Use of home care services by older Veterans and dependants in Melbourne, Australia, 2007-2016

LAY SUMMARY

Military service has an impact on health and well-being across the life course. However, there is little research on older Veterans and dependants who use home care to enable them to remain living in the community. The authors analysed data from a Melbourne, Australia, home care organization’s electronic care records to explore the differences between clients supported by the Department of Veterans’ Affairs and clients in the general home nursing population. Results showed the greater needs of and complexity of care utilized by Veterans and dependants. Funding structures and support services need to account for these needs in older age.

Profiling the risk factors associated with falls in older people with diabetes receiving at-home nursing care: Retrospective analysis of an Australian aged care provider database

Falls among older people with diabetes mellitus (DM) are a major health concern. Preventive measures can be implemented to reduce the likelihood of falls. The aim of this study was to determine the factors most strongly associated with falls in older people living with DM who receive at-home care support services. This will inform home-visiting nurses to prioritise falls prevention strategies in the care of clients who are at high risk of falls. A retrospective analysis of routinely collected data from a large not-for-profit community aged care service provider was undertaken. The sample comprised adults aged ≥65 years residing in Victoria, Australia, with a recorded diagnosis of DM, and who received at least one episode of care by the aged care provider during July 1, 2014 and June 30, 2015. Self-reported data on falls in previous 6 months was obtained via the Comprehensive Health Assessment Tool (CHAT). Selection of factors associated with falls was guided by the Falls Risk for Older People in the Community (FROP-Com) assessment tool. For the study population, data for these factors were obtained from clients' self-reported CHAT data, and from International Classification of Disease codes obtained from medical records. Descriptive statistics were used to identify the demographic and clinical profile; logistic regression was used to assess the strength of association between various factors and the occurrence of a fall. Data were obtained for 1,574 older adults; overall prevalence of falls was 30.6% (n = 482). Significant factors displaying the highest odds of falling were gait issues (OR: 2.11, p = 0.002); needing help to walk (OR: 1.91, p = <0.001); and cognitive dysfunction (OR: 1.55, p = 0.001). Interpreted with caution, several factors contribute to an increased odds of falling in older people with DM. Home-visiting nurses are uniquely placed to introduce preventive interventions to reduce the likelihood of debilitating falls in this population.

Community-Dwelling Older Women: The Association Between Living Alone and Use of a Home Nursing Service

OBJECTIVE

To investigate the use of home nursing by community-dwelling older women to determine the nature of services required by those living alone.

DESIGN

A retrospective cohort study using routinely collected data.

SETTING AND PARTICIPANTS

Women aged 55 years and older living in metropolitan Melbourne who received an episode of nursing care from a large community home-based nursing service provider between January 1, 2006 and December 31, 2015.

METHODS

Descriptive and inferential statistical analyses were used to examine the relationship between client- and service-related factors and use of community nursing services. The primary outcome of interest was the hours of service received in a care episode.

RESULTS

A total of 134,396 episodes of care were analyzed, in which 51,606 (38.4%) episodes involved a woman who lived alone. The median hours of care per episode to women who lived alone was almost 70% more than that for women who lived with others. Multivariable regression identified factors influencing the amount of service use: living alone status, cognitive health status, and number of required home nursing activities. After adjusting for confounding and interactions, living alone was associated with at least 13% more hours of care than is provided to those not living alone. Compared with women who lived with others, women living alone required almost double the amount of assistance with medication management and were 30% more likely to experience a deterioration in their condition or be discharged from home nursing care into an acute hospital. From 2006 to 2015, for all women there was a trend toward fewer hours of nursing service provided per episode.

CONCLUSIONS AND IMPLICATIONS

Community-dwelling older women who live alone have greater service needs and higher rates of discharge to hospital. This knowledge will help guide provision of services and strategies to prevent clinical deterioration for this population.

Emergency demand, repeat and frequent presentations by older patients in metropolitan Melbourne: A retrospective cohort study using routinely collected hospital data

OBJECTIVE

To describe patterns for potentially avoidable general practice (PAGP)-type and non-PAGP-type ED presentations by older patients during 2008 and 2012.

