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Biomedical subjects

D A Ross

Publications and source records attributed to D A Ross.

At least 19 recordsLinked to original sources
PubMed2006

Are schools a good setting for adolescent sexual health promotion in rural Africa? A qualitative assessment from Tanzania.

African adolescents are at high risk of poor sexual health. School-based interventions could reach many adolescents in a sustainable and replicable way, if enrolment, funding and infrastructure are adequate. This study examined pupils', recent school leavers', parents' and teachers' views and experiences of rural Tanzanian primary schools, focusing on the implications for potential sexual health programmes. From 1999 to 2002, participant observation was conducted in nine villages for 158 person-weeks. Half of Year 7 pupils were 15-17 years old, and few went on to secondary school, suggesting that primary schools may be a good venue for such programmes. However, serious challenges include low enrolment and attendance rates, limited teacher training, little access to teaching resources and official and unofficial practices that may alienate pupils and their parents, e.g. corporal punishment, pupils being made to do unpaid work, forced pregnancy examinations, and some teachers' alcohol or sexual abuse. At a national level, improved teacher training and supervision are critical, as well as policies that better prevent, identify and correct undesired practices. At a programme level, intervention developers need to simplify the subject matter, introduce alternative teaching methods, help improve teacher-pupil and teacher-community relationships, and closely supervise and appropriately respond to undesired practices.

Absenteeism↗
PubMed2006

A process evaluation of a school-based adolescent sexual health intervention in rural Tanzania: the MEMA kwa Vijana programme.

This study is a process evaluation of the school component of the adolescent sexual health programme MEMA kwa Vijana (MkV), which was implemented in 62 primary schools in rural Mwanza, Tanzania from 1999 to 2001. The MkV curriculum was a teacher-led and peer-assisted programme based on the Social Learning Theory. Process evaluation included observation of training sessions, monitoring and supervision, annual surveys of implementers, group discussions and 158 person-weeks of participant observation. Most teachers taught curriculum content well, but sometimes had difficulty adopting new teaching styles. Peer educators performed scripted dramas well, but were limited as informal educators and behavioural models. The intervention appeared successful in addressing some cognitions, e.g. knowledge of risks and benefits of behaviours, but not others, e.g. perceived susceptibility to risk. MkV shared the characteristics of other African school-based programmes found to be successful, and similarly found significant improvements in self-reported behaviour in surveys. However, a substantial proportion of MkV survey self-reports were inconsistent, there was no consistent impact on biological markers and extensive process evaluation found little impact on several key theoretical determinants of behaviour. Improvements in self-reported survey data alone may provide only a very limited-and perhaps invalid-indication of adolescent sexual health programme success.

Adolescent↗
PubMed2006

Rationale and design of the MEMA kwa Vijana adolescent sexual and reproductive health intervention in Mwanza Region, Tanzania.

Large-scale innovative, integrated, multifaceted adolescent sexual and reproductive health (ASRH) interventions are urgently needed in sub-Saharan Africa. Implementation through schools and health facilities may maximize intervention coverage and sustainability, however the impact of the use of these structures on intervention content and delivery is not well documented. This paper describes the rationale and design of a large-scale multifaceted ASRH intervention, which was developed and evaluated over three years in rural communities in Mwanza Region, North West Tanzania. The intervention comprised community mobilization, participatory reproductive health education in primary schools, youth-friendly reproductive health services and community-based condom provision for youth. We examine the effect of socioeconomic, cultural and infrastructural factors on intervention content and implementation. This paper demonstrates the means by which such interventions can be feasibly and sustainably implemented to a high standard through existing government health and school structures. However, the use of these structures involves compromise on some key aspects of intervention design and requires the development of complementary strategies to access out-of-school youth and the wider community.

Adolescent↗
PubMed2006

Developmental and nutritional regulation of the prepubertal heifer mammary gland: I. Parenchyma and fat pad mass and composition.

Prior to puberty, elevated nutrient intake has been shown to negatively affect prepubertal mammary development in the heifer. The objective of this study was to evaluate the effects of increased nutrient intake on mammary development in Holstein heifers at multiple body weights from birth through puberty. Specifically, this study evaluated the effects of nutrient intake and body weight at harvest on 1) total weight and DNA content of the parenchyma (PAR) and mammary fat pad (MFP) and 2) PAR and MFP composition. Starting at 45 kg of body weight, heifers (n = 78) were assigned to either a restricted (R) or elevated (E) level of nutrient intake supporting 650 (R) or 950 (E) g/d of body weight gain. Heifers were harvested at 50-kg increments from 100 to 350 kg of body weight. Mammary fat pad weight and DNA content were greater in E- than in R-heifers. Additionally, E-heifers had a greater fraction of lipids and a smaller fraction of protein in their MFP than did R-heifers. Parenchyma weight and DNA were lower in E- than in R-heifers; however, when analyzed with age as a covariate term, treatment was no longer a significant term in the model. Level of nutrient intake had no effect on the lipid, protein, or hydroxyproline composition of the PAR. Collectively, these data demonstrate that PAR is refractory to the level of nutrient intake whereas MFP is not. Furthermore, the covariate analysis demonstrated that age at harvest, not the level of nutrient intake, was the single greatest determinant of total PAR DNA content.

