Population pharmacokinetics and pharmacodynamics of teicoplanin in neonates: making better use of C-reactive protein to deliver individualized therapy

OBJECTIVES

There is uncertainty about the optimal teicoplanin regimens for neonates. The study aim was to determine the population pharmacokinetics (PK) of teicoplanin in neonates, evaluate currently recommended regimens and explore the exposure-effect relationships.

METHODS

An open-label PK study was conducted. Neonates from 26 to 44 weeks post-menstrual age were recruited (n = 18). The teicoplanin regimen was a 16 mg/kg loading dose, followed by 8 mg/kg once daily. Therapeutic drug monitoring and dose adjustment were not conducted. A standard two-compartment PK model was developed, followed by models that incorporated weight. A PK/pharmacodynamic (PD) model with C-reactive protein serial measurements as the PD input was fitted to the data. Monte Carlo simulations (n = 5000) were performed using Pmetrics. The AUCs at steady state and the proportion of patients achieving the recommended drug exposures (i.e. Cmin >15 mg/L) were determined. The study was registered in the European Clinical Trials Database Registry (EudraCT: 2012-005738-12).

RESULTS

The PK allometric model best accounted for the observed data. The PK parameters medians were: clearance = 0.435 × (weight/70)0.75 (L/h); volume = 0.765 (L); Kcp = 1.3 (h-1); and Kpc = 0.629 (h-1). The individual time-course of C-reactive protein was well described using the Bayesian posterior estimates for each patient. The simulated median AUC96-120 was 302.3 mg·h/L and the median Cmin at 120 h was 12.9 mg/L; 38.8% of patients attained a Cmin >15 mg/L by 120 h.

CONCLUSIONS

Teicoplanin population PK is highly variable in neonates, weight being the best descriptor of PK variability. A low percentage of neonates were able to achieve Cmin >15 mg/L. The routine use of therapeutic drug monitoring and improved knowledge on the PD of teicoplanin is required.

Concentrated parenteral nutrition solutions and central venous catheter complications in preterm infants

Standardised, concentrated neonatal parenteral nutrition (PN) regimens can overcome early nutritional deficits in very preterm infants. A PN regimen with increased macronutrient content (standardised, concentrated, added macronutrients parenteral (SCAMP)) has been shown to improve early head growth in a randomised controlled trial. Line complications including late onset sepsis were secondary outcomes of this study. Infants were started on standardised, concentrated PN at birth and randomised at 2-5 days to either switch to SCAMP or remain on control PN. Central venous catheter (CVC), blood culture (BC) and inflammatory marker data were collected for the 28-day intervention period. 150 infants were randomised with mean (SD) birth weight (g) of 900 (158) versus 884 (183) in SCAMP (n=74) and control (n=76) groups, respectively. There were no differences in CVC use/type or duration or in positive/negative BC with/without associated C reactive protein rise in SCAMP versus control groups. Increasing the macronutrient content of a standardised, concentrated neonatal PN regimen does not increase CVC complication rates.

TRIAL REGISTRATION NUMBER

ISRCTN 76597892.

Weight gain in breast cancer patients: Tamoxifen versus anastrazole

10544

Background: Weight gain is a common complaint among breast cancer patients, especially those taking tamoxifen. Aromatase inhibitors have been increasingly used in postmenopausal breast cancer patients, and are generally thought to have a more tolerable side-effect profile than selective estrogen receptor modulators (SERM’s). This study specifically addresses weight gain in patients on the SERM, tamoxifen, compared to patients on the aromatase inhibitor, anastrazole. Methods: Ninety-six outpatients with primary breast cancer of any stage received standard doses of adjuvant hormonal therapy. Seventy received tamoxifen (Group T) and 26 anastrazole (Group A). The nursing staff in the clinic weighed all patients at the time of diagnosis, at start of chemotherapy (if received), at start of hormone therapy, and at 3 month intervals for 12 months after starting hormone therapy. Data were gathered in a retrospective manner. Results: Demographic variables were compared between the two groups. In all patients, it was noted that increasing age was correlated with greater weight gain at 3 months after starting hormone therapy (p = 0.0257), but not at any other intervals. No other variables were significantly correlated with weight gain. In Group T, mean weight gain was clinically (>1.8 kgs) and statistically significant at 9 and 12 months (p = 0.0137, p = 0.0003). In Group A, mean weight gain was not clinically significant at any point. Using the Wilcoxon two-sample tests to compare groups T and A, it was shown that there was no statistically significant difference in weight gain between the two groups at any interval (see table). Conclusions: These results are consistent with previous studies that show significant weight gain in breast cancer patients on tamoxifen. This study failed to show a statistically significant difference in weight gain between patients on tamoxifen and patients on anastrazole. Group A did not have statistically significant weight gain at any interval after starting hormone therapy.