METHODS

Retrospective analysis of ED presentations by patients ≥70 years for 2008 and 2012. Metropolitan Melbourne public hospital data were obtained from the Victorian Emergency Minimum Dataset. Outcomes were characteristics of PAGP-type and non-PAGP-type presentations as defined by the Australian Institute of Health and Welfare; numbers and rates per 1000 population ≥70 years of repeat (×2-3/year) and frequent (≥ ×4/year) PAGP-type and non-PAGP-type presentations.

RESULTS

The older metropolitan Melbourne population increased by 10.3% between 2008 and 2012, whereas the number of ED presentations increased by 12.7%. The volume of PAGP-type presentations decreased by 2.6%, with declining rates per 1000 population ≥70 years of repeat (7.2-6.2) and frequent (0.7-0.4) presentation. In contrast, the volume of non-PAGP-type presentations grew by 15.4%, with increasing repeat (57.6-60.7) and frequent (13.1-14.2) presentation rates per 1000 population ≥70 years. The majority (39%) of non-PAGP-type presentations by frequent ED attenders were due to cardiovascular or respiratory problems.

CONCLUSION

The rate of repeat and frequent PAGP-type presentations by older people decreased in 2012 compared with 2008, suggesting that initiatives implemented to reduce avoidable presentations may have had an effect. However, an increase in the rate of frequent non-PAGP-type presentations, predominately for acute exacerbation of cardiovascular and respiratory conditions, has important implications for planning future healthcare delivery; hence, the importance of initiatives such as the Health Care Home.

Emergency department utilisation by older people in metropolitan Melbourne, 2008–12: findings from the Reducing Older Patient’s Avoidable Presentations for Emergency Care Treatment (REDIRECT) study

Objective Older patients are over-represented in emergency departments (ED), with many presenting for conditions that could potentially be managed in general practice. The aims of the present study were to examine the characteristics of ED presentations by older patients and to identify patient factors contributing to potentially avoidable general practitioner (PAGP)-type presentations. Methods A retrospective analysis was performed of routinely collected data comprising ED presentations by patients aged ≥70 years at public hospitals across metropolitan Melbourne from January 2008 to December 2012. Presentations were classified according to the National Healthcare Agreement definition for PAGP-type presentations. Presentations were characterised according to patient demographic and clinical factors and were compared across PAGP-type and non-PAGP-type groups. Results There were 744 519 presentations to the ED by older people, of which 103 471 (13.9%) were classified as PAGP-type presentations. The volume of such presentations declined over the study period from 20 893 (14.9%) in 2008 to 20 346 (12.8%) in 2012. External injuries were the most common diagnoses (13 761; 13.3%) associated with PAGP-type presentations. Sixty-one per cent of PAGP-type presentations did not involve either an investigation or a procedure. Patients were referred back to a medical officer (including a general practitioner (GP)) in 58.7% of cases. Conclusion Older people made a significant number of PAGP-type presentations to the ED during the period 2008–12. A low rate of referral back to the primary care setting implies a potential lost opportunity to redirect older patients from ED services back to their GPs for ongoing care. What is known about the topic? Older patients are increasingly attending EDs, with a proportion attending for problems that could potentially be managed in the general practice setting (termed PAGP-type presentations). What does this paper add? This study found that PAGP-type presentations, although declining, remain an important component of ED demand. Patients presented for a wide array of conditions and during periods that may indicate difficulty accessing a GP. What are the implications for practitioners? Strategies to redirect PAGP-type presentations to the GP setting are required at both the primary and acute care levels. These include increasing out-of-hours GP services, better triaging and appointment management in GP clinics and improved communication between ED clinicians and patients’ GPs. Although some strategies have been implemented, further examination is required to assess their ongoing effectiveness.

After-hours medical deputising services: patterns of use by older people

OBJECTIVES

To examine how older people use an after-hours medical deputising service that arranges home visits by locum general practitioners; to identify differences in how people who live in the community and those who live in residential aged care facilities (RACFs) use this service.

