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Biomedical subjects

C E Cohen

Publications and source records attributed to C E Cohen.

18 recordsLinked to original sources
PubMed2006

Combined surgery and chemoradiation as a treatment for the Buschke-Löwenstein tumour.

BACKGROUND: The Buschke-Löwenstein tumour (BLT) or giant condyloma acuminata is a rare disease which affects the anogenital region. Although histologically benign, it behaves in a malignant fashion, infiltrating the surrounding tissues. The morbidity and mortality from this tumour is high, as is the risk of recurrence following treatment. It lies on the continuum between the benign condylomata acuminata and squamous cell carcinoma. The human papillomavirus is implicated in its aetiology. Treatment is controversial, with topical chemotherapy, radiotherapy, immunotherapy and radical surgery all having been employed. Chemoradiation remains the mainstay of treatment for anal cancers but has not been routinely employed in the management of the BLT without squamous cell carcinoma transformation. METHODS: Two cases of extensive perineal BLT treated with chemoradiation and subsequent surgical excision are presented. RESULTS: The first patient had a good symptomatic response to the chemoradiation but unfortunately died of recurrent disease following surgery. The second patient had a macroscopically complete response to chemoradiation and remains well following abdominoperineal excision. CONCLUSION: Pre-operative chemoradiation has proved to be useful in management for histologically proven benign BLT

Abdominal Neoplasms↗
PubMed2006

Primary care and the National Strategy for Sexual Health and HIV: an evaluation of one primary care trust.

Windsor, Ascot, Maidenhead (WAM) primary care trust (PCT) currently has no specialist sexual health services. We researched the level of sexual health service provision in WAM compared with targets set out in the National Strategy for Sexual Health and HIV and assessed support for level 2 service expansion. We found practices were already providing much of level 1 and parts of level 2 services. Gaps centred on male and asymptomatic female screening and sexual health promotion. Ten out of 22 practices expressed interest for service development within the PCT, but obstacles cited included lack of resources, training and prioritization of the strategy. The study has identified strengths and weaknesses across the PCT that have guided recent initiatives. This model could be used by other PCTs to ascertain their needs and acknowledge their achievements.

Evaluation Studies as Topic↗
PubMed2006

Microscopy and culture for Trichomonas vaginalis: are both required?

Many genitourinary medicine clinics have stopped routinely performing both wet preparation microscopy and cultures to diagnose Trichomonas vaginalis (TV). Our directorate stopped microscopy when screening asymptomatic women. This audit considers whether both tests continue to be warranted for symptomatic female patients. The discrepancy between microscopy and culture results leads us to recommend that both remain necessary. Sampling standardization and improved documentation are discussed.

Adult↗
PubMed2005

Increasing detection of asymptomatic syphilis in HIV patients.

BACKGROUND/OBJECTIVES: The burden of new syphilis diagnoses in London has mainly been in men who have sex with men (MSM), many of whom are co-infected with HIV. Our HIV unit introduced regular serological screening for syphilis during routine follow up care to detect patients who may be at risk of asymptomatic infection. We assessed if this remained an effective and necessary strategy in the second year since introduction. METHODS: All HIV outpatients with newly positive syphilis serology between 1 May 2002 and 30 April 2003 were identified using a prospectively collected database. Only patients who were asymptomatic at the time of screening were included (cohort B). They were compared to patients in the exact preceding year (cohort A). RESULTS: 2655 patients had at least one CD4 count measured in the period (surrogate marker for patients having routine follow up bloods), of whom 2389 (90%) had syphilis serology performed. 40 individuals were found to have early asymptomatic infection (two were re-infections), compared to 26 patients in cohort A. These 40 patients represented 36% of all patients with infectious syphilis treated within our department and 56% of those who were HIV positive. The event rate in cohort B was 7.3 per 1000 patient years (CI 5.2 to 9.9) compared to 2.8 (CI 1.8 to 4.0) in cohort A. CONCLUSION: Routine screening is effective and has detected increasing numbers of HIV outpatients with early asymptomatic syphilis. Our department will continue this strategy for all HIV patients during their follow up care. We recommend that other units adopt similar initiatives that assist with regional control of the UK syphilis epidemic.

Adult↗
PubMed2004

Sexual trauma associated with fisting and recreational drugs.

There is a rising trend in high risk sexual behaviour among men who have sex with men (MSM), with concomitant use of recreational drugs. Activities include fisting and unprotected anal intercourse with a partner who is HIV serodiscordant or of unknown status. We describe three cases of HIV positive MSM who have recently attended our unit as a result of complications secondary to fisting.

Adult↗
PubMed1997

Taking charge. The role of nursing administrators in removing restraints.

