1
|
Tam CC, Zhu M, Ayres J, Kummer K, Yakhou-Harris F, Cooper JR, Carrington A, Hayden SM. Charge density waves and Fermi surface reconstruction in the clean overdoped cuprate superconductor Tl 2Ba 2CuO 6+δ. Nat Commun 2022; 13:570. [PMID: 35091572 PMCID: PMC8799688 DOI: 10.1038/s41467-022-28124-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 01/10/2022] [Indexed: 12/03/2022] Open
Abstract
Hall effect and quantum oscillation measurements on high temperature cuprate superconductors show that underdoped compositions have small Fermi surface pockets whereas when heavily overdoped, a single much larger pocket is found. The origin of this change in electronic structure has been unclear, but may be related to the high temperature superconductivity. Here we show that the clean overdoped single-layer cuprate Tl2Ba2CuO6+δ (Tl2201) displays CDW order with a remarkably long correlation length ξ ≈ 200 Å which disappears above a hole doping of pCDW ≈ 0.265. We show that the evolution of the electronic properties of Tl2201 as the doping is lowered may be explained by a Fermi surface reconstruction which accompanies the emergence of the CDW below pCDW. Our results demonstrate importance of CDW correlations in understanding the electronic properties of overdoped cuprates. The origin of the Fermi surface reconstruction that occurs in cuprate superconductors as hole doping increases remains unclear. Here, the authors observe long range charge density wave (CDW) order in the overdoped single-layer cuprate Tl2Ba2CuO6+δ, which then disappears above a hole concentration 0.265, suggesting a correlation between Fermi surface reconstruction and the emergence of the CDW.
Collapse
Affiliation(s)
- C C Tam
- H. H. Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, United Kingdom.,Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - M Zhu
- H. H. Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, United Kingdom
| | - J Ayres
- H. H. Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, United Kingdom
| | - K Kummer
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, 38043, Grenoble Cedex 9, France
| | - F Yakhou-Harris
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, 38043, Grenoble Cedex 9, France
| | - J R Cooper
- Department of Physics, University of Cambridge, Madingley Road, Cambridge, CB3 0HE, United Kingdom
| | - A Carrington
- H. H. Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, United Kingdom.
| | - S M Hayden
- H. H. Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, United Kingdom.
| |
Collapse
|
2
|
Ali RF, Offeddu V, Siddiqi DA, Mirza A, Naz N, Abdullah S, Lim JM, Kembhavi G, Tam CC, Chandir S. Adolescent girls’ recommendations for designing Human Papillomavirus Vaccination Program in Pakistan. Eur J Public Health 2021. [DOI: 10.1093/eurpub/ckab165.550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
In Pakistan, cervical cancer is the third most frequent cancer among women. Most cases are caused by sexually-acquired infection with human papillomaviruses (HPV). Vaccination of adolescent girls against HPV significantly reduces the incidence of cervical cancer. HPV vaccination is available in Pakistan, but plans to develop a HPV vaccination program are currently at a very early stage. We conducted a formative study to explore adolescent girls' perspectives on HPV and cervical cancer, and collected their recommendations for implementing an HPV vaccination program. We conducted qualitative focus group discussions (FGDs), with unmarried adolescent girls aged 16-19 years, residing in Karachi. We conducted four FGDs with 12 participants each. The topic guide assessed i) girls' knowledge of cervical cancer and HPV vaccination, ii) vaccination decision-making dynamics within families, and iii) factors girls would consider essential for the successful implementation of HPV vaccination program. Overall, participants displayed a positive attitude towards the HPV vaccine. However, many basic concepts related to female reproductive health were unfamiliar to them. Female relatives were indicated as girls' preferred point of contact for discussions on HPV and cervical cancer, but fathers were portrayed as the definitive decision-making authority on vaccination. Girls gave critical input for the development of a HPV vaccination program. Eligible girls should be recruited through individual household visits and the vaccine should be administered at community-based camps, which would ensure both good accessibility and a large outreach. A solid foundation of trust between girls' families, program managers, and other stakeholders emerged as a key asset for the program's success. Adolescents demonstrated great capacity and shared recommendations for a future program's acceptability. Integrating their perspectives will be essential to design an effective program in local context.
Key messages
Adolescent girls’ perspectives should be incorporated to develop context-specific recommendations for the implementation of a HPV vaccination program. Community-based camps and household visits by adolescent girls to recruit the target population could potentially increase program penetration among communities.