DESIGN, SETTING AND PARTICIPANTS

Retrospective analysis of routinely collected administrative data from the Melbourne Medical Deputising Service (MMDS) for the 5-year period, 1 January 2008 - 31 December 2012. Data for older people (≥ 70 years old) residing in greater Melbourne and surrounding areas were analysed.

MAIN OUTCOME MEASURES

Numbers and rates of MMDS bookings for acute after-hours care, stratified according to living arrangements (RACF v community-dwelling residents).

RESULTS

Of the 357 112 bookings logged for older patients during 2008-2012, 81% were for RACF patients, a disproportionate use of the service compared with that by older people dwelling in the community. Most MMDS bookings resulted in a locum GP visiting the patient. During 2008-2012, the booking rate for RACFs increased from 121 to 168 per 1000 people aged 70 years or more, a 39% increase; the booking rate for people not living in RACFs increased from 33 to 40 per 1000 people aged 70 years or more, a 21% increase.

CONCLUSIONS

After-hours locum GPs booked through the MMDS mainly attended patients living in RACFs during 2008-2012. Further research is required to determine the reasons for differences in the use of locum services by older people living in RACFs and in the community.

Cryptosporidium p30, a galactose/N-acetylgalactosamine-specific lectin, mediates infection in vitro

Cryptosporidium sp. cause human and animal diarrheal disease worldwide. The molecular mechanisms underlying Cryptosporidium attachment to, and invasion of, host cells are poorly understood. Previously, we described a surface-associated Gal/GalNAc-specific lectin activity in sporozoites of Cryptosporidium parvum. Here we describe p30, a 30-kDa Gal/GalNAc-specific lectin isolated from C. parvum and Cryptosporidium hominis sporozoites by Gal-affinity chromatography. p30 is encoded by a single copy gene containing a 906-bp open reading frame, the deduced amino acid sequence of which predicts a 302-amino acid, 31.8-kDa protein with a 22-amino acid N-terminal signal sequence. The p30 gene is expressed at 24-72 h after infection of intestinal epithelial cells. Antisera to recombinant p30 expressed in Escherichia coli react with an approximately 30-kDa protein in C. parvum and C. hominis. p30 is localized to the apical region of sporozoites and is predominantly intracellular in both sporozoites and intracellular stages of the parasite. p30 associates with gp900 and gp40, Gal/GalNAc-containing mucin-like glycoproteins that are also implicated in mediating infection. Native and recombinant p30 bind to Caco-2A cells in a dose-dependent, saturable, and Gal-inhibitable manner. Recombinant p30 inhibits C. parvum attachment to and infection of Caco-2A cells, whereas antisera to the recombinant protein also inhibit infection. Taken together, these findings suggest that p30 mediates C. parvum infection in vitro and raise the possibility that this protein may serve as a target for intervention.

Homologues of insecticidal toxin complex genes in Yersinia enterocolitica biotype 1A and their contribution to virulence

Yersinia enterocolitica is an enteric pathogen that consists of six biotypes: 1A, 1B, 2, 3, 4, and 5. Strains of the latter five biotypes can carry a virulence plasmid, known as pYV, and several well-characterized chromosomally encoded virulence determinants. Y. enterocolitica strains of biotype 1A lack the virulence-associated markers of pYV-bearing strains and were once considered to be avirulent. There is growing epidemiological, clinical, and experimental evidence, however, to suggest that some biotype 1A strains are virulent and can cause gastrointestinal disease. To identify potential virulence genes of pathogenic strains of Y. enterocolitica biotype 1A, we used genomic subtractive hybridization to determine genetic differences between two biotype 1A strains: an environmental isolate, Y. enterocolitica IP2222, and a clinical isolate, Y. enterocolitica T83. Among the Y. enterocolitica T83-specific genes we identified were three, tcbA, tcaC, and tccC, that showed homology to the insecticidal toxin complex (TC) genes first discovered in Photorhabdus luminescens. The Y. enterocolitica T83 TC gene homologues were expressed by Y. enterocolitica T83 and were significantly more prevalent among clinical biotype 1A strains than other Yersinia isolates. Inactivation of the TC genes in Y. enterocolitica T83 resulted in mutants which were attenuated in the ability to colonize the gastrointestinal tracts of perorally infected mice. These results indicate that products of the TC gene complex contribute to the virulence of some strains of Y. enterocolitica biotype 1A, possibly by facilitating their persistence in vivo.

