SARS-CoV-2, Uncontrolled Diabetes and Corticosteroids-An Unholy Trinity in Invasive Fungal Infections of the Maxillofacial Region? A Retrospective, Multi-centric Analysis

OBJECTIVES

Collate and analyse data of maxillofacial/rhino-cerebro-orbital fungal infections reported during the era of the Covid-19 pandemic, with the aim of investigating the common contributing factors leading to such infections and of highlighting the significance of this surge seen in patients infected with SARS-CoV-2.

METHOD

This retrospective observational multi-centric study analysed patient data collected from clinicians belonging to different specialties in Bangalore, India. The data included the presentation and management of patients presenting with aggressive maxillofacial and rhino-cerebro-orbital fungal infections and explored the relationship between SARS-CoV-2, corticosteroid administration and uncontrolled diabetes mellitus.

RESULTS

All 18 patients were Covid positive. Sixteen of the 18 patients received steroids for Covid treatment and 16 patients were diabetic (of whom 15 patients who were diabetics received steroids for Covid-19 treatment). Loss of vision was noted in 12 of the 18 patients and 7 of them underwent orbital exenteration. The fungi noted was mucormycosis in 16 patients, aspergillosis in 1 patient and a mixed fungal infection in 1 patient. Eleven of the patients survived, 6 died and 1 was lost to follow-up. There was a significantly higher incidence of diabetes (p = 0.03) amongst these cohort of patients who were Covid-19 positive with mucormycosis. A significantly higher number (p = 0.0013) of patients were administered steroids at some point during the treatment.

CONCLUSION

Despite the limited sample size, it is evident that there is a significant increase in the incidence of angioinvasive maxillofacial fungal infections in diabetic patients treated for SARS-CoV-2 with a strong association with corticosteroid administration.

Very low frequency oscillations in the power spectra of heart rate variability during dry supine immersion and exposure to non-hypoxic hypobaria

The origin of very low frequency (VLF) oscillations in the power spectra of heart rate variability (HRV) is controversial with possible mechanisms involving thermoregulation and/or renin-angiotensin-aldosterone system. Recently, a major contribution from vagal influences has been suggested. The present study investigated the behaviour of VLF (0.004-0.040 Hz) components of HRV power spectra in a group of healthy male volunteers during their exposure to (1) dry, supine, immersion in thermo-neutral water for 6 h (n = 7) and (2) non-hypoxic hypobaria (breathing 40-60% oxygen at 15,000' simulated in a decompression chamber) for 5 h (n = 15). The two manoeuvres are established to increase vagal outflow. During both the manoeuvres, all the frequency domain indices of HRV exhibited a significant increase. Increase in HRV was much more than that in the R-R interval. At 6 h of immersion, the R-R interval increased by ∼ 15% but the total power increased ∼ fourfold. Similarly, at 5 h of exposure to hypobaria, total power increased ∼ twofold with a very modest increase in an R-R of ∼ 9%. Increase in spectral power was appreciable even after normalization with mean R-R(2). Increase in VLF during immersion was more than reported during enalaprilat blockade of angiotensin convertase enzyme. Plasma renin activity did not vary during hypobaria. There was a significant increase in pNN50, an established marker of cardiac vagal activity. Centre frequencies of the spectra and slope (β) of the relation between log(PSD) and log(frequency) did not change. Results were supportive of the notion that the parasympathetic system is pre-potent to influence slower (than respiratory) frequency components in HRV spectrum. Additionally, such an effect was without a change in the time constant of effector responses or pacemaker frequencies of VLF and LF periodicities and HRV was not a simple linear surrogate for cardiac vagal effects. An invariance of spectral exponent (β) ruled out contamination of VLF and LF spectra from fractal power as an alternate explanation.

Evaluation of efficacy and tolerability of Losartan and Ramipril combination in the management of hypertensive patients with associated diabetes mellitus in India (LORD Trial)

AIM

The study was conducted to evaluate efficacy and tolerability of fixed dose combination (FDC) of Losartan and Ramipril in the management of mild to moderate hypertensive Native Asian Indian patients with associated diabetes mellitus. The secondary objective was to evaluate the efficacy of the combination in reducing microalbuminuria.

MATERIAL AND METHODS

The study was an open, non-comparative, multicentric clinical trial conducted in seven Indian centres in 315 eligible patients. All the patients were treated with Losartan 50 mg + Ramipril 2.5 mg or Losartan 50 mg + Ramipril 5 mg once a day in 12 weeks and consisted of a total of eight visits.