Collapse
Affiliation(s)
- RF Ali
- MCH, Interactive Research & Development, Karachi, Pakistan
| | - V Offeddu
- MCH, IRD-Global, Singapore, Singapore
| | | | - A Mirza
- MCH, Interactive Research & Development, Karachi, Pakistan
| | - N Naz
- MCH, Interactive Research & Development, Karachi, Pakistan
| | - S Abdullah
- MCH, Interactive Research & Development, Karachi, Pakistan
| | - JM Lim
- National University of Singapore, Singapore, Singapore
| | - G Kembhavi
- National University of Singapore, Singapore, Singapore
| | - CC Tam
- National University of Singapore, Singapore, Singapore
| | - S Chandir
- MCH, IRD-Global, Singapore, Singapore
- Harvard Medical School, Boston, MA, USA
| |
Collapse
|
3
|
Cheung KS, Leung LP, Siu YC, Tsang TC, Tsui MSH, Tam CC, Chan RHW. Prehospital electrocardiogram shortens ischaemic time in patients with ST-segment elevation myocardial infarction. Hong Kong Med J 2019; 25:356-362. [PMID: 31619577 DOI: 10.12809/hkmj197995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION Total ischaemic time should be shortened as much as possible in patients with ST-segment elevation myocardial infarction (STEMI). This study evaluated whether prehospital 12-lead electrocardiogram (ECG) could shorten system delay in STEMI management. METHODS From November 2015 to November 2017, 15 ambulances equipped with X Series Monitor/ Defibrillator (Zoll Medical Corporation) were used in the catchment area of Queen Mary Hospital, Hong Kong. Prehospital ECG was performed for patients with chest pain; the data were tele-transmitted to attending emergency physicians at the Accident and Emergency Department (AED) for rapid assessment. Data from patients with STEMI who were transported by these 15 ambulances were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or who used self-arranged transport. RESULTS Data were analysed from 197 patients with STEMI. The median patient delay for activation of the emergency response system was 90 minutes; 12% of patients experienced a delay of >12 hours. There was a significant difference in delay between patients transported by ambulance and those who used self-arranged transport (P<0.001). For system delay, the use of prehospital ECG shortened the median time from ambulance on scene to first ECG (P<0.001). When performed upon ambulance on scene, prehospital ECG was available 5 minutes earlier than if performed in ambulance compartment before departure. Use of prehospital ECG significantly shortened AED door-to-triage time, AED door-to-first AED ECG time, AED door-to-physician consultation time, and length of stay in the AED (P<0.001 for all comparisons). CONCLUSION Prehospital ECG shortened ischaemic time prior to hospital admission.
Collapse
Affiliation(s)
- K S Cheung
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - L P Leung
- Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Y C Siu
- Fire and Ambulance Services Academy, Hong Kong Fire Services Department, Tseung Kwan O, Hong Kong
| | - T C Tsang
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - M S H Tsui
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - C C Tam
- Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
| | - R H W Chan
- Division of Cardiology, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong
| |
Collapse
|
4
|
Cheung KS, Leung LP, Siu YC, Tsang TC, Tsui MS, Tam CC, Chan RH. Prehospital 12-lead electrocardiogram for patients with chest pain: a pilot study. Hong Kong Med J 2018; 24:484-491. [PMID: 30262677 DOI: 10.12809/hkmj177135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION After ST-segment elevation myocardial infarction (STEMI), it is vital to shorten reperfusion time. This study examined data from a pilot project to shorten the door-to-balloon (D2B) time by using prehospital 12-lead electrocardiogram (ECG). METHODS Fifteen ambulances equipped with X Series® Monitor/Defibrillator (Zoll Medical Corporation) were deployed to the catchment area of Queen Mary Hospital, Hong Kong, from November 2015 to December 2016. For patients with chest pain, prehospital 12-lead ECG was performed and tele-transmitted to attending physicians at the accident and emergency department for immediate interpretation. The on-call cardiologist was called before patient arrival if STEMI was suspected. Data from this group of patients with STEMI were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or by self-arranged transport. RESULTS From 841 patients with chest pain, 731 gave verbal consent and prehospital ECG was performed and transmitted. Of these, 25 patients with clinically diagnosed STEMI required emergency coronary angiogram with or without primary percutaneous coronary intervention. The mean D2B time for these 25 patients (93 minutes) was significantly shorter (P=0.003) than that for 58 patients with STEMI transported by ambulances without prehospital ECG (112 minutes) and that for 41 patients with STEMI with self-arranged transport (138 minutes). However, shorter reperfusion time was only recorded during daytime hours (08:00-17:59). No statistically significant difference in 30-day mortality was found. CONCLUSION Prehospital ECG is technologically feasible in Hong Kong and shortens the D2B time. However, shorter reperfusion time was only recorded during daytime hours.
Collapse
Affiliation(s)
- K S Cheung
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - L P Leung
- Emergency Medicine Unit, The Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Y C Siu
- Medical Director, Fire and Ambulance Services Academy, Hong Kong Fire Services Department, Hong Kong
| | - T C Tsang
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - M Sh Tsui
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - C C Tam
- Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
| | - R Hw Chan
- Honorary Consultant Cardiologist, Hong Kong Sanatorium Hospital, Happy Valley, Hong Kong
| |
Collapse
|
5
|
Huang D, Cheng YY, Wong YT, Yung SY, Tam CC, Chan KW, Lam CC, Yiu KH, Hai JJ, Lau CP, Chan WY, Chiang CE, Tse HF, Chan PH, Siu CW. P5554TIMI risk score for secondary prevention of recurrent cardiovascular events in a real world cohort of post acute ST-elevation myocardial infarction patients. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.p5554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- D Huang
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - Y Y Cheng
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - Y T Wong
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - S Y Yung
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - C C Tam
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - K W Chan
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - C C Lam
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - K H Yiu
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - J J Hai
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - C P Lau
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - W Y Chan
- The University of Hong Kong, Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Hong Kong, Hong Kong SAR People's Republic of China
| | - C E Chiang
- National Yang Ming University, Taipei Veterans General Hospital, Division of Cardiology, Taipei, Taiwan ROC
| | - H F Tse
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - P H Chan
