Nutrition support for patients in long-term acute care and subacute care facilities

Long-term acute care and subacute care facilities (also transitional care facilities) have evolved from the need to decrease costs associated with acute care in the hospital. As the length of stay in many medical centers has been reduced, patients are admitted to transitional care facilities to continue recovery and rehabilitation. Rehabilitation and recovery can be enhanced with the provision of optimal medical nutrition therapy. Nutrition screening is essential in identifying patients who are at risk of malnutrition or are malnourished. Nutrition assessment verifies the risk or presence of malnutrition followed by the development, implementation, and monitoring of nutrition intervention. Nutrition screening and intervention promote recovery from illness, minimize morbidity and mortality, and enhance quality of life. The goals of nutrition support are to prevent starvation-associated malnutrition, preserve lean tissue mass, support metabolic functions, and improve clinical outcomes. Oral nutrition is the preferred method of nourishment; however, specialized nutrition support is considered for patients unable to meet their nutrient requirements adequately. Enteral nutrition support is recommended when providing nutrition support however, parenteral nutrition support is used when the gastrointestinal tract can not be safely used. With appropriate intention, administration, and monitoring, nutrition support can be safely administered.

Physical, chemical, and histologic changes in dentin caries lesions of primary teeth induced by regular use of polyol chewing gums

A previous clinical trial showed that long-term use of saliva-stimulating polyol (xylitol and sorbitol) chewing gums was associated with arrest of dental caries in young subjects. After a 20-22-month intervention (when the subjects were 8 years old), a total of 23 primary teeth with extensive dentin caries lesions whose surface in clinical examination was found to be totally rehardened (remineralized) could be removed because the teeth were near their physiologic exfoliation time. These teeth were subjected to histologic, microhardness, and electron microscopic tests. The majority of the specimens had been remineralized from the surface by a non-cellular-mediated process within the remaining collapsed, organic extracellular matrix associated with the remaining dentinal surface. Many of the underlying dentinal tubules were filled with a matrix that had been subsequently mineralized. Dental microanalyses showed that the topmost (outer) 20-microm-thick rehardened layer of the lesions exhibited the highest Ca:P ratio, which leveled off at a depth of approximately 150 microm. The rehardened surface layer (normally <0.1 mm in thickness) was significantly (P < 0.001) harder than sound dentin and nearly as hard as sound enamel. Although the main source of the mineral present in the rehardened layer was most likely of salivary origin, some extracellular remineralization was probably mediated by odontoblasts. The results complete the dinical diagnoses of the original trial and suggest that regular use of polyol chewing gums may induce changes in dentin caries lesions, which in histologic and physiochemical studies show typical characteristics of rehardening and mineralization.

Prognostic significance of DNA content in stage I adenocarcinoma of the lung

PURPOSE

Up to 30% of lung cancers (Stage I) with the most favorable outcome recur within 5 years after surgery. This study reviews the pattern of failure after surgical resection in early lung cancers and determines whether flow cytometric DNA variables were prognostic indicators for survival, disease-free survival (DFS), or distant metastasis-free survival (DMFS).

METHODS AND MATERIALS

Pathologic specimens from 45 patients at The University of Texas M. D. Anderson Cancer Center who underwent surgical resection and mediastinal nodal dissection for stage I (AJCC) adenocarcinomas of the lung were analyzed by flow cytometry for DNA content. Survival was calculated by the method of Desu and Lee. Chi-square and cross tabulation were used in the analysis.