The leadership and commitment of nursing administrators play a pivotal role in minimizing the use of restraints and maintaining a restraint-free environment. This article describes the role of nursing administrators in reducing the use of physical restraints as part of a 2-year, national nursing home restraint-reduction project. It reviews important information about restraint-free care the benefits of restraint-free care, and strategies to reduce the use of restraints in nursing homes, much of which is applicable to settings other than nursing homes.

Aged↗
PubMed1990

Long-term enteral feeding of aged demented nursing home patients.

The terminal phase of dementia is initiated by the inability to swallow. New techniques of enteral alimentation permit more effective, longer intubation. To assess the application of these new techniques to late-stage demented aged patients, all current intubations in a teaching nursing home were reviewed. Of 52 feeding intubations, 26 had been in situ for more than 1 year. A randomly selected comparison group of nonintubated patients was also studied. Weight increased for 48% of the intubated group versus 17% of the nonintubated group (P less than .01). Aspiration pneumonia occurred more often in the intubated group (58%) than in the nonintubated group (17%) (P less than .01). Decubitus ulcers were also more common in the intubated group (21%) than in the nonintubated group (14%). Restraints were used more in the intubated group (71%) than in the nonintubated group (56%). These differences did not reach statistical significance. All of the intubated patients were severely demented, with MMSE scores of zero. Seventy-one percent of the nonintubated group were demented, with MMSE scores of less than 23. Prolongation of the terminal phase of dementia in the aged by tube feeding is now feasible. The implications of this change in the life-span of demented nursing home patients need attention by families, nursing homes, and those who make public health policy.

Aged↗
PubMed1990

Monoclonal antibodies as probes to study the human growth hormone-binding domain to lactogenic rat liver receptors.

A set of monoclonal antibodies (MAb) to human GH (hGH) was used to study the hormone binding orientation to its receptors (R) from female rat liver. The hGH antigenic region left exposed after its binding to liver microsomes was detected by measuring the ability of various [125I]MAb to bind to the preformed hGH-R complexes. Results indicated that a cluster of epitopes defined by the MAb, termed AE5, AC8, and AE12, remains accessible in the hGH-R complex whereas overlapping epitopes 3C11 and HG3 would define a hGH region involved in the binding site. Supporting these findings, solubilization and HPLC gel filtration of [125I]MAb-hGH-R complexes showed a radioactive peak of about 450,000 mol wt for MAb AE5 or AC8, but not for MAb 3C11 or HG3. [125I]MAb AE12 behaved differently, suggesting that epitope AE12 may be masked or altered in hGH-R-solubilized complexes. MAb directed to the putative hGH-binding site (MAb 3C11, HG3, and the closely related MAb 10C1 and NA71) failed to inhibit binding of the preformed [125I]MAb AE5-hGH complex to the receptors, suggesting a hormone modification after MAb AE5 binding. Accordingly competition experiments indicated an increase in the affinity of hGH for its receptors induced by this MAb. A higher hGH concentration was required to obtain 50% [125I]hGH binding to liver microsomes in the presence of MAb AE5 than in its absence. As the MAb used define epitopes that were previously correlated with the hGH structure, we concluded that a high flexible region (sequences 134-150) is exposed in the hGH-R complex. Furthermore, some MAb directed to this region enhance the hormone affinity for its rat liver receptors, probably through an induced conformational change.

Animals↗
PubMed1981

Chloroplast Biogenesis 34: SPECTROFLUOROMETRIC CHARACTERIZATION IN SITU OF THE PROTOCHLOROPHYLL SPECIES IN ETIOLATED TISSUES OF HIGHER PLANTS.

The fluorescence emission and excitation properties of protochlorophyll in etiolated cucumber (Cucumis sativus L.) cotyledons and primary bean (var. Red Kidney) leaves were characterized at 77 K. Contrary to previous studies, it appears that the short-wavelength protochlorophyll emission band consists of four fluorescent components, instead of only one nonphototransformable protochlorophyll. It was demonstrated that etiolated cucumber cotyledons synthesize and accumulate nontransformable protochlorophyll (E(440), F(630)) as well as short-wavelength phototransformable protochlorophyll (E(433), F(633)), (E(444), F(636)), and (E(445), F(640)). Long-wavelength phototransformable protochlorophyll (E(450), F(657)) is also formed. In this context, E refers to the Soret excitation maxima and F refers to the red emission maxima of the protochlorophylls.IN ETIOLATED BEAN LEAVES, THE CORRESPONDING SPECIES WERE: nontransformable protochlorophyll (E(440), F(630)), short-wavelength phototransformable protochlorophylls (E(441), F(633)), (E(442), F(636)), and (E(443), F(640)), and long-wavelength phototransformable protochlorophyll (E(447), F(657)).

Journal Article↗
PubMed1978

Chloroplast Biogenesis: XXII. Contribution of Short Wavelength and Long Wavelength Protochlorophyll Species to the Greening of Higher Plants.

