The “suffocation alarm” theory of panic attacks: A critical commentary

In 1993 Klein proposed a “false suffocation alarm” theory of panic attacks, claiming that many spontaneous panic attacks are due to a “suffocation monitor” in the brain erroneously signaling a lack of useful air, and triggering an evolved “suffocation alarm system”. He proposed that carbon dioxide acts as a panic stimulus because rising arterial CO₂ suggests suffocation may be imminent. The present paper provides a critical analysis of Klein's theory and concludes that there is neither empirical evidence nor compelling argument to support the assumptions or the proposed neurological mechanism of a “suffocation alarm”, true or false, or a CO₂ “suffocation monitor”. Data relevant to the role of breathing in the phenomenon of panic can be parsimoniously subsumed within the domain of dyspnea.     

In vivo MRI of cancer cell fate at the single-cell level in a mouse model of breast cancer metastasis to the brain.

Metastasis (the spread of cancer from a primary tumor to secondary organs) is responsible for most cancer deaths. The ability to follow the fate of a population of tumor cells over time in an experimental animal would provide a powerful new way to monitor the metastatic process. Here we describe a magnetic resonance imaging (MRI) technique that permits the tracking of breast cancer cells in a mouse model of brain metastasis at the single-cell level. Cancer cells that were injected into the left ventricle of the mouse heart and then delivered to the brain were detectable on MR images. This allowed the visualization of the initial delivery and distribution of cells, as well as the growth of tumors from a subset of these cells within the whole intact brain volume. The ability to follow the metastatic process from the single-cell stage through metastatic growth, and to quantify and monitor the presence of solitary undivided cells will facilitate progress in understanding the mechanisms of brain metastasis and tumor dormancy, and the development of therapeutics to treat this disease.     

Screening for glaucoma: age and sex of referrals and confirmed cases in England and Wales

This paper is based on a prospective survey covering 275,600 sight tests by optometrists in England and Wales. It analyses the age and sex distribution of 1402 referrals for suspected glaucoma and 456 confirmed cases of the disease. The proportion of sight tests which led to a confirmed case increased with age, for both sexes, to a maximum at approximately 70 years, and then tended to decline. Cases of glaucoma in people aged 36-51 years accounted for about a tenth of the total, which is more than is generally recognized. Wider adoption of routine tonometry for middle aged people would help to ensure that these cases are detected at an early stage. Confirmed cases of glaucoma in which raised intraocular pressure had not been given as a reason for referral, i.e. probable low tension glaucomas, increased from 5% of patients < 51 years old to 13% of patients > 75 years old. Glaucoma was found to be much more common in men.     

The external genitalia of female gibbons,Hylobates (H.) lar

The external genitalia of one perimenarcheal and five adult female white handed-gibbons (Hylobates (H.) lar) were examined to clarify their gross anatomy. It was found that the vulval structures were complex and exhibited inter-individual variation in arrangement. This complexity appears to result from an ontogenetic process by which the tissues of the vaginal rim (the labia minora) bud-off and extrude extensions toward the vagina immediately prior and subsequent to menarche. Two of these lobular structures surround the urethral meatus with associated prepuce and frenulum and vestigial labia majora, undergo cycles of tumescence and detumescence during intermenstrual intervals. The complex form of the external genitalia and the presence of a swelling cycle are unusual for a monogamous species, are contrary to current applications of sexual selection theory, and raise questions about the significance of mate choice in hominoid evolution.     

Psychiatric morbidity in policemen and the effect of brief psychotherapeutic intervention — a pilot study

The level of psychiatric morbidity and perceived sources of stress among police officers were investigated using the General Health Questionnaire (GHQ) and a stress situation questionnaire, which were sent to 171 officers. Half of the responders were invited to attend group counselling sessions weekly for 12 weeks. Outcome measures studied were a second GHQ completed at the end of the treatment period and the amounts of sick leave taken in the 12-week period before, during and after the treatment period. The results were that 61 people returned the first GHQ of whom 59 were male and of whom 14 were classed as ‘cases’. Of the 31 assigned to the treatment group, 22 attended at least one session. Responses to the stress situation questionnaire and the content of counselling sessions tended to confirm the impression that internal aspects of the organization were viewed as prime sources of stress and dissatisfaction. There were no significant changes in GHQ score within or between groups, nor were there significant differences in the amount of sick leave taken. Nevertheless the sessions appeared to be valued and we conclude that this sort of intervention is at least feasible. We recommend that similar studies measure psychiatric morbidity during treatment and at follow-up, rather than immediately after finishing, when reactions to this termination are prominent.