RESULTS

The mean age of the patients was 62 years, and 52.3% were male. All patients were clinical Stage I (T1-2 N0), Karnofsky performance status > or = 70, and had a weight loss <10 lbs. Median overall survival (OS) and DFS were 50 months and 33 months, respectively. OS, DFS, and DMFS at 1, 3 and 5 years were 73%, 57%, and 35%; 63%, 53%, and 45%; and 67%, 56%, and 48%, respectively. Analysis of all 45 patients revealed 86% of patients developing brain metastasis had an abnormal DNA content > or = 30%, whereas 4% of patients with brain metastasis had abnormal DNA content < 30% (p = 0.01). This correlation maintained significance when only pT1/2 lesions were analyzed. There was a significant statistical correlation between abnormal DNA and 5-year OS, with 74% OS for those with abnormal DNA < 30% vs. 42% for > or = 30% (p = 0.036). The 5-year DFS for pT1/2 patients was significantly correlated with abnormal DNA content: 53% for patients with abnormal DNA < 30% vs. 17% for patients with abnormal DNA > or = 30%, respectively (p = 0.03). Of those with %S fraction (%S) < 2, 13% failed locally compared to 41% of those with %S > or = 2. There was a highly significant correlation between DNA index (DNAI) and aneuploid %S: 68% of patients with a DNAI > or = 1.7 had > or = 2.6 aneuploid %S, whereas only 13% of patients with DNAI > or = 1.7 had aneuploid %S < 2.6. (p < 0.001). Grouping the percent of abnormal DNA and overall %S according to low vs. mixed vs. high values correlated with DFS (p = 0.02).

CONCLUSIONS

This study confirms significant correlation between a high DNA index and a higher frequency of brain metastasis, as well as worse OS. Although DNA content variables were not predictive of recurrence at other sites, brain metastasis represents the worst outcome from distant metastasis. Further studies are needed, as well as prospective trials, for evaluating adjuvant therapy in patients with adverse DNA variables following complete surgical resection for early disease. If high-risk patients could be identified after resection, adjuvant therapy (chemotherapy or elective brain irradiation) could be administered.

The ophthalmic registered nurse's responsibility to the adult patient with low vision

A key goal in the care of adult patients with low vision is to help them focus on their visual abilities rather than their disabilities. This article presents information that every ophthalmic nurse can use to teach patients with low vision some practical ways to change their personal environment to enhance visibility and safety. There are also some myths and misunderstandings about low vision that the nurse can dispel. Before referring patients to low-vision specialty clinics or organizations, every ophthalmic nurse can begin the visual rehabilitation for patients with low vision.

Prognostic biomarker study in pathologically staged N1 non-small cell lung cancer

PURPOSE

The prognostic influence of 6 biomarkers correlated to histologic subtypes of non-small cell lung cancer (NSCLC) on loco-regional control, overall survival, disease-free survival (DFS), and distant disease control (DDC) rates, all measured at 5 years, were examined.

MATERIALS & METHODS

Cell blocks from the primary tumors of 137 patients with pathologically staged N1 NSCLC at MDACC were analyzed by 6-biomarker status correlated to histological subtypes and their outcomes.

RESULTS

The ranges of biomarker values were as follows: apoptotic index, 0.2-2.8%; mitotic index, 0-1.8%; the proportion of cells in S+G2M, 3-36%; p53 status, 0-100%; Ki-67, 0-9.3%; DNA index, 1.0-2.74. Subtypes of 137 cases from the postoperative pathology specimen showed that 74 patients had squamous carcinoma and 63 patients had adenocarcinoma. Mean and median lengths of follow-up were 4.21 years and 2.43 years, respectively. Patients with squamous cell carcinoma (SCC) had a better 5-year survival (p = 0.006), DFS (p = 0.002), and distant metastasis control (p = 0.002) than patients with adenocarcinoma (AC). Among patients with AC, the DNA index was a significant predictor of 5-year DFS (p = 0.02), DDC rate (p = 0.04), and local-regional control (p < 0.05). Higher apoptosis (p = 0.03) and mitosis indices (p = 0.03) were also univariate predictors of increased distant disease among patients with AC. Multivariate analysis of patients with AC revealed that the DNA index and Ki-67 were the only significant independent predictors of distant metastasis (p < 0.04 and p < 0.02, respectively) and DFS (p < 0.04 for both). Among patients with SCC, univariate analysis showed that S+G2M proportion (p < 0.05) and Ki-67 levels (p < 0.02) were significant predictors for local-regional control; for SC, multivariate analysis showed that only mitosis was a significant predictor in this case for overall survival (p < 0.04).