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - C W Siu
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| |
Collapse
|
6
|
Huang D, Cheng YY, Wong YT, Yung SY, Tam CC, Chan KW, Lam CC, Yiu KH, Hai JJ, Lau CP, Chan WY, Chiang CE, Tse HF, Chan PH, Siu CW. P1727TIMI risk score for secondary prevention of recurrent cardiovascular events in a real world cohort of post acute non-ST-elevation myocardial infarction patients. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.p1727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- D Huang
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - Y Y Cheng
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - Y T Wong
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - S Y Yung
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - C C Tam
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - K W Chan
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - C C Lam
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - K H Yiu
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - J J Hai
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - C P Lau
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - W Y Chan
- The University of Hong Kong, Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Hong Kong, Hong Kong SAR People's Republic of China
| | - C E Chiang
- National Yang Ming University, Taipei Veterans General Hospital, Division of Cardiology, Taipei, Taiwan ROC
| | - H F Tse
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - P H Chan
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| | - C W Siu
- The University of Hong Kong, Queen Mary Hospital, Cardiology Division, Department of Medicine, Hong Kong, Hong Kong SAR People's Republic of China
| |
Collapse
|
7
|
Tam CC, Ingraffea AA. Sweet syndrome presenting with an unusual morphology. Cutis 2015; 96:E9-E10. [PMID: 26367765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
|
8
|
Tam CC, Spicknall KE, Ingraffea AA. Multiple firm pink papules and nodules. Cutis 2015; 95:E4-E6. [PMID: 25671456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
|
9
|
Hashemi P, Kao GF, Konia T, Kauffman LC, Tam CC, Sina B. Multicentric primary extramammary Paget disease: a Toker cell disorder? Cutis 2014; 94:35-38. [PMID: 25101342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Toker cells are epithelial clear cells found in the areolar and nipple areas of the breast, vulvar region, and other apocrine gland-bearing areas of the skin. Toker cells have been implicated in the pathogenesis of clear cell papulosis, cutaneous hamartoma with pagetoid cells, and rare cases of primary extramammary Paget disease (EMPD) but not in secondary EMPD with underlying adenocarcinoma. The pathogenesis of primary EMPD is not well defined. We report a case of multicentric primary EMPD with evidence of Toker cell proliferation and nonaggressive biologic behavior in a 63-year-old white man. A detailed description of the morphologic and biologic features of Toker cells and their possible carcinogenetic links also are discussed. Based on the observation and follow-up of our patient, we hypothesize that multicentric primary EMPD starts with Toker cell hyperplasia and can potentially evolve to carcinoma in the genital region.
Collapse
|
10
|
Tam CC, Meier MJ. Discrete papular lichen myxedematosus with an unusual segmental presentation. Acta Dermatovenerol Croat 2014; 22:224-226. [PMID: 25230068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- Christine C Tam
- Christine C. Tam, MD, 3130 Highland Avenue, Cincinnati, Ohio 45267, United States of America;
| | | |
Collapse
|
11
|
Tam CC, Hoover AZ, Elias AR. What is your diagnosis? Desmoplastic Spitz nevus. Cutis 2012; 89:13-22. [PMID: 22439303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Christine C Tam
- Department of Dermatology, Wilford Hall Medical Center, San Antonio, Texas, USA
| | | | | |
Collapse
|
12
|
Tam CC, Ragland PS, Harrington AC. Triple extramammary Paget disease in a white man. Cutis 2011; 88:217-223. [PMID: 22272481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
|
13
|
Tam CC, Harrington AC. What is your diagnosis? Syringocystadenoma papilliferum. Cutis 2011; 88:120-134. [PMID: 22017063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Christine C Tam
- Department of Dermatology, Johns Hopkins University, Baltimore, Maryland, USA
| | | |
Collapse
|
14
|
Tam CC, Dare DM, DiGiovanni JJ, Harrington AC, Deng AC. Recurrent and metastatic primary cutaneous mucinous carcinoma after excision and Mohs micrographic surgery. Cutis 2011; 87:245-248. [PMID: 21699128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Primary cutaneous mucinous carcinoma is a neoplasm of sweat gland origin. Optimal management guidelines have not been established for this rare tumor. It is treated most commonly by traditional excision and more recently by Mohs micrographic surgery in an effort to decrease its recurrence rate. We report a case of primary cutaneous mucinous carcinoma with multiple recurrences and metastases following 3 excisions and 2 Mohs procedures, highlighting the potential difficulty in treating this cancer and suggesting the need for a more effective treatment approach.
Collapse
Affiliation(s)
- Christine C Tam
- Department of Dermatology, University of Maryland, Baltimore, USA.
| | | | | | | | | |
Collapse
|
15
|
Granerod J, Tam CC, Crowcroft NS, Davies NWS, Borchert M, Thomas SL. Challenge of the unknown. A systematic review of acute encephalitis in non-outbreak situations. Neurology 2010; 75:924-32. [PMID: 20820004 DOI: 10.1212/wnl.0b013e3181f11d65] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The threat of emerging infections and recognition of novel immune-mediated forms of encephalitis has raised the profile of this condition in recent years. Incidence is poorly defined and most cases have an unknown cause. There is currently much interest in identification of new microbial agents of encephalitis, but no work has investigated systematically reasons for lack of pathogen identification in studies. METHODS We systematically reviewed published literature on incidence and etiology of encephalitis in non-outbreak settings and explored possible explanations for the large number of cases of unknown etiology. RESULTS Annual incidence ranged from 0.07 to 12.6 cases per 100,000 population with an evident decrease over time (p = 0.01). The proportion of cases with unknown etiology was high across studies (>50% in 26 of 41 studies), with strong evidence of heterogeneity in study findings (p < 0.001). Our meta-regression identified study period, setting, and subsyndrome to be the main contributors to between-study variation, rather than methodologic factors such as study design, case definitions, sample types, and testing strategies. CONCLUSIONS Our findings support the hypothesis that new and emerging infectious agents, or new forms of immune-mediated encephalitis, may be responsible for cases currently of unknown cause and encourage the ongoing global effort to identify these. Our review highlights research areas that might lead to a better understanding of the causes of encephalitis and ultimately reduce the morbidity and mortality associated with this devastating condition.