The contribution of short and long wavelength membrane-bound fluorescing protochlorophyll species to the over-all process of chlorophyll formation was assessed during photoperiodic growth. Protochlorophyll forms were monitored spectrofluorometrically at 77 K during the first six light and dark cycles in homogenates of cucumber (Cucumis sativus L.) cotyledons grown under a 14-hour light/10-hour dark photoperiodic regime, and in cotyledons developing in complete darkness. In the etiolated tissue, short wavelength protochlorophyll having a broad emission maximum between 630 and 640 nm appeared within 24 hours after sowing. Subsequently, the long wavelength species fluorescing at 657 nm appeared, and accumulated rapidly. This resulted in the preponderance of the long wavelength species which characterizes the protochlorophyll profile of etiolated tissues. The forms of protochlorophyll present in etiolated cucumber cotyledons resembled those in etiolated bean leaves in their absorption, fluorescence, and phototransformability. A different pattern of protochlorophyll accumulation was observed during the dark cycles of photoperiodic greening. The short wavelength species appeared within 24 hours after sowing. Subsequently, the long wavelength form accumulated and disappeared. The long wavelength to short wavelength protochlorophyll emission intensity ratio reached a maximum (~3:1) during the second dark cycle, then declined during subsequent dark cycles. Short wavelength species were continuously present in the light and dark. Primary corn and bean leaves exhibited a similar pattern of protochlorophyll accumulation. In cucumber cotyledons, both the short and long wavelengths species appeared to be directly phototransformable at all stages of photoperiodic development. It thus appears that whereas the long wavelength protochlorophyll species is the major chlorophyll precursor during primary photoconversion in older etiolated tissues, both long wavelength and short wavelength species seem to contribute to chlorophyll formation during greening under natural photoperiodic conditions.

Journal Article↗
PubMed1977

Chloroplast Biogenesis: XX. Accumulation of Porphyrin and Phorbin Pigments in Cucumber Cotyledons during Photoperiodic Greening.

A study of greening in cucumber (Cucumis sativus L.) cotyledons grown under a light (14-hour) dark (10-hour) photoperiodic regime was undertaken. The pools of protoporphyrin IX, Mg-protoporphyrin IX monoester, protochlorophyllide, and protochlorophyllide ester were determined spectrofluorometrically. Chlorophyll a and b were monitored spectrophotometrically. Pigments were extracted during the 3rd hour of each light period and at the end of each subsequent dark period during the first seven growth cycles. Protoporphyrin IX did not accumulate during greening. Mg-protoporphyrin IX monoester and longer wavelength metalloporphyrins accumulated during the light cycles and disappeared in the dark. Their disappearance was accompanied by the accumulation of protochlorophyll. Higher levels of protochlorophyll were observed in the dark than in the light, and the greatest accumulation occurred during the third and fourth dark cycles. Protochlorophyllide was present in 3- to 10-fold excess over protochlorophyllide ester; it was detectable during the period of net chlorophyll accumulation as well as afterward. In contrast, protochlorophyllide ester was observable only during the first four photoperiodic cycles, suggesting that it was a metabolic intermediate only during the early stages of chlorophyll accumulation. Between the third and fourth growth cycles, a rapid increase in area and fresh weight per cotyledon began. This was accompanied by a 250-fold increase in the level of chlorophyll a + b during the three subsequent growth cycles. No lag period in the accumulation of chlorophyll b was observed, and at all stages of greening, the chlorophyll a/b ratio was approximately 3.

Journal Article↗
PubMed1976

Changing ratios of phototransformable protochlorophyll and protochlorophyllide of bean seedlings developing in the dark.

Protochlorophyll (Pchl) and protochlorophyllide (Pchlide) are at comparable levels in 2-day-old (young) etiolated bean leaves (Phaseolus vulgaris L. var. Red Kidney). During subsequent development in the dark, both pigments increase, but the rate of Pchlide increase is greater than that of Pchl, leading to the commonly observed predominance of Pchlide beyond 7 days (old leaves). Both protopigments are phototransformable to their respective chlorophyll(ide) photoproducts throughout dark development. The rate of protopigment regeneration in young leaves after illumination is rapid and displays no lag, whereas this process in old leaves begins slowly and achieves only about one-fifth the rate of younger leaves. The rate of chlorophyllide esterification is also faster in the younger tissue. Since the proplastid-related properties of young bean leaves are quite similar to those of Euglena, young leaves and Euglena may represent an evolutionarily primitive case compared with older bean leaves which contain etioplasts. Since Euglena and young beans green perfectly well when exposed to light, the extensive modifications associated with prolonged dark growth do not seem to be obligatory for plastid development. The properties of older beans are viewed as being the consequence of prolonged etiolation which may provide a faster rate of plastid development and appearance of photosynthesis as the plant nears the limits of its stored reserves.

Journal Article↗