CONCLUSION

Spontaneous apoptotic index and Ki-67 were significantly higher in SC than in AC. Patients with SC had less distant metastasis better DFS and overall survival than those with AC. Multivariate analysis revealed that DNA index and Ki-67 status were significant predictors for DDC and DFS in patients with AC, but only mitotic index was a significant predictor of overall survival for patients with SCC.

Low versus high prevalence of AIDS: effect on nursing students' attitudes and knowledge

The purpose of this study was to compare AIDS knowledge and attitudes of baccalaureate nursing students living in a state with a high prevalence of AIDS and those who resided in a state with a low prevalence of AIDS. Students from the high-prevalence state had significantly higher AIDS knowledge scores than did students from the low-prevalence state. However, overall, respondents from the low-prevalence state viewed the person living with AIDS with more accepting attitudes than did the respondents from the high-prevalence state. Students in the high-prevalence state interacted with persons living with AIDS (PLWA) primarily through professional contact. In contrast, students in the low-prevalence state identified both personal and professional contact with PLWA as their most significant interactions. Personal experience of nursing students appears to be a key to decreasing stigmatization of PLWA.

Haematoma block or Bier's block for Colles' fracture reduction in the accident and emergency department--which is best?

OBJECTIVE

To offer clear guidance on the anaesthetic management of Colles' fractures in the accident and emergency (A&E) department in the light of the conflict between existing reports and current trends, and to address the issue of alkalinisation of haematoma blocks.

METHODS

This was a two centre, prospective, randomised clinical trial with consecutive recruitment of adult patients with Colles' fractures requiring manipulation to receive either Bier's block or haematoma block. There was subsequent blinded randomisation to alkalinised or non-alkalinised haematoma block.

RESULTS

72 patients were recruited into the Bier's block group, and 70 into the haematoma block group. Bier's block was less painful to give than the haematoma block (median pain score 2.8 v 5.3; P << 0.001), and fracture manipulation was also less painful in the Bier's block group (median pain score 1.5 v 3.0; P < 0.01). There was no significant difference in overall A&E transit time between the two groups. There was better initial radiological outcome in terms of dorsal angulation in the Bier's block group (-3.6 degrees v 2.1 degrees; P = 0.003). More remanipulations were required in the haematoma block group (17/70 v 4/72; P = 0.003). There was a trend towards decreased pain on administration of the alkalinised haematoma block when compared with non-alkalinised haematoma block, but this did not reach significance. There was no difference in pain score on fracture manipulation. There were no complications in either group.

CONCLUSIONS

Bier's block is superior to haematoma block in terms of efficacy, radiological result, and remanipulation rate; transit times are equal, both procedures are practical in the A&E environment, and there were no complications. Bier's block is the anaesthetic management of choice for Colles' fractures requiring manipulation within the A&E department.

Multidimensional scaling of complex sounds by school-aged children and adults

A paired-comparisons procedure was used to evaluate the processing of complex, nonspeech sounds by 7- and 10-year-old children and adults. Stimuli were brief duration and included pure tones, harmonic complexes, and bands of noise. From their similarity ratings, a three-dimensional multidimensional scaling solution was derived. Results suggested that listeners classified the stimuli into clusters based upon periodicity and the number of spectral peaks. Within each cluster, the stimuli were ordered according to frequency. Because individual differences in the overall weightings of features were large, separate solutions were derived for two subgroups of listeners, formed based upon similarities in the pattern of dimension weights obtained in the group analysis. One subgroup, for whom the full group analysis captured a large proportion of the variance in the ratings, included the adults, many of the 10-year-olds, and a few of the 7-year-olds. The solution derived for this subgroup suggested that spectral and temporal information were weighted equally and integrated into all dimension weights. Frequency information was coded but given less weight and was not used for stimulus classification. A second subgroup of listeners included most of the 7-year-old and some of the 10-year-old children. Examination of their data suggested that they relied heavily on an analysis of the signals according to periodicity as was reflected in their temporal fine structure. Also encoded but of lesser importance were aspects of spectral shape and absolute frequency.