FDG-PET in immunocompetent patients with primary central nervous system lymphoma: correlation with MRI and clinical follow-up

PURPOSE

The role of FDG-PET in primary central nervous system lymphoma (PCNSL) is unclear. It was the aim of this study to investigate the role of FDG-PET in detecting PCNSL and in predicting response to chemotherapy.

METHODS

An FDG-PET scan of the brain was performed in 15 patients with histologically proven PCNSL (16 PET examinations, Siemens ECAT EXACT). PET was planned to investigate patients at the time of primary diagnosis, after chemotherapy and at the time of suspected relapse in seven, five and three cases, respectively. All except two patients simultaneously underwent MRI of the brain. FDG-PET results were correlated with histological results after stereotactic biopsy (primary diagnosis group) and with clinical data and MRI during follow-up.

RESULTS

Six of the seven patients in the primary diagnosis group demonstrated a true positive finding (86%). In one of the true positive PET patients, there were two tumour lesions, one of which was only detectable on the FLAIR MRI sequence. In five patients, FDG-PET showed no sign of PCNSL during ongoing chemotherapy. These results were confirmed by the clinical follow-up (mean 26.6 months). MRI demonstrated minimal residual disease which had disappeared on further follow-up MRI in three of these five patients at the time of PET scanning. Recurrence of disease was confirmed concordantly by FDG-PET and MRI in three different patients. The standardised uptake value of all tumours was 10.2 (4.3-13.7).

CONCLUSION

PCNSLs demonstrate high FDG uptake and can be diagnosed by FDG-PET with high sensitivity. It seems that FDG-PET is suitable for early therapeutic monitoring after chemotherapy.

A simple and fast method for the preparation of n.c.a. 2-[18F]F-A85380 for human use

2-[18F]F-A85380 is the first subtype selective PET-radiotracer to visualize the distribution of alpha4beta2 nicotinic acetylcholine receptors in human brain in vivo. We investigated a fast and safe automated production of 2-[18F]F-A85380 by purification of the BOC-protected intermediate product with a combination of solid phase extraction cartridges. After deprotection, adjustment of the pH and sterile filtration n.c.a. 2-[18F]F-A85380 was applicable for the use in human studies with a high specific activity and an overall radiochemical yield of 55% in 35 minutes.

[Unspecific abdominal complaints: diagnosis with szintigraphy]

This case report describes a 65-year old man with symptomatic abdominal and pelvic splenosis. 50 Years ago he has had splenectomy after a road traffic accident. Ultrasound and CT revealed a bulky mass in the iliac fossa and multifocal intraabdominal nodules suggesting peritoneal carcinomatosis. Scintigraphy with Tc-99m-labelled heat damaged red blood cells led to definitive diagnosis. RBC-scintigraphy is a specific, easy performable diagnostic tool. It is cost-effective and can avoid other diagnostic procedures or explorative surgery.

PET-CT in der Nachsorge des kolorektalen Karzinoms: Einfluss der Bildfusion auf die Staginggenauigkeit

PURPOSE

To evaluate the diagnostic impact of positron emission tomography (PET) with fluorine-18-labeled deoxy-D-glucose (FDG) combined with non-contrast computed tomography (CT) as PET-CT modality in restaging colorectal cancer patients.