RESULTS

The mean age of patients was 52.93 years (range 45 - 60 years). Of the total patients, 62.86% were males and 37.14% were females. The mean prestudy systolic blood pressure was 160.56 +/- 14.44 which was significantly reduced to 126.85 +/- 9.78 at the end of 12 weeks (P < 0.001). Similarly the mean diastolic blood pressure was 98.91 +/- 8.33 at baseline (stage I) which was significantly reduced to 79.82 +/- 5.42 at the end of 12 weeks (P < 0.001). A mean fall of 33.72 mmHg in systolic blood pressure and the mean fall of 19.10 mmHg was observed in systolic and diastolic blood pressure respectively at the end of the treatment which was statistically highly significant (P < 0.001). The JNC-VII goal of blood pressure < 130/80 was achieved in 79.05% patients after the treatment which losartan and ramipril combination only. Microalbuminuria (urinary albumin excretion > 30 but < 300 mg/day) was seen in 83/250 (33.2%) patients and 135 (54%) patients had clinical proteinuria (albuminuria) at baseline. At the end of the therapy 20.8% patients achieved normoalbuminuria. Good to excellent efficacy response was reported in 98.09% patients and 98.41% patients reported good to excellent tolerability to the treatment.

CONCLUSION

The fixed dose combination of Losartan and Ramipril showed good to excellent efficacy response in 98.10% patients and achieved a target blood pressure of 130/80 mmHg in 79.05% patients in 12 weeks. The combination reduced the urinary albumin excretion in majority of the patients with microalbuminuria and proteinuria (the major marker of nephropathy).

Microorganisms as an alternative source of protein

Demand for human food and animal feed proteins from nonconventional sources has increased, particularly in developing countries. Microbial protein is one such source. It is desirable because it is amenable to controlled intensive cultivation and is less dependent on variations in climate, weather, and soil. Microbial proteins must be evaluated for nutritive value, safety, and economic considerations before mass production is undertaken.

Rifamycins: strain improvement program

Rifamycins are primarily produced by Gram-positive bacterium Amycolatopsis mediterranei, which belongs to the order Actinomycetales. These antibiotics, apart from their application against pathogens of tuberculosis and leprosy, have also been found to be effective against several other pathogens including Mycobacterium avium and Pneumococcus. Because of the importance of rifamycin, the producer strain A. mediterranei has been genetically manipulated since 1957 in order to develop a strain that can either produce larger amounts of rifamycin or derivatives of rifamycin. In this article, the importance of the producer strain, traditional methods (mutations and recombination) of strain improvement, their limitations, and the development of a cloning vector and transformation methods that have made recombinant DNA techniques accessible for genetic manipulations of A mediterranei are discussed.

Reduction in the dosage schedule of BPL-inactivated neural tissue vaccine for rabies prophylaxis in man

There exist two different immunization schedules for neural tissue rabies vaccine (NTV) for human use in India, the amount of vaccine given by the schedule recommended by Central Research Institute (CRI), Kasauli, being higher than that recommended by Pasteur Institute of India (PII), Coonoor. A study was therefore undertaken to assess the feasibility of reducing the CRI dosage schedule for rabies prophylaxis. The antirabies antibody response in laboratory animals and human subjects following 7, 10 and 14 daily doses of NTV with or without administering rabies immune globulin (RIG) was much higher than the minimum protective level of 0.5 IU/ml of serum. Based on these results, the CRI schedule could be reduced from 14 x 5 ml of NTV to 10 x 5 ml in class II and class III rabies exposure cases.

Lytic effect of Vibrio cholerae elastase on gram-positive and -negative bacteria

Elastase of Vibrio cholerae caused the lysis of freshly grown cells of Gram-negative (Pseudomonas aeruginosa, Proteus vulgaris, Salmonella paratyphi A and Klebsiella pneumoniae) bacteria. Gram-positive (Staphylococcus aureus and S. epidermidis) organisms were resistant to this enzyme. Heat killed and lyophilized Gram-positive and -negative bacteria (except S. aureus and S. epidermidis) showed higher sensitivity to elastase. Both Gram-negative and -positive bacteria were lyzed maximally by elastase at pH 8.0. At this pH, lytic activity of elastase was maximum in Tris-HCl and glycine-NaOH buffers followed by Tris-maleate and cacodylate buffers.

Oral infectivity of street and fixed rabies virus strains in laboratory animals

Oral transmission of rabies could be produced in laboratory animals like mice, guinea pigs and hamsters using challenge virus strain (CVS) and 2 strains of street virus. Study of virus pathway following ingestion suggested predominant neural spread to brain and centrifugal spread to non neural organs like heart and kidneys. However it was found that virus dose required for oral infection was relatively very high. The role of such a transmission in nature needs to be further evaluated, keeping in view the high dose of virus required for oral infectivity and the frequency of consumption of brain by carnivorous animals.

Evaluation of the new rapid rabies immunodiagnosis technique

The rapid rabies enzyme immuno-diagnosis (RREID) kit was evaluated for its sensitivity and specificity in comparison to fluorescent antibody technique (FAT) and biological test (BT) for the diagnosis of rabies. While 93 per cent correlation was observed in case of fresh brain samples, 71 per cent correlation was noted with glycerol preserved samples, where RREID was more sensitive than FAT. RREID test can be employed for rapid diagnosis of rabies, when facilities for FAT are not available. However, to test, at one time, small number of specimens, the RREID kit needs to be modified.