Single-stranded RNA recognition by the bacteriophage T4 translational repressor, regA

The T4 protein, RegA, is a translational repressor that blocks ribosome binding to multiple T4 messages by interacting with the mRNAs near their respective AUG start codons. Other than the AUG, there are no obvious similarities between the affected mRNAs. High affinity RNA ligands to RegA were isolated using SELEX (systematic evolution of ligands by exponential enrichment). The selected RNAs exhibited the consensus sequence 5'-AAAAUUGUUAUGUAA-3'. The AUG was invariant, suggesting that it is the primary effector of binding specificity. The UU immediately 5' to the AUG and the upstream poly(A) tract were highly conserved among the selected RNAs. Boundary and footprinting experiments are consistent with the consensus sequence defining the RegA-binding site. Interestingly, chemical modification and nuclease digestion data indicate that the RNA-binding site is single-stranded, as if RegA discriminates between targets based on their primary sequence, not their secondary structure. Minor variations from the consensus at positions other than the universally conserved AUG have little effect on RegA binding, but accumulation of mutations has a profound effect on the interaction. Comparison of the in vivo targets for RegA to the SELEX-generated consensus suggests a repression pattern whereby the translation of individual messages is sequentially halted until the least similarly affected message, the regA gene itself, is repressed.

Principles of the Polymerase Chain Reaction in Haematology

The polymerase chain reaction (PCR) is an automated process that specifically amplifies selected DNA sequences that are usually chosen to reflect the presence of genes, or parts of genes, in the sample material. Since many genetic alterations resulting in the onset of disease are now detectable using PCR, it can be used as both a diagnostic and prognostic tool. Genetic changes can occur in DNA due to mutation, deletion, inversion or chromosomal translocation. As a consequence, genes become either non functional or are aberrantly expressed. Research in recent years has now associated many defined genetic abnormalities with specific diseases. Therefore detection and surveillance of such lesions has led to disease diagnosis and subsequent monitoring of disease progression, for example, during and after administration of therapeutic regimens. The major effect of PCR in this area is that genetically abnormal cells can be detected within a normal cell population at a far lower incidence level than any other existing technology. Moreover, PCR can be used to identify naturally existing genetic polymorphisms that can be used as personal identifiers, or tags, for a given individual. Where these polymorphisms occur within a genetically modified region resulting in disease, identification of the polymorphism within families can be used as a predictor of disease carrier status or likelihood of inheritance of the disease.

A specific RNA structural motif mediates high affinity binding by the HIV-1 nucleocapsid protein (NCp7)

Current research indicates that the nucleocapsid protein (NCp7) of human immunodeficiency virus type 1 (HIV-1) interacts with a variety of RNA substrates during the progression of the viral life cycle. The RNA features specifically recognized by the protein, however, have yet to be identified. SELEX was used to generate a set of RNAs whose affinities for nucleocapsid were on the order of 2 x 10(-9) M. Comparative analysis revealed that each RNA contains a highly conserved fourteen nucleotide sequence-block. Computer modeling and structure probing experiments indicate that the RNA ligands use the consensus sequence to fold into hairpins with an identical asymmetric bulge. The presence of the nucleocapsid protein protects the asymmetric bulge from ribonuclease attack, suggesting that it is the key element in protein recognition. A search for similar structural motifs within the HIV genome reveals several potential interaction sites for the nucleocapsid protein.

Electrophysiological analysis of the registration, storage and retrieval of information in delayed matching from samples

Brain processes of registration, storage in working memory and retrieval of different kinds of information were studied by analysis of EEG and ERP activity recorded during two delayed matches from sample tasks: (1) matching the digits in two series of six numbers, and (2) matching the sums of the same two series of six numbers. each trial was composed of six intervals continuing six equally spaced visual stimuli: (1) control--observing a series of six fixation points, P1, on a computer monitor; (2) priming--viewing a series, S1, of six numbers; (3) delay--observing a second series of six fixation points, P2; (4) matching--viewing a second series, S2, of six numbers; (5) response selection--selecting the left button to press if S1 contained all the items in S2 or the right button if any item appeared only in S2, while observing six fixation points; (6) feedback--six color coded fixation points indicate correct or error. Each interval was 4 s in duration and 20 trials were presented in each task. During each interval the visual field flickered at a tracer frequency of 1.5/s, whether numbers or fixation points were on the monitor screen. Very narrow band power spectra (VNB), ERPs elicited by presentation of S1 or S2 information items, and non-contingent probes (NCP) elicited by presentation of fixation points were used to trace the processing of information by neural populations activated by the visual stimulation. Global field power maxima identified latencies at which functional landscapes were analyzed. VNB, ERP, NCP and landscape differences were found between digits and sums. However, though these differences were highly significant within each subject (p < 0.001), no consistency was found across individuals for the electrophysiological changes during the tasks. This suggests that utilization of brain resources in cognition varies greatly with individual cognitive styles and strategies.