MATERIAL AND METHODS

In this retrospective study, 29 consecutive patients with histologically proven colorectal cancer (17 female, 12 male, aged 51-76 years) underwent whole body scans in one session on a dual modality PET-CT system (Siemens Biograph) 90 min. after i.v. administration of 370 MBq 18F-FDG. The CT imaging was performed with 40 mAs, 130 kV, slice-thickness 5 mm and without i.v. contrast administration. PET and CT images were reconstructed with a slice-thickness of 5 mm in coronal, sagittal and transverse planes. During a first step of analysis, PET and CT images were scored blinded and independently by a group of two nuclear medicine physicians and a group of two radiologists, respectively. For this purpose, a five-point-scale was used. The second step of data-analysis consisted of a consensus reading by both groups. During the consensus reading, first a virtual (meaning mental) fusion of PET and CT images and afterwards the "real" fusion (meaning coregistered) PET-CT images were also scored with the same scale. The imaging results were compared with histopathology findings and the course of disease during further follow-up.

RESULTS

The total number of malignant lesions detected with the combined PET/CT were 86. For FDG-PET alone it was n = 68, and for CT alone n = 65. Comparing PET-CT and PET, concordance was found in 81 of 104 lesions. Discrepancies predominantly occurred in the lung, where PET alone often showed true positive results in lymph nodes and soft tissue masses, where CT often was false negative. Comparing mental fusion and "real" co-registered images, concordance was found in 94 of 104 lesions. In 13 lesions or, respectively, in 7 of 29 patients, a relevant information was gathered using fused images.

CONCLUSION

Combined PET/CT leads to greater accuracy in the interpretation of data and is a valuable tool for diagnosis and anatomic localization of metastases in colorectal cancer patients.

Improved diagnosis of advanced bone marrow metastases by means of radiolabeled antigranulocyte antibodies

Assessment of bone marrow metastases using Tc-99m-labeled antigranulocyte antibodies and Tc-99m-labeled nanocolloids is discussed in osseous metastasizing breast cancer. A 53-year-old patient with bone metastases of breast cancer (pT2 pN1biv cM1) developed leukocytopenia WHO Grade III following polychemotherapy. Bone marrow scintigraphy with Tc-99m labeled nanocolloids and Tc-99m-labeled antigranulocyte antibodies revealed pronounced bone marrow infiltration as the cause. Comparing both procedures, the images with antigranulocyte antibodies showed a clearly better bone marrow image, considerably higher contrast and almost no superimposition of the liver over the spine. In osseous metastasizing breast cancer, scintigraphy with Tc-99m-labeled antigranulocyte antibodies enables assessment of metastases in the entire bone marrow.

Hashimoto encephalopathy - is it underdiagnosed in pediatric patients?

Hashimoto encephalopathy (HE) is associated with Hashimoto thyroiditis. Clinically it presents with variable symptoms like seizures, neuropsychiatric changes or focal neurological deficits. Autoimmune phenomena are hypothesized for the pathogenesis. HE has mainly been described in the adult population. We present two 14-year-old patients who presented with recurrent seizures and mental decline. SPECT and PET scans showed distinctly pathological changes. Both patients were diagnosed with HE and improved dramatically on steroids. We feel that HE is a rare but important differential diagnosis of encephalopathy also in the pediatric population. As this disease responds well to steroids, we recommend to obtain basic thyroid function tests as well as thyroid antibodies in all cases of unexplained encephalopathy or unexplained status epilepticus.

[Differentiated short- and long-term effects of a "Training of Emotional Intelligence" and of the "Integrated Psychologic Therapy Program" for schizophrenic patients?]

Social cognition was shown as a rate limiting factor for both psychosocial outcome and response to psychosocial intervention in schizophrenia. In a randomized controlled trial a new cognitive-behavioral group treatment for schizophrenic inpatients (the "Training of Emotional Intelligence", TEI) was tested against the well evaluated "Integrated Psychological Therapy Program" (IPT) of H. Brenner. Within the framework of P. Salovey's work the Training of Emotional Intelligence focussed on three domains of deficits in schizophrenia: emotional perception, emotional understanding and emotional management. In the randomized controlled trial with 41 DSM-IV schizophrenic inpatients no differences were found in problem-solving and negative symptoms, both post treatment and in the 12 months-follow up. Additionally there was a better outcome in affect decoding capacity post treatment, and a progess in regulation of negative affects in the follow up. Emotional role taking behavior and social anxiety returned to baseline level, perhaps by reasons of no "booster sessions" in the follow up. Unfortunately in contrast to our hypotheses we failed to show treatment-specific effects, which may be due to an underpowered statistical testing. There was only one exception of this: While the Integrated Psychological Therapy Program showed a greater reduction of global psychopathology after treatment, the Training of Emotional Intelligence reduced psychopathology in the follow up more strongly. Possible reasons for these results are discussed.