[Table: see text]

No significant financial relationships to disclose.

Structure of lifestyle disruptions in chronic disease: a confirmatory factor analysis of the Illness Intrusiveness Ratings Scale

BACKGROUND

The Illness Intrusiveness Ratings Scale (IIRS) measures the extent to which disease or its treatment or both interfere with activities in important life domains. Before comparing IIRS scores within or across groups it is crucial to determine whether a common underlying factor structure exists across patient populations.

OBJECTIVE

To investigate the factor structure underlying the IIRS and evaluate its stability across diagnoses.

METHODS

IIRS responses from 5,671 respondents were pooled from 15 separate studies concerning quality of life in eight patient groups: rheumatoid arthritis; osteoarthritis; systemic lupus erythematosus; multiple sclerosis; end-stage renal disease (maintenance dialysis); renal transplantation; heart, liver, and lung transplantation; and insomnia. Data were gathered by different methods (eg, interview, self-administered, mail survey) and in diverse contexts (eg, individual vs. group).

RESULTS

Exploratory maximum-likelihood factor analysis identified three underlying factors in a randomly selected subset of respondents (n = 400), corresponding to "Relationships and Personal Development," "Intimacy," and "Instrumental" life domains. Confirmatory factor analysis corroborated the stability of this structure in an independent subsample (n = 2100). Complementary goodness-of-fit indices confirmed the consistency of the three-factor solution, corroborating that IIRS scores are uniquely defined across patient populations. Coefficient alpha was high for total and subscale scores.

CONCLUSIONS

IIRS scores can be compared meaningfully within and across patient groups. Both total and subscale scores can be used depending on research objectives.

Web-based education and support for patients on the cardiac surgery waiting list

We assessed the effectiveness of two methods of patient education, a printed manual and a Website, provided to patients waiting for cardiac surgery. The four-phase study was conducted over two and a half years, and included urban and rural subjects in Vancouver and the interior of British Columbia. The Website was based on the specially developed patient education manual. A pilot evaluation study was carried out to assess the features of the Website and to ensure it was 'user-friendly', after which it was revised. The two education methods were evaluated using both qualitative and quantitative studies. Findings supported the feasibility and viability of both formats. The Web-based format demonstrated two additional benefits over the print-based format, namely increased social support and decreased anxiety. Other findings included the perception of increased support, lifestyle changes and more positive attitudes towards the impending surgery.

Moving beyond information: evaluation of a nutrition education tool based on a theoretical model

OBJECTIVE

This study investigated the relative effectiveness of a nutrition education brochure based on a theoretical model versus a more traditional information-based brochure in getting subjects to accurately assess daily calcium intake, make a plan to increase intake if needed, and to implement the plan.

DESIGN

A randomized trial involving 216 women between the ages of 19-49y. Subjects were randomly assigned to a group which received educational materials containing an interactive brochure designed using the Motivation Generating model (Calcium CalculatorS), or to a group which received a calcium information brochure (An Appetite for Good Health). Within a two week period the women were contacted by telephone to assess use of materials, calcium intake assessment information, and plans for dietary change.

SETTING

Subjects were recruited at five fitness centres in the Vancouver area. The research was conducted by the Institute of Health Promotion Research at the University of British Columbia.