Collapse
Affiliation(s)
- J Granerod
- Health Protection Agency Centre for Infections, Virus Reference Department, 61 Colindale Avenue, London, UK.
| | | | | | | | | | | |
Collapse
|
16
|
Abstract
A number of alpha-ketophosphonates have been prepared and their enol-keto tautomerism has been studied by means of proton and phosphorus NMR and infrared spectroscopy and the ferric chloride test. Aliphatic ketophosphonates exist largely in the keto tautomeric forms, with only a small amount of enol forms present. All the aromatic acylphosphonates studied, however, enolize extensively. An x-ray analysis confirmed enolization and E configuration as the only stereochemical isomer. Reaction of diazomethane with diethyl p-methoxyphenylacetyl phosphonate gave a mixture of O-methylation and carbene insertion products, whereas the same reaction with diethyl isobutyryl phosphonate gave only carbene insertion products.
Collapse
Affiliation(s)
- C C Tam
- Hall-Atwater Laboratories, Wesleyan University, Middletown, Connecticut 06457
| | | | | |
Collapse
|
17
|
Atchison CJ, Tam CC, Hajat S, van Pelt W, Cowden JM, Lopman BA. Temperature-dependent transmission of rotavirus in Great Britain and The Netherlands. Proc Biol Sci 2009; 277:933-42. [PMID: 19939844 DOI: 10.1098/rspb.2009.1755] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In Europe, rotavirus gastroenteritis peaks in late winter or early spring suggesting a role for weather factors in transmission of the virus. In this study, multivariate regression models adapted for time-series data were used to investigate effects of temperature, humidity and rainfall on reported rotavirus infections and the infection-rate parameter, a derived measure of infection transmission that takes into account population immunity, in England, Wales, Scotland and The Netherlands. Delayed effects of weather were investigated by introducing lagged weather terms into the model. Meta-regression was used to pool together country-specific estimates. There was a 13 per cent (95% confidence interval (CI), 11-15%) decrease in reported infections per 1 degrees C increase in temperature above a threshold of 5 degrees C and a 4 per cent (95% CI, 3-5%) decrease in the infection-rate parameter per 1 degrees C increase in temperature across the whole temperature range. The effect of temperature was immediate for the infection-rate parameter but delayed by up to four weeks for reported infections. There was no overall effect of humidity or rainfall. There is a direct and simple relationship between cold weather and rotavirus transmission in Great Britain and The Netherlands. The more complex and delayed temperature effect on disease incidence is likely to be mediated through the effects of weather on transmission.
Collapse
Affiliation(s)
- C J Atchison
- Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
| | | | | | | | | | | |
Collapse
|
18
|
Atchison CJ, Lopman BA, Harris CJ, Tam CC, Iturriza Gómara M, Gray JJ. Clinical laboratory practices for the detection of rotavirus in England and Wales: can surveillance based on routine laboratory testing data be used to evaluate the impact of vaccination? Euro Surveill 2009; 14. [DOI: 10.2807/ese.14.20.19217-en] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two rotavirus vaccines have recently been licensed in Europe. Rotavirus surveillance data in many European countries are based on reports of laboratory-confirmed rotavirus infections. If surveillance data based on routine laboratory testing data are to be used to evaluate the impact of vaccination programmes, it is important to determine how the data are influenced by differences in testing practices, and how these practices are likely to affect the ability of the surveillance data to represent trends in rotavirus disease in the community. We conducted a survey of laboratory testing polices for rotavirus gastroenteritis in England and Wales in 2008. 60% (94/156) of laboratories responded to the survey. 91% of reporting laboratories offered routine testing for rotavirus all year round and 89% of laboratories offered routine rotavirus testing of all stool specimens from children under the age of five years. In 96% of laboratories, rotavirus detection was presently done either by rapid immunochromatographic tests or by enzyme-linked immunosorbent assay. Currently, rotavirus testing policies among laboratories in England and Wales are relatively homogenous. Therefore, surveillance based on laboratory testing data is likely to be representative of rotavirus disease trends in the community in the most frequently affected age groups (children under the age of five years) and could be used to help determine the impact of a rotavirus vaccine.
Collapse
Affiliation(s)
- C J Atchison
- Infectious Diseases Epidemiology Unit, Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - B A Lopman
- Gastrointestinal, Emerging and Zoonotic Infections Department, Centre for Infections, Health Protection Agency, London, United Kingdom
- Infectious Diseases Epidemiology Unit, Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - C J Harris
- Standards Unit, Department of Evaluations and Standards, Centre for Infections, Health Protection Agency, London, United Kingdom
| | - C C Tam
- Infectious Diseases Epidemiology Unit, Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - M Iturriza Gómara
- Enteric Virus Unit, Virus Reference Department, Centre for Infections, Health Protection Agency, London, United Kingdom
| | - J J Gray
- Enteric Virus Unit, Virus Reference Department, Centre for Infections, Health Protection Agency, London, United Kingdom
| |
Collapse
|
19
|
Tam CC, Pierson JC. What is your diagnosis? The diagnosis: angioleiomyoma. Cutis 2008; 81:123-141. [PMID: 18441763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Christine C Tam
- Dermatology Department, Guthrie Ambulatory Health Care Clinic, Fort Drum, New York, USA
| | | |
Collapse
|
20
|
Abstract
Petrolatum rarely causes hypersensitivity reactions. We report a case of a 51-year-old white man with allergic contact dermatitis due to white petrolatum on damaged skin. The patient, who presented with a history of hand dermatitis and intolerance to ointments for years, was patch-tested with white petrolatum on scratched skin. Patch tests with the European Standard series, preservatives, steroids, vehicles, and emulsifiers were also performed. The patch-test reaction to white petrolatum on scratched skin was positive at 48 and 96 hours. All other patch-test results were negative.