JlpA, a novel surface-exposed lipoprotein specific to Campylobacter jejuni, mediates adherence to host epithelial cells

A 1116 bp open reading frame (ORF), designated jlpA, encoding a novel species-specific lipoprotein of Campylobacter jejuni TGH9011, was identified from recombinant plasmid pHIP-O. The jlpA gene encodes a polypeptide (JlpA) of 372 amino acid residues with a molecular mass of 42.3 kDa. JlpA contains a typical signal peptide and lipoprotein processing site at the N-terminus. The presence of a lipid moiety on the JlpA molecule was confirmed by the incorporation of [3H]-palmitic acid. Immunoblotting analysis of cell surface extracts prepared using glycine-acid buffer (pH 2.2) and proteinase K digestion of whole cells indicated that JlpA is a surface-exposed lipoprotein in C. jejuni. JlpA is loosely associated with the cell surface, as it is easily extracted from the C. jejuni outer membrane by detergents, such as sarcosyl and Triton X-100. JlpA is released to the culture medium, and its concentration increases in a time-dependent fashion. The adherence of both insertion and deletion mutants of jlpA to HEp-2 epithelial cells was reduced compared with that of parental C. jejuni TGH9011. Adherence of C. jejuni to HEp-2 cells was inhibited in a dose-dependent manner when the bacterium was preincubated with anti-GST-JlpA antibodies or when HEp-2 cells were preincubated with JlpA protein. A ligand-binding immunoblotting assay showed that JlpA binds to HEp-2 cells, which suggests that JlpA is C. jejuni adhesin.

Expression of the flgFG operon of Campylobacter jejuni in Escherichia coli yields an extra fusion protein

Two Campylobacter jejuni genes with homology to the Escherichia coli flgF and flgG genes encoding two of the basal body rod proteins were isolated, and the nucleotide sequence was determined and analyzed. These two C. jejuni genes were shown, by Northern hybridization analysis, to function as a single operon (flgFG). Two transcriptional start sites were detected upstream of flgF, corresponding to the two RNA transcripts detected in the Northern blot. Western blot immunoassays using anti-FlgF and anti-FlgG antibodies demonstrated the synthesis of FlgF and FlgG proteins in C. jejuni and in Escherichia coli containing the C. jejuni flgF and flgG genes. Maxicell analysis and Western immunoblots using anti-FlgF antibodies to probe flgFG-encoded proteins in E. coli revealed the presence of a protein with a molecular mass of approximately the combined mass of the FlgF and FlgG proteins. Anti-FlgF antibodies detected in C. jejuni cell extracts the native FlgF protein and also a higher-molecular-weight protein that is likely encoded by the flgF and part of the flgG sequences.

Escalating interferon-alpha-2b dose for patients with chronic hepatitis C

BACKGROUND/AIMS

We examined the effectiveness of escalating the dose of interferon-alpha-2b in subjects with chronic hepatitis C who did not respond to usual treatment with 3,000,000 units 3 times a week.

METHODOLOGY

Treatment was started with 3,000,000 units of interferon-alpha-2b 3 times a week. If serum alanine aminotransferase activity was not normal at 12 weeks, the dose was increased to 3,000,000 units daily. If serum alanine aminotransferase activity was not normal after 12 weeks, the dose was increased to 5,000,000 units daily.