RESULTS

Results indicated significantly greater numbers of subjects conducting self- assessment and increased group accuracy for calcium intake assessment in subjects using the interactive brochure.

CONCLUSION

Use of a theoretical model designed to create behaviour change such as the Motivation Generating Model can increase specific behaviours which may lead to improvements in dietary consumption.

Immunological ignorance of an E7-encoded cytolytic T-lymphocyte epitope in transgenic mice expressing the E7 and E6 oncogenes of human papillomavirus type 16

Certain human papillomaviruses (HPV) have been implicated in the etiology of cervical malignancies, and the E7 and E6 gene products of HPV type 16 are frequently expressed in these lesions. However, cytolytic T-lymphocyte (CTL)-mediated responses to HPV are rarely detectable in patients with cervical cancer. To examine whether the T-cell response is deficient during the HPV-induced transformation, we produced lines of transgenic (Tg) mice that expressed the E6 and E7 oncogenes in keratinized epithelia. The mice developed severe hypertrophy of all keratinized epithelia, but no malignancies were observed. Although epithelial cells from Tg mice could present at least an E7-encoded CTL epitope (E7 49-57), CTLs from these mice were neither primed to nor made tolerant of this epitope. No quantitative or qualitative differences were seen in the CTL responses of the Tg mice compared to those of their littermates following immunization with the peptide E7 49-57. Immunization of Tg mice with the E7 49-57 peptide protected them against a subcutaneous challenge with tumor cells expressing a transfected E7 gene, yet the skin was unaffected, although the cultured skin epithelial cells from Tg mice expressed E7. Our results suggest that the Tg mice were immunologically ignorant of HPV oncoproteins with respect to a CTL response and that a similar type of ignorance may explain why HPV-associated cervical cancer cells can escape immunological destruction.

B7-CD28 costimulation unveils the hierarchy of tumor epitopes recognized by major histocompatibility complex class I-restricted CD8+ cytolytic T lymphocytes

Immunization of mice with tumors genetically engineered to express the B7 costimulatory molecules amplifies the antitumor immune response mediated by CD8+ cytolytic T lymphocytes (CTL). In this report, we examined the effect of B7-CD28 costimulation on the hierarchy of tumor epitopes. Using a combination of affinity chromatography/reversed-phase high performance liquid chromatography and CTL cloning, we show that major histocompatibility complex (MHC) class I molecules from EL4 lymphoma cells can present at least six distinct CTL epitopes presented by MHC class I molecules. Nevertheless, mice immunized with wild-type B7-negative EL4 cells develop CTL only to one immunodominant epitope. In contrast, immunization with B7-transduced EL4 cells led to not only the amplification of the CTL response to this immunodominant epitope, but also to the recognition of five otherwise silent subdominant epitopes. The adoptive transfer of a CTL clone against such a subdominant epitope cured mice bearing EL4 lymphoma growing as an ascites tumor. The fact that CTL response can be spread to normally silent epitopes as a result of B7-CD28 costimulation suggests a novel approach to manipulate the hierarchy of CTL epitopes and offers an opportunity to explore novel targets for T cell-mediated cancer therapy.

Rings and watches: should they be removed prior to operative dental procedures?

OBJECTIVES

There is no clear evidence to support the recommendation that rings and watches should be removed prior to operative dental procedures. The aim of this study was to measure and identify the bacteria isolated from the skin under rings and watches worn by a group of dental surgeons and to compare the results with a group of non-clinical staff.

METHODS

Forty volunteers participated in the study; of these 20 were dental surgeons and 20 were non-clinical staff. Four skin sites were sampled for each volunteer; the skin directly under the ring and on the same finger of the other hand and the skin under the watch face and wrist of the control hand. Bacteria on the swabs were dispersed and inoculated onto plates, which were incubated aerobically for 24 h at 37 degrees C.