Production and partial characterization of elastase of Vibrio cholerae Inaba

Conditions are described for the production of extracellular elastase by Vibrio cholerae Inaba 2/57. The yield of the enzyme was maximum in shake cultures grown in alkaline peptone water at 37 degrees C and was stable in culture supernatants. The enzyme, partially purified by ammonium sulphate precipitation and Sephadex G-100 gel filtration showed a molecular weight of 30,000 and an activity between pH 5.0-8.0 with an optimum of 8.0 in Tris-maleate buffer. The elastinolytic activity was maximal in glycine-NaOH buffer and minimal in phosphate buffer. The enzyme activity was adversely affected by temperature greater than or equal to 40 degrees C.

Post exposure studies with human diploid cell rabies vaccine and purified chick embryo cell vaccine: comparative serological responses in man

Rabies-neutralising antibody responses to human diploid cell strain rabies vaccine (HDCSV) and purified chick embryo cell vaccine (PCECV) were studied in 125 patients previously exposed to rabid animals having received 3, 5 and 6 doses on days 0, 3, 7, 14, 30 and 90. Antibody response was significantly higher (P less than 0.05) with HDCSV than PCECV in all subjects irrespective of their sex and age group. Three doses on day 0, 3, 7 given for post-exposure rabies prophylaxis to class I patients with a negligible risk elicited antibody titres significantly higher than the minimum protective level required (0.5 I.U./ml); the mean response was greater than 15 I.U./ml in the case of PCECV and greater than 32 I.U./ml in the case of HDCSV. The use of PCECV is cost-effective and suggested for use in developing countries.

Lytic effect of Pseudomonas aeruginosa elastase on gram-positive and -negative bacteria

Elastase of Pseudomonas aeruginosa P3 caused lysis of freshly grown cells of Gram-positive (Staphylococcus aureus and S. epidermidis) and Gram-negative (Proteus vulgaris and Salmonella typhi) bacteria. Heat killed and lyophilized Gram-negative bacteria showed higher sensitivity to elastase. Both Gram-negative and Gram-positive bacteria were lysed maximally by elastase at pH 8.0. At this pH, the activity of elastase was maximal in Tris-HCl and glycine-NaOH buffers followed by Tris-maleate and Cacodylate buffers.

Production and partial characterization of elastase of Bacillus subtilis isolated from the cervices of human females

Conditions are described for the production of extracellular elastase by Bacillus subtilis. The yield of enzyme was maximum in shake-cultures grown in Syncase medium at 37 degrees C and was stable in culture supernatants. The enzyme, purified by ammonium sulphate precipitation and Sephadex G-75 gel filtration, showed a molecular weight of 25,000 and activity between pH 6.0 and 9.5, with an optimum of 9.0 in Tris-maleate buffer. Elastinolytic activity was maximum in glycine-NaOH buffer and minimum in phosphate buffer. Enzyme activity was adversely affected by temperature greater than or equal to 40 degrees C.

Bacteriology of the cervix in cases of infertility: effect on human and animal spermatozoa and role of elastase

Microorganisms such as Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans isolated from cervices of infertile human females inhibited motility and agglutinated human, cow bull, buffalo bull, and rat spermatozoa in vitro. Fifty percent of the infertile females studied carried elastase-positive microorganisms. Cell-free culture supernatants of 72-hr-old elastase-positive cultures were spermicidal within 60 min of contact with sperm, while elastase-negative cultures were spermicidal in 4-6 hr. Cultures of all the cervical isolates were spermicidal and agglutinated human, cow bull, buffalo bull, and rat spermatozoa, and these activities increased with age of the culture. Human sperm showed only tail-to-tail agglutination, while cow bull, buffalo bull, and rat spermatozoa showed mainly head-to-head agglutination. Spermicidal activity was also attributable to elastase, which was present more in 72-hr-old cultures than in 24-hr-old cultures.

Bacteriology of cervix in cases of infertility: effect on human sperm

Microorganisms such as Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis isolated from cervices of infertile females possessed spermicidal activity. They also agglutinated the human spermatozoa in vitro and showed tail-to-tail agglutination. Cell-free supernatant of these organisms was found to be spermicidal but did not agglutinate spermatozoa in vitro. Spermicidal activity was increased with increase in age of the culture.

Comparison of the bio-physical and biological properties of staphylococcal protein-A extracted by salt-washing and conventional procedure

Staphylococcal protein A could be extracted in large amounts by simple stirring of the cells with physiological saline (pH 7.8). The amount of protein A obtained by the technique was found to be the same as obtained by lysozyme/lysostaphin techniques (45 micrograms/ml). The protein A extracted by salt-washing technique was of higher molecular weight (71,000) and differing in some biological properties like complement fixation from the protein A prepared by lysostaphin technique.