RESULTS

Fifty-one subjects started treatment. Twenty-nine subjects had their dose increased to 3,000,000 units daily and only 1 responded (3%, 95% confidence interval 0-10.9%) while 41% (95% confidence interval 21.4-60.6%) had to discontinue treatment at this dose because of adverse events or intolerance. Of 14 subjects who had their dose increased to 5,000,000 units daily, none (95% confidence interval 0-3.6%) responded, while 43% (95% confidence interval 13.5-72.5%) had to discontinue treatment.

CONCLUSIONS

Escalating doses of interferon-alpha-2b are not effective and are associated with increased toxicity and intolerance in patients with chronic hepatitis who do not respond to initial treatment with 3,000,000 units 2 times a week.

Attachment of Cryptosporidium parvum sporozoites to human intestinal epithelial cells

An enzyme-linked immunosorbent assay-based attachment model using the human intestinal cell line Caco-2A was developed to study attachment of Cryptosporidium parvum sporozoites in vitro and to assess potential inhibitors of sporozoite binding. In this system, attachment was related to sporozoite dose, incubation time, and host cell differentiation status. Polyclonal antibodies to C. parvum as well as glycoprotein inhibitors of a sporozoite lectin reduced attachment. This model will be a valuable tool in elucidating specific molecules and mechanisms involved in sporozoite-host cell attachment.

Cryptosporidia--who is at risk?

Cryptosporidium parvum is a coccidian parasite originally described a century ago and, until recently, not considered to be a human pathogen. It has a complex life cycle, including both sexual and asexual reproduction, an auto-infectious cycle, and the ability to complete its development within a single host. The transmission form is a robust, environmentally resistant oocyst, excreted in the stool, which can exist for long periods of time in the environment. Because animals, in particular domesticated livestock, are its primary host, human infection is usually zoonotic. Oocysts often find their way into water supplies, and it resists chlorination and is incompletely filtered from processed drinking water supplies, even when filtration is working optimally. Transmission via ingestion of fecally contaminated swimming pool water, food, fomites, and sexual activities facilitating fecal-oral inoculation have been demonstrated. The major target of C. parvum in the host is the intestinal epithelial cell, resulting in diarrhea, sometimes profuse and persistent, although it may also infect other organs such as the gall bladder and lungs. Pathogenesis involves attachment, probably via a sporozoite lectin, invasion, probably involving apical organelles, replication within a parasitophorous vacuole with the host cell membrane, causing cellular dysfunction. Diagnosis is generally made by visualization of the oocyst form in stool by staining methods, the best of which appears to be auramine and fluorescence microscopy. Those at greatest risk are immunocompromised adults and children, especially those with AIDS, children in day care, travelers to endemic regions, dairy or cattle farm workers of their families or contacts, household contacts of cases or carriers, and possibly owners of infected dogs or cats or their neighbors. There is no specific therapy available, however in the immunocompetent host the illness is self-limited, lasting from a few days to 3 weeks, and long term carriage is uncommon. In the immunocompromised host, infection is prolonged, sometimes asymptomatic, but may result in chronic debilitating diarrhea with dehydration, malabsorption and wasting. Public health measures to reduce contamination of water supplies and vigilant surveillance will reduce the risk to populations. Reducing behaviors favoring fecal-oral transmission, such as certain sexual activities, and scrupulous hygiene in the day care setting would also reduce the likelihood of transmission but not eliminate it. Given our lack of knowledge about Cryptosporidium biology and pathogenesis, high priority should be given to research designed to increase our understanding of the organism and improve the chance of developing useful therapeutic or preventative drugs or strategies.

Nucleotide sequence of a Porphyromonas gingivalis gene encoding a surface-associated glutamate dehydrogenase and construction of a glutamate dehydrogenase-deficient isogenic mutant