RESULTS

In both groups of volunteers there was a significantly greater number of bacteria isolated from under rings and watches compared with control sites. Few qualitative differences were found between the microflora found on the skin under rings and watches in the two volunteer groups.

CONCLUSIONS

The bacterial flora isolated from volunteers do not commonly cause oral infections but could pose a threat to the immunocompromised patient, particularly in the event of gloves becoming torn or perforated. Effective hand disinfection is difficult to achieve if ring and watches are not removed; they should therefore be removed prior to hand disinfection and donning of gloves.

Preoxygenation--the importance of a good face mask seal

We have studied 16 healthy volunteers whose lungs were preoxygenated six times each in order to assess the amount of room air entrained during tidal volume preoxygenation if a good seal is not maintained between the face mask and the face. With a fresh gas flow of 10 litre min-1, we found that using gravity alone to hold the face mask in position, more than 20% room air was entrained; if the face mask was held adjacent to the face, more than 40% room air was entrained.

B7-1/CD80-transduced tumor cells elicit better systemic immunity than wild-type tumor cells admixed with Corynebacterium parvum

Tumor cells genetically modified by transduction of B7 (B7-1/CD80), a natural ligand for the T-cell costimulatory molecules CD28 and CTLA-4, can elicit potent tumor immunity, and they can be effective for treatment of established cancers in animal models. In this study, three tumor lines, the EL4 lymphoma, the P815 mastocytoma, and the MCA102 sarcoma were transduced with recombinant retrovirus containing the murine B7 gene, and their potency to induce systemic immunity protective against challenge with wild-type tumor was compared to that of the same tumor cells admixed with the commonly used adjuvant Corynebacterium parvum. While admixture of tumor cells with C. parvum resulted in complete regression of tumors in syngeneic mice, it did not induce protective immunity against a subsequent challenge of wild-type cells from any of the 3 tumors tested. In contrast, B7-transduced EL4 and P815 tumors regressed locally and induced a potent systemic immunity to wild-type tumors and a higher level of cytotoxic T-cell activity than did tumor cells admixed with C. parvum. No systemic immunity was induced by B7-transduced nonimmunogenic MCA102 sarcoma cells. Our results demonstrate that immunogenic tumor cells transduced with the B7 gene are superior to tumor cells mixed with C. parvum for the induction of systemic tumor immunity.

Costimulation of tumor-reactive CD4+ and CD8+ T lymphocytes by B7, a natural ligand for CD28, can be used to treat established mouse melanoma

Interactions between the costimulatory molecule B7 on APC and its counter-receptor CD28 on T lymphocytes play a key role in the induction of cell-mediated immune responses. We studied the role of costimulation of tumor-reactive T cells by B7 in the immune destruction of the K1735-M2 mouse melanoma into which the gene encoding the human melanoma-associated Ag, p97, had been transfected. Previous work has demonstrated that the p97 transfectant cl62 is immunogenic but still grows progressively in immunocompetent C3H/HeN mice and that adoptive transfer of p97-specific CD4+ T cells can induce the regression of small established cl62 tumors metastatic to the lungs. We have now shown that expression of B7 in cl62 after retroviral-mediated gene transfer eliminated its ability to grow in immunocompetent mice but not in T cell-deficient nude mice. Mice immunized with B7-transduced p97+ cells had an increased activity of both CD4+ T cells, which could proliferate in response to the p97 Ag, and CD8+ CTL, which could lyse a broad spectrum of cultured syngeneic p97+ and p97- tumor lines but not allogeneic tumor lines or syngeneic lymphoblasts. Both CD4+ and CD8+ T cell subsets were required for tumor rejection, and the depletion of CD4+ T cells in vivo decreased the tumoricidal activity of CD8+ CTL. Treatment of mice bearing an 8-day established s.c. cl62 melanoma by i.p. injection of B7+ cells from 2A, a highly immunogenic p97 transfectant, resulted in complete tumor regression and cure, injection of B7- 2A cells did not. The therapeutic effect was specific for the cl62 tumor. Our results demonstrate that costimulation by B7 can amplify both CD4+ and CD8+ T cell responses against small tumors toward therapeutic benefit.