Collapse
Affiliation(s)
- Christine C Tam
- Department of Dermatology, Brooke Army Medical Center, Fort Sam Houston, TX, USA
| | | |
Collapse
|
21
|
Tam CC, Rodrigues LC, O'Brien SJ, Hajat S. Temperature dependence of reported Campylobacter infection in England, 1989-1999. Epidemiol Infect 2006; 134:119-25. [PMID: 16409658 PMCID: PMC2870373 DOI: 10.1017/s0950268805004899] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2005] [Indexed: 11/07/2022] Open
Abstract
Campylobacter is the most common bacterial cause of gastroenteritis in England and Wales, with 45000 cases reported annually. Campylobacter incidence is highly seasonal; the consistent peak in late spring suggests a role for meteorological factors in the epidemiology of this organism. We investigated the relationship between ambient temperature and Campylobacter enteritis using time-series analysis to study short-term associations between temperature and number of Campylobacter reports adjusted for longer-term trend and seasonal patterns. We found a linear relationship between mean weekly temperature and reported Campylobacter enteritis, with a 1 degrees C rise corresponding to a 5% increase in the number of reports up to a threshold of 14 degrees C. There was no relationship outside this temperature range. Our findings provide evidence that ambient temperature influences Campylobacter incidence, and suggest that its effect is likely to be indirect, acting through other intermediate pathways.
Collapse
Affiliation(s)
- C C Tam
- Environmental and Enteric Diseases Department, Communicable Disease Surveillance Centre, Health Protection Agency Centre for Infections, London, UK.
| | | | | | | |
Collapse
|
22
|
Elias AR, Tam CC, David-Bajar KM. Subacute cutaneous lupus erythematosus associated with leflunomide. Cutis 2005; 76:189-92. [PMID: 16268263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A skin eruption consistent with subacute cutaneous lupus erythematosus (SCLE) occurred in a patient taking leflunomide for rheumatoid arthritis. The eruption resolved after discontinuation of the medication. Suppression of tumor necrosis factor (TNF)-effector mechanisms by leflunomide may have played a role in the pathogenesis of this disorder.
Collapse
Affiliation(s)
- Anthony R Elias
- Dermatology Clinic, US Army Medical Department Activity, Fort Drum, New York 13602, USA.
| | | | | |
Collapse
|
23
|
Tam CC, Lee SJ, Rodrigues LC. Ethnicity and epidemiological research: not so black and white. J Epidemiol Community Health 2004; 58:528-9; author reply 529. [PMID: 15143125 PMCID: PMC1732780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
|
24
|
|
25
|
Abstract
OBJECTIVES Campylobacters are the most common bacterial cause of infectious intestinal disease (IID) in temperate countries. C. jejuni is the predominant cause of campylobacter IID, but the impact of other, less prevalent species has largely been ignored. Here, we present estimates of the burden of indigenously acquired foodborne disease (IFD) due to Campylobacter coli, the second most common cause of human campylobacteriosis. METHODS Data from surveillance sources and specific epidemiologic studies were used to calculate the number of illnesses, presentations to general practice (GP), hospital admissions, hospital occupancy and deaths due to indigenous foodborne C. coli IID in England and Wales for the year 2000. RESULTS We estimate that in the year 2000, C. coli accounted for over 25,000 cases of IFD. This organism was responsible for more than 12,000 presentations to GP, 1000 hospital admissions, nearly 4000 bed days of hospital occupancy and 11 deaths. The cost to patients and the National Health Service was estimated at nearly pound 4 million. CONCLUSIONS Although C. coli comprises a minority of human campylobacter disease, its health burden is considerable and greater than previously thought. Targeted research on this organism is required for its successful control.
Collapse
Affiliation(s)
- C C Tam
- Gastrointestinal Diseases Division, Public Health Laboratory Service, Communicable Disease Surveillance Centre, 61 Colindale Avenue, NW9 5EQ, London, UK.
| | | | | | | | | |
Collapse
|
26
|
Gillespie IA, O'Brien SJ, Adak GK, Tam CC, Frost JA, Bolton FJ, Tompkins DS. Point source outbreaks of Campylobacter jejuni infection--are they more common than we think and what might cause them? Epidemiol Infect 2003; 130:367-75. [PMID: 12825720 PMCID: PMC2869972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023] Open
Abstract
Despite being the commonest bacterial cause of infectious intestinal disease (IID) in England and Wales, outbreaks of campylobacter infection are rarely reported. However, data from the Campylobacter Sentinel Surveillance Scheme suggested that outbreaks might be more common than was previously suspected, since a high proportion of cases reported other illness in the home or in the community at the same time as their illness. To identify factors that might lead to these apparent outbreaks, the exposures of cases of Campylobacter jejuni infection reporting other illness, either in the home or the community, were compared with those for cases not reporting other illness using case-case methodology. Illness in the home was associated with consuming organic meats in the winter, having contact with a pet suffering from diarrhoea or visiting a farm in the 2 weeks before the onset of symptoms. Illness in the community was associated with the consumption of foods in restaurants or drinking unpasteurized milk. Prevention of campylobacter infection requires that better methods of outbreak detection and investigation are developed, which in turn should lead to a better understanding of risk factors.
Collapse
Affiliation(s)
- I A Gillespie
- PHLS Communicable Disease Surveillance Centre, 61 Colindale Avenue, London
| | | | | | | | | | | | | |
Collapse
|
27
|
Tam CC. Campylobacter reporting at its peak year of 1998: don't count your chickens yet. Commun Dis Public Health 2001; 4:194-9. [PMID: 11732359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Infections due to Campylobacter spp. are the most commonly reported bacterial cause of human gastrointestinal illness, and reports of campylobacteriosis in the UK and other temperate countries have been increasing. An all-time peak of 58,059 cases of campylobacter infectious intestinal disease (IID) were reported to the Communicable Disease Surveillance Centre in 1998. An analysis of the age, gender and seasonal and geographical distribution of cases reported in 1998 is presented here, together with population-based estimates of reported incidence. The frequency of reports was highest in late Spring. Reported incidence was highest in males under 1 year of age (214/100,000 population), with a secondary peak in adults aged 25 to 34 years (140/100,000 population). Reported incidence was higher in males than females for all age groups. The highest reported incidence occurred in the South West region (140/100,000 population), while the lowest was observed in London (54/100,000 population). Campylobacter is a major cause of human gastrointestinal illness. Work towards its control must be a priority if the burden of human infectious intestinal disease is to be reduced.