Adipose Tissue↗
PubMed2006

Developmental and nutritional regulation of the prepubertal bovine mammary gland: II. Epithelial cell proliferation, parenchymal accretion rate, and allometric growth.

It is well documented that elevated nutrient intake prior to puberty reduces prepubertal mammary development in the bovine. The companion paper demonstrated that age at harvest is a primary determinant of parenchymal (PAR) mass and that any effects of elevated energy intake on mechanisms regulating mammary development are dwarfed by this effect of time. Therefore, it is hypothesized that while causing a decrease in prepubertal PAR mass, elevated nutrient intake will have no effect on growth characteristics of the mammary gland. The objectives of this experiment were to evaluate the effects of increased nutrient intake from early in life on 1) mammary epithelial cell proliferation, 2) mammary PAR DNA accretion rates, and 3) the dynamics of prepubertal allometric PAR growth. Holstein heifers (n = 78) were fed from 45 kg of body weight either elevated (E) or restricted (R) levels of nutrients to support 950 (E) or 650 (R) g/d of body weight gain. Six heifers per treatment were harvested at 50-kg increments from 100 to 350 kg of body weight. Heifers on the E plane of nutrition had higher plasma leptin and less PAR DNA than their body weight-matched R-intake cohorts. Despite this reduction in PAR DNA, treatment did not negatively influence mammary epithelial cell proliferation or the PAR DNA accretion rate. Dynamics of allometric and isometric mammary growth were also unaffected by the level of nutrient intake, as was exit from allometric growth. This work represents the first demonstrating that the level of nutrient intake and the concomitant increase in plasma leptin have no measurable influence on 1) the rate of PAR DNA accretion, 2) mammary epithelial cell proliferation, or 3) total PAR mass and, by default, the local or systemic controls that coordinate these processes.

Animal Nutritional Physiological Phenomena↗
PubMed2005

Long term follow-up of c-myc, p53 and proliferation measurements in malignant melanoma.

AIMS: We report a prospective study examining the prognostic significance of the c-myc oncoprotein, p53 tumour suppressor gene and proliferation rate measurements in malignant melanoma. METHODS: Flow cytometry (FCM) was used to measure the expression of c-myc, p53 and proliferation parameters in patients who had received an injection of the thymidine analogue bromodeoxyuridine prior to surgery. RESULTS: Sixty-seven patients had successful FCM measurements of the three parameters. c-myc was detected in 97% of patients with a median cell positivity of 62%. The median p53 positivity was 13%. The median potential doubling time (T(pot)) of the tumours wasf 9.4 days. In univariate analysis, each of the parameters showed an association with survival in metatstatic disease with rapid proliferation (p=0.006) or overexpression of c-myc (p=0.038) related to poor survival whereas increased positivity for p53 predicted better survival (p=0.013). CONCLUSIONS: These data indicate that laser cytometric technology can be used to obtain quantitative data on oncoproteins expression and cell proliferation rates in clinical samples of malignant melanoma.

Cell Proliferation↗
PubMed2005

Use of the vertical rectus abdominis myocutaneous flap after abdominoplasty.

A vertical rectus abdominis myocutaneous flap was used to provide cover for a recurrent angiosarcoma in the abdominal skin. Of note, the patient had 9 years previously undergone formal abdominoplasty to allow closure following excision of the primary tumour. This flap is normally reliant on myocutaneous perforators originating from the deep epigastric system, which are divided during abdominoplasty. Despite this, the flap survived well, implying that a new blood supply had formed during the intervening years. This flap can, therefore, be considered a possible option in reconstructive cases where other options are limited, despite a preceding abdominoplasty. In the future because of the increasingly common occurrence of abdominoplasty in young females, this procedure may need to be considered.

Abdominal Neoplasms↗
PubMed2004

Cisplatin, fluorouracil, and leucovorin induction chemotherapy followed by concurrent cisplatin chemoradiotherapy for organ preservation and cure in patients with advanced head and neck cancer: long-term follow-up.