Sternal wound dressings--a research study into risk factors

Papworth Hospital is an internationally renowned centre for cardiothoracic surgery and cardiopulmonary transplantation. Each year approximately 2,000 procedures are carried out. In early 1994 staff had noticed an increase in the number of cardiac patients returning for debridement of sternal wounds following infection. This was obviously an area for concern, and consequently a research project was initiated to examine potential risk factors for sternal wound infection.

Prognostic factors in the treatment of node-negative nonsmall cell lung carcinoma with radiotherapy alone

PURPOSE

For patients with early stage nonsmall cell lung carcinoma (NSCLC) but medically inoperable, aggressive radiation therapy might impact on survival.

METHODS AND MATERIALS

Between 1980 and 1990, 71 patients treated at MDACC by radiation therapy alone for NSCLC because of medical contradindications for surgery were analyzed. All patients had histologic or cytologic confirmation of NSCLC. The median total radiation dose was 63.23 Gy with 79% of patients receiving doses exceeding 60 Gy. The radiographic response was documented at completion of radiation therapy and 6 months after completion of radiation therapy. The median follow-up time was 36 months, ranging from 14-61 months.

RESULTS

Overall survival rates at 3 and 5 years were 19 and 12%, respectively. The disease-specific survival (DSS) rates at 3 and 5 years were 44 and 32%, respectively. The DSS rates at 3 years by T-stage were: 49% for T1, 47% for T2, 26% for T3, and 32% for T4. The local control rates at 3 and 5 years were 66 and 56%, respectively. The local control rates at 3 years by T-stage were: 89% for T1, 61% for T2, 42% for T3, and 55% for T4. Univariately, the significant favorable prognostic factors for DSS were a KPS > or = 70, tumor size < or = 5 cm, no chest-wall invasion, and a radiation dose > or = 50 Gy. The significant favorable prognostic factors for local control were tumor size < or = 4 cm, no chest-wall invasion, a radiation dose > 60 Gy, and a complete response confirmed by chest x-ray at 6 months after radiotherapy (p = 0.04). Coverage of nodal drainage areas did not affect survival or local control. No lethal complications were seen, and documented symptomatic radiation pneumonitis occurred in only 7% of cases. Hence, the significant favorable prognostic factors for DSS were a KPS of > or = 70, tumor size < or = 5 cm, no chest-wall invasion, and a radiation dose > or = 50 Gy. The significant favorable prognostic factors for local control were tumor size of < or = 4 cm, no chest-wall invasion, a radiation dose > 60 Gy, and a complete response confirmed by chest x-ray at 6 months after radiotherapy. Multivariate analysis showed that the most important prognostic factor for DSS was KPS, and the most important prognostic factor for local control was radiation dose.

CONCLUSIONS

Patients with a KPS of > or = 70, a tumor size < 5 cm, and no chest-wall invasion would benefit most from treatment with radiation alone to doses exceeding 60 Gy. This patient group represents the best sample for studying the benefit of conformal radiotherapy.

