimates. Under the experimental conditions employed in this work, where large capillaries were used, the depletion corrections ranged from 4 to 46% (n=8, mean 20%) for model (i) and from 190 to 320% (n=8, mean 250%) for model (ii). The invariance of PSC (ii) results with respect to capillary cross-sectional area (1.52 mm2, 31.1%; 5.4 mm2, 28.2%) suggests that the assumptions of model (ii) provide the more accurate description of the sperm-mucus interaction.

Prenatal sonographic diagnosis of cleidocranial dysostosis

Cleidocranial dysostosis is an autosomal dominant disorder characterized by absence or hypoplasia of the clavicles, skull abnormalities, and abnormal dentition. The prenatal diagnosis of this condition has been reported once previously in a known high-risk pregnancy. In this report we describe the prenatal findings of cleidocranial dysostosis at 19 weeks' gestation in a woman affected with this disorder but undiagnosed before the fetal scan. This report is unique in the sense that an autosomal dominant condition diagnosed in the fetus led to a similar diagnosis in the mother.

Selectivity of the human sperm-zona pellucida binding process to sperm head morphometry

OBJECTIVE

To obtain quantitative measures of morphometric selectivity of the human spermzona pellucida binding process as determined by light microscopy.

DESIGN

Fully automated sperm head morphometric based on a 32-dimensional parameterization of images of Shorr-stained sperm. Zona pellucida selected sperm removed from reinseminated oocytes that previously failed IVF.

SETTING

Academic research group associated with a tertiary infertility service.

PATIENT(S)

Semen samples from 51 infertile patients.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Differences in morphometric parameter means observed before and after swim-up and binding to zonae pellucidae.

RESULT(S)

Significant differences between insemination and bound sperm were observed in 17 parameter means and 21 standard deviations. The sperm-zona pellucida binding process preferentially selects sperm heads with a large anterior region with relatively low optical density, as well as high axial symmetry and minimal neck anomalies. Bias against sperm with pyriform morphology was not observed.

CONCLUSION(S)

A causal link has been established between sperm head morphometry, particularly within the acrosomal region, and the ability of sperm to bind to the human zona pellucida. As sperm-zona binding is necessary for fertility, it is possible to derive a physiologically based assessment for clinical diagnosis of male infertility using the "zona-preferred" morphometry results.

Travel times and radiotherapy uptake in two English counties

OBJECTIVES

To examine whether longer travel times for radiotherapy are associated with reduced overall uptake of radiotherapy treatment, or with reduced uptake of palliative as opposed to radical radiotherapy.

DESIGN

Correlations of weighted average travel times for radiotherapy with overall radiotherapy uptake, and of travel times to one cancer centre with the ratio of palliative to radical radiotherapy at that centre.

SETTING

The fourteen local authority (county) Districts of Bedfordshire and Hertfordshire.

SUBJECTS

Residents of Bedfordshire and Hertfordshire registered by the Cancer Registries as attending hospital with a diagnosis of cancer, and registered as receiving radiotherapy treatment. Residents recorded by single cancer centre as receiving radical or palliative radiotherapy at that centre.

RESULTS

There was no significant correlation between travel times for treatment and overall radiotherapy uptake (r = 0.40, P = 0.18), or with the ratio of palliative to radical radiotherapy at a single centre (r = -0.29, P = 0.34). Both measures of uptake showed considerable variability. Longest travel times were about one hour.

CONCLUSIONS

Travel times up to one hour do not appear to reduce radiotherapy uptake, and the variability observed is likely to be due to other factors. The recommendation of the Chief Medical Officer's expert advisory group on cancers, that radiotherapy should be provided in larger cancer centres, is unlikely to result in lower radiotherapy uptake with travel times of this order.

A translocation at 12q2 refines the interval containing the Holt-Oram syndrome 1 gene

A gene for Holt-Oram syndrome (HOS) has been previously mapped to chromosome 12q2 and designated HOS1. We have identified a HOS patient with a de novo chromosomal rearrangement involving 12q. Detailed cytogenetic analysis of this case reveals three breaks on 12q, and two of these are within the HOS1 interval. By using a combination of chromosome painting and FISH with YACs and cosmids, it has been possible to map these breakpoints within the critical HOS1 interval and thus provide a focus for HOS gene-identification efforts.