The nucleotide sequence for a surface-associated protein (A. Joe, A. Yamamoto, and B. C. McBride, Infect. Immun. 61:3294-3303, 1993) of Porphyromonas gingivalis was determined. The structural gene comprises 1,338 bp and codes for a protein of 445 amino acids. The deduced molecular weight of the protein is 49,243. A data base search for homologous proteins revealed significant sequence similarity to the subunit protein of glutamate dehydrogenases (GDHs) isolated from various sources. This protein, which was previously labelled PgAg1, will now be called GDH. Recombinant GDH was purified to homogeneity, and native GDH was partially purified from P. gingivalis. Both preparations exhibited NAD-dependent GDH activity. Intact P. gingivalis and an extract of cell surface components also demonstrated NAD-dependent GDH activity. To help elucidate the role of this protein, an isogenic mutant of P. gingivalis lacking the GDH protein was generated by deletion disruption. Biological characterization of the mutant strain, P. gingivalis E51, demonstrated complete loss of GDH activity. Immunogold bead labelling of intact cells showed that GDH was no longer present on the surface of the bacterial cell. The GDH-negative mutant displayed impaired cell growth, as demonstrated by an increased generation time and an inability to grow to the same cell density as the parent.

Characterization of recombinant and native forms of a cell surface antigen of Porphyromonas (Bacteroides) gingivalis

The cloning of genes encoding putative cell surface antigens of Porphyromonas gingivalis ATCC 33277 has been reported previously (B. C. McBride, A. Joe, and U. Singh, Arch. Oral Biol. 55:59S-68S, 1990). This study characterizes the recombinant protein rPgAg1, which is highly expressed in clone BA3, and the corresponding 51-kDa native antigen PgAg1. Cellular localization studies with monospecific antibodies to rPgAg1 in a Western immunoblot assay of a P. gingivalis membrane fraction and immunogold labeling of intact P. gingivalis cells confirmed the cell surface location of the native PgAg1 molecule. The pgag1 gene was found to be present in all four strains of P. gingivalis examined, and the gene product was expressed. Highly homologous DNA sequences and immunologically related proteins, however, were not detected in related species in the group formerly known as black-pigmented Bacteroides. This suggests that PgAg1 is specific to P. gingivalis and is highly conserved within this species. A protein data base search with the NH2-terminal amino acid sequence of rPgAg1 did not identify any significantly similar protein sequences. The high level of expression of rPgAg1 was not dependent on the insertional orientation of the cloned fragment. It therefore appears that a P. gingivalis promoter is present which is well recognized by the transcriptional apparatus of the Escherichia coli cloning host. The promoter element and structural gene for a specific cell surface antigen of P. gingivalis have been cloned.

Cloning of Bacteroides gingivalis surface antigens involved in adherence

Despite the acknowledge importance of Bacteroides gingivalis as a periodontal pathogen, relatively little is known about the molecular basis for its pathogenicity. Recombinant DNA technology has created the opportunity to identify and characterize the virulence determinants. A Bact. gingivalis library was prepared in Escherichia coli JM83 with the vector pUC18. The library was screened for surface antigens by colony immunoblot and 337 putative surface antigen recombinants were identified. Two of these clones were found to have haemagglutinating activity. Antiserum raised against one of these clones reacted with a 43 kDa Bact. gingivalis protein that has haemagglutinating activity.

Puerperal Fever and Pyrexias

A classification is made of 219 cases notified as puerperal fever or puerperal pyrexia. Of these, 71 were local uterine infections; 47, pelvic or general peritonitis; 11, pelvic cellulitis; 20, septicaemia or pyaemia; 12, pyelitis, and 58, febrile conditions not due to infection of the genital tract. Fatal cases were all due to general peritonitis or blood infections and the general death-rate for infections of the genital tract is 21.4 per cent. Of 32 maternal deaths, 7 followed abortion; 11 occurred in primiparae, the preponderance of whom showed more or less severe trauma, and 13 in multiparae in whom trauma was absent in the great majority. Similar antecedent circumstances were found in recovered cases of puerperal infection; from these figures an attempt is made to assess the importance of trauma in the production of sepsis. Two cases of puerperal scarlet fever are described and the transmission of infection in puerperal sepsis is discussed. A study has been made of sensitiveness to the haemolytic streptococcal toxin in 103 cases of puerperal sepsis and the results do not bear out the suggestion that infection by the streptococcus in the puerperium is correlated with toxin sensitiveness.