Costimulation of tumor-reactive CD4+ and CD8+ T lymphocytes by B7, a natural ligand for CD28, can be used to treat established mouse melanoma

Interactions between the costimulatory molecule B7 on APC and its counter-receptor CD28 on T lymphocytes play a key role in the induction of cell-mediated immune responses. We studied the role of costimulation of tumor-reactive T cells by B7 in the immune destruction of the K1735-M2 mouse melanoma into which the gene encoding the human melanoma-associated Ag, p97, had been transfected. Previous work has demonstrated that the p97 transfectant cl62 is immunogenic but still grows progressively in immunocompetent C3H/HeN mice and that adoptive transfer of p97-specific CD4+ T cells can induce the regression of small established cl62 tumors metastatic to the lungs. We have now shown that expression of B7 in cl62 after retroviral-mediated gene transfer eliminated its ability to grow in immunocompetent mice but not in T cell-deficient nude mice. Mice immunized with B7-transduced p97+ cells had an increased activity of both CD4+ T cells, which could proliferate in response to the p97 Ag, and CD8+ CTL, which could lyse a broad spectrum of cultured syngeneic p97+ and p97- tumor lines but not allogeneic tumor lines or syngeneic lymphoblasts. Both CD4+ and CD8+ T cell subsets were required for tumor rejection, and the depletion of CD4+ T cells in vivo decreased the tumoricidal activity of CD8+ CTL. Treatment of mice bearing an 8-day established s.c. cl62 melanoma by i.p. injection of B7+ cells from 2A, a highly immunogenic p97 transfectant, resulted in complete tumor regression and cure, injection of B7- 2A cells did not. The therapeutic effect was specific for the cl62 tumor. Our results demonstrate that costimulation by B7 can amplify both CD4+ and CD8+ T cell responses against small tumors toward therapeutic benefit.

Tumor immunogenicity determines the effect of B7 costimulation on T cell-mediated tumor immunity

A costimulatory signal through B7 to its counter-receptor CD28 on T cells enhances T cell activation. We have generated recombinant retroviruses containing cDNA for murine B7 and transduced a panel of murine tumor lines with varying immunogenicity to study the effect of B7 costimulation on antitumor immunity. In contrast to the progressive outgrowth of all wild-type (B7-) tumors in unimmunized syngeneic mice, four immunogenic tumors, lymphoma RMA, EL4, mastocytoma P815, and melanoma E6B2, regressed completely when transduced with the B7 gene. In contrast, four nonimmunogenic tumors, sarcomas MCA101, MCA102, and Ag104, and melanoma B16, remained tumorigenic after transduction of the B7 gene. Immunization with B7-transduced immunogenic tumors enhanced protective immunity and increased specific cytotoxic T lymphocyte (CTL) activity against the respective wild-type tumors as compared to immunization with nontransduced or mock-transduced tumors. Moreover, cocultivation of CTL with B7-transduced EL4 cells augmented the specificity of tumor-reactive CTL in long-term cultures. Treatment by injection of B7-transduced tumor cells cured 60% of mice with established wild-type EL4 lymphoma. In contrast, immunization with nonimmunogenic tumors transduced with B7 did not provide protective immunity and did not increase specific CTL activity. Our results show that tumor immunogenicity is critical to the outcome of costimulation of T cell-mediated tumor immunity by B7.

A comparative study of cephradine, amoxycillin and phenoxymethylpenicillin in the treatment of acute dentoalveolar infection

A comparative double blind trial was undertaken of the efficacy of cephradine, amoxycillin and phenoxymethylpenicillin in the treatment of acute dentoalveolar abscesses. Patients were admitted to the trial with acute dentoalveolar abscesses with systemic involvement and assessments were made of pain, swelling, temperature and lymphadenopathy. After admission to the trial appropriate surgical therapy was undertaken. The patients were then given either phenoxymethylpenicillin 250 mg four times daily, cephradine 500 mg twice daily or amoxycillin 250 mg three times daily, all for 5 days. The patients were assessed after 2 days and 5 days. All the patients recovered with those taking cephradine showing the best recovery in the first two days of treatment.