PURPOSE: The poor functional outcome in patients with advanced head and neck squamous cell carcinoma (HNSCC) with surgery and radiation has led to alternative approaches to advanced disease. We conducted a phase II study of induction chemotherapy followed by concurrent chemoradiotherapy for organ preservation in patients with advanced resectable and unresectable (nasopharyngeal) tumors. PATIENTS AND METHODS: Forty-two patients with stage III to IV resectable HNSCC and nasopharyngeal tumors received induction chemotherapy with two courses of cisplatin (20 mg/m2/d continuous infusion [CI]), fluorouracil (800 mg/m2/d CI), and leucovorin (500 mg/m2/d CI; PFL) for 4 days followed by concurrent therapy with cisplatin (100 mg/m2/d on days 1 and 22) and approximately 70 Gy of external-beam radiotherapy. RESULTS: Response to induction chemotherapy included partial response rate of 52% and complete response rate of 24%. The most common grade 3 or 4 toxicity was neutropenia (59%). After cisplatin chemoradiotherapy the complete response rate was 67%. Toxicities of cisplatin chemoradiotherapy consisted of grade 3 or 4 mucositis (79%) and neutropenia (51%). At a median follow-up of 71.5 months, 43% of the patients are still alive and disease-free. The 5-year progression-free survival (PFS) rate was 60%, and the 2- and 5-year overall survival (OS) rates were 67% and 52%, respectively. Three patients died of second primaries. Late complications of treatment included xerostomia and hoarseness. One patient had persistent dysphagia and required laser epiglotectomy 108 months after treatment. CONCLUSION: Induction chemotherapy with PFL followed by concurrent cisplatin chemoradiotherapy is well tolerated and results in a good likelihood of organ preservation and excellent PFS and OS.

Adolescent↗
PubMed2004

Validation of night blindness reports among children and women in a vitamin A deficient population in rural Tanzania.

OBJECTIVE: This study validates different definitions of reported night blindness (XN) in a vitamin A deficient African population with no local term for XN. DESIGN: Case-control study with follow-up after treatment. SETTING: Eight primary schools and health centres in rural Tanzania. SUBJECTS: A total of 1214 participants were screened for reported XN and other eye signs of xerophthalmia: 461 children aged 24-71 months, 562 primary school-age children and 191 pregnant or breast-feeding women. All 152 cases of reported XN were selected for the validation study and group matched with 321 controls who did not complain of XN. XN reports were validated against serum retinol concentrations and pupillary dark adaptation measurements in cases and controls. INTERVENTION: All children and women who reported XN or had other signs of active xerophthalmia were treated with vitamin A and followed up 3-4 weeks later. Half of the untreated control group who had their serum retinol examined in the baseline examination were also followed up. RESULTS: The overall prevalence of reported XN was 12.5%. At baseline, mean pupillary threshold (-1.52 vs -1.55 log cd/m(2), P=0.501) and median serum retinol concentrations (0.95 vs 0.93 micromol/l, P=0.734) were not significantly different in cases and controls either overall or in each population group. More restricted case definitions reduced the prevalence of reported XN to 5.5% (P<0.001), but there was still no significant difference between cases and controls although the results were in the expected direction. After treatment, the median serum retinol concentration improved significantly only in the most deficient group, the young children. Dark adaptation improved in all the subgroups but the difference was only significant for young children and primary school-age children when the restricted case definitions were used. CONCLUSIONS: XN reports are a poor indicator of vitamin A deficiency in this population. SPONSORSHIP: Task Force Sight and Life, Basel, Switzerland.

Adolescent↗
PubMed2004

Detection of Pentatrichomonas hominis DNA in biological specimens by PCR.

AIM: To develop a sensitive and specific polymerase chain reaction for the detection of Pentatrichomonas hominis in biological specimens. METHODS: Three primers, associated in two primer pairs, were designed to amplify a sequence from the SSU rRNA gene of P. hominis. The specificity of both primer pairs was established by testing DNA extractions of different Trichomonad species, protozoa, bacteria, yeasts, and human leucocytes. The analytical sensitivity was determined through testing dilutions of P. hominis trophozoites. The clinical specificity and applicability of the assay was evaluated on stool samples and self-administered vaginal swabs. CONCLUSIONS: A highly specific and sensitive PCR assay was developed. Both primer pairs performed equally well. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of P. hominis in vaginal specimens has not been reported before.

Animals↗
PubMed2004

The sexual health of pupils in years 4 to 6 of primary schools in rural Tanzania.