Collapse
Affiliation(s)
- C C Tam
- Gastrointestinal Diseases Division, Communicable Disease Surveillance Centre, 61 Colindale Avenue, London NW9 5EQ.
| |
Collapse
|
28
|
Zhao CY, Tam CC, Wong YC. Morphogenesis and ductal development of the prostatic complex of the guinea pig. J Morphol 1993; 217:219-27. [PMID: 8371276 DOI: 10.1002/jmor.1052170209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The morphogenesis of glandular architecture of the three lobes of prostate gland of the guinea pig, lateral, dorsal, and coagulating gland was studied from 35 days gestation to 90 postnatal days. Epithelial ductal tubules of various lobes of the gland were microdissected after treatment by collagenase and displayed two dimensionally. The number of ductal tips was counted, and the volume of the ductal network was quantified using a graphic tablet. The results show that the growth and ductal morphogenesis fall into two phases: prenatal and postnatal. The first outgrowth of prostatic buds begins at 35 days gestation (gestational length is 65 days). Ductal growth and branching continues over the next 15-20 days and by 55 days gestation, approximately 60%, 79%, and 71% of the adult number of ductal tips of the lateral and dorsal lobes and coagulating gland respectively, are formed. The figures increase to 89%, 84%, and 106%, respectively, by birth. There is little increase in number of ductal tips thereafter. Postnatal growth is accomplished mainly by elongation of existing ductal network with a little additional branching but with an increase in size (volume) of the tubules. Canalization of ductal tubules occurs prenatally in all lobes but postnatal functional cytodifferentiation takes a slightly different pace among them. Ductal morphogenesis of the guinea pig prostate gland differs significantly in time-course from that of the mouse in which ductal development occurs mainly postnatally.
Collapse
Affiliation(s)
- C Y Zhao
- Department of Anatomy, Faculty of Medicine, University of Hong Kong, China
| | | | | |
Collapse
|
29
|
Tam CC, Wong YC. Morphometric and stereological study of the glandular epithelium of the seminal vesicle of castrated guinea pigs treated with 17 beta-oestradiol benzoate. Acta Anat (Basel) 1993; 148:181-8. [PMID: 8116330 DOI: 10.1159/000147539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Morphometric and stereological data are presented showing that the average thickness of the glandular epithelium (including secretory and basal cells together with intercellular spaces) of the seminal vesicle of the guinea pig increased significantly after oestradiol administration when compared with castrated controls. The increase in thickness was accompanied by a significant increase in the volume density of intercellular spaces. There were significant decreases in volume, surface and numerical densities of the secretory cell nuclei with respect to the glandular epithelium. The increase in the volume and surface densities of the secretory cell nuclei with respect to the average secretory cell was due to the significant increase in the average volume of the secretory cell. The increase in the mean volume of secretory cells was the result of a significant increase in the average cytoplasmic volume. In comparison with castrated controls, the structural data of cytoplasmic organelles also showed significant increases in total volume and surface area of granular endoplasmic reticulum per average secretory cell following oestradiol administration. This was accompanied by a significant increase in the total volume of Golgi cisternae per cell. The increase in the cytoplasmic volume of secretory cells after oestradiol treatment may be the result of an increase in number of organelles responsible for protein synthesis. The present study has provided quantitative evidence that the secretory function of the seminal vesicle of castrated guinea pigs may have been stimulated after oestradiol administration, which cannot be easily detected in a qualitative manner.