Costimulation of antitumor immunity by the B7 counterreceptor for the T lymphocyte molecules CD28 and CTLA-4

Interaction of the B7 molecule on antigen-presenting cells with its receptors CD28 and CTLA-4 on T cells provides costimulatory signals for T cell activation. We have studied the effects of B7 on antitumor immunity to a murine melanoma that expresses a rejection antigen associated with the E7 gene product of human papillomavirus 16. While this E7+ tumor grows progressively in immunocompetent hosts, cotransfection of its cells with B7 led to tumor regression by a B7-dependent immune response mediated by CD8+ cytolytic T lymphocytes. The immune response induced by E7+B7+ tumor cells also caused regression of E7+B7- tumors at distant sites and was curative for established E7+B7- micrometastases. Our findings suggest that increasing T cell costimulation through the CD28 and CTLA-4 receptors may have therapeutic usefulness for generating immunity against tumors expressing viral antigens.

CD4+ T cell clones specific for the human p97 melanoma-associated antigen can eradicate pulmonary metastases from a murine tumor expressing the p97 antigen

p97 is a human tumor-associated Ag present on most melanoma cells that represents a possible target for immunologic attack. To evaluate the capacity of T cells reactive with this protein to promote elimination of melanoma cells expressing p97, a murine model was developed by transfecting a C3H/HeN melanoma with the p97 cDNA, generating p97-specific CD4+ T cells by in vivo immunization of C3H/HeN mice with a vaccinia/p97 recombinant virus followed by in vitro cloning with soluble p97 protein, and determining whether these CD4+ T cells could mediate rejection of pulmonary metastases. Characterization of the T cell clones demonstrated the presence of both I-Ak and I-Ek-restricted clones, although the majority of clones recognized p97 in the context of I-Ek. Analysis of clonal specificity using truncated p97 proteins revealed that at least three epitopes were immunogenic, and further studies with overlapping 15-amino acid peptides from a region of the p97 molecule defined by these truncated proteins identified an immunodominant epitope responsible for the majority of the I-Ek response. The T cell clones were not capable of directly recognizing the p97-expressing melanoma cells but responded to the tumor if syngeneic APC were present to process the tumor-derived p97 Ag. The therapeutic efficacy of these CD4+ T cell clones was evaluated in an adoptive therapy model in which mice bearing metastatic pulmonary lesions were treated by i.v. administration of the p97-specific cells. Despite the inability of the CD4+ clones to directly respond to or lyse the tumor cells, the clones were effective in promoting tumor eradication. In vitro studies demonstrated that this may have reflected secretion of lymphokines that activated macrophages to lyse the tumor. The results suggest that noncytolytic p97-specific CD4+ T cell clones can be effective in therapy of pulmonary melanoma metastases. Moreover, if human T cells reactive with the p97 protein could be generated, the expression of this tumor-associated Ag in melanoma cells might be adequate for such T cells to mediate a therapeutic antitumor response.

CD4+ T cell clones specific for the human p97 melanoma-associated antigen can eradicate pulmonary metastases from a murine tumor expressing the p97 antigen