Development of auditory information integration abilities

The ability of normal-hearing children (aged 4 through 7 years) and adults to integrate information was measured in an auditory sample discrimination task. On each trial a pair of tonal sequences was played whose component frequencies were randomly drawn from two equal-variance, Gaussian distributions with different means. The listeners task was to identify the sequence drawn from the distribution with the higher mean frequency. Performance was first evaluated as a function of the number of components in each sequence. Results showed that discrimination accuracy improved with increasing age until age 7, at which time performance was adult-like. The 7-year-olds and the adults discriminated the sequences with increasing accuracy as the sequence length was increased, but the 4-to 6-year-old listeners, as a group, did not. Data were fitted with a model with two free parameters, one representing resolution of the components and presumed to reflect peripheral processing, and another representing central noise added to the decision process after the component information is combined [R. Lutfi, J. Acoust. Soc. Am. 86, 934-944 (1989)]. On average, both parameters showed gradual changes as age increased, with adult-like values by 7 years of age. Individual data however suggest that the changes in central noise with age may be less gradual than the changes in peripheral resolution. In a second condition, increases in component duration produced improved performance for the 7-year-olds and the adults, while that of the younger listeners remained the same. Fitted parameters suggested improvements in component resolution for the older children, with no changes in central noise levels. In a third condition, reducing the overlap in the distributions improved performance for only a few of several younger children. This improvement was attributable to lower levels of central noise. Overall, these results suggest that with increasing age children are better able to discriminate between sounds that are variable and have overlapping acoustic characteristics. This age-related improvement may be attributed both to improvements in the ability to resolve the components and to reductions in central noise.

Attitudes of baccalaureate nursing students toward persons with acquired immunodeficiency syndrome according to mode of human immunodeficiency virus transmission

The purpose of this descriptive correlational study was to (1) examine differences in baccalaureate nursing students' attitudes toward persons living with acquired immunodeficiency syndrome (AIDS) (PLWAs) according to mode of transmission and (2) identify demographic and academic variables influencing baccalaureate nursing students' attitudes toward PLWAs. Two hundred forty-six students from five geographically dispersed baccalaureate programs returned a completed demographic data sheet, AIDS Knowledge Scale, and AIDS Attitude Scale. The AIDS Attitude Scale, based on Goffman's theory of stigma, assesses stigmatizing attitudes, perceptions of deservedness of care, and attitudes of respect and regard for PLWAs according to five modes of human immunodeficiency virus transmission. The findings of this study demonstrated overall that baccalaureate students were the most stigmatizing toward persons who had developed AIDS through injecting drugs followed by sexual contact (both homosexual and heterosexual) and least stigmatizing toward PLWAs who contracted the virus through maternal transmission or a blood transfusion. Perhaps the PLWA who contracted AIDS through either maternal transmission or a blood transfusion was viewed as an "innocent victim" of the disease, whereas PLWAs who contracted the virus through either shared needles or sexual transmission were viewed as having acquired the infection through the results of their actions. The demographic characteristics of the respondents did not influence AIDS attitudes.

Apnoea and bradycardia during epileptic seizures: relation to sudden death in epilepsy

OBJECTIVE

To record non-invasively ictal cardiorespiratory variables.

METHODS

Techniques employed in polysomnography were used in patients with epilepsy undergoing EEG-video recording at a telemetry unit.

RESULTS

Apnoea (> 10, range > 10-63, mean 24 s) was seen in 20 of 47 clinical seizures (three secondary generalised, 16 complex partial, and one tonic) and 10 of 17 patients. Apnoea was central in 10 patients, but obstructive apnoea was also recorded in three of 10. Oxyhaemoglobin saturation (SpO2) dropped to less than 85% in 10 seizures (six patients). An increase in heart rate was common (91% of seizures). Bradycardia/sinus arrest was documented in four patients (mean maximum RR interval 5.36, range 2.8-8.6 s) but always in the context of a change in respiratory pattern.

CONCLUSION

Ictal apnoea was often seen. The occurrence of bradycardia in association with apnoea suggests the involvement of cardiorespiratory reflexes. Similar mechanisms may operate in cases of sudden death in epilepsy.