Collapse
Affiliation(s)
- C C Tam
- Department of Anatomy, Faculty of Medicine, University of Hong Kong
| | | |
Collapse
|
30
|
Tam CC, Wong YC. Thiamine pyrophosphatase activity in secretory cells of the lateral prostate and seminal vesicle of normal and castrated guinea pigs and castrates treated with oestradiol. Histochem J 1993; 25:77-85. [PMID: 8432665 DOI: 10.1007/bf00161047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Ultrastructural localization of thiamine pyrophosphatase (TPPase) activity was studied in secretory cells of the lateral prostate and seminal vesicle of normal and castrated guinea pigs and castrates treated with 17 beta-oestradiol benzoate. The present study has demonstrated that TPPase reaction product is consistently localized in the three to four trans cisternae of Golgi complexes in both the lateral prostate and the seminal vesicle. The reaction was intense and the reaction product often filled the cisternae completely. After castration there was a decrease in TPPase activity in both glands as revealed by the reduction in the amount of the reaction product which was found mainly in one to two trans cisternae of the regressed Golgi complex. The reaction product changed from a dense to a more particulate or granular pattern or to discrete deposits of high electron-density. Administration of 17 beta-oestradiol benzoate to the castrates caused changes in the localization and patterns of distribution of TPPase. In the lateral prostate there was an apparent increase in TPPase activity. The reaction product was found in two to four trans cisternae and occasionally in the trans-most cisternae of the dilated Golgi complex. The reaction product appeared as discrete, dense coarse precipitates. In the seminal vesicle TPPase reaction product was consistently found in one to two trans cisternae in cells with larger Golgi complexes. However, almost all cisternae of the smaller Golgi complexes were TPPase-positive.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- C C Tam
- Department of Anatomy, Faculty of Medicine, University of Hong Kong
| | | |
Collapse
|
31
|
Tam CC, Wong YC, Tang F. Ultrastructural and cytochemical studies of the effects of prolactin on the lateral prostate and the seminal vesicle of the castrated guinea pig. Cell Tissue Res 1992; 270:105-12. [PMID: 1423516 DOI: 10.1007/bf00381885] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Administration of ovine prolactin to castrated guinea pigs for 2 weeks induced hypertrophy of secretory cells in the lateral prostate when compared with the castrated controls. This was accompanied by an apparent increase in the number of profiles of granular endoplasmic reticulum and well developed Golgi complexes with dilated cisternae. An increase in the number of low-contrast electron-dense secretory granules was observed 4 weeks after prolactin treatment. In the seminal vesicle, dilatation and degranulation of granular endoplasmic reticulum and an apparent decrease in the number of secretory granules were observed 4 weeks after prolactin administration. Following castration and 2 weeks after prolactin treatment, thiamine pyrophosphatase (TPPase)-reaction product was mainly confined to 1-2 trans cisternae of the Golgi complexes in secretory cells of the lateral prostate and the seminal vesicle. In both glands, a reduction of TPPase activity was observed 2 weeks following prolactin administration, and the reaction product was totally absent after prolonged treatment for 4 weeks. The present study has provided morphological evidence that prolactin is capable of stimulating the secretory function of the lateral prostate while exerting some inhibitory effects on the seminal vesicle of the castrated guinea pig. In both glands, TPPase activity, and hence the process of glycosylation was inhibited after prolactin administration. The results from radioimmunoassay indicated that the action of prolactin on these glands could be a direct effect and not mediated through testosterone.
Collapse
Affiliation(s)
- C C Tam
- Department of Anatomy, Faculty of Medicine, University of Hong Kong
| | | | | |
Collapse
|
32
|
Huang P, Tam CC, Wong YC. Morphometric and stereological study of the seminal vesicle of the guinea pig. Acta Anat (Basel) 1992; 144:1-6. [PMID: 1514353 DOI: 10.1159/000147277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The seminal vesicle of the guinea pig has been widely used as a model for the study of hormonal action on the male accessory sex organ, but there have been few attempts to quantify their cellular and tissue components. In the present study, the seminal vesicle of the guinea pig was described in the form of a morphometric model. Tissue samples were taken from the distal, middle and proximal regions of the gland and processed for light microscopy. Using a combination of a stereological point-counting technique and direct measurement, the relative volumes of different components (lumen, epithelium, lamina propria and fibromuscular layer) were determined. The relative numbers of the secretory cells and basal cells were also estimated. Following the estimation of the average size of the seminal vesicle, the relative volume of different components and the relative number of secretory cells were transformed into absolute data on a per average seminal vesicle basis. Similarly, the average sizes of the secretory cells and nuclei were also determined. The quantitative data generated from the present study will serve as a baseline for further studies of the seminal vesicle of the guinea pig. The techniques used in the present study are easy to apply, and data generated were objective and reproducible.
Collapse
Affiliation(s)
- P Huang
- Department of Biology, Sun Yat-Sen University of Medical Sciences, Guangzhou, People's Republic of China
| | | | | |
Collapse
|
33
|
Tam CC, Wong YC, White FH, Fowler JP. Morphometric and stereological analysis of the effects of 17 beta-estradiol on the glandular epithelium of the castrated guinea pig lateral prostate. Prostate 1991; 19:279-97. [PMID: 1754518 DOI: 10.1002/pros.2990190403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Upon administration of pharmacological doses of estradiol to castrated guinea pigs, the secretory cells of the lateral prostate underwent hypertrophy which resulted from significant increases in nuclear and cytoplasmic volume. There were quantitative increases in the small highly electron-dense granules and multivesicular bodies when compared with the castrated control. The dramatic increase in the number of highly electron-dense granules probably occurred at the expense of the low electron-dense granules. The average size of the condensing granules and mitochondria decreased significantly after estradiol administration. However, significant increase in the number of mitochondria was detected when compared with the castrated control. Ultrastructural data revealed no significant changes in the absolute dimensions of granular endoplasmic reticulum or of the Golgi complex, suggesting that estradiol exerted no significant stimulatory effects on these organelles. Pharmacological doses of estrogen appear to regulate the expression of secretory granules and multivesicular bodies in the lateral prostate of castrated guinea pigs.
Collapse
Affiliation(s)
- C C Tam
- Department of Anatomy, Faculty of Medicine, University of Hong Kong
| | | | | | | |
Collapse
|
34
|
Tam CC, Wong YC. Ultrastructural study of the effects of 17 beta-oestradiol on the lateral prostate and seminal vesicle of the castrated guinea pig. Acta Anat (Basel) 1991; 141:51-62. [PMID: 1950420 DOI: 10.1159/000147099] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Administration of oestradiol to castrated animals induced hypertrophy of the secretory cells in the lateral prostate and seminal vesicle. In the lateral prostate, increases in the number of small highly electron-dense granules, multivesicular bodies and intercellular spaces were the prevailing effects 2 weeks after oestradiol treatment. There was also an apparent increase in the amount of cytokeratin intermediate filaments. Prolonged oestradiol administration for 4 weeks showed no appreciable changes in the glandular epithelium when compared with 2-week treatment. However, an increase in the thickness of the fibromuscular layer was observed. In the seminal vesicle, basal cell hyperplasia was associated with a concurrent increase in the size of intercellular spaces 2 weeks after oestradiol administration. There were also apparent increases in the volume of the lamina propria and in the number of stromal cells. An apparent increase in the density of collagen fibres in the stroma was observed 2 and 4 weeks after oestradiol administration. In conclusion, the responses of the epithelium of the lateral prostate and seminal vesicle to a pharmacological dose of oestradiol are different. Prolonged oestradiol administration exerts a more prominent effect on the smooth muscle in the lateral prostate but not in the seminal vesicle. The effects of oestradiol may be mediated directly or indirectly through the other hormones.