BACKGROUND/OBJECTIVES: There is an urgent need for effective interventions to improve the sexual and reproductive health of adolescents. Reliable data on the sexual health of adolescents are needed to guide the development of such interventions. The aim was to describe the sexual health of pupils in years 4 to 6 of 121 rural primary schools in north western Tanzania, before the implementation of an innovative sexual health intervention in 58 of the schools. METHODS: A cross sectional survey of primary school pupils in rural Tanzania was carried out. The study population comprised pupils registered in years 4 to 6 of 121 primary schools in 20 rural communities in 1998. Basic demographic information was collected from all pupils seen. Those born before 1 January 1985 (aged approximately 14 years and over) were invited to participate in the survey, and asked about their knowledge and attitudes towards sexual health issues, and their sexual experience. A urine specimen was requested and tested for HIV, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and, for females, pregnancy. RESULTS: 9283 pupils born before 1 January 1985 were enrolled and provided demographic information and a urine sample. Male pupils were significantly older than females (mean age 15.5 years v 14.8 years, p<0.001), but all other demographic characteristics were similar between the sexes. 14 (0.2%) of the enrolled pupils (four male and 10 female) were HIV positive, 83 (0.9%) were positive for CT, and 12 (0.1%) for NG. 32 female pupils (0.8%) were positive by pregnancy test. Sexual experience was reported by one fifth of primary school girls, and by almost half of boys. Only 45/114 (39%) girls with biological markers of sexual activity reported having had sex. CONCLUSIONS: HIV, CT, NG, and pregnancy were present though at relatively low levels among pupils in years 4 to 6 of primary school. A high proportion of pupils with a biological marker of sexual activity denied ever having had sex. Alternative ways of collecting sensitive data about the sexual behaviour of school pupils should be explored.

Adolescent↗
PubMed2004

"A bit more truthful": the validity of adolescent sexual behaviour data collected in rural northern Tanzania using five methods.

OBJECTIVE: To assess the validity of sexual behaviour data collected from African adolescents using five methods. METHODS: 9280 Tanzanian adolescents participated in a biological marker and face to face questionnaire survey and 6079 in an assisted self-completion questionnaire survey; 74 participated in in-depth interviews and 56 person weeks of participant observation were conducted. RESULTS: 38% of males and 59% of females reporting sexual activity did so in only one of the two 1998 questionnaires. Only 58% of males and 29% of females with biological markers consistently reported sexual activity in both questionnaires. Nine of 11 (82%) in-depth interview respondents who had had biological markers provided an invalid series of responses about sex in the survey and in-depth interview series. Only one of six female in-depth interview respondents with an STI reported sex in any of the four surveys, but five reported it in the in-depth interviews. CONCLUSION: In this low prevalence population, biological markers on their own revealed that a few adolescents had had sex, but in combination with in-depth interviews they may be useful in identifying risk factors for STIs. Self-reported sexual behaviour data were fraught with inconsistencies. In-depth interviews seem to be more effective than assisted self-completion questionnaires and face to face questionnaires in promoting honest responses among females with STIs. Participant observation was the most useful method for understanding the nature, complexity, and extent of sexual behaviour.

Adolescent↗
PubMed2004

Incidence and clinical background of posttonsillectomy bleeding related blood transfusion over 12 years.

Economies in National Health Systems forces ENT surgeons to review their indications for outpatient tonsillectomy. Therefore, it is important to preoperatively identify special risk groups who frequently have extensive posttonsillectomy bleeding with the need of a blood transfusion. Aim of this study was to estimate the incidence for posttonsillectomy bleeding related blood transfusion, to identify risk factors associated with the need for blood transfusion and to release guidelines for posttonsillectomy bleeding of high risk patients. A retrospective study was done on the medical history of 1720 patients who underwent tonsillectomy for chronic tonsillitis between 1982-1993 in the ENT Department at the University of Kiel. The average transfusion rate was 0.52%. End Stage Renal Disease and hypertension combined with a preoperatively decreased Hb and Hct were the risk factors identified leading to a transfusion. These patients should not get a tonsillectomy as an outpatient procedure. The Hb, Hct, PT, PTT, blood type and crossmatch should be drawn and assessed prior to tonsillectomy. We recommend immediate treatment of secondary hemorrhage in those high risk patients under general anesthesia to avoid severe complications.

Adolescent↗
PubMed2004

Hereditary haemorrhagic telangiectasia: state of the art.