p97 is a human tumor-associated Ag present on most melanoma cells that represents a possible target for immunologic attack. To evaluate the capacity of T cells reactive with this protein to promote elimination of melanoma cells expressing p97, a murine model was developed by transfecting a C3H/HeN melanoma with the p97 cDNA, generating p97-specific CD4+ T cells by in vivo immunization of C3H/HeN mice with a vaccinia/p97 recombinant virus followed by in vitro cloning with soluble p97 protein, and determining whether these CD4+ T cells could mediate rejection of pulmonary metastases. Characterization of the T cell clones demonstrated the presence of both I-Ak and I-Ek-restricted clones, although the majority of clones recognized p97 in the context of I-Ek. Analysis of clonal specificity using truncated p97 proteins revealed that at least three epitopes were immunogenic, and further studies with overlapping 15-amino acid peptides from a region of the p97 molecule defined by these truncated proteins identified an immunodominant epitope responsible for the majority of the I-Ek response. The T cell clones were not capable of directly recognizing the p97-expressing melanoma cells but responded to the tumor if syngeneic APC were present to process the tumor-derived p97 Ag. The therapeutic efficacy of these CD4+ T cell clones was evaluated in an adoptive therapy model in which mice bearing metastatic pulmonary lesions were treated by i.v. administration of the p97-specific cells. Despite the inability of the CD4+ clones to directly respond to or lyse the tumor cells, the clones were effective in promoting tumor eradication. In vitro studies demonstrated that this may have reflected secretion of lymphokines that activated macrophages to lyse the tumor. The results suggest that noncytolytic p97-specific CD4+ T cell clones can be effective in therapy of pulmonary melanoma metastases. Moreover, if human T cells reactive with the p97 protein could be generated, the expression of this tumor-associated Ag in melanoma cells might be adequate for such T cells to mediate a therapeutic antitumor response.

Antibiotic-resistant oral streptococci in dental patients susceptible to infective endocarditis

The aim of this study was to determine the incidence of amoxycillin and erythromycin resistance in oral streptococci in patients at risk from infective endocarditis. Samples of gingival crevicular flora were taken from 65 patients at the site of dental treatment, prior to the prophylactic administration of amoxycillin (54 patients) or erythromycin (11 patients). Samples were also taken from 65 dental patients who were not considered to be at risk from infective endocarditis. No isolate had a minimum inhibitory concentration (MIC) of amoxycillin greater than 24 mg/L. However, erythromycin-resistant oral streptococci with MIC values greater than 3.5 mg/L were isolated from 22% of patients receiving amoxycillin prophylaxis, 9% of patients receiving amoxycillin prophylaxis, 9% of patients given erythromycin prophylaxis and 9% of patients not at risk from infective endocarditis. The antibiotic-resistant streptococci comprised mainly Streptococcus sanguis biotype II, although S. sanguis biotype I, S. mitis and S. salivarius were also frequently recovered.

Psychologic, social, emotional, and practical problems of patients with arthritis

Family physicians will have increasing numbers of patients with arthritis in their practices during the 1990s. Medical management is often complicated by subclinical psychologic, social, and emotional problems, and other problems of everyday living that affect the care of these people. The author reviews some typical patients with arthritis and offers practical suggestions about non-medical treatments that can assist them.

Factors affecting the variability of semen analysis results in infertile men

Infertile men who had 3 or more semen analyses performed in one laboratory were placed in 2 groups (I) oligozoospermic group (n = 106), mean sperm concentration between 1 and 20 million/ml (II) asthenozoospermic group (n = 71), mean sperm concentration greater than 20 million/ml, and mean motility less than 60%. With increasing durations of abstinence from ejaculation before the tests there were significant increases in semen volume and sperm concentration. Semen volume increased over the first 4 days to a similar extent in both groups. Sperm concentrations increased over 15 days, but the effect of abstinence was much greater in the asthenozoospermic group than in the oligozoospermic group (14% compared with 1.4% of the within subject variation). Significant changes in results accompanied repeated testing, notably rises in sperm concentration and motility. Sperm motility was lower in winter and higher in summer in both groups and also, but to a lesser extent, in artificial insemination donors who collected semen in the laboratory.

CONCLUSIONS

duration of abstinence, the elapse of time and seasonal temperature changes affect semen analysis results, and therefore controls for these variables must be incorporated in any therapeutic trial for male infertility. On the other hand, they only account for a small proportion of the total variability and thus routine correction of results would not greatly improve the value of semen analysis in the prediction of fertility. Furthermore because differences in the duration of abstinence have only a small effect on sperm concentration in oligozoospermic men, restricting sexual intercourse to the time of ovulation may not enhance fertility.