Collapse
Affiliation(s)
- C C Tam
- Department of Anatomy, Faculty of Medicine, University of Hong Kong
| | | |
Collapse
|
35
|
Abstract
The glandular epithelium of the lateral prostate of the guinea pig was described within the framework of a morphometric model in terms of relative densities and absolute dimensions. A combination of direct measurement and point and intersection counting techniques was used. The quantitative data generated in the intact animals were compared with those of castrated controls. Castration was accompanied by a significant decrease in height of the glandular epithelium and in sizes of secretory and basal cells and their corresponding nuclei. On a per cell basis, significant decreases in total volume and surface area of granular endoplasmic reticulum were detected after castration. This was accompanied by a significant reduction in the total volume of Golgi cisternae. The total volume, surface area, and number of highly electron-dense and clear granules decreased significantly compared with the intact control animals. However, no significant changes in these parameters of low electron-dense granules were found. Significant reductions in the total volume and surface area of condensing granules, lysosomes, and mitochondria, but not their number, were detected. The average sizes of condensing granules, secretory granules, lysosomes, and mitochondria were decreased significantly after castration. The present study showed that the alterations in the secretory function of the secretory cells of the lateral prostate was reflected by the quantitative changes in granular endoplasmic reticulum, Golgi complexes, and secretory granules on a per cell basis. The data generated in the present study will serve as a baseline for further studies of the lateral prostate of the guinea pig.
Collapse
Affiliation(s)
- C C Tam
- Department of Anatomy, Faculty of Medicine, University of Hong Kong
| | | | | | | |
Collapse
|
36
|
Abstract
The effect of gossypol acetic acid on the prostate gland of the guinea pig was assessed ultrastructurally. The three lobes of the gland showed differences in sensitivity and reacted differently to gossypol treatment. In the lateral prostate, there was a reduction in the profile of the granular endoplasmic reticulum and dense secretory granules with a concurrent appearance of smaller clear granules and an increase in cytoplasmic filamentous bundles. The latter feature was similar to that of the coagulating gland. In the dorsal prostate, the general reaction was similar to that in the lateral prostate except that there was no increase in filamentous content. In the coagulating gland, there was a reduction or total disappearance of apical secretory blebs and an increase in lysosomes, a feature not found in the lateral and dorsal lobes. Damages to mitochondria were observed in the dorsal prostate and coagulating gland but not in the lateral prostate. It is concluded that gossypol affects not only the testis, but also alters the structure and functions of the prostate gland.
Collapse
Affiliation(s)
- Y C Wong
- Department of Anatomy, Faculty of Medicine, University of Hong Kong
| | | |
Collapse
|
37
|
Wong YC, Tam CC. A structural and cytochemical study of the effects of gossypol on the epithelial cells of the guinea-pig seminal vesicle. J Reprod Fertil 1988; 84:659-68. [PMID: 3199385 DOI: 10.1530/jrf.0.0840659] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Gossypol acetic acid, given to guinea-pigs at a concentration of 10 mg/kg daily for up to 7 weeks, exerted an inhibitory effect on the secretory activity of the glandular cells of the seminal vesicles. The diminished secretory function was associated with a decrease in thiamine pyrophosphatase (TPPase) (EC 3.6.1.6) activity in the luminal border and the Golgi cisternae. There was no increase in cytoplasmic filaments, and mitochondrial damage was not observed. The most striking effect was on the basal lamina, where the lamina densa increased significantly in thickness, while the lamina lucida decreased marginally in thickness. This was coupled with an increase in proteoglycan content on both sides of the lamina densa. It would appear that gossypol reduces the luminal secretory function on the one hand, while it increases the basal secretory activity on the other, thus modifying the structure of the basal lamina. The functional significance of these changes remains unknown.
Collapse
Affiliation(s)
- Y C Wong
- Department of Anatomy, Faculty of Medicine, University of Hong Kong
| | | |
Collapse
|
38
|
Tam CC, Wong YC, Tang F. Further regression of seminal vesicles of castrated guinea pig by administration of cyproterone acetate. Acta Anat (Basel) 1985; 124:65-73. [PMID: 2933918 DOI: 10.1159/000146098] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
It has been established that a low level of secretory activity persisted in seminal vesicles of guinea pigs long after castration and that this may be due to a higher extratesticular androgen level in this animal. A RIA study revealed that the normal serum testosterone concentration of the guinea pigs was comparable to that of the rats, but the basal serum testosterone level after castration was ten times higher than rats under a similar condition. It was also shown that cyproterone acetate did not significantly lower the basal serum testosterone concentration in the castrated guinea pigs. The higher basal serum testosterone level is believed to be responsible for the slow and incomplete regression of this gland in the guinea pigs. There was a significant reduction in wet weight of the seminal vesicles after the treatment of castrated guinea pigs with cyproterone acetate. Ultrastructural study showed that there were both qualitative and quantitative changes in the cytoplasmic organelles. The Golgi apparatus further reduced in size and in the number of associated vesicles and vacuoles. There was a marked decrease in the number and size of secretory granules and lysosomes and an increase in the degree of undulation of the basement membrane. Accumulation of lipid droplets and glycogen was commonly observed. All these morphological evidences showed that further regression of the castrated guinea pig seminal vesicles can be achieved by cyproterone acetate treatment.
Collapse
|