Hereditary haemorrhagic teleangiectasia (HHT) or Rendu-Osler-Weber disease is a genetic autosomal-dominant disorder characterised by the presence of vascular telangiectases in mucocutaneous tissues, visceral organs and the Central Nervous System. Pulmonary arteriovenous malformations have a variable incidence rate ranging between 15-33%, and the safest treatment is transcatheter embolotherapy. Haemmorrhages from the gastrointestinal tract occur in 10-40% of patients with HHT localized in duodenum and colon and can be treated with endoscopy and laser coagulation, but this procedure is not efficacious for vascular anomalies in small intestine since this site cannot be easily reached. The prevalence of cerebrovascular malformations in hereditary haemorrhagic telangiectasia patients is 5-27%, and there are several types described including telangiectasias, cavernous angiomas, arteriovenous malformations, and aneurysms. Cerebrovascular malformations can be treated by: neurovascular surgery, embolization, and stereotactic radiosurgery, but the appropriate course of action for dealing with asymptomatic cerebrovascular malformations is still debated. The most common symptom in HHT patients is epistaxis, which can sometimes be so profuse that it requires multiple transfusions and iron supplementation. Nose bleeds begin before 10 years of age and become more severe in later decades. A multitude of different treatments are available, tailored to the severity of epistaxis. These include: hormonal therapy with oestrogens, application of fibrine tissue sealant, laser coagulation, embolization and septal dermoplasty using Saunder's technique. Aim of this study is to review diagnostic and therapeutic techniques, since continuous growth and danger of these arteriovenous malformations require early diagnosis, adequate treatment, prolonged follow-up and screening of the family.

Embolization, Therapeutic↗
PubMed2003

Variations of HIV and STI prevalences within communities neighbouring new goldmines in Tanzania: importance for intervention design.

OBJECTIVES: To measure the prevalence of HIV and other STIs in communities neighbouring new large scale gold mines in northern Tanzania in order to inform the design of a targeted HIV/STI intervention programme. METHODS: Cross sectional surveys were conducted in adults aged 16-54 years from different sectors of communities neighbouring two newly opened, large scale gold mines near Lake Victoria. Mine workers, men, women, and female food and recreational facility workers (FRFW) from the community were randomly selected for interview and HIV and STI testing. RESULTS: 207 male Tanzanian mine workers, 206 FRFW, 202 other male and 205 female community members were enrolled. Overall, 42% of FRFW were HIV positive, compared to 6% of male mine workers, and 16% and 18% of other community men and women respectively. HIV prevalence in FRFW was significantly associated with alcohol consumption (adjusted odds ratio (aOR) = 2.5, 95% confidence interval (CI) 1.1 to 5.5), past or present syphilis (TPPA+) (aOR = 2.7, 95% CI 1.4 to 5.1) and single status (aOR = 3.8, 95% CI 1.2 to 11.9). Among FRFW, 24% had active syphilis (RPR+, TPPA+), 9% Chlamydia trachomatis, and 4% Neisseria gonorrhoeae. Overall, 50% of FRFW and 50% of community men never used condoms during sex, and 55% mineworkers, 61% male, and 20% female community members reported receiving/giving payment for sex during the previous year. CONCLUSIONS: There is a high prevalence of HIV and other STIs in communities around new goldmines in Tanzania, especially in FRFW. HIV and STI prevalence in the mining workforce is still relatively low, but high risk sexual behaviour is reported by all adult subgroups surveyed in this study. Programmes focusing on HIV/STI prevention, with targeted interventions for high risk women such as FRFW, will be extremely important in such high transmission communities where there is substantial recent in-migration of men and women seeking work. Such programmes have recently been initiated by a private/public/NGO partnership.

Adolescent↗
PubMed2002

Myopia in secondary school students in Mwanza City, Tanzania: the need for a national screening programme.

BACKGROUND/AIMS: The prevalence of significant refractive errors and other eye diseases was measured in 2511 secondary school students aged 11-27 years in Mwanza City, Tanzania. Risk factors for myopia were explored. METHODS: A questionnaire assessed the students' socioeconomic background and exposure to near work followed by visual acuity assessment and a full eye examination. Non-cycloplegic objective and subjective refraction was done on all participants with visual acuity of worse than 6/12 in either eye without an obvious cause. RESULTS: 154 (6.1%) students had significant refractive errors. Myopia was the leading refractive error (5.6%). Amblyopia (0.4%), strabismus (0.2%), and other treatable eye disorders were uncommon. Only 30.3% of students with significant refractive errors wore spectacles before the survey. Age, sex, ethnicity, father's educational status, and a family history of siblings with spectacles were significant independent risk factors for myopia. CONCLUSION: The prevalence of uncorrected significant refractive errors is high enough to justify a regular school eye screening programme in secondary schools in Tanzania. Risk factors for myopia are similar to those reported in European, North-American, and Asian populations.

Adolescent↗