Conclusion and review of the Michigan Xylitol Programme (1986-1995) for the prevention of dental caries

The major results of the Michigan Xylitol Programme (1986-1995) are summarised. The Programme consisted of several clinical trials and laboratory investigations designed to study the usage of xylitol-containing saliva stimulants in the prevention of dental caries. The trials patients included young (initially 6 year olds) and adult or geriatric subjects who were given saliva stimulants (mostly chewing gum) for periods of two weeks to 56 months. A special rationale behind these studies was the need to further test the validity of the 'pentitol-hexitol theory' in the prevention of caries. This theory has maintained that pentitols (sugar alcohols with five hydroxyl groups, such as xylitol) may be cariologically more effective than hexitols (sugar alcohols with six hydroxyl groups, such as sorbitol). The accumulated clinical, sialochemical and microbiologic evidence suggests that xylitol, a natural carbohydrate sweetener of the pentitol type, is more effective in preventing dental caries than sorbitol, and cariologically safer than sorbitol, a natural carbohydrate of the hexitol type. Sorbitol was found to be significantly less cariogenic than sucrose. The Programme's results shed additional light on the cariologic and oral biologic effects of natural, dietary polyols, and suggest that the usage of xylitol chewing gum (and in some cases xylitol dragées) can be considered a valuable additional tool in caries prevention and in stabilisation of caries in all age groups.

Polyol chewing gums and caries rates in primary dentition: a 24-month cohort study

The effect of 2-year chewing-gum use on the caries rates of primary teeth was studied in a combined school and home program in a sample of 510 initially 6-year-old subjects with high caries experience, low availability of fluoride, and difficult access to dental care. The gum, formed into either sticks or pellets, comprised either xylitol, sorbitol, or mixtures thereof. The gum was chewed for 5 min under supervision five times a day during the school year, and for variable times during nonschool days. Seven groups were studied. One group received no gum; two xylitol gum groups received either pellet or stick gum as did, two sorbitol gum groups, and two groups received either of two types of xylitol/sorbitol pellet gum. The response variable was the development of a frank carious lesion detectable by physical loss of enamel and probable extension to the dentin for those surfaces of primary teeth that were not cavitated at baseline. Caries rates associated with the use of each of the gum types were compared to the caries rates in the no-gum group. The usage of all polyol gums resulted in a significant decrease of the caries onset rate (p < 0.05). The caries onset risk for a primary surface in the xylitol pellet and the sorbitol pellet groups was 35 and 44% of that in the no-gum group (relative risk, 0.35; 95% confidence interval, 0.21-0.59; relative risk, 0.44; 95% confidence interval, 0.30-0.63, respectively). The caries onset risk in the xylitol stick gum group was 53% of that in the no-gum group (relative risk, 0.53; 95% confidence interval, 0.39-0.72), which was marginally (p = 0.1520) lower than in the sorbitol stick gum group (relative risk, 0.70; 95% confidence interval, 0.52-0.94). The usage of both xylitol/sorbitol mixtures in pellet form was associated with a caries onset rate comparable with the usage of the xylitol stick gum. The largest caries risk reduction was observed in the group receiving xylitol pellet gum.

Survival and growth of Aeromonas hydrophila on modified atmosphere packaged normal and high pH lamb

The growth of A. hydrophila on normal pH (5.5-5.8) and high pH ( > 6.0) lamb stored under modified atmospheres was examined. Lamb pieces and mince, inoculated with A. hydrophila were packaged in air, vacuum pack, 80% O2/20% CO2, 50% CO2/50% N2, or 100% CO2 and stored at 5 or 0 degrees C for up to 42 days. Samples were examined for the survival and/or growth of A. hydrophila by enrichment in alkaline peptone water and/or direct plating on starch ampicillin agar. The pH of each sample was estimated. On lamb pieces and mince of normal pH, A. hydrophila numbers decreased during storage at 5 and 0 degrees C under all the packaging conditions. The organism was not detected after 21 days storage. In contrast, A. hydrophila numbers were maintained or increased on high pH lamb under most storage regimes. Storage at 5 degrees C allowed significant increases in A. hydrophila numbers on high pH lamb under all the atmospheres, except 100% CO2. In lamb held at 5 degrees C under 100% CO2 for up to 42 days, A. hydrophila was recovered from most samples, although cell numbers decreased during storage. After storage at 0 degrees C, A. hydrophila was recovered from high pH packs stored under all atmospheres. Significant increases in cell numbers were only observed in minced lamb of high pH stored under air or vacuum. The pH values of lamb pieces and mince held at 5 or 0 degrees C under any of the packaging atmospheres did not change in a uniform manner during storage.